[NaCl SDK] Add some more logging to nacl_io.

native_client_sdk/src/libraries/nacl_io/socket/udp_node.cc

 // Copyright 2013 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 "nacl_io/socket/udp_node.h"
 
 #include <errno.h>
 #include <string.h>
 
 #include <algorithm>
 
+#include "nacl_io/log.h"
 #include "nacl_io/pepper_interface.h"
 #include "nacl_io/socket/packet.h"
 #include "nacl_io/socket/udp_event_emitter.h"
 #include "nacl_io/stream/stream_fs.h"
 
 namespace {
 const size_t kMaxPacketSize = 65536;
 const size_t kDefaultFifoSize = kMaxPacketSize * 8;
 }
 
@@ skipping 140 matching lines @@
 
 UdpEventEmitter* UdpNode::GetEventEmitter() {
   return emitter_.get();
 }
 
 Error UdpNode::Init(int open_flags) {
   Error err = SocketNode::Init(open_flags);
   if (err != 0)
     return err;
 
-  if (UDPInterface() == NULL)
+  if (UDPInterface() == NULL) {
+    LOG_ERROR("Got NULL interface: UDP");
     return EACCES;
+  }
 
   socket_resource_ =
       UDPInterface()->Create(filesystem_->ppapi()->GetInstance());
-  if (0 == socket_resource_)
+  if (0 == socket_resource_) {
+    LOG_ERROR("Unable to create UDP resource.");
     return EACCES;
+  }
 
   return 0;
 }
 
 void UdpNode::QueueInput() {
   UdpRecvWork* work = new UdpRecvWork(emitter_);
   stream()->EnqueueWork(work);
 }
 
 void UdpNode::QueueOutput() {
@@ skipping 104 matching lines @@
   int capped_len = static_cast<int32_t>(std::min<int>(len, kMaxPacketSize));
   Packet* packet = new Packet(filesystem_->ppapi());
   packet->Copy(buf, capped_len, addr);
 
   emitter_->WriteTXPacket_Locked(packet);
   *out_len = capped_len;
   return 0;
 }
 
 }  // namespace nacl_io