xref: /freebsd/lib/libc/resolv/res_init.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
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 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
206 	u[nserv].sin.sin_family = AF_INET;
207 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
208 #ifdef HAVE_SA_LEN
209 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
210 #endif
211 	nserv++;
212 #ifdef HAS_INET6_STRUCTS
213 	u[nserv].sin6.sin6_addr = in6addr_any;
214 	u[nserv].sin6.sin6_family = AF_INET6;
215 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
216 #ifdef HAVE_SA_LEN
217 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
218 #endif
219 	nserv++;
220 #endif
221 	statp->nscount = 0;
222 	statp->ndots = 1;
223 	statp->pfcode = 0;
224 	statp->_vcsock = -1;
225 	statp->_flags = 0;
226 	statp->qhook = NULL;
227 	statp->rhook = NULL;
228 	statp->_u._ext.nscount = 0;
229 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
230 	if (statp->_u._ext.ext != NULL) {
231 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
232 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
233 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
234 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
235 		statp->_u._ext.ext->reload_period = 2;
236 	} else {
237 		/*
238 		 * Historically res_init() rarely, if at all, failed.
239 		 * Examples and applications exist which do not check
240 		 * our return code.  Furthermore several applications
241 		 * simply call us to get the systems domainname.  So
242 		 * rather then immediately fail here we store the
243 		 * failure, which is returned later, in h_errno.  And
244 		 * prevent the collection of 'nameserver' information
245 		 * by setting maxns to 0.  Thus applications that fail
246 		 * to check our return code wont be able to make
247 		 * queries anyhow.
248 		 */
249 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
250 		maxns = 0;
251 	}
252 #ifdef RESOLVSORT
253 	statp->nsort = 0;
254 #endif
255 	res_setservers(statp, u, nserv);
256 
257 #ifdef	SOLARIS2
258 	/*
259 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
260 	 * We want to keep this behaviour
261 	 */
262 	{
263 		char buf[sizeof(statp->defdname)], *cp;
264 		int ret;
265 
266 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
267 			(unsigned int)ret <= sizeof(buf)) {
268 			if (buf[0] == '+')
269 				buf[0] = '.';
270 			cp = strchr(buf, '.');
271 			cp = (cp == NULL) ? buf : (cp + 1);
272 			strncpy(statp->defdname, cp,
273 				sizeof(statp->defdname) - 1);
274 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
275 		}
276 	}
277 #endif	/* SOLARIS2 */
278 
279 	/* Allow user to override the local domain definition */
280 	if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
281 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
282 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
283 		haveenv++;
284 
285 		/*
286 		 * Set search list to be blank-separated strings
287 		 * from rest of env value.  Permits users of LOCALDOMAIN
288 		 * to still have a search list, and anyone to set the
289 		 * one that they want to use as an individual (even more
290 		 * important now that the rfc1535 stuff restricts searches)
291 		 */
292 		cp = statp->defdname;
293 		pp = statp->dnsrch;
294 		*pp++ = cp;
295 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
296 			if (*cp == '\n')	/*%< silly backwards compat */
297 				break;
298 			else if (*cp == ' ' || *cp == '\t') {
299 				*cp = 0;
300 				n = 1;
301 			} else if (n) {
302 				*pp++ = cp;
303 				n = 0;
304 				havesearch = 1;
305 			}
306 		}
307 		/* null terminate last domain if there are excess */
308 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
309 			cp++;
310 		*cp = '\0';
311 		*pp++ = NULL;
312 	}
313 
314 #define	MATCH(line, name) \
315 	(!strncmp(line, name, sizeof(name) - 1) && \
316 	(line[sizeof(name) - 1] == ' ' || \
317 	 line[sizeof(name) - 1] == '\t'))
318 
319 	nserv = 0;
320 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
321 	    struct stat sb;
322 	    struct timespec now;
323 
324 	    if (statp->_u._ext.ext != NULL) {
325 		if (_fstat(fileno(fp), &sb) == 0) {
326 		    statp->_u._ext.ext->conf_mtim = sb.st_mtim;
327 		    if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) == 0) {
328 			statp->_u._ext.ext->conf_stat = now.tv_sec;
329 		    }
330 		}
331 	    }
332 
333 	    /* read the config file */
334 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
335 		/* skip comments */
336 		if (*buf == ';' || *buf == '#')
337 			continue;
338 		/* read default domain name */
339 		if (MATCH(buf, "domain")) {
340 		    if (haveenv)	/*%< skip if have from environ */
341 			    continue;
342 		    cp = buf + sizeof("domain") - 1;
343 		    while (*cp == ' ' || *cp == '\t')
344 			    cp++;
345 		    if ((*cp == '\0') || (*cp == '\n'))
346 			    continue;
347 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
348 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
349 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
350 			    *cp = '\0';
351 		    havesearch = 0;
352 		    continue;
353 		}
354 		/* set search list */
355 		if (MATCH(buf, "search")) {
356 		    if (haveenv)	/*%< skip if have from environ */
357 			    continue;
358 		    cp = buf + sizeof("search") - 1;
359 		    while (*cp == ' ' || *cp == '\t')
360 			    cp++;
361 		    if ((*cp == '\0') || (*cp == '\n'))
362 			    continue;
363 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
364 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
365 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
366 			    *cp = '\0';
367 		    /*
368 		     * Set search list to be blank-separated strings
369 		     * on rest of line.
370 		     */
371 		    cp = statp->defdname;
372 		    pp = statp->dnsrch;
373 		    *pp++ = cp;
374 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
375 			    if (*cp == ' ' || *cp == '\t') {
376 				    *cp = 0;
377 				    n = 1;
378 			    } else if (n) {
379 				    *pp++ = cp;
380 				    n = 0;
381 			    }
382 		    }
383 		    /* null terminate last domain if there are excess */
384 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
385 			    cp++;
386 		    *cp = '\0';
387 		    *pp++ = NULL;
388 		    havesearch = 1;
389 		    continue;
390 		}
391 		/* read nameservers to query */
392 		if (MATCH(buf, "nameserver") && nserv < maxns) {
393 		    struct addrinfo hints, *ai;
394 		    char sbuf[NI_MAXSERV];
395 		    const size_t minsiz =
396 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
397 
398 		    cp = buf + sizeof("nameserver") - 1;
399 		    while (*cp == ' ' || *cp == '\t')
400 			cp++;
401 		    cp[strcspn(cp, ";# \t\n")] = '\0';
402 		    if ((*cp != '\0') && (*cp != '\n')) {
403 			memset(&hints, 0, sizeof(hints));
404 			hints.ai_family = PF_UNSPEC;
405 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
406 			hints.ai_flags = AI_NUMERICHOST;
407 			sprintf(sbuf, "%u", NAMESERVER_PORT);
408 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0) {
409 			    if (ai->ai_addrlen <= minsiz) {
410 				if (statp->_u._ext.ext != NULL) {
411 				    memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
412 					ai->ai_addr, ai->ai_addrlen);
413 				}
414 				if (ai->ai_addrlen <=
415 				    sizeof(statp->nsaddr_list[nserv])) {
416 				    memcpy(&statp->nsaddr_list[nserv],
417 					ai->ai_addr, ai->ai_addrlen);
418 				} else
419 				    statp->nsaddr_list[nserv].sin_family = 0;
420 				nserv++;
421 			    }
422 			    freeaddrinfo(ai);
423 			}
424 		    }
425 		    continue;
426 		}
427 #ifdef RESOLVSORT
428 		if (MATCH(buf, "sortlist")) {
429 		    struct in_addr a;
430 		    struct in6_addr a6;
431 		    int m, i;
432 		    u_char *u;
433 		    struct __res_state_ext *ext = statp->_u._ext.ext;
434 
435 		    cp = buf + sizeof("sortlist") - 1;
436 		    while (nsort < MAXRESOLVSORT) {
437 			while (*cp == ' ' || *cp == '\t')
438 			    cp++;
439 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
440 			    break;
441 			net = cp;
442 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
443 			       isascii(*cp) && !isspace((unsigned char)*cp))
444 				cp++;
445 			n = *cp;
446 			*cp = 0;
447 			if (inet_aton(net, &a)) {
448 			    statp->sort_list[nsort].addr = a;
449 			    if (ISSORTMASK(n)) {
450 				*cp++ = n;
451 				net = cp;
452 				while (*cp && *cp != ';' &&
453 					isascii(*cp) &&
454 					!isspace((unsigned char)*cp))
455 				    cp++;
456 				n = *cp;
457 				*cp = 0;
458 				if (inet_aton(net, &a)) {
459 				    statp->sort_list[nsort].mask = a.s_addr;
460 				} else {
461 				    statp->sort_list[nsort].mask =
462 					net_mask(statp->sort_list[nsort].addr);
463 				}
464 			    } else {
465 				statp->sort_list[nsort].mask =
466 				    net_mask(statp->sort_list[nsort].addr);
467 			    }
468 			    ext->sort_list[nsort].af = AF_INET;
469 			    ext->sort_list[nsort].addr.ina =
470 				statp->sort_list[nsort].addr;
471 			    ext->sort_list[nsort].mask.ina.s_addr =
472 				statp->sort_list[nsort].mask;
473 			    nsort++;
474 			}
475 			else if (inet_pton(AF_INET6, net, &a6) == 1) {
476 
477 			    ext->sort_list[nsort].af = AF_INET6;
478 			    ext->sort_list[nsort].addr.in6a = a6;
479 			    u = (u_char *)&ext->sort_list[nsort].mask.in6a;
480 			    *cp++ = n;
481 			    net = cp;
482 			    while (*cp && *cp != ';' &&
483 				    isascii(*cp) && !isspace(*cp))
484 				cp++;
485 			    m = n;
486 			    n = *cp;
487 			    *cp = 0;
488 			    switch (m) {
489 			    case '/':
490 				m = atoi(net);
491 				break;
492 			    case '&':
493 				if (inet_pton(AF_INET6, net, u) == 1) {
494 				    m = -1;
495 				    break;
496 				}
497 				/*FALLTHROUGH*/
498 			    default:
499 				m = sizeof(struct in6_addr) * CHAR_BIT;
500 				break;
501 			    }
502 			    if (m >= 0) {
503 				for (i = 0; i < sizeof(struct in6_addr); i++) {
504 				    if (m <= 0) {
505 					*u = 0;
506 				    } else {
507 					m -= CHAR_BIT;
508 					*u = (u_char)~0;
509 					if (m < 0)
510 					    *u <<= -m;
511 				    }
512 				    u++;
513 				}
514 			    }
515 			    statp->sort_list[nsort].addr.s_addr =
516 				(u_int32_t)0xffffffff;
517 			    statp->sort_list[nsort].mask =
518 				(u_int32_t)0xffffffff;
519 			    nsort++;
520 			}
521 			*cp = n;
522 		    }
523 		    continue;
524 		}
525 #endif
526 		if (MATCH(buf, "options")) {
527 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
528 		    continue;
529 		}
530 	    }
531 	    if (nserv > 0)
532 		statp->nscount = nserv;
533 #ifdef RESOLVSORT
534 	    statp->nsort = nsort;
535 #endif
536 	    (void) fclose(fp);
537 	}
538 /*
539  * Last chance to get a nameserver.  This should not normally
540  * be necessary
541  */
542 #ifdef NO_RESOLV_CONF
543 	if(nserv == 0)
544 		nserv = get_nameservers(statp);
545 #endif
546 
547 	if (statp->defdname[0] == 0 &&
548 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
549 	    (cp = strchr(buf, '.')) != NULL)
550 		strcpy(statp->defdname, cp + 1);
551 
552 	/* find components of local domain that might be searched */
553 	if (havesearch == 0) {
554 		pp = statp->dnsrch;
555 		*pp++ = statp->defdname;
556 		*pp = NULL;
557 
558 		dots = 0;
559 		for (cp = statp->defdname; *cp; cp++)
560 			dots += (*cp == '.');
561 
562 		cp = statp->defdname;
563 		while (pp < statp->dnsrch + MAXDFLSRCH) {
564 			if (dots < LOCALDOMAINPARTS)
565 				break;
566 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
567 			*pp++ = cp;
568 			dots--;
569 		}
570 		*pp = NULL;
571 #ifdef DEBUG
572 		if (statp->options & RES_DEBUG) {
573 			printf(";; res_init()... default dnsrch list:\n");
574 			for (pp = statp->dnsrch; *pp; pp++)
575 				printf(";;\t%s\n", *pp);
576 			printf(";;\t..END..\n");
577 		}
578 #endif
579 	}
580 
581 	if (issetugid())
582 		statp->options |= RES_NOALIASES;
583 	else if ((cp = getenv("RES_OPTIONS")) != NULL)
584 		res_setoptions(statp, cp, "env");
585 	statp->options |= RES_INIT;
586 	return (statp->res_h_errno);
587 }
588 
589 static void
590 res_setoptions(res_state statp, const char *options, const char *source)
591 {
592 	const char *cp = options;
593 	int i;
594 	struct __res_state_ext *ext = statp->_u._ext.ext;
595 
596 #ifdef DEBUG
597 	if (statp->options & RES_DEBUG)
598 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
599 		       options, source);
600 #endif
601 	while (*cp) {
602 		/* skip leading and inner runs of spaces */
603 		while (*cp == ' ' || *cp == '\t')
604 			cp++;
605 		/* search for and process individual options */
606 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
607 			i = atoi(cp + sizeof("ndots:") - 1);
608 			if (i <= RES_MAXNDOTS)
609 				statp->ndots = i;
610 			else
611 				statp->ndots = RES_MAXNDOTS;
612 #ifdef DEBUG
613 			if (statp->options & RES_DEBUG)
614 				printf(";;\tndots=%d\n", statp->ndots);
615 #endif
616 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
617 			i = atoi(cp + sizeof("timeout:") - 1);
618 			if (i <= RES_MAXRETRANS)
619 				statp->retrans = i;
620 			else
621 				statp->retrans = RES_MAXRETRANS;
622 #ifdef DEBUG
623 			if (statp->options & RES_DEBUG)
624 				printf(";;\ttimeout=%d\n", statp->retrans);
625 #endif
626 #ifdef	SOLARIS2
627 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
628 			/*
629 		 	 * For backward compatibility, 'retrans' is
630 		 	 * supported as an alias for 'timeout', though
631 		 	 * without an imposed maximum.
632 		 	 */
633 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
634 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
635 			/*
636 			 * For backward compatibility, 'retry' is
637 			 * supported as an alias for 'attempts', though
638 			 * without an imposed maximum.
639 			 */
640 			statp->retry = atoi(cp + sizeof("retry:") - 1);
641 #endif	/* SOLARIS2 */
642 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
643 			i = atoi(cp + sizeof("attempts:") - 1);
644 			if (i <= RES_MAXRETRY)
645 				statp->retry = i;
646 			else
647 				statp->retry = RES_MAXRETRY;
648 #ifdef DEBUG
649 			if (statp->options & RES_DEBUG)
650 				printf(";;\tattempts=%d\n", statp->retry);
651 #endif
652 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
653 #ifdef DEBUG
654 			if (!(statp->options & RES_DEBUG)) {
655 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
656 				       options, source);
657 				statp->options |= RES_DEBUG;
658 			}
659 			printf(";;\tdebug\n");
660 #endif
661 		} else if (!strncmp(cp, "no_tld_query",
662 				    sizeof("no_tld_query") - 1) ||
663 			   !strncmp(cp, "no-tld-query",
664 				    sizeof("no-tld-query") - 1)) {
665 			statp->options |= RES_NOTLDQUERY;
666 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
667 			statp->options |= RES_USE_INET6;
668 		} else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
669 		       statp->options |= RES_INSECURE1;
670 		} else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
671 		       statp->options |= RES_INSECURE2;
672 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
673 			statp->options |= RES_ROTATE;
674 		} else if (!strncmp(cp, "usevc", sizeof("usevc") - 1)) {
675 			statp->options |= RES_USEVC;
676 		} else if (!strncmp(cp, "no-check-names",
677 				    sizeof("no-check-names") - 1)) {
678 			statp->options |= RES_NOCHECKNAME;
679 		} else if (!strncmp(cp, "reload-period:",
680 				    sizeof("reload-period:") - 1)) {
681 			if (ext != NULL) {
682 				ext->reload_period = (u_short)
683 				    atoi(cp + sizeof("reload-period:") - 1);
684 			}
685 		}
686 #ifdef RES_USE_EDNS0
687 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
688 			statp->options |= RES_USE_EDNS0;
689 		}
690 #endif
691 #ifndef _LIBC
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 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
700 			strncpy(ext->nsuffix, cp, i);
701 			ext->nsuffix[i] = '\0';
702 		}
703 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
704 			if (ext == NULL)
705 				goto skip;
706 			cp += sizeof("nibble2:") - 1;
707 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
708 			strncpy(ext->nsuffix2, cp, i);
709 			ext->nsuffix2[i] = '\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 #endif
722 		else {
723 			/* XXX - print a warning here? */
724 		}
725 #ifndef _LIBC
726    skip:
727 #endif
728 		/* skip to next run of spaces */
729 		while (*cp && *cp != ' ' && *cp != '\t')
730 			cp++;
731 	}
732 }
733 
734 #ifdef RESOLVSORT
735 /* XXX - should really support CIDR which means explicit masks always. */
736 static u_int32_t
737 net_mask(struct in_addr in)		/*!< XXX - should really use system's version of this  */
738 {
739 	u_int32_t i = ntohl(in.s_addr);
740 
741 	if (IN_CLASSA(i))
742 		return (htonl(IN_CLASSA_NET));
743 	else if (IN_CLASSB(i))
744 		return (htonl(IN_CLASSB_NET));
745 	return (htonl(IN_CLASSC_NET));
746 }
747 #endif
748 
749 static u_char srnd[16];
750 
751 void
752 res_rndinit(res_state statp)
753 {
754 	struct timeval now;
755 	u_int32_t u32;
756 	u_int16_t u16;
757 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
758 
759 	gettimeofday(&now, NULL);
760 	u32 = now.tv_sec;
761 	memcpy(rnd, &u32, 4);
762 	u32 = now.tv_usec;
763 	memcpy(rnd + 4, &u32, 4);
764 	u32 += now.tv_sec;
765 	memcpy(rnd + 8, &u32, 4);
766 	u16 = getpid();
767 	memcpy(rnd + 12, &u16, 2);
768 }
769 
770 u_int
771 res_nrandomid(res_state statp) {
772 	struct timeval now;
773 	u_int16_t u16;
774 	MD5_CTX ctx;
775 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
776 
777 	gettimeofday(&now, NULL);
778 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
779 	memcpy(rnd + 14, &u16, 2);
780 #ifndef HAVE_MD5
781 	MD5_Init(&ctx);
782 	MD5_Update(&ctx, rnd, 16);
783 	MD5_Final(rnd, &ctx);
784 #else
785 	MD5Init(&ctx);
786 	MD5Update(&ctx, rnd, 16);
787 	MD5Final(rnd, &ctx);
788 #endif
789 	memcpy(&u16, rnd + 14, 2);
790 	return ((u_int) u16);
791 }
792 
793 /*%
794  * This routine is for closing the socket if a virtual circuit is used and
795  * the program wants to close it.  This provides support for endhostent()
796  * which expects to close the socket.
797  *
798  * This routine is not expected to be user visible.
799  */
800 void
801 res_nclose(res_state statp) {
802 	int ns;
803 
804 	if (statp->_vcsock >= 0) {
805 		(void) _close(statp->_vcsock);
806 		statp->_vcsock = -1;
807 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
808 	}
809 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
810 		if (statp->_u._ext.nssocks[ns] != -1) {
811 			(void) _close(statp->_u._ext.nssocks[ns]);
812 			statp->_u._ext.nssocks[ns] = -1;
813 		}
814 	}
815 }
816 
817 void
818 res_ndestroy(res_state statp) {
819 	res_nclose(statp);
820 	if (statp->_u._ext.ext != NULL) {
821 		free(statp->_u._ext.ext);
822 		statp->_u._ext.ext = NULL;
823 	}
824 	if (statp->_rnd != NULL) {
825 		free(statp->_rnd);
826 		statp->_rnd = NULL;
827 	}
828 	statp->options &= ~RES_INIT;
829 }
830 
831 #ifndef _LIBC
832 const char *
833 res_get_nibblesuffix(res_state statp) {
834 	if (statp->_u._ext.ext)
835 		return (statp->_u._ext.ext->nsuffix);
836 	return ("ip6.arpa");
837 }
838 
839 const char *
840 res_get_nibblesuffix2(res_state statp) {
841 	if (statp->_u._ext.ext)
842 		return (statp->_u._ext.ext->nsuffix2);
843 	return ("ip6.int");
844 }
845 #endif
846 
847 void
848 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
849 	int i, nserv;
850 	size_t size;
851 
852 	/* close open servers */
853 	res_nclose(statp);
854 
855 	/* cause rtt times to be forgotten */
856 	statp->_u._ext.nscount = 0;
857 
858 	nserv = 0;
859 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
860 		switch (set->sin.sin_family) {
861 		case AF_INET:
862 			size = sizeof(set->sin);
863 			if (statp->_u._ext.ext)
864 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
865 					&set->sin, size);
866 			if (size <= sizeof(statp->nsaddr_list[nserv]))
867 				memcpy(&statp->nsaddr_list[nserv],
868 					&set->sin, size);
869 			else
870 				statp->nsaddr_list[nserv].sin_family = 0;
871 			nserv++;
872 			break;
873 
874 #ifdef HAS_INET6_STRUCTS
875 		case AF_INET6:
876 			size = sizeof(set->sin6);
877 			if (statp->_u._ext.ext)
878 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
879 					&set->sin6, size);
880 			if (size <= sizeof(statp->nsaddr_list[nserv]))
881 				memcpy(&statp->nsaddr_list[nserv],
882 					&set->sin6, size);
883 			else
884 				statp->nsaddr_list[nserv].sin_family = 0;
885 			nserv++;
886 			break;
887 #endif
888 
889 		default:
890 			break;
891 		}
892 		set++;
893 	}
894 	statp->nscount = nserv;
895 
896 }
897 
898 int
899 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
900 	int i;
901 	size_t size;
902 	u_int16_t family;
903 
904 	for (i = 0; i < statp->nscount && i < cnt; i++) {
905 		if (statp->_u._ext.ext)
906 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
907 		else
908 			family = statp->nsaddr_list[i].sin_family;
909 
910 		switch (family) {
911 		case AF_INET:
912 			size = sizeof(set->sin);
913 			if (statp->_u._ext.ext)
914 				memcpy(&set->sin,
915 				       &statp->_u._ext.ext->nsaddrs[i],
916 				       size);
917 			else
918 				memcpy(&set->sin, &statp->nsaddr_list[i],
919 				       size);
920 			break;
921 
922 #ifdef HAS_INET6_STRUCTS
923 		case AF_INET6:
924 			size = sizeof(set->sin6);
925 			if (statp->_u._ext.ext)
926 				memcpy(&set->sin6,
927 				       &statp->_u._ext.ext->nsaddrs[i],
928 				       size);
929 			else
930 				memcpy(&set->sin6, &statp->nsaddr_list[i],
931 				       size);
932 			break;
933 #endif
934 
935 		default:
936 			set->sin.sin_family = 0;
937 			break;
938 		}
939 		set++;
940 	}
941 	return (statp->nscount);
942 }
943 
944 /*! \file */
945