remoting/host/native_messaging/pipe_messaging_channel.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/host/native_messaging/pipe_messaging_channel.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/bind.h"
   9 #include "base/callback.h"
  10 #include "base/callback_helpers.h"
  11 #include "base/location.h"
  12 #include "base/values.h"
  13
  14 #if defined(OS_POSIX)
  15 #include <unistd.h>
  16 #endif
  17
  18 namespace {
  19
  20 base::File DuplicatePlatformFile(base::File file) {
  21   base::PlatformFile result;
  22 #if defined(OS_WIN)
  23   if (!DuplicateHandle(GetCurrentProcess(),
  24                        file.TakePlatformFile(),
  25                        GetCurrentProcess(),
  26                        &result,
  27                        0,
  28                        FALSE,
  29                        DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS)) {
  30     PLOG(ERROR) << "Failed to duplicate handle " << file.GetPlatformFile();
  31     return base::File();
  32   }
  33   return base::File(result);
  34 #elif defined(OS_POSIX)
  35   result = dup(file.GetPlatformFile());
  36   return base::File(result);
  37 #else
  38 #error Not implemented.
  39 #endif
  40 }
  41
  42 }  // namespace
  43
  44 namespace remoting {
  45
  46 PipeMessagingChannel::PipeMessagingChannel(
  47     base::File input,
  48     base::File output)
  49     : native_messaging_reader_(DuplicatePlatformFile(input.Pass())),
  50       native_messaging_writer_(new NativeMessagingWriter(
  51           DuplicatePlatformFile(output.Pass()))),
  52       event_handler_(nullptr),
  53       weak_factory_(this) {
  54   weak_ptr_ = weak_factory_.GetWeakPtr();
  55 }
  56
  57 PipeMessagingChannel::~PipeMessagingChannel() {
  58 }
  59
  60 void PipeMessagingChannel::Start(EventHandler* event_handler) {
  61   DCHECK(CalledOnValidThread());
  62   DCHECK(!event_handler_);
  63
  64   event_handler_ = event_handler;
  65   DCHECK(event_handler_);
  66
  67   native_messaging_reader_.Start(
  68       base::Bind(&PipeMessagingChannel::ProcessMessage, weak_ptr_),
  69       base::Bind(&PipeMessagingChannel::Shutdown, weak_ptr_));
  70 }
  71
  72 void PipeMessagingChannel::ProcessMessage(scoped_ptr<base::Value> message) {
  73   DCHECK(CalledOnValidThread());
  74
  75   if (event_handler_)
  76     event_handler_->OnMessage(message.Pass());
  77 }
  78
  79 void PipeMessagingChannel::SendMessage(
  80     scoped_ptr<base::Value> message) {
  81   DCHECK(CalledOnValidThread());
  82
  83   bool success = message && native_messaging_writer_;
  84   if (success)
  85     success = native_messaging_writer_->WriteMessage(*message);
  86
  87   if (!success) {
  88     // Close the write pipe so no more responses will be sent.
  89     native_messaging_writer_.reset();
  90     Shutdown();
  91   }
  92 }
  93
  94 void PipeMessagingChannel::Shutdown() {
  95   DCHECK(CalledOnValidThread());
  96
  97   if (event_handler_) {
  98     // Set |event_handler_| to nullptr to indicate the object is in a shutdown
  99     // cycle. Since event_handler->OnDisconnect() will destroy the current
 100     // object, |event_handler_| will become a dangling pointer after
 101     // OnDisconnect() returns. Therefore, we set |event_handler_| to nullptr
 102     // beforehand.
 103     EventHandler* handler = event_handler_;
 104     event_handler_ = nullptr;
 105     handler->OnDisconnect();
 106   }
 107 }
 108
 109 }  // namespace remoting