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, struct in_addr *dc_ip, fstring srv_name)
  33 {
  34         ADS_STRUCT *ads;
  35         const char *realm = domain;
  36
  37         if (strequal(realm, lp_workgroup()))
  38                 realm = lp_realm();
  39
  40         ads = ads_init(realm, domain, NULL);
  41         if (!ads)
  42                 return False;
  43
  44         /* we don't need to bind, just connect */
  45         ads->auth.flags |= ADS_AUTH_NO_BIND;
  46
  47         DEBUG(4,("ads_dc_name: domain=%s\n", domain));
  48
  49 #ifdef HAVE_ADS
  50         /* a full ads_connect() is actually overkill, as we don't srictly need
  51            to do the SASL auth in order to get the info we need, but libads
  52            doesn't offer a better way right now */
  53         ads_connect(ads);
  54 #endif
  55
  56         if (!ads->config.realm)
  57                 return False;
  58
  59         fstrcpy(srv_name, ads->config.ldap_server_name);
  60         strupper_m(srv_name);
  61         *dc_ip = ads->ldap_ip;
  62         ads_destroy(&ads);
  63
  64         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
  65                  srv_name, inet_ntoa(*dc_ip)));
  66
  67         return True;
  68 }
  69
  70 /****************************************************************************
  71  Utility function to return the name of a DC. The name is guaranteed to be
  72  valid since we have already done a name_status_find on it
  73  ***************************************************************************/
  74
  75 static BOOL rpc_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out)
  76 {
  77         struct ip_service *ip_list = NULL;
  78         struct in_addr dc_ip, exclude_ip;
  79         int count, i;
  80         BOOL use_pdc_only;
  81         NTSTATUS result;
  82
  83         zero_ip(&exclude_ip);
  84
  85         use_pdc_only = must_use_pdc(domain);
  86
  87         /* Lookup domain controller name */
  88
  89         if ( use_pdc_only && get_pdc_ip(domain, &dc_ip) )
  90         {
  91                 DEBUG(10,("rpc_dc_name: Atempting to lookup PDC to avoid sam sync delays\n"));
  92
  93                 /* check the connection cache and perform the node status
  94                    lookup only if the IP is not found to be bad */
  95
  96                 if (name_status_find(domain, 0x1b, 0x20, dc_ip, srv_name) ) {
  97                         result = check_negative_conn_cache( domain, srv_name );
  98                         if ( NT_STATUS_IS_OK(result) )
  99                                 goto done;
 100                 }
 101                 /* Didn't get name, remember not to talk to this DC. */
 102                 exclude_ip = dc_ip;
 103         }
 104
 105         /* get a list of all domain controllers */
 106
 107         if ( !get_sorted_dc_list(domain, &ip_list, &count, False) ) {
 108                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
 109                 return False;
 110         }
 111
 112         /* Remove the entry we've already failed with (should be the PDC). */
 113
 114         if ( use_pdc_only ) {
 115                 for (i = 0; i < count; i++) {
 116                         if (ip_equal( exclude_ip, ip_list[i].ip))
 117                                 zero_ip(&ip_list[i].ip);
 118                 }
 119         }
 120
 121         for (i = 0; i < count; i++) {
 122                 if (is_zero_ip(ip_list[i].ip))
 123                         continue;
 124
 125                 if (name_status_find(domain, 0x1c, 0x20, ip_list[i].ip, srv_name)) {
 126                         result = check_negative_conn_cache( domain, srv_name );
 127                         if ( NT_STATUS_IS_OK(result) ) {
 128                                 dc_ip = ip_list[i].ip;
 129                                 goto done;
 130                         }
 131                 }
 132         }
 133
 134
 135         SAFE_FREE(ip_list);
 136
 137         /* No-one to talk to )-: */
 138         return False;           /* Boo-hoo */
 139
 140  done:
 141         /* We have the netbios name and IP address of a domain controller.
 142            Ideally we should sent a SAMLOGON request to determine whether
 143            the DC is alive and kicking.  If we can catch a dead DC before
 144            performing a cli_connect() we can avoid a 30-second timeout. */
 145
 146         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
 147                   inet_ntoa(dc_ip), domain));
 148
 149         *ip_out = dc_ip;
 150
 151         SAFE_FREE(ip_list);
 152
 153         return True;
 154 }
 155
 156 /**********************************************************************
 157  wrapper around ads and rpc methods of finds DC's
 158 **********************************************************************/
 159
 160 BOOL get_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out)
 161 {
 162         struct in_addr dc_ip;
 163         BOOL ret;
 164         BOOL our_domain = False;
 165
 166         zero_ip(&dc_ip);
 167
 168         ret = False;
 169
 170         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), domain) )
 171                 our_domain = True;
 172
 173         /* always try to obey what the admin specified in smb.conf.
 174            If it is not our domain, assume that domain names with periods
 175            in them are realm names */
 176
 177         if ( (our_domain && lp_security()==SEC_ADS) || strchr_m(domain, '.') ) {
 178                 ret = ads_dc_name(domain, &dc_ip, srv_name);
 179         }
 180
 181         if (!ret) {
 182                 /* fall back on rpc methods if the ADS methods fail */
 183                 ret = rpc_dc_name(domain, srv_name, &dc_ip);
 184         }
 185
 186         *ip_out = dc_ip;
 187
 188         return ret;
 189 }
 190