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 #include "ads.h"
  28 #include "../librpc/gen_ndr/nbt.h"
  29 #include "lib/param/loadparm.h"
  30
  31 /**********************************************************************
  32  Is this our primary domain ?
  33 **********************************************************************/
  34
  35 #ifdef HAVE_KRB5
  36 static bool is_our_primary_domain(const char *domain)
  37 {
  38         int role = lp_server_role();
  39
  40         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  41                 return True;
  42         } else if (strequal(get_global_sam_name(), domain)) {
  43                 return True;
  44         }
  45         return False;
  46 }
  47 #endif
  48
  49 /**************************************************************************
  50  Find the name and IP address for a server in the realm/domain
  51  *************************************************************************/
  52
  53 static bool ads_dc_name(const char *domain,
  54                         const char *realm,
  55                         struct sockaddr_storage *dc_ss,
  56                         fstring srv_name)
  57 {
  58         ADS_STRUCT *ads;
  59         char *sitename;
  60         int i;
  61         char addr[INET6_ADDRSTRLEN];
  62
  63         if (!realm && strequal(domain, lp_workgroup())) {
  64                 realm = lp_realm();
  65         }
  66
  67         sitename = sitename_fetch(realm);
  68
  69         /* Try this 3 times then give up. */
  70         for( i =0 ; i < 3; i++) {
  71                 ads = ads_init(realm, domain, NULL);
  72                 if (!ads) {
  73                         SAFE_FREE(sitename);
  74                         return False;
  75                 }
  76
  77                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  78
  79 #ifdef HAVE_ADS
  80                 /* we don't need to bind, just connect */
  81                 ads->auth.flags |= ADS_AUTH_NO_BIND;
  82                 ads_connect(ads);
  83 #endif
  84
  85                 if (!ads->config.realm) {
  86                         SAFE_FREE(sitename);
  87                         ads_destroy(&ads);
  88                         return False;
  89                 }
  90
  91                 /* Now we've found a server, see if our sitename
  92                    has changed. If so, we need to re-do the DNS query
  93                    to ensure we only find servers in our site. */
  94
  95                 if (stored_sitename_changed(realm, sitename)) {
  96                         SAFE_FREE(sitename);
  97                         sitename = sitename_fetch(realm);
  98                         ads_destroy(&ads);
  99                         /* Ensure we don't cache the DC we just connected to. */
 100                         namecache_delete(realm, 0x1C);
 101                         namecache_delete(domain, 0x1C);
 102                         continue;
 103                 }
 104
 105 #ifdef HAVE_ADS
 106                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 107                         if (ads_closest_dc(ads)) {
 108                                 /* We're going to use this KDC for this realm/domain.
 109                                    If we are using sites, then force the krb5 libs
 110                                    to use this KDC. */
 111
 112                                 create_local_private_krb5_conf_for_domain(realm,
 113                                                                         domain,
 114                                                                         sitename,
 115                                                                         &ads->ldap.ss,
 116                                                                         ads->config.ldap_server_name);
 117                         } else {
 118                                 create_local_private_krb5_conf_for_domain(realm,
 119                                                                         domain,
 120                                                                         NULL,
 121                                                                         &ads->ldap.ss,
 122                                                                         ads->config.ldap_server_name);
 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                 SAFE_FREE(sitename);
 133                 ads_destroy(&ads);
 134                 return False;
 135         }
 136
 137         SAFE_FREE(sitename);
 138
 139         fstrcpy(srv_name, ads->config.ldap_server_name);
 140         strupper_m(srv_name);
 141 #ifdef HAVE_ADS
 142         *dc_ss = ads->ldap.ss;
 143 #else
 144         zero_sockaddr(dc_ss);
 145 #endif
 146         ads_destroy(&ads);
 147
 148         print_sockaddr(addr, sizeof(addr), dc_ss);
 149         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 150                  srv_name, addr));
 151
 152         return True;
 153 }
 154
 155 /****************************************************************************
 156  Utility function to return the name of a DC. The name is guaranteed to be
 157  valid since we have already done a name_status_find on it
 158  ***************************************************************************/
 159
 160 static bool rpc_dc_name(const char *domain,
 161                         fstring srv_name,
 162                         struct sockaddr_storage *ss_out)
 163 {
 164         struct ip_service *ip_list = NULL;
 165         struct sockaddr_storage dc_ss;
 166         int count, i;
 167         NTSTATUS result;
 168         char addr[INET6_ADDRSTRLEN];
 169
 170         /* get a list of all domain controllers */
 171
 172         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 173                                                 False))) {
 174                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 175                 return False;
 176         }
 177
 178         /* Remove the entry we've already failed with (should be the PDC). */
 179
 180         for (i = 0; i < count; i++) {
 181                 if (is_zero_addr(&ip_list[i].ss))
 182                         continue;
 183
 184                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
 185                         result = check_negative_conn_cache( domain, srv_name );
 186                         if ( NT_STATUS_IS_OK(result) ) {
 187                                 dc_ss = ip_list[i].ss;
 188                                 goto done;
 189                         }
 190                 }
 191         }
 192
 193         SAFE_FREE(ip_list);
 194
 195         /* No-one to talk to )-: */
 196         return False;           /* Boo-hoo */
 197
 198  done:
 199         /* We have the netbios name and IP address of a domain controller.
 200            Ideally we should sent a SAMLOGON request to determine whether
 201            the DC is alive and kicking.  If we can catch a dead DC before
 202            performing a cli_connect() we can avoid a 30-second timeout. */
 203
 204         print_sockaddr(addr, sizeof(addr), &dc_ss);
 205         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 206                   addr, domain));
 207
 208         *ss_out = dc_ss;
 209         SAFE_FREE(ip_list);
 210
 211         return True;
 212 }
 213
 214 /**********************************************************************
 215  wrapper around ads and rpc methods of finds DC's
 216 **********************************************************************/
 217
 218 bool get_dc_name(const char *domain,
 219                 const char *realm,
 220                 fstring srv_name,
 221                 struct sockaddr_storage *ss_out)
 222 {
 223         struct sockaddr_storage dc_ss;
 224         bool ret;
 225         bool our_domain = False;
 226
 227         zero_sockaddr(&dc_ss);
 228
 229         ret = False;
 230
 231         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 232                 our_domain = True;
 233
 234         /* always try to obey what the admin specified in smb.conf
 235            (for the local domain) */
 236
 237         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 238                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 239         }
 240
 241         if (!domain) {
 242                 /* if we have only the realm we can't do anything else */
 243                 return False;
 244         }
 245
 246         if (!ret) {
 247                 /* fall back on rpc methods if the ADS methods fail */
 248                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 249         }
 250
 251         *ss_out = dc_ss;
 252
 253         return ret;
 254 }