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authorSimo Sorce <idra@samba.org>2012-05-04 16:47:27 -0400
committerAlexander Bokovoy <ab@samba.org>2012-05-23 17:51:48 +0300
commit34a65739d32d7e895e71b2b81298fab82dfd11fe (patch)
tree594e04611fffa3851edb0deeafeee98bf430fe8f /lib/addns
parentcc3321c9ffee9e1688af724b7286fe548ff28793 (diff)
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Move source3/libads/dns.c to lib/addns
Diffstat (limited to 'lib/addns')
-rw-r--r--lib/addns/dnsquery.c910
-rw-r--r--lib/addns/dnsquery.h61
-rwxr-xr-x[-rw-r--r--]lib/addns/wscript_build5
3 files changed, 976 insertions, 0 deletions
diff --git a/lib/addns/dnsquery.c b/lib/addns/dnsquery.c
new file mode 100644
index 0000000000..f680d63258
--- /dev/null
+++ b/lib/addns/dnsquery.c
@@ -0,0 +1,910 @@
+/*
+ Unix SMB/CIFS implementation.
+ DNS utility library
+ Copyright (C) Gerald (Jerry) Carter 2006.
+ Copyright (C) Jeremy Allison 2007.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "lib/util/util_net.h"
+#include "lib/util/tsort.h"
+#include "dnsquery.h"
+
+/* AIX resolv.h uses 'class' in struct ns_rr */
+
+#if defined(AIX)
+# if defined(class)
+# undef class
+# endif
+#endif /* AIX */
+
+/* resolver headers */
+
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <netdb.h>
+
+#define MAX_DNS_PACKET_SIZE 0xffff
+
+#ifdef NS_HFIXEDSZ /* Bind 8/9 interface */
+#if !defined(C_IN) /* AIX 5.3 already defines C_IN */
+# define C_IN ns_c_in
+#endif
+#if !defined(T_A) /* AIX 5.3 already defines T_A */
+# define T_A ns_t_a
+#endif
+
+#if defined(HAVE_IPV6)
+#if !defined(T_AAAA)
+# define T_AAAA ns_t_aaaa
+#endif
+#endif
+
+# define T_SRV ns_t_srv
+#if !defined(T_NS) /* AIX 5.3 already defines T_NS */
+# define T_NS ns_t_ns
+#endif
+#else
+# ifdef HFIXEDSZ
+# define NS_HFIXEDSZ HFIXEDSZ
+# else
+# define NS_HFIXEDSZ sizeof(HEADER)
+# endif /* HFIXEDSZ */
+# ifdef PACKETSZ
+# define NS_PACKETSZ PACKETSZ
+# else /* 512 is usually the default */
+# define NS_PACKETSZ 512
+# endif /* PACKETSZ */
+# define T_SRV 33
+#endif
+
+/*********************************************************************
+*********************************************************************/
+
+static bool ads_dns_parse_query( TALLOC_CTX *ctx, uint8_t *start, uint8_t *end,
+ uint8_t **ptr, struct dns_query *q )
+{
+ uint8_t *p = *ptr;
+ char hostname[MAX_DNS_NAME_LENGTH];
+ int namelen;
+
+ ZERO_STRUCTP( q );
+
+ if ( !start || !end || !q || !*ptr)
+ return false;
+
+ /* See RFC 1035 for details. If this fails, then return. */
+
+ namelen = dn_expand( start, end, p, hostname, sizeof(hostname) );
+ if ( namelen < 0 ) {
+ return false;
+ }
+ p += namelen;
+ q->hostname = talloc_strdup( ctx, hostname );
+
+ /* check that we have space remaining */
+
+ if ( PTR_DIFF(p+4, end) > 0 )
+ return false;
+
+ q->type = RSVAL( p, 0 );
+ q->in_class = RSVAL( p, 2 );
+ p += 4;
+
+ *ptr = p;
+
+ return true;
+}
+
+/*********************************************************************
+*********************************************************************/
+
+static bool ads_dns_parse_rr( TALLOC_CTX *ctx, uint8_t *start, uint8_t *end,
+ uint8_t **ptr, struct dns_rr *rr )
+{
+ uint8_t *p = *ptr;
+ char hostname[MAX_DNS_NAME_LENGTH];
+ int namelen;
+
+ if ( !start || !end || !rr || !*ptr)
+ return -1;
+
+ ZERO_STRUCTP( rr );
+ /* pull the name from the answer */
+
+ namelen = dn_expand( start, end, p, hostname, sizeof(hostname) );
+ if ( namelen < 0 ) {
+ return -1;
+ }
+ p += namelen;
+ rr->hostname = talloc_strdup( ctx, hostname );
+
+ /* check that we have space remaining */
+
+ if ( PTR_DIFF(p+10, end) > 0 )
+ return false;
+
+ /* pull some values and then skip onto the string */
+
+ rr->type = RSVAL(p, 0);
+ rr->in_class = RSVAL(p, 2);
+ rr->ttl = RIVAL(p, 4);
+ rr->rdatalen = RSVAL(p, 8);
+
+ p += 10;
+
+ /* sanity check the available space */
+
+ if ( PTR_DIFF(p+rr->rdatalen, end ) > 0 ) {
+ return false;
+
+ }
+
+ /* save a point to the rdata for this section */
+
+ rr->rdata = p;
+ p += rr->rdatalen;
+
+ *ptr = p;
+
+ return true;
+}
+
+/*********************************************************************
+*********************************************************************/
+
+static bool ads_dns_parse_rr_srv( TALLOC_CTX *ctx, uint8_t *start, uint8_t *end,
+ uint8_t **ptr, struct dns_rr_srv *srv )
+{
+ struct dns_rr rr;
+ uint8_t *p;
+ char dcname[MAX_DNS_NAME_LENGTH];
+ int namelen;
+
+ if ( !start || !end || !srv || !*ptr)
+ return -1;
+
+ /* Parse the RR entry. Coming out of the this, ptr is at the beginning
+ of the next record */
+
+ if ( !ads_dns_parse_rr( ctx, start, end, ptr, &rr ) ) {
+ DEBUG(1,("ads_dns_parse_rr_srv: Failed to parse RR record\n"));
+ return false;
+ }
+
+ if ( rr.type != T_SRV ) {
+ DEBUG(1,("ads_dns_parse_rr_srv: Bad answer type (%d)\n",
+ rr.type));
+ return false;
+ }
+
+ p = rr.rdata;
+
+ srv->priority = RSVAL(p, 0);
+ srv->weight = RSVAL(p, 2);
+ srv->port = RSVAL(p, 4);
+
+ p += 6;
+
+ namelen = dn_expand( start, end, p, dcname, sizeof(dcname) );
+ if ( namelen < 0 ) {
+ DEBUG(1,("ads_dns_parse_rr_srv: Failed to uncompress name!\n"));
+ return false;
+ }
+
+ srv->hostname = talloc_strdup( ctx, dcname );
+
+ DEBUG(10,("ads_dns_parse_rr_srv: Parsed %s [%u, %u, %u]\n",
+ srv->hostname,
+ srv->priority,
+ srv->weight,
+ srv->port));
+
+ return true;
+}
+
+/*********************************************************************
+*********************************************************************/
+
+static bool ads_dns_parse_rr_ns( TALLOC_CTX *ctx, uint8_t *start, uint8_t *end,
+ uint8_t **ptr, struct dns_rr_ns *nsrec )
+{
+ struct dns_rr rr;
+ uint8_t *p;
+ char nsname[MAX_DNS_NAME_LENGTH];
+ int namelen;
+
+ if ( !start || !end || !nsrec || !*ptr)
+ return -1;
+
+ /* Parse the RR entry. Coming out of the this, ptr is at the beginning
+ of the next record */
+
+ if ( !ads_dns_parse_rr( ctx, start, end, ptr, &rr ) ) {
+ DEBUG(1,("ads_dns_parse_rr_ns: Failed to parse RR record\n"));
+ return false;
+ }
+
+ if ( rr.type != T_NS ) {
+ DEBUG(1,("ads_dns_parse_rr_ns: Bad answer type (%d)\n",
+ rr.type));
+ return false;
+ }
+
+ p = rr.rdata;
+
+ /* ame server hostname */
+
+ namelen = dn_expand( start, end, p, nsname, sizeof(nsname) );
+ if ( namelen < 0 ) {
+ DEBUG(1,("ads_dns_parse_rr_ns: Failed to uncompress name!\n"));
+ return false;
+ }
+ nsrec->hostname = talloc_strdup( ctx, nsname );
+
+ return true;
+}
+
+/*********************************************************************
+ Sort SRV record list based on weight and priority. See RFC 2782.
+*********************************************************************/
+
+static int dnssrvcmp( struct dns_rr_srv *a, struct dns_rr_srv *b )
+{
+ if ( a->priority == b->priority ) {
+
+ /* randomize entries with an equal weight and priority */
+ if ( a->weight == b->weight )
+ return 0;
+
+ /* higher weights should be sorted lower */
+ if ( a->weight > b->weight )
+ return -1;
+ else
+ return 1;
+ }
+
+ if ( a->priority < b->priority )
+ return -1;
+
+ return 1;
+}
+
+/*********************************************************************
+ Simple wrapper for a DNS query
+*********************************************************************/
+
+#define DNS_FAILED_WAITTIME 30
+
+static NTSTATUS dns_send_req( TALLOC_CTX *ctx, const char *name, int q_type,
+ uint8_t **buf, int *resp_length )
+{
+ uint8_t *buffer = NULL;
+ size_t buf_len = 0;
+ int resp_len = NS_PACKETSZ;
+ static time_t last_dns_check = 0;
+ static NTSTATUS last_dns_status = NT_STATUS_OK;
+ time_t now = time_mono(NULL);
+
+ /* Try to prevent bursts of DNS lookups if the server is down */
+
+ /* Protect against large clock changes */
+
+ if ( last_dns_check > now )
+ last_dns_check = 0;
+
+ /* IF we had a DNS timeout or a bad server and we are still
+ in the 30 second cache window, just return the previous
+ status and save the network timeout. */
+
+ if ( (NT_STATUS_EQUAL(last_dns_status,NT_STATUS_IO_TIMEOUT) ||
+ NT_STATUS_EQUAL(last_dns_status,NT_STATUS_CONNECTION_REFUSED)) &&
+ (last_dns_check+DNS_FAILED_WAITTIME) > now )
+ {
+ DEBUG(10,("last_dns_check: Returning cached status (%s)\n",
+ nt_errstr(last_dns_status) ));
+ return last_dns_status;
+ }
+
+ /* Send the Query */
+ do {
+ if ( buffer )
+ TALLOC_FREE( buffer );
+
+ buf_len = resp_len * sizeof(uint8_t);
+
+ if (buf_len) {
+ if ((buffer = talloc_array(ctx, uint8_t, buf_len))
+ == NULL ) {
+ DEBUG(0,("ads_dns_lookup_srv: "
+ "talloc() failed!\n"));
+ last_dns_status = NT_STATUS_NO_MEMORY;
+ last_dns_check = time_mono(NULL);
+ return last_dns_status;
+ }
+ }
+
+ if ((resp_len = res_query(name, C_IN, q_type, buffer, buf_len))
+ < 0 ) {
+ DEBUG(3,("ads_dns_lookup_srv: "
+ "Failed to resolve %s (%s)\n",
+ name, strerror(errno)));
+ TALLOC_FREE( buffer );
+ last_dns_status = NT_STATUS_UNSUCCESSFUL;
+
+ if (errno == ETIMEDOUT) {
+ last_dns_status = NT_STATUS_IO_TIMEOUT;
+ }
+ if (errno == ECONNREFUSED) {
+ last_dns_status = NT_STATUS_CONNECTION_REFUSED;
+ }
+ last_dns_check = time_mono(NULL);
+ return last_dns_status;
+ }
+
+ /* On AIX, Solaris, and possibly some older glibc systems (e.g. SLES8)
+ truncated replies never give back a resp_len > buflen
+ which ends up causing DNS resolve failures on large tcp DNS replies */
+
+ if (buf_len == resp_len) {
+ if (resp_len == MAX_DNS_PACKET_SIZE) {
+ DEBUG(1,("dns_send_req: DNS reply too large when resolving %s\n",
+ name));
+ TALLOC_FREE( buffer );
+ last_dns_status = NT_STATUS_BUFFER_TOO_SMALL;
+ last_dns_check = time_mono(NULL);
+ return last_dns_status;
+ }
+
+ resp_len = MIN(resp_len*2, MAX_DNS_PACKET_SIZE);
+ }
+
+
+ } while ( buf_len < resp_len && resp_len <= MAX_DNS_PACKET_SIZE );
+
+ *buf = buffer;
+ *resp_length = resp_len;
+
+ last_dns_check = time_mono(NULL);
+ last_dns_status = NT_STATUS_OK;
+ return last_dns_status;
+}
+
+/*********************************************************************
+ Simple wrapper for a DNS SRV query
+*********************************************************************/
+
+static NTSTATUS ads_dns_lookup_srv( TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *name,
+ struct dns_rr_srv **dclist,
+ int *numdcs)
+{
+ uint8_t *buffer = NULL;
+ int resp_len = 0;
+ struct dns_rr_srv *dcs = NULL;
+ int query_count, answer_count, auth_count, additional_count;
+ uint8_t *p = buffer;
+ int rrnum;
+ int idx = 0;
+ NTSTATUS status;
+
+ if ( !ctx || !name || !dclist ) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ if (dns_hosts_file) {
+ return resolve_dns_hosts_file_as_dns_rr(dns_hosts_file,
+ name, true, ctx,
+ dclist, numdcs);
+ }
+
+ /* Send the request. May have to loop several times in case
+ of large replies */
+
+ status = dns_send_req( ctx, name, T_SRV, &buffer, &resp_len );
+ if ( !NT_STATUS_IS_OK(status) ) {
+ DEBUG(3,("ads_dns_lookup_srv: Failed to send DNS query (%s)\n",
+ nt_errstr(status)));
+ return status;
+ }
+ p = buffer;
+
+ /* For some insane reason, the ns_initparse() et. al. routines are only
+ available in libresolv.a, and not the shared lib. Who knows why....
+ So we have to parse the DNS reply ourselves */
+
+ /* Pull the answer RR's count from the header.
+ * Use the NMB ordering macros */
+
+ query_count = RSVAL( p, 4 );
+ answer_count = RSVAL( p, 6 );
+ auth_count = RSVAL( p, 8 );
+ additional_count = RSVAL( p, 10 );
+
+ DEBUG(4,("ads_dns_lookup_srv: "
+ "%d records returned in the answer section.\n",
+ answer_count));
+
+ if (answer_count) {
+ if ((dcs = talloc_zero_array(ctx, struct dns_rr_srv,
+ answer_count)) == NULL ) {
+ DEBUG(0,("ads_dns_lookup_srv: "
+ "talloc() failure for %d char*'s\n",
+ answer_count));
+ return NT_STATUS_NO_MEMORY;
+ }
+ } else {
+ dcs = NULL;
+ }
+
+ /* now skip the header */
+
+ p += NS_HFIXEDSZ;
+
+ /* parse the query section */
+
+ for ( rrnum=0; rrnum<query_count; rrnum++ ) {
+ struct dns_query q;
+
+ if (!ads_dns_parse_query(ctx, buffer,
+ buffer+resp_len, &p, &q)) {
+ DEBUG(1,("ads_dns_lookup_srv: "
+ "Failed to parse query record [%d]!\n", rrnum));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+
+ /* now we are at the answer section */
+
+ for ( rrnum=0; rrnum<answer_count; rrnum++ ) {
+ if (!ads_dns_parse_rr_srv(ctx, buffer, buffer+resp_len,
+ &p, &dcs[rrnum])) {
+ DEBUG(1,("ads_dns_lookup_srv: "
+ "Failed to parse answer recordi [%d]!\n", rrnum));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+ idx = rrnum;
+
+ /* Parse the authority section */
+ /* just skip these for now */
+
+ for ( rrnum=0; rrnum<auth_count; rrnum++ ) {
+ struct dns_rr rr;
+
+ if (!ads_dns_parse_rr( ctx, buffer,
+ buffer+resp_len, &p, &rr)) {
+ DEBUG(1,("ads_dns_lookup_srv: "
+ "Failed to parse authority record! [%d]\n", rrnum));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+
+ /* Parse the additional records section */
+
+ for ( rrnum=0; rrnum<additional_count; rrnum++ ) {
+ struct dns_rr rr;
+ int i;
+
+ if (!ads_dns_parse_rr(ctx, buffer, buffer+resp_len,
+ &p, &rr)) {
+ DEBUG(1,("ads_dns_lookup_srv: Failed "
+ "to parse additional records section! [%d]\n", rrnum));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+
+ /* Only interested in A or AAAA records as a shortcut for having
+ * to come back later and lookup the name. For multi-homed
+ * hosts, the number of additional records and exceed the
+ * number of answer records. */
+
+ if (rr.type != T_A || rr.rdatalen != 4) {
+#if defined(HAVE_IPV6)
+ /* RFC2874 defines A6 records. This
+ * requires recusive and horribly complex lookups.
+ * Bastards. Ignore this for now.... JRA.
+ * Luckily RFC3363 reprecates A6 records.
+ */
+ if (rr.type != T_AAAA || rr.rdatalen != 16)
+#endif
+ continue;
+ }
+
+ for ( i=0; i<idx; i++ ) {
+ if ( strcmp( rr.hostname, dcs[i].hostname ) == 0 ) {
+ int num_ips = dcs[i].num_ips;
+ struct sockaddr_storage *tmp_ss_s;
+
+ /* allocate new memory */
+
+ if (dcs[i].num_ips == 0) {
+ if ((dcs[i].ss_s = talloc_array(dcs,
+ struct sockaddr_storage, 1 ))
+ == NULL ) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ } else {
+ if ((tmp_ss_s = talloc_realloc(dcs,
+ dcs[i].ss_s,
+ struct sockaddr_storage,
+ dcs[i].num_ips+1))
+ == NULL ) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ dcs[i].ss_s = tmp_ss_s;
+ }
+ dcs[i].num_ips++;
+
+ /* copy the new IP address */
+ if (rr.type == T_A) {
+ struct in_addr ip;
+ memcpy(&ip, rr.rdata, 4);
+ in_addr_to_sockaddr_storage(
+ &dcs[i].ss_s[num_ips],
+ ip);
+ }
+#if defined(HAVE_IPV6)
+ if (rr.type == T_AAAA) {
+ struct in6_addr ip6;
+ memcpy(&ip6, rr.rdata, rr.rdatalen);
+ in6_addr_to_sockaddr_storage(
+ &dcs[i].ss_s[num_ips],
+ ip6);
+ }
+#endif
+ }
+ }
+ }
+
+ TYPESAFE_QSORT(dcs, idx, dnssrvcmp );
+
+ *dclist = dcs;
+ *numdcs = idx;
+
+ return NT_STATUS_OK;
+}
+
+/*********************************************************************
+ Simple wrapper for a DNS NS query
+*********************************************************************/
+
+NTSTATUS ads_dns_lookup_ns(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dnsdomain,
+ struct dns_rr_ns **nslist,
+ int *numns)
+{
+ uint8_t *buffer = NULL;
+ int resp_len = 0;
+ struct dns_rr_ns *nsarray = NULL;
+ int query_count, answer_count, auth_count, additional_count;
+ uint8_t *p;
+ int rrnum;
+ int idx = 0;
+ NTSTATUS status;
+
+ if ( !ctx || !dnsdomain || !nslist ) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ if (dns_hosts_file) {
+ DEBUG(1, ("NO 'NS' lookup available when using resolv:host file"));
+ return NT_STATUS_OBJECT_NAME_NOT_FOUND;
+ }
+
+ /* Send the request. May have to loop several times in case
+ of large replies */
+
+ status = dns_send_req( ctx, dnsdomain, T_NS, &buffer, &resp_len );
+ if ( !NT_STATUS_IS_OK(status) ) {
+ DEBUG(3,("ads_dns_lookup_ns: Failed to send DNS query (%s)\n",
+ nt_errstr(status)));
+ return status;
+ }
+ p = buffer;
+
+ /* For some insane reason, the ns_initparse() et. al. routines are only
+ available in libresolv.a, and not the shared lib. Who knows why....
+ So we have to parse the DNS reply ourselves */
+
+ /* Pull the answer RR's count from the header.
+ * Use the NMB ordering macros */
+
+ query_count = RSVAL( p, 4 );
+ answer_count = RSVAL( p, 6 );
+ auth_count = RSVAL( p, 8 );
+ additional_count = RSVAL( p, 10 );
+
+ DEBUG(4,("ads_dns_lookup_ns: "
+ "%d records returned in the answer section.\n",
+ answer_count));
+
+ if (answer_count) {
+ if ((nsarray = talloc_array(ctx, struct dns_rr_ns,
+ answer_count)) == NULL ) {
+ DEBUG(0,("ads_dns_lookup_ns: "
+ "talloc() failure for %d char*'s\n",
+ answer_count));
+ return NT_STATUS_NO_MEMORY;
+ }
+ } else {
+ nsarray = NULL;
+ }
+
+ /* now skip the header */
+
+ p += NS_HFIXEDSZ;
+
+ /* parse the query section */
+
+ for ( rrnum=0; rrnum<query_count; rrnum++ ) {
+ struct dns_query q;
+
+ if (!ads_dns_parse_query(ctx, buffer, buffer+resp_len,
+ &p, &q)) {
+ DEBUG(1,("ads_dns_lookup_ns: "
+ " Failed to parse query record!\n"));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+
+ /* now we are at the answer section */
+
+ for ( rrnum=0; rrnum<answer_count; rrnum++ ) {
+ if (!ads_dns_parse_rr_ns(ctx, buffer, buffer+resp_len,
+ &p, &nsarray[rrnum])) {
+ DEBUG(1,("ads_dns_lookup_ns: "
+ "Failed to parse answer record!\n"));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+ idx = rrnum;
+
+ /* Parse the authority section */
+ /* just skip these for now */
+
+ for ( rrnum=0; rrnum<auth_count; rrnum++ ) {
+ struct dns_rr rr;
+
+ if ( !ads_dns_parse_rr(ctx, buffer, buffer+resp_len,
+ &p, &rr)) {
+ DEBUG(1,("ads_dns_lookup_ns: "
+ "Failed to parse authority record!\n"));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+ }
+
+ /* Parse the additional records section */
+
+ for ( rrnum=0; rrnum<additional_count; rrnum++ ) {
+ struct dns_rr rr;
+ int i;
+
+ if (!ads_dns_parse_rr(ctx, buffer, buffer+resp_len,
+ &p, &rr)) {
+ DEBUG(1,("ads_dns_lookup_ns: Failed "
+ "to parse additional records section!\n"));
+ return NT_STATUS_UNSUCCESSFUL;
+ }
+
+ /* only interested in A records as a shortcut for having to come
+ back later and lookup the name */
+
+ if (rr.type != T_A || rr.rdatalen != 4) {
+#if defined(HAVE_IPV6)
+ if (rr.type != T_AAAA || rr.rdatalen != 16)
+#endif
+ continue;
+ }
+
+ for ( i=0; i<idx; i++ ) {
+ if (strcmp(rr.hostname, nsarray[i].hostname) == 0) {
+ if (rr.type == T_A) {
+ struct in_addr ip;
+ memcpy(&ip, rr.rdata, 4);
+ in_addr_to_sockaddr_storage(
+ &nsarray[i].ss,
+ ip);
+ }
+#if defined(HAVE_IPV6)
+ if (rr.type == T_AAAA) {
+ struct in6_addr ip6;
+ memcpy(&ip6, rr.rdata, rr.rdatalen);
+ in6_addr_to_sockaddr_storage(
+ &nsarray[i].ss,
+ ip6);
+ }
+#endif
+ }
+ }
+ }
+
+ *nslist = nsarray;
+ *numns = idx;
+
+ return NT_STATUS_OK;
+}
+
+/********************************************************************
+ Query with optional sitename.
+********************************************************************/
+
+static NTSTATUS ads_dns_query_internal(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *servicename,
+ const char *dc_pdc_gc_domains,
+ const char *realm,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ char *name;
+ if (sitename && strlen(sitename)) {
+ name = talloc_asprintf(ctx, "%s._tcp.%s._sites.%s._msdcs.%s",
+ servicename, sitename,
+ dc_pdc_gc_domains, realm);
+ } else {
+ name = talloc_asprintf(ctx, "%s._tcp.%s._msdcs.%s",
+ servicename, dc_pdc_gc_domains, realm);
+ }
+ if (!name) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ return ads_dns_lookup_srv(ctx, dns_hosts_file, name, dclist, numdcs);
+}
+
+/********************************************************************
+ Query for AD DC's.
+********************************************************************/
+
+NTSTATUS ads_dns_query_dcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *realm,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ NTSTATUS status;
+
+ status = ads_dns_query_internal(ctx, dns_hosts_file, "_ldap", "dc",
+ realm, sitename, dclist, numdcs);
+
+ if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+ NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+ return status;
+ }
+
+ if (sitename &&
+ ((!NT_STATUS_IS_OK(status)) ||
+ (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
+ /* Sitename DNS query may have failed. Try without. */
+ status = ads_dns_query_internal(ctx, dns_hosts_file,
+ "_ldap", "dc", realm,
+ NULL, dclist, numdcs);
+ }
+ return status;
+}
+
+/********************************************************************
+ Query for AD GC's.
+********************************************************************/
+
+NTSTATUS ads_dns_query_gcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *realm,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ NTSTATUS status;
+
+ status = ads_dns_query_internal(ctx, dns_hosts_file, "_ldap", "gc",
+ realm, sitename, dclist, numdcs);
+
+ if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+ NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+ return status;
+ }
+
+ if (sitename &&
+ ((!NT_STATUS_IS_OK(status)) ||
+ (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
+ /* Sitename DNS query may have failed. Try without. */
+ status = ads_dns_query_internal(ctx, dns_hosts_file,
+ "_ldap", "gc", realm,
+ NULL, dclist, numdcs);
+ }
+ return status;
+}
+
+/********************************************************************
+ Query for AD KDC's.
+ Even if our underlying kerberos libraries are UDP only, this
+ is pretty safe as it's unlikely that a KDC supports TCP and not UDP.
+********************************************************************/
+
+NTSTATUS ads_dns_query_kdcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_forest_name,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ NTSTATUS status;
+
+ status = ads_dns_query_internal(ctx, dns_hosts_file, "_kerberos", "dc",
+ dns_forest_name, sitename, dclist,
+ numdcs);
+
+ if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT) ||
+ NT_STATUS_EQUAL(status, NT_STATUS_CONNECTION_REFUSED)) {
+ return status;
+ }
+
+ if (sitename &&
+ ((!NT_STATUS_IS_OK(status)) ||
+ (NT_STATUS_IS_OK(status) && (numdcs == 0)))) {
+ /* Sitename DNS query may have failed. Try without. */
+ status = ads_dns_query_internal(ctx, dns_hosts_file,
+ "_kerberos", "dc",
+ dns_forest_name, NULL,
+ dclist, numdcs);
+ }
+ return status;
+}
+
+/********************************************************************
+ Query for AD PDC. Sitename is obsolete here.
+********************************************************************/
+
+NTSTATUS ads_dns_query_pdc(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_domain_name,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ return ads_dns_query_internal(ctx, dns_hosts_file, "_ldap", "pdc",
+ dns_domain_name, NULL, dclist, numdcs);
+}
+
+/********************************************************************
+ Query for AD DC by guid. Sitename is obsolete here.
+********************************************************************/
+
+NTSTATUS ads_dns_query_dcs_guid(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_forest_name,
+ const char *domain_guid,
+ struct dns_rr_srv **dclist,
+ int *numdcs )
+{
+ /*_ldap._tcp.DomainGuid.domains._msdcs.DnsForestName */
+
+ const char *domains;
+
+ /* little hack */
+ domains = talloc_asprintf(ctx, "%s.domains", domain_guid);
+ if (!domains) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ return ads_dns_query_internal(ctx, dns_hosts_file, "_ldap", domains,
+ dns_forest_name, NULL, dclist, numdcs);
+}
diff --git a/lib/addns/dnsquery.h b/lib/addns/dnsquery.h
new file mode 100644
index 0000000000..a3ea47a04e
--- /dev/null
+++ b/lib/addns/dnsquery.h
@@ -0,0 +1,61 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Internal DNS query structures
+ * Copyright (C) Gerald Carter 2006.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ADS_DNS_H
+#define _ADS_DNS_H
+
+#include "libcli/dns/dns.h"
+
+/* The following definitions come from libads/dns.c */
+
+NTSTATUS ads_dns_lookup_ns(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dnsdomain,
+ struct dns_rr_ns **nslist,
+ int *numns);
+NTSTATUS ads_dns_query_dcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *realm,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs );
+NTSTATUS ads_dns_query_gcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *realm,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs );
+NTSTATUS ads_dns_query_kdcs(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_forest_name,
+ const char *sitename,
+ struct dns_rr_srv **dclist,
+ int *numdcs );
+NTSTATUS ads_dns_query_pdc(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_domain_name,
+ struct dns_rr_srv **dclist,
+ int *numdcs );
+NTSTATUS ads_dns_query_dcs_guid(TALLOC_CTX *ctx,
+ const char *dns_hosts_file,
+ const char *dns_forest_name,
+ const char *domain_guid,
+ struct dns_rr_srv **dclist,
+ int *numdcs );
+#endif /* _ADS_DNS_H */
diff --git a/lib/addns/wscript_build b/lib/addns/wscript_build
index 69a4716245..a7010531a0 100644..100755
--- a/lib/addns/wscript_build
+++ b/lib/addns/wscript_build
@@ -5,3 +5,8 @@ bld.SAMBA_LIBRARY('addns',
public_deps='talloc krb5 k5crypto com_err gssapi gssapi_krb5 uuid',
private_library=True,
vars=locals())
+
+bld.SAMBA_SUBSYSTEM('DNSQUERY',
+ source='dnsquery.c',
+ deps='samba-util lmhosts resolv'
+ )