#include "includes.h"
#include "lib/util/util_net.h"
#include "lib/util/tsort.h"
+#include "librpc/gen_ndr/dns.h"
+#include "libcli/dns/dns_lookup.h"
+#include "lib/util/tevent_ntstatus.h"
#include "dnsquery.h"
/* AIX resolv.h uses 'class' in struct ns_rr */
/*********************************************************************
*********************************************************************/
-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 )
{
return last_dns_status;
}
-/*********************************************************************
- Simple wrapper for a DNS SRV query
-*********************************************************************/
+struct ads_dns_lookup_srv_state {
+ struct dns_rr_srv *srvs;
+ size_t num_srvs;
+};
-NTSTATUS ads_dns_lookup_srv(TALLOC_CTX *ctx,
- const char *name,
- struct dns_rr_srv **dclist,
- int *numdcs)
+static void ads_dns_lookup_srv_done(struct tevent_req *subreq);
+
+struct tevent_req *ads_dns_lookup_srv_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ const char *name)
{
- 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;
+ struct tevent_req *req, *subreq;
+ struct ads_dns_lookup_srv_state *state;
- if ( !ctx || !name || !dclist ) {
- return NT_STATUS_INVALID_PARAMETER;
+ req = tevent_req_create(mem_ctx, &state,
+ struct ads_dns_lookup_srv_state);
+ if (req == NULL) {
+ return NULL;
}
- /* Send the request. May have to loop several times in case
- of large replies */
+ subreq = dns_lookup_send(
+ state,
+ ev,
+ NULL,
+ name,
+ DNS_QCLASS_IN,
+ DNS_QTYPE_SRV);
- 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;
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
}
- 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));
+ tevent_req_set_callback(subreq, ads_dns_lookup_srv_done, req);
+ return req;
+}
- 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;
+static void ads_dns_lookup_srv_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct ads_dns_lookup_srv_state *state = tevent_req_data(
+ req, struct ads_dns_lookup_srv_state);
+ int ret;
+ struct dns_name_packet *reply;
+ uint16_t i, idx;
+
+ ret = dns_lookup_recv(subreq, state, &reply);
+ TALLOC_FREE(subreq);
+ if (ret != 0) {
+ tevent_req_nterror(req, map_nt_error_from_unix_common(ret));
+ return;
}
- /* 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;
+ for (i=0; i<reply->ancount; i++) {
+ if (reply->answers[i].rr_type == DNS_QTYPE_SRV) {
+ state->num_srvs += 1;
}
}
- /* 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;
- }
+ state->srvs = talloc_array(state, struct dns_rr_srv, state->num_srvs);
+ if (tevent_req_nomem(state->srvs, req)) {
+ return;
}
- idx = rrnum;
- /* Parse the authority section */
- /* just skip these for now */
+ idx = 0;
- for ( rrnum=0; rrnum<auth_count; rrnum++ ) {
- struct dns_rr rr;
+ for (i=0; i<reply->ancount; i++) {
+ struct dns_res_rec *an = &reply->answers[i];
+ struct dns_rr_srv *dst = &state->srvs[idx];
+ struct dns_srv_record *src;
- 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;
+ if (an->rr_type != DNS_QTYPE_SRV) {
+ continue;
}
+ src = &an->rdata.srv_record;
+
+ *dst = (struct dns_rr_srv) {
+ .hostname = talloc_move(state->srvs, &src->target),
+ .priority = src->priority,
+ .weight = src->weight,
+ .port = src->port,
+ };
+ idx += 1;
}
- /* Parse the additional records section */
-
- for ( rrnum=0; rrnum<additional_count; rrnum++ ) {
- struct dns_rr rr;
- int i;
+ for (i=0; i<reply->arcount; i++) {
+ struct dns_res_rec *ar = &reply->additional[i];
+ struct sockaddr_storage addr;
+ bool ok;
+ size_t j;
- 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;
+ ok = dns_res_rec_get_sockaddr(ar, &addr);
+ if (!ok) {
+ continue;
}
- /* 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. */
+ for (j=0; j<state->num_srvs; j++) {
+ struct dns_rr_srv *srv = &state->srvs[j];
+ struct sockaddr_storage *tmp;
- 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
+ if (strcmp(srv->hostname, ar->name) != 0) {
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++;
+ tmp = talloc_realloc(
+ state->srvs,
+ srv->ss_s,
+ struct sockaddr_storage,
+ srv->num_ips+1);
- /* 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
+ if (tevent_req_nomem(tmp, req)) {
+ return;
}
+ srv->ss_s = tmp;
+
+ srv->ss_s[srv->num_ips] = addr;
+ srv->num_ips += 1;
}
}
- TYPESAFE_QSORT(dcs, idx, dnssrvcmp );
+ TYPESAFE_QSORT(state->srvs, state->num_srvs, dnssrvcmp);
+
+ tevent_req_done(req);
+}
- *dclist = dcs;
- *numdcs = idx;
+NTSTATUS ads_dns_lookup_srv_recv(struct tevent_req *req,
+ TALLOC_CTX *mem_ctx,
+ struct dns_rr_srv **srvs,
+ size_t *num_srvs)
+{
+ struct ads_dns_lookup_srv_state *state = tevent_req_data(
+ req, struct ads_dns_lookup_srv_state);
+ NTSTATUS status;
+ if (tevent_req_is_nterror(req, &status)) {
+ return status;
+ }
+ *srvs = talloc_move(mem_ctx, &state->srvs);
+ *num_srvs = state->num_srvs;
+ tevent_req_received(req);
return NT_STATUS_OK;
}
+/*********************************************************************
+ Simple wrapper for a DNS SRV query
+*********************************************************************/
+
+NTSTATUS ads_dns_lookup_srv(TALLOC_CTX *ctx,
+ const char *name,
+ struct dns_rr_srv **dclist,
+ int *numdcs)
+{
+ struct tevent_context *ev;
+ struct tevent_req *req;
+ NTSTATUS status = NT_STATUS_NO_MEMORY;
+ size_t num_srvs;
+
+ ev = samba_tevent_context_init(ctx);
+ if (ev == NULL) {
+ goto fail;
+ }
+ req = ads_dns_lookup_srv_send(ev, ev, name);
+ if (req == NULL) {
+ goto fail;
+ }
+ if (!tevent_req_poll_ntstatus(req, ev, &status)) {
+ goto fail;
+ }
+ status = ads_dns_lookup_srv_recv(req, ctx, dclist, &num_srvs);
+ *numdcs = num_srvs; /* size_t->int */
+fail:
+ TALLOC_FREE(ev);
+ return status;
+}
+
/*********************************************************************
Simple wrapper for a DNS NS query
*********************************************************************/
git.samba.org / sfrench / samba-autobuild / .git / commitdiff