You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@commons.apache.org by rw...@apache.org on 2008/03/02 17:51:34 UTC
svn commit: r632783 - in /commons/proper/net/branches/NET_2_0/src:
main/java/org/apache/commons/net/util/SubnetUtils.java
test/java/org/apache/commons/net/TestSubnetUtils.java
Author: rwinston
Date: Sun Mar 2 08:51:33 2008
New Revision: 632783
URL: http://svn.apache.org/viewvc?rev=632783&view=rev
Log:
Add SubnetUtils class (NET-189)
Added:
commons/proper/net/branches/NET_2_0/src/main/java/org/apache/commons/net/util/SubnetUtils.java
commons/proper/net/branches/NET_2_0/src/test/java/org/apache/commons/net/TestSubnetUtils.java
Added: commons/proper/net/branches/NET_2_0/src/main/java/org/apache/commons/net/util/SubnetUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/net/branches/NET_2_0/src/main/java/org/apache/commons/net/util/SubnetUtils.java?rev=632783&view=auto
==============================================================================
--- commons/proper/net/branches/NET_2_0/src/main/java/org/apache/commons/net/util/SubnetUtils.java (added)
+++ commons/proper/net/branches/NET_2_0/src/main/java/org/apache/commons/net/util/SubnetUtils.java Sun Mar 2 08:51:33 2008
@@ -0,0 +1,195 @@
+/*
+ * 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
+ * @author <rw...@apache.org>
+ */
+public class SubnetUtils {
+
+ 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{1,3})";
+ 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 int netmask = 0;
+ private int address = 0;
+ private int network = 0;
+ private int broadcast = 0;
+
+ /**
+ * 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"
+ */
+ public SubnetUtils(String cidrNotation) {
+ calculate(cidrNotation);
+ }
+
+ /**
+ * Constructor that takes two dotted decimal addresses.
+ * @param address An IP address, e.g. "192.168.0.1"
+ * @param mask A dotted decimal netmask e.g. "255.255.0.0"
+ */
+ public SubnetUtils(String address, String mask) {
+ calculate(toCidrNotation(address, mask));
+ }
+
+ /**
+ * Convenience container for subnet summary information.
+ *
+ */
+ public final class SubnetInfo {
+ private int netmask() { return netmask; }
+ private int network() { return network; }
+ private int address() { return address; }
+ private int broadcast() { return broadcast; }
+ private int low() { return network() + 1; }
+ private int high() { return broadcast() - 1; }
+
+ public boolean isInRange(String address) { return isInRange(toInteger(address)); }
+ private boolean isInRange(int address) { return ((address-low()) <= (high()-low())); }
+
+ public String getBroadcastAddress() { return format(toArray(broadcast())); }
+
+ public String getNetworkAddress() { return format(toArray(network())); }
+ public String getLowAddress() { return format(toArray(low())); }
+ public String getHighAddress() { return format(toArray(high())); }
+ public int getAddressCount() { return (broadcast() - low()); }
+
+ public String getCidrSignature() {
+ return toCidrNotation(
+ format(toArray(address())),
+ format(toArray(netmask()))
+ );
+ }
+ }
+
+ /**
+ * Return a {@link SubnetInfo} instance that contains subnet-specific statistics
+ * @return
+ */
+ public final SubnetInfo getInfo() { return new SubnetInfo(); }
+
+ /*
+ * Initialize the internal fields from the supplied CIDR mask
+ */
+ private void calculate(String mask) {
+ Matcher matcher = cidrPattern.matcher(mask);
+
+ if (matcher.matches()) {
+ address = matchAddress(matcher);
+
+ /* Create a binary netmask from the number of bits specification /x */
+ int cidrPart = rangeCheck(Integer.valueOf(matcher.group(5)), 0, NBITS-1);
+ for (int j = 0; j < cidrPart; ++j) {
+ netmask |= (1 << 31-j);
+ }
+
+ /* Calculate base network address */
+ network = (address & netmask);
+
+ /* Calculate broadcast address */
+ broadcast = network | ~(netmask);
+ }
+ else
+ throw new IllegalArgumentException("Could not parse [" + mask + "]");
+ }
+
+ /*
+ * Convert a dotted decimal format address to a packed integer format
+ */
+ private int toInteger(String address) {
+ Matcher matcher = addressPattern.matcher(address);
+ if (matcher.matches()) {
+ return matchAddress(matcher);
+ }
+ else
+ throw new IllegalArgumentException("Could not parse [" + address + "]");
+ }
+
+ /*
+ * Convenience method to extract the components of a dotted decimal address and
+ * pack into an integer using a regex match
+ */
+ private int matchAddress(Matcher matcher) {
+ int addr = 0;
+ for (int i = 1; i <= 4; ++i) {
+ int n = (rangeCheck(Integer.valueOf(matcher.group(i)), 0, 255));
+ addr |= ((n & 0xff) << 8*(4-i));
+ }
+ return addr;
+ }
+
+ /*
+ * Convert a packed integer address into a 4-element array
+ */
+ private int[] toArray(int val) {
+ int ret[] = new int[4];
+ for (int j = 3; j >= 0; --j)
+ ret[j] |= ((val >>> 8*(3-j)) & (0xff));
+ return ret;
+ }
+
+ /*
+ * Convert a 4-element array into dotted decimal format
+ */
+ private String format(int[] octets) {
+ StringBuilder str = new StringBuilder();
+ for (int i =0; i < octets.length; ++i)
+ str.append((i == octets.length - 1)
+ ? octets[i] : octets[i] + ".");
+ return str.toString();
+ }
+
+ /*
+ * Convenience function to check integer boundaries
+ */
+ private int rangeCheck(Integer value, int begin, int end) {
+ if (value >= begin && value <= end)
+ return value;
+
+ throw new IllegalArgumentException("Value out of range: [" + value + "]");
+ }
+
+ /*
+ * 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;
+ }
+
+ /* Convert two dotted decimal addresses to a single xxx.xxx.xxx.xxx/yy format
+ * by counting the 1-bit population in the mask address. (It may be better to count
+ * NBITS-#trailing zeroes for this case)
+ */
+ private String toCidrNotation(String addr, String mask) {
+ return addr + "/" + pop(toInteger(mask));
+ }
+
+}
Added: commons/proper/net/branches/NET_2_0/src/test/java/org/apache/commons/net/TestSubnetUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/net/branches/NET_2_0/src/test/java/org/apache/commons/net/TestSubnetUtils.java?rev=632783&view=auto
==============================================================================
--- commons/proper/net/branches/NET_2_0/src/test/java/org/apache/commons/net/TestSubnetUtils.java (added)
+++ commons/proper/net/branches/NET_2_0/src/test/java/org/apache/commons/net/TestSubnetUtils.java Sun Mar 2 08:51:33 2008
@@ -0,0 +1,60 @@
+/*
+ * 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;
+
+import org.apache.commons.net.util.SubnetUtils;
+import org.apache.commons.net.util.SubnetUtils.SubnetInfo;
+
+import junit.framework.TestCase;
+
+public class TestSubnetUtils extends TestCase {
+
+ public void testParseSimpleNetmask() {
+ final String address = "192.168.0.1";
+ final String masks[] = new String[] { "255.0.0.0", "255.255.0.0", "255.255.255.0", "255.255.255.248"};
+ final String bcastAddresses[] = new String[] { "192.255.255.255", "192.168.255.255", "192.168.0.255", "192.168.0.7"};
+ final String lowAddresses[] = new String[] { "192.0.0.1", "192.168.0.1", "192.168.0.1", "192.168.0.1" };
+ final String highAddresses[] = new String[] { "192.255.255.254", "192.168.255.254", "192.168.0.254", "192.168.0.6" };
+ final String networkAddresses[] = new String[] { "192.0.0.0", "192.168.0.0", "192.168.0.0", "192.168.0.0" };
+ final String cidrSignatures[] = new String[] { "192.168.0.1/8", "192.168.0.1/16", "192.168.0.1/24", "192.168.0.1/29" };
+ final int usableAddresses[] = new int[] { 16777214, 65534, 254, 6 };
+
+ for (int i = 0; i < masks.length; ++i) {
+ SubnetUtils utils = new SubnetUtils(address, masks[i]);
+ SubnetInfo info = utils.getInfo();
+ assertEquals(bcastAddresses[i], info.getBroadcastAddress());
+ assertEquals(cidrSignatures[i], info.getCidrSignature());
+ assertEquals(lowAddresses[i], info.getLowAddress());
+ assertEquals(highAddresses[i], info.getHighAddress());
+ assertEquals(networkAddresses[i], info.getNetworkAddress());
+ assertEquals(usableAddresses[i], info.getAddressCount());
+ }
+ }
+
+ public void testAddresses() {
+ SubnetUtils utils = new SubnetUtils("192.168.0.1/29");
+ SubnetInfo info = utils.getInfo();
+ assertTrue(info.isInRange("192.168.0.1"));
+ // We dont count the broadcast address as usable
+ assertFalse(info.isInRange("192.168.0.7"));
+ assertFalse(info.isInRange("192.168.0.8"));
+ assertFalse(info.isInRange("10.10.2.1"));
+ assertFalse(info.isInRange("192.168.1.1"));
+ assertFalse(info.isInRange("192.168.0.255"));
+ }
+}