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 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  Find the name and IP address for a server in he realm/domain
  30  *************************************************************************/
  31
  32 static BOOL ads_dc_name(const char *domain, const char *realm, struct in_addr *dc_ip, fstring srv_name)
  33 {
  34         ADS_STRUCT *ads;
  35
  36         if (!realm && strequal(domain, lp_workgroup()))
  37                 realm = lp_realm();
  38
  39         ads = ads_init(realm, domain, NULL);
  40         if (!ads)
  41                 return False;
  42
  43         DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  44
  45 #ifdef HAVE_ADS
  46         /* we don't need to bind, just connect */
  47         ads->auth.flags |= ADS_AUTH_NO_BIND;
  48
  49         ads_connect(ads);
  50 #endif
  51
  52         if (!ads->config.realm)
  53                 return False;
  54
  55         fstrcpy(srv_name, ads->config.ldap_server_name);
  56         strupper_m(srv_name);
  57         *dc_ip = ads->ldap_ip;
  58         ads_destroy(&ads);
  59
  60         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
  61                  srv_name, inet_ntoa(*dc_ip)));
  62
  63         return True;
  64 }
  65
  66 /****************************************************************************
  67  Utility function to return the name of a DC. The name is guaranteed to be
  68  valid since we have already done a name_status_find on it
  69  ***************************************************************************/
  70
  71 static BOOL rpc_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out)
  72 {
  73         struct ip_service *ip_list = NULL;
  74         struct in_addr dc_ip, exclude_ip;
  75         int count, i;
  76         BOOL use_pdc_only;
  77         NTSTATUS result;
  78
  79         zero_ip(&exclude_ip);
  80
  81         use_pdc_only = must_use_pdc(domain);
  82
  83         /* Lookup domain controller name */
  84
  85         if ( use_pdc_only && get_pdc_ip(domain, &dc_ip) )
  86         {
  87                 DEBUG(10,("rpc_dc_name: Atempting to lookup PDC to avoid sam sync delays\n"));
  88
  89                 /* check the connection cache and perform the node status
  90                    lookup only if the IP is not found to be bad */
  91
  92                 if (name_status_find(domain, 0x1b, 0x20, dc_ip, srv_name) ) {
  93                         result = check_negative_conn_cache( domain, srv_name );
  94                         if ( NT_STATUS_IS_OK(result) )
  95                                 goto done;
  96                 }
  97                 /* Didn't get name, remember not to talk to this DC. */
  98                 exclude_ip = dc_ip;
  99         }
 100
 101         /* get a list of all domain controllers */
 102
 103         if ( !get_sorted_dc_list(domain, &ip_list, &count, False) ) {
 104                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 105                 return False;
 106         }
 107
 108         /* Remove the entry we've already failed with (should be the PDC). */
 109
 110         if ( use_pdc_only ) {
 111                 for (i = 0; i < count; i++) {
 112                         if (ip_equal( exclude_ip, ip_list[i].ip))
 113                                 zero_ip(&ip_list[i].ip);
 114                 }
 115         }
 116
 117         for (i = 0; i < count; i++) {
 118                 if (is_zero_ip(ip_list[i].ip))
 119                         continue;
 120
 121                 if (name_status_find(domain, 0x1c, 0x20, ip_list[i].ip, srv_name)) {
 122                         result = check_negative_conn_cache( domain, srv_name );
 123                         if ( NT_STATUS_IS_OK(result) ) {
 124                                 dc_ip = ip_list[i].ip;
 125                                 goto done;
 126                         }
 127                 }
 128         }
 129
 130
 131         SAFE_FREE(ip_list);
 132
 133         /* No-one to talk to )-: */
 134         return False;           /* Boo-hoo */
 135
 136  done:
 137         /* We have the netbios name and IP address of a domain controller.
 138            Ideally we should sent a SAMLOGON request to determine whether
 139            the DC is alive and kicking.  If we can catch a dead DC before
 140            performing a cli_connect() we can avoid a 30-second timeout. */
 141
 142         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 143                   inet_ntoa(dc_ip), domain));
 144
 145         *ip_out = dc_ip;
 146
 147         SAFE_FREE(ip_list);
 148
 149         return True;
 150 }
 151
 152 /**********************************************************************
 153  wrapper around ads and rpc methods of finds DC's
 154 **********************************************************************/
 155
 156 BOOL get_dc_name(const char *domain, const char *realm, fstring srv_name, struct in_addr *ip_out)
 157 {
 158         struct in_addr dc_ip;
 159         BOOL ret;
 160         BOOL our_domain = False;
 161
 162         zero_ip(&dc_ip);
 163
 164         ret = False;
 165
 166         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 167                 our_domain = True;
 168
 169         /* always try to obey what the admin specified in smb.conf
 170            (for the local domain) */
 171
 172         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 173                 ret = ads_dc_name(domain, realm, &dc_ip, srv_name);
 174         }
 175
 176         if (!ret) {
 177                 /* fall back on rpc methods if the ADS methods fail */
 178                 ret = rpc_dc_name(domain, srv_name, &dc_ip);
 179         }
 180
 181         *ip_out = dc_ip;
 182
 183         return ret;
 184 }
 185