src/ipc/mojo/ipc_channel_mojo_readers.cc

   1 // Copyright 2014 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 "ipc/mojo/ipc_channel_mojo_readers.h"
   6
   7 #include "ipc/mojo/ipc_channel_mojo.h"
   8 #include "mojo/embedder/embedder.h"
   9
  10 #if defined(OS_POSIX) && !defined(OS_NACL)
  11 #include "ipc/file_descriptor_set_posix.h"
  12 #endif
  13
  14 namespace IPC {
  15 namespace internal {
  16
  17 namespace {
  18
  19 // TODO(morrita): This should be built using higher-level Mojo construct
  20 // for clarity and extensibility.
  21 class HelloMessage {
  22  public:
  23   static Pickle CreateRequest(int32 pid) {
  24     Pickle request;
  25     request.WriteString(kHelloRequestMagic);
  26     request.WriteInt(pid);
  27     return request;
  28   }
  29
  30   static bool ReadRequest(Pickle& pickle, int32* pid) {
  31     PickleIterator iter(pickle);
  32     std::string hello;
  33     if (!iter.ReadString(&hello)) {
  34       DLOG(WARNING) << "Failed to Read magic string.";
  35       return false;
  36     }
  37
  38     if (hello != kHelloRequestMagic) {
  39       DLOG(WARNING) << "Magic mismatch:" << hello;
  40       return false;
  41     }
  42
  43     int read_pid;
  44     if (!iter.ReadInt(&read_pid)) {
  45       DLOG(WARNING) << "Failed to Read PID.";
  46       return false;
  47     }
  48
  49     *pid = read_pid;
  50     return true;
  51   }
  52
  53   static Pickle CreateResponse(int32 pid) {
  54     Pickle request;
  55     request.WriteString(kHelloResponseMagic);
  56     request.WriteInt(pid);
  57     return request;
  58   }
  59
  60   static bool ReadResponse(Pickle& pickle, int32* pid) {
  61     PickleIterator iter(pickle);
  62     std::string hello;
  63     if (!iter.ReadString(&hello)) {
  64       DLOG(WARNING) << "Failed to read magic string.";
  65       return false;
  66     }
  67
  68     if (hello != kHelloResponseMagic) {
  69       DLOG(WARNING) << "Magic mismatch:" << hello;
  70       return false;
  71     }
  72
  73     int read_pid;
  74     if (!iter.ReadInt(&read_pid)) {
  75       DLOG(WARNING) << "Failed to read PID.";
  76       return false;
  77     }
  78
  79     *pid = read_pid;
  80     return true;
  81   }
  82
  83  private:
  84   static const char* kHelloRequestMagic;
  85   static const char* kHelloResponseMagic;
  86 };
  87
  88 const char* HelloMessage::kHelloRequestMagic = "MREQ";
  89 const char* HelloMessage::kHelloResponseMagic = "MRES";
  90
  91 }  // namespace
  92
  93 //------------------------------------------------------------------------------
  94
  95 MessageReader::MessageReader(mojo::ScopedMessagePipeHandle pipe,
  96                              ChannelMojo* owner)
  97     : internal::MessagePipeReader(pipe.Pass()), owner_(owner) {
  98 }
  99
 100 void MessageReader::OnMessageReceived() {
 101   Message message(data_buffer().empty() ? "" : &data_buffer()[0],
 102                   static_cast<uint32>(data_buffer().size()));
 103
 104   std::vector<MojoHandle> handle_buffer;
 105   TakeHandleBuffer(&handle_buffer);
 106 #if defined(OS_POSIX) && !defined(OS_NACL)
 107   MojoResult write_result =
 108       ChannelMojo::WriteToFileDescriptorSet(handle_buffer, &message);
 109   if (write_result != MOJO_RESULT_OK) {
 110     CloseWithError(write_result);
 111     return;
 112   }
 113 #else
 114   DCHECK(handle_buffer.empty());
 115 #endif
 116
 117   message.TraceMessageEnd();
 118   owner_->OnMessageReceived(message);
 119 }
 120
 121 void MessageReader::OnPipeClosed() {
 122   if (!owner_)
 123     return;
 124   owner_->OnPipeClosed(this);
 125   owner_ = NULL;
 126 }
 127
 128 void MessageReader::OnPipeError(MojoResult error) {
 129   if (!owner_)
 130     return;
 131   owner_->OnPipeError(this);
 132 }
 133
 134 bool MessageReader::Send(scoped_ptr<Message> message) {
 135   DCHECK(IsValid());
 136
 137   message->TraceMessageBegin();
 138   std::vector<MojoHandle> handles;
 139 #if defined(OS_POSIX) && !defined(OS_NACL)
 140   MojoResult read_result =
 141       ChannelMojo::ReadFromFileDescriptorSet(message.get(), &handles);
 142   if (read_result != MOJO_RESULT_OK) {
 143     std::for_each(handles.begin(), handles.end(), &MojoClose);
 144     CloseWithError(read_result);
 145     return false;
 146   }
 147 #endif
 148   MojoResult write_result =
 149       MojoWriteMessage(handle(),
 150                        message->data(),
 151                        static_cast<uint32>(message->size()),
 152                        handles.empty() ? NULL : &handles[0],
 153                        static_cast<uint32>(handles.size()),
 154                        MOJO_WRITE_MESSAGE_FLAG_NONE);
 155   if (MOJO_RESULT_OK != write_result) {
 156     std::for_each(handles.begin(), handles.end(), &MojoClose);
 157     CloseWithError(write_result);
 158     return false;
 159   }
 160
 161   return true;
 162 }
 163
 164 //------------------------------------------------------------------------------
 165
 166 ControlReader::ControlReader(mojo::ScopedMessagePipeHandle pipe,
 167                              ChannelMojo* owner)
 168     : internal::MessagePipeReader(pipe.Pass()), owner_(owner) {
 169 }
 170
 171 void ControlReader::OnPipeClosed() {
 172   if (!owner_)
 173     return;
 174   owner_->OnPipeClosed(this);
 175   owner_ = NULL;
 176 }
 177
 178 void ControlReader::OnPipeError(MojoResult error) {
 179   if (!owner_)
 180     return;
 181   owner_->OnPipeError(this);
 182 }
 183
 184 bool ControlReader::Connect() {
 185   return true;
 186 }
 187
 188 //------------------------------------------------------------------------------
 189
 190 ServerControlReader::ServerControlReader(mojo::ScopedMessagePipeHandle pipe,
 191                                          ChannelMojo* owner)
 192     : ControlReader(pipe.Pass(), owner) {
 193 }
 194
 195 ServerControlReader::~ServerControlReader() {
 196 }
 197
 198 bool ServerControlReader::Connect() {
 199   MojoResult result = SendHelloRequest();
 200   if (result != MOJO_RESULT_OK) {
 201     CloseWithError(result);
 202     return false;
 203   }
 204
 205   return true;
 206 }
 207
 208 MojoResult ServerControlReader::SendHelloRequest() {
 209   DCHECK(IsValid());
 210   DCHECK(!message_pipe_.is_valid());
 211
 212   mojo::ScopedMessagePipeHandle self;
 213   mojo::ScopedMessagePipeHandle peer;
 214   MojoResult create_result =
 215       mojo::CreateMessagePipe(NULL, &message_pipe_, &peer);
 216   if (MOJO_RESULT_OK != create_result) {
 217     DLOG(WARNING) << "mojo::CreateMessagePipe failed: " << create_result;
 218     return create_result;
 219   }
 220
 221   MojoHandle peer_to_send = peer.get().value();
 222   Pickle request = HelloMessage::CreateRequest(owner_->GetSelfPID());
 223   MojoResult write_result =
 224       MojoWriteMessage(handle(),
 225                        request.data(),
 226                        static_cast<uint32>(request.size()),
 227                        &peer_to_send,
 228                        1,
 229                        MOJO_WRITE_MESSAGE_FLAG_NONE);
 230   if (MOJO_RESULT_OK != write_result) {
 231     DLOG(WARNING) << "Writing Hello request failed: " << create_result;
 232     return write_result;
 233   }
 234
 235   // |peer| is sent and no longer owned by |this|.
 236   (void)peer.release();
 237   return MOJO_RESULT_OK;
 238 }
 239
 240 MojoResult ServerControlReader::RespondHelloResponse() {
 241   Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
 242                  static_cast<uint32>(data_buffer().size()));
 243
 244   int32 read_pid = 0;
 245   if (!HelloMessage::ReadResponse(request, &read_pid)) {
 246     DLOG(ERROR) << "Failed to parse Hello response.";
 247     return MOJO_RESULT_UNKNOWN;
 248   }
 249
 250   base::ProcessId pid = static_cast<base::ProcessId>(read_pid);
 251   owner_->set_peer_pid(pid);
 252   owner_->OnConnected(message_pipe_.Pass());
 253   return MOJO_RESULT_OK;
 254 }
 255
 256 void ServerControlReader::OnMessageReceived() {
 257   MojoResult result = RespondHelloResponse();
 258   if (result != MOJO_RESULT_OK)
 259     CloseWithError(result);
 260 }
 261
 262 //------------------------------------------------------------------------------
 263
 264 ClientControlReader::ClientControlReader(mojo::ScopedMessagePipeHandle pipe,
 265                                          ChannelMojo* owner)
 266     : ControlReader(pipe.Pass(), owner) {
 267 }
 268
 269 MojoResult ClientControlReader::RespondHelloRequest(
 270     MojoHandle message_channel) {
 271   DCHECK(IsValid());
 272
 273   mojo::ScopedMessagePipeHandle received_pipe(
 274       (mojo::MessagePipeHandle(message_channel)));
 275
 276   int32 read_request = 0;
 277   Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
 278                  static_cast<uint32>(data_buffer().size()));
 279   if (!HelloMessage::ReadRequest(request, &read_request)) {
 280     DLOG(ERROR) << "Hello request has wrong magic.";
 281     return MOJO_RESULT_UNKNOWN;
 282   }
 283
 284   base::ProcessId pid = read_request;
 285   Pickle response = HelloMessage::CreateResponse(owner_->GetSelfPID());
 286   MojoResult write_result =
 287       MojoWriteMessage(handle(),
 288                        response.data(),
 289                        static_cast<uint32>(response.size()),
 290                        NULL,
 291                        0,
 292                        MOJO_WRITE_MESSAGE_FLAG_NONE);
 293   if (MOJO_RESULT_OK != write_result) {
 294     DLOG(ERROR) << "Writing Hello response failed: " << write_result;
 295     return write_result;
 296   }
 297
 298   owner_->set_peer_pid(pid);
 299   owner_->OnConnected(received_pipe.Pass());
 300   return MOJO_RESULT_OK;
 301 }
 302
 303 void ClientControlReader::OnMessageReceived() {
 304   std::vector<MojoHandle> handle_buffer;
 305   TakeHandleBuffer(&handle_buffer);
 306   if (handle_buffer.size() != 1) {
 307     DLOG(ERROR) << "Hello request doesn't contains required handle: "
 308                 << handle_buffer.size();
 309     CloseWithError(MOJO_RESULT_UNKNOWN);
 310     return;
 311   }
 312
 313   MojoResult result = RespondHelloRequest(handle_buffer[0]);
 314   if (result != MOJO_RESULT_OK) {
 315     DLOG(ERROR) << "Failed to respond Hello request. Closing: " << result;
 316     CloseWithError(result);
 317   }
 318 }
 319
 320 }  // namespace internal
 321 }  // namespace IPC