Detect FPU by checking CPUID features.
[dragonfly.git] / contrib / bind-9.5.2 / lib / bind / resolv / res_send.c
blob9900dc6e36d168e679f628901ac836f47cae5043
1 /*
2 * Copyright (c) 1985, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
35 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
37 * Permission to use, copy, modify, and distribute this software for any
38 * purpose with or without fee is hereby granted, provided that the above
39 * copyright notice and this permission notice appear in all copies, and that
40 * the name of Digital Equipment Corporation not be used in advertising or
41 * publicity pertaining to distribution of the document or software without
42 * specific, written prior permission.
44 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
47 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51 * SOFTWARE.
55 * Copyright (c) 2005 by Internet Systems Consortium, Inc. ("ISC")
56 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
58 * Permission to use, copy, modify, and distribute this software for any
59 * purpose with or without fee is hereby granted, provided that the above
60 * copyright notice and this permission notice appear in all copies.
62 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
63 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
64 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
65 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
66 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
67 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
68 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static const char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
73 static const char rcsid[] = "$Id: res_send.c,v 1.18.10.1 2008/01/27 02:06:46 marka Exp $";
74 #endif /* LIBC_SCCS and not lint */
76 /*! \file
77 * \brief
78 * Send query to name server and wait for reply.
81 #include "port_before.h"
82 #ifndef USE_KQUEUE
83 #include "fd_setsize.h"
84 #endif
86 #ifdef _LIBC
87 #include "namespace.h"
88 #endif
89 #include <sys/types.h>
90 #include <sys/param.h>
91 #include <sys/time.h>
92 #include <sys/socket.h>
93 #include <sys/uio.h>
95 #include <netinet/in.h>
96 #include <arpa/nameser.h>
97 #include <arpa/inet.h>
99 #include <errno.h>
100 #include <netdb.h>
101 #include <resolv.h>
102 #include <signal.h>
103 #include <stdio.h>
104 #include <stdlib.h>
105 #include <string.h>
106 #include <unistd.h>
108 #include "isc/eventlib.h"
110 #include "port_after.h"
111 #ifdef USE_KQUEUE
112 #include <sys/event.h>
113 #else
115 #ifdef USE_POLL
116 #ifdef HAVE_STROPTS_H
117 #include <stropts.h>
118 #endif
119 #include <poll.h>
120 #endif /* USE_POLL */
121 #endif
123 #ifdef _LIBC
124 #include "un-namespace.h"
125 #endif
127 /* Options. Leave them on. */
128 #define DEBUG
129 #include "res_debug.h"
130 #include "res_private.h"
132 #define EXT(res) ((res)->_u._ext)
134 #if !defined(USE_POLL) && !defined(USE_KQUEUE)
135 static const int highestFD = FD_SETSIZE - 1;
136 #else
137 static int highestFD = 0;
138 #endif
140 /* Forward. */
142 static int get_salen __P((const struct sockaddr *));
143 static struct sockaddr * get_nsaddr __P((res_state, size_t));
144 static int send_vc(res_state, const u_char *, int,
145 u_char *, int, int *, int);
146 static int send_dg(res_state,
147 #ifdef USE_KQUEUE
148 int,
149 #endif
150 const u_char *, int,
151 u_char *, int, int *, int, int,
152 int *, int *);
153 static void Aerror(const res_state, FILE *, const char *, int,
154 const struct sockaddr *, int);
155 static void Perror(const res_state, FILE *, const char *, int);
156 static int sock_eq(struct sockaddr *, struct sockaddr *);
157 #if defined(NEED_PSELECT) && !defined(USE_POLL) && !defined(USE_KQUEUE)
158 static int pselect(int, void *, void *, void *,
159 struct timespec *,
160 const sigset_t *);
161 #endif
162 void res_pquery(const res_state, const u_char *, int, FILE *);
164 static const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
166 /* Public. */
169 * looks up "ina" in _res.ns_addr_list[]
171 * returns:
172 *\li 0 : not found
173 *\li >0 : found
175 * author:
176 *\li paul vixie, 29may94
179 res_ourserver_p(const res_state statp, const struct sockaddr *sa) {
180 const struct sockaddr_in *inp, *srv;
181 const struct sockaddr_in6 *in6p, *srv6;
182 int ns;
184 switch (sa->sa_family) {
185 case AF_INET:
186 inp = (const struct sockaddr_in *)sa;
187 for (ns = 0; ns < statp->nscount; ns++) {
188 srv = (struct sockaddr_in *)get_nsaddr(statp, ns);
189 if (srv->sin_family == inp->sin_family &&
190 srv->sin_port == inp->sin_port &&
191 (srv->sin_addr.s_addr == INADDR_ANY ||
192 srv->sin_addr.s_addr == inp->sin_addr.s_addr))
193 return (1);
195 break;
196 case AF_INET6:
197 if (EXT(statp).ext == NULL)
198 break;
199 in6p = (const struct sockaddr_in6 *)sa;
200 for (ns = 0; ns < statp->nscount; ns++) {
201 srv6 = (struct sockaddr_in6 *)get_nsaddr(statp, ns);
202 if (srv6->sin6_family == in6p->sin6_family &&
203 srv6->sin6_port == in6p->sin6_port &&
204 #ifdef HAVE_SIN6_SCOPE_ID
205 (srv6->sin6_scope_id == 0 ||
206 srv6->sin6_scope_id == in6p->sin6_scope_id) &&
207 #endif
208 (IN6_IS_ADDR_UNSPECIFIED(&srv6->sin6_addr) ||
209 IN6_ARE_ADDR_EQUAL(&srv6->sin6_addr, &in6p->sin6_addr)))
210 return (1);
212 break;
213 default:
214 break;
216 return (0);
220 * look for (name,type,class) in the query section of packet (buf,eom)
222 * requires:
223 *\li buf + HFIXEDSZ <= eom
225 * returns:
226 *\li -1 : format error
227 *\li 0 : not found
228 *\li >0 : found
230 * author:
231 *\li paul vixie, 29may94
234 res_nameinquery(const char *name, int type, int class,
235 const u_char *buf, const u_char *eom)
237 const u_char *cp = buf + HFIXEDSZ;
238 int qdcount = ntohs(((const HEADER*)buf)->qdcount);
240 while (qdcount-- > 0) {
241 char tname[MAXDNAME+1];
242 int n, ttype, tclass;
244 n = dn_expand(buf, eom, cp, tname, sizeof tname);
245 if (n < 0)
246 return (-1);
247 cp += n;
248 if (cp + 2 * INT16SZ > eom)
249 return (-1);
250 ttype = ns_get16(cp); cp += INT16SZ;
251 tclass = ns_get16(cp); cp += INT16SZ;
252 if (ttype == type && tclass == class &&
253 ns_samename(tname, name) == 1)
254 return (1);
256 return (0);
260 * is there a 1:1 mapping of (name,type,class)
261 * in (buf1,eom1) and (buf2,eom2)?
263 * returns:
264 *\li -1 : format error
265 *\li 0 : not a 1:1 mapping
266 *\li >0 : is a 1:1 mapping
268 * author:
269 *\li paul vixie, 29may94
272 res_queriesmatch(const u_char *buf1, const u_char *eom1,
273 const u_char *buf2, const u_char *eom2)
275 const u_char *cp = buf1 + HFIXEDSZ;
276 int qdcount = ntohs(((const HEADER*)buf1)->qdcount);
278 if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
279 return (-1);
282 * Only header section present in replies to
283 * dynamic update packets.
285 if ((((const HEADER *)buf1)->opcode == ns_o_update) &&
286 (((const HEADER *)buf2)->opcode == ns_o_update))
287 return (1);
289 if (qdcount != ntohs(((const HEADER*)buf2)->qdcount))
290 return (0);
291 while (qdcount-- > 0) {
292 char tname[MAXDNAME+1];
293 int n, ttype, tclass;
295 n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
296 if (n < 0)
297 return (-1);
298 cp += n;
299 if (cp + 2 * INT16SZ > eom1)
300 return (-1);
301 ttype = ns_get16(cp); cp += INT16SZ;
302 tclass = ns_get16(cp); cp += INT16SZ;
303 if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
304 return (0);
306 return (1);
310 res_nsend(res_state statp,
311 const u_char *buf, int buflen, u_char *ans, int anssiz)
313 int gotsomewhere, terrno, tries, v_circuit, resplen, ns, n;
314 #ifdef USE_KQUEUE
315 int kq;
316 #endif
317 char abuf[NI_MAXHOST];
319 #ifdef USE_POLL
320 highestFD = sysconf(_SC_OPEN_MAX) - 1;
321 #endif
323 /* No name servers or res_init() failure */
324 if (statp->nscount == 0 || EXT(statp).ext == NULL) {
325 errno = ESRCH;
326 return (-1);
328 if (anssiz < HFIXEDSZ) {
329 errno = EINVAL;
330 return (-1);
332 DprintQ((statp->options & RES_DEBUG) || (statp->pfcode & RES_PRF_QUERY),
333 (stdout, ";; res_send()\n"), buf, buflen);
334 v_circuit = (statp->options & RES_USEVC) || buflen > PACKETSZ;
335 gotsomewhere = 0;
336 terrno = ETIMEDOUT;
338 #ifdef USE_KQUEUE
339 if ((kq = kqueue()) < 0) {
340 Perror(statp, stderr, "kqueue", errno);
341 return (-1);
343 #endif
346 * If the ns_addr_list in the resolver context has changed, then
347 * invalidate our cached copy and the associated timing data.
349 if (EXT(statp).nscount != 0) {
350 int needclose = 0;
351 struct sockaddr_storage peer;
352 ISC_SOCKLEN_T peerlen;
354 if (EXT(statp).nscount != statp->nscount)
355 needclose++;
356 else
357 for (ns = 0; ns < statp->nscount; ns++) {
358 if (statp->nsaddr_list[ns].sin_family &&
359 !sock_eq((struct sockaddr *)&statp->nsaddr_list[ns],
360 (struct sockaddr *)&EXT(statp).ext->nsaddrs[ns])) {
361 needclose++;
362 break;
365 if (EXT(statp).nssocks[ns] == -1)
366 continue;
367 peerlen = sizeof(peer);
368 #ifndef _LIBC
369 if (getsockname(EXT(statp).nssocks[ns],
370 #else
371 if (_getsockname(EXT(statp).nssocks[ns],
372 #endif
373 (struct sockaddr *)&peer, &peerlen) < 0) {
374 needclose++;
375 break;
377 if (!sock_eq((struct sockaddr *)&peer,
378 get_nsaddr(statp, ns))) {
379 needclose++;
380 break;
383 if (needclose) {
384 res_nclose(statp);
385 EXT(statp).nscount = 0;
390 * Maybe initialize our private copy of the ns_addr_list.
392 if (EXT(statp).nscount == 0) {
393 for (ns = 0; ns < statp->nscount; ns++) {
394 EXT(statp).nstimes[ns] = RES_MAXTIME;
395 EXT(statp).nssocks[ns] = -1;
396 if (!statp->nsaddr_list[ns].sin_family)
397 continue;
398 EXT(statp).ext->nsaddrs[ns].sin =
399 statp->nsaddr_list[ns];
401 EXT(statp).nscount = statp->nscount;
405 * Some resolvers want to even out the load on their nameservers.
406 * Note that RES_BLAST overrides RES_ROTATE.
408 if ((statp->options & RES_ROTATE) != 0U &&
409 (statp->options & RES_BLAST) == 0U) {
410 union res_sockaddr_union inu;
411 struct sockaddr_in ina;
412 int lastns = statp->nscount - 1;
413 int fd;
414 u_int16_t nstime;
416 if (EXT(statp).ext != NULL)
417 inu = EXT(statp).ext->nsaddrs[0];
418 ina = statp->nsaddr_list[0];
419 fd = EXT(statp).nssocks[0];
420 nstime = EXT(statp).nstimes[0];
421 for (ns = 0; ns < lastns; ns++) {
422 if (EXT(statp).ext != NULL)
423 EXT(statp).ext->nsaddrs[ns] =
424 EXT(statp).ext->nsaddrs[ns + 1];
425 statp->nsaddr_list[ns] = statp->nsaddr_list[ns + 1];
426 EXT(statp).nssocks[ns] = EXT(statp).nssocks[ns + 1];
427 EXT(statp).nstimes[ns] = EXT(statp).nstimes[ns + 1];
429 if (EXT(statp).ext != NULL)
430 EXT(statp).ext->nsaddrs[lastns] = inu;
431 statp->nsaddr_list[lastns] = ina;
432 EXT(statp).nssocks[lastns] = fd;
433 EXT(statp).nstimes[lastns] = nstime;
437 * Send request, RETRY times, or until successful.
439 for (tries = 0; tries < statp->retry; tries++) {
440 for (ns = 0; ns < statp->nscount; ns++) {
441 struct sockaddr *nsap;
442 int nsaplen;
443 nsap = get_nsaddr(statp, ns);
444 nsaplen = get_salen(nsap);
445 statp->_flags &= ~RES_F_LASTMASK;
446 statp->_flags |= (ns << RES_F_LASTSHIFT);
447 same_ns:
448 if (statp->qhook) {
449 int done = 0, loops = 0;
451 do {
452 res_sendhookact act;
454 act = (*statp->qhook)(&nsap, &buf, &buflen,
455 ans, anssiz, &resplen);
456 switch (act) {
457 case res_goahead:
458 done = 1;
459 break;
460 case res_nextns:
461 res_nclose(statp);
462 goto next_ns;
463 case res_done:
464 #ifdef USE_KQUEUE
465 _close(kq);
466 #endif
467 return (resplen);
468 case res_modified:
469 /* give the hook another try */
470 if (++loops < 42) /*doug adams*/
471 break;
472 /*FALLTHROUGH*/
473 case res_error:
474 /*FALLTHROUGH*/
475 default:
476 goto fail;
478 } while (!done);
481 Dprint(((statp->options & RES_DEBUG) &&
482 getnameinfo(nsap, nsaplen, abuf, sizeof(abuf),
483 NULL, 0, niflags) == 0),
484 (stdout, ";; Querying server (# %d) address = %s\n",
485 ns + 1, abuf));
488 if (v_circuit) {
489 /* Use VC; at most one attempt per server. */
490 tries = statp->retry;
491 n = send_vc(statp, buf, buflen, ans, anssiz, &terrno,
492 ns);
493 if (n < 0)
494 goto fail;
495 if (n == 0)
496 goto next_ns;
497 resplen = n;
498 } else {
499 /* Use datagrams. */
500 n = send_dg(statp,
501 #ifdef USE_KQUEUE
503 #endif
504 buf, buflen, ans, anssiz, &terrno,
505 ns, tries, &v_circuit, &gotsomewhere);
506 if (n < 0)
507 goto fail;
508 if (n == 0)
509 goto next_ns;
510 if (v_circuit)
511 goto same_ns;
512 resplen = n;
515 Dprint((statp->options & RES_DEBUG) ||
516 ((statp->pfcode & RES_PRF_REPLY) &&
517 (statp->pfcode & RES_PRF_HEAD1)),
518 (stdout, ";; got answer:\n"));
520 DprintQ((statp->options & RES_DEBUG) ||
521 (statp->pfcode & RES_PRF_REPLY),
522 (stdout, "%s", ""),
523 ans, (resplen > anssiz) ? anssiz : resplen);
526 * If we have temporarily opened a virtual circuit,
527 * or if we haven't been asked to keep a socket open,
528 * close the socket.
530 if ((v_circuit && (statp->options & RES_USEVC) == 0U) ||
531 (statp->options & RES_STAYOPEN) == 0U) {
532 res_nclose(statp);
534 if (statp->rhook) {
535 int done = 0, loops = 0;
537 do {
538 res_sendhookact act;
540 act = (*statp->rhook)(nsap, buf, buflen,
541 ans, anssiz, &resplen);
542 switch (act) {
543 case res_goahead:
544 case res_done:
545 done = 1;
546 break;
547 case res_nextns:
548 res_nclose(statp);
549 goto next_ns;
550 case res_modified:
551 /* give the hook another try */
552 if (++loops < 42) /*doug adams*/
553 break;
554 /*FALLTHROUGH*/
555 case res_error:
556 /*FALLTHROUGH*/
557 default:
558 goto fail;
560 } while (!done);
563 #ifdef USE_KQUEUE
564 _close(kq);
565 #endif
566 return (resplen);
567 next_ns: ;
568 } /*foreach ns*/
569 } /*foreach retry*/
570 res_nclose(statp);
571 #ifdef USE_KQUEUE
572 _close(kq);
573 #endif
574 if (!v_circuit) {
575 if (!gotsomewhere)
576 errno = ECONNREFUSED; /*%< no nameservers found */
577 else
578 errno = ETIMEDOUT; /*%< no answer obtained */
579 } else
580 errno = terrno;
581 return (-1);
582 fail:
583 res_nclose(statp);
584 return (-1);
587 /* Private */
589 static int
590 get_salen(sa)
591 const struct sockaddr *sa;
594 #ifdef HAVE_SA_LEN
595 /* There are people do not set sa_len. Be forgiving to them. */
596 if (sa->sa_len)
597 return (sa->sa_len);
598 #endif
600 if (sa->sa_family == AF_INET)
601 return (sizeof(struct sockaddr_in));
602 else if (sa->sa_family == AF_INET6)
603 return (sizeof(struct sockaddr_in6));
604 else
605 return (0); /*%< unknown, die on connect */
609 * pick appropriate nsaddr_list for use. see res_init() for initialization.
611 static struct sockaddr *
612 get_nsaddr(statp, n)
613 res_state statp;
614 size_t n;
617 if (!statp->nsaddr_list[n].sin_family && EXT(statp).ext) {
619 * - EXT(statp).ext->nsaddrs[n] holds an address that is larger
620 * than struct sockaddr, and
621 * - user code did not update statp->nsaddr_list[n].
623 return (struct sockaddr *)(void *)&EXT(statp).ext->nsaddrs[n];
624 } else {
626 * - user code updated statp->nsaddr_list[n], or
627 * - statp->nsaddr_list[n] has the same content as
628 * EXT(statp).ext->nsaddrs[n].
630 return (struct sockaddr *)(void *)&statp->nsaddr_list[n];
634 static int
635 send_vc(res_state statp,
636 const u_char *buf, int buflen, u_char *ans, int anssiz,
637 int *terrno, int ns)
639 const HEADER *hp = (const HEADER *) buf;
640 HEADER *anhp = (HEADER *) ans;
641 struct sockaddr *nsap;
642 int nsaplen;
643 int truncating, connreset, resplen, n;
644 struct iovec iov[2];
645 u_short len;
646 u_char *cp;
647 void *tmp;
648 #ifdef SO_NOSIGPIPE
649 int on = 1;
650 #endif
652 nsap = get_nsaddr(statp, ns);
653 nsaplen = get_salen(nsap);
655 connreset = 0;
656 same_ns:
657 truncating = 0;
659 /* Are we still talking to whom we want to talk to? */
660 if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
661 struct sockaddr_storage peer;
662 ISC_SOCKLEN_T size = sizeof peer;
663 #ifndef _LIBC
664 if (getpeername(statp->_vcsock,
665 #else
666 if (_getpeername(statp->_vcsock,
667 #endif
668 (struct sockaddr *)&peer, &size) < 0 ||
669 !sock_eq((struct sockaddr *)&peer, nsap)) {
670 res_nclose(statp);
671 statp->_flags &= ~RES_F_VC;
675 if (statp->_vcsock < 0 || (statp->_flags & RES_F_VC) == 0) {
676 if (statp->_vcsock >= 0)
677 res_nclose(statp);
678 #ifndef _LIBC
679 statp->_vcsock = socket(nsap->sa_family, SOCK_STREAM, 0);
680 #else
681 statp->_vcsock = _socket(nsap->sa_family, SOCK_STREAM, 0);
682 #endif
683 #if !defined(USE_POLL) && !defined(USE_KQUEUE)
684 if (statp->_vcsock > highestFD) {
685 res_nclose(statp);
686 errno = ENOTSOCK;
688 #endif
689 if (statp->_vcsock < 0) {
690 switch (errno) {
691 case EPROTONOSUPPORT:
692 #ifdef EPFNOSUPPORT
693 case EPFNOSUPPORT:
694 #endif
695 case EAFNOSUPPORT:
696 Perror(statp, stderr, "socket(vc)", errno);
697 return (0);
698 default:
699 *terrno = errno;
700 Perror(statp, stderr, "socket(vc)", errno);
701 return (-1);
704 #ifdef SO_NOSIGPIPE
706 * Disable generation of SIGPIPE when writing to a closed
707 * socket. Write should return -1 and set errno to EPIPE
708 * instead.
710 * Push on even if setsockopt(SO_NOSIGPIPE) fails.
712 (void)setsockopt(statp->_vcsock, SOL_SOCKET, SO_NOSIGPIPE, &on,
713 sizeof(on));
714 #endif
715 errno = 0;
716 #ifndef _LIBC
717 if (connect(statp->_vcsock, nsap, nsaplen) < 0) {
718 #else
719 if (_connect(statp->_vcsock, nsap, nsaplen) < 0) {
720 #endif
721 *terrno = errno;
722 Aerror(statp, stderr, "connect/vc", errno, nsap,
723 nsaplen);
724 res_nclose(statp);
725 return (0);
727 statp->_flags |= RES_F_VC;
731 * Send length & message
733 ns_put16((u_short)buflen, (u_char*)&len);
734 iov[0] = evConsIovec(&len, INT16SZ);
735 DE_CONST(buf, tmp);
736 iov[1] = evConsIovec(tmp, buflen);
737 #ifndef _LIBC
738 if (writev(statp->_vcsock, iov, 2) != (INT16SZ + buflen)) {
739 #else
740 if (_writev(statp->_vcsock, iov, 2) != (INT16SZ + buflen)) {
741 #endif
742 *terrno = errno;
743 Perror(statp, stderr, "write failed", errno);
744 res_nclose(statp);
745 return (0);
748 * Receive length & response
750 read_len:
751 cp = ans;
752 len = INT16SZ;
753 #ifndef _LIBC
754 while ((n = read(statp->_vcsock, (char *)cp, (int)len)) > 0) {
755 #else
756 while ((n = _read(statp->_vcsock, (char *)cp, (int)len)) > 0) {
757 #endif
758 cp += n;
759 if ((len -= n) == 0)
760 break;
762 if (n <= 0) {
763 *terrno = errno;
764 Perror(statp, stderr, "read failed", errno);
765 res_nclose(statp);
767 * A long running process might get its TCP
768 * connection reset if the remote server was
769 * restarted. Requery the server instead of
770 * trying a new one. When there is only one
771 * server, this means that a query might work
772 * instead of failing. We only allow one reset
773 * per query to prevent looping.
775 if (*terrno == ECONNRESET && !connreset) {
776 connreset = 1;
777 res_nclose(statp);
778 goto same_ns;
780 res_nclose(statp);
781 return (0);
783 resplen = ns_get16(ans);
784 if (resplen > anssiz) {
785 Dprint(statp->options & RES_DEBUG,
786 (stdout, ";; response truncated\n")
788 truncating = 1;
789 len = anssiz;
790 } else
791 len = resplen;
792 if (len < HFIXEDSZ) {
794 * Undersized message.
796 Dprint(statp->options & RES_DEBUG,
797 (stdout, ";; undersized: %d\n", len));
798 *terrno = EMSGSIZE;
799 res_nclose(statp);
800 return (0);
802 cp = ans;
803 #ifndef _LIBC
804 while (len != 0 && (n = read(statp->_vcsock, (char *)cp, (int)len)) > 0){
805 #else
806 while (len != 0 && (n = _read(statp->_vcsock, (char *)cp, (int)len)) > 0){
807 #endif
808 cp += n;
809 len -= n;
811 if (n <= 0) {
812 *terrno = errno;
813 Perror(statp, stderr, "read(vc)", errno);
814 res_nclose(statp);
815 return (0);
817 if (truncating) {
819 * Flush rest of answer so connection stays in synch.
821 anhp->tc = 1;
822 len = resplen - anssiz;
823 while (len != 0) {
824 char junk[PACKETSZ];
826 #ifndef _LIBC
827 n = read(statp->_vcsock, junk,
828 #else
829 n = _read(statp->_vcsock, junk,
830 #endif
831 (len > sizeof junk) ? sizeof junk : len);
832 if (n > 0)
833 len -= n;
834 else
835 break;
839 * If the calling applicating has bailed out of
840 * a previous call and failed to arrange to have
841 * the circuit closed or the server has got
842 * itself confused, then drop the packet and
843 * wait for the correct one.
845 if (hp->id != anhp->id) {
846 DprintQ((statp->options & RES_DEBUG) ||
847 (statp->pfcode & RES_PRF_REPLY),
848 (stdout, ";; old answer (unexpected):\n"),
849 ans, (resplen > anssiz) ? anssiz: resplen);
850 goto read_len;
854 * All is well, or the error is fatal. Signal that the
855 * next nameserver ought not be tried.
857 return (resplen);
860 static int
861 send_dg(res_state statp,
862 #ifdef USE_KQUEUE
863 int kq,
864 #endif
865 const u_char *buf, int buflen, u_char *ans,
866 int anssiz, int *terrno, int ns, int tries, int *v_circuit,
867 int *gotsomewhere)
869 const HEADER *hp = (const HEADER *) buf;
870 HEADER *anhp = (HEADER *) ans;
871 const struct sockaddr *nsap;
872 int nsaplen;
873 struct timespec now, timeout, finish;
874 struct sockaddr_storage from;
875 ISC_SOCKLEN_T fromlen;
876 int resplen, seconds, n, s;
877 #ifdef USE_KQUEUE
878 struct kevent kv;
879 #else
880 #ifdef USE_POLL
881 int polltimeout;
882 struct pollfd pollfd;
883 #else
884 fd_set dsmask;
885 #endif
886 #endif
888 nsap = get_nsaddr(statp, ns);
889 nsaplen = get_salen(nsap);
890 if (EXT(statp).nssocks[ns] == -1) {
891 #ifndef _LIBC
892 EXT(statp).nssocks[ns] = socket(nsap->sa_family, SOCK_DGRAM, 0);
893 #else
894 EXT(statp).nssocks[ns] = _socket(nsap->sa_family, SOCK_DGRAM, 0);
895 #endif
896 #if !defined(USE_POLL) && !defined(USE_KQUEUE)
897 if (EXT(statp).nssocks[ns] > highestFD) {
898 res_nclose(statp);
899 errno = ENOTSOCK;
901 #endif
902 if (EXT(statp).nssocks[ns] < 0) {
903 switch (errno) {
904 case EPROTONOSUPPORT:
905 #ifdef EPFNOSUPPORT
906 case EPFNOSUPPORT:
907 #endif
908 case EAFNOSUPPORT:
909 Perror(statp, stderr, "socket(dg)", errno);
910 return (0);
911 default:
912 *terrno = errno;
913 Perror(statp, stderr, "socket(dg)", errno);
914 return (-1);
917 #ifndef CANNOT_CONNECT_DGRAM
919 * On a 4.3BSD+ machine (client and server,
920 * actually), sending to a nameserver datagram
921 * port with no nameserver will cause an
922 * ICMP port unreachable message to be returned.
923 * If our datagram socket is "connected" to the
924 * server, we get an ECONNREFUSED error on the next
925 * socket operation, and select returns if the
926 * error message is received. We can thus detect
927 * the absence of a nameserver without timing out.
930 * When the option "insecure1" is specified, we'd
931 * rather expect to see responses from an "unknown"
932 * address. In order to let the kernel accept such
933 * responses, do not connect the socket here.
934 * XXX: or do we need an explicit option to disable
935 * connecting?
937 if (!(statp->options & RES_INSECURE1) &&
938 #ifndef _LIBC
939 connect(EXT(statp).nssocks[ns], nsap, nsaplen) < 0) {
940 #else
941 _connect(EXT(statp).nssocks[ns], nsap, nsaplen) < 0) {
942 #endif
943 Aerror(statp, stderr, "connect(dg)", errno, nsap,
944 nsaplen);
945 res_nclose(statp);
946 return (0);
948 #endif /* !CANNOT_CONNECT_DGRAM */
949 Dprint(statp->options & RES_DEBUG,
950 (stdout, ";; new DG socket\n"))
952 s = EXT(statp).nssocks[ns];
953 #ifndef CANNOT_CONNECT_DGRAM
954 if (statp->options & RES_INSECURE1) {
955 #ifndef _LIBC
956 if (sendto(s,
957 #else
958 if (_sendto(s,
959 #endif
960 (const char*)buf, buflen, 0, nsap, nsaplen) != buflen) {
961 Aerror(statp, stderr, "sendto", errno, nsap, nsaplen);
962 res_nclose(statp);
963 return (0);
965 } else if (send(s, (const char*)buf, buflen, 0) != buflen) {
966 Perror(statp, stderr, "send", errno);
967 res_nclose(statp);
968 return (0);
970 #else /* !CANNOT_CONNECT_DGRAM */
971 #ifndef _LIBC
972 if (sendto(s, (const char*)buf, buflen, 0, nsap, nsaplen) != buflen)
973 #else
974 if (_sendto(s, (const char*)buf, buflen, 0, nsap, nsaplen) != buflen)
975 #endif
977 Aerror(statp, stderr, "sendto", errno, nsap, nsaplen);
978 res_nclose(statp);
979 return (0);
981 #endif /* !CANNOT_CONNECT_DGRAM */
984 * Wait for reply.
986 seconds = (statp->retrans << tries);
987 if (ns > 0)
988 seconds /= statp->nscount;
989 if (seconds <= 0)
990 seconds = 1;
991 now = evNowTime();
992 timeout = evConsTime(seconds, 0);
993 finish = evAddTime(now, timeout);
994 goto nonow;
995 wait:
996 now = evNowTime();
997 nonow:
998 #ifndef USE_POLL
999 if (evCmpTime(finish, now) > 0)
1000 timeout = evSubTime(finish, now);
1001 else
1002 timeout = evConsTime(0, 0);
1003 #ifdef USE_KQUEUE
1004 EV_SET(&kv, s, EVFILT_READ, EV_ADD | EV_ONESHOT, 0, 0, 0);
1005 n = _kevent(kq, &kv, 1, &kv, 1, &timeout);
1006 #else
1007 FD_ZERO(&dsmask);
1008 FD_SET(s, &dsmask);
1009 n = pselect(s + 1, &dsmask, NULL, NULL, &timeout, NULL);
1010 #endif
1011 #else
1012 timeout = evSubTime(finish, now);
1013 if (timeout.tv_sec < 0)
1014 timeout = evConsTime(0, 0);
1015 polltimeout = 1000*timeout.tv_sec +
1016 timeout.tv_nsec/1000000;
1017 pollfd.fd = s;
1018 pollfd.events = POLLRDNORM;
1019 n = poll(&pollfd, 1, polltimeout);
1020 #endif /* USE_POLL */
1022 if (n == 0) {
1023 Dprint(statp->options & RES_DEBUG, (stdout, ";; timeout\n"));
1024 *gotsomewhere = 1;
1025 return (0);
1027 if (n < 0) {
1028 if (errno == EINTR)
1029 goto wait;
1030 #ifdef USE_KQUEUE
1031 Perror(statp, stderr, "kevent", errno);
1032 #else
1033 #ifndef USE_POLL
1034 Perror(statp, stderr, "select", errno);
1035 #else
1036 Perror(statp, stderr, "poll", errno);
1037 #endif /* USE_POLL */
1038 #endif
1039 res_nclose(statp);
1040 return (0);
1042 #ifdef USE_KQUEUE
1043 if (kv.ident != s)
1044 goto wait;
1045 #endif
1046 errno = 0;
1047 fromlen = sizeof(from);
1048 #ifndef _LIBC
1049 resplen = recvfrom(s, (char*)ans, anssiz,0,
1050 #else
1051 resplen = _recvfrom(s, (char*)ans, anssiz,0,
1052 #endif
1053 (struct sockaddr *)&from, &fromlen);
1054 if (resplen <= 0) {
1055 Perror(statp, stderr, "recvfrom", errno);
1056 res_nclose(statp);
1057 return (0);
1059 *gotsomewhere = 1;
1060 if (resplen < HFIXEDSZ) {
1062 * Undersized message.
1064 Dprint(statp->options & RES_DEBUG,
1065 (stdout, ";; undersized: %d\n",
1066 resplen));
1067 *terrno = EMSGSIZE;
1068 res_nclose(statp);
1069 return (0);
1071 if (hp->id != anhp->id) {
1073 * response from old query, ignore it.
1074 * XXX - potential security hazard could
1075 * be detected here.
1077 DprintQ((statp->options & RES_DEBUG) ||
1078 (statp->pfcode & RES_PRF_REPLY),
1079 (stdout, ";; old answer:\n"),
1080 ans, (resplen > anssiz) ? anssiz : resplen);
1081 goto wait;
1083 if (!(statp->options & RES_INSECURE1) &&
1084 !res_ourserver_p(statp, (struct sockaddr *)&from)) {
1086 * response from wrong server? ignore it.
1087 * XXX - potential security hazard could
1088 * be detected here.
1090 DprintQ((statp->options & RES_DEBUG) ||
1091 (statp->pfcode & RES_PRF_REPLY),
1092 (stdout, ";; not our server:\n"),
1093 ans, (resplen > anssiz) ? anssiz : resplen);
1094 goto wait;
1096 #ifdef RES_USE_EDNS0
1097 if (anhp->rcode == FORMERR && (statp->options & RES_USE_EDNS0) != 0U) {
1099 * Do not retry if the server do not understand EDNS0.
1100 * The case has to be captured here, as FORMERR packet do not
1101 * carry query section, hence res_queriesmatch() returns 0.
1103 DprintQ(statp->options & RES_DEBUG,
1104 (stdout, "server rejected query with EDNS0:\n"),
1105 ans, (resplen > anssiz) ? anssiz : resplen);
1106 /* record the error */
1107 statp->_flags |= RES_F_EDNS0ERR;
1108 res_nclose(statp);
1109 return (0);
1111 #endif
1112 if (!(statp->options & RES_INSECURE2) &&
1113 !res_queriesmatch(buf, buf + buflen,
1114 ans, ans + anssiz)) {
1116 * response contains wrong query? ignore it.
1117 * XXX - potential security hazard could
1118 * be detected here.
1120 DprintQ((statp->options & RES_DEBUG) ||
1121 (statp->pfcode & RES_PRF_REPLY),
1122 (stdout, ";; wrong query name:\n"),
1123 ans, (resplen > anssiz) ? anssiz : resplen);
1124 goto wait;
1126 if (anhp->rcode == SERVFAIL ||
1127 anhp->rcode == NOTIMP ||
1128 anhp->rcode == REFUSED) {
1129 DprintQ(statp->options & RES_DEBUG,
1130 (stdout, "server rejected query:\n"),
1131 ans, (resplen > anssiz) ? anssiz : resplen);
1132 res_nclose(statp);
1133 /* don't retry if called from dig */
1134 if (!statp->pfcode)
1135 return (0);
1137 if (!(statp->options & RES_IGNTC) && anhp->tc) {
1139 * To get the rest of answer,
1140 * use TCP with same server.
1142 Dprint(statp->options & RES_DEBUG,
1143 (stdout, ";; truncated answer\n"));
1144 *v_circuit = 1;
1145 res_nclose(statp);
1146 return (1);
1149 * All is well, or the error is fatal. Signal that the
1150 * next nameserver ought not be tried.
1152 return (resplen);
1155 static void
1156 Aerror(const res_state statp, FILE *file, const char *string, int error,
1157 const struct sockaddr *address, int alen)
1159 int save = errno;
1160 char hbuf[NI_MAXHOST];
1161 char sbuf[NI_MAXSERV];
1163 alen = alen;
1165 if ((statp->options & RES_DEBUG) != 0U) {
1166 if (getnameinfo(address, alen, hbuf, sizeof(hbuf),
1167 sbuf, sizeof(sbuf), niflags)) {
1168 strncpy(hbuf, "?", sizeof(hbuf) - 1);
1169 hbuf[sizeof(hbuf) - 1] = '\0';
1170 strncpy(sbuf, "?", sizeof(sbuf) - 1);
1171 sbuf[sizeof(sbuf) - 1] = '\0';
1173 fprintf(file, "res_send: %s ([%s].%s): %s\n",
1174 string, hbuf, sbuf, strerror(error));
1176 errno = save;
1179 static void
1180 Perror(const res_state statp, FILE *file, const char *string, int error) {
1181 int save = errno;
1183 if ((statp->options & RES_DEBUG) != 0U)
1184 fprintf(file, "res_send: %s: %s\n",
1185 string, strerror(error));
1186 errno = save;
1189 static int
1190 sock_eq(struct sockaddr *a, struct sockaddr *b) {
1191 struct sockaddr_in *a4, *b4;
1192 struct sockaddr_in6 *a6, *b6;
1194 if (a->sa_family != b->sa_family)
1195 return 0;
1196 switch (a->sa_family) {
1197 case AF_INET:
1198 a4 = (struct sockaddr_in *)a;
1199 b4 = (struct sockaddr_in *)b;
1200 return a4->sin_port == b4->sin_port &&
1201 a4->sin_addr.s_addr == b4->sin_addr.s_addr;
1202 case AF_INET6:
1203 a6 = (struct sockaddr_in6 *)a;
1204 b6 = (struct sockaddr_in6 *)b;
1205 return a6->sin6_port == b6->sin6_port &&
1206 #ifdef HAVE_SIN6_SCOPE_ID
1207 a6->sin6_scope_id == b6->sin6_scope_id &&
1208 #endif
1209 IN6_ARE_ADDR_EQUAL(&a6->sin6_addr, &b6->sin6_addr);
1210 default:
1211 return 0;
1215 #if defined(NEED_PSELECT) && !defined(USE_POLL) && !defined(USE_KQUEUE)
1216 /* XXX needs to move to the porting library. */
1217 static int
1218 pselect(int nfds, void *rfds, void *wfds, void *efds,
1219 struct timespec *tsp, const sigset_t *sigmask)
1221 struct timeval tv, *tvp;
1222 sigset_t sigs;
1223 int n;
1225 if (tsp) {
1226 tvp = &tv;
1227 tv = evTimeVal(*tsp);
1228 } else
1229 tvp = NULL;
1230 if (sigmask)
1231 sigprocmask(SIG_SETMASK, sigmask, &sigs);
1232 n = select(nfds, rfds, wfds, efds, tvp);
1233 if (sigmask)
1234 sigprocmask(SIG_SETMASK, &sigs, NULL);
1235 if (tsp)
1236 *tsp = evTimeSpec(tv);
1237 return (n);
1239 #endif