Adding PortAllocator option to support cases where sockets can't be bound.

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 1039 matching lines @@
         } else if (config == PROXY_SOCKS) {
           // Block all TCP to/from the endpoint except to the proxy server
           fw()->AddRule(true, rtc::FP_TCP, kPublicAddrs[endpoint],
                         kSocksProxyAddrs[endpoint]);
           fw()->AddRule(false, rtc::FP_TCP, rtc::FD_ANY,
                         kPublicAddrs[endpoint]);
           SetProxy(endpoint, rtc::PROXY_SOCKS5);
         }
         break;
       default:
+        RTC_NOTREACHED();
         break;
     }
   }
 };
 
 // Shorthands for use in the test matrix.
 #define LULU &kLocalUdpToLocalUdp
 #define LUSU &kLocalUdpToStunUdp
 #define LUPU &kLocalUdpToPrflxUdp
 #define PULU &kPrflxUdpToLocalUdp
@@ skipping 489 matching lines @@
 
   EXPECT_TRUE_SIMULATED_WAIT(
       ep1_ch1() != NULL && ep2_ch1() != NULL && ep1_ch1()->receiving() &&
           ep1_ch1()->writable() && ep2_ch1()->receiving() &&
           ep2_ch1()->writable(),
       kMediumTimeout, clock);
 
   DestroyChannels();
 }
 
+// Test that two peers can connect when one can only make outgoing TCP
+// connections. This has been observed in some scenarios involving
+// VPNs/firewalls.
+TEST_F(P2PTransportChannelTest, CanOnlyMakeOutgoingTcpConnections) {
+  // The PORTALLOCATOR_ENABLE_ANY_ADDRESS_PORTS flag is required if the
+  // application needs this use case to work, since the application must accept
+  // the tradeoff that more candidates need to be allocated.
+  //
+  // TODO(deadbeef): Later, make this flag the default, and do more elegant
+  // things to ensure extra candidates don't waste resources?
+  ConfigureEndpoints(
+      OPEN, OPEN,
+      kDefaultPortAllocatorFlags | PORTALLOCATOR_ENABLE_ANY_ADDRESS_PORTS,
+      kDefaultPortAllocatorFlags);
+  // In order to simulate nothing working but outgoing TCP connections, prevent
+  // the endpoint from binding to its interface's address as well as the
+  // "any" addresses. It can then only make a connection by using "Connect()".
+  fw()->SetInvalidBindIps({rtc::GetAnyIP(AF_INET), rtc::GetAnyIP(AF_INET6),
+                           kPublicAddrs[0].ipaddr()});
+  CreateChannels();
+  // Expect a "prflx" candidate on the side that can only make outgoing
+  // connections, endpoint 0.
+  Test(kPrflxTcpToLocalTcp);
+  DestroyChannels();
+}
+
 TEST_F(P2PTransportChannelTest, TestTcpConnectionsFromActiveToPassive) {
   rtc::ScopedFakeClock clock;
   AddAddress(0, kPublicAddrs[0]);
   AddAddress(1, kPublicAddrs[1]);
 
   SetAllocationStepDelay(0, kMinimumStepDelay);
   SetAllocationStepDelay(1, kMinimumStepDelay);
 
   int kOnlyLocalTcpPorts = PORTALLOCATOR_DISABLE_UDP |
                            PORTALLOCATOR_DISABLE_STUN |
@@ skipping 2808 matching lines @@
 
   // TCP Relay/Relay is the next.
   VerifyNextPingableConnection(RELAY_PORT_TYPE, RELAY_PORT_TYPE,
                                TCP_PROTOCOL_NAME);
 
   // Finally, Local/Relay will be pinged.
   VerifyNextPingableConnection(LOCAL_PORT_TYPE, RELAY_PORT_TYPE);
 }
 
 }  // namespace cricket {