source/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 2 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, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25
  26 #include "includes.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 in_addr *dc_ip,
  53                         fstring srv_name)
  54 {
  55         ADS_STRUCT *ads;
  56         char *sitename;
  57         int i;
  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 & ADS_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_ip);
 112                         } else {
 113                                 /* use an off site KDC */
 114                                 create_local_private_krb5_conf_for_domain(realm,
 115                                                                         domain,
 116                                                                         NULL,
 117                                                                         ads->ldap_ip);
 118                         }
 119                 }
 120 #endif
 121                 break;
 122         }
 123
 124         if (i == 3) {
 125                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 126                         sitename ? sitename : ""));
 127                 SAFE_FREE(sitename);
 128                 return False;
 129         }
 130
 131         SAFE_FREE(sitename);
 132
 133         fstrcpy(srv_name, ads->config.ldap_server_name);
 134         strupper_m(srv_name);
 135         *dc_ip = ads->ldap_ip;
 136         ads_destroy(&ads);
 137
 138         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 139                  srv_name, inet_ntoa(*dc_ip)));
 140
 141         return True;
 142 }
 143
 144 /****************************************************************************
 145  Utility function to return the name of a DC. The name is guaranteed to be
 146  valid since we have already done a name_status_find on it
 147  ***************************************************************************/
 148
 149 static BOOL rpc_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out)
 150 {
 151         struct ip_service *ip_list = NULL;
 152         struct in_addr dc_ip, exclude_ip;
 153         int count, i;
 154         NTSTATUS result;
 155
 156         zero_ip(&exclude_ip);
 157
 158         /* get a list of all domain controllers */
 159
 160         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 161                                                 False))) {
 162                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 163                 return False;
 164         }
 165
 166         /* Remove the entry we've already failed with (should be the PDC). */
 167
 168         for (i = 0; i < count; i++) {
 169                 if (is_zero_ip(ip_list[i].ip))
 170                         continue;
 171
 172                 if (name_status_find(domain, 0x1c, 0x20, ip_list[i].ip, srv_name)) {
 173                         result = check_negative_conn_cache( domain, srv_name );
 174                         if ( NT_STATUS_IS_OK(result) ) {
 175                                 dc_ip = ip_list[i].ip;
 176                                 goto done;
 177                         }
 178                 }
 179         }
 180
 181
 182         SAFE_FREE(ip_list);
 183
 184         /* No-one to talk to )-: */
 185         return False;           /* Boo-hoo */
 186
 187  done:
 188         /* We have the netbios name and IP address of a domain controller.
 189            Ideally we should sent a SAMLOGON request to determine whether
 190            the DC is alive and kicking.  If we can catch a dead DC before
 191            performing a cli_connect() we can avoid a 30-second timeout. */
 192
 193         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 194                   inet_ntoa(dc_ip), domain));
 195
 196         *ip_out = dc_ip;
 197
 198         SAFE_FREE(ip_list);
 199
 200         return True;
 201 }
 202
 203 /**********************************************************************
 204  wrapper around ads and rpc methods of finds DC's
 205 **********************************************************************/
 206
 207 BOOL get_dc_name(const char *domain, const char *realm, fstring srv_name, struct in_addr *ip_out)
 208 {
 209         struct in_addr dc_ip;
 210         BOOL ret;
 211         BOOL our_domain = False;
 212
 213         zero_ip(&dc_ip);
 214
 215         ret = False;
 216
 217         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 218                 our_domain = True;
 219
 220         /* always try to obey what the admin specified in smb.conf
 221            (for the local domain) */
 222
 223         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 224                 ret = ads_dc_name(domain, realm, &dc_ip, srv_name);
 225         }
 226
 227         if (!domain) {
 228                 /* if we have only the realm we can't do anything else */
 229                 return False;
 230         }
 231
 232         if (!ret) {
 233                 /* fall back on rpc methods if the ADS methods fail */
 234                 ret = rpc_dc_name(domain, srv_name, &dc_ip);
 235         }
 236
 237         *ip_out = dc_ip;
 238
 239         return ret;
 240 }