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
32static 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
73static 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
158BOOL 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
188