3cfae79257ec310ab0a857245f115882b8681437
[samba.git] / 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 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 #include "libads/sitename_cache.h"
27 #include "ads.h"
28 #include "../librpc/gen_ndr/nbt.h"
29 #include "lib/param/loadparm.h"
30
31 /**********************************************************************
32  Is this our primary domain ?
33 **********************************************************************/
34
35 #ifdef HAVE_KRB5
36 static bool is_our_primary_domain(const char *domain)
37 {
38         int role = lp_server_role();
39
40         if ((role == ROLE_DOMAIN_MEMBER) && strequal(lp_workgroup(), domain)) {
41                 return True;
42         } else if (strequal(get_global_sam_name(), domain)) {
43                 return True;
44         }
45         return False;
46 }
47 #endif
48
49 /**************************************************************************
50  Find the name and IP address for a server in the realm/domain
51  *************************************************************************/
52
53 static bool ads_dc_name(const char *domain,
54                         const char *realm,
55                         struct sockaddr_storage *dc_ss,
56                         fstring srv_name)
57 {
58         ADS_STRUCT *ads;
59         char *sitename;
60         int i;
61         char addr[INET6_ADDRSTRLEN];
62
63         if (!realm && strequal(domain, lp_workgroup())) {
64                 realm = lp_realm();
65         }
66
67         sitename = sitename_fetch(talloc_tos(), realm);
68
69         /* Try this 3 times then give up. */
70         for( i =0 ; i < 3; i++) {
71                 ads = ads_init(realm, domain, NULL);
72                 if (!ads) {
73                         TALLOC_FREE(sitename);
74                         return False;
75                 }
76
77                 DEBUG(4,("ads_dc_name: domain=%s\n", domain));
78
79 #ifdef HAVE_ADS
80                 /* we don't need to bind, just connect */
81                 ads->auth.flags |= ADS_AUTH_NO_BIND;
82                 ads_connect(ads);
83 #endif
84
85                 if (!ads->config.realm) {
86                         TALLOC_FREE(sitename);
87                         ads_destroy(&ads);
88                         return False;
89                 }
90
91                 /* Now we've found a server, see if our sitename
92                    has changed. If so, we need to re-do the DNS query
93                    to ensure we only find servers in our site. */
94
95                 if (stored_sitename_changed(realm, sitename)) {
96                         TALLOC_FREE(sitename);
97                         sitename = sitename_fetch(talloc_tos(), realm);
98                         ads_destroy(&ads);
99                         /* Ensure we don't cache the DC we just connected to. */
100                         namecache_delete(realm, 0x1C);
101                         namecache_delete(domain, 0x1C);
102                         continue;
103                 }
104
105 #ifdef HAVE_ADS
106                 if (is_our_primary_domain(domain) && (ads->config.flags & NBT_SERVER_KDC)) {
107                         if (ads_closest_dc(ads)) {
108                                 /* We're going to use this KDC for this realm/domain.
109                                    If we are using sites, then force the krb5 libs
110                                    to use this KDC. */
111
112                                 create_local_private_krb5_conf_for_domain(realm,
113                                                                         domain,
114                                                                         sitename,
115                                                                         &ads->ldap.ss,
116                                                                         ads->config.ldap_server_name);
117                         } else {
118                                 create_local_private_krb5_conf_for_domain(realm,
119                                                                         domain,
120                                                                         NULL,
121                                                                         &ads->ldap.ss,
122                                                                         ads->config.ldap_server_name);
123                         }
124                 }
125 #endif
126                 break;
127         }
128
129         if (i == 3) {
130                 DEBUG(1,("ads_dc_name: sitename (now \"%s\") keeps changing ???\n",
131                         sitename ? sitename : ""));
132                 TALLOC_FREE(sitename);
133                 ads_destroy(&ads);
134                 return False;
135         }
136
137         TALLOC_FREE(sitename);
138
139         fstrcpy(srv_name, ads->config.ldap_server_name);
140         if (!strupper_m(srv_name)) {
141                 ads_destroy(&ads);
142                 return false;
143         }
144 #ifdef HAVE_ADS
145         *dc_ss = ads->ldap.ss;
146 #else
147         zero_sockaddr(dc_ss);
148 #endif
149         ads_destroy(&ads);
150
151         print_sockaddr(addr, sizeof(addr), dc_ss);
152         DEBUG(4,("ads_dc_name: using server='%s' IP=%s\n",
153                  srv_name, addr));
154
155         return True;
156 }
157
158 /****************************************************************************
159  Utility function to return the name of a DC. The name is guaranteed to be
160  valid since we have already done a name_status_find on it
161  ***************************************************************************/
162
163 static bool rpc_dc_name(const char *domain,
164                         fstring srv_name,
165                         struct sockaddr_storage *ss_out)
166 {
167         struct ip_service *ip_list = NULL;
168         struct sockaddr_storage dc_ss;
169         int count, i;
170         NTSTATUS result;
171         char addr[INET6_ADDRSTRLEN];
172
173         /* get a list of all domain controllers */
174
175         if (!NT_STATUS_IS_OK(get_sorted_dc_list(domain, NULL, &ip_list, &count,
176                                                 False))) {
177                 DEBUG(3, ("Could not look up dc's for domain %s\n", domain));
178                 return False;
179         }
180
181         /* Remove the entry we've already failed with (should be the PDC). */
182
183         for (i = 0; i < count; i++) {
184                 if (is_zero_addr(&ip_list[i].ss))
185                         continue;
186
187                 if (name_status_find(domain, 0x1c, 0x20, &ip_list[i].ss, srv_name)) {
188                         result = check_negative_conn_cache( domain, srv_name );
189                         if ( NT_STATUS_IS_OK(result) ) {
190                                 dc_ss = ip_list[i].ss;
191                                 goto done;
192                         }
193                 }
194         }
195
196         SAFE_FREE(ip_list);
197
198         /* No-one to talk to )-: */
199         return False;           /* Boo-hoo */
200
201  done:
202         /* We have the netbios name and IP address of a domain controller.
203            Ideally we should sent a SAMLOGON request to determine whether
204            the DC is alive and kicking.  If we can catch a dead DC before
205            performing a cli_connect() we can avoid a 30-second timeout. */
206
207         print_sockaddr(addr, sizeof(addr), &dc_ss);
208         DEBUG(3, ("rpc_dc_name: Returning DC %s (%s) for domain %s\n", srv_name,
209                   addr, domain));
210
211         *ss_out = dc_ss;
212         SAFE_FREE(ip_list);
213
214         return True;
215 }
216
217 /**********************************************************************
218  wrapper around ads and rpc methods of finds DC's
219 **********************************************************************/
220
221 bool get_dc_name(const char *domain,
222                 const char *realm,
223                 fstring srv_name,
224                 struct sockaddr_storage *ss_out)
225 {
226         struct sockaddr_storage dc_ss;
227         bool ret;
228         bool our_domain = False;
229
230         zero_sockaddr(&dc_ss);
231
232         ret = False;
233
234         if ( strequal(lp_workgroup(), domain) || strequal(lp_realm(), realm) )
235                 our_domain = True;
236
237         /* always try to obey what the admin specified in smb.conf
238            (for the local domain) */
239
240         if ( (our_domain && lp_security()==SEC_ADS) || realm ) {
241                 ret = ads_dc_name(domain, realm, &dc_ss, srv_name);
242         }
243
244         if (!domain) {
245                 /* if we have only the realm we can't do anything else */
246                 return False;
247         }
248
249         if (!ret) {
250                 /* fall back on rpc methods if the ADS methods fail */
251                 ret = rpc_dc_name(domain, srv_name, &dc_ss);
252         }
253
254         *ss_out = dc_ss;
255
256         return ret;
257 }