source3/libsmb/namequery_dc.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Winbind daemon connection manager
   5
   6    Copyright (C) Tim Potter 2001
   7    Copyright (C) Andrew Bartlett 2002
   8    Copyright (C) Gerald Carter 2003
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24
  25 #include "includes.h"
  26 #include "libsmb/namequery.h"
  27 #include "libads/sitename_cache.h"
  28 #include "ads.h"
  29 #include "../librpc/gen_ndr/nbt.h"
  30 #include "lib/param/loadparm.h"
  31 #include "lib/util/string_wrappers.h"
  32
  33 /**********************************************************************
  34  Is this our primary domain ?
  35 **********************************************************************/
  36
  37 #ifdef HAVE_ADS
  38 static bool is_our_primary_domain(const char *domain)
  39 {
  40         int role = lp_server_role();
  41
  42         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  43                 return True;
  44         } else if (strequal(get_global_sam_name(), domain)) {
  45                 return True;
  46         }
  47         return False;
  48 }
  49 #endif
  50
  51 /**************************************************************************
  52  Find the name and IP address for a server in the realm/domain
  53  *************************************************************************/
  54
  55 static bool ads_dc_name(const char *domain,
  56                         const char *realm,
  57                         struct sockaddr_storage *dc_ss,
  58                         fstring srv_name)
  59 {
  60         ADS_STRUCT *ads;
  61         char *sitename;
  62         int i;
  63         char addr[INET6_ADDRSTRLEN];
  64
  65         if (!realm && strequal(domain, lp_workgroup())) {
  66                 realm = lp_realm();
  67         }
  68
  69         sitename = sitename_fetch(talloc_tos(), realm);
  70
  71         /* Try this 3 times then give up. */
  72         for( i =0 ; i < 3; i++) {
  73                 ads = ads_init(realm, domain, NULL, ADS_SASL_PLAIN);
  74                 if (!ads) {
  75                         TALLOC_FREE(sitename);
  76                         return False;
  77                 }
  78
  79                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  80
  81 #ifdef HAVE_ADS
  82                 /* we don't need to bind, just connect */
  83                 ads->auth.flags |= ADS_AUTH_NO_BIND;
  84                 ads_connect(ads);
  85 #endif
  86
  87                 if (!ads->config.realm) {
  88                         TALLOC_FREE(sitename);
  89                         ads_destroy(&ads);
  90                         return False;
  91                 }
  92
  93                 /* Now we've found a server, see if our sitename
  94                    has changed. If so, we need to re-do the DNS query
  95                    to ensure we only find servers in our site. */
  96
  97                 if (stored_sitename_changed(realm, sitename)) {
  98                         TALLOC_FREE(sitename);
  99                         sitename = sitename_fetch(talloc_tos(), realm);
 100                         ads_destroy(&ads);
 101                         /* Ensure we don't cache the DC we just connected to. */
 102                         namecache_delete(realm, 0x1C);
 103                         namecache_delete(domain, 0x1C);
 104                         continue;
 105                 }
 106
 107 #ifdef HAVE_ADS
 108                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 109                         if (ads_closest_dc(ads)) {
 110                                 /* We're going to use this KDC for this realm/domain.
 111                                    If we are using sites, then force the krb5 libs
 112                                    to use this KDC. */
 113
 114                                 create_local_private_krb5_conf_for_domain(realm,
 115                                                                         domain,
 116                                                                         sitename,
 117                                                                         &ads->ldap.ss);
 118                         } else {
 119                                 create_local_private_krb5_conf_for_domain(realm,
 120                                                                         domain,
 121                                                                         NULL,
 122                                                                         &ads->ldap.ss);
 123                         }
 124                 }
 125 #endif
 126                 break;
 127         }
 128
 129         if (i == 3) {
 130                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 131                         sitename ? sitename : ""));
 132                 TALLOC_FREE(sitename);
 133                 ads_destroy(&ads);
 134                 return False;
 135         }
 136
 137         TALLOC_FREE(sitename);
 138
 139         fstrcpy(srv_name, ads->config.ldap_server_name);
 140         if (!strupper_m(srv_name)) {
 141                 ads_destroy(&ads);
 142                 return false;
 143         }
 144 #ifdef HAVE_ADS
 145         *dc_ss = ads->ldap.ss;
 146 #else
 147         zero_sockaddr(dc_ss);
 148 #endif
 149         ads_destroy(&ads);
 150
 151         print_sockaddr(addr, sizeof(addr), dc_ss);
 152         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 153                  srv_name, addr));
 154
 155         return True;
 156 }
 157
 158 /****************************************************************************
 159  Utility function to return the name of a DC. The name is guaranteed to be
 160  valid since we have already done a name_status_find on it
 161  ***************************************************************************/
 162
 163 static bool rpc_dc_name(const char *domain,
 164                         fstring srv_name,
 165                         struct sockaddr_storage *ss_out)
 166 {
 167         struct samba_sockaddr *sa_list = NULL;
 168         size_t count = 0;
 169         struct sockaddr_storage dc_ss;
 170         size_t i;
 171         NTSTATUS result;
 172         char addr[INET6_ADDRSTRLEN];
 173
 174         /* get a list of all domain controllers */
 175
 176         result = get_sorted_dc_list(talloc_tos(),
 177                                 domain,
 178                                 NULL,
 179                                 &sa_list,
 180                                 &count,
 181                                 false);
 182         if (!NT_STATUS_IS_OK(result)) {
 183                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 184                 return False;
 185         }
 186
 187         /* Remove the entry we've already failed with (should be the PDC). */
 188
 189         for (i = 0; i < count; i++) {
 190                 if (is_zero_addr(&sa_list[i].u.ss))
 191                         continue;
 192
 193                 if (name_status_find(domain, 0x1c, 0x20, &sa_list[i].u.ss, srv_name)) {
 194                         result = check_negative_conn_cache( domain, srv_name );
 195                         if ( NT_STATUS_IS_OK(result) ) {
 196                                 dc_ss = sa_list[i].u.ss;
 197                                 goto done;
 198                         }
 199                 }
 200         }
 201
 202         TALLOC_FREE(sa_list);
 203
 204         /* No-one to talk to )-: */
 205         return False;           /* Boo-hoo */
 206
 207  done:
 208         /* We have the netbios name and IP address of a domain controller.
 209            Ideally we should sent a SAMLOGON request to determine whether
 210            the DC is alive and kicking.  If we can catch a dead DC before
 211            performing a cli_connect() we can avoid a 30-second timeout. */
 212
 213         print_sockaddr(addr, sizeof(addr), &dc_ss);
 214         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 215                   addr, domain));
 216
 217         *ss_out = dc_ss;
 218         TALLOC_FREE(sa_list);
 219
 220         return True;
 221 }
 222
 223 /**********************************************************************
 224  wrapper around ads and rpc methods of finds DC's
 225 **********************************************************************/
 226
 227 bool get_dc_name(const char *domain,
 228                 const char *realm,
 229                 fstring srv_name,
 230                 struct sockaddr_storage *ss_out)
 231 {
 232         struct sockaddr_storage dc_ss;
 233         bool ret;
 234         bool our_domain = False;
 235
 236         zero_sockaddr(&dc_ss);
 237
 238         ret = False;
 239
 240         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 241                 our_domain = True;
 242
 243         /* always try to obey what the admin specified in smb.conf
 244            (for the local domain) */
 245
 246         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 247                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 248         }
 249
 250         if (!domain) {
 251                 /* if we have only the realm we can't do anything else */
 252                 return False;
 253         }
 254
 255         if (!ret) {
 256                 /* fall back on rpc methods if the ADS methods fail */
 257                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 258         }
 259
 260         *ss_out = dc_ss;
 261
 262         return ret;
 263 }