Path probing - ping

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   [#4](https://github.com/netsec-ethz/scion-java-multiping/pull/4)
 - Added path probing for showpaths and --no-probe
   [#5](https://github.com/netsec-ethz/scion-java-multiping/pull/5)
+- Added path probing for ping and --healthy-only
+  [#6](https://github.com/netsec-ethz/scion-java-multiping/pull/6)
 
 ### Fixed
 

src/main/java/org/scion/cli/Cli.java

@@ -113,13 +113,13 @@ private static void printUsage() {
     println("  jpan-cli [command]");
     println();
     println("Available commands: ");
-    println("  address      Show (one of) this host's SCION address(es)");
-    println("  help         Help about any command");
-    println("  ping         Test connectivity to a remote SCION host using SCMP echo packets");
+    println("  address           Show (one of) this host's SCION address(es)");
+    println("  help              Help about any command");
+    println("  ping              Test connectivity to a remote SCION host using SCMP echo packets");
     println("  ping-responder    Starting a server that responds to incoming echo requests.");
-    println("  showpaths    Display paths to a SCION AS");
-    println("  traceroute   Trace the SCION route to a remote SCION AS using SCMP traceroute");
-    println("  version      Show the SCION version information");
+    println("  showpaths         Display paths to a SCION AS");
+    println("  traceroute        Trace the SCION route to a remote SCION AS using SCMP traceroute");
+    println("  version           Show the SCION version information");
     println("");
     println("Flags:");
     println("  -h, --help   help for jpan-cli");

src/main/java/org/scion/cli/Ping.java

@@ -19,11 +19,10 @@
 import java.io.*;
 import java.net.*;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
+import java.util.*;
 import org.scion.cli.util.Errors;
 import org.scion.cli.util.ExitCodeException;
+import org.scion.cli.util.Prober;
 import org.scion.cli.util.Util;
 import org.scion.jpan.*;
 import org.scion.jpan.internal.ScionAddress;
@@ -45,6 +44,8 @@ public class Ping {
   private String dstUrl;
   private InetSocketAddress daemon;
   private int timeoutMs = 1000;
+  private boolean healthyOnly = false;
+  private final Random rnd = new Random();
 
   public static void main(String... args) {
     handleExit(() -> new Ping().run(args));
@@ -61,13 +62,20 @@ public void run(String... args) throws IOException {
     }
     try {
       ScionService service = Scion.defaultService();
+      List<Path> paths;
       if (dstUrl != null) {
-        run(service.lookupPaths(dstUrl, Constants.SCMP_PORT));
+        paths = service.lookupPaths(dstUrl, Constants.SCMP_PORT);
       } else {
-        run(
+        paths =
             service.getPaths(
-                dstAddress.getIsdAs(), dstAddress.getInetAddress(), Constants.SCMP_PORT));
+                dstAddress.getIsdAs(), dstAddress.getInetAddress(), Constants.SCMP_PORT);
       }
+      if (paths.isEmpty()) {
+        String src = ScionUtil.toStringIA(service.getLocalIsdAs());
+        String dst = ScionUtil.toStringIA(dstAddress.getIsdAs());
+        throw new ExitCodeException(2, "No path found from " + src + " to " + dst);
+      }
+      run(paths);
     } finally {
       Scion.closeDefault();
     }
@@ -92,6 +100,9 @@ private void parseArgs(String[] argsArray) {
         case "--help":
           Cli.printUsagePing();
           throw new ExitCodeException(0);
+        case "--healthy-only":
+          healthyOnly = true;
+          break;
         case "--interval":
           intervalMs = parseInt("interval", args);
           break;
@@ -133,7 +144,25 @@ private void parseArgs(String[] argsArray) {
   }
 
   private void run(List<Path> paths) throws IOException {
-    Path path = paths.get(0);
+    Path path;
+    if (healthyOnly) {
+      Map<Integer, Prober.Status> isActive = Prober.probe(localPort, timeoutMs, paths);
+      List<Path> newPaths = new ArrayList<>();
+      for (int i = 0; i < paths.size(); i++) {
+        if (isActive.getOrDefault(i, Prober.Status.Unknown) == Prober.Status.Alive) {
+          newPaths.add(paths.get(i));
+        }
+      }
+      if (newPaths.isEmpty()) {
+        String src = ScionUtil.toStringIA(Scion.defaultService().getLocalIsdAs());
+        String dst = ScionUtil.toStringIA(dstAddress.getIsdAs());
+        throw new ExitCodeException(2, "No path found from " + src + " to " + dst);
+      }
+      path = newPaths.get(rnd.nextInt(paths.size()));
+    } else {
+      path = paths.get(0);
+    }
+
     ByteBuffer data = ByteBuffer.allocate(payloadSize);
     for (int i = 0; i < payloadSize; i++) {
       data.put((byte) i);

src/main/java/org/scion/cli/util/Util.java

@@ -22,6 +22,9 @@
 import java.net.UnknownHostException;
 import java.util.List;
 import java.util.concurrent.Callable;
+import java.util.function.Supplier;
+import org.scion.jpan.Scion;
+import org.scion.jpan.ScionService;
 import org.scion.jpan.ScionUtil;
 import org.scion.jpan.internal.IPHelper;
 import org.scion.jpan.internal.ScionAddress;
@@ -31,9 +34,18 @@ public class Util {
   public static boolean PRINT = true;
   public static boolean DELAYED_PRINT = false; // print only at newlines
   private static final StringBuilder sb = new StringBuilder();
+  private static Supplier<ScionService> serviceSupplier = Scion::defaultService;
 
   private Util() {}
 
+  public static void setServiceSupplier(Supplier<ScionService> serviceSupplier) {
+    Util.serviceSupplier = serviceSupplier;
+  }
+
+  public static ScionService defaultService() {
+    return serviceSupplier.get();
+  }
+
   public static void sleep(long millis) {
     try {
       Thread.sleep(millis);