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/*
* Copyright (c) 2024 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <atomic>
#include "api/stats/rtcstats_objects.h"
#include "api/units/data_rate.h"
#include "api/units/time_delta.h"
#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
#include "modules/rtp_rtcp/source/rtcp_packet/congestion_control_feedback.h"
#include "modules/rtp_rtcp/source/rtcp_packet/rtpfb.h"
#include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
#include "modules/rtp_rtcp/source/rtp_util.h"
#include "pc/test/mock_peer_connection_observers.h"
#include "test/create_frame_generator_capturer.h"
#include "test/field_trial.h"
#include "test/gmock.h"
#include "test/gtest.h"
#include "test/peer_scenario/peer_scenario.h"
#include "test/peer_scenario/peer_scenario_client.h"
namespace webrtc {
namespace {
using test::PeerScenario;
using test::PeerScenarioClient;
using ::testing::HasSubstr;
// Helper class used for counting RTCP feedback messages.
class RtcpFeedbackCounter {
public:
void Count(const EmulatedIpPacket& packet) {
if (!IsRtcpPacket(packet.data)) {
return;
}
rtcp::CommonHeader header;
ASSERT_TRUE(header.Parse(packet.data.cdata(), packet.data.size()));
if (header.type() != rtcp::Rtpfb::kPacketType) {
return;
}
if (header.fmt() == rtcp::CongestionControlFeedback::kFeedbackMessageType) {
++congestion_control_feedback_;
rtcp::CongestionControlFeedback fb;
ASSERT_TRUE(fb.Parse(header));
for (const rtcp::CongestionControlFeedback::PacketInfo& info :
fb.packets()) {
switch (info.ecn) {
case EcnMarking::kNotEct:
++not_ect_;
break;
case EcnMarking::kEct0:
// Not used.
RTC_CHECK_NOTREACHED();
break;
case EcnMarking::kEct1:
// ECN-Capable Transport
++ect1_;
break;
case EcnMarking::kCe:
++ce_;
}
}
}
if (header.fmt() == rtcp::TransportFeedback::kFeedbackMessageType) {
++transport_sequence_number_feedback_;
}
}
int FeedbackAccordingToRfc8888() const {
return congestion_control_feedback_;
}
int FeedbackAccordingToTransportCc() const {
return transport_sequence_number_feedback_;
}
int not_ect() const { return not_ect_; }
int ect1() const { return ect1_; }
int ce() const { return ce_; }
private:
int congestion_control_feedback_ = 0;
int transport_sequence_number_feedback_ = 0;
int not_ect_ = 0;
int ect1_ = 0;
int ce_ = 0;
};
rtc::scoped_refptr<const RTCStatsReport> GetStatsAndProcess(
PeerScenario& s,
PeerScenarioClient* client) {
auto stats_collector =
rtc::make_ref_counted<webrtc::MockRTCStatsCollectorCallback>();
client->pc()->GetStats(stats_collector.get());
s.ProcessMessages(TimeDelta::Millis(0));
RTC_CHECK(stats_collector->called());
return stats_collector->report();
}
DataRate GetAvailableSendBitrate(
const rtc::scoped_refptr<const RTCStatsReport>& report) {
auto stats = report->GetStatsOfType<RTCIceCandidatePairStats>();
if (stats.empty()) {
return DataRate::Zero();
}
return DataRate::BitsPerSec(*stats[0]->available_outgoing_bitrate);
}
TEST(L4STest, NegotiateAndUseCcfbIfEnabled) {
test::ScopedFieldTrials trials(
"WebRTC-RFC8888CongestionControlFeedback/Enabled/");
PeerScenario s(*test_info_);
PeerScenarioClient::Config config = PeerScenarioClient::Config();
config.disable_encryption = true;
PeerScenarioClient* caller = s.CreateClient(config);
PeerScenarioClient* callee = s.CreateClient(config);
// Create network path from caller to callee.
auto send_node = s.net()->NodeBuilder().Build().node;
auto ret_node = s.net()->NodeBuilder().Build().node;
s.net()->CreateRoute(caller->endpoint(), {send_node}, callee->endpoint());
s.net()->CreateRoute(callee->endpoint(), {ret_node}, caller->endpoint());
RtcpFeedbackCounter send_node_feedback_counter;
send_node->router()->SetWatcher([&](const EmulatedIpPacket& packet) {
send_node_feedback_counter.Count(packet);
});
RtcpFeedbackCounter ret_node_feedback_counter;
ret_node->router()->SetWatcher([&](const EmulatedIpPacket& packet) {
ret_node_feedback_counter.Count(packet);
});
auto signaling = s.ConnectSignaling(caller, callee, {send_node}, {ret_node});
PeerScenarioClient::VideoSendTrackConfig video_conf;
video_conf.generator.squares_video->framerate = 15;
caller->CreateVideo("VIDEO_1", video_conf);
callee->CreateVideo("VIDEO_2", video_conf);
signaling.StartIceSignaling();
std::atomic<bool> offer_exchange_done(false);
signaling.NegotiateSdp(
[&](SessionDescriptionInterface* offer) {
std::string offer_str = absl::StrCat(*offer);
// Check that the offer contain both congestion control feedback
// accoring to RFC 8888, and transport-cc and the header extension
EXPECT_THAT(offer_str, HasSubstr("a=rtcp-fb:* ack ccfb\r\n"));
EXPECT_THAT(offer_str, HasSubstr("transport-cc"));
EXPECT_THAT(
offer_str,
"draft-holmer-rmcat-transport-wide-cc-extensions"));
},
[&](const SessionDescriptionInterface& answer) {
std::string answer_str = absl::StrCat(answer);
EXPECT_THAT(answer_str, HasSubstr("a=rtcp-fb:* ack ccfb\r\n"));
// Check that the answer does not contain transport-cc nor the
// header extension
EXPECT_THAT(answer_str, Not(HasSubstr("transport-cc")));
EXPECT_THAT(
answer_str,
"draft-holmer-rmcat-transport-wide-cc-extensions-")));
offer_exchange_done = true;
});
// Wait for SDP negotiation and the packet filter to be setup.
s.WaitAndProcess(&offer_exchange_done);
s.ProcessMessages(TimeDelta::Seconds(2));
EXPECT_GT(send_node_feedback_counter.FeedbackAccordingToRfc8888(), 0);
// TODO: bugs.webrtc.org/42225697 - Fix bug. Caller sends both transport
// sequence number feedback and congestion control feedback. So
// callee still send packets with transport sequence number header extensions
// even though it has been removed from the answer.
// EXPECT_EQ(send_node_feedback_counter.FeedbackAccordingToTransportCc(), 0);
EXPECT_GT(ret_node_feedback_counter.FeedbackAccordingToRfc8888(), 0);
EXPECT_EQ(ret_node_feedback_counter.FeedbackAccordingToTransportCc(), 0);
}
TEST(L4STest, CallerAdaptToLinkCapacityWithoutEcn) {
test::ScopedFieldTrials trials(
"WebRTC-RFC8888CongestionControlFeedback/Enabled/");
PeerScenario s(*test_info_);
PeerScenarioClient::Config config = PeerScenarioClient::Config();
PeerScenarioClient* caller = s.CreateClient(config);
PeerScenarioClient* callee = s.CreateClient(config);
auto caller_to_callee = s.net()
->NodeBuilder()
.capacity(DataRate::KilobitsPerSec(600))
.Build()
.node;
auto callee_to_caller = s.net()->NodeBuilder().Build().node;
s.net()->CreateRoute(caller->endpoint(), {caller_to_callee},
callee->endpoint());
s.net()->CreateRoute(callee->endpoint(), {callee_to_caller},
caller->endpoint());
auto signaling = s.ConnectSignaling(caller, callee, {caller_to_callee},
{callee_to_caller});
PeerScenarioClient::VideoSendTrackConfig video_conf;
video_conf.generator.squares_video->framerate = 15;
caller->CreateVideo("VIDEO_1", video_conf);
signaling.StartIceSignaling();
std::atomic<bool> offer_exchange_done(false);
signaling.NegotiateSdp([&](const SessionDescriptionInterface& answer) {
offer_exchange_done = true;
});
s.WaitAndProcess(&offer_exchange_done);
s.ProcessMessages(TimeDelta::Seconds(3));
DataRate available_bwe =
GetAvailableSendBitrate(GetStatsAndProcess(s, caller));
EXPECT_GT(available_bwe.kbps(), 500);
EXPECT_LT(available_bwe.kbps(), 610);
}
TEST(L4STest, SendsEct1UntilFirstFeedback) {
test::ScopedFieldTrials trials(
"WebRTC-RFC8888CongestionControlFeedback/Enabled/");
PeerScenario s(*test_info_);
PeerScenarioClient::Config config = PeerScenarioClient::Config();
config.disable_encryption = true;
PeerScenarioClient* caller = s.CreateClient(config);
PeerScenarioClient* callee = s.CreateClient(config);
// Create network path from caller to callee.
auto caller_to_callee = s.net()->NodeBuilder().Build().node;
auto callee_to_caller = s.net()->NodeBuilder().Build().node;
s.net()->CreateRoute(caller->endpoint(), {caller_to_callee},
callee->endpoint());
s.net()->CreateRoute(callee->endpoint(), {callee_to_caller},
caller->endpoint());
RtcpFeedbackCounter feedback_counter;
std::atomic<bool> seen_ect1_feedback = false;
std::atomic<bool> seen_not_ect_feedback = false;
callee_to_caller->router()->SetWatcher([&](const EmulatedIpPacket& packet) {
feedback_counter.Count(packet);
if (feedback_counter.ect1() > 0) {
seen_ect1_feedback = true;
RTC_LOG(LS_INFO) << " ect 1" << feedback_counter.ect1();
}
if (feedback_counter.not_ect() > 0) {
seen_not_ect_feedback = true;
RTC_LOG(LS_INFO) << " not ect" << feedback_counter.not_ect();
}
});
auto signaling = s.ConnectSignaling(caller, callee, {caller_to_callee},
{callee_to_caller});
PeerScenarioClient::VideoSendTrackConfig video_conf;
video_conf.generator.squares_video->framerate = 15;
caller->CreateVideo("VIDEO_1", video_conf);
signaling.StartIceSignaling();
std::atomic<bool> offer_exchange_done(false);
signaling.NegotiateSdp([&](const SessionDescriptionInterface& answer) {
offer_exchange_done = true;
});
s.WaitAndProcess(&offer_exchange_done);
// Wait for first feedback where packets have been sent with ECT(1). Then
// feedback for packets sent as not ECT since currently webrtc does not
// implement adaptation to ECN.
EXPECT_TRUE(s.WaitAndProcess(&seen_ect1_feedback, TimeDelta::Seconds(1)));
EXPECT_FALSE(seen_not_ect_feedback);
EXPECT_TRUE(s.WaitAndProcess(&seen_not_ect_feedback, TimeDelta::Seconds(1)));
}
TEST(L4STest, SendsEct1AfterRouteChange) {
test::ScopedFieldTrials trials(
"WebRTC-RFC8888CongestionControlFeedback/Enabled/");
PeerScenario s(*test_info_);
PeerScenarioClient::Config config;
config.disable_encryption = true;
config.endpoints = {{0, {.type = rtc::AdapterType::ADAPTER_TYPE_WIFI}}};
PeerScenarioClient* caller = s.CreateClient(config);
// Callee has booth wifi and cellular adapters.
config.endpoints = {{0, {.type = rtc::AdapterType::ADAPTER_TYPE_WIFI}},
{1, {.type = rtc::AdapterType::ADAPTER_TYPE_CELLULAR}}};
PeerScenarioClient* callee = s.CreateClient(config);
// Create network path from caller to callee.
auto caller_to_callee = s.net()->NodeBuilder().Build().node;
auto callee_to_caller_wifi = s.net()->NodeBuilder().Build().node;
auto callee_to_caller_cellular = s.net()->NodeBuilder().Build().node;
s.net()->CreateRoute(caller->endpoint(0), {caller_to_callee},
callee->endpoint(0));
s.net()->CreateRoute(caller->endpoint(0), {caller_to_callee},
callee->endpoint(1));
s.net()->CreateRoute(callee->endpoint(0), {callee_to_caller_wifi},
caller->endpoint(0));
s.net()->CreateRoute(callee->endpoint(1), {callee_to_caller_cellular},
caller->endpoint(0));
RtcpFeedbackCounter wifi_feedback_counter;
std::atomic<bool> seen_ect1_on_wifi_feedback = false;
std::atomic<bool> seen_not_ect_on_wifi_feedback = false;
callee_to_caller_wifi->router()->SetWatcher(
[&](const EmulatedIpPacket& packet) {
wifi_feedback_counter.Count(packet);
if (wifi_feedback_counter.ect1() > 0) {
seen_ect1_on_wifi_feedback = true;
RTC_LOG(LS_INFO) << " ect 1 feedback on wifi: "
<< wifi_feedback_counter.ect1();
}
if (wifi_feedback_counter.not_ect() > 0) {
seen_not_ect_on_wifi_feedback = true;
RTC_LOG(LS_INFO) << " not ect feedback on wifi: "
<< wifi_feedback_counter.not_ect();
}
});
auto signaling = s.ConnectSignaling(caller, callee, {caller_to_callee},
{callee_to_caller_wifi});
PeerScenarioClient::VideoSendTrackConfig video_conf;
video_conf.generator.squares_video->framerate = 15;
caller->CreateVideo("VIDEO_1", video_conf);
signaling.StartIceSignaling();
std::atomic<bool> offer_exchange_done(false);
signaling.NegotiateSdp([&](const SessionDescriptionInterface& answer) {
offer_exchange_done = true;
});
s.WaitAndProcess(&offer_exchange_done);
// Wait for first feedback where packets have been sent with ECT(1). Then
// feedback for packets sent as not ECT since currently webrtc does not
// implement adaptation to ECN.
EXPECT_TRUE(
s.WaitAndProcess(&seen_ect1_on_wifi_feedback, TimeDelta::Seconds(1)));
EXPECT_FALSE(seen_not_ect_on_wifi_feedback);
EXPECT_TRUE(
s.WaitAndProcess(&seen_not_ect_on_wifi_feedback, TimeDelta::Seconds(1)));
RtcpFeedbackCounter cellular_feedback_counter;
std::atomic<bool> seen_ect1_on_cellular_feedback = false;
callee_to_caller_cellular->router()->SetWatcher(
[&](const EmulatedIpPacket& packet) {
cellular_feedback_counter.Count(packet);
if (cellular_feedback_counter.ect1() > 0) {
seen_ect1_on_cellular_feedback = true;
RTC_LOG(LS_INFO) << " ect 1 feedback on cellular: "
<< cellular_feedback_counter.ect1();
}
});
// Disable callees wifi and expect that the connection switch to cellular and
// sends packets with ECT(1) again.
s.net()->DisableEndpoint(callee->endpoint(0));
EXPECT_TRUE(
s.WaitAndProcess(&seen_ect1_on_cellular_feedback, TimeDelta::Seconds(5)));
}
} // namespace
} // namespace webrtc