xref: /freebsd-src/lib/libc/resolv/res_init.c (revision c70540ec670c9608d4fe1b3264309ef87ca9749c)
1 /*
2  * Copyright (c) 1985, 1989, 1993
3  *    The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32  *
33  * Permission to use, copy, modify, and distribute this software for any
34  * purpose with or without fee is hereby granted, provided that the above
35  * copyright notice and this permission notice appear in all copies, and that
36  * the name of Digital Equipment Corporation not be used in advertising or
37  * publicity pertaining to distribution of the document or software without
38  * specific, written prior permission.
39  *
40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47  * SOFTWARE.
48  */
49 
50 /*
51  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
52  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
53  *
54  * Permission to use, copy, modify, and distribute this software for any
55  * purpose with or without fee is hereby granted, provided that the above
56  * copyright notice and this permission notice appear in all copies.
57  *
58  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
59  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
60  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
61  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
62  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
63  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
64  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
65  */
66 
67 #if defined(LIBC_SCCS) && !defined(lint)
68 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
69 static const char rcsid[] = "$Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp $";
70 #endif /* LIBC_SCCS and not lint */
71 #include <sys/cdefs.h>
72 __FBSDID("$FreeBSD$");
73 
74 #include "port_before.h"
75 
76 #include "namespace.h"
77 
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <sys/socket.h>
81 #include <sys/stat.h>
82 #include <sys/time.h>
83 
84 #include <netinet/in.h>
85 #include <arpa/inet.h>
86 #include <arpa/nameser.h>
87 
88 #include <ctype.h>
89 #include <stdio.h>
90 #include <stdlib.h>
91 #include <string.h>
92 #include <unistd.h>
93 #include <netdb.h>
94 
95 #ifndef HAVE_MD5
96 # include "../dst/md5.h"
97 #else
98 # ifdef SOLARIS2
99 #  include <sys/md5.h>
100 # elif _LIBC
101 # include <md5.h>
102 # endif
103 #endif
104 #ifndef _MD5_H_
105 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
106 #endif
107 
108 #include "un-namespace.h"
109 
110 #include "port_after.h"
111 
112 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
113 #include <resolv.h>
114 
115 #include "res_private.h"
116 
117 /*% Options.  Should all be left alone. */
118 #define RESOLVSORT
119 #define DEBUG
120 
121 #ifdef SOLARIS2
122 #include <sys/systeminfo.h>
123 #endif
124 
125 static void res_setoptions(res_state, const char *, const char *);
126 
127 #ifdef RESOLVSORT
128 static const char sort_mask[] = "/&";
129 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
130 static u_int32_t net_mask(struct in_addr);
131 #endif
132 
133 #if !defined(isascii)	/*%< XXX - could be a function */
134 # define isascii(c) (!(c & 0200))
135 #endif
136 
137 /*
138  * Resolver state default settings.
139  */
140 
141 /*%
142  * Set up default settings.  If the configuration file exist, the values
143  * there will have precedence.  Otherwise, the server address is set to
144  * INADDR_ANY and the default domain name comes from the gethostname().
145  *
146  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
147  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
148  * since it was noted that INADDR_ANY actually meant ``the first interface
149  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
150  * it had to be "up" in order for you to reach your own name server.  It
151  * was later decided that since the recommended practice is to always
152  * install local static routes through 127.0.0.1 for all your network
153  * interfaces, that we could solve this problem without a code change.
154  *
155  * The configuration file should always be used, since it is the only way
156  * to specify a default domain.  If you are running a server on your local
157  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
158  * in the configuration file.
159  *
160  * Return 0 if completes successfully, -1 on error
161  */
162 int
163 res_ninit(res_state statp) {
164 	extern int __res_vinit(res_state, int);
165 
166 	return (__res_vinit(statp, 0));
167 }
168 
169 /*% This function has to be reachable by res_data.c but not publically. */
170 int
171 __res_vinit(res_state statp, int preinit) {
172 	FILE *fp;
173 	char *cp, **pp;
174 	int n;
175 	char buf[BUFSIZ];
176 	int nserv = 0;    /*%< number of nameserver records read from file */
177 	int haveenv = 0;
178 	int havesearch = 0;
179 #ifdef RESOLVSORT
180 	int nsort = 0;
181 	char *net;
182 #endif
183 	int dots;
184 	union res_sockaddr_union u[2];
185 	int maxns = MAXNS;
186 
187 	RES_SET_H_ERRNO(statp, 0);
188 	if (statp->_u._ext.ext != NULL)
189 		res_ndestroy(statp);
190 
191 	if (!preinit) {
192 		statp->retrans = RES_TIMEOUT;
193 		statp->retry = RES_DFLRETRY;
194 		statp->options = RES_DEFAULT;
195 	}
196 
197 	statp->_rnd = malloc(16);
198 	res_rndinit(statp);
199 	statp->id = res_nrandomid(statp);
200 
201 	memset(u, 0, sizeof(u));
202 #ifdef USELOOPBACK
203 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
204 #else
205 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
206 #endif
207 	u[nserv].sin.sin_family = AF_INET;
208 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
209 #ifdef HAVE_SA_LEN
210 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
211 #endif
212 	nserv++;
213 #ifdef HAS_INET6_STRUCTS
214 #ifdef USELOOPBACK
215 	u[nserv].sin6.sin6_addr = in6addr_loopback;
216 #else
217 	u[nserv].sin6.sin6_addr = in6addr_any;
218 #endif
219 	u[nserv].sin6.sin6_family = AF_INET6;
220 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
221 #ifdef HAVE_SA_LEN
222 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
223 #endif
224 	nserv++;
225 #endif
226 	statp->nscount = 0;
227 	statp->ndots = 1;
228 	statp->pfcode = 0;
229 	statp->_vcsock = -1;
230 	statp->_flags = 0;
231 	statp->qhook = NULL;
232 	statp->rhook = NULL;
233 	statp->_u._ext.nscount = 0;
234 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
235 	if (statp->_u._ext.ext != NULL) {
236 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
237 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
238 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
239 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
240 		statp->_u._ext.ext->reload_period = 2;
241 	} else {
242 		/*
243 		 * Historically res_init() rarely, if at all, failed.
244 		 * Examples and applications exist which do not check
245 		 * our return code.  Furthermore several applications
246 		 * simply call us to get the systems domainname.  So
247 		 * rather then immediately fail here we store the
248 		 * failure, which is returned later, in h_errno.  And
249 		 * prevent the collection of 'nameserver' information
250 		 * by setting maxns to 0.  Thus applications that fail
251 		 * to check our return code wont be able to make
252 		 * queries anyhow.
253 		 */
254 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
255 		maxns = 0;
256 	}
257 #ifdef RESOLVSORT
258 	statp->nsort = 0;
259 #endif
260 	res_setservers(statp, u, nserv);
261 
262 #ifdef	SOLARIS2
263 	/*
264 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
265 	 * We want to keep this behaviour
266 	 */
267 	{
268 		char buf[sizeof(statp->defdname)], *cp;
269 		int ret;
270 
271 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
272 			(unsigned int)ret <= sizeof(buf)) {
273 			if (buf[0] == '+')
274 				buf[0] = '.';
275 			cp = strchr(buf, '.');
276 			cp = (cp == NULL) ? buf : (cp + 1);
277 			strncpy(statp->defdname, cp,
278 				sizeof(statp->defdname) - 1);
279 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
280 		}
281 	}
282 #endif	/* SOLARIS2 */
283 
284 	/* Allow user to override the local domain definition */
285 	if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
286 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
287 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
288 		haveenv++;
289 
290 		/*
291 		 * Set search list to be blank-separated strings
292 		 * from rest of env value.  Permits users of LOCALDOMAIN
293 		 * to still have a search list, and anyone to set the
294 		 * one that they want to use as an individual (even more
295 		 * important now that the rfc1535 stuff restricts searches)
296 		 */
297 		cp = statp->defdname;
298 		pp = statp->dnsrch;
299 		*pp++ = cp;
300 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
301 			if (*cp == '\n')	/*%< silly backwards compat */
302 				break;
303 			else if (*cp == ' ' || *cp == '\t') {
304 				*cp = 0;
305 				n = 1;
306 			} else if (n) {
307 				*pp++ = cp;
308 				n = 0;
309 				havesearch = 1;
310 			}
311 		}
312 		/* null terminate last domain if there are excess */
313 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
314 			cp++;
315 		*cp = '\0';
316 		*pp++ = 0;
317 	}
318 
319 #define	MATCH(line, name) \
320 	(!strncmp(line, name, sizeof(name) - 1) && \
321 	(line[sizeof(name) - 1] == ' ' || \
322 	 line[sizeof(name) - 1] == '\t'))
323 
324 	nserv = 0;
325 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
326 	    struct stat sb;
327 	    struct timespec now;
328 
329 	    if (statp->_u._ext.ext != NULL) {
330 		if (_fstat(fileno(fp), &sb) == 0) {
331 		    statp->_u._ext.ext->conf_mtim = sb.st_mtim;
332 		    if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) == 0) {
333 			statp->_u._ext.ext->conf_stat = now.tv_sec;
334 		    }
335 		}
336 	    }
337 
338 	    /* read the config file */
339 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
340 		/* skip comments */
341 		if (*buf == ';' || *buf == '#')
342 			continue;
343 		/* read default domain name */
344 		if (MATCH(buf, "domain")) {
345 		    if (haveenv)	/*%< skip if have from environ */
346 			    continue;
347 		    cp = buf + sizeof("domain") - 1;
348 		    while (*cp == ' ' || *cp == '\t')
349 			    cp++;
350 		    if ((*cp == '\0') || (*cp == '\n'))
351 			    continue;
352 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
353 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
354 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
355 			    *cp = '\0';
356 		    havesearch = 0;
357 		    continue;
358 		}
359 		/* set search list */
360 		if (MATCH(buf, "search")) {
361 		    if (haveenv)	/*%< skip if have from environ */
362 			    continue;
363 		    cp = buf + sizeof("search") - 1;
364 		    while (*cp == ' ' || *cp == '\t')
365 			    cp++;
366 		    if ((*cp == '\0') || (*cp == '\n'))
367 			    continue;
368 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
369 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
370 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
371 			    *cp = '\0';
372 		    /*
373 		     * Set search list to be blank-separated strings
374 		     * on rest of line.
375 		     */
376 		    cp = statp->defdname;
377 		    pp = statp->dnsrch;
378 		    *pp++ = cp;
379 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
380 			    if (*cp == ' ' || *cp == '\t') {
381 				    *cp = 0;
382 				    n = 1;
383 			    } else if (n) {
384 				    *pp++ = cp;
385 				    n = 0;
386 			    }
387 		    }
388 		    /* null terminate last domain if there are excess */
389 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
390 			    cp++;
391 		    *cp = '\0';
392 		    *pp++ = 0;
393 		    havesearch = 1;
394 		    continue;
395 		}
396 		/* read nameservers to query */
397 		if (MATCH(buf, "nameserver") && nserv < maxns) {
398 		    struct addrinfo hints, *ai;
399 		    char sbuf[NI_MAXSERV];
400 		    const size_t minsiz =
401 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
402 
403 		    cp = buf + sizeof("nameserver") - 1;
404 		    while (*cp == ' ' || *cp == '\t')
405 			cp++;
406 		    cp[strcspn(cp, ";# \t\n")] = '\0';
407 		    if ((*cp != '\0') && (*cp != '\n')) {
408 			memset(&hints, 0, sizeof(hints));
409 			hints.ai_family = PF_UNSPEC;
410 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
411 			hints.ai_flags = AI_NUMERICHOST;
412 			sprintf(sbuf, "%u", NAMESERVER_PORT);
413 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
414 			    ai->ai_addrlen <= minsiz) {
415 			    if (statp->_u._ext.ext != NULL) {
416 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
417 				    ai->ai_addr, ai->ai_addrlen);
418 			    }
419 			    if (ai->ai_addrlen <=
420 			        sizeof(statp->nsaddr_list[nserv])) {
421 				memcpy(&statp->nsaddr_list[nserv],
422 				    ai->ai_addr, ai->ai_addrlen);
423 			    } else
424 				statp->nsaddr_list[nserv].sin_family = 0;
425 			    freeaddrinfo(ai);
426 			    nserv++;
427 			}
428 		    }
429 		    continue;
430 		}
431 #ifdef RESOLVSORT
432 		if (MATCH(buf, "sortlist")) {
433 		    struct in_addr a;
434 		    struct in6_addr a6;
435 		    int m, i;
436 		    u_char *u;
437 		    struct __res_state_ext *ext = statp->_u._ext.ext;
438 
439 		    cp = buf + sizeof("sortlist") - 1;
440 		    while (nsort < MAXRESOLVSORT) {
441 			while (*cp == ' ' || *cp == '\t')
442 			    cp++;
443 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
444 			    break;
445 			net = cp;
446 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
447 			       isascii(*cp) && !isspace((unsigned char)*cp))
448 				cp++;
449 			n = *cp;
450 			*cp = 0;
451 			if (inet_aton(net, &a)) {
452 			    statp->sort_list[nsort].addr = a;
453 			    if (ISSORTMASK(n)) {
454 				*cp++ = n;
455 				net = cp;
456 				while (*cp && *cp != ';' &&
457 					isascii(*cp) &&
458 					!isspace((unsigned char)*cp))
459 				    cp++;
460 				n = *cp;
461 				*cp = 0;
462 				if (inet_aton(net, &a)) {
463 				    statp->sort_list[nsort].mask = a.s_addr;
464 				} else {
465 				    statp->sort_list[nsort].mask =
466 					net_mask(statp->sort_list[nsort].addr);
467 				}
468 			    } else {
469 				statp->sort_list[nsort].mask =
470 				    net_mask(statp->sort_list[nsort].addr);
471 			    }
472 			    ext->sort_list[nsort].af = AF_INET;
473 			    ext->sort_list[nsort].addr.ina =
474 				statp->sort_list[nsort].addr;
475 			    ext->sort_list[nsort].mask.ina.s_addr =
476 				statp->sort_list[nsort].mask;
477 			    nsort++;
478 			}
479 			else if (inet_pton(AF_INET6, net, &a6) == 1) {
480 
481 			    ext->sort_list[nsort].af = AF_INET6;
482 			    ext->sort_list[nsort].addr.in6a = a6;
483 			    u = (u_char *)&ext->sort_list[nsort].mask.in6a;
484 			    *cp++ = n;
485 			    net = cp;
486 			    while (*cp && *cp != ';' &&
487 				    isascii(*cp) && !isspace(*cp))
488 				cp++;
489 			    m = n;
490 			    n = *cp;
491 			    *cp = 0;
492 			    switch (m) {
493 			    case '/':
494 				m = atoi(net);
495 				break;
496 			    case '&':
497 				if (inet_pton(AF_INET6, net, u) == 1) {
498 				    m = -1;
499 				    break;
500 				}
501 				/*FALLTHROUGH*/
502 			    default:
503 				m = sizeof(struct in6_addr) * CHAR_BIT;
504 				break;
505 			    }
506 			    if (m >= 0) {
507 				for (i = 0; i < sizeof(struct in6_addr); i++) {
508 				    if (m <= 0) {
509 					*u = 0;
510 				    } else {
511 					m -= CHAR_BIT;
512 					*u = (u_char)~0;
513 					if (m < 0)
514 					    *u <<= -m;
515 				    }
516 				    u++;
517 				}
518 			    }
519 			    statp->sort_list[nsort].addr.s_addr =
520 				(u_int32_t)0xffffffff;
521 			    statp->sort_list[nsort].mask =
522 				(u_int32_t)0xffffffff;
523 			    nsort++;
524 			}
525 			*cp = n;
526 		    }
527 		    continue;
528 		}
529 #endif
530 		if (MATCH(buf, "options")) {
531 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
532 		    continue;
533 		}
534 	    }
535 	    if (nserv > 0)
536 		statp->nscount = nserv;
537 #ifdef RESOLVSORT
538 	    statp->nsort = nsort;
539 #endif
540 	    (void) fclose(fp);
541 	}
542 /*
543  * Last chance to get a nameserver.  This should not normally
544  * be necessary
545  */
546 #ifdef NO_RESOLV_CONF
547 	if(nserv == 0)
548 		nserv = get_nameservers(statp);
549 #endif
550 
551 	if (statp->defdname[0] == 0 &&
552 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
553 	    (cp = strchr(buf, '.')) != NULL)
554 		strcpy(statp->defdname, cp + 1);
555 
556 	/* find components of local domain that might be searched */
557 	if (havesearch == 0) {
558 		pp = statp->dnsrch;
559 		*pp++ = statp->defdname;
560 		*pp = NULL;
561 
562 		dots = 0;
563 		for (cp = statp->defdname; *cp; cp++)
564 			dots += (*cp == '.');
565 
566 		cp = statp->defdname;
567 		while (pp < statp->dnsrch + MAXDFLSRCH) {
568 			if (dots < LOCALDOMAINPARTS)
569 				break;
570 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
571 			*pp++ = cp;
572 			dots--;
573 		}
574 		*pp = NULL;
575 #ifdef DEBUG
576 		if (statp->options & RES_DEBUG) {
577 			printf(";; res_init()... default dnsrch list:\n");
578 			for (pp = statp->dnsrch; *pp; pp++)
579 				printf(";;\t%s\n", *pp);
580 			printf(";;\t..END..\n");
581 		}
582 #endif
583 	}
584 
585 	if (issetugid())
586 		statp->options |= RES_NOALIASES;
587 	else if ((cp = getenv("RES_OPTIONS")) != NULL)
588 		res_setoptions(statp, cp, "env");
589 	statp->options |= RES_INIT;
590 	return (statp->res_h_errno);
591 }
592 
593 static void
594 res_setoptions(res_state statp, const char *options, const char *source)
595 {
596 	const char *cp = options;
597 	int i;
598 	struct __res_state_ext *ext = statp->_u._ext.ext;
599 
600 #ifdef DEBUG
601 	if (statp->options & RES_DEBUG)
602 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
603 		       options, source);
604 #endif
605 	while (*cp) {
606 		/* skip leading and inner runs of spaces */
607 		while (*cp == ' ' || *cp == '\t')
608 			cp++;
609 		/* search for and process individual options */
610 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
611 			i = atoi(cp + sizeof("ndots:") - 1);
612 			if (i <= RES_MAXNDOTS)
613 				statp->ndots = i;
614 			else
615 				statp->ndots = RES_MAXNDOTS;
616 #ifdef DEBUG
617 			if (statp->options & RES_DEBUG)
618 				printf(";;\tndots=%d\n", statp->ndots);
619 #endif
620 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
621 			i = atoi(cp + sizeof("timeout:") - 1);
622 			if (i <= RES_MAXRETRANS)
623 				statp->retrans = i;
624 			else
625 				statp->retrans = RES_MAXRETRANS;
626 #ifdef DEBUG
627 			if (statp->options & RES_DEBUG)
628 				printf(";;\ttimeout=%d\n", statp->retrans);
629 #endif
630 #ifdef	SOLARIS2
631 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
632 			/*
633 		 	 * For backward compatibility, 'retrans' is
634 		 	 * supported as an alias for 'timeout', though
635 		 	 * without an imposed maximum.
636 		 	 */
637 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
638 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
639 			/*
640 			 * For backward compatibility, 'retry' is
641 			 * supported as an alias for 'attempts', though
642 			 * without an imposed maximum.
643 			 */
644 			statp->retry = atoi(cp + sizeof("retry:") - 1);
645 #endif	/* SOLARIS2 */
646 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
647 			i = atoi(cp + sizeof("attempts:") - 1);
648 			if (i <= RES_MAXRETRY)
649 				statp->retry = i;
650 			else
651 				statp->retry = RES_MAXRETRY;
652 #ifdef DEBUG
653 			if (statp->options & RES_DEBUG)
654 				printf(";;\tattempts=%d\n", statp->retry);
655 #endif
656 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
657 #ifdef DEBUG
658 			if (!(statp->options & RES_DEBUG)) {
659 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
660 				       options, source);
661 				statp->options |= RES_DEBUG;
662 			}
663 			printf(";;\tdebug\n");
664 #endif
665 		} else if (!strncmp(cp, "no_tld_query",
666 				    sizeof("no_tld_query") - 1) ||
667 			   !strncmp(cp, "no-tld-query",
668 				    sizeof("no-tld-query") - 1)) {
669 			statp->options |= RES_NOTLDQUERY;
670 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
671 			statp->options |= RES_USE_INET6;
672 		} else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
673 		       statp->options |= RES_INSECURE1;
674 		} else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
675 		       statp->options |= RES_INSECURE2;
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 		} else if (!strncmp(cp, "reload-period:",
682 				    sizeof("reload-period:") - 1)) {
683 			if (ext != NULL) {
684 				ext->reload_period = (u_short)
685 				    atoi(cp + sizeof("reload-period:") - 1);
686 			}
687 		}
688 #ifdef RES_USE_EDNS0
689 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
690 			statp->options |= RES_USE_EDNS0;
691 		}
692 #endif
693 #ifndef _LIBC
694 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
695 			statp->options |= RES_USE_DNAME;
696 		}
697 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
698 			if (ext == NULL)
699 				goto skip;
700 			cp += sizeof("nibble:") - 1;
701 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
702 			strncpy(ext->nsuffix, cp, i);
703 			ext->nsuffix[i] = '\0';
704 		}
705 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
706 			if (ext == NULL)
707 				goto skip;
708 			cp += sizeof("nibble2:") - 1;
709 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
710 			strncpy(ext->nsuffix2, cp, i);
711 			ext->nsuffix2[i] = '\0';
712 		}
713 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
714 			cp += sizeof("v6revmode:") - 1;
715 			/* "nibble" and "bitstring" used to be valid */
716 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
717 				statp->options |= RES_NO_NIBBLE2;
718 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
719 				statp->options &=
720 					 ~RES_NO_NIBBLE2;
721 			}
722 		}
723 #endif
724 		else {
725 			/* XXX - print a warning here? */
726 		}
727 #ifndef _LIBC
728    skip:
729 #endif
730 		/* skip to next run of spaces */
731 		while (*cp && *cp != ' ' && *cp != '\t')
732 			cp++;
733 	}
734 }
735 
736 #ifdef RESOLVSORT
737 /* XXX - should really support CIDR which means explicit masks always. */
738 static u_int32_t
739 net_mask(struct in_addr in)		/*!< XXX - should really use system's version of this  */
740 {
741 	u_int32_t i = ntohl(in.s_addr);
742 
743 	if (IN_CLASSA(i))
744 		return (htonl(IN_CLASSA_NET));
745 	else if (IN_CLASSB(i))
746 		return (htonl(IN_CLASSB_NET));
747 	return (htonl(IN_CLASSC_NET));
748 }
749 #endif
750 
751 static u_char srnd[16];
752 
753 void
754 res_rndinit(res_state statp)
755 {
756 	struct timeval now;
757 	u_int32_t u32;
758 	u_int16_t u16;
759 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
760 
761 	gettimeofday(&now, NULL);
762 	u32 = now.tv_sec;
763 	memcpy(rnd, &u32, 4);
764 	u32 = now.tv_usec;
765 	memcpy(rnd + 4, &u32, 4);
766 	u32 += now.tv_sec;
767 	memcpy(rnd + 8, &u32, 4);
768 	u16 = getpid();
769 	memcpy(rnd + 12, &u16, 2);
770 }
771 
772 u_int
773 res_nrandomid(res_state statp) {
774 	struct timeval now;
775 	u_int16_t u16;
776 	MD5_CTX ctx;
777 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
778 
779 	gettimeofday(&now, NULL);
780 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
781 	memcpy(rnd + 14, &u16, 2);
782 #ifndef HAVE_MD5
783 	MD5_Init(&ctx);
784 	MD5_Update(&ctx, rnd, 16);
785 	MD5_Final(rnd, &ctx);
786 #else
787 	MD5Init(&ctx);
788 	MD5Update(&ctx, rnd, 16);
789 	MD5Final(rnd, &ctx);
790 #endif
791 	memcpy(&u16, rnd + 14, 2);
792 	return ((u_int) u16);
793 }
794 
795 /*%
796  * This routine is for closing the socket if a virtual circuit is used and
797  * the program wants to close it.  This provides support for endhostent()
798  * which expects to close the socket.
799  *
800  * This routine is not expected to be user visible.
801  */
802 void
803 res_nclose(res_state statp) {
804 	int ns;
805 
806 	if (statp->_vcsock >= 0) {
807 		(void) _close(statp->_vcsock);
808 		statp->_vcsock = -1;
809 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
810 	}
811 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
812 		if (statp->_u._ext.nssocks[ns] != -1) {
813 			(void) _close(statp->_u._ext.nssocks[ns]);
814 			statp->_u._ext.nssocks[ns] = -1;
815 		}
816 	}
817 }
818 
819 void
820 res_ndestroy(res_state statp) {
821 	res_nclose(statp);
822 	if (statp->_u._ext.ext != NULL) {
823 		free(statp->_u._ext.ext);
824 		statp->_u._ext.ext = NULL;
825 	}
826 	if (statp->_rnd != NULL) {
827 		free(statp->_rnd);
828 		statp->_rnd = NULL;
829 	}
830 	statp->options &= ~RES_INIT;
831 }
832 
833 #ifndef _LIBC
834 const char *
835 res_get_nibblesuffix(res_state statp) {
836 	if (statp->_u._ext.ext)
837 		return (statp->_u._ext.ext->nsuffix);
838 	return ("ip6.arpa");
839 }
840 
841 const char *
842 res_get_nibblesuffix2(res_state statp) {
843 	if (statp->_u._ext.ext)
844 		return (statp->_u._ext.ext->nsuffix2);
845 	return ("ip6.int");
846 }
847 #endif
848 
849 void
850 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
851 	int i, nserv;
852 	size_t size;
853 
854 	/* close open servers */
855 	res_nclose(statp);
856 
857 	/* cause rtt times to be forgotten */
858 	statp->_u._ext.nscount = 0;
859 
860 	nserv = 0;
861 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
862 		switch (set->sin.sin_family) {
863 		case AF_INET:
864 			size = sizeof(set->sin);
865 			if (statp->_u._ext.ext)
866 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
867 					&set->sin, size);
868 			if (size <= sizeof(statp->nsaddr_list[nserv]))
869 				memcpy(&statp->nsaddr_list[nserv],
870 					&set->sin, size);
871 			else
872 				statp->nsaddr_list[nserv].sin_family = 0;
873 			nserv++;
874 			break;
875 
876 #ifdef HAS_INET6_STRUCTS
877 		case AF_INET6:
878 			size = sizeof(set->sin6);
879 			if (statp->_u._ext.ext)
880 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
881 					&set->sin6, size);
882 			if (size <= sizeof(statp->nsaddr_list[nserv]))
883 				memcpy(&statp->nsaddr_list[nserv],
884 					&set->sin6, size);
885 			else
886 				statp->nsaddr_list[nserv].sin_family = 0;
887 			nserv++;
888 			break;
889 #endif
890 
891 		default:
892 			break;
893 		}
894 		set++;
895 	}
896 	statp->nscount = nserv;
897 
898 }
899 
900 int
901 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
902 	int i;
903 	size_t size;
904 	u_int16_t family;
905 
906 	for (i = 0; i < statp->nscount && i < cnt; i++) {
907 		if (statp->_u._ext.ext)
908 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
909 		else
910 			family = statp->nsaddr_list[i].sin_family;
911 
912 		switch (family) {
913 		case AF_INET:
914 			size = sizeof(set->sin);
915 			if (statp->_u._ext.ext)
916 				memcpy(&set->sin,
917 				       &statp->_u._ext.ext->nsaddrs[i],
918 				       size);
919 			else
920 				memcpy(&set->sin, &statp->nsaddr_list[i],
921 				       size);
922 			break;
923 
924 #ifdef HAS_INET6_STRUCTS
925 		case AF_INET6:
926 			size = sizeof(set->sin6);
927 			if (statp->_u._ext.ext)
928 				memcpy(&set->sin6,
929 				       &statp->_u._ext.ext->nsaddrs[i],
930 				       size);
931 			else
932 				memcpy(&set->sin6, &statp->nsaddr_list[i],
933 				       size);
934 			break;
935 #endif
936 
937 		default:
938 			set->sin.sin_family = 0;
939 			break;
940 		}
941 		set++;
942 	}
943 	return (statp->nscount);
944 }
945 
946 /*! \file */
947