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 uint8_t werr_to_dns_err(WERROR werr)
  34 {
  35         if (W_ERROR_EQUAL(WERR_OK, werr)) {
  36                 return DNS_RCODE_OK;
  37         } else if (W_ERROR_EQUAL(DNS_ERR(FORMAT_ERROR), werr)) {
  38                 return DNS_RCODE_FORMERR;
  39         } else if (W_ERROR_EQUAL(DNS_ERR(SERVER_FAILURE), werr)) {
  40                 return DNS_RCODE_SERVFAIL;
  41         } else if (W_ERROR_EQUAL(DNS_ERR(NAME_ERROR), werr)) {
  42                 return DNS_RCODE_NXDOMAIN;
  43         } else if (W_ERROR_EQUAL(DNS_ERR(NOT_IMPLEMENTED), werr)) {
  44                 return DNS_RCODE_NOTIMP;
  45         } else if (W_ERROR_EQUAL(DNS_ERR(REFUSED), werr)) {
  46                 return DNS_RCODE_REFUSED;
  47         } else if (W_ERROR_EQUAL(DNS_ERR(YXDOMAIN), werr)) {
  48                 return DNS_RCODE_YXDOMAIN;
  49         } else if (W_ERROR_EQUAL(DNS_ERR(YXRRSET), werr)) {
  50                 return DNS_RCODE_YXRRSET;
  51         } else if (W_ERROR_EQUAL(DNS_ERR(NXRRSET), werr)) {
  52                 return DNS_RCODE_NXRRSET;
  53         } else if (W_ERROR_EQUAL(DNS_ERR(NOTAUTH), werr)) {
  54                 return DNS_RCODE_NOTAUTH;
  55         } else if (W_ERROR_EQUAL(DNS_ERR(NOTZONE), werr)) {
  56                 return DNS_RCODE_NOTZONE;
  57         }
  58         DEBUG(5, ("No mapping exists for %%s\n"));
  59         return DNS_RCODE_SERVFAIL;
  60 }
  61
  62 bool dns_name_match(const char *zone, const char *name, size_t *host_part_len)
  63 {
  64         size_t zl = strlen(zone);
  65         size_t nl = strlen(name);
  66         ssize_t zi, ni;
  67         static const size_t fixup = 'a' - 'A';
  68
  69         if (zl > nl) {
  70                 return false;
  71         }
  72
  73         for (zi = zl, ni = nl; zi >= 0; zi--, ni--) {
  74                 char zc = zone[zi];
  75                 char nc = name[ni];
  76
  77                 /* convert to lower case */
  78                 if (zc >= 'A' && zc <= 'Z') {
  79                         zc += fixup;
  80                 }
  81                 if (nc >= 'A' && nc <= 'Z') {
  82                         nc += fixup;
  83                 }
  84
  85                 if (zc != nc) {
  86                         return false;
  87                 }
  88         }
  89
  90         if (ni >= 0) {
  91                 if (name[ni] != '.') {
  92                         return false;
  93                 }
  94
  95                 ni--;
  96         }
  97
  98         *host_part_len = ni+1;
  99
 100         return true;
 101 }
 102
 103 /* Names are equal if they match and there's nothing left over */
 104 bool dns_name_equal(const char *name1, const char *name2)
 105 {
 106         size_t host_part_len;
 107         bool ret = dns_name_match(name1, name2, &host_part_len);
 108
 109         return ret && (host_part_len == 0);
 110 }
 111
 112 WERROR dns_name2dn(struct dns_server *dns,
 113                    TALLOC_CTX *mem_ctx,
 114                    const char *name,
 115                    struct ldb_dn **_dn)
 116 {
 117         struct ldb_dn *base;
 118         struct ldb_dn *dn;
 119         const struct dns_server_zone *z;
 120         size_t host_part_len = 0;
 121
 122         if (name == NULL) {
 123                 return DNS_ERR(FORMAT_ERROR);
 124         }
 125
 126         /*TODO: Check if 'name' is a valid DNS name */
 127
 128         if (strcmp(name, "") == 0) {
 129                 base = ldb_get_default_basedn(dns->samdb);
 130                 dn = ldb_dn_copy(mem_ctx, base);
 131                 ldb_dn_add_child_fmt(dn, "DC=@,DC=RootDNSServers,CN=MicrosoftDNS,CN=System");
 132                 *_dn = dn;
 133                 return WERR_OK;
 134         }
 135
 136         for (z = dns->zones; z != NULL; z = z->next) {
 137                 bool match;
 138
 139                 match = dns_name_match(z->name, name, &host_part_len);
 140                 if (match) {
 141                         break;
 142                 }
 143         }
 144
 145         if (z == NULL) {
 146                 return DNS_ERR(NAME_ERROR);
 147         }
 148
 149         if (host_part_len == 0) {
 150                 dn = ldb_dn_copy(mem_ctx, z->dn);
 151                 ldb_dn_add_child_fmt(dn, "DC=@");
 152                 *_dn = dn;
 153                 return WERR_OK;
 154         }
 155
 156         dn = ldb_dn_copy(mem_ctx, z->dn);
 157         ldb_dn_add_child_fmt(dn, "DC=%*.*s", (int)host_part_len, (int)host_part_len, name);
 158         *_dn = dn;
 159         return WERR_OK;
 160 }