Fix ping/trace in local AS

CHANGELOG.md

@@ -16,6 +16,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   [#15](https://github.com/tzaeschke/phtree-cpp/pull/15)
 
 ### Fixed
+- Fixed: SCMP problem when pinging local AS.
+  [#16](https://github.com/tzaeschke/phtree-cpp/pull/16),
 - Fixed SCMP timeout and error handling (IOExceptions + SCMP errors).
   [#13](https://github.com/tzaeschke/phtree-cpp/pull/13)
 - CI (only) failures on JDK 8. [#10](https://github.com/tzaeschke/phtree-cpp/pull/10)

TODO.md

@@ -76,6 +76,7 @@
   - BUG: Ping to iaOVGU causes 3 CS requests that have type UP,CORE,CORE....?
   - FIX: Ask why requesting an UP segment effectively returns a DOWN segment
     (it needs to be reversed + the SegID needs to be XORed)
+  - Why are Java pings 8 bytes shorter than scionproto pings? -> local AS
 - Docs:
   Add docs for setting up an environment
   https://github.com/marcfrei/scion-time#setting-up-a-scion-test-environment

src/main/java/org/scion/RequestPath.java

@@ -51,6 +51,11 @@ private Daemon.Path protoPath() {
 
   @Override
   public InetSocketAddress getFirstHopAddress() throws UnknownHostException {
+    if (getRawPath() == null || getRawPath().length == 0) {
+      // local AS
+      InetAddress addr = InetAddress.getByAddress(getDestinationAddress());
+      return new InetSocketAddress(addr, getDestinationPort());
+    }
     return getFirstHopAddress(pathProtoc);
   }
 
@@ -175,13 +180,13 @@ public EpicAuths getEpicAuths() {
 
   public enum LinkType {
     /** Unspecified link type. */
-    LINK_TYPE_UNSPECIFIED, // = 0;
+    LINK_TYPE_UNSPECIFIED, // = 0
     /** Direct physical connection. */
-    LINK_TYPE_DIRECT, // = 1;
+    LINK_TYPE_DIRECT, // = 1
     /** Connection with local routing/switching. */
-    LINK_TYPE_MULTI_HOP, // = 2;
+    LINK_TYPE_MULTI_HOP, // = 2
     /** Connection overlayed over publicly routed Internet. */
-    LINK_TYPE_OPEN_NET, // = 3;
+    LINK_TYPE_OPEN_NET, // = 3
   }
 
   public static class EpicAuths {

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

@@ -105,6 +105,10 @@ public void setTimeOut(int milliSeconds) {
     this.timeOutMs = milliSeconds;
   }
 
+  public int getTimeOut() {
+    return this.timeOutMs;
+  }
+
   @Override
   public void close() throws IOException {
     channel.close();

src/main/java/org/scion/internal/PathHeaderParser.java

@@ -20,7 +20,7 @@
 import java.util.ArrayList;
 
 public class PathHeaderParser {
-  public PathHeaderParser() {}
+  private PathHeaderParser() {}
 
   private static int getSegmentCount(byte[] raw) {
     ByteBuffer data = ByteBuffer.wrap(raw);
@@ -51,6 +51,9 @@ public Node(int id, boolean constDirFlag, int posHopFlags, int hopFlags) {
 
   public static ArrayList<Node> getTraceNodes(byte[] raw) {
     ArrayList<Node> nodes = new ArrayList<>();
+    if (raw == null || raw.length == 0) {
+      return nodes;
+    }
 
     ByteBuffer data = ByteBuffer.wrap(raw);
     int i0 = data.getInt();

src/main/java/org/scion/internal/ScionHeaderParser.java

@@ -92,8 +92,11 @@ public static ResponsePath extractResponsePath(
 
     // raw path
     byte[] path = new byte[hdrLenBytes - data.position()];
-    data.get(path);
-    reversePathInPlace(ByteBuffer.wrap(path));
+    if (path.length > 0) {
+      // raw path may be empty for local AS
+      data.get(path);
+      reversePathInPlace(ByteBuffer.wrap(path));
+    }
 
     // get remote port from UDP overlay
     data.position(hdrLenBytes);
@@ -200,8 +203,9 @@ public static String validate(ByteBuffer data) {
           + (hdrLenBytes + payLoadLen);
     }
     int pathType = readInt(i2, 0, 8);
-    if (pathType != 1) {
-      return PRE + "Invalid path type: expected 1, got " + pathType;
+    if (pathType != 1 && pathType != 0) {
+      // Validation against path length happens further down.
+      return PRE + "Invalid path type: expected 0 or 1, got " + pathType;
     }
     int dt = readInt(i2, 8, 2);
     int dl = readInt(i2, 10, 2);
@@ -258,6 +262,12 @@ public static String validate(ByteBuffer data) {
     // raw path
     byte[] path = new byte[start + hdrLenBytes - data.position()];
     data.get(path);
+    if (path.length == 0 && pathType != 0) {
+      return PRE + "Path is empty but path type is: " + pathType;
+    }
+    if (path.length > 0 && pathType != 1) {
+      return PRE + "Path is not empty but path type is: " + pathType;
+    }
     // TODO validate path
 
     if (nextHeader == InternalConstants.HdrTypes.UDP.code()) {
@@ -304,7 +314,7 @@ public static void write(
     i1 = writeInt(i1, 8, 8, newHdrLen); // HdrLen = bytes/4
     i1 = writeInt(i1, 16, 16, userPacketLength); // PayloadLen (+ overlay!)
     data.putInt(i1);
-    i2 = writeInt(i2, 0, 8, 1); // PathType : SCION = 1
+    i2 = writeInt(i2, 0, 8, pathHeaderLength > 0 ? 1 : 0); // PathType : SCION = 1
     i2 = writeInt(i2, 8, 2, 0); // DT
     i2 = writeInt(i2, 10, 2, dl); // DL
     i2 = writeInt(i2, 12, 2, 0); // ST

src/test/java/org/scion/api/SCMPTest.java

@@ -24,7 +24,6 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.scion.*;
 import org.scion.demo.inspector.ScionPacketInspector;
@@ -100,7 +99,6 @@ void echo() throws IOException {
   }
 
   @Test
-  @Disabled
   void echo_localAS() throws IOException {
     testEcho(this::getPathToLocalAS);
   }
@@ -129,11 +127,11 @@ void echo_timeout() throws IOException {
     try (ScmpChannel channel = Scmp.createChannel(getPathTo112())) {
       channel.setScmpErrorListener(scmpMessage -> fail(scmpMessage.getTypeCode().getText()));
       channel.setOption(ScionSocketOptions.SN_API_THROW_PARSER_FAILURE, true);
-      channel.setTimeOut(1_000);
+      channel.setTimeOut(100);
       MockNetwork.dropNextPackets(1);
       Scmp.EchoMessage result1 = channel.sendEchoRequest(42, ByteBuffer.allocate(0));
       assertTrue(result1.isTimedOut());
-      assertEquals(1_000 * 1_000_000, result1.getNanoSeconds());
+      assertEquals(100 * 1_000_000, result1.getNanoSeconds());
       assertEquals(42, result1.getSequenceNumber());
 
       // try again
@@ -183,22 +181,20 @@ void echo_SCMP_error() throws IOException {
 
   @Test
   void traceroute() throws IOException {
-    testTraceroute(this::getPathTo112);
+    testTraceroute(this::getPathTo112, 2);
   }
 
   @Test
-  @Disabled
   void traceroute_localAS() throws IOException {
-    testTraceroute(this::getPathToLocalAS);
+    testTraceroute(this::getPathToLocalAS, 0);
   }
 
-  private void testTraceroute(Supplier<RequestPath> path) throws IOException {
+  private void testTraceroute(Supplier<RequestPath> path, int nHops) throws IOException {
     MockNetwork.startTiny();
     try (ScmpChannel channel = Scmp.createChannel(path.get())) {
       channel.setScmpErrorListener(scmpMessage -> fail(scmpMessage.getTypeCode().getText()));
       channel.setOption(ScionSocketOptions.SN_API_THROW_PARSER_FAILURE, true);
       Collection<Scmp.TracerouteMessage> results = channel.sendTracerouteRequest();
-      channel.setTimeOut(Integer.MAX_VALUE); // TODO ??
 
       int n = 0;
       for (Scmp.TracerouteMessage result : results) {
@@ -217,7 +213,7 @@ private void testTraceroute(Supplier<RequestPath> path) throws IOException {
         }
       }
 
-      assertEquals(2, results.size());
+      assertEquals(nHops, results.size());
     } finally {
       MockNetwork.stopTiny();
     }
@@ -229,13 +225,16 @@ void traceroute_timeout() throws IOException {
     try (ScmpChannel channel = Scmp.createChannel(getPathTo112())) {
       channel.setScmpErrorListener(scmpMessage -> fail(scmpMessage.getTypeCode().getText()));
       channel.setOption(ScionSocketOptions.SN_API_THROW_PARSER_FAILURE, true);
+      assertEquals(1000, channel.getTimeOut());
+      channel.setTimeOut(100);
+      assertEquals(100, channel.getTimeOut());
       MockNetwork.dropNextPackets(1);
       Collection<Scmp.TracerouteMessage> results1 = channel.sendTracerouteRequest();
       assertEquals(1, results1.size());
       for (Scmp.TracerouteMessage result : results1) {
         assertTrue(result.isTimedOut());
         assertEquals(Scmp.ScmpTypeCode.TYPE_130, result.getTypeCode());
-        assertEquals(1_000 * 1_000_000, result.getNanoSeconds());
+        assertEquals(100 * 1_000_000, result.getNanoSeconds());
       }
 
       // retry
@@ -291,7 +290,13 @@ private RequestPath getPathTo112() {
   private RequestPath getPathToLocalAS() {
     ScionService service = Scion.defaultService();
     long dstIA = service.getLocalIsdAs();
-    List<RequestPath> paths = service.getPaths(dstIA, new byte[] {0, 0, 0, 0}, 12345);
-    return paths.get(0);
+    try {
+      InetAddress addr = InetAddress.getByName(MockNetwork.BORDER_ROUTER_HOST);
+      int port = MockNetwork.BORDER_ROUTER_PORT1;
+      List<RequestPath> paths = service.getPaths(dstIA, new InetSocketAddress(addr, port));
+      return paths.get(0);
+    } catch (UnknownHostException e) {
+      throw new RuntimeException(e);
+    }
   }
 }

src/test/java/org/scion/api/ScionServiceTest.java

@@ -17,10 +17,10 @@
 import static org.junit.jupiter.api.Assertions.*;
 
 import java.io.IOException;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.util.List;
 import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.scion.*;
@@ -34,12 +34,6 @@ public class ScionServiceTest {
   private static final String SCION_TXT = "\"scion=1-ff00:0:110,127.0.0.1\"";
   private static final int DEFAULT_PORT = MockDaemon.DEFAULT_PORT;
 
-  @BeforeAll
-  public static void beforeAll() {
-    //    System.setProperty(
-    //        PackageVisibilityHelper.DEBUG_PROPERTY_DNS_MOCK, SCION_HOST + "=" + SCION_TXT);
-  }
-
   @AfterAll
   public static void afterAll() {
     System.clearProperty(PackageVisibilityHelper.DEBUG_PROPERTY_DNS_MOCK);
@@ -165,6 +159,40 @@ void getPaths() throws IOException {
     }
   }
 
+  @Test
+  void getPaths_localAS() throws IOException {
+    InetSocketAddress dstAddress = new InetSocketAddress("::1", 12345);
+    MockDaemon.createAndStartDefault();
+    try {
+      // String daemonAddr = "127.0.0.12:30255"; // from 110-topo
+      List<RequestPath> paths;
+      long dstIA = ScionUtil.parseIA("1-ff00:0:110");
+      try (Scion.CloseableService client =
+          Scion.newServiceWithDaemon(MockDaemon.DEFAULT_ADDRESS_STR)) {
+        paths = client.getPaths(dstIA, dstAddress);
+      } catch (IOException e) {
+        throw new RuntimeException(e);
+      }
+
+      //  Paths found: 1
+      //  Path:  exp=1708596832 / 2024-02-22T10:13:52Z  mtu=1472
+      //  Path: first hop =
+      //          raw: []
+      //  raw: {}
+      assertEquals(1, paths.size());
+      RequestPath path = paths.get(0);
+      InetAddress addr = InetAddress.getByAddress(path.getDestinationAddress());
+      InetSocketAddress sAddr = new InetSocketAddress(addr, path.getDestinationPort());
+      assertEquals(sAddr, path.getFirstHopAddress());
+      assertEquals(dstIA, path.getDestinationIsdAs());
+
+      // get local AS, get PATH
+      assertEquals(2, MockDaemon.getAndResetCallCount());
+    } finally {
+      MockDaemon.closeDefault();
+    }
+  }
+
   @Test
   void getScionAddress() throws IOException {
     // Test that DNS injection via properties works