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
  30 /**********************************************************************
  31  Is this our primary domain ?
  32 **********************************************************************/
  33
  34 #ifdef HAVE_KRB5
  35 static bool is_our_primary_domain(const char *domain)
  36 {
  37         int role = lp_server_role();
  38
  39         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  40                 return True;
  41         } else if (strequal(get_global_sam_name(), domain)) {
  42                 return True;
  43         }
  44         return False;
  45 }
  46 #endif
  47
  48 /**************************************************************************
  49  Find the name and IP address for a server in the realm/domain
  50  *************************************************************************/
  51
  52 static bool ads_dc_name(const char *domain,
  53                         const char *realm,
  54                         struct sockaddr_storage *dc_ss,
  55                         fstring srv_name)
  56 {
  57         ADS_STRUCT *ads;
  58         char *sitename;
  59         int i;
  60         char addr[INET6_ADDRSTRLEN];
  61
  62         if (!realm && strequal(domain, lp_workgroup())) {
  63                 realm = lp_realm();
  64         }
  65
  66         sitename = sitename_fetch(realm);
  67
  68         /* Try this 3 times then give up. */
  69         for( i =0 ; i < 3; i++) {
  70                 ads = ads_init(realm, domain, NULL);
  71                 if (!ads) {
  72                         SAFE_FREE(sitename);
  73                         return False;
  74                 }
  75
  76                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  77
  78 #ifdef HAVE_ADS
  79                 /* we don't need to bind, just connect */
  80                 ads->auth.flags |= ADS_AUTH_NO_BIND;
  81                 ads_connect(ads);
  82 #endif
  83
  84                 if (!ads->config.realm) {
  85                         SAFE_FREE(sitename);
  86                         ads_destroy(&ads);
  87                         return False;
  88                 }
  89
  90                 /* Now we've found a server, see if our sitename
  91                    has changed. If so, we need to re-do the DNS query
  92                    to ensure we only find servers in our site. */
  93
  94                 if (stored_sitename_changed(realm, sitename)) {
  95                         SAFE_FREE(sitename);
  96                         sitename = sitename_fetch(realm);
  97                         ads_destroy(&ads);
  98                         /* Ensure we don't cache the DC we just connected to. */
  99                         namecache_delete(realm, 0x1C);
 100                         namecache_delete(domain, 0x1C);
 101                         continue;
 102                 }
 103
 104 #ifdef HAVE_KRB5
 105                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 106                         if (ads_closest_dc(ads)) {
 107                                 /* We're going to use this KDC for this realm/domain.
 108                                    If we are using sites, then force the krb5 libs
 109                                    to use this KDC. */
 110
 111                                 create_local_private_krb5_conf_for_domain(realm,
 112                                                                         domain,
 113                                                                         sitename,
 114                                                                         &ads->ldap.ss,
 115                                                                         ads->config.ldap_server_name);
 116                         } else {
 117                                 create_local_private_krb5_conf_for_domain(realm,
 118                                                                         domain,
 119                                                                         NULL,
 120                                                                         &ads->ldap.ss,
 121                                                                         ads->config.ldap_server_name);
 122                         }
 123                 }
 124 #endif
 125                 break;
 126         }
 127
 128         if (i == 3) {
 129                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 130                         sitename ? sitename : ""));
 131                 SAFE_FREE(sitename);
 132                 return False;
 133         }
 134
 135         SAFE_FREE(sitename);
 136
 137         fstrcpy(srv_name, ads->config.ldap_server_name);
 138         strupper_m(srv_name);
 139 #ifdef HAVE_ADS
 140         *dc_ss = ads->ldap.ss;
 141 #else
 142         zero_sockaddr(dc_ss);
 143 #endif
 144         ads_destroy(&ads);
 145
 146         print_sockaddr(addr, sizeof(addr), dc_ss);
 147         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 148                  srv_name, addr));
 149
 150         return True;
 151 }
 152
 153 /****************************************************************************
 154  Utility function to return the name of a DC. The name is guaranteed to be
 155  valid since we have already done a name_status_find on it
 156  ***************************************************************************/
 157
 158 static bool rpc_dc_name(const char *domain,
 159                         fstring srv_name,
 160                         struct sockaddr_storage *ss_out)
 161 {
 162         struct ip_service *ip_list = NULL;
 163         struct sockaddr_storage dc_ss;
 164         int count, i;
 165         NTSTATUS result;
 166         char addr[INET6_ADDRSTRLEN];
 167
 168         /* get a list of all domain controllers */
 169
 170         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 171                                                 False))) {
 172                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 173                 return False;
 174         }
 175
 176         /* Remove the entry we've already failed with (should be the PDC). */
 177
 178         for (i = 0; i < count; i++) {
 179                 if (is_zero_addr((struct sockaddr *)&ip_list[i].ss))
 180                         continue;
 181
 182                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
 183                         result = check_negative_conn_cache( domain, srv_name );
 184                         if ( NT_STATUS_IS_OK(result) ) {
 185                                 dc_ss = ip_list[i].ss;
 186                                 goto done;
 187                         }
 188                 }
 189         }
 190
 191         SAFE_FREE(ip_list);
 192
 193         /* No-one to talk to )-: */
 194         return False;           /* Boo-hoo */
 195
 196  done:
 197         /* We have the netbios name and IP address of a domain controller.
 198            Ideally we should sent a SAMLOGON request to determine whether
 199            the DC is alive and kicking.  If we can catch a dead DC before
 200            performing a cli_connect() we can avoid a 30-second timeout. */
 201
 202         print_sockaddr(addr, sizeof(addr), &dc_ss);
 203         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 204                   addr, domain));
 205
 206         *ss_out = dc_ss;
 207         SAFE_FREE(ip_list);
 208
 209         return True;
 210 }
 211
 212 /**********************************************************************
 213  wrapper around ads and rpc methods of finds DC's
 214 **********************************************************************/
 215
 216 bool get_dc_name(const char *domain,
 217                 const char *realm,
 218                 fstring srv_name,
 219                 struct sockaddr_storage *ss_out)
 220 {
 221         struct sockaddr_storage dc_ss;
 222         bool ret;
 223         bool our_domain = False;
 224
 225         zero_sockaddr(&dc_ss);
 226
 227         ret = False;
 228
 229         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 230                 our_domain = True;
 231
 232         /* always try to obey what the admin specified in smb.conf
 233            (for the local domain) */
 234
 235         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 236                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 237         }
 238
 239         if (!domain) {
 240                 /* if we have only the realm we can't do anything else */
 241                 return False;
 242         }
 243
 244         if (!ret) {
 245                 /* fall back on rpc methods if the ADS methods fail */
 246                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 247         }
 248
 249         *ss_out = dc_ss;
 250
 251         return ret;
 252 }