Add support for sending packets with ECT(1) based on packet options in native WebRTC.

With L4S in WebRTC, only RTP packets are supposed to be send with ECT(1)

Bug: webrtc:42225697
Change-Id: If10bf74a867d3ea04fd1fb931cdc2a6380176270
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/367220
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43343}

BUILD.gn

@@ -654,6 +654,7 @@ if (rtc_include_tests && !build_with_chromium) {
       "p2p:rtc_p2p_unittests",
       "rtc_base:async_dns_resolver_unittests",
       "rtc_base:async_packet_socket_unittest",
+      "rtc_base:async_udp_socket_unittest",
       "rtc_base:callback_list_unittests",
       "rtc_base:rtc_base_approved_unittests",
       "rtc_base:rtc_base_unittests",

p2p/BUILD.gn

@@ -781,6 +781,7 @@ rtc_library("stun_port") {
     "../rtc_base:ip_address",
     "../rtc_base:logging",
     "../rtc_base:stringutils",
+    "../rtc_base:timeutils",
     "../rtc_base/experiments:field_trial_parser",
     "../rtc_base/network:received_packet",
     "../rtc_base/system:rtc_export",
@@ -826,6 +827,7 @@ rtc_library("tcp_port") {
     "../rtc_base:net_helper",
     "../rtc_base:rate_tracker",
     "../rtc_base:threading",
+    "../rtc_base:timeutils",
     "../rtc_base/containers:flat_map",
     "../rtc_base/network:received_packet",
     "//third_party/abseil-cpp/absl/algorithm:container",
@@ -1218,6 +1220,7 @@ rtc_library("p2p_server_utils") {
     "../rtc_base:ssl",
     "../rtc_base:ssl_adapter",
     "../rtc_base:stringutils",
+    "../rtc_base:timeutils",
     "../rtc_base/network:received_packet",
     "../rtc_base/third_party/sigslot",
     "//third_party/abseil-cpp/absl/algorithm:container",

p2p/base/stun_port.cc

@@ -26,6 +26,7 @@
 #include "rtc_base/logging.h"
 #include "rtc_base/network/received_packet.h"
 #include "rtc_base/strings/string_builder.h"
+#include "rtc_base/time_utils.h"
 
 namespace cricket {
 

p2p/base/tcp_port.cc

@@ -84,6 +84,7 @@
 #include "rtc_base/network/received_packet.h"
 #include "rtc_base/rate_tracker.h"
 #include "rtc_base/thread.h"
+#include "rtc_base/time_utils.h"
 
 namespace cricket {
 using ::webrtc::IceCandidateType;

p2p/base/turn_server.cc

@@ -30,6 +30,7 @@
 #include "rtc_base/message_digest.h"
 #include "rtc_base/socket_adapters.h"
 #include "rtc_base/strings/string_builder.h"
+#include "rtc_base/time_utils.h"
 
 namespace cricket {
 namespace {

rtc_base/BUILD.gn

@@ -1302,6 +1302,7 @@ rtc_library("async_udp_socket") {
   ]
   deps = [
     ":async_packet_socket",
+    ":buffer",
     ":checks",
     ":logging",
     ":macromagic",
@@ -1311,6 +1312,7 @@ rtc_library("async_udp_socket") {
     ":timeutils",
     "../api:sequence_checker",
     "../api/units:time_delta",
+    "../api/units:timestamp",
     "../system_wrappers:field_trial",
     "network:received_packet",
     "network:sent_packet",
@@ -1328,7 +1330,9 @@ rtc_library("async_packet_socket") {
     ":callback_list",
     ":checks",
     ":dscp",
+    ":macromagic",
     ":socket",
+    ":socket_address",
     ":timeutils",
     "../api:sequence_checker",
     "network:received_packet",
@@ -1336,6 +1340,7 @@ rtc_library("async_packet_socket") {
     "system:no_unique_address",
     "system:rtc_export",
     "third_party/sigslot",
+    "//third_party/abseil-cpp/absl/functional:any_invocable",
   ]
 }
 
@@ -1353,6 +1358,24 @@ if (rtc_include_tests) {
       "third_party/sigslot",
     ]
   }
+
+  rtc_library("async_udp_socket_unittest") {
+    testonly = true
+    visibility = [ "*" ]
+    sources = [ "async_udp_socket_unittest.cc" ]
+    deps = [
+      ":async_packet_socket",
+      ":async_udp_socket",
+      ":gunit_helpers",
+      ":rtc_base_tests_utils",
+      ":socket",
+      ":socket_address",
+      "../test:test_support",
+      "network:received_packet",
+      "third_party/sigslot",
+      "//third_party/abseil-cpp/absl/memory",
+    ]
+  }
 }
 
 rtc_library("mdns_responder_interface") {

rtc_base/async_packet_socket.h

@@ -11,18 +11,24 @@
 #ifndef RTC_BASE_ASYNC_PACKET_SOCKET_H_
 #define RTC_BASE_ASYNC_PACKET_SOCKET_H_
 
+#include <cstddef>
 #include <cstdint>
+#include <functional>
 #include <vector>
 
+#include "absl/functional/any_invocable.h"
 #include "api/sequence_checker.h"
 #include "rtc_base/callback_list.h"
+#include "rtc_base/checks.h"
 #include "rtc_base/dscp.h"
 #include "rtc_base/network/received_packet.h"
 #include "rtc_base/network/sent_packet.h"
 #include "rtc_base/socket.h"
+#include "rtc_base/socket_address.h"
 #include "rtc_base/system/no_unique_address.h"
 #include "rtc_base/system/rtc_export.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
+#include "rtc_base/thread_annotations.h"
 #include "rtc_base/time_utils.h"
 
 namespace rtc {
@@ -54,8 +60,6 @@ struct RTC_EXPORT PacketOptions {
   // Packet will be sent with ECN(1), RFC-3168, Section 5.
   // Intended to be used with L4S
   // https://www.rfc-editor.org/rfc/rfc9331.html
-  // TODO(https://bugs.webrtc.org/15368): Actually implement support for sending
-  // packets with different marking.
   bool ecn_1 = false;
 
   // When used with RTP packets (for example, webrtc::PacketOptions), the value

rtc_base/async_udp_socket.cc

@@ -10,15 +10,22 @@
 
 #include "rtc_base/async_udp_socket.h"
 
+#include <cstddef>
+#include <memory>
 #include <optional>
 
+#include "api/sequence_checker.h"
 #include "api/units/time_delta.h"
+#include "api/units/timestamp.h"
+#include "rtc_base/async_packet_socket.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/network/received_packet.h"
 #include "rtc_base/network/sent_packet.h"
+#include "rtc_base/socket.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/socket_factory.h"
 #include "rtc_base/time_utils.h"
-#include "system_wrappers/include/field_trial.h"
 
 namespace rtc {
 
@@ -73,6 +80,15 @@ int AsyncUDPSocket::SendTo(const void* pv,
   rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis(),
                               options.info_signaled_after_sent);
   CopySocketInformationToPacketInfo(cb, *this, &sent_packet.info);
+  if (has_set_ect1_options_ != options.ecn_1) {
+    // It is unclear what is most efficient, setting options on every sent
+    // packet or when changed. Potentially, can separate send sockets be used?
+    // This is the easier implementation.
+    if (socket_->SetOption(Socket::Option::OPT_SEND_ECN,
+                           options.ecn_1 ? 1 : 0) == 0) {
+      has_set_ect1_options_ = options.ecn_1;
+    }
+  }
   int ret = socket_->SendTo(pv, cb, addr);
   SignalSentPacket(this, sent_packet);
   return ret;

rtc_base/async_udp_socket.h

@@ -13,13 +13,13 @@
 
 #include <stddef.h>
 
-#include <cstdint>
 #include <memory>
 #include <optional>
 
 #include "api/sequence_checker.h"
 #include "api/units/time_delta.h"
 #include "rtc_base/async_packet_socket.h"
+#include "rtc_base/buffer.h"
 #include "rtc_base/socket.h"
 #include "rtc_base/socket_address.h"
 #include "rtc_base/socket_factory.h"
@@ -69,6 +69,7 @@ class AsyncUDPSocket : public AsyncPacketSocket {
 
   RTC_NO_UNIQUE_ADDRESS webrtc::SequenceChecker sequence_checker_;
   std::unique_ptr<Socket> socket_;
+  bool has_set_ect1_options_ = false;
   rtc::Buffer buffer_ RTC_GUARDED_BY(sequence_checker_);
   std::optional<webrtc::TimeDelta> socket_time_offset_
       RTC_GUARDED_BY(sequence_checker_);

rtc_base/async_udp_socket_unittest.cc

@@ -10,41 +10,46 @@
 
 #include "rtc_base/async_udp_socket.h"
 
+#include <cstdint>
 #include <memory>
-#include <string>
 
-#include "rtc_base/gunit.h"
-#include "rtc_base/physical_socket_server.h"
+#include "absl/memory/memory.h"
+#include "rtc_base/async_packet_socket.h"
+#include "rtc_base/socket.h"
+#include "rtc_base/socket_address.h"
 #include "rtc_base/virtual_socket_server.h"
+#include "test/gtest.h"
 
 namespace rtc {
 
-class AsyncUdpSocketTest : public ::testing::Test, public sigslot::has_slots<> {
- public:
-  AsyncUdpSocketTest()
-      : pss_(new rtc::PhysicalSocketServer),
-        vss_(new rtc::VirtualSocketServer(pss_.get())),
-        socket_(vss_->CreateSocket(SOCK_DGRAM)),
-        udp_socket_(new AsyncUDPSocket(socket_)),
-        ready_to_send_(false) {
-    udp_socket_->SignalReadyToSend.connect(this,
-                                           &AsyncUdpSocketTest::OnReadyToSend);
-  }
+static const SocketAddress kAddr("22.22.22.22", 0);
 
-  void OnReadyToSend(rtc::AsyncPacketSocket* socket) { ready_to_send_ = true; }
+TEST(AsyncUDPSocketTest, SetSocketOptionIfEctChange) {
+  VirtualSocketServer socket_server;
+  Socket* socket = socket_server.CreateSocket(kAddr.family(), SOCK_DGRAM);
+  std::unique_ptr<AsyncUDPSocket> udp__socket =
+      absl::WrapUnique(AsyncUDPSocket::Create(socket, kAddr));
 
- protected:
-  std::unique_ptr<PhysicalSocketServer> pss_;
-  std::unique_ptr<VirtualSocketServer> vss_;
-  Socket* socket_;
-  std::unique_ptr<AsyncUDPSocket> udp_socket_;
-  bool ready_to_send_;
-};
+  int ect = 0;
+  socket->GetOption(Socket::OPT_SEND_ECN, &ect);
+  ASSERT_EQ(ect, 0);
 
-TEST_F(AsyncUdpSocketTest, OnWriteEvent) {
-  EXPECT_FALSE(ready_to_send_);
-  socket_->SignalWriteEvent(socket_);
-  EXPECT_TRUE(ready_to_send_);
+  uint8_t buffer[] = "hello";
+  rtc::PacketOptions packet_options;
+  packet_options.ecn_1 = false;
+  udp__socket->SendTo(buffer, 5, kAddr, packet_options);
+  socket->GetOption(Socket::OPT_SEND_ECN, &ect);
+  EXPECT_EQ(ect, 0);
+
+  packet_options.ecn_1 = true;
+  udp__socket->SendTo(buffer, 5, kAddr, packet_options);
+  socket->GetOption(Socket::OPT_SEND_ECN, &ect);
+  EXPECT_EQ(ect, 1);
+
+  packet_options.ecn_1 = false;
+  udp__socket->SendTo(buffer, 5, kAddr, packet_options);
+  socket->GetOption(Socket::OPT_SEND_ECN, &ect);
+  EXPECT_EQ(ect, 0);
 }
 
 }  // namespace rtc