core,okhttp: handle unresolved proxy addresses

core/src/main/java/io/grpc/internal/ProxyDetectorImpl.java

@@ -184,7 +184,8 @@ private static InetSocketAddress overrideProxy(String proxyHostPort) {
             + "be removed in a future release. Use the JVM flags "
             + "\"-Dhttps.proxyHost=HOST -Dhttps.proxyPort=PORT\" to set the https proxy for "
             + "this JVM.");
-    return new InetSocketAddress(parts[0], port);
+    // Return an unresolved InetSocketAddress to avoid DNS lookup
+    return InetSocketAddress.createUnresolved(parts[0], port);
   }
 
   /**

okhttp/src/main/java/io/grpc/okhttp/OkHttpClientTransport.java

@@ -472,7 +472,13 @@ sslSocketFactory, hostnameVerifier, sock, getOverridenHost(), getOverridenPort()
   private Socket createHttpProxySocket(InetSocketAddress address, InetSocketAddress proxyAddress,
       String proxyUsername, String proxyPassword) throws IOException, StatusException {
     try {
-      Socket sock = new Socket(proxyAddress.getAddress(), proxyAddress.getPort());
+      Socket sock;
+      // The proxy address may not be resolved
+      if (proxyAddress.getAddress() != null) {
+        sock = new Socket(proxyAddress.getAddress(), proxyAddress.getPort());
+      } else {
+        sock = new Socket(proxyAddress.getHostName(), proxyAddress.getPort());
+      }
       sock.setTcpNoDelay(true);
 
       Source source = Okio.source(sock);

okhttp/src/test/java/io/grpc/okhttp/OkHttpClientTransportTest.java

@@ -1569,6 +1569,33 @@ public void proxy_immediateServerClose() throws Exception {
     verify(transportListener, timeout(TIME_OUT_MS)).transportTerminated();
   }
 
+  @Test
+  public void proxy_unresolvedProxyAddress() throws Exception {
+    clientTransport = new OkHttpClientTransport(
+        InetSocketAddress.createUnresolved("theservice", 80),
+        "authority",
+        "userAgent",
+        executor,
+        null,
+        null,
+        ConnectionSpec.CLEARTEXT,
+        DEFAULT_MAX_MESSAGE_SIZE,
+        InetSocketAddress.createUnresolved("unresolvedproxy", 80),
+        null,
+        null,
+        tooManyPingsRunnable);
+    clientTransport.start(transportListener);
+
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(transportListener, timeout(TIME_OUT_MS)).transportShutdown(captor.capture());
+    Status error = captor.getValue();
+    assertTrue("Status didn't contain proxy: " + captor.getValue(),
+        error.getDescription().contains("proxy"));
+    assertEquals("Not UNAVAILABLE: " + captor.getValue(),
+        Status.UNAVAILABLE.getCode(), error.getCode());
+    verify(transportListener, timeout(TIME_OUT_MS)).transportTerminated();
+  }
+
   @Test
   public void goAway_notUtf8() throws Exception {
     initTransport();