core: add Grpc.TRANSPORT_ATTR_LOCAL_ADDR (#4906)

Resolves #4135

alts/src/main/java/io/grpc/alts/internal/AltsProtocolNegotiator.java

@@ -145,6 +145,7 @@ public abstract class AltsProtocolNegotiator implements ProtocolNegotiator {
                     .set(TSI_PEER_KEY, altsEvt.peer())
                     .set(ALTS_CONTEXT_KEY, altsContext)
                     .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                    .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
                     .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.PRIVACY_AND_INTEGRITY)
                     .build(),
                 new Security(new OtherSecurity("alts", Any.pack(altsContext.context))));

alts/src/test/java/io/grpc/alts/internal/AltsProtocolNegotiatorTest.java

@@ -347,6 +347,8 @@ public class AltsProtocolNegotiatorTest {
         .isEqualTo(mockedAltsContext);
     assertThat(grpcHandler.attrs.get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR).toString())
         .isEqualTo("embedded");
+    assertThat(grpcHandler.attrs.get(Grpc.TRANSPORT_ATTR_LOCAL_ADDR).toString())
+        .isEqualTo("embedded");
     assertThat(grpcHandler.attrs.get(CallCredentials.ATTR_SECURITY_LEVEL))
         .isEqualTo(SecurityLevel.PRIVACY_AND_INTEGRITY);
   }

core/src/main/java/io/grpc/Grpc.java

@@ -38,6 +38,14 @@ public final class Grpc {
   public static final Attributes.Key<SocketAddress> TRANSPORT_ATTR_REMOTE_ADDR =
       Attributes.Key.create("remote-addr");
 
+  /**
+   * Attribute key for the local address of a transport.
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1710")
+  @TransportAttr
+  public static final Attributes.Key<SocketAddress> TRANSPORT_ATTR_LOCAL_ADDR =
+      Attributes.Key.create("local-addr");
+
   /**
    * Attribute key for SSL session of a transport.
    */

core/src/main/java/io/grpc/inprocess/InProcessTransport.java

@@ -132,6 +132,7 @@ final class InProcessTransport implements ServerTransport, ConnectionClientTrans
         synchronized (InProcessTransport.this) {
           Attributes serverTransportAttrs = Attributes.newBuilder()
               .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InProcessSocketAddress(name))
+              .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, new InProcessSocketAddress(name))
               .build();
           serverStreamAttributes = serverTransportListener.transportReady(serverTransportAttrs);
           clientTransportListener.transportReady();

interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java

@@ -1759,7 +1759,7 @@ public abstract class AbstractInteropTest {
     }
   }
 
-  /** Helper for getting remote address {@link io.grpc.ServerCall#getAttributes()} */
+  /** Helper for getting remote address from {@link io.grpc.ServerCall#getAttributes()} */
   protected SocketAddress obtainRemoteClientAddr() {
     TestServiceGrpc.TestServiceBlockingStub stub =
         blockingStub.withDeadlineAfter(5, TimeUnit.SECONDS);
@@ -1769,6 +1769,16 @@ public abstract class AbstractInteropTest {
     return serverCallCapture.get().getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
   }
 
+  /** Helper for getting local address from {@link io.grpc.ServerCall#getAttributes()} */
+  protected SocketAddress obtainLocalClientAddr() {
+    TestServiceGrpc.TestServiceBlockingStub stub =
+        blockingStub.withDeadlineAfter(5, TimeUnit.SECONDS);
+
+    stub.unaryCall(SimpleRequest.getDefaultInstance());
+
+    return serverCallCapture.get().getAttributes().get(Grpc.TRANSPORT_ATTR_LOCAL_ADDR);
+  }
+
   /** Helper for asserting TLS info in SSLSession {@link io.grpc.ServerCall#getAttributes()} */
   protected void assertX500SubjectDn(String tlsInfo) {
     TestServiceGrpc.TestServiceBlockingStub stub =

interop-testing/src/test/java/io/grpc/testing/integration/Http2NettyTest.java

@@ -87,6 +87,13 @@ public class Http2NettyTest extends AbstractInteropTest {
     assertNotEquals(getPort(), isa.getPort());
   }
 
+  @Test
+  public void localAddr() throws Exception {
+    InetSocketAddress isa = (InetSocketAddress) obtainLocalClientAddr();
+    assertEquals(InetAddress.getLoopbackAddress(), isa.getAddress());
+    assertEquals(getPort(), isa.getPort());
+  }
+
   @Test
   public void tlsInfo() {
     assertX500SubjectDn("CN=testclient, O=Internet Widgits Pty Ltd, ST=Some-State, C=AU");

netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java

@@ -90,6 +90,7 @@ public final class ProtocolNegotiators {
             // Set sttributes before replace to be sure we pass it before accepting any requests.
             handler.handleProtocolNegotiationCompleted(Attributes.newBuilder()
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
                 .build(),
                 /*securityInfo=*/ null);
             // Just replace this handler with the gRPC handler.
@@ -163,6 +164,7 @@ public final class ProtocolNegotiators {
                 Attributes.newBuilder()
                     .set(Grpc.TRANSPORT_ATTR_SSL_SESSION, session)
                     .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                    .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
                     .build(),
                 new InternalChannelz.Security(new InternalChannelz.Tls(session)));
             // Replace this handler with the GRPC handler.
@@ -673,6 +675,7 @@ public final class ProtocolNegotiators {
                 Attributes.newBuilder()
                     .set(Grpc.TRANSPORT_ATTR_SSL_SESSION, session)
                     .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                    .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
                     .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.PRIVACY_AND_INTEGRITY)
                     .build(),
                 new InternalChannelz.Security(new InternalChannelz.Tls(session)));
@@ -721,6 +724,7 @@ public final class ProtocolNegotiators {
           Attributes
               .newBuilder()
               .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+              .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
               .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
               .build(),
           /*securityInfo=*/ null);
@@ -764,6 +768,7 @@ public final class ProtocolNegotiators {
             Attributes
                 .newBuilder()
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
                 .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
                 .build(),
             /*securityInfo=*/ null);

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

@@ -77,12 +77,14 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.InetSocketAddress;
+import java.net.SocketAddress;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import javax.net.ssl.SSLHandshakeException;
@@ -105,6 +107,8 @@ public class NettyClientTransportTest {
   private ManagedClientTransport.Listener clientTransportListener;
 
   private final List<NettyClientTransport> transports = new ArrayList<>();
+  private final LinkedBlockingQueue<Attributes> serverTransportAttributesList =
+      new LinkedBlockingQueue<>();
   private final NioEventLoopGroup group = new NioEventLoopGroup(1);
   private final EchoServerListener serverListener = new EchoServerListener();
   private final InternalChannelz channelz = new InternalChannelz();
@@ -536,6 +540,11 @@ public class NettyClientTransportTest {
 
     assertNotNull(rpc.stream.getAttributes().get(Grpc.TRANSPORT_ATTR_SSL_SESSION));
     assertEquals(address, rpc.stream.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR));
+    Attributes serverTransportAttrs = serverTransportAttributesList.poll(1, TimeUnit.SECONDS);
+    assertNotNull(serverTransportAttrs);
+    SocketAddress clientAddr = serverTransportAttrs.get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
+    assertNotNull(clientAddr);
+    assertEquals(clientAddr, rpc.stream.getAttributes().get(Grpc.TRANSPORT_ATTR_LOCAL_ADDR));
   }
 
   @Test
@@ -749,7 +758,7 @@ public class NettyClientTransportTest {
     }
   }
 
-  private static final class EchoServerListener implements ServerListener {
+  private final class EchoServerListener implements ServerListener {
     final List<NettyServerTransport> transports = new ArrayList<>();
     final List<EchoServerStreamListener> streamListeners =
             Collections.synchronizedList(new ArrayList<EchoServerStreamListener>());
@@ -769,6 +778,7 @@ public class NettyClientTransportTest {
 
         @Override
         public Attributes transportReady(Attributes transportAttrs) {
+          serverTransportAttributesList.add(transportAttrs);
           return transportAttrs;
         }
 

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

@@ -484,6 +484,7 @@ class OkHttpClientTransport implements ConnectionClientTransport, TransportExcep
           attributes = Attributes
               .newBuilder()
               .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, sock.getRemoteSocketAddress())
+              .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, sock.getLocalSocketAddress())
               .set(Grpc.TRANSPORT_ATTR_SSL_SESSION, sslSession)
               .set(CallCredentials.ATTR_SECURITY_LEVEL,
                   sslSession == null ? SecurityLevel.NONE : SecurityLevel.PRIVACY_AND_INTEGRITY)

testing/src/main/java/io/grpc/internal/testing/AbstractTransportTest.java

@@ -707,6 +707,7 @@ public abstract class AbstractTransportTest {
     assertEquals("additional attribute value",
         serverStream.getAttributes().get(ADDITIONAL_TRANSPORT_ATTR_KEY));
     assertNotNull(serverStream.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR));
+    assertNotNull(serverStream.getAttributes().get(Grpc.TRANSPORT_ATTR_LOCAL_ADDR));
 
     serverStream.request(1);
     assertTrue(clientStreamListener.awaitOnReadyAndDrain(TIMEOUT_MS, TimeUnit.MILLISECONDS));