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samba-mirror/source4/dns_server/dns_utils.c

378 lines
9.2 KiB
C

/*
Unix SMB/CIFS implementation.
DNS server utils
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 "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"
uint8_t werr_to_dns_err(WERROR werr)
{
if (W_ERROR_EQUAL(WERR_OK, werr)) {
return DNS_RCODE_OK;
} else if (W_ERROR_EQUAL(DNS_ERR(FORMAT_ERROR), werr)) {
return DNS_RCODE_FORMERR;
} else if (W_ERROR_EQUAL(DNS_ERR(SERVER_FAILURE), werr)) {
return DNS_RCODE_SERVFAIL;
} else if (W_ERROR_EQUAL(DNS_ERR(NAME_ERROR), werr)) {
return DNS_RCODE_NXDOMAIN;
} else if (W_ERROR_EQUAL(DNS_ERR(NOT_IMPLEMENTED), werr)) {
return DNS_RCODE_NOTIMP;
} else if (W_ERROR_EQUAL(DNS_ERR(REFUSED), werr)) {
return DNS_RCODE_REFUSED;
} else if (W_ERROR_EQUAL(DNS_ERR(YXDOMAIN), werr)) {
return DNS_RCODE_YXDOMAIN;
} else if (W_ERROR_EQUAL(DNS_ERR(YXRRSET), werr)) {
return DNS_RCODE_YXRRSET;
} else if (W_ERROR_EQUAL(DNS_ERR(NXRRSET), werr)) {
return DNS_RCODE_NXRRSET;
} else if (W_ERROR_EQUAL(DNS_ERR(NOTAUTH), werr)) {
return DNS_RCODE_NOTAUTH;
} else if (W_ERROR_EQUAL(DNS_ERR(NOTZONE), werr)) {
return DNS_RCODE_NOTZONE;
} else if (W_ERROR_EQUAL(DNS_ERR(BADKEY), werr)) {
return DNS_RCODE_BADKEY;
}
DEBUG(5, ("No mapping exists for %s\n", win_errstr(werr)));
return DNS_RCODE_SERVFAIL;
}
bool dns_name_match(const char *zone, const char *name, size_t *host_part_len)
{
size_t zl = strlen(zone);
size_t nl = strlen(name);
ssize_t zi, ni;
static const size_t fixup = 'a' - 'A';
if (zl > nl) {
return false;
}
for (zi = zl, ni = nl; zi >= 0; zi--, ni--) {
char zc = zone[zi];
char nc = name[ni];
/* convert to lower case */
if (zc >= 'A' && zc <= 'Z') {
zc += fixup;
}
if (nc >= 'A' && nc <= 'Z') {
nc += fixup;
}
if (zc != nc) {
return false;
}
}
if (ni >= 0) {
if (name[ni] != '.') {
return false;
}
ni--;
}
*host_part_len = ni+1;
return true;
}
/* Names are equal if they match and there's nothing left over */
bool dns_name_equal(const char *name1, const char *name2)
{
size_t host_part_len;
bool ret = dns_name_match(name1, name2, &host_part_len);
return ret && (host_part_len == 0);
}
/*
see if two dns records match
*/
bool dns_records_match(struct dnsp_DnssrvRpcRecord *rec1,
struct dnsp_DnssrvRpcRecord *rec2)
{
bool status;
int i;
if (rec1->wType != rec2->wType) {
return false;
}
/* see if the data matches */
switch (rec1->wType) {
case DNS_TYPE_A:
return strcmp(rec1->data.ipv4, rec2->data.ipv4) == 0;
case DNS_TYPE_AAAA:
return strcmp(rec1->data.ipv6, rec2->data.ipv6) == 0;
case DNS_TYPE_CNAME:
return dns_name_equal(rec1->data.cname, rec2->data.cname);
case DNS_TYPE_TXT:
if (rec1->data.txt.count != rec2->data.txt.count) {
return false;
}
status = true;
for (i=0; i<rec1->data.txt.count; i++) {
status = status && (strcmp(rec1->data.txt.str[i],
rec2->data.txt.str[i]) == 0);
}
return status;
case DNS_TYPE_PTR:
return strcmp(rec1->data.ptr, rec2->data.ptr) == 0;
case DNS_TYPE_NS:
return dns_name_equal(rec1->data.ns, rec2->data.ns);
case DNS_TYPE_SRV:
return rec1->data.srv.wPriority == rec2->data.srv.wPriority &&
rec1->data.srv.wWeight == rec2->data.srv.wWeight &&
rec1->data.srv.wPort == rec2->data.srv.wPort &&
dns_name_equal(rec1->data.srv.nameTarget, rec2->data.srv.nameTarget);
case DNS_TYPE_MX:
return rec1->data.mx.wPriority == rec2->data.mx.wPriority &&
dns_name_equal(rec1->data.mx.nameTarget, rec2->data.mx.nameTarget);
case DNS_TYPE_HINFO:
return strcmp(rec1->data.hinfo.cpu, rec2->data.hinfo.cpu) == 0 &&
strcmp(rec1->data.hinfo.os, rec2->data.hinfo.os) == 0;
case DNS_TYPE_SOA:
return dns_name_equal(rec1->data.soa.mname, rec2->data.soa.mname) &&
dns_name_equal(rec1->data.soa.rname, rec2->data.soa.rname) &&
rec1->data.soa.serial == rec2->data.soa.serial &&
rec1->data.soa.refresh == rec2->data.soa.refresh &&
rec1->data.soa.retry == rec2->data.soa.retry &&
rec1->data.soa.expire == rec2->data.soa.expire &&
rec1->data.soa.minimum == rec2->data.soa.minimum;
default:
break;
}
return false;
}
WERROR dns_lookup_records(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
struct ldb_dn *dn,
struct dnsp_DnssrvRpcRecord **records,
uint16_t *rec_count)
{
static const char * const attrs[] = { "dnsRecord", NULL};
struct ldb_message_element *el;
uint16_t ri;
int ret;
struct ldb_message *msg = NULL;
struct dnsp_DnssrvRpcRecord *recs;
ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
if (ret != LDB_SUCCESS) {
/* TODO: we need to check if there's a glue record we need to
* create a referral to */
return DNS_ERR(NAME_ERROR);
}
el = ldb_msg_find_element(msg, attrs[0]);
if (el == NULL) {
*records = NULL;
*rec_count = 0;
return WERR_OK;
}
recs = talloc_zero_array(mem_ctx, struct dnsp_DnssrvRpcRecord, el->num_values);
if (recs == NULL) {
return WERR_NOMEM;
}
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);
}
}
*records = recs;
*rec_count = el->num_values;
return WERR_OK;
}
WERROR dns_replace_records(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
struct ldb_dn *dn,
bool needs_add,
const struct dnsp_DnssrvRpcRecord *records,
uint16_t rec_count)
{
struct ldb_message_element *el;
uint16_t i;
int ret;
struct ldb_message *msg = NULL;
msg = ldb_msg_new(mem_ctx);
W_ERROR_HAVE_NO_MEMORY(msg);
msg->dn = dn;
ret = ldb_msg_add_empty(msg, "dnsRecord", LDB_FLAG_MOD_REPLACE, &el);
if (ret != LDB_SUCCESS) {
return DNS_ERR(SERVER_FAILURE);
}
el->values = talloc_zero_array(el, struct ldb_val, rec_count);
if (rec_count > 0) {
W_ERROR_HAVE_NO_MEMORY(el->values);
}
for (i = 0; i < rec_count; i++) {
static const struct dnsp_DnssrvRpcRecord zero;
struct ldb_val *v = &el->values[el->num_values];
enum ndr_err_code ndr_err;
if (memcmp(&records[i], &zero, sizeof(zero)) == 0) {
continue;
}
ndr_err = ndr_push_struct_blob(v, el->values, &records[i],
(ndr_push_flags_fn_t)ndr_push_dnsp_DnssrvRpcRecord);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
return DNS_ERR(SERVER_FAILURE);
}
el->num_values++;
}
if (el->num_values == 0) {
if (needs_add) {
return WERR_OK;
}
/* TODO: Delete object? */
}
if (needs_add) {
ret = ldb_msg_add_string(msg, "objectClass", "dnsNode");
if (ret != LDB_SUCCESS) {
return DNS_ERR(SERVER_FAILURE);
}
ret = ldb_add(dns->samdb, msg);
if (ret != LDB_SUCCESS) {
return DNS_ERR(SERVER_FAILURE);
}
return WERR_OK;
}
ret = ldb_modify(dns->samdb, msg);
if (ret != LDB_SUCCESS) {
return DNS_ERR(SERVER_FAILURE);
}
return WERR_OK;
}
bool dns_authorative_for_zone(struct dns_server *dns,
const char *name)
{
const struct dns_server_zone *z;
size_t host_part_len = 0;
if (name == NULL) {
return false;
}
if (strcmp(name, "") == 0) {
return true;
}
for (z = dns->zones; z != NULL; z = z->next) {
bool match;
match = dns_name_match(z->name, name, &host_part_len);
if (match) {
break;
}
}
if (z == NULL) {
return false;
}
return true;
}
WERROR dns_name2dn(struct dns_server *dns,
TALLOC_CTX *mem_ctx,
const char *name,
struct ldb_dn **_dn)
{
struct ldb_dn *base;
struct ldb_dn *dn;
const struct dns_server_zone *z;
size_t host_part_len = 0;
if (name == NULL) {
return DNS_ERR(FORMAT_ERROR);
}
/*TODO: Check if 'name' is a valid DNS name */
if (strcmp(name, "") == 0) {
base = ldb_get_default_basedn(dns->samdb);
dn = ldb_dn_copy(mem_ctx, base);
ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
*_dn = dn;
return WERR_OK;
}
for (z = dns->zones; z != NULL; z = z->next) {
bool match;
match = dns_name_match(z->name, name, &host_part_len);
if (match) {
break;
}
}
if (z == NULL) {
return DNS_ERR(NAME_ERROR);
}
if (host_part_len == 0) {
dn = ldb_dn_copy(mem_ctx, z->dn);
ldb_dn_add_child_fmt(dn, "DC=@");
*_dn = dn;
return WERR_OK;
}
dn = ldb_dn_copy(mem_ctx, z->dn);
ldb_dn_add_child_fmt(dn, "DC=%*.*s", (int)host_part_len, (int)host_part_len, name);
*_dn = dn;
return WERR_OK;
}