source: branches/samba-3.0/source/lib/sharesec.c

Last change on this file was 1, checked in by Paul Smedley, 18 years ago

Initial code import
File size: 9.0 KB
Line 
1/*
2 * Unix SMB/Netbios implementation.
3 * SEC_DESC handling functions
4 * Copyright (C) Jeremy R. Allison 1995-2003.
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 2 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, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include "includes.h"
22
23/*******************************************************************
24 Create the share security tdb.
25 ********************************************************************/
26
27static TDB_CONTEXT *share_tdb; /* used for share security descriptors */
28#define SHARE_DATABASE_VERSION_V1 1
29#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
30
31/* Map generic permissions to file object specific permissions */
32
33static struct generic_mapping file_generic_mapping = {
34 FILE_GENERIC_READ,
35 FILE_GENERIC_WRITE,
36 FILE_GENERIC_EXECUTE,
37 FILE_GENERIC_ALL
38};
39
40
41BOOL share_info_db_init(void)
42{
43 const char *vstring = "INFO/version";
44 int32 vers_id;
45
46 if (share_tdb) {
47 return True;
48 }
49
50 share_tdb = tdb_open_log(lock_path("share_info.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
51 if (!share_tdb) {
52 DEBUG(0,("Failed to open share info database %s (%s)\n",
53 lock_path("share_info.tdb"), strerror(errno) ));
54 return False;
55 }
56
57 /* handle a Samba upgrade */
58 tdb_lock_bystring(share_tdb, vstring);
59
60 /* Cope with byte-reversed older versions of the db. */
61 vers_id = tdb_fetch_int32(share_tdb, vstring);
62 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
63 /* Written on a bigendian machine with old fetch_int code. Save as le. */
64 tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2);
65 vers_id = SHARE_DATABASE_VERSION_V2;
66 }
67
68 if (vers_id != SHARE_DATABASE_VERSION_V2) {
69 tdb_traverse(share_tdb, tdb_traverse_delete_fn, NULL);
70 tdb_store_int32(share_tdb, vstring, SHARE_DATABASE_VERSION_V2);
71 }
72 tdb_unlock_bystring(share_tdb, vstring);
73
74 return True;
75}
76
77/*******************************************************************
78 Fake up a Everyone, default access as a default.
79 def_access is a GENERIC_XXX access mode.
80 ********************************************************************/
81
82SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access)
83{
84 SEC_ACCESS sa;
85 SEC_ACE ace;
86 SEC_ACL *psa = NULL;
87 SEC_DESC *psd = NULL;
88 uint32 spec_access = def_access;
89
90 se_map_generic(&spec_access, &file_generic_mapping);
91
92 init_sec_access(&sa, def_access | spec_access );
93 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
94
95 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
96 psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, psize);
97 }
98
99 if (!psd) {
100 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
101 return NULL;
102 }
103
104 return psd;
105}
106
107/*******************************************************************
108 Pull a security descriptor from the share tdb.
109 ********************************************************************/
110
111SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename,
112 size_t *psize)
113{
114 prs_struct ps;
115 fstring key;
116 SEC_DESC *psd = NULL;
117
118 if (!share_info_db_init()) {
119 return NULL;
120 }
121
122 *psize = 0;
123
124 /* Fetch security descriptor from tdb */
125
126 slprintf(key, sizeof(key)-1, "SECDESC/%s", servicename);
127
128 if (tdb_prs_fetch(share_tdb, key, &ps, ctx)!=0 ||
129 !sec_io_desc("get_share_security", &psd, &ps, 1)) {
130
131 DEBUG(4, ("get_share_security: using default secdesc for %s\n",
132 servicename));
133
134 return get_share_security_default(ctx, psize, GENERIC_ALL_ACCESS);
135 }
136
137 if (psd)
138 *psize = sec_desc_size(psd);
139
140 prs_mem_free(&ps);
141 return psd;
142}
143
144/*******************************************************************
145 Store a security descriptor in the share db.
146 ********************************************************************/
147
148BOOL set_share_security(const char *share_name, SEC_DESC *psd)
149{
150 prs_struct ps;
151 TALLOC_CTX *mem_ctx = NULL;
152 fstring key;
153 BOOL ret = False;
154
155 if (!share_info_db_init()) {
156 return False;
157 }
158
159 mem_ctx = talloc_init("set_share_security");
160 if (mem_ctx == NULL)
161 return False;
162
163 prs_init(&ps, (uint32)sec_desc_size(psd), mem_ctx, MARSHALL);
164
165 if (!sec_io_desc("share_security", &psd, &ps, 1))
166 goto out;
167
168 slprintf(key, sizeof(key)-1, "SECDESC/%s", share_name);
169
170 if (tdb_prs_store(share_tdb, key, &ps)==0) {
171 ret = True;
172 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
173 } else {
174 DEBUG(1,("set_share_security: Failed to store secdesc for %s\n", share_name ));
175 }
176
177 /* Free malloc'ed memory */
178
179out:
180
181 prs_mem_free(&ps);
182 if (mem_ctx)
183 talloc_destroy(mem_ctx);
184 return ret;
185}
186
187/*******************************************************************
188 Delete a security descriptor.
189********************************************************************/
190
191BOOL delete_share_security(const struct share_params *params)
192{
193 TDB_DATA kbuf;
194 fstring key;
195
196 slprintf(key, sizeof(key)-1, "SECDESC/%s",
197 lp_servicename(params->service));
198 kbuf.dptr = key;
199 kbuf.dsize = strlen(key)+1;
200
201 if (tdb_trans_delete(share_tdb, kbuf) != 0) {
202 DEBUG(0,("delete_share_security: Failed to delete entry for share %s\n",
203 lp_servicename(params->service) ));
204 return False;
205 }
206
207 return True;
208}
209
210/*******************************************************************
211 Can this user access with share with the required permissions ?
212********************************************************************/
213
214BOOL share_access_check(const NT_USER_TOKEN *token, const char *sharename,
215 uint32 desired_access)
216{
217 uint32 granted;
218 NTSTATUS status;
219 TALLOC_CTX *mem_ctx = NULL;
220 SEC_DESC *psd = NULL;
221 size_t sd_size;
222 BOOL ret = True;
223
224 if (!(mem_ctx = talloc_init("share_access_check"))) {
225 return False;
226 }
227
228 psd = get_share_security(mem_ctx, sharename, &sd_size);
229
230 if (!psd) {
231 TALLOC_FREE(mem_ctx);
232 return True;
233 }
234
235 ret = se_access_check(psd, token, desired_access, &granted, &status);
236
237 talloc_destroy(mem_ctx);
238 return ret;
239}
240
241/***************************************************************************
242 Parse the contents of an acl string from a usershare file.
243***************************************************************************/
244
245BOOL parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd)
246{
247 size_t s_size = 0;
248 const char *pacl = acl_str;
249 int num_aces = 0;
250 SEC_ACE *ace_list = NULL;
251 SEC_ACL *psa = NULL;
252 SEC_DESC *psd = NULL;
253 size_t sd_size = 0;
254 int i;
255
256 *ppsd = NULL;
257
258 /* If the acl string is blank return "Everyone:R" */
259 if (!*acl_str) {
260 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
261 if (!default_psd) {
262 return False;
263 }
264 *ppsd = default_psd;
265 return True;
266 }
267
268 num_aces = 1;
269
270 /* Add the number of ',' characters to get the number of aces. */
271 num_aces += count_chars(pacl,',');
272
273 ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces);
274 if (!ace_list) {
275 return False;
276 }
277
278 for (i = 0; i < num_aces; i++) {
279 SEC_ACCESS sa;
280 uint32 g_access;
281 uint32 s_access;
282 DOM_SID sid;
283 fstring sidstr;
284 uint8 type = SEC_ACE_TYPE_ACCESS_ALLOWED;
285
286 if (!next_token(&pacl, sidstr, ":", sizeof(sidstr))) {
287 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
288 "for ':' in string '%s'\n", pacl));
289 return False;
290 }
291
292 if (!string_to_sid(&sid, sidstr)) {
293 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
294 sidstr ));
295 return False;
296 }
297
298 switch (*pacl) {
299 case 'F': /* Full Control, ie. R+W */
300 case 'f': /* Full Control, ie. R+W */
301 s_access = g_access = GENERIC_ALL_ACCESS;
302 break;
303 case 'R': /* Read only. */
304 case 'r': /* Read only. */
305 s_access = g_access = GENERIC_READ_ACCESS;
306 break;
307 case 'D': /* Deny all to this SID. */
308 case 'd': /* Deny all to this SID. */
309 type = SEC_ACE_TYPE_ACCESS_DENIED;
310 s_access = g_access = GENERIC_ALL_ACCESS;
311 break;
312 default:
313 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
314 pacl ));
315 return False;
316 }
317
318 pacl++;
319 if (*pacl && *pacl != ',') {
320 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
321 pacl ));
322 return False;
323 }
324 pacl++; /* Go past any ',' */
325
326 se_map_generic(&s_access, &file_generic_mapping);
327 init_sec_access(&sa, g_access | s_access );
328 init_sec_ace(&ace_list[i], &sid, type, sa, 0);
329 }
330
331 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
332 psd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, psa, &sd_size);
333 }
334
335 if (!psd) {
336 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
337 return False;
338 }
339
340 *ppsd = psd;
341 return True;
342}
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