xref: /netbsd-src/lib/libc/resolv/res_init.c (revision aad9773e38ed2370a628a6416e098f9008fc10a7)
1 /*	$NetBSD: res_init.c,v 1.29 2014/09/16 01:29:48 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. 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.
22  *
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 
36 /*
37  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38  *
39  * Permission to use, copy, modify, and distribute this software for any
40  * purpose with or without fee is hereby granted, provided that the above
41  * copyright notice and this permission notice appear in all copies, and that
42  * the name of Digital Equipment Corporation not be used in advertising or
43  * publicity pertaining to distribution of the document or software without
44  * specific, written prior permission.
45  *
46  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
47  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
48  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
49  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53  * SOFTWARE.
54  */
55 
56 /*
57  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
58  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
59  *
60  * Permission to use, copy, modify, and distribute this software for any
61  * purpose with or without fee is hereby granted, provided that the above
62  * copyright notice and this permission notice appear in all copies.
63  *
64  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
65  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
66  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
67  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
69  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
70  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71  */
72 
73 #include <sys/cdefs.h>
74 #if defined(LIBC_SCCS) && !defined(lint)
75 #ifdef notdef
76 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
77 static const char rcsid[] = "Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp";
78 #else
79 __RCSID("$NetBSD: res_init.c,v 1.29 2014/09/16 01:29:48 christos Exp $");
80 #endif
81 #endif /* LIBC_SCCS and not lint */
82 
83 #include "port_before.h"
84 
85 #include "namespace.h"
86 #include <sys/types.h>
87 #include <sys/param.h>
88 #include <sys/socket.h>
89 #include <sys/stat.h>
90 #include <sys/time.h>
91 #include <sys/event.h>
92 
93 #include <netinet/in.h>
94 #include <arpa/inet.h>
95 #include <arpa/nameser.h>
96 
97 #include <ctype.h>
98 #include <stdio.h>
99 #include <stdlib.h>
100 #include <string.h>
101 #include <unistd.h>
102 #include <fcntl.h>
103 #include <netdb.h>
104 
105 #define HAVE_MD5
106 #include <md5.h>
107 
108 #ifndef HAVE_MD5
109 # include "../dst/md5.h"
110 #else
111 # ifdef SOLARIS2
112 #  include <sys/md5.h>
113 # endif
114 #endif
115 #ifndef _MD5_H_
116 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
117 #endif
118 
119 #include "port_after.h"
120 
121 #if 0
122 #ifdef __weak_alias
123 __weak_alias(res_ninit,_res_ninit)
124 __weak_alias(res_randomid,__res_randomid)
125 __weak_alias(res_nclose,_res_nclose)
126 __weak_alias(res_ndestroy,_res_ndestroy)
127 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
128 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
129 __weak_alias(res_getservers,__res_getservers)
130 __weak_alias(res_setservers,__res_setservers)
131 #endif
132 #endif
133 
134 
135 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
136 #include <resolv.h>
137 
138 #include "res_private.h"
139 
140 #define RESOLVSORT
141 /*% Options.  Should all be left alone. */
142 #ifndef DEBUG
143 #define DEBUG
144 #endif
145 
146 #ifdef SOLARIS2
147 #include <sys/systeminfo.h>
148 #endif
149 
150 static void res_setoptions(res_state, const char *, const char *);
151 
152 #ifdef RESOLVSORT
153 static const char sort_mask[] = "/&";
154 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
155 static uint32_t net_mask(struct in_addr);
156 #endif
157 
158 #if !defined(isascii)	/*%< XXX - could be a function */
159 # define isascii(c) (!(c & 0200))
160 #endif
161 
162 static struct timespec __res_conf_time;
163 static const struct timespec ts = { 0, 0 };
164 
165 const char *__res_conf_name = _PATH_RESCONF;
166 
167 /*
168  * Resolver state default settings.
169  */
170 
171 /*%
172  * Set up default settings.  If the configuration file exist, the values
173  * there will have precedence.  Otherwise, the server address is set to
174  * INADDR_ANY and the default domain name comes from the gethostname().
175  *
176  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
177  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
178  * since it was noted that INADDR_ANY actually meant ``the first interface
179  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
180  * it had to be "up" in order for you to reach your own name server.  It
181  * was later decided that since the recommended practice is to always
182  * install local static routes through 127.0.0.1 for all your network
183  * interfaces, that we could solve this problem without a code change.
184  *
185  * The configuration file should always be used, since it is the only way
186  * to specify a default domain.  If you are running a server on your local
187  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
188  * in the configuration file.
189  *
190  * Return 0 if completes successfully, -1 on error
191  */
192 int
193 res_ninit(res_state statp) {
194 	return (__res_vinit(statp, 0));
195 }
196 
197 /*% This function has to be reachable by res_data.c but not publically. */
198 int
199 __res_vinit(res_state statp, int preinit) {
200 	register FILE *fp;
201 	register char *cp, **pp;
202 	register int n;
203 	char buf[BUFSIZ];
204 	int nserv = 0;    /*%< number of nameserver records read from file */
205 	int haveenv = 0;
206 	int havesearch = 0;
207 #ifdef RESOLVSORT
208 	int nsort = 0;
209 	char *net;
210 #endif
211 	int dots;
212 	union res_sockaddr_union u[2];
213 	int maxns = MAXNS;
214 
215 	RES_SET_H_ERRNO(statp, 0);
216 
217 	if ((statp->options & RES_INIT) != 0U)
218 		res_ndestroy(statp);
219 
220 	if (!preinit) {
221 		statp->retrans = RES_TIMEOUT;
222 		statp->retry = RES_DFLRETRY;
223 		statp->options = RES_DEFAULT;
224 	}
225 	statp->_rnd = malloc(16);
226 	res_rndinit(statp);
227 	statp->id = res_nrandomid(statp);
228 
229 	memset(u, 0, sizeof(u));
230 #ifdef USELOOPBACK
231 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
232 #else
233 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
234 #endif
235 	u[nserv].sin.sin_family = AF_INET;
236 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
237 #ifdef HAVE_SA_LEN
238 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
239 #endif
240 	nserv++;
241 #ifdef HAS_INET6_STRUCTS
242 #ifdef USELOOPBACK
243 	u[nserv].sin6.sin6_addr = in6addr_loopback;
244 #else
245 	u[nserv].sin6.sin6_addr = in6addr_any;
246 #endif
247 	u[nserv].sin6.sin6_family = AF_INET6;
248 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
249 #ifdef HAVE_SA_LEN
250 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
251 #endif
252 	nserv++;
253 #endif
254 	statp->nscount = 0;
255 	statp->ndots = 1;
256 	statp->pfcode = 0;
257 	statp->_vcsock = -1;
258 	statp->_flags = 0;
259 	statp->qhook = NULL;
260 	statp->rhook = NULL;
261 	statp->_u._ext.nscount = 0;
262 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
263 	if (statp->_u._ext.ext != NULL) {
264 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
265 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
266 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
267 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
268 	} else {
269 		/*
270 		 * Historically res_init() rarely, if at all, failed.
271 		 * Examples and applications exist which do not check
272 		 * our return code.  Furthermore several applications
273 		 * simply call us to get the systems domainname.  So
274 		 * rather than immediately fail here we store the
275 		 * failure, which is returned later, in h_errno.  And
276 		 * prevent the collection of 'nameserver' information
277 		 * by setting maxns to 0.  Thus applications that fail
278 		 * to check our return code wont be able to make
279 		 * queries anyhow.
280 		 */
281 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
282 		maxns = 0;
283 	}
284 #ifdef RESOLVSORT
285 	statp->nsort = 0;
286 #endif
287 	res_setservers(statp, u, nserv);
288 
289 #ifdef	SOLARIS2
290 	/*
291 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
292 	 * We want to keep this behaviour
293 	 */
294 	{
295 		char buf[sizeof(statp->defdname)], *cp;
296 		int ret;
297 
298 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
299 			(unsigned int)ret <= sizeof(buf)) {
300 			if (buf[0] == '+')
301 				buf[0] = '.';
302 			cp = strchr(buf, '.');
303 			cp = (cp == NULL) ? buf : (cp + 1);
304 			(void)strlcpy(statp->defdname, cp,
305 			    sizeof(statp->defdname));
306 		}
307 	}
308 #endif	/* SOLARIS2 */
309 
310 	/* Allow user to override the local domain definition */
311 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
312 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
313 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
314 		haveenv++;
315 
316 		/*
317 		 * Set search list to be blank-separated strings
318 		 * from rest of env value.  Permits users of LOCALDOMAIN
319 		 * to still have a search list, and anyone to set the
320 		 * one that they want to use as an individual (even more
321 		 * important now that the rfc1535 stuff restricts searches)
322 		 */
323 		cp = statp->defdname;
324 		pp = statp->dnsrch;
325 		*pp++ = cp;
326 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
327 			if (*cp == '\n')	/*%< silly backwards compat */
328 				break;
329 			else if (*cp == ' ' || *cp == '\t') {
330 				*cp = 0;
331 				n = 1;
332 			} else if (n) {
333 				*pp++ = cp;
334 				n = 0;
335 				havesearch = 1;
336 			}
337 		}
338 		/* null terminate last domain if there are excess */
339 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
340 			cp++;
341 		*cp = '\0';
342 		*pp++ = 0;
343 	}
344 
345 #define	MATCH(line, name) \
346 	(!strncmp(line, name, sizeof(name) - 1) && \
347 	(line[sizeof(name) - 1] == ' ' || \
348 	 line[sizeof(name) - 1] == '\t'))
349 
350 	nserv = 0;
351 	if ((fp = fopen(__res_conf_name, "re")) != NULL) {
352 	    struct stat st;
353 	    struct kevent kc;
354 
355 	    /* read the config file */
356 	    while (fgets(buf, (int)sizeof(buf), fp) != NULL) {
357 		/* skip comments */
358 		if (*buf == ';' || *buf == '#')
359 			continue;
360 		/* read default domain name */
361 		if (MATCH(buf, "domain")) {
362 		    if (haveenv)	/*%< skip if have from environ */
363 			    continue;
364 		    cp = buf + sizeof("domain") - 1;
365 		    while (*cp == ' ' || *cp == '\t')
366 			    cp++;
367 		    if ((*cp == '\0') || (*cp == '\n'))
368 			    continue;
369 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
370 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
371 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
372 			    *cp = '\0';
373 		    havesearch = 0;
374 		    continue;
375 		}
376 		/* set search list */
377 		if (MATCH(buf, "search")) {
378 		    if (haveenv)	/*%< skip if have from environ */
379 			    continue;
380 		    cp = buf + sizeof("search") - 1;
381 		    while (*cp == ' ' || *cp == '\t')
382 			    cp++;
383 		    if ((*cp == '\0') || (*cp == '\n'))
384 			    continue;
385 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
386 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
387 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
388 			    *cp = '\0';
389 		    /*
390 		     * Set search list to be blank-separated strings
391 		     * on rest of line.
392 		     */
393 		    cp = statp->defdname;
394 		    pp = statp->dnsrch;
395 		    *pp++ = cp;
396 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
397 			    if (*cp == ' ' || *cp == '\t') {
398 				    *cp = 0;
399 				    n = 1;
400 			    } else if (n) {
401 				    *pp++ = cp;
402 				    n = 0;
403 			    }
404 		    }
405 		    /* null terminate last domain if there are excess */
406 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
407 			    cp++;
408 		    *cp = '\0';
409 		    *pp++ = 0;
410 		    havesearch = 1;
411 		    continue;
412 		}
413 		/* read nameservers to query */
414 		if (MATCH(buf, "nameserver") && nserv < maxns) {
415 		    struct addrinfo hints, *ai;
416 		    char sbuf[NI_MAXSERV];
417 		    const size_t minsiz =
418 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
419 
420 		    cp = buf + sizeof("nameserver") - 1;
421 		    while (*cp == ' ' || *cp == '\t')
422 			cp++;
423 		    cp[strcspn(cp, ";# \t\n")] = '\0';
424 		    if ((*cp != '\0') && (*cp != '\n')) {
425 			memset(&hints, 0, sizeof(hints));
426 			hints.ai_family = PF_UNSPEC;
427 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
428 			hints.ai_flags = AI_NUMERICHOST;
429 			sprintf(sbuf, "%u", NAMESERVER_PORT);
430 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
431 			    ai->ai_addrlen <= minsiz) {
432 			    if (statp->_u._ext.ext != NULL) {
433 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
434 				    ai->ai_addr, ai->ai_addrlen);
435 			    }
436 			    if (ai->ai_addrlen <=
437 			        sizeof(statp->nsaddr_list[nserv])) {
438 				memcpy(&statp->nsaddr_list[nserv],
439 				    ai->ai_addr, ai->ai_addrlen);
440 			    } else
441 				statp->nsaddr_list[nserv].sin_family = 0;
442 			    freeaddrinfo(ai);
443 			    nserv++;
444 			}
445 		    }
446 		    continue;
447 		}
448 #ifdef RESOLVSORT
449 		if (MATCH(buf, "sortlist")) {
450 		    struct in_addr a;
451 
452 		    cp = buf + sizeof("sortlist") - 1;
453 		    while (nsort < MAXRESOLVSORT) {
454 			while (*cp == ' ' || *cp == '\t')
455 			    cp++;
456 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
457 			    break;
458 			net = cp;
459 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
460 			       isascii(*cp) && !isspace((unsigned char)*cp))
461 				cp++;
462 			n = *cp;
463 			*cp = 0;
464 			if (inet_aton(net, &a)) {
465 			    statp->sort_list[nsort].addr = a;
466 			    if (ISSORTMASK(n)) {
467 				*cp++ = n;
468 				net = cp;
469 				while (*cp && *cp != ';' &&
470 					isascii(*cp) &&
471 					!isspace((unsigned char)*cp))
472 				    cp++;
473 				n = *cp;
474 				*cp = 0;
475 				if (inet_aton(net, &a)) {
476 				    statp->sort_list[nsort].mask = a.s_addr;
477 				} else {
478 				    statp->sort_list[nsort].mask =
479 					net_mask(statp->sort_list[nsort].addr);
480 				}
481 			    } else {
482 				statp->sort_list[nsort].mask =
483 				    net_mask(statp->sort_list[nsort].addr);
484 			    }
485 			    nsort++;
486 			}
487 			*cp = n;
488 		    }
489 		    continue;
490 		}
491 #endif
492 		if (MATCH(buf, "options")) {
493 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
494 		    continue;
495 		}
496 	    }
497 	    if (nserv > 0)
498 		statp->nscount = nserv;
499 #ifdef RESOLVSORT
500 	    statp->nsort = nsort;
501 #endif
502 	    statp->_u._ext.ext->resfd = fcntl(fileno(fp), F_DUPFD_CLOEXEC);
503 	    (void) fclose(fp);
504 	    if (fstat(statp->_u._ext.ext->resfd, &st) != -1)
505 		    __res_conf_time = statp->_u._ext.ext->res_conf_time =
506 			st.st_mtimespec;
507 	    statp->_u._ext.ext->kq = kqueue1(O_CLOEXEC);
508 	    EV_SET(&kc, statp->_u._ext.ext->resfd, EVFILT_VNODE,
509 		EV_ADD|EV_ENABLE|EV_CLEAR, NOTE_DELETE|NOTE_WRITE| NOTE_EXTEND|
510 		NOTE_ATTRIB|NOTE_LINK|NOTE_RENAME|NOTE_REVOKE, 0, 0);
511 	    (void)kevent(statp->_u._ext.ext->kq, &kc, 1, NULL, 0, &ts);
512 	} else {
513 	    statp->_u._ext.ext->kq = -1;
514 	    statp->_u._ext.ext->resfd = -1;
515 	}
516 /*
517  * Last chance to get a nameserver.  This should not normally
518  * be necessary
519  */
520 #ifdef NO_RESOLV_CONF
521 	if(nserv == 0)
522 		nserv = get_nameservers(statp);
523 #endif
524 
525 	if (statp->defdname[0] == 0 &&
526 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
527 	    (cp = strchr(buf, '.')) != NULL)
528 		strcpy(statp->defdname, cp + 1);
529 
530 	/* find components of local domain that might be searched */
531 	if (havesearch == 0) {
532 		pp = statp->dnsrch;
533 		*pp++ = statp->defdname;
534 		*pp = NULL;
535 
536 		dots = 0;
537 		for (cp = statp->defdname; *cp; cp++)
538 			dots += (*cp == '.');
539 
540 		cp = statp->defdname;
541 		while (pp < statp->dnsrch + MAXDFLSRCH) {
542 			if (dots < LOCALDOMAINPARTS)
543 				break;
544 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
545 			*pp++ = cp;
546 			dots--;
547 		}
548 		*pp = NULL;
549 #ifdef DEBUG
550 		if (statp->options & RES_DEBUG) {
551 			printf(";; res_init()... default dnsrch list:\n");
552 			for (pp = statp->dnsrch; *pp; pp++)
553 				printf(";;\t%s\n", *pp);
554 			printf(";;\t..END..\n");
555 		}
556 #endif
557 	}
558 
559 	if ((cp = getenv("RES_OPTIONS")) != NULL)
560 		res_setoptions(statp, cp, "env");
561 	statp->options |= RES_INIT;
562 	return (statp->res_h_errno);
563 }
564 
565 int
566 res_check(res_state statp, struct timespec *mtime)
567 {
568 	/*
569 	 * If the times are equal, then we check if there
570 	 * was a kevent related to resolv.conf and reload.
571 	 * If the times are not equal, then we don't bother
572 	 * to check the kevent, because another thread already
573 	 * did, loaded and changed the time.
574 	 */
575 	if (timespeccmp(&statp->_u._ext.ext->res_conf_time,
576 	    &__res_conf_time, ==)) {
577 		struct kevent ke;
578 		if (statp->_u._ext.ext->kq == -1)
579 			goto out;
580 
581 		switch (kevent(statp->_u._ext.ext->kq, NULL, 0, &ke, 1, &ts)) {
582 		case 0:
583 		case -1:
584 out:
585 			if (mtime)
586 				*mtime = __res_conf_time;
587 			return 0;
588 		default:
589 			break;
590 		}
591 	}
592 	(void)__res_vinit(statp, 0);
593 	if (mtime)
594 		*mtime = __res_conf_time;
595 	return 1;
596 }
597 
598 static void
599 res_setoptions(res_state statp, const char *options, const char *source)
600 {
601 	const char *cp = options;
602 	int i;
603 	size_t j;
604 	struct __res_state_ext *ext = statp->_u._ext.ext;
605 
606 #ifdef DEBUG
607 	if (statp->options & RES_DEBUG)
608 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
609 		       options, source);
610 #endif
611 	while (*cp) {
612 		/* skip leading and inner runs of spaces */
613 		while (*cp == ' ' || *cp == '\t')
614 			cp++;
615 		/* search for and process individual options */
616 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
617 			i = atoi(cp + sizeof("ndots:") - 1);
618 			if (i <= RES_MAXNDOTS)
619 				statp->ndots = i;
620 			else
621 				statp->ndots = RES_MAXNDOTS;
622 #ifdef DEBUG
623 			if (statp->options & RES_DEBUG)
624 				printf(";;\tndots=%d\n", statp->ndots);
625 #endif
626 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
627 			i = atoi(cp + sizeof("timeout:") - 1);
628 			if (i <= RES_MAXRETRANS)
629 				statp->retrans = i;
630 			else
631 				statp->retrans = RES_MAXRETRANS;
632 #ifdef DEBUG
633 			if (statp->options & RES_DEBUG)
634 				printf(";;\ttimeout=%d\n", statp->retrans);
635 #endif
636 #ifdef	SOLARIS2
637 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
638 			/*
639 		 	 * For backward compatibility, 'retrans' is
640 		 	 * supported as an alias for 'timeout', though
641 		 	 * without an imposed maximum.
642 		 	 */
643 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
644 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
645 			/*
646 			 * For backward compatibility, 'retry' is
647 			 * supported as an alias for 'attempts', though
648 			 * without an imposed maximum.
649 			 */
650 			statp->retry = atoi(cp + sizeof("retry:") - 1);
651 #endif	/* SOLARIS2 */
652 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
653 			i = atoi(cp + sizeof("attempts:") - 1);
654 			if (i <= RES_MAXRETRY)
655 				statp->retry = i;
656 			else
657 				statp->retry = RES_MAXRETRY;
658 #ifdef DEBUG
659 			if (statp->options & RES_DEBUG)
660 				printf(";;\tattempts=%d\n", statp->retry);
661 #endif
662 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
663 #ifdef DEBUG
664 			if (!(statp->options & RES_DEBUG)) {
665 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
666 				       options, source);
667 				statp->options |= RES_DEBUG;
668 			}
669 			printf(";;\tdebug\n");
670 #endif
671 		} else if (!strncmp(cp, "no_tld_query",
672 				    sizeof("no_tld_query") - 1) ||
673 			   !strncmp(cp, "no-tld-query",
674 				    sizeof("no-tld-query") - 1)) {
675 			statp->options |= RES_NOTLDQUERY;
676 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
677 			statp->options |= RES_USE_INET6;
678 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
679 			statp->options |= RES_ROTATE;
680 		} else if (!strncmp(cp, "no-check-names",
681 				    sizeof("no-check-names") - 1)) {
682 			statp->options |= RES_NOCHECKNAME;
683 		} else if (!strncmp(cp, "check-names",
684 				    sizeof("check-names") - 1)) {
685 			statp->options &= ~RES_NOCHECKNAME;
686 		}
687 #ifdef RES_USE_EDNS0
688 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
689 			statp->options |= RES_USE_EDNS0;
690 		}
691 #endif
692 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
693 			statp->options |= RES_USE_DNAME;
694 		}
695 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
696 			if (ext == NULL)
697 				goto skip;
698 			cp += sizeof("nibble:") - 1;
699 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
700 			strncpy(ext->nsuffix, cp, j);
701 			ext->nsuffix[j] = '\0';
702 		}
703 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
704 			if (ext == NULL)
705 				goto skip;
706 			cp += sizeof("nibble2:") - 1;
707 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
708 			strncpy(ext->nsuffix2, cp, j);
709 			ext->nsuffix2[j] = '\0';
710 		}
711 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
712 			cp += sizeof("v6revmode:") - 1;
713 			/* "nibble" and "bitstring" used to be valid */
714 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
715 				statp->options |= RES_NO_NIBBLE2;
716 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
717 				statp->options &=
718 					 ~RES_NO_NIBBLE2;
719 			}
720 		}
721 		else {
722 			/* XXX - print a warning here? */
723 		}
724    skip:
725 		/* skip to next run of spaces */
726 		while (*cp && *cp != ' ' && *cp != '\t')
727 			cp++;
728 	}
729 }
730 
731 #ifdef RESOLVSORT
732 /* XXX - should really support CIDR which means explicit masks always. */
733 static uint32_t
734 net_mask(struct in_addr in) /*!< XXX - should really use system's version of this  */
735 {
736 	register uint32_t i = ntohl(in.s_addr);
737 
738 	if (IN_CLASSA(i))
739 		return (htonl(IN_CLASSA_NET));
740 	else if (IN_CLASSB(i))
741 		return (htonl(IN_CLASSB_NET));
742 	return (htonl(IN_CLASSC_NET));
743 }
744 #endif
745 
746 static u_char srnd[16];
747 
748 void
749 res_rndinit(res_state statp)
750 {
751 	struct timeval now;
752 	uint32_t u32;
753 	uint16_t u16;
754 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
755 
756 	gettimeofday(&now, NULL);
757 	u32 = (uint32_t)now.tv_sec;
758 	memcpy(rnd, &u32, 4);
759 	u32 = now.tv_usec;
760 	memcpy(rnd + 4, &u32, 4);
761 	u32 += (uint32_t)now.tv_sec;
762 	memcpy(rnd + 8, &u32, 4);
763 	u16 = getpid();
764 	memcpy(rnd + 12, &u16, 2);
765 }
766 
767 u_int
768 res_nrandomid(res_state statp)
769 {
770 	struct timeval now;
771 	uint16_t u16;
772 	MD5_CTX ctx;
773 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
774 
775 	gettimeofday(&now, NULL);
776 	u16 = (uint16_t) (now.tv_sec ^ now.tv_usec);
777 	memcpy(rnd + 14, &u16, 2);
778 #ifndef HAVE_MD5
779 	MD5_Init(&ctx);
780 	MD5_Update(&ctx, rnd, 16);
781 	MD5_Final(rnd, &ctx);
782 #else
783 	MD5Init(&ctx);
784 	MD5Update(&ctx, rnd, 16);
785 	MD5Final(rnd, &ctx);
786 #endif
787 	memcpy(&u16, rnd + 14, 2);
788 	return ((u_int) u16);
789 }
790 
791 /*%
792  * This routine is for closing the socket if a virtual circuit is used and
793  * the program wants to close it.  This provides support for endhostent()
794  * which expects to close the socket.
795  *
796  * This routine is not expected to be user visible.
797  */
798 void
799 res_nclose(res_state statp)
800 {
801 	int ns;
802 
803 	if (statp->_vcsock >= 0) {
804 		(void) close(statp->_vcsock);
805 		statp->_vcsock = -1;
806 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
807 	}
808 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
809 		if (statp->_u._ext.nssocks[ns] != -1) {
810 			(void) close(statp->_u._ext.nssocks[ns]);
811 			statp->_u._ext.nssocks[ns] = -1;
812 		}
813 	}
814 }
815 
816 void
817 res_ndestroy(res_state statp)
818 {
819 	res_nclose(statp);
820 	if (statp->_u._ext.ext != NULL) {
821 		if (statp->_u._ext.ext->kq != -1)
822 			(void)close(statp->_u._ext.ext->kq);
823 		if (statp->_u._ext.ext->resfd != -1)
824 			(void)close(statp->_u._ext.ext->resfd);
825 		free(statp->_u._ext.ext);
826 		statp->_u._ext.ext = NULL;
827 	}
828 	if (statp->_rnd != NULL) {
829 		free(statp->_rnd);
830 		statp->_rnd = NULL;
831 	}
832 	statp->options &= ~RES_INIT;
833 }
834 
835 const char *
836 res_get_nibblesuffix(res_state statp)
837 {
838 	if (statp->_u._ext.ext)
839 		return (statp->_u._ext.ext->nsuffix);
840 	return ("ip6.arpa");
841 }
842 
843 const char *
844 res_get_nibblesuffix2(res_state statp)
845 {
846 	if (statp->_u._ext.ext)
847 		return (statp->_u._ext.ext->nsuffix2);
848 	return ("ip6.int");
849 }
850 
851 void
852 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt)
853 {
854 	int i, nserv;
855 	size_t size;
856 
857 	/* close open servers */
858 	res_nclose(statp);
859 
860 	/* cause rtt times to be forgotten */
861 	statp->_u._ext.nscount = 0;
862 
863 	nserv = 0;
864 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
865 		switch (set->sin.sin_family) {
866 		case AF_INET:
867 			size = sizeof(set->sin);
868 			if (statp->_u._ext.ext)
869 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
870 					&set->sin, size);
871 			if (size <= sizeof(statp->nsaddr_list[nserv]))
872 				memcpy(&statp->nsaddr_list[nserv],
873 					&set->sin, size);
874 			else
875 				statp->nsaddr_list[nserv].sin_family = 0;
876 			nserv++;
877 			break;
878 
879 #ifdef HAS_INET6_STRUCTS
880 		case AF_INET6:
881 			size = sizeof(set->sin6);
882 			if (statp->_u._ext.ext)
883 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
884 					&set->sin6, size);
885 			if (size <= sizeof(statp->nsaddr_list[nserv]))
886 				memcpy(&statp->nsaddr_list[nserv],
887 					&set->sin6, size);
888 			else
889 				statp->nsaddr_list[nserv].sin_family = 0;
890 			nserv++;
891 			break;
892 #endif
893 
894 		default:
895 			break;
896 		}
897 		set++;
898 	}
899 	statp->nscount = nserv;
900 
901 }
902 
903 int
904 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt)
905 {
906 	int i;
907 	size_t size;
908 	uint16_t family;
909 
910 	for (i = 0; i < statp->nscount && i < cnt; i++) {
911 		if (statp->_u._ext.ext)
912 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
913 		else
914 			family = statp->nsaddr_list[i].sin_family;
915 
916 		switch (family) {
917 		case AF_INET:
918 			size = sizeof(set->sin);
919 			if (statp->_u._ext.ext)
920 				memcpy(&set->sin,
921 				       &statp->_u._ext.ext->nsaddrs[i],
922 				       size);
923 			else
924 				memcpy(&set->sin, &statp->nsaddr_list[i],
925 				       size);
926 			break;
927 
928 #ifdef HAS_INET6_STRUCTS
929 		case AF_INET6:
930 			size = sizeof(set->sin6);
931 			if (statp->_u._ext.ext)
932 				memcpy(&set->sin6,
933 				       &statp->_u._ext.ext->nsaddrs[i],
934 				       size);
935 			else
936 				memcpy(&set->sin6, &statp->nsaddr_list[i],
937 				       size);
938 			break;
939 #endif
940 
941 		default:
942 			set->sin.sin_family = 0;
943 			break;
944 		}
945 		set++;
946 	}
947 	return (statp->nscount);
948 }
949 
950 /*! \file */
951