xref: /freebsd-src/lib/libc/resolv/res_init.c (revision 3f25740ec6845340de7abaae80607dea9c3a4bb8)
1 /*
2  * Copyright (c) 1985, 1989, 1993
3  *    The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  * 	This product includes software developed by the University of
16  * 	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
36  *
37  * Permission to use, copy, modify, and distribute this software for any
38  * purpose with or without fee is hereby granted, provided that the above
39  * copyright notice and this permission notice appear in all copies, and that
40  * the name of Digital Equipment Corporation not be used in advertising or
41  * publicity pertaining to distribution of the document or software without
42  * specific, written prior permission.
43  *
44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51  * SOFTWARE.
52  */
53 
54 /*
55  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
56  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
57  *
58  * Permission to use, copy, modify, and distribute this software for any
59  * purpose with or without fee is hereby granted, provided that the above
60  * copyright notice and this permission notice appear in all copies.
61  *
62  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
63  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
64  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
65  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
66  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
67  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
68  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
69  */
70 
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
73 static const char rcsid[] = "$Id: res_init.c,v 1.9.2.5.4.6 2006/08/30 23:23:01 marka Exp $";
74 #endif /* LIBC_SCCS and not lint */
75 
76 #include "port_before.h"
77 
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <sys/socket.h>
81 #include <sys/time.h>
82 
83 #include <netinet/in.h>
84 #include <arpa/inet.h>
85 #include <arpa/nameser.h>
86 
87 #include <ctype.h>
88 #include <stdio.h>
89 #include <stdlib.h>
90 #include <string.h>
91 #include <unistd.h>
92 #include <netdb.h>
93 
94 #include "port_after.h"
95 
96 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
97 #include <resolv.h>
98 
99 #include "res_private.h"
100 
101 /* Options.  Should all be left alone. */
102 #define RESOLVSORT
103 #define DEBUG
104 
105 #ifdef SOLARIS2
106 #include <sys/systeminfo.h>
107 #endif
108 
109 static void res_setoptions __P((res_state, const char *, const char *));
110 
111 #ifdef RESOLVSORT
112 static const char sort_mask[] = "/&";
113 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
114 static u_int32_t net_mask __P((struct in_addr));
115 #endif
116 
117 #if !defined(isascii)	/* XXX - could be a function */
118 # define isascii(c) (!(c & 0200))
119 #endif
120 
121 /*
122  * Resolver state default settings.
123  */
124 
125 /*
126  * Set up default settings.  If the configuration file exist, the values
127  * there will have precedence.  Otherwise, the server address is set to
128  * INADDR_ANY and the default domain name comes from the gethostname().
129  *
130  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
131  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
132  * since it was noted that INADDR_ANY actually meant ``the first interface
133  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
134  * it had to be "up" in order for you to reach your own name server.  It
135  * was later decided that since the recommended practice is to always
136  * install local static routes through 127.0.0.1 for all your network
137  * interfaces, that we could solve this problem without a code change.
138  *
139  * The configuration file should always be used, since it is the only way
140  * to specify a default domain.  If you are running a server on your local
141  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
142  * in the configuration file.
143  *
144  * Return 0 if completes successfully, -1 on error
145  */
146 int
147 res_ninit(res_state statp) {
148 	extern int __res_vinit(res_state, int);
149 
150 	return (__res_vinit(statp, 0));
151 }
152 
153 /* This function has to be reachable by res_data.c but not publically. */
154 int
155 __res_vinit(res_state statp, int preinit) {
156 	register FILE *fp;
157 	register char *cp, **pp;
158 	register int n;
159 	char buf[BUFSIZ];
160 	int nserv = 0;    /* number of nameserver records read from file */
161 	int haveenv = 0;
162 	int havesearch = 0;
163 #ifdef RESOLVSORT
164 	int nsort = 0;
165 	char *net;
166 #endif
167 	int dots;
168 	union res_sockaddr_union u[2];
169 
170 	if (statp->_u._ext.ext != NULL)
171 		res_ndestroy(statp);
172 
173 	if (!preinit) {
174 		statp->retrans = RES_TIMEOUT;
175 		statp->retry = RES_DFLRETRY;
176 		statp->options = RES_DEFAULT;
177 		statp->id = res_randomid();
178 	}
179 
180 	memset(u, 0, sizeof(u));
181 #ifdef USELOOPBACK
182 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
183 #else
184 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
185 #endif
186 	u[nserv].sin.sin_family = AF_INET;
187 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
188 #ifdef HAVE_SA_LEN
189 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
190 #endif
191 	nserv++;
192 #ifdef HAS_INET6_STRUCTS
193 #ifdef USELOOPBACK
194 	u[nserv].sin6.sin6_addr = in6addr_loopback;
195 #else
196 	u[nserv].sin6.sin6_addr = in6addr_any;
197 #endif
198 	u[nserv].sin6.sin6_family = AF_INET6;
199 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
200 #ifdef HAVE_SA_LEN
201 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
202 #endif
203 	nserv++;
204 #endif
205 	statp->nscount = 0;
206 	statp->ndots = 1;
207 	statp->pfcode = 0;
208 	statp->_vcsock = -1;
209 	statp->_flags = 0;
210 	statp->qhook = NULL;
211 	statp->rhook = NULL;
212 	statp->_u._ext.nscount = 0;
213 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
214 	if (statp->_u._ext.ext != NULL) {
215 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
216 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
217 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
218 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
219 	} else
220 		return (-1);
221 #ifdef RESOLVSORT
222 	statp->nsort = 0;
223 #endif
224 	res_setservers(statp, u, nserv);
225 
226 #ifdef	SOLARIS2
227 	/*
228 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
229 	 * We want to keep this behaviour
230 	 */
231 	{
232 		char buf[sizeof(statp->defdname)], *cp;
233 		int ret;
234 
235 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
236 			(unsigned int)ret <= sizeof(buf)) {
237 			if (buf[0] == '+')
238 				buf[0] = '.';
239 			cp = strchr(buf, '.');
240 			cp = (cp == NULL) ? buf : (cp + 1);
241 			if (strlen(cp) >= sizeof(statp->defdname))
242 				goto freedata;
243 			strcpy(statp->defdname, cp);
244 		}
245 	}
246 #endif	/* SOLARIS2 */
247 
248 	/* Allow user to override the local domain definition */
249 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
250 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
251 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
252 		haveenv++;
253 
254 		/*
255 		 * Set search list to be blank-separated strings
256 		 * from rest of env value.  Permits users of LOCALDOMAIN
257 		 * to still have a search list, and anyone to set the
258 		 * one that they want to use as an individual (even more
259 		 * important now that the rfc1535 stuff restricts searches)
260 		 */
261 		cp = statp->defdname;
262 		pp = statp->dnsrch;
263 		*pp++ = cp;
264 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
265 			if (*cp == '\n')	/* silly backwards compat */
266 				break;
267 			else if (*cp == ' ' || *cp == '\t') {
268 				*cp = 0;
269 				n = 1;
270 			} else if (n) {
271 				*pp++ = cp;
272 				n = 0;
273 				havesearch = 1;
274 			}
275 		}
276 		/* null terminate last domain if there are excess */
277 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
278 			cp++;
279 		*cp = '\0';
280 		*pp++ = 0;
281 	}
282 
283 #define	MATCH(line, name) \
284 	(!strncmp(line, name, sizeof(name) - 1) && \
285 	(line[sizeof(name) - 1] == ' ' || \
286 	 line[sizeof(name) - 1] == '\t'))
287 
288 	nserv = 0;
289 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
290 	    /* read the config file */
291 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
292 		/* skip comments */
293 		if (*buf == ';' || *buf == '#')
294 			continue;
295 		/* read default domain name */
296 		if (MATCH(buf, "domain")) {
297 		    if (haveenv)	/* skip if have from environ */
298 			    continue;
299 		    cp = buf + sizeof("domain") - 1;
300 		    while (*cp == ' ' || *cp == '\t')
301 			    cp++;
302 		    if ((*cp == '\0') || (*cp == '\n'))
303 			    continue;
304 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
305 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
306 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
307 			    *cp = '\0';
308 		    havesearch = 0;
309 		    continue;
310 		}
311 		/* set search list */
312 		if (MATCH(buf, "search")) {
313 		    if (haveenv)	/* skip if have from environ */
314 			    continue;
315 		    cp = buf + sizeof("search") - 1;
316 		    while (*cp == ' ' || *cp == '\t')
317 			    cp++;
318 		    if ((*cp == '\0') || (*cp == '\n'))
319 			    continue;
320 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
321 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
322 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
323 			    *cp = '\0';
324 		    /*
325 		     * Set search list to be blank-separated strings
326 		     * on rest of line.
327 		     */
328 		    cp = statp->defdname;
329 		    pp = statp->dnsrch;
330 		    *pp++ = cp;
331 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
332 			    if (*cp == ' ' || *cp == '\t') {
333 				    *cp = 0;
334 				    n = 1;
335 			    } else if (n) {
336 				    *pp++ = cp;
337 				    n = 0;
338 			    }
339 		    }
340 		    /* null terminate last domain if there are excess */
341 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
342 			    cp++;
343 		    *cp = '\0';
344 		    *pp++ = 0;
345 		    havesearch = 1;
346 		    continue;
347 		}
348 		/* read nameservers to query */
349 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
350 		    struct addrinfo hints, *ai;
351 		    char sbuf[NI_MAXSERV];
352 		    const size_t minsiz =
353 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
354 
355 		    cp = buf + sizeof("nameserver") - 1;
356 		    while (*cp == ' ' || *cp == '\t')
357 			cp++;
358 		    cp[strcspn(cp, ";# \t\n")] = '\0';
359 		    if ((*cp != '\0') && (*cp != '\n')) {
360 			memset(&hints, 0, sizeof(hints));
361 			hints.ai_family = PF_UNSPEC;
362 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
363 			hints.ai_flags = AI_NUMERICHOST;
364 			sprintf(sbuf, "%u", NAMESERVER_PORT);
365 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
366 			    ai->ai_addrlen <= minsiz) {
367 			    if (statp->_u._ext.ext != NULL) {
368 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
369 				    ai->ai_addr, ai->ai_addrlen);
370 			    }
371 			    if (ai->ai_addrlen <=
372 			        sizeof(statp->nsaddr_list[nserv])) {
373 				memcpy(&statp->nsaddr_list[nserv],
374 				    ai->ai_addr, ai->ai_addrlen);
375 			    } else
376 				statp->nsaddr_list[nserv].sin_family = 0;
377 			    freeaddrinfo(ai);
378 			    nserv++;
379 			}
380 		    }
381 		    continue;
382 		}
383 #ifdef RESOLVSORT
384 		if (MATCH(buf, "sortlist")) {
385 		    struct in_addr a;
386 
387 		    cp = buf + sizeof("sortlist") - 1;
388 		    while (nsort < MAXRESOLVSORT) {
389 			while (*cp == ' ' || *cp == '\t')
390 			    cp++;
391 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
392 			    break;
393 			net = cp;
394 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
395 			       isascii(*cp) && !isspace((unsigned char)*cp))
396 				cp++;
397 			n = *cp;
398 			*cp = 0;
399 			if (inet_aton(net, &a)) {
400 			    statp->sort_list[nsort].addr = a;
401 			    if (ISSORTMASK(n)) {
402 				*cp++ = n;
403 				net = cp;
404 				while (*cp && *cp != ';' &&
405 					isascii(*cp) &&
406 					!isspace((unsigned char)*cp))
407 				    cp++;
408 				n = *cp;
409 				*cp = 0;
410 				if (inet_aton(net, &a)) {
411 				    statp->sort_list[nsort].mask = a.s_addr;
412 				} else {
413 				    statp->sort_list[nsort].mask =
414 					net_mask(statp->sort_list[nsort].addr);
415 				}
416 			    } else {
417 				statp->sort_list[nsort].mask =
418 				    net_mask(statp->sort_list[nsort].addr);
419 			    }
420 			    nsort++;
421 			}
422 			*cp = n;
423 		    }
424 		    continue;
425 		}
426 #endif
427 		if (MATCH(buf, "options")) {
428 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
429 		    continue;
430 		}
431 	    }
432 	    if (nserv > 0)
433 		statp->nscount = nserv;
434 #ifdef RESOLVSORT
435 	    statp->nsort = nsort;
436 #endif
437 	    (void) fclose(fp);
438 	}
439 /*
440  * Last chance to get a nameserver.  This should not normally
441  * be necessary
442  */
443 #ifdef NO_RESOLV_CONF
444 	if(nserv == 0)
445 		nserv = get_nameservers(statp);
446 #endif
447 
448 	if (statp->defdname[0] == 0 &&
449 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
450 	    (cp = strchr(buf, '.')) != NULL)
451 		strcpy(statp->defdname, cp + 1);
452 
453 	/* find components of local domain that might be searched */
454 	if (havesearch == 0) {
455 		pp = statp->dnsrch;
456 		*pp++ = statp->defdname;
457 		*pp = NULL;
458 
459 		dots = 0;
460 		for (cp = statp->defdname; *cp; cp++)
461 			dots += (*cp == '.');
462 
463 		cp = statp->defdname;
464 		while (pp < statp->dnsrch + MAXDFLSRCH) {
465 			if (dots < LOCALDOMAINPARTS)
466 				break;
467 			cp = strchr(cp, '.') + 1;    /* we know there is one */
468 			*pp++ = cp;
469 			dots--;
470 		}
471 		*pp = NULL;
472 #ifdef DEBUG
473 		if (statp->options & RES_DEBUG) {
474 			printf(";; res_init()... default dnsrch list:\n");
475 			for (pp = statp->dnsrch; *pp; pp++)
476 				printf(";;\t%s\n", *pp);
477 			printf(";;\t..END..\n");
478 		}
479 #endif
480 	}
481 
482 	if ((cp = getenv("RES_OPTIONS")) != NULL)
483 		res_setoptions(statp, cp, "env");
484 	statp->options |= RES_INIT;
485 	return (0);
486 
487 #ifdef	SOLARIS2
488  freedata:
489 	if (statp->_u._ext.ext != NULL) {
490 		free(statp->_u._ext.ext);
491 		statp->_u._ext.ext = NULL;
492 	}
493 	return (-1);
494 #endif
495 }
496 
497 static void
498 res_setoptions(res_state statp, const char *options, const char *source)
499 {
500 	const char *cp = options;
501 	int i;
502 	struct __res_state_ext *ext = statp->_u._ext.ext;
503 
504 #ifdef DEBUG
505 	if (statp->options & RES_DEBUG)
506 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
507 		       options, source);
508 #endif
509 	while (*cp) {
510 		/* skip leading and inner runs of spaces */
511 		while (*cp == ' ' || *cp == '\t')
512 			cp++;
513 		/* search for and process individual options */
514 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
515 			i = atoi(cp + sizeof("ndots:") - 1);
516 			if (i <= RES_MAXNDOTS)
517 				statp->ndots = i;
518 			else
519 				statp->ndots = RES_MAXNDOTS;
520 #ifdef DEBUG
521 			if (statp->options & RES_DEBUG)
522 				printf(";;\tndots=%d\n", statp->ndots);
523 #endif
524 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
525 			i = atoi(cp + sizeof("timeout:") - 1);
526 			if (i <= RES_MAXRETRANS)
527 				statp->retrans = i;
528 			else
529 				statp->retrans = RES_MAXRETRANS;
530 #ifdef DEBUG
531 			if (statp->options & RES_DEBUG)
532 				printf(";;\ttimeout=%d\n", statp->retrans);
533 #endif
534 #ifdef	SOLARIS2
535 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
536 			/*
537 		 	 * For backward compatibility, 'retrans' is
538 		 	 * supported as an alias for 'timeout', though
539 		 	 * without an imposed maximum.
540 		 	 */
541 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
542 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
543 			/*
544 			 * For backward compatibility, 'retry' is
545 			 * supported as an alias for 'attempts', though
546 			 * without an imposed maximum.
547 			 */
548 			statp->retry = atoi(cp + sizeof("retry:") - 1);
549 #endif	/* SOLARIS2 */
550 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
551 			i = atoi(cp + sizeof("attempts:") - 1);
552 			if (i <= RES_MAXRETRY)
553 				statp->retry = i;
554 			else
555 				statp->retry = RES_MAXRETRY;
556 #ifdef DEBUG
557 			if (statp->options & RES_DEBUG)
558 				printf(";;\tattempts=%d\n", statp->retry);
559 #endif
560 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
561 #ifdef DEBUG
562 			if (!(statp->options & RES_DEBUG)) {
563 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
564 				       options, source);
565 				statp->options |= RES_DEBUG;
566 			}
567 			printf(";;\tdebug\n");
568 #endif
569 		} else if (!strncmp(cp, "no_tld_query",
570 				    sizeof("no_tld_query") - 1) ||
571 			   !strncmp(cp, "no-tld-query",
572 				    sizeof("no-tld-query") - 1)) {
573 			statp->options |= RES_NOTLDQUERY;
574 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
575 			statp->options |= RES_USE_INET6;
576 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
577 			statp->options |= RES_ROTATE;
578 		} else if (!strncmp(cp, "no-check-names",
579 				    sizeof("no-check-names") - 1)) {
580 			statp->options |= RES_NOCHECKNAME;
581 		}
582 #ifdef RES_USE_EDNS0
583 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
584 			statp->options |= RES_USE_EDNS0;
585 		}
586 #endif
587 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
588 			statp->options |= RES_USE_DNAME;
589 		}
590 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
591 			if (ext == NULL)
592 				goto skip;
593 			cp += sizeof("nibble:") - 1;
594 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
595 			strncpy(ext->nsuffix, cp, i);
596 			ext->nsuffix[i] = '\0';
597 		}
598 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
599 			if (ext == NULL)
600 				goto skip;
601 			cp += sizeof("nibble2:") - 1;
602 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
603 			strncpy(ext->nsuffix2, cp, i);
604 			ext->nsuffix2[i] = '\0';
605 		}
606 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
607 			cp += sizeof("v6revmode:") - 1;
608 			/* "nibble" and "bitstring" used to be valid */
609 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
610 				statp->options |= RES_NO_NIBBLE2;
611 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
612 				statp->options &=
613 					 ~RES_NO_NIBBLE2;
614 			}
615 		}
616 		else {
617 			/* XXX - print a warning here? */
618 		}
619    skip:
620 		/* skip to next run of spaces */
621 		while (*cp && *cp != ' ' && *cp != '\t')
622 			cp++;
623 	}
624 }
625 
626 #ifdef RESOLVSORT
627 /* XXX - should really support CIDR which means explicit masks always. */
628 static u_int32_t
629 net_mask(in)		/* XXX - should really use system's version of this */
630 	struct in_addr in;
631 {
632 	register u_int32_t i = ntohl(in.s_addr);
633 
634 	if (IN_CLASSA(i))
635 		return (htonl(IN_CLASSA_NET));
636 	else if (IN_CLASSB(i))
637 		return (htonl(IN_CLASSB_NET));
638 	return (htonl(IN_CLASSC_NET));
639 }
640 #endif
641 
642 u_int
643 res_randomid(void) {
644 	struct timeval now;
645 
646 	gettimeofday(&now, NULL);
647 	return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
648 }
649 
650 /*
651  * This routine is for closing the socket if a virtual circuit is used and
652  * the program wants to close it.  This provides support for endhostent()
653  * which expects to close the socket.
654  *
655  * This routine is not expected to be user visible.
656  */
657 void
658 res_nclose(res_state statp) {
659 	int ns;
660 
661 	if (statp->_vcsock >= 0) {
662 		(void) close(statp->_vcsock);
663 		statp->_vcsock = -1;
664 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
665 	}
666 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
667 		if (statp->_u._ext.nssocks[ns] != -1) {
668 			(void) close(statp->_u._ext.nssocks[ns]);
669 			statp->_u._ext.nssocks[ns] = -1;
670 		}
671 	}
672 }
673 
674 void
675 res_ndestroy(res_state statp) {
676 	res_nclose(statp);
677 	if (statp->_u._ext.ext != NULL)
678 		free(statp->_u._ext.ext);
679 	statp->options &= ~RES_INIT;
680 	statp->_u._ext.ext = NULL;
681 }
682 
683 const char *
684 res_get_nibblesuffix(res_state statp) {
685 	if (statp->_u._ext.ext)
686 		return (statp->_u._ext.ext->nsuffix);
687 	return ("ip6.arpa");
688 }
689 
690 const char *
691 res_get_nibblesuffix2(res_state statp) {
692 	if (statp->_u._ext.ext)
693 		return (statp->_u._ext.ext->nsuffix2);
694 	return ("ip6.int");
695 }
696 
697 void
698 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
699 	int i, nserv;
700 	size_t size;
701 
702 	/* close open servers */
703 	res_nclose(statp);
704 
705 	/* cause rtt times to be forgotten */
706 	statp->_u._ext.nscount = 0;
707 
708 	nserv = 0;
709 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
710 		switch (set->sin.sin_family) {
711 		case AF_INET:
712 			size = sizeof(set->sin);
713 			if (statp->_u._ext.ext)
714 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
715 					&set->sin, size);
716 			if (size <= sizeof(statp->nsaddr_list[nserv]))
717 				memcpy(&statp->nsaddr_list[nserv],
718 					&set->sin, size);
719 			else
720 				statp->nsaddr_list[nserv].sin_family = 0;
721 			nserv++;
722 			break;
723 
724 #ifdef HAS_INET6_STRUCTS
725 		case AF_INET6:
726 			size = sizeof(set->sin6);
727 			if (statp->_u._ext.ext)
728 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
729 					&set->sin6, size);
730 			if (size <= sizeof(statp->nsaddr_list[nserv]))
731 				memcpy(&statp->nsaddr_list[nserv],
732 					&set->sin6, size);
733 			else
734 				statp->nsaddr_list[nserv].sin_family = 0;
735 			nserv++;
736 			break;
737 #endif
738 
739 		default:
740 			break;
741 		}
742 		set++;
743 	}
744 	statp->nscount = nserv;
745 
746 }
747 
748 int
749 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
750 	int i;
751 	size_t size;
752 	u_int16_t family;
753 
754 	for (i = 0; i < statp->nscount && i < cnt; i++) {
755 		if (statp->_u._ext.ext)
756 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
757 		else
758 			family = statp->nsaddr_list[i].sin_family;
759 
760 		switch (family) {
761 		case AF_INET:
762 			size = sizeof(set->sin);
763 			if (statp->_u._ext.ext)
764 				memcpy(&set->sin,
765 				       &statp->_u._ext.ext->nsaddrs[i],
766 				       size);
767 			else
768 				memcpy(&set->sin, &statp->nsaddr_list[i],
769 				       size);
770 			break;
771 
772 #ifdef HAS_INET6_STRUCTS
773 		case AF_INET6:
774 			size = sizeof(set->sin6);
775 			if (statp->_u._ext.ext)
776 				memcpy(&set->sin6,
777 				       &statp->_u._ext.ext->nsaddrs[i],
778 				       size);
779 			else
780 				memcpy(&set->sin6, &statp->nsaddr_list[i],
781 				       size);
782 			break;
783 #endif
784 
785 		default:
786 			set->sin.sin_family = 0;
787 			break;
788 		}
789 		set++;
790 	}
791 	return (statp->nscount);
792 }
793