xref: /haiku/src/system/libnetwork/netresolv/resolv/res_init.c (revision e1c4049fed1047bdb957b0529e1921e97ef94770)
1 /*	$NetBSD: res_init.c,v 1.31.14.1 2021/10/05 11:06:58 martin 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34  *
35  * Permission to use, copy, modify, and distribute this software for any
36  * purpose with or without fee is hereby granted, provided that the above
37  * copyright notice and this permission notice appear in all copies, and that
38  * the name of Digital Equipment Corporation not be used in advertising or
39  * publicity pertaining to distribution of the document or software without
40  * specific, written prior permission.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
45  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49  * SOFTWARE.
50  */
51 
52 /*
53  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
54  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
55  *
56  * Permission to use, copy, modify, and distribute this software for any
57  * purpose with or without fee is hereby granted, provided that the above
58  * copyright notice and this permission notice appear in all copies.
59  *
60  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
61  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
62  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
63  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
64  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
65  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
66  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
67  */
68 
69 #include "port_before.h"
70 
71 #include <sys/types.h>
72 #include <sys/param.h>
73 #include <sys/socket.h>
74 #include <sys/time.h>
75 
76 #include <netinet/in.h>
77 #include <arpa/inet.h>
78 #include <arpa/nameser.h>
79 
80 #include <ctype.h>
81 #include <stdio.h>
82 #include <stdlib.h>
83 #include <string.h>
84 #include <unistd.h>
85 #include <fcntl.h>
86 #include <netdb.h>
87 
88 #ifndef HAVE_MD5
89 # include "../dst/md5.h"
90 #else
91 # ifdef SOLARIS2
92 #  include <sys/md5.h>
93 # endif
94 #endif
95 #ifndef _MD5_H_
96 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
97 #endif
98 
99 #include "port_after.h"
100 
101 #if 0
102 #ifdef __weak_alias
103 __weak_alias(res_ninit,_res_ninit)
104 __weak_alias(res_randomid,__res_randomid)
105 __weak_alias(res_nclose,_res_nclose)
106 __weak_alias(res_ndestroy,_res_ndestroy)
107 __weak_alias(res_get_nibblesuffix,__res_get_nibblesuffix)
108 __weak_alias(res_get_nibblesuffix2,__res_get_nibblesuffix2)
109 __weak_alias(res_getservers,__res_getservers)
110 __weak_alias(res_setservers,__res_setservers)
111 #endif
112 #endif
113 
114 
115 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
116 #include <resolv.h>
117 
118 #include <FindDirectory.h>
119 
120 #include "res_private.h"
121 
122 #define RESOLVSORT
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(res_state, const char *, const char *);
133 
134 #ifdef RESOLVSORT
135 static const char sort_mask[] = "/&";
136 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
137 static uint32_t net_mask(struct in_addr);
138 #endif
139 
140 #if !defined(isascii)	/*%< XXX - could be a function */
141 # define isascii(c) (!(c & 0200))
142 #endif
143 
144 /*
145  * Resolver state default settings.
146  */
147 
148 /*%
149  * Set up default settings.  If the configuration file exist, the values
150  * there will have precedence.  Otherwise, the server address is set to
151  * INADDR_ANY and the default domain name comes from the gethostname().
152  *
153  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
154  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
155  * since it was noted that INADDR_ANY actually meant ``the first interface
156  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
157  * it had to be "up" in order for you to reach your own name server.  It
158  * was later decided that since the recommended practice is to always
159  * install local static routes through 127.0.0.1 for all your network
160  * interfaces, that we could solve this problem without a code change.
161  *
162  * The configuration file should always be used, since it is the only way
163  * to specify a default domain.  If you are running a server on your local
164  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
165  * in the configuration file.
166  *
167  * Return 0 if completes successfully, -1 on error
168  */
169 int
170 res_ninit(res_state statp) {
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 path[PATH_MAX];
181 	char buf[BUFSIZ];
182 	int nserv = 0;    /*%< number of nameserver records read from file */
183 	int haveenv = 0;
184 	int havesearch = 0;
185 #ifdef RESOLVSORT
186 	int nsort = 0;
187 	char *net;
188 #endif
189 	int dots;
190 	union res_sockaddr_union u[2];
191 	int maxns = MAXNS;
192 
193 	RES_SET_H_ERRNO(statp, 0);
194 
195 	if ((statp->options & RES_INIT) != 0U)
196 		res_ndestroy(statp);
197 
198 	if (!preinit) {
199 		statp->retrans = RES_TIMEOUT;
200 		statp->retry = RES_DFLRETRY;
201 		statp->options = RES_DEFAULT;
202 	}
203 	res_rndinit(statp);
204 	statp->id = res_nrandomid(statp);
205 
206 	memset(u, 0, sizeof(u));
207 #ifdef USELOOPBACK
208 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
209 #else
210 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
211 #endif
212 	u[nserv].sin.sin_family = AF_INET;
213 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
214 #ifdef HAVE_SA_LEN
215 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
216 #endif
217 	nserv++;
218 #ifdef HAS_INET6_STRUCTS
219 #ifdef USELOOPBACK
220 	u[nserv].sin6.sin6_addr = in6addr_loopback;
221 #else
222 	u[nserv].sin6.sin6_addr = in6addr_any;
223 #endif
224 	u[nserv].sin6.sin6_family = AF_INET6;
225 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
226 #ifdef HAVE_SA_LEN
227 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
228 #endif
229 	nserv++;
230 #endif
231 	statp->nscount = 0;
232 	statp->ndots = 1;
233 	statp->pfcode = 0;
234 	statp->_vcsock = -1;
235 	statp->_flags = 0;
236 	statp->qhook = NULL;
237 	statp->rhook = NULL;
238 	statp->_u._ext.nscount = 0;
239 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
240 	if (statp->_u._ext.ext != NULL) {
241 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
242 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
243 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
244 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
245 	} else {
246 		/*
247 		 * Historically res_init() rarely, if at all, failed.
248 		 * Examples and applications exist which do not check
249 		 * our return code.  Furthermore several applications
250 		 * simply call us to get the systems domainname.  So
251 		 * rather than immediately fail here we store the
252 		 * failure, which is returned later, in h_errno.  And
253 		 * prevent the collection of 'nameserver' information
254 		 * by setting maxns to 0.  Thus applications that fail
255 		 * to check our return code wont be able to make
256 		 * queries anyhow.
257 		 */
258 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
259 		maxns = 0;
260 	}
261 #ifdef RESOLVSORT
262 	statp->nsort = 0;
263 #endif
264 	res_setservers(statp, u, nserv);
265 
266 #ifdef	SOLARIS2
267 	/*
268 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
269 	 * We want to keep this behaviour
270 	 */
271 	{
272 		char buf[sizeof(statp->defdname)], *cp;
273 		int ret;
274 
275 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
276 			(unsigned int)ret <= sizeof(buf)) {
277 			if (buf[0] == '+')
278 				buf[0] = '.';
279 			cp = strchr(buf, '.');
280 			cp = (cp == NULL) ? buf : (cp + 1);
281 			(void)strlcpy(statp->defdname, cp,
282 			    sizeof(statp->defdname));
283 		}
284 	}
285 #endif	/* SOLARIS2 */
286 
287 	/* Allow user to override the local domain definition */
288 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
289 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
290 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
291 		haveenv++;
292 
293 		/*
294 		 * Set search list to be blank-separated strings
295 		 * from rest of env value.  Permits users of LOCALDOMAIN
296 		 * to still have a search list, and anyone to set the
297 		 * one that they want to use as an individual (even more
298 		 * important now that the rfc1535 stuff restricts searches)
299 		 */
300 		cp = statp->defdname;
301 		pp = statp->dnsrch;
302 		*pp++ = cp;
303 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
304 			if (*cp == '\n')	/*%< silly backwards compat */
305 				break;
306 			else if (*cp == ' ' || *cp == '\t') {
307 				*cp = 0;
308 				n = 1;
309 			} else if (n) {
310 				*pp++ = cp;
311 				n = 0;
312 				havesearch = 1;
313 			}
314 		}
315 		/* null terminate last domain if there are excess */
316 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
317 			cp++;
318 		*cp = '\0';
319 		*pp++ = 0;
320 	}
321 
322 #define	MATCH(line, name) \
323 	(!strncmp(line, name, sizeof(name) - 1) && \
324 	(line[sizeof(name) - 1] == ' ' || \
325 	 line[sizeof(name) - 1] == '\t'))
326 
327 	if (find_directory(B_SYSTEM_SETTINGS_DIRECTORY, -1, false, path,
328 			sizeof(path)) == B_OK)
329 		strlcat(path, "/network/resolv.conf", sizeof(path));
330 
331 	nserv = 0;
332 	if ((fp = fopen(path, "re")) != NULL) {
333 	    /* read the config file */
334 	    while (fgets(buf, (int)sizeof(buf), fp) != NULL) {
335 		/* skip comments */
336 		if (*buf == ';' || *buf == '#')
337 			continue;
338 		/* read default domain name */
339 		if (MATCH(buf, "domain")) {
340 		    if (haveenv)	/*%< skip if have from environ */
341 			    continue;
342 		    cp = buf + sizeof("domain") - 1;
343 		    while (*cp == ' ' || *cp == '\t')
344 			    cp++;
345 		    if ((*cp == '\0') || (*cp == '\n'))
346 			    continue;
347 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
348 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
349 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
350 			    *cp = '\0';
351 		    havesearch = 0;
352 		    continue;
353 		}
354 		/* set search list */
355 		if (MATCH(buf, "search")) {
356 		    if (haveenv)	/*%< skip if have from environ */
357 			    continue;
358 		    cp = buf + sizeof("search") - 1;
359 		    while (*cp == ' ' || *cp == '\t')
360 			    cp++;
361 		    if ((*cp == '\0') || (*cp == '\n'))
362 			    continue;
363 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
364 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
365 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
366 			    *cp = '\0';
367 		    /*
368 		     * Set search list to be blank-separated strings
369 		     * on rest of line.
370 		     */
371 		    cp = statp->defdname;
372 		    pp = statp->dnsrch;
373 		    *pp++ = cp;
374 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
375 			    if (*cp == ' ' || *cp == '\t') {
376 				    *cp = 0;
377 				    n = 1;
378 			    } else if (n) {
379 				    *pp++ = cp;
380 				    n = 0;
381 			    }
382 		    }
383 		    /* null terminate last domain if there are excess */
384 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
385 			    cp++;
386 		    *cp = '\0';
387 		    *pp++ = 0;
388 		    havesearch = 1;
389 		    continue;
390 		}
391 		/* read nameservers to query */
392 		if (MATCH(buf, "nameserver") && nserv < maxns) {
393 		    struct addrinfo hints, *ai;
394 		    char sbuf[NI_MAXSERV];
395 		    const size_t minsiz =
396 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
397 
398 		    cp = buf + sizeof("nameserver") - 1;
399 		    while (*cp == ' ' || *cp == '\t')
400 			cp++;
401 		    cp[strcspn(cp, ";# \t\n")] = '\0';
402 		    if ((*cp != '\0') && (*cp != '\n')) {
403 			memset(&hints, 0, sizeof(hints));
404 			hints.ai_family = PF_UNSPEC;
405 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
406 			hints.ai_flags = AI_NUMERICHOST;
407 			sprintf(sbuf, "%u", NAMESERVER_PORT);
408 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
409 			    ai->ai_addrlen <= minsiz) {
410 			    if (statp->_u._ext.ext != NULL) {
411 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
412 				    ai->ai_addr, ai->ai_addrlen);
413 			    }
414 			    if (ai->ai_addrlen <=
415 			        sizeof(statp->nsaddr_list[nserv])) {
416 				memcpy(&statp->nsaddr_list[nserv],
417 				    ai->ai_addr, ai->ai_addrlen);
418 			    } else
419 				statp->nsaddr_list[nserv].sin_family = 0;
420 			    freeaddrinfo(ai);
421 			    nserv++;
422 			}
423 		    }
424 		    continue;
425 		}
426 #ifdef RESOLVSORT
427 		if (MATCH(buf, "sortlist")) {
428 		    struct in_addr a;
429 
430 		    cp = buf + sizeof("sortlist") - 1;
431 		    while (nsort < MAXRESOLVSORT) {
432 			while (*cp == ' ' || *cp == '\t')
433 			    cp++;
434 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
435 			    break;
436 			net = cp;
437 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
438 			       isascii(*cp) && !isspace((unsigned char)*cp))
439 				cp++;
440 			n = *cp;
441 			*cp = 0;
442 			if (inet_aton(net, &a)) {
443 			    statp->sort_list[nsort].addr = a;
444 			    if (ISSORTMASK(n)) {
445 				*cp++ = n;
446 				net = cp;
447 				while (*cp && *cp != ';' &&
448 					isascii(*cp) &&
449 					!isspace((unsigned char)*cp))
450 				    cp++;
451 				n = *cp;
452 				*cp = 0;
453 				if (inet_aton(net, &a)) {
454 				    statp->sort_list[nsort].mask = a.s_addr;
455 				} else {
456 				    statp->sort_list[nsort].mask =
457 					net_mask(statp->sort_list[nsort].addr);
458 				}
459 			    } else {
460 				statp->sort_list[nsort].mask =
461 				    net_mask(statp->sort_list[nsort].addr);
462 			    }
463 			    nsort++;
464 			}
465 			*cp = n;
466 		    }
467 		    continue;
468 		}
469 #endif
470 		if (MATCH(buf, "options")) {
471 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
472 		    continue;
473 		}
474 	    }
475 	    if (nserv > 0)
476 		statp->nscount = nserv;
477 #ifdef RESOLVSORT
478 	    statp->nsort = nsort;
479 #endif
480 	    statp->_u._ext.ext->resfd = fcntl(fileno(fp), F_DUPFD_CLOEXEC, 0);
481 	    (void) fclose(fp);
482 	} else {
483 	    statp->_u._ext.ext->kq = -1;
484 	    statp->_u._ext.ext->resfd = -1;
485 	}
486 /*
487  * Last chance to get a nameserver.  This should not normally
488  * be necessary
489  */
490 #ifdef NO_RESOLV_CONF
491 	if(nserv == 0)
492 		nserv = get_nameservers(statp);
493 #endif
494 
495 	if (statp->defdname[0] == 0 &&
496 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
497 	    (cp = strchr(buf, '.')) != NULL)
498 		strcpy(statp->defdname, cp + 1);
499 
500 	/* find components of local domain that might be searched */
501 	if (havesearch == 0) {
502 		pp = statp->dnsrch;
503 		*pp++ = statp->defdname;
504 		*pp = NULL;
505 
506 		dots = 0;
507 		for (cp = statp->defdname; *cp; cp++)
508 			dots += (*cp == '.');
509 
510 		cp = statp->defdname;
511 		while (pp < statp->dnsrch + MAXDFLSRCH) {
512 			if (dots < LOCALDOMAINPARTS)
513 				break;
514 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
515 			*pp++ = cp;
516 			dots--;
517 		}
518 		*pp = NULL;
519 #ifdef DEBUG
520 		if (statp->options & RES_DEBUG) {
521 			printf(";; res_init()... default dnsrch list:\n");
522 			for (pp = statp->dnsrch; *pp; pp++)
523 				printf(";;\t%s\n", *pp);
524 			printf(";;\t..END..\n");
525 		}
526 #endif
527 	}
528 
529 	if ((cp = getenv("RES_OPTIONS")) != NULL)
530 		res_setoptions(statp, cp, "env");
531 	statp->options |= RES_INIT;
532 	return (statp->res_h_errno);
533 }
534 
535 static void
536 res_setoptions(res_state statp, const char *options, const char *source)
537 {
538 	const char *cp = options;
539 	int i;
540 	size_t j;
541 	struct __res_state_ext *ext = statp->_u._ext.ext;
542 
543 #ifdef DEBUG
544 	if (statp->options & RES_DEBUG)
545 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
546 		       options, source);
547 #endif
548 	while (*cp) {
549 		/* skip leading and inner runs of spaces */
550 		while (*cp == ' ' || *cp == '\t')
551 			cp++;
552 		/* search for and process individual options */
553 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
554 			i = atoi(cp + sizeof("ndots:") - 1);
555 			if (i <= RES_MAXNDOTS)
556 				statp->ndots = i;
557 			else
558 				statp->ndots = RES_MAXNDOTS;
559 #ifdef DEBUG
560 			if (statp->options & RES_DEBUG)
561 				printf(";;\tndots=%d\n", statp->ndots);
562 #endif
563 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
564 			i = atoi(cp + sizeof("timeout:") - 1);
565 			if (i <= RES_MAXRETRANS)
566 				statp->retrans = i;
567 			else
568 				statp->retrans = RES_MAXRETRANS;
569 #ifdef DEBUG
570 			if (statp->options & RES_DEBUG)
571 				printf(";;\ttimeout=%d\n", statp->retrans);
572 #endif
573 #ifdef	SOLARIS2
574 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
575 			/*
576 		 	 * For backward compatibility, 'retrans' is
577 		 	 * supported as an alias for 'timeout', though
578 		 	 * without an imposed maximum.
579 		 	 */
580 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
581 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
582 			/*
583 			 * For backward compatibility, 'retry' is
584 			 * supported as an alias for 'attempts', though
585 			 * without an imposed maximum.
586 			 */
587 			statp->retry = atoi(cp + sizeof("retry:") - 1);
588 #endif	/* SOLARIS2 */
589 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
590 			i = atoi(cp + sizeof("attempts:") - 1);
591 			if (i <= RES_MAXRETRY)
592 				statp->retry = i;
593 			else
594 				statp->retry = RES_MAXRETRY;
595 #ifdef DEBUG
596 			if (statp->options & RES_DEBUG)
597 				printf(";;\tattempts=%d\n", statp->retry);
598 #endif
599 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
600 #ifdef DEBUG
601 			if (!(statp->options & RES_DEBUG)) {
602 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
603 				       options, source);
604 				statp->options |= RES_DEBUG;
605 			}
606 			printf(";;\tdebug\n");
607 #endif
608 		} else if (!strncmp(cp, "no_tld_query",
609 				    sizeof("no_tld_query") - 1) ||
610 			   !strncmp(cp, "no-tld-query",
611 				    sizeof("no-tld-query") - 1)) {
612 			statp->options |= RES_NOTLDQUERY;
613 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
614 			statp->options |= RES_USE_INET6;
615 #ifdef RES_USE_INET4
616 		} else if (!strncmp(cp, "inet4", sizeof("inet4") - 1)) {
617 			statp->options |= RES_USE_INET4;
618 #endif
619 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
620 			statp->options |= RES_ROTATE;
621 		} else if (!strncmp(cp, "no-check-names",
622 				    sizeof("no-check-names") - 1)) {
623 			statp->options |= RES_NOCHECKNAME;
624 		} else if (!strncmp(cp, "check-names",
625 				    sizeof("check-names") - 1)) {
626 			statp->options &= ~RES_NOCHECKNAME;
627 		}
628 #ifdef RES_USE_EDNS0
629 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
630 			statp->options |= RES_USE_EDNS0;
631 		}
632 #endif
633 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
634 			statp->options |= RES_USE_DNAME;
635 		}
636 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
637 			if (ext == NULL)
638 				goto skip;
639 			cp += sizeof("nibble:") - 1;
640 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
641 			strncpy(ext->nsuffix, cp, j);
642 			ext->nsuffix[j] = '\0';
643 		}
644 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
645 			if (ext == NULL)
646 				goto skip;
647 			cp += sizeof("nibble2:") - 1;
648 			j = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
649 			strncpy(ext->nsuffix2, cp, j);
650 			ext->nsuffix2[j] = '\0';
651 		}
652 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
653 			cp += sizeof("v6revmode:") - 1;
654 			/* "nibble" and "bitstring" used to be valid */
655 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
656 				statp->options |= RES_NO_NIBBLE2;
657 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
658 				statp->options &=
659 					 ~RES_NO_NIBBLE2;
660 			}
661 		}
662 		else {
663 			/* XXX - print a warning here? */
664 		}
665    skip:
666 		/* skip to next run of spaces */
667 		while (*cp && *cp != ' ' && *cp != '\t')
668 			cp++;
669 	}
670 }
671 
672 #ifdef RESOLVSORT
673 /* XXX - should really support CIDR which means explicit masks always. */
674 static uint32_t
675 net_mask(struct in_addr in) /*!< XXX - should really use system's version of this  */
676 {
677 	register uint32_t i = ntohl(in.s_addr);
678 
679 	if (IN_CLASSA(i))
680 		return (htonl(IN_CLASSA_NET));
681 	else if (IN_CLASSB(i))
682 		return (htonl(IN_CLASSB_NET));
683 	return (htonl(IN_CLASSC_NET));
684 }
685 #endif
686 
687 static u_char srnd[16];
688 
689 void
690 res_rndinit(res_state statp)
691 {
692 	struct timeval now;
693 	uint32_t u32;
694 	uint16_t u16;
695 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
696 
697 	gettimeofday(&now, NULL);
698 	u32 = (uint32_t)now.tv_sec;
699 	memcpy(rnd, &u32, 4);
700 	u32 = now.tv_usec;
701 	memcpy(rnd + 4, &u32, 4);
702 	u32 += (uint32_t)now.tv_sec;
703 	memcpy(rnd + 8, &u32, 4);
704 	u16 = getpid();
705 	memcpy(rnd + 12, &u16, 2);
706 }
707 
708 u_int
709 res_nrandomid(res_state statp)
710 {
711 	struct timeval now;
712 	uint16_t u16;
713 	MD5_CTX ctx;
714 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
715 
716 	gettimeofday(&now, NULL);
717 	u16 = (uint16_t) (now.tv_sec ^ now.tv_usec);
718 	memcpy(rnd + 14, &u16, 2);
719 #ifndef HAVE_MD5
720 	MD5_Init(&ctx);
721 	MD5_Update(&ctx, rnd, 16);
722 	MD5_Final(rnd, &ctx);
723 #else
724 	MD5Init(&ctx);
725 	MD5Update(&ctx, rnd, 16);
726 	MD5Final(rnd, &ctx);
727 #endif
728 	memcpy(&u16, rnd + 14, 2);
729 	return ((u_int) u16);
730 }
731 
732 /*%
733  * This routine is for closing the socket if a virtual circuit is used and
734  * the program wants to close it.  This provides support for endhostent()
735  * which expects to close the socket.
736  *
737  * This routine is not expected to be user visible.
738  */
739 void
740 res_nclose(res_state statp)
741 {
742 	int ns;
743 
744 	if (statp->_vcsock >= 0) {
745 		(void) close(statp->_vcsock);
746 		statp->_vcsock = -1;
747 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
748 	}
749 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
750 		if (statp->_u._ext.nssocks[ns] != -1) {
751 			(void) close(statp->_u._ext.nssocks[ns]);
752 			statp->_u._ext.nssocks[ns] = -1;
753 		}
754 	}
755 }
756 
757 void
758 res_ndestroy(res_state statp)
759 {
760 	struct __res_state_ext *ext = statp->_u._ext.ext;
761 	res_nclose(statp);
762 	if (ext != NULL) {
763 		if (ext->kq != -1)
764 			(void)close(ext->kq);
765 		if (ext->resfd != -1)
766 			(void)close(ext->resfd);
767 		free(ext);
768 		statp->_u._ext.ext = NULL;
769 	}
770 	statp->options &= ~RES_INIT;
771 }
772 
773 const char *
774 res_get_nibblesuffix(res_state statp)
775 {
776 	if (statp->_u._ext.ext)
777 		return (statp->_u._ext.ext->nsuffix);
778 	return ("ip6.arpa");
779 }
780 
781 const char *
782 res_get_nibblesuffix2(res_state statp)
783 {
784 	if (statp->_u._ext.ext)
785 		return (statp->_u._ext.ext->nsuffix2);
786 	return ("ip6.int");
787 }
788 
789 void
790 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt)
791 {
792 	int i, nserv;
793 	size_t size;
794 
795 	/* close open servers */
796 	res_nclose(statp);
797 
798 	/* cause rtt times to be forgotten */
799 	statp->_u._ext.nscount = 0;
800 
801 	nserv = 0;
802 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
803 		switch (set->sin.sin_family) {
804 		case AF_INET:
805 			size = sizeof(set->sin);
806 			if (statp->_u._ext.ext)
807 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
808 					&set->sin, size);
809 			if (size <= sizeof(statp->nsaddr_list[nserv]))
810 				memcpy(&statp->nsaddr_list[nserv],
811 					&set->sin, size);
812 			else
813 				statp->nsaddr_list[nserv].sin_family = 0;
814 			nserv++;
815 			break;
816 
817 #ifdef HAS_INET6_STRUCTS
818 		case AF_INET6:
819 			size = sizeof(set->sin6);
820 			if (statp->_u._ext.ext)
821 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
822 					&set->sin6, size);
823 			if (size <= sizeof(statp->nsaddr_list[nserv]))
824 				memcpy(&statp->nsaddr_list[nserv],
825 					&set->sin6, size);
826 			else
827 				statp->nsaddr_list[nserv].sin_family = 0;
828 			nserv++;
829 			break;
830 #endif
831 
832 		default:
833 			break;
834 		}
835 		set++;
836 	}
837 	statp->nscount = nserv;
838 
839 }
840 
841 int
842 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt)
843 {
844 	int i;
845 	size_t size;
846 	uint16_t family;
847 
848 	for (i = 0; i < statp->nscount && i < cnt; i++) {
849 		if (statp->_u._ext.ext)
850 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
851 		else
852 			family = statp->nsaddr_list[i].sin_family;
853 
854 		switch (family) {
855 		case AF_INET:
856 			size = sizeof(set->sin);
857 			if (statp->_u._ext.ext)
858 				memcpy(&set->sin,
859 				       &statp->_u._ext.ext->nsaddrs[i],
860 				       size);
861 			else
862 				memcpy(&set->sin, &statp->nsaddr_list[i],
863 				       size);
864 			break;
865 
866 #ifdef HAS_INET6_STRUCTS
867 		case AF_INET6:
868 			size = sizeof(set->sin6);
869 			if (statp->_u._ext.ext)
870 				memcpy(&set->sin6,
871 				       &statp->_u._ext.ext->nsaddrs[i],
872 				       size);
873 			else
874 				memcpy(&set->sin6, &statp->nsaddr_list[i],
875 				       size);
876 			break;
877 #endif
878 
879 		default:
880 			set->sin.sin_family = 0;
881 			break;
882 		}
883 		set++;
884 	}
885 	return (statp->nscount);
886 }
887 
888 /*! \file */
889