xref: /freebsd/lib/libc/resolv/res_init.c (revision f3aff7c91bd451d300ffd37ddce5a1fdbe802123)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #if defined(LIBC_SCCS) && !defined(lint)
70 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
71 static const char rcsid[] = "$Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp $";
72 #endif /* LIBC_SCCS and not lint */
73 #include <sys/cdefs.h>
74 __FBSDID("$FreeBSD$");
75 
76 #include "port_before.h"
77 
78 #include "namespace.h"
79 
80 #include <sys/param.h>
81 #include <sys/socket.h>
82 #include <sys/stat.h>
83 #include <sys/time.h>
84 
85 #include <netinet/in.h>
86 #include <arpa/inet.h>
87 #include <arpa/nameser.h>
88 
89 #include <ctype.h>
90 #include <stdio.h>
91 #include <stdlib.h>
92 #include <string.h>
93 #include <unistd.h>
94 #include <netdb.h>
95 
96 #ifndef HAVE_MD5
97 # include "../dst/md5.h"
98 #else
99 # ifdef SOLARIS2
100 #  include <sys/md5.h>
101 # elif _LIBC
102 # include <md5.h>
103 # endif
104 #endif
105 #ifndef _MD5_H_
106 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
107 #endif
108 
109 #include "un-namespace.h"
110 
111 #include "port_after.h"
112 
113 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
114 #include <resolv.h>
115 
116 #include "res_private.h"
117 
118 /*% Options.  Should all be left alone. */
119 #define RESOLVSORT
120 #ifndef	DEBUG
121 #define	DEBUG
122 #endif
123 
124 #ifdef SOLARIS2
125 #include <sys/systeminfo.h>
126 #endif
127 
128 static void res_setoptions(res_state, const char *, const char *);
129 
130 #ifdef RESOLVSORT
131 static const char sort_mask[] = "/&";
132 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
133 static u_int32_t net_mask(struct in_addr);
134 #endif
135 
136 #if !defined(isascii)	/*%< XXX - could be a function */
137 # define isascii(c) (!(c & 0200))
138 #endif
139 
140 /*
141  * Resolver state default settings.
142  */
143 
144 /*%
145  * Set up default settings.  If the configuration file exist, the values
146  * there will have precedence.  Otherwise, the server address is set to
147  * INADDR_ANY and the default domain name comes from the gethostname().
148  *
149  * An interim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
150  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
151  * since it was noted that INADDR_ANY actually meant ``the first interface
152  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
153  * it had to be "up" in order for you to reach your own name server.  It
154  * was later decided that since the recommended practice is to always
155  * install local static routes through 127.0.0.1 for all your network
156  * interfaces, that we could solve this problem without a code change.
157  *
158  * The configuration file should always be used, since it is the only way
159  * to specify a default domain.  If you are running a server on your local
160  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
161  * in the configuration file.
162  *
163  * Return 0 if completes successfully, -1 on error
164  */
165 int
166 res_ninit(res_state statp) {
167 	extern int __res_vinit(res_state, int);
168 
169 	return (__res_vinit(statp, 0));
170 }
171 
172 /*% This function has to be reachable by res_data.c but not publicly. */
173 int
174 __res_vinit(res_state statp, int preinit) {
175 	FILE *fp;
176 	char *cp, **pp;
177 	int n;
178 	char buf[BUFSIZ];
179 	int nserv = 0;    /*%< number of nameserver records read from file */
180 	int haveenv = 0;
181 	int havesearch = 0;
182 #ifdef RESOLVSORT
183 	int nsort = 0;
184 	char *net;
185 #endif
186 	int dots;
187 	union res_sockaddr_union u[2];
188 	int maxns = MAXNS;
189 
190 	RES_SET_H_ERRNO(statp, 0);
191 	if (statp->_u._ext.ext != NULL)
192 		res_ndestroy(statp);
193 
194 	if (!preinit) {
195 		statp->retrans = RES_TIMEOUT;
196 		statp->retry = RES_DFLRETRY;
197 		statp->options = RES_DEFAULT;
198 	}
199 
200 	statp->_rnd = malloc(16);
201 	res_rndinit(statp);
202 	statp->id = res_nrandomid(statp);
203 
204 	memset(u, 0, sizeof(u));
205 #ifdef USELOOPBACK
206 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
207 #else
208 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
209 #endif
210 	u[nserv].sin.sin_family = AF_INET;
211 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
212 #ifdef HAVE_SA_LEN
213 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
214 #endif
215 	nserv++;
216 #ifdef HAS_INET6_STRUCTS
217 #ifdef USELOOPBACK
218 	u[nserv].sin6.sin6_addr = in6addr_loopback;
219 #else
220 	u[nserv].sin6.sin6_addr = in6addr_any;
221 #endif
222 	u[nserv].sin6.sin6_family = AF_INET6;
223 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
224 #ifdef HAVE_SA_LEN
225 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
226 #endif
227 	nserv++;
228 #endif
229 	statp->nscount = 0;
230 	statp->ndots = 1;
231 	statp->pfcode = 0;
232 	statp->_vcsock = -1;
233 	statp->_flags = 0;
234 	statp->qhook = NULL;
235 	statp->rhook = NULL;
236 	statp->_u._ext.nscount = 0;
237 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
238 	if (statp->_u._ext.ext != NULL) {
239 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
240 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
241 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
242 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
243 		statp->_u._ext.ext->reload_period = 2;
244 	} else {
245 		/*
246 		 * Historically res_init() rarely, if at all, failed.
247 		 * Examples and applications exist which do not check
248 		 * our return code.  Furthermore several applications
249 		 * simply call us to get the systems domainname.  So
250 		 * rather then immediately fail here we store the
251 		 * failure, which is returned later, in h_errno.  And
252 		 * prevent the collection of 'nameserver' information
253 		 * by setting maxns to 0.  Thus applications that fail
254 		 * to check our return code wont be able to make
255 		 * queries anyhow.
256 		 */
257 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
258 		maxns = 0;
259 	}
260 #ifdef RESOLVSORT
261 	statp->nsort = 0;
262 #endif
263 	res_setservers(statp, u, nserv);
264 
265 #ifdef	SOLARIS2
266 	/*
267 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
268 	 * We want to keep this behaviour
269 	 */
270 	{
271 		char buf[sizeof(statp->defdname)], *cp;
272 		int ret;
273 
274 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
275 			(unsigned int)ret <= sizeof(buf)) {
276 			if (buf[0] == '+')
277 				buf[0] = '.';
278 			cp = strchr(buf, '.');
279 			cp = (cp == NULL) ? buf : (cp + 1);
280 			strncpy(statp->defdname, cp,
281 				sizeof(statp->defdname) - 1);
282 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
283 		}
284 	}
285 #endif	/* SOLARIS2 */
286 
287 	/* Allow user to override the local domain definition */
288 	if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
289 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
290 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
291 		haveenv++;
292 
293 		/*
294 		 * Set search list to be blank-separated strings
295 		 * from rest of env value.  Permits users of LOCALDOMAIN
296 		 * to still have a search list, and anyone to set the
297 		 * one that they want to use as an individual (even more
298 		 * important now that the rfc1535 stuff restricts searches)
299 		 */
300 		cp = statp->defdname;
301 		pp = statp->dnsrch;
302 		*pp++ = cp;
303 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
304 			if (*cp == '\n')	/*%< silly backwards compat */
305 				break;
306 			else if (*cp == ' ' || *cp == '\t') {
307 				*cp = 0;
308 				n = 1;
309 			} else if (n) {
310 				*pp++ = cp;
311 				n = 0;
312 				havesearch = 1;
313 			}
314 		}
315 		/* null terminate last domain if there are excess */
316 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
317 			cp++;
318 		*cp = '\0';
319 		*pp++ = NULL;
320 	}
321 
322 #define	MATCH(line, name) \
323 	(!strncmp(line, name, sizeof(name) - 1) && \
324 	(line[sizeof(name) - 1] == ' ' || \
325 	 line[sizeof(name) - 1] == '\t'))
326 
327 	nserv = 0;
328 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
329 	    struct stat sb;
330 	    struct timespec now;
331 
332 	    if (statp->_u._ext.ext != NULL) {
333 		if (_fstat(fileno(fp), &sb) == 0) {
334 		    statp->_u._ext.ext->conf_mtim = sb.st_mtim;
335 		    if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) == 0) {
336 			statp->_u._ext.ext->conf_stat = now.tv_sec;
337 		    }
338 		}
339 	    }
340 
341 	    /* read the config file */
342 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
343 		/* skip comments */
344 		if (*buf == ';' || *buf == '#')
345 			continue;
346 		/* read default domain name */
347 		if (MATCH(buf, "domain")) {
348 		    if (haveenv)	/*%< skip if have from environ */
349 			    continue;
350 		    cp = buf + sizeof("domain") - 1;
351 		    while (*cp == ' ' || *cp == '\t')
352 			    cp++;
353 		    if ((*cp == '\0') || (*cp == '\n'))
354 			    continue;
355 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
356 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
357 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
358 			    *cp = '\0';
359 		    havesearch = 0;
360 		    continue;
361 		}
362 		/* set search list */
363 		if (MATCH(buf, "search")) {
364 		    if (haveenv)	/*%< skip if have from environ */
365 			    continue;
366 		    cp = buf + sizeof("search") - 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 = strchr(statp->defdname, '\n')) != NULL)
374 			    *cp = '\0';
375 		    /*
376 		     * Set search list to be blank-separated strings
377 		     * on rest of line.
378 		     */
379 		    cp = statp->defdname;
380 		    pp = statp->dnsrch;
381 		    *pp++ = cp;
382 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
383 			    if (*cp == ' ' || *cp == '\t') {
384 				    *cp = 0;
385 				    n = 1;
386 			    } else if (n) {
387 				    *pp++ = cp;
388 				    n = 0;
389 			    }
390 		    }
391 		    /* null terminate last domain if there are excess */
392 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
393 			    cp++;
394 		    *cp = '\0';
395 		    *pp++ = NULL;
396 		    havesearch = 1;
397 		    continue;
398 		}
399 		/* read nameservers to query */
400 		if (MATCH(buf, "nameserver") && nserv < maxns) {
401 		    struct addrinfo hints, *ai;
402 		    char sbuf[NI_MAXSERV];
403 		    const size_t minsiz =
404 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
405 
406 		    cp = buf + sizeof("nameserver") - 1;
407 		    while (*cp == ' ' || *cp == '\t')
408 			cp++;
409 		    cp[strcspn(cp, ";# \t\n")] = '\0';
410 		    if ((*cp != '\0') && (*cp != '\n')) {
411 			memset(&hints, 0, sizeof(hints));
412 			hints.ai_family = PF_UNSPEC;
413 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
414 			hints.ai_flags = AI_NUMERICHOST;
415 			sprintf(sbuf, "%u", NAMESERVER_PORT);
416 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0) {
417 			    if (ai->ai_addrlen <= minsiz) {
418 				if (statp->_u._ext.ext != NULL) {
419 				    memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
420 					ai->ai_addr, ai->ai_addrlen);
421 				}
422 				if (ai->ai_addrlen <=
423 				    sizeof(statp->nsaddr_list[nserv])) {
424 				    memcpy(&statp->nsaddr_list[nserv],
425 					ai->ai_addr, ai->ai_addrlen);
426 				} else
427 				    statp->nsaddr_list[nserv].sin_family = 0;
428 				nserv++;
429 			    }
430 			    freeaddrinfo(ai);
431 			}
432 		    }
433 		    continue;
434 		}
435 #ifdef RESOLVSORT
436 		if (MATCH(buf, "sortlist")) {
437 		    struct in_addr a;
438 		    struct in6_addr a6;
439 		    int m, i;
440 		    u_char *u;
441 		    struct __res_state_ext *ext = statp->_u._ext.ext;
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 			    ext->sort_list[nsort].af = AF_INET;
477 			    ext->sort_list[nsort].addr.ina =
478 				statp->sort_list[nsort].addr;
479 			    ext->sort_list[nsort].mask.ina.s_addr =
480 				statp->sort_list[nsort].mask;
481 			    nsort++;
482 			}
483 			else if (inet_pton(AF_INET6, net, &a6) == 1) {
484 
485 			    ext->sort_list[nsort].af = AF_INET6;
486 			    ext->sort_list[nsort].addr.in6a = a6;
487 			    u = (u_char *)&ext->sort_list[nsort].mask.in6a;
488 			    *cp++ = n;
489 			    net = cp;
490 			    while (*cp && *cp != ';' &&
491 				    isascii(*cp) && !isspace(*cp))
492 				cp++;
493 			    m = n;
494 			    n = *cp;
495 			    *cp = 0;
496 			    switch (m) {
497 			    case '/':
498 				m = atoi(net);
499 				break;
500 			    case '&':
501 				if (inet_pton(AF_INET6, net, u) == 1) {
502 				    m = -1;
503 				    break;
504 				}
505 				/*FALLTHROUGH*/
506 			    default:
507 				m = sizeof(struct in6_addr) * CHAR_BIT;
508 				break;
509 			    }
510 			    if (m >= 0) {
511 				for (i = 0; i < sizeof(struct in6_addr); i++) {
512 				    if (m <= 0) {
513 					*u = 0;
514 				    } else {
515 					m -= CHAR_BIT;
516 					*u = (u_char)~0;
517 					if (m < 0)
518 					    *u <<= -m;
519 				    }
520 				    u++;
521 				}
522 			    }
523 			    statp->sort_list[nsort].addr.s_addr =
524 				(u_int32_t)0xffffffff;
525 			    statp->sort_list[nsort].mask =
526 				(u_int32_t)0xffffffff;
527 			    nsort++;
528 			}
529 			*cp = n;
530 		    }
531 		    continue;
532 		}
533 #endif
534 		if (MATCH(buf, "options")) {
535 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
536 		    continue;
537 		}
538 	    }
539 	    if (nserv > 0)
540 		statp->nscount = nserv;
541 #ifdef RESOLVSORT
542 	    statp->nsort = nsort;
543 #endif
544 	    (void) fclose(fp);
545 	}
546 /*
547  * Last chance to get a nameserver.  This should not normally
548  * be necessary
549  */
550 #ifdef NO_RESOLV_CONF
551 	if(nserv == 0)
552 		nserv = get_nameservers(statp);
553 #endif
554 
555 	if (statp->defdname[0] == 0 &&
556 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
557 	    (cp = strchr(buf, '.')) != NULL)
558 		strcpy(statp->defdname, cp + 1);
559 
560 	/* find components of local domain that might be searched */
561 	if (havesearch == 0) {
562 		pp = statp->dnsrch;
563 		*pp++ = statp->defdname;
564 		*pp = NULL;
565 
566 		dots = 0;
567 		for (cp = statp->defdname; *cp; cp++)
568 			dots += (*cp == '.');
569 
570 		cp = statp->defdname;
571 		while (pp < statp->dnsrch + MAXDFLSRCH) {
572 			if (dots < LOCALDOMAINPARTS)
573 				break;
574 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
575 			*pp++ = cp;
576 			dots--;
577 		}
578 		*pp = NULL;
579 #ifdef DEBUG
580 		if (statp->options & RES_DEBUG) {
581 			printf(";; res_init()... default dnsrch list:\n");
582 			for (pp = statp->dnsrch; *pp; pp++)
583 				printf(";;\t%s\n", *pp);
584 			printf(";;\t..END..\n");
585 		}
586 #endif
587 	}
588 
589 	if (issetugid())
590 		statp->options |= RES_NOALIASES;
591 	else if ((cp = getenv("RES_OPTIONS")) != NULL)
592 		res_setoptions(statp, cp, "env");
593 	statp->options |= RES_INIT;
594 	return (statp->res_h_errno);
595 }
596 
597 static void
598 res_setoptions(res_state statp, const char *options, const char *source)
599 {
600 	const char *cp = options;
601 	int i;
602 	struct __res_state_ext *ext = statp->_u._ext.ext;
603 
604 #ifdef DEBUG
605 	if (statp->options & RES_DEBUG)
606 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
607 		       options, source);
608 #endif
609 	while (*cp) {
610 		/* skip leading and inner runs of spaces */
611 		while (*cp == ' ' || *cp == '\t')
612 			cp++;
613 		/* search for and process individual options */
614 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
615 			i = atoi(cp + sizeof("ndots:") - 1);
616 			if (i <= RES_MAXNDOTS)
617 				statp->ndots = i;
618 			else
619 				statp->ndots = RES_MAXNDOTS;
620 #ifdef DEBUG
621 			if (statp->options & RES_DEBUG)
622 				printf(";;\tndots=%d\n", statp->ndots);
623 #endif
624 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
625 			i = atoi(cp + sizeof("timeout:") - 1);
626 			if (i <= RES_MAXRETRANS)
627 				statp->retrans = i;
628 			else
629 				statp->retrans = RES_MAXRETRANS;
630 #ifdef DEBUG
631 			if (statp->options & RES_DEBUG)
632 				printf(";;\ttimeout=%d\n", statp->retrans);
633 #endif
634 #ifdef	SOLARIS2
635 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
636 			/*
637 		 	 * For backward compatibility, 'retrans' is
638 		 	 * supported as an alias for 'timeout', though
639 		 	 * without an imposed maximum.
640 		 	 */
641 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
642 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
643 			/*
644 			 * For backward compatibility, 'retry' is
645 			 * supported as an alias for 'attempts', though
646 			 * without an imposed maximum.
647 			 */
648 			statp->retry = atoi(cp + sizeof("retry:") - 1);
649 #endif	/* SOLARIS2 */
650 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
651 			i = atoi(cp + sizeof("attempts:") - 1);
652 			if (i <= RES_MAXRETRY)
653 				statp->retry = i;
654 			else
655 				statp->retry = RES_MAXRETRY;
656 #ifdef DEBUG
657 			if (statp->options & RES_DEBUG)
658 				printf(";;\tattempts=%d\n", statp->retry);
659 #endif
660 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
661 #ifdef DEBUG
662 			if (!(statp->options & RES_DEBUG)) {
663 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
664 				       options, source);
665 				statp->options |= RES_DEBUG;
666 			}
667 			printf(";;\tdebug\n");
668 #endif
669 		} else if (!strncmp(cp, "no_tld_query",
670 				    sizeof("no_tld_query") - 1) ||
671 			   !strncmp(cp, "no-tld-query",
672 				    sizeof("no-tld-query") - 1)) {
673 			statp->options |= RES_NOTLDQUERY;
674 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
675 			statp->options |= RES_USE_INET6;
676 		} else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
677 		       statp->options |= RES_INSECURE1;
678 		} else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
679 		       statp->options |= RES_INSECURE2;
680 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
681 			statp->options |= RES_ROTATE;
682 		} else if (!strncmp(cp, "no-check-names",
683 				    sizeof("no-check-names") - 1)) {
684 			statp->options |= RES_NOCHECKNAME;
685 		} else if (!strncmp(cp, "reload-period:",
686 				    sizeof("reload-period:") - 1)) {
687 			if (ext != NULL) {
688 				ext->reload_period = (u_short)
689 				    atoi(cp + sizeof("reload-period:") - 1);
690 			}
691 		}
692 #ifdef RES_USE_EDNS0
693 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
694 			statp->options |= RES_USE_EDNS0;
695 		}
696 #endif
697 #ifndef _LIBC
698 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
699 			statp->options |= RES_USE_DNAME;
700 		}
701 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
702 			if (ext == NULL)
703 				goto skip;
704 			cp += sizeof("nibble:") - 1;
705 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
706 			strncpy(ext->nsuffix, cp, i);
707 			ext->nsuffix[i] = '\0';
708 		}
709 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
710 			if (ext == NULL)
711 				goto skip;
712 			cp += sizeof("nibble2:") - 1;
713 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
714 			strncpy(ext->nsuffix2, cp, i);
715 			ext->nsuffix2[i] = '\0';
716 		}
717 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
718 			cp += sizeof("v6revmode:") - 1;
719 			/* "nibble" and "bitstring" used to be valid */
720 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
721 				statp->options |= RES_NO_NIBBLE2;
722 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
723 				statp->options &=
724 					 ~RES_NO_NIBBLE2;
725 			}
726 		}
727 #endif
728 		else {
729 			/* XXX - print a warning here? */
730 		}
731 #ifndef _LIBC
732    skip:
733 #endif
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 u_int32_t
743 net_mask(struct in_addr in)		/*!< XXX - should really use system's version of this  */
744 {
745 	u_int32_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
758 res_rndinit(res_state statp)
759 {
760 	struct timeval now;
761 	u_int32_t u32;
762 	u_int16_t u16;
763 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
764 
765 	gettimeofday(&now, NULL);
766 	u32 = now.tv_sec;
767 	memcpy(rnd, &u32, 4);
768 	u32 = now.tv_usec;
769 	memcpy(rnd + 4, &u32, 4);
770 	u32 += now.tv_sec;
771 	memcpy(rnd + 8, &u32, 4);
772 	u16 = getpid();
773 	memcpy(rnd + 12, &u16, 2);
774 }
775 
776 u_int
777 res_nrandomid(res_state statp) {
778 	struct timeval now;
779 	u_int16_t u16;
780 	MD5_CTX ctx;
781 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
782 
783 	gettimeofday(&now, NULL);
784 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
785 	memcpy(rnd + 14, &u16, 2);
786 #ifndef HAVE_MD5
787 	MD5_Init(&ctx);
788 	MD5_Update(&ctx, rnd, 16);
789 	MD5_Final(rnd, &ctx);
790 #else
791 	MD5Init(&ctx);
792 	MD5Update(&ctx, rnd, 16);
793 	MD5Final(rnd, &ctx);
794 #endif
795 	memcpy(&u16, rnd + 14, 2);
796 	return ((u_int) u16);
797 }
798 
799 /*%
800  * This routine is for closing the socket if a virtual circuit is used and
801  * the program wants to close it.  This provides support for endhostent()
802  * which expects to close the socket.
803  *
804  * This routine is not expected to be user visible.
805  */
806 void
807 res_nclose(res_state statp) {
808 	int ns;
809 
810 	if (statp->_vcsock >= 0) {
811 		(void) _close(statp->_vcsock);
812 		statp->_vcsock = -1;
813 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
814 	}
815 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
816 		if (statp->_u._ext.nssocks[ns] != -1) {
817 			(void) _close(statp->_u._ext.nssocks[ns]);
818 			statp->_u._ext.nssocks[ns] = -1;
819 		}
820 	}
821 }
822 
823 void
824 res_ndestroy(res_state statp) {
825 	res_nclose(statp);
826 	if (statp->_u._ext.ext != NULL) {
827 		free(statp->_u._ext.ext);
828 		statp->_u._ext.ext = NULL;
829 	}
830 	if (statp->_rnd != NULL) {
831 		free(statp->_rnd);
832 		statp->_rnd = NULL;
833 	}
834 	statp->options &= ~RES_INIT;
835 }
836 
837 #ifndef _LIBC
838 const char *
839 res_get_nibblesuffix(res_state statp) {
840 	if (statp->_u._ext.ext)
841 		return (statp->_u._ext.ext->nsuffix);
842 	return ("ip6.arpa");
843 }
844 
845 const char *
846 res_get_nibblesuffix2(res_state statp) {
847 	if (statp->_u._ext.ext)
848 		return (statp->_u._ext.ext->nsuffix2);
849 	return ("ip6.int");
850 }
851 #endif
852 
853 void
854 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
855 	int i, nserv;
856 	size_t size;
857 
858 	/* close open servers */
859 	res_nclose(statp);
860 
861 	/* cause rtt times to be forgotten */
862 	statp->_u._ext.nscount = 0;
863 
864 	nserv = 0;
865 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
866 		switch (set->sin.sin_family) {
867 		case AF_INET:
868 			size = sizeof(set->sin);
869 			if (statp->_u._ext.ext)
870 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
871 					&set->sin, size);
872 			if (size <= sizeof(statp->nsaddr_list[nserv]))
873 				memcpy(&statp->nsaddr_list[nserv],
874 					&set->sin, size);
875 			else
876 				statp->nsaddr_list[nserv].sin_family = 0;
877 			nserv++;
878 			break;
879 
880 #ifdef HAS_INET6_STRUCTS
881 		case AF_INET6:
882 			size = sizeof(set->sin6);
883 			if (statp->_u._ext.ext)
884 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
885 					&set->sin6, size);
886 			if (size <= sizeof(statp->nsaddr_list[nserv]))
887 				memcpy(&statp->nsaddr_list[nserv],
888 					&set->sin6, size);
889 			else
890 				statp->nsaddr_list[nserv].sin_family = 0;
891 			nserv++;
892 			break;
893 #endif
894 
895 		default:
896 			break;
897 		}
898 		set++;
899 	}
900 	statp->nscount = nserv;
901 
902 }
903 
904 int
905 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
906 	int i;
907 	size_t size;
908 	u_int16_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