Avoid error messages from UDP sockets in Chromoting client.

remoting/client/plugin/pepper_packet_socket_factory.cc

Index: remoting/client/plugin/pepper_packet_socket_factory.cc
diff --git a/remoting/client/plugin/pepper_packet_socket_factory.cc b/remoting/client/plugin/pepper_packet_socket_factory.cc
index 90d7c61bd94cdb5b345ec0cf456be00776c1d66b..1c6cd432a0c08a92c8ad2cf67526cc1b44094ae4 100644
--- a/remoting/client/plugin/pepper_packet_socket_factory.cc
+++ b/remoting/client/plugin/pepper_packet_socket_factory.cc
@@ -26,6 +26,13 @@ const int kReceiveBufferSize = 65536;
 // reached under normal conditions.
 const int kMaxSendBufferSize = 256 * 1024;
 
+// Returns true if |error| must be ignored when returned from sendto().
+bool IsTransientError(int error) {

[Wez, 2014/06/16 22:36:36]

Are all of these errors really transient per-packet? Are none of them per-socket
transient, or even permanent (e.g. PP_ERROR_NOACCESS)?

[Sergey Ulanov, 2014/06/17 00:53:35]

This list is based on what chrome does for sockets in WebRTC (see
content/browser/renderer_host/p2p/socket_host_udp.cc).
PP_ERROR_NOACCESS can returned when the packet was blocked by the local firewall
(on OSX), see https://code.google.com/p/webrtc/issues/detail?id=1207.

+  return error == PP_ERROR_ADDRESS_UNREACHABLE ||
+         error == PP_ERROR_ADDRESS_INVALID || error == PP_ERROR_NOACCESS ||
+         error == PP_ERROR_CONNECTION_RESET || error == PP_ERROR_NOMEMORY;

[Wez, 2014/06/16 22:36:36]

I think it'd be good to clarify why this particular errors can/should/must be
ignored the first time we see them.

[Sergey Ulanov, 2014/06/17 00:53:35]

Done. Also added |retry| flag. It makes sense to retry sending only for some
errors, but not the others.

+}
+
 class UdpPacketSocket : public talk_base::AsyncPacketSocket {
  public:
   explicit UdpPacketSocket(const pp::InstanceHandle& instance);
@@ -61,6 +68,7 @@ class UdpPacketSocket : public talk_base::AsyncPacketSocket {
 
     scoped_refptr<net::IOBufferWithSize> data;
     pp::NetAddress address;
+    bool retried;
   };
 
   void OnBindCompleted(int error);
@@ -102,7 +110,8 @@ UdpPacketSocket::PendingPacket::PendingPacket(
     int buffer_size,
     const pp::NetAddress& address)
     : data(new net::IOBufferWithSize(buffer_size)),
-      address(address) {
+      address(address),
+      retried(true) {
   memcpy(data->data(), buffer, buffer_size);
 }
 
@@ -177,7 +186,8 @@ void UdpPacketSocket::OnBindCompleted(int result) {
       DCHECK_EQ(result, PP_OK_COMPLETIONPENDING);
     }
   } else {
-    LOG(ERROR) << "Failed to bind UDP socket: " << result;
+    LOG(ERROR) << "Failed to bind UDP socket to " << local_address_.ToString()
+               << ", error: " << result;
   }
 }
 
@@ -281,25 +291,18 @@ void UdpPacketSocket::OnSendCompleted(int result) {
   send_pending_ = false;
 
   if (result < 0) {
-    LOG(ERROR) << "Send failed on a UDP socket: " << result;
-
-    // OS (e.g. OSX) may return EHOSTUNREACH when the peer has the
-    // same subnet address as the local host but connected to a
-    // different network. That error must be ingored because the
-    // socket may still be useful for other ICE canidadates (e.g. for
-    // STUN candidates with a different address). Unfortunately pepper
-    // interface currently returns PP_ERROR_FAILED for any error (see
-    // crbug.com/136406). It's not possible to distinguish that case
-    // from other errors and so we have to ingore all of them. This
-    // behavior matchers the libjingle's AsyncUDPSocket used by the
-    // host.
-    //
-    // TODO(sergeyu): Once implementation of the Pepper UDP interface
-    // is fixed, uncomment the code below, but ignore
-    // host-unreacheable error.
-
-    // error_ = EINVAL;
-    // return;
+    if (!IsTransientError(result)) {
+      LOG(ERROR) << "Send failed on a UDP socket: " << result;
+      return;
+    }
+
+    // If this is a transient error and we haven't tried resending the packet
+    // yet, then try resending it.
+    if (!send_queue_.front().retried) {
+      send_queue_.front().retried = true;
+      DoSend();
+      return;
+    }
   }
 
   send_queue_size_ -= send_queue_.front().data->size();