SHIM

.github/workflows/build.yml

@@ -82,7 +82,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          java-version: 11
+          java-version: 17
           distribution: 'temurin'
       - name: Enable 127.0.0.x addresses
         run: |

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 
 ### TODO for 0.4.0
+- Fix showpaths to show "127.0.0.81:31038" i.o. "/192.168.53.20"
 - Fix @Disabled tests
 - Support topofile port range
   - Upgrade all JUnit topo files to post 0.11 with new format (including port range)
@@ -21,6 +22,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   - Inherit DatagramChannel 
 - Consider using https://github.com/ascopes/protobuf-maven-plugin (more up to date) 
 
+### Added
+- Add a SHIM, required for #130 (topo file port range support).
+  [#130](https://github.com/scionproto-contrib/jpan/pull/130)
+
 ## [0.3.1] - 2024-10-11
 
 ### Added

config/checkstyle/checkstyle-config.xml

@@ -6,7 +6,7 @@
         <!-- Checks for imports                              -->
         <!-- See http://checkstyle.sf.net/config_import.html -->
         <module name="AvoidStarImport">
-            <property name="excludes" value="java.io,java.util,java.net,io.grpc,org.junit.jupiter.api.Assertions,org.scion.jpan.internal,org.scion.jpan,org.scion.jpan.demo.inspector.ByteUtil,org.xbill.DNS"/>
+            <property name="excludes" value="java.io,java.util,java.net,io.grpc,org.junit.jupiter.api,org.junit.jupiter.api.Assertions,org.scion.jpan.internal,org.scion.jpan,org.scion.jpan.demo.inspector.ByteUtil,org.xbill.DNS"/>
 <!--            <property name="severity" value="warning" />-->
         </module>
         <module name="NeedBraces"/>

src/main/java/org/scion/jpan/AbstractDatagramChannel.java

@@ -59,10 +59,6 @@ abstract class AbstractDatagramChannel<C extends AbstractDatagramChannel<?>> imp
   private boolean cfgRemoteDispatcher = false;
   private InetSocketAddress overrideExternalAddress = null;
 
-  protected AbstractDatagramChannel(ScionService service) throws IOException {
-    this(service, DatagramChannel.open());
-  }
-
   protected AbstractDatagramChannel(
       ScionService service, java.nio.channels.DatagramChannel channel) {
     this.channel = channel;

src/main/java/org/scion/jpan/ScionService.java

@@ -126,6 +126,7 @@ protected ScionService(String addressOrHost, Mode mode) {
       segmentStub = SegmentLookupServiceGrpc.newBlockingStub(channel);
     }
     shutdownHook = addShutdownHook();
+    Shim.install(this);
     try {
       getLocalIsdAs(); // Init
     } catch (RuntimeException e) {

src/main/java/org/scion/jpan/Scmp.java

@@ -16,6 +16,7 @@
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.channels.DatagramChannel;
 
 public class Scmp {
 
@@ -426,7 +427,7 @@
    */
   @Deprecated
   public static ScmpChannel createChannel(int listeningPort) throws IOException {
-    return new ScmpChannel(Scion.defaultService(), listeningPort);
+    return new ScmpChannel(Scion.defaultService(), listeningPort, DatagramChannel.open());
   }
 
   /**
@@ -440,7 +441,7 @@
   @Deprecated
   public static ScmpChannel createChannel(ScionService service, int listeningPort)
       throws IOException {
-    return new ScmpChannel(service, listeningPort);
+    return new ScmpChannel(service, listeningPort, DatagramChannel.open());
   }
 
   /**

src/main/java/org/scion/jpan/ScmpChannel.java

@@ -44,11 +44,11 @@ public class ScmpChannel implements AutoCloseable {
   private final InternalChannel channel;
 
   ScmpChannel() throws IOException {
-    this(Scion.defaultService(), 12345);
+    this(Scion.defaultService(), 12345, DatagramChannel.open());
   }
 
-  ScmpChannel(ScionService service, int port) throws IOException {
-    this.channel = new InternalChannel(service, port);
+  ScmpChannel(ScionService service, int port, DatagramChannel channel) throws IOException {
+    this.channel = new InternalChannel(service, port, channel);
   }
 
   /**
@@ -166,8 +166,9 @@ private class InternalChannel extends AbstractDatagramChannel<InternalChannel> {
     private final Selector selector;
     private Predicate<Scmp.EchoMessage> echoListener;
 
-    protected InternalChannel(ScionService service, int port) throws IOException {
-      super(service);
+    protected InternalChannel(ScionService service, int port, DatagramChannel channel)
+        throws IOException {
+      super(service, channel);
 
       // selector
       this.selector = Selector.open();

src/main/java/org/scion/jpan/ScmpResponder.java

@@ -27,15 +27,17 @@
 import org.scion.jpan.internal.InternalConstants;
 import org.scion.jpan.internal.ScionHeaderParser;
 import org.scion.jpan.internal.ScmpParser;
+import org.scion.jpan.internal.Shim;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class ScmpResponder implements AutoCloseable {
   private static final Logger log = LoggerFactory.getLogger(ScmpResponder.class);
   private final InternalChannel channel;
 
-  private ScmpResponder(ScionService service, int port) throws IOException {
-    this.channel = new InternalChannel(service, port);
+  private ScmpResponder(
+      ScionService service, int port, DatagramChannel channel, Selector selector, Shim shim) {
+    this.channel = new InternalChannel(service, port, channel, selector, shim);
   }
 
   public static Builder newBuilder() {
@@ -76,23 +78,31 @@
    * <p>SCMP requests can be monitored and intercepted through a listener, see {@link
    * #setScmpEchoListener(Predicate)}.
    *
-   * <p>This method blocks until the responder's thread is interrupted.
+   * <p>This method blocks until {@link #close()} is called.
    *
    * @throws IOException If an IO exception occurs.
    */
   public void start() throws IOException {
+    this.channel.start();
     this.channel.sendEchoResponses();
   }
 
   private static class InternalChannel extends AbstractDatagramChannel<InternalChannel> {
     private final Selector selector;
     private Predicate<Scmp.EchoMessage> echoListener;
+    private final int port;
+    private final Shim shim;
 
-    protected InternalChannel(ScionService service, int port) throws IOException {
-      super(service);
+    protected InternalChannel(
+        ScionService service, int port, DatagramChannel channel, Selector selector, Shim shim) {
+      super(service, channel);
+      this.shim = shim;
+      this.port = port;
+      this.selector = selector;
+    }
 
+    void start() throws IOException {
       // selector
-      this.selector = Selector.open();
       super.channel().configureBlocking(false);
       super.channel().register(selector, SelectionKey.OP_READ);
 
@@ -121,6 +131,9 @@
               hdrType = receiveExtensionHeader(buffer, hdrType);
 
               if (hdrType != InternalConstants.HdrTypes.SCMP) {
+                if (shim != null) {
+                  shim.forward(buffer, super.channel());
+                }
                 continue; // drop
               }
               return ScionHeaderParser.extractResponsePath(buffer, srcAddress);
@@ -135,6 +148,9 @@
       readLock().lock();
       writeLock().lock();
       try {
+        if (shim != null) {
+          shim.signalReadiness();
+        }
         while (true) {
           ByteBuffer buffer = getBufferReceive(DEFAULT_BUFFER_SIZE);
           ResponsePath path = receiveLoop(buffer);
@@ -163,7 +179,11 @@
             sendRaw(buffer, path);
             log.info("Responded to SCMP {} from {}", type, path.getRemoteAddress());
           } else {
-            log.info("Dropped SCMP message with type {} from {}", type, path.getRemoteAddress());
+            if (shim != null) {
+              shim.forward(buffer, super.channel());
+            } else {
+              log.info("Dropped SCMP message with type {} from {}", type, path.getRemoteAddress());
+            }
           }
         }
       } finally {
@@ -203,6 +223,9 @@
   public static class Builder {
     private ScionService service;
     private int port = Constants.SCMP_PORT;
+    private DatagramChannel channel;
+    private Selector selector;
+    private Shim shim;
 
     public Builder setLocalPort(int localPort) {
       this.port = localPort;
@@ -217,10 +240,17 @@
     public ScmpResponder build() {
       ScionService service2 = service == null ? ScionService.defaultService() : service;
       try {
-        return new ScmpResponder(service2, port);
+        channel = channel == null ? DatagramChannel.open() : channel;
+        selector = selector == null ? Selector.open() : selector;
       } catch (IOException e) {
         throw new ScionRuntimeException(e);
       }
+      return new ScmpResponder(service2, port, channel, selector, shim);
+    }
+
+    public Builder setShim(Shim shim) {
+      this.shim = shim;
+      return this;
     }
   }
 }