Bug 1646592 - P3 Sending endpoint of stream filter via PHttpBackgroundChannel, r=mayhemer,necko-reviewers

Endpoint would be passed by a series of std::move via
nsHttpChannel -> HttpChannelParent -> HttpBackgroundChannelParent ---> HttpBackgroundChannelChild -> HttpChannelChild
												|
												|
   Resolve promise after successfully send IPC<-/

Depends on D81273

Differential Revision: https://phabricator.services.mozilla.com/D81274

netwerk/protocol/http/HttpBackgroundChannelChild.cpp

@@ -411,6 +411,20 @@ IPCResult HttpBackgroundChannelChild::RecvSetClassifierMatchedTrackingInfo(
 
   return IPC_OK();
 }
+
+IPCResult HttpBackgroundChannelChild::RecvAttachStreamFilter(
+    Endpoint<extensions::PStreamFilterParent>&& aEndpoint) {
+  LOG(("HttpBackgroundChannelChild::RecvAttachStreamFilter [this=%p]\n", this));
+  MOZ_ASSERT(OnSocketThread());
+
+  if (NS_WARN_IF(!mChannelChild)) {
+    return IPC_OK();
+  }
+
+  mChannelChild->ProcessAttachStreamFilter(std::move(aEndpoint));
+  return IPC_OK();
+}
+
 void HttpBackgroundChannelChild::ActorDestroy(ActorDestroyReason aWhy) {
   LOG(("HttpBackgroundChannelChild::ActorDestroy[this=%p]\n", this));
   // This function might be called during shutdown phase, so OnSocketThread()

netwerk/protocol/http/HttpBackgroundChannelChild.h

@@ -90,6 +90,9 @@ class HttpBackgroundChannelChild final : public PHttpBackgroundChannelChild {
 
   IPCResult RecvSetClassifierMatchedTrackingInfo(const ClassifierInfo& info);
 
+  IPCResult RecvAttachStreamFilter(
+      Endpoint<extensions::PStreamFilterParent>&& aEndpoint);
+
   void ActorDestroy(ActorDestroyReason aWhy) override;
 
   void CreateDataBridge();

netwerk/protocol/http/HttpBackgroundChannelParent.cpp

@@ -478,6 +478,22 @@ nsISerialEventTarget* HttpBackgroundChannelParent::GetBackgroundTarget() {
   return mBackgroundThread.get();
 }
 
+auto HttpBackgroundChannelParent::AttachStreamFilter(
+    Endpoint<extensions::PStreamFilterParent>&& aParentEndpoint,
+    Endpoint<extensions::PStreamFilterChild>&& aChildEndpoint)
+    -> RefPtr<ChildEndpointPromise> {
+  LOG(("HttpBackgroundChannelParent::AttachStreamFilter [this=%p]\n", this));
+  MOZ_ASSERT(IsOnBackgroundThread());
+
+  if (NS_WARN_IF(!mIPCOpened) ||
+      !SendAttachStreamFilter(std::move(aParentEndpoint))) {
+    return ChildEndpointPromise::CreateAndReject(false, __func__);
+  }
+
+  return ChildEndpointPromise::CreateAndResolve(std::move(aChildEndpoint),
+                                                __func__);
+}
+
 void HttpBackgroundChannelParent::ActorDestroy(ActorDestroyReason aWhy) {
   LOG(("HttpBackgroundChannelParent::ActorDestroy [this=%p]\n", this));
   AssertIsInMainProcess();

netwerk/protocol/http/HttpBackgroundChannelParent.h

@@ -88,6 +88,12 @@ class HttpBackgroundChannelParent final : public PHttpBackgroundChannelParent {
 
   nsISerialEventTarget* GetBackgroundTarget();
 
+  using ChildEndpointPromise =
+      MozPromise<ipc::Endpoint<extensions::PStreamFilterChild>, bool, true>;
+  [[nodiscard]] RefPtr<ChildEndpointPromise> AttachStreamFilter(
+      Endpoint<extensions::PStreamFilterParent>&& aParentEndpoint,
+      Endpoint<extensions::PStreamFilterChild>&& aChildEndpoint);
+
  protected:
   void ActorDestroy(ActorDestroyReason aWhy) override;
 

netwerk/protocol/http/HttpChannelChild.cpp

@@ -3874,10 +3874,39 @@ mozilla::ipc::IPCResult HttpChannelChild::RecvSetPriority(
   return IPC_OK();
 }
 
-mozilla::ipc::IPCResult HttpChannelChild::RecvAttachStreamFilter(
+// We don't have a copyable Endpoint and NeckoTargetChannelFunctionEvent takes
+// std::function<void()>.  It's not possible to avoid the copy from the type of
+// lambda to std::function, so does the capture list. Hence, we're forced to
+// use the old-fashioned channel event inheritance.
+class AttachStreamFilterEvent : public ChannelEvent {
+ public:
+  AttachStreamFilterEvent(HttpChannelChild* aChild,
+                          already_AddRefed<nsIEventTarget> aTarget,
+                          Endpoint<extensions::PStreamFilterParent>&& aEndpoint)
+      : mChild(aChild), mTarget(aTarget), mEndpoint(std::move(aEndpoint)) {}
+
+  already_AddRefed<nsIEventTarget> GetEventTarget() override {
+    nsCOMPtr<nsIEventTarget> target = mTarget;
+    return target.forget();
+  }
+
+  void Run() override {
+    extensions::StreamFilterParent::Attach(mChild, std::move(mEndpoint));
+  }
+
+ private:
+  HttpChannelChild* mChild;
+  nsCOMPtr<nsIEventTarget> mTarget;
+  Endpoint<extensions::PStreamFilterParent> mEndpoint;
+};
+
+void HttpChannelChild::ProcessAttachStreamFilter(
     Endpoint<extensions::PStreamFilterParent>&& aEndpoint) {
-  extensions::StreamFilterParent::Attach(this, std::move(aEndpoint));
-  return IPC_OK();
+  LOG(("HttpChannelChild::ProcessAttachStreamFilter [this=%p]\n", this));
+  MOZ_ASSERT(OnSocketThread());
+
+  mEventQ->RunOrEnqueue(new AttachStreamFilterEvent(this, GetNeckoTarget(),
+                                                    std::move(aEndpoint)));
 }
 
 mozilla::ipc::IPCResult HttpChannelChild::RecvCancelDiversion() {

netwerk/protocol/http/HttpChannelChild.h

@@ -11,6 +11,7 @@
 #include "mozilla/Mutex.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/UniquePtr.h"
+#include "mozilla/extensions/StreamFilterParent.h"
 #include "mozilla/net/HttpBaseChannel.h"
 #include "mozilla/net/NeckoTargetHolder.h"
 #include "mozilla/net/PHttpChannelChild.h"
@@ -154,9 +155,6 @@ class HttpChannelChild final : public PHttpChannelChild,
 
   mozilla::ipc::IPCResult RecvSetPriority(const int16_t& aPriority) override;
 
-  mozilla::ipc::IPCResult RecvAttachStreamFilter(
-      Endpoint<extensions::PStreamFilterParent>&& aEndpoint) override;
-
   mozilla::ipc::IPCResult RecvCancelDiversion() override;
 
   mozilla::ipc::IPCResult RecvOriginalCacheInputStreamAvailable(
@@ -267,6 +265,9 @@ class HttpChannelChild final : public PHttpChannelChild,
 
   void ProcessOnStatus(const nsresult& aStatus);
 
+  void ProcessAttachStreamFilter(
+      Endpoint<extensions::PStreamFilterParent>&& aEndpoint);
+
   // Return true if we need to tell the parent the size of unreported received
   // data
   bool NeedToReportBytesRead();

netwerk/protocol/http/HttpChannelParent.cpp

@@ -2669,11 +2669,24 @@ void HttpChannelParent::OverrideReferrerInfoDuringBeginConnect(
   mOverrideReferrerInfo = aReferrerInfo;
 }
 
-bool HttpChannelParent::AttachStreamFilter(
-    Endpoint<extensions::PStreamFilterParent>&& aEndpoint) {
+auto HttpChannelParent::AttachStreamFilter(
+    Endpoint<extensions::PStreamFilterParent>&& aParentEndpoint,
+    Endpoint<extensions::PStreamFilterChild>&& aChildEndpoint)
+    -> RefPtr<ChildEndpointPromise> {
+  LOG(("HttpChannelParent::AttachStreamFilter [this=%p]", this));
   MOZ_ASSERT(!mAfterOnStartRequestBegun);
   mStreamFilterAttached = true;
-  return SendAttachStreamFilter(std::move(aEndpoint));
+
+  if (mIPCClosed) {
+    return ChildEndpointPromise::CreateAndReject(false, __func__);
+  }
+
+  // If IPC channel is open, background channel should be ready to send
+  // SendAttachStreamFilter.
+  MOZ_ASSERT(mBgParent);
+  return InvokeAsync(mBgParent->GetBackgroundTarget(), mBgParent.get(),
+                     __func__, &HttpBackgroundChannelParent::AttachStreamFilter,
+                     std::move(aParentEndpoint), std::move(aChildEndpoint));
 }
 
 }  // namespace net

netwerk/protocol/http/HttpChannelParent.h

@@ -134,8 +134,11 @@ class HttpChannelParent final : public nsIInterfaceRequestor,
   // BeginConnect.
   void OverrideReferrerInfoDuringBeginConnect(nsIReferrerInfo* aReferrerInfo);
 
-  bool AttachStreamFilter(
-      Endpoint<extensions::PStreamFilterParent>&& aEndpoint);
+  using ChildEndpointPromise =
+      MozPromise<ipc::Endpoint<extensions::PStreamFilterChild>, bool, true>;
+  [[nodiscard]] RefPtr<ChildEndpointPromise> AttachStreamFilter(
+      Endpoint<extensions::PStreamFilterParent>&& aParentEndpoint,
+      Endpoint<extensions::PStreamFilterChild>&& aChildEndpoint);
 
  protected:
   // used to connect redirected-to channel in parent with just created

netwerk/protocol/http/PHttpBackgroundChannel.ipdl

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PBackground;
+include protocol PStreamFilter;
 include NeckoChannelParams;
 include HttpChannelParams;
 include PURLClassifierInfo;
@@ -73,6 +74,8 @@ child:
   // Tell the child information of matched URL againts SafeBrowsing tracking list
   async SetClassifierMatchedTrackingInfo(ClassifierInfo info);
 
+  async AttachStreamFilter(Endpoint<PStreamFilterParent> aEndpoint);
+
   async __delete__();
 
 };

netwerk/protocol/http/PHttpChannel.ipdl

@@ -6,7 +6,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 include protocol PNecko;
-include protocol PStreamFilter;
 include InputStreamParams;
 include URIParams;
 include PBackgroundSharedTypes;
@@ -148,8 +147,6 @@ child:
                             nsString url,
                             nsString contentType);
 
-  async AttachStreamFilter(Endpoint<PStreamFilterParent> aEndpoint);
-
   // See ADivertableParentChannel::CancelDiversion
   async CancelDiversion();
 

netwerk/protocol/http/nsHttpChannel.cpp

@@ -7085,10 +7085,7 @@ auto nsHttpChannel::AttachStreamFilter(base::ProcessId aChildProcessId)
   }
 
   if (RefPtr<HttpChannelParent> httpParent = do_QueryObject(parentChannel)) {
-    if (httpParent->AttachStreamFilter(std::move(parent))) {
-      return ChildEndpointPromise::CreateAndResolve(std::move(child), __func__);
-    }
-    return ChildEndpointPromise::CreateAndReject(false, __func__);
+    return httpParent->AttachStreamFilter(std::move(parent), std::move(child));
   }
 
   extensions::StreamFilterParent::Attach(this, std::move(parent));