Remote Assistance on Chrome OS Part III - NativeMessageHost

remoting/host/it2me/it2me_native_messaging_host.cc

 // Copyright 2013 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 "remoting/host/it2me/it2me_native_messaging_host.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
-#include "base/callback_helpers.h"
-#include "base/message_loop/message_loop.h"
-#include "base/run_loop.h"
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringize_macros.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
 #include "net/base/net_util.h"
 #include "net/url_request/url_fetcher.h"
 #include "remoting/base/auth_token_util.h"
 #include "remoting/base/service_urls.h"
 #include "remoting/host/chromoting_host_context.h"
 #include "remoting/host/host_exit_codes.h"
@@ skipping 10 matching lines @@
     {kReceivedAccessCode, "RECEIVED_ACCESS_CODE"},
     {kConnected, "CONNECTED"},
     {kDisconnecting, "DISCONNECTING"},
     {kError, "ERROR"},
     {kInvalidDomainError, "INVALID_DOMAIN_ERROR"}, };
 
 }  // namespace
 
 It2MeNativeMessagingHost::It2MeNativeMessagingHost(
     scoped_refptr<AutoThreadTaskRunner> task_runner,
-    scoped_ptr<extensions::NativeMessagingChannel> channel,
     scoped_ptr<It2MeHostFactory> factory)
-    : channel_(channel.Pass()),
+    : client_(NULL),
       factory_(factory.Pass()),
       weak_factory_(this) {
   weak_ptr_ = weak_factory_.GetWeakPtr();
 
   // Initialize the host context to manage the threads for the it2me host.
   // The native messaging host, rather than the It2MeHost object, owns and
   // maintains the lifetime of the host context.
 
   host_context_.reset(ChromotingHostContext::Create(task_runner).release());
 
@@ skipping 10 matching lines @@
 
 It2MeNativeMessagingHost::~It2MeNativeMessagingHost() {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   if (it2me_host_.get()) {
     it2me_host_->Disconnect();
     it2me_host_ = NULL;
   }
 }
 
-void It2MeNativeMessagingHost::Start(const base::Closure& quit_closure) {
-  DCHECK(task_runner()->BelongsToCurrentThread());
-  DCHECK(!quit_closure.is_null());
-
-  quit_closure_ = quit_closure;
-
-  channel_->Start(this);
-}
-
-void It2MeNativeMessagingHost::OnMessage(scoped_ptr<base::Value> message) {
+void It2MeNativeMessagingHost::OnMessage(const std::string& message) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
-  if (!message->IsType(base::Value::TYPE_DICTIONARY)) {
-    LOG(ERROR) << "Received a message that's not a dictionary.";
-    channel_->SendMessage(nullptr);
+  scoped_ptr<base::DictionaryValue> response(new base::DictionaryValue());
+  scoped_ptr<base::Value> message_value(
+      make_scoped_ptr(base::JSONReader::Read(message)));

[Sergey Ulanov, 2014/10/03 19:22:10]

don't need make_scoped_ptr() here. scoped_ptr<> can be initialized with a raw
pointer.

[kelvinp, 2014/10/06 04:37:26]

Done.

+  if (message_value->IsType(base::Value::TYPE_DICTIONARY)) {
+    SendErrorAndExit(response.Pass(),
+                     "Received a message that's not a dictionary.");
     return;
   }
 
   scoped_ptr<base::DictionaryValue> message_dict(
-      static_cast<base::DictionaryValue*>(message.release()));
-  scoped_ptr<base::DictionaryValue> response(new base::DictionaryValue());
+      static_cast<base::DictionaryValue*>(message_value.get()));

[Sergey Ulanov, 2014/10/03 19:22:10]

You need release() here instead of get(). With get() here ownership the object
is owned by both scoped_ptr<>, which will cause crash when they are deleted.

[kelvinp, 2014/10/06 04:37:26]

Done.

 
   // If the client supplies an ID, it will expect it in the response. This
   // might be a string or a number, so cope with both.
   const base::Value* id;
   if (message_dict->Get("id", &id))
     response->Set("id", id->DeepCopy());
 
   std::string type;
   if (!message_dict->GetString("type", &type)) {
     SendErrorAndExit(response.Pass(), "'type' not found in request.");
     return;
   }
 
   response->SetString("type", type + "Response");
 
   if (type == "hello") {
     ProcessHello(*message_dict, response.Pass());
   } else if (type == "connect") {
     ProcessConnect(*message_dict, response.Pass());
   } else if (type == "disconnect") {
     ProcessDisconnect(*message_dict, response.Pass());
   } else {
     SendErrorAndExit(response.Pass(), "Unsupported request type: " + type);
   }
 }
 
-void It2MeNativeMessagingHost::OnDisconnect() {
-  if (!quit_closure_.is_null())
-    base::ResetAndReturn(&quit_closure_).Run();
+void It2MeNativeMessagingHost::Start(Client* client) {
+  DCHECK(task_runner()->BelongsToCurrentThread());
+  client_ = client;
+}
+
+void It2MeNativeMessagingHost::SendMessageToClient(
+    scoped_ptr<base::DictionaryValue> message) const {
+  DCHECK(task_runner()->BelongsToCurrentThread());
+  std::string message_json;
+  base::JSONWriter::Write(message.get(), &message_json);
+  client_->PostMessageFromNativeHost(message_json);
 }
 
 void It2MeNativeMessagingHost::ProcessHello(
     const base::DictionaryValue& message,
     scoped_ptr<base::DictionaryValue> response) const {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   response->SetString("version", STRINGIZE(VERSION));
 
   // This list will be populated when new features are added.
   scoped_ptr<base::ListValue> supported_features_list(new base::ListValue());
   response->Set("supportedFeatures", supported_features_list.release());
 
-  channel_->SendMessage(response.Pass());
+  SendMessageToClient(response.Pass());
 }
 
 void It2MeNativeMessagingHost::ProcessConnect(
     const base::DictionaryValue& message,
     scoped_ptr<base::DictionaryValue> response) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   if (it2me_host_.get()) {
     SendErrorAndExit(response.Pass(),
                      "Connect can be called only when disconnected.");
@@ skipping 53 matching lines @@
 #endif  // !defined(NDEBUG)
 
   // Create the It2Me host and start connecting.
   it2me_host_ = factory_->CreateIt2MeHost(host_context_.get(),
                                           host_context_->ui_task_runner(),
                                           weak_ptr_,
                                           xmpp_config,
                                           directory_bot_jid_);
   it2me_host_->Connect();
 
-  channel_->SendMessage(response.Pass());
+  SendMessageToClient(response.Pass());
 }
 
 void It2MeNativeMessagingHost::ProcessDisconnect(
     const base::DictionaryValue& message,
     scoped_ptr<base::DictionaryValue> response) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   if (it2me_host_.get()) {
     it2me_host_->Disconnect();
     it2me_host_ = NULL;
   }
-  channel_->SendMessage(response.Pass());
+  SendMessageToClient(response.Pass());
 }
 
 void It2MeNativeMessagingHost::SendErrorAndExit(
     scoped_ptr<base::DictionaryValue> response,
     const std::string& description) const {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   LOG(ERROR) << description;
 
   response->SetString("type", "error");
   response->SetString("description", description);
-  channel_->SendMessage(response.Pass());
+  SendMessageToClient(response.Pass());
 
-  // Trigger a host shutdown by sending a NULL message.
-  channel_->SendMessage(nullptr);
+  // Trigger a host shutdown by sending an empty message.
+  client_->CloseChannel(std::string());
 }
 
 void It2MeNativeMessagingHost::OnStateChanged(It2MeHostState state) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   state_ = state;
 
   scoped_ptr<base::DictionaryValue> message(new base::DictionaryValue());
 
   message->SetString("type", "hostStateChanged");
@@ skipping 12 matching lines @@
       break;
 
     case kDisconnected:
       client_username_.clear();
       break;
 
     default:
       ;
   }
 
-  channel_->SendMessage(message.Pass());
+  SendMessageToClient(message.Pass());
 }
 
 void It2MeNativeMessagingHost::OnNatPolicyChanged(bool nat_traversal_enabled) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   scoped_ptr<base::DictionaryValue> message(new base::DictionaryValue());
 
   message->SetString("type", "natPolicyChanged");
   message->SetBoolean("natTraversalEnabled", nat_traversal_enabled);
-  channel_->SendMessage(message.Pass());
+  SendMessageToClient(message.Pass());
 }
 
 // Stores the Access Code for the web-app to query.
 void It2MeNativeMessagingHost::OnStoreAccessCode(
     const std::string& access_code,
     base::TimeDelta access_code_lifetime) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   access_code_ = access_code;
   access_code_lifetime_ = access_code_lifetime;
 }
 
 // Stores the client user's name for the web-app to query.
 void It2MeNativeMessagingHost::OnClientAuthenticated(
     const std::string& client_username) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
   client_username_ = client_username;
 }
 
-scoped_refptr<AutoThreadTaskRunner>
+scoped_refptr<base::SingleThreadTaskRunner>
 It2MeNativeMessagingHost::task_runner() const {
   return host_context_->ui_task_runner();
 }
 
 /* static */
 std::string It2MeNativeMessagingHost::HostStateToString(
     It2MeHostState host_state) {
   return ValueToName(kIt2MeHostStates, host_state);
 }
 
 }  // namespace remoting