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[glibc.git] / resolv / res_send.c
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1 /*
2 * ++Copyright++ 1985, 1989, 1993
3 * -
4 * Copyright (c) 1985, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 * -
35 * 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.
52 * -
53 * --Copyright--
56 #if defined(LIBC_SCCS) && !defined(lint)
57 static char sccsid[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
58 static char rcsid[] = "$Id$";
59 #endif /* LIBC_SCCS and not lint */
61 /* change this to "0"
62 * if you talk to a lot
63 * of multi-homed SunOS
64 * ("broken") name servers.
66 #define CHECK_SRVR_ADDR 1 /* XXX - should be in options.h */
69 * Send query to name server and wait for reply.
72 #include <sys/types.h>
73 #include <sys/param.h>
74 #include <sys/poll.h>
75 #include <sys/time.h>
76 #include <sys/socket.h>
77 #include <sys/uio.h>
78 #include <netinet/in.h>
79 #include <arpa/nameser.h>
80 #include <arpa/inet.h>
82 #include <stdio.h>
83 #include <netdb.h>
84 #include <errno.h>
85 #include <resolv.h>
86 #if defined(BSD) && (BSD >= 199306)
87 # include <stdlib.h>
88 # include <string.h>
89 # include <unistd.h>
90 #else
91 # include "../conf/portability.h"
92 #endif
94 #if defined(USE_OPTIONS_H)
95 # include <../conf/options.h>
96 #endif
98 static int s = -1; /* socket used for communications */
99 static int connected = 0; /* is the socket connected */
100 static int vc = 0; /* is the socket a virtual circuit? */
102 /* XXX - this should be done in portability.h */
103 #if (defined(BSD) && (BSD >= 199103)) || defined(linux)
104 # define CAN_RECONNECT 1
105 #else
106 # define CAN_RECONNECT 0
107 #endif
109 #ifndef DEBUG
110 # define Dprint(cond, args) /*empty*/
111 # define DprintQ(cond, args, query, size) /*empty*/
112 # define Aerror(file, string, error, address) /*empty*/
113 # define Perror(file, string, error) /*empty*/
114 #else
115 # define Dprint(cond, args) if (cond) {fprintf args;} else {}
116 # define DprintQ(cond, args, query, size) if (cond) {\
117 fprintf args;\
118 __fp_nquery(query, size, stdout);\
119 } else {}
120 static void
121 Aerror(file, string, error, address)
122 FILE *file;
123 char *string;
124 int error;
125 struct sockaddr_in address;
127 int save = errno;
129 if (_res.options & RES_DEBUG) {
130 fprintf(file, "res_send: %s ([%s].%u): %s\n",
131 string,
132 inet_ntoa(address.sin_addr),
133 ntohs(address.sin_port),
134 strerror(error));
136 __set_errno (save);
138 static void
139 Perror(file, string, error)
140 FILE *file;
141 char *string;
142 int error;
144 int save = errno;
146 if (_res.options & RES_DEBUG) {
147 fprintf(file, "res_send: %s: %s\n",
148 string, strerror(error));
150 __set_errno (save);
152 #endif
154 static res_send_qhook Qhook = NULL;
155 static res_send_rhook Rhook = NULL;
157 void
158 res_send_setqhook(hook)
159 res_send_qhook hook;
162 Qhook = hook;
165 void
166 res_send_setrhook(hook)
167 res_send_rhook hook;
170 Rhook = hook;
173 /* int
174 * res_isourserver(ina)
175 * looks up "ina" in _res.ns_addr_list[]
176 * returns:
177 * 0 : not found
178 * >0 : found
179 * author:
180 * paul vixie, 29may94
183 res_isourserver(inp)
184 const struct sockaddr_in *inp;
186 struct sockaddr_in ina;
187 register int ns, ret;
189 ina = *inp;
190 ret = 0;
191 for (ns = 0; ns < _res.nscount; ns++) {
192 register const struct sockaddr_in *srv = &_res.nsaddr_list[ns];
194 if (srv->sin_family == ina.sin_family &&
195 srv->sin_port == ina.sin_port &&
196 (srv->sin_addr.s_addr == INADDR_ANY ||
197 srv->sin_addr.s_addr == ina.sin_addr.s_addr)) {
198 ret++;
199 break;
202 return (ret);
205 /* int
206 * res_nameinquery(name, type, class, buf, eom)
207 * look for (name,type,class) in the query section of packet (buf,eom)
208 * requires:
209 * buf + HFIXESDZ <= eom
210 * returns:
211 * -1 : format error
212 * 0 : not found
213 * >0 : found
214 * author:
215 * paul vixie, 29may94
218 res_nameinquery(name, type, class, buf, eom)
219 const char *name;
220 register int type, class;
221 const u_char *buf, *eom;
223 register const u_char *cp = buf + HFIXEDSZ;
224 int qdcount = ntohs(((HEADER*)buf)->qdcount);
226 while (qdcount-- > 0) {
227 char tname[MAXDNAME+1];
228 register int n, ttype, tclass;
230 n = dn_expand(buf, eom, cp, tname, sizeof tname);
231 if (n < 0)
232 return (-1);
233 cp += n;
234 if (cp + 2 * INT16SZ > eom)
235 return (-1);
236 ttype = _getshort(cp); cp += INT16SZ;
237 tclass = _getshort(cp); cp += INT16SZ;
238 if (ttype == type &&
239 tclass == class &&
240 strcasecmp(tname, name) == 0)
241 return (1);
243 return (0);
246 /* int
247 * res_queriesmatch(buf1, eom1, buf2, eom2)
248 * is there a 1:1 mapping of (name,type,class)
249 * in (buf1,eom1) and (buf2,eom2)?
250 * returns:
251 * -1 : format error
252 * 0 : not a 1:1 mapping
253 * >0 : is a 1:1 mapping
254 * author:
255 * paul vixie, 29may94
258 res_queriesmatch(buf1, eom1, buf2, eom2)
259 const u_char *buf1, *eom1;
260 const u_char *buf2, *eom2;
262 register const u_char *cp = buf1 + HFIXEDSZ;
263 int qdcount = ntohs(((HEADER*)buf1)->qdcount);
265 if (buf1 + HFIXEDSZ > eom1 || buf2 + HFIXEDSZ > eom2)
266 return (-1);
268 if (qdcount != ntohs(((HEADER*)buf2)->qdcount))
269 return (0);
270 while (qdcount-- > 0) {
271 char tname[MAXDNAME+1];
272 register int n, ttype, tclass;
274 n = dn_expand(buf1, eom1, cp, tname, sizeof tname);
275 if (n < 0)
276 return (-1);
277 cp += n;
278 if (cp + 2 * INT16SZ > eom1)
279 return (-1);
280 ttype = _getshort(cp); cp += INT16SZ;
281 tclass = _getshort(cp); cp += INT16SZ;
282 if (!res_nameinquery(tname, ttype, tclass, buf2, eom2))
283 return (0);
285 return (1);
289 res_send(buf, buflen, ans, anssiz)
290 const u_char *buf;
291 int buflen;
292 u_char *ans;
293 int anssiz;
295 HEADER *hp = (HEADER *) buf;
296 HEADER *anhp = (HEADER *) ans;
297 int gotsomewhere, connreset, terrno, try, v_circuit, resplen, ns;
298 register int n;
299 u_int badns; /* XXX NSMAX can't exceed #/bits in this var */
301 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
302 /* errno should have been set by res_init() in this case. */
303 return (-1);
305 if (anssiz < HFIXEDSZ) {
306 __set_errno (EINVAL);
307 return (-1);
309 DprintQ((_res.options & RES_DEBUG) || (_res.pfcode & RES_PRF_QUERY),
310 (stdout, ";; res_send()\n"), buf, buflen);
311 v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ;
312 gotsomewhere = 0;
313 connreset = 0;
314 terrno = ETIMEDOUT;
315 badns = 0;
318 * Send request, RETRY times, or until successful
320 for (try = 0; try < _res.retry; try++) {
321 for (ns = 0; ns < _res.nscount; ns++) {
322 struct sockaddr_in *nsap = &_res.nsaddr_list[ns];
323 same_ns:
324 if (badns & (1 << ns)) {
325 res_close();
326 goto next_ns;
329 if (Qhook) {
330 int done = 0, loops = 0;
332 do {
333 res_sendhookact act;
335 act = (*Qhook)(&nsap, &buf, &buflen,
336 ans, anssiz, &resplen);
337 switch (act) {
338 case res_goahead:
339 done = 1;
340 break;
341 case res_nextns:
342 res_close();
343 goto next_ns;
344 case res_done:
345 return (resplen);
346 case res_modified:
347 /* give the hook another try */
348 if (++loops < 42) /*doug adams*/
349 break;
350 /*FALLTHROUGH*/
351 case res_error:
352 /*FALLTHROUGH*/
353 default:
354 return (-1);
356 } while (!done);
359 Dprint(_res.options & RES_DEBUG,
360 (stdout, ";; Querying server (# %d) address = %s\n",
361 ns + 1, inet_ntoa(nsap->sin_addr)));
363 if (v_circuit) {
364 int truncated;
365 struct iovec iov[2];
366 u_short len;
367 u_char *cp;
370 * Use virtual circuit;
371 * at most one attempt per server.
373 try = _res.retry;
374 truncated = 0;
375 if ((s < 0) || (!vc)) {
376 if (s >= 0)
377 res_close();
379 s = socket(PF_INET, SOCK_STREAM, 0);
380 if (s < 0) {
381 terrno = errno;
382 Perror(stderr, "socket(vc)", errno);
383 return (-1);
385 __set_errno (0);
386 if (connect(s, (struct sockaddr *)nsap,
387 sizeof(struct sockaddr)) < 0) {
388 terrno = errno;
389 Aerror(stderr, "connect/vc",
390 errno, *nsap);
391 badns |= (1 << ns);
392 res_close();
393 goto next_ns;
395 vc = 1;
398 * Send length & message
400 putshort((u_short)buflen, (u_char*)&len);
401 iov[0].iov_base = (caddr_t)&len;
402 iov[0].iov_len = INT16SZ;
403 iov[1].iov_base = (caddr_t)buf;
404 iov[1].iov_len = buflen;
405 if (writev(s, iov, 2) != (INT16SZ + buflen)) {
406 terrno = errno;
407 Perror(stderr, "write failed", errno);
408 badns |= (1 << ns);
409 res_close();
410 goto next_ns;
413 * Receive length & response
415 read_len:
416 cp = ans;
417 len = INT16SZ;
418 while ((n = read(s, (char *)cp, (int)len)) > 0) {
419 cp += n;
420 if ((len -= n) <= 0)
421 break;
423 if (n <= 0) {
424 terrno = errno;
425 Perror(stderr, "read failed", errno);
426 res_close();
428 * A long running process might get its TCP
429 * connection reset if the remote server was
430 * restarted. Requery the server instead of
431 * trying a new one. When there is only one
432 * server, this means that a query might work
433 * instead of failing. We only allow one reset
434 * per query to prevent looping.
436 if (terrno == ECONNRESET && !connreset) {
437 connreset = 1;
438 res_close();
439 goto same_ns;
441 res_close();
442 goto next_ns;
444 resplen = _getshort(ans);
445 if (resplen > anssiz) {
446 Dprint(_res.options & RES_DEBUG,
447 (stdout, ";; response truncated\n")
449 truncated = 1;
450 len = anssiz;
451 } else
452 len = resplen;
453 if (len < HFIXEDSZ) {
455 * Undersized message.
457 Dprint(_res.options & RES_DEBUG,
458 (stdout, ";; undersized: %d\n", len));
459 terrno = EMSGSIZE;
460 badns |= (1 << ns);
461 res_close();
462 goto next_ns;
464 cp = ans;
465 while (len != 0 &&
466 (n = read(s, (char *)cp, (int)len)) > 0) {
467 cp += n;
468 len -= n;
470 if (n <= 0) {
471 terrno = errno;
472 Perror(stderr, "read(vc)", errno);
473 res_close();
474 goto next_ns;
476 if (truncated) {
478 * Flush rest of answer
479 * so connection stays in synch.
481 anhp->tc = 1;
482 len = resplen - anssiz;
483 while (len != 0) {
484 char junk[PACKETSZ];
486 n = ((size_t) len > sizeof(junk)
487 ? sizeof(junk)
488 : len);
489 if ((n = read(s, junk, n)) > 0)
490 len -= n;
491 else
492 break;
496 * The calling applicating has bailed out of
497 * a previous call and failed to arrange to have
498 * the circuit closed or the server has got
499 * itself confused. Anyway drop the packet and
500 * wait for the correct one.
502 if (hp->id != anhp->id) {
503 DprintQ((_res.options & RES_DEBUG) ||
504 (_res.pfcode & RES_PRF_REPLY),
505 (stdout, ";; old answer (unexpected):\n"),
506 ans, (resplen>anssiz)?anssiz:resplen);
507 goto read_len;
509 } else {
511 * Use datagrams.
513 int timeout;
514 struct pollfd pfd[1];
515 struct sockaddr_in from;
516 socklen_t fromlen;
518 if ((s < 0) || vc) {
519 if (vc)
520 res_close();
521 s = socket(PF_INET, SOCK_DGRAM, 0);
522 if (s < 0) {
523 #if !CAN_RECONNECT
524 bad_dg_sock:
525 #endif
526 terrno = errno;
527 Perror(stderr, "socket(dg)", errno);
528 return (-1);
530 connected = 0;
533 * On a 4.3BSD+ machine (client and server,
534 * actually), sending to a nameserver datagram
535 * port with no nameserver will cause an
536 * ICMP port unreachable message to be returned.
537 * If our datagram socket is "connected" to the
538 * server, we get an ECONNREFUSED error on the next
539 * socket operation, and select returns if the
540 * error message is received. We can thus detect
541 * the absence of a nameserver without timing out.
542 * If we have sent queries to at least two servers,
543 * however, we don't want to remain connected,
544 * as we wish to receive answers from the first
545 * server to respond.
547 if (_res.nscount == 1 || (try == 0 && ns == 0)) {
549 * Connect only if we are sure we won't
550 * receive a response from another server.
552 if (!connected) {
553 if (connect(s, (struct sockaddr *)nsap,
554 sizeof(struct sockaddr)
555 ) < 0) {
556 Aerror(stderr,
557 "connect(dg)",
558 errno, *nsap);
559 badns |= (1 << ns);
560 res_close();
561 goto next_ns;
563 connected = 1;
565 if (send(s, (char*)buf, buflen, 0) != buflen) {
566 Perror(stderr, "send", errno);
567 badns |= (1 << ns);
568 res_close();
569 goto next_ns;
571 } else {
573 * Disconnect if we want to listen
574 * for responses from more than one server.
576 if (connected) {
577 #if CAN_RECONNECT
578 struct sockaddr_in no_addr;
580 no_addr.sin_family = AF_INET;
581 no_addr.sin_addr.s_addr = INADDR_ANY;
582 no_addr.sin_port = 0;
583 (void) connect(s,
584 (struct sockaddr *)
585 &no_addr,
586 sizeof(no_addr));
587 #else
588 int s1 = socket(PF_INET, SOCK_DGRAM,0);
589 if (s1 < 0)
590 goto bad_dg_sock;
591 (void) dup2(s1, s);
592 (void) close(s1);
593 Dprint(_res.options & RES_DEBUG,
594 (stdout, ";; new DG socket\n"))
595 #endif
596 connected = 0;
597 __set_errno (0);
599 if (sendto(s, (char*)buf, buflen, 0,
600 (struct sockaddr *)nsap,
601 sizeof(struct sockaddr))
602 != buflen) {
603 Aerror(stderr, "sendto", errno, *nsap);
604 badns |= (1 << ns);
605 res_close();
606 goto next_ns;
611 * Wait for reply
613 timeout = (_res.retrans << try) * 1000;
614 if (try > 0)
615 timeout /= _res.nscount;
616 if (timeout <= 0)
617 timeout = 1000;
618 wait:
619 if (s < 0 || s >= FD_SETSIZE) {
620 Perror(stderr, "s out-of-bounds", EMFILE);
621 res_close();
622 goto next_ns;
624 pfd[0].fd = s;
625 pfd[0].events = POLLIN;
626 n = __poll(pfd, 1, timeout);
627 if (n < 0) {
628 if (errno == EINTR)
629 goto wait;
630 Perror(stderr, "poll", errno);
631 res_close();
632 goto next_ns;
634 if (n == 0) {
636 * timeout
638 Dprint(_res.options & RES_DEBUG,
639 (stdout, ";; timeout\n"));
640 gotsomewhere = 1;
641 res_close();
642 goto next_ns;
644 __set_errno (0);
645 fromlen = sizeof(struct sockaddr_in);
646 resplen = recvfrom(s, (char*)ans, anssiz, 0,
647 (struct sockaddr *)&from, &fromlen);
648 if (resplen <= 0) {
649 Perror(stderr, "recvfrom", errno);
650 res_close();
651 goto next_ns;
653 gotsomewhere = 1;
654 if (resplen < HFIXEDSZ) {
656 * Undersized message.
658 Dprint(_res.options & RES_DEBUG,
659 (stdout, ";; undersized: %d\n",
660 resplen));
661 terrno = EMSGSIZE;
662 badns |= (1 << ns);
663 res_close();
664 goto next_ns;
666 if (hp->id != anhp->id) {
668 * response from old query, ignore it.
669 * XXX - potential security hazard could
670 * be detected here.
672 DprintQ((_res.options & RES_DEBUG) ||
673 (_res.pfcode & RES_PRF_REPLY),
674 (stdout, ";; old answer:\n"),
675 ans, (resplen>anssiz)?anssiz:resplen);
676 goto wait;
678 #if CHECK_SRVR_ADDR
679 if (!(_res.options & RES_INSECURE1) &&
680 !res_isourserver(&from)) {
682 * response from wrong server? ignore it.
683 * XXX - potential security hazard could
684 * be detected here.
686 DprintQ((_res.options & RES_DEBUG) ||
687 (_res.pfcode & RES_PRF_REPLY),
688 (stdout, ";; not our server:\n"),
689 ans, (resplen>anssiz)?anssiz:resplen);
690 goto wait;
692 #endif
693 if (!(_res.options & RES_INSECURE2) &&
694 !res_queriesmatch(buf, buf + buflen,
695 ans, ans + anssiz)) {
697 * response contains wrong query? ignore it.
698 * XXX - potential security hazard could
699 * be detected here.
701 DprintQ((_res.options & RES_DEBUG) ||
702 (_res.pfcode & RES_PRF_REPLY),
703 (stdout, ";; wrong query name:\n"),
704 ans, (resplen>anssiz)?anssiz:resplen);
705 goto wait;
707 if (anhp->rcode == SERVFAIL ||
708 anhp->rcode == NOTIMP ||
709 anhp->rcode == REFUSED) {
710 DprintQ(_res.options & RES_DEBUG,
711 (stdout, "server rejected query:\n"),
712 ans, (resplen>anssiz)?anssiz:resplen);
713 badns |= (1 << ns);
714 res_close();
715 /* don't retry if called from dig */
716 if (!_res.pfcode)
717 goto next_ns;
719 if (!(_res.options & RES_IGNTC) && anhp->tc) {
721 * get rest of answer;
722 * use TCP with same server.
724 Dprint(_res.options & RES_DEBUG,
725 (stdout, ";; truncated answer\n"));
726 v_circuit = 1;
727 res_close();
728 goto same_ns;
730 } /*if vc/dg*/
731 Dprint((_res.options & RES_DEBUG) ||
732 ((_res.pfcode & RES_PRF_REPLY) &&
733 (_res.pfcode & RES_PRF_HEAD1)),
734 (stdout, ";; got answer:\n"));
735 DprintQ((_res.options & RES_DEBUG) ||
736 (_res.pfcode & RES_PRF_REPLY),
737 (stdout, ""),
738 ans, (resplen>anssiz)?anssiz:resplen);
740 * If using virtual circuits, we assume that the first server
741 * is preferred over the rest (i.e. it is on the local
742 * machine) and only keep that one open.
743 * If we have temporarily opened a virtual circuit,
744 * or if we haven't been asked to keep a socket open,
745 * close the socket.
747 if ((v_circuit && (!(_res.options & RES_USEVC) || ns != 0)) ||
748 !(_res.options & RES_STAYOPEN)) {
749 res_close();
751 if (Rhook) {
752 int done = 0, loops = 0;
754 do {
755 res_sendhookact act;
757 act = (*Rhook)(nsap, buf, buflen,
758 ans, anssiz, &resplen);
759 switch (act) {
760 case res_goahead:
761 case res_done:
762 done = 1;
763 break;
764 case res_nextns:
765 res_close();
766 goto next_ns;
767 case res_modified:
768 /* give the hook another try */
769 if (++loops < 42) /*doug adams*/
770 break;
771 /*FALLTHROUGH*/
772 case res_error:
773 /*FALLTHROUGH*/
774 default:
775 return (-1);
777 } while (!done);
780 return (resplen);
781 next_ns: ;
782 } /*foreach ns*/
783 } /*foreach retry*/
784 res_close();
785 if (!v_circuit)
786 if (!gotsomewhere)
787 __set_errno (ECONNREFUSED); /* no nameservers found */
788 else
789 __set_errno (ETIMEDOUT); /* no answer obtained */
790 else
791 __set_errno (terrno);
792 return (-1);
796 * This routine is for closing the socket if a virtual circuit is used and
797 * the program wants to close it. This provides support for endhostent()
798 * which expects to close the socket.
800 * This routine is not expected to be user visible.
802 void
803 res_close()
805 if (s >= 0) {
806 (void) close(s);
807 s = -1;
808 connected = 0;
809 vc = 0;
813 #ifdef ultrix
814 /* ultrix 4.0 had some icky packaging in its libc.a. alias for it here.
815 * there is more gunk of this kind over in res_debug.c.
818 void
819 _res_close()
821 res_close();
824 #undef res_send
826 res_send(buf, buflen, ans, anssiz)
827 const u_char *buf;
828 int buflen;
829 u_char *ans;
830 int anssiz;
832 return (__res_send(buf, buflen, ans, anssiz));
834 #endif /* Ultrix 4.0 hackery */