]>
Commit | Line | Data |
---|---|---|
e9db92d3 CD |
1 | /* Copyright (C) 2016 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. | |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Lesser General Public | |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Lesser General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Lesser General Public | |
15 | License along with the GNU C Library; if not, see | |
16 | <http://www.gnu.org/licenses/>. */ | |
17 | ||
28f540f4 | 18 | /* |
28f540f4 RM |
19 | * Copyright (c) 1985, 1989, 1993 |
20 | * The Regents of the University of California. All rights reserved. | |
e62b2105 | 21 | * |
28f540f4 RM |
22 | * Redistribution and use in source and binary forms, with or without |
23 | * modification, are permitted provided that the following conditions | |
24 | * are met: | |
25 | * 1. Redistributions of source code must retain the above copyright | |
26 | * notice, this list of conditions and the following disclaimer. | |
27 | * 2. Redistributions in binary form must reproduce the above copyright | |
28 | * notice, this list of conditions and the following disclaimer in the | |
29 | * documentation and/or other materials provided with the distribution. | |
28f540f4 RM |
30 | * 4. Neither the name of the University nor the names of its contributors |
31 | * may be used to endorse or promote products derived from this software | |
32 | * without specific prior written permission. | |
e62b2105 | 33 | * |
28f540f4 RM |
34 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
35 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
36 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
37 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
38 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
39 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
40 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
41 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
42 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
43 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
44 | * SUCH DAMAGE. | |
b43b13ac UD |
45 | */ |
46 | ||
47 | /* | |
28f540f4 | 48 | * Portions Copyright (c) 1993 by Digital Equipment Corporation. |
e62b2105 | 49 | * |
28f540f4 RM |
50 | * Permission to use, copy, modify, and distribute this software for any |
51 | * purpose with or without fee is hereby granted, provided that the above | |
52 | * copyright notice and this permission notice appear in all copies, and that | |
53 | * the name of Digital Equipment Corporation not be used in advertising or | |
54 | * publicity pertaining to distribution of the document or software without | |
55 | * specific, written prior permission. | |
e62b2105 | 56 | * |
28f540f4 RM |
57 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL |
58 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES | |
59 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT | |
60 | * CORPORATION 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. | |
b43b13ac UD |
65 | */ |
66 | ||
67 | /* | |
68 | * Portions Copyright (c) 1996-1999 by Internet Software Consortium. | |
69 | * | |
70 | * Permission to use, copy, modify, and distribute this software for any | |
71 | * purpose with or without fee is hereby granted, provided that the above | |
72 | * copyright notice and this permission notice appear in all copies. | |
73 | * | |
74 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
75 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
76 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
77 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
78 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
79 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
80 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
81 | * SOFTWARE. | |
28f540f4 RM |
82 | */ |
83 | ||
28f540f4 RM |
84 | /* |
85 | * Send query to name server and wait for reply. | |
86 | */ | |
87 | ||
17a10319 | 88 | #include <assert.h> |
df21c858 | 89 | #include <sys/types.h> |
28f540f4 RM |
90 | #include <sys/param.h> |
91 | #include <sys/time.h> | |
92 | #include <sys/socket.h> | |
93 | #include <sys/uio.h> | |
e685e07d | 94 | #include <sys/poll.h> |
b43b13ac | 95 | |
28f540f4 RM |
96 | #include <netinet/in.h> |
97 | #include <arpa/nameser.h> | |
98 | #include <arpa/inet.h> | |
0420d888 | 99 | #include <sys/ioctl.h> |
28f540f4 | 100 | |
28f540f4 | 101 | #include <errno.h> |
f433b06b | 102 | #include <fcntl.h> |
b43b13ac | 103 | #include <netdb.h> |
28f540f4 | 104 | #include <resolv.h> |
b43b13ac UD |
105 | #include <signal.h> |
106 | #include <stdio.h> | |
107 | #include <stdlib.h> | |
108 | #include <string.h> | |
109 | #include <unistd.h> | |
9744268c | 110 | #include <kernel-features.h> |
48e435cd | 111 | #include <libc-internal.h> |
b43b13ac | 112 | |
0420d888 UD |
113 | #if PACKETSZ > 65536 |
114 | #define MAXPACKET PACKETSZ | |
115 | #else | |
116 | #define MAXPACKET 65536 | |
117 | #endif | |
118 | ||
e685e07d | 119 | /* From ev_streams.c. */ |
e62b2105 | 120 | |
25337753 UD |
121 | static inline void |
122 | __attribute ((always_inline)) | |
123 | evConsIovec(void *buf, size_t cnt, struct iovec *vec) { | |
124 | memset(vec, 0xf5, sizeof (*vec)); | |
125 | vec->iov_base = buf; | |
126 | vec->iov_len = cnt; | |
e685e07d | 127 | } |
28f540f4 | 128 | |
e685e07d | 129 | /* From ev_timers.c. */ |
30f9ca19 | 130 | |
b43b13ac | 131 | #define BILLION 1000000000 |
e685e07d | 132 | |
25337753 UD |
133 | static inline void |
134 | evConsTime(struct timespec *res, time_t sec, long nsec) { | |
135 | res->tv_sec = sec; | |
136 | res->tv_nsec = nsec; | |
b43b13ac | 137 | } |
28f540f4 | 138 | |
25337753 UD |
139 | static inline void |
140 | evAddTime(struct timespec *res, const struct timespec *addend1, | |
141 | const struct timespec *addend2) { | |
142 | res->tv_sec = addend1->tv_sec + addend2->tv_sec; | |
143 | res->tv_nsec = addend1->tv_nsec + addend2->tv_nsec; | |
144 | if (res->tv_nsec >= BILLION) { | |
145 | res->tv_sec++; | |
146 | res->tv_nsec -= BILLION; | |
b43b13ac | 147 | } |
b43b13ac UD |
148 | } |
149 | ||
25337753 UD |
150 | static inline void |
151 | evSubTime(struct timespec *res, const struct timespec *minuend, | |
152 | const struct timespec *subtrahend) { | |
153 | res->tv_sec = minuend->tv_sec - subtrahend->tv_sec; | |
154 | if (minuend->tv_nsec >= subtrahend->tv_nsec) | |
155 | res->tv_nsec = minuend->tv_nsec - subtrahend->tv_nsec; | |
b43b13ac | 156 | else { |
25337753 UD |
157 | res->tv_nsec = (BILLION |
158 | - subtrahend->tv_nsec + minuend->tv_nsec); | |
159 | res->tv_sec--; | |
b43b13ac | 160 | } |
b43b13ac UD |
161 | } |
162 | ||
f1d70dad | 163 | static int |
b43b13ac UD |
164 | evCmpTime(struct timespec a, struct timespec b) { |
165 | long x = a.tv_sec - b.tv_sec; | |
166 | ||
167 | if (x == 0L) | |
168 | x = a.tv_nsec - b.tv_nsec; | |
169 | return (x < 0L ? (-1) : x > 0L ? (1) : (0)); | |
170 | } | |
171 | ||
f1d70dad | 172 | static void |
25337753 | 173 | evNowTime(struct timespec *res) { |
b43b13ac UD |
174 | struct timeval now; |
175 | ||
176 | if (gettimeofday(&now, NULL) < 0) | |
25337753 UD |
177 | evConsTime(res, 0, 0); |
178 | else | |
179 | TIMEVAL_TO_TIMESPEC (&now, res); | |
b43b13ac | 180 | } |
b43b13ac | 181 | |
28f540f4 | 182 | |
e685e07d UD |
183 | /* Options. Leave them on. */ |
184 | /* #undef DEBUG */ | |
185 | #include "res_debug.h" | |
b43b13ac | 186 | |
e685e07d | 187 | #define EXT(res) ((res)->_u._ext) |
28f540f4 | 188 | |
e685e07d UD |
189 | /* Forward. */ |
190 | ||
2212c142 | 191 | static struct sockaddr *get_nsaddr (res_state, int); |
e685e07d | 192 | static int send_vc(res_state, const u_char *, int, |
1eb946b9 UD |
193 | const u_char *, int, |
194 | u_char **, int *, int *, int, u_char **, | |
ab09bf61 | 195 | u_char **, int *, int *, int *); |
e685e07d | 196 | static int send_dg(res_state, const u_char *, int, |
1eb946b9 | 197 | const u_char *, int, |
0420d888 | 198 | u_char **, int *, int *, int, |
1eb946b9 | 199 | int *, int *, u_char **, |
ab09bf61 | 200 | u_char **, int *, int *, int *); |
e685e07d UD |
201 | #ifdef DEBUG |
202 | static void Aerror(const res_state, FILE *, const char *, int, | |
020a9a23 | 203 | const struct sockaddr *); |
e685e07d UD |
204 | static void Perror(const res_state, FILE *, const char *, int); |
205 | #endif | |
438e8239 | 206 | static int sock_eq(struct sockaddr_in6 *, struct sockaddr_in6 *); |
e685e07d | 207 | |
e685e07d UD |
208 | /* Public. */ |
209 | ||
28f540f4 RM |
210 | /* int |
211 | * res_isourserver(ina) | |
212 | * looks up "ina" in _res.ns_addr_list[] | |
213 | * returns: | |
214 | * 0 : not found | |
215 | * >0 : found | |
216 | * author: | |
217 | * paul vixie, 29may94 | |
218 | */ | |
219 | int | |
438e8239 | 220 | res_ourserver_p(const res_state statp, const struct sockaddr_in6 *inp) |
438e8239 | 221 | { |
b43b13ac | 222 | int ns; |
28f540f4 | 223 | |
3a85895f PB |
224 | if (inp->sin6_family == AF_INET) { |
225 | struct sockaddr_in *in4p = (struct sockaddr_in *) inp; | |
e62b2105 UD |
226 | in_port_t port = in4p->sin_port; |
227 | in_addr_t addr = in4p->sin_addr.s_addr; | |
438e8239 | 228 | |
2212c142 | 229 | for (ns = 0; ns < statp->nscount; ns++) { |
3a85895f | 230 | const struct sockaddr_in *srv = |
2212c142 | 231 | (struct sockaddr_in *) get_nsaddr (statp, ns); |
438e8239 | 232 | |
2212c142 | 233 | if ((srv->sin_family == AF_INET) && |
3a85895f PB |
234 | (srv->sin_port == port) && |
235 | (srv->sin_addr.s_addr == INADDR_ANY || | |
236 | srv->sin_addr.s_addr == addr)) | |
237 | return (1); | |
238 | } | |
239 | } else if (inp->sin6_family == AF_INET6) { | |
2212c142 AS |
240 | for (ns = 0; ns < statp->nscount; ns++) { |
241 | const struct sockaddr_in6 *srv | |
242 | = (struct sockaddr_in6 *) get_nsaddr (statp, ns); | |
243 | if ((srv->sin6_family == AF_INET6) && | |
3a85895f PB |
244 | (srv->sin6_port == inp->sin6_port) && |
245 | !(memcmp(&srv->sin6_addr, &in6addr_any, | |
246 | sizeof (struct in6_addr)) && | |
247 | memcmp(&srv->sin6_addr, &inp->sin6_addr, | |
248 | sizeof (struct in6_addr)))) | |
249 | return (1); | |
250 | } | |
251 | } | |
b43b13ac | 252 | return (0); |
28f540f4 RM |
253 | } |
254 | ||
255 | /* int | |
256 | * res_nameinquery(name, type, class, buf, eom) | |
257 | * look for (name,type,class) in the query section of packet (buf,eom) | |
66715f83 | 258 | * requires: |
b43b13ac | 259 | * buf + HFIXEDSZ <= eom |
28f540f4 RM |
260 | * returns: |
261 | * -1 : format error | |
262 | * 0 : not found | |
263 | * >0 : found | |
264 | * author: | |
265 | * paul vixie, 29may94 | |
266 | */ | |
267 | int | |
b43b13ac UD |
268 | res_nameinquery(const char *name, int type, int class, |
269 | const u_char *buf, const u_char *eom) | |
28f540f4 | 270 | { |
b43b13ac | 271 | const u_char *cp = buf + HFIXEDSZ; |
28f540f4 RM |
272 | int qdcount = ntohs(((HEADER*)buf)->qdcount); |
273 | ||
274 | while (qdcount-- > 0) { | |
275 | char tname[MAXDNAME+1]; | |
b43b13ac | 276 | int n, ttype, tclass; |
28f540f4 RM |
277 | |
278 | n = dn_expand(buf, eom, cp, tname, sizeof tname); | |
279 | if (n < 0) | |
280 | return (-1); | |
281 | cp += n; | |
66715f83 UD |
282 | if (cp + 2 * INT16SZ > eom) |
283 | return (-1); | |
697e1628 UD |
284 | NS_GET16(ttype, cp); |
285 | NS_GET16(tclass, cp); | |
b43b13ac UD |
286 | if (ttype == type && tclass == class && |
287 | ns_samename(tname, name) == 1) | |
28f540f4 RM |
288 | return (1); |
289 | } | |
290 | return (0); | |
291 | } | |
6f9d8e68 | 292 | libresolv_hidden_def (res_nameinquery) |
28f540f4 RM |
293 | |
294 | /* int | |
295 | * res_queriesmatch(buf1, eom1, buf2, eom2) | |
296 | * is there a 1:1 mapping of (name,type,class) | |
297 | * in (buf1,eom1) and (buf2,eom2)? | |
298 | * returns: | |
299 | * -1 : format error | |
300 | * 0 : not a 1:1 mapping | |
301 | * >0 : is a 1:1 mapping | |
302 | * author: | |
303 | * paul vixie, 29may94 | |
304 | */ | |
305 | int | |
b43b13ac UD |
306 | res_queriesmatch(const u_char *buf1, const u_char *eom1, |
307 | const u_char *buf2, const u_char *eom2) | |
28f540f4 | 308 | { |
66715f83 UD |
309 | if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2) |
310 | return (-1); | |
311 | ||
b43b13ac UD |
312 | /* |
313 | * Only header section present in replies to | |
314 | * dynamic update packets. | |
315 | */ | |
e685e07d UD |
316 | if ((((HEADER *)buf1)->opcode == ns_o_update) && |
317 | (((HEADER *)buf2)->opcode == ns_o_update)) | |
b43b13ac UD |
318 | return (1); |
319 | ||
697e1628 | 320 | /* Note that we initially do not convert QDCOUNT to the host byte |
8e45b1ac | 321 | order. We can compare it with the second buffer's QDCOUNT |
697e1628 UD |
322 | value without doing this. */ |
323 | int qdcount = ((HEADER*)buf1)->qdcount; | |
324 | if (qdcount != ((HEADER*)buf2)->qdcount) | |
28f540f4 | 325 | return (0); |
697e1628 UD |
326 | |
327 | qdcount = htons (qdcount); | |
328 | const u_char *cp = buf1 + HFIXEDSZ; | |
329 | ||
28f540f4 RM |
330 | while (qdcount-- > 0) { |
331 | char tname[MAXDNAME+1]; | |
b43b13ac | 332 | int n, ttype, tclass; |
28f540f4 RM |
333 | |
334 | n = dn_expand(buf1, eom1, cp, tname, sizeof tname); | |
335 | if (n < 0) | |
336 | return (-1); | |
337 | cp += n; | |
66715f83 UD |
338 | if (cp + 2 * INT16SZ > eom1) |
339 | return (-1); | |
697e1628 UD |
340 | NS_GET16(ttype, cp); |
341 | NS_GET16(tclass, cp); | |
28f540f4 RM |
342 | if (!res_nameinquery(tname, ttype, tclass, buf2, eom2)) |
343 | return (0); | |
344 | } | |
345 | return (1); | |
346 | } | |
6f9d8e68 | 347 | libresolv_hidden_def (res_queriesmatch) |
28f540f4 RM |
348 | |
349 | int | |
0420d888 | 350 | __libc_res_nsend(res_state statp, const u_char *buf, int buflen, |
1eb946b9 UD |
351 | const u_char *buf2, int buflen2, |
352 | u_char *ans, int anssiz, u_char **ansp, u_char **ansp2, | |
ab09bf61 | 353 | int *nansp2, int *resplen2, int *ansp2_malloced) |
28f540f4 | 354 | { |
b7da31a1 | 355 | int gotsomewhere, terrno, try, v_circuit, resplen, ns, n; |
28f540f4 | 356 | |
e685e07d UD |
357 | if (statp->nscount == 0) { |
358 | __set_errno (ESRCH); | |
359 | return (-1); | |
360 | } | |
0420d888 | 361 | |
1eb946b9 | 362 | if (anssiz < (buf2 == NULL ? 1 : 2) * HFIXEDSZ) { |
66715f83 UD |
363 | __set_errno (EINVAL); |
364 | return (-1); | |
365 | } | |
0420d888 | 366 | |
b43b13ac | 367 | DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY), |
3d61b63c | 368 | (stdout, ";; res_send()\n"), buf, buflen); |
1eb946b9 UD |
369 | v_circuit = ((statp->options & RES_USEVC) |
370 | || buflen > PACKETSZ | |
371 | || buflen2 > PACKETSZ); | |
28f540f4 | 372 | gotsomewhere = 0; |
28f540f4 | 373 | terrno = ETIMEDOUT; |
28f540f4 | 374 | |
b43b13ac | 375 | /* |
e685e07d UD |
376 | * If the ns_addr_list in the resolver context has changed, then |
377 | * invalidate our cached copy and the associated timing data. | |
b43b13ac | 378 | */ |
2212c142 | 379 | if (EXT(statp).nscount != 0) { |
e685e07d UD |
380 | int needclose = 0; |
381 | ||
382 | if (EXT(statp).nscount != statp->nscount) | |
383 | needclose++; | |
384 | else | |
2212c142 AS |
385 | for (ns = 0; ns < statp->nscount; ns++) { |
386 | if (statp->nsaddr_list[ns].sin_family != 0 | |
b64e1566 | 387 | && !sock_eq((struct sockaddr_in6 *) |
2212c142 | 388 | &statp->nsaddr_list[ns], |
b64e1566 | 389 | EXT(statp).nsaddrs[ns])) |
438e8239 | 390 | { |
e685e07d UD |
391 | needclose++; |
392 | break; | |
393 | } | |
b64e1566 | 394 | } |
2212c142 | 395 | if (needclose) { |
cb07f6f6 | 396 | __res_iclose(statp, false); |
2212c142 AS |
397 | EXT(statp).nscount = 0; |
398 | } | |
e685e07d UD |
399 | } |
400 | ||
401 | /* | |
402 | * Maybe initialize our private copy of the ns_addr_list. | |
403 | */ | |
2212c142 AS |
404 | if (EXT(statp).nscount == 0) { |
405 | for (ns = 0; ns < statp->nscount; ns++) { | |
406 | EXT(statp).nssocks[ns] = -1; | |
407 | if (statp->nsaddr_list[ns].sin_family == 0) | |
408 | continue; | |
409 | if (EXT(statp).nsaddrs[ns] == NULL) | |
410 | EXT(statp).nsaddrs[ns] = | |
438e8239 | 411 | malloc(sizeof (struct sockaddr_in6)); |
2212c142 AS |
412 | if (EXT(statp).nsaddrs[ns] != NULL) |
413 | memset (mempcpy(EXT(statp).nsaddrs[ns], | |
cabba934 | 414 | &statp->nsaddr_list[ns], |
0f8f993c UD |
415 | sizeof (struct sockaddr_in)), |
416 | '\0', | |
417 | sizeof (struct sockaddr_in6) | |
418 | - sizeof (struct sockaddr_in)); | |
b64e1566 | 419 | } |
2212c142 | 420 | EXT(statp).nscount = statp->nscount; |
e685e07d UD |
421 | } |
422 | ||
423 | /* | |
424 | * Some resolvers want to even out the load on their nameservers. | |
425 | * Note that RES_BLAST overrides RES_ROTATE. | |
426 | */ | |
bbe989ee | 427 | if (__builtin_expect ((statp->options & RES_ROTATE) != 0, 0)) { |
2212c142 AS |
428 | struct sockaddr_in ina; |
429 | struct sockaddr_in6 *inp; | |
430 | int lastns = statp->nscount - 1; | |
431 | int fd; | |
432 | ||
433 | inp = EXT(statp).nsaddrs[0]; | |
434 | ina = statp->nsaddr_list[0]; | |
435 | fd = EXT(statp).nssocks[0]; | |
436 | for (ns = 0; ns < lastns; ns++) { | |
437 | EXT(statp).nsaddrs[ns] = EXT(statp).nsaddrs[ns + 1]; | |
438 | statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1]; | |
439 | EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1]; | |
b64e1566 | 440 | } |
2212c142 AS |
441 | EXT(statp).nsaddrs[lastns] = inp; |
442 | statp->nsaddr_list[lastns] = ina; | |
443 | EXT(statp).nssocks[lastns] = fd; | |
b43b13ac | 444 | } |
30f9ca19 | 445 | |
28f540f4 | 446 | /* |
e685e07d | 447 | * Send request, RETRY times, or until successful. |
28f540f4 | 448 | */ |
b43b13ac | 449 | for (try = 0; try < statp->retry; try++) { |
2212c142 | 450 | for (ns = 0; ns < statp->nscount; ns++) |
438e8239 | 451 | { |
a092b645 YD |
452 | #ifdef DEBUG |
453 | char tmpbuf[40]; | |
2212c142 AS |
454 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
455 | #endif | |
438e8239 | 456 | |
1eb946b9 | 457 | same_ns: |
020a9a23 UD |
458 | Dprint(statp->options & RES_DEBUG, |
459 | (stdout, ";; Querying server (# %d) address = %s\n", | |
2212c142 AS |
460 | ns + 1, inet_ntop(nsap->sa_family, |
461 | (nsap->sa_family == AF_INET6 | |
f2b3078e MS |
462 | ? (void *) &((struct sockaddr_in6 *) nsap)->sin6_addr |
463 | : (void *) &((struct sockaddr_in *) nsap)->sin_addr), | |
020a9a23 | 464 | tmpbuf, sizeof (tmpbuf)))); |
28f540f4 | 465 | |
a1ffb40e | 466 | if (__glibc_unlikely (v_circuit)) { |
b43b13ac UD |
467 | /* Use VC; at most one attempt per server. */ |
468 | try = statp->retry; | |
1eb946b9 UD |
469 | n = send_vc(statp, buf, buflen, buf2, buflen2, |
470 | &ans, &anssiz, &terrno, | |
ab09bf61 AS |
471 | ns, ansp, ansp2, nansp2, resplen2, |
472 | ansp2_malloced); | |
e685e07d UD |
473 | if (n < 0) |
474 | return (-1); | |
57912a71 | 475 | if (n == 0 && (buf2 == NULL || *resplen2 == 0)) |
28f540f4 | 476 | goto next_ns; |
28f540f4 | 477 | } else { |
e685e07d | 478 | /* Use datagrams. */ |
1eb946b9 UD |
479 | n = send_dg(statp, buf, buflen, buf2, buflen2, |
480 | &ans, &anssiz, &terrno, | |
481 | ns, &v_circuit, &gotsomewhere, ansp, | |
ab09bf61 | 482 | ansp2, nansp2, resplen2, ansp2_malloced); |
e685e07d UD |
483 | if (n < 0) |
484 | return (-1); | |
57912a71 | 485 | if (n == 0 && (buf2 == NULL || *resplen2 == 0)) |
b43b13ac | 486 | goto next_ns; |
e685e07d | 487 | if (v_circuit) |
1eb946b9 | 488 | // XXX Check whether both requests failed or |
b7da31a1 | 489 | // XXX whether one has been answered successfully |
28f540f4 | 490 | goto same_ns; |
e685e07d UD |
491 | } |
492 | ||
1eb946b9 UD |
493 | resplen = n; |
494 | ||
b43b13ac UD |
495 | Dprint((statp->options & RES_DEBUG) || |
496 | ((statp->pfcode & RES_PRF_REPLY) && | |
497 | (statp->pfcode & RES_PRF_HEAD1)), | |
a4219bc4 | 498 | (stdout, ";; got answer:\n")); |
e685e07d | 499 | |
b43b13ac UD |
500 | DprintQ((statp->options & RES_DEBUG) || |
501 | (statp->pfcode & RES_PRF_REPLY), | |
020a9a23 | 502 | (stdout, "%s", ""), |
e685e07d | 503 | ans, (resplen > anssiz) ? anssiz : resplen); |
a092b645 | 504 | if (buf2 != NULL) { |
1eb946b9 UD |
505 | DprintQ((statp->options & RES_DEBUG) || |
506 | (statp->pfcode & RES_PRF_REPLY), | |
507 | (stdout, "%s", ""), | |
b7da31a1 | 508 | *ansp2, (*resplen2 > *nansp2) ? *nansp2 : *resplen2); |
a092b645 | 509 | } |
e685e07d | 510 | |
28f540f4 | 511 | /* |
28f540f4 RM |
512 | * If we have temporarily opened a virtual circuit, |
513 | * or if we haven't been asked to keep a socket open, | |
514 | * close the socket. | |
515 | */ | |
e685e07d UD |
516 | if ((v_circuit && (statp->options & RES_USEVC) == 0) || |
517 | (statp->options & RES_STAYOPEN) == 0) { | |
cb07f6f6 | 518 | __res_iclose(statp, false); |
28f540f4 | 519 | } |
b43b13ac UD |
520 | return (resplen); |
521 | next_ns: ; | |
28f540f4 RM |
522 | } /*foreach ns*/ |
523 | } /*foreach retry*/ | |
cb07f6f6 | 524 | __res_iclose(statp, false); |
7ef90c15 | 525 | if (!v_circuit) { |
28f540f4 | 526 | if (!gotsomewhere) |
b43b13ac | 527 | __set_errno (ECONNREFUSED); /* no nameservers found */ |
28f540f4 | 528 | else |
b43b13ac | 529 | __set_errno (ETIMEDOUT); /* no answer obtained */ |
7ef90c15 | 530 | } else |
c4029823 | 531 | __set_errno (terrno); |
b43b13ac | 532 | return (-1); |
28f540f4 RM |
533 | } |
534 | ||
0420d888 UD |
535 | int |
536 | res_nsend(res_state statp, | |
537 | const u_char *buf, int buflen, u_char *ans, int anssiz) | |
538 | { | |
1eb946b9 | 539 | return __libc_res_nsend(statp, buf, buflen, NULL, 0, ans, anssiz, |
ab09bf61 | 540 | NULL, NULL, NULL, NULL, NULL); |
0420d888 | 541 | } |
6f9d8e68 | 542 | libresolv_hidden_def (res_nsend) |
0420d888 | 543 | |
e685e07d UD |
544 | /* Private */ |
545 | ||
2212c142 AS |
546 | static struct sockaddr * |
547 | get_nsaddr (res_state statp, int n) | |
548 | { | |
549 | ||
550 | if (statp->nsaddr_list[n].sin_family == 0 && EXT(statp).nsaddrs[n] != NULL) | |
551 | /* EXT(statp).nsaddrs[n] holds an address that is larger than | |
552 | struct sockaddr, and user code did not update | |
553 | statp->nsaddr_list[n]. */ | |
554 | return (struct sockaddr *) EXT(statp).nsaddrs[n]; | |
555 | else | |
556 | /* User code updated statp->nsaddr_list[n], or statp->nsaddr_list[n] | |
557 | has the same content as EXT(statp).nsaddrs[n]. */ | |
558 | return (struct sockaddr *) (void *) &statp->nsaddr_list[n]; | |
559 | } | |
560 | ||
b66d837b FW |
561 | /* Close the resolver structure, assign zero to *RESPLEN2 if RESPLEN2 |
562 | is not NULL, and return zero. */ | |
563 | static int | |
564 | __attribute__ ((warn_unused_result)) | |
565 | close_and_return_error (res_state statp, int *resplen2) | |
566 | { | |
567 | __res_iclose(statp, false); | |
568 | if (resplen2 != NULL) | |
569 | *resplen2 = 0; | |
570 | return 0; | |
571 | } | |
572 | ||
e9db92d3 CD |
573 | /* The send_vc function is responsible for sending a DNS query over TCP |
574 | to the nameserver numbered NS from the res_state STATP i.e. | |
575 | EXT(statp).nssocks[ns]. The function supports sending both IPv4 and | |
576 | IPv6 queries at the same serially on the same socket. | |
577 | ||
578 | Please note that for TCP there is no way to disable sending both | |
579 | queries, unlike UDP, which honours RES_SNGLKUP and RES_SNGLKUPREOP | |
580 | and sends the queries serially and waits for the result after each | |
12f1ae05 | 581 | sent query. This implementation should be corrected to honour these |
e9db92d3 CD |
582 | options. |
583 | ||
584 | Please also note that for TCP we send both queries over the same | |
585 | socket one after another. This technically violates best practice | |
586 | since the server is allowed to read the first query, respond, and | |
587 | then close the socket (to service another client). If the server | |
588 | does this, then the remaining second query in the socket data buffer | |
589 | will cause the server to send the client an RST which will arrive | |
590 | asynchronously and the client's OS will likely tear down the socket | |
591 | receive buffer resulting in a potentially short read and lost | |
592 | response data. This will force the client to retry the query again, | |
593 | and this process may repeat until all servers and connection resets | |
594 | are exhausted and then the query will fail. It's not known if this | |
595 | happens with any frequency in real DNS server implementations. This | |
596 | implementation should be corrected to use two sockets by default for | |
597 | parallel queries. | |
598 | ||
599 | The query stored in BUF of BUFLEN length is sent first followed by | |
600 | the query stored in BUF2 of BUFLEN2 length. Queries are sent | |
601 | serially on the same socket. | |
602 | ||
603 | Answers to the query are stored firstly in *ANSP up to a max of | |
604 | *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP | |
605 | is non-NULL (to indicate that modifying the answer buffer is allowed) | |
606 | then malloc is used to allocate a new response buffer and ANSCP and | |
607 | ANSP will both point to the new buffer. If more than *ANSSIZP bytes | |
608 | are needed but ANSCP is NULL, then as much of the response as | |
609 | possible is read into the buffer, but the results will be truncated. | |
610 | When truncation happens because of a small answer buffer the DNS | |
611 | packets header field TC will bet set to 1, indicating a truncated | |
612 | message and the rest of the socket data will be read and discarded. | |
613 | ||
614 | Answers to the query are stored secondly in *ANSP2 up to a max of | |
615 | *ANSSIZP2 bytes, with the actual response length stored in | |
616 | *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 | |
617 | is non-NULL (required for a second query) then malloc is used to | |
618 | allocate a new response buffer, *ANSSIZP2 is set to the new buffer | |
619 | size and *ANSP2_MALLOCED is set to 1. | |
620 | ||
621 | The ANSP2_MALLOCED argument will eventually be removed as the | |
622 | change in buffer pointer can be used to detect the buffer has | |
623 | changed and that the caller should use free on the new buffer. | |
624 | ||
625 | Note that the answers may arrive in any order from the server and | |
626 | therefore the first and second answer buffers may not correspond to | |
627 | the first and second queries. | |
628 | ||
629 | It is not supported to call this function with a non-NULL ANSP2 | |
630 | but a NULL ANSCP. Put another way, you can call send_vc with a | |
631 | single unmodifiable buffer or two modifiable buffers, but no other | |
632 | combination is supported. | |
633 | ||
634 | It is the caller's responsibility to free the malloc allocated | |
635 | buffers by detecting that the pointers have changed from their | |
636 | original values i.e. *ANSCP or *ANSP2 has changed. | |
637 | ||
638 | If errors are encountered then *TERRNO is set to an appropriate | |
639 | errno value and a zero result is returned for a recoverable error, | |
640 | and a less-than zero result is returned for a non-recoverable error. | |
641 | ||
642 | If no errors are encountered then *TERRNO is left unmodified and | |
643 | a the length of the first response in bytes is returned. */ | |
e685e07d UD |
644 | static int |
645 | send_vc(res_state statp, | |
1eb946b9 UD |
646 | const u_char *buf, int buflen, const u_char *buf2, int buflen2, |
647 | u_char **ansp, int *anssizp, | |
648 | int *terrno, int ns, u_char **anscp, u_char **ansp2, int *anssizp2, | |
ab09bf61 | 649 | int *resplen2, int *ansp2_malloced) |
e685e07d UD |
650 | { |
651 | const HEADER *hp = (HEADER *) buf; | |
1eb946b9 | 652 | const HEADER *hp2 = (HEADER *) buf2; |
e9db92d3 | 653 | HEADER *anhp = (HEADER *) *ansp; |
2212c142 | 654 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
48e435cd SL |
655 | int truncating, connreset, n; |
656 | /* On some architectures compiler might emit a warning indicating | |
657 | 'resplen' may be used uninitialized. However if buf2 == NULL | |
658 | then this code won't be executed; if buf2 != NULL, then first | |
659 | time round the loop recvresp1 and recvresp2 will be 0 so this | |
660 | code won't be executed but "thisresplenp = &resplen;" followed | |
661 | by "*thisresplenp = rlen;" will be executed so that subsequent | |
662 | times round the loop resplen has been initialized. So this is | |
663 | a false-positive. | |
664 | */ | |
48e435cd | 665 | DIAG_PUSH_NEEDS_COMMENT; |
0cb9dcc8 | 666 | DIAG_IGNORE_NEEDS_COMMENT (5, "-Wmaybe-uninitialized"); |
48e435cd | 667 | int resplen; |
48e435cd | 668 | DIAG_POP_NEEDS_COMMENT; |
1eb946b9 | 669 | struct iovec iov[4]; |
e685e07d | 670 | u_short len; |
1eb946b9 | 671 | u_short len2; |
e685e07d UD |
672 | u_char *cp; |
673 | ||
674 | connreset = 0; | |
675 | same_ns: | |
676 | truncating = 0; | |
677 | ||
678 | /* Are we still talking to whom we want to talk to? */ | |
679 | if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) { | |
438e8239 | 680 | struct sockaddr_in6 peer; |
9cfe5381 | 681 | socklen_t size = sizeof peer; |
e685e07d UD |
682 | |
683 | if (getpeername(statp->_vcsock, | |
684 | (struct sockaddr *)&peer, &size) < 0 || | |
2212c142 AS |
685 | !sock_eq(&peer, (struct sockaddr_in6 *) nsap)) { |
686 | __res_iclose(statp, false); | |
e685e07d UD |
687 | statp->_flags &= ~RES_F_VC; |
688 | } | |
689 | } | |
690 | ||
691 | if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) { | |
692 | if (statp->_vcsock >= 0) | |
cb07f6f6 | 693 | __res_iclose(statp, false); |
e685e07d | 694 | |
2212c142 | 695 | statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0); |
e685e07d UD |
696 | if (statp->_vcsock < 0) { |
697 | *terrno = errno; | |
698 | Perror(statp, stderr, "socket(vc)", errno); | |
b9bdfa7c FW |
699 | if (resplen2 != NULL) |
700 | *resplen2 = 0; | |
e685e07d UD |
701 | return (-1); |
702 | } | |
703 | __set_errno (0); | |
2212c142 AS |
704 | if (connect(statp->_vcsock, nsap, |
705 | nsap->sa_family == AF_INET | |
9fc42dfd UD |
706 | ? sizeof (struct sockaddr_in) |
707 | : sizeof (struct sockaddr_in6)) < 0) { | |
e685e07d | 708 | *terrno = errno; |
2212c142 | 709 | Aerror(statp, stderr, "connect/vc", errno, nsap); |
b9bdfa7c | 710 | return close_and_return_error (statp, resplen2); |
e685e07d UD |
711 | } |
712 | statp->_flags |= RES_F_VC; | |
28f540f4 | 713 | } |
e685e07d UD |
714 | |
715 | /* | |
716 | * Send length & message | |
717 | */ | |
1eb946b9 | 718 | len = htons ((u_short) buflen); |
25337753 UD |
719 | evConsIovec(&len, INT16SZ, &iov[0]); |
720 | evConsIovec((void*)buf, buflen, &iov[1]); | |
1eb946b9 UD |
721 | int niov = 2; |
722 | ssize_t explen = INT16SZ + buflen; | |
723 | if (buf2 != NULL) { | |
724 | len2 = htons ((u_short) buflen2); | |
725 | evConsIovec(&len2, INT16SZ, &iov[2]); | |
726 | evConsIovec((void*)buf2, buflen2, &iov[3]); | |
727 | niov = 4; | |
728 | explen += INT16SZ + buflen2; | |
729 | } | |
730 | if (TEMP_FAILURE_RETRY (writev(statp->_vcsock, iov, niov)) != explen) { | |
e685e07d UD |
731 | *terrno = errno; |
732 | Perror(statp, stderr, "write failed", errno); | |
b9bdfa7c | 733 | return close_and_return_error (statp, resplen2); |
e685e07d UD |
734 | } |
735 | /* | |
736 | * Receive length & response | |
737 | */ | |
1eb946b9 | 738 | int recvresp1 = 0; |
e9db92d3 CD |
739 | /* Skip the second response if there is no second query. |
740 | To do that we mark the second response as received. */ | |
1eb946b9 | 741 | int recvresp2 = buf2 == NULL; |
b7da31a1 | 742 | uint16_t rlen16; |
e39e6946 UD |
743 | read_len: |
744 | cp = (u_char *)&rlen16; | |
b7da31a1 | 745 | len = sizeof(rlen16); |
e39e6946 | 746 | while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, cp, |
25337753 | 747 | (int)len))) > 0) { |
e685e07d UD |
748 | cp += n; |
749 | if ((len -= n) <= 0) | |
750 | break; | |
751 | } | |
752 | if (n <= 0) { | |
753 | *terrno = errno; | |
754 | Perror(statp, stderr, "read failed", errno); | |
e685e07d UD |
755 | /* |
756 | * A long running process might get its TCP | |
757 | * connection reset if the remote server was | |
758 | * restarted. Requery the server instead of | |
759 | * trying a new one. When there is only one | |
760 | * server, this means that a query might work | |
761 | * instead of failing. We only allow one reset | |
762 | * per query to prevent looping. | |
763 | */ | |
b9bdfa7c FW |
764 | if (*terrno == ECONNRESET && !connreset) |
765 | { | |
766 | __res_iclose (statp, false); | |
767 | connreset = 1; | |
768 | goto same_ns; | |
769 | } | |
770 | return close_and_return_error (statp, resplen2); | |
e685e07d | 771 | } |
b7da31a1 | 772 | int rlen = ntohs (rlen16); |
1eb946b9 UD |
773 | |
774 | int *thisanssizp; | |
775 | u_char **thisansp; | |
776 | int *thisresplenp; | |
777 | if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { | |
e9db92d3 CD |
778 | /* We have not received any responses |
779 | yet or we only have one response to | |
780 | receive. */ | |
1eb946b9 UD |
781 | thisanssizp = anssizp; |
782 | thisansp = anscp ?: ansp; | |
783 | assert (anscp != NULL || ansp2 == NULL); | |
784 | thisresplenp = &resplen; | |
785 | } else { | |
1eb946b9 UD |
786 | thisanssizp = anssizp2; |
787 | thisansp = ansp2; | |
788 | thisresplenp = resplen2; | |
789 | } | |
790 | anhp = (HEADER *) *thisansp; | |
791 | ||
b7da31a1 | 792 | *thisresplenp = rlen; |
e9db92d3 CD |
793 | /* Is the answer buffer too small? */ |
794 | if (*thisanssizp < rlen) { | |
795 | /* If the current buffer is not the the static | |
796 | user-supplied buffer then we can reallocate | |
797 | it. */ | |
798 | if (thisansp != NULL && thisansp != ansp) { | |
799 | /* Always allocate MAXPACKET, callers expect | |
800 | this specific size. */ | |
1eb946b9 | 801 | u_char *newp = malloc (MAXPACKET); |
b9bdfa7c FW |
802 | if (newp == NULL) |
803 | { | |
804 | *terrno = ENOMEM; | |
805 | return close_and_return_error (statp, resplen2); | |
806 | } | |
1eb946b9 UD |
807 | *thisanssizp = MAXPACKET; |
808 | *thisansp = newp; | |
ab09bf61 AS |
809 | if (thisansp == ansp2) |
810 | *ansp2_malloced = 1; | |
1eb946b9 | 811 | anhp = (HEADER *) newp; |
e9db92d3 CD |
812 | /* A uint16_t can't be larger than MAXPACKET |
813 | thus it's safe to allocate MAXPACKET but | |
814 | read RLEN bytes instead. */ | |
b7da31a1 | 815 | len = rlen; |
0420d888 UD |
816 | } else { |
817 | Dprint(statp->options & RES_DEBUG, | |
818 | (stdout, ";; response truncated\n") | |
819 | ); | |
820 | truncating = 1; | |
1eb946b9 | 821 | len = *thisanssizp; |
0420d888 | 822 | } |
e685e07d | 823 | } else |
b7da31a1 | 824 | len = rlen; |
1eb946b9 | 825 | |
a1ffb40e | 826 | if (__glibc_unlikely (len < HFIXEDSZ)) { |
e685e07d UD |
827 | /* |
828 | * Undersized message. | |
829 | */ | |
830 | Dprint(statp->options & RES_DEBUG, | |
831 | (stdout, ";; undersized: %d\n", len)); | |
832 | *terrno = EMSGSIZE; | |
b9bdfa7c | 833 | return close_and_return_error (statp, resplen2); |
e685e07d | 834 | } |
1eb946b9 UD |
835 | |
836 | cp = *thisansp; | |
e685e07d UD |
837 | while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){ |
838 | cp += n; | |
839 | len -= n; | |
840 | } | |
a1ffb40e | 841 | if (__glibc_unlikely (n <= 0)) { |
e685e07d UD |
842 | *terrno = errno; |
843 | Perror(statp, stderr, "read(vc)", errno); | |
b9bdfa7c | 844 | return close_and_return_error (statp, resplen2); |
e685e07d | 845 | } |
a1ffb40e | 846 | if (__glibc_unlikely (truncating)) { |
e685e07d UD |
847 | /* |
848 | * Flush rest of answer so connection stays in synch. | |
849 | */ | |
850 | anhp->tc = 1; | |
b7da31a1 | 851 | len = rlen - *thisanssizp; |
e685e07d UD |
852 | while (len != 0) { |
853 | char junk[PACKETSZ]; | |
854 | ||
855 | n = read(statp->_vcsock, junk, | |
856 | (len > sizeof junk) ? sizeof junk : len); | |
857 | if (n > 0) | |
858 | len -= n; | |
859 | else | |
860 | break; | |
861 | } | |
862 | } | |
863 | /* | |
c0c3f78a | 864 | * If the calling application has bailed out of |
e685e07d UD |
865 | * a previous call and failed to arrange to have |
866 | * the circuit closed or the server has got | |
867 | * itself confused, then drop the packet and | |
868 | * wait for the correct one. | |
869 | */ | |
1eb946b9 UD |
870 | if ((recvresp1 || hp->id != anhp->id) |
871 | && (recvresp2 || hp2->id != anhp->id)) { | |
e685e07d UD |
872 | DprintQ((statp->options & RES_DEBUG) || |
873 | (statp->pfcode & RES_PRF_REPLY), | |
874 | (stdout, ";; old answer (unexpected):\n"), | |
1eb946b9 | 875 | *thisansp, |
a092b645 | 876 | (rlen > *thisanssizp) ? *thisanssizp: rlen); |
e685e07d UD |
877 | goto read_len; |
878 | } | |
879 | ||
1eb946b9 UD |
880 | /* Mark which reply we received. */ |
881 | if (recvresp1 == 0 && hp->id == anhp->id) | |
882 | recvresp1 = 1; | |
883 | else | |
884 | recvresp2 = 1; | |
885 | /* Repeat waiting if we have a second answer to arrive. */ | |
886 | if ((recvresp1 & recvresp2) == 0) | |
887 | goto read_len; | |
888 | ||
e685e07d UD |
889 | /* |
890 | * All is well, or the error is fatal. Signal that the | |
891 | * next nameserver ought not be tried. | |
892 | */ | |
b7da31a1 | 893 | return resplen; |
28f540f4 | 894 | } |
845dcb57 | 895 | |
b43b13ac | 896 | static int |
44d20bca | 897 | reopen (res_state statp, int *terrno, int ns) |
e685e07d | 898 | { |
e685e07d | 899 | if (EXT(statp).nssocks[ns] == -1) { |
2212c142 | 900 | struct sockaddr *nsap = get_nsaddr (statp, ns); |
ace4e23f | 901 | socklen_t slen; |
44d20bca | 902 | |
438e8239 | 903 | /* only try IPv6 if IPv6 NS and if not failed before */ |
ace4e23f | 904 | if (nsap->sa_family == AF_INET6 && !statp->ipv6_unavail) { |
52fb79d6 FW |
905 | EXT(statp).nssocks[ns] |
906 | = socket(PF_INET6, SOCK_DGRAM|SOCK_NONBLOCK, 0); | |
ae1ad3ae UD |
907 | if (EXT(statp).nssocks[ns] < 0) |
908 | statp->ipv6_unavail = errno == EAFNOSUPPORT; | |
ace4e23f UD |
909 | slen = sizeof (struct sockaddr_in6); |
910 | } else if (nsap->sa_family == AF_INET) { | |
52fb79d6 FW |
911 | EXT(statp).nssocks[ns] |
912 | = socket(PF_INET, SOCK_DGRAM|SOCK_NONBLOCK, 0); | |
ace4e23f | 913 | slen = sizeof (struct sockaddr_in); |
9744268c | 914 | } |
e685e07d UD |
915 | if (EXT(statp).nssocks[ns] < 0) { |
916 | *terrno = errno; | |
917 | Perror(statp, stderr, "socket(dg)", errno); | |
918 | return (-1); | |
919 | } | |
ae1ad3ae | 920 | |
e685e07d UD |
921 | /* |
922 | * On a 4.3BSD+ machine (client and server, | |
923 | * actually), sending to a nameserver datagram | |
924 | * port with no nameserver will cause an | |
925 | * ICMP port unreachable message to be returned. | |
926 | * If our datagram socket is "connected" to the | |
927 | * server, we get an ECONNREFUSED error on the next | |
928 | * socket operation, and select returns if the | |
929 | * error message is received. We can thus detect | |
930 | * the absence of a nameserver without timing out. | |
931 | */ | |
93fe09cb CD |
932 | /* With GCC 5.3 when compiling with -Os the compiler |
933 | emits a warning that slen may be used uninitialized, | |
934 | but that is never true. Both slen and | |
935 | EXT(statp).nssocks[ns] are initialized together or | |
936 | the function return -1 before control flow reaches | |
937 | the call to connect with slen. */ | |
938 | DIAG_PUSH_NEEDS_COMMENT; | |
0cb9dcc8 | 939 | DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized"); |
ace4e23f | 940 | if (connect(EXT(statp).nssocks[ns], nsap, slen) < 0) { |
93fe09cb | 941 | DIAG_POP_NEEDS_COMMENT; |
ace4e23f | 942 | Aerror(statp, stderr, "connect(dg)", errno, nsap); |
cb07f6f6 | 943 | __res_iclose(statp, false); |
e685e07d UD |
944 | return (0); |
945 | } | |
e685e07d | 946 | } |
17a10319 | 947 | |
44d20bca UD |
948 | return 1; |
949 | } | |
950 | ||
e9db92d3 CD |
951 | /* The send_dg function is responsible for sending a DNS query over UDP |
952 | to the nameserver numbered NS from the res_state STATP i.e. | |
953 | EXT(statp).nssocks[ns]. The function supports IPv4 and IPv6 queries | |
954 | along with the ability to send the query in parallel for both stacks | |
955 | (default) or serially (RES_SINGLKUP). It also supports serial lookup | |
956 | with a close and reopen of the socket used to talk to the server | |
957 | (RES_SNGLKUPREOP) to work around broken name servers. | |
958 | ||
959 | The query stored in BUF of BUFLEN length is sent first followed by | |
960 | the query stored in BUF2 of BUFLEN2 length. Queries are sent | |
961 | in parallel (default) or serially (RES_SINGLKUP or RES_SNGLKUPREOP). | |
962 | ||
963 | Answers to the query are stored firstly in *ANSP up to a max of | |
964 | *ANSSIZP bytes. If more than *ANSSIZP bytes are needed and ANSCP | |
965 | is non-NULL (to indicate that modifying the answer buffer is allowed) | |
966 | then malloc is used to allocate a new response buffer and ANSCP and | |
967 | ANSP will both point to the new buffer. If more than *ANSSIZP bytes | |
968 | are needed but ANSCP is NULL, then as much of the response as | |
969 | possible is read into the buffer, but the results will be truncated. | |
970 | When truncation happens because of a small answer buffer the DNS | |
971 | packets header field TC will bet set to 1, indicating a truncated | |
972 | message, while the rest of the UDP packet is discarded. | |
973 | ||
974 | Answers to the query are stored secondly in *ANSP2 up to a max of | |
975 | *ANSSIZP2 bytes, with the actual response length stored in | |
976 | *RESPLEN2. If more than *ANSSIZP bytes are needed and ANSP2 | |
977 | is non-NULL (required for a second query) then malloc is used to | |
978 | allocate a new response buffer, *ANSSIZP2 is set to the new buffer | |
979 | size and *ANSP2_MALLOCED is set to 1. | |
980 | ||
981 | The ANSP2_MALLOCED argument will eventually be removed as the | |
982 | change in buffer pointer can be used to detect the buffer has | |
983 | changed and that the caller should use free on the new buffer. | |
984 | ||
985 | Note that the answers may arrive in any order from the server and | |
986 | therefore the first and second answer buffers may not correspond to | |
987 | the first and second queries. | |
988 | ||
989 | It is not supported to call this function with a non-NULL ANSP2 | |
990 | but a NULL ANSCP. Put another way, you can call send_vc with a | |
991 | single unmodifiable buffer or two modifiable buffers, but no other | |
992 | combination is supported. | |
993 | ||
994 | It is the caller's responsibility to free the malloc allocated | |
995 | buffers by detecting that the pointers have changed from their | |
996 | original values i.e. *ANSCP or *ANSP2 has changed. | |
997 | ||
998 | If an answer is truncated because of UDP datagram DNS limits then | |
999 | *V_CIRCUIT is set to 1 and the return value non-zero to indicate to | |
1000 | the caller to retry with TCP. The value *GOTSOMEWHERE is set to 1 | |
1001 | if any progress was made reading a response from the nameserver and | |
1002 | is used by the caller to distinguish between ECONNREFUSED and | |
1003 | ETIMEDOUT (the latter if *GOTSOMEWHERE is 1). | |
1004 | ||
1005 | If errors are encountered then *TERRNO is set to an appropriate | |
1006 | errno value and a zero result is returned for a recoverable error, | |
1007 | and a less-than zero result is returned for a non-recoverable error. | |
1008 | ||
1009 | If no errors are encountered then *TERRNO is left unmodified and | |
1010 | a the length of the first response in bytes is returned. */ | |
44d20bca UD |
1011 | static int |
1012 | send_dg(res_state statp, | |
1013 | const u_char *buf, int buflen, const u_char *buf2, int buflen2, | |
1014 | u_char **ansp, int *anssizp, | |
1015 | int *terrno, int ns, int *v_circuit, int *gotsomewhere, u_char **anscp, | |
ab09bf61 | 1016 | u_char **ansp2, int *anssizp2, int *resplen2, int *ansp2_malloced) |
44d20bca UD |
1017 | { |
1018 | const HEADER *hp = (HEADER *) buf; | |
1019 | const HEADER *hp2 = (HEADER *) buf2; | |
44d20bca UD |
1020 | struct timespec now, timeout, finish; |
1021 | struct pollfd pfd[1]; | |
3a85895f | 1022 | int ptimeout; |
44d20bca | 1023 | struct sockaddr_in6 from; |
75ded9bc UD |
1024 | int resplen = 0; |
1025 | int n; | |
44d20bca | 1026 | |
f433b06b UD |
1027 | /* |
1028 | * Compute time for the total operation. | |
1029 | */ | |
ae061910 | 1030 | int seconds = (statp->retrans << ns); |
f433b06b UD |
1031 | if (ns > 0) |
1032 | seconds /= statp->nscount; | |
1033 | if (seconds <= 0) | |
1034 | seconds = 1; | |
44d20bca | 1035 | bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; |
c030f70c UD |
1036 | bool single_request = (((statp->options & RES_SNGLKUP) != 0) |
1037 | | single_request_reopen); | |
ae061910 | 1038 | int save_gotsomewhere = *gotsomewhere; |
44d20bca UD |
1039 | |
1040 | int retval; | |
1041 | retry_reopen: | |
1042 | retval = reopen (statp, terrno, ns); | |
1043 | if (retval <= 0) | |
b66d837b FW |
1044 | { |
1045 | if (resplen2 != NULL) | |
1046 | *resplen2 = 0; | |
1047 | return retval; | |
1048 | } | |
ae061910 | 1049 | retry: |
f433b06b UD |
1050 | evNowTime(&now); |
1051 | evConsTime(&timeout, seconds, 0); | |
1052 | evAddTime(&finish, &now, &timeout); | |
1053 | int need_recompute = 0; | |
17a10319 | 1054 | int nwritten = 0; |
1eb946b9 | 1055 | int recvresp1 = 0; |
e9db92d3 CD |
1056 | /* Skip the second response if there is no second query. |
1057 | To do that we mark the second response as received. */ | |
1eb946b9 | 1058 | int recvresp2 = buf2 == NULL; |
17a10319 UD |
1059 | pfd[0].fd = EXT(statp).nssocks[ns]; |
1060 | pfd[0].events = POLLOUT; | |
1061 | wait: | |
1062 | if (need_recompute) { | |
8e45b1ac | 1063 | recompute_resend: |
17a10319 UD |
1064 | evNowTime(&now); |
1065 | if (evCmpTime(finish, now) <= 0) { | |
8e45b1ac UD |
1066 | poll_err_out: |
1067 | Perror(statp, stderr, "poll", errno); | |
b66d837b | 1068 | return close_and_return_error (statp, resplen2); |
17a10319 UD |
1069 | } |
1070 | evSubTime(&timeout, &finish, &now); | |
ae061910 | 1071 | need_recompute = 0; |
17a10319 | 1072 | } |
3a85895f | 1073 | /* Convert struct timespec in milliseconds. */ |
f433b06b UD |
1074 | ptimeout = timeout.tv_sec * 1000 + timeout.tv_nsec / 1000000; |
1075 | ||
17a10319 UD |
1076 | n = 0; |
1077 | if (nwritten == 0) | |
1078 | n = __poll (pfd, 1, 0); | |
a1ffb40e | 1079 | if (__glibc_unlikely (n == 0)) { |
f433b06b UD |
1080 | n = __poll (pfd, 1, ptimeout); |
1081 | need_recompute = 1; | |
1082 | } | |
f433b06b | 1083 | if (n == 0) { |
e2003883 | 1084 | Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n")); |
74b3cf22 | 1085 | if (resplen > 1 && (recvresp1 || (buf2 != NULL && recvresp2))) |
e2003883 | 1086 | { |
ae061910 UD |
1087 | /* There are quite a few broken name servers out |
1088 | there which don't handle two outstanding | |
1089 | requests from the same source. There are also | |
1090 | broken firewall settings. If we time out after | |
1091 | having received one answer switch to the mode | |
1092 | where we send the second request only once we | |
1093 | have received the first answer. */ | |
74b3cf22 UD |
1094 | if (!single_request) |
1095 | { | |
310647e9 | 1096 | statp->options |= RES_SNGLKUP; |
74b3cf22 UD |
1097 | single_request = true; |
1098 | *gotsomewhere = save_gotsomewhere; | |
1099 | goto retry; | |
1100 | } | |
44d20bca UD |
1101 | else if (!single_request_reopen) |
1102 | { | |
1103 | statp->options |= RES_SNGLKUPREOP; | |
1104 | single_request_reopen = true; | |
1105 | *gotsomewhere = save_gotsomewhere; | |
1106 | __res_iclose (statp, false); | |
1107 | goto retry_reopen; | |
1108 | } | |
74b3cf22 UD |
1109 | |
1110 | *resplen2 = 1; | |
1111 | return resplen; | |
e2003883 | 1112 | } |
5908f779 | 1113 | |
f433b06b | 1114 | *gotsomewhere = 1; |
b66d837b FW |
1115 | if (resplen2 != NULL) |
1116 | *resplen2 = 0; | |
1117 | return 0; | |
f433b06b UD |
1118 | } |
1119 | if (n < 0) { | |
8e45b1ac UD |
1120 | if (errno == EINTR) |
1121 | goto recompute_resend; | |
1122 | ||
1123 | goto poll_err_out; | |
f433b06b UD |
1124 | } |
1125 | __set_errno (0); | |
17a10319 | 1126 | if (pfd[0].revents & POLLOUT) { |
c030f70c UD |
1127 | #ifndef __ASSUME_SENDMMSG |
1128 | static int have_sendmmsg; | |
1129 | #else | |
1130 | # define have_sendmmsg 1 | |
1131 | #endif | |
1132 | if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL | |
1133 | && !single_request) | |
1134 | { | |
1135 | struct iovec iov[2]; | |
1136 | struct mmsghdr reqs[2]; | |
1137 | reqs[0].msg_hdr.msg_name = NULL; | |
1138 | reqs[0].msg_hdr.msg_namelen = 0; | |
1139 | reqs[0].msg_hdr.msg_iov = &iov[0]; | |
1140 | reqs[0].msg_hdr.msg_iovlen = 1; | |
1141 | iov[0].iov_base = (void *) buf; | |
1142 | iov[0].iov_len = buflen; | |
1143 | reqs[0].msg_hdr.msg_control = NULL; | |
1144 | reqs[0].msg_hdr.msg_controllen = 0; | |
1145 | ||
1146 | reqs[1].msg_hdr.msg_name = NULL; | |
1147 | reqs[1].msg_hdr.msg_namelen = 0; | |
1148 | reqs[1].msg_hdr.msg_iov = &iov[1]; | |
1149 | reqs[1].msg_hdr.msg_iovlen = 1; | |
1150 | iov[1].iov_base = (void *) buf2; | |
1151 | iov[1].iov_len = buflen2; | |
1152 | reqs[1].msg_hdr.msg_control = NULL; | |
1153 | reqs[1].msg_hdr.msg_controllen = 0; | |
1154 | ||
123be9de | 1155 | int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL); |
a1ffb40e | 1156 | if (__glibc_likely (ndg == 2)) |
c030f70c | 1157 | { |
966977f1 UD |
1158 | if (reqs[0].msg_len != buflen |
1159 | || reqs[1].msg_len != buflen2) | |
1160 | goto fail_sendmmsg; | |
1eb946b9 | 1161 | |
c030f70c UD |
1162 | pfd[0].events = POLLIN; |
1163 | nwritten += 2; | |
1164 | } | |
1165 | else if (ndg == 1 && reqs[0].msg_len == buflen) | |
1166 | goto just_one; | |
966977f1 | 1167 | else if (ndg < 0 && (errno == EINTR || errno == EAGAIN)) |
c030f70c UD |
1168 | goto recompute_resend; |
1169 | else | |
1170 | { | |
1171 | #ifndef __ASSUME_SENDMMSG | |
a1ffb40e | 1172 | if (__glibc_unlikely (have_sendmmsg == 0)) |
c030f70c | 1173 | { |
966977f1 | 1174 | if (ndg < 0 && errno == ENOSYS) |
c030f70c UD |
1175 | { |
1176 | have_sendmmsg = -1; | |
1177 | goto try_send; | |
1178 | } | |
1179 | have_sendmmsg = 1; | |
1180 | } | |
1181 | #endif | |
1182 | ||
966977f1 | 1183 | fail_sendmmsg: |
c030f70c | 1184 | Perror(statp, stderr, "sendmmsg", errno); |
b66d837b | 1185 | return close_and_return_error (statp, resplen2); |
c030f70c UD |
1186 | } |
1187 | } | |
1eb946b9 | 1188 | else |
c030f70c UD |
1189 | { |
1190 | ssize_t sr; | |
1191 | #ifndef __ASSUME_SENDMMSG | |
1192 | try_send: | |
1193 | #endif | |
1194 | if (nwritten != 0) | |
1195 | sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); | |
1196 | else | |
1197 | sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); | |
1198 | ||
8e6d1083 | 1199 | if (sr != (nwritten != 0 ? buflen2 : buflen)) { |
c030f70c UD |
1200 | if (errno == EINTR || errno == EAGAIN) |
1201 | goto recompute_resend; | |
1202 | Perror(statp, stderr, "send", errno); | |
b66d837b | 1203 | return close_and_return_error (statp, resplen2); |
c030f70c UD |
1204 | } |
1205 | just_one: | |
1206 | if (nwritten != 0 || buf2 == NULL || single_request) | |
1207 | pfd[0].events = POLLIN; | |
1208 | else | |
1209 | pfd[0].events = POLLIN | POLLOUT; | |
1210 | ++nwritten; | |
1211 | } | |
17a10319 | 1212 | goto wait; |
8aeb5058 | 1213 | } else if (pfd[0].revents & POLLIN) { |
1eb946b9 UD |
1214 | int *thisanssizp; |
1215 | u_char **thisansp; | |
1216 | int *thisresplenp; | |
1217 | ||
1218 | if ((recvresp1 | recvresp2) == 0 || buf2 == NULL) { | |
e9db92d3 CD |
1219 | /* We have not received any responses |
1220 | yet or we only have one response to | |
1221 | receive. */ | |
1eb946b9 UD |
1222 | thisanssizp = anssizp; |
1223 | thisansp = anscp ?: ansp; | |
1224 | assert (anscp != NULL || ansp2 == NULL); | |
1225 | thisresplenp = &resplen; | |
1226 | } else { | |
1eb946b9 UD |
1227 | thisanssizp = anssizp2; |
1228 | thisansp = ansp2; | |
1229 | thisresplenp = resplen2; | |
1230 | } | |
1231 | ||
1232 | if (*thisanssizp < MAXPACKET | |
e9db92d3 CD |
1233 | /* If the current buffer is not the the static |
1234 | user-supplied buffer then we can reallocate | |
1235 | it. */ | |
1236 | && (thisansp != NULL && thisansp != ansp) | |
c4e42566 | 1237 | #ifdef FIONREAD |
e9db92d3 | 1238 | /* Is the size too small? */ |
1eb946b9 | 1239 | && (ioctl (pfd[0].fd, FIONREAD, thisresplenp) < 0 |
c4e42566 RM |
1240 | || *thisanssizp < *thisresplenp) |
1241 | #endif | |
1242 | ) { | |
e9db92d3 CD |
1243 | /* Always allocate MAXPACKET, callers expect |
1244 | this specific size. */ | |
1eb946b9 UD |
1245 | u_char *newp = malloc (MAXPACKET); |
1246 | if (newp != NULL) { | |
e9db92d3 CD |
1247 | *thisanssizp = MAXPACKET; |
1248 | *thisansp = newp; | |
ab09bf61 AS |
1249 | if (thisansp == ansp2) |
1250 | *ansp2_malloced = 1; | |
17a10319 UD |
1251 | } |
1252 | } | |
e9db92d3 CD |
1253 | /* We could end up with truncation if anscp was NULL |
1254 | (not allowed to change caller's buffer) and the | |
1255 | response buffer size is too small. This isn't a | |
1256 | reliable way to detect truncation because the ioctl | |
1257 | may be an inaccurate report of the UDP message size. | |
1258 | Therefore we use this only to issue debug output. | |
1259 | To do truncation accurately with UDP we need | |
1260 | MSG_TRUNC which is only available on Linux. We | |
1261 | can abstract out the Linux-specific feature in the | |
1262 | future to detect truncation. */ | |
1263 | if (__glibc_unlikely (*thisanssizp < *thisresplenp)) { | |
1264 | Dprint(statp->options & RES_DEBUG, | |
1265 | (stdout, ";; response may be truncated (UDP)\n") | |
1266 | ); | |
1267 | } | |
1268 | ||
1eb946b9 UD |
1269 | HEADER *anhp = (HEADER *) *thisansp; |
1270 | socklen_t fromlen = sizeof(struct sockaddr_in6); | |
1271 | assert (sizeof(from) <= fromlen); | |
1272 | *thisresplenp = recvfrom(pfd[0].fd, (char*)*thisansp, | |
1273 | *thisanssizp, 0, | |
1274 | (struct sockaddr *)&from, &fromlen); | |
a1ffb40e | 1275 | if (__glibc_unlikely (*thisresplenp <= 0)) { |
17a10319 UD |
1276 | if (errno == EINTR || errno == EAGAIN) { |
1277 | need_recompute = 1; | |
1278 | goto wait; | |
1279 | } | |
1280 | Perror(statp, stderr, "recvfrom", errno); | |
b66d837b | 1281 | return close_and_return_error (statp, resplen2); |
17a10319 | 1282 | } |
e685e07d | 1283 | *gotsomewhere = 1; |
a1ffb40e | 1284 | if (__glibc_unlikely (*thisresplenp < HFIXEDSZ)) { |
17a10319 UD |
1285 | /* |
1286 | * Undersized message. | |
1287 | */ | |
1288 | Dprint(statp->options & RES_DEBUG, | |
1289 | (stdout, ";; undersized: %d\n", | |
a092b645 | 1290 | *thisresplenp)); |
17a10319 | 1291 | *terrno = EMSGSIZE; |
b66d837b | 1292 | return close_and_return_error (statp, resplen2); |
17a10319 | 1293 | } |
1eb946b9 UD |
1294 | if ((recvresp1 || hp->id != anhp->id) |
1295 | && (recvresp2 || hp2->id != anhp->id)) { | |
17a10319 UD |
1296 | /* |
1297 | * response from old query, ignore it. | |
1298 | * XXX - potential security hazard could | |
1299 | * be detected here. | |
1300 | */ | |
1301 | DprintQ((statp->options & RES_DEBUG) || | |
1302 | (statp->pfcode & RES_PRF_REPLY), | |
1303 | (stdout, ";; old answer:\n"), | |
94308fd0 | 1304 | *thisansp, |
a092b645 YD |
1305 | (*thisresplenp > *thisanssizp) |
1306 | ? *thisanssizp : *thisresplenp); | |
f433b06b | 1307 | goto wait; |
e685e07d | 1308 | } |
17a10319 UD |
1309 | if (!(statp->options & RES_INSECURE1) && |
1310 | !res_ourserver_p(statp, &from)) { | |
1311 | /* | |
1312 | * response from wrong server? ignore it. | |
1313 | * XXX - potential security hazard could | |
1314 | * be detected here. | |
1315 | */ | |
1316 | DprintQ((statp->options & RES_DEBUG) || | |
1317 | (statp->pfcode & RES_PRF_REPLY), | |
1318 | (stdout, ";; not our server:\n"), | |
94308fd0 | 1319 | *thisansp, |
a092b645 YD |
1320 | (*thisresplenp > *thisanssizp) |
1321 | ? *thisanssizp : *thisresplenp); | |
17a10319 | 1322 | goto wait; |
0420d888 | 1323 | } |
2bbb7d5b UD |
1324 | #ifdef RES_USE_EDNS0 |
1325 | if (anhp->rcode == FORMERR | |
1326 | && (statp->options & RES_USE_EDNS0) != 0U) { | |
1327 | /* | |
1eb946b9 | 1328 | * Do not retry if the server does not understand |
2bbb7d5b UD |
1329 | * EDNS0. The case has to be captured here, as |
1330 | * FORMERR packet do not carry query section, hence | |
1331 | * res_queriesmatch() returns 0. | |
1332 | */ | |
1333 | DprintQ(statp->options & RES_DEBUG, | |
1334 | (stdout, | |
1335 | "server rejected query with EDNS0:\n"), | |
94308fd0 | 1336 | *thisansp, |
a092b645 YD |
1337 | (*thisresplenp > *thisanssizp) |
1338 | ? *thisanssizp : *thisresplenp); | |
2bbb7d5b UD |
1339 | /* record the error */ |
1340 | statp->_flags |= RES_F_EDNS0ERR; | |
b66d837b | 1341 | return close_and_return_error (statp, resplen2); |
3a85895f | 1342 | } |
2bbb7d5b | 1343 | #endif |
1eb946b9 UD |
1344 | if (!(statp->options & RES_INSECURE2) |
1345 | && (recvresp1 || !res_queriesmatch(buf, buf + buflen, | |
1346 | *thisansp, | |
1347 | *thisansp | |
1348 | + *thisanssizp)) | |
1349 | && (recvresp2 || !res_queriesmatch(buf2, buf2 + buflen2, | |
1350 | *thisansp, | |
1351 | *thisansp | |
1352 | + *thisanssizp))) { | |
17a10319 UD |
1353 | /* |
1354 | * response contains wrong query? ignore it. | |
1355 | * XXX - potential security hazard could | |
1356 | * be detected here. | |
1357 | */ | |
1358 | DprintQ((statp->options & RES_DEBUG) || | |
1359 | (statp->pfcode & RES_PRF_REPLY), | |
1360 | (stdout, ";; wrong query name:\n"), | |
94308fd0 | 1361 | *thisansp, |
a092b645 YD |
1362 | (*thisresplenp > *thisanssizp) |
1363 | ? *thisanssizp : *thisresplenp); | |
f433b06b UD |
1364 | goto wait; |
1365 | } | |
17a10319 UD |
1366 | if (anhp->rcode == SERVFAIL || |
1367 | anhp->rcode == NOTIMP || | |
1368 | anhp->rcode == REFUSED) { | |
1369 | DprintQ(statp->options & RES_DEBUG, | |
1370 | (stdout, "server rejected query:\n"), | |
94308fd0 | 1371 | *thisansp, |
a092b645 YD |
1372 | (*thisresplenp > *thisanssizp) |
1373 | ? *thisanssizp : *thisresplenp); | |
e2003883 | 1374 | |
16b293a7 | 1375 | next_ns: |
4769ae77 UD |
1376 | if (recvresp1 || (buf2 != NULL && recvresp2)) { |
1377 | *resplen2 = 0; | |
e28b969b | 1378 | return resplen; |
4769ae77 | 1379 | } |
e2003883 UD |
1380 | if (buf2 != NULL) |
1381 | { | |
4769ae77 UD |
1382 | /* No data from the first reply. */ |
1383 | resplen = 0; | |
e2003883 | 1384 | /* We are waiting for a possible second reply. */ |
e2003883 UD |
1385 | if (hp->id == anhp->id) |
1386 | recvresp1 = 1; | |
1387 | else | |
1388 | recvresp2 = 1; | |
1389 | ||
1390 | goto wait; | |
1391 | } | |
1392 | ||
17a10319 UD |
1393 | /* don't retry if called from dig */ |
1394 | if (!statp->pfcode) | |
b66d837b FW |
1395 | return close_and_return_error (statp, resplen2); |
1396 | __res_iclose(statp, false); | |
17a10319 | 1397 | } |
359bb2ef UD |
1398 | if (anhp->rcode == NOERROR && anhp->ancount == 0 |
1399 | && anhp->aa == 0 && anhp->ra == 0 && anhp->arcount == 0) { | |
1400 | DprintQ(statp->options & RES_DEBUG, | |
1401 | (stdout, "referred query:\n"), | |
94308fd0 | 1402 | *thisansp, |
a092b645 YD |
1403 | (*thisresplenp > *thisanssizp) |
1404 | ? *thisanssizp : *thisresplenp); | |
359bb2ef UD |
1405 | goto next_ns; |
1406 | } | |
17a10319 UD |
1407 | if (!(statp->options & RES_IGNTC) && anhp->tc) { |
1408 | /* | |
1409 | * To get the rest of answer, | |
1410 | * use TCP with same server. | |
1411 | */ | |
1412 | Dprint(statp->options & RES_DEBUG, | |
1413 | (stdout, ";; truncated answer\n")); | |
1414 | *v_circuit = 1; | |
cb07f6f6 | 1415 | __res_iclose(statp, false); |
1eb946b9 UD |
1416 | // XXX if we have received one reply we could |
1417 | // XXX use it and not repeat it over TCP... | |
b66d837b FW |
1418 | if (resplen2 != NULL) |
1419 | *resplen2 = 0; | |
17a10319 UD |
1420 | return (1); |
1421 | } | |
1eb946b9 UD |
1422 | /* Mark which reply we received. */ |
1423 | if (recvresp1 == 0 && hp->id == anhp->id) | |
1424 | recvresp1 = 1; | |
1425 | else | |
1426 | recvresp2 = 1; | |
1427 | /* Repeat waiting if we have a second answer to arrive. */ | |
ae061910 | 1428 | if ((recvresp1 & recvresp2) == 0) { |
c030f70c | 1429 | if (single_request) { |
ae061910 | 1430 | pfd[0].events = POLLOUT; |
44d20bca UD |
1431 | if (single_request_reopen) { |
1432 | __res_iclose (statp, false); | |
1433 | retval = reopen (statp, terrno, ns); | |
1434 | if (retval <= 0) | |
b66d837b FW |
1435 | { |
1436 | if (resplen2 != NULL) | |
1437 | *resplen2 = 0; | |
1438 | return retval; | |
1439 | } | |
f9d2d032 | 1440 | pfd[0].fd = EXT(statp).nssocks[ns]; |
44d20bca UD |
1441 | } |
1442 | } | |
1eb946b9 | 1443 | goto wait; |
ae061910 | 1444 | } |
b66d837b FW |
1445 | /* All is well. We have received both responses (if |
1446 | two responses were requested). */ | |
17a10319 | 1447 | return (resplen); |
b66d837b FW |
1448 | } else if (pfd[0].revents & (POLLERR | POLLHUP | POLLNVAL)) |
1449 | /* Something went wrong. We can stop trying. */ | |
1450 | return close_and_return_error (statp, resplen2); | |
9cfe5381 | 1451 | else { |
4769ae77 | 1452 | /* poll should not have returned > 0 in this case. */ |
9cfe5381 RM |
1453 | abort (); |
1454 | } | |
e685e07d UD |
1455 | } |
1456 | ||
1457 | #ifdef DEBUG | |
1458 | static void | |
1459 | Aerror(const res_state statp, FILE *file, const char *string, int error, | |
020a9a23 | 1460 | const struct sockaddr *address) |
e685e07d UD |
1461 | { |
1462 | int save = errno; | |
1463 | ||
1464 | if ((statp->options & RES_DEBUG) != 0) { | |
020a9a23 | 1465 | char tmp[sizeof "xxxx.xxxx.xxxx.255.255.255.255"]; |
e685e07d UD |
1466 | |
1467 | fprintf(file, "res_send: %s ([%s].%u): %s\n", | |
1468 | string, | |
e2a99d8e UD |
1469 | (address->sa_family == AF_INET |
1470 | ? inet_ntop(address->sa_family, | |
1471 | &((const struct sockaddr_in *) address)->sin_addr, | |
1472 | tmp, sizeof tmp) | |
1473 | : inet_ntop(address->sa_family, | |
1474 | &((const struct sockaddr_in6 *) address)->sin6_addr, | |
1475 | tmp, sizeof tmp)), | |
020a9a23 UD |
1476 | (address->sa_family == AF_INET |
1477 | ? ntohs(((struct sockaddr_in *) address)->sin_port) | |
1478 | : address->sa_family == AF_INET6 | |
1479 | ? ntohs(((struct sockaddr_in6 *) address)->sin6_port) | |
1480 | : 0), | |
e685e07d UD |
1481 | strerror(error)); |
1482 | } | |
1483 | __set_errno (save); | |
1484 | } | |
1485 | ||
1486 | static void | |
1487 | Perror(const res_state statp, FILE *file, const char *string, int error) { | |
1488 | int save = errno; | |
1489 | ||
1490 | if ((statp->options & RES_DEBUG) != 0) | |
1491 | fprintf(file, "res_send: %s: %s\n", | |
1492 | string, strerror(error)); | |
1493 | __set_errno (save); | |
1494 | } | |
1495 | #endif | |
1496 | ||
1497 | static int | |
438e8239 UD |
1498 | sock_eq(struct sockaddr_in6 *a1, struct sockaddr_in6 *a2) { |
1499 | if (a1->sin6_family == a2->sin6_family) { | |
1500 | if (a1->sin6_family == AF_INET) | |
1501 | return ((((struct sockaddr_in *)a1)->sin_port == | |
1502 | ((struct sockaddr_in *)a2)->sin_port) && | |
1503 | (((struct sockaddr_in *)a1)->sin_addr.s_addr == | |
1504 | ((struct sockaddr_in *)a2)->sin_addr.s_addr)); | |
1505 | else | |
1506 | return ((a1->sin6_port == a2->sin6_port) && | |
1507 | !memcmp(&a1->sin6_addr, &a2->sin6_addr, | |
1508 | sizeof (struct in6_addr))); | |
1509 | } | |
1510 | if (a1->sin6_family == AF_INET) { | |
1511 | struct sockaddr_in6 *sap = a1; | |
1512 | a1 = a2; | |
1513 | a2 = sap; | |
1514 | } /* assumes that AF_INET and AF_INET6 are the only possibilities */ | |
1515 | return ((a1->sin6_port == ((struct sockaddr_in *)a2)->sin_port) && | |
1516 | IN6_IS_ADDR_V4MAPPED(&a1->sin6_addr) && | |
1517 | (a1->sin6_addr.s6_addr32[3] == | |
1518 | ((struct sockaddr_in *)a2)->sin_addr.s_addr)); | |
1519 | } |