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 "libads/sitename_cache.h"
  27
  28 /**********************************************************************
  29  Is this our primary domain ?
  30 **********************************************************************/
  31
  32 #ifdef HAVE_KRB5
  33 static bool is_our_primary_domain(const char *domain)
  34 {
  35         int role = lp_server_role();
  36
  37         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  38                 return True;
  39         } else if (strequal(get_global_sam_name(), domain)) {
  40                 return True;
  41         }
  42         return False;
  43 }
  44 #endif
  45
  46 /**************************************************************************
  47  Find the name and IP address for a server in the realm/domain
  48  *************************************************************************/
  49
  50 static bool ads_dc_name(const char *domain,
  51                         const char *realm,
  52                         struct sockaddr_storage *dc_ss,
  53                         fstring srv_name)
  54 {
  55         ADS_STRUCT *ads;
  56         char *sitename;
  57         int i;
  58         char addr[INET6_ADDRSTRLEN];
  59
  60         if (!realm && strequal(domain, lp_workgroup())) {
  61                 realm = lp_realm();
  62         }
  63
  64         sitename = sitename_fetch(realm);
  65
  66         /* Try this 3 times then give up. */
  67         for( i =0 ; i < 3; i++) {
  68                 ads = ads_init(realm, domain, NULL);
  69                 if (!ads) {
  70                         SAFE_FREE(sitename);
  71                         return False;
  72                 }
  73
  74                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  75
  76 #ifdef HAVE_ADS
  77                 /* we don't need to bind, just connect */
  78                 ads->auth.flags |= ADS_AUTH_NO_BIND;
  79                 ads_connect(ads);
  80 #endif
  81
  82                 if (!ads->config.realm) {
  83                         SAFE_FREE(sitename);
  84                         ads_destroy(&ads);
  85                         return False;
  86                 }
  87
  88                 /* Now we've found a server, see if our sitename
  89                    has changed. If so, we need to re-do the DNS query
  90                    to ensure we only find servers in our site. */
  91
  92                 if (stored_sitename_changed(realm, sitename)) {
  93                         SAFE_FREE(sitename);
  94                         sitename = sitename_fetch(realm);
  95                         ads_destroy(&ads);
  96                         /* Ensure we don't cache the DC we just connected to. */
  97                         namecache_delete(realm, 0x1C);
  98                         namecache_delete(domain, 0x1C);
  99                         continue;
 100                 }
 101
 102 #ifdef HAVE_KRB5
 103                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 104                         if (ads_closest_dc(ads)) {
 105                                 /* We're going to use this KDC for this realm/domain.
 106                                    If we are using sites, then force the krb5 libs
 107                                    to use this KDC. */
 108
 109                                 create_local_private_krb5_conf_for_domain(realm,
 110                                                                         domain,
 111                                                                         sitename,
 112                                                                         &ads->ldap.ss,
 113                                                                         ads->config.ldap_server_name);
 114                         } else {
 115                                 create_local_private_krb5_conf_for_domain(realm,
 116                                                                         domain,
 117                                                                         NULL,
 118                                                                         &ads->ldap.ss,
 119                                                                         ads->config.ldap_server_name);
 120                         }
 121                 }
 122 #endif
 123                 break;
 124         }
 125
 126         if (i == 3) {
 127                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 128                         sitename ? sitename : ""));
 129                 SAFE_FREE(sitename);
 130                 return False;
 131         }
 132
 133         SAFE_FREE(sitename);
 134
 135         fstrcpy(srv_name, ads->config.ldap_server_name);
 136         strupper_m(srv_name);
 137 #ifdef HAVE_ADS
 138         *dc_ss = ads->ldap.ss;
 139 #else
 140         zero_sockaddr(dc_ss);
 141 #endif
 142         ads_destroy(&ads);
 143
 144         print_sockaddr(addr, sizeof(addr), dc_ss);
 145         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 146                  srv_name, addr));
 147
 148         return True;
 149 }
 150
 151 /****************************************************************************
 152  Utility function to return the name of a DC. The name is guaranteed to be
 153  valid since we have already done a name_status_find on it
 154  ***************************************************************************/
 155
 156 static bool rpc_dc_name(const char *domain,
 157                         fstring srv_name,
 158                         struct sockaddr_storage *ss_out)
 159 {
 160         struct ip_service *ip_list = NULL;
 161         struct sockaddr_storage dc_ss;
 162         int count, i;
 163         NTSTATUS result;
 164         char addr[INET6_ADDRSTRLEN];
 165
 166         /* get a list of all domain controllers */
 167
 168         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 169                                                 False))) {
 170                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 171                 return False;
 172         }
 173
 174         /* Remove the entry we've already failed with (should be the PDC). */
 175
 176         for (i = 0; i < count; i++) {
 177                 if (is_zero_addr((struct sockaddr *)&ip_list[i].ss))
 178                         continue;
 179
 180                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
 181                         result = check_negative_conn_cache( domain, srv_name );
 182                         if ( NT_STATUS_IS_OK(result) ) {
 183                                 dc_ss = ip_list[i].ss;
 184                                 goto done;
 185                         }
 186                 }
 187         }
 188
 189         SAFE_FREE(ip_list);
 190
 191         /* No-one to talk to )-: */
 192         return False;           /* Boo-hoo */
 193
 194  done:
 195         /* We have the netbios name and IP address of a domain controller.
 196            Ideally we should sent a SAMLOGON request to determine whether
 197            the DC is alive and kicking.  If we can catch a dead DC before
 198            performing a cli_connect() we can avoid a 30-second timeout. */
 199
 200         print_sockaddr(addr, sizeof(addr), &dc_ss);
 201         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 202                   addr, domain));
 203
 204         *ss_out = dc_ss;
 205         SAFE_FREE(ip_list);
 206
 207         return True;
 208 }
 209
 210 /**********************************************************************
 211  wrapper around ads and rpc methods of finds DC's
 212 **********************************************************************/
 213
 214 bool get_dc_name(const char *domain,
 215                 const char *realm,
 216                 fstring srv_name,
 217                 struct sockaddr_storage *ss_out)
 218 {
 219         struct sockaddr_storage dc_ss;
 220         bool ret;
 221         bool our_domain = False;
 222
 223         zero_sockaddr(&dc_ss);
 224
 225         ret = False;
 226
 227         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 228                 our_domain = True;
 229
 230         /* always try to obey what the admin specified in smb.conf
 231            (for the local domain) */
 232
 233         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 234                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 235         }
 236
 237         if (!domain) {
 238                 /* if we have only the realm we can't do anything else */
 239                 return False;
 240         }
 241
 242         if (!ret) {
 243                 /* fall back on rpc methods if the ADS methods fail */
 244                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 245         }
 246
 247         *ss_out = dc_ss;
 248
 249         return ret;
 250 }