1 /* Copyright (C) 1996-2003, 2004 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Extended from original form by Ulrich Drepper <drepper@cygnus.com>, 1996.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 /* Parts of this file are plain copies of the file `gethtnamadr.c' from
21 the bind package and it has the following copyright. */
24 * ++Copyright++ 1985, 1988, 1993
26 * Copyright (c) 1985, 1988, 1993
27 * The Regents of the University of California. All rights reserved.
29 * Redistribution and use in source and binary forms, with or without
30 * modification, are permitted provided that the following conditions
32 * 1. Redistributions of source code must retain the above copyright
33 * notice, this list of conditions and the following disclaimer.
34 * 2. Redistributions in binary form must reproduce the above copyright
35 * notice, this list of conditions and the following disclaimer in the
36 * documentation and/or other materials provided with the distribution.
37 * 4. Neither the name of the University nor the names of its contributors
38 * may be used to endorse or promote products derived from this software
39 * without specific prior written permission.
41 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
55 * Permission to use, copy, modify, and distribute this software for any
56 * purpose with or without fee is hereby granted, provided that the above
57 * copyright notice and this permission notice appear in all copies, and that
58 * the name of Digital Equipment Corporation not be used in advertising or
59 * publicity pertaining to distribution of the document or software without
60 * specific, written prior permission.
62 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
63 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
64 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
65 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
66 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
67 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
68 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
81 #include <sys/syslog.h>
85 /* Get implementation for some internal functions. */
86 #include <resolv/mapv4v6addr.h>
87 #include <resolv/mapv4v6hostent.h>
91 /* Maximum number of aliases we allow. */
92 #define MAX_NR_ALIASES 48
93 #define MAX_NR_ADDRS 48
96 # define MAXPACKET PACKETSZ
98 # define MAXPACKET 65536
100 /* As per RFC 1034 and 1035 a host name cannot exceed 255 octets in length. */
101 #ifdef MAXHOSTNAMELEN
102 # undef MAXHOSTNAMELEN
104 #define MAXHOSTNAMELEN 256
106 static const char AskedForGot
[] = "\
107 gethostby*.getanswer: asked for \"%s\", got \"%s\"";
110 /* We need this time later. */
111 typedef union querybuf
114 u_char buf
[MAXPACKET
];
117 /* These functions are defined in res_comp.c. */
118 #define NS_MAXCDNAME 255 /* maximum compressed domain name */
119 extern int __ns_name_ntop (const u_char
*, char *, size_t);
120 extern int __ns_name_unpack (const u_char
*, const u_char
*,
121 const u_char
*, u_char
*, size_t);
124 static enum nss_status
getanswer_r (const querybuf
*answer
, int anslen
,
125 const char *qname
, int qtype
,
126 struct hostent
*result
, char *buffer
,
127 size_t buflen
, int *errnop
, int *h_errnop
,
128 int map
, int32_t *ttlp
, char **canonp
);
131 _nss_dns_gethostbyname3_r (const char *name
, int af
, struct hostent
*result
,
132 char *buffer
, size_t buflen
, int *errnop
,
133 int *h_errnop
, int32_t *ttlp
, char **canonp
)
140 querybuf
*orig_host_buffer
;
141 char tmp
[NS_MAXDNAME
];
146 enum nss_status status
;
148 if (__res_maybe_init (&_res
, 0) == -1)
149 return NSS_STATUS_UNAVAIL
;
162 *errnop
= EAFNOSUPPORT
;
163 return NSS_STATUS_UNAVAIL
;
166 result
->h_addrtype
= af
;
167 result
->h_length
= size
;
170 * if there aren't any dots, it could be a user-level alias.
171 * this is also done in res_query() since we are not the only
172 * function that looks up host names.
174 if (strchr (name
, '.') == NULL
175 && (cp
= res_hostalias (&_res
, name
, tmp
, sizeof (tmp
))) != NULL
)
178 host_buffer
.buf
= orig_host_buffer
= (querybuf
*) alloca (1024);
180 n
= __libc_res_nsearch (&_res
, name
, C_IN
, type
, host_buffer
.buf
->buf
,
181 1024, &host_buffer
.ptr
);
184 enum nss_status status
= (errno
== ECONNREFUSED
185 ? NSS_STATUS_UNAVAIL
: NSS_STATUS_NOTFOUND
);
187 if (h_errno
== TRY_AGAIN
)
190 __set_errno (olderr
);
192 /* If we are looking for a IPv6 address and mapping is enabled
193 by having the RES_USE_INET6 bit in _res.options set, we try
195 if (af
== AF_INET6
&& (_res
.options
& RES_USE_INET6
))
196 n
= __libc_res_nsearch (&_res
, name
, C_IN
, T_A
, host_buffer
.buf
->buf
,
197 host_buffer
.buf
!= orig_host_buffer
198 ? MAXPACKET
: 1024, &host_buffer
.ptr
);
202 if (host_buffer
.buf
!= orig_host_buffer
)
203 free (host_buffer
.buf
);
209 result
->h_addrtype
= AF_INET
;
210 result
->h_length
= INADDRSZ
;;
213 status
= getanswer_r (host_buffer
.buf
, n
, name
, type
, result
, buffer
, buflen
,
214 errnop
, h_errnop
, map
, ttlp
, canonp
);
215 if (host_buffer
.buf
!= orig_host_buffer
)
216 free (host_buffer
.buf
);
222 _nss_dns_gethostbyname2_r (const char *name
, int af
, struct hostent
*result
,
223 char *buffer
, size_t buflen
, int *errnop
,
226 return _nss_dns_gethostbyname3_r (name
, af
, result
, buffer
, buflen
, errnop
,
227 h_errnop
, NULL
, NULL
);
232 _nss_dns_gethostbyname_r (const char *name
, struct hostent
*result
,
233 char *buffer
, size_t buflen
, int *errnop
,
236 enum nss_status status
= NSS_STATUS_NOTFOUND
;
238 if (_res
.options
& RES_USE_INET6
)
239 status
= _nss_dns_gethostbyname2_r (name
, AF_INET6
, result
, buffer
,
240 buflen
, errnop
, h_errnop
);
241 if (status
== NSS_STATUS_NOTFOUND
)
242 status
= _nss_dns_gethostbyname2_r (name
, AF_INET
, result
, buffer
,
243 buflen
, errnop
, h_errnop
);
250 _nss_dns_gethostbyaddr_r (const void *addr
, socklen_t len
, int af
,
251 struct hostent
*result
, char *buffer
, size_t buflen
,
252 int *errnop
, int *h_errnop
)
254 static const u_char mapped
[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
255 static const u_char tunnelled
[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
256 static const u_char v6local
[] = { 0,0, 0,1 };
257 const u_char
*uaddr
= (const u_char
*)addr
;
260 char *aliases
[MAX_NR_ALIASES
];
261 unsigned char host_addr
[16]; /* IPv4 or IPv6 */
262 char *h_addr_ptrs
[MAX_NR_ADDRS
+ 1];
264 } *host_data
= (struct host_data
*) buffer
;
270 querybuf
*orig_host_buffer
;
271 char qbuf
[MAXDNAME
+1], *qp
= NULL
;
276 if (__res_maybe_init (&_res
, 0) == -1)
277 return NSS_STATUS_UNAVAIL
;
279 if (af
== AF_INET6
&& len
== IN6ADDRSZ
280 && (memcmp (uaddr
, mapped
, sizeof mapped
) == 0
281 || (memcmp (uaddr
, tunnelled
, sizeof tunnelled
) == 0
282 && memcmp (&uaddr
[sizeof tunnelled
], v6local
, sizeof v6local
))))
285 addr
+= sizeof mapped
;
286 uaddr
+= sizeof mapped
;
300 *errnop
= EAFNOSUPPORT
;
301 *h_errnop
= NETDB_INTERNAL
;
302 return NSS_STATUS_UNAVAIL
;
306 *errnop
= EAFNOSUPPORT
;
307 *h_errnop
= NETDB_INTERNAL
;
308 return NSS_STATUS_UNAVAIL
;
311 host_buffer
.buf
= orig_host_buffer
= (querybuf
*) alloca (1024);
316 sprintf (qbuf
, "%u.%u.%u.%u.in-addr.arpa", (uaddr
[3] & 0xff),
317 (uaddr
[2] & 0xff), (uaddr
[1] & 0xff), (uaddr
[0] & 0xff));
320 /* Only lookup with the byte string format if the user wants it. */
321 if (__builtin_expect (_res
.options
& RES_USEBSTRING
, 0))
323 qp
= stpcpy (qbuf
, "\\[x");
324 for (n
= 0; n
< IN6ADDRSZ
; ++n
)
325 qp
+= sprintf (qp
, "%02hhx", uaddr
[n
]);
326 strcpy (qp
, "].ip6.arpa");
327 n
= __libc_res_nquery (&_res
, qbuf
, C_IN
, T_PTR
,
328 host_buffer
.buf
->buf
, 1024, &host_buffer
.ptr
);
333 for (n
= IN6ADDRSZ
- 1; n
>= 0; n
--)
335 static const char nibblechar
[16] = "0123456789abcdef";
336 *qp
++ = nibblechar
[uaddr
[n
] & 0xf];
338 *qp
++ = nibblechar
[(uaddr
[n
] >> 4) & 0xf];
341 strcpy(qp
, "ip6.arpa");
348 n
= __libc_res_nquery (&_res
, qbuf
, C_IN
, T_PTR
, host_buffer
.buf
->buf
,
349 1024, &host_buffer
.ptr
);
350 if (n
< 0 && af
== AF_INET6
&& (_res
.options
& RES_NOIP6DOTINT
) == 0)
352 strcpy (qp
, "ip6.int");
353 n
= __libc_res_nquery (&_res
, qbuf
, C_IN
, T_PTR
, host_buffer
.buf
->buf
,
354 host_buffer
.buf
!= orig_host_buffer
355 ? MAXPACKET
: 1024, &host_buffer
.ptr
);
360 __set_errno (olderr
);
361 if (host_buffer
.buf
!= orig_host_buffer
)
362 free (host_buffer
.buf
);
363 return errno
== ECONNREFUSED
? NSS_STATUS_UNAVAIL
: NSS_STATUS_NOTFOUND
;
367 status
= getanswer_r (host_buffer
.buf
, n
, qbuf
, T_PTR
, result
, buffer
, buflen
,
368 errnop
, h_errnop
, 0 /* XXX */, NULL
, NULL
);
369 if (host_buffer
.buf
!= orig_host_buffer
)
370 free (host_buffer
.buf
);
371 if (status
!= NSS_STATUS_SUCCESS
)
379 This is
not implemented because it is
not possible to use the current
380 source from bind in a multi
-threaded program
.
383 result
->h_addrtype
= af
;
384 result
->h_length
= len
;
385 memcpy (host_data
->host_addr
, addr
, len
);
386 host_data
->h_addr_ptrs
[0] = (char *) host_data
->host_addr
;
387 host_data
->h_addr_ptrs
[1] = NULL
;
389 /* XXX I think this is wrong. Why should an IPv4 address be
390 converted to IPv6 if the user explicitly asked for IPv4? */
391 if (af
== AF_INET
&& (_res
.options
& RES_USE_INET6
))
393 map_v4v6_address ((char *) host_data
->host_addr
,
394 (char *) host_data
->host_addr
);
395 result
->h_addrtype
= AF_INET6
;
396 result
->h_length
= IN6ADDRSZ
;
399 *h_errnop
= NETDB_SUCCESS
;
400 return NSS_STATUS_SUCCESS
;
404 static void addrsort (char **ap
, int num
);
407 addrsort (char **ap
, int num
)
411 short aval
[MAX_NR_ADDRS
];
415 if (num
> MAX_NR_ADDRS
)
417 for (i
= 0; i
< num
; i
++, p
++)
419 for (j
= 0 ; (unsigned)j
< _res
.nsort
; j
++)
420 if (_res
.sort_list
[j
].addr
.s_addr
==
421 (((struct in_addr
*)(*p
))->s_addr
& _res
.sort_list
[j
].mask
))
424 if (needsort
== 0 && i
> 0 && j
< aval
[i
-1])
430 while (needsort
++ < num
)
431 for (j
= needsort
- 2; j
>= 0; j
--)
432 if (aval
[j
] > aval
[j
+1])
449 static enum nss_status
450 getanswer_r (const querybuf
*answer
, int anslen
, const char *qname
, int qtype
,
451 struct hostent
*result
, char *buffer
, size_t buflen
,
452 int *errnop
, int *h_errnop
, int map
, int32_t *ttlp
, char **canonp
)
456 char *aliases
[MAX_NR_ALIASES
];
457 unsigned char host_addr
[16]; /* IPv4 or IPv6 */
458 char *h_addr_ptrs
[0];
459 } *host_data
= (struct host_data
*) buffer
;
460 int linebuflen
= buflen
- sizeof (struct host_data
);
461 register const HEADER
*hp
;
462 const u_char
*end_of_message
, *cp
;
463 int n
, ancount
, qdcount
;
464 int haveanswer
, had_error
;
465 char *bp
, **ap
, **hap
;
468 int (*name_ok
) (const char *);
469 u_char packtmp
[NS_MAXCDNAME
];
473 if (__builtin_expect (linebuflen
, 0) < 0)
475 /* The buffer is too small. */
478 *h_errnop
= NETDB_INTERNAL
;
479 return NSS_STATUS_TRYAGAIN
;
483 result
->h_name
= NULL
;
484 end_of_message
= answer
->buf
+ anslen
;
496 return NSS_STATUS_UNAVAIL
; /* XXX should be abort(); */
500 * find first satisfactory answer
503 ancount
= ntohs (hp
->ancount
);
504 qdcount
= ntohs (hp
->qdcount
);
505 cp
= answer
->buf
+ HFIXEDSZ
;
506 if (__builtin_expect (qdcount
, 1) != 1)
508 *h_errnop
= NO_RECOVERY
;
509 return NSS_STATUS_UNAVAIL
;
511 if (sizeof (struct host_data
) + (ancount
+ 1) * sizeof (char *) >= buflen
)
513 bp
= (char *) &host_data
->h_addr_ptrs
[ancount
+ 1];
514 linebuflen
-= (ancount
+ 1) * sizeof (char *);
516 n
= __ns_name_unpack (answer
->buf
, end_of_message
, cp
,
517 packtmp
, sizeof packtmp
);
518 if (n
!= -1 && __ns_name_ntop (packtmp
, bp
, linebuflen
) == -1)
520 if (__builtin_expect (errno
, 0) == EMSGSIZE
)
526 if (n
> 0 && bp
[0] == '.')
529 if (n
< 0 || (*name_ok
) (bp
) == 0)
532 *h_errnop
= NO_RECOVERY
;
533 return NSS_STATUS_UNAVAIL
;
537 if (qtype
== T_A
|| qtype
== T_AAAA
)
539 /* res_send() has already verified that the query name is the
540 * same as the one we sent; this just gets the expanded name
541 * (i.e., with the succeeding search-domain tacked on).
543 n
= strlen (bp
) + 1; /* for the \0 */
544 if (n
>= MAXHOSTNAMELEN
)
546 *h_errnop
= NO_RECOVERY
;
548 return NSS_STATUS_TRYAGAIN
;
555 /* The qname can be abbreviated, but h_name is now absolute. */
556 qname
= result
->h_name
;
559 ap
= host_data
->aliases
;
561 result
->h_aliases
= host_data
->aliases
;
562 hap
= host_data
->h_addr_ptrs
;
564 result
->h_addr_list
= host_data
->h_addr_ptrs
;
568 while (ancount
-- > 0 && cp
< end_of_message
&& had_error
== 0)
572 n
= __ns_name_unpack (answer
->buf
, end_of_message
, cp
,
573 packtmp
, sizeof packtmp
);
574 if (n
!= -1 && __ns_name_ntop (packtmp
, bp
, linebuflen
) == -1)
576 if (__builtin_expect (errno
, 0) == EMSGSIZE
)
582 if (n
< 0 || (*name_ok
) (bp
) == 0)
588 type
= ns_get16 (cp
);
589 cp
+= INT16SZ
; /* type */
590 class = ns_get16 (cp
);
591 cp
+= INT16SZ
; /* class */
593 cp
+= INT32SZ
; /* TTL */
595 cp
+= INT16SZ
; /* len */
598 /* XXX - debug? syslog? */
600 continue; /* XXX - had_error++ ? */
603 if ((qtype
==T_A
|| qtype
== T_AAAA
) && type
== T_CNAME
)
605 if (ap
>= &host_data
->aliases
[MAX_NR_ALIASES
- 1])
607 n
= dn_expand (answer
->buf
, end_of_message
, cp
, tbuf
, sizeof tbuf
);
608 if (n
< 0 || (*name_ok
) (tbuf
) == 0)
616 n
= strlen (bp
) + 1; /* For the \0. */
617 if (__builtin_expect (n
, 0) >= MAXHOSTNAMELEN
)
624 /* Get canonical name. */
625 n
= strlen (tbuf
) + 1; /* For the \0. */
626 if (__builtin_expect (n
> linebuflen
, 0))
628 if (__builtin_expect (n
, 0) >= MAXHOSTNAMELEN
)
634 bp
= __mempcpy (bp
, tbuf
, n
); /* Cannot overflow. */
639 if (qtype
== T_PTR
&& type
== T_CNAME
)
641 n
= dn_expand (answer
->buf
, end_of_message
, cp
, tbuf
, sizeof tbuf
);
642 if (n
< 0 || res_dnok (tbuf
) == 0)
648 /* Get canonical name. */
649 n
= strlen (tbuf
) + 1; /* For the \0. */
650 if (__builtin_expect (n
> linebuflen
, 0))
652 if (__builtin_expect (n
, 0) >= MAXHOSTNAMELEN
)
658 bp
= __mempcpy (bp
, tbuf
, n
); /* Cannot overflow. */
662 if (__builtin_expect (type
== T_SIG
, 0)
663 || __builtin_expect (type
== T_KEY
, 0)
664 || __builtin_expect (type
== T_NXT
, 0))
666 /* We don't support DNSSEC yet. For now, ignore the record
667 and send a low priority message to syslog. */
668 syslog (LOG_DEBUG
| LOG_AUTH
,
669 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
670 qname
, p_class (C_IN
), p_type(qtype
), p_type (type
));
675 if (type
== T_A
&& qtype
== T_AAAA
&& map
)
677 else if (__builtin_expect (type
!= qtype
, 0))
679 syslog (LOG_NOTICE
| LOG_AUTH
,
680 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
681 qname
, p_class (C_IN
), p_type (qtype
), p_type (type
));
683 continue; /* XXX - had_error++ ? */
689 if (__strcasecmp (tname
, bp
) != 0)
691 syslog (LOG_NOTICE
| LOG_AUTH
, AskedForGot
, qname
, bp
);
693 continue; /* XXX - had_error++ ? */
696 n
= __ns_name_unpack (answer
->buf
, end_of_message
, cp
,
697 packtmp
, sizeof packtmp
);
698 if (n
!= -1 && __ns_name_ntop (packtmp
, bp
, linebuflen
) == -1)
700 if (__builtin_expect (errno
, 0) == EMSGSIZE
)
706 if (n
< 0 || res_hnok (bp
) == 0)
711 #if MULTI_PTRS_ARE_ALIASES
715 else if (ap
< &host_data
->aliases
[MAXALIASES
-1])
721 n
= strlen (bp
) + 1; /* for the \0 */
722 if (__builtin_expect (n
, 0) >= MAXHOSTNAMELEN
)
735 n
= strlen (bp
) + 1; /* for the \0 */
736 if (n
>= MAXHOSTNAMELEN
)
743 map_v4v6_hostent (result
, &bp
, &linebuflen
);
745 *h_errnop
= NETDB_SUCCESS
;
746 return NSS_STATUS_SUCCESS
;
750 if (__builtin_expect (strcasecmp (result
->h_name
, bp
), 0) != 0)
752 syslog (LOG_NOTICE
| LOG_AUTH
, AskedForGot
, result
->h_name
, bp
);
754 continue; /* XXX - had_error++ ? */
756 if (n
!= result
->h_length
)
765 if (ttlp
!= NULL
&& ttl
!= 0)
770 nn
= strlen (bp
) + 1; /* for the \0 */
775 linebuflen
-= sizeof (align
) - ((u_long
) bp
% sizeof (align
));
776 bp
+= sizeof (align
) - ((u_long
) bp
% sizeof (align
));
778 if (__builtin_expect (n
> linebuflen
, 0))
780 bp
= __mempcpy (*hap
++ = bp
, cp
, n
);
795 #if defined RESOLVSORT
797 * Note: we sort even if host can take only one address
798 * in its return structures - should give it the "best"
799 * address in that case, not some random one
801 if (_res
.nsort
&& haveanswer
> 1 && qtype
== T_A
)
802 addrsort (host_data
->h_addr_ptrs
, haveanswer
);
803 #endif /*RESOLVSORT*/
805 if (result
->h_name
== NULL
)
807 n
= strlen (qname
) + 1; /* For the \0. */
810 if (n
>= MAXHOSTNAMELEN
)
813 bp
= __mempcpy (bp
, qname
, n
); /* Cannot overflow. */
818 map_v4v6_hostent (result
, &bp
, &linebuflen
);
819 *h_errnop
= NETDB_SUCCESS
;
820 return NSS_STATUS_SUCCESS
;
823 *h_errnop
= NO_RECOVERY
;
825 return NSS_STATUS_TRYAGAIN
;