2 * Copyright (c) 1985, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
53 * Permission to use, copy, modify, and distribute this software for any
54 * purpose with or without fee is hereby granted, provided that the above
55 * copyright notice and this permission notice appear in all copies.
57 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
58 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
60 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
61 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
62 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
63 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
67 #if defined(LIBC_SCCS) && !defined(lint)
68 static const char sccsid
[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
69 static const char rcsid
[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixie Exp $";
70 #endif /* LIBC_SCCS and not lint */
76 #include <stdio_ext.h>
81 #include <arpa/inet.h>
82 #include <arpa/nameser.h>
84 #include <netinet/in.h>
85 #include <sys/param.h>
86 #include <sys/socket.h>
88 #include <sys/types.h>
90 #include <not-cancel.h>
92 /* Options. Should all be left alone. */
97 static void res_setoptions (res_state
, const char *, const char *)
101 static const char sort_mask_chars
[] = "/&";
102 #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
103 static u_int32_t
net_mask (struct in_addr
) __THROW
;
106 #if !defined(isascii) /* XXX - could be a function */
107 # define isascii(c) (!(c & 0200))
111 unsigned long long int __res_initstamp attribute_hidden
;
115 * Resolver state default settings.
119 * Set up default settings. If the configuration file exist, the values
120 * there will have precedence. Otherwise, the server address is set to
121 * INADDR_LOOPBACK and the default domain name comes from gethostname.
123 * Return 0 if completes successfully, -1 on error
126 res_ninit(res_state statp
) {
127 extern int __res_vinit(res_state
, int);
129 return (__res_vinit(statp
, 0));
132 libc_hidden_def (__res_ninit
)
135 /* This function has to be reachable by res_data.c but not publically. */
137 __res_vinit(res_state statp
, int preinit
) {
142 int nserv
= 0; /* number of nameservers read from file */
154 statp
->_u
._ext
.initstamp
= __res_initstamp
;
158 statp
->retrans
= RES_TIMEOUT
;
159 statp
->retry
= RES_DFLRETRY
;
160 statp
->options
= RES_DEFAULT
;
161 statp
->id
= res_randomid();
165 statp
->defdname
[0] = '\0';
172 statp
->_u
._ext
.nscount
= 0;
173 for (n
= 0; n
< MAXNS
; n
++)
174 statp
->_u
._ext
.nsaddrs
[n
] = NULL
;
176 /* Allow user to override the local domain definition */
177 if ((cp
= getenv("LOCALDOMAIN")) != NULL
) {
178 (void)strncpy(statp
->defdname
, cp
, sizeof(statp
->defdname
) - 1);
179 statp
->defdname
[sizeof(statp
->defdname
) - 1] = '\0';
183 * Set search list to be blank-separated strings
184 * from rest of env value. Permits users of LOCALDOMAIN
185 * to still have a search list, and anyone to set the
186 * one that they want to use as an individual (even more
187 * important now that the rfc1535 stuff restricts searches)
189 cp
= statp
->defdname
;
192 for (n
= 0; *cp
&& pp
< statp
->dnsrch
+ MAXDNSRCH
; cp
++) {
193 if (*cp
== '\n') /* silly backwards compat */
195 else if (*cp
== ' ' || *cp
== '\t') {
204 /* null terminate last domain if there are excess */
205 while (*cp
!= '\0' && *cp
!= ' ' && *cp
!= '\t' && *cp
!= '\n')
211 #define MATCH(line, name) \
212 (!strncmp(line, name, sizeof(name) - 1) && \
213 (line[sizeof(name) - 1] == ' ' || \
214 line[sizeof(name) - 1] == '\t'))
216 if ((fp
= fopen(_PATH_RESCONF
, "rce")) != NULL
) {
217 /* No threads use this stream. */
218 __fsetlocking (fp
, FSETLOCKING_BYCALLER
);
219 /* read the config file */
220 while (__fgets_unlocked(buf
, sizeof(buf
), fp
) != NULL
) {
222 if (*buf
== ';' || *buf
== '#')
224 /* read default domain name */
225 if (MATCH(buf
, "domain")) {
226 if (haveenv
) /* skip if have from environ */
228 cp
= buf
+ sizeof("domain") - 1;
229 while (*cp
== ' ' || *cp
== '\t')
231 if ((*cp
== '\0') || (*cp
== '\n'))
233 strncpy(statp
->defdname
, cp
, sizeof(statp
->defdname
) - 1);
234 statp
->defdname
[sizeof(statp
->defdname
) - 1] = '\0';
235 if ((cp
= strpbrk(statp
->defdname
, " \t\n")) != NULL
)
240 /* set search list */
241 if (MATCH(buf
, "search")) {
242 if (haveenv
) /* skip if have from environ */
244 cp
= buf
+ sizeof("search") - 1;
245 while (*cp
== ' ' || *cp
== '\t')
247 if ((*cp
== '\0') || (*cp
== '\n'))
249 strncpy(statp
->defdname
, cp
, sizeof(statp
->defdname
) - 1);
250 statp
->defdname
[sizeof(statp
->defdname
) - 1] = '\0';
251 if ((cp
= strchr(statp
->defdname
, '\n')) != NULL
)
254 * Set search list to be blank-separated strings
257 cp
= statp
->defdname
;
260 for (n
= 0; *cp
&& pp
< statp
->dnsrch
+ MAXDNSRCH
; cp
++) {
261 if (*cp
== ' ' || *cp
== '\t') {
269 /* null terminate last domain if there are excess */
270 while (*cp
!= '\0' && *cp
!= ' ' && *cp
!= '\t')
277 /* read nameservers to query */
278 if (MATCH(buf
, "nameserver") && nserv
< MAXNS
) {
281 cp
= buf
+ sizeof("nameserver") - 1;
282 while (*cp
== ' ' || *cp
== '\t')
284 if ((*cp
!= '\0') && (*cp
!= '\n')
285 && __inet_aton(cp
, &a
)) {
286 statp
->nsaddr_list
[nserv
].sin_addr
= a
;
287 statp
->nsaddr_list
[nserv
].sin_family
= AF_INET
;
288 statp
->nsaddr_list
[nserv
].sin_port
=
289 htons(NAMESERVER_PORT
);
296 if ((el
= strpbrk(cp
, " \t\n")) != NULL
)
298 if ((el
= strchr(cp
, SCOPE_DELIMITER
)) != NULL
)
301 (__inet_pton(AF_INET6
, cp
, &a6
) > 0)) {
302 struct sockaddr_in6
*sa6
;
304 sa6
= malloc(sizeof(*sa6
));
306 sa6
->sin6_family
= AF_INET6
;
307 sa6
->sin6_port
= htons(NAMESERVER_PORT
);
308 sa6
->sin6_flowinfo
= 0;
311 if (__glibc_likely (el
== NULL
))
312 sa6
->sin6_scope_id
= 0;
314 int try_numericscope
= 1;
315 if (IN6_IS_ADDR_LINKLOCAL (&a6
)
316 || IN6_IS_ADDR_MC_LINKLOCAL (&a6
)) {
318 = __if_nametoindex (el
+ 1);
319 if (sa6
->sin6_scope_id
!= 0)
320 try_numericscope
= 0;
323 if (try_numericscope
) {
326 = (uint32_t) strtoul (el
+ 1, &end
,
329 sa6
->sin6_scope_id
= 0;
333 statp
->nsaddr_list
[nserv
].sin_family
= 0;
334 statp
->_u
._ext
.nsaddrs
[nserv
] = sa6
;
335 statp
->_u
._ext
.nssocks
[nserv
] = -1;
345 if (MATCH(buf
, "sortlist")) {
348 cp
= buf
+ sizeof("sortlist") - 1;
349 while (nsort
< MAXRESOLVSORT
) {
350 while (*cp
== ' ' || *cp
== '\t')
352 if (*cp
== '\0' || *cp
== '\n' || *cp
== ';')
355 while (*cp
&& !ISSORTMASK(*cp
) && *cp
!= ';' &&
356 isascii(*cp
) && !isspace(*cp
))
360 if (__inet_aton(net
, &a
)) {
361 statp
->sort_list
[nsort
].addr
= a
;
365 while (*cp
&& *cp
!= ';' &&
366 isascii(*cp
) && !isspace(*cp
))
370 if (__inet_aton(net
, &a
)) {
371 statp
->sort_list
[nsort
].mask
= a
.s_addr
;
373 statp
->sort_list
[nsort
].mask
=
374 net_mask(statp
->sort_list
[nsort
].addr
);
377 statp
->sort_list
[nsort
].mask
=
378 net_mask(statp
->sort_list
[nsort
].addr
);
387 if (MATCH(buf
, "options")) {
388 res_setoptions(statp
, buf
+ sizeof("options") - 1, "conf");
392 statp
->nscount
= nserv
;
395 /* We try IPv6 servers again. */
396 statp
->ipv6_unavail
= false;
400 statp
->nsort
= nsort
;
404 if (__builtin_expect(statp
->nscount
== 0, 0)) {
405 statp
->nsaddr
.sin_addr
= __inet_makeaddr(IN_LOOPBACKNET
, 1);
406 statp
->nsaddr
.sin_family
= AF_INET
;
407 statp
->nsaddr
.sin_port
= htons(NAMESERVER_PORT
);
410 if (statp
->defdname
[0] == 0 &&
411 __gethostname(buf
, sizeof(statp
->defdname
) - 1) == 0 &&
412 (cp
= strchr(buf
, '.')) != NULL
)
413 strcpy(statp
->defdname
, cp
+ 1);
415 /* find components of local domain that might be searched */
416 if (havesearch
== 0) {
418 *pp
++ = statp
->defdname
;
423 for (cp
= statp
->defdname
; *cp
; cp
++)
424 dots
+= (*cp
== '.');
426 cp
= statp
->defdname
;
427 while (pp
< statp
->dnsrch
+ MAXDFLSRCH
) {
428 if (dots
< LOCALDOMAINPARTS
)
430 cp
= __rawmemchr(cp
, '.') + 1; /* we know there is one */
436 if (statp
->options
& RES_DEBUG
) {
437 printf(";; res_init()... default dnsrch list:\n");
438 for (pp
= statp
->dnsrch
; *pp
; pp
++)
439 printf(";;\t%s\n", *pp
);
440 printf(";;\t..END..\n");
443 #endif /* !RFC1535 */
446 if ((cp
= getenv("RES_OPTIONS")) != NULL
)
447 res_setoptions(statp
, cp
, "env");
448 statp
->options
|= RES_INIT
;
454 res_setoptions(res_state statp
, const char *options
, const char *source
) {
455 const char *cp
= options
;
459 if (statp
->options
& RES_DEBUG
)
460 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
464 /* skip leading and inner runs of spaces */
465 while (*cp
== ' ' || *cp
== '\t')
467 /* search for and process individual options */
468 if (!strncmp(cp
, "ndots:", sizeof("ndots:") - 1)) {
469 i
= atoi(cp
+ sizeof("ndots:") - 1);
470 if (i
<= RES_MAXNDOTS
)
473 statp
->ndots
= RES_MAXNDOTS
;
475 if (statp
->options
& RES_DEBUG
)
476 printf(";;\tndots=%d\n", statp
->ndots
);
478 } else if (!strncmp(cp
, "timeout:", sizeof("timeout:") - 1)) {
479 i
= atoi(cp
+ sizeof("timeout:") - 1);
480 if (i
<= RES_MAXRETRANS
)
483 statp
->retrans
= RES_MAXRETRANS
;
484 } else if (!strncmp(cp
, "attempts:", sizeof("attempts:") - 1)){
485 i
= atoi(cp
+ sizeof("attempts:") - 1);
486 if (i
<= RES_MAXRETRY
)
489 statp
->retry
= RES_MAXRETRY
;
490 } else if (!strncmp(cp
, "debug", sizeof("debug") - 1)) {
492 if (!(statp
->options
& RES_DEBUG
)) {
493 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
495 statp
->options
|= RES_DEBUG
;
497 printf(";;\tdebug\n");
505 unsigned long int flag
;
507 #define STRnLEN(str) str, sizeof (str) - 1
508 { STRnLEN ("inet6"), 0, RES_USE_INET6
},
509 { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING
},
510 { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT
},
511 { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT
},
512 { STRnLEN ("rotate"), 0, RES_ROTATE
},
513 { STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME
},
514 { STRnLEN ("edns0"), 0, RES_USE_EDNS0
},
515 { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP
},
516 { STRnLEN ("single-request"), 0, RES_SNGLKUP
},
517 { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY
},
518 { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY
},
519 { STRnLEN ("use-vc"), 0, RES_USEVC
}
521 #define noptions (sizeof (options) / sizeof (options[0]))
523 for (i
= 0; i
< noptions
; ++i
)
524 if (strncmp (cp
, options
[i
].str
, options
[i
].len
) == 0)
526 if (options
[i
].clear
)
527 statp
->options
&= options
[i
].flag
;
529 statp
->options
|= options
[i
].flag
;
533 /* XXX - print a warning here? */
536 /* skip to next run of spaces */
537 while (*cp
&& *cp
!= ' ' && *cp
!= '\t')
543 /* XXX - should really support CIDR which means explicit masks always. */
544 /* XXX - should really use system's version of this */
546 net_mask (struct in_addr in
)
548 u_int32_t i
= ntohl(in
.s_addr
);
551 return (htonl(IN_CLASSA_NET
));
552 else if (IN_CLASSB(i
))
553 return (htonl(IN_CLASSB_NET
));
554 return (htonl(IN_CLASSC_NET
));
560 return 0xffff & __getpid();
563 libc_hidden_def (__res_randomid
)
568 * This routine is for closing the socket if a virtual circuit is used and
569 * the program wants to close it. This provides support for endhostent()
570 * which expects to close the socket.
572 * This routine is not expected to be user visible.
575 __res_iclose(res_state statp
, bool free_addr
) {
578 if (statp
->_vcsock
>= 0) {
579 close_not_cancel_no_status(statp
->_vcsock
);
581 statp
->_flags
&= ~(RES_F_VC
| RES_F_CONN
);
583 for (ns
= 0; ns
< statp
->nscount
; ns
++)
584 if (statp
->_u
._ext
.nsaddrs
[ns
]) {
585 if (statp
->_u
._ext
.nssocks
[ns
] != -1) {
586 close_not_cancel_no_status(statp
->_u
._ext
.nssocks
[ns
]);
587 statp
->_u
._ext
.nssocks
[ns
] = -1;
590 free (statp
->_u
._ext
.nsaddrs
[ns
]);
591 statp
->_u
._ext
.nsaddrs
[ns
] = NULL
;
595 libc_hidden_def (__res_iclose
)
598 res_nclose(res_state statp
)
600 __res_iclose (statp
, true);
603 libc_hidden_def (__res_nclose
)
607 # ifdef _LIBC_REENTRANT
608 /* This is called when a thread is exiting to free resources held in _res. */
609 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
610 res_thread_freeres (void)
612 if (_res
.nscount
== 0)
613 /* Never called res_ninit. */
616 __res_iclose (&_res
, true); /* Close any VC sockets. */
618 /* Make sure we do a full re-initialization the next time. */
621 text_set_element (__libc_thread_subfreeres
, res_thread_freeres
);
622 text_set_element (__libc_subfreeres
, res_thread_freeres
);