source4/dns_server/dns_utils.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    DNS server utils
   5
   6    Copyright (C) 2010 Kai Blin  <kai@samba.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "libcli/util/ntstatus.h"
  24 #include "libcli/util/werror.h"
  25 #include "librpc/ndr/libndr.h"
  26 #include "librpc/gen_ndr/ndr_dns.h"
  27 #include "librpc/gen_ndr/ndr_dnsp.h"
  28 #include <ldb.h>
  29 #include "dsdb/samdb/samdb.h"
  30 #include "dsdb/common/util.h"
  31 #include "dns_server/dns_server.h"
  32
  33 #undef DBGC_CLASS
  34 #define DBGC_CLASS DBGC_DNS
  35
  36 /* Names are equal if they match and there's nothing left over */
  37 bool dns_name_equal(const char *name1, const char *name2)
  38 {
  39         size_t host_part_len;
  40         bool ret = dns_name_match(name1, name2, &host_part_len);
  41
  42         return ret && (host_part_len == 0);
  43 }
  44
  45 /*
  46   see if two dns records match
  47  */
  48 bool dns_records_match(struct dnsp_DnssrvRpcRecord *rec1,
  49                        struct dnsp_DnssrvRpcRecord *rec2)
  50 {
  51         bool status;
  52         int i;
  53
  54         if (rec1->wType != rec2->wType) {
  55                 return false;
  56         }
  57
  58         /* see if the data matches */
  59         switch (rec1->wType) {
  60         case DNS_TYPE_A:
  61                 return strcmp(rec1->data.ipv4, rec2->data.ipv4) == 0;
  62         case DNS_TYPE_AAAA:
  63                 return strcmp(rec1->data.ipv6, rec2->data.ipv6) == 0;
  64         case DNS_TYPE_CNAME:
  65                 return dns_name_equal(rec1->data.cname, rec2->data.cname);
  66         case DNS_TYPE_TXT:
  67                 if (rec1->data.txt.count != rec2->data.txt.count) {
  68                         return false;
  69                 }
  70                 status = true;
  71                 for (i=0; i<rec1->data.txt.count; i++) {
  72                         status = status && (strcmp(rec1->data.txt.str[i],
  73                                                 rec2->data.txt.str[i]) == 0);
  74                 }
  75                 return status;
  76         case DNS_TYPE_PTR:
  77                 return strcmp(rec1->data.ptr, rec2->data.ptr) == 0;
  78         case DNS_TYPE_NS:
  79                 return dns_name_equal(rec1->data.ns, rec2->data.ns);
  80
  81         case DNS_TYPE_SRV:
  82                 return rec1->data.srv.wPriority == rec2->data.srv.wPriority &&
  83                         rec1->data.srv.wWeight  == rec2->data.srv.wWeight &&
  84                         rec1->data.srv.wPort    == rec2->data.srv.wPort &&
  85                         dns_name_equal(rec1->data.srv.nameTarget, rec2->data.srv.nameTarget);
  86
  87         case DNS_TYPE_MX:
  88                 return rec1->data.mx.wPriority == rec2->data.mx.wPriority &&
  89                         dns_name_equal(rec1->data.mx.nameTarget, rec2->data.mx.nameTarget);
  90
  91         case DNS_TYPE_HINFO:
  92                 return strcmp(rec1->data.hinfo.cpu, rec2->data.hinfo.cpu) == 0 &&
  93                         strcmp(rec1->data.hinfo.os, rec2->data.hinfo.os) == 0;
  94
  95         case DNS_TYPE_SOA:
  96                 return dns_name_equal(rec1->data.soa.mname, rec2->data.soa.mname) &&
  97                         dns_name_equal(rec1->data.soa.rname, rec2->data.soa.rname) &&
  98                         rec1->data.soa.serial == rec2->data.soa.serial &&
  99                         rec1->data.soa.refresh == rec2->data.soa.refresh &&
 100                         rec1->data.soa.retry == rec2->data.soa.retry &&
 101                         rec1->data.soa.expire == rec2->data.soa.expire &&
 102                         rec1->data.soa.minimum == rec2->data.soa.minimum;
 103         default:
 104                 break;
 105         }
 106
 107         return false;
 108 }
 109
 110 WERROR dns_lookup_records(struct dns_server *dns,
 111                           TALLOC_CTX *mem_ctx,
 112                           struct ldb_dn *dn,
 113                           struct dnsp_DnssrvRpcRecord **records,
 114                           uint16_t *rec_count)
 115 {
 116         return dns_common_lookup(dns->samdb, mem_ctx, dn,
 117                                  records, rec_count, NULL);
 118 }
 119
 120 WERROR dns_replace_records(struct dns_server *dns,
 121                            TALLOC_CTX *mem_ctx,
 122                            struct ldb_dn *dn,
 123                            bool needs_add,
 124                            struct dnsp_DnssrvRpcRecord *records,
 125                            uint16_t rec_count)
 126 {
 127         /* TODO: Autogenerate this somehow */
 128         uint32_t dwSerial = 110;
 129         return dns_common_replace(dns->samdb, mem_ctx, dn,
 130                                   needs_add, dwSerial, records, rec_count);
 131 }
 132
 133 bool dns_authoritative_for_zone(struct dns_server *dns,
 134                                 const char *name)
 135 {
 136         const struct dns_server_zone *z;
 137         size_t host_part_len = 0;
 138
 139         if (name == NULL) {
 140                 return false;
 141         }
 142
 143         if (strcmp(name, "") == 0) {
 144                 return true;
 145         }
 146         for (z = dns->zones; z != NULL; z = z->next) {
 147                 bool match;
 148
 149                 match = dns_name_match(z->name, name, &host_part_len);
 150                 if (match) {
 151                         break;
 152                 }
 153         }
 154         if (z == NULL) {
 155                 return false;
 156         }
 157
 158         return true;
 159 }
 160
 161 const char *dns_get_authoritative_zone(struct dns_server *dns,
 162                                        const char *name)
 163 {
 164         const struct dns_server_zone *z;
 165         size_t host_part_len = 0;
 166
 167         for (z = dns->zones; z != NULL; z = z->next) {
 168                 bool match;
 169                 match = dns_name_match(z->name, name, &host_part_len);
 170                 if (match) {
 171                         return z->name;
 172                 }
 173         }
 174         return NULL;
 175 }
 176
 177 WERROR dns_name2dn(struct dns_server *dns,
 178                    TALLOC_CTX *mem_ctx,
 179                    const char *name,
 180                    struct ldb_dn **dn)
 181 {
 182         return dns_common_name2dn(dns->samdb, dns->zones,
 183                                   mem_ctx, name, dn);
 184 }
 185
 186 WERROR dns_generate_options(struct dns_server *dns,
 187                             TALLOC_CTX *mem_ctx,
 188                             struct dns_res_rec **options)
 189 {
 190         struct dns_res_rec *o;
 191
 192         o = talloc_zero(mem_ctx, struct dns_res_rec);
 193         if (o == NULL) {
 194                 return WERR_NOMEM;
 195         }
 196         o->name = NULL;
 197         o->rr_type = DNS_QTYPE_OPT;
 198         /* This is ugly, but RFC2671 wants the payload size in this field */
 199         o->rr_class = (enum dns_qclass) dns->max_payload;
 200         o->ttl = 0;
 201         o->length = 0;
 202
 203         *options = o;
 204         return WERR_OK;
 205 }