# 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_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.
*********************************************************************/
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,("dns_send_req: 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,("dns_send_req: "
- "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,("dns_send_req: "
- "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;
-}
-
struct ads_dns_lookup_srv_state {
struct dns_rr_srv *srvs;
size_t num_srvs;
return status;
}
-/*********************************************************************
- Simple wrapper for a DNS NS query
-*********************************************************************/
+struct ads_dns_lookup_ns_state {
+ struct dns_rr_ns *nss;
+ size_t num_nss;
+};
-NTSTATUS ads_dns_lookup_ns(TALLOC_CTX *ctx,
- const char *dnsdomain,
- struct dns_rr_ns **nslist,
- int *numns)
+static void ads_dns_lookup_ns_done(struct tevent_req *subreq);
+
+struct tevent_req *ads_dns_lookup_ns_send(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ const char *name)
{
- 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;
+ struct tevent_req *req, *subreq;
+ struct ads_dns_lookup_ns_state *state;
- if ( !ctx || !dnsdomain || !nslist ) {
- return NT_STATUS_INVALID_PARAMETER;
+ req = tevent_req_create(mem_ctx, &state,
+ struct ads_dns_lookup_ns_state);
+ if (req == NULL) {
+ return NULL;
}
- /* 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;
+ subreq = dns_lookup_send(state, ev, NULL, name, DNS_QCLASS_IN,
+ DNS_QTYPE_NS);
+ if (tevent_req_nomem(subreq, req)) {
+ return tevent_req_post(req, ev);
}
+ tevent_req_set_callback(subreq, ads_dns_lookup_ns_done, req);
+ return req;
+}
- /* now skip the header */
-
- p += NS_HFIXEDSZ;
-
- /* parse the query section */
+static void ads_dns_lookup_ns_done(struct tevent_req *subreq)
+{
+ struct tevent_req *req = tevent_req_callback_data(
+ subreq, struct tevent_req);
+ struct ads_dns_lookup_ns_state *state = tevent_req_data(
+ req, struct ads_dns_lookup_ns_state);
+ int ret;
+ struct dns_name_packet *reply;
+ uint16_t i, idx;
- for ( rrnum=0; rrnum<query_count; rrnum++ ) {
- struct dns_query q;
+ 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;
+ }
- 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;
+ for (i=0; i<reply->ancount; i++) {
+ if (reply->answers[i].rr_type == DNS_QTYPE_NS) {
+ state->num_nss += 1;
}
}
- /* 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;
- }
+ state->nss = talloc_array(state, struct dns_rr_ns, state->num_nss);
+ if (tevent_req_nomem(state->nss, 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];
- 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;
+ if (an->rr_type != DNS_QTYPE_NS) {
+ continue;
}
- }
- /* Parse the additional records section */
+ state->nss[idx].hostname = talloc_move(state->nss,
+ &an->rdata.ns_record);
+ idx += 1;
+ }
- 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_ns: Failed "
- "to parse additional records section!\n"));
- return NT_STATUS_UNSUCCESSFUL;
+ ok = dns_res_rec_get_sockaddr(ar, &addr);
+ if (!ok) {
+ continue;
}
- /* 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 (j=0; j<state->num_nss; j++) {
+ struct dns_rr_ns *ns = &state->nss[j];
- 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
+ if (strcmp(ns->hostname, ar->name) == 0) {
+ ns->ss = addr;
}
}
}
- *nslist = nsarray;
- *numns = idx;
+ tevent_req_done(req);
+}
+NTSTATUS ads_dns_lookup_ns_recv(struct tevent_req *req,
+ TALLOC_CTX *mem_ctx,
+ struct dns_rr_ns **nss,
+ size_t *num_nss)
+{
+ struct ads_dns_lookup_ns_state *state = tevent_req_data(
+ req, struct ads_dns_lookup_ns_state);
+ NTSTATUS status;
+
+ if (tevent_req_is_nterror(req, &status)) {
+ return status;
+ }
+ *nss = talloc_move(mem_ctx, &state->nss);
+ *num_nss = state->num_nss;
+ tevent_req_received(req);
return NT_STATUS_OK;
}
+/*********************************************************************
+ Simple wrapper for a DNS NS query
+*********************************************************************/
+
+NTSTATUS ads_dns_lookup_ns(TALLOC_CTX *ctx,
+ const char *dnsdomain,
+ struct dns_rr_ns **nslist,
+ int *numns)
+{
+ struct tevent_context *ev;
+ struct tevent_req *req;
+ NTSTATUS status = NT_STATUS_NO_MEMORY;
+ size_t num_ns = 0;
+
+ ev = samba_tevent_context_init(ctx);
+ if (ev == NULL) {
+ goto fail;
+ }
+ req = ads_dns_lookup_ns_send(ev, ev, dnsdomain);
+ if (req == NULL) {
+ goto fail;
+ }
+ if (!tevent_req_poll_ntstatus(req, ev, &status)) {
+ goto fail;
+ }
+ status = ads_dns_lookup_ns_recv(req, ctx, nslist, &num_ns);
+ *numns = num_ns;
+fail:
+ TALLOC_FREE(ev);
+ return status;
+}
+
+
/********************************************************************
Query with optional sitename.
********************************************************************/
git.samba.org / kai / samba-autobuild / .git / commitdiff