diff -r 000000000000 -r 6474c204b198 content/base/src/nsMixedContentBlocker.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/content/base/src/nsMixedContentBlocker.cpp Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,622 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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 "nsMixedContentBlocker.h" + +#include "nsContentPolicyUtils.h" +#include "nsThreadUtils.h" +#include "nsINode.h" +#include "nsCOMPtr.h" +#include "nsIDocShell.h" +#include "nsISecurityEventSink.h" +#include "nsIWebProgressListener.h" +#include "nsContentUtils.h" +#include "nsNetUtil.h" +#include "nsIRequest.h" +#include "nsIDocument.h" +#include "nsIContentViewer.h" +#include "nsIChannel.h" +#include "nsIHttpChannel.h" +#include "mozilla/Preferences.h" +#include "nsIScriptObjectPrincipal.h" +#include "nsISecureBrowserUI.h" +#include "nsIDocumentLoader.h" +#include "nsIWebNavigation.h" +#include "nsLoadGroup.h" +#include "nsIScriptError.h" + +#include "prlog.h" + +using namespace mozilla; + +enum nsMixedContentBlockerMessageType { + eBlocked = 0x00, + eUserOverride = 0x01 +}; + +// Is mixed script blocking (fonts, plugin content, scripts, stylesheets, +// iframes, websockets, XHR) enabled? +bool nsMixedContentBlocker::sBlockMixedScript = false; + +// Is mixed display content blocking (images, audio, video, ) enabled? +bool nsMixedContentBlocker::sBlockMixedDisplay = false; + +// Fired at the document that attempted to load mixed content. The UI could +// handle this event, for example, by displaying an info bar that offers the +// choice to reload the page with mixed content permitted. +class nsMixedContentEvent : public nsRunnable +{ +public: + nsMixedContentEvent(nsISupports *aContext, MixedContentTypes aType) + : mContext(aContext), mType(aType) + {} + + NS_IMETHOD Run() + { + NS_ASSERTION(mContext, + "You can't call this runnable without a requesting context"); + + // To update the security UI in the tab with the blocked mixed content, call + // nsISecurityEventSink::OnSecurityChange. You can get to the event sink by + // calling NS_CP_GetDocShellFromContext on the context, and QI'ing to + // nsISecurityEventSink. + + + // Mixed content was allowed and is about to load; get the document and + // set the approriate flag to true if we are about to load Mixed Active + // Content. + nsCOMPtr docShell = NS_CP_GetDocShellFromContext(mContext); + if (!docShell) { + return NS_OK; + } + nsCOMPtr sameTypeRoot; + docShell->GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot)); + NS_ASSERTION(sameTypeRoot, "No document shell root tree item from document shell tree item!"); + + // now get the document from sameTypeRoot + nsCOMPtr rootDoc = do_GetInterface(sameTypeRoot); + NS_ASSERTION(rootDoc, "No root document from document shell root tree item."); + + + if (mType == eMixedScript) { + // See if the pref will change here. If it will, only then do we need to call OnSecurityChange() to update the UI. + if (rootDoc->GetHasMixedActiveContentLoaded()) { + return NS_OK; + } + rootDoc->SetHasMixedActiveContentLoaded(true); + + // Update the security UI in the tab with the allowed mixed active content + nsCOMPtr eventSink = do_QueryInterface(docShell); + if (eventSink) { + // If mixed display content is loaded, make sure to include that in the state. + if (rootDoc->GetHasMixedDisplayContentLoaded()) { + eventSink->OnSecurityChange(mContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT | + nsIWebProgressListener::STATE_LOADED_MIXED_DISPLAY_CONTENT)); + } else { + eventSink->OnSecurityChange(mContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT)); + } + } + + } else if (mType == eMixedDisplay) { + // See if the pref will change here. If it will, only then do we need to call OnSecurityChange() to update the UI. + if (rootDoc->GetHasMixedDisplayContentLoaded()) { + return NS_OK; + } + rootDoc->SetHasMixedDisplayContentLoaded(true); + + // Update the security UI in the tab with the allowed mixed display content. + nsCOMPtr eventSink = do_QueryInterface(docShell); + if (eventSink) { + // If mixed active content is loaded, make sure to include that in the state. + if (rootDoc->GetHasMixedActiveContentLoaded()) { + eventSink->OnSecurityChange(mContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_DISPLAY_CONTENT | + nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT)); + } else { + eventSink->OnSecurityChange(mContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_DISPLAY_CONTENT)); + } + } + } + + return NS_OK; + } +private: + // The requesting context for the content load. Generally, a DOM node from + // the document that caused the load. + nsCOMPtr mContext; + + // The type of mixed content detected, e.g. active or display + const MixedContentTypes mType; +}; + + +nsMixedContentBlocker::nsMixedContentBlocker() +{ + // Cache the pref for mixed script blocking + Preferences::AddBoolVarCache(&sBlockMixedScript, + "security.mixed_content.block_active_content"); + + // Cache the pref for mixed display blocking + Preferences::AddBoolVarCache(&sBlockMixedDisplay, + "security.mixed_content.block_display_content"); +} + +nsMixedContentBlocker::~nsMixedContentBlocker() +{ +} + +NS_IMPL_ISUPPORTS(nsMixedContentBlocker, nsIContentPolicy) + +static void +LogMixedContentMessage(MixedContentTypes aClassification, + nsIURI* aContentLocation, + nsIDocument* aRootDoc, + nsMixedContentBlockerMessageType aMessageType) +{ + nsAutoCString messageCategory; + uint32_t severityFlag; + nsAutoCString messageLookupKey; + + if (aMessageType == eBlocked) { + severityFlag = nsIScriptError::errorFlag; + messageCategory.AssignLiteral("Mixed Content Blocker"); + if (aClassification == eMixedDisplay) { + messageLookupKey.AssignLiteral("BlockMixedDisplayContent"); + } else { + messageLookupKey.AssignLiteral("BlockMixedActiveContent"); + } + } else { + severityFlag = nsIScriptError::warningFlag; + messageCategory.AssignLiteral("Mixed Content Message"); + if (aClassification == eMixedDisplay) { + messageLookupKey.AssignLiteral("LoadingMixedDisplayContent"); + } else { + messageLookupKey.AssignLiteral("LoadingMixedActiveContent"); + } + } + + nsAutoCString locationSpec; + aContentLocation->GetSpec(locationSpec); + NS_ConvertUTF8toUTF16 locationSpecUTF16(locationSpec); + + const char16_t* strings[] = { locationSpecUTF16.get() }; + nsContentUtils::ReportToConsole(severityFlag, messageCategory, aRootDoc, + nsContentUtils::eSECURITY_PROPERTIES, + messageLookupKey.get(), strings, ArrayLength(strings)); +} + +NS_IMETHODIMP +nsMixedContentBlocker::ShouldLoad(uint32_t aContentType, + nsIURI* aContentLocation, + nsIURI* aRequestingLocation, + nsISupports* aRequestingContext, + const nsACString& aMimeGuess, + nsISupports* aExtra, + nsIPrincipal* aRequestPrincipal, + int16_t* aDecision) +{ + // Asserting that we are on the main thread here and hence do not have to lock + // and unlock sBlockMixedScript and sBlockMixedDisplay before reading/writing + // to them. + MOZ_ASSERT(NS_IsMainThread()); + + // Assume active (high risk) content and blocked by default + MixedContentTypes classification = eMixedScript; + + + // Notes on non-obvious decisions: + // + // TYPE_DTD: A DTD can contain entity definitions that expand to scripts. + // + // TYPE_FONT: The TrueType hinting mechanism is basically a scripting + // language that gets interpreted by the operating system's font rasterizer. + // Mixed content web fonts are relatively uncommon, and we can can fall back + // to built-in fonts with minimal disruption in almost all cases. + // + // TYPE_OBJECT_SUBREQUEST could actually be either active content (e.g. a + // script that a plugin will execute) or display content (e.g. Flash video + // content). Until we have a way to determine active vs passive content + // from plugin requests (bug 836352), we will treat this as passive content. + // This is to prevent false positives from causing users to become + // desensitized to the mixed content blocker. + // + // TYPE_CSP_REPORT: High-risk because they directly leak information about + // the content of the page, and because blocking them does not have any + // negative effect on the page loading. + // + // TYPE_PING: Ping requests are POSTS, not GETs like images and media. + // Also, PING requests have no bearing on the rendering or operation of + // the page when used as designed, so even though they are lower risk than + // scripts, blocking them is basically risk-free as far as compatibility is + // concerned. Ping is turned off by default in Firefox, so unless a user + // opts into ping, no request will be made. Categorizing this as Mixed + // Display Content for now, but this is subject to change. + // + // TYPE_STYLESHEET: XSLT stylesheets can insert scripts. CSS positioning + // and other advanced CSS features can possibly be exploited to cause + // spoofing attacks (e.g. make a "grant permission" button look like a + // "refuse permission" button). + // + // TYPE_BEACON: Beacon requests are similar to TYPE_PING, but are default on. + // + // TYPE_WEBSOCKET: The Websockets API requires browsers to + // reject mixed-content websockets: "If secure is false but the origin of + // the entry script has a scheme component that is itself a secure protocol, + // e.g. HTTPS, then throw a SecurityError exception." We already block mixed + // content websockets within the websockets implementation, so we don't need + // to do any blocking here, nor do we need to provide a way to undo or + // override the blocking. Websockets without TLS are very flaky anyway in the + // face of many HTTP-aware proxies. Compared to psasive content, there is + // additional risk that the script using WebSockets will disclose sensitive + // information from the HTTPS page and/or eval (directly or indirectly) + // received data. + // + // TYPE_XMLHTTPREQUEST: XHR requires either same origin or CORS, so most + // mixed-content XHR will already be blocked by that check. This will also + // block HTTPS-to-HTTP XHR with CORS. The same security concerns mentioned + // above for WebSockets apply to XHR, and XHR should have the same security + // properties as WebSockets w.r.t. mixed content. XHR's handling of redirects + // amplifies these concerns. + + + static_assert(TYPE_DATAREQUEST == TYPE_XMLHTTPREQUEST, + "TYPE_DATAREQUEST is not a synonym for " + "TYPE_XMLHTTPREQUEST"); + + switch (aContentType) { + // The top-level document cannot be mixed content by definition + case TYPE_DOCUMENT: + *aDecision = ACCEPT; + return NS_OK; + // Creating insecure websocket connections in a secure page is blocked already + // in the websocket constructor. We don't need to check the blocking here + // and we don't want to un-block + case TYPE_WEBSOCKET: + *aDecision = ACCEPT; + return NS_OK; + + + // Static display content is considered moderate risk for mixed content so + // these will be blocked according to the mixed display preference + case TYPE_IMAGE: + case TYPE_MEDIA: + case TYPE_OBJECT_SUBREQUEST: + case TYPE_PING: + case TYPE_BEACON: + classification = eMixedDisplay; + break; + + // Active content (or content with a low value/risk-of-blocking ratio) + // that has been explicitly evaluated; listed here for documentation + // purposes and to avoid the assertion and warning for the default case. + case TYPE_CSP_REPORT: + case TYPE_DTD: + case TYPE_FONT: + case TYPE_OBJECT: + case TYPE_SCRIPT: + case TYPE_STYLESHEET: + case TYPE_SUBDOCUMENT: + case TYPE_XBL: + case TYPE_XMLHTTPREQUEST: + case TYPE_XSLT: + case TYPE_OTHER: + break; + + + // This content policy works as a whitelist. + default: + MOZ_ASSERT(false, "Mixed content of unknown type"); + break; + } + + /* Get the scheme of the sub-document resource to be requested. If it is + * a safe to load in an https context then mixed content doesn't apply. + * + * Check Protocol Flags to determine if scheme is safe to load: + * URI_DOES_NOT_RETURN_DATA - e.g. + * "mailto" + * URI_IS_LOCAL_RESOURCE - e.g. + * "data", + * "resource", + * "moz-icon" + * URI_INHERITS_SECURITY_CONTEXT - e.g. + * "javascript" + * URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT - e.g. + * "https", + * "moz-safe-about" + * + */ + bool schemeLocal = false; + bool schemeNoReturnData = false; + bool schemeInherits = false; + bool schemeSecure = false; + if (NS_FAILED(NS_URIChainHasFlags(aContentLocation, nsIProtocolHandler::URI_IS_LOCAL_RESOURCE , &schemeLocal)) || + NS_FAILED(NS_URIChainHasFlags(aContentLocation, nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA, &schemeNoReturnData)) || + NS_FAILED(NS_URIChainHasFlags(aContentLocation, nsIProtocolHandler::URI_INHERITS_SECURITY_CONTEXT, &schemeInherits)) || + NS_FAILED(NS_URIChainHasFlags(aContentLocation, nsIProtocolHandler::URI_SAFE_TO_LOAD_IN_SECURE_CONTEXT, &schemeSecure))) { + return NS_ERROR_FAILURE; + } + + if (schemeLocal || schemeNoReturnData || schemeInherits || schemeSecure) { + return NS_OK; + } + + // Since there are cases where aRequestingLocation and aRequestPrincipal are + // definitely not the owning document, we try to ignore them by extracting the + // requestingLocation in the following order: + // 1) from the aRequestingContext, either extracting + // a) the node's principal, or the + // b) script object's principal. + // 2) if aRequestingContext yields a principal but no location, we check + // if its the system principal. If it is, allow the load. + // 3) Special case handling for: + // a) speculative loads, where shouldLoad is called twice (bug 839235) + // and the first speculative load does not include a context. + // In this case we use aRequestingLocation to set requestingLocation. + // b) TYPE_CSP_REPORT which does not provide a context. In this case we + // use aRequestingLocation to set requestingLocation. + // c) content scripts from addon code that do not provide aRequestingContext + // or aRequestingLocation, but do provide aRequestPrincipal. + // If aRequestPrincipal is an expanded principal, we allow the load. + // 4) If we still end up not having a requestingLocation, we reject the load. + + nsCOMPtr principal; + // 1a) Try to get the principal if aRequestingContext is a node. + nsCOMPtr node = do_QueryInterface(aRequestingContext); + if (node) { + principal = node->NodePrincipal(); + } + + // 1b) Try using the window's script object principal if it's not a node. + if (!principal) { + nsCOMPtr scriptObjPrin = do_QueryInterface(aRequestingContext); + if (scriptObjPrin) { + principal = scriptObjPrin->GetPrincipal(); + } + } + + nsCOMPtr requestingLocation; + if (principal) { + principal->GetURI(getter_AddRefs(requestingLocation)); + } + + // 2) if aRequestingContext yields a principal but no location, we check if its a system principal. + if (principal && !requestingLocation) { + if (nsContentUtils::IsSystemPrincipal(principal)) { + *aDecision = ACCEPT; + return NS_OK; + } + } + + // 3a,b) Special case handling for speculative loads and TYPE_CSP_REPORT. In + // such cases, aRequestingContext doesn't exist, so we use aRequestingLocation. + // Unfortunately we can not distinguish between speculative and normal loads here, + // otherwise we could special case this assignment. + if (!requestingLocation) { + requestingLocation = aRequestingLocation; + } + + // 3c) Special case handling for content scripts from addons code, which only + // provide a aRequestPrincipal; aRequestingContext and aRequestingLocation are + // both null; if the aRequestPrincipal is an expandedPrincipal, we allow the load. + if (!principal && !requestingLocation && aRequestPrincipal) { + nsCOMPtr expanded = do_QueryInterface(aRequestPrincipal); + if (expanded) { + *aDecision = ACCEPT; + return NS_OK; + } + } + + // 4) Giving up. We still don't have a requesting location, therefore we can't tell + // if this is a mixed content load. Deny to be safe. + if (!requestingLocation) { + *aDecision = REJECT_REQUEST; + return NS_OK; + } + + // Check the parent scheme. If it is not an HTTPS page then mixed content + // restrictions do not apply. + bool parentIsHttps; + nsresult rv = requestingLocation->SchemeIs("https", &parentIsHttps); + if (NS_FAILED(rv)) { + NS_ERROR("requestingLocation->SchemeIs failed"); + *aDecision = REJECT_REQUEST; + return NS_OK; + } + if (!parentIsHttps) { + *aDecision = ACCEPT; + return NS_OK; + } + + // Determine if the rootDoc is https and if the user decided to allow Mixed Content + nsCOMPtr docShell = NS_CP_GetDocShellFromContext(aRequestingContext); + NS_ENSURE_TRUE(docShell, NS_OK); + bool rootHasSecureConnection = false; + bool allowMixedContent = false; + bool isRootDocShell = false; + rv = docShell->GetAllowMixedContentAndConnectionData(&rootHasSecureConnection, &allowMixedContent, &isRootDocShell); + if (NS_FAILED(rv)) { + return rv; + } + + + // Get the sameTypeRoot tree item from the docshell + nsCOMPtr sameTypeRoot; + docShell->GetSameTypeRootTreeItem(getter_AddRefs(sameTypeRoot)); + NS_ASSERTION(sameTypeRoot, "No root tree item from docshell!"); + + // When navigating an iframe, the iframe may be https + // but its parents may not be. Check the parents to see if any of them are https. + // If none of the parents are https, allow the load. + if (aContentType == TYPE_SUBDOCUMENT && !rootHasSecureConnection) { + + bool httpsParentExists = false; + + nsCOMPtr parentTreeItem; + parentTreeItem = docShell; + + while(!httpsParentExists && parentTreeItem) { + nsCOMPtr parentAsNav(do_QueryInterface(parentTreeItem)); + NS_ASSERTION(parentAsNav, "No web navigation object from parent's docshell tree item"); + nsCOMPtr parentURI; + + parentAsNav->GetCurrentURI(getter_AddRefs(parentURI)); + if (!parentURI || NS_FAILED(parentURI->SchemeIs("https", &httpsParentExists))) { + // if getting the URI or the scheme fails, assume there is a https parent and break. + httpsParentExists = true; + break; + } + + // When the parent and the root are the same, we have traversed all the way up + // the same type docshell tree. Break out of the while loop. + if(sameTypeRoot == parentTreeItem) { + break; + } + + // update the parent to the grandparent. + nsCOMPtr newParentTreeItem; + parentTreeItem->GetSameTypeParent(getter_AddRefs(newParentTreeItem)); + parentTreeItem = newParentTreeItem; + } // end while loop. + + if (!httpsParentExists) { + *aDecision = nsIContentPolicy::ACCEPT; + return NS_OK; + } + } + + // Get the root document from the sameTypeRoot + nsCOMPtr rootDoc = do_GetInterface(sameTypeRoot); + NS_ASSERTION(rootDoc, "No root document from document shell root tree item."); + + // Get eventSink and the current security state from the docShell + nsCOMPtr eventSink = do_QueryInterface(docShell); + NS_ASSERTION(eventSink, "No eventSink from docShell."); + nsCOMPtr rootShell = do_GetInterface(sameTypeRoot); + NS_ASSERTION(rootShell, "No root docshell from document shell root tree item."); + uint32_t State = nsIWebProgressListener::STATE_IS_BROKEN; + nsCOMPtr securityUI; + rootShell->GetSecurityUI(getter_AddRefs(securityUI)); + // If there is no securityUI, document doesn't have a security state. + // Allow load and return early. + if (!securityUI) { + *aDecision = nsIContentPolicy::ACCEPT; + return NS_OK; + } + nsresult stateRV = securityUI->GetState(&State); + + // If the content is display content, and the pref says display content should be blocked, block it. + if (sBlockMixedDisplay && classification == eMixedDisplay) { + if (allowMixedContent) { + LogMixedContentMessage(classification, aContentLocation, rootDoc, eUserOverride); + *aDecision = nsIContentPolicy::ACCEPT; + rootDoc->SetHasMixedActiveContentLoaded(true); + if (!rootDoc->GetHasMixedDisplayContentLoaded() && NS_SUCCEEDED(stateRV)) { + rootDoc->SetHasMixedDisplayContentLoaded(true); + eventSink->OnSecurityChange(aRequestingContext, (State | nsIWebProgressListener::STATE_LOADED_MIXED_DISPLAY_CONTENT)); + } + } else { + *aDecision = nsIContentPolicy::REJECT_REQUEST; + LogMixedContentMessage(classification, aContentLocation, rootDoc, eBlocked); + if (!rootDoc->GetHasMixedDisplayContentBlocked() && NS_SUCCEEDED(stateRV)) { + rootDoc->SetHasMixedDisplayContentBlocked(true); + eventSink->OnSecurityChange(aRequestingContext, (State | nsIWebProgressListener::STATE_BLOCKED_MIXED_DISPLAY_CONTENT)); + } + } + return NS_OK; + + } else if (sBlockMixedScript && classification == eMixedScript) { + // If the content is active content, and the pref says active content should be blocked, block it + // unless the user has choosen to override the pref + if (allowMixedContent) { + LogMixedContentMessage(classification, aContentLocation, rootDoc, eUserOverride); + *aDecision = nsIContentPolicy::ACCEPT; + // See if the pref will change here. If it will, only then do we need to call OnSecurityChange() to update the UI. + if (rootDoc->GetHasMixedActiveContentLoaded()) { + return NS_OK; + } + rootDoc->SetHasMixedActiveContentLoaded(true); + + if (rootHasSecureConnection) { + // User has decided to override the pref and the root is https, so change the Security State. + if (rootDoc->GetHasMixedDisplayContentLoaded()) { + // If mixed display content is loaded, make sure to include that in the state. + eventSink->OnSecurityChange(aRequestingContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT | + nsIWebProgressListener::STATE_LOADED_MIXED_DISPLAY_CONTENT)); + } else { + eventSink->OnSecurityChange(aRequestingContext, (nsIWebProgressListener::STATE_IS_BROKEN | + nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT)); + } + return NS_OK; + } else { + // User has already overriden the pref and the root is not https; + // mixed content was allowed on an https subframe. + if (NS_SUCCEEDED(stateRV)) { + eventSink->OnSecurityChange(aRequestingContext, (State | nsIWebProgressListener::STATE_LOADED_MIXED_ACTIVE_CONTENT)); + } + return NS_OK; + } + } else { + //User has not overriden the pref by Disabling protection. Reject the request and update the security state. + *aDecision = nsIContentPolicy::REJECT_REQUEST; + LogMixedContentMessage(classification, aContentLocation, rootDoc, eBlocked); + // See if the pref will change here. If it will, only then do we need to call OnSecurityChange() to update the UI. + if (rootDoc->GetHasMixedActiveContentBlocked()) { + return NS_OK; + } + rootDoc->SetHasMixedActiveContentBlocked(true); + + // The user has not overriden the pref, so make sure they still have an option by calling eventSink + // which will invoke the doorhanger + if (NS_SUCCEEDED(stateRV)) { + eventSink->OnSecurityChange(aRequestingContext, (State | nsIWebProgressListener::STATE_BLOCKED_MIXED_ACTIVE_CONTENT)); + } + return NS_OK; + } + + } else { + // The content is not blocked by the mixed content prefs. + + // Log a message that we are loading mixed content. + LogMixedContentMessage(classification, aContentLocation, rootDoc, eUserOverride); + + // Fire the event from a script runner as it is unsafe to run script + // from within ShouldLoad + nsContentUtils::AddScriptRunner( + new nsMixedContentEvent(aRequestingContext, classification)); + return NS_OK; + } + + *aDecision = REJECT_REQUEST; + return NS_OK; +} + +NS_IMETHODIMP +nsMixedContentBlocker::ShouldProcess(uint32_t aContentType, + nsIURI* aContentLocation, + nsIURI* aRequestingLocation, + nsISupports* aRequestingContext, + const nsACString& aMimeGuess, + nsISupports* aExtra, + nsIPrincipal* aRequestPrincipal, + int16_t* aDecision) +{ + if (!aContentLocation) { + // aContentLocation may be null when a plugin is loading without an associated URI resource + if (aContentType == TYPE_OBJECT) { + return NS_OK; + } else { + return NS_ERROR_FAILURE; + } + } + + return ShouldLoad(aContentType, aContentLocation, aRequestingLocation, + aRequestingContext, aMimeGuess, aExtra, aRequestPrincipal, + aDecision); +}