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 3 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, see <http://www.gnu.org/licenses/>.
22*/
23
24
25#include "includes.h"
26
27/**********************************************************************
28 Is this our primary domain ?
29**********************************************************************/
30
31#ifdef HAVE_KRB5
32static bool is_our_primary_domain(const char *domain)
33{
34	int role = lp_server_role();
35
36	if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
37		return True;
38	} else if (strequal(get_global_sam_name(), domain)) {
39		return True;
40	}
41	return False;
42}
43#endif
44
45/**************************************************************************
46 Find the name and IP address for a server in the realm/domain
47 *************************************************************************/
48
49static bool ads_dc_name(const char *domain,
50			const char *realm,
51			struct sockaddr_storage *dc_ss,
52			fstring srv_name)
53{
54	ADS_STRUCT *ads;
55	char *sitename;
56	int i;
57	char addr[INET6_ADDRSTRLEN];
58
59	if (!realm && strequal(domain, lp_workgroup())) {
60		realm = lp_realm();
61	}
62
63	sitename = sitename_fetch(realm);
64
65	/* Try this 3 times then give up. */
66	for( i =0 ; i < 3; i++) {
67		ads = ads_init(realm, domain, NULL);
68		if (!ads) {
69			SAFE_FREE(sitename);
70			return False;
71		}
72
73		DEBUG(4,("ads_dc_name: domain=%s\n", domain));
74
75#ifdef HAVE_ADS
76		/* we don't need to bind, just connect */
77		ads->auth.flags |= ADS_AUTH_NO_BIND;
78		ads_connect(ads);
79#endif
80
81		if (!ads->config.realm) {
82			SAFE_FREE(sitename);
83			ads_destroy(&ads);
84			return False;
85		}
86
87		/* Now we've found a server, see if our sitename
88		   has changed. If so, we need to re-do the DNS query
89		   to ensure we only find servers in our site. */
90
91		if (stored_sitename_changed(realm, sitename)) {
92			SAFE_FREE(sitename);
93			sitename = sitename_fetch(realm);
94			ads_destroy(&ads);
95			/* Ensure we don't cache the DC we just connected to. */
96			namecache_delete(realm, 0x1C);
97			namecache_delete(domain, 0x1C);
98			continue;
99		}
100
101#ifdef HAVE_KRB5
102		if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
103			if (ads_closest_dc(ads)) {
104				/* We're going to use this KDC for this realm/domain.
105				   If we are using sites, then force the krb5 libs
106				   to use this KDC. */
107
108				create_local_private_krb5_conf_for_domain(realm,
109									domain,
110									sitename,
111									&ads->ldap.ss,
112									ads->config.ldap_server_name);
113			} else {
114				create_local_private_krb5_conf_for_domain(realm,
115									domain,
116									NULL,
117									&ads->ldap.ss,
118									ads->config.ldap_server_name);
119			}
120		}
121#endif
122		break;
123	}
124
125	if (i == 3) {
126		DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
127			sitename ? sitename : ""));
128		SAFE_FREE(sitename);
129		return False;
130	}
131
132	SAFE_FREE(sitename);
133
134	fstrcpy(srv_name, ads->config.ldap_server_name);
135	strupper_m(srv_name);
136#ifdef HAVE_ADS
137	*dc_ss = ads->ldap.ss;
138#else
139	zero_sockaddr(dc_ss);
140#endif
141	ads_destroy(&ads);
142
143	print_sockaddr(addr, sizeof(addr), dc_ss);
144	DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
145		 srv_name, addr));
146
147	return True;
148}
149
150/****************************************************************************
151 Utility function to return the name of a DC. The name is guaranteed to be
152 valid since we have already done a name_status_find on it
153 ***************************************************************************/
154
155static bool rpc_dc_name(const char *domain,
156			fstring srv_name,
157			struct sockaddr_storage *ss_out)
158{
159	struct ip_service *ip_list = NULL;
160	struct sockaddr_storage dc_ss;
161	int count, i;
162	NTSTATUS result;
163	char addr[INET6_ADDRSTRLEN];
164
165	/* get a list of all domain controllers */
166
167	if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
168						False))) {
169		DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
170		return False;
171	}
172
173	/* Remove the entry we've already failed with (should be the PDC). */
174
175	for (i = 0; i < count; i++) {
176		if (is_zero_addr((struct sockaddr *)&ip_list[i].ss))
177			continue;
178
179		if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
180			result = check_negative_conn_cache( domain, srv_name );
181			if ( NT_STATUS_IS_OK(result) ) {
182				dc_ss = ip_list[i].ss;
183				goto done;
184			}
185		}
186	}
187
188	SAFE_FREE(ip_list);
189
190	/* No-one to talk to )-: */
191	return False;		/* Boo-hoo */
192
193 done:
194	/* We have the netbios name and IP address of a domain controller.
195	   Ideally we should sent a SAMLOGON request to determine whether
196	   the DC is alive and kicking.  If we can catch a dead DC before
197	   performing a cli_connect() we can avoid a 30-second timeout. */
198
199	print_sockaddr(addr, sizeof(addr), &dc_ss);
200	DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
201		  addr, domain));
202
203	*ss_out = dc_ss;
204	SAFE_FREE(ip_list);
205
206	return True;
207}
208
209/**********************************************************************
210 wrapper around ads and rpc methods of finds DC's
211**********************************************************************/
212
213bool get_dc_name(const char *domain,
214		const char *realm,
215		fstring srv_name,
216		struct sockaddr_storage *ss_out)
217{
218	struct sockaddr_storage dc_ss;
219	bool ret;
220	bool our_domain = False;
221
222	zero_sockaddr(&dc_ss);
223
224	ret = False;
225
226	if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
227		our_domain = True;
228
229	/* always try to obey what the admin specified in smb.conf
230	   (for the local domain) */
231
232	if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
233		ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
234	}
235
236	if (!domain) {
237		/* if we have only the realm we can't do anything else */
238		return False;
239	}
240
241	if (!ret) {
242		/* fall back on rpc methods if the ADS methods fail */
243		ret = rpc_dc_name(domain, srv_name, &dc_ss);
244	}
245
246	*ss_out = dc_ss;
247
248	return ret;
249}
250