src/chrome/browser/extensions/api/messaging/message_service.cc

   1 // Copyright (c) 2012 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 "chrome/browser/extensions/api/messaging/message_service.h"
   6
   7 #include "base/atomic_sequence_num.h"
   8 #include "base/bind.h"
   9 #include "base/callback.h"
  10 #include "base/json/json_writer.h"
  11 #include "base/lazy_instance.h"
  12 #include "base/metrics/histogram.h"
  13 #include "base/stl_util.h"
  14 #include "base/values.h"
  15 #include "chrome/browser/chrome_notification_types.h"
  16 #include "chrome/browser/extensions/api/messaging/extension_message_port.h"
  17 #include "chrome/browser/extensions/api/messaging/incognito_connectability.h"
  18 #include "chrome/browser/extensions/api/messaging/native_message_port.h"
  19 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
  20 #include "chrome/browser/extensions/extension_service.h"
  21 #include "chrome/browser/extensions/extension_tab_util.h"
  22 #include "chrome/browser/extensions/extension_util.h"
  23 #include "chrome/browser/profiles/profile.h"
  24 #include "chrome/browser/tab_contents/tab_util.h"
  25 #include "content/public/browser/notification_service.h"
  26 #include "content/public/browser/render_process_host.h"
  27 #include "content/public/browser/render_view_host.h"
  28 #include "content/public/browser/render_widget_host.h"
  29 #include "content/public/browser/render_widget_host_view.h"
  30 #include "content/public/browser/site_instance.h"
  31 #include "content/public/browser/web_contents.h"
  32 #include "extensions/browser/extension_host.h"
  33 #include "extensions/browser/extension_system.h"
  34 #include "extensions/browser/extension_util.h"
  35 #include "extensions/browser/extensions_browser_client.h"
  36 #include "extensions/browser/lazy_background_task_queue.h"
  37 #include "extensions/browser/process_manager.h"
  38 #include "extensions/common/extension.h"
  39 #include "extensions/common/extension_messages.h"
  40 #include "extensions/common/manifest_constants.h"
  41 #include "extensions/common/manifest_handlers/background_info.h"
  42 #include "extensions/common/manifest_handlers/externally_connectable.h"
  43 #include "extensions/common/manifest_handlers/incognito_info.h"
  44 #include "extensions/common/permissions/permissions_data.h"
  45 #include "net/base/completion_callback.h"
  46 #include "url/gurl.h"
  47
  48 using content::BrowserContext;
  49 using content::SiteInstance;
  50 using content::WebContents;
  51
  52 // Since we have 2 ports for every channel, we just index channels by half the
  53 // port ID.
  54 #define GET_CHANNEL_ID(port_id) ((port_id) / 2)
  55 #define GET_CHANNEL_OPENER_ID(channel_id) ((channel_id) * 2)
  56 #define GET_CHANNEL_RECEIVERS_ID(channel_id) ((channel_id) * 2 + 1)
  57
  58 // Port1 is always even, port2 is always odd.
  59 #define IS_OPENER_PORT_ID(port_id) (((port_id) & 1) == 0)
  60
  61 // Change even to odd and vice versa, to get the other side of a given channel.
  62 #define GET_OPPOSITE_PORT_ID(source_port_id) ((source_port_id) ^ 1)
  63
  64 namespace extensions {
  65
  66 const char kReceivingEndDoesntExistError[] =
  67     "Could not establish connection. Receiving end does not exist.";
  68 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
  69 const char kMissingPermissionError[] =
  70     "Access to native messaging requires nativeMessaging permission.";
  71 const char kProhibitedByPoliciesError[] =
  72     "Access to the native messaging host was disabled by the system "
  73     "administrator.";
  74 #endif
  75
  76 struct MessageService::MessageChannel {
  77   scoped_ptr<MessagePort> opener;
  78   scoped_ptr<MessagePort> receiver;
  79 };
  80
  81 struct MessageService::OpenChannelParams {
  82   content::RenderProcessHost* source;
  83   base::DictionaryValue source_tab;
  84   scoped_ptr<MessagePort> receiver;
  85   int receiver_port_id;
  86   std::string source_extension_id;
  87   std::string target_extension_id;
  88   GURL source_url;
  89   std::string channel_name;
  90   bool include_tls_channel_id;
  91   std::string tls_channel_id;
  92
  93   // Takes ownership of receiver.
  94   OpenChannelParams(content::RenderProcessHost* source,
  95                     scoped_ptr<base::DictionaryValue> source_tab,
  96                     MessagePort* receiver,
  97                     int receiver_port_id,
  98                     const std::string& source_extension_id,
  99                     const std::string& target_extension_id,
 100                     const GURL& source_url,
 101                     const std::string& channel_name,
 102                     bool include_tls_channel_id)
 103       : source(source),
 104         receiver(receiver),
 105         receiver_port_id(receiver_port_id),
 106         source_extension_id(source_extension_id),
 107         target_extension_id(target_extension_id),
 108         source_url(source_url),
 109         channel_name(channel_name),
 110         include_tls_channel_id(include_tls_channel_id) {
 111     if (source_tab)
 112       this->source_tab.Swap(source_tab.get());
 113   }
 114
 115  private:
 116   DISALLOW_COPY_AND_ASSIGN(OpenChannelParams);
 117 };
 118
 119 namespace {
 120
 121 static base::StaticAtomicSequenceNumber g_next_channel_id;
 122 static base::StaticAtomicSequenceNumber g_channel_id_overflow_count;
 123
 124 static content::RenderProcessHost* GetExtensionProcess(
 125     BrowserContext* context,
 126     const std::string& extension_id) {
 127   SiteInstance* site_instance =
 128       ExtensionSystem::Get(context)->process_manager()->GetSiteInstanceForURL(
 129           Extension::GetBaseURLFromExtensionId(extension_id));
 130   return site_instance->HasProcess() ? site_instance->GetProcess() : NULL;
 131 }
 132
 133 }  // namespace
 134
 135 content::RenderProcessHost*
 136     MessageService::MessagePort::GetRenderProcessHost() {
 137   return NULL;
 138 }
 139
 140 // static
 141 void MessageService::AllocatePortIdPair(int* port1, int* port2) {
 142   unsigned channel_id =
 143       static_cast<unsigned>(g_next_channel_id.GetNext()) % (kint32max/2);
 144
 145   if (channel_id == 0) {
 146     int overflow_count = g_channel_id_overflow_count.GetNext();
 147     if (overflow_count > 0)
 148       UMA_HISTOGRAM_BOOLEAN("Extensions.AllocatePortIdPairOverflow", true);
 149   }
 150
 151   unsigned port1_id = channel_id * 2;
 152   unsigned port2_id = channel_id * 2 + 1;
 153
 154   // Sanity checks to make sure our channel<->port converters are correct.
 155   DCHECK(IS_OPENER_PORT_ID(port1_id));
 156   DCHECK_EQ(GET_OPPOSITE_PORT_ID(port1_id), port2_id);
 157   DCHECK_EQ(GET_OPPOSITE_PORT_ID(port2_id), port1_id);
 158   DCHECK_EQ(GET_CHANNEL_ID(port1_id), GET_CHANNEL_ID(port2_id));
 159   DCHECK_EQ(GET_CHANNEL_ID(port1_id), channel_id);
 160   DCHECK_EQ(GET_CHANNEL_OPENER_ID(channel_id), port1_id);
 161   DCHECK_EQ(GET_CHANNEL_RECEIVERS_ID(channel_id), port2_id);
 162
 163   *port1 = port1_id;
 164   *port2 = port2_id;
 165 }
 166
 167 MessageService::MessageService(BrowserContext* context)
 168     : lazy_background_task_queue_(
 169           ExtensionSystem::Get(context)->lazy_background_task_queue()),
 170       weak_factory_(this) {
 171   registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_TERMINATED,
 172                  content::NotificationService::AllBrowserContextsAndSources());
 173   registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
 174                  content::NotificationService::AllBrowserContextsAndSources());
 175 }
 176
 177 MessageService::~MessageService() {
 178   STLDeleteContainerPairSecondPointers(channels_.begin(), channels_.end());
 179   channels_.clear();
 180 }
 181
 182 static base::LazyInstance<BrowserContextKeyedAPIFactory<MessageService> >
 183     g_factory = LAZY_INSTANCE_INITIALIZER;
 184
 185 // static
 186 BrowserContextKeyedAPIFactory<MessageService>*
 187 MessageService::GetFactoryInstance() {
 188   return g_factory.Pointer();
 189 }
 190
 191 // static
 192 MessageService* MessageService::Get(BrowserContext* context) {
 193   return BrowserContextKeyedAPIFactory<MessageService>::Get(context);
 194 }
 195
 196 void MessageService::OpenChannelToExtension(
 197     int source_process_id, int source_routing_id, int receiver_port_id,
 198     const std::string& source_extension_id,
 199     const std::string& target_extension_id,
 200     const GURL& source_url,
 201     const std::string& channel_name,
 202     bool include_tls_channel_id) {
 203   content::RenderProcessHost* source =
 204       content::RenderProcessHost::FromID(source_process_id);
 205   if (!source)
 206     return;
 207   BrowserContext* context = source->GetBrowserContext();
 208
 209   ExtensionSystem* extension_system = ExtensionSystem::Get(context);
 210   DCHECK(extension_system);
 211   const Extension* target_extension = extension_system->extension_service()->
 212       extensions()->GetByID(target_extension_id);
 213   if (!target_extension) {
 214     DispatchOnDisconnect(
 215         source, receiver_port_id, kReceivingEndDoesntExistError);
 216     return;
 217   }
 218
 219   // Only running ephemeral apps can receive messages. Idle cached ephemeral
 220   // apps are invisible and should not be connectable.
 221   if (util::IsEphemeralApp(target_extension_id, context) &&
 222       util::IsExtensionIdle(target_extension_id, context)) {
 223     DispatchOnDisconnect(
 224         source, receiver_port_id, kReceivingEndDoesntExistError);
 225     return;
 226   }
 227
 228   bool is_web_connection = false;
 229
 230   if (source_extension_id != target_extension_id) {
 231     // It's an external connection. Check the externally_connectable manifest
 232     // key if it's present. If it's not, we allow connection from any extension
 233     // but not webpages.
 234     ExternallyConnectableInfo* externally_connectable =
 235         static_cast<ExternallyConnectableInfo*>(
 236             target_extension->GetManifestData(
 237                 manifest_keys::kExternallyConnectable));
 238     bool is_externally_connectable = false;
 239
 240     if (externally_connectable) {
 241       if (source_extension_id.empty()) {
 242         // No source extension ID so the source was a web page. Check that the
 243         // URL matches.
 244         is_web_connection = true;
 245         is_externally_connectable =
 246             externally_connectable->matches.MatchesURL(source_url);
 247         // Only include the TLS channel ID for externally connected web pages.
 248         include_tls_channel_id &=
 249             is_externally_connectable &&
 250             externally_connectable->accepts_tls_channel_id;
 251       } else {
 252         // Source extension ID so the source was an extension. Check that the
 253         // extension matches.
 254         is_externally_connectable =
 255             externally_connectable->IdCanConnect(source_extension_id);
 256       }
 257     } else {
 258       // Default behaviour. Any extension, no webpages.
 259       is_externally_connectable = !source_extension_id.empty();
 260     }
 261
 262     if (!is_externally_connectable) {
 263       // Important: use kReceivingEndDoesntExistError here so that we don't
 264       // leak information about this extension to callers. This way it's
 265       // indistinguishable from the extension just not existing.
 266       DispatchOnDisconnect(
 267           source, receiver_port_id, kReceivingEndDoesntExistError);
 268       return;
 269     }
 270   }
 271
 272   WebContents* source_contents = tab_util::GetWebContentsByID(
 273       source_process_id, source_routing_id);
 274
 275   if (context->IsOffTheRecord() &&
 276       !util::IsIncognitoEnabled(target_extension_id, context)) {
 277     // Give the user a chance to accept an incognito connection from the web if
 278     // they haven't already, with the conditions:
 279     // - Only for spanning-mode incognito. We don't want the complication of
 280     //   spinning up an additional process here which might need to do some
 281     //   setup that we're not expecting.
 282     // - Only for extensions that can't normally be enabled in incognito, since
 283     //   that surface (e.g. chrome://extensions) should be the only one for
 284     //   enabling in incognito. In practice this means platform apps only.
 285     if (!is_web_connection || IncognitoInfo::IsSplitMode(target_extension) ||
 286         target_extension->can_be_incognito_enabled() ||
 287         // This check may show a dialog.
 288         !IncognitoConnectability::Get(context)
 289              ->Query(target_extension, source_contents, source_url)) {
 290       DispatchOnDisconnect(
 291           source, receiver_port_id, kReceivingEndDoesntExistError);
 292       return;
 293     }
 294   }
 295
 296   // Note: we use the source's profile here. If the source is an incognito
 297   // process, we will use the incognito EPM to find the right extension process,
 298   // which depends on whether the extension uses spanning or split mode.
 299   MessagePort* receiver = new ExtensionMessagePort(
 300       GetExtensionProcess(context, target_extension_id),
 301       MSG_ROUTING_CONTROL,
 302       target_extension_id);
 303
 304   // Include info about the opener's tab (if it was a tab).
 305   scoped_ptr<base::DictionaryValue> source_tab;
 306   GURL source_url_for_tab;
 307
 308   if (source_contents && ExtensionTabUtil::GetTabId(source_contents) >= 0) {
 309     // Only the tab id is useful to platform apps for internal use. The
 310     // unnecessary bits will be stripped out in
 311     // MessagingBindings::DispatchOnConnect().
 312     source_tab.reset(ExtensionTabUtil::CreateTabValue(source_contents));
 313     source_url_for_tab = source_url;
 314   }
 315
 316   OpenChannelParams* params = new OpenChannelParams(source,
 317                                                     source_tab.Pass(),
 318                                                     receiver,
 319                                                     receiver_port_id,
 320                                                     source_extension_id,
 321                                                     target_extension_id,
 322                                                     source_url_for_tab,
 323                                                     channel_name,
 324                                                     include_tls_channel_id);
 325
 326   // If the target requests the TLS channel id, begin the lookup for it.
 327   // The target might also be a lazy background page, checked next, but the
 328   // loading of lazy background pages continues asynchronously, so enqueue
 329   // messages awaiting TLS channel ID first.
 330   if (include_tls_channel_id) {
 331     pending_tls_channel_id_channels_[GET_CHANNEL_ID(params->receiver_port_id)]
 332         = PendingMessagesQueue();
 333     property_provider_.GetDomainBoundCert(
 334         Profile::FromBrowserContext(context),
 335         source_url,
 336         base::Bind(&MessageService::GotDomainBoundCert,
 337                    weak_factory_.GetWeakPtr(),
 338                    base::Passed(make_scoped_ptr(params))));
 339     return;
 340   }
 341
 342   // The target might be a lazy background page. In that case, we have to check
 343   // if it is loaded and ready, and if not, queue up the task and load the
 344   // page.
 345   if (MaybeAddPendingLazyBackgroundPageOpenChannelTask(
 346           context, target_extension, params)) {
 347     return;
 348   }
 349
 350   OpenChannelImpl(make_scoped_ptr(params));
 351 }
 352
 353 void MessageService::OpenChannelToNativeApp(
 354     int source_process_id,
 355     int source_routing_id,
 356     int receiver_port_id,
 357     const std::string& source_extension_id,
 358     const std::string& native_app_name) {
 359   content::RenderProcessHost* source =
 360       content::RenderProcessHost::FromID(source_process_id);
 361   if (!source)
 362     return;
 363
 364 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
 365   Profile* profile = Profile::FromBrowserContext(source->GetBrowserContext());
 366   ExtensionService* extension_service =
 367       ExtensionSystem::Get(profile)->extension_service();
 368   bool has_permission = false;
 369   if (extension_service) {
 370     const Extension* extension =
 371         extension_service->GetExtensionById(source_extension_id, false);
 372     has_permission = extension &&
 373                      extension->permissions_data()->HasAPIPermission(
 374                          APIPermission::kNativeMessaging);
 375   }
 376
 377   if (!has_permission) {
 378     DispatchOnDisconnect(source, receiver_port_id, kMissingPermissionError);
 379     return;
 380   }
 381
 382   PrefService* pref_service = profile->GetPrefs();
 383
 384   // Verify that the host is not blocked by policies.
 385   NativeMessageProcessHost::PolicyPermission policy_permission =
 386       NativeMessageProcessHost::IsHostAllowed(pref_service, native_app_name);
 387   if (policy_permission == NativeMessageProcessHost::DISALLOW) {
 388     DispatchOnDisconnect(source, receiver_port_id, kProhibitedByPoliciesError);
 389     return;
 390   }
 391
 392   scoped_ptr<MessageChannel> channel(new MessageChannel());
 393   channel->opener.reset(new ExtensionMessagePort(source, MSG_ROUTING_CONTROL,
 394                                                  source_extension_id));
 395
 396   // Get handle of the native view and pass it to the native messaging host.
 397   gfx::NativeView native_view =
 398       content::RenderWidgetHost::FromID(source_process_id, source_routing_id)->
 399           GetView()->GetNativeView();
 400
 401   scoped_ptr<NativeMessageProcessHost> native_process =
 402       NativeMessageProcessHost::Create(
 403           native_view,
 404           base::WeakPtr<NativeMessageProcessHost::Client>(
 405               weak_factory_.GetWeakPtr()),
 406           source_extension_id, native_app_name, receiver_port_id,
 407           policy_permission == NativeMessageProcessHost::ALLOW_ALL);
 408
 409   // Abandon the channel.
 410   if (!native_process.get()) {
 411     LOG(ERROR) << "Failed to create native process.";
 412     DispatchOnDisconnect(
 413         source, receiver_port_id, kReceivingEndDoesntExistError);
 414     return;
 415   }
 416   channel->receiver.reset(new NativeMessagePort(native_process.release()));
 417
 418   // Keep the opener alive until the channel is closed.
 419   channel->opener->IncrementLazyKeepaliveCount();
 420
 421   AddChannel(channel.release(), receiver_port_id);
 422 #else  // !(defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX))
 423   const char kNativeMessagingNotSupportedError[] =
 424       "Native Messaging is not supported on this platform.";
 425   DispatchOnDisconnect(
 426       source, receiver_port_id, kNativeMessagingNotSupportedError);
 427 #endif  // !(defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX))
 428 }
 429
 430 void MessageService::OpenChannelToTab(
 431     int source_process_id, int source_routing_id, int receiver_port_id,
 432     int tab_id, const std::string& extension_id,
 433     const std::string& channel_name) {
 434   content::RenderProcessHost* source =
 435       content::RenderProcessHost::FromID(source_process_id);
 436   if (!source)
 437     return;
 438   Profile* profile = Profile::FromBrowserContext(source->GetBrowserContext());
 439
 440   WebContents* contents = NULL;
 441   scoped_ptr<MessagePort> receiver;
 442   if (ExtensionTabUtil::GetTabById(tab_id, profile, true,
 443                                    NULL, NULL, &contents, NULL)) {
 444     receiver.reset(new ExtensionMessagePort(
 445         contents->GetRenderProcessHost(),
 446         contents->GetRenderViewHost()->GetRoutingID(),
 447         extension_id));
 448   }
 449
 450   if (contents && contents->GetController().NeedsReload()) {
 451     // The tab isn't loaded yet. Don't attempt to connect.
 452     DispatchOnDisconnect(
 453         source, receiver_port_id, kReceivingEndDoesntExistError);
 454     return;
 455   }
 456
 457   scoped_ptr<OpenChannelParams> params(new OpenChannelParams(
 458         source,
 459         scoped_ptr<base::DictionaryValue>(),  // Source tab doesn't make sense
 460                                               // for opening to tabs.
 461         receiver.release(),
 462         receiver_port_id,
 463         extension_id,
 464         extension_id,
 465         GURL(),  // Source URL doesn't make sense for opening to tabs.
 466         channel_name,
 467         false));  // Connections to tabs don't get TLS channel IDs.
 468   OpenChannelImpl(params.Pass());
 469 }
 470
 471 bool MessageService::OpenChannelImpl(scoped_ptr<OpenChannelParams> params) {
 472   if (!params->source)
 473     return false;  // Closed while in flight.
 474
 475   if (!params->receiver || !params->receiver->GetRenderProcessHost()) {
 476     DispatchOnDisconnect(params->source,
 477                          params->receiver_port_id,
 478                          kReceivingEndDoesntExistError);
 479     return false;
 480   }
 481
 482   // Add extra paranoid CHECKs, since we have crash reports of this being NULL.
 483   // http://code.google.com/p/chromium/issues/detail?id=19067
 484   CHECK(params->receiver->GetRenderProcessHost());
 485
 486   MessageChannel* channel(new MessageChannel);
 487   channel->opener.reset(new ExtensionMessagePort(params->source,
 488                                                  MSG_ROUTING_CONTROL,
 489                                                  params->source_extension_id));
 490   channel->receiver.reset(params->receiver.release());
 491
 492   CHECK(channel->receiver->GetRenderProcessHost());
 493
 494   AddChannel(channel, params->receiver_port_id);
 495
 496   CHECK(channel->receiver->GetRenderProcessHost());
 497
 498   // Send the connect event to the receiver.  Give it the opener's port ID (the
 499   // opener has the opposite port ID).
 500   channel->receiver->DispatchOnConnect(params->receiver_port_id,
 501                                        params->channel_name,
 502                                        params->source_tab,
 503                                        params->source_extension_id,
 504                                        params->target_extension_id,
 505                                        params->source_url,
 506                                        params->tls_channel_id);
 507
 508   // Keep both ends of the channel alive until the channel is closed.
 509   channel->opener->IncrementLazyKeepaliveCount();
 510   channel->receiver->IncrementLazyKeepaliveCount();
 511   return true;
 512 }
 513
 514 void MessageService::AddChannel(MessageChannel* channel, int receiver_port_id) {
 515   int channel_id = GET_CHANNEL_ID(receiver_port_id);
 516   CHECK(channels_.find(channel_id) == channels_.end());
 517   channels_[channel_id] = channel;
 518   pending_lazy_background_page_channels_.erase(channel_id);
 519 }
 520
 521 void MessageService::CloseChannel(int port_id,
 522                                   const std::string& error_message) {
 523   // Note: The channel might be gone already, if the other side closed first.
 524   int channel_id = GET_CHANNEL_ID(port_id);
 525   MessageChannelMap::iterator it = channels_.find(channel_id);
 526   if (it == channels_.end()) {
 527     PendingLazyBackgroundPageChannelMap::iterator pending =
 528         pending_lazy_background_page_channels_.find(channel_id);
 529     if (pending != pending_lazy_background_page_channels_.end()) {
 530       lazy_background_task_queue_->AddPendingTask(
 531           pending->second.first, pending->second.second,
 532           base::Bind(&MessageService::PendingLazyBackgroundPageCloseChannel,
 533                      weak_factory_.GetWeakPtr(), port_id, error_message));
 534     }
 535     return;
 536   }
 537   CloseChannelImpl(it, port_id, error_message, true);
 538 }
 539
 540 void MessageService::CloseChannelImpl(
 541     MessageChannelMap::iterator channel_iter,
 542     int closing_port_id,
 543     const std::string& error_message,
 544     bool notify_other_port) {
 545   MessageChannel* channel = channel_iter->second;
 546
 547   // Notify the other side.
 548   if (notify_other_port) {
 549     MessagePort* port = IS_OPENER_PORT_ID(closing_port_id) ?
 550         channel->receiver.get() : channel->opener.get();
 551     port->DispatchOnDisconnect(GET_OPPOSITE_PORT_ID(closing_port_id),
 552                                error_message);
 553   }
 554
 555   // Balance the IncrementLazyKeepaliveCount() in OpenChannelImpl.
 556   channel->opener->DecrementLazyKeepaliveCount();
 557   channel->receiver->DecrementLazyKeepaliveCount();
 558
 559   delete channel_iter->second;
 560   channels_.erase(channel_iter);
 561 }
 562
 563 void MessageService::PostMessage(int source_port_id, const Message& message) {
 564   int channel_id = GET_CHANNEL_ID(source_port_id);
 565   MessageChannelMap::iterator iter = channels_.find(channel_id);
 566   if (iter == channels_.end()) {
 567     // If this channel is pending, queue up the PostMessage to run once
 568     // the channel opens.
 569     EnqueuePendingMessage(source_port_id, channel_id, message);
 570     return;
 571   }
 572
 573   DispatchMessage(source_port_id, iter->second, message);
 574 }
 575
 576 void MessageService::PostMessageFromNativeProcess(int port_id,
 577                                                   const std::string& message) {
 578   PostMessage(port_id, Message(message, false /* user_gesture */));
 579 }
 580
 581 void MessageService::Observe(int type,
 582                              const content::NotificationSource& source,
 583                              const content::NotificationDetails& details) {
 584   switch (type) {
 585     case content::NOTIFICATION_RENDERER_PROCESS_TERMINATED:
 586     case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
 587       content::RenderProcessHost* renderer =
 588           content::Source<content::RenderProcessHost>(source).ptr();
 589       OnProcessClosed(renderer);
 590       break;
 591     }
 592     default:
 593       NOTREACHED();
 594       return;
 595   }
 596 }
 597
 598 void MessageService::OnProcessClosed(content::RenderProcessHost* process) {
 599   // Close any channels that share this renderer.  We notify the opposite
 600   // port that his pair has closed.
 601   for (MessageChannelMap::iterator it = channels_.begin();
 602        it != channels_.end(); ) {
 603     MessageChannelMap::iterator current = it++;
 604
 605     content::RenderProcessHost* opener_process =
 606         current->second->opener->GetRenderProcessHost();
 607     content::RenderProcessHost* receiver_process =
 608         current->second->receiver->GetRenderProcessHost();
 609
 610     // Only notify the other side if it has a different porocess host.
 611     bool notify_other_port = opener_process && receiver_process &&
 612         opener_process != receiver_process;
 613
 614     if (opener_process == process) {
 615       CloseChannelImpl(current, GET_CHANNEL_OPENER_ID(current->first),
 616                        std::string(), notify_other_port);
 617     } else if (receiver_process == process) {
 618       CloseChannelImpl(current, GET_CHANNEL_RECEIVERS_ID(current->first),
 619                        std::string(), notify_other_port);
 620     }
 621   }
 622 }
 623
 624 void MessageService::EnqueuePendingMessage(int source_port_id,
 625                                            int channel_id,
 626                                            const Message& message) {
 627   PendingTlsChannelIdMap::iterator pending_for_tls_channel_id =
 628       pending_tls_channel_id_channels_.find(channel_id);
 629   if (pending_for_tls_channel_id != pending_tls_channel_id_channels_.end()) {
 630     pending_for_tls_channel_id->second.push_back(
 631         PendingMessage(source_port_id, message));
 632     // Pending messages must only be pending the TLS channel ID or lazy
 633     // background page loading, never both.
 634     return;
 635   }
 636   EnqueuePendingMessageForLazyBackgroundLoad(source_port_id,
 637                                              channel_id,
 638                                              message);
 639 }
 640
 641 void MessageService::EnqueuePendingMessageForLazyBackgroundLoad(
 642     int source_port_id,
 643     int channel_id,
 644     const Message& message) {
 645   PendingLazyBackgroundPageChannelMap::iterator pending =
 646       pending_lazy_background_page_channels_.find(channel_id);
 647   if (pending != pending_lazy_background_page_channels_.end()) {
 648     lazy_background_task_queue_->AddPendingTask(
 649         pending->second.first, pending->second.second,
 650         base::Bind(&MessageService::PendingLazyBackgroundPagePostMessage,
 651                    weak_factory_.GetWeakPtr(), source_port_id, message));
 652   }
 653 }
 654
 655 void MessageService::DispatchMessage(int source_port_id,
 656                                      MessageChannel* channel,
 657                                      const Message& message) {
 658   // Figure out which port the ID corresponds to.
 659   int dest_port_id = GET_OPPOSITE_PORT_ID(source_port_id);
 660   MessagePort* port = IS_OPENER_PORT_ID(dest_port_id) ?
 661       channel->opener.get() : channel->receiver.get();
 662
 663   port->DispatchOnMessage(message, dest_port_id);
 664 }
 665
 666 bool MessageService::MaybeAddPendingLazyBackgroundPageOpenChannelTask(
 667     BrowserContext* context,
 668     const Extension* extension,
 669     OpenChannelParams* params) {
 670   if (!BackgroundInfo::HasLazyBackgroundPage(extension))
 671     return false;
 672
 673   // If the extension uses spanning incognito mode, make sure we're always
 674   // using the original profile since that is what the extension process
 675   // will use.
 676   if (!IncognitoInfo::IsSplitMode(extension))
 677     context = ExtensionsBrowserClient::Get()->GetOriginalContext(context);
 678
 679   if (!lazy_background_task_queue_->ShouldEnqueueTask(context, extension))
 680     return false;
 681
 682   pending_lazy_background_page_channels_
 683       [GET_CHANNEL_ID(params->receiver_port_id)] =
 684           PendingLazyBackgroundPageChannel(context, extension->id());
 685   scoped_ptr<OpenChannelParams> scoped_params(params);
 686   lazy_background_task_queue_->AddPendingTask(
 687       context,
 688       extension->id(),
 689       base::Bind(&MessageService::PendingLazyBackgroundPageOpenChannel,
 690                  weak_factory_.GetWeakPtr(),
 691                  base::Passed(&scoped_params),
 692                  params->source->GetID()));
 693   return true;
 694 }
 695
 696 void MessageService::GotDomainBoundCert(scoped_ptr<OpenChannelParams> params,
 697                                         const std::string& tls_channel_id) {
 698   params->tls_channel_id.assign(tls_channel_id);
 699   int channel_id = GET_CHANNEL_ID(params->receiver_port_id);
 700
 701   PendingTlsChannelIdMap::iterator pending_for_tls_channel_id =
 702       pending_tls_channel_id_channels_.find(channel_id);
 703   if (pending_for_tls_channel_id == pending_tls_channel_id_channels_.end()) {
 704     NOTREACHED();
 705     return;
 706   }
 707
 708   BrowserContext* context = params->source->GetBrowserContext();
 709
 710   const Extension* target_extension =
 711       ExtensionSystem::Get(context)->extension_service()->extensions()->GetByID(
 712           params->target_extension_id);
 713   if (!target_extension) {
 714     pending_tls_channel_id_channels_.erase(channel_id);
 715     DispatchOnDisconnect(
 716         params->source, params->receiver_port_id,
 717         kReceivingEndDoesntExistError);
 718     return;
 719   }
 720   PendingMessagesQueue& pending_messages = pending_for_tls_channel_id->second;
 721   if (MaybeAddPendingLazyBackgroundPageOpenChannelTask(
 722           context, target_extension, params.get())) {
 723     // Lazy background queue took ownership. Release ours.
 724     ignore_result(params.release());
 725     // Messages queued up waiting for the TLS channel ID now need to be queued
 726     // up for the lazy background page to load.
 727     for (PendingMessagesQueue::iterator it = pending_messages.begin();
 728          it != pending_messages.end();
 729          it++) {
 730       EnqueuePendingMessageForLazyBackgroundLoad(it->first, channel_id,
 731                                                  it->second);
 732     }
 733   } else {
 734     OpenChannelImpl(params.Pass());
 735     // Messages queued up waiting for the TLS channel ID can be posted now.
 736     MessageChannelMap::iterator channel_iter = channels_.find(channel_id);
 737     if (channel_iter != channels_.end()) {
 738       for (PendingMessagesQueue::iterator it = pending_messages.begin();
 739            it != pending_messages.end();
 740            it++) {
 741         DispatchMessage(it->first, channel_iter->second, it->second);
 742       }
 743     }
 744   }
 745   pending_tls_channel_id_channels_.erase(channel_id);
 746 }
 747
 748 void MessageService::PendingLazyBackgroundPageOpenChannel(
 749     scoped_ptr<OpenChannelParams> params,
 750     int source_process_id,
 751     ExtensionHost* host) {
 752   if (!host)
 753     return;  // TODO(mpcomplete): notify source of disconnect?
 754
 755   // Re-lookup the source process since it may no longer be valid.
 756   content::RenderProcessHost* source =
 757       content::RenderProcessHost::FromID(source_process_id);
 758   if (!source)
 759     return;
 760
 761   params->source = source;
 762   params->receiver.reset(new ExtensionMessagePort(host->render_process_host(),
 763                                                   MSG_ROUTING_CONTROL,
 764                                                   params->target_extension_id));
 765   OpenChannelImpl(params.Pass());
 766 }
 767
 768 void MessageService::DispatchOnDisconnect(content::RenderProcessHost* source,
 769                                           int port_id,
 770                                           const std::string& error_message) {
 771   ExtensionMessagePort port(source, MSG_ROUTING_CONTROL, "");
 772   port.DispatchOnDisconnect(GET_OPPOSITE_PORT_ID(port_id), error_message);
 773 }
 774
 775 }  // namespace extensions