2 * Copyright (c) 1985, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
53 * Permission to use, copy, modify, and distribute this software for any
54 * purpose with or without fee is hereby granted, provided that the above
55 * copyright notice and this permission notice appear in all copies.
57 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
58 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
60 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
61 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
62 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
63 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
67 #if defined(LIBC_SCCS) && !defined(lint)
68 static const char sccsid
[] = "@(#)res_send.c 8.1 (Berkeley) 6/4/93";
69 static const char rcsid
[] = "$BINDId: res_send.c,v 8.38 2000/03/30 20:16:51 vixie Exp $";
70 #endif /* LIBC_SCCS and not lint */
73 * Send query to name server and wait for reply.
77 #include <sys/types.h>
78 #include <sys/param.h>
80 #include <sys/socket.h>
84 #include <netinet/in.h>
85 #include <arpa/nameser.h>
86 #include <arpa/inet.h>
87 #include <sys/ioctl.h>
100 #define MAXPACKET PACKETSZ
102 #define MAXPACKET 65536
106 /* From ev_streams.c. */
109 __attribute ((always_inline
))
110 evConsIovec(void *buf
, size_t cnt
, struct iovec
*vec
) {
111 memset(vec
, 0xf5, sizeof (*vec
));
116 /* From ev_timers.c. */
118 #define BILLION 1000000000
121 evConsTime(struct timespec
*res
, time_t sec
, long nsec
) {
127 evAddTime(struct timespec
*res
, const struct timespec
*addend1
,
128 const struct timespec
*addend2
) {
129 res
->tv_sec
= addend1
->tv_sec
+ addend2
->tv_sec
;
130 res
->tv_nsec
= addend1
->tv_nsec
+ addend2
->tv_nsec
;
131 if (res
->tv_nsec
>= BILLION
) {
133 res
->tv_nsec
-= BILLION
;
138 evSubTime(struct timespec
*res
, const struct timespec
*minuend
,
139 const struct timespec
*subtrahend
) {
140 res
->tv_sec
= minuend
->tv_sec
- subtrahend
->tv_sec
;
141 if (minuend
->tv_nsec
>= subtrahend
->tv_nsec
)
142 res
->tv_nsec
= minuend
->tv_nsec
- subtrahend
->tv_nsec
;
144 res
->tv_nsec
= (BILLION
145 - subtrahend
->tv_nsec
+ minuend
->tv_nsec
);
151 evCmpTime(struct timespec a
, struct timespec b
) {
152 long x
= a
.tv_sec
- b
.tv_sec
;
155 x
= a
.tv_nsec
- b
.tv_nsec
;
156 return (x
< 0L ? (-1) : x
> 0L ? (1) : (0));
160 evNowTime(struct timespec
*res
) {
163 if (gettimeofday(&now
, NULL
) < 0)
164 evConsTime(res
, 0, 0);
166 TIMEVAL_TO_TIMESPEC (&now
, res
);
170 /* Options. Leave them on. */
172 #include "res_debug.h"
174 #define EXT(res) ((res)->_u._ext)
178 static int send_vc(res_state
, const u_char
*, int,
179 u_char
**, int *, int *, int, u_char
**);
180 static int send_dg(res_state
, const u_char
*, int,
181 u_char
**, int *, int *, int,
182 int *, int *, u_char
**);
184 static void Aerror(const res_state
, FILE *, const char *, int,
185 const struct sockaddr
*);
186 static void Perror(const res_state
, FILE *, const char *, int);
188 static int sock_eq(struct sockaddr_in6
*, struct sockaddr_in6
*);
192 static void convaddr4to6(struct sockaddr_in6
*sa
);
193 void res_pquery(const res_state
, const u_char
*, int, FILE *);
198 * res_isourserver(ina)
199 * looks up "ina" in _res.ns_addr_list[]
204 * paul vixie, 29may94
207 res_ourserver_p(const res_state statp
, const struct sockaddr_in6
*inp
)
211 if (inp
->sin6_family
== AF_INET
) {
212 struct sockaddr_in
*in4p
= (struct sockaddr_in
*) inp
;
213 in_port_t port
= in4p
->sin_port
;
214 in_addr_t addr
= in4p
->sin_addr
.s_addr
;
216 for (ns
= 0; ns
< MAXNS
; ns
++) {
217 const struct sockaddr_in
*srv
=
218 (struct sockaddr_in
*)EXT(statp
).nsaddrs
[ns
];
220 if ((srv
!= NULL
) && (srv
->sin_family
== AF_INET
) &&
221 (srv
->sin_port
== port
) &&
222 (srv
->sin_addr
.s_addr
== INADDR_ANY
||
223 srv
->sin_addr
.s_addr
== addr
))
226 } else if (inp
->sin6_family
== AF_INET6
) {
227 for (ns
= 0; ns
< MAXNS
; ns
++) {
228 const struct sockaddr_in6
*srv
= EXT(statp
).nsaddrs
[ns
];
229 if ((srv
!= NULL
) && (srv
->sin6_family
== AF_INET6
) &&
230 (srv
->sin6_port
== inp
->sin6_port
) &&
231 !(memcmp(&srv
->sin6_addr
, &in6addr_any
,
232 sizeof (struct in6_addr
)) &&
233 memcmp(&srv
->sin6_addr
, &inp
->sin6_addr
,
234 sizeof (struct in6_addr
))))
242 * res_nameinquery(name, type, class, buf, eom)
243 * look for (name,type,class) in the query section of packet (buf,eom)
245 * buf + HFIXEDSZ <= eom
251 * paul vixie, 29may94
254 res_nameinquery(const char *name
, int type
, int class,
255 const u_char
*buf
, const u_char
*eom
)
257 const u_char
*cp
= buf
+ HFIXEDSZ
;
258 int qdcount
= ntohs(((HEADER
*)buf
)->qdcount
);
260 while (qdcount
-- > 0) {
261 char tname
[MAXDNAME
+1];
262 int n
, ttype
, tclass
;
264 n
= dn_expand(buf
, eom
, cp
, tname
, sizeof tname
);
268 if (cp
+ 2 * INT16SZ
> eom
)
271 NS_GET16(tclass
, cp
);
272 if (ttype
== type
&& tclass
== class &&
273 ns_samename(tname
, name
) == 1)
278 libresolv_hidden_def (res_nameinquery
)
281 * res_queriesmatch(buf1, eom1, buf2, eom2)
282 * is there a 1:1 mapping of (name,type,class)
283 * in (buf1,eom1) and (buf2,eom2)?
286 * 0 : not a 1:1 mapping
287 * >0 : is a 1:1 mapping
289 * paul vixie, 29may94
292 res_queriesmatch(const u_char
*buf1
, const u_char
*eom1
,
293 const u_char
*buf2
, const u_char
*eom2
)
295 if (buf1
+ HFIXEDSZ
> eom1
|| buf2
+ HFIXEDSZ
> eom2
)
299 * Only header section present in replies to
300 * dynamic update packets.
302 if ((((HEADER
*)buf1
)->opcode
== ns_o_update
) &&
303 (((HEADER
*)buf2
)->opcode
== ns_o_update
))
306 /* Note that we initially do not convert QDCOUNT to the host byte
307 order. We can compare it with the second buffer's QDCOUNT
308 value without doing this. */
309 int qdcount
= ((HEADER
*)buf1
)->qdcount
;
310 if (qdcount
!= ((HEADER
*)buf2
)->qdcount
)
313 qdcount
= htons (qdcount
);
314 const u_char
*cp
= buf1
+ HFIXEDSZ
;
316 while (qdcount
-- > 0) {
317 char tname
[MAXDNAME
+1];
318 int n
, ttype
, tclass
;
320 n
= dn_expand(buf1
, eom1
, cp
, tname
, sizeof tname
);
324 if (cp
+ 2 * INT16SZ
> eom1
)
327 NS_GET16(tclass
, cp
);
328 if (!res_nameinquery(tname
, ttype
, tclass
, buf2
, eom2
))
333 libresolv_hidden_def (res_queriesmatch
)
336 __libc_res_nsend(res_state statp
, const u_char
*buf
, int buflen
,
337 u_char
*ans
, int anssiz
, u_char
**ansp
)
339 int gotsomewhere
, terrno
, try, v_circuit
, resplen
, ns
, n
;
341 if (statp
->nscount
== 0) {
346 if (anssiz
< HFIXEDSZ
) {
347 __set_errno (EINVAL
);
351 if ((statp
->qhook
|| statp
->rhook
) && anssiz
< MAXPACKET
&& ansp
) {
352 u_char
*buf
= malloc (MAXPACKET
);
355 memcpy (buf
, ans
, HFIXEDSZ
);
361 DprintQ((statp
->options
& RES_DEBUG
) || (statp
->pfcode
& RES_PRF_QUERY
),
362 (stdout
, ";; res_send()\n"), buf
, buflen
);
363 v_circuit
= (statp
->options
& RES_USEVC
) || buflen
> PACKETSZ
;
368 * If the ns_addr_list in the resolver context has changed, then
369 * invalidate our cached copy and the associated timing data.
371 if (EXT(statp
).nsinit
) {
374 if (EXT(statp
).nscount
!= statp
->nscount
)
377 for (ns
= 0; ns
< MAXNS
; ns
++) {
378 unsigned int map
= EXT(statp
).nsmap
[ns
];
380 && !sock_eq((struct sockaddr_in6
*)
381 &statp
->nsaddr_list
[map
],
382 EXT(statp
).nsaddrs
[ns
]))
389 __res_iclose(statp
, false);
393 * Maybe initialize our private copy of the ns_addr_list.
395 if (EXT(statp
).nsinit
== 0) {
396 unsigned char map
[MAXNS
];
398 memset (map
, MAXNS
, sizeof (map
));
399 for (n
= 0; n
< MAXNS
; n
++) {
400 ns
= EXT(statp
).nsmap
[n
];
401 if (ns
< statp
->nscount
)
403 else if (ns
< MAXNS
) {
404 free(EXT(statp
).nsaddrs
[n
]);
405 EXT(statp
).nsaddrs
[n
] = NULL
;
406 EXT(statp
).nsmap
[n
] = MAXNS
;
410 if (statp
->nscount
> EXT(statp
).nscount
)
411 for (n
= EXT(statp
).nscount
, ns
= 0;
412 n
< statp
->nscount
; n
++) {
414 && EXT(statp
).nsmap
[ns
] != MAXNS
)
418 EXT(statp
).nsmap
[ns
] = n
;
421 EXT(statp
).nscount
= n
;
422 for (ns
= 0; ns
< EXT(statp
).nscount
; ns
++) {
424 if (EXT(statp
).nsaddrs
[n
] == NULL
)
425 EXT(statp
).nsaddrs
[n
] =
426 malloc(sizeof (struct sockaddr_in6
));
427 if (EXT(statp
).nsaddrs
[n
] != NULL
) {
428 memcpy(EXT(statp
).nsaddrs
[n
],
429 &statp
->nsaddr_list
[ns
],
430 sizeof (struct sockaddr_in
));
431 EXT(statp
).nssocks
[n
] = -1;
435 EXT(statp
).nsinit
= 1;
439 * Some resolvers want to even out the load on their nameservers.
440 * Note that RES_BLAST overrides RES_ROTATE.
442 if ((statp
->options
& RES_ROTATE
) != 0 &&
443 (statp
->options
& RES_BLAST
) == 0) {
444 struct sockaddr_in6
*ina
;
448 while (n
< MAXNS
&& EXT(statp
).nsmap
[n
] == MAXNS
)
451 ina
= EXT(statp
).nsaddrs
[n
];
452 map
= EXT(statp
).nsmap
[n
];
456 && EXT(statp
).nsmap
[ns
] == MAXNS
)
460 EXT(statp
).nsaddrs
[n
] = EXT(statp
).nsaddrs
[ns
];
461 EXT(statp
).nsmap
[n
] = EXT(statp
).nsmap
[ns
];
464 EXT(statp
).nsaddrs
[n
] = ina
;
465 EXT(statp
).nsmap
[n
] = map
;
470 * Send request, RETRY times, or until successful.
472 for (try = 0; try < statp
->retry
; try++) {
473 for (ns
= 0; ns
< MAXNS
; ns
++)
475 struct sockaddr_in6
*nsap
= EXT(statp
).nsaddrs
[ns
];
481 int done
= 0, loops
= 0;
486 struct sockaddr_in
*nsap4
;
487 nsap4
= (struct sockaddr_in
*) nsap
;
488 act
= (*statp
->qhook
)(&nsap4
, &buf
, &buflen
,
489 ans
, anssiz
, &resplen
);
490 nsap
= (struct sockaddr_in6
*) nsap4
;
496 __res_iclose(statp
, false);
501 /* give the hook another try */
502 if (++loops
< 42) /*doug adams*/
516 Dprint(statp
->options
& RES_DEBUG
,
517 (stdout
, ";; Querying server (# %d) address = %s\n",
518 ns
+ 1, inet_ntop(AF_INET6
, &nsap
->sin6_addr
,
519 tmpbuf
, sizeof (tmpbuf
))));
522 /* Use VC; at most one attempt per server. */
524 n
= send_vc(statp
, buf
, buflen
, &ans
, &anssiz
, &terrno
,
533 n
= send_dg(statp
, buf
, buflen
, &ans
, &anssiz
, &terrno
,
534 ns
, &v_circuit
, &gotsomewhere
, ansp
);
544 Dprint((statp
->options
& RES_DEBUG
) ||
545 ((statp
->pfcode
& RES_PRF_REPLY
) &&
546 (statp
->pfcode
& RES_PRF_HEAD1
)),
547 (stdout
, ";; got answer:\n"));
549 DprintQ((statp
->options
& RES_DEBUG
) ||
550 (statp
->pfcode
& RES_PRF_REPLY
),
552 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
555 * If we have temporarily opened a virtual circuit,
556 * or if we haven't been asked to keep a socket open,
559 if ((v_circuit
&& (statp
->options
& RES_USEVC
) == 0) ||
560 (statp
->options
& RES_STAYOPEN
) == 0) {
561 __res_iclose(statp
, false);
564 int done
= 0, loops
= 0;
569 act
= (*statp
->rhook
)((struct sockaddr_in
*)
571 ans
, anssiz
, &resplen
);
578 __res_iclose(statp
, false);
581 /* give the hook another try */
582 if (++loops
< 42) /*doug adams*/
597 __res_iclose(statp
, false);
600 __set_errno (ECONNREFUSED
); /* no nameservers found */
602 __set_errno (ETIMEDOUT
); /* no answer obtained */
604 __set_errno (terrno
);
609 res_nsend(res_state statp
,
610 const u_char
*buf
, int buflen
, u_char
*ans
, int anssiz
)
612 return __libc_res_nsend(statp
, buf
, buflen
, ans
, anssiz
, NULL
);
614 libresolv_hidden_def (res_nsend
)
619 send_vc(res_state statp
,
620 const u_char
*buf
, int buflen
, u_char
**ansp
, int *anssizp
,
621 int *terrno
, int ns
, u_char
**anscp
)
623 const HEADER
*hp
= (HEADER
*) buf
;
625 int anssiz
= *anssizp
;
626 HEADER
*anhp
= (HEADER
*) ans
;
627 struct sockaddr_in6
*nsap
= EXT(statp
).nsaddrs
[ns
];
628 int truncating
, connreset
, resplen
, n
;
637 /* Are we still talking to whom we want to talk to? */
638 if (statp
->_vcsock
>= 0 && (statp
->_flags
& RES_F_VC
) != 0) {
639 struct sockaddr_in6 peer
;
640 socklen_t size
= sizeof peer
;
642 if (getpeername(statp
->_vcsock
,
643 (struct sockaddr
*)&peer
, &size
) < 0 ||
644 !sock_eq(&peer
, nsap
)) {
645 __res_iclose(statp
, false);
646 statp
->_flags
&= ~RES_F_VC
;
650 if (statp
->_vcsock
< 0 || (statp
->_flags
& RES_F_VC
) == 0) {
651 if (statp
->_vcsock
>= 0)
652 __res_iclose(statp
, false);
654 statp
->_vcsock
= socket(nsap
->sin6_family
, SOCK_STREAM
, 0);
655 if (statp
->_vcsock
< 0) {
657 Perror(statp
, stderr
, "socket(vc)", errno
);
661 if (connect(statp
->_vcsock
, (struct sockaddr
*)nsap
,
662 nsap
->sin6_family
== AF_INET
663 ? sizeof (struct sockaddr_in
)
664 : sizeof (struct sockaddr_in6
)) < 0) {
666 Aerror(statp
, stderr
, "connect/vc", errno
,
667 (struct sockaddr
*) nsap
);
668 __res_iclose(statp
, false);
671 statp
->_flags
|= RES_F_VC
;
675 * Send length & message
677 ns_put16((u_short
)buflen
, (u_char
*)&len
);
678 evConsIovec(&len
, INT16SZ
, &iov
[0]);
679 evConsIovec((void*)buf
, buflen
, &iov
[1]);
680 if (TEMP_FAILURE_RETRY (writev(statp
->_vcsock
, iov
, 2))
681 != (INT16SZ
+ buflen
)) {
683 Perror(statp
, stderr
, "write failed", errno
);
684 __res_iclose(statp
, false);
688 * Receive length & response
693 while ((n
= TEMP_FAILURE_RETRY (read(statp
->_vcsock
, (char *)cp
,
701 Perror(statp
, stderr
, "read failed", errno
);
702 __res_iclose(statp
, false);
704 * A long running process might get its TCP
705 * connection reset if the remote server was
706 * restarted. Requery the server instead of
707 * trying a new one. When there is only one
708 * server, this means that a query might work
709 * instead of failing. We only allow one reset
710 * per query to prevent looping.
712 if (*terrno
== ECONNRESET
&& !connreset
) {
718 resplen
= ns_get16(ans
);
719 if (resplen
> anssiz
) {
721 ans
= malloc (MAXPACKET
);
724 __res_iclose(statp
, false);
728 *anssizp
= MAXPACKET
;
731 anhp
= (HEADER
*) ans
;
734 Dprint(statp
->options
& RES_DEBUG
,
735 (stdout
, ";; response truncated\n")
742 if (len
< HFIXEDSZ
) {
744 * Undersized message.
746 Dprint(statp
->options
& RES_DEBUG
,
747 (stdout
, ";; undersized: %d\n", len
));
749 __res_iclose(statp
, false);
753 while (len
!= 0 && (n
= read(statp
->_vcsock
, (char *)cp
, (int)len
)) > 0){
759 Perror(statp
, stderr
, "read(vc)", errno
);
760 __res_iclose(statp
, false);
765 * Flush rest of answer so connection stays in synch.
768 len
= resplen
- anssiz
;
772 n
= read(statp
->_vcsock
, junk
,
773 (len
> sizeof junk
) ? sizeof junk
: len
);
781 * If the calling applicating has bailed out of
782 * a previous call and failed to arrange to have
783 * the circuit closed or the server has got
784 * itself confused, then drop the packet and
785 * wait for the correct one.
787 if (hp
->id
!= anhp
->id
) {
788 DprintQ((statp
->options
& RES_DEBUG
) ||
789 (statp
->pfcode
& RES_PRF_REPLY
),
790 (stdout
, ";; old answer (unexpected):\n"),
791 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
796 * All is well, or the error is fatal. Signal that the
797 * next nameserver ought not be tried.
803 send_dg(res_state statp
,
804 const u_char
*buf
, int buflen
, u_char
**ansp
, int *anssizp
,
805 int *terrno
, int ns
, int *v_circuit
, int *gotsomewhere
, u_char
**anscp
)
807 const HEADER
*hp
= (HEADER
*) buf
;
809 int anssiz
= *anssizp
;
810 HEADER
*anhp
= (HEADER
*) ans
;
811 struct sockaddr_in6
*nsap
= EXT(statp
).nsaddrs
[ns
];
812 struct timespec now
, timeout
, finish
;
813 struct pollfd pfd
[1];
815 struct sockaddr_in6 from
;
816 static int socket_pf
= 0;
818 int resplen
, seconds
, n
;
820 if (EXT(statp
).nssocks
[ns
] == -1) {
821 /* only try IPv6 if IPv6 NS and if not failed before */
822 if ((EXT(statp
).nscount6
> 0) && (socket_pf
!= PF_INET
)) {
823 EXT(statp
).nssocks
[ns
] =
824 socket(PF_INET6
, SOCK_DGRAM
, 0);
825 socket_pf
= EXT(statp
).nssocks
[ns
] < 0 ? PF_INET
828 if (EXT(statp
).nssocks
[ns
] < 0)
829 EXT(statp
).nssocks
[ns
] = socket(PF_INET
, SOCK_DGRAM
, 0);
830 if (EXT(statp
).nssocks
[ns
] < 0) {
832 Perror(statp
, stderr
, "socket(dg)", errno
);
835 /* If IPv6 socket and nsap is IPv4, make it IPv4-mapped */
836 if ((socket_pf
== PF_INET6
) && (nsap
->sin6_family
== AF_INET
))
839 * On a 4.3BSD+ machine (client and server,
840 * actually), sending to a nameserver datagram
841 * port with no nameserver will cause an
842 * ICMP port unreachable message to be returned.
843 * If our datagram socket is "connected" to the
844 * server, we get an ECONNREFUSED error on the next
845 * socket operation, and select returns if the
846 * error message is received. We can thus detect
847 * the absence of a nameserver without timing out.
849 if (connect(EXT(statp
).nssocks
[ns
], (struct sockaddr
*)nsap
,
851 Aerror(statp
, stderr
, "connect(dg)", errno
,
852 (struct sockaddr
*) nsap
);
853 __res_iclose(statp
, false);
856 /* Make socket non-blocking. */
857 int fl
= __fcntl (EXT(statp
).nssocks
[ns
], F_GETFL
);
859 __fcntl (EXT(statp
).nssocks
[ns
], F_SETFL
,
861 Dprint(statp
->options
& RES_DEBUG
,
862 (stdout
, ";; new DG socket\n"))
866 * Compute time for the total operation.
868 seconds
= (statp
->retrans
<< ns
);
870 seconds
/= statp
->nscount
;
874 evConsTime(&timeout
, seconds
, 0);
875 evAddTime(&finish
, &now
, &timeout
);
876 int need_recompute
= 0;
878 pfd
[0].fd
= EXT(statp
).nssocks
[ns
];
879 pfd
[0].events
= POLLOUT
;
881 if (need_recompute
) {
884 if (evCmpTime(finish
, now
) <= 0) {
886 Perror(statp
, stderr
, "poll", errno
);
888 __res_iclose(statp
, false);
891 evSubTime(&timeout
, &finish
, &now
);
893 /* Convert struct timespec in milliseconds. */
894 ptimeout
= timeout
.tv_sec
* 1000 + timeout
.tv_nsec
/ 1000000;
898 n
= __poll (pfd
, 1, 0);
899 if (__builtin_expect (n
== 0, 0)) {
900 n
= __poll (pfd
, 1, ptimeout
);
904 Dprint(statp
->options
& RES_DEBUG
, (stdout
,
905 ";; timeout sending\n"));
911 goto recompute_resend
;
916 if (pfd
[0].revents
& POLLOUT
) {
917 if (send (pfd
[0].fd
, buf
, buflen
, MSG_NOSIGNAL
) != buflen
) {
918 if (errno
== EINTR
|| errno
== EAGAIN
)
919 goto recompute_resend
;
920 Perror(statp
, stderr
, "send", errno
);
923 pfd
[0].events
= POLLIN
;
926 } else if (pfd
[0].revents
& POLLIN
) {
927 fromlen
= sizeof(struct sockaddr_in6
);
928 if (anssiz
< MAXPACKET
930 && (ioctl (pfd
[0].fd
, FIONREAD
, &resplen
) < 0
931 || anssiz
< resplen
)) {
932 ans
= malloc (MAXPACKET
);
937 *anssizp
= MAXPACKET
;
940 anhp
= (HEADER
*) ans
;
943 resplen
= recvfrom(pfd
[0].fd
, (char*)ans
, anssiz
,0,
944 (struct sockaddr
*)&from
, &fromlen
);
946 if (errno
== EINTR
|| errno
== EAGAIN
) {
950 Perror(statp
, stderr
, "recvfrom", errno
);
954 if (resplen
< HFIXEDSZ
) {
956 * Undersized message.
958 Dprint(statp
->options
& RES_DEBUG
,
959 (stdout
, ";; undersized: %d\n",
964 if (hp
->id
!= anhp
->id
) {
966 * response from old query, ignore it.
967 * XXX - potential security hazard could
970 DprintQ((statp
->options
& RES_DEBUG
) ||
971 (statp
->pfcode
& RES_PRF_REPLY
),
972 (stdout
, ";; old answer:\n"),
973 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
976 if (!(statp
->options
& RES_INSECURE1
) &&
977 !res_ourserver_p(statp
, &from
)) {
979 * response from wrong server? ignore it.
980 * XXX - potential security hazard could
983 DprintQ((statp
->options
& RES_DEBUG
) ||
984 (statp
->pfcode
& RES_PRF_REPLY
),
985 (stdout
, ";; not our server:\n"),
986 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
990 if (anhp
->rcode
== FORMERR
991 && (statp
->options
& RES_USE_EDNS0
) != 0U) {
993 * Do not retry if the server do not understand
994 * EDNS0. The case has to be captured here, as
995 * FORMERR packet do not carry query section, hence
996 * res_queriesmatch() returns 0.
998 DprintQ(statp
->options
& RES_DEBUG
,
1000 "server rejected query with EDNS0:\n"),
1001 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
1002 /* record the error */
1003 statp
->_flags
|= RES_F_EDNS0ERR
;
1007 if (!(statp
->options
& RES_INSECURE2
) &&
1008 !res_queriesmatch(buf
, buf
+ buflen
,
1009 ans
, ans
+ anssiz
)) {
1011 * response contains wrong query? ignore it.
1012 * XXX - potential security hazard could
1015 DprintQ((statp
->options
& RES_DEBUG
) ||
1016 (statp
->pfcode
& RES_PRF_REPLY
),
1017 (stdout
, ";; wrong query name:\n"),
1018 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
1021 if (anhp
->rcode
== SERVFAIL
||
1022 anhp
->rcode
== NOTIMP
||
1023 anhp
->rcode
== REFUSED
) {
1024 DprintQ(statp
->options
& RES_DEBUG
,
1025 (stdout
, "server rejected query:\n"),
1026 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
1028 __res_iclose(statp
, false);
1029 /* don't retry if called from dig */
1033 if (anhp
->rcode
== NOERROR
&& anhp
->ancount
== 0
1034 && anhp
->aa
== 0 && anhp
->ra
== 0 && anhp
->arcount
== 0) {
1035 DprintQ(statp
->options
& RES_DEBUG
,
1036 (stdout
, "referred query:\n"),
1037 ans
, (resplen
> anssiz
) ? anssiz
: resplen
);
1040 if (!(statp
->options
& RES_IGNTC
) && anhp
->tc
) {
1042 * To get the rest of answer,
1043 * use TCP with same server.
1045 Dprint(statp
->options
& RES_DEBUG
,
1046 (stdout
, ";; truncated answer\n"));
1048 __res_iclose(statp
, false);
1052 * All is well, or the error is fatal. Signal that the
1053 * next nameserver ought not be tried.
1056 } else if (pfd
[0].revents
& (POLLERR
| POLLHUP
| POLLNVAL
)) {
1057 /* Something went wrong. We can stop trying. */
1061 /* poll should not have returned > 0 in this case. */
1068 Aerror(const res_state statp
, FILE *file
, const char *string
, int error
,
1069 const struct sockaddr
*address
)
1073 if ((statp
->options
& RES_DEBUG
) != 0) {
1074 char tmp
[sizeof "xxxx.xxxx.xxxx.255.255.255.255"];
1076 fprintf(file
, "res_send: %s ([%s].%u): %s\n",
1078 (address
->sa_family
== AF_INET
1079 ? inet_ntop(address
->sa_family
,
1080 &((const struct sockaddr_in
*) address
)->sin_addr
,
1082 : inet_ntop(address
->sa_family
,
1083 &((const struct sockaddr_in6
*) address
)->sin6_addr
,
1085 (address
->sa_family
== AF_INET
1086 ? ntohs(((struct sockaddr_in
*) address
)->sin_port
)
1087 : address
->sa_family
== AF_INET6
1088 ? ntohs(((struct sockaddr_in6
*) address
)->sin6_port
)
1096 Perror(const res_state statp
, FILE *file
, const char *string
, int error
) {
1099 if ((statp
->options
& RES_DEBUG
) != 0)
1100 fprintf(file
, "res_send: %s: %s\n",
1101 string
, strerror(error
));
1107 sock_eq(struct sockaddr_in6
*a1
, struct sockaddr_in6
*a2
) {
1108 if (a1
->sin6_family
== a2
->sin6_family
) {
1109 if (a1
->sin6_family
== AF_INET
)
1110 return ((((struct sockaddr_in
*)a1
)->sin_port
==
1111 ((struct sockaddr_in
*)a2
)->sin_port
) &&
1112 (((struct sockaddr_in
*)a1
)->sin_addr
.s_addr
==
1113 ((struct sockaddr_in
*)a2
)->sin_addr
.s_addr
));
1115 return ((a1
->sin6_port
== a2
->sin6_port
) &&
1116 !memcmp(&a1
->sin6_addr
, &a2
->sin6_addr
,
1117 sizeof (struct in6_addr
)));
1119 if (a1
->sin6_family
== AF_INET
) {
1120 struct sockaddr_in6
*sap
= a1
;
1123 } /* assumes that AF_INET and AF_INET6 are the only possibilities */
1124 return ((a1
->sin6_port
== ((struct sockaddr_in
*)a2
)->sin_port
) &&
1125 IN6_IS_ADDR_V4MAPPED(&a1
->sin6_addr
) &&
1126 (a1
->sin6_addr
.s6_addr32
[3] ==
1127 ((struct sockaddr_in
*)a2
)->sin_addr
.s_addr
));
1131 * Converts IPv4 family, address and port to
1132 * IPv6 family, IPv4-mapped IPv6 address and port.
1135 convaddr4to6(struct sockaddr_in6
*sa
)
1137 struct sockaddr_in
*sa4p
= (struct sockaddr_in
*) sa
;
1138 in_port_t port
= sa4p
->sin_port
;
1139 in_addr_t addr
= sa4p
->sin_addr
.s_addr
;
1141 sa
->sin6_family
= AF_INET6
;
1142 sa
->sin6_port
= port
;
1143 sa
->sin6_addr
.s6_addr32
[0] = 0;
1144 sa
->sin6_addr
.s6_addr32
[1] = 0;
1145 sa
->sin6_addr
.s6_addr32
[2] = htonl(0xFFFF);
1146 sa
->sin6_addr
.s6_addr32
[3] = addr
;