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 #include "lib/util/string_wrappers.h"
  32
  33 /**********************************************************************
  34  Is this our primary domain ?
  35 **********************************************************************/
  36
  37 #ifdef HAVE_ADS
  38 static bool is_our_primary_domain(const char *domain)
  39 {
  40         int role = lp_server_role();
  41
  42         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
  43                 return True;
  44         } else if (strequal(get_global_sam_name(), domain)) {
  45                 return True;
  46         }
  47         return False;
  48 }
  49 #endif
  50
  51 /**************************************************************************
  52  Find the name and IP address for a server in the realm/domain
  53  *************************************************************************/
  54
  55 static bool ads_dc_name(const char *domain,
  56                         const char *realm,
  57                         struct sockaddr_storage *dc_ss,
  58                         fstring srv_name)
  59 {
  60         TALLOC_CTX *tmp_ctx = talloc_stackframe();
  61         bool ok = false;
  62         ADS_STRUCT *ads;
  63         const char *sitename;
  64         int i;
  65         char addr[INET6_ADDRSTRLEN];
  66
  67         if (!realm && strequal(domain, lp_workgroup())) {
  68                 realm = lp_realm();
  69         }
  70
  71         sitename = sitename_fetch(tmp_ctx, realm);
  72
  73         /* Try this 3 times then give up. */
  74         for( i =0 ; i < 3; i++) {
  75                 ads = ads_init(tmp_ctx, realm, domain, NULL, ADS_SASL_PLAIN);
  76                 if (!ads) {
  77                         ok = false;
  78                         goto out;
  79                 }
  80
  81                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  82
  83 #ifdef HAVE_ADS
  84                 /* we don't need to bind, just connect */
  85                 ads_connect_cldap_only(ads);
  86 #endif
  87
  88                 if (!ads->config.realm) {
  89                         ok = false;
  90                         goto out;
  91                 }
  92
  93                 /* Now we've found a server, see if our sitename
  94                    has changed. If so, we need to re-do the DNS query
  95                    to ensure we only find servers in our site. */
  96
  97 #ifdef HAVE_ADS
  98                 if (ads_closest_dc(ads)) {
  99                         sitename = ads->config.client_site_name;
 100                 } else
 101 #endif
 102                 if (stored_sitename_changed(realm, sitename)) {
 103                         sitename = sitename_fetch(tmp_ctx, realm);
 104                         TALLOC_FREE(ads);
 105                         /* Ensure we don't cache the DC we just connected to. */
 106                         namecache_delete(realm, 0x1C);
 107                         namecache_delete(domain, 0x1C);
 108                         continue;
 109                 }
 110
 111 #ifdef HAVE_ADS
 112                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
 113                         if (ads_closest_dc(ads)) {
 114                                 /* We're going to use this KDC for this realm/domain.
 115                                    If we are using sites, then force the krb5 libs
 116                                    to use this KDC. */
 117
 118                                 create_local_private_krb5_conf_for_domain(realm,
 119                                                                         domain,
 120                                                                         sitename,
 121                                                                         &ads->ldap.ss);
 122                         } else {
 123                                 create_local_private_krb5_conf_for_domain(realm,
 124                                                                         domain,
 125                                                                         NULL,
 126                                                                         &ads->ldap.ss);
 127                         }
 128                 }
 129 #endif
 130                 break;
 131         }
 132
 133         if (i == 3) {
 134                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
 135                         sitename ? sitename : ""));
 136                 ok = false;
 137                 goto out;
 138         }
 139
 140         fstrcpy(srv_name, ads->config.ldap_server_name);
 141         if (!strupper_m(srv_name)) {
 142                 ok = false;
 143                 goto out;
 144         }
 145 #ifdef HAVE_ADS
 146         *dc_ss = ads->ldap.ss;
 147 #else
 148         zero_sockaddr(dc_ss);
 149 #endif
 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         ok = true;
 155 out:
 156         TALLOC_FREE(tmp_ctx);
 157
 158         return ok;
 159 }
 160
 161 /****************************************************************************
 162  Utility function to return the name of a DC. The name is guaranteed to be
 163  valid since we have already done a name_status_find on it
 164  ***************************************************************************/
 165
 166 static bool rpc_dc_name(const char *domain,
 167                         fstring srv_name,
 168                         struct sockaddr_storage *ss_out)
 169 {
 170         struct samba_sockaddr *sa_list = NULL;
 171         size_t count = 0;
 172         struct sockaddr_storage dc_ss;
 173         size_t i;
 174         NTSTATUS result;
 175         char addr[INET6_ADDRSTRLEN];
 176
 177         /* get a list of all domain controllers */
 178
 179         result = get_sorted_dc_list(talloc_tos(),
 180                                 domain,
 181                                 NULL,
 182                                 &sa_list,
 183                                 &count,
 184                                 false);
 185         if (!NT_STATUS_IS_OK(result)) {
 186                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 187                 return False;
 188         }
 189
 190         /* Remove the entry we've already failed with (should be the PDC). */
 191
 192         for (i = 0; i < count; i++) {
 193                 if (is_zero_addr(&sa_list[i].u.ss))
 194                         continue;
 195
 196                 if (name_status_find(domain, 0x1c, 0x20, &sa_list[i].u.ss, srv_name)) {
 197                         result = check_negative_conn_cache( domain, srv_name );
 198                         if ( NT_STATUS_IS_OK(result) ) {
 199                                 dc_ss = sa_list[i].u.ss;
 200                                 goto done;
 201                         }
 202                 }
 203         }
 204
 205         TALLOC_FREE(sa_list);
 206
 207         /* No-one to talk to )-: */
 208         return False;           /* Boo-hoo */
 209
 210  done:
 211         /* We have the netbios name and IP address of a domain controller.
 212            Ideally we should sent a SAMLOGON request to determine whether
 213            the DC is alive and kicking.  If we can catch a dead DC before
 214            performing a cli_connect() we can avoid a 30-second timeout. */
 215
 216         print_sockaddr(addr, sizeof(addr), &dc_ss);
 217         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 218                   addr, domain));
 219
 220         *ss_out = dc_ss;
 221         TALLOC_FREE(sa_list);
 222
 223         return True;
 224 }
 225
 226 /**********************************************************************
 227  wrapper around ads and rpc methods of finds DC's
 228 **********************************************************************/
 229
 230 bool get_dc_name(const char *domain,
 231                 const char *realm,
 232                 fstring srv_name,
 233                 struct sockaddr_storage *ss_out)
 234 {
 235         struct sockaddr_storage dc_ss;
 236         bool ret;
 237         bool our_domain = False;
 238
 239         zero_sockaddr(&dc_ss);
 240
 241         ret = False;
 242
 243         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 244                 our_domain = True;
 245
 246         /* always try to obey what the admin specified in smb.conf
 247            (for the local domain) */
 248
 249         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 250                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
 251         }
 252
 253         if (!domain) {
 254                 /* if we have only the realm we can't do anything else */
 255                 return False;
 256         }
 257
 258         if (!ret) {
 259                 /* fall back on rpc methods if the ADS methods fail */
 260                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
 261         }
 262
 263         *ss_out = dc_ss;
 264
 265         return ret;
 266 }