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(talloc_tos(), 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                         TALLOC_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                         TALLOC_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                         TALLOC_FREE(sitename);
  97                         sitename = sitename_fetch(talloc_tos(), 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                         } else {
 117                                 create_local_private_krb5_conf_for_domain(realm,
 118                                                                         domain,
 119                                                                         NULL,
 120                                                                         &ads->ldap.ss);
 121                         }
 122                 }
 123 #endif
 124                 break;
 125         }
 126
 127         if (i == 3) {
 128                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 129                         sitename ? sitename : ""));
 130                 TALLOC_FREE(sitename);
 131                 ads_destroy(&ads);
 132                 return False;
 133         }
 134
 135         TALLOC_FREE(sitename);
 136
 137         fstrcpy(srv_name, ads->config.ldap_server_name);
 138         if (!strupper_m(srv_name)) {
 139                 ads_destroy(&ads);
 140                 return false;
 141         }
 142 #ifdef HAVE_ADS
 143         *dc_ss = ads->ldap.ss;
 144 #else
 145         zero_sockaddr(dc_ss);
 146 #endif
 147         ads_destroy(&ads);
 148
 149         print_sockaddr(addr, sizeof(addr), dc_ss);
 150         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 151                  srv_name, addr));
 152
 153         return True;
 154 }
 155
 156 /****************************************************************************
 157  Utility function to return the name of a DC. The name is guaranteed to be
 158  valid since we have already done a name_status_find on it
 159  ***************************************************************************/
 160
 161 static bool rpc_dc_name(const char *domain,
 162                         fstring srv_name,
 163                         struct sockaddr_storage *ss_out)
 164 {
 165         struct ip_service *ip_list = NULL;
 166         struct sockaddr_storage dc_ss;
 167         int count, i;
 168         NTSTATUS result;
 169         char addr[INET6_ADDRSTRLEN];
 170
 171         /* get a list of all domain controllers */
 172
 173         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 174                                                 False))) {
 175                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 176                 return False;
 177         }
 178
 179         /* Remove the entry we've already failed with (should be the PDC). */
 180
 181         for (i = 0; i < count; i++) {
 182                 if (is_zero_addr(&ip_list[i].ss))
 183                         continue;
 184
 185                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
 186                         result = check_negative_conn_cache( domain, srv_name );
 187                         if ( NT_STATUS_IS_OK(result) ) {
 188                                 dc_ss = ip_list[i].ss;
 189                                 goto done;
 190                         }
 191                 }
 192         }
 193
 194         SAFE_FREE(ip_list);
 195
 196         /* No-one to talk to )-: */
 197         return False;           /* Boo-hoo */
 198
 199  done:
 200         /* We have the netbios name and IP address of a domain controller.
 201            Ideally we should sent a SAMLOGON request to determine whether
 202            the DC is alive and kicking.  If we can catch a dead DC before
 203            performing a cli_connect() we can avoid a 30-second timeout. */
 204
 205         print_sockaddr(addr, sizeof(addr), &dc_ss);
 206         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 207                   addr, domain));
 208
 209         *ss_out = dc_ss;
 210         SAFE_FREE(ip_list);
 211
 212         return True;
 213 }
 214
 215 /**********************************************************************
 216  wrapper around ads and rpc methods of finds DC's
 217 **********************************************************************/
 218
 219 bool get_dc_name(const char *domain,
 220                 const char *realm,
 221                 fstring srv_name,
 222                 struct sockaddr_storage *ss_out)
 223 {
 224         struct sockaddr_storage dc_ss;
 225         bool ret;
 226         bool our_domain = False;
 227
 228         zero_sockaddr(&dc_ss);
 229
 230         ret = False;
 231
 232         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 233                 our_domain = True;
 234
 235         /* always try to obey what the admin specified in smb.conf
 236            (for the local domain) */
 237
 238         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 239                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 240         }
 241
 242         if (!domain) {
 243                 /* if we have only the realm we can't do anything else */
 244                 return False;
 245         }
 246
 247         if (!ret) {
 248                 /* fall back on rpc methods if the ADS methods fail */
 249                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 250         }
 251
 252         *ss_out = dc_ss;
 253
 254         return ret;
 255 }