making mkConn of WarpTLS interruptible

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

@@ -95,6 +95,8 @@ import UnliftIO.Exception (
     try,
  )
 import qualified UnliftIO.Exception as E
+import UnliftIO.Concurrent (newEmptyMVar, putMVar, takeMVar, forkIOWithUnmask)
+import UnliftIO.Timeout (timeout)
 
 ----------------------------------------------------------------
 
@@ -318,8 +320,18 @@ mkConn
     -> Socket
     -> params
     -> IO (Connection, Transport)
-mkConn tlsset set s params = (safeRecv s 4096 >>= switch) `onException` close s
+mkConn tlsset set s params = do
+    var <- newEmptyMVar
+    _ <- forkIOWithUnmask $ \umask -> do
+        let tm = settingsTimeout set * 1000000
+        mct <- umask (timeout tm recvFirstBS)
+        putMVar var mct
+    mbs <- takeMVar var
+    case mbs of
+      Nothing -> throwIO IncompleteHeaders
+      Just bs -> switch bs
   where
+    recvFirstBS = safeRecv s 4096 `onException` close s
     switch firstBS
         | S.null firstBS = close s >> throwIO ClientClosedConnectionPrematurely
         | S.head firstBS == 0x16 = httpOverTls tlsset set s firstBS params
@@ -335,22 +347,24 @@ httpOverTls
     -> S.ByteString
     -> params
     -> IO (Connection, Transport)
-httpOverTls TLSSettings{..} _set s bs0 params = do
-    pool <- newBufferPool 2048 16384
-    rawRecvN <- makeRecvN bs0 $ receive s pool
-    let recvN = wrappedRecvN rawRecvN
-    ctx <- TLS.contextNew (backend recvN) params
-    TLS.contextHookSetLogging ctx tlsLogging
-    TLS.handshake ctx
-    h2 <- (== Just "h2") <$> TLS.getNegotiatedProtocol ctx
-    isH2 <- I.newIORef h2
-    writeBuffer <- createWriteBuffer 16384
-    writeBufferRef <- I.newIORef writeBuffer
-    -- Creating a cache for leftover input data.
-    tls <- getTLSinfo ctx
-    mysa <- getSocketName s
-    return (conn ctx writeBufferRef isH2 mysa, tls)
+httpOverTls TLSSettings{..} _set s bs0 params =
+    makeConn `onException` close s
   where
+    makeConn = do
+        pool <- newBufferPool 2048 16384
+        rawRecvN <- makeRecvN bs0 $ receive s pool
+        let recvN = wrappedRecvN rawRecvN
+        ctx <- TLS.contextNew (backend recvN) params
+        TLS.contextHookSetLogging ctx tlsLogging
+        TLS.handshake ctx
+        h2 <- (== Just "h2") <$> TLS.getNegotiatedProtocol ctx
+        isH2 <- I.newIORef h2
+        writeBuffer <- createWriteBuffer 16384
+        writeBufferRef <- I.newIORef writeBuffer
+        -- Creating a cache for leftover input data.
+        tls <- getTLSinfo ctx
+        mysa <- getSocketName s
+        return (conn ctx writeBufferRef isH2 mysa, tls)
     backend recvN =
         TLS.Backend
             { TLS.backendFlush = return ()