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 | * Portions Copyright (c) 1996-1999 by Internet Software Consortium. |
52 | * |
53 | * Permission to use, copy, modify, and distribute this software for any |
54 | * purpose with or without fee is hereby granted, provided that the above |
55 | * copyright notice and this permission notice appear in all copies. |
56 | * |
57 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
58 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
59 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
60 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
61 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
62 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
63 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
64 | * SOFTWARE. |
65 | */ |
66 | |
67 | #include <ctype.h> |
68 | #include <netdb.h> |
69 | #include <resolv/resolv-internal.h> |
70 | #include <stdio.h> |
71 | #include <stdio_ext.h> |
72 | #include <stdlib.h> |
73 | #include <string.h> |
74 | #include <unistd.h> |
75 | #include <stdint.h> |
76 | #include <arpa/inet.h> |
77 | #include <arpa/nameser.h> |
78 | #include <net/if.h> |
79 | #include <netinet/in.h> |
80 | #include <sys/param.h> |
81 | #include <sys/socket.h> |
82 | #include <sys/time.h> |
83 | #include <sys/types.h> |
84 | #include <inet/net-internal.h> |
85 | |
86 | #include <not-cancel.h> |
87 | |
88 | /* Options. Should all be left alone. */ |
89 | /* #undef DEBUG */ |
90 | |
91 | static void res_setoptions (res_state, const char *, const char *) |
92 | internal_function; |
93 | |
94 | static const char sort_mask_chars[] = "/&" ; |
95 | #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL) |
96 | static u_int32_t net_mask (struct in_addr) __THROW; |
97 | |
98 | unsigned long long int __res_initstamp attribute_hidden; |
99 | |
100 | /* |
101 | * Resolver state default settings. |
102 | */ |
103 | |
104 | /* |
105 | * Set up default settings. If the configuration file exist, the values |
106 | * there will have precedence. Otherwise, the server address is set to |
107 | * INADDR_LOOPBACK and the default domain name comes from gethostname. |
108 | * |
109 | * Return 0 if completes successfully, -1 on error |
110 | */ |
111 | int |
112 | res_ninit(res_state statp) { |
113 | extern int __res_vinit(res_state, int); |
114 | |
115 | return (__res_vinit(statp, 0)); |
116 | } |
117 | libc_hidden_def (__res_ninit) |
118 | |
119 | /* This function has to be reachable by res_data.c but not publically. */ |
120 | int |
121 | __res_vinit(res_state statp, int preinit) { |
122 | FILE *fp; |
123 | char *cp, **pp; |
124 | int n; |
125 | char buf[BUFSIZ]; |
126 | int nserv = 0; /* number of nameservers read from file */ |
127 | int have_serv6 = 0; |
128 | int haveenv = 0; |
129 | int havesearch = 0; |
130 | int nsort = 0; |
131 | char *net; |
132 | statp->_u._ext.initstamp = __res_initstamp; |
133 | |
134 | if (!preinit) { |
135 | statp->retrans = RES_TIMEOUT; |
136 | statp->retry = RES_DFLRETRY; |
137 | statp->options = RES_DEFAULT; |
138 | statp->id = res_randomid(); |
139 | } |
140 | |
141 | statp->nscount = 0; |
142 | statp->defdname[0] = '\0'; |
143 | statp->ndots = 1; |
144 | statp->pfcode = 0; |
145 | statp->_vcsock = -1; |
146 | statp->_flags = 0; |
147 | statp->__glibc_unused_qhook = NULL; |
148 | statp->__glibc_unused_rhook = NULL; |
149 | statp->_u._ext.nscount = 0; |
150 | for (n = 0; n < MAXNS; n++) |
151 | statp->_u._ext.nsaddrs[n] = NULL; |
152 | |
153 | /* Allow user to override the local domain definition */ |
154 | if ((cp = getenv("LOCALDOMAIN" )) != NULL) { |
155 | (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); |
156 | statp->defdname[sizeof(statp->defdname) - 1] = '\0'; |
157 | haveenv++; |
158 | |
159 | /* |
160 | * Set search list to be blank-separated strings |
161 | * from rest of env value. Permits users of LOCALDOMAIN |
162 | * to still have a search list, and anyone to set the |
163 | * one that they want to use as an individual (even more |
164 | * important now that the rfc1535 stuff restricts searches) |
165 | */ |
166 | cp = statp->defdname; |
167 | pp = statp->dnsrch; |
168 | *pp++ = cp; |
169 | for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) { |
170 | if (*cp == '\n') /* silly backwards compat */ |
171 | break; |
172 | else if (*cp == ' ' || *cp == '\t') { |
173 | *cp = 0; |
174 | n = 1; |
175 | } else if (n) { |
176 | *pp++ = cp; |
177 | n = 0; |
178 | havesearch = 1; |
179 | } |
180 | } |
181 | /* null terminate last domain if there are excess */ |
182 | while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n') |
183 | cp++; |
184 | *cp = '\0'; |
185 | *pp++ = 0; |
186 | } |
187 | |
188 | #define MATCH(line, name) \ |
189 | (!strncmp(line, name, sizeof(name) - 1) && \ |
190 | (line[sizeof(name) - 1] == ' ' || \ |
191 | line[sizeof(name) - 1] == '\t')) |
192 | |
193 | if ((fp = fopen(_PATH_RESCONF, "rce" )) != NULL) { |
194 | /* No threads use this stream. */ |
195 | __fsetlocking (fp, FSETLOCKING_BYCALLER); |
196 | /* read the config file */ |
197 | while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) { |
198 | /* skip comments */ |
199 | if (*buf == ';' || *buf == '#') |
200 | continue; |
201 | /* read default domain name */ |
202 | if (MATCH(buf, "domain" )) { |
203 | if (haveenv) /* skip if have from environ */ |
204 | continue; |
205 | cp = buf + sizeof("domain" ) - 1; |
206 | while (*cp == ' ' || *cp == '\t') |
207 | cp++; |
208 | if ((*cp == '\0') || (*cp == '\n')) |
209 | continue; |
210 | strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); |
211 | statp->defdname[sizeof(statp->defdname) - 1] = '\0'; |
212 | if ((cp = strpbrk(statp->defdname, " \t\n" )) != NULL) |
213 | *cp = '\0'; |
214 | havesearch = 0; |
215 | continue; |
216 | } |
217 | /* set search list */ |
218 | if (MATCH(buf, "search" )) { |
219 | if (haveenv) /* skip if have from environ */ |
220 | continue; |
221 | cp = buf + sizeof("search" ) - 1; |
222 | while (*cp == ' ' || *cp == '\t') |
223 | cp++; |
224 | if ((*cp == '\0') || (*cp == '\n')) |
225 | continue; |
226 | strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1); |
227 | statp->defdname[sizeof(statp->defdname) - 1] = '\0'; |
228 | if ((cp = strchr(statp->defdname, '\n')) != NULL) |
229 | *cp = '\0'; |
230 | /* |
231 | * Set search list to be blank-separated strings |
232 | * on rest of line. |
233 | */ |
234 | cp = statp->defdname; |
235 | pp = statp->dnsrch; |
236 | *pp++ = cp; |
237 | for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) { |
238 | if (*cp == ' ' || *cp == '\t') { |
239 | *cp = 0; |
240 | n = 1; |
241 | } else if (n) { |
242 | *pp++ = cp; |
243 | n = 0; |
244 | } |
245 | } |
246 | /* null terminate last domain if there are excess */ |
247 | while (*cp != '\0' && *cp != ' ' && *cp != '\t') |
248 | cp++; |
249 | *cp = '\0'; |
250 | *pp++ = 0; |
251 | havesearch = 1; |
252 | continue; |
253 | } |
254 | /* read nameservers to query */ |
255 | if (MATCH(buf, "nameserver" ) && nserv < MAXNS) { |
256 | struct in_addr a; |
257 | |
258 | cp = buf + sizeof("nameserver" ) - 1; |
259 | while (*cp == ' ' || *cp == '\t') |
260 | cp++; |
261 | if ((*cp != '\0') && (*cp != '\n') |
262 | && __inet_aton(cp, &a)) { |
263 | statp->nsaddr_list[nserv].sin_addr = a; |
264 | statp->nsaddr_list[nserv].sin_family = AF_INET; |
265 | statp->nsaddr_list[nserv].sin_port = |
266 | htons(NAMESERVER_PORT); |
267 | nserv++; |
268 | } else { |
269 | struct in6_addr a6; |
270 | char *el; |
271 | |
272 | if ((el = strpbrk(cp, " \t\n" )) != NULL) |
273 | *el = '\0'; |
274 | if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL) |
275 | *el = '\0'; |
276 | if ((*cp != '\0') && |
277 | (__inet_pton(AF_INET6, cp, &a6) > 0)) { |
278 | struct sockaddr_in6 *sa6; |
279 | |
280 | sa6 = malloc(sizeof(*sa6)); |
281 | if (sa6 != NULL) { |
282 | sa6->sin6_family = AF_INET6; |
283 | sa6->sin6_port = htons(NAMESERVER_PORT); |
284 | sa6->sin6_flowinfo = 0; |
285 | sa6->sin6_addr = a6; |
286 | |
287 | sa6->sin6_scope_id = 0; |
288 | if (__glibc_likely (el != NULL)) { |
289 | /* Ignore errors, for backwards |
290 | compatibility. */ |
291 | (void) __inet6_scopeid_pton |
292 | (&a6, el + 1, &sa6->sin6_scope_id); |
293 | } |
294 | |
295 | statp->nsaddr_list[nserv].sin_family = 0; |
296 | statp->_u._ext.nsaddrs[nserv] = sa6; |
297 | statp->_u._ext.nssocks[nserv] = -1; |
298 | have_serv6 = 1; |
299 | nserv++; |
300 | } |
301 | } |
302 | } |
303 | continue; |
304 | } |
305 | if (MATCH(buf, "sortlist" )) { |
306 | struct in_addr a; |
307 | |
308 | cp = buf + sizeof("sortlist" ) - 1; |
309 | while (nsort < MAXRESOLVSORT) { |
310 | while (*cp == ' ' || *cp == '\t') |
311 | cp++; |
312 | if (*cp == '\0' || *cp == '\n' || *cp == ';') |
313 | break; |
314 | net = cp; |
315 | while (*cp && !ISSORTMASK(*cp) && *cp != ';' && |
316 | isascii(*cp) && !isspace(*cp)) |
317 | cp++; |
318 | n = *cp; |
319 | *cp = 0; |
320 | if (__inet_aton(net, &a)) { |
321 | statp->sort_list[nsort].addr = a; |
322 | if (ISSORTMASK(n)) { |
323 | *cp++ = n; |
324 | net = cp; |
325 | while (*cp && *cp != ';' && |
326 | isascii(*cp) && !isspace(*cp)) |
327 | cp++; |
328 | n = *cp; |
329 | *cp = 0; |
330 | if (__inet_aton(net, &a)) { |
331 | statp->sort_list[nsort].mask = a.s_addr; |
332 | } else { |
333 | statp->sort_list[nsort].mask = |
334 | net_mask(statp->sort_list[nsort].addr); |
335 | } |
336 | } else { |
337 | statp->sort_list[nsort].mask = |
338 | net_mask(statp->sort_list[nsort].addr); |
339 | } |
340 | nsort++; |
341 | } |
342 | *cp = n; |
343 | } |
344 | continue; |
345 | } |
346 | if (MATCH(buf, "options" )) { |
347 | res_setoptions(statp, buf + sizeof("options" ) - 1, "conf" ); |
348 | continue; |
349 | } |
350 | } |
351 | statp->nscount = nserv; |
352 | if (have_serv6) { |
353 | /* We try IPv6 servers again. */ |
354 | statp->ipv6_unavail = false; |
355 | } |
356 | statp->nsort = nsort; |
357 | (void) fclose(fp); |
358 | } |
359 | if (__builtin_expect(statp->nscount == 0, 0)) { |
360 | statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1); |
361 | statp->nsaddr.sin_family = AF_INET; |
362 | statp->nsaddr.sin_port = htons(NAMESERVER_PORT); |
363 | statp->nscount = 1; |
364 | } |
365 | if (statp->defdname[0] == 0 && |
366 | __gethostname(buf, sizeof(statp->defdname) - 1) == 0 && |
367 | (cp = strchr(buf, '.')) != NULL) |
368 | strcpy(statp->defdname, cp + 1); |
369 | |
370 | /* find components of local domain that might be searched */ |
371 | if (havesearch == 0) { |
372 | pp = statp->dnsrch; |
373 | *pp++ = statp->defdname; |
374 | *pp = NULL; |
375 | |
376 | } |
377 | |
378 | if ((cp = getenv("RES_OPTIONS" )) != NULL) |
379 | res_setoptions(statp, cp, "env" ); |
380 | statp->options |= RES_INIT; |
381 | return (0); |
382 | } |
383 | |
384 | static void |
385 | internal_function |
386 | res_setoptions(res_state statp, const char *options, const char *source) { |
387 | const char *cp = options; |
388 | int i; |
389 | |
390 | #ifdef DEBUG |
391 | if (statp->options & RES_DEBUG) |
392 | printf(";; res_setoptions(\"%s\", \"%s\")...\n" , |
393 | options, source); |
394 | #endif |
395 | while (*cp) { |
396 | /* skip leading and inner runs of spaces */ |
397 | while (*cp == ' ' || *cp == '\t') |
398 | cp++; |
399 | /* search for and process individual options */ |
400 | if (!strncmp(cp, "ndots:" , sizeof("ndots:" ) - 1)) { |
401 | i = atoi(cp + sizeof("ndots:" ) - 1); |
402 | if (i <= RES_MAXNDOTS) |
403 | statp->ndots = i; |
404 | else |
405 | statp->ndots = RES_MAXNDOTS; |
406 | #ifdef DEBUG |
407 | if (statp->options & RES_DEBUG) |
408 | printf(";;\tndots=%d\n" , statp->ndots); |
409 | #endif |
410 | } else if (!strncmp(cp, "timeout:" , sizeof("timeout:" ) - 1)) { |
411 | i = atoi(cp + sizeof("timeout:" ) - 1); |
412 | if (i <= RES_MAXRETRANS) |
413 | statp->retrans = i; |
414 | else |
415 | statp->retrans = RES_MAXRETRANS; |
416 | } else if (!strncmp(cp, "attempts:" , sizeof("attempts:" ) - 1)){ |
417 | i = atoi(cp + sizeof("attempts:" ) - 1); |
418 | if (i <= RES_MAXRETRY) |
419 | statp->retry = i; |
420 | else |
421 | statp->retry = RES_MAXRETRY; |
422 | } else if (!strncmp(cp, "debug" , sizeof("debug" ) - 1)) { |
423 | #ifdef DEBUG |
424 | if (!(statp->options & RES_DEBUG)) { |
425 | printf(";; res_setoptions(\"%s\", \"%s\")..\n" , |
426 | options, source); |
427 | statp->options |= RES_DEBUG; |
428 | } |
429 | printf(";;\tdebug\n" ); |
430 | #endif |
431 | } else { |
432 | static const struct |
433 | { |
434 | char str[22]; |
435 | uint8_t len; |
436 | uint8_t clear; |
437 | unsigned long int flag; |
438 | } options[] = { |
439 | #define STRnLEN(str) str, sizeof (str) - 1 |
440 | { STRnLEN ("inet6" ), 0, DEPRECATED_RES_USE_INET6 }, |
441 | { STRnLEN ("rotate" ), 0, RES_ROTATE }, |
442 | { STRnLEN ("edns0" ), 0, RES_USE_EDNS0 }, |
443 | { STRnLEN ("single-request-reopen" ), 0, RES_SNGLKUPREOP }, |
444 | { STRnLEN ("single-request" ), 0, RES_SNGLKUP }, |
445 | { STRnLEN ("no_tld_query" ), 0, RES_NOTLDQUERY }, |
446 | { STRnLEN ("no-tld-query" ), 0, RES_NOTLDQUERY }, |
447 | { STRnLEN ("use-vc" ), 0, RES_USEVC } |
448 | }; |
449 | #define noptions (sizeof (options) / sizeof (options[0])) |
450 | int i; |
451 | for (i = 0; i < noptions; ++i) |
452 | if (strncmp (cp, options[i].str, options[i].len) == 0) |
453 | { |
454 | if (options[i].clear) |
455 | statp->options &= options[i].flag; |
456 | else |
457 | statp->options |= options[i].flag; |
458 | break; |
459 | } |
460 | if (i == noptions) { |
461 | /* XXX - print a warning here? */ |
462 | } |
463 | } |
464 | /* skip to next run of spaces */ |
465 | while (*cp && *cp != ' ' && *cp != '\t') |
466 | cp++; |
467 | } |
468 | } |
469 | |
470 | /* XXX - should really support CIDR which means explicit masks always. */ |
471 | /* XXX - should really use system's version of this */ |
472 | static u_int32_t |
473 | net_mask (struct in_addr in) |
474 | { |
475 | u_int32_t i = ntohl(in.s_addr); |
476 | |
477 | if (IN_CLASSA(i)) |
478 | return (htonl(IN_CLASSA_NET)); |
479 | else if (IN_CLASSB(i)) |
480 | return (htonl(IN_CLASSB_NET)); |
481 | return (htonl(IN_CLASSC_NET)); |
482 | } |
483 | |
484 | u_int |
485 | res_randomid(void) { |
486 | return 0xffff & __getpid(); |
487 | } |
488 | libc_hidden_def (__res_randomid) |
489 | |
490 | |
491 | /* |
492 | * This routine is for closing the socket if a virtual circuit is used and |
493 | * the program wants to close it. This provides support for endhostent() |
494 | * which expects to close the socket. |
495 | * |
496 | * This routine is not expected to be user visible. |
497 | */ |
498 | void |
499 | __res_iclose(res_state statp, bool free_addr) { |
500 | int ns; |
501 | |
502 | if (statp->_vcsock >= 0) { |
503 | close_not_cancel_no_status(statp->_vcsock); |
504 | statp->_vcsock = -1; |
505 | statp->_flags &= ~(RES_F_VC | RES_F_CONN); |
506 | } |
507 | for (ns = 0; ns < statp->nscount; ns++) |
508 | if (statp->_u._ext.nsaddrs[ns]) { |
509 | if (statp->_u._ext.nssocks[ns] != -1) { |
510 | close_not_cancel_no_status(statp->_u._ext.nssocks[ns]); |
511 | statp->_u._ext.nssocks[ns] = -1; |
512 | } |
513 | if (free_addr) { |
514 | free (statp->_u._ext.nsaddrs[ns]); |
515 | statp->_u._ext.nsaddrs[ns] = NULL; |
516 | } |
517 | } |
518 | } |
519 | libc_hidden_def (__res_iclose) |
520 | |
521 | void |
522 | res_nclose(res_state statp) |
523 | { |
524 | __res_iclose (statp, true); |
525 | } |
526 | libc_hidden_def (__res_nclose) |
527 | |
528 | /* This is called when a thread is exiting to free resources held in _res. */ |
529 | static void __attribute__ ((section ("__libc_thread_freeres_fn" ))) |
530 | res_thread_freeres (void) |
531 | { |
532 | if (_res.nscount == 0) |
533 | /* Never called res_ninit. */ |
534 | return; |
535 | |
536 | __res_iclose (&_res, true); /* Close any VC sockets. */ |
537 | |
538 | /* Make sure we do a full re-initialization the next time. */ |
539 | _res.options = 0; |
540 | } |
541 | text_set_element (__libc_thread_subfreeres, res_thread_freeres); |
542 | text_set_element (__libc_subfreeres, res_thread_freeres); |
543 | |