ONOS-4086 to ONOS-4091, ONOS-4098 to ONOS-4100:ISIS controller implementation

Change-Id: I7be52805652fe762baf808515401d6b5042b2aa5
diff --git a/protocols/isis/isisio/src/main/java/org/onosproject/isis/io/util/IsisUtil.java b/protocols/isis/isisio/src/main/java/org/onosproject/isis/io/util/IsisUtil.java
index 44ad9e0..c21a93b 100644
--- a/protocols/isis/isisio/src/main/java/org/onosproject/isis/io/util/IsisUtil.java
+++ b/protocols/isis/isisio/src/main/java/org/onosproject/isis/io/util/IsisUtil.java
@@ -391,7 +391,7 @@
         isisHeader.setIrpDiscriminator((byte) IsisConstants.IRPDISCRIMINATOR);
         isisHeader.setPduHeaderLength((byte) IsisConstants.P2PHELLOHEADERLENGTH);
         isisHeader.setVersion((byte) IsisConstants.ISISVERSION);
-        isisHeader.setIdLength((byte) IsisConstants.IDLENGTH);
+        isisHeader.setIdLength((byte) IsisConstants.SYSTEMIDLENGTH);
         isisHeader.setIsisPduType(IsisPduType.P2PHELLOPDU.value());
         isisHeader.setVersion2((byte) IsisConstants.ISISVERSION);
         //isisHeader.setReserved((byte) IsisConstants.RESERVED);
@@ -484,7 +484,7 @@
         isisHeader.setIrpDiscriminator((byte) IsisConstants.IRPDISCRIMINATOR);
         isisHeader.setPduHeaderLength((byte) IsisConstants.HELLOHEADERLENGTH);
         isisHeader.setVersion((byte) IsisConstants.ISISVERSION);
-        isisHeader.setIdLength((byte) IsisConstants.IDLENGTH);
+        isisHeader.setIdLength((byte) IsisConstants.SYSTEMIDLENGTH);
         if (isisPduType == IsisPduType.L1HELLOPDU) {
             isisHeader.setIsisPduType(IsisPduType.L1HELLOPDU.value());
             lanId = isisInterface.l1LanId();
@@ -693,4 +693,19 @@
         }
         return prefix;
     }
+
+    /**
+     * Converts the prefix to bytes.
+     *
+     * @param prefix prefix
+     * @return prefix to bytes
+     */
+    public static byte[] prefixToBytes(String prefix) {
+        List<Byte> byteList = new ArrayList<>();
+        StringTokenizer tokenizer = new StringTokenizer(prefix, ".");
+        while (tokenizer.hasMoreTokens()) {
+            byteList.add((byte) Integer.parseInt(tokenizer.nextToken()));
+        }
+        return Bytes.toArray(byteList);
+    }
 }
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