From 6b83b07e9950f40884a49159b4b113921bd2a653 Mon Sep 17 00:00:00 2001
From: Aaro Altonen <aaro.altonen@tuni.fi>
Date: Mon, 17 Jun 2019 12:01:23 +0300
Subject: [PATCH] Add PACKED_STRUCT macro

We must use packed structures because the structs we're sending must
not be padded at all
---
 src/frame.hh | 10 +++++-----
 src/util.hh  | 13 +++++++++++++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/frame.hh b/src/frame.hh
index 587c301..fdaa21e 100644
--- a/src/frame.hh
+++ b/src/frame.hh
@@ -46,7 +46,7 @@ namespace kvz_rtp {
             rtp_type_t type;
         };
 
-        struct rtcp_header {
+        PACKED_STRUCT(rtcp_header) {
             uint8_t version:2;
             uint8_t padding:1;
             uint8_t report_cnt:5;
@@ -54,7 +54,7 @@ namespace kvz_rtp {
             uint16_t length;
         };
 
-        struct rtcp_sender_info {
+        PACKED_STRUCT(rtcp_sender_info) {
             uint32_t ntp_msw;
             uint32_t ntp_lsw;
             uint32_t rtp_timestamp;
@@ -62,7 +62,7 @@ namespace kvz_rtp {
             uint32_t byte_count;
         };
 
-        struct rtcp_report_block {
+        PACKED_STRUCT(rtcp_report_block) {
             uint32_t ssrc;
             uint8_t  fraction_lost;
             uint32_t cumulative_pkt_lost:24;
@@ -72,13 +72,13 @@ namespace kvz_rtp {
             uint32_t delay_since_last_sr;
         };
 
-        struct rtcp_sender_frame {
+        PACKED_STRUCT(rtcp_sender_frame) {
             struct rtcp_header header;
             struct rtcp_sender_info s_info;
             struct rtcp_report_block blocks[0];
         };
 
-        struct rtcp_receiver_frame {
+        PACKED_STRUCT(rtcp_receiver_frame) {
             struct rtcp_header header;
             struct rtcp_report_block blocks[0];
         };
diff --git a/src/util.hh b/src/util.hh
index 5862e90..9a58a40 100644
--- a/src/util.hh
+++ b/src/util.hh
@@ -4,6 +4,19 @@
 #include <cstddef>
 #include <cstdio>
 
+#ifdef _WIN32
+
+/* TODO: make sure this works on windows too! */
+
+#define PACKED_STRUCT_WIN(name) \
+    __pragma(pack(push, 1)) \
+    struct name \
+    __pragma(pack(pop))
+#else
+#define PACKED_STRUCT(name) \
+    struct __attribute__((packed)) name
+#endif
+
 const int MAX_PACKET      = 65536;
 const int MAX_PAYLOAD     = 1000;