Create a new connection if a candidate reuses an address

webrtc/p2p/base/port.cc

 /*
  *  Copyright 2004 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 252 matching lines @@
   c.set_network_type(network_->type());
   c.set_related_address(related_address);
   candidates_.push_back(c);
   SignalCandidateReady(this, c);
 
   if (final) {
     SignalPortComplete(this);
   }
 }
 
-void Port::AddConnection(Connection* conn) {
-  connections_[conn->remote_candidate().address()] = conn;
+void Port::AddOrReplaceConnection(Connection* conn) {
+  auto ret = connections_.insert(
+      std::make_pair(conn->remote_candidate().address(), conn));
+  // If there is a different connection on the same remote address, replace
+  // it with the new one and destroy the old one.
+  if (ret.second == false && ret.first->second != conn) {
+    LOG_J(LS_WARNING, this)
+        << "A new connection was created on an existing remote address. "
+        << "New remote candidate: " << conn->remote_candidate().ToString();
+    ret.first->second->Destroy();
+    ret.first->second = conn;
+  }
   conn->SignalDestroyed.connect(this, &Port::OnConnectionDestroyed);
   SignalConnectionCreated(this, conn);
 }
 
 void Port::OnReadPacket(
     const char* data, size_t size, const rtc::SocketAddress& addr,
     ProtocolType proto) {
   // If the user has enabled port packets, just hand this over.
   if (enable_port_packets_) {
     SignalReadPacket(this, data, size, addr);
@@ skipping 395 matching lines @@
 }
 
 void Port::EnablePortPackets() {
   enable_port_packets_ = true;
 }
 
 void Port::OnConnectionDestroyed(Connection* conn) {
   AddressMap::iterator iter =
       connections_.find(conn->remote_candidate().address());
   ASSERT(iter != connections_.end());
+  if (iter->second != conn) {
+    // If the deleted connection is different than what we have now, ignore it.
+    return;
+  }
   connections_.erase(iter);
+  HandleConnectionDestroyed(conn);
 
   // On the controlled side, ports time out after all connections fail.
   // Note: If a new connection is added after this message is posted, but it
   // fails and is removed before kPortTimeoutDelay, then this message will
   // still cause the Port to be destroyed.
   if (dead()) {
     thread_->PostDelayed(timeout_delay_, this, MSG_DEAD);
   }
 }
 
@@ skipping 804 matching lines @@
     ASSERT(sent < 0);
     error_ = port_->GetError();
     sent_packets_discarded_++;
   } else {
     send_rate_tracker_.AddSamples(sent);
   }
   return sent;
 }
 
 }  // namespace cricket