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 "libsmb/namequery.h"
  27 #include "libads/sitename_cache.h"
  28 #include "ads.h"
  29 #include "../librpc/gen_ndr/nbt.h"
  30 #include "lib/param/loadparm.h"
  31
  32 /**********************************************************************
  33  Is this our primary domain ?
  34 **********************************************************************/
  35
  36 #ifdef HAVE_ADS
  37 static bool is_our_primary_domain(const char *domain)
  38 {
  39         int role = lp_server_role();
  40
  41         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  42                 return True;
  43         } else if (strequal(get_global_sam_name(), domain)) {
  44                 return True;
  45         }
  46         return False;
  47 }
  48 #endif
  49
  50 /**************************************************************************
  51  Find the name and IP address for a server in the realm/domain
  52  *************************************************************************/
  53
  54 static bool ads_dc_name(const char *domain,
  55                         const char *realm,
  56                         struct sockaddr_storage *dc_ss,
  57                         fstring srv_name)
  58 {
  59         ADS_STRUCT *ads;
  60         char *sitename;
  61         int i;
  62         char addr[INET6_ADDRSTRLEN];
  63
  64         if (!realm && strequal(domain, lp_workgroup())) {
  65                 realm = lp_realm();
  66         }
  67
  68         sitename = sitename_fetch(talloc_tos(), realm);
  69
  70         /* Try this 3 times then give up. */
  71         for( i =0 ; i < 3; i++) {
  72                 ads = ads_init(realm, domain, NULL, ADS_SASL_PLAIN);
  73                 if (!ads) {
  74                         TALLOC_FREE(sitename);
  75                         return False;
  76                 }
  77
  78                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  79
  80 #ifdef HAVE_ADS
  81                 /* we don't need to bind, just connect */
  82                 ads->auth.flags |= ADS_AUTH_NO_BIND;
  83                 ads_connect(ads);
  84 #endif
  85
  86                 if (!ads->config.realm) {
  87                         TALLOC_FREE(sitename);
  88                         ads_destroy(&ads);
  89                         return False;
  90                 }
  91
  92                 /* Now we've found a server, see if our sitename
  93                    has changed. If so, we need to re-do the DNS query
  94                    to ensure we only find servers in our site. */
  95
  96                 if (stored_sitename_changed(realm, sitename)) {
  97                         TALLOC_FREE(sitename);
  98                         sitename = sitename_fetch(talloc_tos(), realm);
  99                         ads_destroy(&ads);
 100                         /* Ensure we don't cache the DC we just connected to. */
 101                         namecache_delete(realm, 0x1C);
 102                         namecache_delete(domain, 0x1C);
 103                         continue;
 104                 }
 105
 106 #ifdef HAVE_ADS
 107                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 108                         if (ads_closest_dc(ads)) {
 109                                 /* We're going to use this KDC for this realm/domain.
 110                                    If we are using sites, then force the krb5 libs
 111                                    to use this KDC. */
 112
 113                                 create_local_private_krb5_conf_for_domain(realm,
 114                                                                         domain,
 115                                                                         sitename,
 116                                                                         &ads->ldap.ss);
 117                         } else {
 118                                 create_local_private_krb5_conf_for_domain(realm,
 119                                                                         domain,
 120                                                                         NULL,
 121                                                                         &ads->ldap.ss);
 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                 TALLOC_FREE(sitename);
 132                 ads_destroy(&ads);
 133                 return False;
 134         }
 135
 136         TALLOC_FREE(sitename);
 137
 138         fstrcpy(srv_name, ads->config.ldap_server_name);
 139         if (!strupper_m(srv_name)) {
 140                 ads_destroy(&ads);
 141                 return false;
 142         }
 143 #ifdef HAVE_ADS
 144         *dc_ss = ads->ldap.ss;
 145 #else
 146         zero_sockaddr(dc_ss);
 147 #endif
 148         ads_destroy(&ads);
 149
 150         print_sockaddr(addr, sizeof(addr), dc_ss);
 151         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
 152                  srv_name, addr));
 153
 154         return True;
 155 }
 156
 157 /****************************************************************************
 158  Utility function to return the name of a DC. The name is guaranteed to be
 159  valid since we have already done a name_status_find on it
 160  ***************************************************************************/
 161
 162 static bool rpc_dc_name(const char *domain,
 163                         fstring srv_name,
 164                         struct sockaddr_storage *ss_out)
 165 {
 166         struct ip_service *ip_list = NULL;
 167         struct sockaddr_storage dc_ss;
 168         int count, i;
 169         NTSTATUS result;
 170         char addr[INET6_ADDRSTRLEN];
 171
 172         /* get a list of all domain controllers */
 173
 174         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
 175                                                 False))) {
 176                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 177                 return False;
 178         }
 179
 180         /* Remove the entry we've already failed with (should be the PDC). */
 181
 182         for (i = 0; i < count; i++) {
 183                 if (is_zero_addr(&ip_list[i].ss))
 184                         continue;
 185
 186                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
 187                         result = check_negative_conn_cache( domain, srv_name );
 188                         if ( NT_STATUS_IS_OK(result) ) {
 189                                 dc_ss = ip_list[i].ss;
 190                                 goto done;
 191                         }
 192                 }
 193         }
 194
 195         SAFE_FREE(ip_list);
 196
 197         /* No-one to talk to )-: */
 198         return False;           /* Boo-hoo */
 199
 200  done:
 201         /* We have the netbios name and IP address of a domain controller.
 202            Ideally we should sent a SAMLOGON request to determine whether
 203            the DC is alive and kicking.  If we can catch a dead DC before
 204            performing a cli_connect() we can avoid a 30-second timeout. */
 205
 206         print_sockaddr(addr, sizeof(addr), &dc_ss);
 207         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 208                   addr, domain));
 209
 210         *ss_out = dc_ss;
 211         SAFE_FREE(ip_list);
 212
 213         return True;
 214 }
 215
 216 /**********************************************************************
 217  wrapper around ads and rpc methods of finds DC's
 218 **********************************************************************/
 219
 220 bool get_dc_name(const char *domain,
 221                 const char *realm,
 222                 fstring srv_name,
 223                 struct sockaddr_storage *ss_out)
 224 {
 225         struct sockaddr_storage dc_ss;
 226         bool ret;
 227         bool our_domain = False;
 228
 229         zero_sockaddr(&dc_ss);
 230
 231         ret = False;
 232
 233         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 234                 our_domain = True;
 235
 236         /* always try to obey what the admin specified in smb.conf
 237            (for the local domain) */
 238
 239         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 240                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 241         }
 242
 243         if (!domain) {
 244                 /* if we have only the realm we can't do anything else */
 245                 return False;
 246         }
 247
 248         if (!ret) {
 249                 /* fall back on rpc methods if the ADS methods fail */
 250                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 251         }
 252
 253         *ss_out = dc_ss;
 254
 255         return ret;
 256 }