diff options
Diffstat (limited to 'netwerk/url-classifier/nsChannelClassifier.cpp')
| -rw-r--r-- | netwerk/url-classifier/nsChannelClassifier.cpp | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/netwerk/url-classifier/nsChannelClassifier.cpp b/netwerk/url-classifier/nsChannelClassifier.cpp new file mode 100644 index 0000000000..b9bdb3a050 --- /dev/null +++ b/netwerk/url-classifier/nsChannelClassifier.cpp @@ -0,0 +1,483 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set sw=2 sts=2 ts=8 et tw=80 : */ +/* 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 "nsChannelClassifier.h" + +#include "nsCharSeparatedTokenizer.h" +#include "nsICacheEntry.h" +#include "nsICachingChannel.h" +#include "nsIChannel.h" +#include "nsIObserverService.h" +#include "nsIProtocolHandler.h" +#include "nsIScriptSecurityManager.h" +#include "nsNetUtil.h" +#include "nsXULAppAPI.h" +#include "nsQueryObject.h" +#include "nsPrintfCString.h" + +#include "mozilla/Components.h" +#include "mozilla/ErrorNames.h" +#include "mozilla/Logging.h" +#include "mozilla/Preferences.h" +#include "mozilla/net/UrlClassifierCommon.h" +#include "mozilla/net/UrlClassifierFeatureFactory.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/Services.h" + +namespace mozilla { +namespace net { + +#define URLCLASSIFIER_EXCEPTION_HOSTNAMES "urlclassifier.skipHostnames" + +// Put CachedPrefs in anonymous namespace to avoid any collision from outside of +// this file. +namespace { + +/** + * It is not recommended to read from Preference everytime a channel is + * connected. + * That is not fast and we should cache preference values and reuse them + */ +class CachedPrefs final { + public: + static CachedPrefs* GetInstance(); + + void Init(); + + nsCString GetExceptionHostnames() const { return mExceptionHostnames; } + void SetExceptionHostnames(const nsACString& aHostnames) { + mExceptionHostnames = aHostnames; + } + + private: + friend class StaticAutoPtr<CachedPrefs>; + CachedPrefs(); + ~CachedPrefs(); + + static void OnPrefsChange(const char* aPrefName, void*); + + nsCString mExceptionHostnames; + + static StaticAutoPtr<CachedPrefs> sInstance; +}; + +StaticAutoPtr<CachedPrefs> CachedPrefs::sInstance; + +// static +void CachedPrefs::OnPrefsChange(const char* aPref, void* aPrefs) { + auto* prefs = static_cast<CachedPrefs*>(aPrefs); + + if (!strcmp(aPref, URLCLASSIFIER_EXCEPTION_HOSTNAMES)) { + nsCString exceptionHostnames; + Preferences::GetCString(URLCLASSIFIER_EXCEPTION_HOSTNAMES, + exceptionHostnames); + ToLowerCase(exceptionHostnames); + prefs->SetExceptionHostnames(exceptionHostnames); + } +} + +void CachedPrefs::Init() { + Preferences::RegisterCallbackAndCall(CachedPrefs::OnPrefsChange, + URLCLASSIFIER_EXCEPTION_HOSTNAMES, this); +} + +// static +CachedPrefs* CachedPrefs::GetInstance() { + if (!sInstance) { + sInstance = new CachedPrefs(); + sInstance->Init(); + ClearOnShutdown(&sInstance); + } + MOZ_ASSERT(sInstance); + return sInstance; +} + +CachedPrefs::CachedPrefs() { MOZ_COUNT_CTOR(CachedPrefs); } + +CachedPrefs::~CachedPrefs() { + MOZ_COUNT_DTOR(CachedPrefs); + + Preferences::UnregisterCallback(CachedPrefs::OnPrefsChange, + URLCLASSIFIER_EXCEPTION_HOSTNAMES, this); +} + +} // anonymous namespace + +NS_IMPL_ISUPPORTS(nsChannelClassifier, nsIURIClassifierCallback, nsIObserver) + +nsChannelClassifier::nsChannelClassifier(nsIChannel* aChannel) + : mIsAllowListed(false), mSuspendedChannel(false), mChannel(aChannel) { + UC_LOG_LEAK(("nsChannelClassifier::nsChannelClassifier [this=%p]", this)); + MOZ_ASSERT(mChannel); +} + +nsChannelClassifier::~nsChannelClassifier() { + UC_LOG_LEAK(("nsChannelClassifier::~nsChannelClassifier [this=%p]", this)); +} + +void nsChannelClassifier::Start() { + nsresult rv = StartInternal(); + if (NS_FAILED(rv)) { + // If we aren't getting a callback for any reason, assume a good verdict and + // make sure we resume the channel if necessary. + OnClassifyComplete(NS_OK, ""_ns, ""_ns, ""_ns); + } +} + +nsresult nsChannelClassifier::StartInternal() { + // Should only be called in the parent process. + MOZ_ASSERT(XRE_IsParentProcess()); + + // Don't bother to run the classifier on a load that has already failed. + // (this might happen after a redirect) + nsresult status; + mChannel->GetStatus(&status); + if (NS_FAILED(status)) return status; + + // Don't bother to run the classifier on a cached load that was + // previously classified as good. + if (HasBeenClassified(mChannel)) { + return NS_ERROR_UNEXPECTED; + } + + nsCOMPtr<nsIURI> uri; + nsresult rv = mChannel->GetURI(getter_AddRefs(uri)); + NS_ENSURE_SUCCESS(rv, rv); + + // Don't bother checking certain types of URIs. + if (uri->SchemeIs("about")) { + return NS_ERROR_UNEXPECTED; + } + + bool hasFlags; + rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_DANGEROUS_TO_LOAD, + &hasFlags); + NS_ENSURE_SUCCESS(rv, rv); + if (hasFlags) return NS_ERROR_UNEXPECTED; + + rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_IS_LOCAL_FILE, + &hasFlags); + NS_ENSURE_SUCCESS(rv, rv); + if (hasFlags) return NS_ERROR_UNEXPECTED; + + rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_IS_UI_RESOURCE, + &hasFlags); + NS_ENSURE_SUCCESS(rv, rv); + if (hasFlags) return NS_ERROR_UNEXPECTED; + + rv = NS_URIChainHasFlags(uri, nsIProtocolHandler::URI_IS_LOCAL_RESOURCE, + &hasFlags); + NS_ENSURE_SUCCESS(rv, rv); + if (hasFlags) return NS_ERROR_UNEXPECTED; + + nsCString exceptionHostnames = + CachedPrefs::GetInstance()->GetExceptionHostnames(); + if (!exceptionHostnames.IsEmpty()) { + UC_LOG( + ("nsChannelClassifier::StartInternal - entitylisted hostnames = %s " + "[this=%p]", + exceptionHostnames.get(), this)); + if (IsHostnameEntitylisted(uri, exceptionHostnames)) { + return NS_ERROR_UNEXPECTED; + } + } + + nsCOMPtr<nsIURIClassifier> uriClassifier = + do_GetService(NS_URICLASSIFIERSERVICE_CONTRACTID, &rv); + if (rv == NS_ERROR_FACTORY_NOT_REGISTERED || rv == NS_ERROR_NOT_AVAILABLE) { + // no URI classifier, ignore this failure. + return NS_ERROR_NOT_AVAILABLE; + } + NS_ENSURE_SUCCESS(rv, rv); + + nsCOMPtr<nsIScriptSecurityManager> securityManager = + do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv); + NS_ENSURE_SUCCESS(rv, rv); + + nsCOMPtr<nsIPrincipal> principal; + rv = securityManager->GetChannelURIPrincipal(mChannel, + getter_AddRefs(principal)); + NS_ENSURE_SUCCESS(rv, rv); + + bool expectCallback; + if (UC_LOG_ENABLED()) { + nsCOMPtr<nsIURI> principalURI; + nsCString spec; + principal->GetAsciiSpec(spec); + spec.Truncate(std::min(spec.Length(), UrlClassifierCommon::sMaxSpecLength)); + UC_LOG( + ("nsChannelClassifier::StartInternal - classifying principal %s on " + "channel %p [this=%p]", + spec.get(), mChannel.get(), this)); + } + // The classify is running in parent process, no need to give a valid event + // target + rv = uriClassifier->Classify(principal, this, &expectCallback); + if (NS_FAILED(rv)) { + return rv; + } + + if (expectCallback) { + // Suspend the channel, it will be resumed when we get the classifier + // callback. + rv = mChannel->Suspend(); + if (NS_FAILED(rv)) { + // Some channels (including nsJSChannel) fail on Suspend. This + // shouldn't be fatal, but will prevent malware from being + // blocked on these channels. + UC_LOG_WARN( + ("nsChannelClassifier::StartInternal - couldn't suspend channel " + "[this=%p]", + this)); + return rv; + } + + mSuspendedChannel = true; + UC_LOG( + ("nsChannelClassifier::StartInternal - suspended channel %p [this=%p]", + mChannel.get(), this)); + } else { + UC_LOG_WARN(( + "nsChannelClassifier::StartInternal - not expecting callback [this=%p]", + this)); + return NS_ERROR_FAILURE; + } + + // Add an observer for shutdown + AddShutdownObserver(); + return NS_OK; +} + +bool nsChannelClassifier::IsHostnameEntitylisted( + nsIURI* aUri, const nsACString& aEntitylisted) { + nsAutoCString host; + nsresult rv = aUri->GetHost(host); + if (NS_FAILED(rv) || host.IsEmpty()) { + return false; + } + ToLowerCase(host); + + for (const nsACString& token : + nsCCharSeparatedTokenizer(aEntitylisted, ',').ToRange()) { + if (token.Equals(host)) { + UC_LOG( + ("nsChannelClassifier::StartInternal - skipping %s (entitylisted) " + "[this=%p]", + host.get(), this)); + return true; + } + } + + return false; +} + +// Note in the cache entry that this URL was classified, so that future +// cached loads don't need to be checked. +void nsChannelClassifier::MarkEntryClassified(nsresult status) { + // Should only be called in the parent process. + MOZ_ASSERT(XRE_IsParentProcess()); + + // Don't cache tracking classifications because we support allowlisting. + if (UrlClassifierFeatureFactory::IsClassifierBlockingErrorCode(status) || + mIsAllowListed) { + return; + } + + if (UC_LOG_ENABLED()) { + nsAutoCString errorName; + GetErrorName(status, errorName); + nsCOMPtr<nsIURI> uri; + mChannel->GetURI(getter_AddRefs(uri)); + nsAutoCString spec; + uri->GetAsciiSpec(spec); + spec.Truncate(std::min(spec.Length(), UrlClassifierCommon::sMaxSpecLength)); + UC_LOG( + ("nsChannelClassifier::MarkEntryClassified - result is %s " + "for uri %s [this=%p, channel=%p]", + errorName.get(), spec.get(), this, mChannel.get())); + } + + nsCOMPtr<nsICachingChannel> cachingChannel = do_QueryInterface(mChannel); + if (!cachingChannel) { + return; + } + + nsCOMPtr<nsISupports> cacheToken; + cachingChannel->GetCacheToken(getter_AddRefs(cacheToken)); + if (!cacheToken) { + return; + } + + nsCOMPtr<nsICacheEntry> cacheEntry = do_QueryInterface(cacheToken); + if (!cacheEntry) { + return; + } + + cacheEntry->SetMetaDataElement("necko:classified", + NS_SUCCEEDED(status) ? "1" : nullptr); +} + +bool nsChannelClassifier::HasBeenClassified(nsIChannel* aChannel) { + // Should only be called in the parent process. + MOZ_ASSERT(XRE_IsParentProcess()); + + nsCOMPtr<nsICachingChannel> cachingChannel = do_QueryInterface(aChannel); + if (!cachingChannel) { + return false; + } + + // Only check the tag if we are loading from the cache without + // validation. + bool fromCache; + if (NS_FAILED(cachingChannel->IsFromCache(&fromCache)) || !fromCache) { + return false; + } + + nsCOMPtr<nsISupports> cacheToken; + cachingChannel->GetCacheToken(getter_AddRefs(cacheToken)); + if (!cacheToken) { + return false; + } + + nsCOMPtr<nsICacheEntry> cacheEntry = do_QueryInterface(cacheToken); + if (!cacheEntry) { + return false; + } + + nsCString tag; + cacheEntry->GetMetaDataElement("necko:classified", getter_Copies(tag)); + return tag.EqualsLiteral("1"); +} + +/* static */ +nsresult nsChannelClassifier::SendThreatHitReport(nsIChannel* aChannel, + const nsACString& aProvider, + const nsACString& aList, + const nsACString& aFullHash) { + NS_ENSURE_ARG_POINTER(aChannel); + + nsAutoCString provider(aProvider); + nsPrintfCString reportEnablePref( + "browser.safebrowsing.provider.%s.dataSharing.enabled", provider.get()); + if (!Preferences::GetBool(reportEnablePref.get(), false)) { + UC_LOG( + ("nsChannelClassifier::SendThreatHitReport - data sharing disabled for " + "%s", + provider.get())); + return NS_OK; + } + + nsCOMPtr<nsIURIClassifier> uriClassifier = + components::UrlClassifierDB::Service(); + if (!uriClassifier) { + return NS_ERROR_UNEXPECTED; + } + + nsresult rv = + uriClassifier->SendThreatHitReport(aChannel, aProvider, aList, aFullHash); + NS_ENSURE_SUCCESS(rv, rv); + + return NS_OK; +} + +NS_IMETHODIMP +nsChannelClassifier::OnClassifyComplete(nsresult aErrorCode, + const nsACString& aList, + const nsACString& aProvider, + const nsACString& aFullHash) { + // Should only be called in the parent process. + MOZ_ASSERT(XRE_IsParentProcess()); + MOZ_ASSERT( + !UrlClassifierFeatureFactory::IsClassifierBlockingErrorCode(aErrorCode)); + + if (mSuspendedChannel) { + MarkEntryClassified(aErrorCode); + + if (NS_FAILED(aErrorCode)) { + if (UC_LOG_ENABLED()) { + nsAutoCString errorName; + GetErrorName(aErrorCode, errorName); + + nsCOMPtr<nsIURI> uri; + mChannel->GetURI(getter_AddRefs(uri)); + nsCString spec = uri->GetSpecOrDefault(); + spec.Truncate( + std::min(spec.Length(), UrlClassifierCommon::sMaxSpecLength)); + UC_LOG( + ("nsChannelClassifier::OnClassifyComplete - cancelling channel %p " + "for %s " + "with error code %s [this=%p]", + mChannel.get(), spec.get(), errorName.get(), this)); + } + + // Channel will be cancelled (page element blocked) due to Safe Browsing. + // Do update the security state of the document and fire a security + // change event. + UrlClassifierCommon::SetBlockedContent(mChannel, aErrorCode, aList, + aProvider, aFullHash); + + if (aErrorCode == NS_ERROR_MALWARE_URI || + aErrorCode == NS_ERROR_PHISHING_URI || + aErrorCode == NS_ERROR_UNWANTED_URI || + aErrorCode == NS_ERROR_HARMFUL_URI) { + SendThreatHitReport(mChannel, aProvider, aList, aFullHash); + } + + mChannel->Cancel(aErrorCode); + } + UC_LOG( + ("nsChannelClassifier::OnClassifyComplete - resuming channel %p " + "[this=%p]", + mChannel.get(), this)); + mChannel->Resume(); + } + + mChannel = nullptr; + RemoveShutdownObserver(); + + return NS_OK; +} + +void nsChannelClassifier::AddShutdownObserver() { + nsCOMPtr<nsIObserverService> observerService = + mozilla::services::GetObserverService(); + if (observerService) { + observerService->AddObserver(this, "profile-change-net-teardown", false); + } +} + +void nsChannelClassifier::RemoveShutdownObserver() { + nsCOMPtr<nsIObserverService> observerService = + mozilla::services::GetObserverService(); + if (observerService) { + observerService->RemoveObserver(this, "profile-change-net-teardown"); + } +} + +/////////////////////////////////////////////////////////////////////////////// +// nsIObserver implementation +NS_IMETHODIMP +nsChannelClassifier::Observe(nsISupports* aSubject, const char* aTopic, + const char16_t* aData) { + if (!strcmp(aTopic, "profile-change-net-teardown")) { + // If we aren't getting a callback for any reason, make sure + // we resume the channel. + + if (mChannel && mSuspendedChannel) { + mSuspendedChannel = false; + mChannel->Cancel(NS_ERROR_ABORT); + mChannel->Resume(); + mChannel = nullptr; + } + + RemoveShutdownObserver(); + } + + return NS_OK; +} + +} // namespace net +} // namespace mozilla |