Bug 4865: Enable connectivity when the remote peer is on public internet.

webrtc/base/virtualsocketserver.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.
  */
 
 #include "webrtc/base/virtualsocketserver.h"
 
 #include <errno.h>
 #include <math.h>
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/base/common.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/physicalsocketserver.h"
 #include "webrtc/base/socketaddresspair.h"
 #include "webrtc/base/thread.h"
 #include "webrtc/base/timeutils.h"
 
 namespace rtc {
 #if defined(WEBRTC_WIN)
 const in_addr kInitialNextIPv4 = { {0x01, 0, 0, 0} };
@@ skipping 624 matching lines @@
     }
   }
 
   return Bind(socket, *addr);
 }
 
 VirtualSocket* VirtualSocketServer::LookupBinding(const SocketAddress& addr) {
   SocketAddress normalized(addr.ipaddr().Normalized(),
                            addr.port());
   AddressMap::iterator it = bindings_->find(normalized);
-  return (bindings_->end() != it) ? it->second : NULL;
+  if (it != bindings_->end()) {
+    return it->second;
+  }
+
+  if (addr.ipaddr() == GetDefaultRoute(addr.ipaddr().family())) {
+    // If we can't find a binding for the packet which is sent to the interface
+    // corresponding to the default route, it should match a binding with the
+    // correct port to the any address.
+    SocketAddress sock_addr =
+        EmptySocketAddressWithFamily(addr.ipaddr().family());
+    sock_addr.SetPort(addr.port());
+    return LookupBinding(sock_addr);

[juberti1, 2015/08/13 21:23:59]

Is there any chance this could infinitely recurse if the default route isn't set
properly? Should this just do another bindings_->find()?

[guoweis_webrtc, 2015/08/14 05:24:25]

If the addr is Unspec, yes, it'll be a infinite loop. I added a check to make
sure the default route is specified.

+  }
+
+  return nullptr;
 }
 
 int VirtualSocketServer::Unbind(const SocketAddress& addr,
                                 VirtualSocket* socket) {
   SocketAddress normalized(addr.ipaddr().Normalized(),
                            addr.port());
   ASSERT((*bindings_)[normalized] == socket);
   bindings_->erase(bindings_->find(normalized));
   return 0;
 }
@@ skipping 184 matching lines @@
   entry.size = data_size + header_size;
 
   sender->network_size_ += entry.size;
   uint32 send_delay = SendDelay(static_cast<uint32>(sender->network_size_));
   entry.done_time = cur_time + send_delay;
   sender->network_.push_back(entry);
 
   // Find the delay for crossing the many virtual hops of the network.
   uint32 transit_delay = GetRandomTransitDelay();
 
+  // When the incoming packet is from a binding of the any address, translate it
+  // to the default route here such that the STUN server will see the default

[juberti1, 2015/08/13 21:23:59]

"STUN server" -> "recipient"

[guoweis_webrtc, 2015/08/14 05:24:25]

Done.

+  // route.
+  SocketAddress sender_addr = sender->local_addr_;
+  IPAddress default_ip = GetDefaultRoute(sender_addr.ipaddr().family());
+  if (sender_addr.IsAnyIP() && !IPIsUnspec(default_ip)) {
+    sender_addr.SetIP(default_ip);
+  }
+
   // Post the packet as a message to be delivered (on our own thread)
-  Packet* p = new Packet(data, data_size, sender->local_addr_);
+  Packet* p = new Packet(data, data_size, sender_addr);
+
   uint32 ts = TimeAfter(send_delay + transit_delay);
   if (ordered) {
     // Ensure that new packets arrive after previous ones
     // TODO: consider ordering on a per-socket basis, since this
     // introduces artifical delay.
     ts = TimeMax(ts, network_delay_);
   }
   msg_queue_->PostAt(ts, recipient, MSG_ID_PACKET, p);
   network_delay_ = TimeMax(ts, network_delay_);
 }
@@ skipping 192 matching lines @@
   if (local_ip.family() == AF_INET6 && local->was_any()) {
     return true;
   }
   if (remote_ip.family() == AF_INET6 && remote->was_any()) {
     return true;
   }
 
   return false;
 }
 
+IPAddress VirtualSocketServer::GetDefaultRoute(int family) {
+  if (family == AF_INET) {
+    return default_route_v4_;
+  }
+  if (family == AF_INET6) {
+    return default_route_v6_;
+  }
+  return IPAddress();
+}
+void VirtualSocketServer::SetDefaultRoute(const IPAddress& from_addr) {
+  DCHECK(!IPIsAny(from_addr));
+  if (from_addr.family() == AF_INET) {
+    default_route_v4_ = from_addr;
+  } else if (from_addr.family() == AF_INET6) {
+    default_route_v6_ = from_addr;
+  }
+}
+
 }  // namespace rtc