1 /*
2 * Copyright (c) 1995, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.net;
27
28 import java.util.NavigableSet;
29 import java.util.ArrayList;
30 import java.util.Objects;
31 import java.util.Scanner;
32 import java.security.AccessController;
33 import java.io.File;
34 import java.io.FileNotFoundException;
35 import java.io.ObjectStreamException;
36 import java.io.ObjectStreamField;
37 import java.io.IOException;
38 import java.io.ObjectInputStream;
39 import java.io.ObjectInputStream.GetField;
40 import java.io.ObjectOutputStream;
41 import java.io.ObjectOutputStream.PutField;
42 import java.lang.annotation.Native;
43 import java.util.concurrent.ConcurrentHashMap;
44 import java.util.concurrent.ConcurrentMap;
45 import java.util.concurrent.ConcurrentSkipListSet;
46 import java.util.concurrent.atomic.AtomicLong;
47
48 import jdk.internal.misc.JavaNetInetAddressAccess;
49 import jdk.internal.misc.SharedSecrets;
50 import sun.security.action.*;
51 import sun.net.InetAddressCachePolicy;
52 import sun.net.util.IPAddressUtil;
53
54 /**
55 * This class represents an Internet Protocol (IP) address.
56 *
57 * <p> An IP address is either a 32-bit or 128-bit unsigned number
58 * used by IP, a lower-level protocol on which protocols like UDP and
59 * TCP are built. The IP address architecture is defined by <a
60 * href="http://www.ietf.org/rfc/rfc790.txt"><i>RFC 790:
61 * Assigned Numbers</i></a>, <a
62 * href="http://www.ietf.org/rfc/rfc1918.txt"> <i>RFC 1918:
63 * Address Allocation for Private Internets</i></a>, <a
64 * href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC 2365:
65 * Administratively Scoped IP Multicast</i></a>, and <a
66 * href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC 2373: IP
67 * Version 6 Addressing Architecture</i></a>. An instance of an
68 * InetAddress consists of an IP address and possibly its
69 * corresponding host name (depending on whether it is constructed
70 * with a host name or whether it has already done reverse host name
71 * resolution).
72 *
73 * <h3> Address types </h3>
74 *
75 * <blockquote><table cellspacing=2 summary="Description of unicast and multicast address types">
76 * <tr><th valign=top><i>unicast</i></th>
77 * <td>An identifier for a single interface. A packet sent to
78 * a unicast address is delivered to the interface identified by
79 * that address.
80 *
81 * <p> The Unspecified Address -- Also called anylocal or wildcard
82 * address. It must never be assigned to any node. It indicates the
83 * absence of an address. One example of its use is as the target of
84 * bind, which allows a server to accept a client connection on any
85 * interface, in case the server host has multiple interfaces.
86 *
87 * <p> The <i>unspecified</i> address must not be used as
88 * the destination address of an IP packet.
89 *
90 * <p> The <i>Loopback</i> Addresses -- This is the address
91 * assigned to the loopback interface. Anything sent to this
92 * IP address loops around and becomes IP input on the local
93 * host. This address is often used when testing a
94 * client.</td></tr>
95 * <tr><th valign=top><i>multicast</i></th>
96 * <td>An identifier for a set of interfaces (typically belonging
97 * to different nodes). A packet sent to a multicast address is
98 * delivered to all interfaces identified by that address.</td></tr>
99 * </table></blockquote>
100 *
101 * <h4> IP address scope </h4>
102 *
103 * <p> <i>Link-local</i> addresses are designed to be used for addressing
104 * on a single link for purposes such as auto-address configuration,
105 * neighbor discovery, or when no routers are present.
106 *
107 * <p> <i>Site-local</i> addresses are designed to be used for addressing
108 * inside of a site without the need for a global prefix.
109 *
110 * <p> <i>Global</i> addresses are unique across the internet.
111 *
112 * <h4> Textual representation of IP addresses </h4>
113 *
114 * The textual representation of an IP address is address family specific.
115 *
116 * <p>
117 *
118 * For IPv4 address format, please refer to <A
119 * HREF="Inet4Address.html#format">Inet4Address#format</A>; For IPv6
120 * address format, please refer to <A
121 * HREF="Inet6Address.html#format">Inet6Address#format</A>.
122 *
123 * <P>There is a <a href="doc-files/net-properties.html#Ipv4IPv6">couple of
124 * System Properties</a> affecting how IPv4 and IPv6 addresses are used.</P>
125 *
126 * <h4> Host Name Resolution </h4>
127 *
128 * Host name-to-IP address <i>resolution</i> is accomplished through
129 * the use of a combination of local machine configuration information
130 * and network naming services such as the Domain Name System (DNS)
131 * and Network Information Service(NIS). The particular naming
132 * services(s) being used is by default the local machine configured
133 * one. For any host name, its corresponding IP address is returned.
134 *
135 * <p> <i>Reverse name resolution</i> means that for any IP address,
136 * the host associated with the IP address is returned.
137 *
138 * <p> The InetAddress class provides methods to resolve host names to
139 * their IP addresses and vice versa.
140 *
141 * <h4> InetAddress Caching </h4>
142 *
143 * The InetAddress class has a cache to store successful as well as
144 * unsuccessful host name resolutions.
145 *
146 * <p> By default, when a security manager is installed, in order to
147 * protect against DNS spoofing attacks,
148 * the result of positive host name resolutions are
149 * cached forever. When a security manager is not installed, the default
150 * behavior is to cache entries for a finite (implementation dependent)
151 * period of time. The result of unsuccessful host
152 * name resolution is cached for a very short period of time (10
153 * seconds) to improve performance.
154 *
155 * <p> If the default behavior is not desired, then a Java security property
156 * can be set to a different Time-to-live (TTL) value for positive
157 * caching. Likewise, a system admin can configure a different
158 * negative caching TTL value when needed.
159 *
160 * <p> Two Java security properties control the TTL values used for
161 * positive and negative host name resolution caching:
162 *
163 * <blockquote>
164 * <dl>
165 * <dt><b>networkaddress.cache.ttl</b></dt>
166 * <dd>Indicates the caching policy for successful name lookups from
167 * the name service. The value is specified as an integer to indicate
168 * the number of seconds to cache the successful lookup. The default
169 * setting is to cache for an implementation specific period of time.
170 * <p>
171 * A value of -1 indicates "cache forever".
172 * </dd>
173 * <dt><b>networkaddress.cache.negative.ttl</b> (default: 10)</dt>
174 * <dd>Indicates the caching policy for un-successful name lookups
175 * from the name service. The value is specified as an integer to
176 * indicate the number of seconds to cache the failure for
177 * un-successful lookups.
178 * <p>
179 * A value of 0 indicates "never cache".
180 * A value of -1 indicates "cache forever".
181 * </dd>
182 * </dl>
183 * </blockquote>
184 *
185 * @author Chris Warth
186 * @see java.net.InetAddress#getByAddress(byte[])
187 * @see java.net.InetAddress#getByAddress(java.lang.String, byte[])
188 * @see java.net.InetAddress#getAllByName(java.lang.String)
189 * @see java.net.InetAddress#getByName(java.lang.String)
190 * @see java.net.InetAddress#getLocalHost()
191 * @since 1.0
192 */
193 public
194 class InetAddress implements java.io.Serializable {
195
196 @Native static final int PREFER_IPV4_VALUE = 0;
197 @Native static final int PREFER_IPV6_VALUE = 1;
198 @Native static final int PREFER_SYSTEM_VALUE = 2;
199
200 /**
201 * Specify the address family: Internet Protocol, Version 4
202 * @since 1.4
203 */
204 static final int IPv4 = 1;
205
206 /**
207 * Specify the address family: Internet Protocol, Version 6
208 * @since 1.4
209 */
210 static final int IPv6 = 2;
211
212 /* Specify address family preference */
213 static transient final int preferIPv6Address;
214
215 static class InetAddressHolder {
216 /**
217 * Reserve the original application specified hostname.
218 *
219 * The original hostname is useful for domain-based endpoint
220 * identification (see RFC 2818 and RFC 6125). If an address
221 * was created with a raw IP address, a reverse name lookup
222 * may introduce endpoint identification security issue via
223 * DNS forging.
224 *
225 * Oracle JSSE provider is using this original hostname, via
226 * jdk.internal.misc.JavaNetAccess, for SSL/TLS endpoint identification.
227 *
228 * Note: May define a new public method in the future if necessary.
229 */
230 String originalHostName;
231
232 InetAddressHolder() {}
233
234 InetAddressHolder(String hostName, int address, int family) {
235 this.originalHostName = hostName;
236 this.hostName = hostName;
237 this.address = address;
238 this.family = family;
239 }
240
241 void init(String hostName, int family) {
242 this.originalHostName = hostName;
243 this.hostName = hostName;
244 if (family != -1) {
245 this.family = family;
246 }
247 }
248
249 String hostName;
250
251 String getHostName() {
252 return hostName;
253 }
254
255 String getOriginalHostName() {
256 return originalHostName;
257 }
258
259 /**
260 * Holds a 32-bit IPv4 address.
261 */
262 int address;
263
264 int getAddress() {
265 return address;
266 }
267
268 /**
269 * Specifies the address family type, for instance, '1' for IPv4
270 * addresses, and '2' for IPv6 addresses.
271 */
272 int family;
273
274 int getFamily() {
275 return family;
276 }
277 }
278
279 /* Used to store the serializable fields of InetAddress */
280 final transient InetAddressHolder holder;
281
282 InetAddressHolder holder() {
283 return holder;
284 }
285
286 /* Used to store the name service provider */
287 private static transient NameService nameService = null;
288
289 /* Used to store the best available hostname */
290 private transient String canonicalHostName = null;
291
292 /** use serialVersionUID from JDK 1.0.2 for interoperability */
293 private static final long serialVersionUID = 3286316764910316507L;
294
295 /*
296 * Load net library into runtime, and perform initializations.
297 */
298 static {
299 String str = java.security.AccessController.doPrivileged(
300 new GetPropertyAction("java.net.preferIPv6Addresses"));
301 if (str == null) {
302 preferIPv6Address = PREFER_IPV4_VALUE;
303 } else if (str.equalsIgnoreCase("true")) {
304 preferIPv6Address = PREFER_IPV6_VALUE;
305 } else if (str.equalsIgnoreCase("false")) {
306 preferIPv6Address = PREFER_IPV4_VALUE;
307 } else if (str.equalsIgnoreCase("system")) {
308 preferIPv6Address = PREFER_SYSTEM_VALUE;
309 } else {
310 preferIPv6Address = PREFER_IPV4_VALUE;
311 }
312 AccessController.doPrivileged(
313 new java.security.PrivilegedAction<>() {
314 public Void run() {
315 System.loadLibrary("net");
316 return null;
317 }
318 });
319 SharedSecrets.setJavaNetInetAddressAccess(
320 new JavaNetInetAddressAccess() {
321 public String getOriginalHostName(InetAddress ia) {
322 return ia.holder.getOriginalHostName();
323 }
324
325 public InetAddress getByName(String hostName,
326 InetAddress hostAddress)
327 throws UnknownHostException
328 {
329 return InetAddress.getByName(hostName, hostAddress);
330 }
331 }
332 );
333 init();
334 }
335
336 /**
337 * Constructor for the Socket.accept() method.
338 * This creates an empty InetAddress, which is filled in by
339 * the accept() method. This InetAddress, however, is not
340 * put in the address cache, since it is not created by name.
341 */
342 InetAddress() {
343 holder = new InetAddressHolder();
344 }
345
346 /**
347 * Replaces the de-serialized object with an Inet4Address object.
348 *
349 * @return the alternate object to the de-serialized object.
350 *
351 * @throws ObjectStreamException if a new object replacing this
352 * object could not be created
353 */
354 private Object readResolve() throws ObjectStreamException {
355 // will replace the deserialized 'this' object
356 return new Inet4Address(holder().getHostName(), holder().getAddress());
357 }
358
359 /**
360 * Utility routine to check if the InetAddress is an
361 * IP multicast address.
362 * @return a {@code boolean} indicating if the InetAddress is
363 * an IP multicast address
364 * @since 1.1
365 */
366 public boolean isMulticastAddress() {
367 return false;
368 }
369
370 /**
371 * Utility routine to check if the InetAddress is a wildcard address.
372 * @return a {@code boolean} indicating if the Inetaddress is
373 * a wildcard address.
374 * @since 1.4
375 */
376 public boolean isAnyLocalAddress() {
377 return false;
378 }
379
380 /**
381 * Utility routine to check if the InetAddress is a loopback address.
382 *
383 * @return a {@code boolean} indicating if the InetAddress is
384 * a loopback address; or false otherwise.
385 * @since 1.4
386 */
387 public boolean isLoopbackAddress() {
388 return false;
389 }
390
391 /**
392 * Utility routine to check if the InetAddress is an link local address.
393 *
394 * @return a {@code boolean} indicating if the InetAddress is
395 * a link local address; or false if address is not a link local unicast address.
396 * @since 1.4
397 */
398 public boolean isLinkLocalAddress() {
399 return false;
400 }
401
402 /**
403 * Utility routine to check if the InetAddress is a site local address.
404 *
405 * @return a {@code boolean} indicating if the InetAddress is
406 * a site local address; or false if address is not a site local unicast address.
407 * @since 1.4
408 */
409 public boolean isSiteLocalAddress() {
410 return false;
411 }
412
413 /**
414 * Utility routine to check if the multicast address has global scope.
415 *
416 * @return a {@code boolean} indicating if the address has
417 * is a multicast address of global scope, false if it is not
418 * of global scope or it is not a multicast address
419 * @since 1.4
420 */
421 public boolean isMCGlobal() {
422 return false;
423 }
424
425 /**
426 * Utility routine to check if the multicast address has node scope.
427 *
428 * @return a {@code boolean} indicating if the address has
429 * is a multicast address of node-local scope, false if it is not
430 * of node-local scope or it is not a multicast address
431 * @since 1.4
432 */
433 public boolean isMCNodeLocal() {
434 return false;
435 }
436
437 /**
438 * Utility routine to check if the multicast address has link scope.
439 *
440 * @return a {@code boolean} indicating if the address has
441 * is a multicast address of link-local scope, false if it is not
442 * of link-local scope or it is not a multicast address
443 * @since 1.4
444 */
445 public boolean isMCLinkLocal() {
446 return false;
447 }
448
449 /**
450 * Utility routine to check if the multicast address has site scope.
451 *
452 * @return a {@code boolean} indicating if the address has
453 * is a multicast address of site-local scope, false if it is not
454 * of site-local scope or it is not a multicast address
455 * @since 1.4
456 */
457 public boolean isMCSiteLocal() {
458 return false;
459 }
460
461 /**
462 * Utility routine to check if the multicast address has organization scope.
463 *
464 * @return a {@code boolean} indicating if the address has
465 * is a multicast address of organization-local scope,
466 * false if it is not of organization-local scope
467 * or it is not a multicast address
468 * @since 1.4
469 */
470 public boolean isMCOrgLocal() {
471 return false;
472 }
473
474
475 /**
476 * Test whether that address is reachable. Best effort is made by the
477 * implementation to try to reach the host, but firewalls and server
478 * configuration may block requests resulting in a unreachable status
479 * while some specific ports may be accessible.
480 * A typical implementation will use ICMP ECHO REQUESTs if the
481 * privilege can be obtained, otherwise it will try to establish
482 * a TCP connection on port 7 (Echo) of the destination host.
483 * <p>
484 * The timeout value, in milliseconds, indicates the maximum amount of time
485 * the try should take. If the operation times out before getting an
486 * answer, the host is deemed unreachable. A negative value will result
487 * in an IllegalArgumentException being thrown.
488 *
489 * @param timeout the time, in milliseconds, before the call aborts
490 * @return a {@code boolean} indicating if the address is reachable.
491 * @throws IOException if a network error occurs
492 * @throws IllegalArgumentException if {@code timeout} is negative.
493 * @since 1.5
494 */
495 public boolean isReachable(int timeout) throws IOException {
496 return isReachable(null, 0 , timeout);
497 }
498
499 /**
500 * Test whether that address is reachable. Best effort is made by the
501 * implementation to try to reach the host, but firewalls and server
502 * configuration may block requests resulting in a unreachable status
503 * while some specific ports may be accessible.
504 * A typical implementation will use ICMP ECHO REQUESTs if the
505 * privilege can be obtained, otherwise it will try to establish
506 * a TCP connection on port 7 (Echo) of the destination host.
507 * <p>
508 * The {@code network interface} and {@code ttl} parameters
509 * let the caller specify which network interface the test will go through
510 * and the maximum number of hops the packets should go through.
511 * A negative value for the {@code ttl} will result in an
512 * IllegalArgumentException being thrown.
513 * <p>
514 * The timeout value, in milliseconds, indicates the maximum amount of time
515 * the try should take. If the operation times out before getting an
516 * answer, the host is deemed unreachable. A negative value will result
517 * in an IllegalArgumentException being thrown.
518 *
519 * @param netif the NetworkInterface through which the
520 * test will be done, or null for any interface
521 * @param ttl the maximum numbers of hops to try or 0 for the
522 * default
523 * @param timeout the time, in milliseconds, before the call aborts
524 * @throws IllegalArgumentException if either {@code timeout}
525 * or {@code ttl} are negative.
526 * @return a {@code boolean}indicating if the address is reachable.
527 * @throws IOException if a network error occurs
528 * @since 1.5
529 */
530 public boolean isReachable(NetworkInterface netif, int ttl,
531 int timeout) throws IOException {
532 if (ttl < 0)
533 throw new IllegalArgumentException("ttl can't be negative");
534 if (timeout < 0)
535 throw new IllegalArgumentException("timeout can't be negative");
536
537 return impl.isReachable(this, timeout, netif, ttl);
538 }
539
540 /**
541 * Gets the host name for this IP address.
542 *
543 * <p>If this InetAddress was created with a host name,
544 * this host name will be remembered and returned;
545 * otherwise, a reverse name lookup will be performed
546 * and the result will be returned based on the system
547 * configured name lookup service. If a lookup of the name service
548 * is required, call
549 * {@link #getCanonicalHostName() getCanonicalHostName}.
550 *
551 * <p>If there is a security manager, its
552 * {@code checkConnect} method is first called
553 * with the hostname and {@code -1}
554 * as its arguments to see if the operation is allowed.
555 * If the operation is not allowed, it will return
556 * the textual representation of the IP address.
557 *
558 * @return the host name for this IP address, or if the operation
559 * is not allowed by the security check, the textual
560 * representation of the IP address.
561 *
562 * @see InetAddress#getCanonicalHostName
563 * @see SecurityManager#checkConnect
564 */
565 public String getHostName() {
566 return getHostName(true);
567 }
568
569 /**
570 * Returns the hostname for this address.
571 * If the host is equal to null, then this address refers to any
572 * of the local machine's available network addresses.
573 * this is package private so SocketPermission can make calls into
574 * here without a security check.
575 *
576 * <p>If there is a security manager, this method first
577 * calls its {@code checkConnect} method
578 * with the hostname and {@code -1}
579 * as its arguments to see if the calling code is allowed to know
580 * the hostname for this IP address, i.e., to connect to the host.
581 * If the operation is not allowed, it will return
582 * the textual representation of the IP address.
583 *
584 * @return the host name for this IP address, or if the operation
585 * is not allowed by the security check, the textual
586 * representation of the IP address.
587 *
588 * @param check make security check if true
589 *
590 * @see SecurityManager#checkConnect
591 */
592 String getHostName(boolean check) {
593 if (holder().getHostName() == null) {
594 holder().hostName = InetAddress.getHostFromNameService(this, check);
595 }
596 return holder().getHostName();
597 }
598
599 /**
600 * Gets the fully qualified domain name for this IP address.
601 * Best effort method, meaning we may not be able to return
602 * the FQDN depending on the underlying system configuration.
603 *
604 * <p>If there is a security manager, this method first
605 * calls its {@code checkConnect} method
606 * with the hostname and {@code -1}
607 * as its arguments to see if the calling code is allowed to know
608 * the hostname for this IP address, i.e., to connect to the host.
609 * If the operation is not allowed, it will return
610 * the textual representation of the IP address.
611 *
612 * @return the fully qualified domain name for this IP address,
613 * or if the operation is not allowed by the security check,
614 * the textual representation of the IP address.
615 *
616 * @see SecurityManager#checkConnect
617 *
618 * @since 1.4
619 */
620 public String getCanonicalHostName() {
621 if (canonicalHostName == null) {
622 canonicalHostName =
623 InetAddress.getHostFromNameService(this, true);
624 }
625 return canonicalHostName;
626 }
627
628 /**
629 * Returns the hostname for this address.
630 *
631 * <p>If there is a security manager, this method first
632 * calls its {@code checkConnect} method
633 * with the hostname and {@code -1}
634 * as its arguments to see if the calling code is allowed to know
635 * the hostname for this IP address, i.e., to connect to the host.
636 * If the operation is not allowed, it will return
637 * the textual representation of the IP address.
638 *
639 * @return the host name for this IP address, or if the operation
640 * is not allowed by the security check, the textual
641 * representation of the IP address.
642 *
643 * @param check make security check if true
644 *
645 * @see SecurityManager#checkConnect
646 */
647 private static String getHostFromNameService(InetAddress addr, boolean check) {
648 String host = null;
649 try {
650 // first lookup the hostname
651 host = nameService.getHostByAddr(addr.getAddress());
652
653 /* check to see if calling code is allowed to know
654 * the hostname for this IP address, ie, connect to the host
655 */
656 if (check) {
657 SecurityManager sec = System.getSecurityManager();
658 if (sec != null) {
659 sec.checkConnect(host, -1);
660 }
661 }
662
663 /* now get all the IP addresses for this hostname,
664 * and make sure one of them matches the original IP
665 * address. We do this to try and prevent spoofing.
666 */
667
668 InetAddress[] arr = InetAddress.getAllByName0(host, check);
669 boolean ok = false;
670
671 if(arr != null) {
672 for(int i = 0; !ok && i < arr.length; i++) {
673 ok = addr.equals(arr[i]);
674 }
675 }
676
677 //XXX: if it looks a spoof just return the address?
678 if (!ok) {
679 host = addr.getHostAddress();
680 return host;
681 }
682 } catch (SecurityException e) {
683 host = addr.getHostAddress();
684 } catch (UnknownHostException e) {
685 host = addr.getHostAddress();
686 // let next provider resolve the hostname
687 }
688 return host;
689 }
690
691 /**
692 * Returns the raw IP address of this {@code InetAddress}
693 * object. The result is in network byte order: the highest order
694 * byte of the address is in {@code getAddress()[0]}.
695 *
696 * @return the raw IP address of this object.
697 */
698 public byte[] getAddress() {
699 return null;
700 }
701
702 /**
703 * Returns the IP address string in textual presentation.
704 *
705 * @return the raw IP address in a string format.
706 * @since 1.0.2
707 */
708 public String getHostAddress() {
709 return null;
710 }
711
712 /**
713 * Returns a hashcode for this IP address.
714 *
715 * @return a hash code value for this IP address.
716 */
717 public int hashCode() {
718 return -1;
719 }
720
721 /**
722 * Compares this object against the specified object.
723 * The result is {@code true} if and only if the argument is
724 * not {@code null} and it represents the same IP address as
725 * this object.
726 * <p>
727 * Two instances of {@code InetAddress} represent the same IP
728 * address if the length of the byte arrays returned by
729 * {@code getAddress} is the same for both, and each of the
730 * array components is the same for the byte arrays.
731 *
732 * @param obj the object to compare against.
733 * @return {@code true} if the objects are the same;
734 * {@code false} otherwise.
735 * @see java.net.InetAddress#getAddress()
736 */
737 public boolean equals(Object obj) {
738 return false;
739 }
740
741 /**
742 * Converts this IP address to a {@code String}. The
743 * string returned is of the form: hostname / literal IP
744 * address.
745 *
746 * If the host name is unresolved, no reverse name service lookup
747 * is performed. The hostname part will be represented by an empty string.
748 *
749 * @return a string representation of this IP address.
750 */
751 public String toString() {
752 String hostName = holder().getHostName();
753 return Objects.toString(hostName, "")
754 + "/" + getHostAddress();
755 }
756
757 // mapping from host name to Addresses - either NameServiceAddresses (while
758 // still being looked-up by NameService(s)) or CachedAddresses when cached
759 private static final ConcurrentMap<String, Addresses> cache =
760 new ConcurrentHashMap<>();
761
762 // CachedAddresses that have to expire are kept ordered in this NavigableSet
763 // which is scanned on each access
764 private static final NavigableSet<CachedAddresses> expirySet =
765 new ConcurrentSkipListSet<>();
766
767 // common interface
768 private interface Addresses {
769 InetAddress[] get() throws UnknownHostException;
770 }
771
772 // a holder for cached addresses with required metadata
773 private static final class CachedAddresses implements Addresses, Comparable<CachedAddresses> {
774 private static final AtomicLong seq = new AtomicLong();
775 final String host;
776 final InetAddress[] inetAddresses;
777 final long expiryTime; // time of expiry (in terms of System.nanoTime())
778 final long id = seq.incrementAndGet(); // each instance is unique
779
780 CachedAddresses(String host, InetAddress[] inetAddresses, long expiryTime) {
781 this.host = host;
782 this.inetAddresses = inetAddresses;
783 this.expiryTime = expiryTime;
784 }
785
786 @Override
787 public InetAddress[] get() throws UnknownHostException {
788 if (inetAddresses == null) {
789 throw new UnknownHostException(host);
790 }
791 return inetAddresses;
792 }
793
794 @Override
795 public int compareTo(CachedAddresses other) {
796 // natural order is expiry time -
797 // compare difference of expiry times rather than
798 // expiry times directly, to avoid possible overflow.
799 // (see System.nanoTime() recommendations...)
800 long diff = this.expiryTime - other.expiryTime;
801 if (diff < 0L) return -1;
802 if (diff > 0L) return 1;
803 // ties are broken using unique id
804 return Long.compare(this.id, other.id);
805 }
806 }
807
808 // a name service lookup based Addresses implementation which replaces itself
809 // in cache when the result is obtained
810 private static final class NameServiceAddresses implements Addresses {
811 private final String host;
812 private final InetAddress reqAddr;
813
814 NameServiceAddresses(String host, InetAddress reqAddr) {
815 this.host = host;
816 this.reqAddr = reqAddr;
817 }
818
819 @Override
820 public InetAddress[] get() throws UnknownHostException {
821 Addresses addresses;
822 // only one thread is doing lookup to name service
823 // for particular host at any time.
824 synchronized (this) {
825 // re-check that we are still us + re-install us if slot empty
826 addresses = cache.putIfAbsent(host, this);
827 if (addresses == null) {
828 // this can happen when we were replaced by CachedAddresses in
829 // some other thread, then CachedAddresses expired and were
830 // removed from cache while we were waiting for lock...
831 addresses = this;
832 }
833 // still us ?
834 if (addresses == this) {
835 // lookup name services
836 InetAddress[] inetAddresses;
837 UnknownHostException ex;
838 int cachePolicy;
839 try {
840 inetAddresses = getAddressesFromNameService(host, reqAddr);
841 ex = null;
842 cachePolicy = InetAddressCachePolicy.get();
843 } catch (UnknownHostException uhe) {
844 inetAddresses = null;
845 ex = uhe;
846 cachePolicy = InetAddressCachePolicy.getNegative();
847 }
848 // remove or replace us with cached addresses according to cachePolicy
849 if (cachePolicy == InetAddressCachePolicy.NEVER) {
850 cache.remove(host, this);
851 } else {
852 CachedAddresses cachedAddresses = new CachedAddresses(
853 host,
854 inetAddresses,
855 cachePolicy == InetAddressCachePolicy.FOREVER
856 ? 0L
857 // cachePolicy is in [s] - we need [ns]
858 : System.nanoTime() + 1000_000_000L * cachePolicy
859 );
860 if (cache.replace(host, this, cachedAddresses) &&
861 cachePolicy != InetAddressCachePolicy.FOREVER) {
862 // schedule expiry
863 expirySet.add(cachedAddresses);
864 }
865 }
866 if (inetAddresses == null) {
867 throw ex == null ? new UnknownHostException(host) : ex;
868 }
869 return inetAddresses;
870 }
871 // else addresses != this
872 }
873 // delegate to different addresses when we are already replaced
874 // but outside of synchronized block to avoid any chance of dead-locking
875 return addresses.get();
876 }
877 }
878
879 /**
880 * NameService provides host and address lookup service
881 *
882 * @since 9
883 */
884 private interface NameService {
885
886 /**
887 * Lookup a host mapping by name. Retrieve the IP addresses
888 * associated with a host
889 *
890 * @param host the specified hostname
891 * @return array of IP addresses for the requested host
892 * @throws UnknownHostException
893 * if no IP address for the {@code host} could be found
894 */
895 InetAddress[] lookupAllHostAddr(String host)
896 throws UnknownHostException;
897
898 /**
899 * Lookup the host corresponding to the IP address provided
900 *
901 * @param addr byte array representing an IP address
902 * @return {@code String} representing the host name mapping
903 * @throws UnknownHostException
904 * if no host found for the specified IP address
905 */
906 String getHostByAddr(byte[] addr) throws UnknownHostException;
907
908 }
909
910 /**
911 * The default NameService implementation, which delegates to the underlying
912 * OS network libraries to resolve host address mappings.
913 *
914 * @since 9
915 */
916 private static final class PlatformNameService implements NameService {
917
918 public InetAddress[] lookupAllHostAddr(String host)
919 throws UnknownHostException
920 {
921 return impl.lookupAllHostAddr(host);
922 }
923
924 public String getHostByAddr(byte[] addr)
925 throws UnknownHostException
926 {
927 return impl.getHostByAddr(addr);
928 }
929 }
930
931 /**
932 * The HostsFileNameService provides host address mapping
933 * by reading the entries in a hosts file, which is specified by
934 * {@code jdk.net.hosts.file} system property
935 *
936 * <p>The file format is that which corresponds with the /etc/hosts file
937 * IP Address host alias list.
938 *
939 * <p>When the file lookup is enabled it replaces the default NameService
940 * implementation
941 *
942 * @since 9
943 */
944 private static final class HostsFileNameService implements NameService {
945
946 private final String hostsFile;
947
948 public HostsFileNameService (String hostsFileName) {
949 this.hostsFile = hostsFileName;
950 }
951
952 private String addrToString(byte addr[]) {
953 String stringifiedAddress = null;
954
955 if (addr.length == Inet4Address.INADDRSZ) {
956 stringifiedAddress = Inet4Address.numericToTextFormat(addr);
957 } else { // treat as an IPV6 jobby
958 byte[] newAddr
959 = IPAddressUtil.convertFromIPv4MappedAddress(addr);
960 if (newAddr != null) {
961 stringifiedAddress = Inet4Address.numericToTextFormat(addr);
962 } else {
963 stringifiedAddress = Inet6Address.numericToTextFormat(addr);
964 }
965 }
966 return stringifiedAddress;
967 }
968
969 /**
970 * Lookup the host name corresponding to the IP address provided.
971 * Search the configured host file a host name corresponding to
972 * the specified IP address.
973 *
974 * @param addr byte array representing an IP address
975 * @return {@code String} representing the host name mapping
976 * @throws UnknownHostException
977 * if no host found for the specified IP address
978 */
979 @Override
980 public String getHostByAddr(byte[] addr) throws UnknownHostException {
981 String hostEntry;
982 String host = null;
983
984 String addrString = addrToString(addr);
985 try (Scanner hostsFileScanner = new Scanner(new File(hostsFile), "UTF-8")) {
986 while (hostsFileScanner.hasNextLine()) {
987 hostEntry = hostsFileScanner.nextLine();
988 if (!hostEntry.startsWith("#")) {
989 hostEntry = removeComments(hostEntry);
990 if (hostEntry.contains(addrString)) {
991 host = extractHost(hostEntry, addrString);
992 if (host != null) {
993 break;
994 }
995 }
996 }
997 }
998 } catch (FileNotFoundException e) {
999 throw new UnknownHostException("Unable to resolve address "
1000 + addrString + " as hosts file " + hostsFile
1001 + " not found ");
1002 }
1003
1004 if ((host == null) || (host.equals("")) || (host.equals(" "))) {
1005 throw new UnknownHostException("Requested address "
1006 + addrString
1007 + " resolves to an invalid entry in hosts file "
1008 + hostsFile);
1009 }
1010 return host;
1011 }
1012
1013 /**
1014 * <p>Lookup a host mapping by name. Retrieve the IP addresses
1015 * associated with a host.
1016 *
1017 * <p>Search the configured hosts file for the addresses assocaited with
1018 * with the specified host name.
1019 *
1020 * @param host the specified hostname
1021 * @return array of IP addresses for the requested host
1022 * @throws UnknownHostException
1023 * if no IP address for the {@code host} could be found
1024 */
1025 public InetAddress[] lookupAllHostAddr(String host)
1026 throws UnknownHostException {
1027 String hostEntry;
1028 String addrStr = null;
1029 InetAddress[] res = null;
1030 byte addr[] = new byte[4];
1031 ArrayList<InetAddress> inetAddresses = null;
1032
1033 // lookup the file and create a list InetAddress for the specfied host
1034 try (Scanner hostsFileScanner = new Scanner(new File(hostsFile), "UTF-8")) {
1035 while (hostsFileScanner.hasNextLine()) {
1036 hostEntry = hostsFileScanner.nextLine();
1037 if (!hostEntry.startsWith("#")) {
1038 hostEntry = removeComments(hostEntry);
1039 if (hostEntry.contains(host)) {
1040 addrStr = extractHostAddr(hostEntry, host);
1041 if ((addrStr != null) && (!addrStr.equals(""))) {
1042 addr = createAddressByteArray(addrStr);
1043 if (inetAddresses == null) {
1044 inetAddresses = new ArrayList<>(1);
1045 }
1046 if (addr != null) {
1047 inetAddresses.add(InetAddress.getByAddress(host, addr));
1048 }
1049 }
1050 }
1051 }
1052 }
1053 } catch (FileNotFoundException e) {
1054 throw new UnknownHostException("Unable to resolve host " + host
1055 + " as hosts file " + hostsFile + " not found ");
1056 }
1057
1058 if (inetAddresses != null) {
1059 res = inetAddresses.toArray(new InetAddress[inetAddresses.size()]);
1060 } else {
1061 throw new UnknownHostException("Unable to resolve host " + host
1062 + " in hosts file " + hostsFile);
1063 }
1064 return res;
1065 }
1066
1067 private String removeComments(String hostsEntry) {
1068 String filteredEntry = hostsEntry;
1069 int hashIndex;
1070
1071 if ((hashIndex = hostsEntry.indexOf("#")) != -1) {
1072 filteredEntry = hostsEntry.substring(0, hashIndex);
1073 }
1074 return filteredEntry;
1075 }
1076
1077 private byte [] createAddressByteArray(String addrStr) {
1078 byte[] addrArray;
1079 // check if IPV4 address - most likely
1080 addrArray = IPAddressUtil.textToNumericFormatV4(addrStr);
1081 if (addrArray == null) {
1082 addrArray = IPAddressUtil.textToNumericFormatV6(addrStr);
1083 }
1084 return addrArray;
1085 }
1086
1087 /** host to ip address mapping */
1088 private String extractHostAddr(String hostEntry, String host) {
1089 String[] mapping = hostEntry.split("\\s+");
1090 String hostAddr = null;
1091
1092 if (mapping.length >= 2) {
1093 // look at the host aliases
1094 for (int i = 1; i < mapping.length; i++) {
1095 if (mapping[i].equalsIgnoreCase(host)) {
1096 hostAddr = mapping[0];
1097 }
1098 }
1099 }
1100 return hostAddr;
1101 }
1102
1103 /**
1104 * IP Address to host mapping
1105 * use first host alias in list
1106 */
1107 private String extractHost(String hostEntry, String addrString) {
1108 String[] mapping = hostEntry.split("\\s+");
1109 String host = null;
1110
1111 if (mapping.length >= 2) {
1112 if (mapping[0].equalsIgnoreCase(addrString)) {
1113 host = mapping[1];
1114 }
1115 }
1116 return host;
1117 }
1118 }
1119
1120 static final InetAddressImpl impl;
1121
1122 static {
1123 // create the impl
1124 impl = InetAddressImplFactory.create();
1125
1126 // create name service
1127 nameService = createNameService();
1128 }
1129
1130 /**
1131 * Create an instance of the NameService interface based on
1132 * the setting of the {@codejdk.net.hosts.file} system property.
1133 *
1134 * <p>The default NameService is the PlatformNameService, which typically
1135 * delegates name and address resolution calls to the underlying
1136 * OS network libraries.
1137 *
1138 * <p> A HostsFileNameService is created if the {@code jdk.net.hosts.file}
1139 * system property is set. If the specified file doesn't exist, the name or
1140 * address lookup will result in an UnknownHostException. Thus, non existent
1141 * hosts file is handled as if the file is empty.
1142 *
1143 * @return a NameService
1144 */
1145 private static NameService createNameService() {
1146
1147 String hostsFileName =
1148 GetPropertyAction.privilegedGetProperty("jdk.net.hosts.file");
1149 NameService theNameService;
1150 if (hostsFileName != null) {
1151 theNameService = new HostsFileNameService(hostsFileName);
1152 } else {
1153 theNameService = new PlatformNameService();
1154 }
1155 return theNameService;
1156 }
1157
1158 /**
1159 * Creates an InetAddress based on the provided host name and IP address.
1160 * No name service is checked for the validity of the address.
1161 *
1162 * <p> The host name can either be a machine name, such as
1163 * "{@code java.sun.com}", or a textual representation of its IP
1164 * address.
1165 * <p> No validity checking is done on the host name either.
1166 *
1167 * <p> If addr specifies an IPv4 address an instance of Inet4Address
1168 * will be returned; otherwise, an instance of Inet6Address
1169 * will be returned.
1170 *
1171 * <p> IPv4 address byte array must be 4 bytes long and IPv6 byte array
1172 * must be 16 bytes long
1173 *
1174 * @param host the specified host
1175 * @param addr the raw IP address in network byte order
1176 * @return an InetAddress object created from the raw IP address.
1177 * @exception UnknownHostException if IP address is of illegal length
1178 * @since 1.4
1179 */
1180 public static InetAddress getByAddress(String host, byte[] addr)
1181 throws UnknownHostException {
1182 if (host != null && host.length() > 0 && host.charAt(0) == '[') {
1183 if (host.charAt(host.length()-1) == ']') {
1184 host = host.substring(1, host.length() -1);
1185 }
1186 }
1187 if (addr != null) {
1188 if (addr.length == Inet4Address.INADDRSZ) {
1189 return new Inet4Address(host, addr);
1190 } else if (addr.length == Inet6Address.INADDRSZ) {
1191 byte[] newAddr
1192 = IPAddressUtil.convertFromIPv4MappedAddress(addr);
1193 if (newAddr != null) {
1194 return new Inet4Address(host, newAddr);
1195 } else {
1196 return new Inet6Address(host, addr);
1197 }
1198 }
1199 }
1200 throw new UnknownHostException("addr is of illegal length");
1201 }
1202
1203
1204 /**
1205 * Determines the IP address of a host, given the host's name.
1206 *
1207 * <p> The host name can either be a machine name, such as
1208 * "{@code java.sun.com}", or a textual representation of its
1209 * IP address. If a literal IP address is supplied, only the
1210 * validity of the address format is checked.
1211 *
1212 * <p> For {@code host} specified in literal IPv6 address,
1213 * either the form defined in RFC 2732 or the literal IPv6 address
1214 * format defined in RFC 2373 is accepted. IPv6 scoped addresses are also
1215 * supported. See <a href="Inet6Address.html#scoped">here</a> for a description of IPv6
1216 * scoped addresses.
1217 *
1218 * <p> If the host is {@code null} then an {@code InetAddress}
1219 * representing an address of the loopback interface is returned.
1220 * See <a href="http://www.ietf.org/rfc/rfc3330.txt">RFC 3330</a>
1221 * section 2 and <a href="http://www.ietf.org/rfc/rfc2373.txt">RFC 2373</a>
1222 * section 2.5.3. </p>
1223 *
1224 * @param host the specified host, or {@code null}.
1225 * @return an IP address for the given host name.
1226 * @exception UnknownHostException if no IP address for the
1227 * {@code host} could be found, or if a scope_id was specified
1228 * for a global IPv6 address.
1229 * @exception SecurityException if a security manager exists
1230 * and its checkConnect method doesn't allow the operation
1231 */
1232 public static InetAddress getByName(String host)
1233 throws UnknownHostException {
1234 return InetAddress.getAllByName(host)[0];
1235 }
1236
1237 // called from deployment cache manager
1238 private static InetAddress getByName(String host, InetAddress reqAddr)
1239 throws UnknownHostException {
1240 return InetAddress.getAllByName(host, reqAddr)[0];
1241 }
1242
1243 /**
1244 * Given the name of a host, returns an array of its IP addresses,
1245 * based on the configured name service on the system.
1246 *
1247 * <p> The host name can either be a machine name, such as
1248 * "{@code java.sun.com}", or a textual representation of its IP
1249 * address. If a literal IP address is supplied, only the
1250 * validity of the address format is checked.
1251 *
1252 * <p> For {@code host} specified in <i>literal IPv6 address</i>,
1253 * either the form defined in RFC 2732 or the literal IPv6 address
1254 * format defined in RFC 2373 is accepted. A literal IPv6 address may
1255 * also be qualified by appending a scoped zone identifier or scope_id.
1256 * The syntax and usage of scope_ids is described
1257 * <a href="Inet6Address.html#scoped">here</a>.
1258 * <p> If the host is {@code null} then an {@code InetAddress}
1259 * representing an address of the loopback interface is returned.
1260 * See <a href="http://www.ietf.org/rfc/rfc3330.txt">RFC 3330</a>
1261 * section 2 and <a href="http://www.ietf.org/rfc/rfc2373.txt">RFC 2373</a>
1262 * section 2.5.3. </p>
1263 *
1264 * <p> If there is a security manager and {@code host} is not
1265 * null and {@code host.length() } is not equal to zero, the
1266 * security manager's
1267 * {@code checkConnect} method is called
1268 * with the hostname and {@code -1}
1269 * as its arguments to see if the operation is allowed.
1270 *
1271 * @param host the name of the host, or {@code null}.
1272 * @return an array of all the IP addresses for a given host name.
1273 *
1274 * @exception UnknownHostException if no IP address for the
1275 * {@code host} could be found, or if a scope_id was specified
1276 * for a global IPv6 address.
1277 * @exception SecurityException if a security manager exists and its
1278 * {@code checkConnect} method doesn't allow the operation.
1279 *
1280 * @see SecurityManager#checkConnect
1281 */
1282 public static InetAddress[] getAllByName(String host)
1283 throws UnknownHostException {
1284 return getAllByName(host, null);
1285 }
1286
1287 private static InetAddress[] getAllByName(String host, InetAddress reqAddr)
1288 throws UnknownHostException {
1289
1290 if (host == null || host.length() == 0) {
1291 InetAddress[] ret = new InetAddress[1];
1292 ret[0] = impl.loopbackAddress();
1293 return ret;
1294 }
1295
1296 boolean ipv6Expected = false;
1297 if (host.charAt(0) == '[') {
1298 // This is supposed to be an IPv6 literal
1299 if (host.length() > 2 && host.charAt(host.length()-1) == ']') {
1300 host = host.substring(1, host.length() -1);
1301 ipv6Expected = true;
1302 } else {
1303 // This was supposed to be a IPv6 address, but it's not!
1304 throw new UnknownHostException(host + ": invalid IPv6 address");
1305 }
1306 }
1307
1308 // if host is an IP address, we won't do further lookup
1309 if (Character.digit(host.charAt(0), 16) != -1
1310 || (host.charAt(0) == ':')) {
1311 byte[] addr = null;
1312 int numericZone = -1;
1313 String ifname = null;
1314 // see if it is IPv4 address
1315 addr = IPAddressUtil.textToNumericFormatV4(host);
1316 if (addr == null) {
1317 // This is supposed to be an IPv6 literal
1318 // Check if a numeric or string zone id is present
1319 int pos;
1320 if ((pos=host.indexOf ('%')) != -1) {
1321 numericZone = checkNumericZone (host);
1322 if (numericZone == -1) { /* remainder of string must be an ifname */
1323 ifname = host.substring (pos+1);
1324 }
1325 }
1326 if ((addr = IPAddressUtil.textToNumericFormatV6(host)) == null && host.contains(":")) {
1327 throw new UnknownHostException(host + ": invalid IPv6 address");
1328 }
1329 } else if (ipv6Expected) {
1330 // Means an IPv4 litteral between brackets!
1331 throw new UnknownHostException("["+host+"]");
1332 }
1333 InetAddress[] ret = new InetAddress[1];
1334 if(addr != null) {
1335 if (addr.length == Inet4Address.INADDRSZ) {
1336 ret[0] = new Inet4Address(null, addr);
1337 } else {
1338 if (ifname != null) {
1339 ret[0] = new Inet6Address(null, addr, ifname);
1340 } else {
1341 ret[0] = new Inet6Address(null, addr, numericZone);
1342 }
1343 }
1344 return ret;
1345 }
1346 } else if (ipv6Expected) {
1347 // We were expecting an IPv6 Litteral, but got something else
1348 throw new UnknownHostException("["+host+"]");
1349 }
1350 return getAllByName0(host, reqAddr, true, true);
1351 }
1352
1353 /**
1354 * Returns the loopback address.
1355 * <p>
1356 * The InetAddress returned will represent the IPv4
1357 * loopback address, 127.0.0.1, or the IPv6 loopback
1358 * address, ::1. The IPv4 loopback address returned
1359 * is only one of many in the form 127.*.*.*
1360 *
1361 * @return the InetAddress loopback instance.
1362 * @since 1.7
1363 */
1364 public static InetAddress getLoopbackAddress() {
1365 return impl.loopbackAddress();
1366 }
1367
1368
1369 /**
1370 * check if the literal address string has %nn appended
1371 * returns -1 if not, or the numeric value otherwise.
1372 *
1373 * %nn may also be a string that represents the displayName of
1374 * a currently available NetworkInterface.
1375 */
1376 private static int checkNumericZone (String s) throws UnknownHostException {
1377 int percent = s.indexOf ('%');
1378 int slen = s.length();
1379 int digit, zone=0;
1380 if (percent == -1) {
1381 return -1;
1382 }
1383 for (int i=percent+1; i<slen; i++) {
1384 char c = s.charAt(i);
1385 if (c == ']') {
1386 if (i == percent+1) {
1387 /* empty per-cent field */
1388 return -1;
1389 }
1390 break;
1391 }
1392 if ((digit = Character.digit (c, 10)) < 0) {
1393 return -1;
1394 }
1395 zone = (zone * 10) + digit;
1396 }
1397 return zone;
1398 }
1399
1400 private static InetAddress[] getAllByName0 (String host)
1401 throws UnknownHostException
1402 {
1403 return getAllByName0(host, true);
1404 }
1405
1406 /**
1407 * package private so SocketPermission can call it
1408 */
1409 static InetAddress[] getAllByName0 (String host, boolean check)
1410 throws UnknownHostException {
1411 return getAllByName0 (host, null, check, true);
1412 }
1413
1414 /**
1415 * Designated lookup method.
1416 *
1417 * @param host host name to look up
1418 * @param reqAddr requested address to be the 1st in returned array
1419 * @param check perform security check
1420 * @param useCache use cached value if not expired else always
1421 * perform name service lookup (and cache the result)
1422 * @return array of InetAddress(es)
1423 * @throws UnknownHostException if host name is not found
1424 */
1425 private static InetAddress[] getAllByName0(String host,
1426 InetAddress reqAddr,
1427 boolean check,
1428 boolean useCache)
1429 throws UnknownHostException {
1430
1431 /* If it gets here it is presumed to be a hostname */
1432
1433 /* make sure the connection to the host is allowed, before we
1434 * give out a hostname
1435 */
1436 if (check) {
1437 SecurityManager security = System.getSecurityManager();
1438 if (security != null) {
1439 security.checkConnect(host, -1);
1440 }
1441 }
1442
1443 // remove expired addresses from cache - expirySet keeps them ordered
1444 // by expiry time so we only need to iterate the prefix of the NavigableSet...
1445 long now = System.nanoTime();
1446 for (CachedAddresses caddrs : expirySet) {
1447 // compare difference of time instants rather than
1448 // time instants directly, to avoid possible overflow.
1449 // (see System.nanoTime() recommendations...)
1450 if ((caddrs.expiryTime - now) < 0L) {
1451 // ConcurrentSkipListSet uses weakly consistent iterator,
1452 // so removing while iterating is OK...
1453 if (expirySet.remove(caddrs)) {
1454 // ... remove from cache
1455 cache.remove(caddrs.host, caddrs);
1456 }
1457 } else {
1458 // we encountered 1st element that expires in future
1459 break;
1460 }
1461 }
1462
1463 // look-up or remove from cache
1464 Addresses addrs;
1465 if (useCache) {
1466 addrs = cache.get(host);
1467 } else {
1468 addrs = cache.remove(host);
1469 if (addrs != null) {
1470 if (addrs instanceof CachedAddresses) {
1471 // try removing from expirySet too if CachedAddresses
1472 expirySet.remove(addrs);
1473 }
1474 addrs = null;
1475 }
1476 }
1477
1478 if (addrs == null) {
1479 // create a NameServiceAddresses instance which will look up
1480 // the name service and install it within cache...
1481 Addresses oldAddrs = cache.putIfAbsent(
1482 host,
1483 addrs = new NameServiceAddresses(host, reqAddr)
1484 );
1485 if (oldAddrs != null) { // lost putIfAbsent race
1486 addrs = oldAddrs;
1487 }
1488 }
1489
1490 // ask Addresses to get an array of InetAddress(es) and clone it
1491 return addrs.get().clone();
1492 }
1493
1494 static InetAddress[] getAddressesFromNameService(String host, InetAddress reqAddr)
1495 throws UnknownHostException
1496 {
1497 InetAddress[] addresses = null;
1498 UnknownHostException ex = null;
1499
1500 try {
1501 addresses = nameService.lookupAllHostAddr(host);
1502 } catch (UnknownHostException uhe) {
1503 if (host.equalsIgnoreCase("localhost")) {
1504 addresses = new InetAddress[] { impl.loopbackAddress() };
1505 }
1506 else {
1507 ex = uhe;
1508 }
1509 }
1510
1511 if (addresses == null) {
1512 throw ex == null ? new UnknownHostException(host) : ex;
1513 }
1514
1515 // More to do?
1516 if (reqAddr != null && addresses.length > 1 && !addresses[0].equals(reqAddr)) {
1517 // Find it?
1518 int i = 1;
1519 for (; i < addresses.length; i++) {
1520 if (addresses[i].equals(reqAddr)) {
1521 break;
1522 }
1523 }
1524 // Rotate
1525 if (i < addresses.length) {
1526 InetAddress tmp, tmp2 = reqAddr;
1527 for (int j = 0; j < i; j++) {
1528 tmp = addresses[j];
1529 addresses[j] = tmp2;
1530 tmp2 = tmp;
1531 }
1532 addresses[i] = tmp2;
1533 }
1534 }
1535
1536 return addresses;
1537 }
1538
1539 /**
1540 * Returns an {@code InetAddress} object given the raw IP address .
1541 * The argument is in network byte order: the highest order
1542 * byte of the address is in {@code getAddress()[0]}.
1543 *
1544 * <p> This method doesn't block, i.e. no reverse name service lookup
1545 * is performed.
1546 *
1547 * <p> IPv4 address byte array must be 4 bytes long and IPv6 byte array
1548 * must be 16 bytes long
1549 *
1550 * @param addr the raw IP address in network byte order
1551 * @return an InetAddress object created from the raw IP address.
1552 * @exception UnknownHostException if IP address is of illegal length
1553 * @since 1.4
1554 */
1555 public static InetAddress getByAddress(byte[] addr)
1556 throws UnknownHostException {
1557 return getByAddress(null, addr);
1558 }
1559
1560 private static final class CachedLocalHost {
1561 final String host;
1562 final InetAddress addr;
1563 final long expiryTime = System.nanoTime() + 5000_000_000L; // now + 5s;
1564
1565 CachedLocalHost(String host, InetAddress addr) {
1566 this.host = host;
1567 this.addr = addr;
1568 }
1569 }
1570
1571 private static volatile CachedLocalHost cachedLocalHost;
1572
1573 /**
1574 * Returns the address of the local host. This is achieved by retrieving
1575 * the name of the host from the system, then resolving that name into
1576 * an {@code InetAddress}.
1577 *
1578 * <P>Note: The resolved address may be cached for a short period of time.
1579 * </P>
1580 *
1581 * <p>If there is a security manager, its
1582 * {@code checkConnect} method is called
1583 * with the local host name and {@code -1}
1584 * as its arguments to see if the operation is allowed.
1585 * If the operation is not allowed, an InetAddress representing
1586 * the loopback address is returned.
1587 *
1588 * @return the address of the local host.
1589 *
1590 * @exception UnknownHostException if the local host name could not
1591 * be resolved into an address.
1592 *
1593 * @see SecurityManager#checkConnect
1594 * @see java.net.InetAddress#getByName(java.lang.String)
1595 */
1596 public static InetAddress getLocalHost() throws UnknownHostException {
1597
1598 SecurityManager security = System.getSecurityManager();
1599 try {
1600 // is cached data still valid?
1601 CachedLocalHost clh = cachedLocalHost;
1602 if (clh != null && (clh.expiryTime - System.nanoTime()) >= 0L) {
1603 if (security != null) {
1604 security.checkConnect(clh.host, -1);
1605 }
1606 return clh.addr;
1607 }
1608
1609 String local = impl.getLocalHostName();
1610
1611 if (security != null) {
1612 security.checkConnect(local, -1);
1613 }
1614
1615 InetAddress localAddr;
1616 if (local.equals("localhost")) {
1617 // shortcut for "localhost" host name
1618 localAddr = impl.loopbackAddress();
1619 } else {
1620 // call getAllByName0 without security checks and
1621 // without using cached data
1622 try {
1623 localAddr = getAllByName0(local, null, false, false)[0];
1624 } catch (UnknownHostException uhe) {
1625 // Rethrow with a more informative error message.
1626 UnknownHostException uhe2 =
1627 new UnknownHostException(local + ": " +
1628 uhe.getMessage());
1629 uhe2.initCause(uhe);
1630 throw uhe2;
1631 }
1632 }
1633 cachedLocalHost = new CachedLocalHost(local, localAddr);
1634 return localAddr;
1635 } catch (java.lang.SecurityException e) {
1636 return impl.loopbackAddress();
1637 }
1638 }
1639
1640 /**
1641 * Perform class load-time initializations.
1642 */
1643 private static native void init();
1644
1645
1646 /*
1647 * Returns the InetAddress representing anyLocalAddress
1648 * (typically 0.0.0.0 or ::0)
1649 */
1650 static InetAddress anyLocalAddress() {
1651 return impl.anyLocalAddress();
1652 }
1653
1654 /*
1655 * Load and instantiate an underlying impl class
1656 */
1657 static InetAddressImpl loadImpl(String implName) {
1658 Object impl = null;
1659
1660 /*
1661 * Property "impl.prefix" will be prepended to the classname
1662 * of the implementation object we instantiate, to which we
1663 * delegate the real work (like native methods). This
1664 * property can vary across implementations of the java.
1665 * classes. The default is an empty String "".
1666 */
1667 String prefix = GetPropertyAction.privilegedGetProperty("impl.prefix", "");
1668 try {
1669 @SuppressWarnings("deprecation")
1670 Object tmp = Class.forName("java.net." + prefix + implName).newInstance();
1671 impl = tmp;
1672 } catch (ClassNotFoundException e) {
1673 System.err.println("Class not found: java.net." + prefix +
1674 implName + ":\ncheck impl.prefix property " +
1675 "in your properties file.");
1676 } catch (InstantiationException e) {
1677 System.err.println("Could not instantiate: java.net." + prefix +
1678 implName + ":\ncheck impl.prefix property " +
1679 "in your properties file.");
1680 } catch (IllegalAccessException e) {
1681 System.err.println("Cannot access class: java.net." + prefix +
1682 implName + ":\ncheck impl.prefix property " +
1683 "in your properties file.");
1684 }
1685
1686 if (impl == null) {
1687 try {
1688 @SuppressWarnings("deprecation")
1689 Object tmp = Class.forName(implName).newInstance();
1690 impl = tmp;
1691 } catch (Exception e) {
1692 throw new Error("System property impl.prefix incorrect");
1693 }
1694 }
1695
1696 return (InetAddressImpl) impl;
1697 }
1698
1699 private void readObjectNoData (ObjectInputStream s) throws
1700 IOException, ClassNotFoundException {
1701 if (getClass().getClassLoader() != null) {
1702 throw new SecurityException ("invalid address type");
1703 }
1704 }
1705
1706 private static final long FIELDS_OFFSET;
1707 private static final jdk.internal.misc.Unsafe UNSAFE;
1708
1709 static {
1710 try {
1711 jdk.internal.misc.Unsafe unsafe = jdk.internal.misc.Unsafe.getUnsafe();
1712 FIELDS_OFFSET = unsafe.objectFieldOffset(
1713 InetAddress.class.getDeclaredField("holder")
1714 );
1715 UNSAFE = unsafe;
1716 } catch (ReflectiveOperationException e) {
1717 throw new Error(e);
1718 }
1719 }
1720
1721 private void readObject (ObjectInputStream s) throws
1722 IOException, ClassNotFoundException {
1723 if (getClass().getClassLoader() != null) {
1724 throw new SecurityException ("invalid address type");
1725 }
1726 GetField gf = s.readFields();
1727 String host = (String)gf.get("hostName", null);
1728 int address= gf.get("address", 0);
1729 int family= gf.get("family", 0);
1730 InetAddressHolder h = new InetAddressHolder(host, address, family);
1731 UNSAFE.putObject(this, FIELDS_OFFSET, h);
1732 }
1733
1734 /* needed because the serializable fields no longer exist */
1735
1736 /**
1737 * @serialField hostName String
1738 * @serialField address int
1739 * @serialField family int
1740 */
1741 private static final ObjectStreamField[] serialPersistentFields = {
1742 new ObjectStreamField("hostName", String.class),
1743 new ObjectStreamField("address", int.class),
1744 new ObjectStreamField("family", int.class),
1745 };
1746
1747 private void writeObject (ObjectOutputStream s) throws
1748 IOException {
1749 if (getClass().getClassLoader() != null) {
1750 throw new SecurityException ("invalid address type");
1751 }
1752 PutField pf = s.putFields();
1753 pf.put("hostName", holder().getHostName());
1754 pf.put("address", holder().getAddress());
1755 pf.put("family", holder().getFamily());
1756 s.writeFields();
1757 }
1758 }
1759
1760 /*
1761 * Simple factory to create the impl
1762 */
1763 class InetAddressImplFactory {
1764
1765 static InetAddressImpl create() {
1766 return InetAddress.loadImpl(isIPv6Supported() ?
1767 "Inet6AddressImpl" : "Inet4AddressImpl");
1768 }
1769
1770 static native boolean isIPv6Supported();
1771 }