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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  * 	This product includes software developed by the University of
16  * 	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
36  *
37  * Permission to use, copy, modify, and distribute this software for any
38  * purpose with or without fee is hereby granted, provided that the above
39  * copyright notice and this permission notice appear in all copies, and that
40  * the name of Digital Equipment Corporation not be used in advertising or
41  * publicity pertaining to distribution of the document or software without
42  * specific, written prior permission.
43  *
44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51  * SOFTWARE.
52  */
53 
54 /*
55  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
56  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
57  *
58  * Permission to use, copy, modify, and distribute this software for any
59  * purpose with or without fee is hereby granted, provided that the above
60  * copyright notice and this permission notice appear in all copies.
61  *
62  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
63  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
64  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
65  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
66  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
67  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
68  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
69  */
70 
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
73 static const char rcsid[] = "$Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp $";
74 #endif /* LIBC_SCCS and not lint */
75 
76 #include "port_before.h"
77 
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <sys/socket.h>
81 #include <sys/time.h>
82 
83 #include <netinet/in.h>
84 #include <arpa/inet.h>
85 #include <arpa/nameser.h>
86 
87 #include <ctype.h>
88 #include <stdio.h>
89 #include <stdlib.h>
90 #include <string.h>
91 #include <unistd.h>
92 #include <netdb.h>
93 
94 #ifndef HAVE_MD5
95 # include "../dst/md5.h"
96 #else
97 # ifdef SOLARIS2
98 #  include <sys/md5.h>
99 # endif
100 #endif
101 #ifndef _MD5_H_
102 # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
103 #endif
104 
105 #include "port_after.h"
106 
107 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
108 #include <resolv.h>
109 
110 #include "res_private.h"
111 
112 /*% Options.  Should all be left alone. */
113 #define RESOLVSORT
114 #define DEBUG
115 
116 #ifdef SOLARIS2
117 #include <sys/systeminfo.h>
118 #endif
119 
120 static void res_setoptions __P((res_state, const char *, const char *));
121 
122 #ifdef RESOLVSORT
123 static const char sort_mask[] = "/&";
124 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
125 static u_int32_t net_mask __P((struct in_addr));
126 #endif
127 
128 #if !defined(isascii)	/*%< XXX - could be a function */
129 # define isascii(c) (!(c & 0200))
130 #endif
131 
132 /*
133  * Resolver state default settings.
134  */
135 
136 /*%
137  * Set up default settings.  If the configuration file exist, the values
138  * there will have precedence.  Otherwise, the server address is set to
139  * INADDR_ANY and the default domain name comes from the gethostname().
140  *
141  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
142  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
143  * since it was noted that INADDR_ANY actually meant ``the first interface
144  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
145  * it had to be "up" in order for you to reach your own name server.  It
146  * was later decided that since the recommended practice is to always
147  * install local static routes through 127.0.0.1 for all your network
148  * interfaces, that we could solve this problem without a code change.
149  *
150  * The configuration file should always be used, since it is the only way
151  * to specify a default domain.  If you are running a server on your local
152  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
153  * in the configuration file.
154  *
155  * Return 0 if completes successfully, -1 on error
156  */
157 int
res_ninit(res_state statp)158 res_ninit(res_state statp) {
159 	extern int __res_vinit(res_state, int);
160 
161 	return (__res_vinit(statp, 0));
162 }
163 
164 /*% This function has to be reachable by res_data.c but not publically. */
165 int
__res_vinit(res_state statp,int preinit)166 __res_vinit(res_state statp, int preinit) {
167 	register FILE *fp;
168 	register char *cp, **pp;
169 	register int n;
170 	char buf[BUFSIZ];
171 	int nserv = 0;    /*%< number of nameserver records read from file */
172 	int haveenv = 0;
173 	int havesearch = 0;
174 #ifdef RESOLVSORT
175 	int nsort = 0;
176 	char *net;
177 #endif
178 	int dots;
179 	union res_sockaddr_union u[2];
180 	int maxns = MAXNS;
181 
182 	RES_SET_H_ERRNO(statp, 0);
183 	if (statp->_u._ext.ext != NULL)
184 		res_ndestroy(statp);
185 
186 	if (!preinit) {
187 		statp->retrans = RES_TIMEOUT;
188 		statp->retry = RES_DFLRETRY;
189 		statp->options = RES_DEFAULT;
190 		res_rndinit(statp);
191 		statp->id = res_nrandomid(statp);
192 	}
193 
194 	memset(u, 0, sizeof(u));
195 #ifdef USELOOPBACK
196 	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
197 #else
198 	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
199 #endif
200 	u[nserv].sin.sin_family = AF_INET;
201 	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
202 #ifdef HAVE_SA_LEN
203 	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
204 #endif
205 	nserv++;
206 #ifdef HAS_INET6_STRUCTS
207 #ifdef USELOOPBACK
208 	u[nserv].sin6.sin6_addr = in6addr_loopback;
209 #else
210 	u[nserv].sin6.sin6_addr = in6addr_any;
211 #endif
212 	u[nserv].sin6.sin6_family = AF_INET6;
213 	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
214 #ifdef HAVE_SA_LEN
215 	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
216 #endif
217 	nserv++;
218 #endif
219 	statp->nscount = 0;
220 	statp->ndots = 1;
221 	statp->pfcode = 0;
222 	statp->_vcsock = -1;
223 	statp->_flags = 0;
224 	statp->qhook = NULL;
225 	statp->rhook = NULL;
226 	statp->_u._ext.nscount = 0;
227 	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
228 	if (statp->_u._ext.ext != NULL) {
229 	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
230 		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
231 		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
232 		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
233 	} else {
234 		/*
235 		 * Historically res_init() rarely, if at all, failed.
236 		 * Examples and applications exist which do not check
237 		 * our return code.  Furthermore several applications
238 		 * simply call us to get the systems domainname.  So
239 		 * rather then immediately fail here we store the
240 		 * failure, which is returned later, in h_errno.  And
241 		 * prevent the collection of 'nameserver' information
242 		 * by setting maxns to 0.  Thus applications that fail
243 		 * to check our return code wont be able to make
244 		 * queries anyhow.
245 		 */
246 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
247 		maxns = 0;
248 	}
249 #ifdef RESOLVSORT
250 	statp->nsort = 0;
251 #endif
252 	res_setservers(statp, u, nserv);
253 
254 #ifdef	SOLARIS2
255 	/*
256 	 * The old libresolv derived the defaultdomain from NIS/NIS+.
257 	 * We want to keep this behaviour
258 	 */
259 	{
260 		char buf[sizeof(statp->defdname)], *cp;
261 		int ret;
262 
263 		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
264 			(unsigned int)ret <= sizeof(buf)) {
265 			if (buf[0] == '+')
266 				buf[0] = '.';
267 			cp = strchr(buf, '.');
268 			cp = (cp == NULL) ? buf : (cp + 1);
269 			strncpy(statp->defdname, cp,
270 				sizeof(statp->defdname) - 1);
271 			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
272 		}
273 	}
274 #endif	/* SOLARIS2 */
275 
276 	/* Allow user to override the local domain definition */
277 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
278 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
279 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
280 		haveenv++;
281 
282 		/*
283 		 * Set search list to be blank-separated strings
284 		 * from rest of env value.  Permits users of LOCALDOMAIN
285 		 * to still have a search list, and anyone to set the
286 		 * one that they want to use as an individual (even more
287 		 * important now that the rfc1535 stuff restricts searches)
288 		 */
289 		cp = statp->defdname;
290 		pp = statp->dnsrch;
291 		*pp++ = cp;
292 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
293 			if (*cp == '\n')	/*%< silly backwards compat */
294 				break;
295 			else if (*cp == ' ' || *cp == '\t') {
296 				*cp = 0;
297 				n = 1;
298 			} else if (n) {
299 				*pp++ = cp;
300 				n = 0;
301 				havesearch = 1;
302 			}
303 		}
304 		/* null terminate last domain if there are excess */
305 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
306 			cp++;
307 		*cp = '\0';
308 		*pp++ = 0;
309 	}
310 
311 #define	MATCH(line, name) \
312 	(!strncmp(line, name, sizeof(name) - 1) && \
313 	(line[sizeof(name) - 1] == ' ' || \
314 	 line[sizeof(name) - 1] == '\t'))
315 
316 	nserv = 0;
317 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
318 	    /* read the config file */
319 	    while (fgets(buf, sizeof(buf), fp) != NULL) {
320 		/* skip comments */
321 		if (*buf == ';' || *buf == '#')
322 			continue;
323 		/* read default domain name */
324 		if (MATCH(buf, "domain")) {
325 		    if (haveenv)	/*%< skip if have from environ */
326 			    continue;
327 		    cp = buf + sizeof("domain") - 1;
328 		    while (*cp == ' ' || *cp == '\t')
329 			    cp++;
330 		    if ((*cp == '\0') || (*cp == '\n'))
331 			    continue;
332 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
333 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
334 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
335 			    *cp = '\0';
336 		    havesearch = 0;
337 		    continue;
338 		}
339 		/* set search list */
340 		if (MATCH(buf, "search")) {
341 		    if (haveenv)	/*%< skip if have from environ */
342 			    continue;
343 		    cp = buf + sizeof("search") - 1;
344 		    while (*cp == ' ' || *cp == '\t')
345 			    cp++;
346 		    if ((*cp == '\0') || (*cp == '\n'))
347 			    continue;
348 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
349 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
350 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
351 			    *cp = '\0';
352 		    /*
353 		     * Set search list to be blank-separated strings
354 		     * on rest of line.
355 		     */
356 		    cp = statp->defdname;
357 		    pp = statp->dnsrch;
358 		    *pp++ = cp;
359 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
360 			    if (*cp == ' ' || *cp == '\t') {
361 				    *cp = 0;
362 				    n = 1;
363 			    } else if (n) {
364 				    *pp++ = cp;
365 				    n = 0;
366 			    }
367 		    }
368 		    /* null terminate last domain if there are excess */
369 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
370 			    cp++;
371 		    *cp = '\0';
372 		    *pp++ = 0;
373 		    havesearch = 1;
374 		    continue;
375 		}
376 		/* read nameservers to query */
377 		if (MATCH(buf, "nameserver") && nserv < maxns) {
378 		    struct addrinfo hints, *ai;
379 		    char sbuf[NI_MAXSERV];
380 		    const size_t minsiz =
381 		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
382 
383 		    cp = buf + sizeof("nameserver") - 1;
384 		    while (*cp == ' ' || *cp == '\t')
385 			cp++;
386 		    cp[strcspn(cp, ";# \t\n")] = '\0';
387 		    if ((*cp != '\0') && (*cp != '\n')) {
388 			memset(&hints, 0, sizeof(hints));
389 			hints.ai_family = PF_UNSPEC;
390 			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
391 			hints.ai_flags = AI_NUMERICHOST;
392 			sprintf(sbuf, "%u", NAMESERVER_PORT);
393 			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
394 			    ai->ai_addrlen <= minsiz) {
395 			    if (statp->_u._ext.ext != NULL) {
396 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
397 				    ai->ai_addr, ai->ai_addrlen);
398 			    }
399 			    if (ai->ai_addrlen <=
400 			        sizeof(statp->nsaddr_list[nserv])) {
401 				memcpy(&statp->nsaddr_list[nserv],
402 				    ai->ai_addr, ai->ai_addrlen);
403 			    } else
404 				statp->nsaddr_list[nserv].sin_family = 0;
405 			    freeaddrinfo(ai);
406 			    nserv++;
407 			}
408 		    }
409 		    continue;
410 		}
411 #ifdef RESOLVSORT
412 		if (MATCH(buf, "sortlist")) {
413 		    struct in_addr a;
414 
415 		    cp = buf + sizeof("sortlist") - 1;
416 		    while (nsort < MAXRESOLVSORT) {
417 			while (*cp == ' ' || *cp == '\t')
418 			    cp++;
419 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
420 			    break;
421 			net = cp;
422 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
423 			       isascii(*cp) && !isspace((unsigned char)*cp))
424 				cp++;
425 			n = *cp;
426 			*cp = 0;
427 			if (inet_aton(net, &a)) {
428 			    statp->sort_list[nsort].addr = a;
429 			    if (ISSORTMASK(n)) {
430 				*cp++ = n;
431 				net = cp;
432 				while (*cp && *cp != ';' &&
433 					isascii(*cp) &&
434 					!isspace((unsigned char)*cp))
435 				    cp++;
436 				n = *cp;
437 				*cp = 0;
438 				if (inet_aton(net, &a)) {
439 				    statp->sort_list[nsort].mask = a.s_addr;
440 				} else {
441 				    statp->sort_list[nsort].mask =
442 					net_mask(statp->sort_list[nsort].addr);
443 				}
444 			    } else {
445 				statp->sort_list[nsort].mask =
446 				    net_mask(statp->sort_list[nsort].addr);
447 			    }
448 			    nsort++;
449 			}
450 			*cp = n;
451 		    }
452 		    continue;
453 		}
454 #endif
455 		if (MATCH(buf, "options")) {
456 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
457 		    continue;
458 		}
459 	    }
460 	    if (nserv > 0)
461 		statp->nscount = nserv;
462 #ifdef RESOLVSORT
463 	    statp->nsort = nsort;
464 #endif
465 	    (void) fclose(fp);
466 	}
467 /*
468  * Last chance to get a nameserver.  This should not normally
469  * be necessary
470  */
471 #ifdef NO_RESOLV_CONF
472 	if(nserv == 0)
473 		nserv = get_nameservers(statp);
474 #endif
475 
476 	if (statp->defdname[0] == 0 &&
477 	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
478 	    (cp = strchr(buf, '.')) != NULL)
479 		strcpy(statp->defdname, cp + 1);
480 
481 	/* find components of local domain that might be searched */
482 	if (havesearch == 0) {
483 		pp = statp->dnsrch;
484 		*pp++ = statp->defdname;
485 		*pp = NULL;
486 
487 		dots = 0;
488 		for (cp = statp->defdname; *cp; cp++)
489 			dots += (*cp == '.');
490 
491 		cp = statp->defdname;
492 		while (pp < statp->dnsrch + MAXDFLSRCH) {
493 			if (dots < LOCALDOMAINPARTS)
494 				break;
495 			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
496 			*pp++ = cp;
497 			dots--;
498 		}
499 		*pp = NULL;
500 #ifdef DEBUG
501 		if (statp->options & RES_DEBUG) {
502 			printf(";; res_init()... default dnsrch list:\n");
503 			for (pp = statp->dnsrch; *pp; pp++)
504 				printf(";;\t%s\n", *pp);
505 			printf(";;\t..END..\n");
506 		}
507 #endif
508 	}
509 
510 	if ((cp = getenv("RES_OPTIONS")) != NULL)
511 		res_setoptions(statp, cp, "env");
512 	statp->options |= RES_INIT;
513 	return (statp->res_h_errno);
514 }
515 
516 static void
res_setoptions(res_state statp,const char * options,const char * source)517 res_setoptions(res_state statp, const char *options, const char *source)
518 {
519 	const char *cp = options;
520 	int i;
521 	struct __res_state_ext *ext = statp->_u._ext.ext;
522 
523 #ifdef DEBUG
524 	if (statp->options & RES_DEBUG)
525 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
526 		       options, source);
527 #endif
528 	while (*cp) {
529 		/* skip leading and inner runs of spaces */
530 		while (*cp == ' ' || *cp == '\t')
531 			cp++;
532 		/* search for and process individual options */
533 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
534 			i = atoi(cp + sizeof("ndots:") - 1);
535 			if (i <= RES_MAXNDOTS)
536 				statp->ndots = i;
537 			else
538 				statp->ndots = RES_MAXNDOTS;
539 #ifdef DEBUG
540 			if (statp->options & RES_DEBUG)
541 				printf(";;\tndots=%d\n", statp->ndots);
542 #endif
543 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
544 			i = atoi(cp + sizeof("timeout:") - 1);
545 			if (i <= RES_MAXRETRANS)
546 				statp->retrans = i;
547 			else
548 				statp->retrans = RES_MAXRETRANS;
549 #ifdef DEBUG
550 			if (statp->options & RES_DEBUG)
551 				printf(";;\ttimeout=%d\n", statp->retrans);
552 #endif
553 #ifdef	SOLARIS2
554 		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
555 			/*
556 		 	 * For backward compatibility, 'retrans' is
557 		 	 * supported as an alias for 'timeout', though
558 		 	 * without an imposed maximum.
559 		 	 */
560 			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
561 		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
562 			/*
563 			 * For backward compatibility, 'retry' is
564 			 * supported as an alias for 'attempts', though
565 			 * without an imposed maximum.
566 			 */
567 			statp->retry = atoi(cp + sizeof("retry:") - 1);
568 #endif	/* SOLARIS2 */
569 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
570 			i = atoi(cp + sizeof("attempts:") - 1);
571 			if (i <= RES_MAXRETRY)
572 				statp->retry = i;
573 			else
574 				statp->retry = RES_MAXRETRY;
575 #ifdef DEBUG
576 			if (statp->options & RES_DEBUG)
577 				printf(";;\tattempts=%d\n", statp->retry);
578 #endif
579 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
580 #ifdef DEBUG
581 			if (!(statp->options & RES_DEBUG)) {
582 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
583 				       options, source);
584 				statp->options |= RES_DEBUG;
585 			}
586 			printf(";;\tdebug\n");
587 #endif
588 		} else if (!strncmp(cp, "no_tld_query",
589 				    sizeof("no_tld_query") - 1) ||
590 			   !strncmp(cp, "no-tld-query",
591 				    sizeof("no-tld-query") - 1)) {
592 			statp->options |= RES_NOTLDQUERY;
593 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
594 			statp->options |= RES_USE_INET6;
595 		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
596 			statp->options |= RES_ROTATE;
597 		} else if (!strncmp(cp, "no-check-names",
598 				    sizeof("no-check-names") - 1)) {
599 			statp->options |= RES_NOCHECKNAME;
600 		}
601 #ifdef RES_USE_EDNS0
602 		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
603 			statp->options |= RES_USE_EDNS0;
604 		}
605 #endif
606 		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
607 			statp->options |= RES_USE_DNAME;
608 		}
609 		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
610 			if (ext == NULL)
611 				goto skip;
612 			cp += sizeof("nibble:") - 1;
613 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
614 			strncpy(ext->nsuffix, cp, i);
615 			ext->nsuffix[i] = '\0';
616 		}
617 		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
618 			if (ext == NULL)
619 				goto skip;
620 			cp += sizeof("nibble2:") - 1;
621 			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
622 			strncpy(ext->nsuffix2, cp, i);
623 			ext->nsuffix2[i] = '\0';
624 		}
625 		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
626 			cp += sizeof("v6revmode:") - 1;
627 			/* "nibble" and "bitstring" used to be valid */
628 			if (!strncmp(cp, "single", sizeof("single") - 1)) {
629 				statp->options |= RES_NO_NIBBLE2;
630 			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
631 				statp->options &=
632 					 ~RES_NO_NIBBLE2;
633 			}
634 		}
635 		else {
636 			/* XXX - print a warning here? */
637 		}
638    skip:
639 		/* skip to next run of spaces */
640 		while (*cp && *cp != ' ' && *cp != '\t')
641 			cp++;
642 	}
643 }
644 
645 #ifdef RESOLVSORT
646 /* XXX - should really support CIDR which means explicit masks always. */
647 static u_int32_t
net_mask(in)648 net_mask(in)		/*!< XXX - should really use system's version of this  */
649 	struct in_addr in;
650 {
651 	register u_int32_t i = ntohl(in.s_addr);
652 
653 	if (IN_CLASSA(i))
654 		return (htonl(IN_CLASSA_NET));
655 	else if (IN_CLASSB(i))
656 		return (htonl(IN_CLASSB_NET));
657 	return (htonl(IN_CLASSC_NET));
658 }
659 #endif
660 
661 void
res_rndinit(res_state statp)662 res_rndinit(res_state statp)
663 {
664 	struct timeval now;
665 	u_int32_t u32;
666 	u_int16_t u16;
667 
668 	gettimeofday(&now, NULL);
669 	u32 = now.tv_sec;
670 	memcpy(statp->_rnd, &u32, 4);
671 	u32 = now.tv_usec;
672 	memcpy(statp->_rnd + 4, &u32, 4);
673 	u32 += now.tv_sec;
674 	memcpy(statp->_rnd + 8, &u32, 4);
675 	u16 = getpid();
676 	memcpy(statp->_rnd + 12, &u16, 2);
677 }
678 
679 u_int
res_nrandomid(res_state statp)680 res_nrandomid(res_state statp) {
681 	struct timeval now;
682 	u_int16_t u16;
683 	MD5_CTX ctx;
684 
685 	gettimeofday(&now, NULL);
686 	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
687 	memcpy(statp->_rnd + 14, &u16, 2);
688 #ifndef HAVE_MD5
689 	MD5_Init(&ctx);
690 	MD5_Update(&ctx, statp->_rnd, 16);
691 	MD5_Final(statp->_rnd, &ctx);
692 #else
693 	MD5Init(&ctx);
694 	MD5Update(&ctx, statp->_rnd, 16);
695 	MD5Final(statp->_rnd, &ctx);
696 #endif
697 	memcpy(&u16, statp->_rnd + 14, 2);
698 	return ((u_int) u16);
699 }
700 
701 /*%
702  * This routine is for closing the socket if a virtual circuit is used and
703  * the program wants to close it.  This provides support for endhostent()
704  * which expects to close the socket.
705  *
706  * This routine is not expected to be user visible.
707  */
708 void
res_nclose(res_state statp)709 res_nclose(res_state statp) {
710 	int ns;
711 
712 	if (statp->_vcsock >= 0) {
713 		(void) close(statp->_vcsock);
714 		statp->_vcsock = -1;
715 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
716 	}
717 	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
718 		if (statp->_u._ext.nssocks[ns] != -1) {
719 			(void) close(statp->_u._ext.nssocks[ns]);
720 			statp->_u._ext.nssocks[ns] = -1;
721 		}
722 	}
723 }
724 
725 void
res_ndestroy(res_state statp)726 res_ndestroy(res_state statp) {
727 	res_nclose(statp);
728 	if (statp->_u._ext.ext != NULL)
729 		free(statp->_u._ext.ext);
730 	statp->options &= ~RES_INIT;
731 	statp->_u._ext.ext = NULL;
732 }
733 
734 const char *
res_get_nibblesuffix(res_state statp)735 res_get_nibblesuffix(res_state statp) {
736 	if (statp->_u._ext.ext)
737 		return (statp->_u._ext.ext->nsuffix);
738 	return ("ip6.arpa");
739 }
740 
741 const char *
res_get_nibblesuffix2(res_state statp)742 res_get_nibblesuffix2(res_state statp) {
743 	if (statp->_u._ext.ext)
744 		return (statp->_u._ext.ext->nsuffix2);
745 	return ("ip6.int");
746 }
747 
748 void
res_setservers(res_state statp,const union res_sockaddr_union * set,int cnt)749 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
750 	int i, nserv;
751 	size_t size;
752 
753 	/* close open servers */
754 	res_nclose(statp);
755 
756 	/* cause rtt times to be forgotten */
757 	statp->_u._ext.nscount = 0;
758 
759 	nserv = 0;
760 	for (i = 0; i < cnt && nserv < MAXNS; i++) {
761 		switch (set->sin.sin_family) {
762 		case AF_INET:
763 			size = sizeof(set->sin);
764 			if (statp->_u._ext.ext)
765 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
766 					&set->sin, size);
767 			if (size <= sizeof(statp->nsaddr_list[nserv]))
768 				memcpy(&statp->nsaddr_list[nserv],
769 					&set->sin, size);
770 			else
771 				statp->nsaddr_list[nserv].sin_family = 0;
772 			nserv++;
773 			break;
774 
775 #ifdef HAS_INET6_STRUCTS
776 		case AF_INET6:
777 			size = sizeof(set->sin6);
778 			if (statp->_u._ext.ext)
779 				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
780 					&set->sin6, size);
781 			if (size <= sizeof(statp->nsaddr_list[nserv]))
782 				memcpy(&statp->nsaddr_list[nserv],
783 					&set->sin6, size);
784 			else
785 				statp->nsaddr_list[nserv].sin_family = 0;
786 			nserv++;
787 			break;
788 #endif
789 
790 		default:
791 			break;
792 		}
793 		set++;
794 	}
795 	statp->nscount = nserv;
796 
797 }
798 
799 int
res_getservers(res_state statp,union res_sockaddr_union * set,int cnt)800 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
801 	int i;
802 	size_t size;
803 	u_int16_t family;
804 
805 	for (i = 0; i < statp->nscount && i < cnt; i++) {
806 		if (statp->_u._ext.ext)
807 			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
808 		else
809 			family = statp->nsaddr_list[i].sin_family;
810 
811 		switch (family) {
812 		case AF_INET:
813 			size = sizeof(set->sin);
814 			if (statp->_u._ext.ext)
815 				memcpy(&set->sin,
816 				       &statp->_u._ext.ext->nsaddrs[i],
817 				       size);
818 			else
819 				memcpy(&set->sin, &statp->nsaddr_list[i],
820 				       size);
821 			break;
822 
823 #ifdef HAS_INET6_STRUCTS
824 		case AF_INET6:
825 			size = sizeof(set->sin6);
826 			if (statp->_u._ext.ext)
827 				memcpy(&set->sin6,
828 				       &statp->_u._ext.ext->nsaddrs[i],
829 				       size);
830 			else
831 				memcpy(&set->sin6, &statp->nsaddr_list[i],
832 				       size);
833 			break;
834 #endif
835 
836 		default:
837 			set->sin.sin_family = 0;
838 			break;
839 		}
840 		set++;
841 	}
842 	return (statp->nscount);
843 }
844 
845 /*! \file */
846