Filter out Host header when proxying websockets (#134) (#136)

Co-authored-by: Björn Husberg <[email protected]>

Author: tsegismont

src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java

@@ -21,8 +21,7 @@
 
 import java.util.*;
 
-import static io.vertx.core.http.HttpHeaders.CONNECTION;
-import static io.vertx.core.http.HttpHeaders.UPGRADE;
+import static io.vertx.core.http.HttpHeaders.*;
 
 public class ReverseProxy implements HttpProxy {
 
@@ -95,7 +94,18 @@ private void handleWebSocketUpgrade(ProxyContext proxyContext) {
         HttpClientRequest request = ar.result();
         request.setMethod(HttpMethod.GET);
         request.setURI(proxiedRequest.uri());
-        request.headers().addAll(proxiedRequest.headers()).set(CONNECTION, UPGRADE);
+        for (Map.Entry<String, String> header : proxiedRequest.headers()) {
+          String name = header.getKey();
+          if (name.equalsIgnoreCase(CONNECTION.toString())) {
+            // Firefox is known to send an unexpected connection header value
+            // Connection=keep-alive, Upgrade
+            // It leads to a failure in websocket proxying
+            // So we make sure the standard value is sent to the backend
+            request.headers().set(CONNECTION, UPGRADE);
+          } else if (!name.equalsIgnoreCase(HOST.toString())) {
+            request.headers().add(name, header.getValue());
+          }
+        }
         Future<HttpClientResponse> fut2 = request.connect();
         proxiedRequest.handler(request::write);
         proxiedRequest.endHandler(v -> request.end());

src/test/java/io/vertx/httpproxy/WebSocketTest.java

@@ -144,6 +144,37 @@ public void testWebSocketFirefox(TestContext ctx) {
     }));
   }
 
+  @Test
+  public void testWebSocketHostHeader(TestContext ctx) {
+    Async async = ctx.async();
+    SocketAddress backend = startHttpBackend(ctx, 8081, req -> {
+      ctx.assertEquals("localhost:8081", req.headers().get("Host"));
+      Future<ServerWebSocket> fut = req.toWebSocket();
+      fut.onComplete(ctx.asyncAssertSuccess(ws -> {
+        ws.closeHandler(v -> {
+          async.complete();
+        });
+      }));
+    });
+    startProxy(backend);
+    HttpClient httpClient = vertx.createHttpClient();
+    RequestOptions options = new RequestOptions()
+      .setPort(8080)
+      .setHost("localhost")
+      .setURI("/ws")
+      .putHeader("Origin", "http://localhost:8080")
+      .putHeader("Connection", "Upgrade")
+      .putHeader("Upgrade", "Websocket")
+      .putHeader("Sec-WebSocket-Version", "13")
+      .putHeader("Sec-WebSocket-Key", "xy6UoM3l3TcREmAeAhZuYQ==");
+    httpClient.request(options).onComplete(ctx.asyncAssertSuccess(clientRequest -> {
+      clientRequest.connect().onComplete(ctx.asyncAssertSuccess(response -> {
+        ctx.assertEquals(101, response.statusCode());
+        response.netSocket().close();
+      }));
+    }));
+  }
+
   @Test
   public void testWebSocketExtensionsNegotiatedBetweenClientAndBackend(TestContext ctx) {
     Async async = ctx.async();