Refactoring: Move MessagePipeReader subclasess out from ChannelMojo

ipc/mojo/ipc_channel_mojo_readers.cc

+// Copyright 2014 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 "ipc/mojo/ipc_channel_mojo_readers.h"
+
+#include "ipc/mojo/ipc_channel_mojo.h"
+#include "mojo/embedder/embedder.h"
+
+#if defined(OS_POSIX) && !defined(OS_NACL)
+#include "ipc/file_descriptor_set_posix.h"
+#endif
+
+namespace IPC {
+namespace internal {
+
+namespace {
+
+// TODO(morrita): This should be built using higher-level Mojo construct
+// for clarity and extensibility.
+class HelloMessage {
+ public:
+  static Pickle CreateRequest(int32 pid) {
+    Pickle request;
+    request.WriteString(kHelloRequestMagic);
+    request.WriteInt(pid);
+    return request;
+  }
+
+  static bool ReadRequest(Pickle& pickle, int32* pid) {
+    PickleIterator iter(pickle);
+    std::string hello;
+    if (!iter.ReadString(&hello)) {
+      DLOG(WARNING) << "Failed to Read magic string.";
+      return false;
+    }
+
+    if (hello != kHelloRequestMagic) {
+      DLOG(WARNING) << "Magic mismatch:" << hello;
+      return false;
+    }
+
+    int read_pid;
+    if (!iter.ReadInt(&read_pid)) {
+      DLOG(WARNING) << "Failed to Read PID.";
+      return false;
+    }
+
+    *pid = read_pid;
+    return true;
+  }
+
+  static Pickle CreateResponse(int32 pid) {
+    Pickle request;
+    request.WriteString(kHelloResponseMagic);
+    request.WriteInt(pid);
+    return request;
+  }
+
+  static bool ReadResponse(Pickle& pickle, int32* pid) {
+    PickleIterator iter(pickle);
+    std::string hello;
+    if (!iter.ReadString(&hello)) {
+      DLOG(WARNING) << "Failed to read magic string.";
+      return false;
+    }
+
+    if (hello != kHelloResponseMagic) {
+      DLOG(WARNING) << "Magic mismatch:" << hello;
+      return false;
+    }
+
+    int read_pid;
+    if (!iter.ReadInt(&read_pid)) {
+      DLOG(WARNING) << "Failed to read PID.";
+      return false;
+    }
+
+    *pid = read_pid;
+    return true;
+  }
+
+ private:
+  static const char* kHelloRequestMagic;
+  static const char* kHelloResponseMagic;
+};
+
+const char* HelloMessage::kHelloRequestMagic = "MREQ";
+const char* HelloMessage::kHelloResponseMagic = "MRES";
+
+}  // namespace
+
+//------------------------------------------------------------------------------
+
+MessageReader::MessageReader(mojo::ScopedMessagePipeHandle pipe,
+                             ChannelMojo* owner)
+    : internal::MessagePipeReader(pipe.Pass()), owner_(owner) {
+}
+
+void MessageReader::OnMessageReceived() {
+  Message message(data_buffer().empty() ? "" : &data_buffer()[0],
+                  static_cast<uint32>(data_buffer().size()));
+
+  std::vector<MojoHandle> handle_buffer;
+  TakeHandleBuffer(&handle_buffer);
+#if defined(OS_POSIX) && !defined(OS_NACL)
+  MojoResult write_result =
+      ChannelMojo::WriteToFileDescriptorSet(handle_buffer, &message);
+  if (write_result != MOJO_RESULT_OK) {
+    CloseWithError(write_result);
+    return;
+  }
+#else
+  DCHECK(handle_buffer.empty());
+#endif
+
+  message.TraceMessageEnd();
+  owner_->OnMessageReceived(message);
+}
+
+void MessageReader::OnPipeClosed() {
+  if (!owner_)
+    return;
+  owner_->OnPipeClosed(this);
+  owner_ = NULL;
+}
+
+void MessageReader::OnPipeError(MojoResult error) {
+  if (!owner_)
+    return;
+  owner_->OnPipeError(this);
+}
+
+bool MessageReader::Send(scoped_ptr<Message> message) {
+  DCHECK(IsValid());
+
+  message->TraceMessageBegin();
+  std::vector<MojoHandle> handles;
+#if defined(OS_POSIX) && !defined(OS_NACL)
+  MojoResult read_result =
+      ChannelMojo::ReadFromFileDescriptorSet(*message, &handles);
+  if (read_result != MOJO_RESULT_OK) {
+    std::for_each(handles.begin(), handles.end(), &MojoClose);
+    CloseWithError(read_result);
+    return false;
+  }
+#endif
+  MojoResult write_result =
+      MojoWriteMessage(handle(),
+                       message->data(),
+                       static_cast<uint32>(message->size()),
+                       handles.empty() ? NULL : &handles[0],
+                       static_cast<uint32>(handles.size()),
+                       MOJO_WRITE_MESSAGE_FLAG_NONE);
+  if (MOJO_RESULT_OK != write_result) {
+    std::for_each(handles.begin(), handles.end(), &MojoClose);
+    CloseWithError(write_result);
+    return false;
+  }
+
+  return true;
+}
+
+//------------------------------------------------------------------------------
+
+ControlReader::ControlReader(mojo::ScopedMessagePipeHandle pipe,
+                             ChannelMojo* owner)
+    : internal::MessagePipeReader(pipe.Pass()), owner_(owner) {
+}
+
+void ControlReader::OnPipeClosed() {
+  if (!owner_)
+    return;
+  owner_->OnPipeClosed(this);
+  owner_ = NULL;
+}
+
+void ControlReader::OnPipeError(MojoResult error) {
+  if (!owner_)
+    return;
+  owner_->OnPipeError(this);
+}
+
+bool ControlReader::Connect() {
+  return true;
+}
+
+//------------------------------------------------------------------------------
+
+ServerControlReader::ServerControlReader(mojo::ScopedMessagePipeHandle pipe,
+                                         ChannelMojo* owner)
+    : ControlReader(pipe.Pass(), owner) {
+}
+
+ServerControlReader::~ServerControlReader() {
+}
+
+bool ServerControlReader::Connect() {
+  MojoResult result = SendHelloRequest();
+  if (result != MOJO_RESULT_OK) {
+    CloseWithError(result);
+    return false;
+  }
+
+  return true;
+}
+
+MojoResult ServerControlReader::SendHelloRequest() {
+  DCHECK(IsValid());
+  DCHECK(!message_pipe_.is_valid());
+
+  mojo::ScopedMessagePipeHandle self;
+  mojo::ScopedMessagePipeHandle peer;
+  MojoResult create_result =
+      mojo::CreateMessagePipe(NULL, &message_pipe_, &peer);
+  if (MOJO_RESULT_OK != create_result) {
+    DLOG(WARNING) << "mojo::CreateMessagePipe failed: " << create_result;
+    return create_result;
+  }
+
+  MojoHandle peer_to_send = peer.get().value();
+  Pickle request = HelloMessage::CreateRequest(owner_->GetSelfPID());
+  MojoResult write_result =
+      MojoWriteMessage(handle(),
+                       request.data(),
+                       static_cast<uint32>(request.size()),
+                       &peer_to_send,
+                       1,
+                       MOJO_WRITE_MESSAGE_FLAG_NONE);
+  if (MOJO_RESULT_OK != write_result) {
+    DLOG(WARNING) << "Writing Hello request failed: " << create_result;
+    return write_result;
+  }
+
+  // |peer| is sent and no longer owned by |this|.
+  (void)peer.release();
+  return MOJO_RESULT_OK;
+}
+
+MojoResult ServerControlReader::RespondHelloResponse() {
+  Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
+                 static_cast<uint32>(data_buffer().size()));
+
+  int32 read_pid = 0;
+  if (!HelloMessage::ReadResponse(request, &read_pid)) {
+    DLOG(ERROR) << "Failed to parse Hello response.";
+    return MOJO_RESULT_UNKNOWN;
+  }
+
+  base::ProcessId pid = static_cast<base::ProcessId>(read_pid);
+  owner_->set_peer_pid(pid);
+  owner_->OnConnected(message_pipe_.Pass());
+  return MOJO_RESULT_OK;
+}
+
+void ServerControlReader::OnMessageReceived() {
+  MojoResult result = RespondHelloResponse();
+  if (result != MOJO_RESULT_OK)
+    CloseWithError(result);
+}
+
+//------------------------------------------------------------------------------
+
+ClientControlReader::ClientControlReader(mojo::ScopedMessagePipeHandle pipe,
+                                         ChannelMojo* owner)
+    : ControlReader(pipe.Pass(), owner) {
+}
+
+MojoResult ClientControlReader::RespondHelloRequest(
+    MojoHandle message_channel) {
+  DCHECK(IsValid());
+
+  mojo::ScopedMessagePipeHandle received_pipe(
+      (mojo::MessagePipeHandle(message_channel)));
+
+  int32 read_request = 0;
+  Pickle request(data_buffer().empty() ? "" : &data_buffer()[0],
+                 static_cast<uint32>(data_buffer().size()));
+  if (!HelloMessage::ReadRequest(request, &read_request)) {
+    DLOG(ERROR) << "Hello request has wrong magic.";
+    return MOJO_RESULT_UNKNOWN;
+  }
+
+  base::ProcessId pid = read_request;
+  Pickle response = HelloMessage::CreateResponse(owner_->GetSelfPID());
+  MojoResult write_result =
+      MojoWriteMessage(handle(),
+                       response.data(),
+                       static_cast<uint32>(response.size()),
+                       NULL,
+                       0,
+                       MOJO_WRITE_MESSAGE_FLAG_NONE);
+  if (MOJO_RESULT_OK != write_result) {
+    DLOG(ERROR) << "Writing Hello response failed: " << write_result;
+    return write_result;
+  }
+
+  owner_->set_peer_pid(pid);
+  owner_->OnConnected(received_pipe.Pass());
+  return MOJO_RESULT_OK;
+}
+
+void ClientControlReader::OnMessageReceived() {
+  std::vector<MojoHandle> handle_buffer;
+  TakeHandleBuffer(&handle_buffer);
+  if (handle_buffer.size() != 1) {
+    DLOG(ERROR) << "Hello request doesn't contains required handle: "
+                << handle_buffer.size();
+    CloseWithError(MOJO_RESULT_UNKNOWN);
+    return;
+  }
+
+  MojoResult result = RespondHelloRequest(handle_buffer[0]);
+  if (result != MOJO_RESULT_OK) {
+    DLOG(ERROR) << "Failed to respond Hello request. Closing: " << result;
+    CloseWithError(result);
+  }
+}
+
+}  // namespace internal
+}  // namespace IPC