source4/dns_server/dnsserver_common.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server utils
   5
   6    Copyright (C) 2010 Kai Blin
   7    Copyright (C) 2014 Stefan Metzmacher
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "libcli/util/ntstatus.h"
  25 #include "libcli/util/werror.h"
  26 #include "librpc/ndr/libndr.h"
  27 #include "librpc/gen_ndr/ndr_dns.h"
  28 #include "librpc/gen_ndr/ndr_dnsp.h"
  29 #include <ldb.h>
  30 #include "dsdb/samdb/samdb.h"
  31 #include "dsdb/common/util.h"
  32 #include "dns_server/dnsserver_common.h"
  33
  34 #undef DBGC_CLASS
  35 #define DBGC_CLASS DBGC_DNS
  36
  37 uint8_t werr_to_dns_err(WERROR werr)
  38 {
  39         if (W_ERROR_EQUAL(WERR_OK, werr)) {
  40                 return DNS_RCODE_OK;
  41         } else if (W_ERROR_EQUAL(DNS_ERR(FORMAT_ERROR), werr)) {
  42                 return DNS_RCODE_FORMERR;
  43         } else if (W_ERROR_EQUAL(DNS_ERR(SERVER_FAILURE), werr)) {
  44                 return DNS_RCODE_SERVFAIL;
  45         } else if (W_ERROR_EQUAL(DNS_ERR(NAME_ERROR), werr)) {
  46                 return DNS_RCODE_NXDOMAIN;
  47         } else if (W_ERROR_EQUAL(WERR_DNS_ERROR_NAME_DOES_NOT_EXIST, werr)) {
  48                 return DNS_RCODE_NXDOMAIN;
  49         } else if (W_ERROR_EQUAL(DNS_ERR(NOT_IMPLEMENTED), werr)) {
  50                 return DNS_RCODE_NOTIMP;
  51         } else if (W_ERROR_EQUAL(DNS_ERR(REFUSED), werr)) {
  52                 return DNS_RCODE_REFUSED;
  53         } else if (W_ERROR_EQUAL(DNS_ERR(YXDOMAIN), werr)) {
  54                 return DNS_RCODE_YXDOMAIN;
  55         } else if (W_ERROR_EQUAL(DNS_ERR(YXRRSET), werr)) {
  56                 return DNS_RCODE_YXRRSET;
  57         } else if (W_ERROR_EQUAL(DNS_ERR(NXRRSET), werr)) {
  58                 return DNS_RCODE_NXRRSET;
  59         } else if (W_ERROR_EQUAL(DNS_ERR(NOTAUTH), werr)) {
  60                 return DNS_RCODE_NOTAUTH;
  61         } else if (W_ERROR_EQUAL(DNS_ERR(NOTZONE), werr)) {
  62                 return DNS_RCODE_NOTZONE;
  63         } else if (W_ERROR_EQUAL(DNS_ERR(BADKEY), werr)) {
  64                 return DNS_RCODE_BADKEY;
  65         }
  66         DEBUG(5, ("No mapping exists for %s\n", win_errstr(werr)));
  67         return DNS_RCODE_SERVFAIL;
  68 }
  69
  70 WERROR dns_common_extract(const struct ldb_message_element *el,
  71                           TALLOC_CTX *mem_ctx,
  72                           struct dnsp_DnssrvRpcRecord **records,
  73                           uint16_t *num_records)
  74 {
  75         uint16_t ri;
  76         struct dnsp_DnssrvRpcRecord *recs;
  77
  78         *records = NULL;
  79         *num_records = 0;
  80
  81         recs = talloc_zero_array(mem_ctx, struct dnsp_DnssrvRpcRecord,
  82                                  el->num_values);
  83         if (recs == NULL) {
  84                 return WERR_NOMEM;
  85         }
  86         for (ri = 0; ri < el->num_values; ri++) {
  87                 struct ldb_val *v = &el->values[ri];
  88                 enum ndr_err_code ndr_err;
  89
  90                 ndr_err = ndr_pull_struct_blob(v, recs, &recs[ri],
  91                                 (ndr_pull_flags_fn_t)ndr_pull_dnsp_DnssrvRpcRecord);
  92                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  93                         TALLOC_FREE(recs);
  94                         DEBUG(0, ("Failed to grab dnsp_DnssrvRpcRecord\n"));
  95                         return DNS_ERR(SERVER_FAILURE);
  96                 }
  97         }
  98         *records = recs;
  99         *num_records = el->num_values;
 100         return WERR_OK;
 101 }
 102
 103 WERROR dns_common_lookup(struct ldb_context *samdb,
 104                          TALLOC_CTX *mem_ctx,
 105                          struct ldb_dn *dn,
 106                          struct dnsp_DnssrvRpcRecord **records,
 107                          uint16_t *num_records,
 108                          bool *tombstoned)
 109 {
 110         static const char * const attrs[] = {
 111                 "dnsRecord",
 112                 "dNSTombstoned",
 113                 NULL
 114         };
 115         int ret;
 116         WERROR werr;
 117         struct ldb_message *msg = NULL;
 118         struct ldb_message_element *el;
 119
 120         *records = NULL;
 121         *num_records = 0;
 122
 123         if (tombstoned != NULL) {
 124                 *tombstoned = false;
 125                 ret = dsdb_search_one(samdb, mem_ctx, &msg, dn,
 126                         LDB_SCOPE_BASE, attrs, 0,
 127                         "(objectClass=dnsNode)");
 128         } else {
 129                 ret = dsdb_search_one(samdb, mem_ctx, &msg, dn,
 130                         LDB_SCOPE_BASE, attrs, 0,
 131                         "(&(objectClass=dnsNode)(!(dNSTombstoned=TRUE)))");
 132         }
 133         if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 134                 return WERR_DNS_ERROR_NAME_DOES_NOT_EXIST;
 135         }
 136         if (ret != LDB_SUCCESS) {
 137                 /* TODO: we need to check if there's a glue record we need to
 138                  * create a referral to */
 139                 return DNS_ERR(NAME_ERROR);
 140         }
 141
 142         if (tombstoned != NULL) {
 143                 *tombstoned = ldb_msg_find_attr_as_bool(msg,
 144                                         "dNSTombstoned", false);
 145         }
 146
 147         el = ldb_msg_find_element(msg, "dnsRecord");
 148         if (el == NULL) {
 149                 TALLOC_FREE(msg);
 150                 if (tombstoned != NULL) {
 151                         struct dnsp_DnssrvRpcRecord *recs;
 152                         /*
 153                          * records produced by older Samba releases
 154                          * keep dnsNode objects without dnsRecord and
 155                          * without setting dNSTombstoned=TRUE.
 156                          *
 157                          * We just pretend they're tombstones.
 158                          */
 159                         recs = talloc_array(mem_ctx,
 160                                             struct dnsp_DnssrvRpcRecord,
 161                                             1);
 162                         if (recs == NULL) {
 163                                 return WERR_NOMEM;
 164                         }
 165                         recs[0] = (struct dnsp_DnssrvRpcRecord) {
 166                                 .wType = DNS_TYPE_TOMBSTONE,
 167                                 /*
 168                                  * A value of timestamp != 0
 169                                  * indicated that the object was already
 170                                  * a tombstone, this will be used
 171                                  * in dns_common_replace()
 172                                  */
 173                                 .data.timestamp = 1,
 174                         };
 175
 176                         *tombstoned = true;
 177                         *records = recs;
 178                         *num_records = 1;
 179                         return WERR_OK;
 180                 }
 181                 return DNS_ERR(NAME_ERROR);
 182         }
 183
 184         werr = dns_common_extract(el, mem_ctx, records, num_records);
 185         TALLOC_FREE(msg);
 186         if (!W_ERROR_IS_OK(werr)) {
 187                 return werr;
 188         }
 189
 190         return WERR_OK;
 191 }
 192
 193 WERROR dns_common_replace(struct ldb_context *samdb,
 194                           TALLOC_CTX *mem_ctx,
 195                           struct ldb_dn *dn,
 196                           bool needs_add,
 197                           uint32_t serial,
 198                           struct dnsp_DnssrvRpcRecord *records,
 199                           uint16_t rec_count)
 200 {
 201         struct ldb_message_element *el;
 202         uint16_t i;
 203         int ret;
 204         struct ldb_message *msg = NULL;
 205
 206         msg = ldb_msg_new(mem_ctx);
 207         W_ERROR_HAVE_NO_MEMORY(msg);
 208
 209         msg->dn = dn;
 210
 211         ret = ldb_msg_add_empty(msg, "dnsRecord", LDB_FLAG_MOD_REPLACE, &el);
 212         if (ret != LDB_SUCCESS) {
 213                 return DNS_ERR(SERVER_FAILURE);
 214         }
 215
 216         el->values = talloc_zero_array(el, struct ldb_val, rec_count);
 217         if (rec_count > 0) {
 218                 W_ERROR_HAVE_NO_MEMORY(el->values);
 219         }
 220
 221         for (i = 0; i < rec_count; i++) {
 222                 static const struct dnsp_DnssrvRpcRecord zero;
 223                 struct ldb_val *v = &el->values[el->num_values];
 224                 enum ndr_err_code ndr_err;
 225
 226                 if (memcmp(&records[i], &zero, sizeof(zero)) == 0) {
 227                         continue;
 228                 }
 229
 230                 records[i].dwSerial = serial;
 231                 ndr_err = ndr_push_struct_blob(v, el->values, &records[i],
 232                                 (ndr_push_flags_fn_t)ndr_push_dnsp_DnssrvRpcRecord);
 233                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 234                         DEBUG(0, ("Failed to push dnsp_DnssrvRpcRecord\n"));
 235                         return DNS_ERR(SERVER_FAILURE);
 236                 }
 237                 el->num_values++;
 238         }
 239
 240         if (needs_add) {
 241                 if (el->num_values == 0) {
 242                         return WERR_OK;
 243                 }
 244
 245                 ret = ldb_msg_add_string(msg, "objectClass", "dnsNode");
 246                 if (ret != LDB_SUCCESS) {
 247                         return DNS_ERR(SERVER_FAILURE);
 248                 }
 249
 250                 ret = ldb_add(samdb, msg);
 251                 if (ret != LDB_SUCCESS) {
 252                         return DNS_ERR(SERVER_FAILURE);
 253                 }
 254
 255                 return WERR_OK;
 256         }
 257
 258         if (el->num_values == 0) {
 259                 el->flags = LDB_FLAG_MOD_DELETE;
 260         }
 261
 262         ret = ldb_modify(samdb, msg);
 263         if (ret != LDB_SUCCESS) {
 264                 NTSTATUS nt = dsdb_ldb_err_to_ntstatus(ret);
 265                 return ntstatus_to_werror(nt);
 266         }
 267
 268         return WERR_OK;
 269 }