DatagramSocket works! (#32)

Co-authored-by: Tilmann Zäschke <tilmann.zaeschke@inf.ethz.ch>

CHANGELOG.md

@@ -10,43 +10,44 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Changed
 - BREAKING CHANGE: Changed maven artifactId to "client"
-  [#9](https://github.com/tzaeschke/phtree-cpp/pull/9)
+  [#9](https://github.com/netsec-ethz/scion-java-client/pull/9)
 - BREAKING CHANGE: SCMP refactoring, renamed several SCMP related classes.
-  [#14](https://github.com/tzaeschke/phtree-cpp/pull/14), 
-  [#15](https://github.com/tzaeschke/phtree-cpp/pull/15),
-  [#17](https://github.com/tzaeschke/phtree-cpp/pull/17),
-  [#19](https://github.com/tzaeschke/phtree-cpp/pull/19),
-  [#20](https://github.com/tzaeschke/phtree-cpp/pull/21)
+  [#14](https://github.com/netsec-ethz/scion-java-client/pull/14), 
+  [#15](https://github.com/netsec-ethz/scion-java-client/pull/15),
+  [#17](https://github.com/netsec-ethz/scion-java-client/pull/17),
+  [#19](https://github.com/netsec-ethz/scion-java-client/pull/19),
+  [#20](https://github.com/netsec-ethz/scion-java-client/pull/21)
 - BREAKING CHANGE:`ScionService` instances created via `Scion.newXYZ`
   will not be considered by `Scion.defaultService()`. Also, `DatagramChannel.getService()`
   does not create a service if none exists.
-  [#18](https://github.com/tzaeschke/phtree-cpp/pull/18)
+  [#18](https://github.com/netsec-ethz/scion-java-client/pull/18)
 - Doc cleanup
-  [#22](https://github.com/tzaeschke/phtree-cpp/pull/22)
+  [#22](https://github.com/netsec-ethz/scion-java-client/pull/22)
 - BREAKING CHANGE: `getCurrentPath()` renamed to `getConnectionPath()`
-  [#31](https://github.com/tzaeschke/phtree-cpp/pull/31)
+  [#30](https://github.com/netsec-ethz/scion-java-client/pull/30)
 
 ### Fixed
 - Fixed: SCMP problem when pinging local AS.
-  [#16](https://github.com/tzaeschke/phtree-cpp/pull/16),
+  [#16](https://github.com/netsec-ethz/scion-java-client/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)
-- Sporadic CI (only) failures. [#12](https://github.com/tzaeschke/phtree-cpp/pull/12)
+  [#13](https://github.com/netsec-ethz/scion-java-client/pull/13)
+- CI (only) failures on JDK 8. [#10](https://github.com/netsec-ethz/scion-java-client/pull/10)
+- Sporadic CI (only) failures. [#12](https://github.com/netsec-ethz/scion-java-client/pull/12)
+- Small fixes for 0.1.0 release. [#32](https://github.com/netsec-ethz/scion-java-client/pull/32)
 
 ### Removed
 
 - Removed all code related to DatagramSockets
-  [#21](https://github.com/tzaeschke/phtree-cpp/pull/21)
+  [#21](https://github.com/netsec-ethz/scion-java-client/pull/21)
 
 
 ## [0.1.0-ALPHA] - 2024-02-01
 
 ### Added
-- `DatagramSocket` [#7](https://github.com/tzaeschke/phtree-cpp/pull/7)
-- `Path`, `RequestPath`, `ResponsePath` [#7](https://github.com/tzaeschke/phtree-cpp/pull/7)
-- `Scion`, `ScionService` [#7](https://github.com/tzaeschke/phtree-cpp/pull/7)
-- `ScmpChannel` for SCMP [#7](https://github.com/tzaeschke/phtree-cpp/pull/7)
+- `DatagramSocket` [#7](https://github.com/netsec-ethz/scion-java-client/pull/7)
+- `Path`, `RequestPath`, `ResponsePath` [#7](https://github.com/netsec-ethz/scion-java-client/pull/7)
+- `Scion`, `ScionService` [#7](https://github.com/netsec-ethz/scion-java-client/pull/7)
+- `ScmpChannel` for SCMP [#7](https://github.com/netsec-ethz/scion-java-client/pull/7)
 
 ### Changed
 - Nothing

TODO.md

@@ -11,6 +11,9 @@
 - Review + clean up
 
 ### 0.2.0
+- Allow disabling local address resolution in DNS to local-IA. Resolving 127.0.0.x to
+  localIA is fine for many purposes, but it can be confusing when testing a local
+  mock-network (tiny, minimal, ...)
 - SCMP errors handling (above)
   - Especially for type ¨5: External Interface Down" and "6: Internal Connectivity Down"
     Problem: we need to receive() or read() to actually receive SCMP errors.

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

@@ -86,7 +86,7 @@ public synchronized void setPathPolicy(PathPolicy pathPolicy) throws IOException
     }
   }
 
-  protected synchronized ScionService getOrCreateService() {
+  public synchronized ScionService getOrCreateService() {
     if (service == null) {
       service = ScionService.defaultService();
     }
@@ -111,6 +111,15 @@ public synchronized InetSocketAddress getLocalAddress() throws IOException {
     return (InetSocketAddress) channel.getLocalAddress();
   }
 
+  public SocketAddress getRemoteAddress() throws UnknownHostException {
+    Path path = getConnectionPath();
+    if (path != null) {
+      InetAddress ip = InetAddress.getByAddress(path.getDestinationAddress());
+      return new InetSocketAddress(ip, path.getDestinationPort());
+    }
+    return null;
+  }
+
   public synchronized void disconnect() throws IOException {
     channel.disconnect();
     connection = null;

src/main/java/org/scion/DatagramChannel.java

@@ -17,6 +17,7 @@
 import java.io.Closeable;
 import java.io.IOException;
 import java.net.*;
+import java.nio.BufferOverflowException;
 import java.nio.ByteBuffer;
 import java.nio.channels.ByteChannel;
 import java.nio.channels.NotYetConnectedException;
@@ -118,7 +119,11 @@ public synchronized Path send(ByteBuffer srcBuffer, Path path) throws IOExceptio
     // + 8 for UDP overlay header length
     Path actualPath =
         buildHeader(bufferSend, path, srcBuffer.remaining() + 8, InternalConstants.HdrTypes.UDP);
-    bufferSend.put(srcBuffer);
+    try {
+      bufferSend.put(srcBuffer);
+    } catch (BufferOverflowException e) {
+      throw new IOException("Packet is larger than max send buffer size.");
+    }
     bufferSend.flip();
     sendRaw(bufferSend, actualPath.getFirstHopAddress());
     return actualPath;

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

@@ -225,8 +225,10 @@ void isConnected_InetSocket() throws IOException {
     InetSocketAddress address = new InetSocketAddress("127.0.0.1", 12345);
     try (DatagramChannel channel = DatagramChannel.open()) {
       assertFalse(channel.isConnected());
+      assertNull(channel.getRemoteAddress());
       channel.connect(address);
       assertTrue(channel.isConnected());
+      assertEquals(address, channel.getRemoteAddress());
 
       // try connecting again
       // Should be AlreadyConnectedException but Temurin throws IllegalStateException
@@ -236,12 +238,14 @@ void isConnected_InetSocket() throws IOException {
       // disconnect
       channel.disconnect();
       assertFalse(channel.isConnected());
+      assertNull(channel.getRemoteAddress());
       channel.disconnect();
       assertFalse(channel.isConnected());
 
       // Connect again
       channel.connect(address);
       assertTrue(channel.isConnected());
+      assertEquals(address, channel.getRemoteAddress());
       channel.close();
       assertFalse(channel.isConnected());
     }
@@ -250,10 +254,14 @@ void isConnected_InetSocket() throws IOException {
   @Test
   void isConnected_Path() throws IOException {
     RequestPath path = PackageVisibilityHelper.createDummyPath();
+    InetAddress ip = InetAddress.getByAddress(path.getDestinationAddress());
+    InetSocketAddress address = new InetSocketAddress(ip, path.getDestinationPort());
     try (DatagramChannel channel = DatagramChannel.open()) {
       assertFalse(channel.isConnected());
+      assertNull(channel.getRemoteAddress());
       channel.connect(path);
       assertTrue(channel.isConnected());
+      assertEquals(address, channel.getRemoteAddress());
 
       // try connecting again
       // Should be AlreadyConnectedException, but Temurin throws IllegalStateException
@@ -263,6 +271,7 @@ void isConnected_Path() throws IOException {
       // disconnect
       channel.disconnect();
       assertFalse(channel.isConnected());
+      assertNull(channel.getRemoteAddress());
       channel.disconnect();
       assertFalse(channel.isConnected());
 
@@ -279,6 +288,8 @@ void getService_default() throws IOException {
     ScionService service1 = Scion.defaultService();
     ScionService service2 = Scion.newServiceWithDaemon(MockDaemon.DEFAULT_ADDRESS_STR);
     try (DatagramChannel channel = DatagramChannel.open()) {
+      // The initial channel should NOT have a service.
+      // A server side channel may never need a service so we shouldn't create it.
       assertNull(channel.getService());
 
       // trigger service initialization in channel
@@ -312,53 +323,6 @@ void getPathPolicy() throws IOException {
     }
   }
 
-  @Test
-  void receive_bufferTooSmall() throws IOException {
-    MockDaemon.closeDefault(); // We don't need the daemon here
-    PingPongHelper.Server serverFn = PingPongHelper::defaultServer;
-    PingPongHelper.Client clientFn =
-        (channel, serverAddress, id) -> {
-          String message = PingPongHelper.MSG + "-" + id;
-          ByteBuffer sendBuf = ByteBuffer.wrap(message.getBytes());
-          channel.send(sendBuf, serverAddress);
-
-          // System.out.println("CLIENT: Receiving ... (" + channel.getLocalAddress() + ")");
-          ByteBuffer response = ByteBuffer.allocate(5);
-          channel.receive(response);
-
-          response.flip();
-          assertEquals(5, response.limit());
-          String pong = Charset.defaultCharset().decode(response).toString();
-          assertEquals(message.substring(0, 5), pong);
-        };
-    PingPongHelper pph = new PingPongHelper(1, 1, 1);
-    pph.runPingPong(serverFn, clientFn);
-  }
-
-  @Test
-  void read_bufferTooSmall() throws IOException {
-    MockDaemon.closeDefault(); // We don't need the daemon here
-    PingPongHelper.Server serverFn = PingPongHelper::defaultServer;
-    PingPongHelper.Client clientFn =
-        (channel, serverAddress, id) -> {
-          String message = PingPongHelper.MSG + "-" + id;
-          ByteBuffer sendBuf = ByteBuffer.wrap(message.getBytes());
-          // System.out.println("CLIENT: Writing ... (" + channel.getLocalAddress() + ")");
-          channel.write(sendBuf);
-
-          // System.out.println("CLIENT: Receiving ... (" + channel.getLocalAddress() + ")");
-          ByteBuffer response = ByteBuffer.allocate(5);
-          int len = channel.read(response);
-          assertEquals(5, len);
-
-          response.flip();
-          String pong = Charset.defaultCharset().decode(response).toString();
-          assertEquals(message.substring(0, 5), pong);
-        };
-    PingPongHelper pph = new PingPongHelper(1, 1, 1);
-    pph.runPingPong(serverFn, clientFn);
-  }
-
   @Test
   void send_bufferTooLarge() {
     RequestPath addr = ExamplePacket.PATH;
@@ -375,7 +339,7 @@ void send_bufferTooLarge() {
   }
 
   @Test
-  void write_bufferToLarge() {
+  void write_bufferTooLarge() {
     RequestPath addr = ExamplePacket.PATH;
     ByteBuffer buffer = ByteBuffer.allocate(65440);
     buffer.limit(buffer.capacity());
@@ -513,7 +477,7 @@ private RequestPath createExpiredPath(Path basePath) throws UnknownHostException
   }
 
   @Test
-  void getCurrentPath() {
+  void getConnectionPath() {
     RequestPath addr = ExamplePacket.PATH;
     ByteBuffer buffer = ByteBuffer.allocate(50);
     try (DatagramChannel channel = DatagramChannel.open()) {

src/test/java/org/scion/testutil/DNSUtil.java

@@ -39,7 +39,7 @@ public static void installNAPTR(String asHost, byte[] topoAddr, int topoPort) {
       Name name = Name.fromString(asHost + "."); // "iinf.ethz.ch.";
       Name replacement = new Name("topohost.x.y."); // "netsec-w37w3w.inf.ethz.ch."
 
-      Cache c = new Cache(DClass.IN);
+      Cache c = Lookup.getDefaultCache(DClass.IN);
       TXTRecord txt = new TXTRecord(name, DClass.IN, 5000, "x-sciondiscovery=" + topoPort);
       c.addRecord(txt, 10);
 

src/test/java/org/scion/testutil/MockNetwork.java

@@ -15,6 +15,7 @@
 package org.scion.testutil;
 
 import java.io.IOException;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.nio.ByteBuffer;
@@ -48,6 +49,7 @@ public class MockNetwork {
 
   public static final String BORDER_ROUTER_HOST = "127.0.0.1";
   public static final String TINY_SRV_ADDR_1 = "127.0.0.112";
+  public static final byte[] TINY_SRV_ADDR_BYTES_1 = {127, 0, 0, 112};
   public static final int TINY_SRV_PORT_1 = 22233;
   public static final String TINY_SRV_ISD_AS = "1-ff00:0:112";
   public static final String TINY_SRV_NAME_1 = "server.as112.test";
@@ -154,8 +156,9 @@ public static synchronized void stopTiny() {
     scmpErrorOnNextPacket.set(null);
   }
 
-  public static InetSocketAddress getTinyServerAddress() {
-    return new InetSocketAddress(TINY_SRV_ADDR_1, TINY_SRV_PORT_1);
+  public static InetSocketAddress getTinyServerAddress() throws IOException {
+    return new InetSocketAddress(
+        InetAddress.getByAddress(TINY_SRV_NAME_1, TINY_SRV_ADDR_BYTES_1), TINY_SRV_PORT_1);
   }
 
   public static int getAndResetForwardCount() {