HTTP/2 GOAWAY are not delivered to clients sometime because close(2)

is called immediately. This is reported in #673.

We can reproduce this with h2spec:

% h2spec http2/5.4 http2/7
  5. Streams and Multiplexing
    5.4. Error Handling
      5.4.1. Connection Error Handling
        × 1: Sends an invalid PING frame for connection close
          -> The endpoint MUST close the TCP connection
             Expected: Connection closed
               Actual: Error: read tcp 127.0.0.1:56529->127.0.0.1:80: read: connection reset by peer

  7. Error Codes
    × 1: Sends a GOAWAY frame with unknown error code
      -> The endpoint MUST NOT trigger any special behavior.
         Expected: Connection closed
                   PING Frame (length:8, flags:0x01, stream_id:0, opaque_data:h2spec)
           Actual: Error: read tcp 127.0.0.1:56578->127.0.0.1:80: read: connection reset by peer

To fix this, we use "gracefulClose" in the network library.

warp-tls/Network/Wai/Handler/WarpTLS.hs

@@ -53,6 +53,9 @@ import qualified Data.IORef as I
 import Data.Streaming.Network (bindPortTCP, safeRecv)
 import Data.Typeable (Typeable)
 import Network.Socket (Socket, close, withSocketsDo, SockAddr, accept)
+#if MIN_VERSION_network(3,1,1)
+import Network.Socket (gracefulClose)
+#endif
 import Network.Socket.ByteString (sendAll)
 import qualified Network.TLS as TLS
 import qualified Crypto.PubKey.DH as DH
@@ -355,7 +358,11 @@ httpOverTls TLSSettings{..} s bs0 params = do
   where
     backend recvN = TLS.Backend {
         TLS.backendFlush = return ()
+#if MIN_VERSION_network(3,1,1)
+      , TLS.backendClose = gracefulClose s 5000
+#else
       , TLS.backendClose = close s
+#endif
       , TLS.backendSend  = sendAll' s
       , TLS.backendRecv  = recvN
       }

warp/Network/Wai/Handler/Warp/Run.hs

@@ -23,6 +23,9 @@ import Foreign.C.Error (Errno(..), eCONNABORTED)
 import GHC.IO.Exception (IOException(..))
 import qualified Network.HTTP2 as H2
 import Network.Socket (Socket, close, accept, withSocketsDo, SockAddr(SockAddrInet, SockAddrInet6), setSocketOption, SocketOption(..))
+#if MIN_VERSION_network(3,1,1)
+import Network.Socket (gracefulClose)
+#endif
 import qualified Network.Socket.ByteString as Sock
 import Network.Wai
 import Network.Wai.Internal (ResponseReceived (ResponseReceived))
@@ -64,7 +67,11 @@ socketConnection s = do
         connSendMany = Sock.sendMany s
       , connSendAll = sendall
       , connSendFile = sendFile s writeBuf bufferSize sendall
+#if MIN_VERSION_network(3,1,1)
+      , connClose = gracefulClose s 5000
+#else
       , connClose = close s
+#endif
       , connFree = freeBuffer writeBuf
       , connRecv = receive s bufferPool
       , connRecvBuf = receiveBuf s