source: branches/samba-3.3.x/source/lib/sharesec.c@ 221

Last change on this file since 221 was 206, checked in by Herwig Bauernfeind, 16 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)
File size: 10.1 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 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
22/*******************************************************************
23 Create the share security tdb.
24 ********************************************************************/
25
26static struct db_context *share_db; /* used for share security descriptors */
27#define SHARE_DATABASE_VERSION_V1 1
28#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
29
30/* Map generic permissions to file object specific permissions */
31
32static const struct generic_mapping file_generic_mapping = {
33 FILE_GENERIC_READ,
34 FILE_GENERIC_WRITE,
35 FILE_GENERIC_EXECUTE,
36 FILE_GENERIC_ALL
37};
38
39static int delete_fn(struct db_record *rec, void *priv)
40{
41 rec->delete_rec(rec);
42 return 0;
43}
44
45static bool share_info_db_init(void)
46{
47 const char *vstring = "INFO/version";
48 int32 vers_id;
49
50 if (share_db != NULL) {
51 return True;
52 }
53
54 share_db = db_open(NULL, state_path("share_info.tdb"), 0,
55 TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
56 if (share_db == NULL) {
57 DEBUG(0,("Failed to open share info database %s (%s)\n",
58 state_path("share_info.tdb"), strerror(errno) ));
59 return False;
60 }
61
62 vers_id = dbwrap_fetch_int32(share_db, vstring);
63 if (vers_id == SHARE_DATABASE_VERSION_V2) {
64 return true;
65 }
66
67 if (share_db->transaction_start(share_db) != 0) {
68 DEBUG(0, ("transaction_start failed\n"));
69 TALLOC_FREE(share_db);
70 return false;
71 }
72
73 vers_id = dbwrap_fetch_int32(share_db, vstring);
74 if (vers_id == SHARE_DATABASE_VERSION_V2) {
75 /*
76 * Race condition
77 */
78 if (share_db->transaction_cancel(share_db)) {
79 smb_panic("transaction_cancel failed");
80 }
81 return true;
82 }
83
84 /* Cope with byte-reversed older versions of the db. */
85 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
86 /* Written on a bigendian machine with old fetch_int code. Save as le. */
87
88 if (dbwrap_store_int32(share_db, vstring,
89 SHARE_DATABASE_VERSION_V2) != 0) {
90 DEBUG(0, ("dbwrap_store_int32 failed\n"));
91 goto cancel;
92 }
93 vers_id = SHARE_DATABASE_VERSION_V2;
94 }
95
96 if (vers_id != SHARE_DATABASE_VERSION_V2) {
97 int ret;
98 ret = share_db->traverse(share_db, delete_fn, NULL);
99 if (ret < 0) {
100 DEBUG(0, ("traverse failed\n"));
101 goto cancel;
102 }
103 if (dbwrap_store_int32(share_db, vstring,
104 SHARE_DATABASE_VERSION_V2) != 0) {
105 DEBUG(0, ("dbwrap_store_int32 failed\n"));
106 goto cancel;
107 }
108 }
109
110 if (share_db->transaction_commit(share_db) != 0) {
111 DEBUG(0, ("transaction_commit failed\n"));
112 return false;
113 }
114
115 return true;
116
117 cancel:
118 if (share_db->transaction_cancel(share_db)) {
119 smb_panic("transaction_cancel failed");
120 }
121
122 return false;
123}
124
125/*******************************************************************
126 Fake up a Everyone, default access as a default.
127 def_access is a GENERIC_XXX access mode.
128 ********************************************************************/
129
130SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access)
131{
132 uint32_t sa;
133 SEC_ACE ace;
134 SEC_ACL *psa = NULL;
135 SEC_DESC *psd = NULL;
136 uint32 spec_access = def_access;
137
138 se_map_generic(&spec_access, &file_generic_mapping);
139
140 sa = (def_access | spec_access );
141 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
142
143 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
144 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
145 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
146 psa, psize);
147 }
148
149 if (!psd) {
150 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
151 return NULL;
152 }
153
154 return psd;
155}
156
157/*******************************************************************
158 Pull a security descriptor from the share tdb.
159 ********************************************************************/
160
161SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename,
162 size_t *psize)
163{
164 char *key;
165 SEC_DESC *psd = NULL;
166 TDB_DATA data;
167 NTSTATUS status;
168
169 if (!share_info_db_init()) {
170 return NULL;
171 }
172
173 if (!(key = talloc_asprintf(ctx, "SECDESC/%s", servicename))) {
174 DEBUG(0, ("talloc_asprintf failed\n"));
175 return NULL;
176 }
177
178 data = dbwrap_fetch_bystring(share_db, talloc_tos(), key);
179
180 TALLOC_FREE(key);
181
182 if (data.dptr == NULL) {
183 return get_share_security_default(ctx, psize,
184 GENERIC_ALL_ACCESS);
185 }
186
187 status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd);
188
189 TALLOC_FREE(data.dptr);
190
191 if (!NT_STATUS_IS_OK(status)) {
192 DEBUG(0, ("unmarshall_sec_desc failed: %s\n",
193 nt_errstr(status)));
194 return NULL;
195 }
196
197 if (psd)
198 *psize = ndr_size_security_descriptor(psd, 0);
199
200 return psd;
201}
202
203/*******************************************************************
204 Store a security descriptor in the share db.
205 ********************************************************************/
206
207bool set_share_security(const char *share_name, SEC_DESC *psd)
208{
209 TALLOC_CTX *frame;
210 char *key;
211 bool ret = False;
212 TDB_DATA blob;
213 NTSTATUS status;
214
215 if (!share_info_db_init()) {
216 return False;
217 }
218
219 frame = talloc_stackframe();
220
221 status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize);
222
223 if (!NT_STATUS_IS_OK(status)) {
224 DEBUG(0, ("marshall_sec_desc failed: %s\n",
225 nt_errstr(status)));
226 goto out;
227 }
228
229 if (!(key = talloc_asprintf(frame, "SECDESC/%s", share_name))) {
230 DEBUG(0, ("talloc_asprintf failed\n"));
231 goto out;
232 }
233
234 status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob,
235 TDB_REPLACE);
236 if (!NT_STATUS_IS_OK(status)) {
237 DEBUG(1, ("set_share_security: Failed to store secdesc for "
238 "%s: %s\n", share_name, nt_errstr(status)));
239 goto out;
240 }
241
242 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
243 ret = True;
244
245 out:
246 TALLOC_FREE(frame);
247 return ret;
248}
249
250/*******************************************************************
251 Delete a security descriptor.
252********************************************************************/
253
254bool delete_share_security(const char *servicename)
255{
256 TDB_DATA kbuf;
257 char *key;
258 NTSTATUS status;
259
260 if (!(key = talloc_asprintf(talloc_tos(), "SECDESC/%s",
261 servicename))) {
262 return False;
263 }
264 kbuf = string_term_tdb_data(key);
265
266 status = dbwrap_trans_delete(share_db, kbuf);
267 if (!NT_STATUS_IS_OK(status)) {
268 DEBUG(0, ("delete_share_security: Failed to delete entry for "
269 "share %s: %s\n", servicename, nt_errstr(status)));
270 return False;
271 }
272
273 return True;
274}
275
276/*******************************************************************
277 Can this user access with share with the required permissions ?
278********************************************************************/
279
280bool share_access_check(const NT_USER_TOKEN *token, const char *sharename,
281 uint32 desired_access)
282{
283 uint32 granted;
284 NTSTATUS status;
285 SEC_DESC *psd = NULL;
286 size_t sd_size;
287
288 psd = get_share_security(talloc_tos(), sharename, &sd_size);
289
290 if (!psd) {
291 return True;
292 }
293
294 status = se_access_check(psd, token, desired_access, &granted);
295
296 TALLOC_FREE(psd);
297
298 return NT_STATUS_IS_OK(status);
299}
300
301/***************************************************************************
302 Parse the contents of an acl string from a usershare file.
303***************************************************************************/
304
305bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd)
306{
307 size_t s_size = 0;
308 const char *pacl = acl_str;
309 int num_aces = 0;
310 SEC_ACE *ace_list = NULL;
311 SEC_ACL *psa = NULL;
312 SEC_DESC *psd = NULL;
313 size_t sd_size = 0;
314 int i;
315
316 *ppsd = NULL;
317
318 /* If the acl string is blank return "Everyone:R" */
319 if (!*acl_str) {
320 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
321 if (!default_psd) {
322 return False;
323 }
324 *ppsd = default_psd;
325 return True;
326 }
327
328 num_aces = 1;
329
330 /* Add the number of ',' characters to get the number of aces. */
331 num_aces += count_chars(pacl,',');
332
333 ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces);
334 if (!ace_list) {
335 return False;
336 }
337
338 for (i = 0; i < num_aces; i++) {
339 uint32_t sa;
340 uint32 g_access;
341 uint32 s_access;
342 DOM_SID sid;
343 char *sidstr;
344 enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED;
345
346 if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) {
347 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
348 "for ':' in string '%s'\n", pacl));
349 return False;
350 }
351
352 if (!string_to_sid(&sid, sidstr)) {
353 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
354 sidstr ));
355 return False;
356 }
357
358 switch (*pacl) {
359 case 'F': /* Full Control, ie. R+W */
360 case 'f': /* Full Control, ie. R+W */
361 s_access = g_access = GENERIC_ALL_ACCESS;
362 break;
363 case 'R': /* Read only. */
364 case 'r': /* Read only. */
365 s_access = g_access = GENERIC_READ_ACCESS;
366 break;
367 case 'D': /* Deny all to this SID. */
368 case 'd': /* Deny all to this SID. */
369 type = SEC_ACE_TYPE_ACCESS_DENIED;
370 s_access = g_access = GENERIC_ALL_ACCESS;
371 break;
372 default:
373 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
374 pacl ));
375 return False;
376 }
377
378 pacl++;
379 if (*pacl && *pacl != ',') {
380 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
381 pacl ));
382 return False;
383 }
384 pacl++; /* Go past any ',' */
385
386 se_map_generic(&s_access, &file_generic_mapping);
387 sa = (g_access | s_access);
388 init_sec_ace(&ace_list[i], &sid, type, sa, 0);
389 }
390
391 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
392 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
393 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
394 psa, &sd_size);
395 }
396
397 if (!psd) {
398 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
399 return False;
400 }
401
402 *ppsd = psd;
403 return True;
404}
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