1 /* $NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $ */
2
3 /*
4 * Copyright (c) 1985, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 /*
37 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38 *
39 * Permission to use, copy, modify, and distribute this software for any
40 * purpose with or without fee is hereby granted, provided that the above
41 * copyright notice and this permission notice appear in all copies, and that
42 * the name of Digital Equipment Corporation not be used in advertising or
43 * publicity pertaining to distribution of the document or software without
44 * specific, written prior permission.
45 *
46 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
47 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
49 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53 * SOFTWARE.
54 */
55
56 /*
57 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
58 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
59 *
60 * Permission to use, copy, modify, and distribute this software for any
61 * purpose with or without fee is hereby granted, provided that the above
62 * copyright notice and this permission notice appear in all copies.
63 *
64 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
65 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
66 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
67 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
68 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
69 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
70 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71 */
72
73 #include <sys/cdefs.h>
74 #if defined(LIBC_SCCS) && !defined(lint)
75 #ifdef notdef
76 static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
77 static const char rcsid[] = "Id: res_init.c,v 1.9.2.5.4.2 2004/03/16 12:34:18 marka Exp";
78 #else
79 __RCSID("$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $");
80 #endif
81 #endif /* LIBC_SCCS and not lint */
82
83
84
85 #include <sys/types.h>
86 #include <sys/param.h>
87 #include <sys/socket.h>
88 #include <sys/time.h>
89
90 #include <netinet/in.h>
91 #include <arpa/inet.h>
92 #include "arpa_nameser.h"
93
94 #include <ctype.h>
95 #include <stdio.h>
96 #include <stdlib.h>
97 #include <string.h>
98 #include <unistd.h>
99 #include <netdb.h>
100
101 #ifdef ANDROID_CHANGES
102 #include <errno.h>
103 #include <fcntl.h>
104 #include <sys/system_properties.h>
105 #endif /* ANDROID_CHANGES */
106
107 #ifndef MIN
108 #define MIN(x,y) ((x)<(y)?(x):(y))
109 #endif
110
111 /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
112 #ifdef ANDROID_CHANGES
113 #include "resolv_private.h"
114 #define MAX_DNS_PROPERTIES 8
115 #define DNS_PROP_NAME_PREFIX "net.dns"
116 #define DNS_CHANGE_PROP_NAME "net.dnschange"
117 #define DNS_SEARCH_PROP_NAME "net.dns.search"
118 static const prop_info *dns_change_prop;
119 static int dns_last_change_counter;
120 static int _get_dns_change_count();
121 #else
122 #include <resolv.h>
123 #endif
124
125 #include "res_private.h"
126
127 /* Options. Should all be left alone. */
128 #ifndef DEBUG
129 #define DEBUG
130 #endif
131
132 static void res_setoptions __P((res_state, const char *, const char *));
133
134 static const char sort_mask[] = "/&";
135 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
136 static u_int32_t net_mask __P((struct in_addr));
137
138 #if !defined(isascii) /* XXX - could be a function */
139 # define isascii(c) (!(c & 0200))
140 #endif
141
142 /*
143 * Resolver state default settings.
144 */
145
146 /*
147 * Set up default settings. If the configuration file exist, the values
148 * there will have precedence. Otherwise, the server address is set to
149 * INADDR_ANY and the default domain name comes from the gethostname().
150 *
151 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
152 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
153 * since it was noted that INADDR_ANY actually meant ``the first interface
154 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
155 * it had to be "up" in order for you to reach your own name server. It
156 * was later decided that since the recommended practice is to always
157 * install local static routes through 127.0.0.1 for all your network
158 * interfaces, that we could solve this problem without a code change.
159 *
160 * The configuration file should always be used, since it is the only way
161 * to specify a default domain. If you are running a server on your local
162 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
163 * in the configuration file.
164 *
165 * Return 0 if completes successfully, -1 on error
166 */
167 int
res_ninit(res_state statp)168 res_ninit(res_state statp) {
169 extern int __res_vinit(res_state, int);
170
171 return (__res_vinit(statp, 0));
172 }
173
174 #ifdef ANDROID_CHANGES
load_domain_search_list(res_state statp)175 static int load_domain_search_list(res_state statp) {
176 char propvalue[PROP_VALUE_MAX];
177 register char *cp, **pp;
178
179 if(__system_property_get(DNS_SEARCH_PROP_NAME, propvalue) >= 1) {
180 strlcpy(statp->defdname, propvalue, sizeof(statp->defdname));
181 if ((cp = strchr(statp->defdname, '\n')) != NULL)
182 *cp = '\0';
183 cp = statp->defdname;
184 pp = statp->dnsrch;
185 while ( pp < statp->dnsrch + MAXDNSRCH ) {
186 while (*cp == ' ' || *cp == '\t') /* skip leading white space */
187 cp++;
188 if (*cp == '\0') /* stop if nothing more */
189 break;
190 *pp++ = cp; /* record this search domain */
191 while (*cp) { /* zero-terminate it */
192 if (*cp == ' ' || *cp == '\t') {
193 *cp++ = '\0';
194 break;
195 }
196 cp++;
197 }
198 }
199 *pp = NULL; /* statp->dnsrch has MAXDNSRCH+1 items */
200 if (pp > statp->dnsrch)
201 return 1;
202 }
203 statp->defdname[0] = '\0'; /* no default domain name on Android */
204 statp->dnsrch[0] = NULL;
205 return 0;
206 }
207 #endif
208
209 /* This function has to be reachable by res_data.c but not publicly. */
210 int
__res_vinit(res_state statp,int preinit)211 __res_vinit(res_state statp, int preinit) {
212 register FILE *fp;
213 register char *cp, **pp;
214 register int n;
215 char buf[BUFSIZ];
216 int nserv = 0; /* number of nameserver records read from file */
217 int haveenv = 0;
218 int havesearch = 0;
219 int nsort = 0;
220 char *net;
221 int dots;
222 union res_sockaddr_union u[2];
223 #ifdef ANDROID_CHANGES
224 pid_t mypid = getpid();
225 int use_proc_props = 0;
226 int found_prop;
227 char dnsProperty[PROP_VALUE_MAX];
228 #endif
229
230 if ((statp->options & RES_INIT) != 0U)
231 res_ndestroy(statp);
232
233 if (!preinit) {
234 statp->retrans = RES_TIMEOUT;
235 statp->retry = RES_DFLRETRY;
236 statp->options = RES_DEFAULT;
237 statp->id = res_randomid();
238 }
239
240 memset(u, 0, sizeof(u));
241 #ifdef USELOOPBACK
242 u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
243 #else
244 u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
245 #endif
246 u[nserv].sin.sin_family = AF_INET;
247 u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
248 #ifdef HAVE_SA_LEN
249 u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
250 #endif
251 nserv++;
252 #ifdef HAS_INET6_STRUCTS
253 #ifdef USELOOPBACK
254 u[nserv].sin6.sin6_addr = in6addr_loopback;
255 #else
256 u[nserv].sin6.sin6_addr = in6addr_any;
257 #endif
258 u[nserv].sin6.sin6_family = AF_INET6;
259 u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
260 #ifdef HAVE_SA_LEN
261 u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
262 #endif
263 nserv++;
264 #endif
265 statp->nscount = 0;
266 statp->ndots = 1;
267 statp->pfcode = 0;
268 statp->_vcsock = -1;
269 statp->_flags = 0;
270 statp->qhook = NULL;
271 statp->rhook = NULL;
272 statp->_u._ext.nscount = 0;
273 statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
274 if (statp->_u._ext.ext != NULL) {
275 memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
276 statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
277 strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
278 strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
279 }
280 statp->nsort = 0;
281 res_setservers(statp, u, nserv);
282
283 #if 0 /* IGNORE THE ENVIRONMENT */
284 /* Allow user to override the local domain definition */
285 if ((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 if (nserv > 0)
319 statp->nscount = nserv;
320 #endif
321 #ifdef ANDROID_CHANGES /* READ FROM SYSTEM PROPERTIES */
322 dns_last_change_counter = _get_dns_change_count();
323
324 nserv = 0;
325 for(n = 1; n <= MAX_DNS_PROPERTIES && nserv < MAXNS; n++) {
326 char propname[PROP_NAME_MAX];
327 char propvalue[PROP_VALUE_MAX];
328
329 struct addrinfo hints, *ai;
330 char sbuf[NI_MAXSERV];
331 const size_t minsiz = sizeof(statp->_u._ext.ext->nsaddrs[0]);
332
333 /*
334 * Check first for process-specific properties, and if those don't
335 * exist, try the generic properties.
336 */
337 found_prop = 0;
338 if (n == 1 || use_proc_props) {
339 snprintf(propname, sizeof(propname), "%s%d.%d", DNS_PROP_NAME_PREFIX, n, mypid);
340 if(__system_property_get(propname, propvalue) < 1) {
341 if (use_proc_props) {
342 break;
343 }
344 } else {
345 found_prop = 1;
346 use_proc_props = 1;
347 }
348 }
349 if (!found_prop) {
350 snprintf(propname, sizeof(propname), "%s%d", DNS_PROP_NAME_PREFIX, n);
351 if(__system_property_get(propname, propvalue) < 1) {
352 break;
353 }
354 }
355
356 cp = propvalue;
357
358 while (*cp == ' ' || *cp == '\t')
359 cp++;
360 cp[strcspn(cp, ";# \t\n")] = '\0';
361 if ((*cp != '\0') && (*cp != '\n')) {
362 memset(&hints, 0, sizeof(hints));
363 hints.ai_family = PF_UNSPEC;
364 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
365 hints.ai_flags = AI_NUMERICHOST;
366 sprintf(sbuf, "%u", NAMESERVER_PORT);
367 if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
368 (size_t)ai->ai_addrlen <= minsiz) {
369 if (statp->_u._ext.ext != NULL) {
370 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
371 ai->ai_addr, ai->ai_addrlen);
372 }
373 if ((size_t)ai->ai_addrlen <=
374 sizeof(statp->nsaddr_list[nserv])) {
375 memcpy(&statp->nsaddr_list[nserv],
376 ai->ai_addr, ai->ai_addrlen);
377 } else {
378 statp->nsaddr_list[nserv].sin_family = 0;
379 }
380 freeaddrinfo(ai);
381 nserv++;
382 }
383 }
384 }
385
386 /* Add the domain search list */
387 havesearch = load_domain_search_list(statp);
388 #else /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
389 #define MATCH(line, name) \
390 (!strncmp(line, name, sizeof(name) - 1) && \
391 (line[sizeof(name) - 1] == ' ' || \
392 line[sizeof(name) - 1] == '\t'))
393
394 nserv = 0;
395 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
396 /* read the config file */
397 while (fgets(buf, sizeof(buf), fp) != NULL) {
398 /* skip comments */
399 if (*buf == ';' || *buf == '#')
400 continue;
401 /* read default domain name */
402 if (MATCH(buf, "domain")) {
403 if (haveenv) /* skip if have from environ */
404 continue;
405 cp = buf + sizeof("domain") - 1;
406 while (*cp == ' ' || *cp == '\t')
407 cp++;
408 if ((*cp == '\0') || (*cp == '\n'))
409 continue;
410 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
411 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
412 if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
413 *cp = '\0';
414 havesearch = 0;
415 continue;
416 }
417 /* set search list */
418 if (MATCH(buf, "search")) {
419 if (haveenv) /* skip if have from environ */
420 continue;
421 cp = buf + sizeof("search") - 1;
422 while (*cp == ' ' || *cp == '\t')
423 cp++;
424 if ((*cp == '\0') || (*cp == '\n'))
425 continue;
426 strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
427 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
428 if ((cp = strchr(statp->defdname, '\n')) != NULL)
429 *cp = '\0';
430 /*
431 * Set search list to be blank-separated strings
432 * on rest of line.
433 */
434 cp = statp->defdname;
435 pp = statp->dnsrch;
436 *pp++ = cp;
437 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
438 if (*cp == ' ' || *cp == '\t') {
439 *cp = 0;
440 n = 1;
441 } else if (n) {
442 *pp++ = cp;
443 n = 0;
444 }
445 }
446 /* null terminate last domain if there are excess */
447 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
448 cp++;
449 *cp = '\0';
450 *pp++ = 0;
451 havesearch = 1;
452 continue;
453 }
454 /* read nameservers to query */
455 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
456 struct addrinfo hints, *ai;
457 char sbuf[NI_MAXSERV];
458 const size_t minsiz =
459 sizeof(statp->_u._ext.ext->nsaddrs[0]);
460
461 cp = buf + sizeof("nameserver") - 1;
462 while (*cp == ' ' || *cp == '\t')
463 cp++;
464 cp[strcspn(cp, ";# \t\n")] = '\0';
465 if ((*cp != '\0') && (*cp != '\n')) {
466 memset(&hints, 0, sizeof(hints));
467 hints.ai_family = PF_UNSPEC;
468 hints.ai_socktype = SOCK_DGRAM; /*dummy*/
469 hints.ai_flags = AI_NUMERICHOST;
470 sprintf(sbuf, "%u", NAMESERVER_PORT);
471 if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
472 ai->ai_addrlen <= minsiz) {
473 if (statp->_u._ext.ext != NULL) {
474 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
475 ai->ai_addr, ai->ai_addrlen);
476 }
477 if (ai->ai_addrlen <=
478 sizeof(statp->nsaddr_list[nserv])) {
479 memcpy(&statp->nsaddr_list[nserv],
480 ai->ai_addr, ai->ai_addrlen);
481 } else
482 statp->nsaddr_list[nserv].sin_family = 0;
483 freeaddrinfo(ai);
484 nserv++;
485 }
486 }
487 continue;
488 }
489 if (MATCH(buf, "sortlist")) {
490 struct in_addr a;
491
492 cp = buf + sizeof("sortlist") - 1;
493 while (nsort < MAXRESOLVSORT) {
494 while (*cp == ' ' || *cp == '\t')
495 cp++;
496 if (*cp == '\0' || *cp == '\n' || *cp == ';')
497 break;
498 net = cp;
499 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
500 isascii(*cp) && !isspace((unsigned char)*cp))
501 cp++;
502 n = *cp;
503 *cp = 0;
504 if (inet_aton(net, &a)) {
505 statp->sort_list[nsort].addr = a;
506 if (ISSORTMASK(n)) {
507 *cp++ = n;
508 net = cp;
509 while (*cp && *cp != ';' &&
510 isascii(*cp) &&
511 !isspace((unsigned char)*cp))
512 cp++;
513 n = *cp;
514 *cp = 0;
515 if (inet_aton(net, &a)) {
516 statp->sort_list[nsort].mask = a.s_addr;
517 } else {
518 statp->sort_list[nsort].mask =
519 net_mask(statp->sort_list[nsort].addr);
520 }
521 } else {
522 statp->sort_list[nsort].mask =
523 net_mask(statp->sort_list[nsort].addr);
524 }
525 nsort++;
526 }
527 *cp = n;
528 }
529 continue;
530 }
531 if (MATCH(buf, "options")) {
532 res_setoptions(statp, buf + sizeof("options") - 1, "conf");
533 continue;
534 }
535 }
536 if (nserv > 0)
537 statp->nscount = nserv;
538 statp->nsort = nsort;
539 (void) fclose(fp);
540 }
541 #endif /* !ANDROID_CHANGES */
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 ((cp = getenv("RES_OPTIONS")) != NULL)
586 res_setoptions(statp, cp, "env");
587 if (nserv > 0) {
588 statp->nscount = nserv;
589 statp->options |= RES_INIT;
590 }
591 return (0);
592 }
593
594 static void
res_setoptions(res_state statp,const char * options,const char * source)595 res_setoptions(res_state statp, const char *options, const char *source)
596 {
597 const char *cp = options;
598 int i;
599 struct __res_state_ext *ext = statp->_u._ext.ext;
600
601 #ifdef DEBUG
602 if (statp->options & RES_DEBUG)
603 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
604 options, source);
605 #endif
606 while (*cp) {
607 /* skip leading and inner runs of spaces */
608 while (*cp == ' ' || *cp == '\t')
609 cp++;
610 /* search for and process individual options */
611 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
612 i = atoi(cp + sizeof("ndots:") - 1);
613 if (i <= RES_MAXNDOTS)
614 statp->ndots = i;
615 else
616 statp->ndots = RES_MAXNDOTS;
617 #ifdef DEBUG
618 if (statp->options & RES_DEBUG)
619 printf(";;\tndots=%d\n", statp->ndots);
620 #endif
621 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
622 i = atoi(cp + sizeof("timeout:") - 1);
623 if (i <= RES_MAXRETRANS)
624 statp->retrans = i;
625 else
626 statp->retrans = RES_MAXRETRANS;
627 #ifdef DEBUG
628 if (statp->options & RES_DEBUG)
629 printf(";;\ttimeout=%d\n", statp->retrans);
630 #endif
631 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
632 i = atoi(cp + sizeof("attempts:") - 1);
633 if (i <= RES_MAXRETRY)
634 statp->retry = i;
635 else
636 statp->retry = RES_MAXRETRY;
637 #ifdef DEBUG
638 if (statp->options & RES_DEBUG)
639 printf(";;\tattempts=%d\n", statp->retry);
640 #endif
641 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
642 #ifdef DEBUG
643 if (!(statp->options & RES_DEBUG)) {
644 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
645 options, source);
646 statp->options |= RES_DEBUG;
647 }
648 printf(";;\tdebug\n");
649 #endif
650 } else if (!strncmp(cp, "no_tld_query",
651 sizeof("no_tld_query") - 1) ||
652 !strncmp(cp, "no-tld-query",
653 sizeof("no-tld-query") - 1)) {
654 statp->options |= RES_NOTLDQUERY;
655 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
656 statp->options |= RES_USE_INET6;
657 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
658 statp->options |= RES_ROTATE;
659 } else if (!strncmp(cp, "no-check-names",
660 sizeof("no-check-names") - 1)) {
661 statp->options |= RES_NOCHECKNAME;
662 }
663 #ifdef RES_USE_EDNS0
664 else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
665 statp->options |= RES_USE_EDNS0;
666 }
667 #endif
668 else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
669 statp->options |= RES_USE_DNAME;
670 }
671 else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
672 if (ext == NULL)
673 goto skip;
674 cp += sizeof("nibble:") - 1;
675 i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
676 strncpy(ext->nsuffix, cp, (size_t)i);
677 ext->nsuffix[i] = '\0';
678 }
679 else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
680 if (ext == NULL)
681 goto skip;
682 cp += sizeof("nibble2:") - 1;
683 i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
684 strncpy(ext->nsuffix2, cp, (size_t)i);
685 ext->nsuffix2[i] = '\0';
686 }
687 else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
688 cp += sizeof("v6revmode:") - 1;
689 /* "nibble" and "bitstring" used to be valid */
690 if (!strncmp(cp, "single", sizeof("single") - 1)) {
691 statp->options |= RES_NO_NIBBLE2;
692 } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
693 statp->options &=
694 ~RES_NO_NIBBLE2;
695 }
696 }
697 else {
698 /* XXX - print a warning here? */
699 }
700 skip:
701 /* skip to next run of spaces */
702 while (*cp && *cp != ' ' && *cp != '\t')
703 cp++;
704 }
705 }
706
707 /* XXX - should really support CIDR which means explicit masks always. */
708 static u_int32_t
net_mask(in)709 net_mask(in) /* XXX - should really use system's version of this */
710 struct in_addr in;
711 {
712 register u_int32_t i = ntohl(in.s_addr);
713
714 if (IN_CLASSA(i))
715 return (htonl(IN_CLASSA_NET));
716 else if (IN_CLASSB(i))
717 return (htonl(IN_CLASSB_NET));
718 return (htonl(IN_CLASSC_NET));
719 }
720
721 #ifdef ANDROID_CHANGES
722 static int
real_randomid(u_int * random_value)723 real_randomid(u_int *random_value) {
724 /* open the nonblocking random device, returning -1 on failure */
725 int random_device = open("/dev/urandom", O_RDONLY);
726 if (random_device < 0) {
727 return -1;
728 }
729
730 /* read from the random device, returning -1 on failure (or too many retries)*/
731 u_int retry = 5;
732 for (retry; retry > 0; retry--) {
733 int retval = read(random_device, random_value, sizeof(u_int));
734 if (retval == sizeof(u_int)) {
735 *random_value &= 0xffff;
736 close(random_device);
737 return 0;
738 } else if ((retval < 0) && (errno != EINTR)) {
739 break;
740 }
741 }
742
743 close(random_device);
744 return -1;
745 }
746 #endif /* ANDROID_CHANGES */
747
748 u_int
res_randomid(void)749 res_randomid(void) {
750 #ifdef ANDROID_CHANGES
751 int status = 0;
752 u_int output = 0;
753 status = real_randomid(&output);
754 if (status != -1) {
755 return output;
756 }
757 #endif /* ANDROID_CHANGES */
758 struct timeval now;
759 gettimeofday(&now, NULL);
760 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
761 }
762
763 /*
764 * This routine is for closing the socket if a virtual circuit is used and
765 * the program wants to close it. This provides support for endhostent()
766 * which expects to close the socket.
767 *
768 * This routine is not expected to be user visible.
769 */
770 void
res_nclose(res_state statp)771 res_nclose(res_state statp) {
772 int ns;
773
774 if (statp->_vcsock >= 0) {
775 (void) close(statp->_vcsock);
776 statp->_vcsock = -1;
777 statp->_flags &= ~(RES_F_VC | RES_F_CONN);
778 }
779 for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
780 if (statp->_u._ext.nssocks[ns] != -1) {
781 (void) close(statp->_u._ext.nssocks[ns]);
782 statp->_u._ext.nssocks[ns] = -1;
783 }
784 }
785 }
786
787 void
res_ndestroy(res_state statp)788 res_ndestroy(res_state statp) {
789 res_nclose(statp);
790 if (statp->_u._ext.ext != NULL)
791 free(statp->_u._ext.ext);
792 statp->options &= ~RES_INIT;
793 statp->_u._ext.ext = NULL;
794 }
795
796 const char *
res_get_nibblesuffix(res_state statp)797 res_get_nibblesuffix(res_state statp) {
798 if (statp->_u._ext.ext)
799 return (statp->_u._ext.ext->nsuffix);
800 return ("ip6.arpa");
801 }
802
803 const char *
res_get_nibblesuffix2(res_state statp)804 res_get_nibblesuffix2(res_state statp) {
805 if (statp->_u._ext.ext)
806 return (statp->_u._ext.ext->nsuffix2);
807 return ("ip6.int");
808 }
809
810 void
res_setservers(res_state statp,const union res_sockaddr_union * set,int cnt)811 res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
812 int i, nserv;
813 size_t size;
814
815 /* close open servers */
816 res_nclose(statp);
817
818 /* cause rtt times to be forgotten */
819 statp->_u._ext.nscount = 0;
820
821 nserv = 0;
822 for (i = 0; i < cnt && nserv < MAXNS; i++) {
823 switch (set->sin.sin_family) {
824 case AF_INET:
825 size = sizeof(set->sin);
826 if (statp->_u._ext.ext)
827 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
828 &set->sin, size);
829 if (size <= sizeof(statp->nsaddr_list[nserv]))
830 memcpy(&statp->nsaddr_list[nserv],
831 &set->sin, size);
832 #ifdef notdef
833 else
834 statp->nsaddr_list[nserv].sin_family = 0;
835 #endif
836 nserv++;
837 break;
838
839 #ifdef HAS_INET6_STRUCTS
840 case AF_INET6:
841 size = sizeof(set->sin6);
842 if (statp->_u._ext.ext)
843 memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
844 &set->sin6, size);
845 if (size <= sizeof(statp->nsaddr_list[nserv]))
846 memcpy(&statp->nsaddr_list[nserv],
847 &set->sin6, size);
848 else
849 statp->nsaddr_list[nserv].sin_family = 0;
850 nserv++;
851 break;
852 #endif
853
854 default:
855 break;
856 }
857 set++;
858 }
859 statp->nscount = nserv;
860
861 }
862
863 int
res_getservers(res_state statp,union res_sockaddr_union * set,int cnt)864 res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
865 int i;
866 size_t size;
867 u_int16_t family;
868
869 for (i = 0; i < statp->nscount && i < cnt; i++) {
870 if (statp->_u._ext.ext)
871 family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
872 else
873 family = statp->nsaddr_list[i].sin_family;
874
875 switch (family) {
876 case AF_INET:
877 size = sizeof(set->sin);
878 if (statp->_u._ext.ext)
879 memcpy(&set->sin,
880 &statp->_u._ext.ext->nsaddrs[i],
881 size);
882 else
883 memcpy(&set->sin, &statp->nsaddr_list[i],
884 size);
885 break;
886
887 #ifdef HAS_INET6_STRUCTS
888 case AF_INET6:
889 size = sizeof(set->sin6);
890 if (statp->_u._ext.ext)
891 memcpy(&set->sin6,
892 &statp->_u._ext.ext->nsaddrs[i],
893 size);
894 else
895 memcpy(&set->sin6, &statp->nsaddr_list[i],
896 size);
897 break;
898 #endif
899
900 default:
901 set->sin.sin_family = 0;
902 break;
903 }
904 set++;
905 }
906 return (statp->nscount);
907 }
908
909 #ifdef ANDROID_CHANGES
_get_dns_change_count()910 static int _get_dns_change_count()
911 {
912 if (dns_change_prop == NULL) {
913 dns_change_prop = __system_property_find(DNS_CHANGE_PROP_NAME);
914 }
915 if (dns_change_prop != NULL) {
916 char propvalue[PROP_VALUE_MAX];
917 if (__system_property_read(dns_change_prop, NULL, propvalue) >= 1) {
918 return atoi(propvalue);
919 }
920 }
921 return -1;
922 }
923
res_get_dns_changed()924 int res_get_dns_changed()
925 {
926 int change_count;
927
928 change_count = _get_dns_change_count();
929 if (change_count != dns_last_change_counter) {
930 if (change_count != -1) {
931 dns_last_change_counter = change_count;
932 }
933 return 1;
934 } else {
935 return 0;
936 }
937 }
938 #endif /* ANDROID_CHANGES */
939