The Tor Browser: uriloader/base/nsURILoader.cpp@ac0c01689b40 (annotated)

uriloader/base/nsURILoader.cpp@ac0c01689b40 (annotated)

uriloader/base/nsURILoader.cpp

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
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 "nsURILoader.h"
 #include "nsAutoPtr.h"
 #include "nsIURIContentListener.h"
 #include "nsIContentHandler.h"
 #include "nsILoadGroup.h"
 #include "nsIDocumentLoader.h"
 #include "nsIWebProgress.h"
 #include "nsIWebProgressListener.h"
 #include "nsIIOService.h"
 #include "nsIServiceManager.h"
 #include "nsIStreamListener.h"
 #include "nsIURI.h"
 #include "nsIChannel.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIProgressEventSink.h"
 #include "nsIInputStream.h"
 #include "nsIStreamConverterService.h"
 #include "nsWeakReference.h"
 #include "nsIHttpChannel.h"
 #include "nsIMultiPartChannel.h"
 #include "netCore.h"
 #include "nsCRT.h"
 #include "nsIDocShell.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIThreadRetargetableStreamListener.h"
 #include "nsXPIDLString.h"
 #include "nsString.h"
 #include "nsNetUtil.h"
 #include "nsThreadUtils.h"
 #include "nsReadableUtils.h"
 #include "nsError.h"
 #include "nsICategoryManager.h"
 #include "nsCExternalHandlerService.h" // contains contractids for the helper app service
 #include "nsIMIMEHeaderParam.h"
 #include "nsNetCID.h"
 #include "nsMimeTypes.h"
 #include "nsDocLoader.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/Preferences.h"
 #ifdef PR_LOGGING
 PRLogModuleInfo* nsURILoader::mLog = nullptr;
 #endif
 #define LOG(args) PR_LOG(nsURILoader::mLog, PR_LOG_DEBUG, args)
 #define LOG_ERROR(args) PR_LOG(nsURILoader::mLog, PR_LOG_ERROR, args)
 #define LOG_ENABLED() PR_LOG_TEST(nsURILoader::mLog, PR_LOG_DEBUG)
 #define NS_PREF_DISABLE_BACKGROUND_HANDLING \
     "security.exthelperapp.disable_background_handling"
 /**
  * The nsDocumentOpenInfo contains the state required when a single
  * document is being opened in order to discover the content type...
  * Each instance remains alive until its target URL has been loaded
  * (or aborted).
  */
 class nsDocumentOpenInfo MOZ_FINAL : public nsIStreamListener
                                    , public nsIThreadRetargetableStreamListener
 {
 public:
   // Needed for nsCOMPtr to work right... Don't call this!
   nsDocumentOpenInfo();
   // Real constructor
   // aFlags is a combination of the flags on nsIURILoader
   nsDocumentOpenInfo(nsIInterfaceRequestor* aWindowContext,
                      uint32_t aFlags,
                      nsURILoader* aURILoader);
   NS_DECL_THREADSAFE_ISUPPORTS
   /**
    * Prepares this object for receiving data. The stream
    * listener methods of this class must not be called before calling this
    * method.
    */
   nsresult Prepare();
   // Call this (from OnStartRequest) to attempt to find an nsIStreamListener to
   // take the data off our hands.
   nsresult DispatchContent(nsIRequest *request, nsISupports * aCtxt);
   // Call this if we need to insert a stream converter from aSrcContentType to
   // aOutContentType into the StreamListener chain.  DO NOT call it if the two
   // types are the same, since no conversion is needed in that case.
   nsresult ConvertData(nsIRequest *request,
                        nsIURIContentListener *aListener,
                        const nsACString & aSrcContentType,
                        const nsACString & aOutContentType);
   /**
    * Function to attempt to use aListener to handle the load.  If
    * true is returned, nothing else needs to be done; if false
    * is returned, then a different way of handling the load should be
    * tried.
    */
   bool TryContentListener(nsIURIContentListener* aListener,
                             nsIChannel* aChannel);
   // nsIRequestObserver methods:
   NS_DECL_NSIREQUESTOBSERVER
   // nsIStreamListener methods:
   NS_DECL_NSISTREAMLISTENER
   // nsIThreadRetargetableStreamListener
   NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
 protected:
   ~nsDocumentOpenInfo();
 protected:
   /**
    * The first content listener to try dispatching data to.  Typically
    * the listener associated with the entity that originated the load.
    */
   nsCOMPtr<nsIURIContentListener> m_contentListener;
   /**
    * The stream listener to forward nsIStreamListener notifications
    * to.  This is set once the load is dispatched.
    */
   nsCOMPtr<nsIStreamListener> m_targetStreamListener;
   /**
    * A pointer to the entity that originated the load. We depend on getting
    * things like nsIURIContentListeners, nsIDOMWindows, etc off of it.
    */
   nsCOMPtr<nsIInterfaceRequestor> m_originalContext;
   /**
    * IS_CONTENT_PREFERRED is used for the boolean to pass to CanHandleContent
    * (also determines whether we use CanHandleContent or IsPreferred).
    * DONT_RETARGET means that we will only try m_originalContext, no other
    * listeners.
    */
   uint32_t mFlags;
   /**
    * The type of the data we will be trying to dispatch.
    */
   nsCString mContentType;
   /**
    * Reference to the URILoader service so we can access its list of
    * nsIURIContentListeners.
    */
   nsRefPtr<nsURILoader> mURILoader;
 };
 NS_IMPL_ADDREF(nsDocumentOpenInfo)
 NS_IMPL_RELEASE(nsDocumentOpenInfo)
 NS_INTERFACE_MAP_BEGIN(nsDocumentOpenInfo)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRequestObserver)
   NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
   NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
   NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableStreamListener)
 NS_INTERFACE_MAP_END_THREADSAFE
 nsDocumentOpenInfo::nsDocumentOpenInfo()
 {
   NS_NOTREACHED("This should never be called\n");
 }
 nsDocumentOpenInfo::nsDocumentOpenInfo(nsIInterfaceRequestor* aWindowContext,
                                        uint32_t aFlags,
                                        nsURILoader* aURILoader)
   : m_originalContext(aWindowContext),
     mFlags(aFlags),
     mURILoader(aURILoader)
 {
 }
 nsDocumentOpenInfo::~nsDocumentOpenInfo()
 {
 }
 nsresult nsDocumentOpenInfo::Prepare()
 {
   LOG(("[0x%p] nsDocumentOpenInfo::Prepare", this));
   nsresult rv;
   // ask our window context if it has a uri content listener...
   m_contentListener = do_GetInterface(m_originalContext, &rv);
   return rv;
 }
 NS_IMETHODIMP nsDocumentOpenInfo::OnStartRequest(nsIRequest *request, nsISupports * aCtxt)
 {
   LOG(("[0x%p] nsDocumentOpenInfo::OnStartRequest", this));
   MOZ_ASSERT(request);
   if (!request) {
     return NS_ERROR_UNEXPECTED;
   }
   nsresult rv = NS_OK;
   //
   // Deal with "special" HTTP responses:
   //
   // - In the case of a 204 (No Content) or 205 (Reset Content) response, do
   //   not try to find a content handler.  Return NS_BINDING_ABORTED to cancel
   //   the request.  This has the effect of ensuring that the DocLoader does
   //   not try to interpret this as a real request.
   //
   nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(request, &rv));
   if (NS_SUCCEEDED(rv)) {
     uint32_t responseCode = 0;
     rv = httpChannel->GetResponseStatus(&responseCode);
     if (NS_FAILED(rv)) {
       LOG_ERROR(("  Failed to get HTTP response status"));
       // behave as in the canceled case
       return NS_OK;
     }
     LOG(("  HTTP response status: %d", responseCode));
     if (204 == responseCode || 205 == responseCode) {
       return NS_BINDING_ABORTED;
     }
   }
   //
   // Make sure that the transaction has succeeded, so far...
   //
   nsresult status;
   rv = request->GetStatus(&status);
   NS_ASSERTION(NS_SUCCEEDED(rv), "Unable to get request status!");
   if (NS_FAILED(rv)) return rv;
   if (NS_FAILED(status)) {
     LOG_ERROR(("  Request failed, status: 0x%08X", rv));
     //
     // The transaction has already reported an error - so it will be torn
     // down. Therefore, it is not necessary to return an error code...
     //
     return NS_OK;
   }
   rv = DispatchContent(request, aCtxt);
   LOG(("  After dispatch, m_targetStreamListener: 0x%p, rv: 0x%08X", m_targetStreamListener.get(), rv));
   NS_ASSERTION(NS_SUCCEEDED(rv) || !m_targetStreamListener,
                "Must not have an m_targetStreamListener with a failure return!");
   NS_ENSURE_SUCCESS(rv, rv);
   if (m_targetStreamListener)
     rv = m_targetStreamListener->OnStartRequest(request, aCtxt);
   LOG(("  OnStartRequest returning: 0x%08X", rv));
   return rv;
 }
 NS_IMETHODIMP
 nsDocumentOpenInfo::CheckListenerChain()
 {
   NS_ASSERTION(NS_IsMainThread(), "Should be on the main thread!");
   nsresult rv = NS_OK;
   nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
     do_QueryInterface(m_targetStreamListener, &rv);
   if (retargetableListener) {
     rv = retargetableListener->CheckListenerChain();
   }
   LOG(("[0x%p] nsDocumentOpenInfo::CheckListenerChain %s listener %p rv %x",
        this, (NS_SUCCEEDED(rv) ? "success" : "failure"),
        (nsIStreamListener*)m_targetStreamListener, rv));
   return rv;
 }
 NS_IMETHODIMP
 nsDocumentOpenInfo::OnDataAvailable(nsIRequest *request, nsISupports * aCtxt,
                                     nsIInputStream * inStr,
                                     uint64_t sourceOffset, uint32_t count)
 {
   // if we have retarged to the end stream listener, then forward the call....
   // otherwise, don't do anything
   nsresult rv = NS_OK;
   if (m_targetStreamListener)
     rv = m_targetStreamListener->OnDataAvailable(request, aCtxt, inStr, sourceOffset, count);
   return rv;
 }
 NS_IMETHODIMP nsDocumentOpenInfo::OnStopRequest(nsIRequest *request, nsISupports *aCtxt,
                                                 nsresult aStatus)
 {
   LOG(("[0x%p] nsDocumentOpenInfo::OnStopRequest", this));
   if ( m_targetStreamListener)
   {
     nsCOMPtr<nsIStreamListener> listener(m_targetStreamListener);
     // If this is a multipart stream, we could get another
     // OnStartRequest after this... reset state.
     m_targetStreamListener = 0;
     mContentType.Truncate();
     listener->OnStopRequest(request, aCtxt, aStatus);
   }
   // Remember...
   // In the case of multiplexed streams (such as multipart/x-mixed-replace)
   // these stream listener methods could be called again :-)
   //
   return NS_OK;
 }
 nsresult nsDocumentOpenInfo::DispatchContent(nsIRequest *request, nsISupports * aCtxt)
 {
   LOG(("[0x%p] nsDocumentOpenInfo::DispatchContent for type '%s'", this, mContentType.get()));
   NS_PRECONDITION(!m_targetStreamListener,
                   "Why do we already have a target stream listener?");
   nsresult rv;
   nsCOMPtr<nsIChannel> aChannel = do_QueryInterface(request);
   if (!aChannel) {
     LOG_ERROR(("  Request is not a channel.  Bailing."));
     return NS_ERROR_FAILURE;
   }
   NS_NAMED_LITERAL_CSTRING(anyType, "*/*");
   if (mContentType.IsEmpty() || mContentType == anyType) {
     rv = aChannel->GetContentType(mContentType);
     if (NS_FAILED(rv)) return rv;
     LOG(("  Got type from channel: '%s'", mContentType.get()));
   }
   bool isGuessFromExt =
     mContentType.LowerCaseEqualsASCII(APPLICATION_GUESS_FROM_EXT);
   if (isGuessFromExt) {
     // Reset to application/octet-stream for now; no one other than the
     // external helper app service should see APPLICATION_GUESS_FROM_EXT.
     mContentType = APPLICATION_OCTET_STREAM;
     aChannel->SetContentType(NS_LITERAL_CSTRING(APPLICATION_OCTET_STREAM));
   }
   // Check whether the data should be forced to be handled externally.  This
   // could happen because the Content-Disposition header is set so, or, in the
   // future, because the user has specified external handling for the MIME
   // type.
   bool forceExternalHandling = false;
   uint32_t disposition;
   rv = aChannel->GetContentDisposition(&disposition);
   if (NS_SUCCEEDED(rv) && disposition == nsIChannel::DISPOSITION_ATTACHMENT)
     forceExternalHandling = true;
   LOG(("  forceExternalHandling: %s", forceExternalHandling ? "yes" : "no"));
   // We're going to try to find a contentListener that can handle our data
   nsCOMPtr<nsIURIContentListener> contentListener;
   // The type or data the contentListener wants.
   nsXPIDLCString desiredContentType;
   if (!forceExternalHandling)
   {
     //
     // First step: See whether m_contentListener wants to handle this
     // content type.
     //
     if (m_contentListener && TryContentListener(m_contentListener, aChannel)) {
       LOG(("  Success!  Our default listener likes this type"));
       // All done here
       return NS_OK;
     }
     // If we aren't allowed to try other listeners, just skip through to
     // trying to convert the data.
     if (!(mFlags & nsIURILoader::DONT_RETARGET)) {
       //
       // Second step: See whether some other registered listener wants
       // to handle this content type.
       //
       int32_t count = mURILoader->m_listeners.Count();
       nsCOMPtr<nsIURIContentListener> listener;
       for (int32_t i = 0; i < count; i++) {
         listener = do_QueryReferent(mURILoader->m_listeners[i]);
         if (listener) {
           if (TryContentListener(listener, aChannel)) {
             LOG(("  Found listener registered on the URILoader"));
             return NS_OK;
           }
         } else {
           // remove from the listener list, reset i and update count
           mURILoader->m_listeners.RemoveObjectAt(i--);
           --count;
         }
       }
       //
       // Third step: Try to find a content listener that has not yet had
       // the chance to register, as it is contained in a not-yet-loaded
       // module, but which has registered a contract ID.
       //
       nsCOMPtr<nsICategoryManager> catman =
         do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
       if (catman) {
         nsXPIDLCString contractidString;
         rv = catman->GetCategoryEntry(NS_CONTENT_LISTENER_CATEGORYMANAGER_ENTRY,
                                       mContentType.get(),
                                       getter_Copies(contractidString));
         if (NS_SUCCEEDED(rv) && !contractidString.IsEmpty()) {
           LOG(("  Listener contractid for '%s' is '%s'",
                mContentType.get(), contractidString.get()));
           listener = do_CreateInstance(contractidString);
           LOG(("  Listener from category manager: 0x%p", listener.get()));
           if (listener && TryContentListener(listener, aChannel)) {
             LOG(("  Listener from category manager likes this type"));
             return NS_OK;
           }
         }
       }
       //
       // Fourth step: try to find an nsIContentHandler for our type.
       //
       nsAutoCString handlerContractID (NS_CONTENT_HANDLER_CONTRACTID_PREFIX);
       handlerContractID += mContentType;
       nsCOMPtr<nsIContentHandler> contentHandler =
         do_CreateInstance(handlerContractID.get());
       if (contentHandler) {
         LOG(("  Content handler found"));
         rv = contentHandler->HandleContent(mContentType.get(),
                                            m_originalContext, request);
         // XXXbz returning an error code to represent handling the
         // content is just bizarre!
         if (rv != NS_ERROR_WONT_HANDLE_CONTENT) {
           if (NS_FAILED(rv)) {
             // The content handler has unexpectedly failed.  Cancel the request
             // just in case the handler didn't...
             LOG(("  Content handler failed.  Aborting load"));
             request->Cancel(rv);
           }
 #ifdef PR_LOGGING
           else {
             LOG(("  Content handler taking over load"));
           }
 #endif
           return rv;
         }
       }
     } else {
       LOG(("  DONT_RETARGET flag set, so skipped over random other content "
            "listeners and content handlers"));
     }
     //
     // Fifth step:  If no listener prefers this type, see if any stream
     //              converters exist to transform this content type into
     //              some other.
     //
     // Don't do this if the server sent us a MIME type of "*/*" because they saw
     // it in our Accept header and got confused.
     // XXXbz have to be careful here; may end up in some sort of bizarre infinite
     // decoding loop.
     if (mContentType != anyType) {
       rv = ConvertData(request, m_contentListener, mContentType, anyType);
       if (NS_FAILED(rv)) {
         m_targetStreamListener = nullptr;
       } else if (m_targetStreamListener) {
         // We found a converter for this MIME type.  We'll just pump data into it
         // and let the downstream nsDocumentOpenInfo handle things.
         LOG(("  Converter taking over now"));
         return NS_OK;
       }
     }
   }
   NS_ASSERTION(!m_targetStreamListener,
                "If we found a listener, why are we not using it?");
   if (mFlags & nsIURILoader::DONT_RETARGET) {
     LOG(("  External handling forced or (listener not interested and no "
          "stream converter exists), and retargeting disallowed -> aborting"));
     return NS_ERROR_WONT_HANDLE_CONTENT;
   }
   // Before dispatching to the external helper app service, check for an HTTP
   // error page.  If we got one, we don't want to handle it with a helper app,
   // really.
   nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(request));
   if (httpChannel) {
     bool requestSucceeded;
     httpChannel->GetRequestSucceeded(&requestSucceeded);
     if (!requestSucceeded) {
       // returning error from OnStartRequest will cancel the channel
       return NS_ERROR_FILE_NOT_FOUND;
     }
   }
   // Sixth step:
   //
   // All attempts to dispatch this content have failed.  Just pass it off to
   // the helper app service.
   //
   //
   // Optionally, we may want to disable background handling by the external
   // helper application service.
   //
   if (mozilla::Preferences::GetBool(NS_PREF_DISABLE_BACKGROUND_HANDLING,
                                     false)) {
     // First, we will ensure that the parent docshell is in an active
     // state as we will disallow all external application handling unless it is
     // in the foreground.
     nsCOMPtr<nsIDocShell> docShell(do_GetInterface(m_originalContext));
     if (!docShell) {
       // If we can't perform our security check we definitely don't want to go
       // any further!
       LOG(("Failed to get DocShell to ensure it is active before anding off to "
            "helper app service. Aborting."));
       return NS_ERROR_FAILURE;
     }
     // Ensure the DocShell is active before continuing.
     bool isActive = false;
     docShell->GetIsActive(&isActive);
     if (!isActive) {
       LOG(("  Check for active DocShell returned false. Aborting hand off to "
            "helper app service."));
       return NS_ERROR_DOM_SECURITY_ERR;
     }
   }
   nsCOMPtr<nsIExternalHelperAppService> helperAppService =
     do_GetService(NS_EXTERNALHELPERAPPSERVICE_CONTRACTID, &rv);
   if (helperAppService) {
     LOG(("  Passing load off to helper app service"));
     // Set these flags to indicate that the channel has been targeted and that
     // we are not using the original consumer.
     nsLoadFlags loadFlags = 0;
     request->GetLoadFlags(&loadFlags);
     request->SetLoadFlags(loadFlags | nsIChannel::LOAD_RETARGETED_DOCUMENT_URI
                                     | nsIChannel::LOAD_TARGETED);
     if (isGuessFromExt) {
       mContentType = APPLICATION_GUESS_FROM_EXT;
       aChannel->SetContentType(NS_LITERAL_CSTRING(APPLICATION_GUESS_FROM_EXT));
     }
     rv = helperAppService->DoContent(mContentType,
                                      request,
                                      m_originalContext,
                                      false,
                                      getter_AddRefs(m_targetStreamListener));
     if (NS_FAILED(rv)) {
       request->SetLoadFlags(loadFlags);
       m_targetStreamListener = nullptr;
     }
   }
   NS_ASSERTION(m_targetStreamListener || NS_FAILED(rv),
                "There is no way we should be successful at this point without a m_targetStreamListener");
   return rv;
 }
 nsresult
 nsDocumentOpenInfo::ConvertData(nsIRequest *request,
                                 nsIURIContentListener* aListener,
                                 const nsACString& aSrcContentType,
                                 const nsACString& aOutContentType)
 {
   LOG(("[0x%p] nsDocumentOpenInfo::ConvertData from '%s' to '%s'", this,
        PromiseFlatCString(aSrcContentType).get(),
        PromiseFlatCString(aOutContentType).get()));
   NS_PRECONDITION(aSrcContentType != aOutContentType,
                   "ConvertData called when the two types are the same!");
   nsresult rv = NS_OK;
   nsCOMPtr<nsIStreamConverterService> StreamConvService =
     do_GetService(NS_STREAMCONVERTERSERVICE_CONTRACTID, &rv);
   if (NS_FAILED(rv)) return rv;
   LOG(("  Got converter service"));
   // When applying stream decoders, it is necessary to "insert" an
   // intermediate nsDocumentOpenInfo instance to handle the targeting of
   // the "final" stream or streams.
   //
   // For certain content types (ie. multi-part/x-mixed-replace) the input
   // stream is split up into multiple destination streams.  This
   // intermediate instance is used to target these "decoded" streams...
   //
   nsRefPtr<nsDocumentOpenInfo> nextLink =
     new nsDocumentOpenInfo(m_originalContext, mFlags, mURILoader);
   if (!nextLink) return NS_ERROR_OUT_OF_MEMORY;
   LOG(("  Downstream DocumentOpenInfo would be: 0x%p", nextLink.get()));
   // Make sure nextLink starts with the contentListener that said it wanted the
   // results of this decode.
   nextLink->m_contentListener = aListener;
   // Also make sure it has to look for a stream listener to pump data into.
   nextLink->m_targetStreamListener = nullptr;
   // Make sure that nextLink treats the data as aOutContentType when
   // dispatching; that way even if the stream converters don't change the type
   // on the channel we will still do the right thing.  If aOutContentType is
   // */*, that's OK -- that will just indicate to nextLink that it should get
   // the type off the channel.
   nextLink->mContentType = aOutContentType;
   // The following call sets m_targetStreamListener to the input end of the
   // stream converter and sets the output end of the stream converter to
   // nextLink.  As we pump data into m_targetStreamListener the stream
   // converter will convert it and pass the converted data to nextLink.
   return StreamConvService->AsyncConvertData(PromiseFlatCString(aSrcContentType).get(),
                                              PromiseFlatCString(aOutContentType).get(),
                                              nextLink,
                                              request,
                                              getter_AddRefs(m_targetStreamListener));
 }
 bool
 nsDocumentOpenInfo::TryContentListener(nsIURIContentListener* aListener,
                                        nsIChannel* aChannel)
 {
   LOG(("[0x%p] nsDocumentOpenInfo::TryContentListener; mFlags = 0x%x",
        this, mFlags));
   NS_PRECONDITION(aListener, "Must have a non-null listener");
   NS_PRECONDITION(aChannel, "Must have a channel");
   bool listenerWantsContent = false;
   nsXPIDLCString typeToUse;
   if (mFlags & nsIURILoader::IS_CONTENT_PREFERRED) {
     aListener->IsPreferred(mContentType.get(),
                            getter_Copies(typeToUse),
                            &listenerWantsContent);
   } else {
     aListener->CanHandleContent(mContentType.get(), false,
                                 getter_Copies(typeToUse),
                                 &listenerWantsContent);
   }
   if (!listenerWantsContent) {
     LOG(("  Listener is not interested"));
     return false;
   }
   if (!typeToUse.IsEmpty() && typeToUse != mContentType) {
     // Need to do a conversion here.
     nsresult rv = ConvertData(aChannel, aListener, mContentType, typeToUse);
     if (NS_FAILED(rv)) {
       // No conversion path -- we don't want this listener, if we got one
       m_targetStreamListener = nullptr;
     }
     LOG(("  Found conversion: %s", m_targetStreamListener ? "yes" : "no"));
     // m_targetStreamListener is now the input end of the converter, and we can
     // just pump the data in there, if it exists.  If it does not, we need to
     // try other nsIURIContentListeners.
     return m_targetStreamListener != nullptr;
   }
   // At this point, aListener wants data of type mContentType.  Let 'em have
   // it.  But first, if we are retargeting, set an appropriate flag on the
   // channel
   nsLoadFlags loadFlags = 0;
   aChannel->GetLoadFlags(&loadFlags);
   // Set this flag to indicate that the channel has been targeted at a final
   // consumer.  This load flag is tested in nsDocLoader::OnProgress.
   nsLoadFlags newLoadFlags = nsIChannel::LOAD_TARGETED;
   nsCOMPtr<nsIURIContentListener> originalListener =
     do_GetInterface(m_originalContext);
   if (originalListener != aListener) {
     newLoadFlags |= nsIChannel::LOAD_RETARGETED_DOCUMENT_URI;
   }
   aChannel->SetLoadFlags(loadFlags | newLoadFlags);
   bool abort = false;
   bool isPreferred = (mFlags & nsIURILoader::IS_CONTENT_PREFERRED) != 0;
   nsresult rv = aListener->DoContent(mContentType.get(),
                                      isPreferred,
                                      aChannel,
                                      getter_AddRefs(m_targetStreamListener),
                                      &abort);
   if (NS_FAILED(rv)) {
     LOG_ERROR(("  DoContent failed"));
     // Unset the RETARGETED_DOCUMENT_URI flag if we set it...
     aChannel->SetLoadFlags(loadFlags);
     m_targetStreamListener = nullptr;
     return false;
   }
   if (abort) {
     // Nothing else to do here -- aListener is handling it all.  Make
     // sure m_targetStreamListener is null so we don't do anything
     // after this point.
     LOG(("  Listener has aborted the load"));
     m_targetStreamListener = nullptr;
   }
   NS_ASSERTION(abort || m_targetStreamListener, "DoContent returned no listener?");
   // aListener is handling the load from this point on.
   return true;
 }
 ///////////////////////////////////////////////////////////////////////////////////////////////
 // Implementation of nsURILoader
 ///////////////////////////////////////////////////////////////////////////////////////////////
 nsURILoader::nsURILoader()
 {
 #ifdef PR_LOGGING
   if (!mLog) {
     mLog = PR_NewLogModule("URILoader");
   }
 #endif
 }
 nsURILoader::~nsURILoader()
 {
 }
 NS_IMPL_ADDREF(nsURILoader)
 NS_IMPL_RELEASE(nsURILoader)
 NS_INTERFACE_MAP_BEGIN(nsURILoader)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIURILoader)
    NS_INTERFACE_MAP_ENTRY(nsIURILoader)
 NS_INTERFACE_MAP_END
 NS_IMETHODIMP nsURILoader::RegisterContentListener(nsIURIContentListener * aContentListener)
 {
   nsresult rv = NS_OK;
   nsWeakPtr weakListener = do_GetWeakReference(aContentListener);
   NS_ASSERTION(weakListener, "your URIContentListener must support weak refs!\n");
   if (weakListener)
     m_listeners.AppendObject(weakListener);
   return rv;
 }
 NS_IMETHODIMP nsURILoader::UnRegisterContentListener(nsIURIContentListener * aContentListener)
 {
   nsWeakPtr weakListener = do_GetWeakReference(aContentListener);
   if (weakListener)
     m_listeners.RemoveObject(weakListener);
   return NS_OK;
 }
 NS_IMETHODIMP nsURILoader::OpenURI(nsIChannel *channel,
                                    uint32_t aFlags,
                                    nsIInterfaceRequestor *aWindowContext)
 {
   NS_ENSURE_ARG_POINTER(channel);
 #ifdef PR_LOGGING
   if (LOG_ENABLED()) {
     nsCOMPtr<nsIURI> uri;
     channel->GetURI(getter_AddRefs(uri));
     nsAutoCString spec;
     uri->GetAsciiSpec(spec);
     LOG(("nsURILoader::OpenURI for %s", spec.get()));
   }
 #endif
   nsCOMPtr<nsIStreamListener> loader;
   nsresult rv = OpenChannel(channel,
                             aFlags,
                             aWindowContext,
                             false,
                             getter_AddRefs(loader));
   if (NS_SUCCEEDED(rv)) {
     // this method is not complete!!! Eventually, we should first go
     // to the content listener and ask them for a protocol handler...
     // if they don't give us one, we need to go to the registry and get
     // the preferred protocol handler.
     // But for now, I'm going to let necko do the work for us....
     rv = channel->AsyncOpen(loader, nullptr);
     // no content from this load - that's OK.
     if (rv == NS_ERROR_NO_CONTENT) {
       LOG(("  rv is NS_ERROR_NO_CONTENT -- doing nothing"));
       rv = NS_OK;
     }
   } else if (rv == NS_ERROR_WONT_HANDLE_CONTENT) {
     // Not really an error, from this method's point of view
     rv = NS_OK;
   }
   return rv;
 }
 nsresult nsURILoader::OpenChannel(nsIChannel* channel,
                                   uint32_t aFlags,
                                   nsIInterfaceRequestor* aWindowContext,
                                   bool aChannelIsOpen,
                                   nsIStreamListener** aListener)
 {
   NS_ASSERTION(channel, "Trying to open a null channel!");
   NS_ASSERTION(aWindowContext, "Window context must not be null");
 #ifdef PR_LOGGING
   if (LOG_ENABLED()) {
     nsCOMPtr<nsIURI> uri;
     channel->GetURI(getter_AddRefs(uri));
     nsAutoCString spec;
     uri->GetAsciiSpec(spec);
     LOG(("nsURILoader::OpenChannel for %s", spec.get()));
   }
 #endif
   // Let the window context's uriListener know that the open is starting.  This
   // gives that window a chance to abort the load process.
   nsCOMPtr<nsIURIContentListener> winContextListener(do_GetInterface(aWindowContext));
   if (winContextListener) {
     nsCOMPtr<nsIURI> uri;
     channel->GetURI(getter_AddRefs(uri));
     if (uri) {
       bool doAbort = false;
       winContextListener->OnStartURIOpen(uri, &doAbort);
       if (doAbort) {
         LOG(("  OnStartURIOpen aborted load"));
         return NS_ERROR_WONT_HANDLE_CONTENT;
       }
     }
   }
   // we need to create a DocumentOpenInfo object which will go ahead and open
   // the url and discover the content type....
   nsRefPtr<nsDocumentOpenInfo> loader =
     new nsDocumentOpenInfo(aWindowContext, aFlags, this);
   if (!loader) return NS_ERROR_OUT_OF_MEMORY;
   // Set the correct loadgroup on the channel
   nsCOMPtr<nsILoadGroup> loadGroup(do_GetInterface(aWindowContext));
   if (!loadGroup) {
     // XXXbz This context is violating what we'd like to be the new uriloader
     // api.... Set up a nsDocLoader to handle the loadgroup for this context.
     // This really needs to go away!
     nsCOMPtr<nsIURIContentListener> listener(do_GetInterface(aWindowContext));
     if (listener) {
       nsCOMPtr<nsISupports> cookie;
       listener->GetLoadCookie(getter_AddRefs(cookie));
       if (!cookie) {
         nsRefPtr<nsDocLoader> newDocLoader = new nsDocLoader();
         if (!newDocLoader)
           return NS_ERROR_OUT_OF_MEMORY;
         nsresult rv = newDocLoader->Init();
         if (NS_FAILED(rv))
           return rv;
         rv = nsDocLoader::AddDocLoaderAsChildOfRoot(newDocLoader);
         if (NS_FAILED(rv))
           return rv;
         cookie = nsDocLoader::GetAsSupports(newDocLoader);
         listener->SetLoadCookie(cookie);
       }
       loadGroup = do_GetInterface(cookie);
     }
   }
   // If the channel is pending, then we need to remove it from its current
   // loadgroup
   nsCOMPtr<nsILoadGroup> oldGroup;
   channel->GetLoadGroup(getter_AddRefs(oldGroup));
   if (aChannelIsOpen && !SameCOMIdentity(oldGroup, loadGroup)) {
     // It is important to add the channel to the new group before
     // removing it from the old one, so that the load isn't considered
     // done as soon as the request is removed.
     loadGroup->AddRequest(channel, nullptr);
    if (oldGroup) {
       oldGroup->RemoveRequest(channel, nullptr, NS_BINDING_RETARGETED);
     }
   }
   channel->SetLoadGroup(loadGroup);
   // prepare the loader for receiving data
   nsresult rv = loader->Prepare();
   if (NS_SUCCEEDED(rv))
     NS_ADDREF(*aListener = loader);
   return rv;
 }
 NS_IMETHODIMP nsURILoader::OpenChannel(nsIChannel* channel,
                                        uint32_t aFlags,
                                        nsIInterfaceRequestor* aWindowContext,
                                        nsIStreamListener** aListener)
 {
   bool pending;
   if (NS_FAILED(channel->IsPending(&pending))) {
     pending = false;
   }
   return OpenChannel(channel, aFlags, aWindowContext, pending, aListener);
 }
 NS_IMETHODIMP nsURILoader::Stop(nsISupports* aLoadCookie)
 {
   nsresult rv;
   nsCOMPtr<nsIDocumentLoader> docLoader;
   NS_ENSURE_ARG_POINTER(aLoadCookie);
   docLoader = do_GetInterface(aLoadCookie, &rv);
   if (docLoader) {
     rv = docLoader->Stop();
   }
   return rv;
 }

The Tor Browser / annotate

uriloader/base/nsURILoader.cpp@ac0c01689b40 (annotated)

uriloader/base/nsURILoader.cpp