xref: /freebsd/lib/libc/resolv/res_init.c (revision cd0756cef21079104967969e275c18b84dc45053)
1 /*-
2  * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
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 "namespace.h"
72 
73 #include <sys/param.h>
74 #include <sys/socket.h>
75 #include <sys/stat.h>
76 #include <sys/time.h>
77 
78 #include <netinet/in.h>
79 #include <arpa/inet.h>
80 #include <arpa/nameser.h>
81 
82 #include <ctype.h>
83 #include <stdio.h>
84 #include <stdlib.h>
85 #include <string.h>
86 #include <unistd.h>
87 #include <netdb.h>
88 
89 #ifndef HAVE_MD5
90 # include "../dst/md5.h"
91 #else
92 # ifdef SOLARIS2
93 #  include <sys/md5.h>
94 # elif _LIBC
95 # include <md5.h>
96 # endif
97 #endif
98 #ifndef _MD5_H_
99 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
100 #endif
101 
102 #include "un-namespace.h"
103 
104 #include "port_after.h"
105 
106 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
107 #include <resolv.h>
108 
109 #include "res_private.h"
110 
111 #ifdef SOLARIS2
112 #include <sys/systeminfo.h>
113 #endif
114 
115 static void res_setoptions(res_state, const char *, const char *);
116 
117 #ifdef RESOLVSORT
118 static const char sort_mask[] = "/&";
119 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
120 static u_int32_t net_mask(struct in_addr);
121 #endif
122 
123 #if !defined(isascii)	/*%< XXX - could be a function */
124 # define isascii(c) (!(c & 0200))
125 #endif
126 
127 /*
128  * Resolver state default settings.
129  */
130 
131 /*%
132  * Set up default settings.  If the configuration file exist, the values
133  * there will have precedence.  Otherwise, the server address is set to
134  * INADDR_ANY and the default domain name comes from the gethostname().
135  *
136  * An interim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
137  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
138  * since it was noted that INADDR_ANY actually meant ``the first interface
139  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
140  * it had to be "up" in order for you to reach your own name server.  It
141  * was later decided that since the recommended practice is to always
142  * install local static routes through 127.0.0.1 for all your network
143  * interfaces, that we could solve this problem without a code change.
144  *
145  * The configuration file should always be used, since it is the only way
146  * to specify a default domain.  If you are running a server on your local
147  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
148  * in the configuration file.
149  *
150  * Return 0 if completes successfully, -1 on error
151  */
152 int
res_ninit(res_state statp)153 res_ninit(res_state statp) {
154 	extern int __res_vinit(res_state, int);
155 
156 	return (__res_vinit(statp, 0));
157 }
158 
159 /*% This function has to be reachable by res_data.c but not publicly. */
160 int
__res_vinit(res_state statp,int preinit)161 __res_vinit(res_state statp, int preinit) {
162 	FILE *fp;
163 	char *cp, **pp;
164 	int n;
165 	char buf[BUFSIZ];
166 	int nserv = 0;    /*%< number of nameserver records read from file */
167 	int haveenv = 0;
168 	int havesearch = 0;
169 #ifdef RESOLVSORT
170 	int nsort = 0;
171 	char *net;
172 #endif
173 	int dots;
174 	union res_sockaddr_union u[2];
175 	int maxns = MAXNS;
176 
177 	RES_SET_H_ERRNO(statp, 0);
178 	if (statp->_u._ext.ext != NULL)
179 		res_ndestroy(statp);
180 
181 	if (!preinit) {
182 		statp->retrans = RES_TIMEOUT;
183 		statp->retry = RES_DFLRETRY;
184 		statp->options = RES_DEFAULT;
185 	}
186 
187 	statp->_rnd = malloc(16);
188 	res_rndinit(statp);
189 	statp->id = res_nrandomid(statp);
190 
191 	memset(u, 0, sizeof(u));
192 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
193 	u[nserv].sin.sin_family = AF_INET;
194 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
195 #ifdef HAVE_SA_LEN
196 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
197 #endif
198 	nserv++;
199 #ifdef HAS_INET6_STRUCTS
200 	u[nserv].sin6.sin6_addr = in6addr_any;
201 	u[nserv].sin6.sin6_family = AF_INET6;
202 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
203 #ifdef HAVE_SA_LEN
204 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
205 #endif
206 	nserv++;
207 #endif
208 	statp->nscount = 0;
209 	statp->ndots = 1;
210 	statp->pfcode = 0;
211 	statp->_vcsock = -1;
212 	statp->_flags = 0;
213 	statp->qhook = NULL;
214 	statp->rhook = NULL;
215 	statp->_u._ext.nscount = 0;
216 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
217 	if (statp->_u._ext.ext != NULL) {
218 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
219 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
220 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
221 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
222 		statp->_u._ext.ext->reload_period = 2;
223 	} else {
224 		/*
225 		 * Historically res_init() rarely, if at all, failed.
226 		 * Examples and applications exist which do not check
227 		 * our return code.  Furthermore several applications
228 		 * simply call us to get the systems domainname.  So
229 		 * rather then immediately fail here we store the
230 		 * failure, which is returned later, in h_errno.  And
231 		 * prevent the collection of 'nameserver' information
232 		 * by setting maxns to 0.  Thus applications that fail
233 		 * to check our return code wont be able to make
234 		 * queries anyhow.
235 		 */
236 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
237 		maxns = 0;
238 	}
239 #ifdef RESOLVSORT
240 	statp->nsort = 0;
241 #endif
242 	res_setservers(statp, u, nserv);
243 
244 #ifdef	SOLARIS2
245 	/*
246 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
247 	 * We want to keep this behaviour
248 	 */
249 	{
250 		char buf[sizeof(statp->defdname)], *cp;
251 		int ret;
252 
253 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
254 			(unsigned int)ret <= sizeof(buf)) {
255 			if (buf[0] == '+')
256 				buf[0] = '.';
257 			cp = strchr(buf, '.');
258 			cp = (cp == NULL) ? buf : (cp + 1);
259 			strncpy(statp->defdname, cp,
260 				sizeof(statp->defdname) - 1);
261 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
262 		}
263 	}
264 #endif	/* SOLARIS2 */
265 
266 	/* Allow user to override the local domain definition */
267 	if ((cp = secure_getenv("LOCALDOMAIN")) != NULL) {
268 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
269 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
270 		haveenv++;
271 
272 		/*
273 		 * Set search list to be blank-separated strings
274 		 * from rest of env value.  Permits users of LOCALDOMAIN
275 		 * to still have a search list, and anyone to set the
276 		 * one that they want to use as an individual (even more
277 		 * important now that the rfc1535 stuff restricts searches)
278 		 */
279 		cp = statp->defdname;
280 		pp = statp->dnsrch;
281 		*pp++ = cp;
282 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
283 			if (*cp == '\n')	/*%< silly backwards compat */
284 				break;
285 			else if (*cp == ' ' || *cp == '\t') {
286 				*cp = 0;
287 				n = 1;
288 			} else if (n) {
289 				*pp++ = cp;
290 				n = 0;
291 				havesearch = 1;
292 			}
293 		}
294 		/* null terminate last domain if there are excess */
295 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
296 			cp++;
297 		*cp = '\0';
298 		*pp++ = NULL;
299 	}
300 
301 #define	MATCH(line, name) \
302 	(!strncmp(line, name, sizeof(name) - 1) && \
303 	(line[sizeof(name) - 1] == ' ' || \
304 	 line[sizeof(name) - 1] == '\t'))
305 
306 	nserv = 0;
307 	if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
308 	    struct stat sb;
309 	    struct timespec now;
310 
311 	    if (statp->_u._ext.ext != NULL) {
312 		if (_fstat(fileno(fp), &sb) == 0) {
313 		    statp->_u._ext.ext->conf_mtim = sb.st_mtim;
314 		    if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) == 0) {
315 			statp->_u._ext.ext->conf_stat = now.tv_sec;
316 		    }
317 		}
318 	    }
319 
320 	    /* read the config file */
321 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
322 		/* skip comments */
323 		if (*buf == ';' || *buf == '#')
324 			continue;
325 		/* read default domain name */
326 		if (MATCH(buf, "domain")) {
327 		    if (haveenv)	/*%< skip if have from environ */
328 			    continue;
329 		    cp = buf + sizeof("domain") - 1;
330 		    while (*cp == ' ' || *cp == '\t')
331 			    cp++;
332 		    if ((*cp == '\0') || (*cp == '\n'))
333 			    continue;
334 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
335 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
336 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
337 			    *cp = '\0';
338 		    havesearch = 0;
339 		    continue;
340 		}
341 		/* set search list */
342 		if (MATCH(buf, "search")) {
343 		    if (haveenv)	/*%< skip if have from environ */
344 			    continue;
345 		    cp = buf + sizeof("search") - 1;
346 		    while (*cp == ' ' || *cp == '\t')
347 			    cp++;
348 		    if ((*cp == '\0') || (*cp == '\n'))
349 			    continue;
350 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
351 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
352 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
353 			    *cp = '\0';
354 		    /*
355 		     * Set search list to be blank-separated strings
356 		     * on rest of line.
357 		     */
358 		    cp = statp->defdname;
359 		    pp = statp->dnsrch;
360 		    *pp++ = cp;
361 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
362 			    if (*cp == ' ' || *cp == '\t') {
363 				    *cp = 0;
364 				    n = 1;
365 			    } else if (n) {
366 				    *pp++ = cp;
367 				    n = 0;
368 			    }
369 		    }
370 		    /* null terminate last domain if there are excess */
371 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
372 			    cp++;
373 		    *cp = '\0';
374 		    *pp++ = NULL;
375 		    havesearch = 1;
376 		    continue;
377 		}
378 		/* read nameservers to query */
379 		if (MATCH(buf, "nameserver") && nserv < maxns) {
380 		    struct addrinfo hints, *ai;
381 		    char sbuf[NI_MAXSERV];
382 		    const size_t minsiz =
383 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
384 
385 		    cp = buf + sizeof("nameserver") - 1;
386 		    while (*cp == ' ' || *cp == '\t')
387 			cp++;
388 		    cp[strcspn(cp, ";# \t\n")] = '\0';
389 		    if ((*cp != '\0') && (*cp != '\n')) {
390 			memset(&hints, 0, sizeof(hints));
391 			hints.ai_family = PF_UNSPEC;
392 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
393 			hints.ai_flags = AI_NUMERICHOST;
394 			sprintf(sbuf, "%u", NAMESERVER_PORT);
395 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0) {
396 			    if (ai->ai_addrlen <= minsiz) {
397 				if (statp->_u._ext.ext != NULL) {
398 				    memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
399 					ai->ai_addr, ai->ai_addrlen);
400 				}
401 				if (ai->ai_addrlen <=
402 				    sizeof(statp->nsaddr_list[nserv])) {
403 				    memcpy(&statp->nsaddr_list[nserv],
404 					ai->ai_addr, ai->ai_addrlen);
405 				} else
406 				    statp->nsaddr_list[nserv].sin_family = 0;
407 				nserv++;
408 			    }
409 			    freeaddrinfo(ai);
410 			}
411 		    }
412 		    continue;
413 		}
414 #ifdef RESOLVSORT
415 		if (MATCH(buf, "sortlist")) {
416 		    struct in_addr a;
417 		    struct in6_addr a6;
418 		    int m, i;
419 		    u_char *u;
420 		    struct __res_state_ext *ext = statp->_u._ext.ext;
421 
422 		    cp = buf + sizeof("sortlist") - 1;
423 		    while (nsort < MAXRESOLVSORT) {
424 			while (*cp == ' ' || *cp == '\t')
425 			    cp++;
426 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
427 			    break;
428 			net = cp;
429 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
430 			       isascii(*cp) && !isspace((unsigned char)*cp))
431 				cp++;
432 			n = *cp;
433 			*cp = 0;
434 			if (inet_aton(net, &a)) {
435 			    statp->sort_list[nsort].addr = a;
436 			    if (ISSORTMASK(n)) {
437 				*cp++ = n;
438 				net = cp;
439 				while (*cp && *cp != ';' &&
440 					isascii(*cp) &&
441 					!isspace((unsigned char)*cp))
442 				    cp++;
443 				n = *cp;
444 				*cp = 0;
445 				if (inet_aton(net, &a)) {
446 				    statp->sort_list[nsort].mask = a.s_addr;
447 				} else {
448 				    statp->sort_list[nsort].mask =
449 					net_mask(statp->sort_list[nsort].addr);
450 				}
451 			    } else {
452 				statp->sort_list[nsort].mask =
453 				    net_mask(statp->sort_list[nsort].addr);
454 			    }
455 			    ext->sort_list[nsort].af = AF_INET;
456 			    ext->sort_list[nsort].addr.ina =
457 				statp->sort_list[nsort].addr;
458 			    ext->sort_list[nsort].mask.ina.s_addr =
459 				statp->sort_list[nsort].mask;
460 			    nsort++;
461 			}
462 			else if (inet_pton(AF_INET6, net, &a6) == 1) {
463 
464 			    ext->sort_list[nsort].af = AF_INET6;
465 			    ext->sort_list[nsort].addr.in6a = a6;
466 			    u = (u_char *)&ext->sort_list[nsort].mask.in6a;
467 			    *cp++ = n;
468 			    net = cp;
469 			    while (*cp && *cp != ';' &&
470 				    isascii(*cp) && !isspace(*cp))
471 				cp++;
472 			    m = n;
473 			    n = *cp;
474 			    *cp = 0;
475 			    switch (m) {
476 			    case '/':
477 				m = atoi(net);
478 				break;
479 			    case '&':
480 				if (inet_pton(AF_INET6, net, u) == 1) {
481 				    m = -1;
482 				    break;
483 				}
484 				/*FALLTHROUGH*/
485 			    default:
486 				m = sizeof(struct in6_addr) * CHAR_BIT;
487 				break;
488 			    }
489 			    if (m >= 0) {
490 				for (i = 0; i < sizeof(struct in6_addr); i++) {
491 				    if (m <= 0) {
492 					*u = 0;
493 				    } else {
494 					m -= CHAR_BIT;
495 					*u = (u_char)~0;
496 					if (m < 0)
497 					    *u <<= -m;
498 				    }
499 				    u++;
500 				}
501 			    }
502 			    statp->sort_list[nsort].addr.s_addr =
503 				(u_int32_t)0xffffffff;
504 			    statp->sort_list[nsort].mask =
505 				(u_int32_t)0xffffffff;
506 			    nsort++;
507 			}
508 			*cp = n;
509 		    }
510 		    continue;
511 		}
512 #endif
513 		if (MATCH(buf, "options")) {
514 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
515 		    continue;
516 		}
517 	    }
518 	    if (nserv > 0)
519 		statp->nscount = nserv;
520 #ifdef RESOLVSORT
521 	    statp->nsort = nsort;
522 #endif
523 	    (void) fclose(fp);
524 	}
525 /*
526  * Last chance to get a nameserver.  This should not normally
527  * be necessary
528  */
529 #ifdef NO_RESOLV_CONF
530 	if(nserv == 0)
531 		nserv = get_nameservers(statp);
532 #endif
533 
534 	if (statp->defdname[0] == 0 &&
535 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
536 	    (cp = strchr(buf, '.')) != NULL)
537 		strcpy(statp->defdname, cp + 1);
538 
539 	/* find components of local domain that might be searched */
540 	if (havesearch == 0) {
541 		pp = statp->dnsrch;
542 		*pp++ = statp->defdname;
543 		*pp = NULL;
544 
545 		dots = 0;
546 		for (cp = statp->defdname; *cp; cp++)
547 			dots += (*cp == '.');
548 
549 		cp = statp->defdname;
550 		while (pp < statp->dnsrch + MAXDFLSRCH) {
551 			if (dots < LOCALDOMAINPARTS)
552 				break;
553 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
554 			*pp++ = cp;
555 			dots--;
556 		}
557 		*pp = NULL;
558 #ifdef DEBUG
559 		if (statp->options & RES_DEBUG) {
560 			printf(";; res_init()... default dnsrch list:\n");
561 			for (pp = statp->dnsrch; *pp; pp++)
562 				printf(";;\t%s\n", *pp);
563 			printf(";;\t..END..\n");
564 		}
565 #endif
566 	}
567 
568 	if (issetugid())
569 		statp->options |= RES_NOALIASES;
570 	else if ((cp = getenv("RES_OPTIONS")) != NULL)
571 		res_setoptions(statp, cp, "env");
572 	statp->options |= RES_INIT;
573 	return (statp->res_h_errno);
574 }
575 
576 static void
res_setoptions(res_state statp,const char * options,const char * source)577 res_setoptions(res_state statp, const char *options, const char *source)
578 {
579 	const char *cp = options;
580 	int i;
581 	struct __res_state_ext *ext = statp->_u._ext.ext;
582 
583 #ifdef DEBUG
584 	if (statp->options & RES_DEBUG)
585 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
586 		       options, source);
587 #endif
588 	while (*cp) {
589 		/* skip leading and inner runs of spaces */
590 		while (*cp == ' ' || *cp == '\t')
591 			cp++;
592 		/* search for and process individual options */
593 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
594 			i = atoi(cp + sizeof("ndots:") - 1);
595 			if (i <= RES_MAXNDOTS)
596 				statp->ndots = i;
597 			else
598 				statp->ndots = RES_MAXNDOTS;
599 #ifdef DEBUG
600 			if (statp->options & RES_DEBUG)
601 				printf(";;\tndots=%d\n", statp->ndots);
602 #endif
603 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
604 			i = atoi(cp + sizeof("timeout:") - 1);
605 			if (i <= RES_MAXRETRANS)
606 				statp->retrans = i;
607 			else
608 				statp->retrans = RES_MAXRETRANS;
609 #ifdef DEBUG
610 			if (statp->options & RES_DEBUG)
611 				printf(";;\ttimeout=%d\n", statp->retrans);
612 #endif
613 #ifdef	SOLARIS2
614 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
615 			/*
616 		 	 * For backward compatibility, 'retrans' is
617 		 	 * supported as an alias for 'timeout', though
618 		 	 * without an imposed maximum.
619 		 	 */
620 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
621 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
622 			/*
623 			 * For backward compatibility, 'retry' is
624 			 * supported as an alias for 'attempts', though
625 			 * without an imposed maximum.
626 			 */
627 			statp->retry = atoi(cp + sizeof("retry:") - 1);
628 #endif	/* SOLARIS2 */
629 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
630 			i = atoi(cp + sizeof("attempts:") - 1);
631 			if (i <= RES_MAXRETRY)
632 				statp->retry = i;
633 			else
634 				statp->retry = RES_MAXRETRY;
635 #ifdef DEBUG
636 			if (statp->options & RES_DEBUG)
637 				printf(";;\tattempts=%d\n", statp->retry);
638 #endif
639 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
640 #ifdef DEBUG
641 			if (!(statp->options & RES_DEBUG)) {
642 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
643 				       options, source);
644 				statp->options |= RES_DEBUG;
645 			}
646 			printf(";;\tdebug\n");
647 #endif
648 		} else if (!strncmp(cp, "no_tld_query",
649 				    sizeof("no_tld_query") - 1) ||
650 			   !strncmp(cp, "no-tld-query",
651 				    sizeof("no-tld-query") - 1)) {
652 			statp->options |= RES_NOTLDQUERY;
653 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
654 			statp->options |= RES_USE_INET6;
655 		} else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
656 		       statp->options |= RES_INSECURE1;
657 		} else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
658 		       statp->options |= RES_INSECURE2;
659 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
660 			statp->options |= RES_ROTATE;
661 		} else if (!strncmp(cp, "usevc", sizeof("usevc") - 1)) {
662 			statp->options |= RES_USEVC;
663 		} else if (!strncmp(cp, "no-check-names",
664 				    sizeof("no-check-names") - 1)) {
665 			statp->options |= RES_NOCHECKNAME;
666 		} else if (!strncmp(cp, "reload-period:",
667 				    sizeof("reload-period:") - 1)) {
668 			if (ext != NULL) {
669 				ext->reload_period = (u_short)
670 				    atoi(cp + sizeof("reload-period:") - 1);
671 			}
672 		}
673 #ifdef RES_USE_EDNS0
674 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
675 			statp->options |= RES_USE_EDNS0;
676 		}
677 #endif
678 #ifndef _LIBC
679 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
680 			statp->options |= RES_USE_DNAME;
681 		}
682 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
683 			if (ext == NULL)
684 				goto skip;
685 			cp += sizeof("nibble:") - 1;
686 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
687 			strncpy(ext->nsuffix, cp, i);
688 			ext->nsuffix[i] = '\0';
689 		}
690 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
691 			if (ext == NULL)
692 				goto skip;
693 			cp += sizeof("nibble2:") - 1;
694 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
695 			strncpy(ext->nsuffix2, cp, i);
696 			ext->nsuffix2[i] = '\0';
697 		}
698 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
699 			cp += sizeof("v6revmode:") - 1;
700 			/* "nibble" and "bitstring" used to be valid */
701 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
702 				statp->options |= RES_NO_NIBBLE2;
703 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
704 				statp->options &=
705 					 ~RES_NO_NIBBLE2;
706 			}
707 		}
708 #endif
709 		else {
710 			/* XXX - print a warning here? */
711 		}
712 #ifndef _LIBC
713    skip:
714 #endif
715 		/* skip to next run of spaces */
716 		while (*cp && *cp != ' ' && *cp != '\t')
717 			cp++;
718 	}
719 }
720 
721 #ifdef RESOLVSORT
722 /* XXX - should really support CIDR which means explicit masks always. */
723 static u_int32_t
net_mask(struct in_addr in)724 net_mask(struct in_addr in)		/*!< XXX - should really use system's version of this  */
725 {
726 	u_int32_t i = ntohl(in.s_addr);
727 
728 	if (IN_CLASSA(i))
729 		return (htonl(IN_CLASSA_NET));
730 	else if (IN_CLASSB(i))
731 		return (htonl(IN_CLASSB_NET));
732 	return (htonl(IN_CLASSC_NET));
733 }
734 #endif
735 
736 static u_char srnd[16];
737 
738 void
res_rndinit(res_state statp)739 res_rndinit(res_state statp)
740 {
741 	struct timeval now;
742 	u_int32_t u32;
743 	u_int16_t u16;
744 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
745 
746 	gettimeofday(&now, NULL);
747 	u32 = now.tv_sec;
748 	memcpy(rnd, &u32, 4);
749 	u32 = now.tv_usec;
750 	memcpy(rnd + 4, &u32, 4);
751 	u32 += now.tv_sec;
752 	memcpy(rnd + 8, &u32, 4);
753 	u16 = getpid();
754 	memcpy(rnd + 12, &u16, 2);
755 }
756 
757 u_int
res_nrandomid(res_state statp)758 res_nrandomid(res_state statp) {
759 	struct timeval now;
760 	u_int16_t u16;
761 	MD5_CTX ctx;
762 	u_char *rnd = statp->_rnd == NULL ? srnd : statp->_rnd;
763 
764 	gettimeofday(&now, NULL);
765 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
766 	memcpy(rnd + 14, &u16, 2);
767 #ifndef HAVE_MD5
768 	MD5_Init(&ctx);
769 	MD5_Update(&ctx, rnd, 16);
770 	MD5_Final(rnd, &ctx);
771 #else
772 	MD5Init(&ctx);
773 	MD5Update(&ctx, rnd, 16);
774 	MD5Final(rnd, &ctx);
775 #endif
776 	memcpy(&u16, rnd + 14, 2);
777 	return ((u_int) u16);
778 }
779 
780 /*%
781  * This routine is for closing the socket if a virtual circuit is used and
782  * the program wants to close it.  This provides support for endhostent()
783  * which expects to close the socket.
784  *
785  * This routine is not expected to be user visible.
786  */
787 void
res_nclose(res_state statp)788 res_nclose(res_state statp) {
789 	int ns;
790 
791 	if (statp->_vcsock >= 0) {
792 		(void) _close(statp->_vcsock);
793 		statp->_vcsock = -1;
794 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
795 	}
796 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
797 		if (statp->_u._ext.nssocks[ns] != -1) {
798 			(void) _close(statp->_u._ext.nssocks[ns]);
799 			statp->_u._ext.nssocks[ns] = -1;
800 		}
801 	}
802 }
803 
804 void
res_ndestroy(res_state statp)805 res_ndestroy(res_state statp) {
806 	res_nclose(statp);
807 	if (statp->_u._ext.ext != NULL) {
808 		free(statp->_u._ext.ext);
809 		statp->_u._ext.ext = NULL;
810 	}
811 	if (statp->_rnd != NULL) {
812 		free(statp->_rnd);
813 		statp->_rnd = NULL;
814 	}
815 	statp->options &= ~RES_INIT;
816 }
817 
818 #ifndef _LIBC
819 const char *
res_get_nibblesuffix(res_state statp)820 res_get_nibblesuffix(res_state statp) {
821 	if (statp->_u._ext.ext)
822 		return (statp->_u._ext.ext->nsuffix);
823 	return ("ip6.arpa");
824 }
825 
826 const char *
res_get_nibblesuffix2(res_state statp)827 res_get_nibblesuffix2(res_state statp) {
828 	if (statp->_u._ext.ext)
829 		return (statp->_u._ext.ext->nsuffix2);
830 	return ("ip6.int");
831 }
832 #endif
833 
834 void
res_setservers(res_state statp,const union res_sockaddr_union * set,int cnt)835 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
836 	int i, nserv;
837 	size_t size;
838 
839 	/* close open servers */
840 	res_nclose(statp);
841 
842 	/* cause rtt times to be forgotten */
843 	statp->_u._ext.nscount = 0;
844 
845 	nserv = 0;
846 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
847 		switch (set->sin.sin_family) {
848 		case AF_INET:
849 			size = sizeof(set->sin);
850 			if (statp->_u._ext.ext)
851 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
852 					&set->sin, size);
853 			if (size <= sizeof(statp->nsaddr_list[nserv]))
854 				memcpy(&statp->nsaddr_list[nserv],
855 					&set->sin, size);
856 			else
857 				statp->nsaddr_list[nserv].sin_family = 0;
858 			nserv++;
859 			break;
860 
861 #ifdef HAS_INET6_STRUCTS
862 		case AF_INET6:
863 			size = sizeof(set->sin6);
864 			if (statp->_u._ext.ext)
865 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
866 					&set->sin6, size);
867 			if (size <= sizeof(statp->nsaddr_list[nserv]))
868 				memcpy(&statp->nsaddr_list[nserv],
869 					&set->sin6, size);
870 			else
871 				statp->nsaddr_list[nserv].sin_family = 0;
872 			nserv++;
873 			break;
874 #endif
875 
876 		default:
877 			break;
878 		}
879 		set++;
880 	}
881 	statp->nscount = nserv;
882 
883 }
884 
885 int
res_getservers(res_state statp,union res_sockaddr_union * set,int cnt)886 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
887 	int i;
888 	size_t size;
889 	u_int16_t family;
890 
891 	for (i = 0; i < statp->nscount && i < cnt; i++) {
892 		if (statp->_u._ext.ext)
893 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
894 		else
895 			family = statp->nsaddr_list[i].sin_family;
896 
897 		switch (family) {
898 		case AF_INET:
899 			size = sizeof(set->sin);
900 			if (statp->_u._ext.ext)
901 				memcpy(&set->sin,
902 				       &statp->_u._ext.ext->nsaddrs[i],
903 				       size);
904 			else
905 				memcpy(&set->sin, &statp->nsaddr_list[i],
906 				       size);
907 			break;
908 
909 #ifdef HAS_INET6_STRUCTS
910 		case AF_INET6:
911 			size = sizeof(set->sin6);
912 			if (statp->_u._ext.ext)
913 				memcpy(&set->sin6,
914 				       &statp->_u._ext.ext->nsaddrs[i],
915 				       size);
916 			else
917 				memcpy(&set->sin6, &statp->nsaddr_list[i],
918 				       size);
919 			break;
920 #endif
921 
922 		default:
923 			set->sin.sin_family = 0;
924 			break;
925 		}
926 		set++;
927 	}
928 	return (statp->nscount);
929 }
930 
931 /*! \file */
932