IPC::ChannelMojo: Introduce IPC::MojoBootstrap for Windows

ChannelMojo doesn't work on Windows with existing implementaion
and this CL fixes it.

On Windows, ChannelHandle isn't immediately usable: The handle has
to be activated through ConnectNamedPipe() windows API, which is done in
its own Connect() handlshaking phase. ChannelMojo didn't Connect()
underlying channel and took the ChannelHandle over so the handle
wasn't activated.

Instead of hijacking underlying ChannelHandle, this CL actually Connect()s
underlying channel, creates a pipe on the server side, send one side of the
pipe to the client process, and use the pipe for the MessagePipe
initialization.

These initialization task is encapsulated behind new MojoBootstrap class.
ChannelMojo creates MojoBootstrap class to get the PlatformHandle which
is already activated and usable.

BUG=377980
TEST=ipc_mojo_bootstrap_unittest.cc, ipc_channel_mojo_unittest.cc
R=viettrungluu@chromium.org, darin@chromium.org, yzshen@chromium.org

Review URL: https://codereview.chromium.org/553283002

Cr-Commit-Position: refs/heads/master@{#296248}

1 files changed, 205 insertions, 0 deletions

diff --git a/ipc/mojo/ipc_mojo_bootstrap.cc b/ipc/mojo/ipc_mojo_bootstrap.cc
new file mode 100644
index 0000000..0082fb8
--- /dev/null
+++ b/ipc/mojo/ipc_mojo_bootstrap.cc
@@ -0,0 +1,205 @@
+// 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_mojo_bootstrap.h"
+
+#include "base/logging.h"
+#include "base/process/process_handle.h"
+#include "ipc/ipc_message_utils.h"
+#include "ipc/ipc_platform_file.h"
+#include "mojo/embedder/platform_channel_pair.h"
+
+namespace IPC {
+
+namespace {
+
+// MojoBootstrap for the server process. You should create the instance
+// using MojoBootstrap::Create().
+class IPC_MOJO_EXPORT MojoServerBootstrap : public MojoBootstrap {
+ public:
+  MojoServerBootstrap();
+
+  virtual void OnClientLaunched(base::ProcessHandle process) OVERRIDE;
+
+ private:
+  void SendClientPipe();
+  void SendClientPipeIfReady();
+
+  // Listener implementations
+  virtual bool OnMessageReceived(const Message& message) OVERRIDE;
+  virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
+
+  mojo::embedder::ScopedPlatformHandle server_pipe_;
+  base::ProcessHandle client_process_;
+  bool connected_;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoServerBootstrap);
+};
+
+MojoServerBootstrap::MojoServerBootstrap()
+    : client_process_(base::kNullProcessHandle), connected_(false) {
+}
+
+void MojoServerBootstrap::SendClientPipe() {
+  DCHECK_EQ(state(), STATE_INITIALIZED);
+  DCHECK_NE(client_process_, base::kNullProcessHandle);
+  DCHECK(connected_);
+
+  mojo::embedder::PlatformChannelPair channel_pair;
+  server_pipe_ = channel_pair.PassServerHandle();
+  PlatformFileForTransit client_pipe = GetFileHandleForProcess(
+#if defined(OS_POSIX)
+      channel_pair.PassClientHandle().release().fd,
+#else
+      channel_pair.PassClientHandle().release().handle,
+#endif
+      client_process_,
+      true);
+  CHECK(client_pipe != IPC::InvalidPlatformFileForTransit());
+  scoped_ptr<Message> message(new Message());
+  ParamTraits<PlatformFileForTransit>::Write(message.get(), client_pipe);
+  Send(message.release());
+
+  set_state(STATE_WAITING_ACK);
+}
+
+void MojoServerBootstrap::SendClientPipeIfReady() {
+  // Is the client launched?
+  if (client_process_ == base::kNullProcessHandle)
+    return;
+  // Has the bootstrap channel been made?
+  if (!connected_)
+    return;
+  SendClientPipe();
+}
+
+void MojoServerBootstrap::OnClientLaunched(base::ProcessHandle process) {
+  DCHECK_EQ(state(), STATE_INITIALIZED);
+  DCHECK_NE(process, base::kNullProcessHandle);
+  client_process_ = process;
+  SendClientPipeIfReady();
+}
+
+void MojoServerBootstrap::OnChannelConnected(int32 peer_pid) {
+  DCHECK_EQ(state(), STATE_INITIALIZED);
+  connected_ = true;
+  SendClientPipeIfReady();
+}
+
+bool MojoServerBootstrap::OnMessageReceived(const Message&) {
+  DCHECK_EQ(state(), STATE_WAITING_ACK);
+  set_state(STATE_READY);
+
+  delegate()->OnPipeAvailable(
+      mojo::embedder::ScopedPlatformHandle(server_pipe_.release()));
+
+  return true;
+}
+
+// MojoBootstrap for client processes. You should create the instance
+// using MojoBootstrap::Create().
+class IPC_MOJO_EXPORT MojoClientBootstrap : public MojoBootstrap {
+ public:
+  MojoClientBootstrap();
+
+  virtual void OnClientLaunched(base::ProcessHandle process) OVERRIDE;
+
+ private:
+  // Listener implementations
+  virtual bool OnMessageReceived(const Message& message) OVERRIDE;
+  virtual void OnChannelConnected(int32 peer_pid) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoClientBootstrap);
+};
+
+MojoClientBootstrap::MojoClientBootstrap() {
+}
+
+bool MojoClientBootstrap::OnMessageReceived(const Message& message) {
+  PlatformFileForTransit pipe;
+  PickleIterator iter(message);
+  if (!ParamTraits<PlatformFileForTransit>::Read(&message, &iter, &pipe)) {
+    DLOG(WARNING) << "Failed to read a file handle from bootstrap channel.";
+    message.set_dispatch_error();
+    return false;
+  }
+
+  // Sends ACK back.
+  Send(new Message());
+  set_state(STATE_READY);
+  delegate()->OnPipeAvailable(
+      mojo::embedder::ScopedPlatformHandle(mojo::embedder::PlatformHandle(
+          PlatformFileForTransitToPlatformFile(pipe))));
+
+  return true;
+}
+
+void MojoClientBootstrap::OnClientLaunched(base::ProcessHandle process) {
+  // This notification should happen only on server processes.
+  NOTREACHED();
+}
+
+void MojoClientBootstrap::OnChannelConnected(int32 peer_pid) {
+}
+
+}  // namespace
+
+// MojoBootstrap
+
+// static
+scoped_ptr<MojoBootstrap> MojoBootstrap::Create(ChannelHandle handle,
+                                                Channel::Mode mode,
+                                                Delegate* delegate) {
+  CHECK(mode == Channel::MODE_CLIENT || mode == Channel::MODE_SERVER);
+  scoped_ptr<MojoBootstrap> self =
+      mode == Channel::MODE_CLIENT
+          ? scoped_ptr<MojoBootstrap>(new MojoClientBootstrap())
+          : scoped_ptr<MojoBootstrap>(new MojoServerBootstrap());
+  scoped_ptr<Channel> bootstrap_channel =
+      Channel::Create(handle, mode, self.get());
+  self->Init(bootstrap_channel.Pass(), delegate);
+  return self.Pass();
+}
+
+MojoBootstrap::MojoBootstrap() : delegate_(NULL), state_(STATE_INITIALIZED) {
+}
+
+MojoBootstrap::~MojoBootstrap() {
+}
+
+void MojoBootstrap::Init(scoped_ptr<Channel> channel, Delegate* delegate) {
+  channel_ = channel.Pass();
+  delegate_ = delegate;
+}
+
+bool MojoBootstrap::Connect() {
+  return channel_->Connect();
+}
+
+void MojoBootstrap::OnBadMessageReceived(const Message& message) {
+  delegate_->OnBootstrapError();
+}
+
+void MojoBootstrap::OnChannelError() {
+  if (state_ == STATE_READY)
+    return;
+  DLOG(WARNING) << "Detected error on Mojo bootstrap channel.";
+  delegate()->OnBootstrapError();
+}
+
+bool MojoBootstrap::Send(Message* message) {
+  return channel_->Send(message);
+}
+
+#if defined(OS_POSIX) && !defined(OS_NACL)
+int MojoBootstrap::GetClientFileDescriptor() const {
+  return channel_->GetClientFileDescriptor();
+}
+
+int MojoBootstrap::TakeClientFileDescriptor() {
+  return channel_->TakeClientFileDescriptor();
+}
+#endif  // defined(OS_POSIX) && !defined(OS_NACL)
+
+}  // namespace IPC