Add DatagramClientSocket::BindToDefaultNetwork(),GetBoundNetwork()

net/udp/udp_socket_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/udp/udp_socket_posix.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <net/if.h>
 #include <netdb.h>
@@ skipping 308 matching lines @@
   if (rv < 0)
     return rv;
 
   is_connected_ = true;
   local_address_.reset();
   return rv;
 }
 
 int UDPSocketPosix::BindToNetwork(
     NetworkChangeNotifier::NetworkHandle network) {
-#if defined(OS_ANDROID)
   DCHECK_NE(socket_, kInvalidSocket);
   DCHECK(CalledOnValidThread());
   DCHECK(!is_connected());
+  if (network == NetworkChangeNotifier::kInvalidNetworkHandle)
+    return ERR_INVALID_ARGUMENT;
+#if defined(OS_ANDROID)
   // Android prior to Lollipop didn't have support for binding sockets to
   // networks.
   if (base::android::BuildInfo::GetInstance()->sdk_int() <
       base::android::SDK_VERSION_LOLLIPOP) {
     return ERR_NOT_IMPLEMENTED;
   }
   // NOTE(pauljensen): This does rely on Android implementation details, but
   // these details are unlikely to change.
   typedef int (*SetNetworkForSocket)(unsigned netId, int socketFd);
   static SetNetworkForSocket setNetworkForSocket;
   // This is racy, but all racers should come out with the same answer so it
   // shouldn't matter.
   if (setNetworkForSocket == nullptr) {
     // Android's netd client library should always be loaded in our address
     // space as it shims libc functions like connect().
     base::FilePath file(base::FilePath::FromUTF16Unsafe(
         base::GetNativeLibraryName(base::ASCIIToUTF16("netd_client"))));
     base::NativeLibrary lib = base::LoadNativeLibrary(file, nullptr);
     setNetworkForSocket = reinterpret_cast<SetNetworkForSocket>(
         base::GetFunctionPointerFromNativeLibrary(lib, "setNetworkForSocket"));
   }
   if (setNetworkForSocket == nullptr)
     return ERR_NOT_IMPLEMENTED;
-  return MapSystemError(setNetworkForSocket(network, socket_));
+  int rv = setNetworkForSocket(network, socket_);
+  // If |network| has since disconnected, surface this as ERR_NETWORK_CHANGED,
+  // rather than MapSystemError(ENONET) giving back the less descriptive
+  // ERR_FAILED.
+  if (rv == ENONET)
+    return ERR_NETWORK_CHANGED;
+  return MapSystemError(rv);
 #else
   NOTIMPLEMENTED();
   return ERR_NOT_IMPLEMENTED;
 #endif
 }
 
 int UDPSocketPosix::SetReceiveBufferSize(int32 size) {
   DCHECK_NE(socket_, kInvalidSocket);
   DCHECK(CalledOnValidThread());
   int rv = setsockopt(socket_, SOL_SOCKET, SO_RCVBUF,
@@ skipping 419 matching lines @@
     return MapSystemError(errno);
 
   return OK;
 }
 
 void UDPSocketPosix::DetachFromThread() {
   base::NonThreadSafe::DetachFromThread();
 }
 
 }  // namespace net