Create a new connection if a candidate reuses an address

webrtc/p2p/base/p2ptransportchannel_unittest.cc

 /*
  *  Copyright 2009 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.
  */
 
@@ skipping 1966 matching lines @@
   }
 
   void OnSelectedCandidatePairChanged(
       cricket::TransportChannel* transport_channel,
       cricket::CandidatePairInterface* selected_candidate_pair,
       int last_sent_packet_id) {
     last_selected_candidate_pair_ = selected_candidate_pair;
     last_sent_packet_id_ = last_sent_packet_id;
   }
 
+  void ReceivePingOnConnection(cricket::Connection* conn,
+                               const std::string& remote_ufrag,
+                               int priority) {
+    cricket::IceMessage msg;
+    msg.SetType(cricket::STUN_BINDING_REQUEST);
+    msg.AddAttribute(new cricket::StunByteStringAttribute(
+        cricket::STUN_ATTR_USERNAME,
+        conn->local_candidate().username() + ":" + remote_ufrag));
+    msg.AddAttribute(new cricket::StunUInt32Attribute(
+        cricket::STUN_ATTR_PRIORITY, priority));
+    msg.SetTransactionID(
+        rtc::CreateRandomString(cricket::kStunTransactionIdLength));
+    msg.AddMessageIntegrity(conn->local_candidate().password());
+    msg.AddFingerprint();
+    rtc::ByteBufferWriter buf;
+    msg.Write(&buf);
+    conn->OnReadPacket(buf.Data(), buf.Length(), rtc::CreatePacketTime(0));
+  }
+
   void OnReadyToSend(cricket::TransportChannel* channel) {
     channel_ready_to_send_ = true;
   }
   void OnChannelStateChanged(cricket::TransportChannelImpl* channel) {
     channel_state_ = channel->GetState();
   }
 
   cricket::CandidatePairInterface* last_selected_candidate_pair() {
     return last_selected_candidate_pair_;
   }
@@ skipping 449 matching lines @@
   EXPECT_EQ(conn3, ch.best_connection());
 
   // Now another data packet will not switch the best connection because the
   // best connection was nominated by the controlling side.
   conn2->ReceivedPing();
   conn2->ReceivedPingResponse();
   conn2->OnReadPacket("XYZ", 3, rtc::CreatePacketTime(0));
   EXPECT_EQ(conn3, ch.best_connection());
 }
 
+// Test that if a new remote candidate has the same address and port with
+// an old one, it will be used to create a new connection.
+TEST_F(P2PTransportChannelPingTest, TestAddRemoteCandidateWithAddressReuse) {
+  cricket::FakePortAllocator pa(rtc::Thread::Current(), nullptr);
+  cricket::P2PTransportChannel ch("candidate reuse", 1, &pa);
+  PrepareChannel(&ch);
+  ch.Connect();
+  ch.MaybeStartGathering();
+  const std::string host_address = "1.1.1.1";
+  const int port_num = 1;
+
+  // kIceUfrag[1] is the current generation ufrag.
+  cricket::Candidate candidate =
+      CreateHostCandidate(host_address, port_num, 1, kIceUfrag[1]);
+  ch.AddRemoteCandidate(candidate);
+  cricket::Connection* conn1 = WaitForConnectionTo(&ch, host_address, port_num);
+  ASSERT_TRUE(conn1 != nullptr);
+  EXPECT_EQ(0u, conn1->remote_candidate().generation());
+
+  // Simply adding the same candidate again won't create a new connection.
+  ch.AddRemoteCandidate(candidate);
+  cricket::Connection* conn2 = GetConnectionTo(&ch, host_address, port_num);
+  EXPECT_EQ(conn1, conn2);
+
+  // Update the ufrag of the candidate and add it again.
+  candidate.set_username(kIceUfrag[2]);
+  ch.AddRemoteCandidate(candidate);
+  conn2 = GetConnectionTo(&ch, host_address, port_num);
+  EXPECT_NE(conn1, conn2);
+  EXPECT_EQ(kIceUfrag[2], conn2->remote_candidate().username());
+  EXPECT_EQ(1u, conn2->remote_candidate().generation());
+
+  // Verify that a ping with the new ufrag can be received on the new
+  // connection.
+  EXPECT_EQ(0, conn2->last_ping_received());
+  ReceivePingOnConnection(conn2, kIceUfrag[2], 1 /* priority */);
+  EXPECT_TRUE(conn2->last_ping_received() > 0);
+}
+
 // When the current best connection is strong, lower-priority connections will
 // be pruned. Otherwise, lower-priority connections are kept.
 TEST_F(P2PTransportChannelPingTest, TestDontPruneWhenWeak) {
   cricket::FakePortAllocator pa(rtc::Thread::Current(), nullptr);
   cricket::P2PTransportChannel ch("test channel", 1, &pa);
   PrepareChannel(&ch);
   ch.SetIceRole(cricket::ICEROLE_CONTROLLED);
   ch.Connect();
   ch.MaybeStartGathering();
   ch.AddRemoteCandidate(CreateHostCandidate("1.1.1.1", 1, 1));
@@ skipping 391 matching lines @@
 
   // TCP Relay/Relay is the next.
   VerifyNextPingableConnection(cricket::RELAY_PORT_TYPE,
                                cricket::RELAY_PORT_TYPE,
                                cricket::TCP_PROTOCOL_NAME);
 
   // Finally, Local/Relay will be pinged.
   VerifyNextPingableConnection(cricket::LOCAL_PORT_TYPE,
                                cricket::RELAY_PORT_TYPE);
 }