2 Unix SMB/CIFS implementation.
4 Copyright (C) Gerald (Jerry) Carter 2006.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 /* AIX resolv.h uses 'class' in struct ns_rr */
31 /* resolver headers */
33 #include <sys/types.h>
34 #include <netinet/in.h>
35 #include <arpa/nameser.h>
39 #define MAX_DNS_PACKET_SIZE 0xffff
41 #ifdef NS_HFIXEDSZ /* Bind 8/9 interface */
42 #if !defined(C_IN) /* AIX 5.3 already defines C_IN */
45 #if !defined(T_A) /* AIX 5.3 already defines T_A */
48 # define T_SRV ns_t_srv
49 #if !defined(T_NS) /* AIX 5.3 already defines T_NS */
54 # define NS_HFIXEDSZ HFIXEDSZ
56 # define NS_HFIXEDSZ sizeof(HEADER)
57 # endif /* HFIXEDSZ */
59 # define NS_PACKETSZ PACKETSZ
60 # else /* 512 is usually the default */
61 # define NS_PACKETSZ 512
62 # endif /* PACKETSZ */
66 /*********************************************************************
67 *********************************************************************/
69 static BOOL
ads_dns_parse_query( TALLOC_CTX
*ctx
, uint8
*start
, uint8
*end
,
70 uint8
**ptr
, struct dns_query
*q
)
78 if ( !start
|| !end
|| !q
|| !*ptr
)
81 /* See RFC 1035 for details. If this fails, then return. */
83 namelen
= dn_expand( start
, end
, p
, hostname
, sizeof(hostname
) );
88 q
->hostname
= talloc_strdup( ctx
, hostname
);
90 /* check that we have space remaining */
92 if ( PTR_DIFF(p
+4, end
) > 0 )
95 q
->type
= RSVAL( p
, 0 );
96 q
->in_class
= RSVAL( p
, 2 );
104 /*********************************************************************
105 *********************************************************************/
107 static BOOL
ads_dns_parse_rr( TALLOC_CTX
*ctx
, uint8
*start
, uint8
*end
,
108 uint8
**ptr
, struct dns_rr
*rr
)
114 if ( !start
|| !end
|| !rr
|| !*ptr
)
118 /* pull the name from the answer */
120 namelen
= dn_expand( start
, end
, p
, hostname
, sizeof(hostname
) );
125 rr
->hostname
= talloc_strdup( ctx
, hostname
);
127 /* check that we have space remaining */
129 if ( PTR_DIFF(p
+10, end
) > 0 )
132 /* pull some values and then skip onto the string */
134 rr
->type
= RSVAL(p
, 0);
135 rr
->in_class
= RSVAL(p
, 2);
136 rr
->ttl
= RIVAL(p
, 4);
137 rr
->rdatalen
= RSVAL(p
, 8);
141 /* sanity check the available space */
143 if ( PTR_DIFF(p
+rr
->rdatalen
, end
) > 0 ) {
148 /* save a point to the rdata for this section */
158 /*********************************************************************
159 *********************************************************************/
161 static BOOL
ads_dns_parse_rr_srv( TALLOC_CTX
*ctx
, uint8
*start
, uint8
*end
,
162 uint8
**ptr
, struct dns_rr_srv
*srv
)
169 if ( !start
|| !end
|| !srv
|| !*ptr
)
172 /* Parse the RR entry. Coming out of the this, ptr is at the beginning
173 of the next record */
175 if ( !ads_dns_parse_rr( ctx
, start
, end
, ptr
, &rr
) ) {
176 DEBUG(1,("ads_dns_parse_rr_srv: Failed to parse RR record\n"));
180 if ( rr
.type
!= T_SRV
) {
181 DEBUG(1,("ads_dns_parse_rr_srv: Bad answer type (%d)\n", rr
.type
));
187 srv
->priority
= RSVAL(p
, 0);
188 srv
->weight
= RSVAL(p
, 2);
189 srv
->port
= RSVAL(p
, 4);
193 namelen
= dn_expand( start
, end
, p
, dcname
, sizeof(dcname
) );
195 DEBUG(1,("ads_dns_parse_rr_srv: Failed to uncompress name!\n"));
198 srv
->hostname
= talloc_strdup( ctx
, dcname
);
203 /*********************************************************************
204 *********************************************************************/
206 static BOOL
ads_dns_parse_rr_ns( TALLOC_CTX
*ctx
, uint8
*start
, uint8
*end
,
207 uint8
**ptr
, struct dns_rr_ns
*nsrec
)
214 if ( !start
|| !end
|| !nsrec
|| !*ptr
)
217 /* Parse the RR entry. Coming out of the this, ptr is at the beginning
218 of the next record */
220 if ( !ads_dns_parse_rr( ctx
, start
, end
, ptr
, &rr
) ) {
221 DEBUG(1,("ads_dns_parse_rr_ns: Failed to parse RR record\n"));
225 if ( rr
.type
!= T_NS
) {
226 DEBUG(1,("ads_dns_parse_rr_ns: Bad answer type (%d)\n", rr
.type
));
232 /* ame server hostname */
234 namelen
= dn_expand( start
, end
, p
, nsname
, sizeof(nsname
) );
236 DEBUG(1,("ads_dns_parse_rr_ns: Failed to uncompress name!\n"));
239 nsrec
->hostname
= talloc_strdup( ctx
, nsname
);
244 /*********************************************************************
245 Sort SRV record list based on weight and priority. See RFC 2782.
246 *********************************************************************/
248 static int dnssrvcmp( struct dns_rr_srv
*a
, struct dns_rr_srv
*b
)
250 if ( a
->priority
== b
->priority
) {
252 /* randomize entries with an equal weight and priority */
253 if ( a
->weight
== b
->weight
)
256 /* higher weights should be sorted lower */
257 if ( a
->weight
> b
->weight
)
263 if ( a
->priority
< b
->priority
)
269 /*********************************************************************
270 Simple wrapper for a DNS query
271 *********************************************************************/
273 #define DNS_FAILED_WAITTIME 30
275 static NTSTATUS
dns_send_req( TALLOC_CTX
*ctx
, const char *name
, int q_type
,
276 uint8
**buf
, int *resp_length
)
278 uint8
*buffer
= NULL
;
280 int resp_len
= NS_PACKETSZ
;
281 static time_t last_dns_check
= 0;
282 static NTSTATUS last_dns_status
= NT_STATUS_OK
;
283 time_t now
= time(NULL
);
285 /* Try to prevent bursts of DNS lookups if the server is down */
287 /* Protect against large clock changes */
289 if ( last_dns_check
> now
)
292 /* IF we had a DNS timeout or a bad server and we are still
293 in the 30 second cache window, just return the previous
294 status and save the network timeout. */
296 if ( (NT_STATUS_EQUAL(last_dns_status
,NT_STATUS_IO_TIMEOUT
) ||
297 NT_STATUS_EQUAL(last_dns_status
,NT_STATUS_CONNECTION_REFUSED
)) &&
298 (last_dns_check
+DNS_FAILED_WAITTIME
) > now
)
300 DEBUG(10,("last_dns_check: Returning cached status (%s)\n",
301 nt_errstr(last_dns_status
) ));
302 return last_dns_status
;
308 TALLOC_FREE( buffer
);
310 buf_len
= resp_len
* sizeof(uint8
);
313 if ( (buffer
= TALLOC_ARRAY(ctx
, uint8
, buf_len
)) == NULL
) {
314 DEBUG(0,("ads_dns_lookup_srv: talloc() failed!\n"));
315 last_dns_status
= NT_STATUS_NO_MEMORY
;
316 last_dns_check
= time(NULL
);
317 return last_dns_status
;
321 if ( (resp_len
= res_query(name
, C_IN
, q_type
, buffer
, buf_len
)) < 0 ) {
322 DEBUG(3,("ads_dns_lookup_srv: Failed to resolve %s (%s)\n", name
, strerror(errno
)));
323 TALLOC_FREE( buffer
);
324 last_dns_status
= NT_STATUS_UNSUCCESSFUL
;
326 if (errno
== ETIMEDOUT
) {
327 last_dns_status
= NT_STATUS_IO_TIMEOUT
;
329 if (errno
== ECONNREFUSED
) {
330 last_dns_status
= NT_STATUS_CONNECTION_REFUSED
;
332 last_dns_check
= time(NULL
);
333 return last_dns_status
;
335 } while ( buf_len
< resp_len
&& resp_len
< MAX_DNS_PACKET_SIZE
);
338 *resp_length
= resp_len
;
340 last_dns_check
= time(NULL
);
341 last_dns_status
= NT_STATUS_OK
;
342 return last_dns_status
;
345 /*********************************************************************
346 Simple wrapper for a DNS SRV query
347 *********************************************************************/
349 static NTSTATUS
ads_dns_lookup_srv( TALLOC_CTX
*ctx
, const char *name
, struct dns_rr_srv
**dclist
, int *numdcs
)
351 uint8
*buffer
= NULL
;
353 struct dns_rr_srv
*dcs
= NULL
;
354 int query_count
, answer_count
, auth_count
, additional_count
;
360 if ( !ctx
|| !name
|| !dclist
) {
361 return NT_STATUS_INVALID_PARAMETER
;
364 /* Send the request. May have to loop several times in case
367 status
= dns_send_req( ctx
, name
, T_SRV
, &buffer
, &resp_len
);
368 if ( !NT_STATUS_IS_OK(status
) ) {
369 DEBUG(3,("ads_dns_lookup_srv: Failed to send DNS query (%s)\n",
375 /* For some insane reason, the ns_initparse() et. al. routines are only
376 available in libresolv.a, and not the shared lib. Who knows why....
377 So we have to parse the DNS reply ourselves */
379 /* Pull the answer RR's count from the header. Use the NMB ordering macros */
381 query_count
= RSVAL( p
, 4 );
382 answer_count
= RSVAL( p
, 6 );
383 auth_count
= RSVAL( p
, 8 );
384 additional_count
= RSVAL( p
, 10 );
386 DEBUG(4,("ads_dns_lookup_srv: %d records returned in the answer section.\n",
390 if ( (dcs
= TALLOC_ZERO_ARRAY(ctx
, struct dns_rr_srv
, answer_count
)) == NULL
) {
391 DEBUG(0,("ads_dns_lookup_srv: talloc() failure for %d char*'s\n",
393 return NT_STATUS_NO_MEMORY
;
399 /* now skip the header */
403 /* parse the query section */
405 for ( rrnum
=0; rrnum
<query_count
; rrnum
++ ) {
408 if ( !ads_dns_parse_query( ctx
, buffer
, buffer
+resp_len
, &p
, &q
) ) {
409 DEBUG(1,("ads_dns_lookup_srv: Failed to parse query record!\n"));
410 return NT_STATUS_UNSUCCESSFUL
;
414 /* now we are at the answer section */
416 for ( rrnum
=0; rrnum
<answer_count
; rrnum
++ ) {
417 if ( !ads_dns_parse_rr_srv( ctx
, buffer
, buffer
+resp_len
, &p
, &dcs
[rrnum
] ) ) {
418 DEBUG(1,("ads_dns_lookup_srv: Failed to parse answer record!\n"));
419 return NT_STATUS_UNSUCCESSFUL
;
424 /* Parse the authority section */
425 /* just skip these for now */
427 for ( rrnum
=0; rrnum
<auth_count
; rrnum
++ ) {
430 if ( !ads_dns_parse_rr( ctx
, buffer
, buffer
+resp_len
, &p
, &rr
) ) {
431 DEBUG(1,("ads_dns_lookup_srv: Failed to parse authority record!\n"));
432 return NT_STATUS_UNSUCCESSFUL
;
436 /* Parse the additional records section */
438 for ( rrnum
=0; rrnum
<additional_count
; rrnum
++ ) {
442 if ( !ads_dns_parse_rr( ctx
, buffer
, buffer
+resp_len
, &p
, &rr
) ) {
443 DEBUG(1,("ads_dns_lookup_srv: Failed to parse additional records section!\n"));
444 return NT_STATUS_UNSUCCESSFUL
;
447 /* only interested in A records as a shortcut for having to come
448 back later and lookup the name. For multi-homed hosts, the
449 number of additional records and exceed the number of answer
453 if ( (rr
.type
!= T_A
) || (rr
.rdatalen
!= 4) )
456 for ( i
=0; i
<idx
; i
++ ) {
457 if ( strcmp( rr
.hostname
, dcs
[i
].hostname
) == 0 ) {
458 int num_ips
= dcs
[i
].num_ips
;
460 struct in_addr
*tmp_ips
;
462 /* allocate new memory */
464 if ( dcs
[i
].num_ips
== 0 ) {
465 if ( (dcs
[i
].ips
= TALLOC_ARRAY( dcs
,
466 struct in_addr
, 1 )) == NULL
)
468 return NT_STATUS_NO_MEMORY
;
471 if ( (tmp_ips
= TALLOC_REALLOC_ARRAY( dcs
, dcs
[i
].ips
,
472 struct in_addr
, dcs
[i
].num_ips
+1)) == NULL
)
474 return NT_STATUS_NO_MEMORY
;
477 dcs
[i
].ips
= tmp_ips
;
481 /* copy the new IP address */
483 buf
= (uint8
*)&dcs
[i
].ips
[num_ips
].s_addr
;
484 memcpy( buf
, rr
.rdata
, 4 );
489 qsort( dcs
, idx
, sizeof(struct dns_rr_srv
), QSORT_CAST dnssrvcmp
);
497 /*********************************************************************
498 Simple wrapper for a DNS NS query
499 *********************************************************************/
501 NTSTATUS
ads_dns_lookup_ns( TALLOC_CTX
*ctx
, const char *dnsdomain
, struct dns_rr_ns
**nslist
, int *numns
)
503 uint8
*buffer
= NULL
;
505 struct dns_rr_ns
*nsarray
= NULL
;
506 int query_count
, answer_count
, auth_count
, additional_count
;
512 if ( !ctx
|| !dnsdomain
|| !nslist
) {
513 return NT_STATUS_INVALID_PARAMETER
;
516 /* Send the request. May have to loop several times in case
519 status
= dns_send_req( ctx
, dnsdomain
, T_NS
, &buffer
, &resp_len
);
520 if ( !NT_STATUS_IS_OK(status
) ) {
521 DEBUG(3,("ads_dns_lookup_ns: Failed to send DNS query (%s)\n",
527 /* For some insane reason, the ns_initparse() et. al. routines are only
528 available in libresolv.a, and not the shared lib. Who knows why....
529 So we have to parse the DNS reply ourselves */
531 /* Pull the answer RR's count from the header. Use the NMB ordering macros */
533 query_count
= RSVAL( p
, 4 );
534 answer_count
= RSVAL( p
, 6 );
535 auth_count
= RSVAL( p
, 8 );
536 additional_count
= RSVAL( p
, 10 );
538 DEBUG(4,("ads_dns_lookup_ns: %d records returned in the answer section.\n",
542 if ( (nsarray
= TALLOC_ARRAY(ctx
, struct dns_rr_ns
, answer_count
)) == NULL
) {
543 DEBUG(0,("ads_dns_lookup_ns: talloc() failure for %d char*'s\n",
545 return NT_STATUS_NO_MEMORY
;
551 /* now skip the header */
555 /* parse the query section */
557 for ( rrnum
=0; rrnum
<query_count
; rrnum
++ ) {
560 if ( !ads_dns_parse_query( ctx
, buffer
, buffer
+resp_len
, &p
, &q
) ) {
561 DEBUG(1,("ads_dns_lookup_ns: Failed to parse query record!\n"));
562 return NT_STATUS_UNSUCCESSFUL
;
566 /* now we are at the answer section */
568 for ( rrnum
=0; rrnum
<answer_count
; rrnum
++ ) {
569 if ( !ads_dns_parse_rr_ns( ctx
, buffer
, buffer
+resp_len
, &p
, &nsarray
[rrnum
] ) ) {
570 DEBUG(1,("ads_dns_lookup_ns: Failed to parse answer record!\n"));
571 return NT_STATUS_UNSUCCESSFUL
;
576 /* Parse the authority section */
577 /* just skip these for now */
579 for ( rrnum
=0; rrnum
<auth_count
; rrnum
++ ) {
582 if ( !ads_dns_parse_rr( ctx
, buffer
, buffer
+resp_len
, &p
, &rr
) ) {
583 DEBUG(1,("ads_dns_lookup_ns: Failed to parse authority record!\n"));
584 return NT_STATUS_UNSUCCESSFUL
;
588 /* Parse the additional records section */
590 for ( rrnum
=0; rrnum
<additional_count
; rrnum
++ ) {
594 if ( !ads_dns_parse_rr( ctx
, buffer
, buffer
+resp_len
, &p
, &rr
) ) {
595 DEBUG(1,("ads_dns_lookup_ns: Failed to parse additional records section!\n"));
596 return NT_STATUS_UNSUCCESSFUL
;
599 /* only interested in A records as a shortcut for having to come
600 back later and lookup the name */
602 if ( (rr
.type
!= T_A
) || (rr
.rdatalen
!= 4) )
605 for ( i
=0; i
<idx
; i
++ ) {
606 if ( strcmp( rr
.hostname
, nsarray
[i
].hostname
) == 0 ) {
607 uint8
*buf
= (uint8
*)&nsarray
[i
].ip
.s_addr
;
608 memcpy( buf
, rr
.rdata
, 4 );
619 /****************************************************************************
620 Store and fetch the AD client sitename.
621 ****************************************************************************/
623 #define SITENAME_KEY "AD_SITENAME/DOMAIN/%s"
625 static char *sitename_key(const char *realm
)
629 if (asprintf(&keystr
, SITENAME_KEY
, strupper_static(realm
)) == -1) {
637 /****************************************************************************
638 Store the AD client sitename.
639 We store indefinately as every new CLDAP query will re-write this.
640 ****************************************************************************/
642 BOOL
sitename_store(const char *realm
, const char *sitename
)
648 if (!gencache_init()) {
652 if (!realm
|| (strlen(realm
) == 0)) {
653 DEBUG(0,("sitename_store: no realm\n"));
657 key
= sitename_key(realm
);
659 if (!sitename
|| (sitename
&& !*sitename
)) {
660 DEBUG(5,("sitename_store: deleting empty sitename!\n"));
661 ret
= gencache_del(key
);
666 expire
= get_time_t_max(); /* Store indefinately. */
668 DEBUG(10,("sitename_store: realm = [%s], sitename = [%s], expire = [%u]\n",
669 realm
, sitename
, (unsigned int)expire
));
671 ret
= gencache_set( key
, sitename
, expire
);
676 /****************************************************************************
677 Fetch the AD client sitename.
679 ****************************************************************************/
681 char *sitename_fetch(const char *realm
)
683 char *sitename
= NULL
;
686 const char *query_realm
;
689 if (!gencache_init()) {
693 if (!realm
|| (strlen(realm
) == 0)) {
694 query_realm
= lp_realm();
699 key
= sitename_key(query_realm
);
701 ret
= gencache_get( key
, &sitename
, &timeout
);
704 DEBUG(5,("sitename_fetch: No stored sitename for %s\n",
707 DEBUG(5,("sitename_fetch: Returning sitename for %s: \"%s\"\n",
708 query_realm
, sitename
));
713 /****************************************************************************
714 Did the sitename change ?
715 ****************************************************************************/
717 BOOL
stored_sitename_changed(const char *realm
, const char *sitename
)
723 if (!realm
|| (strlen(realm
) == 0)) {
724 DEBUG(0,("stored_sitename_changed: no realm\n"));
728 new_sitename
= sitename_fetch(realm
);
730 if (sitename
&& new_sitename
&& !strequal(sitename
, new_sitename
)) {
732 } else if ((sitename
&& !new_sitename
) ||
733 (!sitename
&& new_sitename
)) {
736 SAFE_FREE(new_sitename
);
740 /********************************************************************
741 Query with optional sitename.
742 ********************************************************************/
744 NTSTATUS
ads_dns_query_internal(TALLOC_CTX
*ctx
,
745 const char *servicename
,
747 const char *sitename
,
748 struct dns_rr_srv
**dclist
,
753 name
= talloc_asprintf(ctx
, "%s._tcp.%s._sites.dc._msdcs.%s",
754 servicename
, sitename
, realm
);
756 name
= talloc_asprintf(ctx
, "%s._tcp.dc._msdcs.%s",
757 servicename
, realm
);
760 return NT_STATUS_NO_MEMORY
;
762 return ads_dns_lookup_srv( ctx
, name
, dclist
, numdcs
);
765 /********************************************************************
767 ********************************************************************/
769 NTSTATUS
ads_dns_query_dcs(TALLOC_CTX
*ctx
,
771 const char *sitename
,
772 struct dns_rr_srv
**dclist
,
777 status
= ads_dns_query_internal(ctx
, "_ldap", realm
, sitename
,
780 if (NT_STATUS_EQUAL(status
, NT_STATUS_IO_TIMEOUT
) ||
781 NT_STATUS_EQUAL(status
, NT_STATUS_CONNECTION_REFUSED
)) {
785 if (sitename
&& !NT_STATUS_IS_OK(status
)) {
786 /* Sitename DNS query may have failed. Try without. */
787 status
= ads_dns_query_internal(ctx
, "_ldap", realm
, NULL
,
793 /********************************************************************
795 Even if our underlying kerberos libraries are UDP only, this
796 is pretty safe as it's unlikely that a KDC supports TCP and not UDP.
797 ********************************************************************/
799 NTSTATUS
ads_dns_query_kdcs(TALLOC_CTX
*ctx
,
801 const char *sitename
,
802 struct dns_rr_srv
**dclist
,
807 status
= ads_dns_query_internal(ctx
, "_kerberos", realm
, sitename
,
810 if (NT_STATUS_EQUAL(status
, NT_STATUS_IO_TIMEOUT
) ||
811 NT_STATUS_EQUAL(status
, NT_STATUS_CONNECTION_REFUSED
)) {
815 if (sitename
&& !NT_STATUS_IS_OK(status
)) {
816 /* Sitename DNS query may have failed. Try without. */
817 status
= ads_dns_query_internal(ctx
, "_kerberos", realm
, NULL
,