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res_init.c revision 1.24
      1 /*	$NetBSD: res_init.c,v 1.24 2012/03/13 21:13:43 christos 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 1.26 2008/12/11 09:59:00 marka Exp";
     78 #else
     79 __RCSID("$NetBSD: res_init.c,v 1.24 2012/03/13 21:13:43 christos 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/stat.h>
     90 #include <sys/time.h>
     91 #include <sys/event.h>
     92 
     93 #include <netinet/in.h>
     94 #include <arpa/inet.h>
     95 #include <arpa/nameser.h>
     96 
     97 #include <ctype.h>
     98 #include <stdio.h>
     99 #include <stdlib.h>
    100 #include <string.h>
    101 #include <unistd.h>
    102 #include <fcntl.h>
    103 #include <netdb.h>
    104 
    105 #define HAVE_MD5
    106 #include <md5.h>
    107 
    108 #ifndef HAVE_MD5
    109 # include "../dst/md5.h"
    110 #else
    111 # ifdef SOLARIS2
    112 #  include <sys/md5.h>
    113 # endif
    114 #endif
    115 #ifndef _MD5_H_
    116 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
    117 #endif
    118 
    119 #include "port_after.h"
    120 
    121 #if 0
    122 #ifdef __weak_alias
    123 __weak_alias(res_ninit,_res_ninit)
    124 __weak_alias(res_randomid,__res_randomid)
    125 __weak_alias(res_nclose,_res_nclose)
    126 __weak_alias(res_ndestroy,_res_ndestroy)
    127 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
    128 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
    129 __weak_alias(res_getservers,__res_getservers)
    130 __weak_alias(res_setservers,__res_setservers)
    131 #endif
    132 #endif
    133 
    134 
    135 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
    136 #include <resolv.h>
    137 
    138 #include "res_private.h"
    139 
    140 #define RESOLVSORT
    141 /*% Options.  Should all be left alone. */
    142 #ifndef DEBUG
    143 #define DEBUG
    144 #endif
    145 
    146 #ifdef SOLARIS2
    147 #include <sys/systeminfo.h>
    148 #endif
    149 
    150 static void res_setoptions __P((res_state, const char *, const char *));
    151 
    152 #ifdef RESOLVSORT
    153 static const char sort_mask[] = "/&";
    154 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
    155 static u_int32_t net_mask __P((struct in_addr));
    156 #endif
    157 
    158 #if !defined(isascii)	/*%< XXX - could be a function */
    159 # define isascii(c) (!(c & 0200))
    160 #endif
    161 
    162 static struct timespec __res_conf_time;
    163 static const struct timespec ts = { 0, 0 };
    164 
    165 /*
    166  * Resolver state default settings.
    167  */
    168 
    169 /*%
    170  * Set up default settings.  If the configuration file exist, the values
    171  * there will have precedence.  Otherwise, the server address is set to
    172  * INADDR_ANY and the default domain name comes from the gethostname().
    173  *
    174  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
    175  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
    176  * since it was noted that INADDR_ANY actually meant ``the first interface
    177  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
    178  * it had to be "up" in order for you to reach your own name server.  It
    179  * was later decided that since the recommended practice is to always
    180  * install local static routes through 127.0.0.1 for all your network
    181  * interfaces, that we could solve this problem without a code change.
    182  *
    183  * The configuration file should always be used, since it is the only way
    184  * to specify a default domain.  If you are running a server on your local
    185  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
    186  * in the configuration file.
    187  *
    188  * Return 0 if completes successfully, -1 on error
    189  */
    190 int
    191 res_ninit(res_state statp) {
    192 	return (__res_vinit(statp, 0));
    193 }
    194 
    195 /*% This function has to be reachable by res_data.c but not publically. */
    196 int
    197 __res_vinit(res_state statp, int preinit) {
    198 	register FILE *fp;
    199 	register char *cp, **pp;
    200 	register int n;
    201 	char buf[BUFSIZ];
    202 	int nserv = 0;    /*%< number of nameserver records read from file */
    203 	int haveenv = 0;
    204 	int havesearch = 0;
    205 #ifdef RESOLVSORT
    206 	int nsort = 0;
    207 	char *net;
    208 #endif
    209 	int dots;
    210 	union res_sockaddr_union u[2];
    211 	int maxns = MAXNS;
    212 
    213 	RES_SET_H_ERRNO(statp, 0);
    214 
    215 	if ((statp->options & RES_INIT) != 0U)
    216 		res_ndestroy(statp);
    217 
    218 	if (!preinit) {
    219 		statp->retrans = RES_TIMEOUT;
    220 		statp->retry = RES_DFLRETRY;
    221 		statp->options = RES_DEFAULT;
    222 	}
    223 	statp->_rnd = malloc(16);
    224 	res_rndinit(statp);
    225 	statp->id = res_nrandomid(statp);
    226 
    227 	memset(u, 0, sizeof(u));
    228 #ifdef USELOOPBACK
    229 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
    230 #else
    231 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
    232 #endif
    233 	u[nserv].sin.sin_family = AF_INET;
    234 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
    235 #ifdef HAVE_SA_LEN
    236 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
    237 #endif
    238 	nserv++;
    239 #ifdef HAS_INET6_STRUCTS
    240 #ifdef USELOOPBACK
    241 	u[nserv].sin6.sin6_addr = in6addr_loopback;
    242 #else
    243 	u[nserv].sin6.sin6_addr = in6addr_any;
    244 #endif
    245 	u[nserv].sin6.sin6_family = AF_INET6;
    246 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
    247 #ifdef HAVE_SA_LEN
    248 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
    249 #endif
    250 	nserv++;
    251 #endif
    252 	statp->nscount = 0;
    253 	statp->ndots = 1;
    254 	statp->pfcode = 0;
    255 	statp->_vcsock = -1;
    256 	statp->_flags = 0;
    257 	statp->qhook = NULL;
    258 	statp->rhook = NULL;
    259 	statp->_u._ext.nscount = 0;
    260 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
    261 	if (statp->_u._ext.ext != NULL) {
    262 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
    263 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
    264 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
    265 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
    266 	} else {
    267 		/*
    268 		 * Historically res_init() rarely, if at all, failed.
    269 		 * Examples and applications exist which do not check
    270 		 * our return code.  Furthermore several applications
    271 		 * simply call us to get the systems domainname.  So
    272 		 * rather then immediately fail here we store the
    273 		 * failure, which is returned later, in h_errno.  And
    274 		 * prevent the collection of 'nameserver' information
    275 		 * by setting maxns to 0.  Thus applications that fail
    276 		 * to check our return code wont be able to make
    277 		 * queries anyhow.
    278 		 */
    279 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
    280 		maxns = 0;
    281 	}
    282 #ifdef RESOLVSORT
    283 	statp->nsort = 0;
    284 #endif
    285 	res_setservers(statp, u, nserv);
    286 
    287 #ifdef	SOLARIS2
    288 	/*
    289 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
    290 	 * We want to keep this behaviour
    291 	 */
    292 	{
    293 		char buf[sizeof(statp->defdname)], *cp;
    294 		int ret;
    295 
    296 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
    297 			(unsigned int)ret <= sizeof(buf)) {
    298 			if (buf[0] == '+')
    299 				buf[0] = '.';
    300 			cp = strchr(buf, '.');
    301 			cp = (cp == NULL) ? buf : (cp + 1);
    302 			(void)strlcpy(statp->defdname, cp,
    303 			    sizeof(statp->defdname));
    304 		}
    305 	}
    306 #endif	/* SOLARIS2 */
    307 
    308 	/* Allow user to override the local domain definition */
    309 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
    310 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    311 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    312 		haveenv++;
    313 
    314 		/*
    315 		 * Set search list to be blank-separated strings
    316 		 * from rest of env value.  Permits users of LOCALDOMAIN
    317 		 * to still have a search list, and anyone to set the
    318 		 * one that they want to use as an individual (even more
    319 		 * important now that the rfc1535 stuff restricts searches)
    320 		 */
    321 		cp = statp->defdname;
    322 		pp = statp->dnsrch;
    323 		*pp++ = cp;
    324 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
    325 			if (*cp == '\n')	/*%< silly backwards compat */
    326 				break;
    327 			else if (*cp == ' ' || *cp == '\t') {
    328 				*cp = 0;
    329 				n = 1;
    330 			} else if (n) {
    331 				*pp++ = cp;
    332 				n = 0;
    333 				havesearch = 1;
    334 			}
    335 		}
    336 		/* null terminate last domain if there are excess */
    337 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
    338 			cp++;
    339 		*cp = '\0';
    340 		*pp++ = 0;
    341 	}
    342 
    343 #define	MATCH(line, name) \
    344 	(!strncmp(line, name, sizeof(name) - 1) && \
    345 	(line[sizeof(name) - 1] == ' ' || \
    346 	 line[sizeof(name) - 1] == '\t'))
    347 
    348 	nserv = 0;
    349 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
    350 	    struct stat st;
    351 	    struct kevent kc;
    352 
    353 	    /* read the config file */
    354 	    while (fgets(buf, (int)sizeof(buf), fp) != NULL) {
    355 		/* skip comments */
    356 		if (*buf == ';' || *buf == '#')
    357 			continue;
    358 		/* read default domain name */
    359 		if (MATCH(buf, "domain")) {
    360 		    if (haveenv)	/*%< skip if have from environ */
    361 			    continue;
    362 		    cp = buf + sizeof("domain") - 1;
    363 		    while (*cp == ' ' || *cp == '\t')
    364 			    cp++;
    365 		    if ((*cp == '\0') || (*cp == '\n'))
    366 			    continue;
    367 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    368 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    369 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
    370 			    *cp = '\0';
    371 		    havesearch = 0;
    372 		    continue;
    373 		}
    374 		/* set search list */
    375 		if (MATCH(buf, "search")) {
    376 		    if (haveenv)	/*%< skip if have from environ */
    377 			    continue;
    378 		    cp = buf + sizeof("search") - 1;
    379 		    while (*cp == ' ' || *cp == '\t')
    380 			    cp++;
    381 		    if ((*cp == '\0') || (*cp == '\n'))
    382 			    continue;
    383 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    384 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    385 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
    386 			    *cp = '\0';
    387 		    /*
    388 		     * Set search list to be blank-separated strings
    389 		     * on rest of line.
    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 == ' ' || *cp == '\t') {
    396 				    *cp = 0;
    397 				    n = 1;
    398 			    } else if (n) {
    399 				    *pp++ = cp;
    400 				    n = 0;
    401 			    }
    402 		    }
    403 		    /* null terminate last domain if there are excess */
    404 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
    405 			    cp++;
    406 		    *cp = '\0';
    407 		    *pp++ = 0;
    408 		    havesearch = 1;
    409 		    continue;
    410 		}
    411 		/* read nameservers to query */
    412 		if (MATCH(buf, "nameserver") && nserv < maxns) {
    413 		    struct addrinfo hints, *ai;
    414 		    char sbuf[NI_MAXSERV];
    415 		    const size_t minsiz =
    416 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
    417 
    418 		    cp = buf + sizeof("nameserver") - 1;
    419 		    while (*cp == ' ' || *cp == '\t')
    420 			cp++;
    421 		    cp[strcspn(cp, ";# \t\n")] = '\0';
    422 		    if ((*cp != '\0') && (*cp != '\n')) {
    423 			memset(&hints, 0, sizeof(hints));
    424 			hints.ai_family = PF_UNSPEC;
    425 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
    426 			hints.ai_flags = AI_NUMERICHOST;
    427 			sprintf(sbuf, "%u", NAMESERVER_PORT);
    428 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
    429 			    ai->ai_addrlen <= minsiz) {
    430 			    if (statp->_u._ext.ext != NULL) {
    431 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    432 				    ai->ai_addr, ai->ai_addrlen);
    433 			    }
    434 			    if (ai->ai_addrlen <=
    435 			        sizeof(statp->nsaddr_list[nserv])) {
    436 				memcpy(&statp->nsaddr_list[nserv],
    437 				    ai->ai_addr, ai->ai_addrlen);
    438 			    } else
    439 				statp->nsaddr_list[nserv].sin_family = 0;
    440 			    freeaddrinfo(ai);
    441 			    nserv++;
    442 			}
    443 		    }
    444 		    continue;
    445 		}
    446 #ifdef RESOLVSORT
    447 		if (MATCH(buf, "sortlist")) {
    448 		    struct in_addr a;
    449 
    450 		    cp = buf + sizeof("sortlist") - 1;
    451 		    while (nsort < MAXRESOLVSORT) {
    452 			while (*cp == ' ' || *cp == '\t')
    453 			    cp++;
    454 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
    455 			    break;
    456 			net = cp;
    457 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
    458 			       isascii(*cp) && !isspace((unsigned char)*cp))
    459 				cp++;
    460 			n = *cp;
    461 			*cp = 0;
    462 			if (inet_aton(net, &a)) {
    463 			    statp->sort_list[nsort].addr = a;
    464 			    if (ISSORTMASK(n)) {
    465 				*cp++ = n;
    466 				net = cp;
    467 				while (*cp && *cp != ';' &&
    468 					isascii(*cp) &&
    469 					!isspace((unsigned char)*cp))
    470 				    cp++;
    471 				n = *cp;
    472 				*cp = 0;
    473 				if (inet_aton(net, &a)) {
    474 				    statp->sort_list[nsort].mask = a.s_addr;
    475 				} else {
    476 				    statp->sort_list[nsort].mask =
    477 					net_mask(statp->sort_list[nsort].addr);
    478 				}
    479 			    } else {
    480 				statp->sort_list[nsort].mask =
    481 				    net_mask(statp->sort_list[nsort].addr);
    482 			    }
    483 			    nsort++;
    484 			}
    485 			*cp = n;
    486 		    }
    487 		    continue;
    488 		}
    489 #endif
    490 		if (MATCH(buf, "options")) {
    491 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
    492 		    continue;
    493 		}
    494 	    }
    495 	    if (nserv > 0)
    496 		statp->nscount = nserv;
    497 #ifdef RESOLVSORT
    498 	    statp->nsort = nsort;
    499 #endif
    500 	    statp->_u._ext.ext->resfd = dup(fileno(fp));
    501 	    (void) fclose(fp);
    502 	    if (fstat(statp->_u._ext.ext->resfd, &st) != -1)
    503 		    __res_conf_time = statp->_u._ext.ext->res_conf_time =
    504 			st.st_mtimespec;
    505 	    statp->_u._ext.ext->kq = kqueue1(O_CLOEXEC);
    506 	    EV_SET(&kc, statp->_u._ext.ext->resfd, EVFILT_VNODE,
    507 		EV_ADD|EV_ENABLE|EV_CLEAR, NOTE_DELETE|NOTE_WRITE| NOTE_EXTEND|
    508 		NOTE_ATTRIB|NOTE_LINK|NOTE_RENAME|NOTE_REVOKE, 0, 0);
    509 	    (void)kevent(statp->_u._ext.ext->kq, &kc, 1, NULL, 0, &ts);
    510 	} else {
    511 	    statp->_u._ext.ext->kq = -1;
    512 	    statp->_u._ext.ext->resfd = -1;
    513 	}
    514 /*
    515  * Last chance to get a nameserver.  This should not normally
    516  * be necessary
    517  */
    518 #ifdef NO_RESOLV_CONF
    519 	if(nserv == 0)
    520 		nserv = get_nameservers(statp);
    521 #endif
    522 
    523 	if (statp->defdname[0] == 0 &&
    524 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
    525 	    (cp = strchr(buf, '.')) != NULL)
    526 		strcpy(statp->defdname, cp + 1);
    527 
    528 	/* find components of local domain that might be searched */
    529 	if (havesearch == 0) {
    530 		pp = statp->dnsrch;
    531 		*pp++ = statp->defdname;
    532 		*pp = NULL;
    533 
    534 		dots = 0;
    535 		for (cp = statp->defdname; *cp; cp++)
    536 			dots += (*cp == '.');
    537 
    538 		cp = statp->defdname;
    539 		while (pp < statp->dnsrch + MAXDFLSRCH) {
    540 			if (dots < LOCALDOMAINPARTS)
    541 				break;
    542 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
    543 			*pp++ = cp;
    544 			dots--;
    545 		}
    546 		*pp = NULL;
    547 #ifdef DEBUG
    548 		if (statp->options & RES_DEBUG) {
    549 			printf(";; res_init()... default dnsrch list:\n");
    550 			for (pp = statp->dnsrch; *pp; pp++)
    551 				printf(";;\t%s\n", *pp);
    552 			printf(";;\t..END..\n");
    553 		}
    554 #endif
    555 	}
    556 
    557 	if ((cp = getenv("RES_OPTIONS")) != NULL)
    558 		res_setoptions(statp, cp, "env");
    559 	statp->options |= RES_INIT;
    560 	return (statp->res_h_errno);
    561 }
    562 
    563 int
    564 res_check(res_state statp, struct timespec *mtime)
    565 {
    566 	/*
    567 	 * If the times are equal, then we check if there
    568 	 * was a kevent related to resolv.conf and reload.
    569 	 * If the times are not equal, then we don't bother
    570 	 * to check the kevent, because another thread already
    571 	 * did, loaded and changed the time.
    572 	 */
    573 	if (timespeccmp(&statp->_u._ext.ext->res_conf_time,
    574 	    &__res_conf_time, ==)) {
    575 		struct kevent ke;
    576 		if (statp->_u._ext.ext->kq == -1)
    577 			goto out;
    578 
    579 		switch (kevent(statp->_u._ext.ext->kq, NULL, 0, &ke, 1, &ts)) {
    580 		case 0:
    581 		case -1:
    582 out:
    583 			if (mtime)
    584 				*mtime = __res_conf_time;
    585 			return 0;
    586 		default:
    587 			break;
    588 		}
    589 	}
    590 	(void)__res_vinit(statp, 0);
    591 	if (mtime)
    592 		*mtime = __res_conf_time;
    593 	return 1;
    594 }
    595 
    596 static void
    597 res_setoptions(res_state statp, const char *options, const char *source)
    598 {
    599 	const char *cp = options;
    600 	int i;
    601 	size_t j;
    602 	struct __res_state_ext *ext = statp->_u._ext.ext;
    603 
    604 #ifdef DEBUG
    605 	if (statp->options & RES_DEBUG)
    606 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
    607 		       options, source);
    608 #endif
    609 	while (*cp) {
    610 		/* skip leading and inner runs of spaces */
    611 		while (*cp == ' ' || *cp == '\t')
    612 			cp++;
    613 		/* search for and process individual options */
    614 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
    615 			i = atoi(cp + sizeof("ndots:") - 1);
    616 			if (i <= RES_MAXNDOTS)
    617 				statp->ndots = i;
    618 			else
    619 				statp->ndots = RES_MAXNDOTS;
    620 #ifdef DEBUG
    621 			if (statp->options & RES_DEBUG)
    622 				printf(";;\tndots=%d\n", statp->ndots);
    623 #endif
    624 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
    625 			i = atoi(cp + sizeof("timeout:") - 1);
    626 			if (i <= RES_MAXRETRANS)
    627 				statp->retrans = i;
    628 			else
    629 				statp->retrans = RES_MAXRETRANS;
    630 #ifdef DEBUG
    631 			if (statp->options & RES_DEBUG)
    632 				printf(";;\ttimeout=%d\n", statp->retrans);
    633 #endif
    634 #ifdef	SOLARIS2
    635 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
    636 			/*
    637 		 	 * For backward compatibility, 'retrans' is
    638 		 	 * supported as an alias for 'timeout', though
    639 		 	 * without an imposed maximum.
    640 		 	 */
    641 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
    642 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
    643 			/*
    644 			 * For backward compatibility, 'retry' is
    645 			 * supported as an alias for 'attempts', though
    646 			 * without an imposed maximum.
    647 			 */
    648 			statp->retry = atoi(cp + sizeof("retry:") - 1);
    649 #endif	/* SOLARIS2 */
    650 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
    651 			i = atoi(cp + sizeof("attempts:") - 1);
    652 			if (i <= RES_MAXRETRY)
    653 				statp->retry = i;
    654 			else
    655 				statp->retry = RES_MAXRETRY;
    656 #ifdef DEBUG
    657 			if (statp->options & RES_DEBUG)
    658 				printf(";;\tattempts=%d\n", statp->retry);
    659 #endif
    660 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
    661 #ifdef DEBUG
    662 			if (!(statp->options & RES_DEBUG)) {
    663 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
    664 				       options, source);
    665 				statp->options |= RES_DEBUG;
    666 			}
    667 			printf(";;\tdebug\n");
    668 #endif
    669 		} else if (!strncmp(cp, "no_tld_query",
    670 				    sizeof("no_tld_query") - 1) ||
    671 			   !strncmp(cp, "no-tld-query",
    672 				    sizeof("no-tld-query") - 1)) {
    673 			statp->options |= RES_NOTLDQUERY;
    674 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
    675 			statp->options |= RES_USE_INET6;
    676 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
    677 			statp->options |= RES_ROTATE;
    678 		} else if (!strncmp(cp, "no-check-names",
    679 				    sizeof("no-check-names") - 1)) {
    680 			statp->options |= RES_NOCHECKNAME;
    681 		}
    682 #ifdef RES_USE_EDNS0
    683 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
    684 			statp->options |= RES_USE_EDNS0;
    685 		}
    686 #endif
    687 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
    688 			statp->options |= RES_USE_DNAME;
    689 		}
    690 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
    691 			if (ext == NULL)
    692 				goto skip;
    693 			cp += sizeof("nibble:") - 1;
    694 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
    695 			strncpy(ext->nsuffix, cp, j);
    696 			ext->nsuffix[j] = '\0';
    697 		}
    698 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
    699 			if (ext == NULL)
    700 				goto skip;
    701 			cp += sizeof("nibble2:") - 1;
    702 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
    703 			strncpy(ext->nsuffix2, cp, j);
    704 			ext->nsuffix2[j] = '\0';
    705 		}
    706 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
    707 			cp += sizeof("v6revmode:") - 1;
    708 			/* "nibble" and "bitstring" used to be valid */
    709 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
    710 				statp->options |= RES_NO_NIBBLE2;
    711 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
    712 				statp->options &=
    713 					 ~RES_NO_NIBBLE2;
    714 			}
    715 		}
    716 		else {
    717 			/* XXX - print a warning here? */
    718 		}
    719    skip:
    720 		/* skip to next run of spaces */
    721 		while (*cp && *cp != ' ' && *cp != '\t')
    722 			cp++;
    723 	}
    724 }
    725 
    726 #ifdef RESOLVSORT
    727 /* XXX - should really support CIDR which means explicit masks always. */
    728 static u_int32_t
    729 net_mask(in)		/*!< XXX - should really use system's version of this  */
    730 	struct in_addr in;
    731 {
    732 	register u_int32_t i = ntohl(in.s_addr);
    733 
    734 	if (IN_CLASSA(i))
    735 		return (htonl(IN_CLASSA_NET));
    736 	else if (IN_CLASSB(i))
    737 		return (htonl(IN_CLASSB_NET));
    738 	return (htonl(IN_CLASSC_NET));
    739 }
    740 #endif
    741 
    742 static u_char srnd[16];
    743 
    744 void
    745 res_rndinit(res_state statp)
    746 {
    747 	struct timeval now;
    748 	u_int32_t u32;
    749 	u_int16_t u16;
    750 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
    751 
    752 	gettimeofday(&now, NULL);
    753 	u32 = (u_int32_t)now.tv_sec;
    754 	memcpy(rnd, &u32, 4);
    755 	u32 = now.tv_usec;
    756 	memcpy(rnd + 4, &u32, 4);
    757 	u32 += (u_int32_t)now.tv_sec;
    758 	memcpy(rnd + 8, &u32, 4);
    759 	u16 = getpid();
    760 	memcpy(rnd + 12, &u16, 2);
    761 }
    762 
    763 u_int
    764 res_nrandomid(res_state statp) {
    765 	struct timeval now;
    766 	u_int16_t u16;
    767 	MD5_CTX ctx;
    768 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
    769 
    770 	gettimeofday(&now, NULL);
    771 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
    772 	memcpy(rnd + 14, &u16, 2);
    773 #ifndef HAVE_MD5
    774 	MD5_Init(&ctx);
    775 	MD5_Update(&ctx, rnd, 16);
    776 	MD5_Final(rnd, &ctx);
    777 #else
    778 	MD5Init(&ctx);
    779 	MD5Update(&ctx, rnd, 16);
    780 	MD5Final(rnd, &ctx);
    781 #endif
    782 	memcpy(&u16, rnd + 14, 2);
    783 	return ((u_int) u16);
    784 }
    785 
    786 /*%
    787  * This routine is for closing the socket if a virtual circuit is used and
    788  * the program wants to close it.  This provides support for endhostent()
    789  * which expects to close the socket.
    790  *
    791  * This routine is not expected to be user visible.
    792  */
    793 void
    794 res_nclose(res_state statp) {
    795 	int ns;
    796 
    797 	if (statp->_vcsock >= 0) {
    798 		(void) close(statp->_vcsock);
    799 		statp->_vcsock = -1;
    800 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
    801 	}
    802 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
    803 		if (statp->_u._ext.nssocks[ns] != -1) {
    804 			(void) close(statp->_u._ext.nssocks[ns]);
    805 			statp->_u._ext.nssocks[ns] = -1;
    806 		}
    807 	}
    808 }
    809 
    810 void
    811 res_ndestroy(res_state statp) {
    812 	res_nclose(statp);
    813 	if (statp->_u._ext.ext != NULL) {
    814 		if (statp->_u._ext.ext->kq != -1)
    815 			(void)close(statp->_u._ext.ext->kq);
    816 		if (statp->_u._ext.ext->resfd != -1)
    817 			(void)close(statp->_u._ext.ext->resfd);
    818 		free(statp->_u._ext.ext);
    819 		statp->_u._ext.ext = NULL;
    820 	}
    821 	if (statp->_rnd != NULL) {
    822 		free(statp->_rnd);
    823 		statp->_rnd = NULL;
    824 	}
    825 	statp->options &= ~RES_INIT;
    826 }
    827 
    828 const char *
    829 res_get_nibblesuffix(res_state statp) {
    830 	if (statp->_u._ext.ext)
    831 		return (statp->_u._ext.ext->nsuffix);
    832 	return ("ip6.arpa");
    833 }
    834 
    835 const char *
    836 res_get_nibblesuffix2(res_state statp) {
    837 	if (statp->_u._ext.ext)
    838 		return (statp->_u._ext.ext->nsuffix2);
    839 	return ("ip6.int");
    840 }
    841 
    842 void
    843 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
    844 	int i, nserv;
    845 	size_t size;
    846 
    847 	/* close open servers */
    848 	res_nclose(statp);
    849 
    850 	/* cause rtt times to be forgotten */
    851 	statp->_u._ext.nscount = 0;
    852 
    853 	nserv = 0;
    854 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
    855 		switch (set->sin.sin_family) {
    856 		case AF_INET:
    857 			size = sizeof(set->sin);
    858 			if (statp->_u._ext.ext)
    859 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    860 					&set->sin, size);
    861 			if (size <= sizeof(statp->nsaddr_list[nserv]))
    862 				memcpy(&statp->nsaddr_list[nserv],
    863 					&set->sin, size);
    864 			else
    865 				statp->nsaddr_list[nserv].sin_family = 0;
    866 			nserv++;
    867 			break;
    868 
    869 #ifdef HAS_INET6_STRUCTS
    870 		case AF_INET6:
    871 			size = sizeof(set->sin6);
    872 			if (statp->_u._ext.ext)
    873 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    874 					&set->sin6, size);
    875 			if (size <= sizeof(statp->nsaddr_list[nserv]))
    876 				memcpy(&statp->nsaddr_list[nserv],
    877 					&set->sin6, size);
    878 			else
    879 				statp->nsaddr_list[nserv].sin_family = 0;
    880 			nserv++;
    881 			break;
    882 #endif
    883 
    884 		default:
    885 			break;
    886 		}
    887 		set++;
    888 	}
    889 	statp->nscount = nserv;
    890 
    891 }
    892 
    893 int
    894 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
    895 	int i;
    896 	size_t size;
    897 	u_int16_t family;
    898 
    899 	for (i = 0; i < statp->nscount && i < cnt; i++) {
    900 		if (statp->_u._ext.ext)
    901 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
    902 		else
    903 			family = statp->nsaddr_list[i].sin_family;
    904 
    905 		switch (family) {
    906 		case AF_INET:
    907 			size = sizeof(set->sin);
    908 			if (statp->_u._ext.ext)
    909 				memcpy(&set->sin,
    910 				       &statp->_u._ext.ext->nsaddrs[i],
    911 				       size);
    912 			else
    913 				memcpy(&set->sin, &statp->nsaddr_list[i],
    914 				       size);
    915 			break;
    916 
    917 #ifdef HAS_INET6_STRUCTS
    918 		case AF_INET6:
    919 			size = sizeof(set->sin6);
    920 			if (statp->_u._ext.ext)
    921 				memcpy(&set->sin6,
    922 				       &statp->_u._ext.ext->nsaddrs[i],
    923 				       size);
    924 			else
    925 				memcpy(&set->sin6, &statp->nsaddr_list[i],
    926 				       size);
    927 			break;
    928 #endif
    929 
    930 		default:
    931 			set->sin.sin_family = 0;
    932 			break;
    933 		}
    934 		set++;
    935 	}
    936 	return (statp->nscount);
    937 }
    938 
    939 /*! \file */
    940