netwerk/base/nsChannelClassifier.cpp
author Andrew Osmond <aosmond@mozilla.com>
Fri, 17 Nov 2017 06:45:28 -0500
changeset 392351 b9a29d94ccac646c9336fa75e084bbc8581501ad
parent 386401 2ba74c11715485090a2179a951a7273f56e0cd06
child 394886 611182749ede187917dee4c304b783a09d6ab6a8
permissions -rw-r--r--
Bug 1368776 - Part 15. Cache flags passed to ImageResource::GetImageContainerImpl for consistency. r=tnikkel When FLAG_HIGH_QUALITY_SCALING is used, we need to make sure we continue using that flag when we update the container. We should also use it for comparing whether or not an existing image container is equivalent.

/* -*- 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 "mozIThirdPartyUtil.h"
#include "nsCharSeparatedTokenizer.h"
#include "nsContentUtils.h"
#include "nsIAddonPolicyService.h"
#include "nsICacheEntry.h"
#include "nsICachingChannel.h"
#include "nsIChannel.h"
#include "nsIClassOfService.h"
#include "nsIDocShell.h"
#include "nsIDocument.h"
#include "nsIDOMDocument.h"
#include "nsIHttpChannel.h"
#include "nsIHttpChannelInternal.h"
#include "nsIIOService.h"
#include "nsIParentChannel.h"
#include "nsIPermissionManager.h"
#include "nsIPrivateBrowsingTrackingProtectionWhitelist.h"
#include "nsIProtocolHandler.h"
#include "nsIScriptError.h"
#include "nsIScriptSecurityManager.h"
#include "nsISecureBrowserUI.h"
#include "nsISecurityEventSink.h"
#include "nsISupportsPriority.h"
#include "nsIURL.h"
#include "nsIWebProgressListener.h"
#include "nsNetUtil.h"
#include "nsPIDOMWindow.h"
#include "nsXULAppAPI.h"
#include "nsQueryObject.h"
#include "nsIUrlClassifierDBService.h"
#include "nsIURLFormatter.h"

#include "mozilla/ErrorNames.h"
#include "mozilla/Logging.h"
#include "mozilla/Preferences.h"
#include "mozilla/net/HttpBaseChannel.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Unused.h"

namespace mozilla {
namespace net {

//
// MOZ_LOG=nsChannelClassifier:5
//
static LazyLogModule gChannelClassifierLog("nsChannelClassifier");


#undef LOG
#define LOG(args)     MOZ_LOG(gChannelClassifierLog, LogLevel::Debug, args)
#define LOG_ENABLED() MOZ_LOG_TEST(gChannelClassifierLog, LogLevel::Debug)

#define URLCLASSIFIER_SKIP_HOSTNAMES       "urlclassifier.skipHostnames"
#define URLCLASSIFIER_TRACKING_WHITELIST   "urlclassifier.trackingWhitelistTable"
#define URLCLASSIFIER_TRACKING_TABLE       "urlclassifier.trackingTable"

// 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();
  bool IsAllowListExample() { return sAllowListExample;}
  bool IsLowerNetworkPriority() { return sLowerNetworkPriority;}
  bool IsAnnotateChannelEnabled() { return sAnnotateChannelEnabled;}
  nsCString GetTrackingWhiteList() { return mTrackingWhitelist; }
  void SetTrackingWhiteList(const nsACString& aList) { mTrackingWhitelist = aList; }
  nsCString GetSkipHostnames() { return mSkipHostnames; }
  void SetSkipHostnames(const nsACString& aHostnames) { mSkipHostnames = aHostnames; }
  void SetTrackingBlackList(const nsACString& aList) { mTrackingBlacklist = aList; }
  nsCString GetTrackingBlackList() { return mTrackingBlacklist; }

private:
  friend class StaticAutoPtr<CachedPrefs>;
  CachedPrefs();
  ~CachedPrefs();

  static void OnPrefsChange(const char* aPrefName, void* );

  // Whether channels should be annotated as being on the tracking protection
  // list.
  static bool sAnnotateChannelEnabled;
  // Whether the priority of the channels annotated as being on the tracking
  // protection list should be lowered.
  static bool sLowerNetworkPriority;
  static bool sAllowListExample;

  nsCString mTrackingWhitelist;
  nsCString mSkipHostnames;
  nsCString mTrackingBlacklist;

  static StaticAutoPtr<CachedPrefs> sInstance;
};

bool CachedPrefs::sAllowListExample = false;
bool CachedPrefs::sLowerNetworkPriority = false;
bool CachedPrefs::sAnnotateChannelEnabled = false;

StaticAutoPtr<CachedPrefs> CachedPrefs::sInstance;

// static
void
CachedPrefs::OnPrefsChange(const char* aPref, void* aClosure)
{
  CachedPrefs* prefs = static_cast<CachedPrefs*> (aClosure);

  if (!strcmp(aPref, URLCLASSIFIER_SKIP_HOSTNAMES)) {
    nsCString skipHostnames;
    Preferences::GetCString(URLCLASSIFIER_SKIP_HOSTNAMES, skipHostnames);
    ToLowerCase(skipHostnames);
    prefs->SetSkipHostnames(skipHostnames);
  } else if (!strcmp(aPref, URLCLASSIFIER_TRACKING_WHITELIST)) {
    nsCString trackingWhitelist;
    Preferences::GetCString(URLCLASSIFIER_TRACKING_WHITELIST,
                            trackingWhitelist);
    prefs->SetTrackingWhiteList(trackingWhitelist);
  } else if (!strcmp(aPref, URLCLASSIFIER_TRACKING_TABLE)) {
    nsCString trackingBlacklist;
    Preferences::GetCString(URLCLASSIFIER_TRACKING_TABLE, trackingBlacklist);
    prefs->SetTrackingBlackList(trackingBlacklist);
  }
}

void
CachedPrefs::Init()
{
  Preferences::AddBoolVarCache(&sAnnotateChannelEnabled,
                               "privacy.trackingprotection.annotate_channels");
  Preferences::AddBoolVarCache(&sLowerNetworkPriority,
                               "privacy.trackingprotection.lower_network_priority");
  Preferences::AddBoolVarCache(&sAllowListExample,
                               "channelclassifier.allowlist_example");
  Preferences::RegisterCallbackAndCall(CachedPrefs::OnPrefsChange,
                                       URLCLASSIFIER_SKIP_HOSTNAMES, this);
  Preferences::RegisterCallbackAndCall(CachedPrefs::OnPrefsChange,
                                       URLCLASSIFIER_TRACKING_WHITELIST, this);
  Preferences::RegisterCallbackAndCall(CachedPrefs::OnPrefsChange,
                                       URLCLASSIFIER_TRACKING_TABLE, 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_SKIP_HOSTNAMES, this);
  Preferences::UnregisterCallback(CachedPrefs::OnPrefsChange, URLCLASSIFIER_TRACKING_WHITELIST, this);
  Preferences::UnregisterCallback(CachedPrefs::OnPrefsChange, URLCLASSIFIER_TRACKING_TABLE, this);
}
} // anonymous namespace

static void
SetIsTrackingResourceHelper(nsIChannel* aChannel)
{
  MOZ_ASSERT(aChannel);

  nsCOMPtr<nsIParentChannel> parentChannel;
  NS_QueryNotificationCallbacks(aChannel, parentChannel);
  if (parentChannel) {
    // This channel is a parent-process proxy for a child process
    // request. We should notify the child process as well.
    parentChannel->NotifyTrackingResource();
  }

  RefPtr<HttpBaseChannel> httpChannel = do_QueryObject(aChannel);
  if (httpChannel) {
    httpChannel->SetIsTrackingResource();
  }
}

static void
LowerPriorityHelper(nsIChannel* aChannel)
{
  MOZ_ASSERT(aChannel);

  bool isBlockingResource = false;

  nsCOMPtr<nsIClassOfService> cos(do_QueryInterface(aChannel));
  if (cos) {
    if (nsContentUtils::IsTailingEnabled()) {
      uint32_t cosFlags = 0;
      cos->GetClassFlags(&cosFlags);
      isBlockingResource = cosFlags & (nsIClassOfService::UrgentStart |
                                       nsIClassOfService::Leader |
                                       nsIClassOfService::Unblocked);

      // Requests not allowed to be tailed are usually those with higher
      // prioritization.  That overweights being a tracker: don't throttle
      // them when not in background.
      if (!(cosFlags & nsIClassOfService::TailForbidden)) {
        cos->AddClassFlags(nsIClassOfService::Throttleable);
      }
    } else {
      // Yes, we even don't want to evaluate the isBlockingResource when tailing is off
      // see bug 1395525.

      cos->AddClassFlags(nsIClassOfService::Throttleable);
    }
  }

  if (!isBlockingResource) {
    nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(aChannel);
    if (p) {
      p->SetPriority(nsISupportsPriority::PRIORITY_LOWEST);
    }
  }
}

NS_IMPL_ISUPPORTS(nsChannelClassifier,
                  nsIURIClassifierCallback,
                  nsIObserver)

nsChannelClassifier::nsChannelClassifier(nsIChannel *aChannel)
  : mIsAllowListed(false),
    mSuspendedChannel(false),
    mChannel(aChannel),
    mTrackingProtectionEnabled(Nothing()),
    mTrackingAnnotationEnabled(Nothing())
{
  LOG(("nsChannelClassifier::nsChannelClassifier %p", this));
  MOZ_ASSERT(mChannel);
}

nsChannelClassifier::~nsChannelClassifier()
{
  LOG(("nsChannelClassifier::~nsChannelClassifier %p", this));
}

bool
nsChannelClassifier::ShouldEnableTrackingProtection()
{
  if (mTrackingProtectionEnabled) {
    return mTrackingProtectionEnabled.value();
  }

  mTrackingProtectionEnabled = Some(false);

  nsCOMPtr<nsILoadContext> loadContext;
  NS_QueryNotificationCallbacks(mChannel, loadContext);
  if (loadContext && loadContext->UseTrackingProtection()) {
    Unused << ShouldEnableTrackingProtectionInternal(
      mChannel, false, mTrackingProtectionEnabled.ptr());
  }

  return mTrackingProtectionEnabled.value();
}

bool
nsChannelClassifier::ShouldEnableTrackingAnnotation()
{
  if (mTrackingAnnotationEnabled) {
    return mTrackingAnnotationEnabled.value();
  }

  mTrackingAnnotationEnabled = Some(false);

  if (!CachedPrefs::GetInstance()->IsAnnotateChannelEnabled()) {
    return mTrackingAnnotationEnabled.value();
  }

  // If tracking protection is enabled, no need to do channel annotation.
  if (ShouldEnableTrackingProtection()) {
    return mTrackingAnnotationEnabled.value();
  }

  // To prevent calling ShouldEnableTrackingProtectionInternal() again,
  // check loadContext->UseTrackingProtection() here.
  // If loadContext->UseTrackingProtection() is true, here it means
  // ShouldEnableTrackingProtectionInternal() has been called before in
  // ShouldEnableTrackingProtection() above and the result is false.
  // So, we can just return false.
  nsCOMPtr<nsILoadContext> loadContext;
  NS_QueryNotificationCallbacks(mChannel, loadContext);
  if (loadContext && loadContext->UseTrackingProtection()) {
    return mTrackingAnnotationEnabled.value();
  }

  Unused << ShouldEnableTrackingProtectionInternal(
      mChannel, true, mTrackingAnnotationEnabled.ptr());

  return mTrackingAnnotationEnabled.value();
}

nsresult
nsChannelClassifier::ShouldEnableTrackingProtectionInternal(
                                                         nsIChannel *aChannel,
                                                         bool aAnnotationsOnly,
                                                         bool *result)
{
    // Should only be called in the parent process.
    MOZ_ASSERT(XRE_IsParentProcess());

    NS_ENSURE_ARG(result);
    *result = false;

    nsresult rv;
    nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
        do_GetService(THIRDPARTYUTIL_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIHttpChannelInternal> chan = do_QueryInterface(aChannel, &rv);
    if (NS_FAILED(rv) || !chan) {
      LOG(("nsChannelClassifier[%p]: Not an HTTP channel", this));
      return NS_OK;
    }

    nsCOMPtr<nsIURI> topWinURI;
    rv = chan->GetTopWindowURI(getter_AddRefs(topWinURI));
    NS_ENSURE_SUCCESS(rv, rv);

    if (!topWinURI) {
      LOG(("nsChannelClassifier[%p]: No window URI\n", this));
    }

    nsCOMPtr<nsIURI> chanURI;
    rv = aChannel->GetURI(getter_AddRefs(chanURI));
    NS_ENSURE_SUCCESS(rv, rv);

    // Third party checks don't work for chrome:// URIs in mochitests, so just
    // default to isThirdParty = true. We check isThirdPartyWindow to expand
    // the list of domains that are considered first party (e.g., if
    // facebook.com includes an iframe from fatratgames.com, all subsources
    // included in that iframe are considered third-party with
    // isThirdPartyChannel, even if they are not third-party w.r.t.
    // facebook.com), and isThirdPartyChannel to prevent top-level navigations
    // from being detected as third-party.
    bool isThirdPartyChannel = true;
    bool isThirdPartyWindow = true;
    thirdPartyUtil->IsThirdPartyURI(chanURI, topWinURI, &isThirdPartyWindow);
    thirdPartyUtil->IsThirdPartyChannel(aChannel, nullptr, &isThirdPartyChannel);
    if (!isThirdPartyWindow || !isThirdPartyChannel) {
      *result = false;
      if (LOG_ENABLED()) {
        LOG(("nsChannelClassifier[%p]: Skipping tracking protection checks "
             "for first party or top-level load channel[%p] with uri %s",
             this, aChannel, chanURI->GetSpecOrDefault().get()));
      }
      return NS_OK;
    }

    // Unlike full Tracking Protection, annotations don't block anything
    // so we don't need to take into account add-ons or user exceptions.
    if (aAnnotationsOnly) {
      *result = true;
      return NS_OK;
    }

    if (AddonMayLoad(aChannel, chanURI)) {
        return NS_OK;
    }

    nsCOMPtr<nsIIOService> ios = do_GetService(NS_IOSERVICE_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    if (!topWinURI && CachedPrefs::GetInstance()->IsAllowListExample()) {
      LOG(("nsChannelClassifier[%p]: Allowlisting test domain\n", this));
      rv = ios->NewURI(NS_LITERAL_CSTRING("http://allowlisted.example.com"),
                       nullptr, nullptr, getter_AddRefs(topWinURI));
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // Take the host/port portion so we can allowlist by site. Also ignore the
    // scheme, since users who put sites on the allowlist probably don't expect
    // allowlisting to depend on scheme.
    nsCOMPtr<nsIURL> url = do_QueryInterface(topWinURI, &rv);
    if (NS_FAILED(rv)) {
      return rv; // normal for some loads, no need to print a warning
    }

    nsCString escaped(NS_LITERAL_CSTRING("https://"));
    nsAutoCString temp;
    rv = url->GetHostPort(temp);
    NS_ENSURE_SUCCESS(rv, rv);
    escaped.Append(temp);

    // Stuff the whole thing back into a URI for the permission manager.
    rv = ios->NewURI(escaped, nullptr, nullptr, getter_AddRefs(topWinURI));
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIPermissionManager> permMgr =
        do_GetService(NS_PERMISSIONMANAGER_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    uint32_t permissions = nsIPermissionManager::UNKNOWN_ACTION;
    rv = permMgr->TestPermission(topWinURI, "trackingprotection", &permissions);
    NS_ENSURE_SUCCESS(rv, rv);

    if (permissions == nsIPermissionManager::ALLOW_ACTION) {
      LOG(("nsChannelClassifier[%p]: Allowlisting channel[%p] for %s", this,
           aChannel, escaped.get()));
      mIsAllowListed = true;
      *result = false;
    } else {
      *result = true;
    }

    // In Private Browsing Mode we also check against an in-memory list.
    if (NS_UsePrivateBrowsing(aChannel)) {
      nsCOMPtr<nsIPrivateBrowsingTrackingProtectionWhitelist> pbmtpWhitelist =
          do_GetService(NS_PBTRACKINGPROTECTIONWHITELIST_CONTRACTID, &rv);
      NS_ENSURE_SUCCESS(rv, rv);

      bool exists = false;
      rv = pbmtpWhitelist->ExistsInAllowList(topWinURI, &exists);
      NS_ENSURE_SUCCESS(rv, rv);

      if (exists) {
        mIsAllowListed = true;
        LOG(("nsChannelClassifier[%p]: Allowlisting channel[%p] in PBM for %s",
             this, aChannel, escaped.get()));
      }

      *result = !exists;
    }

    // Tracking protection will be enabled so return without updating
    // the security state. If any channels are subsequently cancelled
    // (page elements blocked) the state will be then updated.
    if (*result) {
      if (LOG_ENABLED()) {
        LOG(("nsChannelClassifier[%p]: Enabling tracking protection checks on "
             "channel[%p] with uri %s for toplevel window %s", this, aChannel,
             chanURI->GetSpecOrDefault().get(),
             topWinURI->GetSpecOrDefault().get()));
      }
      return NS_OK;
    }

    // Tracking protection will be disabled so update the security state
    // of the document and fire a secure change event. If we can't get the
    // window for the channel, then the shield won't show up so we can't send
    // an event to the securityUI anyway.
    return NotifyTrackingProtectionDisabled(aChannel);
}

bool
nsChannelClassifier::AddonMayLoad(nsIChannel *aChannel, nsIURI *aUri)
{
    nsCOMPtr<nsILoadInfo> channelLoadInfo = aChannel->GetLoadInfo();
    if (!channelLoadInfo)
        return false;

    // loadingPrincipal is used here to ensure we are loading into an
    // addon principal.  This allows an addon, with explicit permission, to
    // call out to API endpoints that may otherwise get blocked.
    nsIPrincipal* loadingPrincipal = channelLoadInfo->LoadingPrincipal();
    if (!loadingPrincipal)
        return false;

    return BasePrincipal::Cast(loadingPrincipal)->AddonAllowsLoad(aUri, true);
}

// static
nsresult
nsChannelClassifier::NotifyTrackingProtectionDisabled(nsIChannel *aChannel)
{
    // Can be called in EITHER the parent or child process.
    nsCOMPtr<nsIParentChannel> parentChannel;
    NS_QueryNotificationCallbacks(aChannel, parentChannel);
    if (parentChannel) {
      // This channel is a parent-process proxy for a child process request.
      // Tell the child process channel to do this instead.
      parentChannel->NotifyTrackingProtectionDisabled();
      return NS_OK;
    }

    nsresult rv;
    nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
        do_GetService(THIRDPARTYUTIL_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<mozIDOMWindowProxy> win;
    rv = thirdPartyUtil->GetTopWindowForChannel(aChannel, getter_AddRefs(win));
    NS_ENSURE_SUCCESS(rv, rv);

    auto* pwin = nsPIDOMWindowOuter::From(win);
    nsCOMPtr<nsIDocShell> docShell = pwin->GetDocShell();
    if (!docShell) {
      return NS_OK;
    }
    nsCOMPtr<nsIDocument> doc = docShell->GetDocument();
    NS_ENSURE_TRUE(doc, NS_OK);

    // Notify nsIWebProgressListeners of this security event.
    // Can be used to change the UI state.
    nsCOMPtr<nsISecurityEventSink> eventSink = do_QueryInterface(docShell, &rv);
    NS_ENSURE_SUCCESS(rv, NS_OK);
    uint32_t state = 0;
    nsCOMPtr<nsISecureBrowserUI> securityUI;
    docShell->GetSecurityUI(getter_AddRefs(securityUI));
    if (!securityUI) {
      return NS_OK;
    }
    doc->SetHasTrackingContentLoaded(true);
    securityUI->GetState(&state);
    state |= nsIWebProgressListener::STATE_LOADED_TRACKING_CONTENT;
    eventSink->OnSecurityChange(nullptr, state);

    return NS_OK;
}

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_LITERAL_CSTRING(""),NS_LITERAL_CSTRING(""),
                       NS_LITERAL_CSTRING(""));
  }
}

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.
    bool isAbout = false;
    rv = uri->SchemeIs("about", &isAbout);
    NS_ENSURE_SUCCESS(rv, rv);
    if (isAbout) 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 skipHostnames = CachedPrefs::GetInstance()->GetSkipHostnames();
    if (!skipHostnames.IsEmpty()) {
      LOG(("nsChannelClassifier[%p]:StartInternal whitelisted hostnames = %s",
           this, skipHostnames.get()));
      if (IsHostnameWhitelisted(uri, skipHostnames)) {
        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 (LOG_ENABLED()) {
      nsCOMPtr<nsIURI> principalURI;
      principal->GetURI(getter_AddRefs(principalURI));
      LOG(("nsChannelClassifier[%p]: Classifying principal %s on channel with "
           "uri %s", this, principalURI->GetSpecOrDefault().get(),
           uri->GetSpecOrDefault().get()));
    }
    // The classify is running in parent process, no need to give a valid event
    // target
    rv = uriClassifier->Classify(principal, nullptr,
                                 false,
                                 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.
            LOG(("nsChannelClassifier[%p]: Couldn't suspend channel", this));
            return rv;
        }

        mSuspendedChannel = true;
        LOG(("nsChannelClassifier[%p]: suspended channel %p",
             this, mChannel.get()));
    } else {
        LOG(("nsChannelClassifier[%p]: not expecting callback", this));
        return NS_ERROR_FAILURE;
    }

    // Add an observer for shutdown
    AddShutdownObserver();
    return NS_OK;
}

bool
nsChannelClassifier::IsHostnameWhitelisted(nsIURI *aUri,
                                           const nsACString &aWhitelisted)
{
  nsAutoCString host;
  nsresult rv = aUri->GetHost(host);
  if (NS_FAILED(rv) || host.IsEmpty()) {
    return false;
  }
  ToLowerCase(host);

  nsCCharSeparatedTokenizer tokenizer(aWhitelisted, ',');
  while (tokenizer.hasMoreTokens()) {
    const nsACString& token = tokenizer.nextToken();
    if (token.Equals(host)) {
      LOG(("nsChannelClassifier[%p]:StartInternal skipping %s (whitelisted)",
           this, host.get()));
      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 (status == NS_ERROR_TRACKING_URI || mIsAllowListed) {
        return;
    }

    if (LOG_ENABLED()) {
      nsAutoCString errorName;
      GetErrorName(status, errorName);
      nsCOMPtr<nsIURI> uri;
      mChannel->GetURI(getter_AddRefs(uri));
      nsAutoCString spec;
      uri->GetAsciiSpec(spec);
      LOG(("nsChannelClassifier::MarkEntryClassified[%s] %s",
           errorName.get(), spec.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
bool
nsChannelClassifier::SameLoadingURI(nsIDocument *aDoc, nsIChannel *aChannel)
{
  nsCOMPtr<nsIURI> docURI = aDoc->GetDocumentURI();
  nsCOMPtr<nsILoadInfo> channelLoadInfo = aChannel->GetLoadInfo();
  if (!channelLoadInfo || !docURI) {
    return false;
  }

  nsCOMPtr<nsIPrincipal> channelLoadingPrincipal = channelLoadInfo->LoadingPrincipal();
  if (!channelLoadingPrincipal) {
    // TYPE_DOCUMENT loads will not have a channelLoadingPrincipal. But top level
    // loads should not be blocked by Tracking Protection, so we will return
    // false
    return false;
  }
  nsCOMPtr<nsIURI> channelLoadingURI;
  channelLoadingPrincipal->GetURI(getter_AddRefs(channelLoadingURI));
  if (!channelLoadingURI) {
    return false;
  }
  bool equals = false;
  nsresult rv = docURI->EqualsExceptRef(channelLoadingURI, &equals);
  return NS_SUCCEEDED(rv) && equals;
}

// static
nsresult
nsChannelClassifier::SetBlockedContent(nsIChannel *channel,
                                       nsresult aErrorCode,
                                       const nsACString& aList,
                                       const nsACString& aProvider,
                                       const nsACString& aFullHash)
{
  NS_ENSURE_ARG(!aList.IsEmpty());

  // Can be called in EITHER the parent or child process.
  nsCOMPtr<nsIParentChannel> parentChannel;
  NS_QueryNotificationCallbacks(channel, parentChannel);
  if (parentChannel) {
    // This channel is a parent-process proxy for a child process request.
    // Tell the child process channel to do this instead.
    parentChannel->SetClassifierMatchedInfo(aList, aProvider, aFullHash);
    return NS_OK;
  }

  nsresult rv;
  nsCOMPtr<nsIClassifiedChannel> classifiedChannel = do_QueryInterface(channel, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  if (classifiedChannel) {
    classifiedChannel->SetMatchedInfo(aList, aProvider, aFullHash);
  }

  nsCOMPtr<mozIDOMWindowProxy> win;
  nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil =
    do_GetService(THIRDPARTYUTIL_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, NS_OK);
  rv = thirdPartyUtil->GetTopWindowForChannel(channel, getter_AddRefs(win));
  NS_ENSURE_SUCCESS(rv, NS_OK);
  auto* pwin = nsPIDOMWindowOuter::From(win);
  nsCOMPtr<nsIDocShell> docShell = pwin->GetDocShell();
  if (!docShell) {
    return NS_OK;
  }
  nsCOMPtr<nsIDocument> doc = docShell->GetDocument();
  NS_ENSURE_TRUE(doc, NS_OK);

  // This event might come after the user has navigated to another page.
  // To prevent showing the TrackingProtection UI on the wrong page, we need to
  // check that the loading URI for the channel is the same as the URI currently
  // loaded in the document.
  if (!SameLoadingURI(doc, channel)) {
    return NS_OK;
  }

  // Notify nsIWebProgressListeners of this security event.
  // Can be used to change the UI state.
  nsCOMPtr<nsISecurityEventSink> eventSink = do_QueryInterface(docShell, &rv);
  NS_ENSURE_SUCCESS(rv, NS_OK);
  uint32_t state = 0;
  nsCOMPtr<nsISecureBrowserUI> securityUI;
  docShell->GetSecurityUI(getter_AddRefs(securityUI));
  if (!securityUI) {
    return NS_OK;
  }
  securityUI->GetState(&state);
  if (aErrorCode == NS_ERROR_TRACKING_URI) {
    doc->SetHasTrackingContentBlocked(true);
    state |= nsIWebProgressListener::STATE_BLOCKED_TRACKING_CONTENT;
  } else {
    state |= nsIWebProgressListener::STATE_BLOCKED_UNSAFE_CONTENT;
  }

  eventSink->OnSecurityChange(channel, state);

  // Log a warning to the web console.
  nsCOMPtr<nsIURI> uri;
  channel->GetURI(getter_AddRefs(uri));
  NS_ConvertUTF8toUTF16 spec(uri->GetSpecOrDefault());
  const char16_t* params[] = { spec.get() };
  const char* message = (aErrorCode == NS_ERROR_TRACKING_URI) ?
    "TrackingUriBlocked" : "UnsafeUriBlocked";
  nsCString category = (aErrorCode == NS_ERROR_TRACKING_URI) ?
    NS_LITERAL_CSTRING("Tracking Protection") :
    NS_LITERAL_CSTRING("Safe Browsing");

  nsContentUtils::ReportToConsole(nsIScriptError::warningFlag,
                                  category,
                                  doc,
                                  nsContentUtils::eNECKO_PROPERTIES,
                                  message,
                                  params, ArrayLength(params));

  return NS_OK;
}

namespace {

// This class is designed to get the results of checking blacklist and whitelist.
// |mExpectWhitelistResult| is used to indicate that |OnClassifyComplete| is called
// for the result of blacklist or whitelist check.
class TrackingURICallback final : public nsIURIClassifierCallback {
public:
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIURICLASSIFIERCALLBACK

  explicit TrackingURICallback(nsChannelClassifier* aChannelClassifier,
                               std::function<void()>&& aCallback)
    : mChannelClassifier(aChannelClassifier)
    , mChannelCallback(std::move(aCallback))
    , mExpectWhitelistResult(false)
  {
    MOZ_ASSERT(mChannelClassifier);
  }

private:
  ~TrackingURICallback() = default;
  nsresult OnBlacklistResult(nsresult aErrorCode);
  nsresult OnWhitelistResult(nsresult aErrorCode);
  void OnTrackerFound(nsresult aErrorCode);

  RefPtr<nsChannelClassifier> mChannelClassifier;
  std::function<void()> mChannelCallback;
  bool mExpectWhitelistResult;

  // Only need to save the result of blacklist check.
  nsCString mList;
  nsCString mProvider;
  nsCString mFullHash;
};

NS_IMPL_ISUPPORTS(TrackingURICallback, nsIURIClassifierCallback)

/*virtual*/ nsresult
TrackingURICallback::OnClassifyComplete(nsresult aErrorCode,
                                        const nsACString& aLists,
                                        const nsACString& aProvider,
                                        const nsACString& aFullHash)
{
  if (!mExpectWhitelistResult) {
    nsresult status = aLists.IsEmpty() ? NS_OK : NS_ERROR_TRACKING_URI;
    mList = aLists;
    mProvider = aProvider;
    mFullHash = aFullHash;
    return OnBlacklistResult(status);
  }

  nsresult status = aLists.IsEmpty() ? NS_ERROR_TRACKING_URI : NS_OK;
  return OnWhitelistResult(status);
}

nsresult
TrackingURICallback::OnBlacklistResult(nsresult aErrorCode)
{
  LOG(("TrackingURICallback[%p]::OnBlacklistResult aErrorCode=0x%" PRIx32,
       mChannelClassifier.get(), static_cast<uint32_t>(aErrorCode)));

  if (NS_SUCCEEDED(aErrorCode)) {
    mChannelCallback();
    return NS_OK;
  }

  if (LOG_ENABLED()) {
    nsCOMPtr<nsIChannel> channel = mChannelClassifier->GetChannel();
    nsCOMPtr<nsIURI> uri;
    channel->GetURI(getter_AddRefs(uri));
    LOG(("TrackingURICallback[%p]::OnBlacklistResult channel [%p] "
         "uri=%s, is in blacklist. Start checking whitelist.",
         mChannelClassifier.get(), channel.get(),
         uri->GetSpecOrDefault().get()));
  }

  nsCOMPtr<nsIURI> whitelistURI = mChannelClassifier->CreateWhiteListURI();

  // If IsTrackerWhitelisted has failed, it means the uri is not in whitelist.
  if (NS_FAILED(mChannelClassifier->IsTrackerWhitelisted(whitelistURI, this))) {
    LOG(("TrackingURICallback[%p]:OnBlacklistResult "
         "IsTrackerWhitelisted has failed.",
         mChannelClassifier.get()));

    OnTrackerFound(aErrorCode);
    mChannelCallback();
  } else {
    mExpectWhitelistResult = true;
  }

  return NS_OK;
}

nsresult
TrackingURICallback::OnWhitelistResult(nsresult aErrorCode)
{
  LOG(("TrackingURICallback[%p]::OnWhitelistResult aErrorCode=0x%" PRIx32,
       mChannelClassifier.get(), static_cast<uint32_t>(aErrorCode)));

  if (NS_SUCCEEDED(aErrorCode)) {
    LOG(("TrackingURICallback[%p]::OnWhitelistResult tracker found "
         "in whitelist so we won't block it", mChannelClassifier.get()));
    mChannelCallback();
    return NS_OK;
  }

  if (LOG_ENABLED()) {
    nsCOMPtr<nsIChannel> channel = mChannelClassifier->GetChannel();
    nsCOMPtr<nsIURI> uri;
    channel->GetURI(getter_AddRefs(uri));
    LOG(("TrackingURICallback[%p]::OnWhitelistResult "
         "channel [%p] uri=%s, is not in whitelist",
         mChannelClassifier.get(), channel.get(),
         uri->GetSpecOrDefault().get()));
  }

  OnTrackerFound(aErrorCode);
  mChannelCallback();
  return NS_OK;
}

void
TrackingURICallback::OnTrackerFound(nsresult aErrorCode)
{
  nsCOMPtr<nsIChannel> channel = mChannelClassifier->GetChannel();
  if (mChannelClassifier->ShouldEnableTrackingProtection()) {
    mChannelClassifier->SetBlockedContent(channel, aErrorCode,
                                          mList, mProvider, mFullHash);
    channel->Cancel(aErrorCode);
  } else {
    MOZ_ASSERT(mChannelClassifier->ShouldEnableTrackingAnnotation());

    SetIsTrackingResourceHelper(channel);
    if (CachedPrefs::GetInstance()->IsLowerNetworkPriority()) {
      LowerPriorityHelper(channel);
    }
  }
}

} // end of unnamed namespace/

already_AddRefed<nsIURI>
nsChannelClassifier::CreateWhiteListURI() const
{
  nsresult rv;
  nsCOMPtr<nsIHttpChannelInternal> chan = do_QueryInterface(mChannel, &rv);
  if (!chan) {
    return nullptr;
  }

  nsCOMPtr<nsIURI> topWinURI;
  rv = chan->GetTopWindowURI(getter_AddRefs(topWinURI));
  NS_ENSURE_SUCCESS(rv, nullptr);
  if (!topWinURI) {
    LOG(("nsChannelClassifier[%p]: No window URI", this));
    return nullptr;
  }

  nsCOMPtr<nsIScriptSecurityManager> securityManager =
    do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, nullptr);
  nsCOMPtr<nsIPrincipal> chanPrincipal;
  rv = securityManager->GetChannelURIPrincipal(mChannel,
                                               getter_AddRefs(chanPrincipal));
  if (NS_FAILED(rv)) {
    return nullptr;
  }

  // Craft a whitelist URL like "toplevel.page/?resource=third.party.domain"
  nsAutoCString pageHostname, resourceDomain;
  rv = topWinURI->GetHost(pageHostname);
  NS_ENSURE_SUCCESS(rv, nullptr);
  rv = chanPrincipal->GetBaseDomain(resourceDomain);
  NS_ENSURE_SUCCESS(rv, nullptr);
  nsAutoCString whitelistEntry = NS_LITERAL_CSTRING("http://") +
    pageHostname + NS_LITERAL_CSTRING("/?resource=") + resourceDomain;
  LOG(("nsChannelClassifier[%p]: Looking for %s in the whitelist",
       this, whitelistEntry.get()));

  nsCOMPtr<nsIURI> whitelistURI;
  rv = NS_NewURI(getter_AddRefs(whitelistURI), whitelistEntry);

  return NS_SUCCEEDED(rv) ? whitelistURI.forget() : nullptr;
}

nsresult
nsChannelClassifier::IsTrackerWhitelisted(nsIURI* aWhiteListURI,
                                          nsIURIClassifierCallback *aCallback)
{
  if (!aCallback || !aWhiteListURI) {
    return NS_ERROR_INVALID_ARG;
  }

  nsresult rv;
  nsCOMPtr<nsIURIClassifier> uriClassifier =
    do_GetService(NS_URICLASSIFIERSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCString trackingWhitelist = CachedPrefs::GetInstance()->GetTrackingWhiteList();
  if (trackingWhitelist.IsEmpty()) {
    LOG(("nsChannelClassifier[%p]:IsTrackerWhitelisted whitelist disabled",
         this));
    return NS_ERROR_TRACKING_URI;
  }

  return uriClassifier->AsyncClassifyLocalWithTables(aWhiteListURI, trackingWhitelist, aCallback);
}

nsresult
nsChannelClassifier::SendThreatHitReport(nsIChannel *aChannel,
                                         const nsACString& aProvider)
{

  nsAutoCString provider(aProvider);
  nsPrintfCString reportEnablePref("browser.safebrowsing.provider.%s.dataSharing.enabled",
                                   provider.get());
  if (!Preferences::GetBool(reportEnablePref.get(), false)) {
    return NS_OK;
  }

  nsCOMPtr<nsIURIClassifier> uriClassifier =
    do_GetService(NS_URLCLASSIFIERDBSERVICE_CONTRACTID);
  if (!uriClassifier) {
    return NS_ERROR_UNEXPECTED;
  }

  nsresult rv = uriClassifier->SendThreatHitReport(mChannel);
  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(aErrorCode != NS_ERROR_TRACKING_URI);

  if (mSuspendedChannel) {
    nsAutoCString errorName;
    if (LOG_ENABLED()) {
      GetErrorName(aErrorCode, errorName);
      LOG(("nsChannelClassifier[%p]:OnClassifyComplete %s (suspended channel)",
           this, errorName.get()));
    }
    MarkEntryClassified(aErrorCode);

    if (NS_FAILED(aErrorCode)) {
      if (LOG_ENABLED()) {
        nsCOMPtr<nsIURI> uri;
        mChannel->GetURI(getter_AddRefs(uri));
        LOG(("nsChannelClassifier[%p]: cancelling channel %p for %s "
             "with error code %s", this, mChannel.get(),
              uri->GetSpecOrDefault().get(), errorName.get()));
      }

      // 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.
      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);
      }

      mChannel->Cancel(aErrorCode);
    }
    LOG(("nsChannelClassifier[%p]: resuming channel %p from "
         "OnClassifyComplete", this, mChannel.get()));
    mChannel->Resume();
  }

  mChannel = nullptr;
  RemoveShutdownObserver();

  return NS_OK;
}

nsresult
nsChannelClassifier::CheckIsTrackerWithLocalTable(std::function<void()>&& aCallback)
{
  nsresult rv;

  if (!aCallback) {
    return NS_ERROR_INVALID_ARG;
  }

  nsCOMPtr<nsIURIClassifier> uriClassifier =
    do_GetService(NS_URICLASSIFIERSERVICE_CONTRACTID, &rv);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (!ShouldEnableTrackingProtection() && !ShouldEnableTrackingAnnotation()) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIURI> uri;
  rv = mChannel->GetURI(getter_AddRefs(uri));
  if (NS_FAILED(rv) || !uri) {
    return rv;
  }

  nsCString trackingBlacklist =
    CachedPrefs::GetInstance()->GetTrackingBlackList();
  if (trackingBlacklist.IsEmpty()) {
    LOG(("nsChannelClassifier[%p]:CheckIsTrackerWithLocalTable blacklist is empty",
         this));
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIURIClassifierCallback> callback =
    new TrackingURICallback(this, std::move(aCallback));

  LOG(("nsChannelClassifier[%p]:CheckIsTrackerWithLocalTable for uri=%s\n",
       this, uri->GetSpecOrDefault().get()));
  return uriClassifier->AsyncClassifyLocalWithTables(uri,
                                                     trackingBlacklist,
                                                     callback);
}

already_AddRefed<nsIChannel>
nsChannelClassifier::GetChannel()
{
  nsCOMPtr<nsIChannel> channel = mChannel;
  return channel.forget();
}

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;
}

#undef LOG_ENABLED

} // namespace net
} // namespace mozilla