xref: /netbsd-src/lib/libc/resolv/res_init.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: res_init.c,v 1.13 2007/03/30 20:23:04 ghen 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 1.16.18.5 2006/08/30 23:23:13 marka Exp";
78 #else
79 __RCSID("$NetBSD: res_init.c,v 1.13 2007/03/30 20:23:04 ghen 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 #include "port_after.h"
103 
104 #if 0
105 #ifdef __weak_alias
106 __weak_alias(res_ninit,_res_ninit)
107 __weak_alias(res_randomid,__res_randomid)
108 __weak_alias(res_nclose,_res_nclose)
109 __weak_alias(res_ndestroy,_res_ndestroy)
110 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
111 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
112 __weak_alias(res_getservers,__res_getservers)
113 __weak_alias(res_setservers,__res_setservers)
114 #endif
115 #endif
116 
117 
118 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
119 #include <resolv.h>
120 
121 #include "res_private.h"
122 
123 /*% Options.  Should all be left alone. */
124 #ifndef DEBUG
125 #define DEBUG
126 #endif
127 
128 #ifdef SOLARIS2
129 #include <sys/systeminfo.h>
130 #endif
131 
132 static void res_setoptions __P((res_state, const char *, const char *));
133 
134 static const char sort_mask[] = "/&";
135 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
136 static u_int32_t net_mask __P((struct in_addr));
137 
138 #if !defined(isascii)	/*%< XXX - could be a function */
139 # define isascii(c) (!(c & 0200))
140 #endif
141 
142 /*
143  * Resolver state default settings.
144  */
145 
146 /*%
147  * Set up default settings.  If the configuration file exist, the values
148  * there will have precedence.  Otherwise, the server address is set to
149  * INADDR_ANY and the default domain name comes from the gethostname().
150  *
151  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
152  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
153  * since it was noted that INADDR_ANY actually meant ``the first interface
154  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
155  * it had to be "up" in order for you to reach your own name server.  It
156  * was later decided that since the recommended practice is to always
157  * install local static routes through 127.0.0.1 for all your network
158  * interfaces, that we could solve this problem without a code change.
159  *
160  * The configuration file should always be used, since it is the only way
161  * to specify a default domain.  If you are running a server on your local
162  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
163  * in the configuration file.
164  *
165  * Return 0 if completes successfully, -1 on error
166  */
167 int
168 res_ninit(res_state statp) {
169 	extern int __res_vinit(res_state, int);
170 
171 	return (__res_vinit(statp, 0));
172 }
173 
174 /*% This function has to be reachable by res_data.c but not publically. */
175 int
176 __res_vinit(res_state statp, int preinit) {
177 	register FILE *fp;
178 	register char *cp, **pp;
179 	register int n;
180 	char buf[BUFSIZ];
181 	int nserv = 0;    /*%< number of nameserver records read from file */
182 	int haveenv = 0;
183 	int havesearch = 0;
184 	int nsort = 0;
185 	char *net;
186 	int dots;
187 	union res_sockaddr_union u[2];
188 
189 	if (!preinit) {
190 		statp->retrans = RES_TIMEOUT;
191 		statp->retry = RES_DFLRETRY;
192 		statp->options = RES_DEFAULT;
193 		statp->id = res_randomid();
194 	}
195 
196 	if ((statp->options & RES_INIT) != 0U)
197 		res_ndestroy(statp);
198 
199 	memset(u, 0, sizeof(u));
200 #ifdef USELOOPBACK
201 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
202 #else
203 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
204 #endif
205 	u[nserv].sin.sin_family = AF_INET;
206 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
207 #ifdef HAVE_SA_LEN
208 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
209 #endif
210 	nserv++;
211 #ifdef HAS_INET6_STRUCTS
212 #ifdef USELOOPBACK
213 	u[nserv].sin6.sin6_addr = in6addr_loopback;
214 #else
215 	u[nserv].sin6.sin6_addr = in6addr_any;
216 #endif
217 	u[nserv].sin6.sin6_family = AF_INET6;
218 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
219 #ifdef HAVE_SA_LEN
220 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
221 #endif
222 	nserv++;
223 #endif
224 	statp->nscount = 0;
225 	statp->ndots = 1;
226 	statp->pfcode = 0;
227 	statp->_vcsock = -1;
228 	statp->_flags = 0;
229 	statp->qhook = NULL;
230 	statp->rhook = NULL;
231 	statp->_u._ext.nscount = 0;
232 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
233 	if (statp->_u._ext.ext != NULL) {
234 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
235 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
236 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
237 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
238 	} else
239 		return (-1);
240 	statp->nsort = 0;
241 	res_setservers(statp, u, nserv);
242 
243 #ifdef	SOLARIS2
244 	/*
245 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
246 	 * We want to keep this behaviour
247 	 */
248 	{
249 		char buf[sizeof(statp->defdname)], *cp;
250 		int ret;
251 
252 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
253 			(unsigned int)ret <= sizeof(buf)) {
254 			if (buf[0] == '+')
255 				buf[0] = '.';
256 			cp = strchr(buf, '.');
257 			cp = (cp == NULL) ? buf : (cp + 1);
258 			if (strlen(cp) >= sizeof(statp->defdname))
259 				goto freedata;
260 			strcpy(statp->defdname, cp);
261 		}
262 	}
263 #endif	/* SOLARIS2 */
264 
265 	/* Allow user to override the local domain definition */
266 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
267 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
268 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
269 		haveenv++;
270 
271 		/*
272 		 * Set search list to be blank-separated strings
273 		 * from rest of env value.  Permits users of LOCALDOMAIN
274 		 * to still have a search list, and anyone to set the
275 		 * one that they want to use as an individual (even more
276 		 * important now that the rfc1535 stuff restricts searches)
277 		 */
278 		cp = statp->defdname;
279 		pp = statp->dnsrch;
280 		*pp++ = cp;
281 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
282 			if (*cp == '\n')	/*%< silly backwards compat */
283 				break;
284 			else if (*cp == ' ' || *cp == '\t') {
285 				*cp = 0;
286 				n = 1;
287 			} else if (n) {
288 				*pp++ = cp;
289 				n = 0;
290 				havesearch = 1;
291 			}
292 		}
293 		/* null terminate last domain if there are excess */
294 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
295 			cp++;
296 		*cp = '\0';
297 		*pp++ = 0;
298 	}
299 
300 #define	MATCH(line, name) \
301 	(!strncmp(line, name, sizeof(name) - 1) && \
302 	(line[sizeof(name) - 1] == ' ' || \
303 	 line[sizeof(name) - 1] == '\t'))
304 
305 	nserv = 0;
306 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
307 	    /* read the config file */
308 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
309 		/* skip comments */
310 		if (*buf == ';' || *buf == '#')
311 			continue;
312 		/* read default domain name */
313 		if (MATCH(buf, "domain")) {
314 		    if (haveenv)	/*%< skip if have from environ */
315 			    continue;
316 		    cp = buf + sizeof("domain") - 1;
317 		    while (*cp == ' ' || *cp == '\t')
318 			    cp++;
319 		    if ((*cp == '\0') || (*cp == '\n'))
320 			    continue;
321 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
322 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
323 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
324 			    *cp = '\0';
325 		    havesearch = 0;
326 		    continue;
327 		}
328 		/* set search list */
329 		if (MATCH(buf, "search")) {
330 		    if (haveenv)	/*%< skip if have from environ */
331 			    continue;
332 		    cp = buf + sizeof("search") - 1;
333 		    while (*cp == ' ' || *cp == '\t')
334 			    cp++;
335 		    if ((*cp == '\0') || (*cp == '\n'))
336 			    continue;
337 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
338 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
339 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
340 			    *cp = '\0';
341 		    /*
342 		     * Set search list to be blank-separated strings
343 		     * on rest of line.
344 		     */
345 		    cp = statp->defdname;
346 		    pp = statp->dnsrch;
347 		    *pp++ = cp;
348 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
349 			    if (*cp == ' ' || *cp == '\t') {
350 				    *cp = 0;
351 				    n = 1;
352 			    } else if (n) {
353 				    *pp++ = cp;
354 				    n = 0;
355 			    }
356 		    }
357 		    /* null terminate last domain if there are excess */
358 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
359 			    cp++;
360 		    *cp = '\0';
361 		    *pp++ = 0;
362 		    havesearch = 1;
363 		    continue;
364 		}
365 		/* read nameservers to query */
366 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
367 		    struct addrinfo hints, *ai;
368 		    char sbuf[NI_MAXSERV];
369 		    const size_t minsiz =
370 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
371 
372 		    cp = buf + sizeof("nameserver") - 1;
373 		    while (*cp == ' ' || *cp == '\t')
374 			cp++;
375 		    cp[strcspn(cp, ";# \t\n")] = '\0';
376 		    if ((*cp != '\0') && (*cp != '\n')) {
377 			memset(&hints, 0, sizeof(hints));
378 			hints.ai_family = PF_UNSPEC;
379 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
380 			hints.ai_flags = AI_NUMERICHOST;
381 			sprintf(sbuf, "%u", NAMESERVER_PORT);
382 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
383 			    ai->ai_addrlen <= minsiz) {
384 			    if (statp->_u._ext.ext != NULL) {
385 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
386 				    ai->ai_addr, ai->ai_addrlen);
387 			    }
388 			    if (ai->ai_addrlen <=
389 			        sizeof(statp->nsaddr_list[nserv])) {
390 				memcpy(&statp->nsaddr_list[nserv],
391 				    ai->ai_addr, ai->ai_addrlen);
392 			    } else
393 				statp->nsaddr_list[nserv].sin_family = 0;
394 			    freeaddrinfo(ai);
395 			    nserv++;
396 			}
397 		    }
398 		    continue;
399 		}
400 		if (MATCH(buf, "sortlist")) {
401 		    struct in_addr a;
402 
403 		    cp = buf + sizeof("sortlist") - 1;
404 		    while (nsort < MAXRESOLVSORT) {
405 			while (*cp == ' ' || *cp == '\t')
406 			    cp++;
407 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
408 			    break;
409 			net = cp;
410 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
411 			       isascii(*cp) && !isspace((unsigned char)*cp))
412 				cp++;
413 			n = *cp;
414 			*cp = 0;
415 			if (inet_aton(net, &a)) {
416 			    statp->sort_list[nsort].addr = a;
417 			    if (ISSORTMASK(n)) {
418 				*cp++ = n;
419 				net = cp;
420 				while (*cp && *cp != ';' &&
421 					isascii(*cp) &&
422 					!isspace((unsigned char)*cp))
423 				    cp++;
424 				n = *cp;
425 				*cp = 0;
426 				if (inet_aton(net, &a)) {
427 				    statp->sort_list[nsort].mask = a.s_addr;
428 				} else {
429 				    statp->sort_list[nsort].mask =
430 					net_mask(statp->sort_list[nsort].addr);
431 				}
432 			    } else {
433 				statp->sort_list[nsort].mask =
434 				    net_mask(statp->sort_list[nsort].addr);
435 			    }
436 			    nsort++;
437 			}
438 			*cp = n;
439 		    }
440 		    continue;
441 		}
442 		if (MATCH(buf, "options")) {
443 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
444 		    continue;
445 		}
446 	    }
447 	    if (nserv > 0)
448 		statp->nscount = nserv;
449 	    statp->nsort = nsort;
450 	    (void) fclose(fp);
451 	}
452 /*
453  * Last chance to get a nameserver.  This should not normally
454  * be necessary
455  */
456 #ifdef NO_RESOLV_CONF
457 	if(nserv == 0)
458 		nserv = get_nameservers(statp);
459 #endif
460 
461 	if (statp->defdname[0] == 0 &&
462 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
463 	    (cp = strchr(buf, '.')) != NULL)
464 		strcpy(statp->defdname, cp + 1);
465 
466 	/* find components of local domain that might be searched */
467 	if (havesearch == 0) {
468 		pp = statp->dnsrch;
469 		*pp++ = statp->defdname;
470 		*pp = NULL;
471 
472 		dots = 0;
473 		for (cp = statp->defdname; *cp; cp++)
474 			dots += (*cp == '.');
475 
476 		cp = statp->defdname;
477 		while (pp < statp->dnsrch + MAXDFLSRCH) {
478 			if (dots < LOCALDOMAINPARTS)
479 				break;
480 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
481 			*pp++ = cp;
482 			dots--;
483 		}
484 		*pp = NULL;
485 #ifdef DEBUG
486 		if (statp->options & RES_DEBUG) {
487 			printf(";; res_init()... default dnsrch list:\n");
488 			for (pp = statp->dnsrch; *pp; pp++)
489 				printf(";;\t%s\n", *pp);
490 			printf(";;\t..END..\n");
491 		}
492 #endif
493 	}
494 
495 	if ((cp = getenv("RES_OPTIONS")) != NULL)
496 		res_setoptions(statp, cp, "env");
497 	statp->options |= RES_INIT;
498 	return (0);
499 
500 #ifdef	SOLARIS2
501  freedata:
502 	if (statp->_u._ext.ext != NULL) {
503 		free(statp->_u._ext.ext);
504 		statp->_u._ext.ext = NULL;
505 	}
506 	return (-1);
507 #endif
508 }
509 
510 static void
511 res_setoptions(res_state statp, const char *options, const char *source)
512 {
513 	const char *cp = options;
514 	int i;
515 	struct __res_state_ext *ext = statp->_u._ext.ext;
516 
517 #ifdef DEBUG
518 	if (statp->options & RES_DEBUG)
519 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
520 		       options, source);
521 #endif
522 	while (*cp) {
523 		/* skip leading and inner runs of spaces */
524 		while (*cp == ' ' || *cp == '\t')
525 			cp++;
526 		/* search for and process individual options */
527 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
528 			i = atoi(cp + sizeof("ndots:") - 1);
529 			if (i <= RES_MAXNDOTS)
530 				statp->ndots = i;
531 			else
532 				statp->ndots = RES_MAXNDOTS;
533 #ifdef DEBUG
534 			if (statp->options & RES_DEBUG)
535 				printf(";;\tndots=%d\n", statp->ndots);
536 #endif
537 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
538 			i = atoi(cp + sizeof("timeout:") - 1);
539 			if (i <= RES_MAXRETRANS)
540 				statp->retrans = i;
541 			else
542 				statp->retrans = RES_MAXRETRANS;
543 #ifdef DEBUG
544 			if (statp->options & RES_DEBUG)
545 				printf(";;\ttimeout=%d\n", statp->retrans);
546 #endif
547 #ifdef	SOLARIS2
548 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
549 			/*
550 		 	 * For backward compatibility, 'retrans' is
551 		 	 * supported as an alias for 'timeout', though
552 		 	 * without an imposed maximum.
553 		 	 */
554 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
555 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
556 			/*
557 			 * For backward compatibility, 'retry' is
558 			 * supported as an alias for 'attempts', though
559 			 * without an imposed maximum.
560 			 */
561 			statp->retry = atoi(cp + sizeof("retry:") - 1);
562 #endif	/* SOLARIS2 */
563 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
564 			i = atoi(cp + sizeof("attempts:") - 1);
565 			if (i <= RES_MAXRETRY)
566 				statp->retry = i;
567 			else
568 				statp->retry = RES_MAXRETRY;
569 #ifdef DEBUG
570 			if (statp->options & RES_DEBUG)
571 				printf(";;\tattempts=%d\n", statp->retry);
572 #endif
573 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
574 #ifdef DEBUG
575 			if (!(statp->options & RES_DEBUG)) {
576 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
577 				       options, source);
578 				statp->options |= RES_DEBUG;
579 			}
580 			printf(";;\tdebug\n");
581 #endif
582 		} else if (!strncmp(cp, "no_tld_query",
583 				    sizeof("no_tld_query") - 1) ||
584 			   !strncmp(cp, "no-tld-query",
585 				    sizeof("no-tld-query") - 1)) {
586 			statp->options |= RES_NOTLDQUERY;
587 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
588 			statp->options |= RES_USE_INET6;
589 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
590 			statp->options |= RES_ROTATE;
591 		} else if (!strncmp(cp, "no-check-names",
592 				    sizeof("no-check-names") - 1)) {
593 			statp->options |= RES_NOCHECKNAME;
594 		}
595 #ifdef RES_USE_EDNS0
596 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
597 			statp->options |= RES_USE_EDNS0;
598 		}
599 #endif
600 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
601 			statp->options |= RES_USE_DNAME;
602 		}
603 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
604 			if (ext == NULL)
605 				goto skip;
606 			cp += sizeof("nibble:") - 1;
607 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
608 			strncpy(ext->nsuffix, cp, (size_t)i);
609 			ext->nsuffix[i] = '\0';
610 		}
611 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
612 			if (ext == NULL)
613 				goto skip;
614 			cp += sizeof("nibble2:") - 1;
615 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
616 			strncpy(ext->nsuffix2, cp, (size_t)i);
617 			ext->nsuffix2[i] = '\0';
618 		}
619 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
620 			cp += sizeof("v6revmode:") - 1;
621 			/* "nibble" and "bitstring" used to be valid */
622 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
623 				statp->options |= RES_NO_NIBBLE2;
624 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
625 				statp->options &=
626 					 ~RES_NO_NIBBLE2;
627 			}
628 		}
629 		else {
630 			/* XXX - print a warning here? */
631 		}
632    skip:
633 		/* skip to next run of spaces */
634 		while (*cp && *cp != ' ' && *cp != '\t')
635 			cp++;
636 	}
637 }
638 
639 /* XXX - should really support CIDR which means explicit masks always. */
640 static u_int32_t
641 net_mask(in)		/*!< XXX - should really use system's version of this  */
642 	struct in_addr in;
643 {
644 	register u_int32_t i = ntohl(in.s_addr);
645 
646 	if (IN_CLASSA(i))
647 		return (htonl(IN_CLASSA_NET));
648 	else if (IN_CLASSB(i))
649 		return (htonl(IN_CLASSB_NET));
650 	return (htonl(IN_CLASSC_NET));
651 }
652 
653 u_int
654 res_randomid(void) {
655 	struct timeval now;
656 
657 	gettimeofday(&now, NULL);
658 	return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
659 }
660 
661 /*%
662  * This routine is for closing the socket if a virtual circuit is used and
663  * the program wants to close it.  This provides support for endhostent()
664  * which expects to close the socket.
665  *
666  * This routine is not expected to be user visible.
667  */
668 void
669 res_nclose(res_state statp) {
670 	int ns;
671 
672 	if (statp->_vcsock >= 0) {
673 		(void) close(statp->_vcsock);
674 		statp->_vcsock = -1;
675 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
676 	}
677 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
678 		if (statp->_u._ext.nssocks[ns] != -1) {
679 			(void) close(statp->_u._ext.nssocks[ns]);
680 			statp->_u._ext.nssocks[ns] = -1;
681 		}
682 	}
683 }
684 
685 void
686 res_ndestroy(res_state statp) {
687 	res_nclose(statp);
688 	if (statp->_u._ext.ext != NULL)
689 		free(statp->_u._ext.ext);
690 	statp->options &= ~RES_INIT;
691 	statp->_u._ext.ext = NULL;
692 }
693 
694 const char *
695 res_get_nibblesuffix(res_state statp) {
696 	if (statp->_u._ext.ext)
697 		return (statp->_u._ext.ext->nsuffix);
698 	return ("ip6.arpa");
699 }
700 
701 const char *
702 res_get_nibblesuffix2(res_state statp) {
703 	if (statp->_u._ext.ext)
704 		return (statp->_u._ext.ext->nsuffix2);
705 	return ("ip6.int");
706 }
707 
708 void
709 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
710 	int i, nserv;
711 	size_t size;
712 
713 	/* close open servers */
714 	res_nclose(statp);
715 
716 	/* cause rtt times to be forgotten */
717 	statp->_u._ext.nscount = 0;
718 
719 	nserv = 0;
720 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
721 		switch (set->sin.sin_family) {
722 		case AF_INET:
723 			size = sizeof(set->sin);
724 			if (statp->_u._ext.ext)
725 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
726 					&set->sin, size);
727 			if (size <= sizeof(statp->nsaddr_list[nserv]))
728 				memcpy(&statp->nsaddr_list[nserv],
729 					&set->sin, size);
730 #ifdef notdef
731 			else
732 				statp->nsaddr_list[nserv].sin_family = 0;
733 #endif
734 			nserv++;
735 			break;
736 
737 #ifdef HAS_INET6_STRUCTS
738 		case AF_INET6:
739 			size = sizeof(set->sin6);
740 			if (statp->_u._ext.ext)
741 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
742 					&set->sin6, size);
743 			if (size <= sizeof(statp->nsaddr_list[nserv]))
744 				memcpy(&statp->nsaddr_list[nserv],
745 					&set->sin6, size);
746 			else
747 				statp->nsaddr_list[nserv].sin_family = 0;
748 			nserv++;
749 			break;
750 #endif
751 
752 		default:
753 			break;
754 		}
755 		set++;
756 	}
757 	statp->nscount = nserv;
758 
759 }
760 
761 int
762 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
763 	int i;
764 	size_t size;
765 	u_int16_t family;
766 
767 	for (i = 0; i < statp->nscount && i < cnt; i++) {
768 		if (statp->_u._ext.ext)
769 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
770 		else
771 			family = statp->nsaddr_list[i].sin_family;
772 
773 		switch (family) {
774 		case AF_INET:
775 			size = sizeof(set->sin);
776 			if (statp->_u._ext.ext)
777 				memcpy(&set->sin,
778 				       &statp->_u._ext.ext->nsaddrs[i],
779 				       size);
780 			else
781 				memcpy(&set->sin, &statp->nsaddr_list[i],
782 				       size);
783 			break;
784 
785 #ifdef HAS_INET6_STRUCTS
786 		case AF_INET6:
787 			size = sizeof(set->sin6);
788 			if (statp->_u._ext.ext)
789 				memcpy(&set->sin6,
790 				       &statp->_u._ext.ext->nsaddrs[i],
791 				       size);
792 			else
793 				memcpy(&set->sin6, &statp->nsaddr_list[i],
794 				       size);
795 			break;
796 #endif
797 
798 		default:
799 			set->sin.sin_family = 0;
800 			break;
801 		}
802 		set++;
803 	}
804 	return (statp->nscount);
805 }
806 
807 /*! \file */
808