Ip6SubnetFilterRule Class — netty Architecture

Source Code

handler/src/main/java/io/netty/handler/ipfilter/IpSubnetFilterRule.java lines 210–254

    static final class Ip6SubnetFilterRule implements IpFilterRule {

        private static final BigInteger MINUS_ONE = BigInteger.valueOf(-1);

        private final BigInteger networkAddress;
        private final BigInteger subnetMask;
        private final IpFilterRuleType ruleType;

        private Ip6SubnetFilterRule(Inet6Address ipAddress, int cidrPrefix, IpFilterRuleType ruleType) {
            if (cidrPrefix < 0 || cidrPrefix > 128) {
                throw new IllegalArgumentException(String.format("IPv6 requires the subnet prefix to be in range of "
                        + "[0,128]. The prefix was: %d", cidrPrefix));
            }

            subnetMask = prefixToSubnetMask(cidrPrefix);
            networkAddress = ipToInt(ipAddress).and(subnetMask);
            this.ruleType = ruleType;
        }

        @Override
        public boolean matches(InetSocketAddress remoteAddress) {
            final InetAddress inetAddress = remoteAddress.getAddress();
            if (inetAddress instanceof Inet6Address) {
                BigInteger ipAddress = ipToInt((Inet6Address) inetAddress);
                return ipAddress.and(subnetMask).equals(subnetMask) || ipAddress.and(subnetMask).equals(networkAddress);
            }
            return false;
        }

        @Override
        public IpFilterRuleType ruleType() {
            return ruleType;
        }

        private static BigInteger ipToInt(Inet6Address ipAddress) {
            byte[] octets = ipAddress.getAddress();
            assert octets.length == 16;

            return new BigInteger(octets);
        }

        private static BigInteger prefixToSubnetMask(int cidrPrefix) {
            return MINUS_ONE.shiftLeft(128 - cidrPrefix);
        }
    }