xref: /minix3/lib/libc/resolv/res_init.c (revision ef01931f760fe8114e6dd99a6864c92b3a85ae12)
1 /*	$NetBSD: res_init.c,v 1.22 2009/10/24 17:24:01 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 1.22 2009/10/24 17:24:01 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 #ifndef __minix
92 #include <sys/event.h>
93 #endif /* !__minix */
94 
95 #include <netinet/in.h>
96 #include <arpa/inet.h>
97 #include <arpa/nameser.h>
98 
99 #include <ctype.h>
100 #include <stdio.h>
101 #include <stdlib.h>
102 #include <string.h>
103 #include <unistd.h>
104 #include <fcntl.h>
105 #include <netdb.h>
106 
107 #define HAVE_MD5
108 #include <md5.h>
109 
110 #ifndef HAVE_MD5
111 # include "../dst/md5.h"
112 #else
113 # ifdef SOLARIS2
114 #  include <sys/md5.h>
115 # endif
116 #endif
117 #ifndef _MD5_H_
118 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
119 #endif
120 
121 #include "port_after.h"
122 
123 #if 0
124 #ifdef __weak_alias
125 __weak_alias(res_ninit,_res_ninit)
126 __weak_alias(res_randomid,__res_randomid)
127 __weak_alias(res_nclose,_res_nclose)
128 __weak_alias(res_ndestroy,_res_ndestroy)
129 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
130 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
131 __weak_alias(res_getservers,__res_getservers)
132 __weak_alias(res_setservers,__res_setservers)
133 #endif
134 #endif
135 
136 
137 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
138 #include <resolv.h>
139 
140 #include "res_private.h"
141 
142 #define RESOLVSORT
143 /*% Options.  Should all be left alone. */
144 #ifndef DEBUG
145 #define DEBUG
146 #endif
147 
148 #ifdef SOLARIS2
149 #include <sys/systeminfo.h>
150 #endif
151 
152 static void res_setoptions __P((res_state, const char *, const char *));
153 
154 #ifdef RESOLVSORT
155 static const char sort_mask[] = "/&";
156 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
157 static u_int32_t net_mask __P((struct in_addr));
158 #endif
159 
160 #if !defined(isascii)	/*%< XXX - could be a function */
161 # define isascii(c) (!(c & 0200))
162 #endif
163 
164 static struct timespec __res_conf_time;
165 static const struct timespec ts = { 0, 0 };
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 then 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(_PATH_RESCONF, "r")) != NULL) {
352 	    struct stat st;
353 #ifndef __minix
354 	    struct kevent kc;
355 #endif /* !__minix */
356 
357 	    /* read the config file */
358 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
359 		/* skip comments */
360 		if (*buf == ';' || *buf == '#')
361 			continue;
362 		/* read default domain name */
363 		if (MATCH(buf, "domain")) {
364 		    if (haveenv)	/*%< skip if have from environ */
365 			    continue;
366 		    cp = buf + sizeof("domain") - 1;
367 		    while (*cp == ' ' || *cp == '\t')
368 			    cp++;
369 		    if ((*cp == '\0') || (*cp == '\n'))
370 			    continue;
371 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
372 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
373 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
374 			    *cp = '\0';
375 		    havesearch = 0;
376 		    continue;
377 		}
378 		/* set search list */
379 		if (MATCH(buf, "search")) {
380 		    if (haveenv)	/*%< skip if have from environ */
381 			    continue;
382 		    cp = buf + sizeof("search") - 1;
383 		    while (*cp == ' ' || *cp == '\t')
384 			    cp++;
385 		    if ((*cp == '\0') || (*cp == '\n'))
386 			    continue;
387 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
388 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
389 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
390 			    *cp = '\0';
391 		    /*
392 		     * Set search list to be blank-separated strings
393 		     * on rest of line.
394 		     */
395 		    cp = statp->defdname;
396 		    pp = statp->dnsrch;
397 		    *pp++ = cp;
398 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
399 			    if (*cp == ' ' || *cp == '\t') {
400 				    *cp = 0;
401 				    n = 1;
402 			    } else if (n) {
403 				    *pp++ = cp;
404 				    n = 0;
405 			    }
406 		    }
407 		    /* null terminate last domain if there are excess */
408 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
409 			    cp++;
410 		    *cp = '\0';
411 		    *pp++ = 0;
412 		    havesearch = 1;
413 		    continue;
414 		}
415 		/* read nameservers to query */
416 		if (MATCH(buf, "nameserver") && nserv < maxns) {
417 		    struct addrinfo hints, *ai;
418 		    char sbuf[NI_MAXSERV];
419 		    const size_t minsiz =
420 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
421 
422 		    cp = buf + sizeof("nameserver") - 1;
423 		    while (*cp == ' ' || *cp == '\t')
424 			cp++;
425 		    cp[strcspn(cp, ";# \t\n")] = '\0';
426 		    if ((*cp != '\0') && (*cp != '\n')) {
427 			memset(&hints, 0, sizeof(hints));
428 			hints.ai_family = PF_UNSPEC;
429 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
430 			hints.ai_flags = AI_NUMERICHOST;
431 			sprintf(sbuf, "%u", NAMESERVER_PORT);
432 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
433 			    ai->ai_addrlen <= minsiz) {
434 			    if (statp->_u._ext.ext != NULL) {
435 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
436 				    ai->ai_addr, ai->ai_addrlen);
437 			    }
438 			    if (ai->ai_addrlen <=
439 			        sizeof(statp->nsaddr_list[nserv])) {
440 				memcpy(&statp->nsaddr_list[nserv],
441 				    ai->ai_addr, ai->ai_addrlen);
442 			    } else
443 				statp->nsaddr_list[nserv].sin_family = 0;
444 			    freeaddrinfo(ai);
445 			    nserv++;
446 			}
447 		    }
448 		    continue;
449 		}
450 #ifdef RESOLVSORT
451 		if (MATCH(buf, "sortlist")) {
452 		    struct in_addr a;
453 
454 		    cp = buf + sizeof("sortlist") - 1;
455 		    while (nsort < MAXRESOLVSORT) {
456 			while (*cp == ' ' || *cp == '\t')
457 			    cp++;
458 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
459 			    break;
460 			net = cp;
461 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
462 			       isascii(*cp) && !isspace((unsigned char)*cp))
463 				cp++;
464 			n = *cp;
465 			*cp = 0;
466 			if (inet_aton(net, &a)) {
467 			    statp->sort_list[nsort].addr = a;
468 			    if (ISSORTMASK(n)) {
469 				*cp++ = n;
470 				net = cp;
471 				while (*cp && *cp != ';' &&
472 					isascii(*cp) &&
473 					!isspace((unsigned char)*cp))
474 				    cp++;
475 				n = *cp;
476 				*cp = 0;
477 				if (inet_aton(net, &a)) {
478 				    statp->sort_list[nsort].mask = a.s_addr;
479 				} else {
480 				    statp->sort_list[nsort].mask =
481 					net_mask(statp->sort_list[nsort].addr);
482 				}
483 			    } else {
484 				statp->sort_list[nsort].mask =
485 				    net_mask(statp->sort_list[nsort].addr);
486 			    }
487 			    nsort++;
488 			}
489 			*cp = n;
490 		    }
491 		    continue;
492 		}
493 #endif
494 		if (MATCH(buf, "options")) {
495 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
496 		    continue;
497 		}
498 	    }
499 	    if (nserv > 0)
500 		statp->nscount = nserv;
501 #ifdef RESOLVSORT
502 	    statp->nsort = nsort;
503 #endif
504 	    statp->_u._ext.ext->resfd = dup(fileno(fp));
505 	    (void) fclose(fp);
506 	    if (fstat(statp->_u._ext.ext->resfd, &st) != -1)
507 		    __res_conf_time = statp->_u._ext.ext->res_conf_time =
508 			st.st_mtimespec;
509 #ifndef __minix
510 	    statp->_u._ext.ext->kq = kqueue();
511 	    (void)fcntl(statp->_u._ext.ext->kq, F_SETFD, FD_CLOEXEC);
512 	    (void)fcntl(statp->_u._ext.ext->resfd, F_SETFD, FD_CLOEXEC);
513 	    EV_SET(&kc, statp->_u._ext.ext->resfd, EVFILT_VNODE,
514 		EV_ADD|EV_ENABLE|EV_CLEAR, NOTE_DELETE|NOTE_WRITE| NOTE_EXTEND|
515 		NOTE_ATTRIB|NOTE_LINK|NOTE_RENAME|NOTE_REVOKE, 0, 0);
516 	    (void)kevent(statp->_u._ext.ext->kq, &kc, 1, NULL, 0, &ts);
517 #else /* __minix */
518 	statp->_u._ext.ext->kq = -1;
519 #endif /* !__minix */
520 	} else {
521 	    statp->_u._ext.ext->kq = -1;
522 	    statp->_u._ext.ext->resfd = -1;
523 	}
524 /*
525  * Last chance to get a nameserver.  This should not normally
526  * be necessary
527  */
528 #ifdef NO_RESOLV_CONF
529 	if(nserv == 0)
530 		nserv = get_nameservers(statp);
531 #endif
532 
533 	if (statp->defdname[0] == 0 &&
534 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
535 	    (cp = strchr(buf, '.')) != NULL)
536 		strcpy(statp->defdname, cp + 1);
537 
538 	/* find components of local domain that might be searched */
539 	if (havesearch == 0) {
540 		pp = statp->dnsrch;
541 		*pp++ = statp->defdname;
542 		*pp = NULL;
543 
544 		dots = 0;
545 		for (cp = statp->defdname; *cp; cp++)
546 			dots += (*cp == '.');
547 
548 		cp = statp->defdname;
549 		while (pp < statp->dnsrch + MAXDFLSRCH) {
550 			if (dots < LOCALDOMAINPARTS)
551 				break;
552 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
553 			*pp++ = cp;
554 			dots--;
555 		}
556 		*pp = NULL;
557 #ifdef DEBUG
558 		if (statp->options & RES_DEBUG) {
559 			printf(";; res_init()... default dnsrch list:\n");
560 			for (pp = statp->dnsrch; *pp; pp++)
561 				printf(";;\t%s\n", *pp);
562 			printf(";;\t..END..\n");
563 		}
564 #endif
565 	}
566 
567 	if ((cp = getenv("RES_OPTIONS")) != NULL)
568 		res_setoptions(statp, cp, "env");
569 	statp->options |= RES_INIT;
570 	return (statp->res_h_errno);
571 }
572 
573 int
574 res_check(res_state statp, struct timespec *mtime)
575 {
576 #ifdef __minix
577 	/*
578 	 * XXX: No update on change.
579 	 */
580 	return 0;
581 #else /* !__minix */
582 	/*
583 	 * If the times are equal, then we check if there
584 	 * was a kevent related to resolv.conf and reload.
585 	 * If the times are not equal, then we don't bother
586 	 * to check the kevent, because another thread already
587 	 * did, loaded and changed the time.
588 	 */
589 	if (timespeccmp(&statp->_u._ext.ext->res_conf_time,
590 	    &__res_conf_time, ==)) {
591 		struct kevent ke;
592 		if (statp->_u._ext.ext->kq == -1)
593 			goto out;
594 
595 		switch (kevent(statp->_u._ext.ext->kq, NULL, 0, &ke, 1, &ts)) {
596 		case 0:
597 		case -1:
598 out:
599 			if (mtime)
600 				*mtime = __res_conf_time;
601 			return 0;
602 		default:
603 			break;
604 		}
605 	}
606 	(void)__res_vinit(statp, 0);
607 	if (mtime)
608 		*mtime = __res_conf_time;
609 	return 1;
610 #endif /* !__minix */
611 }
612 
613 static void
614 res_setoptions(res_state statp, const char *options, const char *source)
615 {
616 	const char *cp = options;
617 	int i;
618 	struct __res_state_ext *ext = statp->_u._ext.ext;
619 
620 #ifdef DEBUG
621 	if (statp->options & RES_DEBUG)
622 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
623 		       options, source);
624 #endif
625 	while (*cp) {
626 		/* skip leading and inner runs of spaces */
627 		while (*cp == ' ' || *cp == '\t')
628 			cp++;
629 		/* search for and process individual options */
630 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
631 			i = atoi(cp + sizeof("ndots:") - 1);
632 			if (i <= RES_MAXNDOTS)
633 				statp->ndots = i;
634 			else
635 				statp->ndots = RES_MAXNDOTS;
636 #ifdef DEBUG
637 			if (statp->options & RES_DEBUG)
638 				printf(";;\tndots=%d\n", statp->ndots);
639 #endif
640 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
641 			i = atoi(cp + sizeof("timeout:") - 1);
642 			if (i <= RES_MAXRETRANS)
643 				statp->retrans = i;
644 			else
645 				statp->retrans = RES_MAXRETRANS;
646 #ifdef DEBUG
647 			if (statp->options & RES_DEBUG)
648 				printf(";;\ttimeout=%d\n", statp->retrans);
649 #endif
650 #ifdef	SOLARIS2
651 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
652 			/*
653 		 	 * For backward compatibility, 'retrans' is
654 		 	 * supported as an alias for 'timeout', though
655 		 	 * without an imposed maximum.
656 		 	 */
657 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
658 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
659 			/*
660 			 * For backward compatibility, 'retry' is
661 			 * supported as an alias for 'attempts', though
662 			 * without an imposed maximum.
663 			 */
664 			statp->retry = atoi(cp + sizeof("retry:") - 1);
665 #endif	/* SOLARIS2 */
666 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
667 			i = atoi(cp + sizeof("attempts:") - 1);
668 			if (i <= RES_MAXRETRY)
669 				statp->retry = i;
670 			else
671 				statp->retry = RES_MAXRETRY;
672 #ifdef DEBUG
673 			if (statp->options & RES_DEBUG)
674 				printf(";;\tattempts=%d\n", statp->retry);
675 #endif
676 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
677 #ifdef DEBUG
678 			if (!(statp->options & RES_DEBUG)) {
679 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
680 				       options, source);
681 				statp->options |= RES_DEBUG;
682 			}
683 			printf(";;\tdebug\n");
684 #endif
685 		} else if (!strncmp(cp, "no_tld_query",
686 				    sizeof("no_tld_query") - 1) ||
687 			   !strncmp(cp, "no-tld-query",
688 				    sizeof("no-tld-query") - 1)) {
689 			statp->options |= RES_NOTLDQUERY;
690 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
691 			statp->options |= RES_USE_INET6;
692 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
693 			statp->options |= RES_ROTATE;
694 		} else if (!strncmp(cp, "no-check-names",
695 				    sizeof("no-check-names") - 1)) {
696 			statp->options |= RES_NOCHECKNAME;
697 		}
698 #ifdef RES_USE_EDNS0
699 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
700 			statp->options |= RES_USE_EDNS0;
701 		}
702 #endif
703 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
704 			statp->options |= RES_USE_DNAME;
705 		}
706 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
707 			if (ext == NULL)
708 				goto skip;
709 			cp += sizeof("nibble:") - 1;
710 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
711 			strncpy(ext->nsuffix, cp, (size_t)i);
712 			ext->nsuffix[i] = '\0';
713 		}
714 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
715 			if (ext == NULL)
716 				goto skip;
717 			cp += sizeof("nibble2:") - 1;
718 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
719 			strncpy(ext->nsuffix2, cp, (size_t)i);
720 			ext->nsuffix2[i] = '\0';
721 		}
722 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
723 			cp += sizeof("v6revmode:") - 1;
724 			/* "nibble" and "bitstring" used to be valid */
725 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
726 				statp->options |= RES_NO_NIBBLE2;
727 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
728 				statp->options &=
729 					 ~RES_NO_NIBBLE2;
730 			}
731 		}
732 		else {
733 			/* XXX - print a warning here? */
734 		}
735    skip:
736 		/* skip to next run of spaces */
737 		while (*cp && *cp != ' ' && *cp != '\t')
738 			cp++;
739 	}
740 }
741 
742 #ifdef RESOLVSORT
743 /* XXX - should really support CIDR which means explicit masks always. */
744 static u_int32_t
745 net_mask(in)		/*!< XXX - should really use system's version of this  */
746 	struct in_addr in;
747 {
748 	register u_int32_t i = ntohl(in.s_addr);
749 
750 	if (IN_CLASSA(i))
751 		return (htonl(IN_CLASSA_NET));
752 	else if (IN_CLASSB(i))
753 		return (htonl(IN_CLASSB_NET));
754 	return (htonl(IN_CLASSC_NET));
755 }
756 #endif
757 
758 static u_char srnd[16];
759 
760 void
761 res_rndinit(res_state statp)
762 {
763 	struct timeval now;
764 	u_int32_t u32;
765 	u_int16_t u16;
766 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
767 
768 	gettimeofday(&now, NULL);
769 	u32 = (u_int32_t)now.tv_sec;
770 	memcpy(rnd, &u32, 4);
771 	u32 = now.tv_usec;
772 	memcpy(rnd + 4, &u32, 4);
773 	u32 += (u_int32_t)now.tv_sec;
774 	memcpy(rnd + 8, &u32, 4);
775 	u16 = getpid();
776 	memcpy(rnd + 12, &u16, 2);
777 }
778 
779 u_int
780 res_nrandomid(res_state statp) {
781 	struct timeval now;
782 	u_int16_t u16;
783 	MD5_CTX ctx;
784 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
785 
786 	gettimeofday(&now, NULL);
787 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
788 	memcpy(rnd + 14, &u16, 2);
789 #ifndef HAVE_MD5
790 	MD5_Init(&ctx);
791 	MD5_Update(&ctx, rnd, 16);
792 	MD5_Final(rnd, &ctx);
793 #else
794 	MD5Init(&ctx);
795 	MD5Update(&ctx, rnd, 16);
796 	MD5Final(rnd, &ctx);
797 #endif
798 	memcpy(&u16, rnd + 14, 2);
799 	return ((u_int) u16);
800 }
801 
802 /*%
803  * This routine is for closing the socket if a virtual circuit is used and
804  * the program wants to close it.  This provides support for endhostent()
805  * which expects to close the socket.
806  *
807  * This routine is not expected to be user visible.
808  */
809 void
810 res_nclose(res_state statp) {
811 	int ns;
812 
813 	if (statp->_vcsock >= 0) {
814 		(void) close(statp->_vcsock);
815 		statp->_vcsock = -1;
816 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
817 	}
818 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
819 		if (statp->_u._ext.nssocks[ns] != -1) {
820 			(void) close(statp->_u._ext.nssocks[ns]);
821 			statp->_u._ext.nssocks[ns] = -1;
822 		}
823 	}
824 }
825 
826 void
827 res_ndestroy(res_state statp) {
828 	res_nclose(statp);
829 	if (statp->_u._ext.ext != NULL) {
830 		if (statp->_u._ext.ext->kq != -1)
831 			(void)close(statp->_u._ext.ext->kq);
832 		if (statp->_u._ext.ext->resfd != -1)
833 			(void)close(statp->_u._ext.ext->resfd);
834 		free(statp->_u._ext.ext);
835 		statp->_u._ext.ext = NULL;
836 	}
837 	if (statp->_rnd != NULL) {
838 		free(statp->_rnd);
839 		statp->_rnd = NULL;
840 	}
841 	statp->options &= ~RES_INIT;
842 }
843 
844 const char *
845 res_get_nibblesuffix(res_state statp) {
846 	if (statp->_u._ext.ext)
847 		return (statp->_u._ext.ext->nsuffix);
848 	return ("ip6.arpa");
849 }
850 
851 const char *
852 res_get_nibblesuffix2(res_state statp) {
853 	if (statp->_u._ext.ext)
854 		return (statp->_u._ext.ext->nsuffix2);
855 	return ("ip6.int");
856 }
857 
858 void
859 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
860 	int i, nserv;
861 	size_t size;
862 
863 	/* close open servers */
864 	res_nclose(statp);
865 
866 	/* cause rtt times to be forgotten */
867 	statp->_u._ext.nscount = 0;
868 
869 	nserv = 0;
870 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
871 		switch (set->sin.sin_family) {
872 		case AF_INET:
873 			size = sizeof(set->sin);
874 			if (statp->_u._ext.ext)
875 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
876 					&set->sin, size);
877 			if (size <= sizeof(statp->nsaddr_list[nserv]))
878 				memcpy(&statp->nsaddr_list[nserv],
879 					&set->sin, size);
880 			else
881 				statp->nsaddr_list[nserv].sin_family = 0;
882 			nserv++;
883 			break;
884 
885 #ifdef HAS_INET6_STRUCTS
886 		case AF_INET6:
887 			size = sizeof(set->sin6);
888 			if (statp->_u._ext.ext)
889 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
890 					&set->sin6, size);
891 			if (size <= sizeof(statp->nsaddr_list[nserv]))
892 				memcpy(&statp->nsaddr_list[nserv],
893 					&set->sin6, size);
894 			else
895 				statp->nsaddr_list[nserv].sin_family = 0;
896 			nserv++;
897 			break;
898 #endif
899 
900 		default:
901 			break;
902 		}
903 		set++;
904 	}
905 	statp->nscount = nserv;
906 
907 }
908 
909 int
910 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
911 	int i;
912 	size_t size;
913 	u_int16_t family;
914 
915 	for (i = 0; i < statp->nscount && i < cnt; i++) {
916 		if (statp->_u._ext.ext)
917 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
918 		else
919 			family = statp->nsaddr_list[i].sin_family;
920 
921 		switch (family) {
922 		case AF_INET:
923 			size = sizeof(set->sin);
924 			if (statp->_u._ext.ext)
925 				memcpy(&set->sin,
926 				       &statp->_u._ext.ext->nsaddrs[i],
927 				       size);
928 			else
929 				memcpy(&set->sin, &statp->nsaddr_list[i],
930 				       size);
931 			break;
932 
933 #ifdef HAS_INET6_STRUCTS
934 		case AF_INET6:
935 			size = sizeof(set->sin6);
936 			if (statp->_u._ext.ext)
937 				memcpy(&set->sin6,
938 				       &statp->_u._ext.ext->nsaddrs[i],
939 				       size);
940 			else
941 				memcpy(&set->sin6, &statp->nsaddr_list[i],
942 				       size);
943 			break;
944 #endif
945 
946 		default:
947 			set->sin.sin_family = 0;
948 			break;
949 		}
950 		set++;
951 	}
952 	return (statp->nscount);
953 }
954 
955 /*! \file */
956