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
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24
  25 #include "includes.h"
  26
  27
  28 /*
  29   find the DC for a domain using methods appropriate for a RPC domain
  30 */
  31 BOOL rpc_find_dc(const char *domain, fstring srv_name, struct in_addr *ip_out)
  32 {
  33         struct in_addr *ip_list = NULL, dc_ip, exclude_ip;
  34         int count, i;
  35         BOOL list_ordered;
  36         BOOL use_pdc_only;
  37
  38         zero_ip(&exclude_ip);
  39
  40         use_pdc_only = must_use_pdc(domain);
  41
  42         /* Lookup domain controller name */
  43
  44         if ( use_pdc_only && get_pdc_ip(domain, &dc_ip) ) {
  45                 DEBUG(10,("rpc_find_dc: Atempting to lookup PDC to avoid sam sync delays\n"));
  46
  47                 if (name_status_find(domain, 0x1c, 0x20, dc_ip, srv_name)) {
  48                         goto done;
  49                 }
  50                 /* Didn't get name, remember not to talk to this DC. */
  51                 exclude_ip = dc_ip;
  52         }
  53
  54         /* get a list of all domain controllers */
  55
  56         if (!get_dc_list( domain, &ip_list, &count, &list_ordered) ) {
  57                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
  58                 return False;
  59         }
  60
  61         /* Remove the entry we've already failed with (should be the PDC). */
  62
  63         if ( use_pdc_only ) {
  64                 for (i = 0; i < count; i++) {
  65                         if (ip_equal( exclude_ip, ip_list[i]))
  66                                 zero_ip(&ip_list[i]);
  67                 }
  68         }
  69
  70         /* Pick a nice close server, but only if the list was not ordered */
  71         if (!list_ordered && (count > 1) ) {
  72                 qsort(ip_list, count, sizeof(struct in_addr), QSORT_CAST ip_compare);
  73         }
  74
  75         for (i = 0; i < count; i++) {
  76                 if (is_zero_ip(ip_list[i]))
  77                         continue;
  78
  79                 if (name_status_find(domain, 0x1c, 0x20, ip_list[i], srv_name)) {
  80                         dc_ip = ip_list[i];
  81                         goto done;
  82                 }
  83         }
  84
  85
  86         SAFE_FREE(ip_list);
  87
  88         return False;
  89 done:
  90         /* We have the netbios name and IP address of a domain controller.
  91            Ideally we should sent a SAMLOGON request to determine whether
  92            the DC is alive and kicking.  If we can catch a dead DC before
  93            performing a cli_connect() we can avoid a 30-second timeout. */
  94
  95         DEBUG(3, ("rpc_find_dc: Returning DC %s (%s) for domain %s\n", srv_name,
  96                   inet_ntoa(dc_ip), domain));
  97
  98         *ip_out = dc_ip;
  99
 100         SAFE_FREE(ip_list);
 101
 102         return True;
 103 }
 104