chrome/browser/custom_handlers/protocol_handler_registry.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/custom_handlers/protocol_handler_registry.h"
   6
   7 #include <utility>
   8
   9 #include "base/bind.h"
  10 #include "base/command_line.h"
  11 #include "base/logging.h"
  12 #include "base/prefs/pref_service.h"
  13 #include "chrome/browser/chrome_notification_types.h"
  14 #include "chrome/browser/custom_handlers/register_protocol_handler_infobar_delegate.h"
  15 #include "chrome/browser/net/chrome_url_request_context.h"
  16 #include "chrome/browser/profiles/profile_io_data.h"
  17 #include "chrome/common/chrome_switches.h"
  18 #include "chrome/common/custom_handlers/protocol_handler.h"
  19 #include "chrome/common/pref_names.h"
  20 #include "components/user_prefs/pref_registry_syncable.h"
  21 #include "content/public/browser/child_process_security_policy.h"
  22 #include "grit/generated_resources.h"
  23 #include "net/base/network_delegate.h"
  24 #include "net/url_request/url_request_redirect_job.h"
  25 #include "ui/base/l10n/l10n_util.h"
  26
  27 using content::BrowserThread;
  28 using content::ChildProcessSecurityPolicy;
  29
  30 namespace {
  31
  32 const ProtocolHandler& LookupHandler(
  33     const ProtocolHandlerRegistry::ProtocolHandlerMap& handler_map,
  34     const std::string& scheme) {
  35   ProtocolHandlerRegistry::ProtocolHandlerMap::const_iterator p =
  36       handler_map.find(scheme);
  37
  38   if (p != handler_map.end())
  39     return p->second;
  40
  41   return ProtocolHandler::EmptyProtocolHandler();
  42 }
  43
  44 // If true default protocol handlers will be removed if the OS level
  45 // registration for a protocol is no longer Chrome.
  46 bool ShouldRemoveHandlersNotInOS() {
  47 #if defined(OS_LINUX)
  48   // We don't do this on Linux as the OS registration there is not reliable,
  49   // and Chrome OS doesn't have any notion of OS registration.
  50   // TODO(benwells): When Linux support is more reliable remove this
  51   // difference (http://crbug.com/88255).
  52   return false;
  53 #else
  54   return ShellIntegration::CanSetAsDefaultProtocolClient() !=
  55       ShellIntegration::SET_DEFAULT_NOT_ALLOWED;
  56 #endif
  57 }
  58
  59 }  // namespace
  60
  61 // IOThreadDelegate ------------------------------------------------------------
  62
  63 // IOThreadDelegate is an IO thread specific object. Access to the class should
  64 // all be done via the IO thread. The registry living on the UI thread makes
  65 // a best effort to update the IO object after local updates are completed.
  66 class ProtocolHandlerRegistry::IOThreadDelegate
  67     : public base::RefCountedThreadSafe<
  68           ProtocolHandlerRegistry::IOThreadDelegate> {
  69  public:
  70
  71   // Creates a new instance. If |enabled| is true the registry is considered
  72   // enabled on the IO thread.
  73   explicit IOThreadDelegate(bool enabled);
  74
  75   // Returns true if the protocol has a default protocol handler.
  76   // Should be called only from the IO thread.
  77   bool IsHandledProtocol(const std::string& scheme) const;
  78
  79   // Clears the default for the provided protocol.
  80   // Should be called only from the IO thread.
  81   void ClearDefault(const std::string& scheme);
  82
  83   // Makes this ProtocolHandler the default handler for its protocol.
  84   // Should be called only from the IO thread.
  85   void SetDefault(const ProtocolHandler& handler);
  86
  87   // Creates a URL request job for the given request if there is a matching
  88   // protocol handler, returns NULL otherwise.
  89   net::URLRequestJob* MaybeCreateJob(
  90       net::URLRequest* request, net::NetworkDelegate* network_delegate) const;
  91
  92   // Indicate that the registry has been enabled in the IO thread's
  93   // copy of the data.
  94   void Enable() { enabled_ = true; }
  95
  96   // Indicate that the registry has been disabled in the IO thread's copy of
  97   // the data.
  98   void Disable() { enabled_ = false; }
  99
 100  private:
 101   friend class base::RefCountedThreadSafe<IOThreadDelegate>;
 102   virtual ~IOThreadDelegate();
 103
 104   // Copy of protocol handlers use only on the IO thread.
 105   ProtocolHandlerRegistry::ProtocolHandlerMap default_handlers_;
 106
 107   // Is the registry enabled on the IO thread.
 108   bool enabled_;
 109
 110   DISALLOW_COPY_AND_ASSIGN(IOThreadDelegate);
 111 };
 112
 113 ProtocolHandlerRegistry::IOThreadDelegate::IOThreadDelegate(bool)
 114     : enabled_(true) {}
 115 ProtocolHandlerRegistry::IOThreadDelegate::~IOThreadDelegate() {}
 116
 117 bool ProtocolHandlerRegistry::IOThreadDelegate::IsHandledProtocol(
 118     const std::string& scheme) const {
 119   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 120   return enabled_ && !LookupHandler(default_handlers_, scheme).IsEmpty();
 121 }
 122
 123 void ProtocolHandlerRegistry::IOThreadDelegate::ClearDefault(
 124     const std::string& scheme) {
 125   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 126   default_handlers_.erase(scheme);
 127 }
 128
 129 void ProtocolHandlerRegistry::IOThreadDelegate::SetDefault(
 130     const ProtocolHandler& handler) {
 131   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 132   ClearDefault(handler.protocol());
 133   default_handlers_.insert(std::make_pair(handler.protocol(), handler));
 134 }
 135
 136 // Create a new job for the supplied |URLRequest| if a default handler
 137 // is registered and the associated handler is able to interpret
 138 // the url from |request|.
 139 net::URLRequestJob* ProtocolHandlerRegistry::IOThreadDelegate::MaybeCreateJob(
 140     net::URLRequest* request, net::NetworkDelegate* network_delegate) const {
 141   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 142
 143   ProtocolHandler handler = LookupHandler(default_handlers_,
 144                                           request->url().scheme());
 145   if (handler.IsEmpty())
 146     return NULL;
 147
 148   GURL translated_url(handler.TranslateUrl(request->url()));
 149   if (!translated_url.is_valid())
 150     return NULL;
 151
 152   return new net::URLRequestRedirectJob(
 153       request, network_delegate, translated_url,
 154       net::URLRequestRedirectJob::REDIRECT_307_TEMPORARY_REDIRECT);
 155 }
 156
 157 // JobInterceptorFactory -------------------------------------------------------
 158
 159 // Instances of JobInterceptorFactory are produced for ownership by the IO
 160 // thread where it handler URL requests. We should never hold
 161 // any pointers on this class, only produce them in response to
 162 // requests via |ProtocolHandlerRegistry::CreateJobInterceptorFactory|.
 163 ProtocolHandlerRegistry::JobInterceptorFactory::JobInterceptorFactory(
 164     IOThreadDelegate* io_thread_delegate)
 165     : io_thread_delegate_(io_thread_delegate) {
 166   DCHECK(io_thread_delegate_.get());
 167   DetachFromThread();
 168 }
 169
 170 ProtocolHandlerRegistry::JobInterceptorFactory::~JobInterceptorFactory() {
 171 }
 172
 173 void ProtocolHandlerRegistry::JobInterceptorFactory::Chain(
 174     scoped_ptr<net::URLRequestJobFactory> job_factory) {
 175   job_factory_ = job_factory.Pass();
 176 }
 177
 178 net::URLRequestJob*
 179 ProtocolHandlerRegistry::JobInterceptorFactory::
 180 MaybeCreateJobWithProtocolHandler(
 181     const std::string& scheme,
 182     net::URLRequest* request,
 183     net::NetworkDelegate* network_delegate) const {
 184   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 185   net::URLRequestJob* job = io_thread_delegate_->MaybeCreateJob(
 186       request, network_delegate);
 187   if (job)
 188     return job;
 189   return job_factory_->MaybeCreateJobWithProtocolHandler(
 190       scheme, request, network_delegate);
 191 }
 192
 193 bool ProtocolHandlerRegistry::JobInterceptorFactory::IsHandledProtocol(
 194     const std::string& scheme) const {
 195   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 196   return io_thread_delegate_->IsHandledProtocol(scheme) ||
 197       job_factory_->IsHandledProtocol(scheme);
 198 }
 199
 200 bool ProtocolHandlerRegistry::JobInterceptorFactory::IsHandledURL(
 201     const GURL& url) const {
 202   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 203   return (url.is_valid() &&
 204       io_thread_delegate_->IsHandledProtocol(url.scheme())) ||
 205       job_factory_->IsHandledURL(url);
 206 }
 207
 208 bool ProtocolHandlerRegistry::JobInterceptorFactory::IsSafeRedirectTarget(
 209     const GURL& location) const {
 210   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 211   return job_factory_->IsSafeRedirectTarget(location);
 212 }
 213
 214 // DefaultClientObserver ------------------------------------------------------
 215
 216 ProtocolHandlerRegistry::DefaultClientObserver::DefaultClientObserver(
 217     ProtocolHandlerRegistry* registry)
 218     : worker_(NULL),
 219       registry_(registry) {
 220   DCHECK(registry_);
 221 }
 222
 223 ProtocolHandlerRegistry::DefaultClientObserver::~DefaultClientObserver() {
 224   if (worker_)
 225     worker_->ObserverDestroyed();
 226
 227   DefaultClientObserverList::iterator iter = std::find(
 228       registry_->default_client_observers_.begin(),
 229       registry_->default_client_observers_.end(), this);
 230   registry_->default_client_observers_.erase(iter);
 231 }
 232
 233 void ProtocolHandlerRegistry::DefaultClientObserver::SetDefaultWebClientUIState(
 234     ShellIntegration::DefaultWebClientUIState state) {
 235   if (worker_) {
 236     if (ShouldRemoveHandlersNotInOS() &&
 237         (state == ShellIntegration::STATE_NOT_DEFAULT)) {
 238       registry_->ClearDefault(worker_->protocol());
 239     }
 240   } else {
 241     NOTREACHED();
 242   }
 243 }
 244
 245 bool ProtocolHandlerRegistry::DefaultClientObserver::
 246     IsInteractiveSetDefaultPermitted() {
 247   return true;
 248 }
 249
 250 void ProtocolHandlerRegistry::DefaultClientObserver::SetWorker(
 251     ShellIntegration::DefaultProtocolClientWorker* worker) {
 252   worker_ = worker;
 253 }
 254
 255 bool ProtocolHandlerRegistry::DefaultClientObserver::IsOwnedByWorker() {
 256   return true;
 257 }
 258
 259 // Delegate --------------------------------------------------------------------
 260
 261 ProtocolHandlerRegistry::Delegate::~Delegate() {}
 262
 263 void ProtocolHandlerRegistry::Delegate::RegisterExternalHandler(
 264     const std::string& protocol) {
 265   ChildProcessSecurityPolicy* policy =
 266     ChildProcessSecurityPolicy::GetInstance();
 267   if (!policy->IsWebSafeScheme(protocol)) {
 268     policy->RegisterWebSafeScheme(protocol);
 269   }
 270 }
 271
 272 void ProtocolHandlerRegistry::Delegate::DeregisterExternalHandler(
 273     const std::string& protocol) {
 274 }
 275
 276 bool ProtocolHandlerRegistry::Delegate::IsExternalHandlerRegistered(
 277     const std::string& protocol) {
 278   // NOTE(koz): This function is safe to call from any thread, despite living
 279   // in ProfileIOData.
 280   return ProfileIOData::IsHandledProtocol(protocol);
 281 }
 282
 283 ShellIntegration::DefaultProtocolClientWorker*
 284 ProtocolHandlerRegistry::Delegate::CreateShellWorker(
 285     ShellIntegration::DefaultWebClientObserver* observer,
 286     const std::string& protocol) {
 287   return new ShellIntegration::DefaultProtocolClientWorker(observer, protocol);
 288 }
 289
 290 ProtocolHandlerRegistry::DefaultClientObserver*
 291 ProtocolHandlerRegistry::Delegate::CreateShellObserver(
 292     ProtocolHandlerRegistry* registry) {
 293   return new DefaultClientObserver(registry);
 294 }
 295
 296 void ProtocolHandlerRegistry::Delegate::RegisterWithOSAsDefaultClient(
 297     const std::string& protocol, ProtocolHandlerRegistry* registry) {
 298   DefaultClientObserver* observer = CreateShellObserver(registry);
 299   // The worker pointer is reference counted. While it is running the
 300   // message loops of the FILE and UI thread will hold references to it
 301   // and it will be automatically freed once all its tasks have finished.
 302   scoped_refptr<ShellIntegration::DefaultProtocolClientWorker> worker;
 303   worker = CreateShellWorker(observer, protocol);
 304   observer->SetWorker(worker.get());
 305   registry->default_client_observers_.push_back(observer);
 306   worker->StartSetAsDefault();
 307 }
 308
 309 // ProtocolHandlerRegistry -----------------------------------------------------
 310
 311 ProtocolHandlerRegistry::ProtocolHandlerRegistry(Profile* profile,
 312     Delegate* delegate)
 313     : profile_(profile),
 314       delegate_(delegate),
 315       enabled_(true),
 316       is_loading_(false),
 317       is_loaded_(false),
 318       io_thread_delegate_(new IOThreadDelegate(enabled_)){
 319 }
 320
 321 bool ProtocolHandlerRegistry::SilentlyHandleRegisterHandlerRequest(
 322     const ProtocolHandler& handler) {
 323   if (handler.IsEmpty() || !CanSchemeBeOverridden(handler.protocol()))
 324     return true;
 325
 326   if (!enabled() || IsRegistered(handler) || HasIgnoredEquivalent(handler))
 327     return true;
 328
 329   if (AttemptReplace(handler))
 330     return true;
 331
 332   return false;
 333 }
 334
 335 void ProtocolHandlerRegistry::OnAcceptRegisterProtocolHandler(
 336     const ProtocolHandler& handler) {
 337   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 338   RegisterProtocolHandler(handler);
 339   SetDefault(handler);
 340   Save();
 341   NotifyChanged();
 342 }
 343
 344 void ProtocolHandlerRegistry::OnDenyRegisterProtocolHandler(
 345     const ProtocolHandler& handler) {
 346   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 347   RegisterProtocolHandler(handler);
 348   Save();
 349   NotifyChanged();
 350 }
 351
 352 void ProtocolHandlerRegistry::OnIgnoreRegisterProtocolHandler(
 353     const ProtocolHandler& handler) {
 354   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 355   IgnoreProtocolHandler(handler);
 356   Save();
 357   NotifyChanged();
 358 }
 359
 360 bool ProtocolHandlerRegistry::AttemptReplace(const ProtocolHandler& handler) {
 361   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 362   ProtocolHandler old_default = GetHandlerFor(handler.protocol());
 363   bool make_new_handler_default = handler.IsSameOrigin(old_default);
 364   ProtocolHandlerList to_replace(GetReplacedHandlers(handler));
 365   if (to_replace.empty())
 366     return false;
 367   for (ProtocolHandlerList::iterator p = to_replace.begin();
 368        p != to_replace.end(); ++p) {
 369     RemoveHandler(*p);
 370   }
 371   if (make_new_handler_default) {
 372     OnAcceptRegisterProtocolHandler(handler);
 373   } else {
 374     InsertHandler(handler);
 375     NotifyChanged();
 376   }
 377   return true;
 378 }
 379
 380 ProtocolHandlerRegistry::ProtocolHandlerList
 381 ProtocolHandlerRegistry::GetReplacedHandlers(
 382     const ProtocolHandler& handler) const {
 383   ProtocolHandlerList replaced_handlers;
 384   const ProtocolHandlerList* handlers = GetHandlerList(handler.protocol());
 385   if (!handlers)
 386     return replaced_handlers;
 387   for (ProtocolHandlerList::const_iterator p = handlers->begin();
 388        p != handlers->end(); p++) {
 389     if (handler.IsSameOrigin(*p)) {
 390       replaced_handlers.push_back(*p);
 391     }
 392   }
 393   return replaced_handlers;
 394 }
 395
 396 void ProtocolHandlerRegistry::ClearDefault(const std::string& scheme) {
 397   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 398
 399   default_handlers_.erase(scheme);
 400   BrowserThread::PostTask(
 401       BrowserThread::IO,
 402       FROM_HERE,
 403       base::Bind(&IOThreadDelegate::ClearDefault, io_thread_delegate_, scheme));
 404   Save();
 405   NotifyChanged();
 406 }
 407
 408 bool ProtocolHandlerRegistry::IsDefault(
 409     const ProtocolHandler& handler) const {
 410   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 411   return GetHandlerFor(handler.protocol()) == handler;
 412 }
 413
 414 void ProtocolHandlerRegistry::InstallDefaultsForChromeOS() {
 415 #if defined(OS_CHROMEOS)
 416   // Only chromeos has default protocol handlers at this point.
 417   AddPredefinedHandler(
 418       ProtocolHandler::CreateProtocolHandler(
 419           "mailto",
 420           GURL(l10n_util::GetStringUTF8(IDS_GOOGLE_MAILTO_HANDLER_URL)),
 421           l10n_util::GetStringUTF16(IDS_GOOGLE_MAILTO_HANDLER_NAME)));
 422   AddPredefinedHandler(
 423       ProtocolHandler::CreateProtocolHandler(
 424           "webcal",
 425           GURL(l10n_util::GetStringUTF8(IDS_GOOGLE_WEBCAL_HANDLER_URL)),
 426           l10n_util::GetStringUTF16(IDS_GOOGLE_WEBCAL_HANDLER_NAME)));
 427 #else
 428   NOTREACHED();  // this method should only ever be called in chromeos.
 429 #endif
 430 }
 431
 432 void ProtocolHandlerRegistry::InitProtocolSettings() {
 433   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 434
 435   // Any further default additions to the table will get rejected from now on.
 436   is_loaded_ = true;
 437   is_loading_ = true;
 438
 439   PrefService* prefs = profile_->GetPrefs();
 440   if (prefs->HasPrefPath(prefs::kCustomHandlersEnabled)) {
 441     if (prefs->GetBoolean(prefs::kCustomHandlersEnabled)) {
 442       Enable();
 443     } else {
 444       Disable();
 445     }
 446   }
 447   std::vector<const base::DictionaryValue*> registered_handlers =
 448       GetHandlersFromPref(prefs::kRegisteredProtocolHandlers);
 449   for (std::vector<const base::DictionaryValue*>::const_iterator p =
 450        registered_handlers.begin();
 451        p != registered_handlers.end(); ++p) {
 452     ProtocolHandler handler = ProtocolHandler::CreateProtocolHandler(*p);
 453     RegisterProtocolHandler(handler);
 454     bool is_default = false;
 455     if ((*p)->GetBoolean("default", &is_default) && is_default) {
 456       SetDefault(handler);
 457     }
 458   }
 459   std::vector<const base::DictionaryValue*> ignored_handlers =
 460     GetHandlersFromPref(prefs::kIgnoredProtocolHandlers);
 461   for (std::vector<const base::DictionaryValue*>::const_iterator p =
 462        ignored_handlers.begin();
 463        p != ignored_handlers.end(); ++p) {
 464     IgnoreProtocolHandler(ProtocolHandler::CreateProtocolHandler(*p));
 465   }
 466   is_loading_ = false;
 467
 468   // For each default protocol handler, check that we are still registered
 469   // with the OS as the default application.
 470   if (ShouldRemoveHandlersNotInOS()) {
 471     for (ProtocolHandlerMap::const_iterator p = default_handlers_.begin();
 472          p != default_handlers_.end(); ++p) {
 473       ProtocolHandler handler = p->second;
 474       DefaultClientObserver* observer = delegate_->CreateShellObserver(this);
 475       scoped_refptr<ShellIntegration::DefaultProtocolClientWorker> worker;
 476       worker = delegate_->CreateShellWorker(observer, handler.protocol());
 477       observer->SetWorker(worker.get());
 478       default_client_observers_.push_back(observer);
 479       worker->StartCheckIsDefault();
 480     }
 481   }
 482 }
 483
 484 int ProtocolHandlerRegistry::GetHandlerIndex(const std::string& scheme) const {
 485   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 486   const ProtocolHandler& handler = GetHandlerFor(scheme);
 487   if (handler.IsEmpty())
 488     return -1;
 489   const ProtocolHandlerList* handlers = GetHandlerList(scheme);
 490   if (!handlers)
 491     return -1;
 492
 493   ProtocolHandlerList::const_iterator p;
 494   int i;
 495   for (i = 0, p = handlers->begin(); p != handlers->end(); ++p, ++i) {
 496     if (*p == handler)
 497       return i;
 498   }
 499   return -1;
 500 }
 501
 502 ProtocolHandlerRegistry::ProtocolHandlerList
 503 ProtocolHandlerRegistry::GetHandlersFor(
 504     const std::string& scheme) const {
 505   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 506   ProtocolHandlerMultiMap::const_iterator p = protocol_handlers_.find(scheme);
 507   if (p == protocol_handlers_.end()) {
 508     return ProtocolHandlerList();
 509   }
 510   return p->second;
 511 }
 512
 513 ProtocolHandlerRegistry::ProtocolHandlerList
 514 ProtocolHandlerRegistry::GetIgnoredHandlers() {
 515   return ignored_protocol_handlers_;
 516 }
 517
 518 void ProtocolHandlerRegistry::GetRegisteredProtocols(
 519     std::vector<std::string>* output) const {
 520   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 521   ProtocolHandlerMultiMap::const_iterator p;
 522   for (p = protocol_handlers_.begin(); p != protocol_handlers_.end(); ++p) {
 523     if (!p->second.empty())
 524       output->push_back(p->first);
 525   }
 526 }
 527
 528 bool ProtocolHandlerRegistry::CanSchemeBeOverridden(
 529     const std::string& scheme) const {
 530   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 531   const ProtocolHandlerList* handlers = GetHandlerList(scheme);
 532   // If we already have a handler for this scheme, we can add more.
 533   if (handlers != NULL && !handlers->empty())
 534     return true;
 535   // Don't override a scheme if it already has an external handler.
 536   return !delegate_->IsExternalHandlerRegistered(scheme);
 537 }
 538
 539 bool ProtocolHandlerRegistry::IsRegistered(
 540     const ProtocolHandler& handler) const {
 541   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 542   const ProtocolHandlerList* handlers = GetHandlerList(handler.protocol());
 543   if (!handlers) {
 544     return false;
 545   }
 546   return std::find(handlers->begin(), handlers->end(), handler) !=
 547       handlers->end();
 548 }
 549
 550 bool ProtocolHandlerRegistry::IsIgnored(const ProtocolHandler& handler) const {
 551   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 552   ProtocolHandlerList::const_iterator i;
 553   for (i = ignored_protocol_handlers_.begin();
 554        i != ignored_protocol_handlers_.end(); ++i) {
 555     if (*i == handler) {
 556       return true;
 557     }
 558   }
 559   return false;
 560 }
 561
 562 bool ProtocolHandlerRegistry::HasRegisteredEquivalent(
 563     const ProtocolHandler& handler) const {
 564   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 565   const ProtocolHandlerList* handlers = GetHandlerList(handler.protocol());
 566   if (!handlers) {
 567     return false;
 568   }
 569   ProtocolHandlerList::const_iterator i;
 570   for (i = handlers->begin(); i != handlers->end(); ++i) {
 571     if (handler.IsEquivalent(*i)) {
 572       return true;
 573     }
 574   }
 575   return false;
 576 }
 577
 578 bool ProtocolHandlerRegistry::HasIgnoredEquivalent(
 579     const ProtocolHandler& handler) const {
 580   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 581   ProtocolHandlerList::const_iterator i;
 582   for (i = ignored_protocol_handlers_.begin();
 583        i != ignored_protocol_handlers_.end(); ++i) {
 584     if (handler.IsEquivalent(*i)) {
 585       return true;
 586     }
 587   }
 588   return false;
 589 }
 590
 591 void ProtocolHandlerRegistry::RemoveIgnoredHandler(
 592     const ProtocolHandler& handler) {
 593   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 594   bool should_notify = false;
 595   ProtocolHandlerList::iterator p = std::find(
 596       ignored_protocol_handlers_.begin(), ignored_protocol_handlers_.end(),
 597       handler);
 598   if (p != ignored_protocol_handlers_.end()) {
 599     ignored_protocol_handlers_.erase(p);
 600     Save();
 601     should_notify = true;
 602   }
 603   if (should_notify)
 604     NotifyChanged();
 605 }
 606
 607 bool ProtocolHandlerRegistry::IsHandledProtocol(
 608     const std::string& scheme) const {
 609   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 610   return enabled_ && !GetHandlerFor(scheme).IsEmpty();
 611 }
 612
 613 void ProtocolHandlerRegistry::RemoveHandler(
 614     const ProtocolHandler& handler) {
 615   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 616   ProtocolHandlerList& handlers = protocol_handlers_[handler.protocol()];
 617   ProtocolHandlerList::iterator p =
 618       std::find(handlers.begin(), handlers.end(), handler);
 619   if (p != handlers.end()) {
 620     handlers.erase(p);
 621   }
 622   ProtocolHandlerMap::iterator q = default_handlers_.find(handler.protocol());
 623   if (q != default_handlers_.end() && q->second == handler) {
 624     // Make the new top handler in the list the default.
 625     if (!handlers.empty()) {
 626       // NOTE We pass a copy because SetDefault() modifies handlers.
 627       SetDefault(ProtocolHandler(handlers[0]));
 628     } else {
 629       BrowserThread::PostTask(
 630           BrowserThread::IO, FROM_HERE,
 631           base::Bind(&IOThreadDelegate::ClearDefault, io_thread_delegate_,
 632                      q->second.protocol()));
 633
 634       default_handlers_.erase(q);
 635     }
 636   }
 637
 638   if (!IsHandledProtocol(handler.protocol())) {
 639     delegate_->DeregisterExternalHandler(handler.protocol());
 640   }
 641   Save();
 642   NotifyChanged();
 643 }
 644
 645 void ProtocolHandlerRegistry::RemoveDefaultHandler(const std::string& scheme) {
 646   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 647   ProtocolHandler current_default = GetHandlerFor(scheme);
 648   if (!current_default.IsEmpty())
 649     RemoveHandler(current_default);
 650 }
 651
 652 const ProtocolHandler& ProtocolHandlerRegistry::GetHandlerFor(
 653     const std::string& scheme) const {
 654   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 655   return LookupHandler(default_handlers_, scheme);
 656 }
 657
 658 void ProtocolHandlerRegistry::Enable() {
 659   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 660   if (enabled_) {
 661     return;
 662   }
 663   enabled_ = true;
 664   BrowserThread::PostTask(
 665       BrowserThread::IO,
 666       FROM_HERE,
 667       base::Bind(&IOThreadDelegate::Enable, io_thread_delegate_));
 668
 669   ProtocolHandlerMap::const_iterator p;
 670   for (p = default_handlers_.begin(); p != default_handlers_.end(); ++p) {
 671     delegate_->RegisterExternalHandler(p->first);
 672   }
 673   Save();
 674   NotifyChanged();
 675 }
 676
 677 void ProtocolHandlerRegistry::Disable() {
 678   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 679   if (!enabled_) {
 680     return;
 681   }
 682   enabled_ = false;
 683   BrowserThread::PostTask(
 684       BrowserThread::IO,
 685       FROM_HERE,
 686       base::Bind(&IOThreadDelegate::Disable, io_thread_delegate_));
 687
 688   ProtocolHandlerMap::const_iterator p;
 689   for (p = default_handlers_.begin(); p != default_handlers_.end(); ++p) {
 690     delegate_->DeregisterExternalHandler(p->first);
 691   }
 692   Save();
 693   NotifyChanged();
 694 }
 695
 696 void ProtocolHandlerRegistry::Shutdown() {
 697   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 698   delegate_.reset(NULL);
 699   // We free these now in case there are any outstanding workers running. If
 700   // we didn't free them they could respond to workers and try to update the
 701   // protocol handler registry after it was deleted.
 702   // Observers remove themselves from this list when they are deleted; so
 703   // we delete the last item until none are left in the list.
 704   while (!default_client_observers_.empty()) {
 705     delete default_client_observers_.back();
 706   }
 707 }
 708
 709 // static
 710 void ProtocolHandlerRegistry::RegisterProfilePrefs(
 711     user_prefs::PrefRegistrySyncable* registry) {
 712   registry->RegisterListPref(prefs::kRegisteredProtocolHandlers,
 713                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 714   registry->RegisterListPref(prefs::kIgnoredProtocolHandlers,
 715                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 716   registry->RegisterBooleanPref(
 717       prefs::kCustomHandlersEnabled,
 718       true,
 719       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 720 }
 721
 722 ProtocolHandlerRegistry::~ProtocolHandlerRegistry() {
 723   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 724   DCHECK(default_client_observers_.empty());
 725 }
 726
 727 void ProtocolHandlerRegistry::PromoteHandler(const ProtocolHandler& handler) {
 728   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 729   DCHECK(IsRegistered(handler));
 730   ProtocolHandlerMultiMap::iterator p =
 731       protocol_handlers_.find(handler.protocol());
 732   ProtocolHandlerList& list = p->second;
 733   list.erase(std::find(list.begin(), list.end(), handler));
 734   list.insert(list.begin(), handler);
 735 }
 736
 737 void ProtocolHandlerRegistry::Save() {
 738   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 739   if (is_loading_) {
 740     return;
 741   }
 742   scoped_ptr<base::Value> registered_protocol_handlers(
 743       EncodeRegisteredHandlers());
 744   scoped_ptr<base::Value> ignored_protocol_handlers(EncodeIgnoredHandlers());
 745   scoped_ptr<base::Value> enabled(base::Value::CreateBooleanValue(enabled_));
 746   profile_->GetPrefs()->Set(prefs::kRegisteredProtocolHandlers,
 747       *registered_protocol_handlers);
 748   profile_->GetPrefs()->Set(prefs::kIgnoredProtocolHandlers,
 749       *ignored_protocol_handlers);
 750   profile_->GetPrefs()->Set(prefs::kCustomHandlersEnabled, *enabled);
 751 }
 752
 753 const ProtocolHandlerRegistry::ProtocolHandlerList*
 754 ProtocolHandlerRegistry::GetHandlerList(
 755     const std::string& scheme) const {
 756   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 757   ProtocolHandlerMultiMap::const_iterator p = protocol_handlers_.find(scheme);
 758   if (p == protocol_handlers_.end()) {
 759     return NULL;
 760   }
 761   return &p->second;
 762 }
 763
 764 void ProtocolHandlerRegistry::SetDefault(const ProtocolHandler& handler) {
 765   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 766   ProtocolHandlerMap::const_iterator p = default_handlers_.find(
 767       handler.protocol());
 768   // If we're not loading, and we are setting a default for a new protocol,
 769   // register with the OS.
 770   if (!is_loading_ && p == default_handlers_.end())
 771       delegate_->RegisterWithOSAsDefaultClient(handler.protocol(), this);
 772   default_handlers_.erase(handler.protocol());
 773   default_handlers_.insert(std::make_pair(handler.protocol(), handler));
 774   PromoteHandler(handler);
 775   BrowserThread::PostTask(
 776       BrowserThread::IO,
 777       FROM_HERE,
 778       base::Bind(&IOThreadDelegate::SetDefault, io_thread_delegate_, handler));
 779 }
 780
 781 void ProtocolHandlerRegistry::InsertHandler(const ProtocolHandler& handler) {
 782   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 783   ProtocolHandlerMultiMap::iterator p =
 784       protocol_handlers_.find(handler.protocol());
 785
 786   if (p != protocol_handlers_.end()) {
 787     p->second.push_back(handler);
 788     return;
 789   }
 790
 791   ProtocolHandlerList new_list;
 792   new_list.push_back(handler);
 793   protocol_handlers_[handler.protocol()] = new_list;
 794 }
 795
 796 base::Value* ProtocolHandlerRegistry::EncodeRegisteredHandlers() {
 797   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 798   base::ListValue* protocol_handlers = new base::ListValue();
 799   for (ProtocolHandlerMultiMap::iterator i = protocol_handlers_.begin();
 800        i != protocol_handlers_.end(); ++i) {
 801     for (ProtocolHandlerList::iterator j = i->second.begin();
 802          j != i->second.end(); ++j) {
 803       base::DictionaryValue* encoded = j->Encode();
 804       if (IsDefault(*j)) {
 805         encoded->Set("default", base::Value::CreateBooleanValue(true));
 806       }
 807       protocol_handlers->Append(encoded);
 808     }
 809   }
 810   return protocol_handlers;
 811 }
 812
 813 base::Value* ProtocolHandlerRegistry::EncodeIgnoredHandlers() {
 814   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 815   base::ListValue* handlers = new base::ListValue();
 816   for (ProtocolHandlerList::iterator i = ignored_protocol_handlers_.begin();
 817        i != ignored_protocol_handlers_.end(); ++i) {
 818     handlers->Append(i->Encode());
 819   }
 820   return handlers;
 821 }
 822
 823 void ProtocolHandlerRegistry::NotifyChanged() {
 824   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 825   content::NotificationService::current()->Notify(
 826       chrome::NOTIFICATION_PROTOCOL_HANDLER_REGISTRY_CHANGED,
 827       content::Source<Profile>(profile_),
 828       content::NotificationService::NoDetails());
 829 }
 830
 831 void ProtocolHandlerRegistry::RegisterProtocolHandler(
 832     const ProtocolHandler& handler) {
 833   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 834   DCHECK(CanSchemeBeOverridden(handler.protocol()));
 835   DCHECK(!handler.IsEmpty());
 836   if (IsRegistered(handler)) {
 837     return;
 838   }
 839   if (enabled_ && !delegate_->IsExternalHandlerRegistered(handler.protocol()))
 840     delegate_->RegisterExternalHandler(handler.protocol());
 841   InsertHandler(handler);
 842 }
 843
 844 std::vector<const base::DictionaryValue*>
 845 ProtocolHandlerRegistry::GetHandlersFromPref(const char* pref_name) const {
 846   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 847   std::vector<const base::DictionaryValue*> result;
 848   PrefService* prefs = profile_->GetPrefs();
 849   if (!prefs->HasPrefPath(pref_name)) {
 850     return result;
 851   }
 852
 853   const base::ListValue* handlers = prefs->GetList(pref_name);
 854   if (handlers) {
 855     for (size_t i = 0; i < handlers->GetSize(); ++i) {
 856       const base::DictionaryValue* dict;
 857       if (!handlers->GetDictionary(i, &dict))
 858         continue;
 859       if (ProtocolHandler::IsValidDict(dict)) {
 860         result.push_back(dict);
 861       }
 862     }
 863   }
 864   return result;
 865 }
 866
 867 void ProtocolHandlerRegistry::IgnoreProtocolHandler(
 868     const ProtocolHandler& handler) {
 869   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 870   ignored_protocol_handlers_.push_back(handler);
 871 }
 872
 873 void ProtocolHandlerRegistry::AddPredefinedHandler(
 874     const ProtocolHandler& handler) {
 875   DCHECK(!is_loaded_);  // Must be called prior InitProtocolSettings.
 876   RegisterProtocolHandler(handler);
 877   SetDefault(handler);
 878 }
 879
 880 scoped_ptr<ProtocolHandlerRegistry::JobInterceptorFactory>
 881 ProtocolHandlerRegistry::CreateJobInterceptorFactory() {
 882   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 883   // this is always created on the UI thread (in profile_io's
 884   // InitializeOnUIThread. Any method calls must be done
 885   // on the IO thread (this is checked).
 886   return scoped_ptr<JobInterceptorFactory>(
 887       new JobInterceptorFactory(io_thread_delegate_.get()));
 888 }