001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * https://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.net.util; 018 019import java.util.Iterator; 020import java.util.regex.Matcher; 021import java.util.regex.Pattern; 022import java.util.stream.Stream; 023import java.util.stream.StreamSupport; 024 025/** 026 * Performs subnet calculations given a network address and a subnet mask. 027 * 028 * @see "http://www.faqs.org/rfcs/rfc1519.html" 029 * @since 2.0 030 */ 031public class SubnetUtils { 032 033 /** 034 * Allows an object to be the target of the "for-each loop" statement for a SubnetInfo. 035 */ 036 private static final class SubnetAddressStringIterable implements Iterable<String> { 037 038 private final SubnetInfo subnetInfo; 039 040 /** 041 * Constructs a new instance. 042 * 043 * @param subnetInfo the SubnetInfo to iterate. 044 */ 045 private SubnetAddressStringIterable(final SubnetInfo subnetInfo) { 046 this.subnetInfo = subnetInfo; 047 } 048 049 @Override 050 public Iterator<String> iterator() { 051 return new SubnetAddressStringIterator(subnetInfo); 052 } 053 } 054 055 /** 056 * Iterates over a SubnetInfo. 057 */ 058 private static final class SubnetAddressStringIterator implements Iterator<String> { 059 060 private int currentAddress; 061 062 private final SubnetInfo subnetInfo; 063 064 /** 065 * Constructs a new instance. 066 * 067 * @param subnetInfo the SubnetInfo to iterate. 068 */ 069 private SubnetAddressStringIterator(final SubnetInfo subnetInfo) { 070 this.subnetInfo = subnetInfo; 071 currentAddress = subnetInfo.low(); 072 } 073 074 @Override 075 public boolean hasNext() { 076 return subnetInfo.getAddressCountLong() > 0 && currentAddress <= subnetInfo.high(); 077 } 078 079 @Override 080 public String next() { 081 return format(toArray4(currentAddress++)); 082 } 083 } 084 085 /** 086 * Contains subnet summary information. 087 */ 088 public final class SubnetInfo { 089 090 /** Mask to convert unsigned int to a long (i.e. keep 32 bits). */ 091 private static final long UNSIGNED_INT_MASK = 0x0FFFFFFFFL; 092 093 private SubnetInfo() { 094 } 095 096 /** 097 * Converts a dotted decimal format address to a packed integer format. 098 * 099 * @param address a dotted decimal format address. 100 * @return packed integer formatted int. 101 */ 102 public int asInteger(final String address) { 103 return toInteger(address); 104 } 105 106 private long broadcastLong() { 107 return broadcast & UNSIGNED_INT_MASK; 108 } 109 110 /** 111 * Gets this instance's address into a dotted decimal String. 112 * 113 * @return a dotted decimal String. 114 */ 115 public String getAddress() { 116 return format(toArray4(address)); 117 } 118 119 /** 120 * Gets the count of available addresses. Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. 121 * 122 * @return the count of addresses, may be zero. 123 * @throws RuntimeException if the correct count is greater than {@code Integer.MAX_VALUE} 124 * @deprecated (3.4) use {@link #getAddressCountLong()} instead 125 */ 126 @Deprecated 127 public int getAddressCount() { 128 final long countLong = getAddressCountLong(); 129 if (countLong > Integer.MAX_VALUE) { 130 throw new IllegalStateException("Count is larger than an integer: " + countLong); 131 } 132 // Cannot be negative here 133 return (int) countLong; 134 } 135 136 /** 137 * Gets the count of available addresses. Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. 138 * 139 * @return the count of addresses, may be zero. 140 * @since 3.4 141 */ 142 public long getAddressCountLong() { 143 final long b = broadcastLong(); 144 final long n = networkLong(); 145 final long count = b - n + (isInclusiveHostCount() ? 1 : -1); 146 return count < 0 ? 0 : count; 147 } 148 149 /** 150 * Gets all addresses in this subnet, the return array could be huge. 151 * <p> 152 * For large ranges, you can iterate or stream over the addresses instead using {@link #iterableAddressStrings()} or {@link #streamAddressStrings()}. 153 * </p> 154 * 155 * @return all addresses in this subnet. 156 * @see #iterableAddressStrings() 157 * @see #streamAddressStrings() 158 */ 159 public String[] getAllAddresses() { 160 final int ct = getAddressCount(); 161 final String[] addresses = new String[ct]; 162 if (ct == 0) { 163 return addresses; 164 } 165 final int high = high(); 166 for (int add = low(), j = 0; add <= high; ++add, ++j) { 167 addresses[j] = format(toArray4(add)); 168 } 169 return addresses; 170 } 171 172 /** 173 * Gets the broadcast address for this subnet. 174 * 175 * @return the broadcast address for this subnet. 176 */ 177 public String getBroadcastAddress() { 178 return format(toArray4(broadcast)); 179 } 180 181 /** 182 * Gets the CIDR signature for this subnet. 183 * 184 * @return the CIDR signature for this subnet. 185 */ 186 public String getCidrSignature() { 187 return format(toArray4(address)) + "/" + Integer.bitCount(netmask); 188 } 189 190 /** 191 * Gets the high address as a dotted IP address. Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. 192 * 193 * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address 194 */ 195 public String getHighAddress() { 196 return format(toArray4(high())); 197 } 198 199 /** 200 * Gets the low address as a dotted IP address. Will be zero for CIDR/31 and CIDR/32 if the inclusive flag is false. 201 * 202 * @return the IP address in dotted format, may be "0.0.0.0" if there is no valid address 203 */ 204 public String getLowAddress() { 205 return format(toArray4(low())); 206 } 207 208 /** 209 * Gets the network mask for this subnet. 210 * 211 * @return the network mask for this subnet. 212 */ 213 public String getNetmask() { 214 return format(toArray4(netmask)); 215 } 216 217 /** 218 * Gets the network address for this subnet. 219 * 220 * @return the network address for this subnet. 221 */ 222 public String getNetworkAddress() { 223 return format(toArray4(network)); 224 } 225 226 /** 227 * Gets the next address for this subnet. 228 * 229 * @return the next address for this subnet. 230 */ 231 public String getNextAddress() { 232 return format(toArray4(address + 1)); 233 } 234 235 /** 236 * Gets the previous address for this subnet. 237 * 238 * @return the previous address for this subnet. 239 */ 240 public String getPreviousAddress() { 241 return format(toArray4(address - 1)); 242 } 243 244 private int high() { 245 return isInclusiveHostCount() ? broadcast : broadcastLong() - networkLong() > 1 ? broadcast - 1 : 0; 246 } 247 248 /** 249 * Tests if the parameter {@code address} is in the range of usable endpoint addresses for this subnet. This excludes the network and broadcast 250 * addresses by default. Use {@link SubnetUtils#setInclusiveHostCount(boolean)} to change this. 251 * 252 * @param address the address to check 253 * @return true if it is in range 254 * @since 3.4 (made public) 255 */ 256 public boolean isInRange(final int address) { 257 if (address == 0) { // cannot ever be in range; rejecting now avoids problems with CIDR/31,32 258 return false; 259 } 260 final long addLong = address & UNSIGNED_INT_MASK; 261 final long lowLong = low() & UNSIGNED_INT_MASK; 262 final long highLong = high() & UNSIGNED_INT_MASK; 263 return addLong >= lowLong && addLong <= highLong; 264 } 265 266 /** 267 * Tests if the parameter {@code address} is in the range of usable endpoint addresses for this subnet. This excludes the network and broadcast 268 * addresses. Use {@link SubnetUtils#setInclusiveHostCount(boolean)} to change this. 269 * 270 * @param address A dot-delimited IPv4 address, e.g. "192.168.0.1" 271 * @return True if in range, false otherwise 272 */ 273 public boolean isInRange(final String address) { 274 return isInRange(toInteger(address)); 275 } 276 277 /** 278 * Creates a new Iterable of address Strings. 279 * 280 * @return a new Iterable of address Strings 281 * @see #getAllAddresses() 282 * @see #streamAddressStrings() 283 * @since 3.12.0 284 */ 285 public Iterable<String> iterableAddressStrings() { 286 return new SubnetAddressStringIterable(this); 287 } 288 289 private int low() { 290 return isInclusiveHostCount() ? network : broadcastLong() - networkLong() > 1 ? network + 1 : 0; 291 } 292 293 /** Long versions of the values (as unsigned int) which are more suitable for range checking. */ 294 private long networkLong() { 295 return network & UNSIGNED_INT_MASK; 296 } 297 298 /** 299 * Creates a new Stream of address Strings. 300 * 301 * @return a new Stream of address Strings. 302 * @see #getAllAddresses() 303 * @see #iterableAddressStrings() 304 * @since 3.12.0 305 */ 306 public Stream<String> streamAddressStrings() { 307 return StreamSupport.stream(iterableAddressStrings().spliterator(), false); 308 } 309 310 /** 311 * {@inheritDoc} 312 * 313 * @since 2.2 314 */ 315 @Override 316 public String toString() { 317 final StringBuilder buf = new StringBuilder(); 318 // @formatter:off 319 buf.append("CIDR Signature:\t[").append(getCidrSignature()).append("]\n") 320 .append(" Netmask: [").append(getNetmask()).append("]\n") 321 .append(" Network: [").append(getNetworkAddress()).append("]\n") 322 .append(" Broadcast: [").append(getBroadcastAddress()).append("]\n") 323 .append(" First address: [").append(getLowAddress()).append("]\n") 324 .append(" Last address: [").append(getHighAddress()).append("]\n") 325 .append(" Address Count: [").append(getAddressCountLong()).append("]\n"); 326 // @formatter:on 327 return buf.toString(); 328 } 329 } 330 331 private static final String IP_ADDRESS = "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})"; 332 333 private static final String SLASH_FORMAT = IP_ADDRESS + "/(\\d{1,2})"; // 0 -> 32 334 335 private static final Pattern ADDRESS_PATTERN = Pattern.compile(IP_ADDRESS); 336 private static final Pattern CIDR_PATTERN = Pattern.compile(SLASH_FORMAT); 337 private static final int NBITS = 32; 338 private static final String PARSE_FAIL = "Could not parse [%s]"; 339 340 /** 341 * Converts a 4-element array into dotted decimal format. 342 */ 343 private static String format(final int[] octets) { 344 final int last = octets.length - 1; 345 final StringBuilder builder = new StringBuilder(); 346 for (int i = 0;; i++) { 347 builder.append(octets[i]); 348 if (i == last) { 349 return builder.toString(); 350 } 351 builder.append('.'); 352 } 353 } 354 /** 355 * Extracts the components of a dotted decimal address and pack into an integer using a regex match 356 */ 357 private static int matchAddress(final Matcher matcher) { 358 int addr = 0; 359 for (int i = 1; i <= 4; ++i) { 360 final int n = rangeCheck(Integer.parseInt(matcher.group(i)), 0, 255); 361 addr |= (n & 0xff) << 8 * (4 - i); 362 } 363 return addr; 364 } 365 366 /** 367 * Checks integer boundaries. Checks if a value x is in the range [begin,end]. Returns x if it is in range, throws an exception otherwise. 368 */ 369 private static int rangeCheck(final int value, final int begin, final int end) { 370 if (value >= begin && value <= end) { // (begin,end] 371 return value; 372 } 373 throw new IllegalArgumentException("Value [" + value + "] not in range [" + begin + "," + end + "]"); 374 } 375 376 /** 377 * Converts a packed integer address into a 4-element array 378 */ 379 private static int[] toArray4(final int val) { 380 final int[] ret = new int[4]; 381 for (int j = 3; j >= 0; --j) { 382 ret[j] |= val >>> 8 * (3 - j) & 0xff; 383 } 384 return ret; 385 } 386 387 /** 388 * Converts a dotted decimal format address to a packed integer format. 389 */ 390 private static int toInteger(final String address) { 391 final Matcher matcher = ADDRESS_PATTERN.matcher(address); 392 if (matcher.matches()) { 393 return matchAddress(matcher); 394 } 395 throw new IllegalArgumentException(String.format(PARSE_FAIL, address)); 396 } 397 398 private final int address; 399 400 private final int broadcast; 401 402 /** Whether the broadcast/network address are included in host count */ 403 private boolean inclusiveHostCount; 404 405 private final int netmask; 406 407 private final int network; 408 409 /** 410 * Constructs an instance from a CIDR-notation string, e.g. "192.168.0.1/16" 411 * 412 * @param cidrNotation A CIDR-notation string, e.g. "192.168.0.1/16" 413 * @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 414 * 0-32 415 */ 416 public SubnetUtils(final String cidrNotation) { 417 final Matcher matcher = CIDR_PATTERN.matcher(cidrNotation); 418 419 if (!matcher.matches()) { 420 throw new IllegalArgumentException(String.format(PARSE_FAIL, cidrNotation)); 421 } 422 this.address = matchAddress(matcher); 423 424 // Create a binary netmask from the number of bits specification /x 425 426 final int trailingZeroes = NBITS - rangeCheck(Integer.parseInt(matcher.group(5)), 0, NBITS); 427 428 // 429 // An IPv4 netmask consists of 32 bits, a contiguous sequence 430 // of the specified number of ones followed by all zeros. 431 // So, it can be obtained by shifting an unsigned integer (32 bits) to the left by 432 // the number of trailing zeros which is (32 - the # bits specification). 433 // Note that there is no unsigned left shift operator, so we have to use 434 // a long to ensure that the left-most bit is shifted out correctly. 435 // 436 this.netmask = (int) (0x0FFFFFFFFL << trailingZeroes); 437 438 // Calculate base network address 439 this.network = address & netmask; 440 441 // Calculate broadcast address 442 this.broadcast = network | ~netmask; 443 } 444 445 /** 446 * Constructs an instance from a dotted decimal address and a dotted decimal mask. 447 * 448 * @param address An IP address, e.g. "192.168.0.1" 449 * @param mask A dotted decimal netmask e.g. "255.255.0.0" 450 * @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 451 */ 452 public SubnetUtils(final String address, final String mask) { 453 this.address = toInteger(address); 454 this.netmask = toInteger(mask); 455 456 if ((this.netmask & -this.netmask) - 1 != ~this.netmask) { 457 throw new IllegalArgumentException(String.format(PARSE_FAIL, mask)); 458 } 459 460 // Calculate base network address 461 this.network = this.address & this.netmask; 462 463 // Calculate broadcast address 464 this.broadcast = this.network | ~this.netmask; 465 } 466 467 /** 468 * Gets a {@link SubnetInfo} instance that contains subnet-specific statistics 469 * 470 * @return new instance 471 */ 472 public final SubnetInfo getInfo() { 473 return new SubnetInfo(); 474 } 475 476 /** 477 * Gets the next subnet for this instance. 478 * 479 * @return the next subnet for this instance. 480 */ 481 public SubnetUtils getNext() { 482 return new SubnetUtils(getInfo().getNextAddress(), getInfo().getNetmask()); 483 } 484 485 /** 486 * Gets the previous subnet for this instance. 487 * 488 * @return the next previous for this instance. 489 */ 490 public SubnetUtils getPrevious() { 491 return new SubnetUtils(getInfo().getPreviousAddress(), getInfo().getNetmask()); 492 } 493 494 /** 495 * Tests if the return value of {@link SubnetInfo#getAddressCount()} includes the network and broadcast addresses. 496 * 497 * @return true if the host count includes the network and broadcast addresses 498 * @since 2.2 499 */ 500 public boolean isInclusiveHostCount() { 501 return inclusiveHostCount; 502 } 503 504 /** 505 * Sets to {@code true} if you want the return value of {@link SubnetInfo#getAddressCount()} to include the network and broadcast addresses. This also 506 * applies to {@link SubnetInfo#isInRange(int)} 507 * 508 * @param inclusiveHostCount true if network and broadcast addresses are to be included 509 * @since 2.2 510 */ 511 public void setInclusiveHostCount(final boolean inclusiveHostCount) { 512 this.inclusiveHostCount = inclusiveHostCount; 513 } 514 515 /** 516 * Converts this instance to a debug String. 517 * 518 * @return this instance to a debug String. 519 * @since 3.11.0 520 */ 521 @Override 522 public String toString() { 523 return getInfo().toString(); 524 } 525}