xref: /titanic_41/usr/src/lib/libresolv2/common/resolv/res_init.c (revision 68c47f65208790c466e5e484f2293d3baed71c6a)
1 /*
2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * Copyright (c) 1985, 1989, 1993
9  *    The Regents of the University of California.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  * 	This product includes software developed by the University of
22  * 	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 /*
41  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
42  *
43  * Permission to use, copy, modify, and distribute this software for any
44  * purpose with or without fee is hereby granted, provided that the above
45  * copyright notice and this permission notice appear in all copies, and that
46  * the name of Digital Equipment Corporation not be used in advertising or
47  * publicity pertaining to distribution of the document or software without
48  * specific, written prior permission.
49  *
50  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
51  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
52  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
53  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
54  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
55  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
56  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
57  * SOFTWARE.
58  */
59 
60 /*
61  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
62  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
63  *
64  * Permission to use, copy, modify, and distribute this software for any
65  * purpose with or without fee is hereby granted, provided that the above
66  * copyright notice and this permission notice appear in all copies.
67  *
68  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
69  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
70  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
71  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
72  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
73  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
74  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
75  */
76 
77 #if defined(LIBC_SCCS) && !defined(lint)
78 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
79 static const char rcsid[] = "$Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp $";
80 #endif /* LIBC_SCCS and not lint */
81 
82 #include "port_before.h"
83 
84 #include <sys/types.h>
85 #include <sys/param.h>
86 #include <sys/socket.h>
87 #include <sys/time.h>
88 
89 #include <netinet/in.h>
90 #include <arpa/inet.h>
91 #include <arpa/nameser.h>
92 
93 #include <ctype.h>
94 #include <stdio.h>
95 #include <stdlib.h>
96 #include <string.h>
97 #include <unistd.h>
98 #include <netdb.h>
99 
100 #ifndef HAVE_MD5
101 # include "../dst/md5.h"
102 #else
103 # ifdef SOLARIS2
104 #  include <sys/md5.h>
105 # endif
106 #endif
107 #ifndef _MD5_H_
108 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
109 #endif
110 
111 
112 #include "port_after.h"
113 
114 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
115 #include <resolv.h>
116 
117 /* ISC purposely put port_after.h before <resolv.h> to force in6 stuff
118  * (above) so we explicitly include port_resolv.h here */
119 #include "port_resolv.h"
120 
121 #include "res_private.h"
122 
123 /*% Options.  Should all be left alone. */
124 #define RESOLVSORT
125 #define DEBUG
126 
127 #ifdef  SUNW_INITCHKIF
128 #include <net/if.h>
129 #include <netinet/if_ether.h>
130 #include <sys/sockio.h>
131 #define MAXIFS  8192
132 #endif  /* SUNW_INITCHKIF */
133 
134 #ifdef SOLARIS2
135 #include <sys/systeminfo.h>
136 #endif
137 
138 static void res_setoptions __P((res_state, const char *, const char *));
139 
140 #ifdef RESOLVSORT
141 static const char sort_mask[] = "/&";
142 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
143 static u_int32_t net_mask __P((struct in_addr));
144 #endif
145 
146 #if !defined(isascii)	/*%< XXX - could be a function */
147 # define isascii(c) (!(c & 0200))
148 #endif
149 
150 /*
151  * Resolver state default settings.
152  */
153 
154 /*%
155  * Set up default settings.  If the configuration file exist, the values
156  * there will have precedence.  Otherwise, the server address is set to
157  * INADDR_ANY and the default domain name comes from the gethostname().
158  *
159  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
160  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
161  * since it was noted that INADDR_ANY actually meant ``the first interface
162  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
163  * it had to be "up" in order for you to reach your own name server.  It
164  * was later decided that since the recommended practice is to always
165  * install local static routes through 127.0.0.1 for all your network
166  * interfaces, that we could solve this problem without a code change.
167  *
168  * The configuration file should always be used, since it is the only way
169  * to specify a default domain.  If you are running a server on your local
170  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
171  * in the configuration file.
172  *
173  * Return 0 if completes successfully, -1 on error
174  */
175 int
176 res_ninit(res_state statp) {
177 	extern int __res_vinit(res_state, int);
178 	return (__res_vinit(statp, 0));
179 }
180 
181 /*% This function has to be reachable by res_data.c but not publically. */
182 int
183 __res_vinit(res_state statp, int preinit) {
184 	register FILE *fp;
185 	register char *cp, **pp;
186 	register int n;
187 	char buf[BUFSIZ];
188 	int nserv = 0;    /*%< number of nameserver records read from file */
189 	int haveenv = 0;
190 	int havesearch = 0;
191 #ifdef RESOLVSORT
192 	int nsort = 0;
193 	char *net;
194 #endif
195 	int dots;
196 	union res_sockaddr_union u[2];
197 	int maxns = MAXNS;
198 
199 	RES_SET_H_ERRNO(statp, 0);
200 	if (statp->_u._ext.ext != NULL)
201 		res_ndestroy(statp);
202 
203 	if (!preinit) {
204 		statp->retrans = RES_TIMEOUT;
205 		statp->retry = RES_DFLRETRY;
206 		statp->options = RES_DEFAULT;
207 		res_rndinit(statp);
208 		statp->id = res_nrandomid(statp);
209 	}
210 
211 	memset(u, 0, sizeof(u));
212 #ifdef USELOOPBACK
213 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
214 #else
215 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
216 #endif
217 	u[nserv].sin.sin_family = AF_INET;
218 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
219 #ifdef HAVE_SA_LEN
220 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
221 #endif
222 	nserv++;
223 #ifdef HAS_INET6_STRUCTS
224 #ifdef USELOOPBACK
225 	u[nserv].sin6.sin6_addr = in6addr_loopback;
226 #else
227 	u[nserv].sin6.sin6_addr = in6addr_any;
228 #endif
229 	u[nserv].sin6.sin6_family = AF_INET6;
230 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
231 #ifdef HAVE_SA_LEN
232 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
233 #endif
234 	nserv++;
235 #endif
236 	statp->nscount = 0;
237 	statp->ndots = 1;
238 	statp->pfcode = 0;
239 	statp->_vcsock = -1;
240 	statp->_flags = 0;
241 	statp->qhook = NULL;
242 	statp->rhook = NULL;
243 	statp->_u._ext.nscount = 0;
244 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
245 	if (statp->_u._ext.ext != NULL) {
246 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
247 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
248 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
249 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
250 	} else {
251 		/*
252 		 * Historically res_init() rarely, if at all, failed.
253 		 * Examples and applications exist which do not check
254 		 * our return code.  Furthermore several applications
255 		 * simply call us to get the systems domainname.  So
256 		 * rather then immediately fail here we store the
257 		 * failure, which is returned later, in h_errno.  And
258 		 * prevent the collection of 'nameserver' information
259 		 * by setting maxns to 0.  Thus applications that fail
260 		 * to check our return code wont be able to make
261 		 * queries anyhow.
262 		 */
263 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
264 		maxns = 0;
265 	}
266 #ifdef RESOLVSORT
267 	statp->nsort = 0;
268 #endif
269 	res_setservers(statp, u, nserv);
270 
271 #ifdef  SUNW_INITCHKIF
272 /*
273  * Short circuit res_init() if no non-loopback interfaces are up. This is
274  * done to avoid boot delays if "dns" comes before "files" in nsswitch.conf.
275  * An additional fix has been added to this code, to count all external
276  * interfaces, which includes the IPv6 interfaces. If no external interfaces
277  * are found, an additional check is carried out to determine if any deprecated
278  * interfaces are up.
279  */
280 	{
281 		int s;
282 		struct lifnum lifn;
283 
284 		if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
285 			perror("res_init: socket");
286 			goto freedata;
287 		}
288 		lifn.lifn_family = AF_UNSPEC;
289 		lifn.lifn_flags = LIFC_EXTERNAL_SOURCE;
290 		if (ioctl(s, SIOCGLIFNUM, (char *)&lifn) < 0) {
291 			close(s);
292 			goto freedata;
293 		}
294 		if (lifn.lifn_count == 0) {
295 			/*
296 			 * Check if there are any deprecated interfaces up
297 			 */
298 			struct lifconf lifc;
299 			uchar_t *buf;
300 			int buflen, i, int_up = 0;
301 
302 			lifn.lifn_flags = 0;
303 			if ((ioctl(s, SIOCGLIFNUM, (char *)&lifn) < 0) ||
304 					(lifn.lifn_count < 1)) {
305 				close(s);
306 				goto freedata;
307 			}
308 
309 			buflen = lifn.lifn_count * sizeof (struct lifreq);
310 			buf = (uchar_t *)malloc(buflen);
311 			if (buf == NULL) {
312 				close(s);
313 				goto freedata;
314 			}
315 
316 			lifc.lifc_family = AF_UNSPEC;
317 			lifc.lifc_flags = 0;
318 			lifc.lifc_len = buflen;
319 			lifc.lifc_lifcu.lifcu_buf = (caddr_t)buf;
320 			if (ioctl(s, SIOCGLIFCONF, (char *)&lifc) < 0) {
321 				close(s);
322 				free(buf);
323 				goto freedata;
324 			}
325 
326 			for (i = 0; i < lifn.lifn_count; ++i) {
327 				struct lifreq *lreqp, lreq;
328 
329 				lreqp = (struct lifreq *)&lifc.lifc_req[i];
330 				strlcpy(lreq.lifr_name, lreqp->lifr_name,
331 						sizeof (lreq.lifr_name));
332 				if (ioctl(s, SIOCGLIFFLAGS, &lreq) < 0) {
333 					close(s);
334 					free(buf);
335 					goto freedata;
336 				}
337 				if ((lreq.lifr_flags & IFF_UP) &&
338 					!(lreq.lifr_flags & IFF_NOLOCAL) &&
339 					!(lreq.lifr_flags & IFF_NOXMIT) &&
340 					!(lreq.lifr_flags & IFF_LOOPBACK)) {
341 					int_up = 1;
342 					break;
343 				}
344 			}
345 			free(buf);
346 
347 			if (!int_up) {
348 				close(s);
349 				goto freedata;
350 			}
351 		}
352 		close(s);
353 	}
354 #endif  /* SUNW_INITCHKIF */
355 
356 #ifdef	SOLARIS2
357 	/*
358 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
359 	 * We want to keep this behaviour
360 	 */
361 	{
362 		char buf[sizeof(statp->defdname)], *cp;
363 		int ret;
364 
365 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
366 			(unsigned int)ret <= sizeof(buf)) {
367 			if (buf[0] == '+')
368 				buf[0] = '.';
369 			cp = strchr(buf, '.');
370 			cp = (cp == NULL) ? buf : (cp + 1);
371 			strncpy(statp->defdname, cp,
372 				sizeof(statp->defdname) - 1);
373 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
374 		}
375 	}
376 #endif	/* SOLARIS2 */
377 
378 	/* Allow user to override the local domain definition */
379 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
380 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
381 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
382 		haveenv++;
383 
384 		/*
385 		 * Set search list to be blank-separated strings
386 		 * from rest of env value.  Permits users of LOCALDOMAIN
387 		 * to still have a search list, and anyone to set the
388 		 * one that they want to use as an individual (even more
389 		 * important now that the rfc1535 stuff restricts searches)
390 		 */
391 		cp = statp->defdname;
392 		pp = statp->dnsrch;
393 		*pp++ = cp;
394 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
395 			if (*cp == '\n')	/*%< silly backwards compat */
396 				break;
397 			else if (*cp == ' ' || *cp == '\t') {
398 				*cp = 0;
399 				n = 1;
400 			} else if (n) {
401 				*pp++ = cp;
402 				n = 0;
403 				havesearch = 1;
404 			}
405 		}
406 		/* null terminate last domain if there are excess */
407 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
408 			cp++;
409 		*cp = '\0';
410 		*pp++ = 0;
411 	}
412 
413 #define	MATCH(line, name) \
414 	(!strncmp(line, name, sizeof(name) - 1) && \
415 	(line[sizeof(name) - 1] == ' ' || \
416 	 line[sizeof(name) - 1] == '\t'))
417 
418 	nserv = 0;
419 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
420 	    /* read the config file */
421 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
422 		/* skip comments */
423 		if (*buf == ';' || *buf == '#')
424 			continue;
425 		/* read default domain name */
426 		if (MATCH(buf, "domain")) {
427 		    if (haveenv)	/*%< skip if have from environ */
428 			    continue;
429 		    cp = buf + sizeof("domain") - 1;
430 		    while (*cp == ' ' || *cp == '\t')
431 			    cp++;
432 		    if ((*cp == '\0') || (*cp == '\n'))
433 			    continue;
434 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
435 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
436 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
437 			    *cp = '\0';
438 		    havesearch = 0;
439 		    continue;
440 		}
441 		/* set search list */
442 		if (MATCH(buf, "search")) {
443 		    if (haveenv)	/*%< skip if have from environ */
444 			    continue;
445 		    cp = buf + sizeof("search") - 1;
446 		    while (*cp == ' ' || *cp == '\t')
447 			    cp++;
448 		    if ((*cp == '\0') || (*cp == '\n'))
449 			    continue;
450 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
451 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
452 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
453 			    *cp = '\0';
454 		    /*
455 		     * Set search list to be blank-separated strings
456 		     * on rest of line.
457 		     */
458 		    cp = statp->defdname;
459 		    pp = statp->dnsrch;
460 		    *pp++ = cp;
461 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
462 			    if (*cp == ' ' || *cp == '\t') {
463 				    *cp = 0;
464 				    n = 1;
465 			    } else if (n) {
466 				    *pp++ = cp;
467 				    n = 0;
468 			    }
469 		    }
470 		    /* null terminate last domain if there are excess */
471 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
472 			    cp++;
473 		    *cp = '\0';
474 		    *pp++ = 0;
475 		    havesearch = 1;
476 		    continue;
477 		}
478 		/* read nameservers to query */
479 		if (MATCH(buf, "nameserver") && nserv < maxns) {
480 		    struct addrinfo hints, *ai;
481 		    char sbuf[NI_MAXSERV];
482 		    const size_t minsiz =
483 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
484 
485 		    cp = buf + sizeof("nameserver") - 1;
486 		    while (*cp == ' ' || *cp == '\t')
487 			cp++;
488 		    cp[strcspn(cp, ";# \t\n")] = '\0';
489 		    if ((*cp != '\0') && (*cp != '\n')) {
490 			memset(&hints, 0, sizeof(hints));
491 			hints.ai_family = PF_UNSPEC;
492 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
493 			hints.ai_flags = AI_NUMERICHOST;
494 			sprintf(sbuf, "%u", NAMESERVER_PORT);
495 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
496 			    ai->ai_addrlen <= minsiz) {
497 			    if (statp->_u._ext.ext != NULL) {
498 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
499 				    ai->ai_addr, ai->ai_addrlen);
500 			    }
501 			    if (ai->ai_addrlen <=
502 			        sizeof(statp->nsaddr_list[nserv])) {
503 				memcpy(&statp->nsaddr_list[nserv],
504 				    ai->ai_addr, ai->ai_addrlen);
505 			    } else
506 				statp->nsaddr_list[nserv].sin_family = 0;
507 			    freeaddrinfo(ai);
508 			    nserv++;
509 			}
510 		    }
511 		    continue;
512 		}
513 #ifdef RESOLVSORT
514 		if (MATCH(buf, "sortlist")) {
515 		    struct in_addr a;
516 
517 		    cp = buf + sizeof("sortlist") - 1;
518 		    while (nsort < MAXRESOLVSORT) {
519 			while (*cp == ' ' || *cp == '\t')
520 			    cp++;
521 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
522 			    break;
523 			net = cp;
524 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
525 			       isascii(*cp) && !isspace((unsigned char)*cp))
526 				cp++;
527 			n = *cp;
528 			*cp = 0;
529 			if (inet_aton(net, &a)) {
530 			    statp->sort_list[nsort].addr = a;
531 			    if (ISSORTMASK(n)) {
532 				*cp++ = n;
533 				net = cp;
534 				while (*cp && *cp != ';' &&
535 					isascii(*cp) &&
536 					!isspace((unsigned char)*cp))
537 				    cp++;
538 				n = *cp;
539 				*cp = 0;
540 				if (inet_aton(net, &a)) {
541 				    statp->sort_list[nsort].mask = a.s_addr;
542 				} else {
543 				    statp->sort_list[nsort].mask =
544 					net_mask(statp->sort_list[nsort].addr);
545 				}
546 			    } else {
547 				statp->sort_list[nsort].mask =
548 				    net_mask(statp->sort_list[nsort].addr);
549 			    }
550 			    nsort++;
551 			}
552 			*cp = n;
553 		    }
554 		    continue;
555 		}
556 #endif
557 		if (MATCH(buf, "options")) {
558 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
559 		    continue;
560 		}
561 	    }
562 	    if (nserv > 0)
563 		statp->nscount = nserv;
564 #ifdef RESOLVSORT
565 	    statp->nsort = nsort;
566 #endif
567 	    (void) fclose(fp);
568 	}
569 /*
570  * Last chance to get a nameserver.  This should not normally
571  * be necessary
572  */
573 #ifdef NO_RESOLV_CONF
574 	if(nserv == 0)
575 		nserv = get_nameservers(statp);
576 #endif
577 
578 	if (statp->defdname[0] == 0 &&
579 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
580 	    (cp = strchr(buf, '.')) != NULL)
581 		strcpy(statp->defdname, cp + 1);
582 
583 	/* find components of local domain that might be searched */
584 	if (havesearch == 0) {
585 		pp = statp->dnsrch;
586 		*pp++ = statp->defdname;
587 		*pp = NULL;
588 
589 		dots = 0;
590 		for (cp = statp->defdname; *cp; cp++)
591 			dots += (*cp == '.');
592 
593 		cp = statp->defdname;
594 		while (pp < statp->dnsrch + MAXDFLSRCH) {
595 			if (dots < LOCALDOMAINPARTS)
596 				break;
597 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
598 			*pp++ = cp;
599 			dots--;
600 		}
601 		*pp = NULL;
602 #ifdef DEBUG
603 		if (statp->options & RES_DEBUG) {
604 			printf(";; res_init()... default dnsrch list:\n");
605 			for (pp = statp->dnsrch; *pp; pp++)
606 				printf(";;\t%s\n", *pp);
607 			printf(";;\t..END..\n");
608 		}
609 #endif
610 	}
611 
612 	if ((cp = getenv("RES_OPTIONS")) != NULL)
613 		res_setoptions(statp, cp, "env");
614 	statp->options |= RES_INIT;
615 	return (statp->res_h_errno);
616 #ifdef  SUNW_INITCHKIF
617 freedata:
618 	if (statp->_u._ext.ext != NULL) {
619 		free(statp->_u._ext.ext);
620 		statp->_u._ext.ext = NULL;
621 	}
622 	return (-1);
623 #endif  /* SUNW_INITCHKIF */
624 
625 }
626 
627 static void
628 res_setoptions(res_state statp, const char *options, const char *source)
629 {
630 	const char *cp = options;
631 	int i;
632 	struct __res_state_ext *ext = statp->_u._ext.ext;
633 
634 #ifdef DEBUG
635 	if (statp->options & RES_DEBUG)
636 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
637 		       options, source);
638 #endif
639 	while (*cp) {
640 		/* skip leading and inner runs of spaces */
641 		while (*cp == ' ' || *cp == '\t')
642 			cp++;
643 		/* search for and process individual options */
644 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
645 			i = atoi(cp + sizeof("ndots:") - 1);
646 			if (i <= RES_MAXNDOTS)
647 				statp->ndots = i;
648 			else
649 				statp->ndots = RES_MAXNDOTS;
650 #ifdef DEBUG
651 			if (statp->options & RES_DEBUG)
652 				printf(";;\tndots=%d\n", statp->ndots);
653 #endif
654 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
655 			i = atoi(cp + sizeof("timeout:") - 1);
656 			if (i <= RES_MAXRETRANS)
657 				statp->retrans = i;
658 			else
659 				statp->retrans = RES_MAXRETRANS;
660 #ifdef DEBUG
661 			if (statp->options & RES_DEBUG)
662 				printf(";;\ttimeout=%d\n", statp->retrans);
663 #endif
664 #ifdef	SOLARIS2
665 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
666 			/*
667 		 	 * For backward compatibility, 'retrans' is
668 		 	 * supported as an alias for 'timeout', though
669 		 	 * without an imposed maximum.
670 		 	 */
671 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
672 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
673 			/*
674 			 * For backward compatibility, 'retry' is
675 			 * supported as an alias for 'attempts', though
676 			 * without an imposed maximum.
677 			 */
678 			statp->retry = atoi(cp + sizeof("retry:") - 1);
679 #endif	/* SOLARIS2 */
680 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
681 			i = atoi(cp + sizeof("attempts:") - 1);
682 			if (i <= RES_MAXRETRY)
683 				statp->retry = i;
684 			else
685 				statp->retry = RES_MAXRETRY;
686 #ifdef DEBUG
687 			if (statp->options & RES_DEBUG)
688 				printf(";;\tattempts=%d\n", statp->retry);
689 #endif
690 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
691 #ifdef DEBUG
692 			if (!(statp->options & RES_DEBUG)) {
693 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
694 				       options, source);
695 				statp->options |= RES_DEBUG;
696 			}
697 			printf(";;\tdebug\n");
698 #endif
699 		} else if (!strncmp(cp, "no_tld_query",
700 				    sizeof("no_tld_query") - 1) ||
701 			   !strncmp(cp, "no-tld-query",
702 				    sizeof("no-tld-query") - 1)) {
703 			statp->options |= RES_NOTLDQUERY;
704 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
705 			statp->options |= RES_USE_INET6;
706 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
707 			statp->options |= RES_ROTATE;
708 		} else if (!strncmp(cp, "no-check-names",
709 				    sizeof("no-check-names") - 1)) {
710 			statp->options |= RES_NOCHECKNAME;
711 		}
712 #ifdef RES_USE_EDNS0
713 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
714 			statp->options |= RES_USE_EDNS0;
715 		}
716 #endif
717 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
718 			statp->options |= RES_USE_DNAME;
719 		}
720 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
721 			if (ext == NULL)
722 				goto skip;
723 			cp += sizeof("nibble:") - 1;
724 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
725 			strncpy(ext->nsuffix, cp, i);
726 			ext->nsuffix[i] = '\0';
727 		}
728 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
729 			if (ext == NULL)
730 				goto skip;
731 			cp += sizeof("nibble2:") - 1;
732 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
733 			strncpy(ext->nsuffix2, cp, i);
734 			ext->nsuffix2[i] = '\0';
735 		}
736 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
737 			cp += sizeof("v6revmode:") - 1;
738 			/* "nibble" and "bitstring" used to be valid */
739 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
740 				statp->options |= RES_NO_NIBBLE2;
741 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
742 				statp->options &=
743 					 ~RES_NO_NIBBLE2;
744 			}
745 		}
746 		else {
747 			/* XXX - print a warning here? */
748 		}
749    skip:
750 		/* skip to next run of spaces */
751 		while (*cp && *cp != ' ' && *cp != '\t')
752 			cp++;
753 	}
754 }
755 
756 #ifdef RESOLVSORT
757 /* XXX - should really support CIDR which means explicit masks always. */
758 static u_int32_t
759 net_mask(in)		/*!< XXX - should really use system's version of this  */
760 	struct in_addr in;
761 {
762 	register u_int32_t i = ntohl(in.s_addr);
763 
764 	if (IN_CLASSA(i))
765 		return (htonl(IN_CLASSA_NET));
766 	else if (IN_CLASSB(i))
767 		return (htonl(IN_CLASSB_NET));
768 	return (htonl(IN_CLASSC_NET));
769 }
770 #endif
771 
772 void
773 res_rndinit(res_state statp)
774 {
775 	struct timeval now;
776 	u_int32_t u32;
777 	u_int16_t u16;
778 
779 	gettimeofday(&now, NULL);
780 	u32 = now.tv_sec;
781 	memcpy(statp->_u._ext._rnd, &u32, 4);
782 	u32 = now.tv_usec;
783 	memcpy(statp->_u._ext._rnd + 4, &u32, 4);
784 	u32 += now.tv_sec;
785 	memcpy(statp->_u._ext._rnd + 8, &u32, 4);
786 	u16 = getpid();
787 	memcpy(statp->_u._ext._rnd + 12, &u16, 2);
788 
789 }
790 
791 u_int
792 res_nrandomid(res_state statp) {
793 	struct timeval now;
794 	u_int16_t u16;
795 	MD5_CTX ctx;
796 
797 	gettimeofday(&now, NULL);
798 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
799 
800 	memcpy(statp->_u._ext._rnd + 14, &u16, 2);
801 #ifndef HAVE_MD5
802 	MD5_Init(&ctx);
803 	MD5_Update(&ctx, statp->_u._ext._rnd, 16);
804 	MD5_Final(statp->_u._ext._rnd, &ctx);
805 #else
806 	MD5Init(&ctx);
807 	MD5Update(&ctx, statp->_u._ext._rnd, 16);
808 	MD5Final(statp->_u._ext._rnd, &ctx);
809 #endif
810 	memcpy(&u16, statp->_u._ext._rnd + 14, 2);
811 	return ((u_int) u16);
812 }
813 
814 /*%
815  * This routine is for closing the socket if a virtual circuit is used and
816  * the program wants to close it.  This provides support for endhostent()
817  * which expects to close the socket.
818  *
819  * This routine is not expected to be user visible.
820  */
821 void
822 res_nclose(res_state statp) {
823 	int ns;
824 
825 	if (statp->_vcsock >= 0) {
826 		(void) close(statp->_vcsock);
827 		statp->_vcsock = -1;
828 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
829 	}
830 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
831 		if (statp->_u._ext.nssocks[ns] != -1) {
832 			(void) close(statp->_u._ext.nssocks[ns]);
833 			statp->_u._ext.nssocks[ns] = -1;
834 		}
835 	}
836 }
837 
838 void
839 res_ndestroy(res_state statp) {
840 	res_nclose(statp);
841 	if (statp->_u._ext.ext != NULL)
842 		free(statp->_u._ext.ext);
843 	statp->options &= ~RES_INIT;
844 	statp->_u._ext.ext = NULL;
845 }
846 
847 const char *
848 res_get_nibblesuffix(res_state statp) {
849 	if (statp->_u._ext.ext)
850 		return (statp->_u._ext.ext->nsuffix);
851 	return ("ip6.arpa");
852 }
853 
854 const char *
855 res_get_nibblesuffix2(res_state statp) {
856 	if (statp->_u._ext.ext)
857 		return (statp->_u._ext.ext->nsuffix2);
858 	return ("ip6.int");
859 }
860 
861 void
862 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
863 	int i, nserv;
864 	size_t size;
865 
866 	/* close open servers */
867 	res_nclose(statp);
868 
869 	/* cause rtt times to be forgotten */
870 	statp->_u._ext.nscount = 0;
871 
872 	nserv = 0;
873 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
874 		switch (set->sin.sin_family) {
875 		case AF_INET:
876 			size = sizeof(set->sin);
877 			if (statp->_u._ext.ext)
878 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
879 					&set->sin, size);
880 			if (size <= sizeof(statp->nsaddr_list[nserv]))
881 				memcpy(&statp->nsaddr_list[nserv],
882 					&set->sin, size);
883 			else
884 				statp->nsaddr_list[nserv].sin_family = 0;
885 			nserv++;
886 			break;
887 
888 #ifdef HAS_INET6_STRUCTS
889 		case AF_INET6:
890 			size = sizeof(set->sin6);
891 			if (statp->_u._ext.ext)
892 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
893 					&set->sin6, size);
894 			if (size <= sizeof(statp->nsaddr_list[nserv]))
895 				memcpy(&statp->nsaddr_list[nserv],
896 					&set->sin6, size);
897 			else
898 				statp->nsaddr_list[nserv].sin_family = 0;
899 			nserv++;
900 			break;
901 #endif
902 
903 		default:
904 			break;
905 		}
906 		set++;
907 	}
908 	statp->nscount = nserv;
909 
910 }
911 
912 int
913 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
914 	int i;
915 	size_t size;
916 	u_int16_t family;
917 
918 	for (i = 0; i < statp->nscount && i < cnt; i++) {
919 		if (statp->_u._ext.ext)
920 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
921 		else
922 			family = statp->nsaddr_list[i].sin_family;
923 
924 		switch (family) {
925 		case AF_INET:
926 			size = sizeof(set->sin);
927 			if (statp->_u._ext.ext)
928 				memcpy(&set->sin,
929 				       &statp->_u._ext.ext->nsaddrs[i],
930 				       size);
931 			else
932 				memcpy(&set->sin, &statp->nsaddr_list[i],
933 				       size);
934 			break;
935 
936 #ifdef HAS_INET6_STRUCTS
937 		case AF_INET6:
938 			size = sizeof(set->sin6);
939 			if (statp->_u._ext.ext)
940 				memcpy(&set->sin6,
941 				       &statp->_u._ext.ext->nsaddrs[i],
942 				       size);
943 			else
944 				memcpy(&set->sin6, &statp->nsaddr_list[i],
945 				       size);
946 			break;
947 #endif
948 
949 		default:
950 			set->sin.sin_family = 0;
951 			break;
952 		}
953 		set++;
954 	}
955 	return (statp->nscount);
956 }
957 
958 /*! \file */
959