[mojo] Ports EDK

mojo/edk/system/remote_message_pipe_bootstrap.cc

+// Copyright 2016 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 "mojo/edk/system/remote_message_pipe_bootstrap.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/macros.h"
+#include "base/thread_task_runner_handle.h"
+#include "mojo/edk/embedder/embedder.h"
+#include "mojo/edk/system/node_controller.h"
+
+namespace mojo {
+namespace edk {
+
+namespace {
+
+const size_t kMaxTokenSize = 256;
+
+class ParentBootstrap : public RemoteMessagePipeBootstrap {
+ public:
+  static void Create(NodeController* node_controller,
+                     ScopedPlatformHandle platform_handle,
+                     const std::string& token) {
+    // Owns itself.
+    new ParentBootstrap(node_controller, std::move(platform_handle), token);
+  }
+
+ private:
+  ParentBootstrap(NodeController* node_controller,
+                  ScopedPlatformHandle platform_handle,
+                  const std::string& token)
+      : RemoteMessagePipeBootstrap(std::move(platform_handle)),
+        node_controller_(node_controller),
+        token_(token) {
+    DCHECK_LE(token_.size(), kMaxTokenSize);
+    Channel::MessagePtr message(new Channel::Message(token_.size(), 0));
+    memcpy(message->mutable_payload(), token_.data(), token_.size());
+    channel_->Write(std::move(message));
+  }
+
+  ~ParentBootstrap() override {}
+
+  void OnTokenReceived(const std::string& token) override {
+    // It's possible for two different endpoints in the same parent process to
+    // initiate parent bootstrap on the same platform channel without being
+    // aware of the other.
+    //
+    // This will successfully connect the two endpoints as long as at least one
+    // of the ParentBootstrap instances receives the other's token. It's OK that
+    // they race. NodeController will silently ignore any missed reservations.
+    node_controller_->ConnectReservedPorts(token_, token);
+    ShutDown();
+  }
+
+  NodeController* node_controller_;
+  const std::string token_;
+
+  DISALLOW_COPY_AND_ASSIGN(ParentBootstrap);
+};
+
+class ChildBootstrap : public RemoteMessagePipeBootstrap {
+ public:
+  static void Create(NodeController* node_controller,
+                     ScopedPlatformHandle platform_handle,
+                     const ports::PortRef& port,
+                     const base::Closure& callback) {
+    // Owns itself.
+    new ChildBootstrap(
+        node_controller, std::move(platform_handle), port, callback);
+  }
+
+ private:
+  ChildBootstrap(NodeController* node_controller,
+                 ScopedPlatformHandle platform_handle,
+                 const ports::PortRef& port,
+                 const base::Closure& callback)
+      : RemoteMessagePipeBootstrap(std::move(platform_handle)),
+        node_controller_(node_controller),
+        port_(port),
+        callback_(callback) {
+  }
+
+  ~ChildBootstrap() override {}
+
+  void OnTokenReceived(const std::string& token) override {
+    CHECK(!callback_.is_null());
+    base::Closure callback = callback_;
+    callback_.Reset();
+
+    node_controller_->ConnectToParentPort(port_, token, callback);
+    ShutDown();
+  }
+
+  NodeController* const node_controller_;
+  const ports::PortRef port_;
+  base::Closure callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChildBootstrap);
+};
+
+}  // namespace
+
+// static
+void RemoteMessagePipeBootstrap::CreateForParent(
+    NodeController* node_controller,
+    ScopedPlatformHandle platform_handle,
+    const std::string& token) {
+  node_controller->io_task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&ParentBootstrap::Create, base::Unretained(node_controller),
+                 base::Passed(&platform_handle), token));
+}
+
+// static
+void RemoteMessagePipeBootstrap::CreateForChild(
+    NodeController* node_controller,
+    ScopedPlatformHandle platform_handle,
+    const ports::PortRef& port,
+    const base::Closure& callback) {
+  node_controller->io_task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&ChildBootstrap::Create, base::Unretained(node_controller),
+                 base::Passed(&platform_handle), port, callback));
+}
+
+RemoteMessagePipeBootstrap::~RemoteMessagePipeBootstrap() {
+  DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
+  base::MessageLoop::current()->RemoveDestructionObserver(this);
+  if (channel_)
+    channel_->ShutDown();
+}
+
+RemoteMessagePipeBootstrap::RemoteMessagePipeBootstrap(
+    ScopedPlatformHandle platform_handle)
+    : io_task_runner_(base::ThreadTaskRunnerHandle::Get()),
+      channel_(Channel::Create(this, std::move(platform_handle),
+                               io_task_runner_)) {
+  base::MessageLoop::current()->AddDestructionObserver(this);
+  channel_->Start();
+}
+
+void RemoteMessagePipeBootstrap::ShutDown() {
+  DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
+
+  if (shutting_down_)
+    return;
+
+  shutting_down_ = true;
+
+  // Shut down asynchronously so implementations are free to call it whenever.
+  io_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RemoteMessagePipeBootstrap::ShutDownNow,
+                 base::Unretained(this)));
+}
+
+void RemoteMessagePipeBootstrap::WillDestroyCurrentMessageLoop() {
+  DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
+  ShutDownNow();
+}
+
+void RemoteMessagePipeBootstrap::OnChannelMessage(
+    const void* payload,
+    size_t payload_size,
+    ScopedPlatformHandleVectorPtr handles) {
+  DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
+  DCHECK(!handles || !handles->size());
+  if (payload_size > kMaxTokenSize) {
+    DLOG(ERROR) << "Invalid token payload. Dropping message pipe bootstrap.";
+    ShutDown();
+    return;
+  }
+
+  OnTokenReceived(std::string(static_cast<const char*>(payload), payload_size));
+}
+
+void RemoteMessagePipeBootstrap::OnChannelError() {
+  DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
+  ShutDown();
+}
+
+void RemoteMessagePipeBootstrap::ShutDownNow() {
+  delete this;
+}
+
+}  // namespace edk
+}  // namespace mojo