The Tor Browser: uriloader/exthandler/nsExternalProtocolHandler.cpp@97036ab72558 (annotated)

uriloader/exthandler/nsExternalProtocolHandler.cpp@97036ab72558 (annotated)

uriloader/exthandler/nsExternalProtocolHandler.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  * vim:set ts=2 sts=2 sw=2 et cin:
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "nsIURI.h"
 #include "nsIURL.h"
 #include "nsExternalProtocolHandler.h"
 #include "nsXPIDLString.h"
 #include "nsReadableUtils.h"
 #include "nsCOMPtr.h"
 #include "nsIServiceManager.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIStringBundle.h"
 #include "nsIPrefService.h"
 #include "nsIPrompt.h"
 #include "nsNetUtil.h"
 #include "nsExternalHelperAppService.h"
 // used to dispatch urls to default protocol handlers
 #include "nsCExternalHandlerService.h"
 #include "nsIExternalProtocolService.h"
 ////////////////////////////////////////////////////////////////////////
 // a stub channel implemenation which will map calls to AsyncRead and OpenInputStream
 // to calls in the OS for loading the url.
 ////////////////////////////////////////////////////////////////////////
 class nsExtProtocolChannel : public nsIChannel
 {
 public:
     NS_DECL_THREADSAFE_ISUPPORTS
     NS_DECL_NSICHANNEL
     NS_DECL_NSIREQUEST
     nsExtProtocolChannel();
     virtual ~nsExtProtocolChannel();
     nsresult SetURI(nsIURI*);
 private:
     nsresult OpenURL();
     void Finish(nsresult aResult);
     nsCOMPtr<nsIURI> mUrl;
     nsCOMPtr<nsIURI> mOriginalURI;
     nsresult mStatus;
     nsLoadFlags mLoadFlags;
     bool mWasOpened;
     nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
     nsCOMPtr<nsILoadGroup> mLoadGroup;
 };
 NS_IMPL_ADDREF(nsExtProtocolChannel)
 NS_IMPL_RELEASE(nsExtProtocolChannel)
 NS_INTERFACE_MAP_BEGIN(nsExtProtocolChannel)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIChannel)
    NS_INTERFACE_MAP_ENTRY(nsIChannel)
    NS_INTERFACE_MAP_ENTRY(nsIRequest)
 NS_INTERFACE_MAP_END_THREADSAFE
 nsExtProtocolChannel::nsExtProtocolChannel() : mStatus(NS_OK),
                                                mWasOpened(false)
 {
 }
 nsExtProtocolChannel::~nsExtProtocolChannel()
 {}
 NS_IMETHODIMP nsExtProtocolChannel::GetLoadGroup(nsILoadGroup * *aLoadGroup)
 {
   NS_IF_ADDREF(*aLoadGroup = mLoadGroup);
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetLoadGroup(nsILoadGroup * aLoadGroup)
 {
   mLoadGroup = aLoadGroup;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetNotificationCallbacks(nsIInterfaceRequestor* *aCallbacks)
 {
   NS_IF_ADDREF(*aCallbacks = mCallbacks);
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetNotificationCallbacks(nsIInterfaceRequestor* aCallbacks)
 {
   mCallbacks = aCallbacks;
   return NS_OK;
 }
 NS_IMETHODIMP
 nsExtProtocolChannel::GetSecurityInfo(nsISupports * *aSecurityInfo)
 {
   *aSecurityInfo = nullptr;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetOriginalURI(nsIURI* *aURI)
 {
   NS_ADDREF(*aURI = mOriginalURI);
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetOriginalURI(nsIURI* aURI)
 {
   NS_ENSURE_ARG_POINTER(aURI);
   mOriginalURI = aURI;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetURI(nsIURI* *aURI)
 {
   *aURI = mUrl;
   NS_IF_ADDREF(*aURI);
   return NS_OK;
 }
 nsresult nsExtProtocolChannel::SetURI(nsIURI* aURI)
 {
   mUrl = aURI;
   return NS_OK;
 }
 nsresult nsExtProtocolChannel::OpenURL()
 {
   nsresult rv = NS_ERROR_FAILURE;
   nsCOMPtr<nsIExternalProtocolService> extProtService (do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID));
   if (extProtService)
   {
 #ifdef DEBUG
     nsAutoCString urlScheme;
     mUrl->GetScheme(urlScheme);
     bool haveHandler = false;
     extProtService->ExternalProtocolHandlerExists(urlScheme.get(), &haveHandler);
     NS_ASSERTION(haveHandler, "Why do we have a channel for this url if we don't support the protocol?");
 #endif
     nsCOMPtr<nsIInterfaceRequestor> aggCallbacks;
     rv = NS_NewNotificationCallbacksAggregation(mCallbacks, mLoadGroup,
                                                 getter_AddRefs(aggCallbacks));
     if (NS_FAILED(rv)) {
       goto finish;
     }
     rv = extProtService->LoadURI(mUrl, aggCallbacks);
     if (NS_SUCCEEDED(rv)) {
         // despite success, we need to abort this channel, at the very least
         // to make it clear to the caller that no on{Start,Stop}Request
         // should be expected.
         rv = NS_ERROR_NO_CONTENT;
     }
   }
 finish:
   mCallbacks = 0;
   return rv;
 }
 NS_IMETHODIMP nsExtProtocolChannel::Open(nsIInputStream **_retval)
 {
   return OpenURL();
 }
 NS_IMETHODIMP nsExtProtocolChannel::AsyncOpen(nsIStreamListener *listener, nsISupports *ctxt)
 {
   NS_ENSURE_ARG_POINTER(listener);
   NS_ENSURE_TRUE(!mWasOpened, NS_ERROR_ALREADY_OPENED);
   mWasOpened = true;
   return OpenURL();
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetLoadFlags(nsLoadFlags *aLoadFlags)
 {
   *aLoadFlags = mLoadFlags;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetLoadFlags(nsLoadFlags aLoadFlags)
 {
   mLoadFlags = aLoadFlags;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentType(nsACString &aContentType)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetContentType(const nsACString &aContentType)
 {
   return NS_ERROR_FAILURE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentCharset(nsACString &aContentCharset)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetContentCharset(const nsACString &aContentCharset)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentDisposition(uint32_t *aContentDisposition)
 {
   return NS_ERROR_NOT_AVAILABLE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetContentDisposition(uint32_t aContentDisposition)
 {
   return NS_ERROR_NOT_AVAILABLE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentDispositionFilename(nsAString &aContentDispositionFilename)
 {
   return NS_ERROR_NOT_AVAILABLE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetContentDispositionFilename(const nsAString &aContentDispositionFilename)
 {
   return NS_ERROR_NOT_AVAILABLE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentDispositionHeader(nsACString &aContentDispositionHeader)
 {
   return NS_ERROR_NOT_AVAILABLE;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetContentLength(int64_t * aContentLength)
 {
   *aContentLength = -1;
   return NS_OK;
 }
 NS_IMETHODIMP
 nsExtProtocolChannel::SetContentLength(int64_t aContentLength)
 {
   NS_NOTREACHED("SetContentLength");
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetOwner(nsISupports * *aPrincipal)
 {
   NS_NOTREACHED("GetOwner");
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::SetOwner(nsISupports * aPrincipal)
 {
   NS_NOTREACHED("SetOwner");
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 ////////////////////////////////////////////////////////////////////////////////
 // From nsIRequest
 ////////////////////////////////////////////////////////////////////////////////
 NS_IMETHODIMP nsExtProtocolChannel::GetName(nsACString &result)
 {
   return mUrl->GetSpec(result);
 }
 NS_IMETHODIMP nsExtProtocolChannel::IsPending(bool *result)
 {
   *result = false;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::GetStatus(nsresult *status)
 {
   *status = mStatus;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::Cancel(nsresult status)
 {
   mStatus = status;
   return NS_OK;
 }
 NS_IMETHODIMP nsExtProtocolChannel::Suspend()
 {
   NS_NOTREACHED("Suspend");
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsExtProtocolChannel::Resume()
 {
   NS_NOTREACHED("Resume");
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 ///////////////////////////////////////////////////////////////////////
 // the default protocol handler implementation
 //////////////////////////////////////////////////////////////////////
 nsExternalProtocolHandler::nsExternalProtocolHandler()
 {
   m_schemeName = "default";
 }
 nsExternalProtocolHandler::~nsExternalProtocolHandler()
 {}
 NS_IMPL_ADDREF(nsExternalProtocolHandler)
 NS_IMPL_RELEASE(nsExternalProtocolHandler)
 NS_INTERFACE_MAP_BEGIN(nsExternalProtocolHandler)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIProtocolHandler)
    NS_INTERFACE_MAP_ENTRY(nsIProtocolHandler)
    NS_INTERFACE_MAP_ENTRY(nsIExternalProtocolHandler)
    NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
 NS_INTERFACE_MAP_END_THREADSAFE
 NS_IMETHODIMP nsExternalProtocolHandler::GetScheme(nsACString &aScheme)
 {
   aScheme = m_schemeName;
   return NS_OK;
 }
 NS_IMETHODIMP nsExternalProtocolHandler::GetDefaultPort(int32_t *aDefaultPort)
 {
   *aDefaultPort = 0;
     return NS_OK;
 }
 NS_IMETHODIMP
 nsExternalProtocolHandler::AllowPort(int32_t port, const char *scheme, bool *_retval)
 {
     // don't override anything.
     *_retval = false;
     return NS_OK;
 }
 // returns TRUE if the OS can handle this protocol scheme and false otherwise.
 bool nsExternalProtocolHandler::HaveExternalProtocolHandler(nsIURI * aURI)
 {
   bool haveHandler = false;
   if (aURI)
   {
     nsAutoCString scheme;
     aURI->GetScheme(scheme);
     nsCOMPtr<nsIExternalProtocolService> extProtSvc(do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID));
     if (extProtSvc)
       extProtSvc->ExternalProtocolHandlerExists(scheme.get(), &haveHandler);
   }
   return haveHandler;
 }
 NS_IMETHODIMP nsExternalProtocolHandler::GetProtocolFlags(uint32_t *aUritype)
 {
     // Make it norelative since it is a simple uri
     *aUritype = URI_NORELATIVE | URI_NOAUTH | URI_LOADABLE_BY_ANYONE |
         URI_NON_PERSISTABLE | URI_DOES_NOT_RETURN_DATA;
     return NS_OK;
 }
 NS_IMETHODIMP nsExternalProtocolHandler::NewURI(const nsACString &aSpec,
                                                 const char *aCharset, // ignore charset info
                                                 nsIURI *aBaseURI,
                                                 nsIURI **_retval)
 {
   nsresult rv;
   nsCOMPtr<nsIURI> uri = do_CreateInstance(NS_SIMPLEURI_CONTRACTID, &rv);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = uri->SetSpec(aSpec);
   NS_ENSURE_SUCCESS(rv, rv);
   NS_ADDREF(*_retval = uri);
   return NS_OK;
 }
 NS_IMETHODIMP nsExternalProtocolHandler::NewChannel(nsIURI *aURI, nsIChannel **_retval)
 {
   // Only try to return a channel if we have a protocol handler for the url.
   // nsOSHelperAppService::LoadUriInternal relies on this to check trustedness
   // for some platforms at least.  (win uses ::ShellExecute and unix uses
   // gnome_url_show.)
   bool haveExternalHandler = HaveExternalProtocolHandler(aURI);
   if (haveExternalHandler)
   {
     nsCOMPtr<nsIChannel> channel = new nsExtProtocolChannel();
     if (!channel) return NS_ERROR_OUT_OF_MEMORY;
     ((nsExtProtocolChannel*) channel.get())->SetURI(aURI);
     channel->SetOriginalURI(aURI);
     if (_retval)
     {
       *_retval = channel;
       NS_IF_ADDREF(*_retval);
       return NS_OK;
     }
   }
   return NS_ERROR_UNKNOWN_PROTOCOL;
 }
 ///////////////////////////////////////////////////////////////////////
 // External protocol handler interface implementation
 //////////////////////////////////////////////////////////////////////
 NS_IMETHODIMP nsExternalProtocolHandler::ExternalAppExistsForScheme(const nsACString& aScheme, bool *_retval)
 {
   nsCOMPtr<nsIExternalProtocolService> extProtSvc(do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID));
   if (extProtSvc)
     return extProtSvc->ExternalProtocolHandlerExists(
       PromiseFlatCString(aScheme).get(), _retval);
   // In case we don't have external protocol service.
   *_retval = false;
   return NS_OK;
 }

The Tor Browser / annotate

uriloader/exthandler/nsExternalProtocolHandler.cpp@97036ab72558 (annotated)

uriloader/exthandler/nsExternalProtocolHandler.cpp