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  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                 ads_destroy(&ads);
  54                 return False;
  55         }
  56
  57         fstrcpy(srv_name, ads->config.ldap_server_name);
  58         strupper_m(srv_name);
  59         *dc_ip = ads->ldap_ip;
  60         ads_destroy(&ads);
  61
  62         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
  63                  srv_name, inet_ntoa(*dc_ip)));
  64
  65         return True;
  66 }
  67
  68 /****************************************************************************
  69  Utility function to return the name of a DC. The name is guaranteed to be
  70  valid since we have already done a name_status_find on it
  71  ***************************************************************************/
  72
  73 static BOOL rpc_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out)
  74 {
  75         struct ip_service *ip_list = NULL;
  76         struct in_addr dc_ip, exclude_ip;
  77         int count, i;
  78         BOOL use_pdc_only;
  79         NTSTATUS result;
  80
  81         zero_ip(&exclude_ip);
  82
  83         use_pdc_only = must_use_pdc(domain);
  84
  85         /* Lookup domain controller name */
  86
  87         if ( use_pdc_only && get_pdc_ip(domain, &dc_ip) )
  88         {
  89                 DEBUG(10,("rpc_dc_name: Atempting to lookup PDC to avoid sam sync delays\n"));
  90
  91                 /* check the connection cache and perform the node status
  92                    lookup only if the IP is not found to be bad */
  93
  94                 if (name_status_find(domain, 0x1b, 0x20, dc_ip, srv_name) ) {
  95                         result = check_negative_conn_cache( domain, srv_name );
  96                         if ( NT_STATUS_IS_OK(result) )
  97                                 goto done;
  98                 }
  99                 /* Didn't get name, remember not to talk to this DC. */
 100                 exclude_ip = dc_ip;
 101         }
 102
 103         /* get a list of all domain controllers */
 104
 105         if ( !get_sorted_dc_list(domain, &ip_list, &count, False) ) {
 106                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 107                 return False;
 108         }
 109
 110         /* Remove the entry we've already failed with (should be the PDC). */
 111
 112         if ( use_pdc_only ) {
 113                 for (i = 0; i < count; i++) {
 114                         if (ip_equal( exclude_ip, ip_list[i].ip))
 115                                 zero_ip(&ip_list[i].ip);
 116                 }
 117         }
 118
 119         for (i = 0; i < count; i++) {
 120                 if (is_zero_ip(ip_list[i].ip))
 121                         continue;
 122
 123                 if (name_status_find(domain, 0x1c, 0x20, ip_list[i].ip, srv_name)) {
 124                         result = check_negative_conn_cache( domain, srv_name );
 125                         if ( NT_STATUS_IS_OK(result) ) {
 126                                 dc_ip = ip_list[i].ip;
 127                                 goto done;
 128                         }
 129                 }
 130         }
 131
 132
 133         SAFE_FREE(ip_list);
 134
 135         /* No-one to talk to )-: */
 136         return False;           /* Boo-hoo */
 137
 138  done:
 139         /* We have the netbios name and IP address of a domain controller.
 140            Ideally we should sent a SAMLOGON request to determine whether
 141            the DC is alive and kicking.  If we can catch a dead DC before
 142            performing a cli_connect() we can avoid a 30-second timeout. */
 143
 144         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 145                   inet_ntoa(dc_ip), domain));
 146
 147         *ip_out = dc_ip;
 148
 149         SAFE_FREE(ip_list);
 150
 151         return True;
 152 }
 153
 154 /**********************************************************************
 155  wrapper around ads and rpc methods of finds DC's
 156 **********************************************************************/
 157
 158 BOOL get_dc_name(const char *domain, const char *realm, fstring srv_name, struct in_addr *ip_out)
 159 {
 160         struct in_addr dc_ip;
 161         BOOL ret;
 162         BOOL our_domain = False;
 163
 164         zero_ip(&dc_ip);
 165
 166         ret = False;
 167
 168         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
 169                 our_domain = True;
 170
 171         /* always try to obey what the admin specified in smb.conf
 172            (for the local domain) */
 173
 174         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
 175                 ret = ads_dc_name(domain, realm, &dc_ip, srv_name);
 176         }
 177
 178         if (!ret) {
 179                 /* fall back on rpc methods if the ADS methods fail */
 180                 ret = rpc_dc_name(domain, srv_name, &dc_ip);
 181         }
 182
 183         *ip_out = dc_ip;
 184
 185         return ret;
 186 }
 187