001/* 002 * Copyright (C) 2008 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 005 * in compliance with the License. You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software distributed under the License 010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 011 * or implied. See the License for the specific language governing permissions and limitations under 012 * the License. 013 */ 014 015package com.google.common.net; 016 017import static com.google.common.base.Preconditions.checkArgument; 018import static com.google.common.base.Preconditions.checkNotNull; 019 020import com.google.common.annotations.GwtIncompatible; 021import com.google.common.base.CharMatcher; 022import com.google.common.base.MoreObjects; 023import com.google.common.hash.Hashing; 024import com.google.common.io.ByteStreams; 025import com.google.common.primitives.Ints; 026import com.google.errorprone.annotations.CanIgnoreReturnValue; 027import java.math.BigInteger; 028import java.net.Inet4Address; 029import java.net.Inet6Address; 030import java.net.InetAddress; 031import java.net.UnknownHostException; 032import java.nio.ByteBuffer; 033import java.util.Arrays; 034import java.util.Locale; 035import javax.annotation.CheckForNull; 036 037/** 038 * Static utility methods pertaining to {@link InetAddress} instances. 039 * 040 * <p><b>Important note:</b> Unlike {@code InetAddress.getByName()}, the methods of this class never 041 * cause DNS services to be accessed. For this reason, you should prefer these methods as much as 042 * possible over their JDK equivalents whenever you are expecting to handle only IP address string 043 * literals -- there is no blocking DNS penalty for a malformed string. 044 * 045 * <p>When dealing with {@link Inet4Address} and {@link Inet6Address} objects as byte arrays (vis. 046 * {@code InetAddress.getAddress()}) they are 4 and 16 bytes in length, respectively, and represent 047 * the address in network byte order. 048 * 049 * <p>Examples of IP addresses and their byte representations: 050 * 051 * <dl> 052 * <dt>The IPv4 loopback address, {@code "127.0.0.1"}. 053 * <dd>{@code 7f 00 00 01} 054 * <dt>The IPv6 loopback address, {@code "::1"}. 055 * <dd>{@code 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01} 056 * <dt>From the IPv6 reserved documentation prefix ({@code 2001:db8::/32}), {@code "2001:db8::1"}. 057 * <dd>{@code 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01} 058 * <dt>An IPv6 "IPv4 compatible" (or "compat") address, {@code "::192.168.0.1"}. 059 * <dd>{@code 00 00 00 00 00 00 00 00 00 00 00 00 c0 a8 00 01} 060 * <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}. 061 * <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01} 062 * </dl> 063 * 064 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java. 065 * 066 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6 067 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY} 068 * socket option on an IPv6 socket). Yes, it's confusing. Nevertheless, these "mapped" addresses 069 * were never supposed to be seen on the wire. That assumption was dropped, some say mistakenly, in 070 * later RFCs with the apparent aim of making IPv4-to-IPv6 transition simpler. 071 * 072 * <p>Technically one <i>can</i> create a 128bit IPv6 address with the wire format of a "mapped" 073 * address, as shown above, and transmit it in an IPv6 packet header. However, Java's InetAddress 074 * creation methods appear to adhere doggedly to the original intent of the "mapped" address: all 075 * "mapped" addresses return {@link Inet4Address} objects. 076 * 077 * <p>For added safety, it is common for IPv6 network operators to filter all packets where either 078 * the source or destination address appears to be a "compat" or "mapped" address. Filtering 079 * suggestions usually recommend discarding any packets with source or destination addresses in the 080 * invalid range {@code ::/3}, which includes both of these bizarre address formats. For more 081 * information on "bogons", including lists of IPv6 bogon space, see: 082 * 083 * <ul> 084 * <li><a target="_parent" 085 * href="http://en.wikipedia.org/wiki/Bogon_filtering">http://en.wikipedia. 086 * org/wiki/Bogon_filtering</a> 087 * <li><a target="_parent" 088 * href="http://www.cymru.com/Bogons/ipv6.txt">http://www.cymru.com/Bogons/ ipv6.txt</a> 089 * <li><a target="_parent" href="http://www.cymru.com/Bogons/v6bogon.html">http://www.cymru.com/ 090 * Bogons/v6bogon.html</a> 091 * <li><a target="_parent" href="http://www.space.net/~gert/RIPE/ipv6-filters.html">http://www. 092 * space.net/~gert/RIPE/ipv6-filters.html</a> 093 * </ul> 094 * 095 * @author Erik Kline 096 * @since 5.0 097 */ 098@GwtIncompatible 099@ElementTypesAreNonnullByDefault 100public final class InetAddresses { 101 private static final int IPV4_PART_COUNT = 4; 102 private static final int IPV6_PART_COUNT = 8; 103 private static final char IPV4_DELIMITER = '.'; 104 private static final char IPV6_DELIMITER = ':'; 105 private static final CharMatcher IPV4_DELIMITER_MATCHER = CharMatcher.is(IPV4_DELIMITER); 106 private static final CharMatcher IPV6_DELIMITER_MATCHER = CharMatcher.is(IPV6_DELIMITER); 107 private static final Inet4Address LOOPBACK4 = (Inet4Address) forString("127.0.0.1"); 108 private static final Inet4Address ANY4 = (Inet4Address) forString("0.0.0.0"); 109 110 private InetAddresses() {} 111 112 /** 113 * Returns an {@link Inet4Address}, given a byte array representation of the IPv4 address. 114 * 115 * @param bytes byte array representing an IPv4 address (should be of length 4) 116 * @return {@link Inet4Address} corresponding to the supplied byte array 117 * @throws IllegalArgumentException if a valid {@link Inet4Address} can not be created 118 */ 119 private static Inet4Address getInet4Address(byte[] bytes) { 120 checkArgument( 121 bytes.length == 4, 122 "Byte array has invalid length for an IPv4 address: %s != 4.", 123 bytes.length); 124 125 // Given a 4-byte array, this cast should always succeed. 126 return (Inet4Address) bytesToInetAddress(bytes); 127 } 128 129 /** 130 * Returns the {@link InetAddress} having the given string representation. 131 * 132 * <p>This deliberately avoids all nameservice lookups (e.g. no DNS). 133 * 134 * <p>Anything after a {@code %} in an IPv6 address is ignored (assumed to be a Scope ID). 135 * 136 * <p>This method accepts non-ASCII digits, for example {@code "192.168.0.1"} (those are fullwidth 137 * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you 138 * want to accept ASCII digits only, you can use something like {@code 139 * CharMatcher.ascii().matchesAllOf(ipString)}. 140 * 141 * @param ipString {@code String} containing an IPv4 or IPv6 string literal, e.g. {@code 142 * "192.168.0.1"} or {@code "2001:db8::1"} 143 * @return {@link InetAddress} representing the argument 144 * @throws IllegalArgumentException if the argument is not a valid IP string literal 145 */ 146 @CanIgnoreReturnValue // TODO(b/219820829): consider removing 147 public static InetAddress forString(String ipString) { 148 byte[] addr = ipStringToBytes(ipString); 149 150 // The argument was malformed, i.e. not an IP string literal. 151 if (addr == null) { 152 throw formatIllegalArgumentException("'%s' is not an IP string literal.", ipString); 153 } 154 155 return bytesToInetAddress(addr); 156 } 157 158 /** 159 * Returns {@code true} if the supplied string is a valid IP string literal, {@code false} 160 * otherwise. 161 * 162 * <p>This method accepts non-ASCII digits, for example {@code "192.168.0.1"} (those are fullwidth 163 * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you 164 * want to accept ASCII digits only, you can use something like {@code 165 * CharMatcher.ascii().matchesAllOf(ipString)}. 166 * 167 * @param ipString {@code String} to evaluated as an IP string literal 168 * @return {@code true} if the argument is a valid IP string literal 169 */ 170 public static boolean isInetAddress(String ipString) { 171 return ipStringToBytes(ipString) != null; 172 } 173 174 /** Returns {@code null} if unable to parse into a {@code byte[]}. */ 175 @CheckForNull 176 private static byte[] ipStringToBytes(String ipStringParam) { 177 String ipString = ipStringParam; 178 // Make a first pass to categorize the characters in this string. 179 boolean hasColon = false; 180 boolean hasDot = false; 181 int percentIndex = -1; 182 for (int i = 0; i < ipString.length(); i++) { 183 char c = ipString.charAt(i); 184 if (c == '.') { 185 hasDot = true; 186 } else if (c == ':') { 187 if (hasDot) { 188 return null; // Colons must not appear after dots. 189 } 190 hasColon = true; 191 } else if (c == '%') { 192 percentIndex = i; 193 break; // everything after a '%' is ignored (it's a Scope ID): http://superuser.com/a/99753 194 } else if (Character.digit(c, 16) == -1) { 195 return null; // Everything else must be a decimal or hex digit. 196 } 197 } 198 199 // Now decide which address family to parse. 200 if (hasColon) { 201 if (hasDot) { 202 ipString = convertDottedQuadToHex(ipString); 203 if (ipString == null) { 204 return null; 205 } 206 } 207 if (percentIndex != -1) { 208 ipString = ipString.substring(0, percentIndex); 209 } 210 return textToNumericFormatV6(ipString); 211 } else if (hasDot) { 212 if (percentIndex != -1) { 213 return null; // Scope IDs are not supported for IPV4 214 } 215 return textToNumericFormatV4(ipString); 216 } 217 return null; 218 } 219 220 @CheckForNull 221 private static byte[] textToNumericFormatV4(String ipString) { 222 if (IPV4_DELIMITER_MATCHER.countIn(ipString) + 1 != IPV4_PART_COUNT) { 223 return null; // Wrong number of parts 224 } 225 226 byte[] bytes = new byte[IPV4_PART_COUNT]; 227 int start = 0; 228 // Iterate through the parts of the ip string. 229 // Invariant: start is always the beginning of an octet. 230 for (int i = 0; i < IPV4_PART_COUNT; i++) { 231 int end = ipString.indexOf(IPV4_DELIMITER, start); 232 if (end == -1) { 233 end = ipString.length(); 234 } 235 try { 236 bytes[i] = parseOctet(ipString, start, end); 237 } catch (NumberFormatException ex) { 238 return null; 239 } 240 start = end + 1; 241 } 242 243 return bytes; 244 } 245 246 @CheckForNull 247 private static byte[] textToNumericFormatV6(String ipString) { 248 // An address can have [2..8] colons. 249 int delimiterCount = IPV6_DELIMITER_MATCHER.countIn(ipString); 250 if (delimiterCount < 2 || delimiterCount > IPV6_PART_COUNT) { 251 return null; 252 } 253 int partsSkipped = IPV6_PART_COUNT - (delimiterCount + 1); // estimate; may be modified later 254 boolean hasSkip = false; 255 // Scan for the appearance of ::, to mark a skip-format IPV6 string and adjust the partsSkipped 256 // estimate. 257 for (int i = 0; i < ipString.length() - 1; i++) { 258 if (ipString.charAt(i) == IPV6_DELIMITER && ipString.charAt(i + 1) == IPV6_DELIMITER) { 259 if (hasSkip) { 260 return null; // Can't have more than one :: 261 } 262 hasSkip = true; 263 partsSkipped++; // :: means we skipped an extra part in between the two delimiters. 264 if (i == 0) { 265 partsSkipped++; // Begins with ::, so we skipped the part preceding the first : 266 } 267 if (i == ipString.length() - 2) { 268 partsSkipped++; // Ends with ::, so we skipped the part after the last : 269 } 270 } 271 } 272 if (ipString.charAt(0) == IPV6_DELIMITER && ipString.charAt(1) != IPV6_DELIMITER) { 273 return null; // ^: requires ^:: 274 } 275 if (ipString.charAt(ipString.length() - 1) == IPV6_DELIMITER 276 && ipString.charAt(ipString.length() - 2) != IPV6_DELIMITER) { 277 return null; // :$ requires ::$ 278 } 279 if (hasSkip && partsSkipped <= 0) { 280 return null; // :: must expand to at least one '0' 281 } 282 if (!hasSkip && delimiterCount + 1 != IPV6_PART_COUNT) { 283 return null; // Incorrect number of parts 284 } 285 286 ByteBuffer rawBytes = ByteBuffer.allocate(2 * IPV6_PART_COUNT); 287 try { 288 // Iterate through the parts of the ip string. 289 // Invariant: start is always the beginning of a hextet, or the second ':' of the skip 290 // sequence "::" 291 int start = 0; 292 if (ipString.charAt(0) == IPV6_DELIMITER) { 293 start = 1; 294 } 295 while (start < ipString.length()) { 296 int end = ipString.indexOf(IPV6_DELIMITER, start); 297 if (end == -1) { 298 end = ipString.length(); 299 } 300 if (ipString.charAt(start) == IPV6_DELIMITER) { 301 // expand zeroes 302 for (int i = 0; i < partsSkipped; i++) { 303 rawBytes.putShort((short) 0); 304 } 305 306 } else { 307 rawBytes.putShort(parseHextet(ipString, start, end)); 308 } 309 start = end + 1; 310 } 311 } catch (NumberFormatException ex) { 312 return null; 313 } 314 return rawBytes.array(); 315 } 316 317 @CheckForNull 318 private static String convertDottedQuadToHex(String ipString) { 319 int lastColon = ipString.lastIndexOf(':'); 320 String initialPart = ipString.substring(0, lastColon + 1); 321 String dottedQuad = ipString.substring(lastColon + 1); 322 byte[] quad = textToNumericFormatV4(dottedQuad); 323 if (quad == null) { 324 return null; 325 } 326 String penultimate = Integer.toHexString(((quad[0] & 0xff) << 8) | (quad[1] & 0xff)); 327 String ultimate = Integer.toHexString(((quad[2] & 0xff) << 8) | (quad[3] & 0xff)); 328 return initialPart + penultimate + ":" + ultimate; 329 } 330 331 private static byte parseOctet(String ipString, int start, int end) { 332 // Note: we already verified that this string contains only hex digits, but the string may still 333 // contain non-decimal characters. 334 int length = end - start; 335 if (length <= 0 || length > 3) { 336 throw new NumberFormatException(); 337 } 338 // Disallow leading zeroes, because no clear standard exists on 339 // whether these should be interpreted as decimal or octal. 340 if (length > 1 && ipString.charAt(start) == '0') { 341 throw new NumberFormatException(); 342 } 343 int octet = 0; 344 for (int i = start; i < end; i++) { 345 octet *= 10; 346 int digit = Character.digit(ipString.charAt(i), 10); 347 if (digit < 0) { 348 throw new NumberFormatException(); 349 } 350 octet += digit; 351 } 352 if (octet > 255) { 353 throw new NumberFormatException(); 354 } 355 return (byte) octet; 356 } 357 358 // Parse a hextet out of the ipString from start (inclusive) to end (exclusive) 359 private static short parseHextet(String ipString, int start, int end) { 360 // Note: we already verified that this string contains only hex digits. 361 int length = end - start; 362 if (length <= 0 || length > 4) { 363 throw new NumberFormatException(); 364 } 365 int hextet = 0; 366 for (int i = start; i < end; i++) { 367 hextet = hextet << 4; 368 hextet |= Character.digit(ipString.charAt(i), 16); 369 } 370 return (short) hextet; 371 } 372 373 /** 374 * Convert a byte array into an InetAddress. 375 * 376 * <p>{@link InetAddress#getByAddress} is documented as throwing a checked exception "if IP 377 * address is of illegal length." We replace it with an unchecked exception, for use by callers 378 * who already know that addr is an array of length 4 or 16. 379 * 380 * @param addr the raw 4-byte or 16-byte IP address in big-endian order 381 * @return an InetAddress object created from the raw IP address 382 */ 383 private static InetAddress bytesToInetAddress(byte[] addr) { 384 try { 385 return InetAddress.getByAddress(addr); 386 } catch (UnknownHostException e) { 387 throw new AssertionError(e); 388 } 389 } 390 391 /** 392 * Returns the string representation of an {@link InetAddress}. 393 * 394 * <p>For IPv4 addresses, this is identical to {@link InetAddress#getHostAddress()}, but for IPv6 395 * addresses, the output follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a> section 396 * 4. The main difference is that this method uses "::" for zero compression, while Java's version 397 * uses the uncompressed form. 398 * 399 * <p>This method uses hexadecimal for all IPv6 addresses, including IPv4-mapped IPv6 addresses 400 * such as "::c000:201". The output does not include a Scope ID. 401 * 402 * @param ip {@link InetAddress} to be converted to an address string 403 * @return {@code String} containing the text-formatted IP address 404 * @since 10.0 405 */ 406 public static String toAddrString(InetAddress ip) { 407 checkNotNull(ip); 408 if (ip instanceof Inet4Address) { 409 // For IPv4, Java's formatting is good enough. 410 return ip.getHostAddress(); 411 } 412 checkArgument(ip instanceof Inet6Address); 413 byte[] bytes = ip.getAddress(); 414 int[] hextets = new int[IPV6_PART_COUNT]; 415 for (int i = 0; i < hextets.length; i++) { 416 hextets[i] = Ints.fromBytes((byte) 0, (byte) 0, bytes[2 * i], bytes[2 * i + 1]); 417 } 418 compressLongestRunOfZeroes(hextets); 419 return hextetsToIPv6String(hextets); 420 } 421 422 /** 423 * Identify and mark the longest run of zeroes in an IPv6 address. 424 * 425 * <p>Only runs of two or more hextets are considered. In case of a tie, the leftmost run wins. If 426 * a qualifying run is found, its hextets are replaced by the sentinel value -1. 427 * 428 * @param hextets {@code int[]} mutable array of eight 16-bit hextets 429 */ 430 private static void compressLongestRunOfZeroes(int[] hextets) { 431 int bestRunStart = -1; 432 int bestRunLength = -1; 433 int runStart = -1; 434 for (int i = 0; i < hextets.length + 1; i++) { 435 if (i < hextets.length && hextets[i] == 0) { 436 if (runStart < 0) { 437 runStart = i; 438 } 439 } else if (runStart >= 0) { 440 int runLength = i - runStart; 441 if (runLength > bestRunLength) { 442 bestRunStart = runStart; 443 bestRunLength = runLength; 444 } 445 runStart = -1; 446 } 447 } 448 if (bestRunLength >= 2) { 449 Arrays.fill(hextets, bestRunStart, bestRunStart + bestRunLength, -1); 450 } 451 } 452 453 /** 454 * Convert a list of hextets into a human-readable IPv6 address. 455 * 456 * <p>In order for "::" compression to work, the input should contain negative sentinel values in 457 * place of the elided zeroes. 458 * 459 * @param hextets {@code int[]} array of eight 16-bit hextets, or -1s 460 */ 461 private static String hextetsToIPv6String(int[] hextets) { 462 // While scanning the array, handle these state transitions: 463 // start->num => "num" start->gap => "::" 464 // num->num => ":num" num->gap => "::" 465 // gap->num => "num" gap->gap => "" 466 StringBuilder buf = new StringBuilder(39); 467 boolean lastWasNumber = false; 468 for (int i = 0; i < hextets.length; i++) { 469 boolean thisIsNumber = hextets[i] >= 0; 470 if (thisIsNumber) { 471 if (lastWasNumber) { 472 buf.append(':'); 473 } 474 buf.append(Integer.toHexString(hextets[i])); 475 } else { 476 if (i == 0 || lastWasNumber) { 477 buf.append("::"); 478 } 479 } 480 lastWasNumber = thisIsNumber; 481 } 482 return buf.toString(); 483 } 484 485 /** 486 * Returns the string representation of an {@link InetAddress} suitable for inclusion in a URI. 487 * 488 * <p>For IPv4 addresses, this is identical to {@link InetAddress#getHostAddress()}, but for IPv6 489 * addresses it compresses zeroes and surrounds the text with square brackets; for example {@code 490 * "[2001:db8::1]"}. 491 * 492 * <p>Per section 3.2.2 of <a target="_parent" 493 * href="http://tools.ietf.org/html/rfc3986#section-3.2.2">RFC 3986</a>, a URI containing an IPv6 494 * string literal is of the form {@code "http://[2001:db8::1]:8888/index.html"}. 495 * 496 * <p>Use of either {@link InetAddresses#toAddrString}, {@link InetAddress#getHostAddress()}, or 497 * this method is recommended over {@link InetAddress#toString()} when an IP address string 498 * literal is desired. This is because {@link InetAddress#toString()} prints the hostname and the 499 * IP address string joined by a "/". 500 * 501 * @param ip {@link InetAddress} to be converted to URI string literal 502 * @return {@code String} containing URI-safe string literal 503 */ 504 public static String toUriString(InetAddress ip) { 505 if (ip instanceof Inet6Address) { 506 return "[" + toAddrString(ip) + "]"; 507 } 508 return toAddrString(ip); 509 } 510 511 /** 512 * Returns an InetAddress representing the literal IPv4 or IPv6 host portion of a URL, encoded in 513 * the format specified by RFC 3986 section 3.2.2. 514 * 515 * <p>This method is similar to {@link InetAddresses#forString(String)}, however, it requires that 516 * IPv6 addresses are surrounded by square brackets. 517 * 518 * <p>This method is the inverse of {@link InetAddresses#toUriString(java.net.InetAddress)}. 519 * 520 * <p>This method accepts non-ASCII digits, for example {@code "192.168.0.1"} (those are fullwidth 521 * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you 522 * want to accept ASCII digits only, you can use something like {@code 523 * CharMatcher.ascii().matchesAllOf(ipString)}. 524 * 525 * @param hostAddr A RFC 3986 section 3.2.2 encoded IPv4 or IPv6 address 526 * @return an InetAddress representing the address in {@code hostAddr} 527 * @throws IllegalArgumentException if {@code hostAddr} is not a valid IPv4 address, or IPv6 528 * address surrounded by square brackets 529 */ 530 public static InetAddress forUriString(String hostAddr) { 531 InetAddress addr = forUriStringNoThrow(hostAddr); 532 if (addr == null) { 533 throw formatIllegalArgumentException("Not a valid URI IP literal: '%s'", hostAddr); 534 } 535 536 return addr; 537 } 538 539 @CheckForNull 540 private static InetAddress forUriStringNoThrow(String hostAddr) { 541 checkNotNull(hostAddr); 542 543 // Decide if this should be an IPv6 or IPv4 address. 544 String ipString; 545 int expectBytes; 546 if (hostAddr.startsWith("[") && hostAddr.endsWith("]")) { 547 ipString = hostAddr.substring(1, hostAddr.length() - 1); 548 expectBytes = 16; 549 } else { 550 ipString = hostAddr; 551 expectBytes = 4; 552 } 553 554 // Parse the address, and make sure the length/version is correct. 555 byte[] addr = ipStringToBytes(ipString); 556 if (addr == null || addr.length != expectBytes) { 557 return null; 558 } 559 560 return bytesToInetAddress(addr); 561 } 562 563 /** 564 * Returns {@code true} if the supplied string is a valid URI IP string literal, {@code false} 565 * otherwise. 566 * 567 * <p>This method accepts non-ASCII digits, for example {@code "192.168.0.1"} (those are fullwidth 568 * characters). That is consistent with {@link InetAddress}, but not with various RFCs. If you 569 * want to accept ASCII digits only, you can use something like {@code 570 * CharMatcher.ascii().matchesAllOf(ipString)}. 571 * 572 * @param ipString {@code String} to evaluated as an IP URI host string literal 573 * @return {@code true} if the argument is a valid IP URI host 574 */ 575 public static boolean isUriInetAddress(String ipString) { 576 return forUriStringNoThrow(ipString) != null; 577 } 578 579 /** 580 * Evaluates whether the argument is an IPv6 "compat" address. 581 * 582 * <p>An "IPv4 compatible", or "compat", address is one with 96 leading bits of zero, with the 583 * remaining 32 bits interpreted as an IPv4 address. These are conventionally represented in 584 * string literals as {@code "::192.168.0.1"}, though {@code "::c0a8:1"} is also considered an 585 * IPv4 compatible address (and equivalent to {@code "::192.168.0.1"}). 586 * 587 * <p>For more on IPv4 compatible addresses see section 2.5.5.1 of <a target="_parent" 588 * href="http://tools.ietf.org/html/rfc4291#section-2.5.5.1">RFC 4291</a>. 589 * 590 * <p>NOTE: This method is different from {@link Inet6Address#isIPv4CompatibleAddress} in that it 591 * more correctly classifies {@code "::"} and {@code "::1"} as proper IPv6 addresses (which they 592 * are), NOT IPv4 compatible addresses (which they are generally NOT considered to be). 593 * 594 * @param ip {@link Inet6Address} to be examined for embedded IPv4 compatible address format 595 * @return {@code true} if the argument is a valid "compat" address 596 */ 597 public static boolean isCompatIPv4Address(Inet6Address ip) { 598 if (!ip.isIPv4CompatibleAddress()) { 599 return false; 600 } 601 602 byte[] bytes = ip.getAddress(); 603 if ((bytes[12] == 0) 604 && (bytes[13] == 0) 605 && (bytes[14] == 0) 606 && ((bytes[15] == 0) || (bytes[15] == 1))) { 607 return false; 608 } 609 610 return true; 611 } 612 613 /** 614 * Returns the IPv4 address embedded in an IPv4 compatible address. 615 * 616 * @param ip {@link Inet6Address} to be examined for an embedded IPv4 address 617 * @return {@link Inet4Address} of the embedded IPv4 address 618 * @throws IllegalArgumentException if the argument is not a valid IPv4 compatible address 619 */ 620 public static Inet4Address getCompatIPv4Address(Inet6Address ip) { 621 checkArgument( 622 isCompatIPv4Address(ip), "Address '%s' is not IPv4-compatible.", toAddrString(ip)); 623 624 return getInet4Address(Arrays.copyOfRange(ip.getAddress(), 12, 16)); 625 } 626 627 /** 628 * Evaluates whether the argument is a 6to4 address. 629 * 630 * <p>6to4 addresses begin with the {@code "2002::/16"} prefix. The next 32 bits are the IPv4 631 * address of the host to which IPv6-in-IPv4 tunneled packets should be routed. 632 * 633 * <p>For more on 6to4 addresses see section 2 of <a target="_parent" 634 * href="http://tools.ietf.org/html/rfc3056#section-2">RFC 3056</a>. 635 * 636 * @param ip {@link Inet6Address} to be examined for 6to4 address format 637 * @return {@code true} if the argument is a 6to4 address 638 */ 639 public static boolean is6to4Address(Inet6Address ip) { 640 byte[] bytes = ip.getAddress(); 641 return (bytes[0] == (byte) 0x20) && (bytes[1] == (byte) 0x02); 642 } 643 644 /** 645 * Returns the IPv4 address embedded in a 6to4 address. 646 * 647 * @param ip {@link Inet6Address} to be examined for embedded IPv4 in 6to4 address 648 * @return {@link Inet4Address} of embedded IPv4 in 6to4 address 649 * @throws IllegalArgumentException if the argument is not a valid IPv6 6to4 address 650 */ 651 public static Inet4Address get6to4IPv4Address(Inet6Address ip) { 652 checkArgument(is6to4Address(ip), "Address '%s' is not a 6to4 address.", toAddrString(ip)); 653 654 return getInet4Address(Arrays.copyOfRange(ip.getAddress(), 2, 6)); 655 } 656 657 /** 658 * A simple immutable data class to encapsulate the information to be found in a Teredo address. 659 * 660 * <p>All of the fields in this class are encoded in various portions of the IPv6 address as part 661 * of the protocol. More protocols details can be found at: <a target="_parent" 662 * href="http://en.wikipedia.org/wiki/Teredo_tunneling">http://en.wikipedia. 663 * org/wiki/Teredo_tunneling</a>. 664 * 665 * <p>The RFC can be found here: <a target="_parent" href="http://tools.ietf.org/html/rfc4380">RFC 666 * 4380</a>. 667 * 668 * @since 5.0 669 */ 670 public static final class TeredoInfo { 671 private final Inet4Address server; 672 private final Inet4Address client; 673 private final int port; 674 private final int flags; 675 676 /** 677 * Constructs a TeredoInfo instance. 678 * 679 * <p>Both server and client can be {@code null}, in which case the value {@code "0.0.0.0"} will 680 * be assumed. 681 * 682 * @throws IllegalArgumentException if either of the {@code port} or the {@code flags} arguments 683 * are out of range of an unsigned short 684 */ 685 // TODO: why is this public? 686 public TeredoInfo( 687 @CheckForNull Inet4Address server, @CheckForNull Inet4Address client, int port, int flags) { 688 checkArgument( 689 (port >= 0) && (port <= 0xffff), "port '%s' is out of range (0 <= port <= 0xffff)", port); 690 checkArgument( 691 (flags >= 0) && (flags <= 0xffff), 692 "flags '%s' is out of range (0 <= flags <= 0xffff)", 693 flags); 694 695 this.server = MoreObjects.firstNonNull(server, ANY4); 696 this.client = MoreObjects.firstNonNull(client, ANY4); 697 this.port = port; 698 this.flags = flags; 699 } 700 701 public Inet4Address getServer() { 702 return server; 703 } 704 705 public Inet4Address getClient() { 706 return client; 707 } 708 709 public int getPort() { 710 return port; 711 } 712 713 public int getFlags() { 714 return flags; 715 } 716 } 717 718 /** 719 * Evaluates whether the argument is a Teredo address. 720 * 721 * <p>Teredo addresses begin with the {@code "2001::/32"} prefix. 722 * 723 * @param ip {@link Inet6Address} to be examined for Teredo address format 724 * @return {@code true} if the argument is a Teredo address 725 */ 726 public static boolean isTeredoAddress(Inet6Address ip) { 727 byte[] bytes = ip.getAddress(); 728 return (bytes[0] == (byte) 0x20) 729 && (bytes[1] == (byte) 0x01) 730 && (bytes[2] == 0) 731 && (bytes[3] == 0); 732 } 733 734 /** 735 * Returns the Teredo information embedded in a Teredo address. 736 * 737 * @param ip {@link Inet6Address} to be examined for embedded Teredo information 738 * @return extracted {@code TeredoInfo} 739 * @throws IllegalArgumentException if the argument is not a valid IPv6 Teredo address 740 */ 741 public static TeredoInfo getTeredoInfo(Inet6Address ip) { 742 checkArgument(isTeredoAddress(ip), "Address '%s' is not a Teredo address.", toAddrString(ip)); 743 744 byte[] bytes = ip.getAddress(); 745 Inet4Address server = getInet4Address(Arrays.copyOfRange(bytes, 4, 8)); 746 747 int flags = ByteStreams.newDataInput(bytes, 8).readShort() & 0xffff; 748 749 // Teredo obfuscates the mapped client port, per section 4 of the RFC. 750 int port = ~ByteStreams.newDataInput(bytes, 10).readShort() & 0xffff; 751 752 byte[] clientBytes = Arrays.copyOfRange(bytes, 12, 16); 753 for (int i = 0; i < clientBytes.length; i++) { 754 // Teredo obfuscates the mapped client IP, per section 4 of the RFC. 755 clientBytes[i] = (byte) ~clientBytes[i]; 756 } 757 Inet4Address client = getInet4Address(clientBytes); 758 759 return new TeredoInfo(server, client, port, flags); 760 } 761 762 /** 763 * Evaluates whether the argument is an ISATAP address. 764 * 765 * <p>From RFC 5214: "ISATAP interface identifiers are constructed in Modified EUI-64 format [...] 766 * by concatenating the 24-bit IANA OUI (00-00-5E), the 8-bit hexadecimal value 0xFE, and a 32-bit 767 * IPv4 address in network byte order [...]" 768 * 769 * <p>For more on ISATAP addresses see section 6.1 of <a target="_parent" 770 * href="http://tools.ietf.org/html/rfc5214#section-6.1">RFC 5214</a>. 771 * 772 * @param ip {@link Inet6Address} to be examined for ISATAP address format 773 * @return {@code true} if the argument is an ISATAP address 774 */ 775 public static boolean isIsatapAddress(Inet6Address ip) { 776 777 // If it's a Teredo address with the right port (41217, or 0xa101) 778 // which would be encoded as 0x5efe then it can't be an ISATAP address. 779 if (isTeredoAddress(ip)) { 780 return false; 781 } 782 783 byte[] bytes = ip.getAddress(); 784 785 if ((bytes[8] | (byte) 0x03) != (byte) 0x03) { 786 787 // Verify that high byte of the 64 bit identifier is zero, modulo 788 // the U/L and G bits, with which we are not concerned. 789 return false; 790 } 791 792 return (bytes[9] == (byte) 0x00) && (bytes[10] == (byte) 0x5e) && (bytes[11] == (byte) 0xfe); 793 } 794 795 /** 796 * Returns the IPv4 address embedded in an ISATAP address. 797 * 798 * @param ip {@link Inet6Address} to be examined for embedded IPv4 in ISATAP address 799 * @return {@link Inet4Address} of embedded IPv4 in an ISATAP address 800 * @throws IllegalArgumentException if the argument is not a valid IPv6 ISATAP address 801 */ 802 public static Inet4Address getIsatapIPv4Address(Inet6Address ip) { 803 checkArgument(isIsatapAddress(ip), "Address '%s' is not an ISATAP address.", toAddrString(ip)); 804 805 return getInet4Address(Arrays.copyOfRange(ip.getAddress(), 12, 16)); 806 } 807 808 /** 809 * Examines the Inet6Address to determine if it is an IPv6 address of one of the specified address 810 * types that contain an embedded IPv4 address. 811 * 812 * <p>NOTE: ISATAP addresses are explicitly excluded from this method due to their trivial 813 * spoofability. With other transition addresses spoofing involves (at least) infection of one's 814 * BGP routing table. 815 * 816 * @param ip {@link Inet6Address} to be examined for embedded IPv4 client address 817 * @return {@code true} if there is an embedded IPv4 client address 818 * @since 7.0 819 */ 820 public static boolean hasEmbeddedIPv4ClientAddress(Inet6Address ip) { 821 return isCompatIPv4Address(ip) || is6to4Address(ip) || isTeredoAddress(ip); 822 } 823 824 /** 825 * Examines the Inet6Address to extract the embedded IPv4 client address if the InetAddress is an 826 * IPv6 address of one of the specified address types that contain an embedded IPv4 address. 827 * 828 * <p>NOTE: ISATAP addresses are explicitly excluded from this method due to their trivial 829 * spoofability. With other transition addresses spoofing involves (at least) infection of one's 830 * BGP routing table. 831 * 832 * @param ip {@link Inet6Address} to be examined for embedded IPv4 client address 833 * @return {@link Inet4Address} of embedded IPv4 client address 834 * @throws IllegalArgumentException if the argument does not have a valid embedded IPv4 address 835 */ 836 public static Inet4Address getEmbeddedIPv4ClientAddress(Inet6Address ip) { 837 if (isCompatIPv4Address(ip)) { 838 return getCompatIPv4Address(ip); 839 } 840 841 if (is6to4Address(ip)) { 842 return get6to4IPv4Address(ip); 843 } 844 845 if (isTeredoAddress(ip)) { 846 return getTeredoInfo(ip).getClient(); 847 } 848 849 throw formatIllegalArgumentException("'%s' has no embedded IPv4 address.", toAddrString(ip)); 850 } 851 852 /** 853 * Evaluates whether the argument is an "IPv4 mapped" IPv6 address. 854 * 855 * <p>An "IPv4 mapped" address is anything in the range ::ffff:0:0/96 (sometimes written as 856 * ::ffff:0.0.0.0/96), with the last 32 bits interpreted as an IPv4 address. 857 * 858 * <p>For more on IPv4 mapped addresses see section 2.5.5.2 of <a target="_parent" 859 * href="http://tools.ietf.org/html/rfc4291#section-2.5.5.2">RFC 4291</a>. 860 * 861 * <p>Note: This method takes a {@code String} argument because {@link InetAddress} automatically 862 * collapses mapped addresses to IPv4. (It is actually possible to avoid this using one of the 863 * obscure {@link Inet6Address} methods, but it would be unwise to depend on such a 864 * poorly-documented feature.) 865 * 866 * <p>This method accepts non-ASCII digits. That is consistent with {@link InetAddress}, but not 867 * with various RFCs. If you want to accept ASCII digits only, you can use something like {@code 868 * CharMatcher.ascii().matchesAllOf(ipString)}. 869 * 870 * @param ipString {@code String} to be examined for embedded IPv4-mapped IPv6 address format 871 * @return {@code true} if the argument is a valid "mapped" address 872 * @since 10.0 873 */ 874 public static boolean isMappedIPv4Address(String ipString) { 875 byte[] bytes = ipStringToBytes(ipString); 876 if (bytes != null && bytes.length == 16) { 877 for (int i = 0; i < 10; i++) { 878 if (bytes[i] != 0) { 879 return false; 880 } 881 } 882 for (int i = 10; i < 12; i++) { 883 if (bytes[i] != (byte) 0xff) { 884 return false; 885 } 886 } 887 return true; 888 } 889 return false; 890 } 891 892 /** 893 * Coerces an IPv6 address into an IPv4 address. 894 * 895 * <p>HACK: As long as applications continue to use IPv4 addresses for indexing into tables, 896 * accounting, et cetera, it may be necessary to <b>coerce</b> IPv6 addresses into IPv4 addresses. 897 * This method does so by hashing 64 bits of the IPv6 address into {@code 224.0.0.0/3} (64 bits 898 * into 29 bits): 899 * 900 * <ul> 901 * <li>If the IPv6 address contains an embedded IPv4 address, the function hashes that. 902 * <li>Otherwise, it hashes the upper 64 bits of the IPv6 address. 903 * </ul> 904 * 905 * <p>A "coerced" IPv4 address is equivalent to itself. 906 * 907 * <p>NOTE: This method is failsafe for security purposes: ALL IPv6 addresses (except localhost 908 * (::1)) are hashed to avoid the security risk associated with extracting an embedded IPv4 909 * address that might permit elevated privileges. 910 * 911 * @param ip {@link InetAddress} to "coerce" 912 * @return {@link Inet4Address} represented "coerced" address 913 * @since 7.0 914 */ 915 public static Inet4Address getCoercedIPv4Address(InetAddress ip) { 916 if (ip instanceof Inet4Address) { 917 return (Inet4Address) ip; 918 } 919 920 // Special cases: 921 byte[] bytes = ip.getAddress(); 922 boolean leadingBytesOfZero = true; 923 for (int i = 0; i < 15; ++i) { 924 if (bytes[i] != 0) { 925 leadingBytesOfZero = false; 926 break; 927 } 928 } 929 if (leadingBytesOfZero && (bytes[15] == 1)) { 930 return LOOPBACK4; // ::1 931 } else if (leadingBytesOfZero && (bytes[15] == 0)) { 932 return ANY4; // ::0 933 } 934 935 Inet6Address ip6 = (Inet6Address) ip; 936 long addressAsLong = 0; 937 if (hasEmbeddedIPv4ClientAddress(ip6)) { 938 addressAsLong = getEmbeddedIPv4ClientAddress(ip6).hashCode(); 939 } else { 940 // Just extract the high 64 bits (assuming the rest is user-modifiable). 941 addressAsLong = ByteBuffer.wrap(ip6.getAddress(), 0, 8).getLong(); 942 } 943 944 // Many strategies for hashing are possible. This might suffice for now. 945 int coercedHash = Hashing.murmur3_32_fixed().hashLong(addressAsLong).asInt(); 946 947 // Squash into 224/4 Multicast and 240/4 Reserved space (i.e. 224/3). 948 coercedHash |= 0xe0000000; 949 950 // Fixup to avoid some "illegal" values. Currently the only potential 951 // illegal value is 255.255.255.255. 952 if (coercedHash == 0xffffffff) { 953 coercedHash = 0xfffffffe; 954 } 955 956 return getInet4Address(Ints.toByteArray(coercedHash)); 957 } 958 959 /** 960 * Returns an integer representing an IPv4 address regardless of whether the supplied argument is 961 * an IPv4 address or not. 962 * 963 * <p>IPv6 addresses are <b>coerced</b> to IPv4 addresses before being converted to integers. 964 * 965 * <p>As long as there are applications that assume that all IP addresses are IPv4 addresses and 966 * can therefore be converted safely to integers (for whatever purpose) this function can be used 967 * to handle IPv6 addresses as well until the application is suitably fixed. 968 * 969 * <p>NOTE: an IPv6 address coerced to an IPv4 address can only be used for such purposes as 970 * rudimentary identification or indexing into a collection of real {@link InetAddress}es. They 971 * cannot be used as real addresses for the purposes of network communication. 972 * 973 * @param ip {@link InetAddress} to convert 974 * @return {@code int}, "coerced" if ip is not an IPv4 address 975 * @since 7.0 976 */ 977 public static int coerceToInteger(InetAddress ip) { 978 return ByteStreams.newDataInput(getCoercedIPv4Address(ip).getAddress()).readInt(); 979 } 980 981 /** 982 * Returns a BigInteger representing the address. 983 * 984 * <p>Unlike {@code coerceToInteger}, IPv6 addresses are not coerced to IPv4 addresses. 985 * 986 * @param address {@link InetAddress} to convert 987 * @return {@code BigInteger} representation of the address 988 * @since 28.2 989 */ 990 public static BigInteger toBigInteger(InetAddress address) { 991 return new BigInteger(1, address.getAddress()); 992 } 993 994 /** 995 * Returns an Inet4Address having the integer value specified by the argument. 996 * 997 * @param address {@code int}, the 32bit integer address to be converted 998 * @return {@link Inet4Address} equivalent of the argument 999 */ 1000 public static Inet4Address fromInteger(int address) { 1001 return getInet4Address(Ints.toByteArray(address)); 1002 } 1003 1004 /** 1005 * Returns the {@code Inet4Address} corresponding to a given {@code BigInteger}. 1006 * 1007 * @param address BigInteger representing the IPv4 address 1008 * @return Inet4Address representation of the given BigInteger 1009 * @throws IllegalArgumentException if the BigInteger is not between 0 and 2^32-1 1010 * @since 28.2 1011 */ 1012 public static Inet4Address fromIPv4BigInteger(BigInteger address) { 1013 return (Inet4Address) fromBigInteger(address, false); 1014 } 1015 /** 1016 * Returns the {@code Inet6Address} corresponding to a given {@code BigInteger}. 1017 * 1018 * @param address BigInteger representing the IPv6 address 1019 * @return Inet6Address representation of the given BigInteger 1020 * @throws IllegalArgumentException if the BigInteger is not between 0 and 2^128-1 1021 * @since 28.2 1022 */ 1023 public static Inet6Address fromIPv6BigInteger(BigInteger address) { 1024 return (Inet6Address) fromBigInteger(address, true); 1025 } 1026 1027 /** 1028 * Converts a BigInteger to either an IPv4 or IPv6 address. If the IP is IPv4, it must be 1029 * constrainted to 32 bits, otherwise it is constrained to 128 bits. 1030 * 1031 * @param address the address represented as a big integer 1032 * @param isIpv6 whether the created address should be IPv4 or IPv6 1033 * @return the BigInteger converted to an address 1034 * @throws IllegalArgumentException if the BigInteger is not between 0 and maximum value for IPv4 1035 * or IPv6 respectively 1036 */ 1037 private static InetAddress fromBigInteger(BigInteger address, boolean isIpv6) { 1038 checkArgument(address.signum() >= 0, "BigInteger must be greater than or equal to 0"); 1039 1040 int numBytes = isIpv6 ? 16 : 4; 1041 1042 byte[] addressBytes = address.toByteArray(); 1043 byte[] targetCopyArray = new byte[numBytes]; 1044 1045 int srcPos = Math.max(0, addressBytes.length - numBytes); 1046 int copyLength = addressBytes.length - srcPos; 1047 int destPos = numBytes - copyLength; 1048 1049 // Check the extra bytes in the BigInteger are all zero. 1050 for (int i = 0; i < srcPos; i++) { 1051 if (addressBytes[i] != 0x00) { 1052 throw formatIllegalArgumentException( 1053 "BigInteger cannot be converted to InetAddress because it has more than %d" 1054 + " bytes: %s", 1055 numBytes, address); 1056 } 1057 } 1058 1059 // Copy the bytes into the least significant positions. 1060 System.arraycopy(addressBytes, srcPos, targetCopyArray, destPos, copyLength); 1061 1062 try { 1063 return InetAddress.getByAddress(targetCopyArray); 1064 } catch (UnknownHostException impossible) { 1065 throw new AssertionError(impossible); 1066 } 1067 } 1068 1069 /** 1070 * Returns an address from a <b>little-endian ordered</b> byte array (the opposite of what {@link 1071 * InetAddress#getByAddress} expects). 1072 * 1073 * <p>IPv4 address byte array must be 4 bytes long and IPv6 byte array must be 16 bytes long. 1074 * 1075 * @param addr the raw IP address in little-endian byte order 1076 * @return an InetAddress object created from the raw IP address 1077 * @throws UnknownHostException if IP address is of illegal length 1078 */ 1079 public static InetAddress fromLittleEndianByteArray(byte[] addr) throws UnknownHostException { 1080 byte[] reversed = new byte[addr.length]; 1081 for (int i = 0; i < addr.length; i++) { 1082 reversed[i] = addr[addr.length - i - 1]; 1083 } 1084 return InetAddress.getByAddress(reversed); 1085 } 1086 1087 /** 1088 * Returns a new InetAddress that is one less than the passed in address. This method works for 1089 * both IPv4 and IPv6 addresses. 1090 * 1091 * @param address the InetAddress to decrement 1092 * @return a new InetAddress that is one less than the passed in address 1093 * @throws IllegalArgumentException if InetAddress is at the beginning of its range 1094 * @since 18.0 1095 */ 1096 public static InetAddress decrement(InetAddress address) { 1097 byte[] addr = address.getAddress(); 1098 int i = addr.length - 1; 1099 while (i >= 0 && addr[i] == (byte) 0x00) { 1100 addr[i] = (byte) 0xff; 1101 i--; 1102 } 1103 1104 checkArgument(i >= 0, "Decrementing %s would wrap.", address); 1105 1106 addr[i]--; 1107 return bytesToInetAddress(addr); 1108 } 1109 1110 /** 1111 * Returns a new InetAddress that is one more than the passed in address. This method works for 1112 * both IPv4 and IPv6 addresses. 1113 * 1114 * @param address the InetAddress to increment 1115 * @return a new InetAddress that is one more than the passed in address 1116 * @throws IllegalArgumentException if InetAddress is at the end of its range 1117 * @since 10.0 1118 */ 1119 public static InetAddress increment(InetAddress address) { 1120 byte[] addr = address.getAddress(); 1121 int i = addr.length - 1; 1122 while (i >= 0 && addr[i] == (byte) 0xff) { 1123 addr[i] = 0; 1124 i--; 1125 } 1126 1127 checkArgument(i >= 0, "Incrementing %s would wrap.", address); 1128 1129 addr[i]++; 1130 return bytesToInetAddress(addr); 1131 } 1132 1133 /** 1134 * Returns true if the InetAddress is either 255.255.255.255 for IPv4 or 1135 * ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff for IPv6. 1136 * 1137 * @return true if the InetAddress is either 255.255.255.255 for IPv4 or 1138 * ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff for IPv6 1139 * @since 10.0 1140 */ 1141 public static boolean isMaximum(InetAddress address) { 1142 byte[] addr = address.getAddress(); 1143 for (byte b : addr) { 1144 if (b != (byte) 0xff) { 1145 return false; 1146 } 1147 } 1148 return true; 1149 } 1150 1151 private static IllegalArgumentException formatIllegalArgumentException( 1152 String format, Object... args) { 1153 return new IllegalArgumentException(String.format(Locale.ROOT, format, args)); 1154 } 1155}