1 /* $NetBSD: res_init.c,v 1.32 2021/09/30 12:35:55 christos Exp $ */
2
3 /*
4 * Copyright (c) 1985, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34 *
35 * Permission to use, copy, modify, and distribute this software for any
36 * purpose with or without fee is hereby granted, provided that the above
37 * copyright notice and this permission notice appear in all copies, and that
38 * the name of Digital Equipment Corporation not be used in advertising or
39 * publicity pertaining to distribution of the document or software without
40 * specific, written prior permission.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49 * SOFTWARE.
50 */
51
52 /*
53 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
54 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
55 *
56 * Permission to use, copy, modify, and distribute this software for any
57 * purpose with or without fee is hereby granted, provided that the above
58 * copyright notice and this permission notice appear in all copies.
59 *
60 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
61 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
62 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
63 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
64 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
65 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
66 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
67 */
68
69 #include <sys/cdefs.h>
70 #if defined(LIBC_SCCS) && !defined(lint)
71 #ifdef notdef
72 static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
73 static const char rcsid[] = "Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp";
74 #else
75 __RCSID("$NetBSD: res_init.c,v 1.32 2021/09/30 12:35:55 christos Exp $");
76 #endif
77 #endif /* LIBC_SCCS and not lint */
78
79 #include "port_before.h"
80
81 #include "namespace.h"
82 #include <sys/types.h>
83 #include <sys/param.h>
84 #include <sys/socket.h>
85 #include <sys/stat.h>
86 #include <sys/time.h>
87 #include <sys/event.h>
88
89 #include <netinet/in.h>
90 #include <arpa/inet.h>
91 #include <arpa/nameser.h>
92
93 #include <ctype.h>
94 #include <stdio.h>
95 #include <stdlib.h>
96 #include <string.h>
97 #include <unistd.h>
98 #include <fcntl.h>
99 #include <netdb.h>
100
101 #define HAVE_MD5
102 #include <md5.h>
103
104 #ifndef HAVE_MD5
105 # include "../dst/md5.h"
106 #else
107 # ifdef SOLARIS2
108 # include <sys/md5.h>
109 # endif
110 #endif
111 #ifndef _MD5_H_
112 # define _MD5_H_ 1 /*%< make sure we do not include rsaref md5.h file */
113 #endif
114
115 #include "port_after.h"
116
117 #if 0
118 #ifdef __weak_alias
119 __weak_alias(res_ninit,_res_ninit)
120 __weak_alias(res_randomid,__res_randomid)
121 __weak_alias(res_nclose,_res_nclose)
122 __weak_alias(res_ndestroy,_res_ndestroy)
123 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
124 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
125 __weak_alias(res_getservers,__res_getservers)
126 __weak_alias(res_setservers,__res_setservers)
127 #endif
128 #endif
129
130
131 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
132 #include <resolv.h>
133
134 #include "res_private.h"
135
136 #define RESOLVSORT
137 /*% Options. Should all be left alone. */
138 #ifndef DEBUG
139 #define DEBUG
140 #endif
141
142 #ifdef SOLARIS2
143 #include <sys/systeminfo.h>
144 #endif
145
146 static void res_setoptions(res_state, const char *, const char *);
147
148 #ifdef RESOLVSORT
149 static const char sort_mask[] = "/&";
150 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
151 static uint32_t net_mask(struct in_addr);
152 #endif
153
154 #if !defined(isascii) /*%< XXX - could be a function */
155 # define isascii(c) (!(c & 0200))
156 #endif
157
158 static struct timespec __res_conf_time;
159 static const struct timespec ts = { 0, 0 };
160
161 const char *__res_conf_name = _PATH_RESCONF;
162
163 /*
164 * Resolver state default settings.
165 */
166
167 /*%
168 * Set up default settings. If the configuration file exist, the values
169 * there will have precedence. Otherwise, the server address is set to
170 * INADDR_ANY and the default domain name comes from the gethostname().
171 *
172 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
173 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
174 * since it was noted that INADDR_ANY actually meant ``the first interface
175 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
176 * it had to be "up" in order for you to reach your own name server. It
177 * was later decided that since the recommended practice is to always
178 * install local static routes through 127.0.0.1 for all your network
179 * interfaces, that we could solve this problem without a code change.
180 *
181 * The configuration file should always be used, since it is the only way
182 * to specify a default domain. If you are running a server on your local
183 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
184 * in the configuration file.
185 *
186 * Return 0 if completes successfully, -1 on error
187 */
188 int
res_ninit(res_state statp)189 res_ninit(res_state statp) {
190 return (__res_vinit(statp, 0));
191 }
192
193 static int
__res_kqinit(res_state statp)194 __res_kqinit(res_state statp)
195 {
196 struct kevent kc;
197 struct __res_state_ext *ext = statp->_u._ext.ext;
198
199 ext->kq = kqueue1(O_CLOEXEC);
200 ext->kqpid = getpid();
201 EV_SET(&kc, ext->resfd, EVFILT_VNODE,
202 EV_ADD|EV_ENABLE|EV_CLEAR, NOTE_DELETE|NOTE_WRITE| NOTE_EXTEND|
203 NOTE_ATTRIB|NOTE_LINK|NOTE_RENAME|NOTE_REVOKE, 0, 0);
204 (void)kevent(ext->kq, &kc, 1, NULL, 0, &ts);
205 return ext->kq;
206 }
207
208 /*% This function has to be reachable by res_data.c but not publically. */
209 int
__res_vinit(res_state statp,int preinit)210 __res_vinit(res_state statp, int preinit) {
211 register FILE *fp;
212 register char *cp, **pp;
213 register int n;
214 char buf[BUFSIZ];
215 int nserv = 0; /*%< number of nameserver records read from file */
216 int haveenv = 0;
217 int havesearch = 0;
218 #ifdef RESOLVSORT
219 int nsort = 0;
220 char *net;
221 #endif
222 int dots;
223 union res_sockaddr_union u[2];
224 int maxns = MAXNS;
225
226 RES_SET_H_ERRNO(statp, 0);
227
228 if ((statp->options & RES_INIT) != 0U)
229 res_ndestroy(statp);
230
231 if (!preinit) {
232 statp->retrans = RES_TIMEOUT;
233 statp->retry = RES_DFLRETRY;
234 statp->options = RES_DEFAULT;
235 }
236 statp->_rnd = malloc(16);
237 res_rndinit(statp);
238 statp->id = res_nrandomid(statp);
239
240 memset(u, 0, sizeof(u));
241 #ifdef USELOOPBACK
242 u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
243 #else
244 u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
245 #endif
246 u[nserv].sin.sin_family = AF_INET;
247 u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
248 #ifdef HAVE_SA_LEN
249 u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
250 #endif
251 nserv++;
252 #ifdef HAS_INET6_STRUCTS
253 #ifdef USELOOPBACK
254 u[nserv].sin6.sin6_addr = in6addr_loopback;
255 #else
256 u[nserv].sin6.sin6_addr = in6addr_any;
257 #endif
258 u[nserv].sin6.sin6_family = AF_INET6;
259 u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
260 #ifdef HAVE_SA_LEN
261 u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
262 #endif
263 nserv++;
264 #endif
265 statp->nscount = 0;
266 statp->ndots = 1;
267 statp->pfcode = 0;
268 statp->_vcsock = -1;
269 statp->_flags = 0;
270 statp->qhook = NULL;
271 statp->rhook = NULL;
272 statp->_u._ext.nscount = 0;
273 statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
274 if (statp->_u._ext.ext != NULL) {
275 memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
276 statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
277 strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
278 strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
279 } else {
280 /*
281 * Historically res_init() rarely, if at all, failed.
282 * Examples and applications exist which do not check
283 * our return code. Furthermore several applications
284 * simply call us to get the systems domainname. So
285 * rather than immediately fail here we store the
286 * failure, which is returned later, in h_errno. And
287 * prevent the collection of 'nameserver' information
288 * by setting maxns to 0. Thus applications that fail
289 * to check our return code wont be able to make
290 * queries anyhow.
291 */
292 RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
293 maxns = 0;
294 }
295 #ifdef RESOLVSORT
296 statp->nsort = 0;
297 #endif
298 res_setservers(statp, u, nserv);
299
300 #ifdef SOLARIS2
301 /*
302 * The old libresolv derived the defaultdomain from NIS/NIS+.
303 * We want to keep this behaviour
304 */
305 {
306 char buf[sizeof(statp->defdname)], *cp;
307 int ret;
308
309 if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
310 (unsigned int)ret <= sizeof(buf)) {
311 if (buf[0] == '+')
312 buf[0] = '.';
313 cp = strchr(buf, '.');
314 cp = (cp == NULL) ? buf : (cp + 1);
315 (void)strlcpy(statp->defdname, cp,
316 sizeof(statp->defdname));
317 }
318 }
319 #endif /* SOLARIS2 */
320
321 /* Allow user to override the local domain definition */
322 if ((cp = getenv("LOCALDOMAIN")) != NULL) {
323 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
324 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
325 haveenv++;
326
327 /*
328 * Set search list to be blank-separated strings
329 * from rest of env value. Permits users of LOCALDOMAIN
330 * to still have a search list, and anyone to set the
331 * one that they want to use as an individual (even more
332 * important now that the rfc1535 stuff restricts searches)
333 */
334 cp = statp->defdname;
335 pp = statp->dnsrch;
336 *pp++ = cp;
337 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
338 if (*cp == '\n') /*%< silly backwards compat */
339 break;
340 else if (*cp == ' ' || *cp == '\t') {
341 *cp = 0;
342 n = 1;
343 } else if (n) {
344 *pp++ = cp;
345 n = 0;
346 havesearch = 1;
347 }
348 }
349 /* null terminate last domain if there are excess */
350 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
351 cp++;
352 *cp = '\0';
353 *pp++ = 0;
354 }
355
356 #define MATCH(line, name) \
357 (!strncmp(line, name, sizeof(name) - 1) && \
358 (line[sizeof(name) - 1] == ' ' || \
359 line[sizeof(name) - 1] == '\t'))
360
361 nserv = 0;
362 if ((fp = fopen(__res_conf_name, "re")) != NULL) {
363 struct stat st;
364
365 /* read the config file */
366 while (fgets(buf, (int)sizeof(buf), fp) != NULL) {
367 /* skip comments */
368 if (*buf == ';' || *buf == '#')
369 continue;
370 /* read default domain name */
371 if (MATCH(buf, "domain")) {
372 if (haveenv) /*%< skip if have from environ */
373 continue;
374 cp = buf + sizeof("domain") - 1;
375 while (*cp == ' ' || *cp == '\t')
376 cp++;
377 if ((*cp == '\0') || (*cp == '\n'))
378 continue;
379 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
380 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
381 if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
382 *cp = '\0';
383 havesearch = 0;
384 continue;
385 }
386 /* set search list */
387 if (MATCH(buf, "search")) {
388 if (haveenv) /*%< skip if have from environ */
389 continue;
390 cp = buf + sizeof("search") - 1;
391 while (*cp == ' ' || *cp == '\t')
392 cp++;
393 if ((*cp == '\0') || (*cp == '\n'))
394 continue;
395 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
396 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
397 if ((cp = strchr(statp->defdname, '\n')) != NULL)
398 *cp = '\0';
399 /*
400 * Set search list to be blank-separated strings
401 * on rest of line.
402 */
403 cp = statp->defdname;
404 pp = statp->dnsrch;
405 *pp++ = cp;
406 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
407 if (*cp == ' ' || *cp == '\t') {
408 *cp = 0;
409 n = 1;
410 } else if (n) {
411 *pp++ = cp;
412 n = 0;
413 }
414 }
415 /* null terminate last domain if there are excess */
416 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
417 cp++;
418 *cp = '\0';
419 *pp++ = 0;
420 havesearch = 1;
421 continue;
422 }
423 /* read nameservers to query */
424 if (MATCH(buf, "nameserver") && nserv < maxns) {
425 struct addrinfo hints, *ai;
426 char sbuf[NI_MAXSERV];
427 const size_t minsiz =
428 sizeof(statp->_u._ext.ext->nsaddrs[0]);
429
430 cp = buf + sizeof("nameserver") - 1;
431 while (*cp == ' ' || *cp == '\t')
432 cp++;
433 cp[strcspn(cp, ";# \t\n")] = '\0';
434 if ((*cp != '\0') && (*cp != '\n')) {
435 memset(&hints, 0, sizeof(hints));
436 hints.ai_family = PF_UNSPEC;
437 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
438 hints.ai_flags = AI_NUMERICHOST;
439 sprintf(sbuf, "%u", NAMESERVER_PORT);
440 if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
441 ai->ai_addrlen <= minsiz) {
442 if (statp->_u._ext.ext != NULL) {
443 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
444 ai->ai_addr, ai->ai_addrlen);
445 }
446 if (ai->ai_addrlen <=
447 sizeof(statp->nsaddr_list[nserv])) {
448 memcpy(&statp->nsaddr_list[nserv],
449 ai->ai_addr, ai->ai_addrlen);
450 } else
451 statp->nsaddr_list[nserv].sin_family = 0;
452 freeaddrinfo(ai);
453 nserv++;
454 }
455 }
456 continue;
457 }
458 #ifdef RESOLVSORT
459 if (MATCH(buf, "sortlist")) {
460 struct in_addr a;
461
462 cp = buf + sizeof("sortlist") - 1;
463 while (nsort < MAXRESOLVSORT) {
464 while (*cp == ' ' || *cp == '\t')
465 cp++;
466 if (*cp == '\0' || *cp == '\n' || *cp == ';')
467 break;
468 net = cp;
469 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
470 isascii(*cp) && !isspace((unsigned char)*cp))
471 cp++;
472 n = *cp;
473 *cp = 0;
474 if (inet_aton(net, &a)) {
475 statp->sort_list[nsort].addr = a;
476 if (ISSORTMASK(n)) {
477 *cp++ = n;
478 net = cp;
479 while (*cp && *cp != ';' &&
480 isascii(*cp) &&
481 !isspace((unsigned char)*cp))
482 cp++;
483 n = *cp;
484 *cp = 0;
485 if (inet_aton(net, &a)) {
486 statp->sort_list[nsort].mask = a.s_addr;
487 } else {
488 statp->sort_list[nsort].mask =
489 net_mask(statp->sort_list[nsort].addr);
490 }
491 } else {
492 statp->sort_list[nsort].mask =
493 net_mask(statp->sort_list[nsort].addr);
494 }
495 nsort++;
496 }
497 *cp = n;
498 }
499 continue;
500 }
501 #endif
502 if (MATCH(buf, "options")) {
503 res_setoptions(statp, buf + sizeof("options") - 1, "conf");
504 continue;
505 }
506 }
507 if (nserv > 0)
508 statp->nscount = nserv;
509 #ifdef RESOLVSORT
510 statp->nsort = nsort;
511 #endif
512 statp->_u._ext.ext->resfd = fcntl(fileno(fp), F_DUPFD_CLOEXEC, 0);
513 (void) fclose(fp);
514 if (fstat(statp->_u._ext.ext->resfd, &st) != -1)
515 __res_conf_time = statp->_u._ext.ext->res_conf_time =
516 st.st_mtimespec;
517 __res_kqinit(statp);
518 } else {
519 statp->_u._ext.ext->kq = -1;
520 statp->_u._ext.ext->resfd = -1;
521 }
522 /*
523 * Last chance to get a nameserver. This should not normally
524 * be necessary
525 */
526 #ifdef NO_RESOLV_CONF
527 if(nserv == 0)
528 nserv = get_nameservers(statp);
529 #endif
530
531 if (statp->defdname[0] == 0 &&
532 gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
533 (cp = strchr(buf, '.')) != NULL)
534 strcpy(statp->defdname, cp + 1);
535
536 /* find components of local domain that might be searched */
537 if (havesearch == 0) {
538 pp = statp->dnsrch;
539 *pp++ = statp->defdname;
540 *pp = NULL;
541
542 dots = 0;
543 for (cp = statp->defdname; *cp; cp++)
544 dots += (*cp == '.');
545
546 cp = statp->defdname;
547 while (pp < statp->dnsrch + MAXDFLSRCH) {
548 if (dots < LOCALDOMAINPARTS)
549 break;
550 cp = strchr(cp, '.') + 1; /*%< we know there is one */
551 *pp++ = cp;
552 dots--;
553 }
554 *pp = NULL;
555 #ifdef DEBUG
556 if (statp->options & RES_DEBUG) {
557 printf(";; res_init()... default dnsrch list:\n");
558 for (pp = statp->dnsrch; *pp; pp++)
559 printf(";;\t%s\n", *pp);
560 printf(";;\t..END..\n");
561 }
562 #endif
563 }
564
565 if ((cp = getenv("RES_OPTIONS")) != NULL)
566 res_setoptions(statp, cp, "env");
567 statp->options |= RES_INIT;
568 return (statp->res_h_errno);
569 }
570
571 int
res_check(res_state statp,struct timespec * mtime)572 res_check(res_state statp, struct timespec *mtime)
573 {
574 /*
575 * If the times are equal, then we check if there
576 * was a kevent related to resolv.conf and reload.
577 * If the times are not equal, then we don't bother
578 * to check the kevent, because another thread already
579 * did, loaded and changed the time.
580 */
581 if (timespeccmp(&statp->_u._ext.ext->res_conf_time,
582 &__res_conf_time, ==)) {
583 struct kevent ke;
584 if (statp->_u._ext.ext->kq == -1)
585 goto out;
586 if (statp->_u._ext.ext->kqpid != getpid() &&
587 __res_kqinit(statp) == -1)
588 goto out;
589
590 switch (kevent(statp->_u._ext.ext->kq, NULL, 0, &ke, 1, &ts)) {
591 case 0:
592 case -1:
593 out:
594 if (mtime)
595 *mtime = __res_conf_time;
596 return 0;
597 default:
598 break;
599 }
600 }
601 (void)__res_vinit(statp, 0);
602 if (mtime)
603 *mtime = __res_conf_time;
604 return 1;
605 }
606
607 static void
res_setoptions(res_state statp,const char * options,const char * source)608 res_setoptions(res_state statp, const char *options, const char *source)
609 {
610 const char *cp = options;
611 int i;
612 size_t j;
613 struct __res_state_ext *ext = statp->_u._ext.ext;
614
615 #ifdef DEBUG
616 if (statp->options & RES_DEBUG)
617 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
618 options, source);
619 #endif
620 while (*cp) {
621 /* skip leading and inner runs of spaces */
622 while (*cp == ' ' || *cp == '\t')
623 cp++;
624 /* search for and process individual options */
625 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
626 i = atoi(cp + sizeof("ndots:") - 1);
627 if (i <= RES_MAXNDOTS)
628 statp->ndots = i;
629 else
630 statp->ndots = RES_MAXNDOTS;
631 #ifdef DEBUG
632 if (statp->options & RES_DEBUG)
633 printf(";;\tndots=%d\n", statp->ndots);
634 #endif
635 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
636 i = atoi(cp + sizeof("timeout:") - 1);
637 if (i <= RES_MAXRETRANS)
638 statp->retrans = i;
639 else
640 statp->retrans = RES_MAXRETRANS;
641 #ifdef DEBUG
642 if (statp->options & RES_DEBUG)
643 printf(";;\ttimeout=%d\n", statp->retrans);
644 #endif
645 #ifdef SOLARIS2
646 } else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
647 /*
648 * For backward compatibility, 'retrans' is
649 * supported as an alias for 'timeout', though
650 * without an imposed maximum.
651 */
652 statp->retrans = atoi(cp + sizeof("retrans:") - 1);
653 } else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
654 /*
655 * For backward compatibility, 'retry' is
656 * supported as an alias for 'attempts', though
657 * without an imposed maximum.
658 */
659 statp->retry = atoi(cp + sizeof("retry:") - 1);
660 #endif /* SOLARIS2 */
661 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
662 i = atoi(cp + sizeof("attempts:") - 1);
663 if (i <= RES_MAXRETRY)
664 statp->retry = i;
665 else
666 statp->retry = RES_MAXRETRY;
667 #ifdef DEBUG
668 if (statp->options & RES_DEBUG)
669 printf(";;\tattempts=%d\n", statp->retry);
670 #endif
671 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
672 #ifdef DEBUG
673 if (!(statp->options & RES_DEBUG)) {
674 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
675 options, source);
676 statp->options |= RES_DEBUG;
677 }
678 printf(";;\tdebug\n");
679 #endif
680 } else if (!strncmp(cp, "no_tld_query",
681 sizeof("no_tld_query") - 1) ||
682 !strncmp(cp, "no-tld-query",
683 sizeof("no-tld-query") - 1)) {
684 statp->options |= RES_NOTLDQUERY;
685 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
686 statp->options |= RES_USE_INET6;
687 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
688 statp->options |= RES_ROTATE;
689 } else if (!strncmp(cp, "no-check-names",
690 sizeof("no-check-names") - 1)) {
691 statp->options |= RES_NOCHECKNAME;
692 } else if (!strncmp(cp, "check-names",
693 sizeof("check-names") - 1)) {
694 statp->options &= ~RES_NOCHECKNAME;
695 }
696 #ifdef RES_USE_EDNS0
697 else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
698 statp->options |= RES_USE_EDNS0;
699 }
700 #endif
701 else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
702 statp->options |= RES_USE_DNAME;
703 }
704 else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
705 if (ext == NULL)
706 goto skip;
707 cp += sizeof("nibble:") - 1;
708 j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
709 strncpy(ext->nsuffix, cp, j);
710 ext->nsuffix[j] = '\0';
711 }
712 else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
713 if (ext == NULL)
714 goto skip;
715 cp += sizeof("nibble2:") - 1;
716 j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
717 strncpy(ext->nsuffix2, cp, j);
718 ext->nsuffix2[j] = '\0';
719 }
720 else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
721 cp += sizeof("v6revmode:") - 1;
722 /* "nibble" and "bitstring" used to be valid */
723 if (!strncmp(cp, "single", sizeof("single") - 1)) {
724 statp->options |= RES_NO_NIBBLE2;
725 } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
726 statp->options &=
727 ~RES_NO_NIBBLE2;
728 }
729 }
730 else {
731 /* XXX - print a warning here? */
732 }
733 skip:
734 /* skip to next run of spaces */
735 while (*cp && *cp != ' ' && *cp != '\t')
736 cp++;
737 }
738 }
739
740 #ifdef RESOLVSORT
741 /* XXX - should really support CIDR which means explicit masks always. */
742 static uint32_t
net_mask(struct in_addr in)743 net_mask(struct in_addr in) /*!< XXX - should really use system's version of this */
744 {
745 register uint32_t i = ntohl(in.s_addr);
746
747 if (IN_CLASSA(i))
748 return (htonl(IN_CLASSA_NET));
749 else if (IN_CLASSB(i))
750 return (htonl(IN_CLASSB_NET));
751 return (htonl(IN_CLASSC_NET));
752 }
753 #endif
754
755 static u_char srnd[16];
756
757 void
res_rndinit(res_state statp)758 res_rndinit(res_state statp)
759 {
760 struct timeval now;
761 uint32_t u32;
762 uint16_t u16;
763 u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
764
765 gettimeofday(&now, NULL);
766 u32 = (uint32_t)now.tv_sec;
767 memcpy(rnd, &u32, 4);
768 u32 = now.tv_usec;
769 memcpy(rnd + 4, &u32, 4);
770 u32 += (uint32_t)now.tv_sec;
771 memcpy(rnd + 8, &u32, 4);
772 u16 = getpid();
773 memcpy(rnd + 12, &u16, 2);
774 }
775
776 u_int
res_nrandomid(res_state statp)777 res_nrandomid(res_state statp)
778 {
779 struct timeval now;
780 uint16_t u16;
781 MD5_CTX ctx;
782 u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
783
784 gettimeofday(&now, NULL);
785 u16 = (uint16_t) (now.tv_sec ^ now.tv_usec);
786 memcpy(rnd + 14, &u16, 2);
787 #ifndef HAVE_MD5
788 MD5_Init(&ctx);
789 MD5_Update(&ctx, rnd, 16);
790 MD5_Final(rnd, &ctx);
791 #else
792 MD5Init(&ctx);
793 MD5Update(&ctx, rnd, 16);
794 MD5Final(rnd, &ctx);
795 #endif
796 memcpy(&u16, rnd + 14, 2);
797 return ((u_int) u16);
798 }
799
800 /*%
801 * This routine is for closing the socket if a virtual circuit is used and
802 * the program wants to close it. This provides support for endhostent()
803 * which expects to close the socket.
804 *
805 * This routine is not expected to be user visible.
806 */
807 void
res_nclose(res_state statp)808 res_nclose(res_state statp)
809 {
810 int ns;
811
812 if (statp->_vcsock >= 0) {
813 (void) close(statp->_vcsock);
814 statp->_vcsock = -1;
815 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
816 }
817 for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
818 if (statp->_u._ext.nssocks[ns] != -1) {
819 (void) close(statp->_u._ext.nssocks[ns]);
820 statp->_u._ext.nssocks[ns] = -1;
821 }
822 }
823 }
824
825 void
res_ndestroy(res_state statp)826 res_ndestroy(res_state statp)
827 {
828 struct __res_state_ext *ext = statp->_u._ext.ext;
829 res_nclose(statp);
830 if (ext != NULL) {
831 if (ext->kq != -1 && ext->kqpid == getpid())
832 (void)close(ext->kq);
833 if (ext->resfd != -1)
834 (void)close(ext->resfd);
835 free(ext);
836 statp->_u._ext.ext = NULL;
837 }
838 if (statp->_rnd != NULL) {
839 free(statp->_rnd);
840 statp->_rnd = NULL;
841 }
842 statp->options &= ~RES_INIT;
843 }
844
845 const char *
res_get_nibblesuffix(res_state statp)846 res_get_nibblesuffix(res_state statp)
847 {
848 if (statp->_u._ext.ext)
849 return (statp->_u._ext.ext->nsuffix);
850 return ("ip6.arpa");
851 }
852
853 const char *
res_get_nibblesuffix2(res_state statp)854 res_get_nibblesuffix2(res_state statp)
855 {
856 if (statp->_u._ext.ext)
857 return (statp->_u._ext.ext->nsuffix2);
858 return ("ip6.int");
859 }
860
861 void
res_setservers(res_state statp,const union res_sockaddr_union * set,int cnt)862 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt)
863 {
864 int i, nserv;
865 size_t size;
866
867 /* close open servers */
868 res_nclose(statp);
869
870 /* cause rtt times to be forgotten */
871 statp->_u._ext.nscount = 0;
872
873 nserv = 0;
874 for (i = 0; i < cnt && nserv < MAXNS; i++) {
875 switch (set->sin.sin_family) {
876 case AF_INET:
877 size = sizeof(set->sin);
878 if (statp->_u._ext.ext)
879 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
880 &set->sin, size);
881 if (size <= sizeof(statp->nsaddr_list[nserv]))
882 memcpy(&statp->nsaddr_list[nserv],
883 &set->sin, size);
884 else
885 statp->nsaddr_list[nserv].sin_family = 0;
886 nserv++;
887 break;
888
889 #ifdef HAS_INET6_STRUCTS
890 case AF_INET6:
891 size = sizeof(set->sin6);
892 if (statp->_u._ext.ext)
893 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
894 &set->sin6, size);
895 if (size <= sizeof(statp->nsaddr_list[nserv]))
896 memcpy(&statp->nsaddr_list[nserv],
897 &set->sin6, size);
898 else
899 statp->nsaddr_list[nserv].sin_family = 0;
900 nserv++;
901 break;
902 #endif
903
904 default:
905 break;
906 }
907 set++;
908 }
909 statp->nscount = nserv;
910
911 }
912
913 int
res_getservers(res_state statp,union res_sockaddr_union * set,int cnt)914 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt)
915 {
916 int i;
917 size_t size;
918 uint16_t family;
919
920 for (i = 0; i < statp->nscount && i < cnt; i++) {
921 if (statp->_u._ext.ext)
922 family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
923 else
924 family = statp->nsaddr_list[i].sin_family;
925
926 switch (family) {
927 case AF_INET:
928 size = sizeof(set->sin);
929 if (statp->_u._ext.ext)
930 memcpy(&set->sin,
931 &statp->_u._ext.ext->nsaddrs[i],
932 size);
933 else
934 memcpy(&set->sin, &statp->nsaddr_list[i],
935 size);
936 break;
937
938 #ifdef HAS_INET6_STRUCTS
939 case AF_INET6:
940 size = sizeof(set->sin6);
941 if (statp->_u._ext.ext)
942 memcpy(&set->sin6,
943 &statp->_u._ext.ext->nsaddrs[i],
944 size);
945 else
946 memcpy(&set->sin6, &statp->nsaddr_list[i],
947 size);
948 break;
949 #endif
950
951 default:
952 set->sin.sin_family = 0;
953 break;
954 }
955 set++;
956 }
957 return (statp->nscount);
958 }
959
960 /*! \file */
961