asterinas/kernel/src/syscall/symlink.rs

58 lines
1.6 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use super::SyscallReturn;
use crate::{
fs,
fs::{
file_table::FileDesc,
path::{AT_FDCWD, FsPath},
utils::{InodeType, mkmod},
},
prelude::*,
syscall::constants::MAX_FILENAME_LEN,
};
pub fn sys_symlinkat(
target_addr: Vaddr,
dirfd: FileDesc,
linkpath_addr: Vaddr,
ctx: &Context,
) -> Result<SyscallReturn> {
let user_space = ctx.user_space();
let target = user_space.read_cstring(target_addr, MAX_FILENAME_LEN)?;
let link_path_name = user_space.read_cstring(linkpath_addr, MAX_FILENAME_LEN)?;
debug!(
"target = {:?}, dirfd = {}, linkpath = {:?}",
target, dirfd, link_path_name
);
let target = target.to_string_lossy();
if target.is_empty() {
return_errno_with_message!(Errno::ENOENT, "the symlink path is empty");
}
let (dir_path, link_name) = {
let link_path_name = link_path_name.to_string_lossy();
let fs_path = FsPath::from_fd_and_path(dirfd, &link_path_name)?;
ctx.thread_local
.borrow_fs()
.resolver()
.read()
.lookup_unresolved_no_follow(&fs_path)?
.into_parent_and_filename()?
};
let new_path = dir_path.new_fs_child(&link_name, InodeType::SymLink, mkmod!(a+rwx))?;
new_path.inode().write_link(&target)?;
fs::notify::on_create(&dir_path, || link_name);
Ok(SyscallReturn::Return(0))
}
pub fn sys_symlink(
target_addr: Vaddr,
linkpath_addr: Vaddr,
ctx: &Context,
) -> Result<SyscallReturn> {
self::sys_symlinkat(target_addr, AT_FDCWD, linkpath_addr, ctx)
}