Backed out changeset 9ccaad4630db (bug 1816677) for causing DNS related crashes (bug 1837252). a=backout

modules/libpref/init/StaticPrefList.yaml

@@ -12526,12 +12526,6 @@
   value: false
   mirror: always
 
-# When a Http/3 connection failed, whether to retry with a different IP address.
-- name: network.http.http3.retry_different_ip_family
-  type: RelaxedAtomicBool
-  value: true
-  mirror: always
-
 # When true, a http request will be upgraded to https when HTTPS RR is
 # available.
 - name: network.dns.upgrade_with_https_rr

netwerk/protocol/http/ConnectionEntry.cpp

@@ -1004,53 +1004,5 @@ nsresult ConnectionEntry::CreateDnsAndConnectSocket(
   return NS_OK;
 }
 
-bool ConnectionEntry::AllowToRetryDifferentIPFamilyForHttp3(nsresult aError) {
-  LOG(
-      ("ConnectionEntry::AllowToRetryDifferentIPFamilyForHttp3 %p "
-       "error=%" PRIx32,
-       this, static_cast<uint32_t>(aError)));
-  if (!IsHttp3()) {
-    MOZ_ASSERT(false, "Should not be called for non Http/3 connection");
-    return false;
-  }
-
-  if (!StaticPrefs::network_http_http3_retry_different_ip_family()) {
-    return false;
-  }
-
-  // Only allow to retry with these two errors.
-  if (aError != NS_ERROR_CONNECTION_REFUSED &&
-      aError != NS_ERROR_PROXY_CONNECTION_REFUSED) {
-    return false;
-  }
-
-  // Already retried once.
-  if (mRetriedDifferentIPFamilyForHttp3) {
-    return false;
-  }
-
-  return true;
-}
-
-void ConnectionEntry::SetRetryDifferentIPFamilyForHttp3(uint16_t aIPFamily) {
-  LOG(("ConnectionEntry::SetRetryDifferentIPFamilyForHttp3 %p, af=%u", this,
-       aIPFamily));
-
-  mPreferIPv4 = false;
-  mPreferIPv6 = false;
-
-  if (aIPFamily == AF_INET) {
-    mPreferIPv6 = true;
-  }
-
-  if (aIPFamily == AF_INET6) {
-    mPreferIPv4 = true;
-  }
-
-  LOG(("  %p prefer ipv4=%d, ipv6=%d", this, (bool)mPreferIPv4,
-       (bool)mPreferIPv6));
-  MOZ_DIAGNOSTIC_ASSERT(mPreferIPv4 ^ mPreferIPv6);
-}
-
 }  // namespace net
 }  // namespace mozilla

netwerk/protocol/http/ConnectionEntry.h

@@ -195,9 +195,6 @@ class ConnectionEntry {
 
   void MaybeUpdateEchConfig(nsHttpConnectionInfo* aConnInfo);
 
-  bool AllowToRetryDifferentIPFamilyForHttp3(nsresult aError);
-  void SetRetryDifferentIPFamilyForHttp3(uint16_t aIPFamily);
-
  private:
   void InsertIntoIdleConnections_internal(nsHttpConnection* conn);
   void RemoveFromIdleConnectionsIndex(size_t inx);
@@ -214,8 +211,6 @@ class ConnectionEntry {
 
   PendingTransactionQueue mPendingQ;
   ~ConnectionEntry();
-
-  bool mRetriedDifferentIPFamilyForHttp3 = false;
 };
 
 }  // namespace net

netwerk/protocol/http/Http3Session.cpp

@@ -230,18 +230,11 @@ void Http3Session::Shutdown() {
 
   bool isEchRetry = mError == mozilla::psm::GetXPCOMFromNSSError(
                                   SSL_ERROR_ECH_RETRY_WITH_ECH);
-  bool allowToRetryWithDifferentIPFamily =
-      mBeforeConnectedError &&
-      gHttpHandler->ConnMgr()->AllowToRetryDifferentIPFamilyForHttp3(mConnInfo,
-                                                                     mError);
-  LOG(("Http3Session::Shutdown %p allowToRetryWithDifferentIPFamily=%d", this,
-       allowToRetryWithDifferentIPFamily));
   if ((mBeforeConnectedError ||
        (mError == NS_ERROR_NET_HTTP3_PROTOCOL_ERROR)) &&
       (mError !=
        mozilla::psm::GetXPCOMFromNSSError(SSL_ERROR_BAD_CERT_DOMAIN)) &&
-      !isEchRetry && !mConnInfo->GetWebTransport() &&
-      !allowToRetryWithDifferentIPFamily && !mDontExclude) {
+      !isEchRetry && !mConnInfo->GetWebTransport()) {
     gHttpHandler->ExcludeHttp3(mConnInfo);
   }
 
@@ -256,28 +249,7 @@ void Http3Session::Shutdown() {
         // transaction will be restarted with a new echConfig.
         stream->Close(mError);
       } else {
-        if (allowToRetryWithDifferentIPFamily && mNetAddr) {
-          NetAddr addr;
-          mNetAddr->GetNetAddr(&addr);
-          gHttpHandler->ConnMgr()->SetRetryDifferentIPFamilyForHttp3(
-              mConnInfo, addr.raw.family);
-          nsHttpTransaction* trans =
-              stream->Transaction()->QueryHttpTransaction();
-          if (trans) {
-            // This is a bit hacky. We redispatch the transaction here to avoid
-            // touching the complicated retry logic in nsHttpTransaction.
-            trans->RemoveConnection();
-            Unused << gHttpHandler->InitiateTransaction(trans,
-                                                        trans->Priority());
-          } else {
-            stream->Close(NS_ERROR_NET_RESET);
-          }
-          // Since Http3Session::Shutdown can be called multiple times, we set
-          // mDontExclude for not putting this domain into the excluded list.
-          mDontExclude = true;
-        } else {
-          stream->Close(NS_ERROR_NET_RESET);
-        }
+        stream->Close(NS_ERROR_NET_RESET);
       }
     } else if (!stream->HasStreamId()) {
       if (NS_SUCCEEDED(mError)) {

netwerk/protocol/http/Http3Session.h

@@ -370,8 +370,6 @@ class Http3Session final : public nsAHttpTransaction, public nsAHttpConnection {
   nsTArray<RefPtr<Http3StreamBase>> mWebTransportStreams;
 
   bool mHasWebTransportSession = false;
-  // When true, we don't add this connection info into the Http/3 excluded list.
-  bool mDontExclude = false;
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(Http3Session, NS_HTTP3SESSION_IID);

netwerk/protocol/http/nsHttpConnectionMgr.cpp

@@ -3818,24 +3818,4 @@ void nsHttpConnectionMgr::CheckTransInPendingQueue(nsHttpTransaction* aTrans) {
 #endif
 }
 
-bool nsHttpConnectionMgr::AllowToRetryDifferentIPFamilyForHttp3(
-    nsHttpConnectionInfo* ci, nsresult aError) {
-  ConnectionEntry* ent = mCT.GetWeak(ci->HashKey());
-  if (!ent) {
-    return false;
-  }
-
-  return ent->AllowToRetryDifferentIPFamilyForHttp3(aError);
-}
-
-void nsHttpConnectionMgr::SetRetryDifferentIPFamilyForHttp3(
-    nsHttpConnectionInfo* ci, uint16_t aIPFamily) {
-  ConnectionEntry* ent = mCT.GetWeak(ci->HashKey());
-  if (!ent) {
-    return;
-  }
-
-  ent->SetRetryDifferentIPFamilyForHttp3(aIPFamily);
-}
-
 }  // namespace mozilla::net

netwerk/protocol/http/nsHttpConnectionMgr.h

@@ -191,11 +191,6 @@ class nsHttpConnectionMgr final : public HttpConnectionMgrShell,
   // connection
   bool BeConservativeIfProxied(nsIProxyInfo* proxy);
 
-  bool AllowToRetryDifferentIPFamilyForHttp3(nsHttpConnectionInfo* ci,
-                                             nsresult aError);
-  void SetRetryDifferentIPFamilyForHttp3(nsHttpConnectionInfo* ci,
-                                         uint16_t aIPFamily);
-
  protected:
   friend class ConnectionEntry;
   void IncrementActiveConnCount();

netwerk/protocol/http/nsHttpTransaction.cpp

@@ -3534,9 +3534,4 @@ void nsHttpTransaction::SetIsForWebTransport(bool aIsForWebTransport) {
   mIsForWebTransport = aIsForWebTransport;
 }
 
-void nsHttpTransaction::RemoveConnection() {
-  MutexAutoLock lock(mLock);
-  mConnection = nullptr;
-}
-
 }  // namespace mozilla::net

netwerk/protocol/http/nsHttpTransaction.h

@@ -88,7 +88,7 @@ class nsHttpTransaction final : public nsAHttpTransaction,
   void MakeNonSticky() override { mCaps &= ~NS_HTTP_STICKY_CONNECTION; }
   void MakeRestartable() override { mCaps |= NS_HTTP_CONNECTION_RESTARTABLE; }
   void MakeNonRestartable() { mCaps &= ~NS_HTTP_CONNECTION_RESTARTABLE; }
-  void RemoveConnection();
+
   void SetIsHttp2Websocket(bool h2ws) override { mIsHttp2Websocket = h2ws; }
   bool IsHttp2Websocket() override { return mIsHttp2Websocket; }