Only try to pair protocol matching candidates for creating connections.

webrtc/p2p/base/port_unittest.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 123 matching lines @@
     }
     return code;
   }
 
   virtual void PrepareAddress() {
     rtc::SocketAddress addr(ip(), min_port());
     AddAddress(addr, addr, rtc::SocketAddress(), "udp", "", "", Type(),
                ICE_TYPE_PREFERENCE_HOST, 0, true);
   }
 
+  virtual bool ProtocolMatch(const std::string& protocol) const { return true; }

[pthatcher1, 2015/12/11 02:05:36]

Shouldn't we use the enum instead of the string?

And a better name might be "SupportsProtocol"

[honghaiz3, 2015/12/11 18:36:31]

I am using string because candidate.protocol() returns string. 
This just make the comparison slightly easier. 
Changed the name.

+
   // Exposed for testing candidate building.
   void AddCandidateAddress(const rtc::SocketAddress& addr) {
     AddAddress(addr, addr, rtc::SocketAddress(), "udp", "", "", Type(),
                type_preference_, 0, false);
   }
   void AddCandidateAddress(const rtc::SocketAddress& addr,
                            const rtc::SocketAddress& base_address,
                            const std::string& type,
                            int type_preference,
                            bool final) {
@@ skipping 2334 matching lines @@
   StartConnectAndStopChannels(&ch1, &ch2);
   // Switch the role after all connections are destroyed.
   EXPECT_TRUE_WAIT(ch2.conn() == nullptr, kTimeout);
   port1->SetIceRole(cricket::ICEROLE_CONTROLLED);
   port2->SetIceRole(cricket::ICEROLE_CONTROLLING);
 
   // After the connection is destroyed, the port should not be destroyed.
   rtc::Thread::Current()->ProcessMessages(kTimeout);
   EXPECT_FALSE(destroyed());
 }
+
+TEST_F(PortTest, TestProtocolMatch) {
+  rtc::scoped_ptr<Port> udp_port(CreateUdpPort(kLocalAddr1));
+  EXPECT_TRUE(udp_port->ProtocolMatch(UDP_PROTOCOL_NAME));
+  EXPECT_FALSE(udp_port->ProtocolMatch(TCP_PROTOCOL_NAME));
+
+  rtc::scoped_ptr<Port> stun_port(
+      CreateStunPort(kLocalAddr1, nat_socket_factory1()));
+  EXPECT_TRUE(stun_port->ProtocolMatch(UDP_PROTOCOL_NAME));
+  EXPECT_FALSE(stun_port->ProtocolMatch(TCP_PROTOCOL_NAME));
+
+  rtc::scoped_ptr<Port> tcp_port(CreateTcpPort(kLocalAddr1));
+  EXPECT_TRUE(tcp_port->ProtocolMatch(TCP_PROTOCOL_NAME));
+  EXPECT_TRUE(tcp_port->ProtocolMatch(SSLTCP_PROTOCOL_NAME));
+  EXPECT_FALSE(tcp_port->ProtocolMatch(UDP_PROTOCOL_NAME));
+
+  rtc::scoped_ptr<Port> turn_port(
+      CreateTurnPort(kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  EXPECT_TRUE(turn_port->ProtocolMatch(UDP_PROTOCOL_NAME));
+  EXPECT_FALSE(turn_port->ProtocolMatch(TCP_PROTOCOL_NAME));
+}