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      1 /*	$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 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 1.9.2.5.4.2 2004/03/16 12:34:18 marka Exp";
     78 #else
     79 __RCSID("$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $");
     80 #endif
     81 #endif /* LIBC_SCCS and not lint */
     82 
     83 
     84 
     85 #include <sys/types.h>
     86 #include <sys/param.h>
     87 #include <sys/socket.h>
     88 #include <sys/time.h>
     89 
     90 #include <netinet/in.h>
     91 #include <arpa/inet.h>
     92 #include <arpa/nameser.h>
     93 
     94 #include <ctype.h>
     95 #include <stdio.h>
     96 #include <stdlib.h>
     97 #include <string.h>
     98 #include <unistd.h>
     99 #include <netdb.h>
    100 
    101 #ifdef ANDROID_CHANGES
    102 #include <errno.h>
    103 #include <fcntl.h>
    104 #include <sys/system_properties.h>
    105 #endif /* ANDROID_CHANGES */
    106 
    107 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
    108 #ifdef ANDROID_CHANGES
    109 #include "resolv_netid.h"
    110 #include "resolv_private.h"
    111 #else
    112 #include <resolv.h>
    113 #endif
    114 
    115 #include "res_private.h"
    116 
    117 /* Options.  Should all be left alone. */
    118 #ifndef DEBUG
    119 #define DEBUG
    120 #endif
    121 
    122 static void res_setoptions __P((res_state, const char *, const char *));
    123 
    124 #ifdef RESOLVSORT
    125 static const char sort_mask[] = "/&";
    126 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
    127 static uint32_t net_mask(struct in_addr);
    128 #endif
    129 
    130 #if !defined(isascii)	/* XXX - could be a function */
    131 # define isascii(c) (!(c & 0200))
    132 #endif
    133 
    134 /*
    135  * Resolver state default settings.
    136  */
    137 
    138 /*
    139  * Set up default settings.  If the configuration file exist, the values
    140  * there will have precedence.  Otherwise, the server address is set to
    141  * INADDR_ANY and the default domain name comes from the gethostname().
    142  *
    143  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
    144  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
    145  * since it was noted that INADDR_ANY actually meant ``the first interface
    146  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
    147  * it had to be "up" in order for you to reach your own name server.  It
    148  * was later decided that since the recommended practice is to always
    149  * install local static routes through 127.0.0.1 for all your network
    150  * interfaces, that we could solve this problem without a code change.
    151  *
    152  * The configuration file should always be used, since it is the only way
    153  * to specify a default domain.  If you are running a server on your local
    154  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
    155  * in the configuration file.
    156  *
    157  * Return 0 if completes successfully, -1 on error
    158  */
    159 int
    160 res_ninit(res_state statp) {
    161 	extern int __res_vinit(res_state, int);
    162 
    163 	return (__res_vinit(statp, 0));
    164 }
    165 
    166 /* This function has to be reachable by res_data.c but not publicly. */
    167 int
    168 __res_vinit(res_state statp, int preinit) {
    169 #if !defined(__ANDROID__)
    170 	register FILE *fp;
    171 #endif
    172 	register char *cp, **pp;
    173 #if !defined(__ANDROID__)
    174 	register int n;
    175 #endif
    176 	char buf[BUFSIZ];
    177 	int nserv = 0;    /* number of nameserver records read from file */
    178 #if !defined(__ANDROID__)
    179 	int haveenv = 0;
    180 #endif
    181 	int havesearch = 0;
    182 #ifdef RESOLVSORT
    183 	int nsort = 0;
    184 #endif
    185 #if !defined(__ANDROID__)
    186 	char *net;
    187 #endif
    188 	int dots;
    189 	union res_sockaddr_union u[2];
    190 
    191         if ((statp->options & RES_INIT) != 0U)
    192                 res_ndestroy(statp);
    193 
    194 	if (!preinit) {
    195 		statp->netid = NETID_UNSET;
    196 		statp->retrans = RES_TIMEOUT;
    197 		statp->retry = RES_DFLRETRY;
    198 		statp->options = RES_DEFAULT;
    199 		statp->id = res_randomid();
    200 		statp->_mark = MARK_UNSET;
    201 	}
    202 
    203 	memset(u, 0, sizeof(u));
    204 #ifdef USELOOPBACK
    205 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
    206 #else
    207 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
    208 #endif
    209 	u[nserv].sin.sin_family = AF_INET;
    210 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
    211 #ifdef HAVE_SA_LEN
    212 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
    213 #endif
    214 	nserv++;
    215 #ifdef HAS_INET6_STRUCTS
    216 #ifdef USELOOPBACK
    217 	u[nserv].sin6.sin6_addr = in6addr_loopback;
    218 #else
    219 	u[nserv].sin6.sin6_addr = in6addr_any;
    220 #endif
    221 	u[nserv].sin6.sin6_family = AF_INET6;
    222 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
    223 #ifdef HAVE_SA_LEN
    224 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
    225 #endif
    226 	nserv++;
    227 #endif
    228 	statp->nscount = 0;
    229 	statp->ndots = 1;
    230 	statp->pfcode = 0;
    231 	statp->_vcsock = -1;
    232 	statp->_flags = 0;
    233 	statp->qhook = NULL;
    234 	statp->rhook = NULL;
    235 	statp->_u._ext.nscount = 0;
    236 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
    237 	if (statp->_u._ext.ext != NULL) {
    238 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
    239 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
    240 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
    241 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
    242 	}
    243 	statp->nsort = 0;
    244 	res_setservers(statp, u, nserv);
    245 
    246 #if !defined(__ANDROID__) /* IGNORE THE ENVIRONMENT */
    247 	/* Allow user to override the local domain definition */
    248 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
    249 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    250 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    251 		haveenv++;
    252 
    253 		/*
    254 		 * Set search list to be blank-separated strings
    255 		 * from rest of env value.  Permits users of LOCALDOMAIN
    256 		 * to still have a search list, and anyone to set the
    257 		 * one that they want to use as an individual (even more
    258 		 * important now that the rfc1535 stuff restricts searches)
    259 		 */
    260 		cp = statp->defdname;
    261 		pp = statp->dnsrch;
    262 		*pp++ = cp;
    263 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
    264 			if (*cp == '\n')	/* silly backwards compat */
    265 				break;
    266 			else if (*cp == ' ' || *cp == '\t') {
    267 				*cp = 0;
    268 				n = 1;
    269 			} else if (n) {
    270 				*pp++ = cp;
    271 				n = 0;
    272 				havesearch = 1;
    273 			}
    274 		}
    275 		/* null terminate last domain if there are excess */
    276 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
    277 			cp++;
    278 		*cp = '\0';
    279 		*pp++ = 0;
    280 	}
    281 	if (nserv > 0)
    282 		statp->nscount = nserv;
    283 #endif
    284 
    285 #ifndef ANDROID_CHANGES /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
    286 #define	MATCH(line, name) \
    287 	(!strncmp(line, name, sizeof(name) - 1) && \
    288 	(line[sizeof(name) - 1] == ' ' || \
    289 	 line[sizeof(name) - 1] == '\t'))
    290 
    291 	nserv = 0;
    292 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
    293 	    /* read the config file */
    294 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
    295 		/* skip comments */
    296 		if (*buf == ';' || *buf == '#')
    297 			continue;
    298 		/* read default domain name */
    299 		if (MATCH(buf, "domain")) {
    300 		    if (haveenv)	/* skip if have from environ */
    301 			    continue;
    302 		    cp = buf + sizeof("domain") - 1;
    303 		    while (*cp == ' ' || *cp == '\t')
    304 			    cp++;
    305 		    if ((*cp == '\0') || (*cp == '\n'))
    306 			    continue;
    307 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    308 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    309 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
    310 			    *cp = '\0';
    311 		    havesearch = 0;
    312 		    continue;
    313 		}
    314 		/* set search list */
    315 		if (MATCH(buf, "search")) {
    316 		    if (haveenv)	/* skip if have from environ */
    317 			    continue;
    318 		    cp = buf + sizeof("search") - 1;
    319 		    while (*cp == ' ' || *cp == '\t')
    320 			    cp++;
    321 		    if ((*cp == '\0') || (*cp == '\n'))
    322 			    continue;
    323 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
    324 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
    325 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
    326 			    *cp = '\0';
    327 		    /*
    328 		     * Set search list to be blank-separated strings
    329 		     * on rest of line.
    330 		     */
    331 		    cp = statp->defdname;
    332 		    pp = statp->dnsrch;
    333 		    *pp++ = cp;
    334 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
    335 			    if (*cp == ' ' || *cp == '\t') {
    336 				    *cp = 0;
    337 				    n = 1;
    338 			    } else if (n) {
    339 				    *pp++ = cp;
    340 				    n = 0;
    341 			    }
    342 		    }
    343 		    /* null terminate last domain if there are excess */
    344 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
    345 			    cp++;
    346 		    *cp = '\0';
    347 		    *pp++ = 0;
    348 		    havesearch = 1;
    349 		    continue;
    350 		}
    351 		/* read nameservers to query */
    352 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
    353 		    struct addrinfo hints, *ai;
    354 		    char sbuf[NI_MAXSERV];
    355 		    const size_t minsiz =
    356 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
    357 
    358 		    cp = buf + sizeof("nameserver") - 1;
    359 		    while (*cp == ' ' || *cp == '\t')
    360 			cp++;
    361 		    cp[strcspn(cp, ";# \t\n")] = '\0';
    362 		    if ((*cp != '\0') && (*cp != '\n')) {
    363 			memset(&hints, 0, sizeof(hints));
    364 			hints.ai_family = PF_UNSPEC;
    365 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
    366 			hints.ai_flags = AI_NUMERICHOST;
    367 			sprintf(sbuf, "%u", NAMESERVER_PORT);
    368 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
    369 			    ai->ai_addrlen <= minsiz) {
    370 			    if (statp->_u._ext.ext != NULL) {
    371 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    372 				    ai->ai_addr, ai->ai_addrlen);
    373 			    }
    374 			    if (ai->ai_addrlen <=
    375 			        sizeof(statp->nsaddr_list[nserv])) {
    376 				memcpy(&statp->nsaddr_list[nserv],
    377 				    ai->ai_addr, ai->ai_addrlen);
    378 			    } else
    379 				statp->nsaddr_list[nserv].sin_family = 0;
    380 			    freeaddrinfo(ai);
    381 			    nserv++;
    382 			}
    383 		    }
    384 		    continue;
    385 		}
    386 		if (MATCH(buf, "sortlist")) {
    387 		    struct in_addr a;
    388 
    389 		    cp = buf + sizeof("sortlist") - 1;
    390 		    while (nsort < MAXRESOLVSORT) {
    391 			while (*cp == ' ' || *cp == '\t')
    392 			    cp++;
    393 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
    394 			    break;
    395 			net = cp;
    396 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
    397 			       isascii(*cp) && !isspace((unsigned char)*cp))
    398 				cp++;
    399 			n = *cp;
    400 			*cp = 0;
    401 			if (inet_aton(net, &a)) {
    402 			    statp->sort_list[nsort].addr = a;
    403 			    if (ISSORTMASK(n)) {
    404 				*cp++ = n;
    405 				net = cp;
    406 				while (*cp && *cp != ';' &&
    407 					isascii(*cp) &&
    408 					!isspace((unsigned char)*cp))
    409 				    cp++;
    410 				n = *cp;
    411 				*cp = 0;
    412 				if (inet_aton(net, &a)) {
    413 				    statp->sort_list[nsort].mask = a.s_addr;
    414 				} else {
    415 				    statp->sort_list[nsort].mask =
    416 					net_mask(statp->sort_list[nsort].addr);
    417 				}
    418 			    } else {
    419 				statp->sort_list[nsort].mask =
    420 				    net_mask(statp->sort_list[nsort].addr);
    421 			    }
    422 			    nsort++;
    423 			}
    424 			*cp = n;
    425 		    }
    426 		    continue;
    427 		}
    428 		if (MATCH(buf, "options")) {
    429 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
    430 		    continue;
    431 		}
    432 	    }
    433 	    if (nserv > 0)
    434 		statp->nscount = nserv;
    435 	    statp->nsort = nsort;
    436 	    (void) fclose(fp);
    437 	}
    438 #endif /* !ANDROID_CHANGES */
    439 /*
    440  * Last chance to get a nameserver.  This should not normally
    441  * be necessary
    442  */
    443 #ifdef NO_RESOLV_CONF
    444 	if(nserv == 0)
    445 		nserv = get_nameservers(statp);
    446 #endif
    447 
    448 	if (statp->defdname[0] == 0 &&
    449 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
    450 	    (cp = strchr(buf, '.')) != NULL)
    451 		strcpy(statp->defdname, cp + 1);
    452 
    453 	/* find components of local domain that might be searched */
    454 	if (havesearch == 0) {
    455 		pp = statp->dnsrch;
    456 		*pp++ = statp->defdname;
    457 		*pp = NULL;
    458 
    459 		dots = 0;
    460 		for (cp = statp->defdname; *cp; cp++)
    461 			dots += (*cp == '.');
    462 
    463 		cp = statp->defdname;
    464 		while (pp < statp->dnsrch + MAXDFLSRCH) {
    465 			if (dots < LOCALDOMAINPARTS)
    466 				break;
    467 			cp = strchr(cp, '.') + 1;    /* we know there is one */
    468 			*pp++ = cp;
    469 			dots--;
    470 		}
    471 		*pp = NULL;
    472 #ifdef DEBUG
    473 		if (statp->options & RES_DEBUG) {
    474 			printf(";; res_init()... default dnsrch list:\n");
    475 			for (pp = statp->dnsrch; *pp; pp++)
    476 				printf(";;\t%s\n", *pp);
    477 			printf(";;\t..END..\n");
    478 		}
    479 #endif
    480 	}
    481 
    482 	if ((cp = getenv("RES_OPTIONS")) != NULL)
    483 		res_setoptions(statp, cp, "env");
    484 	if (nserv > 0) {
    485 		statp->nscount = nserv;
    486 		statp->options |= RES_INIT;
    487 	}
    488 	return (0);
    489 }
    490 
    491 static void
    492 res_setoptions(res_state statp, const char *options, const char *source)
    493 {
    494 	const char *cp = options;
    495 	int i;
    496 	struct __res_state_ext *ext = statp->_u._ext.ext;
    497 
    498 #ifdef DEBUG
    499 	if (statp->options & RES_DEBUG)
    500 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
    501 		       options, source);
    502 #endif
    503 	while (*cp) {
    504 		/* skip leading and inner runs of spaces */
    505 		while (*cp == ' ' || *cp == '\t')
    506 			cp++;
    507 		/* search for and process individual options */
    508 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
    509 			i = atoi(cp + sizeof("ndots:") - 1);
    510 			if (i <= RES_MAXNDOTS)
    511 				statp->ndots = i;
    512 			else
    513 				statp->ndots = RES_MAXNDOTS;
    514 #ifdef DEBUG
    515 			if (statp->options & RES_DEBUG)
    516 				printf(";;\tndots=%d\n", statp->ndots);
    517 #endif
    518 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
    519 			i = atoi(cp + sizeof("timeout:") - 1);
    520 			if (i <= RES_MAXRETRANS)
    521 				statp->retrans = i;
    522 			else
    523 				statp->retrans = RES_MAXRETRANS;
    524 #ifdef DEBUG
    525 			if (statp->options & RES_DEBUG)
    526 				printf(";;\ttimeout=%d\n", statp->retrans);
    527 #endif
    528 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
    529 			i = atoi(cp + sizeof("attempts:") - 1);
    530 			if (i <= RES_MAXRETRY)
    531 				statp->retry = i;
    532 			else
    533 				statp->retry = RES_MAXRETRY;
    534 #ifdef DEBUG
    535 			if (statp->options & RES_DEBUG)
    536 				printf(";;\tattempts=%d\n", statp->retry);
    537 #endif
    538 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
    539 #ifdef DEBUG
    540 			if (!(statp->options & RES_DEBUG)) {
    541 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
    542 				       options, source);
    543 				statp->options |= RES_DEBUG;
    544 			}
    545 			printf(";;\tdebug\n");
    546 #endif
    547 		} else if (!strncmp(cp, "no_tld_query",
    548 				    sizeof("no_tld_query") - 1) ||
    549 			   !strncmp(cp, "no-tld-query",
    550 				    sizeof("no-tld-query") - 1)) {
    551 			statp->options |= RES_NOTLDQUERY;
    552 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
    553 			statp->options |= RES_USE_INET6;
    554 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
    555 			statp->options |= RES_ROTATE;
    556 		} else if (!strncmp(cp, "no-check-names",
    557 				    sizeof("no-check-names") - 1)) {
    558 			statp->options |= RES_NOCHECKNAME;
    559 		}
    560 #ifdef RES_USE_EDNS0
    561 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
    562 			statp->options |= RES_USE_EDNS0;
    563 		}
    564 #endif
    565 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
    566 			statp->options |= RES_USE_DNAME;
    567 		}
    568 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
    569 			if (ext == NULL)
    570 				goto skip;
    571 			cp += sizeof("nibble:") - 1;
    572 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
    573 			strncpy(ext->nsuffix, cp, (size_t)i);
    574 			ext->nsuffix[i] = '\0';
    575 		}
    576 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
    577 			if (ext == NULL)
    578 				goto skip;
    579 			cp += sizeof("nibble2:") - 1;
    580 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
    581 			strncpy(ext->nsuffix2, cp, (size_t)i);
    582 			ext->nsuffix2[i] = '\0';
    583 		}
    584 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
    585 			cp += sizeof("v6revmode:") - 1;
    586 			/* "nibble" and "bitstring" used to be valid */
    587 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
    588 				statp->options |= RES_NO_NIBBLE2;
    589 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
    590 				statp->options &=
    591 					 ~RES_NO_NIBBLE2;
    592 			}
    593 		}
    594 		else {
    595 			/* XXX - print a warning here? */
    596 		}
    597    skip:
    598 		/* skip to next run of spaces */
    599 		while (*cp && *cp != ' ' && *cp != '\t')
    600 			cp++;
    601 	}
    602 }
    603 
    604 #ifdef RESOLVSORT
    605 /* XXX - should really support CIDR which means explicit masks always. */
    606 static uint32_t
    607 net_mask(struct in_addr in)	/*!< XXX - should really use system's version of this */
    608 {
    609 	register uint32_t i = ntohl(in.s_addr);
    610 
    611 	if (IN_CLASSA(i))
    612 		return (htonl(IN_CLASSA_NET));
    613 	else if (IN_CLASSB(i))
    614 		return (htonl(IN_CLASSB_NET));
    615 	return (htonl(IN_CLASSC_NET));
    616 }
    617 #endif
    618 
    619 /*%
    620  * This routine is for closing the socket if a virtual circuit is used and
    621  * the program wants to close it.  This provides support for endhostent()
    622  * which expects to close the socket.
    623  *
    624  * This routine is not expected to be user visible.
    625  */
    626 void
    627 res_nclose(res_state statp)
    628 {
    629 	int ns;
    630 
    631 	if (statp->_vcsock >= 0) {
    632 		(void) close(statp->_vcsock);
    633 		statp->_vcsock = -1;
    634 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
    635 	}
    636 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
    637 		if (statp->_u._ext.nssocks[ns] != -1) {
    638 			(void) close(statp->_u._ext.nssocks[ns]);
    639 			statp->_u._ext.nssocks[ns] = -1;
    640 		}
    641 	}
    642 }
    643 
    644 void
    645 res_ndestroy(res_state statp)
    646 {
    647 	res_nclose(statp);
    648 	if (statp->_u._ext.ext != NULL)
    649 		free(statp->_u._ext.ext);
    650 	statp->options &= ~RES_INIT;
    651 	statp->_u._ext.ext = NULL;
    652 }
    653 
    654 const char *
    655 res_get_nibblesuffix(res_state statp)
    656 {
    657 	if (statp->_u._ext.ext)
    658 		return (statp->_u._ext.ext->nsuffix);
    659 	return ("ip6.arpa");
    660 }
    661 
    662 const char *
    663 res_get_nibblesuffix2(res_state statp)
    664 {
    665 	if (statp->_u._ext.ext)
    666 		return (statp->_u._ext.ext->nsuffix2);
    667 	return ("ip6.int");
    668 }
    669 
    670 void
    671 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt)
    672 {
    673 	int i, nserv;
    674 	size_t size;
    675 
    676 	/* close open servers */
    677 	res_nclose(statp);
    678 
    679 	/* cause rtt times to be forgotten */
    680 	statp->_u._ext.nscount = 0;
    681 
    682 	nserv = 0;
    683 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
    684 		switch (set->sin.sin_family) {
    685 		case AF_INET:
    686 			size = sizeof(set->sin);
    687 			if (statp->_u._ext.ext)
    688 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    689 					&set->sin, size);
    690 			if (size <= sizeof(statp->nsaddr_list[nserv]))
    691 				memcpy(&statp->nsaddr_list[nserv],
    692 					&set->sin, size);
    693 			else
    694 				statp->nsaddr_list[nserv].sin_family = 0;
    695 			nserv++;
    696 			break;
    697 
    698 #ifdef HAS_INET6_STRUCTS
    699 		case AF_INET6:
    700 			size = sizeof(set->sin6);
    701 			if (statp->_u._ext.ext)
    702 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
    703 					&set->sin6, size);
    704 			if (size <= sizeof(statp->nsaddr_list[nserv]))
    705 				memcpy(&statp->nsaddr_list[nserv],
    706 					&set->sin6, size);
    707 			else
    708 				statp->nsaddr_list[nserv].sin_family = 0;
    709 			nserv++;
    710 			break;
    711 #endif
    712 
    713 		default:
    714 			break;
    715 		}
    716 		set++;
    717 	}
    718 	statp->nscount = nserv;
    719 
    720 }
    721 
    722 int
    723 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt)
    724 {
    725 	int i;
    726 	size_t size;
    727 	uint16_t family;
    728 
    729 	for (i = 0; i < statp->nscount && i < cnt; i++) {
    730 		if (statp->_u._ext.ext)
    731 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
    732 		else
    733 			family = statp->nsaddr_list[i].sin_family;
    734 
    735 		switch (family) {
    736 		case AF_INET:
    737 			size = sizeof(set->sin);
    738 			if (statp->_u._ext.ext)
    739 				memcpy(&set->sin,
    740 				       &statp->_u._ext.ext->nsaddrs[i],
    741 				       size);
    742 			else
    743 				memcpy(&set->sin, &statp->nsaddr_list[i],
    744 				       size);
    745 			break;
    746 
    747 #ifdef HAS_INET6_STRUCTS
    748 		case AF_INET6:
    749 			size = sizeof(set->sin6);
    750 			if (statp->_u._ext.ext)
    751 				memcpy(&set->sin6,
    752 				       &statp->_u._ext.ext->nsaddrs[i],
    753 				       size);
    754 			else
    755 				memcpy(&set->sin6, &statp->nsaddr_list[i],
    756 				       size);
    757 			break;
    758 #endif
    759 
    760 		default:
    761 			set->sin.sin_family = 0;
    762 			break;
    763 		}
    764 		set++;
    765 	}
    766 	return (statp->nscount);
    767 }
    768 
    769 #ifdef ANDROID_CHANGES
    770 void res_setnetid(res_state statp, unsigned netid)
    771 {
    772 	if (statp != NULL) {
    773 		statp->netid = netid;
    774 	}
    775 }
    776 
    777 void res_setmark(res_state statp, unsigned mark)
    778 {
    779 	if (statp != NULL) {
    780 		statp->_mark = mark;
    781 	}
    782 }
    783 
    784 #endif /* ANDROID_CHANGES */
    785