Netris pass v6 gateway

* pass v6 gateway to netris

* pass v6 gateway to netris

* refactor to address comments

* remove imports

Author: Pearl1594

plugins/network-elements/netris/src/main/java/org/apache/cloudstack/service/NetrisApiClientImpl.java

@@ -1883,7 +1883,7 @@ private InlineResponse2004Data updateIpamSubnetInternal(Integer netrisSubnetId,
         }
     }
 
-    VnetResAddBody createVnetInternal(VPCListing associatedVpc, String netrisVnetName, String netrisGateway, String netrisV6Gateway, Integer vxlanId, String netrisTag) {
+    VnetResAddBody createVnetInternal(VPCListing associatedVpc, String netrisVnetName, String netrisGateway, String netrisV6Cidr, Integer vxlanId, String netrisTag) {
         logger.debug("Creating Netris VPC vNet {} for CIDR {}", netrisVnetName, netrisGateway);
         try {
             VnetAddBody vnetBody = new VnetAddBody();
@@ -1901,9 +1901,9 @@ VnetResAddBody createVnetInternal(VPCListing associatedVpc, String netrisVnetNam
             List<VnetAddBodyGateways> gatewaysList = new ArrayList<>();
             gatewaysList.add(gatewayV4);
 
-            if (Objects.nonNull(netrisV6Gateway)) {
+            if (Objects.nonNull(netrisV6Cidr)) {
                 VnetAddBodyGateways gatewayV6 = new VnetAddBodyGateways();
-                gatewayV6.prefix(netrisV6Gateway);
+                gatewayV6.prefix(NetUtils.getIpv6Gateway(netrisV6Cidr));
                 gatewayV6.setDhcpEnabled(false);
                 gatewayV6.setDhcp(dhcp);
                 gatewaysList.add(gatewayV6);
@@ -1952,6 +1952,8 @@ VnetResAddBody createVnetInternal(VPCListing associatedVpc, String netrisVnetNam
         }
     }
 
+
+
     private String getNetrisVpcNameSuffix(Long vpcId, String vpcName, Long networkId, String networkName, boolean isVpc) {
         String suffix = null;
         if (isVpc) {

utils/src/main/java/com/cloud/utils/net/NetUtils.java

@@ -1901,4 +1901,11 @@ public static String transformCidr(final String cidr) {
         final long start = (ip & startNetMask);
         return String.format("%s/%s", long2Ip(start), size);
     }
+
+    public static String getIpv6Gateway(String ipv6Cidr) {
+        IPv6Network network = IPv6Network.fromString(ipv6Cidr);
+        IPv6Address netrisV6Gateway = network.getFirst().add(1);
+        String netmask = network.getNetmask().toString();
+        return netrisV6Gateway.toString() + "/" + netmask;
+    }
 }