bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
|
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
|
|
|
|
|
|
|
|
|
|
#include <linux/bpf.h>
|
2020-09-09 16:27:11 +00:00
|
|
|
#include <linux/btf_ids.h>
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
#include <linux/filter.h>
|
|
|
|
|
#include <linux/errno.h>
|
|
|
|
|
#include <linux/file.h>
|
|
|
|
|
#include <linux/net.h>
|
|
|
|
|
#include <linux/workqueue.h>
|
|
|
|
|
#include <linux/skmsg.h>
|
|
|
|
|
#include <linux/list.h>
|
|
|
|
|
#include <linux/jhash.h>
|
2020-02-18 17:10:18 +00:00
|
|
|
#include <linux/sock_diag.h>
|
2020-03-09 11:12:39 +00:00
|
|
|
#include <net/udp.h>
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
struct bpf_stab {
|
|
|
|
|
struct bpf_map map;
|
|
|
|
|
struct sock **sks;
|
|
|
|
|
struct sk_psock_progs progs;
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spinlock_t lock;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
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};
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#define SOCK_CREATE_FLAG_MASK \
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(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
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2021-02-23 18:49:31 +00:00
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static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
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struct bpf_prog *old, u32 which);
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2021-03-31 02:32:28 +00:00
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static struct sk_psock_progs *sock_map_progs(struct bpf_map *map);
|
2021-02-23 18:49:31 +00:00
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
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static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
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{
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struct bpf_stab *stab;
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if (attr->max_entries == 0 ||
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attr->key_size != 4 ||
|
2020-02-18 17:10:18 +00:00
|
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(attr->value_size != sizeof(u32) &&
|
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|
attr->value_size != sizeof(u64)) ||
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
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|
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return ERR_PTR(-EINVAL);
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|
2023-02-03 13:41:55 +00:00
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|
stab = bpf_map_area_alloc(sizeof(*stab), NUMA_NO_NODE);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (!stab)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
bpf_map_init_from_attr(&stab->map, attr);
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_init(&stab->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
2021-06-13 14:34:39 +00:00
|
|
|
stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries *
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sizeof(struct sock *),
|
|
|
|
|
stab->map.numa_node);
|
2020-12-01 21:58:54 +00:00
|
|
|
if (!stab->sks) {
|
2023-02-03 13:41:55 +00:00
|
|
|
bpf_map_area_free(stab);
|
2020-12-01 21:58:54 +00:00
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return &stab->map;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
|
|
|
{
|
|
|
|
|
u32 ufd = attr->target_fd;
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
struct fd f;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2020-06-29 09:56:27 +00:00
|
|
|
if (attr->attach_flags || attr->replace_bpf_fd)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
f = fdget(ufd);
|
|
|
|
|
map = __bpf_map_get(f);
|
|
|
|
|
if (IS_ERR(map))
|
|
|
|
|
return PTR_ERR(map);
|
2020-06-29 09:56:28 +00:00
|
|
|
ret = sock_map_prog_update(map, prog, NULL, attr->attach_type);
|
|
|
|
|
fdput(f);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
|
|
|
|
|
{
|
|
|
|
|
u32 ufd = attr->target_fd;
|
|
|
|
|
struct bpf_prog *prog;
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
struct fd f;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
if (attr->attach_flags || attr->replace_bpf_fd)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
f = fdget(ufd);
|
|
|
|
|
map = __bpf_map_get(f);
|
|
|
|
|
if (IS_ERR(map))
|
|
|
|
|
return PTR_ERR(map);
|
|
|
|
|
|
|
|
|
|
prog = bpf_prog_get(attr->attach_bpf_fd);
|
|
|
|
|
if (IS_ERR(prog)) {
|
|
|
|
|
ret = PTR_ERR(prog);
|
|
|
|
|
goto put_map;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (prog->type != ptype) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto put_prog;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = sock_map_prog_update(map, NULL, prog, attr->attach_type);
|
|
|
|
|
put_prog:
|
|
|
|
|
bpf_prog_put(prog);
|
|
|
|
|
put_map:
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
fdput(f);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_sk_acquire(struct sock *sk)
|
|
|
|
|
__acquires(&sk->sk_lock.slock)
|
|
|
|
|
{
|
|
|
|
|
lock_sock(sk);
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_sk_release(struct sock *sk)
|
|
|
|
|
__releases(&sk->sk_lock.slock)
|
|
|
|
|
{
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
release_sock(sk);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_add_link(struct sk_psock *psock,
|
|
|
|
|
struct sk_psock_link *link,
|
|
|
|
|
struct bpf_map *map, void *link_raw)
|
|
|
|
|
{
|
|
|
|
|
link->link_raw = link_raw;
|
|
|
|
|
link->map = map;
|
|
|
|
|
spin_lock_bh(&psock->link_lock);
|
|
|
|
|
list_add_tail(&link->list, &psock->link);
|
|
|
|
|
spin_unlock_bh(&psock->link_lock);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_del_link(struct sock *sk,
|
|
|
|
|
struct sk_psock *psock, void *link_raw)
|
|
|
|
|
{
|
2020-10-11 05:09:38 +00:00
|
|
|
bool strp_stop = false, verdict_stop = false;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct sk_psock_link *link, *tmp;
|
|
|
|
|
|
|
|
|
|
spin_lock_bh(&psock->link_lock);
|
|
|
|
|
list_for_each_entry_safe(link, tmp, &psock->link, list) {
|
|
|
|
|
if (link->link_raw == link_raw) {
|
|
|
|
|
struct bpf_map *map = link->map;
|
2023-11-07 14:31:32 +00:00
|
|
|
struct sk_psock_progs *progs = sock_map_progs(map);
|
|
|
|
|
|
|
|
|
|
if (psock->saved_data_ready && progs->stream_parser)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
strp_stop = true;
|
2023-11-07 14:31:32 +00:00
|
|
|
if (psock->saved_data_ready && progs->stream_verdict)
|
2020-10-11 05:09:38 +00:00
|
|
|
verdict_stop = true;
|
2023-11-07 14:31:32 +00:00
|
|
|
if (psock->saved_data_ready && progs->skb_verdict)
|
2021-03-31 02:32:30 +00:00
|
|
|
verdict_stop = true;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
list_del(&link->list);
|
|
|
|
|
sk_psock_free_link(link);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
spin_unlock_bh(&psock->link_lock);
|
2020-10-11 05:09:38 +00:00
|
|
|
if (strp_stop || verdict_stop) {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
write_lock_bh(&sk->sk_callback_lock);
|
2020-10-11 05:09:38 +00:00
|
|
|
if (strp_stop)
|
|
|
|
|
sk_psock_stop_strp(sk, psock);
|
2022-05-05 10:35:13 +00:00
|
|
|
if (verdict_stop)
|
2020-10-11 05:09:38 +00:00
|
|
|
sk_psock_stop_verdict(sk, psock);
|
2022-05-05 10:35:13 +00:00
|
|
|
|
|
|
|
|
if (psock->psock_update_sk_prot)
|
|
|
|
|
psock->psock_update_sk_prot(sk, psock, false);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_unref(struct sock *sk, void *link_raw)
|
|
|
|
|
{
|
|
|
|
|
struct sk_psock *psock = sk_psock(sk);
|
|
|
|
|
|
|
|
|
|
if (likely(psock)) {
|
|
|
|
|
sock_map_del_link(sk, psock, link_raw);
|
|
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2020-03-09 11:12:37 +00:00
|
|
|
static int sock_map_init_proto(struct sock *sk, struct sk_psock *psock)
|
2020-03-09 11:12:36 +00:00
|
|
|
{
|
2021-03-31 02:32:31 +00:00
|
|
|
if (!sk->sk_prot->psock_update_sk_prot)
|
2020-03-09 11:12:39 +00:00
|
|
|
return -EINVAL;
|
2021-03-31 02:32:31 +00:00
|
|
|
psock->psock_update_sk_prot = sk->sk_prot->psock_update_sk_prot;
|
2021-04-07 03:21:11 +00:00
|
|
|
return sk->sk_prot->psock_update_sk_prot(sk, psock, false);
|
2020-03-09 11:12:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct sk_psock *sock_map_psock_get_checked(struct sock *sk)
|
|
|
|
|
{
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
psock = sk_psock(sk);
|
|
|
|
|
if (psock) {
|
2020-03-09 11:12:39 +00:00
|
|
|
if (sk->sk_prot->close != sock_map_close) {
|
2020-03-09 11:12:36 +00:00
|
|
|
psock = ERR_PTR(-EBUSY);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!refcount_inc_not_zero(&psock->refcnt))
|
|
|
|
|
psock = ERR_PTR(-EBUSY);
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
return psock;
|
|
|
|
|
}
|
|
|
|
|
|
2021-03-31 02:32:28 +00:00
|
|
|
static int sock_map_link(struct bpf_map *map, struct sock *sk)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
2021-03-31 02:32:28 +00:00
|
|
|
struct sk_psock_progs *progs = sock_map_progs(map);
|
2021-03-31 02:32:29 +00:00
|
|
|
struct bpf_prog *stream_verdict = NULL;
|
|
|
|
|
struct bpf_prog *stream_parser = NULL;
|
2021-03-31 02:32:30 +00:00
|
|
|
struct bpf_prog *skb_verdict = NULL;
|
2021-03-31 02:32:29 +00:00
|
|
|
struct bpf_prog *msg_parser = NULL;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct sk_psock *psock;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2021-02-23 18:49:30 +00:00
|
|
|
stream_verdict = READ_ONCE(progs->stream_verdict);
|
|
|
|
|
if (stream_verdict) {
|
|
|
|
|
stream_verdict = bpf_prog_inc_not_zero(stream_verdict);
|
|
|
|
|
if (IS_ERR(stream_verdict))
|
|
|
|
|
return PTR_ERR(stream_verdict);
|
2020-10-11 05:09:07 +00:00
|
|
|
}
|
2020-10-12 17:09:53 +00:00
|
|
|
|
2021-02-23 18:49:30 +00:00
|
|
|
stream_parser = READ_ONCE(progs->stream_parser);
|
|
|
|
|
if (stream_parser) {
|
|
|
|
|
stream_parser = bpf_prog_inc_not_zero(stream_parser);
|
|
|
|
|
if (IS_ERR(stream_parser)) {
|
|
|
|
|
ret = PTR_ERR(stream_parser);
|
|
|
|
|
goto out_put_stream_verdict;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
msg_parser = READ_ONCE(progs->msg_parser);
|
|
|
|
|
if (msg_parser) {
|
|
|
|
|
msg_parser = bpf_prog_inc_not_zero(msg_parser);
|
|
|
|
|
if (IS_ERR(msg_parser)) {
|
|
|
|
|
ret = PTR_ERR(msg_parser);
|
2021-02-23 18:49:30 +00:00
|
|
|
goto out_put_stream_parser;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2021-03-31 02:32:30 +00:00
|
|
|
skb_verdict = READ_ONCE(progs->skb_verdict);
|
|
|
|
|
if (skb_verdict) {
|
|
|
|
|
skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
|
|
|
|
|
if (IS_ERR(skb_verdict)) {
|
|
|
|
|
ret = PTR_ERR(skb_verdict);
|
|
|
|
|
goto out_put_msg_parser;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2020-03-09 11:12:36 +00:00
|
|
|
psock = sock_map_psock_get_checked(sk);
|
2018-10-18 20:58:35 +00:00
|
|
|
if (IS_ERR(psock)) {
|
|
|
|
|
ret = PTR_ERR(psock);
|
|
|
|
|
goto out_progs;
|
|
|
|
|
}
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (psock) {
|
|
|
|
|
if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
|
2021-02-23 18:49:30 +00:00
|
|
|
(stream_parser && READ_ONCE(psock->progs.stream_parser)) ||
|
2021-03-31 02:32:30 +00:00
|
|
|
(skb_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
|
|
|
|
|
(skb_verdict && READ_ONCE(psock->progs.stream_verdict)) ||
|
|
|
|
|
(stream_verdict && READ_ONCE(psock->progs.skb_verdict)) ||
|
2021-02-23 18:49:30 +00:00
|
|
|
(stream_verdict && READ_ONCE(psock->progs.stream_verdict))) {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
ret = -EBUSY;
|
|
|
|
|
goto out_progs;
|
|
|
|
|
}
|
|
|
|
|
} else {
|
|
|
|
|
psock = sk_psock_init(sk, map->numa_node);
|
2020-08-21 10:29:43 +00:00
|
|
|
if (IS_ERR(psock)) {
|
|
|
|
|
ret = PTR_ERR(psock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
goto out_progs;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (msg_parser)
|
|
|
|
|
psock_set_prog(&psock->progs.msg_parser, msg_parser);
|
2022-05-05 10:35:07 +00:00
|
|
|
if (stream_parser)
|
|
|
|
|
psock_set_prog(&psock->progs.stream_parser, stream_parser);
|
|
|
|
|
if (stream_verdict)
|
|
|
|
|
psock_set_prog(&psock->progs.stream_verdict, stream_verdict);
|
|
|
|
|
if (skb_verdict)
|
|
|
|
|
psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
|
2020-03-09 11:12:34 +00:00
|
|
|
|
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071619
commit 218d747a4142f281a256687bb513a135c905867b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Jan 4 13:46:45 2022 -0800
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
sock_map_link() is called to update a sockmap entry with a sk. But, if the
sock_map_init_proto() call fails then we return an error to the map_update
op against the sockmap. In the error path though we need to cleanup psock
and dec the refcnt on any programs associated with the map, because we
refcnt them early in the update process to ensure they are pinned for the
psock. (This avoids a race where user deletes programs while also updating
the map with new socks.)
In current code we do the prog refcnt dec explicitely by calling
bpf_prog_put() when the program was found in the map. But, after commit
'38207a5e81230' in this error path we've already done the prog to psock
assignment so the programs have a reference from the psock as well. This
then causes the psock tear down logic, invoked by sk_psock_put() in the
error path, to similarly call bpf_prog_put on the programs there.
To be explicit this logic does the prog->psock assignment:
if (msg_*)
psock_set_prog(...)
Then the error path under the out_progs label does a similar check and
dec with:
if (msg_*)
bpf_prog_put(...)
And the teardown logic sk_psock_put() does ...
psock_set_prog(msg_*, NULL)
... triggering another bpf_prog_put(...). Then KASAN gives us this splat,
found by syzbot because we've created an inbalance between bpf_prog_inc and
bpf_prog_put calling put twice on the program.
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
BUG: KASAN: vmalloc-out-of-bounds in bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
Read of size 8 at addr ffffc90000e76038 by task syz-executor020/3641
To fix clean up error path so it doesn't try to do the bpf_prog_put in the
error path once progs are assigned then it relies on the normal psock
tear down logic to do complete cleanup.
For completness we also cover the case whereh sk_psock_init_strp() fails,
but this is not expected because it indicates an incorrect socket type
and should be caught earlier.
Fixes: 38207a5e8123 ("bpf, sockmap: Attach map progs to psock early for feature probes")
Reported-by: syzbot+bb73e71cf4b8fd376a4f@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220104214645.290900-1-john.fastabend@gmail.com
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2022-05-05 10:36:01 +00:00
|
|
|
/* msg_* and stream_* programs references tracked in psock after this
|
|
|
|
|
* point. Reference dec and cleanup will occur through psock destructor
|
|
|
|
|
*/
|
2020-03-09 11:12:37 +00:00
|
|
|
ret = sock_map_init_proto(sk, psock);
|
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071619
commit 218d747a4142f281a256687bb513a135c905867b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Jan 4 13:46:45 2022 -0800
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
sock_map_link() is called to update a sockmap entry with a sk. But, if the
sock_map_init_proto() call fails then we return an error to the map_update
op against the sockmap. In the error path though we need to cleanup psock
and dec the refcnt on any programs associated with the map, because we
refcnt them early in the update process to ensure they are pinned for the
psock. (This avoids a race where user deletes programs while also updating
the map with new socks.)
In current code we do the prog refcnt dec explicitely by calling
bpf_prog_put() when the program was found in the map. But, after commit
'38207a5e81230' in this error path we've already done the prog to psock
assignment so the programs have a reference from the psock as well. This
then causes the psock tear down logic, invoked by sk_psock_put() in the
error path, to similarly call bpf_prog_put on the programs there.
To be explicit this logic does the prog->psock assignment:
if (msg_*)
psock_set_prog(...)
Then the error path under the out_progs label does a similar check and
dec with:
if (msg_*)
bpf_prog_put(...)
And the teardown logic sk_psock_put() does ...
psock_set_prog(msg_*, NULL)
... triggering another bpf_prog_put(...). Then KASAN gives us this splat,
found by syzbot because we've created an inbalance between bpf_prog_inc and
bpf_prog_put calling put twice on the program.
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
BUG: KASAN: vmalloc-out-of-bounds in bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
Read of size 8 at addr ffffc90000e76038 by task syz-executor020/3641
To fix clean up error path so it doesn't try to do the bpf_prog_put in the
error path once progs are assigned then it relies on the normal psock
tear down logic to do complete cleanup.
For completness we also cover the case whereh sk_psock_init_strp() fails,
but this is not expected because it indicates an incorrect socket type
and should be caught earlier.
Fixes: 38207a5e8123 ("bpf, sockmap: Attach map progs to psock early for feature probes")
Reported-by: syzbot+bb73e71cf4b8fd376a4f@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220104214645.290900-1-john.fastabend@gmail.com
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2022-05-05 10:36:01 +00:00
|
|
|
if (ret < 0) {
|
|
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
write_lock_bh(&sk->sk_callback_lock);
|
2021-02-23 18:49:30 +00:00
|
|
|
if (stream_parser && stream_verdict && !psock->saved_data_ready) {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
ret = sk_psock_init_strp(sk, psock);
|
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071619
commit 218d747a4142f281a256687bb513a135c905867b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Jan 4 13:46:45 2022 -0800
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
sock_map_link() is called to update a sockmap entry with a sk. But, if the
sock_map_init_proto() call fails then we return an error to the map_update
op against the sockmap. In the error path though we need to cleanup psock
and dec the refcnt on any programs associated with the map, because we
refcnt them early in the update process to ensure they are pinned for the
psock. (This avoids a race where user deletes programs while also updating
the map with new socks.)
In current code we do the prog refcnt dec explicitely by calling
bpf_prog_put() when the program was found in the map. But, after commit
'38207a5e81230' in this error path we've already done the prog to psock
assignment so the programs have a reference from the psock as well. This
then causes the psock tear down logic, invoked by sk_psock_put() in the
error path, to similarly call bpf_prog_put on the programs there.
To be explicit this logic does the prog->psock assignment:
if (msg_*)
psock_set_prog(...)
Then the error path under the out_progs label does a similar check and
dec with:
if (msg_*)
bpf_prog_put(...)
And the teardown logic sk_psock_put() does ...
psock_set_prog(msg_*, NULL)
... triggering another bpf_prog_put(...). Then KASAN gives us this splat,
found by syzbot because we've created an inbalance between bpf_prog_inc and
bpf_prog_put calling put twice on the program.
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
BUG: KASAN: vmalloc-out-of-bounds in bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
Read of size 8 at addr ffffc90000e76038 by task syz-executor020/3641
To fix clean up error path so it doesn't try to do the bpf_prog_put in the
error path once progs are assigned then it relies on the normal psock
tear down logic to do complete cleanup.
For completness we also cover the case whereh sk_psock_init_strp() fails,
but this is not expected because it indicates an incorrect socket type
and should be caught earlier.
Fixes: 38207a5e8123 ("bpf, sockmap: Attach map progs to psock early for feature probes")
Reported-by: syzbot+bb73e71cf4b8fd376a4f@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220104214645.290900-1-john.fastabend@gmail.com
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2022-05-05 10:36:01 +00:00
|
|
|
if (ret) {
|
|
|
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sk_psock_start_strp(sk, psock);
|
2021-02-23 18:49:30 +00:00
|
|
|
} else if (!stream_parser && stream_verdict && !psock->saved_data_ready) {
|
2020-10-11 05:09:38 +00:00
|
|
|
sk_psock_start_verdict(sk,psock);
|
2021-03-31 02:32:30 +00:00
|
|
|
} else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) {
|
|
|
|
|
sk_psock_start_verdict(sk, psock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
|
|
|
return 0;
|
|
|
|
|
out_progs:
|
2021-03-31 02:32:30 +00:00
|
|
|
if (skb_verdict)
|
|
|
|
|
bpf_prog_put(skb_verdict);
|
|
|
|
|
out_put_msg_parser:
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (msg_parser)
|
|
|
|
|
bpf_prog_put(msg_parser);
|
2021-02-23 18:49:30 +00:00
|
|
|
out_put_stream_parser:
|
|
|
|
|
if (stream_parser)
|
|
|
|
|
bpf_prog_put(stream_parser);
|
|
|
|
|
out_put_stream_verdict:
|
|
|
|
|
if (stream_verdict)
|
|
|
|
|
bpf_prog_put(stream_verdict);
|
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071619
commit 218d747a4142f281a256687bb513a135c905867b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Jan 4 13:46:45 2022 -0800
bpf, sockmap: Fix double bpf_prog_put on error case in map_link
sock_map_link() is called to update a sockmap entry with a sk. But, if the
sock_map_init_proto() call fails then we return an error to the map_update
op against the sockmap. In the error path though we need to cleanup psock
and dec the refcnt on any programs associated with the map, because we
refcnt them early in the update process to ensure they are pinned for the
psock. (This avoids a race where user deletes programs while also updating
the map with new socks.)
In current code we do the prog refcnt dec explicitely by calling
bpf_prog_put() when the program was found in the map. But, after commit
'38207a5e81230' in this error path we've already done the prog to psock
assignment so the programs have a reference from the psock as well. This
then causes the psock tear down logic, invoked by sk_psock_put() in the
error path, to similarly call bpf_prog_put on the programs there.
To be explicit this logic does the prog->psock assignment:
if (msg_*)
psock_set_prog(...)
Then the error path under the out_progs label does a similar check and
dec with:
if (msg_*)
bpf_prog_put(...)
And the teardown logic sk_psock_put() does ...
psock_set_prog(msg_*, NULL)
... triggering another bpf_prog_put(...). Then KASAN gives us this splat,
found by syzbot because we've created an inbalance between bpf_prog_inc and
bpf_prog_put calling put twice on the program.
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline]
BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put kernel/bpf/syscall.c:1812 [inline] kernel/bpf/syscall.c:1829
BUG: KASAN: vmalloc-out-of-bounds in bpf_prog_put+0x8c/0x4f0 kernel/bpf/syscall.c:1829 kernel/bpf/syscall.c:1829
Read of size 8 at addr ffffc90000e76038 by task syz-executor020/3641
To fix clean up error path so it doesn't try to do the bpf_prog_put in the
error path once progs are assigned then it relies on the normal psock
tear down logic to do complete cleanup.
For completness we also cover the case whereh sk_psock_init_strp() fails,
but this is not expected because it indicates an incorrect socket type
and should be caught earlier.
Fixes: 38207a5e8123 ("bpf, sockmap: Attach map progs to psock early for feature probes")
Reported-by: syzbot+bb73e71cf4b8fd376a4f@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220104214645.290900-1-john.fastabend@gmail.com
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2022-05-05 10:36:01 +00:00
|
|
|
out:
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_free(struct bpf_map *map)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
int i;
|
|
|
|
|
|
bpf, sockmap: Remove bucket->lock from sock_{hash|map}_free
The bucket->lock is not needed in the sock_hash_free and sock_map_free
calls, in fact it is causing a splat due to being inside rcu block.
| BUG: sleeping function called from invalid context at net/core/sock.c:2935
| in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 62, name: kworker/0:1
| 3 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffff8881381f6df8 (&stab->lock){+...}, at: sock_map_free+0x26/0x180
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04008-g7b083332376e #454
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep.cold+0xa6/0xb6
| lock_sock_nested+0x28/0x90
| sock_map_free+0x5f/0x180
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
The reason we have stab->lock and bucket->locks in sockmap code is to
handle checking EEXIST in update/delete cases. We need to be careful during
an update operation that we check for EEXIST and we need to ensure that the
psock object is not in some partial state of removal/insertion while we do
this. So both map_update_common and sock_map_delete need to guard from being
run together potentially deleting an entry we are checking, etc. But by the
time we get to the tear-down code in sock_{ma[|hash}_free we have already
disconnected the map and we just did synchronize_rcu() in the line above so
no updates/deletes should be in flight. Because of this we can drop the
bucket locks from the map free'ing code, noting no update/deletes can be
in-flight.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/158385850787.30597.8346421465837046618.stgit@john-Precision-5820-Tower
2020-03-10 16:41:48 +00:00
|
|
|
/* After the sync no updates or deletes will be in-flight so it
|
|
|
|
|
* is safe to walk map and remove entries without risking a race
|
|
|
|
|
* in EEXIST update case.
|
|
|
|
|
*/
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
synchronize_rcu();
|
|
|
|
|
for (i = 0; i < stab->map.max_entries; i++) {
|
|
|
|
|
struct sock **psk = &stab->sks[i];
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
|
|
|
|
|
sk = xchg(psk, NULL);
|
2020-01-11 06:12:00 +00:00
|
|
|
if (sk) {
|
2023-01-26 14:48:31 +00:00
|
|
|
sock_hold(sk);
|
2020-01-11 06:12:00 +00:00
|
|
|
lock_sock(sk);
|
bpf, sockmap: Don't sleep while holding RCU lock on tear-down
rcu_read_lock is needed to protect access to psock inside sock_map_unref
when tearing down the map. However, we can't afford to sleep in lock_sock
while in RCU read-side critical section. Grab the RCU lock only after we
have locked the socket.
This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a
sockmap/sockhash that contains at least one socket:
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73 #450 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170
| #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_map_free+0x95/0x170
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0
| #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_hash_free+0xec/0x1d0
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200206111652.694507-2-jakub@cloudflare.com
2020-02-06 11:16:50 +00:00
|
|
|
rcu_read_lock();
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sock_map_unref(sk, psk);
|
bpf, sockmap: Don't sleep while holding RCU lock on tear-down
rcu_read_lock is needed to protect access to psock inside sock_map_unref
when tearing down the map. However, we can't afford to sleep in lock_sock
while in RCU read-side critical section. Grab the RCU lock only after we
have locked the socket.
This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a
sockmap/sockhash that contains at least one socket:
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73 #450 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170
| #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_map_free+0x95/0x170
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0
| #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_hash_free+0xec/0x1d0
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200206111652.694507-2-jakub@cloudflare.com
2020-02-06 11:16:50 +00:00
|
|
|
rcu_read_unlock();
|
2020-01-11 06:12:00 +00:00
|
|
|
release_sock(sk);
|
2023-01-26 14:48:31 +00:00
|
|
|
sock_put(sk);
|
2020-01-11 06:12:00 +00:00
|
|
|
}
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
2020-02-06 11:16:51 +00:00
|
|
|
/* wait for psock readers accessing its map link */
|
2019-07-19 17:29:20 +00:00
|
|
|
synchronize_rcu();
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
bpf_map_area_free(stab->sks);
|
2023-02-03 13:41:55 +00:00
|
|
|
bpf_map_area_free(stab);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_release_progs(struct bpf_map *map)
|
|
|
|
|
{
|
|
|
|
|
psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
|
|
|
|
|
if (unlikely(key >= map->max_entries))
|
|
|
|
|
return NULL;
|
|
|
|
|
return READ_ONCE(stab->sks[key]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *sock_map_lookup(struct bpf_map *map, void *key)
|
|
|
|
|
{
|
2020-04-29 18:11:52 +00:00
|
|
|
struct sock *sk;
|
|
|
|
|
|
|
|
|
|
sk = __sock_map_lookup_elem(map, *(u32 *)key);
|
2020-09-09 16:27:10 +00:00
|
|
|
if (!sk)
|
2020-04-29 18:11:52 +00:00
|
|
|
return NULL;
|
|
|
|
|
if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
|
|
|
|
|
return NULL;
|
|
|
|
|
return sk;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
2020-02-18 17:10:18 +00:00
|
|
|
static void *sock_map_lookup_sys(struct bpf_map *map, void *key)
|
|
|
|
|
{
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
|
|
|
|
|
if (map->value_size != sizeof(u64))
|
|
|
|
|
return ERR_PTR(-ENOSPC);
|
|
|
|
|
|
|
|
|
|
sk = __sock_map_lookup_elem(map, *(u32 *)key);
|
|
|
|
|
if (!sk)
|
|
|
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
|
|
2020-09-30 15:18:16 +00:00
|
|
|
__sock_gen_cookie(sk);
|
2020-02-18 17:10:18 +00:00
|
|
|
return &sk->sk_cookie;
|
|
|
|
|
}
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
|
|
|
|
|
struct sock **psk)
|
|
|
|
|
{
|
bpf, sockmap: Fix race between element replace and close()
JIRA: https://issues.redhat.com/browse/RHEL-68071
JIRA: https://issues.redhat.com/browse/RHEL-72246
CVE: CVE-2024-56664
Conflicts:
- Context difference because irq disabled check was added and later
reverted upstream (3b9ce0491a43 ("Revert "bpf, sockmap: Prevent lock
inversion deadlock in map delete elem"")) because was not needed anymore.
It's not needed here either, but also does no harm.
commit ed1fc5d76b81a4d681211333c026202cad4d5649
Author: Michal Luczaj <mhal@rbox.co>
Date: Mon Dec 2 12:29:25 2024 +0100
bpf, sockmap: Fix race between element replace and close()
Element replace (with a socket different from the one stored) may race
with socket's close() link popping & unlinking. __sock_map_delete()
unconditionally unrefs the (wrong) element:
// set map[0] = s0
map_update_elem(map, 0, s0)
// drop fd of s0
close(s0)
sock_map_close()
lock_sock(sk) (s0!)
sock_map_remove_links(sk)
link = sk_psock_link_pop()
sock_map_unlink(sk, link)
sock_map_delete_from_link
// replace map[0] with s1
map_update_elem(map, 0, s1)
sock_map_update_elem
(s1!) lock_sock(sk)
sock_map_update_common
psock = sk_psock(sk)
spin_lock(&stab->lock)
osk = stab->sks[idx]
sock_map_add_link(..., &stab->sks[idx])
sock_map_unref(osk, &stab->sks[idx])
psock = sk_psock(osk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test(&psock))
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
unlock_sock(sk)
__sock_map_delete
spin_lock(&stab->lock)
sk = *psk // s1 replaced s0; sk == s1
if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch
sk = xchg(psk, NULL)
if (sk)
sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle
psock = sk_psock(sk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test())
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
release_sock(sk)
Then close(map) enqueues bpf_map_free_deferred, which finally calls
sock_map_free(). This results in some refcount_t warnings along with
a KASAN splat [1].
Fix __sock_map_delete(), do not allow sock_map_unref() on elements that
may have been replaced.
[1]:
BUG: KASAN: slab-use-after-free in sock_map_free+0x10e/0x330
Write of size 4 at addr ffff88811f5b9100 by task kworker/u64:12/1063
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Not tainted 6.12.0+ #125
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
kasan_check_range+0x10f/0x1e0
sock_map_free+0x10e/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1202:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
unix_create1+0x88/0x8a0
unix_create+0xc5/0x180
__sock_create+0x241/0x650
__sys_socketpair+0x1ce/0x420
__x64_sys_socketpair+0x92/0x100
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 46:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
sk_psock_destroy+0x73e/0xa50
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff88811f5b9080
which belongs to the cache UNIX-STREAM of size 1984
The buggy address is located 128 bytes inside of
freed 1984-byte region [ffff88811f5b9080, ffff88811f5b9840)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11f5b8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888127d49401
flags: 0x17ffffc0000040(head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401
head: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000
head: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401
head: 0017ffffc0000003 ffffea00047d6e01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88811f5b9000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88811f5b9080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88811f5b9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88811f5b9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Disabling lock debugging due to kernel taint
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 14 PID: 1063 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B 6.12.0+ #125
Tainted: [B]=BAD_PAGE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:refcount_warn_saturate+0xce/0x150
Code: 34 73 eb 03 01 e8 82 53 ad fe 0f 0b eb b1 80 3d 27 73 eb 03 00 75 a8 48 c7 c7 80 bd 95 84 c6 05 17 73 eb 03 01 e8 62 53 ad fe <0f> 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05
RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed10bcde6349
R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000
R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024
FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0
PKRU: 55555554
Call Trace:
<TASK>
? __warn.cold+0x5f/0x1ff
? refcount_warn_saturate+0xce/0x150
? report_bug+0x1ec/0x390
? handle_bug+0x58/0x90
? exc_invalid_op+0x13/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0xce/0x150
sock_map_free+0x2e5/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
irq event stamp: 10741
hardirqs last enabled at (10741): [<ffffffff84400ec6>] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (10740): [<ffffffff811e532d>] handle_softirqs+0x60d/0x770
softirqs last enabled at (10506): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
softirqs last disabled at (10301): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
refcount_t: underflow; use-after-free.
WARNING: CPU: 14 PID: 1063 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B W 6.12.0+ #125
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:refcount_warn_saturate+0xee/0x150
Code: 17 73 eb 03 01 e8 62 53 ad fe 0f 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05 f6 72 eb 03 01 e8 42 53 ad fe <0f> 0b e9 6e ff ff ff 80 3d e6 72 eb 03 00 0f 85 61 ff ff ff 48 c7
RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: 0000000000000003 R08: 0000000000000001 R09: ffffed10bcde6349
R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000
R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024
FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0
PKRU: 55555554
Call Trace:
<TASK>
? __warn.cold+0x5f/0x1ff
? refcount_warn_saturate+0xee/0x150
? report_bug+0x1ec/0x390
? handle_bug+0x58/0x90
? exc_invalid_op+0x13/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0xee/0x150
sock_map_free+0x2d3/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
irq event stamp: 10741
hardirqs last enabled at (10741): [<ffffffff84400ec6>] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (10740): [<ffffffff811e532d>] handle_softirqs+0x60d/0x770
softirqs last enabled at (10506): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
softirqs last disabled at (10301): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20241202-sockmap-replace-v1-3-1e88579e7bd5@rbox.co
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2025-01-09 16:15:47 +00:00
|
|
|
struct sock *sk = NULL;
|
2019-07-19 17:29:19 +00:00
|
|
|
int err = 0;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
2024-04-16 08:22:26 +00:00
|
|
|
if (irqs_disabled())
|
|
|
|
|
return -EOPNOTSUPP; /* locks here are hardirq-unsafe */
|
|
|
|
|
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&stab->lock);
|
bpf, sockmap: Fix race between element replace and close()
JIRA: https://issues.redhat.com/browse/RHEL-68071
JIRA: https://issues.redhat.com/browse/RHEL-72246
CVE: CVE-2024-56664
Conflicts:
- Context difference because irq disabled check was added and later
reverted upstream (3b9ce0491a43 ("Revert "bpf, sockmap: Prevent lock
inversion deadlock in map delete elem"")) because was not needed anymore.
It's not needed here either, but also does no harm.
commit ed1fc5d76b81a4d681211333c026202cad4d5649
Author: Michal Luczaj <mhal@rbox.co>
Date: Mon Dec 2 12:29:25 2024 +0100
bpf, sockmap: Fix race between element replace and close()
Element replace (with a socket different from the one stored) may race
with socket's close() link popping & unlinking. __sock_map_delete()
unconditionally unrefs the (wrong) element:
// set map[0] = s0
map_update_elem(map, 0, s0)
// drop fd of s0
close(s0)
sock_map_close()
lock_sock(sk) (s0!)
sock_map_remove_links(sk)
link = sk_psock_link_pop()
sock_map_unlink(sk, link)
sock_map_delete_from_link
// replace map[0] with s1
map_update_elem(map, 0, s1)
sock_map_update_elem
(s1!) lock_sock(sk)
sock_map_update_common
psock = sk_psock(sk)
spin_lock(&stab->lock)
osk = stab->sks[idx]
sock_map_add_link(..., &stab->sks[idx])
sock_map_unref(osk, &stab->sks[idx])
psock = sk_psock(osk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test(&psock))
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
unlock_sock(sk)
__sock_map_delete
spin_lock(&stab->lock)
sk = *psk // s1 replaced s0; sk == s1
if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch
sk = xchg(psk, NULL)
if (sk)
sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle
psock = sk_psock(sk)
sk_psock_put(sk, psock)
if (refcount_dec_and_test())
sk_psock_drop(sk, psock)
spin_unlock(&stab->lock)
release_sock(sk)
Then close(map) enqueues bpf_map_free_deferred, which finally calls
sock_map_free(). This results in some refcount_t warnings along with
a KASAN splat [1].
Fix __sock_map_delete(), do not allow sock_map_unref() on elements that
may have been replaced.
[1]:
BUG: KASAN: slab-use-after-free in sock_map_free+0x10e/0x330
Write of size 4 at addr ffff88811f5b9100 by task kworker/u64:12/1063
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Not tainted 6.12.0+ #125
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
Call Trace:
<TASK>
dump_stack_lvl+0x68/0x90
print_report+0x174/0x4f6
kasan_report+0xb9/0x190
kasan_check_range+0x10f/0x1e0
sock_map_free+0x10e/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1202:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
__kasan_slab_alloc+0x85/0x90
kmem_cache_alloc_noprof+0x131/0x450
sk_prot_alloc+0x5b/0x220
sk_alloc+0x2c/0x870
unix_create1+0x88/0x8a0
unix_create+0xc5/0x180
__sock_create+0x241/0x650
__sys_socketpair+0x1ce/0x420
__x64_sys_socketpair+0x92/0x100
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 46:
kasan_save_stack+0x1e/0x40
kasan_save_track+0x10/0x30
kasan_save_free_info+0x37/0x60
__kasan_slab_free+0x4b/0x70
kmem_cache_free+0x1a1/0x590
__sk_destruct+0x388/0x5a0
sk_psock_destroy+0x73e/0xa50
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff88811f5b9080
which belongs to the cache UNIX-STREAM of size 1984
The buggy address is located 128 bytes inside of
freed 1984-byte region [ffff88811f5b9080, ffff88811f5b9840)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11f5b8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888127d49401
flags: 0x17ffffc0000040(head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: f5(slab)
raw: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401
head: 0017ffffc0000040 ffff8881042e4500 dead000000000122 0000000000000000
head: 0000000000000000 00000000800f000f 00000001f5000000 ffff888127d49401
head: 0017ffffc0000003 ffffea00047d6e01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88811f5b9000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88811f5b9080: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88811f5b9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88811f5b9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Disabling lock debugging due to kernel taint
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 14 PID: 1063 at lib/refcount.c:25 refcount_warn_saturate+0xce/0x150
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B 6.12.0+ #125
Tainted: [B]=BAD_PAGE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:refcount_warn_saturate+0xce/0x150
Code: 34 73 eb 03 01 e8 82 53 ad fe 0f 0b eb b1 80 3d 27 73 eb 03 00 75 a8 48 c7 c7 80 bd 95 84 c6 05 17 73 eb 03 01 e8 62 53 ad fe <0f> 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05
RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed10bcde6349
R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000
R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024
FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0
PKRU: 55555554
Call Trace:
<TASK>
? __warn.cold+0x5f/0x1ff
? refcount_warn_saturate+0xce/0x150
? report_bug+0x1ec/0x390
? handle_bug+0x58/0x90
? exc_invalid_op+0x13/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0xce/0x150
sock_map_free+0x2e5/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
irq event stamp: 10741
hardirqs last enabled at (10741): [<ffffffff84400ec6>] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (10740): [<ffffffff811e532d>] handle_softirqs+0x60d/0x770
softirqs last enabled at (10506): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
softirqs last disabled at (10301): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
refcount_t: underflow; use-after-free.
WARNING: CPU: 14 PID: 1063 at lib/refcount.c:28 refcount_warn_saturate+0xee/0x150
CPU: 14 UID: 0 PID: 1063 Comm: kworker/u64:12 Tainted: G B W 6.12.0+ #125
Tainted: [B]=BAD_PAGE, [W]=WARN
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:refcount_warn_saturate+0xee/0x150
Code: 17 73 eb 03 01 e8 62 53 ad fe 0f 0b eb 91 80 3d 06 73 eb 03 00 75 88 48 c7 c7 e0 bd 95 84 c6 05 f6 72 eb 03 01 e8 42 53 ad fe <0f> 0b e9 6e ff ff ff 80 3d e6 72 eb 03 00 0f 85 61 ff ff ff 48 c7
RSP: 0018:ffff88815c49fc70 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88811f5b9100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: 0000000000000003 R08: 0000000000000001 R09: ffffed10bcde6349
R10: ffff8885e6f31a4b R11: 0000000000000000 R12: ffff88813be0b000
R13: ffff88811f5b9100 R14: ffff88811f5b9080 R15: ffff88813be0b024
FS: 0000000000000000(0000) GS:ffff8885e6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dda99b0250 CR3: 000000015dbac000 CR4: 0000000000752ef0
PKRU: 55555554
Call Trace:
<TASK>
? __warn.cold+0x5f/0x1ff
? refcount_warn_saturate+0xee/0x150
? report_bug+0x1ec/0x390
? handle_bug+0x58/0x90
? exc_invalid_op+0x13/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0xee/0x150
sock_map_free+0x2d3/0x330
bpf_map_free_deferred+0x173/0x320
process_one_work+0x846/0x1420
worker_thread+0x5b3/0xf80
kthread+0x29e/0x360
ret_from_fork+0x2d/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
irq event stamp: 10741
hardirqs last enabled at (10741): [<ffffffff84400ec6>] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (10740): [<ffffffff811e532d>] handle_softirqs+0x60d/0x770
softirqs last enabled at (10506): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
softirqs last disabled at (10301): [<ffffffff811e55a9>] __irq_exit_rcu+0x109/0x210
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20241202-sockmap-replace-v1-3-1e88579e7bd5@rbox.co
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
2025-01-09 16:15:47 +00:00
|
|
|
if (!sk_test || sk_test == *psk)
|
2019-07-19 17:29:19 +00:00
|
|
|
sk = xchg(psk, NULL);
|
|
|
|
|
|
|
|
|
|
if (likely(sk))
|
|
|
|
|
sock_map_unref(sk, psk);
|
|
|
|
|
else
|
|
|
|
|
err = -EINVAL;
|
|
|
|
|
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&stab->lock);
|
2019-07-19 17:29:19 +00:00
|
|
|
return err;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
|
|
|
|
|
void *link_raw)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
|
|
|
|
|
__sock_map_delete(stab, sk, link_raw);
|
|
|
|
|
}
|
|
|
|
|
|
bpf: return long from bpf_map_ops funcs
Bugzilla: https://bugzilla.redhat.com/2221599
commit d7ba4cc900bf1eea2d8c807c6b1fc6bd61f41237
Author: JP Kobryn <inwardvessel@gmail.com>
Date: Wed Mar 22 12:47:54 2023 -0700
bpf: return long from bpf_map_ops funcs
This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the sign bit in the absence of sign extension during situations where
inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative
error is returned.
The definitions of the helper funcs are generated from comments in the bpf
uapi header at `include/uapi/linux/bpf.h`. The return type of these
helpers was previously changed from int to long in commit bdb7b79b4ce8. For
any case where one of the map helpers call the bpf_map_ops funcs that are
still returning 32-bit int, a compiler might not include sign extension
instructions to properly convert the 32-bit negative value a 64-bit
negative value.
For example:
bpf assembly excerpt of an inlined helper calling a kernel function and
checking for a specific error:
; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST);
...
46: call 0xffffffffe103291c ; htab_map_update_elem
; if (err && err != -EEXIST) {
4b: cmp $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax
kernel function assembly excerpt of return value from
`htab_map_update_elem` returning 32-bit int:
movl $0xffffffef, %r9d
...
movl %r9d, %eax
...results in the comparison:
cmp $0xffffffffffffffef, $0x00000000ffffffef
Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long")
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
2023-07-10 13:58:49 +00:00
|
|
|
static long sock_map_delete_elem(struct bpf_map *map, void *key)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
u32 i = *(u32 *)key;
|
|
|
|
|
struct sock **psk;
|
|
|
|
|
|
|
|
|
|
if (unlikely(i >= map->max_entries))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
psk = &stab->sks[i];
|
|
|
|
|
return __sock_map_delete(stab, NULL, psk);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
u32 i = key ? *(u32 *)key : U32_MAX;
|
|
|
|
|
u32 *key_next = next;
|
|
|
|
|
|
|
|
|
|
if (i == stab->map.max_entries - 1)
|
|
|
|
|
return -ENOENT;
|
|
|
|
|
if (i >= stab->map.max_entries)
|
|
|
|
|
*key_next = 0;
|
|
|
|
|
else
|
|
|
|
|
*key_next = i + 1;
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_map_update_common(struct bpf_map *map, u32 idx,
|
|
|
|
|
struct sock *sk, u64 flags)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
|
struct sk_psock_link *link;
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
struct sock *osk;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
if (unlikely(flags > BPF_EXIST))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
if (unlikely(idx >= map->max_entries))
|
|
|
|
|
return -E2BIG;
|
|
|
|
|
|
|
|
|
|
link = sk_psock_init_link();
|
|
|
|
|
if (!link)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
2021-03-31 02:32:29 +00:00
|
|
|
ret = sock_map_link(map, sk);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (ret < 0)
|
|
|
|
|
goto out_free;
|
|
|
|
|
|
|
|
|
|
psock = sk_psock(sk);
|
|
|
|
|
WARN_ON_ONCE(!psock);
|
|
|
|
|
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&stab->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
osk = stab->sks[idx];
|
|
|
|
|
if (osk && flags == BPF_NOEXIST) {
|
|
|
|
|
ret = -EEXIST;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
} else if (!osk && flags == BPF_EXIST) {
|
|
|
|
|
ret = -ENOENT;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
sock_map_add_link(psock, link, map, &stab->sks[idx]);
|
|
|
|
|
stab->sks[idx] = sk;
|
|
|
|
|
if (osk)
|
|
|
|
|
sock_map_unref(osk, &stab->sks[idx]);
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&stab->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return 0;
|
|
|
|
|
out_unlock:
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&stab->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (psock)
|
|
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
out_free:
|
|
|
|
|
sk_psock_free_link(link);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
|
|
|
|
|
{
|
|
|
|
|
return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
|
2020-02-18 17:10:16 +00:00
|
|
|
ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB ||
|
|
|
|
|
ops->op == BPF_SOCK_OPS_TCP_LISTEN_CB;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
2020-06-11 17:25:20 +00:00
|
|
|
static bool sock_map_redirect_allowed(const struct sock *sk)
|
|
|
|
|
{
|
2021-03-31 02:32:35 +00:00
|
|
|
if (sk_is_tcp(sk))
|
|
|
|
|
return sk->sk_state != TCP_LISTEN;
|
|
|
|
|
else
|
|
|
|
|
return sk->sk_state == TCP_ESTABLISHED;
|
2020-06-11 17:25:20 +00:00
|
|
|
}
|
|
|
|
|
|
2020-03-09 11:12:39 +00:00
|
|
|
static bool sock_map_sk_is_suitable(const struct sock *sk)
|
|
|
|
|
{
|
2021-03-31 02:32:31 +00:00
|
|
|
return !!sk->sk_prot->psock_update_sk_prot;
|
2020-03-09 11:12:39 +00:00
|
|
|
}
|
|
|
|
|
|
2020-02-18 17:10:16 +00:00
|
|
|
static bool sock_map_sk_state_allowed(const struct sock *sk)
|
|
|
|
|
{
|
2020-03-09 11:12:39 +00:00
|
|
|
if (sk_is_tcp(sk))
|
|
|
|
|
return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_LISTEN);
|
2022-05-12 15:29:43 +00:00
|
|
|
return true;
|
2020-02-18 17:10:16 +00:00
|
|
|
}
|
|
|
|
|
|
2020-08-21 10:29:44 +00:00
|
|
|
static int sock_hash_update_common(struct bpf_map *map, void *key,
|
|
|
|
|
struct sock *sk, u64 flags);
|
|
|
|
|
|
2020-08-21 10:29:45 +00:00
|
|
|
int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
|
|
|
|
|
u64 flags)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
struct socket *sock;
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
int ret;
|
2020-02-18 17:10:18 +00:00
|
|
|
u64 ufd;
|
|
|
|
|
|
|
|
|
|
if (map->value_size == sizeof(u64))
|
|
|
|
|
ufd = *(u64 *)value;
|
|
|
|
|
else
|
|
|
|
|
ufd = *(u32 *)value;
|
|
|
|
|
if (ufd > S32_MAX)
|
|
|
|
|
return -EINVAL;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
sock = sockfd_lookup(ufd, &ret);
|
|
|
|
|
if (!sock)
|
|
|
|
|
return ret;
|
|
|
|
|
sk = sock->sk;
|
|
|
|
|
if (!sk) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2020-02-07 10:37:12 +00:00
|
|
|
if (!sock_map_sk_is_suitable(sk)) {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
ret = -EOPNOTSUPP;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
sock_map_sk_acquire(sk);
|
2020-02-18 17:10:16 +00:00
|
|
|
if (!sock_map_sk_state_allowed(sk))
|
2020-02-07 10:37:12 +00:00
|
|
|
ret = -EOPNOTSUPP;
|
2020-08-21 10:29:44 +00:00
|
|
|
else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
|
|
|
|
|
ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
|
2020-02-07 10:37:12 +00:00
|
|
|
else
|
2020-08-21 10:29:44 +00:00
|
|
|
ret = sock_hash_update_common(map, key, sk, flags);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sock_map_sk_release(sk);
|
|
|
|
|
out:
|
2020-12-29 13:48:34 +00:00
|
|
|
sockfd_put(sock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
bpf: return long from bpf_map_ops funcs
Bugzilla: https://bugzilla.redhat.com/2221599
commit d7ba4cc900bf1eea2d8c807c6b1fc6bd61f41237
Author: JP Kobryn <inwardvessel@gmail.com>
Date: Wed Mar 22 12:47:54 2023 -0700
bpf: return long from bpf_map_ops funcs
This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the sign bit in the absence of sign extension during situations where
inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative
error is returned.
The definitions of the helper funcs are generated from comments in the bpf
uapi header at `include/uapi/linux/bpf.h`. The return type of these
helpers was previously changed from int to long in commit bdb7b79b4ce8. For
any case where one of the map helpers call the bpf_map_ops funcs that are
still returning 32-bit int, a compiler might not include sign extension
instructions to properly convert the 32-bit negative value a 64-bit
negative value.
For example:
bpf assembly excerpt of an inlined helper calling a kernel function and
checking for a specific error:
; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST);
...
46: call 0xffffffffe103291c ; htab_map_update_elem
; if (err && err != -EEXIST) {
4b: cmp $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax
kernel function assembly excerpt of return value from
`htab_map_update_elem` returning 32-bit int:
movl $0xffffffef, %r9d
...
movl %r9d, %eax
...results in the comparison:
cmp $0xffffffffffffffef, $0x00000000ffffffef
Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long")
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
2023-07-10 13:58:49 +00:00
|
|
|
static long sock_map_update_elem(struct bpf_map *map, void *key,
|
|
|
|
|
void *value, u64 flags)
|
2020-08-21 10:29:47 +00:00
|
|
|
{
|
|
|
|
|
struct sock *sk = (struct sock *)value;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2020-09-28 09:08:02 +00:00
|
|
|
if (unlikely(!sk || !sk_fullsock(sk)))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
2020-08-21 10:29:47 +00:00
|
|
|
if (!sock_map_sk_is_suitable(sk))
|
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
|
|
|
|
|
local_bh_disable();
|
|
|
|
|
bh_lock_sock(sk);
|
|
|
|
|
if (!sock_map_sk_state_allowed(sk))
|
|
|
|
|
ret = -EOPNOTSUPP;
|
|
|
|
|
else if (map->map_type == BPF_MAP_TYPE_SOCKMAP)
|
|
|
|
|
ret = sock_map_update_common(map, *(u32 *)key, sk, flags);
|
|
|
|
|
else
|
|
|
|
|
ret = sock_hash_update_common(map, key, sk, flags);
|
|
|
|
|
bh_unlock_sock(sk);
|
|
|
|
|
local_bh_enable();
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
|
|
|
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
|
|
|
{
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
|
|
|
|
|
if (likely(sock_map_sk_is_suitable(sops->sk) &&
|
|
|
|
|
sock_map_op_okay(sops)))
|
|
|
|
|
return sock_map_update_common(map, *(u32 *)key, sops->sk,
|
|
|
|
|
flags);
|
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_sock_map_update_proto = {
|
|
|
|
|
.func = bpf_sock_map_update,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.pkt_access = true,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
|
|
|
|
|
struct bpf_map *, map, u32, key, u64, flags)
|
|
|
|
|
{
|
2020-02-18 17:10:16 +00:00
|
|
|
struct sock *sk;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
sk = __sock_map_lookup_elem(map, key);
|
|
|
|
|
if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
2021-02-23 18:49:29 +00:00
|
|
|
skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_PASS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_sk_redirect_map_proto = {
|
|
|
|
|
.func = bpf_sk_redirect_map,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_ANYTHING,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
|
|
|
|
|
struct bpf_map *, map, u32, key, u64, flags)
|
|
|
|
|
{
|
2020-02-18 17:10:16 +00:00
|
|
|
struct sock *sk;
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
sk = __sock_map_lookup_elem(map, key);
|
|
|
|
|
if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_DROP;
|
2023-11-07 14:31:48 +00:00
|
|
|
if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
msg->flags = flags;
|
|
|
|
|
msg->sk_redir = sk;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_PASS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_msg_redirect_map_proto = {
|
|
|
|
|
.func = bpf_msg_redirect_map,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_ANYTHING,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
2020-09-09 16:27:11 +00:00
|
|
|
struct sock_map_seq_info {
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
u32 index;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct bpf_iter__sockmap {
|
|
|
|
|
__bpf_md_ptr(struct bpf_iter_meta *, meta);
|
|
|
|
|
__bpf_md_ptr(struct bpf_map *, map);
|
|
|
|
|
__bpf_md_ptr(void *, key);
|
|
|
|
|
__bpf_md_ptr(struct sock *, sk);
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
DEFINE_BPF_ITER_FUNC(sockmap, struct bpf_iter_meta *meta,
|
|
|
|
|
struct bpf_map *map, void *key,
|
|
|
|
|
struct sock *sk)
|
|
|
|
|
|
|
|
|
|
static void *sock_map_seq_lookup_elem(struct sock_map_seq_info *info)
|
|
|
|
|
{
|
|
|
|
|
if (unlikely(info->index >= info->map->max_entries))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
info->sk = __sock_map_lookup_elem(info->map, info->index);
|
|
|
|
|
|
|
|
|
|
/* can't return sk directly, since that might be NULL */
|
|
|
|
|
return info;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *sock_map_seq_start(struct seq_file *seq, loff_t *pos)
|
2020-10-12 09:18:50 +00:00
|
|
|
__acquires(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_map_seq_info *info = seq->private;
|
|
|
|
|
|
|
|
|
|
if (*pos == 0)
|
|
|
|
|
++*pos;
|
|
|
|
|
|
|
|
|
|
/* pairs with sock_map_seq_stop */
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
return sock_map_seq_lookup_elem(info);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *sock_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
2020-10-12 09:18:50 +00:00
|
|
|
__must_hold(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_map_seq_info *info = seq->private;
|
|
|
|
|
|
|
|
|
|
++*pos;
|
|
|
|
|
++info->index;
|
|
|
|
|
|
|
|
|
|
return sock_map_seq_lookup_elem(info);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_map_seq_show(struct seq_file *seq, void *v)
|
2020-10-12 09:18:50 +00:00
|
|
|
__must_hold(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_map_seq_info *info = seq->private;
|
|
|
|
|
struct bpf_iter__sockmap ctx = {};
|
|
|
|
|
struct bpf_iter_meta meta;
|
|
|
|
|
struct bpf_prog *prog;
|
|
|
|
|
|
|
|
|
|
meta.seq = seq;
|
|
|
|
|
prog = bpf_iter_get_info(&meta, !v);
|
|
|
|
|
if (!prog)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
ctx.meta = &meta;
|
|
|
|
|
ctx.map = info->map;
|
|
|
|
|
if (v) {
|
|
|
|
|
ctx.key = &info->index;
|
|
|
|
|
ctx.sk = info->sk;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return bpf_iter_run_prog(prog, &ctx);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_seq_stop(struct seq_file *seq, void *v)
|
2020-10-12 09:18:50 +00:00
|
|
|
__releases(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
if (!v)
|
|
|
|
|
(void)sock_map_seq_show(seq, NULL);
|
|
|
|
|
|
|
|
|
|
/* pairs with sock_map_seq_start */
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct seq_operations sock_map_seq_ops = {
|
|
|
|
|
.start = sock_map_seq_start,
|
|
|
|
|
.next = sock_map_seq_next,
|
|
|
|
|
.stop = sock_map_seq_stop,
|
|
|
|
|
.show = sock_map_seq_show,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int sock_map_init_seq_private(void *priv_data,
|
|
|
|
|
struct bpf_iter_aux_info *aux)
|
|
|
|
|
{
|
|
|
|
|
struct sock_map_seq_info *info = priv_data;
|
|
|
|
|
|
2022-10-31 15:04:38 +00:00
|
|
|
bpf_map_inc_with_uref(aux->map);
|
2020-09-09 16:27:11 +00:00
|
|
|
info->map = aux->map;
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2022-10-31 15:04:38 +00:00
|
|
|
static void sock_map_fini_seq_private(void *priv_data)
|
|
|
|
|
{
|
|
|
|
|
struct sock_map_seq_info *info = priv_data;
|
|
|
|
|
|
|
|
|
|
bpf_map_put_with_uref(info->map);
|
|
|
|
|
}
|
|
|
|
|
|
2023-07-10 13:13:52 +00:00
|
|
|
static u64 sock_map_mem_usage(const struct bpf_map *map)
|
|
|
|
|
{
|
|
|
|
|
u64 usage = sizeof(struct bpf_stab);
|
|
|
|
|
|
|
|
|
|
usage += (u64)map->max_entries * sizeof(struct sock *);
|
|
|
|
|
return usage;
|
|
|
|
|
}
|
|
|
|
|
|
2020-09-09 16:27:11 +00:00
|
|
|
static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
|
|
|
|
|
.seq_ops = &sock_map_seq_ops,
|
|
|
|
|
.init_seq_private = sock_map_init_seq_private,
|
2022-10-31 15:04:38 +00:00
|
|
|
.fini_seq_private = sock_map_fini_seq_private,
|
2020-09-09 16:27:11 +00:00
|
|
|
.seq_priv_size = sizeof(struct sock_map_seq_info),
|
|
|
|
|
};
|
|
|
|
|
|
2022-10-06 10:42:35 +00:00
|
|
|
BTF_ID_LIST_SINGLE(sock_map_btf_ids, struct, bpf_stab)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
const struct bpf_map_ops sock_map_ops = {
|
2020-08-28 01:18:06 +00:00
|
|
|
.map_meta_equal = bpf_map_meta_equal,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
.map_alloc = sock_map_alloc,
|
|
|
|
|
.map_free = sock_map_free,
|
|
|
|
|
.map_get_next_key = sock_map_get_next_key,
|
2020-02-18 17:10:18 +00:00
|
|
|
.map_lookup_elem_sys_only = sock_map_lookup_sys,
|
2020-08-21 10:29:47 +00:00
|
|
|
.map_update_elem = sock_map_update_elem,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
.map_delete_elem = sock_map_delete_elem,
|
|
|
|
|
.map_lookup_elem = sock_map_lookup,
|
|
|
|
|
.map_release_uref = sock_map_release_progs,
|
|
|
|
|
.map_check_btf = map_check_no_btf,
|
2023-07-10 13:13:52 +00:00
|
|
|
.map_mem_usage = sock_map_mem_usage,
|
2022-10-06 10:42:35 +00:00
|
|
|
.map_btf_id = &sock_map_btf_ids[0],
|
2020-09-09 16:27:11 +00:00
|
|
|
.iter_seq_info = &sock_map_iter_seq_info,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
};
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct rcu_head rcu;
|
|
|
|
|
u32 hash;
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
struct hlist_node node;
|
2020-02-17 20:01:11 +00:00
|
|
|
u8 key[];
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
};
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_bucket {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct hlist_head head;
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spinlock_t lock;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
};
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct bpf_map map;
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_bucket *buckets;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
u32 buckets_num;
|
|
|
|
|
u32 elem_size;
|
|
|
|
|
struct sk_psock_progs progs;
|
|
|
|
|
atomic_t count;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
|
|
|
|
|
{
|
|
|
|
|
return jhash(key, len, 0);
|
|
|
|
|
}
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
static struct bpf_shtab_bucket *sock_hash_select_bucket(struct bpf_shtab *htab,
|
|
|
|
|
u32 hash)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
return &htab->buckets[hash & (htab->buckets_num - 1)];
|
|
|
|
|
}
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
static struct bpf_shtab_elem *
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
|
|
|
|
|
u32 key_size)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem *elem;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
hlist_for_each_entry_rcu(elem, head, node) {
|
|
|
|
|
if (elem->hash == hash &&
|
|
|
|
|
!memcmp(&elem->key, key, key_size))
|
|
|
|
|
return elem;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
u32 key_size = map->key_size, hash;
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_bucket *bucket;
|
|
|
|
|
struct bpf_shtab_elem *elem;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
|
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
|
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
|
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
|
|
|
|
|
|
|
|
return elem ? elem->sk : NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
static void sock_hash_free_elem(struct bpf_shtab *htab,
|
|
|
|
|
struct bpf_shtab_elem *elem)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
atomic_dec(&htab->count);
|
|
|
|
|
kfree_rcu(elem, rcu);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
|
|
|
|
|
void *link_raw)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
|
|
|
|
struct bpf_shtab_elem *elem_probe, *elem = link_raw;
|
|
|
|
|
struct bpf_shtab_bucket *bucket;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
bucket = sock_hash_select_bucket(htab, elem->hash);
|
|
|
|
|
|
|
|
|
|
/* elem may be deleted in parallel from the map, but access here
|
|
|
|
|
* is okay since it's going away only after RCU grace period.
|
|
|
|
|
* However, we need to check whether it's still present.
|
|
|
|
|
*/
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
|
|
|
|
|
elem->key, map->key_size);
|
|
|
|
|
if (elem_probe && elem_probe == elem) {
|
|
|
|
|
hlist_del_rcu(&elem->node);
|
|
|
|
|
sock_map_unref(elem->sk, elem);
|
|
|
|
|
sock_hash_free_elem(htab, elem);
|
|
|
|
|
}
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
bpf: return long from bpf_map_ops funcs
Bugzilla: https://bugzilla.redhat.com/2221599
commit d7ba4cc900bf1eea2d8c807c6b1fc6bd61f41237
Author: JP Kobryn <inwardvessel@gmail.com>
Date: Wed Mar 22 12:47:54 2023 -0700
bpf: return long from bpf_map_ops funcs
This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the sign bit in the absence of sign extension during situations where
inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative
error is returned.
The definitions of the helper funcs are generated from comments in the bpf
uapi header at `include/uapi/linux/bpf.h`. The return type of these
helpers was previously changed from int to long in commit bdb7b79b4ce8. For
any case where one of the map helpers call the bpf_map_ops funcs that are
still returning 32-bit int, a compiler might not include sign extension
instructions to properly convert the 32-bit negative value a 64-bit
negative value.
For example:
bpf assembly excerpt of an inlined helper calling a kernel function and
checking for a specific error:
; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST);
...
46: call 0xffffffffe103291c ; htab_map_update_elem
; if (err && err != -EEXIST) {
4b: cmp $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax
kernel function assembly excerpt of return value from
`htab_map_update_elem` returning 32-bit int:
movl $0xffffffef, %r9d
...
movl %r9d, %eax
...results in the comparison:
cmp $0xffffffffffffffef, $0x00000000ffffffef
Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long")
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
2023-07-10 13:58:49 +00:00
|
|
|
static long sock_hash_delete_elem(struct bpf_map *map, void *key)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
u32 hash, key_size = map->key_size;
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_bucket *bucket;
|
|
|
|
|
struct bpf_shtab_elem *elem;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
int ret = -ENOENT;
|
|
|
|
|
|
2024-04-16 08:22:26 +00:00
|
|
|
if (irqs_disabled())
|
|
|
|
|
return -EOPNOTSUPP; /* locks here are hardirq-unsafe */
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
|
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
|
|
|
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
|
|
|
if (elem) {
|
|
|
|
|
hlist_del_rcu(&elem->node);
|
|
|
|
|
sock_map_unref(elem->sk, elem);
|
|
|
|
|
sock_hash_free_elem(htab, elem);
|
|
|
|
|
ret = 0;
|
|
|
|
|
}
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2020-06-19 21:11:42 +00:00
|
|
|
static struct bpf_shtab_elem *sock_hash_alloc_elem(struct bpf_shtab *htab,
|
|
|
|
|
void *key, u32 key_size,
|
|
|
|
|
u32 hash, struct sock *sk,
|
|
|
|
|
struct bpf_shtab_elem *old)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem *new;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
|
|
|
|
|
if (!old) {
|
|
|
|
|
atomic_dec(&htab->count);
|
|
|
|
|
return ERR_PTR(-E2BIG);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2020-12-01 21:58:42 +00:00
|
|
|
new = bpf_map_kmalloc_node(&htab->map, htab->elem_size,
|
|
|
|
|
GFP_ATOMIC | __GFP_NOWARN,
|
|
|
|
|
htab->map.numa_node);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (!new) {
|
|
|
|
|
atomic_dec(&htab->count);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
memcpy(new->key, key, key_size);
|
|
|
|
|
new->sk = sk;
|
|
|
|
|
new->hash = hash;
|
|
|
|
|
return new;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_hash_update_common(struct bpf_map *map, void *key,
|
|
|
|
|
struct sock *sk, u64 flags)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
u32 key_size = map->key_size, hash;
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem *elem, *elem_new;
|
|
|
|
|
struct bpf_shtab_bucket *bucket;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct sk_psock_link *link;
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
if (unlikely(flags > BPF_EXIST))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
link = sk_psock_init_link();
|
|
|
|
|
if (!link)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
2021-03-31 02:32:29 +00:00
|
|
|
ret = sock_map_link(map, sk);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (ret < 0)
|
|
|
|
|
goto out_free;
|
|
|
|
|
|
|
|
|
|
psock = sk_psock(sk);
|
|
|
|
|
WARN_ON_ONCE(!psock);
|
|
|
|
|
|
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
|
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
|
|
|
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
|
|
|
if (elem && flags == BPF_NOEXIST) {
|
|
|
|
|
ret = -EEXIST;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
} else if (!elem && flags == BPF_EXIST) {
|
|
|
|
|
ret = -ENOENT;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
|
|
|
|
|
if (IS_ERR(elem_new)) {
|
|
|
|
|
ret = PTR_ERR(elem_new);
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
sock_map_add_link(psock, link, map, elem_new);
|
|
|
|
|
/* Add new element to the head of the list, so that
|
|
|
|
|
* concurrent search will find it before old elem.
|
|
|
|
|
*/
|
|
|
|
|
hlist_add_head_rcu(&elem_new->node, &bucket->head);
|
|
|
|
|
if (elem) {
|
|
|
|
|
hlist_del_rcu(&elem->node);
|
|
|
|
|
sock_map_unref(elem->sk, elem);
|
|
|
|
|
sock_hash_free_elem(htab, elem);
|
|
|
|
|
}
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return 0;
|
|
|
|
|
out_unlock:
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&bucket->lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sk_psock_put(sk, psock);
|
|
|
|
|
out_free:
|
|
|
|
|
sk_psock_free_link(link);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_hash_get_next_key(struct bpf_map *map, void *key,
|
|
|
|
|
void *key_next)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
|
|
|
|
struct bpf_shtab_elem *elem, *elem_next;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
u32 hash, key_size = map->key_size;
|
|
|
|
|
struct hlist_head *head;
|
|
|
|
|
int i = 0;
|
|
|
|
|
|
|
|
|
|
if (!key)
|
|
|
|
|
goto find_first_elem;
|
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
|
|
|
head = &sock_hash_select_bucket(htab, hash)->head;
|
|
|
|
|
elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
|
|
|
|
|
if (!elem)
|
|
|
|
|
goto find_first_elem;
|
|
|
|
|
|
2020-09-09 16:27:11 +00:00
|
|
|
elem_next = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&elem->node)),
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem, node);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (elem_next) {
|
|
|
|
|
memcpy(key_next, elem_next->key, key_size);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
i = hash & (htab->buckets_num - 1);
|
|
|
|
|
i++;
|
|
|
|
|
find_first_elem:
|
|
|
|
|
for (; i < htab->buckets_num; i++) {
|
|
|
|
|
head = &sock_hash_select_bucket(htab, i)->head;
|
2020-09-09 16:27:11 +00:00
|
|
|
elem_next = hlist_entry_safe(rcu_dereference(hlist_first_rcu(head)),
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem, node);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (elem_next) {
|
|
|
|
|
memcpy(key_next, elem_next->key, key_size);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return -ENOENT;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
int i, err;
|
|
|
|
|
|
|
|
|
|
if (attr->max_entries == 0 ||
|
|
|
|
|
attr->key_size == 0 ||
|
2020-02-18 17:10:18 +00:00
|
|
|
(attr->value_size != sizeof(u32) &&
|
|
|
|
|
attr->value_size != sizeof(u64)) ||
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
|
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
if (attr->key_size > MAX_BPF_STACK)
|
|
|
|
|
return ERR_PTR(-E2BIG);
|
|
|
|
|
|
2023-02-03 13:41:55 +00:00
|
|
|
htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (!htab)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
bpf_map_init_from_attr(&htab->map, attr);
|
|
|
|
|
|
|
|
|
|
htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
|
2020-06-19 21:11:42 +00:00
|
|
|
htab->elem_size = sizeof(struct bpf_shtab_elem) +
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
round_up(htab->map.key_size, 8);
|
|
|
|
|
if (htab->buckets_num == 0 ||
|
2020-06-19 21:11:42 +00:00
|
|
|
htab->buckets_num > U32_MAX / sizeof(struct bpf_shtab_bucket)) {
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
err = -EINVAL;
|
|
|
|
|
goto free_htab;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
htab->buckets = bpf_map_area_alloc(htab->buckets_num *
|
2020-06-19 21:11:42 +00:00
|
|
|
sizeof(struct bpf_shtab_bucket),
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
htab->map.numa_node);
|
|
|
|
|
if (!htab->buckets) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free_htab;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < htab->buckets_num; i++) {
|
|
|
|
|
INIT_HLIST_HEAD(&htab->buckets[i].head);
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_init(&htab->buckets[i].lock);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return &htab->map;
|
|
|
|
|
free_htab:
|
2023-02-03 13:41:55 +00:00
|
|
|
bpf_map_area_free(htab);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return ERR_PTR(err);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_hash_free(struct bpf_map *map)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
|
|
|
|
struct bpf_shtab_bucket *bucket;
|
2020-06-07 20:52:29 +00:00
|
|
|
struct hlist_head unlink_list;
|
2020-06-19 21:11:42 +00:00
|
|
|
struct bpf_shtab_elem *elem;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
struct hlist_node *node;
|
|
|
|
|
int i;
|
|
|
|
|
|
bpf, sockmap: Remove bucket->lock from sock_{hash|map}_free
The bucket->lock is not needed in the sock_hash_free and sock_map_free
calls, in fact it is causing a splat due to being inside rcu block.
| BUG: sleeping function called from invalid context at net/core/sock.c:2935
| in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 62, name: kworker/0:1
| 3 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffff8881381f6df8 (&stab->lock){+...}, at: sock_map_free+0x26/0x180
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04008-g7b083332376e #454
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep.cold+0xa6/0xb6
| lock_sock_nested+0x28/0x90
| sock_map_free+0x5f/0x180
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
The reason we have stab->lock and bucket->locks in sockmap code is to
handle checking EEXIST in update/delete cases. We need to be careful during
an update operation that we check for EEXIST and we need to ensure that the
psock object is not in some partial state of removal/insertion while we do
this. So both map_update_common and sock_map_delete need to guard from being
run together potentially deleting an entry we are checking, etc. But by the
time we get to the tear-down code in sock_{ma[|hash}_free we have already
disconnected the map and we just did synchronize_rcu() in the line above so
no updates/deletes should be in flight. Because of this we can drop the
bucket locks from the map free'ing code, noting no update/deletes can be
in-flight.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: Jakub Sitnicki <jakub@cloudflare.com>
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/158385850787.30597.8346421465837046618.stgit@john-Precision-5820-Tower
2020-03-10 16:41:48 +00:00
|
|
|
/* After the sync no updates or deletes will be in-flight so it
|
|
|
|
|
* is safe to walk map and remove entries without risking a race
|
|
|
|
|
* in EEXIST update case.
|
|
|
|
|
*/
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
synchronize_rcu();
|
|
|
|
|
for (i = 0; i < htab->buckets_num; i++) {
|
|
|
|
|
bucket = sock_hash_select_bucket(htab, i);
|
2020-06-07 20:52:29 +00:00
|
|
|
|
|
|
|
|
/* We are racing with sock_hash_delete_from_link to
|
|
|
|
|
* enter the spin-lock critical section. Every socket on
|
|
|
|
|
* the list is still linked to sockhash. Since link
|
|
|
|
|
* exists, psock exists and holds a ref to socket. That
|
|
|
|
|
* lets us to grab a socket ref too.
|
|
|
|
|
*/
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_lock_bh(&bucket->lock);
|
2020-06-07 20:52:29 +00:00
|
|
|
hlist_for_each_entry(elem, &bucket->head, node)
|
|
|
|
|
sock_hold(elem->sk);
|
|
|
|
|
hlist_move_list(&bucket->head, &unlink_list);
|
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
JIRA: https://issues.redhat.com/browse/RHEL-10691
commit 35d2b7ffffc1d9b3dc6c761010aa3338da49165b
Author: John Fastabend <john.fastabend@gmail.com>
Date: Tue Aug 29 22:35:17 2023 -0700
bpf, sockmap: Fix preempt_rt splat when using raw_spin_lock_t
Sockmap and sockhash maps are a collection of psocks that are
objects representing a socket plus a set of metadata needed
to manage the BPF programs associated with the socket. These
maps use the stab->lock to protect from concurrent operations
on the maps, e.g. trying to insert to objects into the array
at the same time in the same slot. Additionally, a sockhash map
has a bucket lock to protect iteration and insert/delete into
the hash entry.
Each psock has a psock->link which is a linked list of all the
maps that a psock is attached to. This allows a psock (socket)
to be included in multiple sockmap and sockhash maps. This
linked list is protected the psock->link_lock.
They _must_ be nested correctly to avoid deadlock:
lock(stab->lock)
: do BPF map operations and psock insert/delete
lock(psock->link_lock)
: add map to psock linked list of maps
unlock(psock->link_lock)
unlock(stab->lock)
For non PREEMPT_RT kernels both raw_spin_lock_t and spin_lock_t
are guaranteed to not sleep. But, with PREEMPT_RT kernels the
spin_lock_t variants may sleep. In the current code we have
many patterns like this:
rcu_critical_section:
raw_spin_lock(stab->lock)
spin_lock(psock->link_lock) <- may sleep ouch
spin_unlock(psock->link_lock)
raw_spin_unlock(stab->lock)
rcu_critical_section
Nesting spin_lock() inside a raw_spin_lock() violates locking
rules for PREEMPT_RT kernels. And additionally we do alloc(GFP_ATOMICS)
inside the stab->lock, but those might sleep on PREEMPT_RT kernels.
The result is splats like this:
./test_progs -t sockmap_basic
[ 33.344330] bpf_testmod: loading out-of-tree module taints kernel.
[ 33.441933]
[ 33.442089] =============================
[ 33.442421] [ BUG: Invalid wait context ]
[ 33.442763] 6.5.0-rc5-01731-gec0ded2e0282 #4958 Tainted: G O
[ 33.443320] -----------------------------
[ 33.443624] test_progs/2073 is trying to lock:
[ 33.443960] ffff888102a1c290 (&psock->link_lock){....}-{3:3}, at: sock_map_update_common+0x2c2/0x3d0
[ 33.444636] other info that might help us debug this:
[ 33.444991] context-{5:5}
[ 33.445183] 3 locks held by test_progs/2073:
[ 33.445498] #0: ffff88811a208d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: sock_map_update_elem_sys+0xff/0x330
[ 33.446159] #1: ffffffff842539e0 (rcu_read_lock){....}-{1:3}, at: sock_map_update_elem_sys+0xf5/0x330
[ 33.446809] #2: ffff88810d687240 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x177/0x3d0
[ 33.447445] stack backtrace:
[ 33.447655] CPU: 10 PID
To fix observe we can't readily remove the allocations (for that
we would need to use/create something similar to bpf_map_alloc). So
convert raw_spin_lock_t to spin_lock_t. We note that sock_map_update
that would trigger the allocate and potential sleep is only allowed
through sys_bpf ops and via sock_ops which precludes hw interrupts
and low level atomic sections in RT preempt kernel. On non RT
preempt kernel there are no changes here and spin locks sections
and alloc(GFP_ATOMIC) are still not sleepable.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230830053517.166611-1-john.fastabend@gmail.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
2023-11-27 17:56:30 +00:00
|
|
|
spin_unlock_bh(&bucket->lock);
|
2020-06-07 20:52:29 +00:00
|
|
|
|
|
|
|
|
/* Process removed entries out of atomic context to
|
|
|
|
|
* block for socket lock before deleting the psock's
|
|
|
|
|
* link to sockhash.
|
|
|
|
|
*/
|
|
|
|
|
hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
|
|
|
|
|
hlist_del(&elem->node);
|
2020-01-11 06:12:00 +00:00
|
|
|
lock_sock(elem->sk);
|
bpf, sockmap: Don't sleep while holding RCU lock on tear-down
rcu_read_lock is needed to protect access to psock inside sock_map_unref
when tearing down the map. However, we can't afford to sleep in lock_sock
while in RCU read-side critical section. Grab the RCU lock only after we
have locked the socket.
This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a
sockmap/sockhash that contains at least one socket:
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73 #450 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170
| #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_map_free+0x95/0x170
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0
| #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_hash_free+0xec/0x1d0
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200206111652.694507-2-jakub@cloudflare.com
2020-02-06 11:16:50 +00:00
|
|
|
rcu_read_lock();
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
sock_map_unref(elem->sk, elem);
|
bpf, sockmap: Don't sleep while holding RCU lock on tear-down
rcu_read_lock is needed to protect access to psock inside sock_map_unref
when tearing down the map. However, we can't afford to sleep in lock_sock
while in RCU read-side critical section. Grab the RCU lock only after we
have locked the socket.
This fixes RCU warnings triggerable on a VM with 1 vCPU when free'ing a
sockmap/sockhash that contains at least one socket:
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73 #450 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_map_free+0x5/0x170
| #3: ffff8881368c5df8 (&stab->lock){+...}, at: sock_map_free+0x64/0x170
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73 #450
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_map_free+0x95/0x170
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
| =============================
| WARNING: suspicious RCU usage
| 5.5.0-04005-g8fc91b972b73-dirty #452 Not tainted
| -----------------------------
| include/linux/rcupdate.h:272 Illegal context switch in RCU read-side critical section!
|
| other info that might help us debug this:
|
|
| rcu_scheduler_active = 2, debug_locks = 1
| 4 locks held by kworker/0:1/62:
| #0: ffff88813b019748 ((wq_completion)events){+.+.}, at: process_one_work+0x1d7/0x5e0
| #1: ffffc900000abe50 ((work_completion)(&map->work)){+.+.}, at: process_one_work+0x1d7/0x5e0
| #2: ffffffff82065d20 (rcu_read_lock){....}, at: sock_hash_free+0x5/0x1d0
| #3: ffff888139966e00 (&htab->buckets[i].lock){+...}, at: sock_hash_free+0x92/0x1d0
|
| stack backtrace:
| CPU: 0 PID: 62 Comm: kworker/0:1 Not tainted 5.5.0-04005-g8fc91b972b73-dirty #452
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
| Workqueue: events bpf_map_free_deferred
| Call Trace:
| dump_stack+0x71/0xa0
| ___might_sleep+0x105/0x190
| lock_sock_nested+0x28/0x90
| sock_hash_free+0xec/0x1d0
| bpf_map_free_deferred+0x58/0x80
| process_one_work+0x260/0x5e0
| worker_thread+0x4d/0x3e0
| kthread+0x108/0x140
| ? process_one_work+0x5e0/0x5e0
| ? kthread_park+0x90/0x90
| ret_from_fork+0x3a/0x50
Fixes: 7e81a3530206 ("bpf: Sockmap, ensure sock lock held during tear down")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200206111652.694507-2-jakub@cloudflare.com
2020-02-06 11:16:50 +00:00
|
|
|
rcu_read_unlock();
|
2020-01-11 06:12:00 +00:00
|
|
|
release_sock(elem->sk);
|
2020-06-07 20:52:29 +00:00
|
|
|
sock_put(elem->sk);
|
2020-06-07 20:52:28 +00:00
|
|
|
sock_hash_free_elem(htab, elem);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
2024-10-29 16:24:57 +00:00
|
|
|
cond_resched();
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
2020-02-06 11:16:51 +00:00
|
|
|
/* wait for psock readers accessing its map link */
|
|
|
|
|
synchronize_rcu();
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
bpf_map_area_free(htab->buckets);
|
2023-02-03 13:41:55 +00:00
|
|
|
bpf_map_area_free(htab);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
2020-02-18 17:10:18 +00:00
|
|
|
static void *sock_hash_lookup_sys(struct bpf_map *map, void *key)
|
|
|
|
|
{
|
|
|
|
|
struct sock *sk;
|
|
|
|
|
|
|
|
|
|
if (map->value_size != sizeof(u64))
|
|
|
|
|
return ERR_PTR(-ENOSPC);
|
|
|
|
|
|
|
|
|
|
sk = __sock_hash_lookup_elem(map, key);
|
|
|
|
|
if (!sk)
|
|
|
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
|
|
2020-09-30 15:18:16 +00:00
|
|
|
__sock_gen_cookie(sk);
|
2020-02-18 17:10:18 +00:00
|
|
|
return &sk->sk_cookie;
|
|
|
|
|
}
|
|
|
|
|
|
2020-02-18 17:10:19 +00:00
|
|
|
static void *sock_hash_lookup(struct bpf_map *map, void *key)
|
|
|
|
|
{
|
2020-04-29 18:11:52 +00:00
|
|
|
struct sock *sk;
|
|
|
|
|
|
|
|
|
|
sk = __sock_hash_lookup_elem(map, key);
|
2020-09-09 16:27:10 +00:00
|
|
|
if (!sk)
|
2020-04-29 18:11:52 +00:00
|
|
|
return NULL;
|
|
|
|
|
if (sk_is_refcounted(sk) && !refcount_inc_not_zero(&sk->sk_refcnt))
|
|
|
|
|
return NULL;
|
|
|
|
|
return sk;
|
2020-02-18 17:10:19 +00:00
|
|
|
}
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
static void sock_hash_release_progs(struct bpf_map *map)
|
|
|
|
|
{
|
2020-06-19 21:11:42 +00:00
|
|
|
psock_progs_drop(&container_of(map, struct bpf_shtab, map)->progs);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
|
|
|
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
|
|
|
{
|
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
|
|
|
|
|
|
if (likely(sock_map_sk_is_suitable(sops->sk) &&
|
|
|
|
|
sock_map_op_okay(sops)))
|
|
|
|
|
return sock_hash_update_common(map, key, sops->sk, flags);
|
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_sock_hash_update_proto = {
|
|
|
|
|
.func = bpf_sock_hash_update,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.pkt_access = true,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
|
|
|
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
|
|
|
{
|
2020-02-18 17:10:16 +00:00
|
|
|
struct sock *sk;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
|
|
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
sk = __sock_hash_lookup_elem(map, key);
|
|
|
|
|
if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
2021-02-23 18:49:29 +00:00
|
|
|
skb_bpf_set_redir(skb, sk, flags & BPF_F_INGRESS);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_PASS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
|
|
|
|
|
.func = bpf_sk_redirect_hash,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
|
|
|
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
|
|
|
{
|
2020-02-18 17:10:16 +00:00
|
|
|
struct sock *sk;
|
|
|
|
|
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
sk = __sock_hash_lookup_elem(map, key);
|
|
|
|
|
if (unlikely(!sk || !sock_map_redirect_allowed(sk)))
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_DROP;
|
2023-11-07 14:31:48 +00:00
|
|
|
if (!(flags & BPF_F_INGRESS) && !sk_is_tcp(sk))
|
|
|
|
|
return SK_DROP;
|
2020-02-18 17:10:16 +00:00
|
|
|
|
|
|
|
|
msg->flags = flags;
|
|
|
|
|
msg->sk_redir = sk;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return SK_PASS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
|
|
|
|
|
.func = bpf_msg_redirect_hash,
|
|
|
|
|
.gpl_only = false,
|
|
|
|
|
.ret_type = RET_INTEGER,
|
|
|
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
|
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
|
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
|
|
|
.arg4_type = ARG_ANYTHING,
|
|
|
|
|
};
|
|
|
|
|
|
2020-09-09 16:27:11 +00:00
|
|
|
struct sock_hash_seq_info {
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
struct bpf_shtab *htab;
|
|
|
|
|
u32 bucket_id;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static void *sock_hash_seq_find_next(struct sock_hash_seq_info *info,
|
|
|
|
|
struct bpf_shtab_elem *prev_elem)
|
|
|
|
|
{
|
|
|
|
|
const struct bpf_shtab *htab = info->htab;
|
|
|
|
|
struct bpf_shtab_bucket *bucket;
|
|
|
|
|
struct bpf_shtab_elem *elem;
|
|
|
|
|
struct hlist_node *node;
|
|
|
|
|
|
|
|
|
|
/* try to find next elem in the same bucket */
|
|
|
|
|
if (prev_elem) {
|
|
|
|
|
node = rcu_dereference(hlist_next_rcu(&prev_elem->node));
|
|
|
|
|
elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
|
|
|
|
|
if (elem)
|
|
|
|
|
return elem;
|
|
|
|
|
|
|
|
|
|
/* no more elements, continue in the next bucket */
|
|
|
|
|
info->bucket_id++;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (; info->bucket_id < htab->buckets_num; info->bucket_id++) {
|
|
|
|
|
bucket = &htab->buckets[info->bucket_id];
|
|
|
|
|
node = rcu_dereference(hlist_first_rcu(&bucket->head));
|
|
|
|
|
elem = hlist_entry_safe(node, struct bpf_shtab_elem, node);
|
|
|
|
|
if (elem)
|
|
|
|
|
return elem;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *sock_hash_seq_start(struct seq_file *seq, loff_t *pos)
|
2020-10-12 09:18:50 +00:00
|
|
|
__acquires(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_hash_seq_info *info = seq->private;
|
|
|
|
|
|
|
|
|
|
if (*pos == 0)
|
|
|
|
|
++*pos;
|
|
|
|
|
|
|
|
|
|
/* pairs with sock_hash_seq_stop */
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
return sock_hash_seq_find_next(info, NULL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *sock_hash_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
2020-10-12 09:18:50 +00:00
|
|
|
__must_hold(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_hash_seq_info *info = seq->private;
|
|
|
|
|
|
|
|
|
|
++*pos;
|
|
|
|
|
return sock_hash_seq_find_next(info, v);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_hash_seq_show(struct seq_file *seq, void *v)
|
2020-10-12 09:18:50 +00:00
|
|
|
__must_hold(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_hash_seq_info *info = seq->private;
|
|
|
|
|
struct bpf_iter__sockmap ctx = {};
|
|
|
|
|
struct bpf_shtab_elem *elem = v;
|
|
|
|
|
struct bpf_iter_meta meta;
|
|
|
|
|
struct bpf_prog *prog;
|
|
|
|
|
|
|
|
|
|
meta.seq = seq;
|
|
|
|
|
prog = bpf_iter_get_info(&meta, !elem);
|
|
|
|
|
if (!prog)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
ctx.meta = &meta;
|
|
|
|
|
ctx.map = info->map;
|
|
|
|
|
if (elem) {
|
|
|
|
|
ctx.key = elem->key;
|
|
|
|
|
ctx.sk = elem->sk;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return bpf_iter_run_prog(prog, &ctx);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_hash_seq_stop(struct seq_file *seq, void *v)
|
2020-10-12 09:18:50 +00:00
|
|
|
__releases(rcu)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
if (!v)
|
|
|
|
|
(void)sock_hash_seq_show(seq, NULL);
|
|
|
|
|
|
|
|
|
|
/* pairs with sock_hash_seq_start */
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct seq_operations sock_hash_seq_ops = {
|
|
|
|
|
.start = sock_hash_seq_start,
|
|
|
|
|
.next = sock_hash_seq_next,
|
|
|
|
|
.stop = sock_hash_seq_stop,
|
|
|
|
|
.show = sock_hash_seq_show,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int sock_hash_init_seq_private(void *priv_data,
|
2022-10-31 15:04:38 +00:00
|
|
|
struct bpf_iter_aux_info *aux)
|
2020-09-09 16:27:11 +00:00
|
|
|
{
|
|
|
|
|
struct sock_hash_seq_info *info = priv_data;
|
|
|
|
|
|
2022-10-31 15:04:38 +00:00
|
|
|
bpf_map_inc_with_uref(aux->map);
|
2020-09-09 16:27:11 +00:00
|
|
|
info->map = aux->map;
|
|
|
|
|
info->htab = container_of(aux->map, struct bpf_shtab, map);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2022-10-31 15:04:38 +00:00
|
|
|
static void sock_hash_fini_seq_private(void *priv_data)
|
|
|
|
|
{
|
|
|
|
|
struct sock_hash_seq_info *info = priv_data;
|
|
|
|
|
|
|
|
|
|
bpf_map_put_with_uref(info->map);
|
|
|
|
|
}
|
|
|
|
|
|
2023-07-10 13:13:52 +00:00
|
|
|
static u64 sock_hash_mem_usage(const struct bpf_map *map)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_shtab *htab = container_of(map, struct bpf_shtab, map);
|
|
|
|
|
u64 usage = sizeof(*htab);
|
|
|
|
|
|
|
|
|
|
usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket);
|
|
|
|
|
usage += atomic_read(&htab->count) * (u64)htab->elem_size;
|
|
|
|
|
return usage;
|
|
|
|
|
}
|
|
|
|
|
|
2020-09-09 16:27:11 +00:00
|
|
|
static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
|
|
|
|
|
.seq_ops = &sock_hash_seq_ops,
|
|
|
|
|
.init_seq_private = sock_hash_init_seq_private,
|
2022-10-31 15:04:38 +00:00
|
|
|
.fini_seq_private = sock_hash_fini_seq_private,
|
2020-09-09 16:27:11 +00:00
|
|
|
.seq_priv_size = sizeof(struct sock_hash_seq_info),
|
|
|
|
|
};
|
|
|
|
|
|
2022-10-06 10:42:35 +00:00
|
|
|
BTF_ID_LIST_SINGLE(sock_hash_map_btf_ids, struct, bpf_shtab)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
const struct bpf_map_ops sock_hash_ops = {
|
2020-08-28 01:18:06 +00:00
|
|
|
.map_meta_equal = bpf_map_meta_equal,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
.map_alloc = sock_hash_alloc,
|
|
|
|
|
.map_free = sock_hash_free,
|
|
|
|
|
.map_get_next_key = sock_hash_get_next_key,
|
2020-08-21 10:29:47 +00:00
|
|
|
.map_update_elem = sock_map_update_elem,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
.map_delete_elem = sock_hash_delete_elem,
|
2020-02-18 17:10:19 +00:00
|
|
|
.map_lookup_elem = sock_hash_lookup,
|
2020-02-18 17:10:18 +00:00
|
|
|
.map_lookup_elem_sys_only = sock_hash_lookup_sys,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
.map_release_uref = sock_hash_release_progs,
|
|
|
|
|
.map_check_btf = map_check_no_btf,
|
2023-07-10 13:13:52 +00:00
|
|
|
.map_mem_usage = sock_hash_mem_usage,
|
2022-10-06 10:42:35 +00:00
|
|
|
.map_btf_id = &sock_hash_map_btf_ids[0],
|
2020-09-09 16:27:11 +00:00
|
|
|
.iter_seq_info = &sock_hash_iter_seq_info,
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
|
|
|
|
|
{
|
|
|
|
|
switch (map->map_type) {
|
|
|
|
|
case BPF_MAP_TYPE_SOCKMAP:
|
|
|
|
|
return &container_of(map, struct bpf_stab, map)->progs;
|
|
|
|
|
case BPF_MAP_TYPE_SOCKHASH:
|
2020-06-19 21:11:42 +00:00
|
|
|
return &container_of(map, struct bpf_shtab, map)->progs;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
default:
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2022-09-05 13:36:04 +00:00
|
|
|
static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,
|
|
|
|
|
u32 which)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
struct sk_psock_progs *progs = sock_map_progs(map);
|
|
|
|
|
|
|
|
|
|
if (!progs)
|
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
|
|
|
|
|
switch (which) {
|
|
|
|
|
case BPF_SK_MSG_VERDICT:
|
2022-09-05 13:36:04 +00:00
|
|
|
*pprog = &progs->msg_parser;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
break;
|
2021-02-23 18:49:26 +00:00
|
|
|
#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
case BPF_SK_SKB_STREAM_PARSER:
|
2022-09-05 13:36:04 +00:00
|
|
|
*pprog = &progs->stream_parser;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
break;
|
2021-02-23 18:49:26 +00:00
|
|
|
#endif
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
case BPF_SK_SKB_STREAM_VERDICT:
|
2021-03-31 02:32:30 +00:00
|
|
|
if (progs->skb_verdict)
|
|
|
|
|
return -EBUSY;
|
2022-09-05 13:36:04 +00:00
|
|
|
*pprog = &progs->stream_verdict;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
break;
|
2021-03-31 02:32:30 +00:00
|
|
|
case BPF_SK_SKB_VERDICT:
|
|
|
|
|
if (progs->stream_verdict)
|
|
|
|
|
return -EBUSY;
|
2022-09-05 13:36:04 +00:00
|
|
|
*pprog = &progs->skb_verdict;
|
2021-03-31 02:32:30 +00:00
|
|
|
break;
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
default:
|
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
}
|
|
|
|
|
|
2022-09-05 13:36:04 +00:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
|
|
|
|
|
struct bpf_prog *old, u32 which)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_prog **pprog;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = sock_map_prog_lookup(map, &pprog, which);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
|
|
|
|
|
2020-06-29 09:56:28 +00:00
|
|
|
if (old)
|
|
|
|
|
return psock_replace_prog(pprog, prog, old);
|
|
|
|
|
|
|
|
|
|
psock_set_prog(pprog, prog);
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2022-09-05 13:36:04 +00:00
|
|
|
int sock_map_bpf_prog_query(const union bpf_attr *attr,
|
|
|
|
|
union bpf_attr __user *uattr)
|
|
|
|
|
{
|
|
|
|
|
__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
|
|
|
|
|
u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;
|
|
|
|
|
struct bpf_prog **pprog;
|
|
|
|
|
struct bpf_prog *prog;
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
struct fd f;
|
|
|
|
|
u32 id = 0;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
if (attr->query.query_flags)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
f = fdget(ufd);
|
|
|
|
|
map = __bpf_map_get(f);
|
|
|
|
|
if (IS_ERR(map))
|
|
|
|
|
return PTR_ERR(map);
|
|
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
|
|
|
|
|
ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto end;
|
|
|
|
|
|
|
|
|
|
prog = *pprog;
|
|
|
|
|
prog_cnt = !prog ? 0 : 1;
|
|
|
|
|
|
|
|
|
|
if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
|
|
|
|
|
goto end;
|
|
|
|
|
|
|
|
|
|
/* we do not hold the refcnt, the bpf prog may be released
|
|
|
|
|
* asynchronously and the id would be set to 0.
|
|
|
|
|
*/
|
|
|
|
|
id = data_race(prog->aux->id);
|
|
|
|
|
if (id == 0)
|
|
|
|
|
prog_cnt = 0;
|
|
|
|
|
|
|
|
|
|
end:
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
|
|
if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||
|
|
|
|
|
(id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||
|
|
|
|
|
copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
|
|
|
|
|
ret = -EFAULT;
|
|
|
|
|
|
|
|
|
|
fdput(f);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2020-03-09 11:12:36 +00:00
|
|
|
static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)
|
bpf, sockmap: convert to generic sk_msg interface
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-13 00:45:58 +00:00
|
|
|
{
|
|
|
|
|
switch (link->map->map_type) {
|
|
|
|
|
case BPF_MAP_TYPE_SOCKMAP:
|
|
|
|
|
return sock_map_delete_from_link(link->map, sk,
|
|
|
|
|
link->link_raw);
|
|
|
|
|
case BPF_MAP_TYPE_SOCKHASH:
|
|
|
|
|
return sock_hash_delete_from_link(link->map, sk,
|
|
|
|
|
link->link_raw);
|
|
|
|
|
default:
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
2020-03-09 11:12:36 +00:00
|
|
|
|
|
|
|
|
static void sock_map_remove_links(struct sock *sk, struct sk_psock *psock)
|
|
|
|
|
{
|
|
|
|
|
struct sk_psock_link *link;
|
|
|
|
|
|
|
|
|
|
while ((link = sk_psock_link_pop(psock))) {
|
|
|
|
|
sock_map_unlink(sk, link);
|
|
|
|
|
sk_psock_free_link(link);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void sock_map_unhash(struct sock *sk)
|
|
|
|
|
{
|
|
|
|
|
void (*saved_unhash)(struct sock *sk);
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
psock = sk_psock(sk);
|
|
|
|
|
if (unlikely(!psock)) {
|
|
|
|
|
rcu_read_unlock();
|
2023-03-29 13:38:18 +00:00
|
|
|
saved_unhash = READ_ONCE(sk->sk_prot)->unhash;
|
|
|
|
|
} else {
|
|
|
|
|
saved_unhash = psock->saved_unhash;
|
|
|
|
|
sock_map_remove_links(sk, psock);
|
|
|
|
|
rcu_read_unlock();
|
2020-03-09 11:12:36 +00:00
|
|
|
}
|
2023-03-29 13:38:18 +00:00
|
|
|
if (WARN_ON_ONCE(saved_unhash == sock_map_unhash))
|
|
|
|
|
return;
|
|
|
|
|
if (saved_unhash)
|
|
|
|
|
saved_unhash(sk);
|
2020-03-09 11:12:36 +00:00
|
|
|
}
|
2022-05-12 15:29:50 +00:00
|
|
|
EXPORT_SYMBOL_GPL(sock_map_unhash);
|
2020-03-09 11:12:36 +00:00
|
|
|
|
2022-10-31 09:12:45 +00:00
|
|
|
void sock_map_destroy(struct sock *sk)
|
|
|
|
|
{
|
|
|
|
|
void (*saved_destroy)(struct sock *sk);
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
psock = sk_psock_get(sk);
|
|
|
|
|
if (unlikely(!psock)) {
|
|
|
|
|
rcu_read_unlock();
|
2023-03-29 13:38:18 +00:00
|
|
|
saved_destroy = READ_ONCE(sk->sk_prot)->destroy;
|
|
|
|
|
} else {
|
|
|
|
|
saved_destroy = psock->saved_destroy;
|
|
|
|
|
sock_map_remove_links(sk, psock);
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
sk_psock_stop(psock);
|
|
|
|
|
sk_psock_put(sk, psock);
|
2022-10-31 09:12:45 +00:00
|
|
|
}
|
2023-03-29 13:38:18 +00:00
|
|
|
if (WARN_ON_ONCE(saved_destroy == sock_map_destroy))
|
|
|
|
|
return;
|
|
|
|
|
if (saved_destroy)
|
|
|
|
|
saved_destroy(sk);
|
2022-10-31 09:12:45 +00:00
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL_GPL(sock_map_destroy);
|
|
|
|
|
|
2020-03-09 11:12:36 +00:00
|
|
|
void sock_map_close(struct sock *sk, long timeout)
|
|
|
|
|
{
|
|
|
|
|
void (*saved_close)(struct sock *sk, long timeout);
|
|
|
|
|
struct sk_psock *psock;
|
|
|
|
|
|
|
|
|
|
lock_sock(sk);
|
|
|
|
|
rcu_read_lock();
|
sock_map: avoid race between sock_map_close and sk_psock_put
JIRA: https://issues.redhat.com/browse/RHEL-47670
CVE: CVE-2024-39500
commit 4b4647add7d3c8530493f7247d11e257ee425bf0
Author: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Date: Fri May 24 11:47:02 2024 -0300
sock_map: avoid race between sock_map_close and sk_psock_put
sk_psock_get will return NULL if the refcount of psock has gone to 0, which
will happen when the last call of sk_psock_put is done. However,
sk_psock_drop may not have finished yet, so the close callback will still
point to sock_map_close despite psock being NULL.
This can be reproduced with a thread deleting an element from the sock map,
while the second one creates a socket, adds it to the map and closes it.
That will trigger the WARN_ON_ONCE:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7220 at net/core/sock_map.c:1701 sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Modules linked in:
CPU: 1 PID: 7220 Comm: syz-executor380 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Code: df e8 92 29 88 f8 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 79 29 88 f8 4c 8b 23 eb 89 e8 4f 15 23 f8 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 13 26 3d 02
RSP: 0018:ffffc9000441fda8 EFLAGS: 00010293
RAX: ffffffff89731ae1 RBX: ffffffff94b87540 RCX: ffff888029470000
RDX: 0000000000000000 RSI: ffffffff8bcab5c0 RDI: ffffffff8c1faba0
RBP: 0000000000000000 R08: ffffffff92f9b61f R09: 1ffffffff25f36c3
R10: dffffc0000000000 R11: fffffbfff25f36c4 R12: ffffffff89731840
R13: ffff88804b587000 R14: ffff88804b587000 R15: ffffffff89731870
FS: 000055555e080380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000207d4000 CR4: 0000000000350ef0
Call Trace:
<TASK>
unix_release+0x87/0xc0 net/unix/af_unix.c:1048
__sock_release net/socket.c:659 [inline]
sock_close+0xbe/0x240 net/socket.c:1421
__fput+0x42b/0x8a0 fs/file_table.c:422
__do_sys_close fs/open.c:1556 [inline]
__se_sys_close fs/open.c:1541 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1541
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb37d618070
Code: 00 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d4 e8 10 2c 00 00 80 3d 31 f0 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007ffcd4a525d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb37d618070
RDX: 0000000000000010 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000100000000 R09: 0000000100000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Use sk_psock, which will only check that the pointer is not been set to
NULL yet, which should only happen after the callbacks are restored. If,
then, a reference can still be gotten, we may call sk_psock_stop and cancel
psock->work.
As suggested by Paolo Abeni, reorder the condition so the control flow is
less convoluted.
After that change, the reproducer does not trigger the WARN_ON_ONCE
anymore.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reported-by: syzbot+07a2e4a1a57118ef7355@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=07a2e4a1a57118ef7355
Fixes: aadb2bb83ff7 ("sock_map: Fix a potential use-after-free in sock_map_close()")
Fixes: 5b4a79ba65a1 ("bpf, sockmap: Don't let sock_map_{close,destroy,unhash} call itself")
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20240524144702.1178377-1-cascardo@igalia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
2024-07-15 09:21:05 +00:00
|
|
|
psock = sk_psock(sk);
|
|
|
|
|
if (likely(psock)) {
|
2023-03-29 13:38:18 +00:00
|
|
|
saved_close = psock->saved_close;
|
|
|
|
|
sock_map_remove_links(sk, psock);
|
sock_map: avoid race between sock_map_close and sk_psock_put
JIRA: https://issues.redhat.com/browse/RHEL-47670
CVE: CVE-2024-39500
commit 4b4647add7d3c8530493f7247d11e257ee425bf0
Author: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Date: Fri May 24 11:47:02 2024 -0300
sock_map: avoid race between sock_map_close and sk_psock_put
sk_psock_get will return NULL if the refcount of psock has gone to 0, which
will happen when the last call of sk_psock_put is done. However,
sk_psock_drop may not have finished yet, so the close callback will still
point to sock_map_close despite psock being NULL.
This can be reproduced with a thread deleting an element from the sock map,
while the second one creates a socket, adds it to the map and closes it.
That will trigger the WARN_ON_ONCE:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7220 at net/core/sock_map.c:1701 sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Modules linked in:
CPU: 1 PID: 7220 Comm: syz-executor380 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Code: df e8 92 29 88 f8 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 79 29 88 f8 4c 8b 23 eb 89 e8 4f 15 23 f8 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 13 26 3d 02
RSP: 0018:ffffc9000441fda8 EFLAGS: 00010293
RAX: ffffffff89731ae1 RBX: ffffffff94b87540 RCX: ffff888029470000
RDX: 0000000000000000 RSI: ffffffff8bcab5c0 RDI: ffffffff8c1faba0
RBP: 0000000000000000 R08: ffffffff92f9b61f R09: 1ffffffff25f36c3
R10: dffffc0000000000 R11: fffffbfff25f36c4 R12: ffffffff89731840
R13: ffff88804b587000 R14: ffff88804b587000 R15: ffffffff89731870
FS: 000055555e080380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000207d4000 CR4: 0000000000350ef0
Call Trace:
<TASK>
unix_release+0x87/0xc0 net/unix/af_unix.c:1048
__sock_release net/socket.c:659 [inline]
sock_close+0xbe/0x240 net/socket.c:1421
__fput+0x42b/0x8a0 fs/file_table.c:422
__do_sys_close fs/open.c:1556 [inline]
__se_sys_close fs/open.c:1541 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1541
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb37d618070
Code: 00 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d4 e8 10 2c 00 00 80 3d 31 f0 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007ffcd4a525d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb37d618070
RDX: 0000000000000010 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000100000000 R09: 0000000100000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Use sk_psock, which will only check that the pointer is not been set to
NULL yet, which should only happen after the callbacks are restored. If,
then, a reference can still be gotten, we may call sk_psock_stop and cancel
psock->work.
As suggested by Paolo Abeni, reorder the condition so the control flow is
less convoluted.
After that change, the reproducer does not trigger the WARN_ON_ONCE
anymore.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reported-by: syzbot+07a2e4a1a57118ef7355@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=07a2e4a1a57118ef7355
Fixes: aadb2bb83ff7 ("sock_map: Fix a potential use-after-free in sock_map_close()")
Fixes: 5b4a79ba65a1 ("bpf, sockmap: Don't let sock_map_{close,destroy,unhash} call itself")
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20240524144702.1178377-1-cascardo@igalia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
2024-07-15 09:21:05 +00:00
|
|
|
psock = sk_psock_get(sk);
|
|
|
|
|
if (unlikely(!psock))
|
|
|
|
|
goto no_psock;
|
2023-03-29 13:38:18 +00:00
|
|
|
rcu_read_unlock();
|
|
|
|
|
sk_psock_stop(psock);
|
|
|
|
|
release_sock(sk);
|
|
|
|
|
cancel_work_sync(&psock->work);
|
|
|
|
|
sk_psock_put(sk, psock);
|
sock_map: avoid race between sock_map_close and sk_psock_put
JIRA: https://issues.redhat.com/browse/RHEL-47670
CVE: CVE-2024-39500
commit 4b4647add7d3c8530493f7247d11e257ee425bf0
Author: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Date: Fri May 24 11:47:02 2024 -0300
sock_map: avoid race between sock_map_close and sk_psock_put
sk_psock_get will return NULL if the refcount of psock has gone to 0, which
will happen when the last call of sk_psock_put is done. However,
sk_psock_drop may not have finished yet, so the close callback will still
point to sock_map_close despite psock being NULL.
This can be reproduced with a thread deleting an element from the sock map,
while the second one creates a socket, adds it to the map and closes it.
That will trigger the WARN_ON_ONCE:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7220 at net/core/sock_map.c:1701 sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Modules linked in:
CPU: 1 PID: 7220 Comm: syz-executor380 Not tainted 6.9.0-syzkaller-07726-g3c999d1ae3c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:sock_map_close+0x2a2/0x2d0 net/core/sock_map.c:1701
Code: df e8 92 29 88 f8 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 79 29 88 f8 4c 8b 23 eb 89 e8 4f 15 23 f8 90 <0f> 0b 90 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d e9 13 26 3d 02
RSP: 0018:ffffc9000441fda8 EFLAGS: 00010293
RAX: ffffffff89731ae1 RBX: ffffffff94b87540 RCX: ffff888029470000
RDX: 0000000000000000 RSI: ffffffff8bcab5c0 RDI: ffffffff8c1faba0
RBP: 0000000000000000 R08: ffffffff92f9b61f R09: 1ffffffff25f36c3
R10: dffffc0000000000 R11: fffffbfff25f36c4 R12: ffffffff89731840
R13: ffff88804b587000 R14: ffff88804b587000 R15: ffffffff89731870
FS: 000055555e080380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000207d4000 CR4: 0000000000350ef0
Call Trace:
<TASK>
unix_release+0x87/0xc0 net/unix/af_unix.c:1048
__sock_release net/socket.c:659 [inline]
sock_close+0xbe/0x240 net/socket.c:1421
__fput+0x42b/0x8a0 fs/file_table.c:422
__do_sys_close fs/open.c:1556 [inline]
__se_sys_close fs/open.c:1541 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1541
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb37d618070
Code: 00 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d4 e8 10 2c 00 00 80 3d 31 f0 07 00 00 74 17 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c
RSP: 002b:00007ffcd4a525d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fb37d618070
RDX: 0000000000000010 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000100000000 R09: 0000000100000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Use sk_psock, which will only check that the pointer is not been set to
NULL yet, which should only happen after the callbacks are restored. If,
then, a reference can still be gotten, we may call sk_psock_stop and cancel
psock->work.
As suggested by Paolo Abeni, reorder the condition so the control flow is
less convoluted.
After that change, the reproducer does not trigger the WARN_ON_ONCE
anymore.
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reported-by: syzbot+07a2e4a1a57118ef7355@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=07a2e4a1a57118ef7355
Fixes: aadb2bb83ff7 ("sock_map: Fix a potential use-after-free in sock_map_close()")
Fixes: 5b4a79ba65a1 ("bpf, sockmap: Don't let sock_map_{close,destroy,unhash} call itself")
Cc: stable@vger.kernel.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20240524144702.1178377-1-cascardo@igalia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>
2024-07-15 09:21:05 +00:00
|
|
|
} else {
|
|
|
|
|
saved_close = READ_ONCE(sk->sk_prot)->close;
|
|
|
|
|
no_psock:
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
release_sock(sk);
|
2020-03-09 11:12:36 +00:00
|
|
|
}
|
2023-03-29 13:38:18 +00:00
|
|
|
/* Make sure we do not recurse. This is a bug.
|
|
|
|
|
* Leak the socket instead of crashing on a stack overflow.
|
|
|
|
|
*/
|
|
|
|
|
if (WARN_ON_ONCE(saved_close == sock_map_close))
|
|
|
|
|
return;
|
2020-03-09 11:12:36 +00:00
|
|
|
saved_close(sk, timeout);
|
|
|
|
|
}
|
2022-05-12 15:29:44 +00:00
|
|
|
EXPORT_SYMBOL_GPL(sock_map_close);
|
2020-09-09 16:27:11 +00:00
|
|
|
|
|
|
|
|
static int sock_map_iter_attach_target(struct bpf_prog *prog,
|
|
|
|
|
union bpf_iter_link_info *linfo,
|
|
|
|
|
struct bpf_iter_aux_info *aux)
|
|
|
|
|
{
|
|
|
|
|
struct bpf_map *map;
|
|
|
|
|
int err = -EINVAL;
|
|
|
|
|
|
|
|
|
|
if (!linfo->map.map_fd)
|
|
|
|
|
return -EBADF;
|
|
|
|
|
|
|
|
|
|
map = bpf_map_get_with_uref(linfo->map.map_fd);
|
|
|
|
|
if (IS_ERR(map))
|
|
|
|
|
return PTR_ERR(map);
|
|
|
|
|
|
|
|
|
|
if (map->map_type != BPF_MAP_TYPE_SOCKMAP &&
|
|
|
|
|
map->map_type != BPF_MAP_TYPE_SOCKHASH)
|
|
|
|
|
goto put_map;
|
|
|
|
|
|
|
|
|
|
if (prog->aux->max_rdonly_access > map->key_size) {
|
|
|
|
|
err = -EACCES;
|
|
|
|
|
goto put_map;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
aux->map = map;
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
put_map:
|
|
|
|
|
bpf_map_put_with_uref(map);
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void sock_map_iter_detach_target(struct bpf_iter_aux_info *aux)
|
|
|
|
|
{
|
|
|
|
|
bpf_map_put_with_uref(aux->map);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct bpf_iter_reg sock_map_iter_reg = {
|
|
|
|
|
.target = "sockmap",
|
|
|
|
|
.attach_target = sock_map_iter_attach_target,
|
|
|
|
|
.detach_target = sock_map_iter_detach_target,
|
|
|
|
|
.show_fdinfo = bpf_iter_map_show_fdinfo,
|
|
|
|
|
.fill_link_info = bpf_iter_map_fill_link_info,
|
|
|
|
|
.ctx_arg_info_size = 2,
|
|
|
|
|
.ctx_arg_info = {
|
|
|
|
|
{ offsetof(struct bpf_iter__sockmap, key),
|
2022-06-10 13:12:52 +00:00
|
|
|
PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
|
2020-09-09 16:27:11 +00:00
|
|
|
{ offsetof(struct bpf_iter__sockmap, sk),
|
|
|
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
|
|
|
},
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int __init bpf_sockmap_iter_init(void)
|
|
|
|
|
{
|
|
|
|
|
sock_map_iter_reg.ctx_arg_info[1].btf_id =
|
|
|
|
|
btf_sock_ids[BTF_SOCK_TYPE_SOCK];
|
|
|
|
|
return bpf_iter_reg_target(&sock_map_iter_reg);
|
|
|
|
|
}
|
|
|
|
|
late_initcall(bpf_sockmap_iter_init);
|
