Bug 1581637 - Part 10 - Implement a posibility to use alt-svc on transaction restart in some cases. r=mayhemer mayhemer

Differential Revision: https://phabricator.services.mozilla.com/D46654

--HG--
extra : moz-landing-system : lando

netwerk/protocol/http/Http3Session.cpp

@@ -645,6 +645,9 @@ void Http3Session::ResetRecvd(uint64_t aStreamId, Http3AppError aError) {
     CloseStream(stream, NS_ERROR_NET_RESET);
   } else if (aError.tag == Http3AppError::Tag::RequestRejected) {
     // This request was rejected because server is probably busy or going away.
+    // We can restart the request using alt-svc. Without calling
+    // DoNotRemoveAltSvc the alt-svc route will be removed.
+    stream->Transaction()->DoNotRemoveAltSvc();
     CloseStream(stream, NS_ERROR_NET_RESET);
   } else {
     if (stream->RecvdData()) {

netwerk/protocol/http/nsAHttpTransaction.h

@@ -183,6 +183,14 @@ class nsAHttpTransaction : public nsSupportsWeakReference {
   virtual void MakeNonSticky() {}
   virtual void ReuseConnectionOnRestartOK(bool) {}
 
+  // We call this function if we want to use alt-svc host again on the next
+  // restart. If this function is not called on the next restart the
+  // transaction will use the original route.
+  // For example in case we receive a GOAWAY frame from a server, we can
+  // restart and use the same alt-svc. If we get VersionFallback we do not
+  // want to use the alt-svc on the restart.
+  virtual void DoNotRemoveAltSvc() {}
+
   // Returns true if early-data or fast open is possible.
   virtual MOZ_MUST_USE bool CanDo0RTT() { return false; }
   // Returns true if early-data is possible and transaction will remember

netwerk/protocol/http/nsHttpTransaction.cpp

@@ -115,6 +115,7 @@ nsHttpTransaction::nsHttpTransaction()
       mContentDecodingCheck(false),
       mDeferredSendProgress(false),
       mWaitingOnPipeOut(false),
+      mDoNotRemoveAltSvc(false),
       mReportedStart(false),
       mReportedResponseHeader(false),
       mResponseHeadTaken(false),
@@ -1293,7 +1294,7 @@ nsresult nsHttpTransaction::Restart() {
   // to the next
   mReuseOnRestart = false;
 
-  if (!mConnInfo->GetRoutedHost().IsEmpty()) {
+  if (!mDoNotRemoveAltSvc && !mConnInfo->GetRoutedHost().IsEmpty()) {
     MutexAutoLock lock(*nsHttp::GetLock());
     RefPtr<nsHttpConnectionInfo> ci;
     mConnInfo->CloneAsDirectRoute(getter_AddRefs(ci));
@@ -1305,6 +1306,9 @@ nsresult nsHttpTransaction::Restart() {
     }
   }
 
+  // Reset mDoNotRemoveAltSvc for the next try.
+  mDoNotRemoveAltSvc = false;
+
   return gHttpHandler->InitiateTransaction(this, mPriority);
 }
 

netwerk/protocol/http/nsHttpTransaction.h

@@ -142,6 +142,8 @@ class nsHttpTransaction final : public nsAHttpTransaction,
 
   void DisableSpdy() override;
 
+  void DoNotRemoveAltSvc() override { mDoNotRemoveAltSvc = true; }
+
   nsHttpTransaction* QueryHttpTransaction() override { return this; }
 
   already_AddRefed<Http2PushedStreamWrapper> GetPushedStream() {
@@ -380,6 +382,8 @@ class nsHttpTransaction final : public nsAHttpTransaction,
   bool mDeferredSendProgress;
   bool mWaitingOnPipeOut;
 
+  bool mDoNotRemoveAltSvc;
+
   // mClosed           := transaction has been explicitly closed
   // mTransactionDone  := transaction ran to completion or was interrupted
   // mResponseComplete := transaction ran to completion