CID-1116483 cidr to netmask bitshifts guarded with casts

 and simple test

Author: DaanHoogland

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

@@ -921,7 +921,7 @@ public static String getCidrSubNet(final String cidr) {
     }
 
     public static String getCidrNetmask(final long cidrSize) {
-        final long numericNetmask = 0xffffffff >> MAX_CIDR - cidrSize << MAX_CIDR - cidrSize;
+        final long numericNetmask = (long)0xffffffff >> MAX_CIDR - cidrSize << MAX_CIDR - cidrSize;
         return long2Ip(numericNetmask);
     }
 

utils/src/test/java/com/cloud/utils/net/NetUtilsTest.java

@@ -419,6 +419,13 @@ public void testIs31PrefixCidr() {
         assertTrue("It should pass! 31 bit prefix.", is31PrefixCidr);
     }
 
+    @Test
+    public void testGetCidrNetMask() {
+        final String cidr = "10.10.0.0/16";
+        String netmask = NetUtils.getCidrNetmask("10.10.10.10/16");
+        assertTrue(cidr + " does not generate valid netmask " + netmask,NetUtils.isValidNetmask(netmask));
+    }
+
     @Test
     public void testGetCidrSubNet() {
         final String cidr = "10.10.0.0/16";
@@ -430,6 +437,6 @@ public void testGetCidrSubNet() {
     public void testGetCidrSubNetWithWidth() {
         final String cidr = "10.10.0.0/16";
         String subnet = NetUtils.getCidrSubNet("10.10.10.10", 16);
-        assertTrue(NetUtils.isIpWithtInCidrRange(subnet, cidr));
+        assertTrue(cidr + " does not contain " + subnet,NetUtils.isIpWithtInCidrRange(subnet, cidr));
     }
 }