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[glibc.git] / resolv / res_init.c
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1 /*
2 * ++Copyright++ 1985, 1989, 1993
3 * -
4 * Copyright (c) 1985, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 * -
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
51 * SOFTWARE.
52 * -
53 * --Copyright--
56 #if defined(LIBC_SCCS) && !defined(lint)
57 static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
58 static char rcsid[] = "$Id$";
59 #endif /* LIBC_SCCS and not lint */
61 #include <sys/types.h>
62 #include <sys/param.h>
63 #include <sys/socket.h>
64 #include <sys/time.h>
65 #include <netinet/in.h>
66 #include <arpa/inet.h>
67 #include <arpa/nameser.h>
69 #include <stdio.h>
70 #include <ctype.h>
71 #include <resolv.h>
72 #if defined(BSD) && (BSD >= 199103)
73 # include <unistd.h>
74 # include <stdlib.h>
75 # include <string.h>
76 #else
77 # include "../conf/portability.h"
78 #endif
80 /*-------------------------------------- info about "sortlist" --------------
81 * Marc Majka 1994/04/16
82 * Allan Nathanson 1994/10/29 (BIND 4.9.3.x)
84 * NetInfo resolver configuration directory support.
86 * Allow a NetInfo directory to be created in the hierarchy which
87 * contains the same information as the resolver configuration file.
89 * - The local domain name is stored as the value of the "domain" property.
90 * - The Internet address(es) of the name server(s) are stored as values
91 * of the "nameserver" property.
92 * - The name server addresses are stored as values of the "nameserver"
93 * property.
94 * - The search list for host-name lookup is stored as values of the
95 * "search" property.
96 * - The sortlist comprised of IP address netmask pairs are stored as
97 * values of the "sortlist" property. The IP address and optional netmask
98 * should be separated by a slash (/) or ampersand (&) character.
99 * - Internal resolver variables can be set from the value of the "options"
100 * property.
102 #if defined(NeXT)
103 # include <netinfo/ni.h>
104 # define NI_PATH_RESCONF "/locations/resolver"
105 # define NI_TIMEOUT 10
106 static int netinfo_res_init __P((int *haveenv, int *havesearch));
107 #endif
109 #if defined(USE_OPTIONS_H)
110 # include "../conf/options.h"
111 #endif
113 static void res_setoptions __P((char *, char *)) internal_function;
115 #ifdef RESOLVSORT
116 static const char sort_mask[] = "/&";
117 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
118 static u_int32_t net_mask __P((struct in_addr));
119 #endif
121 #if !defined(isascii) /* XXX - could be a function */
122 # define isascii(c) (!(c & 0200))
123 #endif
126 * Resolver state default settings.
129 struct __res_state _res
130 # if defined(__BIND_RES_TEXT)
131 = { RES_TIMEOUT, } /* Motorola, et al. */
132 # endif
136 * Set up default settings. If the configuration file exist, the values
137 * there will have precedence. Otherwise, the server address is set to
138 * INADDR_ANY and the default domain name comes from the gethostname().
140 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
141 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
142 * since it was noted that INADDR_ANY actually meant ``the first interface
143 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
144 * it had to be "up" in order for you to reach your own name server. It
145 * was later decided that since the recommended practice is to always
146 * install local static routes through 127.0.0.1 for all your network
147 * interfaces, that we could solve this problem without a code change.
149 * The configuration file should always be used, since it is the only way
150 * to specify a default domain. If you are running a server on your local
151 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
152 * in the configuration file.
154 * Return 0 if completes successfully, -1 on error
157 res_init()
159 register FILE *fp;
160 register char *cp, **pp;
161 register int n;
162 char buf[MAXDNAME];
163 int nserv = 0; /* number of nameserver records read from file */
164 int haveenv = 0;
165 int havesearch = 0;
166 #ifdef RESOLVSORT
167 int nsort = 0;
168 char *net;
169 #endif
170 #ifndef RFC1535
171 int dots;
172 #endif
175 * These three fields used to be statically initialized. This made
176 * it hard to use this code in a shared library. It is necessary,
177 * now that we're doing dynamic initialization here, that we preserve
178 * the old semantics: if an application modifies one of these three
179 * fields of _res before res_init() is called, res_init() will not
180 * alter them. Of course, if an application is setting them to
181 * _zero_ before calling res_init(), hoping to override what used
182 * to be the static default, we can't detect it and unexpected results
183 * will follow. Zero for any of these fields would make no sense,
184 * so one can safely assume that the applications were already getting
185 * unexpected results.
187 * _res.options is tricky since some apps were known to diddle the bits
188 * before res_init() was first called. We can't replicate that semantic
189 * with dynamic initialization (they may have turned bits off that are
190 * set in RES_DEFAULT). Our solution is to declare such applications
191 * "broken". They could fool us by setting RES_INIT but none do (yet).
193 if (!_res.retrans)
194 _res.retrans = RES_TIMEOUT;
195 if (!_res.retry)
196 _res.retry = 4;
197 if (!(_res.options & RES_INIT))
198 _res.options = RES_DEFAULT;
201 * This one used to initialize implicitly to zero, so unless the app
202 * has set it to something in particular, we can randomize it now.
204 if (!_res.id)
205 _res.id = res_randomid();
207 #ifdef USELOOPBACK
208 _res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
209 #else
210 _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
211 #endif
212 _res.nsaddr.sin_family = AF_INET;
213 _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
214 _res.nscount = 1;
215 _res.ndots = 1;
216 _res.pfcode = 0;
218 /* Allow user to override the local domain definition */
219 if ((cp = __secure_getenv("LOCALDOMAIN")) != NULL) {
220 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
221 haveenv++;
224 * Set search list to be blank-separated strings
225 * from rest of env value. Permits users of LOCALDOMAIN
226 * to still have a search list, and anyone to set the
227 * one that they want to use as an individual (even more
228 * important now that the rfc1535 stuff restricts searches)
230 cp = _res.defdname;
231 pp = _res.dnsrch;
232 *pp++ = cp;
233 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
234 if (*cp == '\n') /* silly backwards compat */
235 break;
236 else if (*cp == ' ' || *cp == '\t') {
237 *cp = 0;
238 n = 1;
239 } else if (n) {
240 *pp++ = cp;
241 n = 0;
242 havesearch = 1;
245 /* null terminate last domain if there are excess */
246 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
247 cp++;
248 *cp = '\0';
249 *pp++ = 0;
252 #define MATCH(line, name) \
253 (!strncmp(line, name, sizeof(name) - 1) && \
254 (line[sizeof(name) - 1] == ' ' || \
255 line[sizeof(name) - 1] == '\t'))
257 #ifdef NeXT
258 if (netinfo_res_init(&haveenv, &havesearch) == 0)
259 #endif
260 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
261 /* read the config file */
262 while (fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
263 /* skip comments */
264 if (*buf == ';' || *buf == '#')
265 continue;
266 /* read default domain name */
267 if (MATCH(buf, "domain")) {
268 if (haveenv) /* skip if have from environ */
269 continue;
270 cp = buf + sizeof("domain") - 1;
271 while (*cp == ' ' || *cp == '\t')
272 cp++;
273 if ((*cp == '\0') || (*cp == '\n'))
274 continue;
275 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
276 if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
277 *cp = '\0';
278 havesearch = 0;
279 continue;
281 /* set search list */
282 if (MATCH(buf, "search")) {
283 if (haveenv) /* skip if have from environ */
284 continue;
285 cp = buf + sizeof("search") - 1;
286 while (*cp == ' ' || *cp == '\t')
287 cp++;
288 if ((*cp == '\0') || (*cp == '\n'))
289 continue;
290 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
291 if ((cp = strchr(_res.defdname, '\n')) != NULL)
292 *cp = '\0';
294 * Set search list to be blank-separated strings
295 * on rest of line.
297 cp = _res.defdname;
298 pp = _res.dnsrch;
299 *pp++ = cp;
300 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
301 if (*cp == ' ' || *cp == '\t') {
302 *cp = 0;
303 n = 1;
304 } else if (n) {
305 *pp++ = cp;
306 n = 0;
309 /* null terminate last domain if there are excess */
310 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
311 cp++;
312 *cp = '\0';
313 *pp++ = 0;
314 havesearch = 1;
315 continue;
317 /* read nameservers to query */
318 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
319 struct in_addr a;
321 cp = buf + sizeof("nameserver") - 1;
322 while (*cp == ' ' || *cp == '\t')
323 cp++;
324 if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
325 _res.nsaddr_list[nserv].sin_addr = a;
326 _res.nsaddr_list[nserv].sin_family = AF_INET;
327 _res.nsaddr_list[nserv].sin_port =
328 htons(NAMESERVER_PORT);
329 nserv++;
331 continue;
333 #ifdef RESOLVSORT
334 if (MATCH(buf, "sortlist")) {
335 struct in_addr a;
337 cp = buf + sizeof("sortlist") - 1;
338 while (nsort < MAXRESOLVSORT) {
339 while (*cp == ' ' || *cp == '\t')
340 cp++;
341 if (*cp == '\0' || *cp == '\n' || *cp == ';')
342 break;
343 net = cp;
344 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
345 isascii(*cp) && !isspace(*cp))
346 cp++;
347 n = *cp;
348 *cp = 0;
349 if (inet_aton(net, &a)) {
350 _res.sort_list[nsort].addr = a;
351 if (ISSORTMASK(n)) {
352 *cp++ = n;
353 net = cp;
354 while (*cp && *cp != ';' &&
355 isascii(*cp) && !isspace(*cp))
356 cp++;
357 n = *cp;
358 *cp = 0;
359 if (inet_aton(net, &a)) {
360 _res.sort_list[nsort].mask = a.s_addr;
361 } else {
362 _res.sort_list[nsort].mask =
363 net_mask(_res.sort_list[nsort].addr);
365 } else {
366 _res.sort_list[nsort].mask =
367 net_mask(_res.sort_list[nsort].addr);
369 nsort++;
371 *cp = n;
373 continue;
375 #endif
376 if (MATCH(buf, "options")) {
377 res_setoptions(buf + sizeof("options") - 1, "conf");
378 continue;
381 if (nserv > 1)
382 _res.nscount = nserv;
383 #ifdef RESOLVSORT
384 _res.nsort = nsort;
385 #endif
386 (void) fclose(fp);
388 if (_res.defdname[0] == 0 &&
389 gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
390 (cp = strchr(buf, '.')) != NULL)
391 strcpy(_res.defdname, cp + 1);
393 /* find components of local domain that might be searched */
394 if (havesearch == 0) {
395 pp = _res.dnsrch;
396 *pp++ = _res.defdname;
397 *pp = NULL;
399 #ifndef RFC1535
400 dots = 0;
401 for (cp = _res.defdname; *cp; cp++)
402 dots += (*cp == '.');
404 cp = _res.defdname;
405 while (pp < _res.dnsrch + MAXDFLSRCH) {
406 if (dots < LOCALDOMAINPARTS)
407 break;
408 cp = strchr(cp, '.') + 1; /* we know there is one */
409 *pp++ = cp;
410 dots--;
412 *pp = NULL;
413 #ifdef DEBUG
414 if (_res.options & RES_DEBUG) {
415 printf(";; res_init()... default dnsrch list:\n");
416 for (pp = _res.dnsrch; *pp; pp++)
417 printf(";;\t%s\n", *pp);
418 printf(";;\t..END..\n");
420 #endif /* DEBUG */
421 #endif /* !RFC1535 */
424 if ((cp = __secure_getenv("RES_OPTIONS")) != NULL)
425 res_setoptions(cp, "env");
426 _res.options |= RES_INIT;
427 return (0);
430 static void
431 internal_function
432 res_setoptions(options, source)
433 char *options, *source;
435 char *cp = options;
436 int i;
438 #ifdef DEBUG
439 if (_res.options & RES_DEBUG)
440 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
441 options, source);
442 #endif
443 while (*cp) {
444 /* skip leading and inner runs of spaces */
445 while (*cp == ' ' || *cp == '\t')
446 cp++;
447 /* search for and process individual options */
448 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
449 i = atoi(cp + sizeof("ndots:") - 1);
450 if (i <= RES_MAXNDOTS)
451 _res.ndots = i;
452 else
453 _res.ndots = RES_MAXNDOTS;
454 #ifdef DEBUG
455 if (_res.options & RES_DEBUG)
456 printf(";;\tndots=%d\n", _res.ndots);
457 #endif
458 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
459 #ifdef DEBUG
460 if (!(_res.options & RES_DEBUG)) {
461 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
462 options, source);
463 _res.options |= RES_DEBUG;
465 printf(";;\tdebug\n");
466 #endif
467 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
468 _res.options |= RES_USE_INET6;
469 } else {
470 /* XXX - print a warning here? */
472 /* skip to next run of spaces */
473 while (*cp && *cp != ' ' && *cp != '\t')
474 cp++;
478 #ifdef RESOLVSORT
479 /* XXX - should really support CIDR which means explicit masks always. */
480 static u_int32_t
481 net_mask(in) /* XXX - should really use system's version of this */
482 struct in_addr in;
484 register u_int32_t i = ntohl(in.s_addr);
486 if (IN_CLASSA(i))
487 return (htonl(IN_CLASSA_NET));
488 else if (IN_CLASSB(i))
489 return (htonl(IN_CLASSB_NET));
490 return (htonl(IN_CLASSC_NET));
492 #endif
494 #ifdef NeXT
495 static int
496 netinfo_res_init(haveenv, havesearch)
497 int *haveenv;
498 int *havesearch;
500 register int n;
501 void *domain, *parent;
502 ni_id dir;
503 ni_status status;
504 ni_namelist nl;
505 int nserv = 0;
506 #ifdef RESOLVSORT
507 int nsort = 0;
508 #endif
510 status = ni_open(NULL, ".", &domain);
511 if (status == NI_OK) {
512 ni_setreadtimeout(domain, NI_TIMEOUT);
513 ni_setabort(domain, 1);
515 /* climb the NetInfo hierarchy to find a resolver directory */
516 while (status == NI_OK) {
517 status = ni_pathsearch(domain, &dir, NI_PATH_RESCONF);
518 if (status == NI_OK) {
519 /* found a resolver directory */
521 if (*haveenv == 0) {
522 /* get the default domain name */
523 status = ni_lookupprop(domain, &dir, "domain", &nl);
524 if (status == NI_OK && nl.ni_namelist_len > 0) {
525 (void)strncpy(_res.defdname,
526 nl.ni_namelist_val[0],
527 sizeof(_res.defdname) - 1);
528 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
529 ni_namelist_free(&nl);
530 *havesearch = 0;
533 /* get search list */
534 status = ni_lookupprop(domain, &dir, "search", &nl);
535 if (status == NI_OK && nl.ni_namelist_len > 0) {
536 (void)strncpy(_res.defdname,
537 nl.ni_namelist_val[0],
538 sizeof(_res.defdname) - 1);
539 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
540 /* copy */
541 for (n = 0;
542 n < nl.ni_namelist_len && n < MAXDNSRCH;
543 n++) {
544 /* duplicate up to MAXDNSRCH servers */
545 char *cp = nl.ni_namelist_val[n];
546 _res.dnsrch[n] =
547 strcpy((char *)malloc(strlen(cp) + 1), cp);
549 ni_namelist_free(&nl);
550 *havesearch = 1;
554 /* get list of nameservers */
555 status = ni_lookupprop(domain, &dir, "nameserver", &nl);
556 if (status == NI_OK && nl.ni_namelist_len > 0) {
557 /* copy up to MAXNS servers */
558 for (n = 0;
559 n < nl.ni_namelist_len && nserv < MAXNS;
560 n++) {
561 struct in_addr a;
563 if (inet_aton(nl.ni_namelist_val[n], &a)) {
564 _res.nsaddr_list[nserv].sin_addr = a;
565 _res.nsaddr_list[nserv].sin_family = AF_INET;
566 _res.nsaddr_list[nserv].sin_port =
567 htons(NAMESERVER_PORT);
568 nserv++;
571 ni_namelist_free(&nl);
574 if (nserv > 1)
575 _res.nscount = nserv;
577 #ifdef RESOLVSORT
578 /* get sort order */
579 status = ni_lookupprop(domain, &dir, "sortlist", &nl);
580 if (status == NI_OK && nl.ni_namelist_len > 0) {
582 /* copy up to MAXRESOLVSORT address/netmask pairs */
583 for (n = 0;
584 n < nl.ni_namelist_len && nsort < MAXRESOLVSORT;
585 n++) {
586 char ch;
587 char *cp;
588 const char *sp;
589 struct in_addr a;
591 cp = NULL;
592 for (sp = sort_mask; *sp; sp++) {
593 char *cp1;
594 cp1 = strchr(nl.ni_namelist_val[n], *sp);
595 if (cp && cp1)
596 cp = (cp < cp1)? cp : cp1;
597 else if (cp1)
598 cp = cp1;
600 if (cp != NULL) {
601 ch = *cp;
602 *cp = '\0';
603 break;
605 if (inet_aton(nl.ni_namelist_val[n], &a)) {
606 _res.sort_list[nsort].addr = a;
607 if (*cp && ISSORTMASK(ch)) {
608 *cp++ = ch;
609 if (inet_aton(cp, &a)) {
610 _res.sort_list[nsort].mask = a.s_addr;
611 } else {
612 _res.sort_list[nsort].mask =
613 net_mask(_res.sort_list[nsort].addr);
615 } else {
616 _res.sort_list[nsort].mask =
617 net_mask(_res.sort_list[nsort].addr);
619 nsort++;
622 ni_namelist_free(&nl);
625 _res.nsort = nsort;
626 #endif
628 /* get resolver options */
629 status = ni_lookupprop(domain, &dir, "options", &nl);
630 if (status == NI_OK && nl.ni_namelist_len > 0) {
631 res_setoptions(nl.ni_namelist_val[0], "conf");
632 ni_namelist_free(&nl);
635 ni_free(domain);
636 return(1); /* using DNS configuration from NetInfo */
639 status = ni_open(domain, "..", &parent);
640 ni_free(domain);
641 if (status == NI_OK)
642 domain = parent;
645 return(0); /* if not using DNS configuration from NetInfo */
647 #endif /* NeXT */
649 u_int
650 res_randomid()
652 struct timeval now;
654 gettimeofday(&now, NULL);
655 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));