| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.commons.net.util; |
| |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * A class that performs some subnet calculations given a network address and a subnet mask. |
| * @see "http://www.faqs.org/rfcs/rfc1519.html" |
| * @since 2.0 |
| */ |
| public class SubnetUtils { |
| |
| /** |
| * Convenience container for subnet summary information. |
| * |
| */ |
| public final class SubnetInfo { |
| /* Mask to convert unsigned int to a long (i.e. keep 32 bits) */ |
| private static final long UNSIGNED_INT_MASK = 0x0FFFFFFFFL; |
| |
| private SubnetInfo() {} |
| |
| public int asInteger(final String address) { |
| return toInteger(address); |
| } |
| private long broadcastLong(){ return broadcast & UNSIGNED_INT_MASK; } |
| |
| /* |
| * Convert a 4-element array into dotted decimal format |
| */ |
| private String format(final int[] octets) { |
| final StringBuilder str = new StringBuilder(); |
| for (int i =0; i < octets.length; ++i){ |
| str.append(octets[i]); |
| if (i != octets.length - 1) { |
| str.append("."); |
| } |
| } |
| return str.toString(); |
| } |
| |
| public String getAddress() { |
| return format(toArray(address)); |
| } |
| |
| /** |
| * Get the count of available addresses. |
| * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. |
| * @return the count of addresses, may be zero. |
| * @throws RuntimeException if the correct count is greater than {@code Integer.MAX_VALUE} |
| * @deprecated (3.4) use {@link #getAddressCountLong()} instead |
| */ |
| @Deprecated |
| public int getAddressCount() { |
| final long countLong = getAddressCountLong(); |
| if (countLong > Integer.MAX_VALUE) { |
| throw new RuntimeException("Count is larger than an integer: " + countLong); |
| } |
| // N.B. cannot be negative |
| return (int)countLong; |
| } |
| |
| /** |
| * Get the count of available addresses. |
| * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. |
| * @return the count of addresses, may be zero. |
| * @since 3.4 |
| */ |
| public long getAddressCountLong() { |
| final long b = broadcastLong(); |
| final long n = networkLong(); |
| final long count = b - n + (isInclusiveHostCount() ? 1 : -1); |
| return count < 0 ? 0 : count; |
| } |
| |
| public String[] getAllAddresses() { |
| final int ct = getAddressCount(); |
| final String[] addresses = new String[ct]; |
| if (ct == 0) { |
| return addresses; |
| } |
| for (int add = low(), j=0; add <= high(); ++add, ++j) { |
| addresses[j] = format(toArray(add)); |
| } |
| return addresses; |
| } |
| |
| public String getBroadcastAddress() { |
| return format(toArray(broadcast)); |
| } |
| |
| public String getCidrSignature() { |
| return format(toArray(address)) + "/" + pop(netmask); |
| } |
| |
| /** |
| * Return the high address as a dotted IP address. |
| * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. |
| * |
| * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address |
| */ |
| public String getHighAddress() { |
| return format(toArray(high())); |
| } |
| |
| /** |
| * Return the low address as a dotted IP address. |
| * Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. |
| * |
| * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address |
| */ |
| public String getLowAddress() { |
| return format(toArray(low())); |
| } |
| |
| public String getNetmask() { |
| return format(toArray(netmask)); |
| } |
| |
| public String getNetworkAddress() { |
| return format(toArray(network)); |
| } |
| |
| public String getNextAddress() { |
| return format(toArray(address + 1)); |
| } |
| |
| public String getPreviousAddress() { |
| return format(toArray(address - 1)); |
| } |
| |
| private int high() { |
| return isInclusiveHostCount() ? broadcast : |
| broadcastLong() - networkLong() > 1 ? broadcast -1 : 0; |
| } |
| |
| /** |
| * Returns true if the parameter <code>address</code> is in the |
| * range of usable endpoint addresses for this subnet. This excludes the |
| * network and broadcast addresses by default. Use {@link SubnetUtils#setInclusiveHostCount(boolean)} |
| * to change this. |
| * @param address the address to check |
| * @return true if it is in range |
| * @since 3.4 (made public) |
| */ |
| public boolean isInRange(final int address) { |
| if (address == 0) { // cannot ever be in range; rejecting now avoids problems with CIDR/31,32 |
| return false; |
| } |
| final long addLong = address & UNSIGNED_INT_MASK; |
| final long lowLong = low() & UNSIGNED_INT_MASK; |
| final long highLong = high() & UNSIGNED_INT_MASK; |
| return addLong >= lowLong && addLong <= highLong; |
| } |
| |
| /** |
| * Returns true if the parameter <code>address</code> is in the |
| * range of usable endpoint addresses for this subnet. This excludes the |
| * network and broadcast addresses. Use {@link SubnetUtils#setInclusiveHostCount(boolean)} |
| * to change this. |
| * @param address A dot-delimited IPv4 address, e.g. "192.168.0.1" |
| * @return True if in range, false otherwise |
| */ |
| public boolean isInRange(final String address) { |
| return isInRange(toInteger(address)); |
| } |
| |
| private int low() { |
| return isInclusiveHostCount() ? network : |
| broadcastLong() - networkLong() > 1 ? network + 1 : 0; |
| } |
| |
| // long versions of the values (as unsigned int) which are more suitable for range checking |
| private long networkLong() { return network & UNSIGNED_INT_MASK; } |
| |
| /* |
| * Convert a packed integer address into a 4-element array |
| */ |
| private int[] toArray(final int val) { |
| final int ret[] = new int[4]; |
| for (int j = 3; j >= 0; --j) { |
| ret[j] |= val >>> 8*(3-j) & 0xff; |
| } |
| return ret; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * @since 2.2 |
| */ |
| @Override |
| public String toString() { |
| final StringBuilder buf = new StringBuilder(); |
| buf.append("CIDR Signature:\t[").append(getCidrSignature()).append("]") |
| .append(" Netmask: [").append(getNetmask()).append("]\n") |
| .append("Network:\t[").append(getNetworkAddress()).append("]\n") |
| .append("Broadcast:\t[").append(getBroadcastAddress()).append("]\n") |
| .append("First Address:\t[").append(getLowAddress()).append("]\n") |
| .append("Last Address:\t[").append(getHighAddress()).append("]\n") |
| .append("# Addresses:\t[").append(getAddressCount()).append("]\n"); |
| return buf.toString(); |
| } |
| } |
| private static final String IP_ADDRESS = "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})"; |
| private static final String SLASH_FORMAT = IP_ADDRESS + "/(\\d{1,2})"; // 0 -> 32 |
| private static final Pattern addressPattern = Pattern.compile(IP_ADDRESS); |
| private static final Pattern cidrPattern = Pattern.compile(SLASH_FORMAT); |
| |
| private static final int NBITS = 32; |
| |
| private static final String PARSE_FAIL = "Could not parse [%s]"; |
| /* |
| * Convenience method to extract the components of a dotted decimal address and |
| * pack into an integer using a regex match |
| */ |
| private static int matchAddress(final Matcher matcher) { |
| int addr = 0; |
| for (int i = 1; i <= 4; ++i) { |
| final int n = rangeCheck(Integer.parseInt(matcher.group(i)), 0, 255); |
| addr |= (n & 0xff) << 8*(4-i); |
| } |
| return addr; |
| } |
| /* |
| * Convenience function to check integer boundaries. |
| * Checks if a value x is in the range [begin,end]. |
| * Returns x if it is in range, throws an exception otherwise. |
| */ |
| private static int rangeCheck(final int value, final int begin, final int end) { |
| if (value >= begin && value <= end) { // (begin,end] |
| return value; |
| } |
| |
| throw new IllegalArgumentException("Value [" + value + "] not in range ["+begin+","+end+"]"); |
| } |
| /* |
| * Convert a dotted decimal format address to a packed integer format |
| */ |
| private static int toInteger(final String address) { |
| final Matcher matcher = addressPattern.matcher(address); |
| if (matcher.matches()) { |
| return matchAddress(matcher); |
| } |
| throw new IllegalArgumentException(String.format(PARSE_FAIL, address)); |
| } |
| |
| private final int netmask; |
| |
| |
| private final int address; |
| |
| private final int network; |
| |
| |
| private final int broadcast; |
| |
| /** Whether the broadcast/network address are included in host count */ |
| private boolean inclusiveHostCount; |
| |
| |
| |
| /** |
| * Constructor that takes a CIDR-notation string, e.g. "192.168.0.1/16" |
| * @param cidrNotation A CIDR-notation string, e.g. "192.168.0.1/16" |
| * @throws IllegalArgumentException if the parameter is invalid, |
| * i.e. does not match n.n.n.n/m where n=1-3 decimal digits, m = 1-2 decimal digits in range 0-32 |
| */ |
| public SubnetUtils(final String cidrNotation) { |
| final Matcher matcher = cidrPattern.matcher(cidrNotation); |
| |
| if (!matcher.matches()) { |
| throw new IllegalArgumentException(String.format(PARSE_FAIL, cidrNotation)); |
| } |
| this.address = matchAddress(matcher); |
| |
| /* Create a binary netmask from the number of bits specification /x */ |
| |
| final int trailingZeroes = NBITS - rangeCheck(Integer.parseInt(matcher.group(5)), 0, NBITS); |
| /* |
| * An IPv4 netmask consists of 32 bits, a contiguous sequence |
| * of the specified number of ones followed by all zeros. |
| * So, it can be obtained by shifting an unsigned integer (32 bits) to the left by |
| * the number of trailing zeros which is (32 - the # bits specification). |
| * Note that there is no unsigned left shift operator, so we have to use |
| * a long to ensure that the left-most bit is shifted out correctly. |
| */ |
| this.netmask = (int) (0x0FFFFFFFFL << trailingZeroes ); |
| |
| /* Calculate base network address */ |
| this.network = address & netmask; |
| |
| /* Calculate broadcast address */ |
| this.broadcast = network | ~netmask; |
| } |
| |
| /** |
| * Constructor that takes a dotted decimal address and a dotted decimal mask. |
| * @param address An IP address, e.g. "192.168.0.1" |
| * @param mask A dotted decimal netmask e.g. "255.255.0.0" |
| * @throws IllegalArgumentException if the address or mask is invalid, |
| * i.e. does not match n.n.n.n where n=1-3 decimal digits and the mask is not all zeros |
| */ |
| public SubnetUtils(final String address, final String mask) { |
| this.address = toInteger(address); |
| this.netmask = toInteger(mask); |
| |
| if ((this.netmask & -this.netmask) - 1 != ~this.netmask) { |
| throw new IllegalArgumentException(String.format(PARSE_FAIL, mask)); |
| } |
| |
| /* Calculate base network address */ |
| this.network = this.address & this.netmask; |
| |
| /* Calculate broadcast address */ |
| this.broadcast = this.network | ~this.netmask; |
| } |
| |
| /** |
| * Return a {@link SubnetInfo} instance that contains subnet-specific statistics |
| * @return new instance |
| */ |
| public final SubnetInfo getInfo() { return new SubnetInfo(); } |
| |
| public SubnetUtils getNext() { |
| return new SubnetUtils(getInfo().getNextAddress(), getInfo().getNetmask()); |
| } |
| |
| public SubnetUtils getPrevious() { |
| return new SubnetUtils(getInfo().getPreviousAddress(), getInfo().getNetmask()); |
| } |
| |
| /** |
| * Returns <code>true</code> if the return value of {@link SubnetInfo#getAddressCount()} |
| * includes the network and broadcast addresses. |
| * @since 2.2 |
| * @return true if the host count includes the network and broadcast addresses |
| */ |
| public boolean isInclusiveHostCount() { |
| return inclusiveHostCount; |
| } |
| |
| /* |
| * Count the number of 1-bits in a 32-bit integer using a divide-and-conquer strategy |
| * see Hacker's Delight section 5.1 |
| */ |
| int pop(int x) { |
| x = x - (x >>> 1 & 0x55555555); |
| x = (x & 0x33333333) + (x >>> 2 & 0x33333333); |
| x = x + (x >>> 4) & 0x0F0F0F0F; |
| x = x + (x >>> 8); |
| x = x + (x >>> 16); |
| return x & 0x0000003F; |
| } |
| |
| /** |
| * Set to <code>true</code> if you want the return value of {@link SubnetInfo#getAddressCount()} |
| * to include the network and broadcast addresses. |
| * This also applies to {@link SubnetInfo#isInRange(int)} |
| * @param inclusiveHostCount true if network and broadcast addresses are to be included |
| * @since 2.2 |
| */ |
| public void setInclusiveHostCount(final boolean inclusiveHostCount) { |
| this.inclusiveHostCount = inclusiveHostCount; |
| } |
| |
| } |