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/*
Unix SMB/CIFS implementation.
DNS server handler for queries
Copyright (C) 2010 Kai Blin <kai@samba.org>
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 "libcli/util/werror.h"
#include "librpc/ndr/libndr.h"
#include "librpc/gen_ndr/ndr_dns.h"
#include "librpc/gen_ndr/ndr_dnsp.h"
#include <ldb.h>
#include "dsdb/samdb/samdb.h"
#include "dsdb/common/util.h"
#include "dns_server/dns_server.h"
static WERROR handle_question(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
const struct dns_name_question *question,
struct dns_res_rec **answers, uint16_t *ancount)
{
struct dns_res_rec *ans;
struct ldb_dn *dn = NULL;
WERROR werror;
static const char * const attrs[] = { "dnsRecord", NULL};
int ret;
uint16_t ai = *ancount;
unsigned int ri;
struct ldb_message *msg = NULL;
struct dnsp_DnssrvRpcRecord *recs;
struct ldb_message_element *el;
werror = dns_name2dn(dns, mem_ctx, question->name, &dn);
W_ERROR_NOT_OK_RETURN(werror);
ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
if (ret != LDB_SUCCESS) {
return DNS_ERR(NAME_ERROR);
}
el = ldb_msg_find_element(msg, attrs[0]);
if (el == NULL) {
return DNS_ERR(NAME_ERROR);
}
recs = talloc_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
for (ri = 0; ri < el->num_values; ri++) {
struct ldb_val *v = &el->values[ri];
enum ndr_err_code ndr_err;
ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
(ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
return DNS_ERR(SERVER_FAILURE);
}
}
ans = talloc_realloc(mem_ctx, *answers, struct dns_res_rec,
ai + el->num_values);
W_ERROR_HAVE_NO_MEMORY(ans);
switch (question->question_type) {
case DNS_QTYPE_CNAME:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
ZERO_STRUCT(ans[ai]);
ans[ai].name = talloc_strdup(ans, question->name);
ans[ai].rr_type = DNS_QTYPE_CNAME;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.cname_record = talloc_strdup(ans, recs[ri].data.cname);
ai++;
}
break;
case DNS_QTYPE_A:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
/* TODO: if the record actually is a DNS_QTYPE_A */
ZERO_STRUCT(ans[ai]);
ans[ai].name = talloc_strdup(ans, question->name);
ans[ai].rr_type = DNS_QTYPE_A;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.ipv4_record = talloc_strdup(ans, recs[ri].data.ipv4);
ai++;
}
break;
case DNS_QTYPE_AAAA:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
ZERO_STRUCT(ans[ai]);
ans[ai].name = talloc_strdup(ans, question->name);
ans[ai].rr_type = DNS_QTYPE_AAAA;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.ipv6_record = recs[ri].data.ipv6;
ai++;
}
break;
case DNS_QTYPE_NS:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
ZERO_STRUCT(ans[ai]);
ans[ai].name = question->name;
ans[ai].rr_type = DNS_QTYPE_NS;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.ns_record = recs[ri].data.ns;
ai++;
}
break;
case DNS_QTYPE_SRV:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
ZERO_STRUCT(ans[ai]);
ans[ai].name = question->name;
ans[ai].rr_type = DNS_QTYPE_SRV;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.srv_record.priority = recs[ri].data.srv.wPriority;
ans[ai].rdata.srv_record.weight = recs[ri].data.srv.wWeight;
ans[ai].rdata.srv_record.port = recs[ri].data.srv.wPort;
ans[ai].rdata.srv_record.target = recs[ri].data.srv.nameTarget;
ai++;
}
break;
case DNS_QTYPE_SOA:
for (ri = 0; ri < el->num_values; ri++) {
if (recs[ri].wType != question->question_type) {
continue;
}
ZERO_STRUCT(ans[ai]);
ans[ai].name = question->name;
ans[ai].rr_type = DNS_QTYPE_SOA;
ans[ai].rr_class = DNS_QCLASS_IP;
ans[ai].ttl = recs[ri].dwTtlSeconds;
ans[ai].length = UINT16_MAX;
ans[ai].rdata.soa_record.mname = recs[ri].data.soa.mname;
ans[ai].rdata.soa_record.rname = recs[ri].data.soa.rname;
ans[ai].rdata.soa_record.serial = recs[ri].data.soa.serial;
ans[ai].rdata.soa_record.refresh= recs[ri].data.soa.refresh;
ans[ai].rdata.soa_record.retry = recs[ri].data.soa.retry;
ans[ai].rdata.soa_record.expire = recs[ri].data.soa.expire;
ans[ai].rdata.soa_record.minimum= recs[ri].data.soa.minimum;
ai++;
}
break;
default:
return DNS_ERR(NOT_IMPLEMENTED);
}
if (*ancount == ai) {
return DNS_ERR(NAME_ERROR);
}
*ancount = ai;
*answers = ans;
return WERR_OK;
}
WERROR dns_server_process_query(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
struct dns_name_packet *in,
struct dns_res_rec **answers, uint16_t *ancount,
struct dns_res_rec **nsrecs, uint16_t *nscount,
struct dns_res_rec **additional, uint16_t *arcount)
{
uint16_t i, num_answers=0;
struct dns_res_rec *ans=NULL;
WERROR werror;
ans = talloc_array(mem_ctx, struct dns_res_rec, 0);
W_ERROR_HAVE_NO_MEMORY(ans);
for (i = 0; i < in->qdcount; ++i) {
werror = handle_question(dns, mem_ctx, &in->questions[i], &ans, &num_answers);
W_ERROR_NOT_OK_RETURN(werror);
}
*answers = ans;
*ancount = num_answers;
/*FIXME: Do something for these */
*nsrecs = NULL;
*nscount = 0;
*additional = NULL;
*arcount = 0;
return WERR_OK;
}
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