| /* |
| * Copyright 2014-2016 Open Networking Laboratory |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.onlab.packet; |
| |
| import java.util.Objects; |
| |
| /** |
| * A class representing an IP prefix. A prefix consists of an IP address and |
| * a subnet mask. |
| * This class is immutable. |
| * <p> |
| * NOTE: The stored IP address in the result IP prefix is masked to |
| * contain zeroes in all bits after the prefix length. |
| * </p> |
| */ |
| public class IpPrefix { |
| /** |
| * Longest IPv4 network prefix. |
| */ |
| public static final int MAX_INET_MASK_LENGTH = IpAddress.INET_BIT_LENGTH; |
| /** |
| * Longest IPv6 network prefix. |
| */ |
| public static final int MAX_INET6_MASK_LENGTH = IpAddress.INET6_BIT_LENGTH; |
| /** |
| * An IpPrefix that contains all IPv4 multicast addresses. |
| */ |
| @Deprecated |
| public static final IpPrefix MULTICAST_RANGE = IpPrefix.valueOf("224.0.0.0/4"); |
| /** |
| * An IpPrefix that contains all IPv4 multicast addresses. |
| */ |
| public static final IpPrefix IPV4_MULTICAST_PREFIX = IpPrefix.valueOf("224.0.0.0/4"); |
| /** |
| * An IpPrefix that contains all IPv6 multicast addresses. |
| */ |
| public static final IpPrefix IPV6_MULTICAST_PREFIX = IpPrefix.valueOf("ff00::/8"); |
| |
| private final IpAddress address; |
| private final short prefixLength; |
| |
| /** |
| * Constructor for given IP address, and a prefix length. |
| * |
| * @param address the IP address |
| * @param prefixLength the prefix length |
| * @throws IllegalArgumentException if the prefix length value is invalid |
| */ |
| protected IpPrefix(IpAddress address, int prefixLength) { |
| checkPrefixLength(address.version(), prefixLength); |
| this.address = IpAddress.makeMaskedAddress(address, prefixLength); |
| this.prefixLength = (short) prefixLength; |
| } |
| |
| /** |
| * Returns the IP version of the prefix. |
| * |
| * @return the IP version of the prefix |
| */ |
| public IpAddress.Version version() { |
| return address.version(); |
| } |
| |
| /** |
| * Tests whether the IP version of this prefix is IPv4. |
| * |
| * @return true if the IP version of this prefix is IPv4, otherwise false. |
| */ |
| public boolean isIp4() { |
| return address.isIp4(); |
| } |
| |
| /** |
| * Tests whether the IP version of this prefix is IPv6. |
| * |
| * @return true if the IP version of this prefix is IPv6, otherwise false. |
| */ |
| public boolean isIp6() { |
| return address.isIp6(); |
| } |
| |
| /** |
| * Check if this IP prefix is a multicast prefix. |
| * |
| * @return true if this prefix a multicast prefix |
| */ |
| public boolean isMulticast() { |
| return isIp4() ? |
| IPV4_MULTICAST_PREFIX.contains(this.getIp4Prefix()) : |
| IPV6_MULTICAST_PREFIX.contains(this.getIp6Prefix()); |
| } |
| |
| /** |
| * Returns the IP address value of the prefix. |
| * |
| * @return the IP address value of the prefix |
| */ |
| public IpAddress address() { |
| return address; |
| } |
| |
| /** |
| * Returns the IP address prefix length. |
| * |
| * @return the IP address prefix length |
| */ |
| public int prefixLength() { |
| return prefixLength; |
| } |
| |
| /** |
| * Gets the {@link Ip4Prefix} view of the IP prefix. |
| * |
| * @return the {@link Ip4Prefix} view of the IP prefix if it is IPv4, |
| * otherwise null |
| */ |
| public Ip4Prefix getIp4Prefix() { |
| if (!isIp4()) { |
| return null; |
| } |
| |
| // Return this object itself if it is already instance of Ip4Prefix |
| if (this instanceof Ip4Prefix) { |
| return (Ip4Prefix) this; |
| } |
| return Ip4Prefix.valueOf(address.getIp4Address(), prefixLength); |
| } |
| |
| /** |
| * Gets the {@link Ip6Prefix} view of the IP prefix. |
| * |
| * @return the {@link Ip6Prefix} view of the IP prefix if it is IPv6, |
| * otherwise null |
| */ |
| public Ip6Prefix getIp6Prefix() { |
| if (!isIp6()) { |
| return null; |
| } |
| |
| // Return this object itself if it is already instance of Ip6Prefix |
| if (this instanceof Ip6Prefix) { |
| return (Ip6Prefix) this; |
| } |
| return Ip6Prefix.valueOf(address.getIp6Address(), prefixLength); |
| } |
| |
| /** |
| * Converts an integer and a prefix length into an IPv4 prefix. |
| * |
| * @param address an integer representing the IPv4 address |
| * @param prefixLength the prefix length |
| * @return an IP prefix |
| * @throws IllegalArgumentException if the prefix length value is invalid |
| */ |
| public static IpPrefix valueOf(int address, int prefixLength) { |
| return new IpPrefix(IpAddress.valueOf(address), prefixLength); |
| } |
| |
| /** |
| * Converts a byte array and a prefix length into an IP prefix. |
| * |
| * @param version the IP address version |
| * @param address the IP address value stored in network byte order |
| * @param prefixLength the prefix length |
| * @return an IP prefix |
| * @throws IllegalArgumentException if the prefix length value is invalid |
| */ |
| public static IpPrefix valueOf(IpAddress.Version version, byte[] address, |
| int prefixLength) { |
| return new IpPrefix(IpAddress.valueOf(version, address), prefixLength); |
| } |
| |
| /** |
| * Converts an IP address and a prefix length into an IP prefix. |
| * |
| * @param address the IP address |
| * @param prefixLength the prefix length |
| * @return an IP prefix |
| * @throws IllegalArgumentException if the prefix length value is invalid |
| */ |
| public static IpPrefix valueOf(IpAddress address, int prefixLength) { |
| return new IpPrefix(address, prefixLength); |
| } |
| |
| /** |
| * Converts a CIDR (slash) notation string (e.g., "10.1.0.0/16" or |
| * "1111:2222::/64") into an IP prefix. |
| * |
| * @param address an IP prefix in string form (e.g. "10.1.0.0/16" or |
| * "1111:2222::/64") |
| * @return an IP prefix |
| * @throws IllegalArgumentException if the arguments are invalid |
| */ |
| public static IpPrefix valueOf(String address) { |
| final String[] parts = address.split("/"); |
| if (parts.length != 2) { |
| String msg = "Malformed IP prefix string: " + address + ". " + |
| "Address must take form \"x.x.x.x/y\" or " + |
| "\"xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/y\""; |
| throw new IllegalArgumentException(msg); |
| } |
| IpAddress ipAddress = IpAddress.valueOf(parts[0]); |
| int prefixLength = Integer.parseInt(parts[1]); |
| |
| return new IpPrefix(ipAddress, prefixLength); |
| } |
| |
| /** |
| * Determines whether a given IP prefix is contained within this prefix. |
| * |
| * @param other the IP prefix to test |
| * @return true if the other IP prefix is contained in this prefix, |
| * otherwise false |
| */ |
| public boolean contains(IpPrefix other) { |
| if (version() != other.version()) { |
| return false; |
| } |
| |
| if (this.prefixLength > other.prefixLength) { |
| return false; // This prefix has smaller prefix size |
| } |
| |
| // |
| // Mask the other address with my prefix length. |
| // If the other prefix is within this prefix, the masked address must |
| // be same as the address of this prefix. |
| // |
| IpAddress maskedAddr = |
| IpAddress.makeMaskedAddress(other.address, this.prefixLength); |
| return this.address.equals(maskedAddr); |
| } |
| |
| /** |
| * Determines whether a given IP address is contained within this prefix. |
| * |
| * @param other the IP address to test |
| * @return true if the IP address is contained in this prefix, otherwise |
| * false |
| */ |
| public boolean contains(IpAddress other) { |
| if (version() != other.version()) { |
| return false; |
| } |
| |
| // |
| // Mask the other address with my prefix length. |
| // If the other prefix is within this prefix, the masked address must |
| // be same as the address of this prefix. |
| // |
| IpAddress maskedAddr = |
| IpAddress.makeMaskedAddress(other, this.prefixLength); |
| return this.address.equals(maskedAddr); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(address, prefixLength); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if ((obj == null) || (!(obj instanceof IpPrefix))) { |
| return false; |
| } |
| IpPrefix other = (IpPrefix) obj; |
| return ((prefixLength == other.prefixLength) && |
| address.equals(other.address)); |
| } |
| |
| @Override |
| /* |
| * (non-Javadoc) |
| * The format is "x.x.x.x/y" for IPv4 prefixes. |
| * |
| * @see java.lang.Object#toString() |
| */ |
| public String toString() { |
| final StringBuilder builder = new StringBuilder(); |
| builder.append(address.toString()); |
| builder.append("/"); |
| builder.append(String.format("%d", prefixLength)); |
| return builder.toString(); |
| } |
| |
| /** |
| * Checks whether the prefix length is valid. |
| * |
| * @param version the IP address version |
| * @param prefixLength the prefix length value to check |
| * @throws IllegalArgumentException if the prefix length value is invalid |
| */ |
| private static void checkPrefixLength(IpAddress.Version version, |
| int prefixLength) { |
| int maxPrefixLen = 0; |
| |
| switch (version) { |
| case INET: |
| maxPrefixLen = MAX_INET_MASK_LENGTH; |
| break; |
| case INET6: |
| maxPrefixLen = MAX_INET6_MASK_LENGTH; |
| break; |
| default: |
| String msg = "Invalid IP version " + version; |
| throw new IllegalArgumentException(msg); |
| } |
| |
| if ((prefixLength < 0) || (prefixLength > maxPrefixLen)) { |
| String msg = "Invalid prefix length " + prefixLength + ". " + |
| "The value must be in the interval [0, " + |
| maxPrefixLen + "]"; |
| throw new IllegalArgumentException(msg); |
| } |
| } |
| } |