source: branches/samba-3.5.x/source3/smbd/share_access.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 7.3 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Check access based on valid users, read list and friends
4 Copyright (C) Volker Lendecke 2005
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
18*/
19
20#include "includes.h"
21#include "smbd/globals.h"
22
23/*
24 * No prefix means direct username
25 * @name means netgroup first, then unix group
26 * &name means netgroup
27 * +name means unix group
28 * + and & may be combined
29 */
30
31static bool do_group_checks(const char **name, const char **pattern)
32{
33 if ((*name)[0] == '@') {
34 *pattern = "&+";
35 *name += 1;
36 return True;
37 }
38
39 if (((*name)[0] == '+') && ((*name)[1] == '&')) {
40 *pattern = "+&";
41 *name += 2;
42 return True;
43 }
44
45 if ((*name)[0] == '+') {
46 *pattern = "+";
47 *name += 1;
48 return True;
49 }
50
51 if (((*name)[0] == '&') && ((*name)[1] == '+')) {
52 *pattern = "&+";
53 *name += 2;
54 return True;
55 }
56
57 if ((*name)[0] == '&') {
58 *pattern = "&";
59 *name += 1;
60 return True;
61 }
62
63 return False;
64}
65
66static bool token_contains_name(TALLOC_CTX *mem_ctx,
67 const char *username,
68 const char *domain,
69 const char *sharename,
70 const struct nt_user_token *token,
71 const char *name)
72{
73 const char *prefix;
74 DOM_SID sid;
75 enum lsa_SidType type;
76 struct smbd_server_connection *sconn = smbd_server_conn;
77
78 if (username != NULL) {
79 name = talloc_sub_basic(mem_ctx, username, domain, name);
80 }
81 if (sharename != NULL) {
82 name = talloc_string_sub(mem_ctx, name, "%S", sharename);
83 }
84
85 if (name == NULL) {
86 /* This is too security sensitive, better panic than return a
87 * result that might be interpreted in a wrong way. */
88 smb_panic("substitutions failed");
89 }
90
91 /* check to see is we already have a SID */
92
93 if ( string_to_sid( &sid, name ) ) {
94 DEBUG(5,("token_contains_name: Checking for SID [%s] in token\n", name));
95 return nt_token_check_sid( &sid, token );
96 }
97
98 if (!do_group_checks(&name, &prefix)) {
99 if (!lookup_name_smbconf(mem_ctx, name, LOOKUP_NAME_ALL,
100 NULL, NULL, &sid, &type)) {
101 DEBUG(5, ("lookup_name %s failed\n", name));
102 return False;
103 }
104 if (type != SID_NAME_USER) {
105 DEBUG(5, ("%s is a %s, expected a user\n",
106 name, sid_type_lookup(type)));
107 return False;
108 }
109 return nt_token_check_sid(&sid, token);
110 }
111
112 for (/* initialized above */ ; *prefix != '\0'; prefix++) {
113 if (*prefix == '+') {
114 if (!lookup_name_smbconf(mem_ctx, name,
115 LOOKUP_NAME_ALL|LOOKUP_NAME_GROUP,
116 NULL, NULL, &sid, &type)) {
117 DEBUG(5, ("lookup_name %s failed\n", name));
118 return False;
119 }
120 if ((type != SID_NAME_DOM_GRP) &&
121 (type != SID_NAME_ALIAS) &&
122 (type != SID_NAME_WKN_GRP)) {
123 DEBUG(5, ("%s is a %s, expected a group\n",
124 name, sid_type_lookup(type)));
125 return False;
126 }
127 if (nt_token_check_sid(&sid, token)) {
128 return True;
129 }
130 continue;
131 }
132 if (*prefix == '&') {
133 if (username) {
134 if (user_in_netgroup(sconn, username, name)) {
135 return True;
136 }
137 }
138 continue;
139 }
140 smb_panic("got invalid prefix from do_groups_check");
141 }
142 return False;
143}
144
145/*
146 * Check whether a user is contained in the list provided.
147 *
148 * Please note that the user name and share names passed in here mainly for
149 * the substitution routines that expand the parameter values, the decision
150 * whether a user is in the list is done after a lookup_name on the expanded
151 * parameter value, solely based on comparing the SIDs in token.
152 *
153 * The other use is the netgroup check when using @group or &group.
154 */
155
156bool token_contains_name_in_list(const char *username,
157 const char *domain,
158 const char *sharename,
159 const struct nt_user_token *token,
160 const char **list)
161{
162 TALLOC_CTX *mem_ctx;
163
164 if (list == NULL) {
165 return False;
166 }
167
168 if ( (mem_ctx = talloc_new(NULL)) == NULL ) {
169 smb_panic("talloc_new failed");
170 }
171
172 while (*list != NULL) {
173 if (token_contains_name(mem_ctx, username, domain, sharename,
174 token, *list)) {
175 TALLOC_FREE(mem_ctx);
176 return True;
177 }
178 list += 1;
179 }
180
181 TALLOC_FREE(mem_ctx);
182 return False;
183}
184
185/*
186 * Check whether the user described by "token" has access to share snum.
187 *
188 * This looks at "invalid users", "valid users" and "only user/username"
189 *
190 * Please note that the user name and share names passed in here mainly for
191 * the substitution routines that expand the parameter values, the decision
192 * whether a user is in the list is done after a lookup_name on the expanded
193 * parameter value, solely based on comparing the SIDs in token.
194 *
195 * The other use is the netgroup check when using @group or &group.
196 */
197
198bool user_ok_token(const char *username, const char *domain,
199 const struct nt_user_token *token, int snum)
200{
201 if (lp_invalid_users(snum) != NULL) {
202 if (token_contains_name_in_list(username, domain,
203 lp_servicename(snum),
204 token,
205 lp_invalid_users(snum))) {
206 DEBUG(10, ("User %s in 'invalid users'\n", username));
207 return False;
208 }
209 }
210
211 if (lp_valid_users(snum) != NULL) {
212 if (!token_contains_name_in_list(username, domain,
213 lp_servicename(snum), token,
214 lp_valid_users(snum))) {
215 DEBUG(10, ("User %s not in 'valid users'\n",
216 username));
217 return False;
218 }
219 }
220
221 if (lp_onlyuser(snum)) {
222 const char *list[2];
223 list[0] = lp_username(snum);
224 list[1] = NULL;
225 if ((list[0] == NULL) || (*list[0] == '\0')) {
226 DEBUG(0, ("'only user = yes' and no 'username ='\n"));
227 return False;
228 }
229 if (!token_contains_name_in_list(NULL, domain,
230 lp_servicename(snum),
231 token, list)) {
232 DEBUG(10, ("%s != 'username'\n", username));
233 return False;
234 }
235 }
236
237 DEBUG(10, ("user_ok_token: share %s is ok for unix user %s\n",
238 lp_servicename(snum), username));
239
240 return True;
241}
242
243/*
244 * Check whether the user described by "token" is restricted to read-only
245 * access on share snum.
246 *
247 * This looks at "invalid users", "valid users" and "only user/username"
248 *
249 * Please note that the user name and share names passed in here mainly for
250 * the substitution routines that expand the parameter values, the decision
251 * whether a user is in the list is done after a lookup_name on the expanded
252 * parameter value, solely based on comparing the SIDs in token.
253 *
254 * The other use is the netgroup check when using @group or &group.
255 */
256
257bool is_share_read_only_for_token(const char *username,
258 const char *domain,
259 const struct nt_user_token *token,
260 connection_struct *conn)
261{
262 int snum = SNUM(conn);
263 bool result = conn->read_only;
264
265 if (lp_readlist(snum) != NULL) {
266 if (token_contains_name_in_list(username, domain,
267 lp_servicename(snum), token,
268 lp_readlist(snum))) {
269 result = True;
270 }
271 }
272
273 if (lp_writelist(snum) != NULL) {
274 if (token_contains_name_in_list(username, domain,
275 lp_servicename(snum), token,
276 lp_writelist(snum))) {
277 result = False;
278 }
279 }
280
281 DEBUG(10,("is_share_read_only_for_user: share %s is %s for unix user "
282 "%s\n", lp_servicename(snum),
283 result ? "read-only" : "read-write", username));
284
285 return result;
286}
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