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      1 /*
      2  * libjingle SCTP
      3  * Copyright 2013 Google Inc
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <errno.h>
     29 #include <stdarg.h>
     30 #include <stdio.h>
     31 #include <string>
     32 #include <vector>
     33 
     34 #include "talk/media/base/constants.h"
     35 #include "talk/media/base/mediachannel.h"
     36 #include "talk/media/sctp/sctpdataengine.h"
     37 #include "webrtc/base/bind.h"
     38 #include "webrtc/base/buffer.h"
     39 #include "webrtc/base/criticalsection.h"
     40 #include "webrtc/base/gunit.h"
     41 #include "webrtc/base/helpers.h"
     42 #include "webrtc/base/messagehandler.h"
     43 #include "webrtc/base/messagequeue.h"
     44 #include "webrtc/base/scoped_ptr.h"
     45 #include "webrtc/base/ssladapter.h"
     46 #include "webrtc/base/thread.h"
     47 
     48 #ifdef HAVE_NSS_SSL_H
     49 // TODO(thorcarpenter): Remove after webrtc switches over to BoringSSL.
     50 #include "webrtc/base/nssstreamadapter.h"
     51 #endif  // HAVE_NSS_SSL_H
     52 
     53 enum {
     54   MSG_PACKET = 1,
     55 };
     56 
     57 // Fake NetworkInterface that sends/receives sctp packets.  The one in
     58 // talk/media/base/fakenetworkinterface.h only works with rtp/rtcp.
     59 class SctpFakeNetworkInterface : public cricket::MediaChannel::NetworkInterface,
     60                                  public rtc::MessageHandler {
     61  public:
     62   explicit SctpFakeNetworkInterface(rtc::Thread* thread)
     63     : thread_(thread),
     64       dest_(NULL) {
     65   }
     66 
     67   void SetDestination(cricket::DataMediaChannel* dest) { dest_ = dest; }
     68 
     69  protected:
     70   // Called to send raw packet down the wire (e.g. SCTP an packet).
     71   virtual bool SendPacket(rtc::Buffer* packet,
     72                           rtc::DiffServCodePoint dscp) {
     73     LOG(LS_VERBOSE) << "SctpFakeNetworkInterface::SendPacket";
     74 
     75     // TODO(ldixon): Can/should we use Buffer.TransferTo here?
     76     // Note: this assignment does a deep copy of data from packet.
     77     rtc::Buffer* buffer = new rtc::Buffer(packet->data(), packet->length());
     78     thread_->Post(this, MSG_PACKET, rtc::WrapMessageData(buffer));
     79     LOG(LS_VERBOSE) << "SctpFakeNetworkInterface::SendPacket, Posted message.";
     80     return true;
     81   }
     82 
     83   // Called when a raw packet has been recieved. This passes the data to the
     84   // code that will interpret the packet. e.g. to get the content payload from
     85   // an SCTP packet.
     86   virtual void OnMessage(rtc::Message* msg) {
     87     LOG(LS_VERBOSE) << "SctpFakeNetworkInterface::OnMessage";
     88     rtc::scoped_ptr<rtc::Buffer> buffer(
     89         static_cast<rtc::TypedMessageData<rtc::Buffer*>*>(
     90             msg->pdata)->data());
     91     if (dest_) {
     92       dest_->OnPacketReceived(buffer.get(), rtc::PacketTime());
     93     }
     94     delete msg->pdata;
     95   }
     96 
     97   // Unsupported functions required to exist by NetworkInterface.
     98   // TODO(ldixon): Refactor parent NetworkInterface class so these are not
     99   // required. They are RTC specific and should be in an appropriate subclass.
    100   virtual bool SendRtcp(rtc::Buffer* packet,
    101                         rtc::DiffServCodePoint dscp) {
    102     LOG(LS_WARNING) << "Unsupported: SctpFakeNetworkInterface::SendRtcp.";
    103     return false;
    104   }
    105   virtual int SetOption(SocketType type, rtc::Socket::Option opt,
    106                         int option) {
    107     LOG(LS_WARNING) << "Unsupported: SctpFakeNetworkInterface::SetOption.";
    108     return 0;
    109   }
    110   virtual void SetDefaultDSCPCode(rtc::DiffServCodePoint dscp) {
    111     LOG(LS_WARNING) << "Unsupported: SctpFakeNetworkInterface::SetOption.";
    112   }
    113 
    114  private:
    115   // Not owned by this class.
    116   rtc::Thread* thread_;
    117   cricket::DataMediaChannel* dest_;
    118 };
    119 
    120 // This is essentially a buffer to hold recieved data. It stores only the last
    121 // received data. Calling OnDataReceived twice overwrites old data with the
    122 // newer one.
    123 // TODO(ldixon): Implement constraints, and allow new data to be added to old
    124 // instead of replacing it.
    125 class SctpFakeDataReceiver : public sigslot::has_slots<> {
    126  public:
    127   SctpFakeDataReceiver() : received_(false) {}
    128 
    129   void Clear() {
    130     received_ = false;
    131     last_data_ = "";
    132     last_params_ = cricket::ReceiveDataParams();
    133   }
    134 
    135   virtual void OnDataReceived(const cricket::ReceiveDataParams& params,
    136                               const char* data, size_t length) {
    137     received_ = true;
    138     last_data_ = std::string(data, length);
    139     last_params_ = params;
    140   }
    141 
    142   bool received() const { return received_; }
    143   std::string last_data() const { return last_data_; }
    144   cricket::ReceiveDataParams last_params() const { return last_params_; }
    145 
    146  private:
    147   bool received_;
    148   std::string last_data_;
    149   cricket::ReceiveDataParams last_params_;
    150 };
    151 
    152 class SignalReadyToSendObserver : public sigslot::has_slots<> {
    153  public:
    154   SignalReadyToSendObserver() : signaled_(false), writable_(false) {}
    155 
    156   void OnSignaled(bool writable) {
    157     signaled_ = true;
    158     writable_ = writable;
    159   }
    160 
    161   bool IsSignaled(bool writable) {
    162     return signaled_ && (writable_ == writable);
    163   }
    164 
    165  private:
    166   bool signaled_;
    167   bool writable_;
    168 };
    169 
    170 class SignalChannelClosedObserver : public sigslot::has_slots<> {
    171  public:
    172   SignalChannelClosedObserver() {}
    173   void BindSelf(cricket::SctpDataMediaChannel* channel) {
    174     channel->SignalStreamClosedRemotely.connect(
    175         this, &SignalChannelClosedObserver::OnStreamClosed);
    176   }
    177   void OnStreamClosed(uint32 stream) {
    178     streams_.push_back(stream);
    179   }
    180 
    181   int StreamCloseCount(uint32 stream) {
    182     return std::count(streams_.begin(), streams_.end(), stream);
    183   }
    184 
    185   bool WasStreamClosed(uint32 stream) {
    186     return std::find(streams_.begin(), streams_.end(), stream)
    187         != streams_.end();
    188   }
    189 
    190  private:
    191   std::vector<uint32> streams_;
    192 };
    193 
    194 class SignalChannelClosedReopener : public sigslot::has_slots<> {
    195  public:
    196   SignalChannelClosedReopener(cricket::SctpDataMediaChannel* channel,
    197                               cricket::SctpDataMediaChannel* peer)
    198       : channel_(channel), peer_(peer) {}
    199 
    200   void OnStreamClosed(int stream) {
    201     cricket::StreamParams p(cricket::StreamParams::CreateLegacy(stream));
    202     channel_->AddSendStream(p);
    203     channel_->AddRecvStream(p);
    204     peer_->AddSendStream(p);
    205     peer_->AddRecvStream(p);
    206     streams_.push_back(stream);
    207   }
    208 
    209   int StreamCloseCount(int stream) {
    210     return std::count(streams_.begin(), streams_.end(), stream);
    211   }
    212 
    213  private:
    214   cricket::SctpDataMediaChannel* channel_;
    215   cricket::SctpDataMediaChannel* peer_;
    216   std::vector<int> streams_;
    217 };
    218 
    219 // SCTP Data Engine testing framework.
    220 class SctpDataMediaChannelTest : public testing::Test,
    221                                  public sigslot::has_slots<> {
    222  protected:
    223   // usrsctp uses the NSS random number generator on non-Android platforms,
    224   // so we need to initialize SSL.
    225   static void SetUpTestCase() {
    226 #ifdef HAVE_NSS_SSL_H
    227   // TODO(thorcarpenter): Remove after webrtc switches over to BoringSSL.
    228   if (!rtc::NSSContext::InitializeSSL(NULL)) {
    229     LOG(LS_WARNING) << "Unabled to initialize NSS.";
    230   }
    231 #endif  // HAVE_NSS_SSL_H
    232     rtc::InitializeSSL();
    233   }
    234 
    235   static void TearDownTestCase() {
    236     rtc::CleanupSSL();
    237   }
    238 
    239   virtual void SetUp() {
    240     engine_.reset(new cricket::SctpDataEngine());
    241   }
    242 
    243   void SetupConnectedChannels() {
    244     net1_.reset(new SctpFakeNetworkInterface(rtc::Thread::Current()));
    245     net2_.reset(new SctpFakeNetworkInterface(rtc::Thread::Current()));
    246     recv1_.reset(new SctpFakeDataReceiver());
    247     recv2_.reset(new SctpFakeDataReceiver());
    248     chan1_.reset(CreateChannel(net1_.get(), recv1_.get()));
    249     chan1_->set_debug_name("chan1/connector");
    250     chan2_.reset(CreateChannel(net2_.get(), recv2_.get()));
    251     chan2_->set_debug_name("chan2/listener");
    252     // Setup two connected channels ready to send and receive.
    253     net1_->SetDestination(chan2_.get());
    254     net2_->SetDestination(chan1_.get());
    255 
    256     LOG(LS_VERBOSE) << "Channel setup ----------------------------- ";
    257     AddStream(1);
    258     AddStream(2);
    259 
    260     LOG(LS_VERBOSE) << "Connect the channels -----------------------------";
    261     // chan1 wants to setup a data connection.
    262     chan1_->SetReceive(true);
    263     // chan1 will have sent chan2 a request to setup a data connection. After
    264     // chan2 accepts the offer, chan2 connects to chan1 with the following.
    265     chan2_->SetReceive(true);
    266     chan2_->SetSend(true);
    267     // Makes sure that network packets are delivered and simulates a
    268     // deterministic and realistic small timing delay between the SetSend calls.
    269     ProcessMessagesUntilIdle();
    270 
    271     // chan1 and chan2 are now connected so chan1 enables sending to complete
    272     // the creation of the connection.
    273     chan1_->SetSend(true);
    274   }
    275 
    276   virtual void TearDown() {
    277     channel1()->SetSend(false);
    278     channel2()->SetSend(false);
    279 
    280     // Process messages until idle to prevent a sent packet from being dropped
    281     // and causing memory leaks (not being deleted by the receiver).
    282     ProcessMessagesUntilIdle();
    283   }
    284 
    285   void AddStream(int ssrc) {
    286     cricket::StreamParams p(cricket::StreamParams::CreateLegacy(ssrc));
    287     chan1_->AddSendStream(p);
    288     chan1_->AddRecvStream(p);
    289     chan2_->AddSendStream(p);
    290     chan2_->AddRecvStream(p);
    291   }
    292 
    293   cricket::SctpDataMediaChannel* CreateChannel(
    294       SctpFakeNetworkInterface* net, SctpFakeDataReceiver* recv) {
    295     cricket::SctpDataMediaChannel* channel =
    296         static_cast<cricket::SctpDataMediaChannel*>(engine_->CreateChannel(
    297             cricket::DCT_SCTP));
    298     channel->SetInterface(net);
    299     // When data is received, pass it to the SctpFakeDataReceiver.
    300     channel->SignalDataReceived.connect(
    301         recv, &SctpFakeDataReceiver::OnDataReceived);
    302     return channel;
    303   }
    304 
    305   bool SendData(cricket::SctpDataMediaChannel* chan, uint32 ssrc,
    306                 const std::string& msg,
    307                 cricket::SendDataResult* result) {
    308     cricket::SendDataParams params;
    309     params.ssrc = ssrc;
    310 
    311     return chan->SendData(params, rtc::Buffer(
    312         &msg[0], msg.length()), result);
    313   }
    314 
    315   bool ReceivedData(const SctpFakeDataReceiver* recv, uint32 ssrc,
    316                     const std::string& msg ) {
    317     return (recv->received() &&
    318             recv->last_params().ssrc == ssrc &&
    319             recv->last_data() == msg);
    320   }
    321 
    322   bool ProcessMessagesUntilIdle() {
    323     rtc::Thread* thread = rtc::Thread::Current();
    324     while (!thread->empty()) {
    325       rtc::Message msg;
    326       if (thread->Get(&msg, rtc::kForever)) {
    327         thread->Dispatch(&msg);
    328       }
    329     }
    330     return !thread->IsQuitting();
    331   }
    332 
    333   cricket::SctpDataMediaChannel* channel1() { return chan1_.get(); }
    334   cricket::SctpDataMediaChannel* channel2() { return chan2_.get(); }
    335   SctpFakeDataReceiver* receiver1() { return recv1_.get(); }
    336   SctpFakeDataReceiver* receiver2() { return recv2_.get(); }
    337 
    338  private:
    339   rtc::scoped_ptr<cricket::SctpDataEngine> engine_;
    340   rtc::scoped_ptr<SctpFakeNetworkInterface> net1_;
    341   rtc::scoped_ptr<SctpFakeNetworkInterface> net2_;
    342   rtc::scoped_ptr<SctpFakeDataReceiver> recv1_;
    343   rtc::scoped_ptr<SctpFakeDataReceiver> recv2_;
    344   rtc::scoped_ptr<cricket::SctpDataMediaChannel> chan1_;
    345   rtc::scoped_ptr<cricket::SctpDataMediaChannel> chan2_;
    346 };
    347 
    348 // Verifies that SignalReadyToSend is fired.
    349 TEST_F(SctpDataMediaChannelTest, SignalReadyToSend) {
    350   SetupConnectedChannels();
    351 
    352   SignalReadyToSendObserver signal_observer_1;
    353   SignalReadyToSendObserver signal_observer_2;
    354 
    355   channel1()->SignalReadyToSend.connect(&signal_observer_1,
    356                                         &SignalReadyToSendObserver::OnSignaled);
    357   channel2()->SignalReadyToSend.connect(&signal_observer_2,
    358                                         &SignalReadyToSendObserver::OnSignaled);
    359 
    360   cricket::SendDataResult result;
    361   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    362   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    363   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    364   ASSERT_TRUE(SendData(channel2(), 2, "hi chan1", &result));
    365   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    366   EXPECT_TRUE_WAIT(ReceivedData(receiver1(), 2, "hi chan1"), 1000);
    367 
    368   EXPECT_TRUE_WAIT(signal_observer_1.IsSignaled(true), 1000);
    369   EXPECT_TRUE_WAIT(signal_observer_2.IsSignaled(true), 1000);
    370 }
    371 
    372 TEST_F(SctpDataMediaChannelTest, SendData) {
    373   SetupConnectedChannels();
    374 
    375   cricket::SendDataResult result;
    376   LOG(LS_VERBOSE) << "chan1 sending: 'hello?' -----------------------------";
    377   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    378   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    379   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    380   LOG(LS_VERBOSE) << "recv2.received=" << receiver2()->received()
    381                   << ", recv2.last_params.ssrc="
    382                   << receiver2()->last_params().ssrc
    383                   << ", recv2.last_params.timestamp="
    384                   << receiver2()->last_params().ssrc
    385                   << ", recv2.last_params.seq_num="
    386                   << receiver2()->last_params().seq_num
    387                   << ", recv2.last_data=" << receiver2()->last_data();
    388 
    389   LOG(LS_VERBOSE) << "chan2 sending: 'hi chan1' -----------------------------";
    390   ASSERT_TRUE(SendData(channel2(), 2, "hi chan1", &result));
    391   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    392   EXPECT_TRUE_WAIT(ReceivedData(receiver1(), 2, "hi chan1"), 1000);
    393   LOG(LS_VERBOSE) << "recv1.received=" << receiver1()->received()
    394                   << ", recv1.last_params.ssrc="
    395                   << receiver1()->last_params().ssrc
    396                   << ", recv1.last_params.timestamp="
    397                   << receiver1()->last_params().ssrc
    398                   << ", recv1.last_params.seq_num="
    399                   << receiver1()->last_params().seq_num
    400                   << ", recv1.last_data=" << receiver1()->last_data();
    401 }
    402 
    403 // Sends a lot of large messages at once and verifies SDR_BLOCK is returned.
    404 TEST_F(SctpDataMediaChannelTest, SendDataBlocked) {
    405   SetupConnectedChannels();
    406 
    407   cricket::SendDataResult result;
    408   cricket::SendDataParams params;
    409   params.ssrc = 1;
    410 
    411   std::vector<char> buffer(1024 * 64, 0);
    412 
    413   for (size_t i = 0; i < 100; ++i) {
    414     channel1()->SendData(
    415         params, rtc::Buffer(&buffer[0], buffer.size()), &result);
    416     if (result == cricket::SDR_BLOCK)
    417       break;
    418   }
    419 
    420   EXPECT_EQ(cricket::SDR_BLOCK, result);
    421 }
    422 
    423 TEST_F(SctpDataMediaChannelTest, ClosesRemoteStream) {
    424   SetupConnectedChannels();
    425   SignalChannelClosedObserver chan_1_sig_receiver, chan_2_sig_receiver;
    426   chan_1_sig_receiver.BindSelf(channel1());
    427   chan_2_sig_receiver.BindSelf(channel2());
    428 
    429   cricket::SendDataResult result;
    430   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    431   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    432   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    433   ASSERT_TRUE(SendData(channel2(), 2, "hi chan1", &result));
    434   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    435   EXPECT_TRUE_WAIT(ReceivedData(receiver1(), 2, "hi chan1"), 1000);
    436 
    437   // Close channel 1.  Channel 2 should notify us.
    438   channel1()->RemoveSendStream(1);
    439   EXPECT_TRUE_WAIT(chan_2_sig_receiver.WasStreamClosed(1), 1000);
    440 }
    441 
    442 TEST_F(SctpDataMediaChannelTest, ClosesTwoRemoteStreams) {
    443   SetupConnectedChannels();
    444   AddStream(3);
    445   SignalChannelClosedObserver chan_1_sig_receiver, chan_2_sig_receiver;
    446   chan_1_sig_receiver.BindSelf(channel1());
    447   chan_2_sig_receiver.BindSelf(channel2());
    448 
    449   cricket::SendDataResult result;
    450   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    451   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    452   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    453   ASSERT_TRUE(SendData(channel2(), 2, "hi chan1", &result));
    454   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    455   EXPECT_TRUE_WAIT(ReceivedData(receiver1(), 2, "hi chan1"), 1000);
    456 
    457   // Close two streams on one side.
    458   channel2()->RemoveSendStream(2);
    459   channel2()->RemoveSendStream(3);
    460   EXPECT_TRUE_WAIT(chan_1_sig_receiver.WasStreamClosed(2), 1000);
    461   EXPECT_TRUE_WAIT(chan_1_sig_receiver.WasStreamClosed(3), 1000);
    462 }
    463 
    464 TEST_F(SctpDataMediaChannelTest, ClosesStreamsOnBothSides) {
    465   SetupConnectedChannels();
    466   AddStream(3);
    467   AddStream(4);
    468   SignalChannelClosedObserver chan_1_sig_receiver, chan_2_sig_receiver;
    469   chan_1_sig_receiver.BindSelf(channel1());
    470   chan_2_sig_receiver.BindSelf(channel2());
    471 
    472   cricket::SendDataResult result;
    473   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    474   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    475   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    476   ASSERT_TRUE(SendData(channel2(), 2, "hi chan1", &result));
    477   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    478   EXPECT_TRUE_WAIT(ReceivedData(receiver1(), 2, "hi chan1"), 1000);
    479 
    480   // Close one stream on channel1(), while closing three streams on
    481   // channel2().  They will conflict (only one side can close anything at a
    482   // time, apparently).  Test the resolution of the conflict.
    483   channel1()->RemoveSendStream(1);
    484 
    485   channel2()->RemoveSendStream(2);
    486   channel2()->RemoveSendStream(3);
    487   channel2()->RemoveSendStream(4);
    488   EXPECT_TRUE_WAIT(chan_2_sig_receiver.WasStreamClosed(1), 1000);
    489   EXPECT_TRUE_WAIT(chan_1_sig_receiver.WasStreamClosed(2), 1000);
    490   EXPECT_TRUE_WAIT(chan_1_sig_receiver.WasStreamClosed(3), 1000);
    491   EXPECT_TRUE_WAIT(chan_1_sig_receiver.WasStreamClosed(4), 1000);
    492 }
    493 
    494 TEST_F(SctpDataMediaChannelTest, ReusesAStream) {
    495   // Shut down channel 1, then open it up again for reuse.
    496   SetupConnectedChannels();
    497   cricket::SendDataResult result;
    498   SignalChannelClosedObserver chan_2_sig_receiver;
    499   chan_2_sig_receiver.BindSelf(channel2());
    500 
    501   ASSERT_TRUE(SendData(channel1(), 1, "hello?", &result));
    502   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    503   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hello?"), 1000);
    504 
    505   channel1()->RemoveSendStream(1);
    506   EXPECT_TRUE_WAIT(chan_2_sig_receiver.WasStreamClosed(1), 1000);
    507   // Channel 1 is gone now.
    508 
    509   // Create a new channel 1.
    510   AddStream(1);
    511   ASSERT_TRUE(SendData(channel1(), 1, "hi?", &result));
    512   EXPECT_EQ(cricket::SDR_SUCCESS, result);
    513   EXPECT_TRUE_WAIT(ReceivedData(receiver2(), 1, "hi?"), 1000);
    514   channel1()->RemoveSendStream(1);
    515   EXPECT_TRUE_WAIT(chan_2_sig_receiver.StreamCloseCount(1) == 2, 1000);
    516 }
    517