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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
37 * Permission to use, copy, modify, and distribute this software for any
38 * purpose with or without fee is hereby granted, provided that the above
39 * copyright notice and this permission notice appear in all copies, and that
40 * the name of Digital Equipment Corporation not be used in advertising or
41 * publicity pertaining to distribution of the document or software without
42 * specific, written prior permission.
44 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
47 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
55 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
56 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
58 * Permission to use, copy, modify, and distribute this software for any
59 * purpose with or without fee is hereby granted, provided that the above
60 * copyright notice and this permission notice appear in all copies.
62 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
63 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
64 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
65 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
66 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
67 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
68 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
73 static const char rcsid[] = "$Id: res_init.c,v 1.23 2007/07/09 01:43:23 marka Exp $";
74 #endif /* LIBC_SCCS and not lint */
76 #include "port_before.h"
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <sys/socket.h>
83 #include <netinet/in.h>
84 #include <arpa/inet.h>
85 #include <arpa/nameser.h>
94 #include "port_after.h"
96 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
99 #include "res_private.h"
101 /*% Options. Should all be left alone. */
106 #include <sys/systeminfo.h>
109 static void res_setoptions __P((res_state, const char *, const char *));
112 static const char sort_mask[] = "/&";
113 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
114 static u_int32_t net_mask __P((struct in_addr));
117 #if !defined(isascii) /*%< XXX - could be a function */
118 # define isascii(c) (!(c & 0200))
122 * Resolver state default settings.
126 * Set up default settings. If the configuration file exist, the values
127 * there will have precedence. Otherwise, the server address is set to
128 * INADDR_ANY and the default domain name comes from the gethostname().
130 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
131 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
132 * since it was noted that INADDR_ANY actually meant ``the first interface
133 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
134 * it had to be "up" in order for you to reach your own name server. It
135 * was later decided that since the recommended practice is to always
136 * install local static routes through 127.0.0.1 for all your network
137 * interfaces, that we could solve this problem without a code change.
139 * The configuration file should always be used, since it is the only way
140 * to specify a default domain. If you are running a server on your local
141 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
142 * in the configuration file.
144 * Return 0 if completes successfully, -1 on error
147 res_ninit(res_state statp) {
148 extern int __res_vinit(res_state, int);
150 return (__res_vinit(statp, 0));
153 /*% This function has to be reachable by res_data.c but not publically. */
155 __res_vinit(res_state statp, int preinit) {
157 register char *cp, **pp;
160 int nserv = 0; /*%< number of nameserver records read from file */
168 union res_sockaddr_union u[2];
171 RES_SET_H_ERRNO(statp, 0);
172 if (statp->_u._ext.ext != NULL)
176 statp->retrans = RES_TIMEOUT;
177 statp->retry = RES_DFLRETRY;
178 statp->options = RES_DEFAULT;
179 statp->id = res_randomid();
182 memset(u, 0, sizeof(u));
184 u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
186 u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
188 u[nserv].sin.sin_family = AF_INET;
189 u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
191 u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
194 #ifdef HAS_INET6_STRUCTS
196 u[nserv].sin6.sin6_addr = in6addr_loopback;
198 u[nserv].sin6.sin6_addr = in6addr_any;
200 u[nserv].sin6.sin6_family = AF_INET6;
201 u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
203 u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
214 statp->_u._ext.nscount = 0;
215 statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
216 if (statp->_u._ext.ext != NULL) {
217 memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
218 statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
219 strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
220 strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
223 * Historically res_init() rarely, if at all, failed.
224 * Examples and applications exist which do not check
225 * our return code. Furthermore several applications
226 * simply call us to get the systems domainname. So
227 * rather then immediately fail here we store the
228 * failure, which is returned later, in h_errno. And
229 * prevent the collection of 'nameserver' information
230 * by setting maxns to 0. Thus applications that fail
231 * to check our return code wont be able to make
234 RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
240 res_setservers(statp, u, nserv);
244 * The old libresolv derived the defaultdomain from NIS/NIS+.
245 * We want to keep this behaviour
248 char buf[sizeof(statp->defdname)], *cp;
251 if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
252 (unsigned int)ret <= sizeof(buf)) {
255 cp = strchr(buf, '.');
256 cp = (cp == NULL) ? buf : (cp + 1);
257 strncpy(statp->defdname, cp,
258 sizeof(statp->defdname) - 1);
259 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
262 #endif /* SOLARIS2 */
264 /* Allow user to override the local domain definition */
265 if ((cp = getenv("LOCALDOMAIN")) != NULL) {
266 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
267 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
271 * Set search list to be blank-separated strings
272 * from rest of env value. Permits users of LOCALDOMAIN
273 * to still have a search list, and anyone to set the
274 * one that they want to use as an individual (even more
275 * important now that the rfc1535 stuff restricts searches)
277 cp = statp->defdname;
280 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
281 if (*cp == '\n') /*%< silly backwards compat */
283 else if (*cp == ' ' || *cp == '\t') {
292 /* null terminate last domain if there are excess */
293 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
299 #define MATCH(line, name) \
300 (!strncmp(line, name, sizeof(name) - 1) && \
301 (line[sizeof(name) - 1] == ' ' || \
302 line[sizeof(name) - 1] == '\t'))
305 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
306 /* read the config file */
307 while (fgets(buf, sizeof(buf), fp) != NULL) {
309 if (*buf == ';' || *buf == '#')
311 /* read default domain name */
312 if (MATCH(buf, "domain")) {
313 if (haveenv) /*%< skip if have from environ */
315 cp = buf + sizeof("domain") - 1;
316 while (*cp == ' ' || *cp == '\t')
318 if ((*cp == '\0') || (*cp == '\n'))
320 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
321 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
322 if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
327 /* set search list */
328 if (MATCH(buf, "search")) {
329 if (haveenv) /*%< skip if have from environ */
331 cp = buf + sizeof("search") - 1;
332 while (*cp == ' ' || *cp == '\t')
334 if ((*cp == '\0') || (*cp == '\n'))
336 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
337 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
338 if ((cp = strchr(statp->defdname, '\n')) != NULL)
341 * Set search list to be blank-separated strings
344 cp = statp->defdname;
347 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
348 if (*cp == ' ' || *cp == '\t') {
356 /* null terminate last domain if there are excess */
357 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
364 /* read nameservers to query */
365 if (MATCH(buf, "nameserver") && nserv < maxns) {
366 struct addrinfo hints, *ai;
367 char sbuf[NI_MAXSERV];
368 const size_t minsiz =
369 sizeof(statp->_u._ext.ext->nsaddrs[0]);
371 cp = buf + sizeof("nameserver") - 1;
372 while (*cp == ' ' || *cp == '\t')
374 cp[strcspn(cp, ";# \t\n")] = '\0';
375 if ((*cp != '\0') && (*cp != '\n')) {
376 memset(&hints, 0, sizeof(hints));
377 hints.ai_family = PF_UNSPEC;
378 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
379 hints.ai_flags = AI_NUMERICHOST;
380 sprintf(sbuf, "%u", NAMESERVER_PORT);
381 if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
382 ai->ai_addrlen <= minsiz) {
383 if (statp->_u._ext.ext != NULL) {
384 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
385 ai->ai_addr, ai->ai_addrlen);
387 if (ai->ai_addrlen <=
388 sizeof(statp->nsaddr_list[nserv])) {
389 memcpy(&statp->nsaddr_list[nserv],
390 ai->ai_addr, ai->ai_addrlen);
392 statp->nsaddr_list[nserv].sin_family = 0;
400 if (MATCH(buf, "sortlist")) {
403 cp = buf + sizeof("sortlist") - 1;
404 while (nsort < MAXRESOLVSORT) {
405 while (*cp == ' ' || *cp == '\t')
407 if (*cp == '\0' || *cp == '\n' || *cp == ';')
410 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
411 isascii(*cp) && !isspace((unsigned char)*cp))
415 if (inet_aton(net, &a)) {
416 statp->sort_list[nsort].addr = a;
420 while (*cp && *cp != ';' &&
422 !isspace((unsigned char)*cp))
426 if (inet_aton(net, &a)) {
427 statp->sort_list[nsort].mask = a.s_addr;
429 statp->sort_list[nsort].mask =
430 net_mask(statp->sort_list[nsort].addr);
433 statp->sort_list[nsort].mask =
434 net_mask(statp->sort_list[nsort].addr);
443 if (MATCH(buf, "options")) {
444 res_setoptions(statp, buf + sizeof("options") - 1, "conf");
449 statp->nscount = nserv;
451 statp->nsort = nsort;
456 * Last chance to get a nameserver. This should not normally
459 #ifdef NO_RESOLV_CONF
461 nserv = get_nameservers(statp);
464 if (statp->defdname[0] == 0 &&
465 gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
466 (cp = strchr(buf, '.')) != NULL)
467 strcpy(statp->defdname, cp + 1);
469 /* find components of local domain that might be searched */
470 if (havesearch == 0) {
472 *pp++ = statp->defdname;
476 for (cp = statp->defdname; *cp; cp++)
477 dots += (*cp == '.');
479 cp = statp->defdname;
480 while (pp < statp->dnsrch + MAXDFLSRCH) {
481 if (dots < LOCALDOMAINPARTS)
483 cp = strchr(cp, '.') + 1; /*%< we know there is one */
489 if (statp->options & RES_DEBUG) {
490 printf(";; res_init()... default dnsrch list:\n");
491 for (pp = statp->dnsrch; *pp; pp++)
492 printf(";;\t%s\n", *pp);
493 printf(";;\t..END..\n");
498 if ((cp = getenv("RES_OPTIONS")) != NULL)
499 res_setoptions(statp, cp, "env");
500 statp->options |= RES_INIT;
501 return (statp->res_h_errno);
505 res_setoptions(res_state statp, const char *options, const char *source)
507 const char *cp = options;
509 struct __res_state_ext *ext = statp->_u._ext.ext;
512 if (statp->options & RES_DEBUG)
513 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
517 /* skip leading and inner runs of spaces */
518 while (*cp == ' ' || *cp == '\t')
520 /* search for and process individual options */
521 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
522 i = atoi(cp + sizeof("ndots:") - 1);
523 if (i <= RES_MAXNDOTS)
526 statp->ndots = RES_MAXNDOTS;
528 if (statp->options & RES_DEBUG)
529 printf(";;\tndots=%d\n", statp->ndots);
531 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
532 i = atoi(cp + sizeof("timeout:") - 1);
533 if (i <= RES_MAXRETRANS)
536 statp->retrans = RES_MAXRETRANS;
538 if (statp->options & RES_DEBUG)
539 printf(";;\ttimeout=%d\n", statp->retrans);
542 } else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
544 * For backward compatibility, 'retrans' is
545 * supported as an alias for 'timeout', though
546 * without an imposed maximum.
548 statp->retrans = atoi(cp + sizeof("retrans:") - 1);
549 } else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
551 * For backward compatibility, 'retry' is
552 * supported as an alias for 'attempts', though
553 * without an imposed maximum.
555 statp->retry = atoi(cp + sizeof("retry:") - 1);
556 #endif /* SOLARIS2 */
557 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
558 i = atoi(cp + sizeof("attempts:") - 1);
559 if (i <= RES_MAXRETRY)
562 statp->retry = RES_MAXRETRY;
564 if (statp->options & RES_DEBUG)
565 printf(";;\tattempts=%d\n", statp->retry);
567 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
569 if (!(statp->options & RES_DEBUG)) {
570 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
572 statp->options |= RES_DEBUG;
574 printf(";;\tdebug\n");
576 } else if (!strncmp(cp, "no_tld_query",
577 sizeof("no_tld_query") - 1) ||
578 !strncmp(cp, "no-tld-query",
579 sizeof("no-tld-query") - 1)) {
580 statp->options |= RES_NOTLDQUERY;
581 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
582 statp->options |= RES_USE_INET6;
583 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
584 statp->options |= RES_ROTATE;
585 } else if (!strncmp(cp, "no-check-names",
586 sizeof("no-check-names") - 1)) {
587 statp->options |= RES_NOCHECKNAME;
590 else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
591 statp->options |= RES_USE_EDNS0;
594 else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
595 statp->options |= RES_USE_DNAME;
597 else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
600 cp += sizeof("nibble:") - 1;
601 i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
602 strncpy(ext->nsuffix, cp, i);
603 ext->nsuffix[i] = '\0';
605 else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
608 cp += sizeof("nibble2:") - 1;
609 i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
610 strncpy(ext->nsuffix2, cp, i);
611 ext->nsuffix2[i] = '\0';
613 else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
614 cp += sizeof("v6revmode:") - 1;
615 /* "nibble" and "bitstring" used to be valid */
616 if (!strncmp(cp, "single", sizeof("single") - 1)) {
617 statp->options |= RES_NO_NIBBLE2;
618 } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
624 /* XXX - print a warning here? */
627 /* skip to next run of spaces */
628 while (*cp && *cp != ' ' && *cp != '\t')
634 /* XXX - should really support CIDR which means explicit masks always. */
636 net_mask(in) /*!< XXX - should really use system's version of this */
639 register u_int32_t i = ntohl(in.s_addr);
642 return (htonl(IN_CLASSA_NET));
643 else if (IN_CLASSB(i))
644 return (htonl(IN_CLASSB_NET));
645 return (htonl(IN_CLASSC_NET));
653 gettimeofday(&now, NULL);
654 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
658 * This routine is for closing the socket if a virtual circuit is used and
659 * the program wants to close it. This provides support for endhostent()
660 * which expects to close the socket.
662 * This routine is not expected to be user visible.
665 res_nclose(res_state statp) {
668 if (statp->_vcsock >= 0) {
669 (void) close(statp->_vcsock);
671 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
673 for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
674 if (statp->_u._ext.nssocks[ns] != -1) {
675 (void) close(statp->_u._ext.nssocks[ns]);
676 statp->_u._ext.nssocks[ns] = -1;
682 res_ndestroy(res_state statp) {
684 if (statp->_u._ext.ext != NULL)
685 free(statp->_u._ext.ext);
686 statp->options &= ~RES_INIT;
687 statp->_u._ext.ext = NULL;
691 res_get_nibblesuffix(res_state statp) {
692 if (statp->_u._ext.ext)
693 return (statp->_u._ext.ext->nsuffix);
698 res_get_nibblesuffix2(res_state statp) {
699 if (statp->_u._ext.ext)
700 return (statp->_u._ext.ext->nsuffix2);
705 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
709 /* close open servers */
712 /* cause rtt times to be forgotten */
713 statp->_u._ext.nscount = 0;
716 for (i = 0; i < cnt && nserv < MAXNS; i++) {
717 switch (set->sin.sin_family) {
719 size = sizeof(set->sin);
720 if (statp->_u._ext.ext)
721 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
723 if (size <= sizeof(statp->nsaddr_list[nserv]))
724 memcpy(&statp->nsaddr_list[nserv],
727 statp->nsaddr_list[nserv].sin_family = 0;
731 #ifdef HAS_INET6_STRUCTS
733 size = sizeof(set->sin6);
734 if (statp->_u._ext.ext)
735 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
737 if (size <= sizeof(statp->nsaddr_list[nserv]))
738 memcpy(&statp->nsaddr_list[nserv],
741 statp->nsaddr_list[nserv].sin_family = 0;
751 statp->nscount = nserv;
756 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
761 for (i = 0; i < statp->nscount && i < cnt; i++) {
762 if (statp->_u._ext.ext)
763 family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
765 family = statp->nsaddr_list[i].sin_family;
769 size = sizeof(set->sin);
770 if (statp->_u._ext.ext)
772 &statp->_u._ext.ext->nsaddrs[i],
775 memcpy(&set->sin, &statp->nsaddr_list[i],
779 #ifdef HAS_INET6_STRUCTS
781 size = sizeof(set->sin6);
782 if (statp->_u._ext.ext)
784 &statp->_u._ext.ext->nsaddrs[i],
787 memcpy(&set->sin6, &statp->nsaddr_list[i],
793 set->sin.sin_family = 0;
798 return (statp->nscount);