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/*
Unix SMB/CIFS implementation.
DNS server handler for update requests
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/ntstatus.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 check_prerequsites(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
const struct dns_name_packet *in,
const struct dns_res_rec *prereqs, uint16_t count)
{
const struct dns_name_question *zone;
size_t host_part_len = 0;
uint16_t i;
zone = in->questions;
for (i = 0; i < count; i++) {
const struct dns_res_rec *r = &prereqs[i];
bool match;
if (r->ttl != 0) {
return DNS_ERR(FORMAT_ERROR);
}
match = dns_name_match(zone->name, r->name, &host_part_len);
if (!match) {
/* TODO: check if we need to echo all prereqs if the
* first fails */
return DNS_ERR(NOTZONE);
}
if (r->rr_class == DNS_QCLASS_ANY) {
if (r->length != 0) {
return DNS_ERR(FORMAT_ERROR);
}
if (r->rr_type == DNS_QTYPE_ALL) {
/* TODO: Check if zone has at least one RR */
return DNS_ERR(NAME_ERROR);
} else {
/* TODO: Check if RR exists of the specified type */
return DNS_ERR(NXRRSET);
}
continue;
}
if (r->rr_class == DNS_QCLASS_NONE) {
if (r->length != 0) {
return DNS_ERR(FORMAT_ERROR);
}
if (r->rr_type == DNS_QTYPE_ALL) {
/* TODO: Return this error if the given name exits in this zone */
return DNS_ERR(YXDOMAIN);
} else {
/* TODO: Return error if there's an RRset of this type in the zone */
return DNS_ERR(YXRRSET);
}
continue;
}
if (r->rr_class == zone->question_class) {
/* Check if there's a RR with this */
return DNS_ERR(NOT_IMPLEMENTED);
} else {
return DNS_ERR(FORMAT_ERROR);
}
}
return WERR_OK;
}
static WERROR update_prescan(const struct dns_name_question *zone,
const struct dns_res_rec *updates, uint16_t count)
{
const struct dns_res_rec *r;
uint16_t i;
size_t host_part_len;
bool match;
for (i = 0; i < count; i++) {
r = &updates[i];
match = dns_name_match(zone->name, r->name, &host_part_len);
if (!match) {
return DNS_ERR(NOTZONE);
}
if (zone->question_class == r->rr_class) {
/*TODO: also check for AXFR,MAILA,MAILB */
if (r->rr_type == DNS_QTYPE_ALL) {
return DNS_ERR(FORMAT_ERROR);
}
} else if (r->rr_class == DNS_QCLASS_ANY) {
if (r->ttl != 0 || r->length != 0) {
return DNS_ERR(FORMAT_ERROR);
}
} else if (r->rr_class == DNS_QCLASS_NONE) {
if (r->ttl != 0 || r->rr_type == DNS_QTYPE_ALL) {
return DNS_ERR(FORMAT_ERROR);
}
} else {
return DNS_ERR(FORMAT_ERROR);
}
}
return WERR_OK;
}
WERROR dns_server_process_update(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
struct dns_name_packet *in,
const struct dns_res_rec *prereqs, uint16_t prereq_count,
struct dns_res_rec **updates, uint16_t *update_count,
struct dns_res_rec **additional, uint16_t *arcount)
{
struct dns_name_question *zone;
const struct dns_server_zone *z;
size_t host_part_len = 0;
WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
bool update_allowed = false;
if (in->qdcount != 1) {
return DNS_ERR(FORMAT_ERROR);
}
zone = in->questions;
if (zone->question_type != DNS_QTYPE_SOA) {
return DNS_ERR(FORMAT_ERROR);
}
DEBUG(0, ("Got a dns update request.\n"));
for (z = dns->zones; z != NULL; z = z->next) {
bool match;
match = dns_name_match(z->name, zone->name, &host_part_len);
if (match) {
break;
}
}
if (z == NULL) {
return DNS_ERR(NOTAUTH);
}
if (host_part_len != 0) {
/* TODO: We need to delegate this one */
return DNS_ERR(NOT_IMPLEMENTED);
}
werror = check_prerequsites(dns, mem_ctx, in, prereqs, prereq_count);
W_ERROR_NOT_OK_RETURN(werror);
/* TODO: Check if update is allowed, we probably want "always",
* key-based GSSAPI, key-based bind-style TSIG and "never" as
* smb.conf options. */
if (!update_allowed) {
return DNS_ERR(REFUSED);
}
werror = update_prescan(in->questions, *updates, *update_count);
W_ERROR_NOT_OK_RETURN(werror);
return werror;
}
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