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
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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 * Portions Copyright (c) 1996 by Internet Software Consortium.
57 * Permission to use, copy, modify, and distribute this software for any
58 * purpose with or without fee is hereby granted, provided that the above
59 * copyright notice and this permission notice appear in all copies.
61 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
62 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
63 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
64 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
65 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
66 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
67 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
73 static char orig_rcsid[] = "From: Id: res_init.c,v 8.7 1996/11/18 09:10:04 vixie Exp $";
74 static char rcsid[] = "$FreeBSD$";
75 #endif /* LIBC_SCCS and not lint */
77 #include <sys/types.h>
78 #include <sys/param.h>
79 #include <sys/socket.h>
81 #include <netinet/in.h>
82 #include <arpa/inet.h>
83 #include <arpa/nameser.h>
92 #include "res_config.h"
94 static void res_setoptions __P((char *, char *));
97 static const char sort_mask[] = "/&";
98 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
99 static u_int32_t net_mask __P((struct in_addr));
102 #if !defined(isascii) /* XXX - could be a function */
103 # define isascii(c) (!(c & 0200))
107 * Resolver state default settings.
110 struct __res_state _res
111 # if defined(__BIND_RES_TEXT)
112 = { RES_TIMEOUT, } /* Motorola, et al. */
116 struct __res_state_ext _res_ext;
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_ANY and the default domain name comes from the gethostname().
123 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
124 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
125 * since it was noted that INADDR_ANY actually meant ``the first interface
126 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
127 * it had to be "up" in order for you to reach your own name server. It
128 * was later decided that since the recommended practice is to always
129 * install local static routes through 127.0.0.1 for all your network
130 * interfaces, that we could solve this problem without a code change.
132 * The configuration file should always be used, since it is the only way
133 * to specify a default domain. If you are running a server on your local
134 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
135 * in the configuration file.
137 * Return 0 if completes successfully, -1 on error
143 register char *cp, **pp;
146 int nserv = 0; /* number of nameserver records read from file */
158 * These three fields used to be statically initialized. This made
159 * it hard to use this code in a shared library. It is necessary,
160 * now that we're doing dynamic initialization here, that we preserve
161 * the old semantics: if an application modifies one of these three
162 * fields of _res before res_init() is called, res_init() will not
163 * alter them. Of course, if an application is setting them to
164 * _zero_ before calling res_init(), hoping to override what used
165 * to be the static default, we can't detect it and unexpected results
166 * will follow. Zero for any of these fields would make no sense,
167 * so one can safely assume that the applications were already getting
168 * unexpected results.
170 * _res.options is tricky since some apps were known to diddle the bits
171 * before res_init() was first called. We can't replicate that semantic
172 * with dynamic initialization (they may have turned bits off that are
173 * set in RES_DEFAULT). Our solution is to declare such applications
174 * "broken". They could fool us by setting RES_INIT but none do (yet).
177 _res.retrans = RES_TIMEOUT;
180 if (!(_res.options & RES_INIT))
181 _res.options = RES_DEFAULT;
184 * This one used to initialize implicitly to zero, so unless the app
185 * has set it to something in particular, we can randomize it now.
188 _res.id = res_randomid();
191 _res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
193 _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
195 _res.nsaddr.sin_family = AF_INET;
196 _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
197 _res.nsaddr.sin_len = sizeof(struct sockaddr_in);
198 if (sizeof(_res_ext.nsaddr) >= _res.nsaddr.sin_len)
199 memcpy(&_res_ext.nsaddr, &_res.nsaddr, _res.nsaddr.sin_len);
204 /* Allow user to override the local domain definition */
205 if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
206 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
207 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
211 * Set search list to be blank-separated strings
212 * from rest of env value. Permits users of LOCALDOMAIN
213 * to still have a search list, and anyone to set the
214 * one that they want to use as an individual (even more
215 * important now that the rfc1535 stuff restricts searches)
220 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
221 if (*cp == '\n') /* silly backwards compat */
223 else if (*cp == ' ' || *cp == '\t') {
232 /* null terminate last domain if there are excess */
233 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
239 #define MATCH(line, name) \
240 (!strncmp(line, name, sizeof(name) - 1) && \
241 (line[sizeof(name) - 1] == ' ' || \
242 line[sizeof(name) - 1] == '\t'))
244 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
245 /* read the config file */
246 while (fgets(buf, sizeof(buf), fp) != NULL) {
248 if (*buf == ';' || *buf == '#')
250 /* read default domain name */
251 if (MATCH(buf, "domain")) {
252 if (haveenv) /* skip if have from environ */
254 cp = buf + sizeof("domain") - 1;
255 while (*cp == ' ' || *cp == '\t')
257 if ((*cp == '\0') || (*cp == '\n'))
259 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
260 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
261 if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
266 /* set search list */
267 if (MATCH(buf, "search")) {
268 if (haveenv) /* skip if have from environ */
270 cp = buf + sizeof("search") - 1;
271 while (*cp == ' ' || *cp == '\t')
273 if ((*cp == '\0') || (*cp == '\n'))
275 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
276 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
277 if ((cp = strchr(_res.defdname, '\n')) != NULL)
280 * Set search list to be blank-separated strings
286 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
287 if (*cp == ' ' || *cp == '\t') {
295 /* null terminate last domain if there are excess */
296 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
303 /* read nameservers to query */
304 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
306 struct addrinfo hints, *res;
307 char pbuf[NI_MAXSERV];
309 cp = buf + sizeof("nameserver") - 1;
310 while (*cp == ' ' || *cp == '\t')
312 if ((*cp == '\0') || (*cp == '\n'))
314 for (q = cp; *q; q++) {
320 memset(&hints, 0, sizeof(hints));
321 hints.ai_flags = AI_NUMERICHOST;
322 hints.ai_socktype = SOCK_DGRAM;
323 snprintf(pbuf, sizeof(pbuf), "%d", NAMESERVER_PORT);
324 if (getaddrinfo(cp, pbuf, &hints, &res) == 0 &&
325 res->ai_next == NULL) {
326 if (res->ai_addrlen <= sizeof(_res_ext.nsaddr_list[nserv])) {
327 memcpy(&_res_ext.nsaddr_list[nserv], res->ai_addr,
330 memset(&_res_ext.nsaddr_list[nserv], 0,
331 sizeof(_res_ext.nsaddr_list[nserv]));
333 if (res->ai_addrlen <= sizeof(_res.nsaddr_list[nserv])) {
334 memcpy(&_res.nsaddr_list[nserv], res->ai_addr,
337 memset(&_res.nsaddr_list[nserv], 0,
338 sizeof(_res.nsaddr_list[nserv]));
347 if (MATCH(buf, "sortlist")) {
353 cp = buf + sizeof("sortlist") - 1;
354 while (nsort < MAXRESOLVSORT) {
355 while (*cp == ' ' || *cp == '\t')
357 if (*cp == '\0' || *cp == '\n' || *cp == ';')
360 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
361 isascii(*cp) && !isspace(*cp))
365 if (inet_aton(net, &a)) {
366 _res.sort_list[nsort].addr = a;
370 while (*cp && *cp != ';' &&
371 isascii(*cp) && !isspace(*cp))
375 if (inet_aton(net, &a)) {
376 _res.sort_list[nsort].mask = a.s_addr;
378 _res.sort_list[nsort].mask =
379 net_mask(_res.sort_list[nsort].addr);
382 _res.sort_list[nsort].mask =
383 net_mask(_res.sort_list[nsort].addr);
385 _res_ext.sort_list[nsort].af = AF_INET;
386 _res_ext.sort_list[nsort].addr.ina =
387 _res.sort_list[nsort].addr;
388 _res_ext.sort_list[nsort].mask.ina.s_addr =
389 _res.sort_list[nsort].mask;
392 else if (inet_pton(AF_INET6, net, &a6) == 1) {
394 _res_ext.sort_list[nsort].af = AF_INET6;
395 _res_ext.sort_list[nsort].addr.in6a = a6;
396 u = (u_char *)&_res_ext.sort_list[nsort].mask.in6a;
399 while (*cp && *cp != ';' &&
400 isascii(*cp) && !isspace(*cp))
410 if (inet_pton(AF_INET6, net, u) == 1) {
416 m = sizeof(struct in6_addr) * NBBY;
420 for (i = 0; i < sizeof(struct in6_addr); i++) {
432 _res.sort_list[nsort].addr.s_addr =
433 (u_int32_t)0xffffffff;
434 _res.sort_list[nsort].mask = (u_int32_t)0xffffffff;
442 if (MATCH(buf, "options")) {
443 res_setoptions(buf + sizeof("options") - 1, "conf");
448 _res.nscount = nserv;
454 if (_res.defdname[0] == 0 &&
455 gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
456 (cp = strchr(buf, '.')) != NULL)
457 strcpy(_res.defdname, cp + 1);
459 /* find components of local domain that might be searched */
460 if (havesearch == 0) {
462 *pp++ = _res.defdname;
467 for (cp = _res.defdname; *cp; cp++)
468 dots += (*cp == '.');
471 while (pp < _res.dnsrch + MAXDFLSRCH) {
472 if (dots < LOCALDOMAINPARTS)
474 cp = strchr(cp, '.') + 1; /* we know there is one */
480 if (_res.options & RES_DEBUG) {
481 printf(";; res_init()... default dnsrch list:\n");
482 for (pp = _res.dnsrch; *pp; pp++)
483 printf(";;\t%s\n", *pp);
484 printf(";;\t..END..\n");
487 #endif /* !RFC1535 */
491 _res.options |= RES_NOALIASES;
492 else if ((cp = getenv("RES_OPTIONS")) != NULL)
493 res_setoptions(cp, "env");
494 _res.options |= RES_INIT;
499 res_setoptions(options, source)
500 char *options, *source;
506 if (_res.options & RES_DEBUG)
507 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
511 /* skip leading and inner runs of spaces */
512 while (*cp == ' ' || *cp == '\t')
514 /* search for and process individual options */
515 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
516 i = atoi(cp + sizeof("ndots:") - 1);
517 if (i <= RES_MAXNDOTS)
520 _res.ndots = RES_MAXNDOTS;
522 if (_res.options & RES_DEBUG)
523 printf(";;\tndots=%d\n", _res.ndots);
525 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
527 if (!(_res.options & RES_DEBUG)) {
528 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
530 _res.options |= RES_DEBUG;
532 printf(";;\tdebug\n");
534 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
535 _res.options |= RES_USE_INET6;
536 } else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1)) {
537 _res.options |= RES_NOTLDQUERY;
538 } else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
539 _res.options |= RES_USE_EDNS0;
541 /* XXX - print a warning here? */
543 /* skip to next run of spaces */
544 while (*cp && *cp != ' ' && *cp != '\t')
550 /* XXX - should really support CIDR which means explicit masks always. */
552 net_mask(in) /* XXX - should really use system's version of this */
555 register u_int32_t i = ntohl(in.s_addr);
558 return (htonl(IN_CLASSA_NET));
559 else if (IN_CLASSB(i))
560 return (htonl(IN_CLASSB_NET));
561 return (htonl(IN_CLASSC_NET));
570 gettimeofday(&now, NULL);
571 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
575 * Weak aliases for applications that use certain private entry points,
576 * and fail to include <resolv.h>.
579 __weak_reference(__res_init, res_init);