core: Gracefully handle GOAWAY frames with unrecognized error codes (v1.79.x backport) (#13048)

Backport of #13035 to v1.79.x.

Author: AgraVator

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

@@ -31,13 +31,10 @@ public final class GoAwayDisconnectError implements DisconnectError {
   /**
    * Creates a GoAway reason.
    *
-   * @param errorCode The specific, non-null HTTP/2 error code (e.g., "NO_ERROR").
+   * @param errorCode The specific HTTP/2 error code (e.g., "NO_ERROR").
    */
   public GoAwayDisconnectError(GrpcUtil.Http2Error errorCode) {
-    if (errorCode == null) {
-      throw new NullPointerException("Http2Error cannot be null for GOAWAY");
-    }
-    this.errorCode = errorCode;
+    this.errorCode = errorCode != null ? errorCode : GrpcUtil.Http2Error.INTERNAL_ERROR;
   }
 
   @Override

core/src/test/java/io/grpc/internal/GrpcUtilTest.java

@@ -391,4 +391,56 @@ public void getTransportFromPickResult_dropPickResult_failFast() {
 
     verify(listener).closed(eq(status), eq(RpcProgress.DROPPED), any(Metadata.class));
   }
+
+  @Test
+  public void goAwayDisconnectError_standardErrorCode() {
+    GoAwayDisconnectError error = new GoAwayDisconnectError(GrpcUtil.Http2Error.NO_ERROR);
+    assertEquals("GOAWAY NO_ERROR", error.toErrorString());
+  }
+
+  @Test
+  public void goAwayDisconnectError_nullErrorCodeFallsBackToInternalError() {
+    GoAwayDisconnectError error = new GoAwayDisconnectError(null);
+    assertEquals("GOAWAY INTERNAL_ERROR", error.toErrorString());
+    assertEquals(new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR), error);
+  }
+
+  @Test
+  public void goAwayDisconnectError_unrecognizedErrorCodeFallsBackToInternalError() {
+    // Apache httpd APR_TIMEUP error code
+    GoAwayDisconnectError apacheError =
+        new GoAwayDisconnectError(GrpcUtil.Http2Error.forCode(70007L));
+    assertEquals("GOAWAY INTERNAL_ERROR", apacheError.toErrorString());
+    assertEquals(new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR), apacheError);
+
+    // Arbitrary unknown error code
+    GoAwayDisconnectError unknownError =
+        new GoAwayDisconnectError(GrpcUtil.Http2Error.forCode(0x12345678L));
+    assertEquals("GOAWAY INTERNAL_ERROR", unknownError.toErrorString());
+    assertEquals(new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR), unknownError);
+
+    // Negative code
+    GoAwayDisconnectError negativeError =
+        new GoAwayDisconnectError(GrpcUtil.Http2Error.forCode(-1L));
+    assertEquals("GOAWAY INTERNAL_ERROR", negativeError.toErrorString());
+    assertEquals(new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR), negativeError);
+  }
+
+  @Test
+  public void goAwayDisconnectError_equalsAndHashCode() {
+    GoAwayDisconnectError err1 =
+        new GoAwayDisconnectError(GrpcUtil.Http2Error.forCode(70007L));
+    GoAwayDisconnectError err2 = new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR);
+    GoAwayDisconnectError err3 = new GoAwayDisconnectError(null);
+    GoAwayDisconnectError err4 = new GoAwayDisconnectError(GrpcUtil.Http2Error.NO_ERROR);
+
+    assertEquals(err1, err2);
+    assertEquals(err2, err3);
+    assertEquals(err1.hashCode(), err2.hashCode());
+    assertEquals(err2.hashCode(), err3.hashCode());
+
+    assertFalse(err1.equals(err4));
+    assertFalse(err1.hashCode() == err4.hashCode());
+  }
 }
+

netty/src/test/java/io/grpc/netty/NettyClientHandlerTest.java

@@ -63,6 +63,8 @@
 import io.grpc.internal.ClientStreamListener.RpcProgress;
 import io.grpc.internal.ClientTransport;
 import io.grpc.internal.ClientTransport.PingCallback;
+import io.grpc.internal.DisconnectError;
+import io.grpc.internal.GoAwayDisconnectError;
 import io.grpc.internal.GrpcAttributes;
 import io.grpc.internal.GrpcUtil;
 import io.grpc.internal.KeepAliveManager;
@@ -587,6 +589,55 @@ public void receivedGoAwayShouldFailNewStreams() throws Exception {
         status.getDescription());
   }
 
+  @Test
+  public void receivedGoAway_unrecognizedErrorCode_shouldFailNewStreamsAndReportMetric()
+      throws Exception {
+    // Read a GOAWAY with an unrecognized error code (e.g. Apache httpd error code 70007).
+    channelRead(goAwayFrame(0, 70007, Unpooled.copiedBuffer("apache error", UTF_8)));
+
+    ArgumentCaptor<Status> statusCaptor = ArgumentCaptor.forClass(Status.class);
+    ArgumentCaptor<DisconnectError> disconnectErrorCaptor =
+        ArgumentCaptor.forClass(DisconnectError.class);
+    verify(listener).transportShutdown(statusCaptor.capture(), disconnectErrorCaptor.capture());
+
+    assertEquals(Status.UNAVAILABLE.getCode(), statusCaptor.getValue().getCode());
+    assertEquals(
+        "GOAWAY shut down transport. Unrecognized HTTP/2 error code: 70007, "
+            + "debug data: apache error",
+        statusCaptor.getValue().getDescription());
+
+    DisconnectError disconnectError = disconnectErrorCaptor.getValue();
+    assertEquals(
+        new GoAwayDisconnectError(GrpcUtil.Http2Error.INTERNAL_ERROR), disconnectError);
+
+    // Creating new stream must fail immediately with UNAVAILABLE
+    ChannelFuture future = enqueue(newCreateStreamCommand(grpcHeaders, streamTransportState));
+    assertTrue(future.isDone());
+    assertFalse(future.isSuccess());
+    Status status = Status.fromThrowable(future.cause());
+    assertEquals(Status.UNAVAILABLE.getCode(), status.getCode());
+    assertEquals(
+        "GOAWAY shut down transport. Unrecognized HTTP/2 error code: 70007, "
+            + "debug data: apache error",
+        status.getDescription());
+  }
+
+  @Test
+  public void receivedGoAway_unrecognizedErrorCode_shouldCloseActiveStreams() throws Exception {
+    createStream();
+
+    // Read a GOAWAY indicating our stream (id 3) was not processed.
+    channelRead(goAwayFrame(0, 70007, Unpooled.copiedBuffer("apache error", UTF_8)));
+
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(streamListener).closed(captor.capture(), eq(PROCESSED), ArgumentMatchers.notNull());
+    assertEquals(Status.INTERNAL.getCode(), captor.getValue().getCode());
+    assertEquals(
+        "Abrupt GOAWAY closed sent stream. Unrecognized HTTP/2 error code: 70007, "
+            + "debug data: apache error",
+        captor.getValue().getDescription());
+  }
+
   // This test is not as useful as it looks, because the HTTP/2 Netty code catches and doesn't
   // propagate exceptions during the onGoAwayReceived callback.
   @Test