| /* |
| * Copyright (c) 2020 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 "media/base/stream_params.h" |
| #include "modules/rtp_rtcp/source/byte_io.h" |
| #include "modules/rtp_rtcp/source/rtp_util.h" |
| #include "pc/media_session.h" |
| #include "pc/session_description.h" |
| #include "test/field_trial.h" |
| #include "test/gmock.h" |
| #include "test/gtest.h" |
| #include "test/peer_scenario/peer_scenario.h" |
| |
| namespace webrtc { |
| namespace test { |
| namespace { |
| |
| enum class MidTestConfiguration { |
| // Legacy endpoint setup where PT demuxing is used. |
| kMidNotNegotiated, |
| // MID is negotiated but missing from packets. PT demuxing is disabled, so |
| // SSRCs have to be added to the SDP for WebRTC to forward packets correctly. |
| // Happens when client is spec compliant but the SFU isn't. Popular legacy. |
| kMidNegotiatedButMissingFromPackets, |
| // Fully spec-compliant: MID is present so we can safely drop packets with |
| // unknown MIDs. |
| kMidNegotiatedAndPresentInPackets, |
| }; |
| |
| // Gives the parameterized test a readable suffix. |
| std::string TestParametersMidTestConfigurationToString( |
| testing::TestParamInfo<MidTestConfiguration> info) { |
| switch (info.param) { |
| case MidTestConfiguration::kMidNotNegotiated: |
| return "MidNotNegotiated"; |
| case MidTestConfiguration::kMidNegotiatedButMissingFromPackets: |
| return "MidNegotiatedButMissingFromPackets"; |
| case MidTestConfiguration::kMidNegotiatedAndPresentInPackets: |
| return "MidNegotiatedAndPresentInPackets"; |
| } |
| } |
| |
| class FrameObserver : public rtc::VideoSinkInterface<VideoFrame> { |
| public: |
| FrameObserver() : frame_observed_(false) {} |
| void OnFrame(const VideoFrame&) override { frame_observed_ = true; } |
| |
| std::atomic<bool> frame_observed_; |
| }; |
| |
| uint32_t get_ssrc(SessionDescriptionInterface* offer, size_t track_index) { |
| EXPECT_LT(track_index, offer->description()->contents().size()); |
| return offer->description() |
| ->contents()[track_index] |
| .media_description() |
| ->streams()[0] |
| .ssrcs[0]; |
| } |
| |
| void set_ssrc(SessionDescriptionInterface* offer, size_t index, uint32_t ssrc) { |
| EXPECT_LT(index, offer->description()->contents().size()); |
| cricket::StreamParams& new_stream_params = offer->description() |
| ->contents()[index] |
| .media_description() |
| ->mutable_streams()[0]; |
| new_stream_params.ssrcs[0] = ssrc; |
| new_stream_params.ssrc_groups[0].ssrcs[0] = ssrc; |
| } |
| |
| } // namespace |
| |
| class UnsignaledStreamTest |
| : public ::testing::Test, |
| public ::testing::WithParamInterface<MidTestConfiguration> {}; |
| |
| TEST_P(UnsignaledStreamTest, ReplacesUnsignaledStreamOnCompletedSignaling) { |
| // This test covers a scenario that might occur if a remote client starts |
| // sending media packets before negotiation has completed. Depending on setup, |
| // these packets either get dropped or trigger an unsignalled default stream |
| // to be created, and connects that to a default video sink. |
| // In some edge cases using Unified Plan and PT demuxing, the default stream |
| // is create in a different transceiver to where the media SSRC will actually |
| // be used. This test verifies that the default stream is removed properly, |
| // and that packets are demuxed and video frames reach the desired sink. |
| const MidTestConfiguration kMidTestConfiguration = GetParam(); |
| |
| // Defined before PeerScenario so it gets destructed after, to avoid use after |
| // free. |
| PeerScenario s(*::testing::UnitTest::GetInstance()->current_test_info()); |
| |
| PeerScenarioClient::Config config = PeerScenarioClient::Config(); |
| // Disable encryption so that we can inject a fake early media packet without |
| // triggering srtp failures. |
| auto* caller = s.CreateClient(config); |
| auto* callee = s.CreateClient(config); |
| |
| 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()); |
| |
| auto signaling = s.ConnectSignaling(caller, callee, {send_node}, {ret_node}); |
| PeerScenarioClient::VideoSendTrackConfig video_conf; |
| video_conf.generator.squares_video->framerate = 15; |
| |
| auto first_track = caller->CreateVideo("VIDEO", video_conf); |
| FrameObserver first_sink; |
| callee->AddVideoReceiveSink(first_track.track->id(), &first_sink); |
| |
| signaling.StartIceSignaling(); |
| std::atomic<bool> offer_exchange_done(false); |
| std::atomic<bool> got_unsignaled_packet(false); |
| |
| // We will capture the media ssrc of the first added stream, and preemptively |
| // inject a new media packet using a different ssrc. What happens depends on |
| // the test configuration. |
| // |
| // MidTestConfiguration::kMidNotNegotiated: |
| // - MID is not negotiated which means PT-based demuxing is enabled. Because |
| // the packets have no MID, the second ssrc packet gets forwarded to the |
| // first m= section. This will create a "default stream" for the second ssrc |
| // and connect it to the default video sink (not set in this test). The test |
| // verifies we can recover from this when we later get packets for the first |
| // ssrc. |
| // |
| // MidTestConfiguration::kMidNegotiatedButMissingFromPackets: |
| // - MID is negotiated wich means PT-based demuxing is disabled. Because we |
| // modify the packets not to contain the MID anyway (simulating a legacy SFU |
| // that does not negotiate properly) unknown SSRCs are dropped but do not |
| // otherwise cause any issues. |
| // |
| // MidTestConfiguration::kMidNegotiatedAndPresentInPackets: |
| // - MID is negotiated which means PT-based demuxing is enabled. In this case |
| // the packets have the MID so they either get forwarded or dropped |
| // depending on if the MID is known. The spec-compliant way is also the most |
| // straight-forward one. |
| |
| uint32_t first_ssrc = 0; |
| uint32_t second_ssrc = 0; |
| absl::optional<int> mid_header_extension_id = absl::nullopt; |
| |
| signaling.NegotiateSdp( |
| /* munge_sdp = */ |
| [&](SessionDescriptionInterface* offer) { |
| // Obtain the MID header extension ID and if we want the |
| // MidTestConfiguration::kMidNotNegotiated setup then we remove the MID |
| // header extension through SDP munging (otherwise SDP is not modified). |
| for (cricket::ContentInfo& content_info : |
| offer->description()->contents()) { |
| std::vector<RtpExtension> header_extensions = |
| content_info.media_description()->rtp_header_extensions(); |
| for (auto it = header_extensions.begin(); |
| it != header_extensions.end(); ++it) { |
| if (it->uri == RtpExtension::kMidUri) { |
| // MID header extension found! |
| mid_header_extension_id = it->id; |
| if (kMidTestConfiguration == |
| MidTestConfiguration::kMidNotNegotiated) { |
| // Munge away the extension. |
| header_extensions.erase(it); |
| } |
| break; |
| } |
| } |
| content_info.media_description()->set_rtp_header_extensions( |
| std::move(header_extensions)); |
| } |
| ASSERT_TRUE(mid_header_extension_id.has_value()); |
| }, |
| /* modify_sdp = */ |
| [&](SessionDescriptionInterface* offer) { |
| first_ssrc = get_ssrc(offer, 0); |
| second_ssrc = first_ssrc + 1; |
| |
| send_node->router()->SetWatcher([&](const EmulatedIpPacket& packet) { |
| if (IsRtpPacket(packet.data) && |
| ByteReader<uint32_t>::ReadBigEndian(&(packet.cdata()[8])) == |
| first_ssrc && |
| !got_unsignaled_packet) { |
| // Parse packet and modify the SSRC to simulate a second m= |
| // section that has not been negotiated yet. |
| std::vector<RtpExtension> extensions; |
| extensions.emplace_back(RtpExtension::kMidUri, |
| mid_header_extension_id.value()); |
| RtpHeaderExtensionMap extensions_map(extensions); |
| RtpPacket parsed_packet; |
| parsed_packet.IdentifyExtensions(extensions_map); |
| ASSERT_TRUE(parsed_packet.Parse(packet.data)); |
| parsed_packet.SetSsrc(second_ssrc); |
| // The MID extension is present if and only if it was negotiated. |
| // If present, we either want to remove it or modify it depending |
| // on setup. |
| switch (kMidTestConfiguration) { |
| case MidTestConfiguration::kMidNotNegotiated: |
| EXPECT_FALSE(parsed_packet.HasExtension<RtpMid>()); |
| break; |
| case MidTestConfiguration::kMidNegotiatedButMissingFromPackets: |
| EXPECT_TRUE(parsed_packet.HasExtension<RtpMid>()); |
| ASSERT_TRUE(parsed_packet.RemoveExtension(RtpMid::kId)); |
| break; |
| case MidTestConfiguration::kMidNegotiatedAndPresentInPackets: |
| EXPECT_TRUE(parsed_packet.HasExtension<RtpMid>()); |
| // The simulated second m= section would have a different MID. |
| // If we don't modify it here then `second_ssrc` would end up |
| // being mapped to the first m= section which would cause SSRC |
| // conflicts if we later add the same SSRC to a second m= |
| // section. Hidden assumption: first m= section does not use |
| // MID:1. |
| ASSERT_TRUE(parsed_packet.SetExtension<RtpMid>("1")); |
| break; |
| } |
| // Inject the modified packet. |
| rtc::CopyOnWriteBuffer updated_buffer = parsed_packet.Buffer(); |
| EmulatedIpPacket updated_packet( |
| packet.from, packet.to, updated_buffer, packet.arrival_time); |
| send_node->OnPacketReceived(std::move(updated_packet)); |
| got_unsignaled_packet = true; |
| } |
| }); |
| }, |
| [&](const SessionDescriptionInterface& answer) { |
| EXPECT_EQ(answer.description()->contents().size(), 1u); |
| offer_exchange_done = true; |
| }); |
| EXPECT_TRUE(s.WaitAndProcess(&offer_exchange_done)); |
| EXPECT_TRUE(s.WaitAndProcess(&got_unsignaled_packet)); |
| EXPECT_TRUE(s.WaitAndProcess(&first_sink.frame_observed_)); |
| |
| auto second_track = caller->CreateVideo("VIDEO2", video_conf); |
| FrameObserver second_sink; |
| callee->AddVideoReceiveSink(second_track.track->id(), &second_sink); |
| |
| // Create a second video stream, munge the sdp to force it to use our fake |
| // early media ssrc. |
| offer_exchange_done = false; |
| signaling.NegotiateSdp( |
| /* munge_sdp = */ |
| [&](SessionDescriptionInterface* offer) { |
| set_ssrc(offer, 1, second_ssrc); |
| }, |
| /* modify_sdp = */ {}, |
| [&](const SessionDescriptionInterface& answer) { |
| EXPECT_EQ(answer.description()->contents().size(), 2u); |
| offer_exchange_done = true; |
| }); |
| EXPECT_TRUE(s.WaitAndProcess(&offer_exchange_done)); |
| EXPECT_TRUE(s.WaitAndProcess(&second_sink.frame_observed_)); |
| caller->pc()->Close(); |
| callee->pc()->Close(); |
| } |
| |
| INSTANTIATE_TEST_SUITE_P( |
| All, |
| UnsignaledStreamTest, |
| ::testing::Values(MidTestConfiguration::kMidNotNegotiated, |
| MidTestConfiguration::kMidNegotiatedButMissingFromPackets, |
| MidTestConfiguration::kMidNegotiatedAndPresentInPackets), |
| TestParametersMidTestConfigurationToString); |
| |
| } // namespace test |
| } // namespace webrtc |
