update and test multicastMacFromIPv6

Signed-off-by: Emil Gustafsson <[email protected]>

Author: Emil Gustafsson

src/main/java/com/cisco/trex/stateless/IPv6NeighborDiscoveryService.java

@@ -196,15 +196,24 @@ public EthernetPacket sendNeighborSolicitation(int portIdx, int timeout, String
     }
     String srcMac = portStatus.getAttr().getLayerConiguration().getL2Configuration().getSrc();
     PortVlan vlan = portStatus.getAttr().getVlan();
-    return sendNeighborSolicitation(vlan, portIdx, timeout, srcMac, null, dstIp);
+    return sendNeighborSolicitation(vlan, portIdx, timeout, srcMac, null, null, dstIp);
   }
 
   public EthernetPacket sendNeighborSolicitation(
-      PortVlan vlan, int portIdx, int timeout, String srcMac, String srcIp, String dstIp) {
+      PortVlan vlan,
+      int portIdx,
+      int timeout,
+      String srcMac,
+      String dstMac,
+      String srcIp,
+      String dstIp) {
     long endTs = System.currentTimeMillis() + timeout * 1000;
 
-    Packet icmpv6NSPkt =
-        buildICMPV6NSPkt(vlan, srcMac, multicastMacFromIPv6(dstIp).toString(), dstIp, srcIp);
+    if (dstMac == null) {
+      dstMac = multicastMacFromIPv6(dstIp).toString();
+    }
+
+    Packet icmpv6NSPkt = buildICMPV6NSPkt(vlan, srcMac, dstMac, dstIp, srcIp);
 
     tRexClient.startStreamsIntermediate(portIdx, Arrays.asList(buildStream(icmpv6NSPkt)));
 
@@ -616,7 +625,13 @@ public static EthernetPacket buildICMPV6EchoReq(
     return buildICMPV6EchoReq(srcIp, srcMacString, dstMacString, dstIp, 0, 0);
   }
 
-  private static MacAddress multicastMacFromIPv6(String ipV6) {
+  /**
+   * Convert to solicitated-node multicast described in RFC 2624 section 7
+   *
+   * @param ipV6
+   * @return
+   */
+  static MacAddress multicastMacFromIPv6(String ipV6) {
     String expandedIPv6 = expandIPv6Address(ipV6);
     List<Long> ipv6Octets =
         Arrays.stream(expandedIPv6.split(":"))
@@ -627,8 +642,7 @@ private static MacAddress multicastMacFromIPv6(String ipV6) {
     int preLastIdx = ipv6Octets.size() - 2;
     String macAddressStr =
         String.format(
-            "33:33:%02x:%02x:%02x:%02x",
-            divMod(ipv6Octets.get(preLastIdx), 256)[0],
+            "33:33:ff:%02x:%02x:%02x",
             divMod(ipv6Octets.get(preLastIdx), 256)[1],
             divMod(ipv6Octets.get(lastIdx), 256)[0],
             divMod(ipv6Octets.get(lastIdx), 256)[1]);

src/main/java/com/cisco/trex/stateless/TRexClient.java

@@ -619,7 +619,7 @@ public String resolveIpv6(
 
     EthernetPacket naPacket =
         new IPv6NeighborDiscoveryService(this)
-            .sendNeighborSolicitation(vlan, portIndex, 5, srcMac, srcIp, dstIp);
+            .sendNeighborSolicitation(vlan, portIndex, 5, srcMac, null, srcIp, dstIp);
     if (naPacket != null) {
       return naPacket.getHeader().getSrcAddr().toString();
     }

src/test/java/com/cisco/trex/stateless/IPv6NeighborDiscoveryServiceTest.java

@@ -3,6 +3,7 @@
 import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
+import org.pcap4j.util.MacAddress;
 
 public class IPv6NeighborDiscoveryServiceTest {
 
@@ -11,4 +12,11 @@ public void generateIPv6AddrFromMACTest() {
     String ipV6Address = IPv6NeighborDiscoveryService.generateIPv6AddrFromMAC("10:62:E5:09:A0:64");
     assertEquals("fe80::1262:e5ff:fe09:a064", ipV6Address);
   }
+
+  @Test
+  public void generateMulticastMacFromIPv6Test() {
+    MacAddress multicastMac =
+        IPv6NeighborDiscoveryService.multicastMacFromIPv6("fe80::4a5d:60ff:fee8:658f");
+    assertEquals("33:33:ff:e8:65:8f", multicastMac.toString());
+  }
 }