fix: inappropriate connection reuse when using HTTP proxy

There is an extra CONNECT request needs to send before the real request to the HTTP proxy and the 2nd request only happens if the CONNECT request succeeds. When CONNECT failed, the connection should be dropped as it's not in connected state.

Signed-off-by: Jason Joo <[email protected]>

Author: jasonjoo2010

client/src/main/java/org/asynchttpclient/netty/handler/HttpHandler.java

@@ -21,6 +21,7 @@
 import io.netty.handler.codec.DecoderResultProvider;
 import io.netty.handler.codec.http.HttpContent;
 import io.netty.handler.codec.http.HttpHeaders;
+import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.HttpResponse;
 import io.netty.handler.codec.http.LastHttpContent;
@@ -32,6 +33,7 @@
 import org.asynchttpclient.netty.NettyResponseStatus;
 import org.asynchttpclient.netty.channel.ChannelManager;
 import org.asynchttpclient.netty.request.NettyRequestSender;
+import org.asynchttpclient.util.HttpConstants.ResponseStatusCodes;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
@@ -43,8 +45,11 @@ public HttpHandler(AsyncHttpClientConfig config, ChannelManager channelManager,
         super(config, channelManager, requestSender);
     }
 
-    private static boolean abortAfterHandlingStatus(AsyncHandler<?> handler, NettyResponseStatus status) throws Exception {
-        return handler.onStatusReceived(status) == State.ABORT;
+    private static boolean abortAfterHandlingStatus(AsyncHandler<?> handler, HttpMethod httpMethod, NettyResponseStatus status) throws Exception {
+        // For non-200 response of a CONNECT request, it's still unconnected.
+        // We need to either close the connection or reuse it but send CONNECT request again.
+        // The former one is easier or we have to attach more state to Channel.
+        return handler.onStatusReceived(status) == State.ABORT || httpMethod == HttpMethod.CONNECT && status.getStatusCode() != ResponseStatusCodes.OK_200;
     }
 
     private static boolean abortAfterHandlingHeaders(AsyncHandler<?> handler, HttpHeaders responseHeaders) throws Exception {
@@ -61,7 +66,7 @@ private void handleHttpResponse(final HttpResponse response, final Channel chann
         HttpHeaders responseHeaders = response.headers();
 
         if (!interceptors.exitAfterIntercept(channel, future, handler, response, status, responseHeaders)) {
-            boolean abort = abortAfterHandlingStatus(handler, status) || abortAfterHandlingHeaders(handler, responseHeaders);
+            boolean abort = abortAfterHandlingStatus(handler, httpRequest.method(), status) || abortAfterHandlingHeaders(handler, responseHeaders);
             if (abort) {
                 finishUpdate(future, channel, true);
             }