vsock: test: Skip SocketChannelTest test when bind fails

In some environments, such as an already virtualized environment like
WSL 2, binding to a AF_VSOCK server socket may fail with an
AddressUnavailableSocketException.

Handle this situation by failing an assertion, and logging the
exception.

junixsocket-common/src/test/java/org/newsclub/net/unix/SocketChannelTest.java

@@ -229,6 +229,20 @@ private void testDoubleBind(boolean reuseAddress) throws Exception {
     }
   }
 
+  /**
+   * Bind the given address to the given {@link ServerSocketChannel}.
+   * 
+   * By default, this just calls `ssc.bind(sa)`, but you may handle some exceptions by overriding
+   * this method in a subclass.
+   * 
+   * @param ssc
+   * @param sa
+   * @throws IOException
+   */
+  protected void handleBind(ServerSocketChannel ssc, SocketAddress sa) throws IOException {
+    ssc.bind(sa);
+  }
+
   @Test
   public void testByteBufferWithPositionOffset() throws Exception {
     SocketAddress sa = newTempAddress();
@@ -240,7 +254,7 @@ public void testByteBufferWithPositionOffset() throws Exception {
     getRandom().nextBytes(data);
 
     try (ServerSocketChannel ssc = selectorProvider().openServerSocketChannel()) {
-      ssc.bind(sa);
+      handleBind(ssc, sa);
 
       ByteBuffer bb1 = ByteBuffer.allocate(data.length + bb1Offset);
       bb1.position(bb1Offset);

junixsocket-vsock/src/test/java/org/newsclub/net/unix/vsock/SocketChannelTest.java

@@ -17,9 +17,16 @@
  */
 package org.newsclub.net.unix.vsock;
 
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+import java.io.IOException;
+import java.net.SocketAddress;
+import java.nio.channels.ServerSocketChannel;
+
 import org.newsclub.net.unix.AFSocketCapability;
 import org.newsclub.net.unix.AFSocketCapabilityRequirement;
 import org.newsclub.net.unix.AFVSOCKSocketAddress;
+import org.newsclub.net.unix.AddressUnavailableSocketException;
 
 import com.kohlschutter.annotations.compiletime.SuppressFBWarnings;
 
@@ -46,4 +53,14 @@ protected String checkKnownBugFirstAcceptCallNotTerminated() {
       return null;
     }
   }
+
+  @Override
+  protected void handleBind(ServerSocketChannel ssc, SocketAddress sa) throws IOException {
+    try {
+      super.handleBind(ssc, sa);
+    } catch (AddressUnavailableSocketException e) {
+      e.printStackTrace();
+      assumeTrue(false, "Could not bind AF_VSOCK server socket; check kernel capabilities");
+    }
+  }
 }