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