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/* -*- 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
#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