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>
80 #include <arpa/inet.h>
81 #include <arpa/nameser.h>
83 #include <netinet/in.h>
84 #include <sys/param.h>
85 #include <sys/socket.h>
87 #include <sys/types.h>
89 #include <not-cancel.h>
91 /* Options. Should all be left alone. */
96 static void res_setoptions (res_state, const char *, const char *)
100 static const char sort_mask_chars[] = "/&";
101 #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
102 static u_int32_t net_mask (struct in_addr) __THROW;
105 #if !defined(isascii) /* XXX - could be a function */
106 # define isascii(c) (!(c & 0200))
110 unsigned long long int __res_initstamp attribute_hidden;
114 * Resolver state default settings.
118 * Set up default settings. If the configuration file exist, the values
119 * there will have precedence. Otherwise, the server address is set to
120 * INADDR_ANY and the default domain name comes from the gethostname().
122 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
123 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
124 * since it was noted that INADDR_ANY actually meant ``the first interface
125 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
126 * it had to be "up" in order for you to reach your own name server. It
127 * was later decided that since the recommended practice is to always
128 * install local static routes through 127.0.0.1 for all your network
129 * interfaces, that we could solve this problem without a code change.
131 * The configuration file should always be used, since it is the only way
132 * to specify a default domain. If you are running a server on your local
133 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
134 * in the configuration file.
136 * Return 0 if completes successfully, -1 on error
139 res_ninit(res_state statp) {
140 extern int __res_vinit(res_state, int);
142 return (__res_vinit(statp, 0));
145 libc_hidden_def (__res_ninit)
148 /* This function has to be reachable by res_data.c but not publically. */
150 __res_vinit(res_state statp, int preinit) {
152 register char *cp, **pp;
155 int nserv = 0; /* number of nameserver records read from file */
157 int nservall = 0; /* number of NS records read, nserv IPv4 only */
169 statp->_u._ext.initstamp = __res_initstamp;
173 statp->retrans = RES_TIMEOUT;
174 statp->retry = RES_DFLRETRY;
175 statp->options = RES_DEFAULT;
176 statp->id = res_randomid();
180 statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
182 statp->nsaddr.sin_addr.s_addr = INADDR_ANY;
184 statp->nsaddr.sin_family = AF_INET;
185 statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
193 statp->_u._ext.nsinit = 0;
194 statp->_u._ext.nscount = 0;
196 statp->_u._ext.nscount6 = 0;
197 for (n = 0; n < MAXNS; n++) {
198 statp->_u._ext.nsaddrs[n] = NULL;
199 statp->_u._ext.nsmap[n] = MAXNS;
203 /* Allow user to override the local domain definition */
204 if ((cp = getenv("LOCALDOMAIN")) != NULL) {
205 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
206 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
210 * Set search list to be blank-separated strings
211 * from rest of env value. Permits users of LOCALDOMAIN
212 * to still have a search list, and anyone to set the
213 * one that they want to use as an individual (even more
214 * important now that the rfc1535 stuff restricts searches)
216 cp = statp->defdname;
219 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
220 if (*cp == '\n') /* silly backwards compat */
222 else if (*cp == ' ' || *cp == '\t') {
231 /* null terminate last domain if there are excess */
232 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
238 #define MATCH(line, name) \
239 (!strncmp(line, name, sizeof(name) - 1) && \
240 (line[sizeof(name) - 1] == ' ' || \
241 line[sizeof(name) - 1] == '\t'))
243 if ((fp = fopen(_PATH_RESCONF, "rc")) != NULL) {
244 /* No threads use this stream. */
245 __fsetlocking (fp, FSETLOCKING_BYCALLER);
246 /* read the config file */
247 while (fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
249 if (*buf == ';' || *buf == '#')
251 /* read default domain name */
252 if (MATCH(buf, "domain")) {
253 if (haveenv) /* skip if have from environ */
255 cp = buf + sizeof("domain") - 1;
256 while (*cp == ' ' || *cp == '\t')
258 if ((*cp == '\0') || (*cp == '\n'))
260 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
261 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
262 if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
267 /* set search list */
268 if (MATCH(buf, "search")) {
269 if (haveenv) /* skip if have from environ */
271 cp = buf + sizeof("search") - 1;
272 while (*cp == ' ' || *cp == '\t')
274 if ((*cp == '\0') || (*cp == '\n'))
276 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
277 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
278 if ((cp = strchr(statp->defdname, '\n')) != NULL)
281 * Set search list to be blank-separated strings
284 cp = statp->defdname;
287 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
288 if (*cp == ' ' || *cp == '\t') {
296 /* null terminate last domain if there are excess */
297 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
304 /* read nameservers to query */
306 if (MATCH(buf, "nameserver") && nservall < MAXNS) {
308 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
312 cp = buf + sizeof("nameserver") - 1;
313 while (*cp == ' ' || *cp == '\t')
315 if ((*cp != '\0') && (*cp != '\n')
316 && __inet_aton(cp, &a)) {
317 statp->nsaddr_list[nservall].sin_addr = a;
318 statp->nsaddr_list[nservall].sin_family = AF_INET;
319 statp->nsaddr_list[nservall].sin_port =
320 htons(NAMESERVER_PORT);
328 if ((el = strchr(cp, '\n')) != NULL)
330 if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
333 (inet_pton(AF_INET6, cp, &a6) > 0)) {
334 struct sockaddr_in6 *sa6;
336 sa6 = malloc(sizeof(*sa6));
338 sa6->sin6_family = AF_INET6;
339 sa6->sin6_port = htons(NAMESERVER_PORT);
340 sa6->sin6_flowinfo = 0;
343 if (__builtin_expect (el == NULL, 1))
344 sa6->sin6_scope_id = 0;
346 int try_numericscope = 1;
347 if (IN6_IS_ADDR_LINKLOCAL (&a6)
348 || IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
350 = if_nametoindex (el + 1);
351 if (sa6->sin6_scope_id != 0)
352 try_numericscope = 0;
355 if (try_numericscope) {
358 = (uint32_t) strtoul (el + 1, &end,
361 sa6->sin6_scope_id = 0;
365 statp->_u._ext.nsaddrs[nservall] = sa6;
366 statp->_u._ext.nssocks[nservall] = -1;
367 statp->_u._ext.nsmap[nservall] = MAXNS + 1;
376 if (MATCH(buf, "sortlist")) {
379 cp = buf + sizeof("sortlist") - 1;
380 while (nsort < MAXRESOLVSORT) {
381 while (*cp == ' ' || *cp == '\t')
383 if (*cp == '\0' || *cp == '\n' || *cp == ';')
386 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
387 isascii(*cp) && !isspace(*cp))
391 if (__inet_aton(net, &a)) {
392 statp->sort_list[nsort].addr = a;
396 while (*cp && *cp != ';' &&
397 isascii(*cp) && !isspace(*cp))
401 if (__inet_aton(net, &a)) {
402 statp->sort_list[nsort].mask = a.s_addr;
404 statp->sort_list[nsort].mask =
405 net_mask(statp->sort_list[nsort].addr);
408 statp->sort_list[nsort].mask =
409 net_mask(statp->sort_list[nsort].addr);
418 if (MATCH(buf, "options")) {
419 res_setoptions(statp, buf + sizeof("options") - 1, "conf");
423 statp->nscount = nservall;
425 if (nservall - nserv > 0) {
426 statp->_u._ext.nscount6 = nservall - nserv;
427 /* We try IPv6 servers again. */
428 statp->ipv6_unavail = false;
432 statp->nsort = nsort;
436 if (statp->defdname[0] == 0 &&
437 __gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
438 (cp = strchr(buf, '.')) != NULL)
439 strcpy(statp->defdname, cp + 1);
441 /* find components of local domain that might be searched */
442 if (havesearch == 0) {
444 *pp++ = statp->defdname;
449 for (cp = statp->defdname; *cp; cp++)
450 dots += (*cp == '.');
452 cp = statp->defdname;
453 while (pp < statp->dnsrch + MAXDFLSRCH) {
454 if (dots < LOCALDOMAINPARTS)
456 cp = __rawmemchr(cp, '.') + 1; /* we know there is one */
462 if (statp->options & RES_DEBUG) {
463 printf(";; res_init()... default dnsrch list:\n");
464 for (pp = statp->dnsrch; *pp; pp++)
465 printf(";;\t%s\n", *pp);
466 printf(";;\t..END..\n");
469 #endif /* !RFC1535 */
472 if ((cp = getenv("RES_OPTIONS")) != NULL)
473 res_setoptions(statp, cp, "env");
474 statp->options |= RES_INIT;
480 res_setoptions(res_state statp, const char *options, const char *source) {
481 const char *cp = options;
485 if (statp->options & RES_DEBUG)
486 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
490 /* skip leading and inner runs of spaces */
491 while (*cp == ' ' || *cp == '\t')
493 /* search for and process individual options */
494 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
495 i = atoi(cp + sizeof("ndots:") - 1);
496 if (i <= RES_MAXNDOTS)
499 statp->ndots = RES_MAXNDOTS;
501 if (statp->options & RES_DEBUG)
502 printf(";;\tndots=%d\n", statp->ndots);
504 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
505 i = atoi(cp + sizeof("timeout:") - 1);
506 if (i <= RES_MAXRETRANS)
509 statp->retrans = RES_MAXRETRANS;
510 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
511 i = atoi(cp + sizeof("attempts:") - 1);
512 if (i <= RES_MAXRETRY)
515 statp->retry = RES_MAXRETRY;
516 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
518 if (!(statp->options & RES_DEBUG)) {
519 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
521 statp->options |= RES_DEBUG;
523 printf(";;\tdebug\n");
525 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
526 statp->options |= RES_USE_INET6;
527 } else if (!strncmp(cp, "ip6-bytestring",
528 sizeof("ip6-bytestring") - 1)) {
529 statp->options |= RES_USEBSTRING;
530 } else if (!strncmp(cp, "no-ip6-dotint",
531 sizeof("no-ip6-dotint") - 1)) {
532 statp->options |= RES_NOIP6DOTINT;
533 } else if (!strncmp(cp, "ip6-dotint",
534 sizeof("ip6-dotint") - 1)) {
535 statp->options &= ~RES_NOIP6DOTINT;
536 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
537 statp->options |= RES_ROTATE;
538 } else if (!strncmp(cp, "no-check-names",
539 sizeof("no-check-names") - 1)) {
540 statp->options |= RES_NOCHECKNAME;
541 } else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
542 statp->options |= RES_USE_EDNS0;
543 } else if (!strncmp(cp, "single-request-reopen",
544 sizeof("single-request-reopen") - 1)) {
545 statp->options |= RES_SNGLKUPREOP;
546 } else if (!strncmp(cp, "single-request",
547 sizeof("single-request") - 1)) {
548 statp->options |= RES_SNGLKUP;
550 /* XXX - print a warning here? */
552 /* skip to next run of spaces */
553 while (*cp && *cp != ' ' && *cp != '\t')
559 /* XXX - should really support CIDR which means explicit masks always. */
561 net_mask(in) /* XXX - should really use system's version of this */
564 register u_int32_t i = ntohl(in.s_addr);
567 return (htonl(IN_CLASSA_NET));
568 else if (IN_CLASSB(i))
569 return (htonl(IN_CLASSB_NET));
570 return (htonl(IN_CLASSC_NET));
576 return 0xffff & __getpid();
579 libc_hidden_def (__res_randomid)
584 * This routine is for closing the socket if a virtual circuit is used and
585 * the program wants to close it. This provides support for endhostent()
586 * which expects to close the socket.
588 * This routine is not expected to be user visible.
591 __res_iclose(res_state statp, bool free_addr) {
594 if (statp->_vcsock >= 0) {
595 close_not_cancel_no_status(statp->_vcsock);
597 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
600 for (ns = 0; ns < MAXNS; ns++)
602 for (ns = 0; ns < statp->_u._ext.nscount; ns++)
604 if (statp->_u._ext.nsaddrs[ns]) {
605 if (statp->_u._ext.nssocks[ns] != -1) {
606 close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
607 statp->_u._ext.nssocks[ns] = -1;
610 free (statp->_u._ext.nsaddrs[ns]);
611 statp->_u._ext.nsaddrs[ns] = NULL;
614 statp->_u._ext.nsinit = 0;
616 libc_hidden_def (__res_iclose)
619 res_nclose(res_state statp)
621 __res_iclose (statp, true);
624 libc_hidden_def (__res_nclose)
628 # ifdef _LIBC_REENTRANT
629 /* This is called when a thread is exiting to free resources held in _res. */
630 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
631 res_thread_freeres (void)
633 if (_res.nscount == 0)
634 /* Never called res_ninit. */
637 __res_iclose (&_res, true); /* Close any VC sockets. */
639 /* Make sure we do a full re-initialization the next time. */
642 text_set_element (__libc_thread_subfreeres, res_thread_freeres);
643 text_set_element (__libc_subfreeres, res_thread_freeres);