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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 *));
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(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 res_setoptions(options, source)
432 char *options, *source;
434 char *cp = options;
435 int i;
437 #ifdef DEBUG
438 if (_res.options & RES_DEBUG)
439 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
440 options, source);
441 #endif
442 while (*cp) {
443 /* skip leading and inner runs of spaces */
444 while (*cp == ' ' || *cp == '\t')
445 cp++;
446 /* search for and process individual options */
447 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
448 i = atoi(cp + sizeof("ndots:") - 1);
449 if (i <= RES_MAXNDOTS)
450 _res.ndots = i;
451 else
452 _res.ndots = RES_MAXNDOTS;
453 #ifdef DEBUG
454 if (_res.options & RES_DEBUG)
455 printf(";;\tndots=%d\n", _res.ndots);
456 #endif
457 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
458 #ifdef DEBUG
459 if (!(_res.options & RES_DEBUG)) {
460 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
461 options, source);
462 _res.options |= RES_DEBUG;
464 printf(";;\tdebug\n");
465 #endif
466 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
467 _res.options |= RES_USE_INET6;
468 } else {
469 /* XXX - print a warning here? */
471 /* skip to next run of spaces */
472 while (*cp && *cp != ' ' && *cp != '\t')
473 cp++;
477 #ifdef RESOLVSORT
478 /* XXX - should really support CIDR which means explicit masks always. */
479 static u_int32_t
480 net_mask(in) /* XXX - should really use system's version of this */
481 struct in_addr in;
483 register u_int32_t i = ntohl(in.s_addr);
485 if (IN_CLASSA(i))
486 return (htonl(IN_CLASSA_NET));
487 else if (IN_CLASSB(i))
488 return (htonl(IN_CLASSB_NET));
489 return (htonl(IN_CLASSC_NET));
491 #endif
493 #ifdef NeXT
494 static int
495 netinfo_res_init(haveenv, havesearch)
496 int *haveenv;
497 int *havesearch;
499 register int n;
500 void *domain, *parent;
501 ni_id dir;
502 ni_status status;
503 ni_namelist nl;
504 int nserv = 0;
505 #ifdef RESOLVSORT
506 int nsort = 0;
507 #endif
509 status = ni_open(NULL, ".", &domain);
510 if (status == NI_OK) {
511 ni_setreadtimeout(domain, NI_TIMEOUT);
512 ni_setabort(domain, 1);
514 /* climb the NetInfo hierarchy to find a resolver directory */
515 while (status == NI_OK) {
516 status = ni_pathsearch(domain, &dir, NI_PATH_RESCONF);
517 if (status == NI_OK) {
518 /* found a resolver directory */
520 if (*haveenv == 0) {
521 /* get the default domain name */
522 status = ni_lookupprop(domain, &dir, "domain", &nl);
523 if (status == NI_OK && nl.ni_namelist_len > 0) {
524 (void)strncpy(_res.defdname,
525 nl.ni_namelist_val[0],
526 sizeof(_res.defdname) - 1);
527 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
528 ni_namelist_free(&nl);
529 *havesearch = 0;
532 /* get search list */
533 status = ni_lookupprop(domain, &dir, "search", &nl);
534 if (status == NI_OK && nl.ni_namelist_len > 0) {
535 (void)strncpy(_res.defdname,
536 nl.ni_namelist_val[0],
537 sizeof(_res.defdname) - 1);
538 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
539 /* copy */
540 for (n = 0;
541 n < nl.ni_namelist_len && n < MAXDNSRCH;
542 n++) {
543 /* duplicate up to MAXDNSRCH servers */
544 char *cp = nl.ni_namelist_val[n];
545 _res.dnsrch[n] =
546 strcpy((char *)malloc(strlen(cp) + 1), cp);
548 ni_namelist_free(&nl);
549 *havesearch = 1;
553 /* get list of nameservers */
554 status = ni_lookupprop(domain, &dir, "nameserver", &nl);
555 if (status == NI_OK && nl.ni_namelist_len > 0) {
556 /* copy up to MAXNS servers */
557 for (n = 0;
558 n < nl.ni_namelist_len && nserv < MAXNS;
559 n++) {
560 struct in_addr a;
562 if (inet_aton(nl.ni_namelist_val[n], &a)) {
563 _res.nsaddr_list[nserv].sin_addr = a;
564 _res.nsaddr_list[nserv].sin_family = AF_INET;
565 _res.nsaddr_list[nserv].sin_port =
566 htons(NAMESERVER_PORT);
567 nserv++;
570 ni_namelist_free(&nl);
573 if (nserv > 1)
574 _res.nscount = nserv;
576 #ifdef RESOLVSORT
577 /* get sort order */
578 status = ni_lookupprop(domain, &dir, "sortlist", &nl);
579 if (status == NI_OK && nl.ni_namelist_len > 0) {
581 /* copy up to MAXRESOLVSORT address/netmask pairs */
582 for (n = 0;
583 n < nl.ni_namelist_len && nsort < MAXRESOLVSORT;
584 n++) {
585 char ch;
586 char *cp;
587 const char *sp;
588 struct in_addr a;
590 cp = NULL;
591 for (sp = sort_mask; *sp; sp++) {
592 char *cp1;
593 cp1 = strchr(nl.ni_namelist_val[n], *sp);
594 if (cp && cp1)
595 cp = (cp < cp1)? cp : cp1;
596 else if (cp1)
597 cp = cp1;
599 if (cp != NULL) {
600 ch = *cp;
601 *cp = '\0';
602 break;
604 if (inet_aton(nl.ni_namelist_val[n], &a)) {
605 _res.sort_list[nsort].addr = a;
606 if (*cp && ISSORTMASK(ch)) {
607 *cp++ = ch;
608 if (inet_aton(cp, &a)) {
609 _res.sort_list[nsort].mask = a.s_addr;
610 } else {
611 _res.sort_list[nsort].mask =
612 net_mask(_res.sort_list[nsort].addr);
614 } else {
615 _res.sort_list[nsort].mask =
616 net_mask(_res.sort_list[nsort].addr);
618 nsort++;
621 ni_namelist_free(&nl);
624 _res.nsort = nsort;
625 #endif
627 /* get resolver options */
628 status = ni_lookupprop(domain, &dir, "options", &nl);
629 if (status == NI_OK && nl.ni_namelist_len > 0) {
630 res_setoptions(nl.ni_namelist_val[0], "conf");
631 ni_namelist_free(&nl);
634 ni_free(domain);
635 return(1); /* using DNS configuration from NetInfo */
638 status = ni_open(domain, "..", &parent);
639 ni_free(domain);
640 if (status == NI_OK)
641 domain = parent;
644 return(0); /* if not using DNS configuration from NetInfo */
646 #endif /* NeXT */
648 u_int
649 res_randomid()
651 struct timeval now;
653 gettimeofday(&now, NULL);
654 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));