xref: /netbsd-src/lib/libc/resolv/res_init.c (revision da9817918ec7e88db2912a2882967c7570a83f47)
1 /*	$NetBSD: res_init.c,v 1.20 2009/04/20 14:42:12 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 1.20 2009/04/20 14:42:12 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/time.h>
90 
91 #include <netinet/in.h>
92 #include <arpa/inet.h>
93 #include <arpa/nameser.h>
94 
95 #include <ctype.h>
96 #include <stdio.h>
97 #include <stdlib.h>
98 #include <string.h>
99 #include <unistd.h>
100 #include <netdb.h>
101 
102 #define HAVE_MD5
103 #include <md5.h>
104 
105 #ifndef HAVE_MD5
106 # include "../dst/md5.h"
107 #else
108 # ifdef SOLARIS2
109 #  include <sys/md5.h>
110 # endif
111 #endif
112 #ifndef _MD5_H_
113 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
114 #endif
115 
116 #include "port_after.h"
117 
118 #if 0
119 #ifdef __weak_alias
120 __weak_alias(res_ninit,_res_ninit)
121 __weak_alias(res_randomid,__res_randomid)
122 __weak_alias(res_nclose,_res_nclose)
123 __weak_alias(res_ndestroy,_res_ndestroy)
124 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
125 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
126 __weak_alias(res_getservers,__res_getservers)
127 __weak_alias(res_setservers,__res_setservers)
128 #endif
129 #endif
130 
131 
132 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
133 #include <resolv.h>
134 
135 #include "res_private.h"
136 
137 #define RESOLVSORT
138 /*% Options.  Should all be left alone. */
139 #ifndef DEBUG
140 #define DEBUG
141 #endif
142 
143 #ifdef SOLARIS2
144 #include <sys/systeminfo.h>
145 #endif
146 
147 static void res_setoptions __P((res_state, const char *, const char *));
148 
149 #ifdef RESOLVSORT
150 static const char sort_mask[] = "/&";
151 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
152 static u_int32_t net_mask __P((struct in_addr));
153 #endif
154 
155 #if !defined(isascii)	/*%< XXX - could be a function */
156 # define isascii(c) (!(c & 0200))
157 #endif
158 
159 /*
160  * Resolver state default settings.
161  */
162 
163 /*%
164  * Set up default settings.  If the configuration file exist, the values
165  * there will have precedence.  Otherwise, the server address is set to
166  * INADDR_ANY and the default domain name comes from the gethostname().
167  *
168  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
169  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
170  * since it was noted that INADDR_ANY actually meant ``the first interface
171  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
172  * it had to be "up" in order for you to reach your own name server.  It
173  * was later decided that since the recommended practice is to always
174  * install local static routes through 127.0.0.1 for all your network
175  * interfaces, that we could solve this problem without a code change.
176  *
177  * The configuration file should always be used, since it is the only way
178  * to specify a default domain.  If you are running a server on your local
179  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
180  * in the configuration file.
181  *
182  * Return 0 if completes successfully, -1 on error
183  */
184 int
185 res_ninit(res_state statp) {
186 	extern int __res_vinit(res_state, int);
187 
188 	return (__res_vinit(statp, 0));
189 }
190 
191 /*% This function has to be reachable by res_data.c but not publically. */
192 int
193 __res_vinit(res_state statp, int preinit) {
194 	register FILE *fp;
195 	register char *cp, **pp;
196 	register int n;
197 	char buf[BUFSIZ];
198 	int nserv = 0;    /*%< number of nameserver records read from file */
199 	int haveenv = 0;
200 	int havesearch = 0;
201 #ifdef RESOLVSORT
202 	int nsort = 0;
203 	char *net;
204 #endif
205 	int dots;
206 	union res_sockaddr_union u[2];
207 	int maxns = MAXNS;
208 
209 	RES_SET_H_ERRNO(statp, 0);
210 
211 	if (!preinit) {
212 		statp->retrans = RES_TIMEOUT;
213 		statp->retry = RES_DFLRETRY;
214 		statp->options = RES_DEFAULT;
215 		statp->_rnd = malloc(16);
216 		res_rndinit(statp);
217 		statp->id = res_nrandomid(statp);
218 	}
219 
220 	if ((statp->options & RES_INIT) != 0U)
221 		res_ndestroy(statp);
222 
223 	memset(u, 0, sizeof(u));
224 #ifdef USELOOPBACK
225 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
226 #else
227 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
228 #endif
229 	u[nserv].sin.sin_family = AF_INET;
230 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
231 #ifdef HAVE_SA_LEN
232 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
233 #endif
234 	nserv++;
235 #ifdef HAS_INET6_STRUCTS
236 #ifdef USELOOPBACK
237 	u[nserv].sin6.sin6_addr = in6addr_loopback;
238 #else
239 	u[nserv].sin6.sin6_addr = in6addr_any;
240 #endif
241 	u[nserv].sin6.sin6_family = AF_INET6;
242 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
243 #ifdef HAVE_SA_LEN
244 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
245 #endif
246 	nserv++;
247 #endif
248 	statp->nscount = 0;
249 	statp->ndots = 1;
250 	statp->pfcode = 0;
251 	statp->_vcsock = -1;
252 	statp->_flags = 0;
253 	statp->qhook = NULL;
254 	statp->rhook = NULL;
255 	statp->_u._ext.nscount = 0;
256 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
257 	if (statp->_u._ext.ext != NULL) {
258 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
259 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
260 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
261 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
262 	} else {
263 		/*
264 		 * Historically res_init() rarely, if at all, failed.
265 		 * Examples and applications exist which do not check
266 		 * our return code.  Furthermore several applications
267 		 * simply call us to get the systems domainname.  So
268 		 * rather then immediately fail here we store the
269 		 * failure, which is returned later, in h_errno.  And
270 		 * prevent the collection of 'nameserver' information
271 		 * by setting maxns to 0.  Thus applications that fail
272 		 * to check our return code wont be able to make
273 		 * queries anyhow.
274 		 */
275 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
276 		maxns = 0;
277 	}
278 #ifdef RESOLVSORT
279 	statp->nsort = 0;
280 #endif
281 	res_setservers(statp, u, nserv);
282 
283 #ifdef	SOLARIS2
284 	/*
285 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
286 	 * We want to keep this behaviour
287 	 */
288 	{
289 		char buf[sizeof(statp->defdname)], *cp;
290 		int ret;
291 
292 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
293 			(unsigned int)ret <= sizeof(buf)) {
294 			if (buf[0] == '+')
295 				buf[0] = '.';
296 			cp = strchr(buf, '.');
297 			cp = (cp == NULL) ? buf : (cp + 1);
298 			(void)strlcpy(statp->defdname, cp,
299 			    sizeof(statp->defdname));
300 		}
301 	}
302 #endif	/* SOLARIS2 */
303 
304 	/* Allow user to override the local domain definition */
305 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
306 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
307 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
308 		haveenv++;
309 
310 		/*
311 		 * Set search list to be blank-separated strings
312 		 * from rest of env value.  Permits users of LOCALDOMAIN
313 		 * to still have a search list, and anyone to set the
314 		 * one that they want to use as an individual (even more
315 		 * important now that the rfc1535 stuff restricts searches)
316 		 */
317 		cp = statp->defdname;
318 		pp = statp->dnsrch;
319 		*pp++ = cp;
320 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
321 			if (*cp == '\n')	/*%< silly backwards compat */
322 				break;
323 			else if (*cp == ' ' || *cp == '\t') {
324 				*cp = 0;
325 				n = 1;
326 			} else if (n) {
327 				*pp++ = cp;
328 				n = 0;
329 				havesearch = 1;
330 			}
331 		}
332 		/* null terminate last domain if there are excess */
333 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
334 			cp++;
335 		*cp = '\0';
336 		*pp++ = 0;
337 	}
338 
339 #define	MATCH(line, name) \
340 	(!strncmp(line, name, sizeof(name) - 1) && \
341 	(line[sizeof(name) - 1] == ' ' || \
342 	 line[sizeof(name) - 1] == '\t'))
343 
344 	nserv = 0;
345 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
346 	    /* read the config file */
347 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
348 		/* skip comments */
349 		if (*buf == ';' || *buf == '#')
350 			continue;
351 		/* read default domain name */
352 		if (MATCH(buf, "domain")) {
353 		    if (haveenv)	/*%< skip if have from environ */
354 			    continue;
355 		    cp = buf + sizeof("domain") - 1;
356 		    while (*cp == ' ' || *cp == '\t')
357 			    cp++;
358 		    if ((*cp == '\0') || (*cp == '\n'))
359 			    continue;
360 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
361 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
362 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
363 			    *cp = '\0';
364 		    havesearch = 0;
365 		    continue;
366 		}
367 		/* set search list */
368 		if (MATCH(buf, "search")) {
369 		    if (haveenv)	/*%< skip if have from environ */
370 			    continue;
371 		    cp = buf + sizeof("search") - 1;
372 		    while (*cp == ' ' || *cp == '\t')
373 			    cp++;
374 		    if ((*cp == '\0') || (*cp == '\n'))
375 			    continue;
376 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
377 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
378 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
379 			    *cp = '\0';
380 		    /*
381 		     * Set search list to be blank-separated strings
382 		     * on rest of line.
383 		     */
384 		    cp = statp->defdname;
385 		    pp = statp->dnsrch;
386 		    *pp++ = cp;
387 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
388 			    if (*cp == ' ' || *cp == '\t') {
389 				    *cp = 0;
390 				    n = 1;
391 			    } else if (n) {
392 				    *pp++ = cp;
393 				    n = 0;
394 			    }
395 		    }
396 		    /* null terminate last domain if there are excess */
397 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
398 			    cp++;
399 		    *cp = '\0';
400 		    *pp++ = 0;
401 		    havesearch = 1;
402 		    continue;
403 		}
404 		/* read nameservers to query */
405 		if (MATCH(buf, "nameserver") && nserv < maxns) {
406 		    struct addrinfo hints, *ai;
407 		    char sbuf[NI_MAXSERV];
408 		    const size_t minsiz =
409 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
410 
411 		    cp = buf + sizeof("nameserver") - 1;
412 		    while (*cp == ' ' || *cp == '\t')
413 			cp++;
414 		    cp[strcspn(cp, ";# \t\n")] = '\0';
415 		    if ((*cp != '\0') && (*cp != '\n')) {
416 			memset(&hints, 0, sizeof(hints));
417 			hints.ai_family = PF_UNSPEC;
418 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
419 			hints.ai_flags = AI_NUMERICHOST;
420 			sprintf(sbuf, "%u", NAMESERVER_PORT);
421 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
422 			    ai->ai_addrlen <= minsiz) {
423 			    if (statp->_u._ext.ext != NULL) {
424 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
425 				    ai->ai_addr, ai->ai_addrlen);
426 			    }
427 			    if (ai->ai_addrlen <=
428 			        sizeof(statp->nsaddr_list[nserv])) {
429 				memcpy(&statp->nsaddr_list[nserv],
430 				    ai->ai_addr, ai->ai_addrlen);
431 			    } else
432 				statp->nsaddr_list[nserv].sin_family = 0;
433 			    freeaddrinfo(ai);
434 			    nserv++;
435 			}
436 		    }
437 		    continue;
438 		}
439 #ifdef RESOLVSORT
440 		if (MATCH(buf, "sortlist")) {
441 		    struct in_addr a;
442 
443 		    cp = buf + sizeof("sortlist") - 1;
444 		    while (nsort < MAXRESOLVSORT) {
445 			while (*cp == ' ' || *cp == '\t')
446 			    cp++;
447 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
448 			    break;
449 			net = cp;
450 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
451 			       isascii(*cp) && !isspace((unsigned char)*cp))
452 				cp++;
453 			n = *cp;
454 			*cp = 0;
455 			if (inet_aton(net, &a)) {
456 			    statp->sort_list[nsort].addr = a;
457 			    if (ISSORTMASK(n)) {
458 				*cp++ = n;
459 				net = cp;
460 				while (*cp && *cp != ';' &&
461 					isascii(*cp) &&
462 					!isspace((unsigned char)*cp))
463 				    cp++;
464 				n = *cp;
465 				*cp = 0;
466 				if (inet_aton(net, &a)) {
467 				    statp->sort_list[nsort].mask = a.s_addr;
468 				} else {
469 				    statp->sort_list[nsort].mask =
470 					net_mask(statp->sort_list[nsort].addr);
471 				}
472 			    } else {
473 				statp->sort_list[nsort].mask =
474 				    net_mask(statp->sort_list[nsort].addr);
475 			    }
476 			    nsort++;
477 			}
478 			*cp = n;
479 		    }
480 		    continue;
481 		}
482 #endif
483 		if (MATCH(buf, "options")) {
484 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
485 		    continue;
486 		}
487 	    }
488 	    if (nserv > 0)
489 		statp->nscount = nserv;
490 #ifdef RESOLVSORT
491 	    statp->nsort = nsort;
492 #endif
493 	    (void) fclose(fp);
494 	}
495 /*
496  * Last chance to get a nameserver.  This should not normally
497  * be necessary
498  */
499 #ifdef NO_RESOLV_CONF
500 	if(nserv == 0)
501 		nserv = get_nameservers(statp);
502 #endif
503 
504 	if (statp->defdname[0] == 0 &&
505 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
506 	    (cp = strchr(buf, '.')) != NULL)
507 		strcpy(statp->defdname, cp + 1);
508 
509 	/* find components of local domain that might be searched */
510 	if (havesearch == 0) {
511 		pp = statp->dnsrch;
512 		*pp++ = statp->defdname;
513 		*pp = NULL;
514 
515 		dots = 0;
516 		for (cp = statp->defdname; *cp; cp++)
517 			dots += (*cp == '.');
518 
519 		cp = statp->defdname;
520 		while (pp < statp->dnsrch + MAXDFLSRCH) {
521 			if (dots < LOCALDOMAINPARTS)
522 				break;
523 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
524 			*pp++ = cp;
525 			dots--;
526 		}
527 		*pp = NULL;
528 #ifdef DEBUG
529 		if (statp->options & RES_DEBUG) {
530 			printf(";; res_init()... default dnsrch list:\n");
531 			for (pp = statp->dnsrch; *pp; pp++)
532 				printf(";;\t%s\n", *pp);
533 			printf(";;\t..END..\n");
534 		}
535 #endif
536 	}
537 
538 	if ((cp = getenv("RES_OPTIONS")) != NULL)
539 		res_setoptions(statp, cp, "env");
540 	statp->options |= RES_INIT;
541 	return (statp->res_h_errno);
542 }
543 
544 static void
545 res_setoptions(res_state statp, const char *options, const char *source)
546 {
547 	const char *cp = options;
548 	int i;
549 	struct __res_state_ext *ext = statp->_u._ext.ext;
550 
551 #ifdef DEBUG
552 	if (statp->options & RES_DEBUG)
553 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
554 		       options, source);
555 #endif
556 	while (*cp) {
557 		/* skip leading and inner runs of spaces */
558 		while (*cp == ' ' || *cp == '\t')
559 			cp++;
560 		/* search for and process individual options */
561 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
562 			i = atoi(cp + sizeof("ndots:") - 1);
563 			if (i <= RES_MAXNDOTS)
564 				statp->ndots = i;
565 			else
566 				statp->ndots = RES_MAXNDOTS;
567 #ifdef DEBUG
568 			if (statp->options & RES_DEBUG)
569 				printf(";;\tndots=%d\n", statp->ndots);
570 #endif
571 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
572 			i = atoi(cp + sizeof("timeout:") - 1);
573 			if (i <= RES_MAXRETRANS)
574 				statp->retrans = i;
575 			else
576 				statp->retrans = RES_MAXRETRANS;
577 #ifdef DEBUG
578 			if (statp->options & RES_DEBUG)
579 				printf(";;\ttimeout=%d\n", statp->retrans);
580 #endif
581 #ifdef	SOLARIS2
582 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
583 			/*
584 		 	 * For backward compatibility, 'retrans' is
585 		 	 * supported as an alias for 'timeout', though
586 		 	 * without an imposed maximum.
587 		 	 */
588 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
589 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
590 			/*
591 			 * For backward compatibility, 'retry' is
592 			 * supported as an alias for 'attempts', though
593 			 * without an imposed maximum.
594 			 */
595 			statp->retry = atoi(cp + sizeof("retry:") - 1);
596 #endif	/* SOLARIS2 */
597 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
598 			i = atoi(cp + sizeof("attempts:") - 1);
599 			if (i <= RES_MAXRETRY)
600 				statp->retry = i;
601 			else
602 				statp->retry = RES_MAXRETRY;
603 #ifdef DEBUG
604 			if (statp->options & RES_DEBUG)
605 				printf(";;\tattempts=%d\n", statp->retry);
606 #endif
607 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
608 #ifdef DEBUG
609 			if (!(statp->options & RES_DEBUG)) {
610 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
611 				       options, source);
612 				statp->options |= RES_DEBUG;
613 			}
614 			printf(";;\tdebug\n");
615 #endif
616 		} else if (!strncmp(cp, "no_tld_query",
617 				    sizeof("no_tld_query") - 1) ||
618 			   !strncmp(cp, "no-tld-query",
619 				    sizeof("no-tld-query") - 1)) {
620 			statp->options |= RES_NOTLDQUERY;
621 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
622 			statp->options |= RES_USE_INET6;
623 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
624 			statp->options |= RES_ROTATE;
625 		} else if (!strncmp(cp, "no-check-names",
626 				    sizeof("no-check-names") - 1)) {
627 			statp->options |= RES_NOCHECKNAME;
628 		}
629 #ifdef RES_USE_EDNS0
630 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
631 			statp->options |= RES_USE_EDNS0;
632 		}
633 #endif
634 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
635 			statp->options |= RES_USE_DNAME;
636 		}
637 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
638 			if (ext == NULL)
639 				goto skip;
640 			cp += sizeof("nibble:") - 1;
641 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
642 			strncpy(ext->nsuffix, cp, (size_t)i);
643 			ext->nsuffix[i] = '\0';
644 		}
645 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
646 			if (ext == NULL)
647 				goto skip;
648 			cp += sizeof("nibble2:") - 1;
649 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
650 			strncpy(ext->nsuffix2, cp, (size_t)i);
651 			ext->nsuffix2[i] = '\0';
652 		}
653 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
654 			cp += sizeof("v6revmode:") - 1;
655 			/* "nibble" and "bitstring" used to be valid */
656 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
657 				statp->options |= RES_NO_NIBBLE2;
658 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
659 				statp->options &=
660 					 ~RES_NO_NIBBLE2;
661 			}
662 		}
663 		else {
664 			/* XXX - print a warning here? */
665 		}
666    skip:
667 		/* skip to next run of spaces */
668 		while (*cp && *cp != ' ' && *cp != '\t')
669 			cp++;
670 	}
671 }
672 
673 #ifdef RESOLVSORT
674 /* XXX - should really support CIDR which means explicit masks always. */
675 static u_int32_t
676 net_mask(in)		/*!< XXX - should really use system's version of this  */
677 	struct in_addr in;
678 {
679 	register u_int32_t i = ntohl(in.s_addr);
680 
681 	if (IN_CLASSA(i))
682 		return (htonl(IN_CLASSA_NET));
683 	else if (IN_CLASSB(i))
684 		return (htonl(IN_CLASSB_NET));
685 	return (htonl(IN_CLASSC_NET));
686 }
687 #endif
688 
689 static u_char srnd[16];
690 
691 void
692 res_rndinit(res_state statp)
693 {
694 	struct timeval now;
695 	u_int32_t u32;
696 	u_int16_t u16;
697 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
698 
699 	gettimeofday(&now, NULL);
700 	u32 = (u_int32_t)now.tv_sec;
701 	memcpy(rnd, &u32, 4);
702 	u32 = now.tv_usec;
703 	memcpy(rnd + 4, &u32, 4);
704 	u32 += (u_int32_t)now.tv_sec;
705 	memcpy(rnd + 8, &u32, 4);
706 	u16 = getpid();
707 	memcpy(rnd + 12, &u16, 2);
708 }
709 
710 u_int
711 res_nrandomid(res_state statp) {
712 	struct timeval now;
713 	u_int16_t u16;
714 	MD5_CTX ctx;
715 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
716 
717 	gettimeofday(&now, NULL);
718 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
719 	memcpy(rnd + 14, &u16, 2);
720 #ifndef HAVE_MD5
721 	MD5_Init(&ctx);
722 	MD5_Update(&ctx, rnd, 16);
723 	MD5_Final(rnd, &ctx);
724 #else
725 	MD5Init(&ctx);
726 	MD5Update(&ctx, rnd, 16);
727 	MD5Final(rnd, &ctx);
728 #endif
729 	memcpy(&u16, rnd + 14, 2);
730 	return ((u_int) u16);
731 }
732 
733 /*%
734  * This routine is for closing the socket if a virtual circuit is used and
735  * the program wants to close it.  This provides support for endhostent()
736  * which expects to close the socket.
737  *
738  * This routine is not expected to be user visible.
739  */
740 void
741 res_nclose(res_state statp) {
742 	int ns;
743 
744 	if (statp->_vcsock >= 0) {
745 		(void) close(statp->_vcsock);
746 		statp->_vcsock = -1;
747 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
748 	}
749 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
750 		if (statp->_u._ext.nssocks[ns] != -1) {
751 			(void) close(statp->_u._ext.nssocks[ns]);
752 			statp->_u._ext.nssocks[ns] = -1;
753 		}
754 	}
755 }
756 
757 void
758 res_ndestroy(res_state statp) {
759 	res_nclose(statp);
760 	if (statp->_u._ext.ext != NULL) {
761 		free(statp->_u._ext.ext);
762 		statp->_u._ext.ext = NULL;
763 	}
764 	if (statp->_rnd != NULL) {
765 		free(statp->_rnd);
766 		statp->_rnd = NULL;
767 	}
768 	statp->options &= ~RES_INIT;
769 }
770 
771 const char *
772 res_get_nibblesuffix(res_state statp) {
773 	if (statp->_u._ext.ext)
774 		return (statp->_u._ext.ext->nsuffix);
775 	return ("ip6.arpa");
776 }
777 
778 const char *
779 res_get_nibblesuffix2(res_state statp) {
780 	if (statp->_u._ext.ext)
781 		return (statp->_u._ext.ext->nsuffix2);
782 	return ("ip6.int");
783 }
784 
785 void
786 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
787 	int i, nserv;
788 	size_t size;
789 
790 	/* close open servers */
791 	res_nclose(statp);
792 
793 	/* cause rtt times to be forgotten */
794 	statp->_u._ext.nscount = 0;
795 
796 	nserv = 0;
797 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
798 		switch (set->sin.sin_family) {
799 		case AF_INET:
800 			size = sizeof(set->sin);
801 			if (statp->_u._ext.ext)
802 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
803 					&set->sin, size);
804 			if (size <= sizeof(statp->nsaddr_list[nserv]))
805 				memcpy(&statp->nsaddr_list[nserv],
806 					&set->sin, size);
807 			else
808 				statp->nsaddr_list[nserv].sin_family = 0;
809 			nserv++;
810 			break;
811 
812 #ifdef HAS_INET6_STRUCTS
813 		case AF_INET6:
814 			size = sizeof(set->sin6);
815 			if (statp->_u._ext.ext)
816 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
817 					&set->sin6, size);
818 			if (size <= sizeof(statp->nsaddr_list[nserv]))
819 				memcpy(&statp->nsaddr_list[nserv],
820 					&set->sin6, size);
821 			else
822 				statp->nsaddr_list[nserv].sin_family = 0;
823 			nserv++;
824 			break;
825 #endif
826 
827 		default:
828 			break;
829 		}
830 		set++;
831 	}
832 	statp->nscount = nserv;
833 
834 }
835 
836 int
837 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
838 	int i;
839 	size_t size;
840 	u_int16_t family;
841 
842 	for (i = 0; i < statp->nscount && i < cnt; i++) {
843 		if (statp->_u._ext.ext)
844 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
845 		else
846 			family = statp->nsaddr_list[i].sin_family;
847 
848 		switch (family) {
849 		case AF_INET:
850 			size = sizeof(set->sin);
851 			if (statp->_u._ext.ext)
852 				memcpy(&set->sin,
853 				       &statp->_u._ext.ext->nsaddrs[i],
854 				       size);
855 			else
856 				memcpy(&set->sin, &statp->nsaddr_list[i],
857 				       size);
858 			break;
859 
860 #ifdef HAS_INET6_STRUCTS
861 		case AF_INET6:
862 			size = sizeof(set->sin6);
863 			if (statp->_u._ext.ext)
864 				memcpy(&set->sin6,
865 				       &statp->_u._ext.ext->nsaddrs[i],
866 				       size);
867 			else
868 				memcpy(&set->sin6, &statp->nsaddr_list[i],
869 				       size);
870 			break;
871 #endif
872 
873 		default:
874 			set->sin.sin_family = 0;
875 			break;
876 		}
877 		set++;
878 	}
879 	return (statp->nscount);
880 }
881 
882 /*! \file */
883