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res_init.c revision 1.12
      1 /*	$NetBSD: res_init.c,v 1.12 2007/02/09 22:29:40 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 1.16.18.5 2006/08/30 23:23:13 marka Exp";
     78 #else
     79 __RCSID("$NetBSD: res_init.c,v 1.12 2007/02/09 22:29:40 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/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