Bug 1669731 - P3. Add Allow API to ChannelClassifierService. r=timhuang,nhnt11

UI needs to distinguish the cases when a channel is shimmed and is
unshimmed.
When a channel is unshimmed, we unblock the channel and simply treat the channel as a
non-tracking channel.
When a channel is shimmed, although the channel is unblocked by
URLCLassifier, we still want to show it in the UI. For this case,
URLClassifier will notify a content blocking event when a channel is
unblocked.

This patch adds a new allow API, so the caller can use unblock() or
allow() depending upon the case it requires.

Differential Revision: https://phabricator.services.mozilla.com/D93271

Author: DimiDL

netwerk/url-classifier/ChannelClassifierService.cpp

@@ -136,6 +136,15 @@ UrlClassifierBlockedChannel::GetIsPrivateBrowsing(bool* aIsPrivateBrowsing) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+UrlClassifierBlockedChannel::Allow() {
+  UC_LOG(("ChannelClassifierService: allow loading the channel %p",
+          mChannel.get()));
+
+  mDecision = ChannelBlockDecision::Allowed;
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 UrlClassifierBlockedChannel::Unblock() {
   UC_LOG(("ChannelClassifierService: unblock channel %p", mChannel.get()));
@@ -249,9 +258,7 @@ nsresult ChannelClassifierService::OnBeforeBlockChannel(
         NS_ISUPPORTS_CAST(nsIUrlClassifierBlockedChannel*, channel),
         "urlclassifier-before-block-channel", nullptr);
 
-    if (channel->IsUnblocked()) {
-      aDecision = ChannelBlockDecision::Unblocked;
-    }
+    aDecision = channel->GetDecision();
   }
 
   return NS_OK;

netwerk/url-classifier/ChannelClassifierService.h

@@ -16,6 +16,7 @@ namespace net {
 enum class ChannelBlockDecision {
   Blocked,
   Unblocked,
+  Allowed,
 };
 
 class UrlClassifierBlockedChannel final
@@ -30,6 +31,8 @@ class UrlClassifierBlockedChannel final
     return mDecision != ChannelBlockDecision::Blocked;
   }
 
+  ChannelBlockDecision GetDecision() { return mDecision; };
+
   void SetReason(const nsACString& aFeatureName, const nsACString& aTableName);
 
  protected:

netwerk/url-classifier/UrlClassifierFeatureCryptominingProtection.cpp

@@ -143,11 +143,14 @@ UrlClassifierFeatureCryptominingProtection::ProcessChannel(
   nsAutoCString list;
   UrlClassifierCommon::TablesToString(aList, list);
 
-  if (ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list) ==
-      ChannelBlockDecision::Unblocked) {
-    ContentBlockingNotifier::OnEvent(
-        aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
-        false);
+  ChannelBlockDecision decision =
+      ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list);
+  if (decision != ChannelBlockDecision::Blocked) {
+    if (decision == ChannelBlockDecision::Unblocked) {
+      ContentBlockingNotifier::OnEvent(
+          aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
+          false);
+    }
     *aShouldContinue = true;
     return NS_OK;
   }

netwerk/url-classifier/UrlClassifierFeatureFingerprintingProtection.cpp

@@ -150,11 +150,14 @@ UrlClassifierFeatureFingerprintingProtection::ProcessChannel(
   nsAutoCString list;
   UrlClassifierCommon::TablesToString(aList, list);
 
-  if (ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list) ==
-      ChannelBlockDecision::Unblocked) {
-    ContentBlockingNotifier::OnEvent(
-        aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
-        false);
+  ChannelBlockDecision decision =
+      ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list);
+  if (decision != ChannelBlockDecision::Blocked) {
+    if (decision == ChannelBlockDecision::Unblocked) {
+      ContentBlockingNotifier::OnEvent(
+          aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
+          false);
+    }
     *aShouldContinue = true;
     return NS_OK;
   }

netwerk/url-classifier/UrlClassifierFeatureSocialTrackingProtection.cpp

@@ -146,11 +146,14 @@ UrlClassifierFeatureSocialTrackingProtection::ProcessChannel(
   nsAutoCString list;
   UrlClassifierCommon::TablesToString(aList, list);
 
-  if (ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list) ==
-      ChannelBlockDecision::Unblocked) {
-    ContentBlockingNotifier::OnEvent(
-        aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
-        false);
+  ChannelBlockDecision decision =
+      ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list);
+  if (decision != ChannelBlockDecision::Blocked) {
+    if (decision == ChannelBlockDecision::Unblocked) {
+      ContentBlockingNotifier::OnEvent(
+          aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
+          false);
+    }
     *aShouldContinue = true;
     return NS_OK;
   }

netwerk/url-classifier/UrlClassifierFeatureTrackingProtection.cpp

@@ -150,11 +150,14 @@ UrlClassifierFeatureTrackingProtection::ProcessChannel(
   nsAutoCString list;
   UrlClassifierCommon::TablesToString(aList, list);
 
-  if (ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list) ==
-      ChannelBlockDecision::Unblocked) {
-    ContentBlockingNotifier::OnEvent(
-        aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
-        false);
+  ChannelBlockDecision decision =
+      ChannelClassifierService::OnBeforeBlockChannel(aChannel, mName, list);
+  if (decision != ChannelBlockDecision::Blocked) {
+    if (decision == ChannelBlockDecision::Unblocked) {
+      ContentBlockingNotifier::OnEvent(
+          aChannel, nsIWebProgressListener::STATE_UNBLOCKED_TRACKING_CONTENT,
+          false);
+    }
     *aShouldContinue = true;
     return NS_OK;
   }

netwerk/url-classifier/nsIChannelClassifierService.idl

@@ -35,7 +35,16 @@ interface nsIUrlClassifierBlockedChannel: nsISupports
   readonly attribute AString topLevelUrl;
 
   // Ask UrlClassifier to unblock the load.
+  // This is similar to allow(), the only difference is that the unblocked channel
+  // is still considered as a tracking channel, so classifier will notify UI
+  // content blocking event for the channel.
   void unblock();
+
+  // Ask UrlClassifier to allow the load.
+  // This is similar to unblock(), the only difference is that the allowed channel
+  // is not considered as a tracking channel anymore. UI will not receive content
+  // blocking event for the channel.
+  void allow();
 };
 
 [scriptable, uuid(9411409c-5dac-40b9-ba36-2738a7237a4c)]