source: trunk/server/source3/lib/sharesec.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 14.8 KB
RevLine 
[745]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#include "system/filesys.h"
22#include "../libcli/security/security.h"
23#include "../librpc/gen_ndr/ndr_security.h"
24#include "dbwrap.h"
25#include "util_tdb.h"
26
27/*******************************************************************
28 Create the share security tdb.
29 ********************************************************************/
30
31static struct db_context *share_db; /* used for share security descriptors */
32#define SHARE_DATABASE_VERSION_V1 1
33#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
34#define SHARE_DATABASE_VERSION_V3 3 /* canonicalized sharenames as lower case */
35
36#define SHARE_SECURITY_DB_KEY_PREFIX_STR "SECDESC/"
37/* Map generic permissions to file object specific permissions */
38
39extern const struct generic_mapping file_generic_mapping;
40
41static int delete_fn(struct db_record *rec, void *priv)
42{
43 rec->delete_rec(rec);
44 return 0;
45}
46
47/*****************************************************
48 Looking for keys of the form: SHARE_SECURITY_DB_KEY_PREFIX_STR + "non lower case str".
49 If we find one re-write it into a canonical case form.
50*****************************************************/
51
52static int upgrade_v2_to_v3(struct db_record *rec, void *priv)
53{
54 size_t prefix_len = strlen(SHARE_SECURITY_DB_KEY_PREFIX_STR);
55 const char *servicename = NULL;
56 char *c_servicename = NULL;
57 char *newkey = NULL;
58 bool *p_upgrade_ok = (bool *)priv;
59 NTSTATUS status;
60
61 /* Is there space for a one character sharename ? */
62 if (rec->key.dsize <= prefix_len+2) {
63 return 0;
64 }
65
66 /* Does it start with the share key prefix ? */
67 if (memcmp(rec->key.dptr, SHARE_SECURITY_DB_KEY_PREFIX_STR,
68 prefix_len) != 0) {
69 return 0;
70 }
71
72 /* Is it a null terminated string as a key ? */
73 if (rec->key.dptr[rec->key.dsize-1] != '\0') {
74 return 0;
75 }
76
77 /* Bytes after the prefix are the sharename string. */
78 servicename = (char *)&rec->key.dptr[prefix_len];
79 c_servicename = canonicalize_servicename(talloc_tos(), servicename);
80 if (!c_servicename) {
81 smb_panic("out of memory upgrading share security db from v2 -> v3");
82 }
83
84 if (strcmp(servicename, c_servicename) == 0) {
85 /* Old and new names match. No canonicalization needed. */
86 TALLOC_FREE(c_servicename);
87 return 0;
88 }
89
90 /* Oops. Need to canonicalize name, delete old then store new. */
91 status = rec->delete_rec(rec);
92 if (!NT_STATUS_IS_OK(status)) {
93 DEBUG(1, ("upgrade_v2_to_v3: Failed to delete secdesc for "
94 "%s: %s\n", rec->key.dptr, nt_errstr(status)));
95 TALLOC_FREE(c_servicename);
96 *p_upgrade_ok = false;
97 return -1;
98 } else {
99 DEBUG(10, ("upgrade_v2_to_v3: deleted secdesc for "
100 "%s\n", rec->key.dptr ));
101 }
102
103 if (!(newkey = talloc_asprintf(talloc_tos(),
104 SHARE_SECURITY_DB_KEY_PREFIX_STR "%s",
105 c_servicename))) {
106 smb_panic("out of memory upgrading share security db from v2 -> v3");
107 }
108
109 status = dbwrap_store(share_db,
110 string_term_tdb_data(newkey),
111 rec->value,
112 TDB_REPLACE);
113
114 if (!NT_STATUS_IS_OK(status)) {
115 DEBUG(1, ("upgrade_v2_to_v3: Failed to store secdesc for "
116 "%s: %s\n", c_servicename, nt_errstr(status)));
117 TALLOC_FREE(c_servicename);
118 TALLOC_FREE(newkey);
119 *p_upgrade_ok = false;
120 return -1;
121 } else {
122 DEBUG(10, ("upgrade_v2_to_v3: stored secdesc for "
123 "%s\n", newkey ));
124 }
125
126 TALLOC_FREE(newkey);
127 TALLOC_FREE(c_servicename);
128
129 return 0;
130}
131
132bool share_info_db_init(void)
133{
134 const char *vstring = "INFO/version";
135 int32 vers_id;
136 int ret;
137 bool upgrade_ok = true;
138
139 if (share_db != NULL) {
140 return True;
141 }
142
143 share_db = db_open(NULL, state_path("share_info.tdb"), 0,
144 TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
145 if (share_db == NULL) {
146 DEBUG(0,("Failed to open share info database %s (%s)\n",
147 state_path("share_info.tdb"), strerror(errno) ));
148 return False;
149 }
150
151 vers_id = dbwrap_fetch_int32(share_db, vstring);
152 if (vers_id == SHARE_DATABASE_VERSION_V3) {
153 return true;
154 }
155
156 if (share_db->transaction_start(share_db) != 0) {
157 DEBUG(0, ("transaction_start failed\n"));
158 TALLOC_FREE(share_db);
159 return false;
160 }
161
162 vers_id = dbwrap_fetch_int32(share_db, vstring);
163 if (vers_id == SHARE_DATABASE_VERSION_V3) {
164 /*
165 * Race condition
166 */
167 if (share_db->transaction_cancel(share_db)) {
168 smb_panic("transaction_cancel failed");
169 }
170 return true;
171 }
172
173 /* Move to at least V2. */
174
175 /* Cope with byte-reversed older versions of the db. */
176 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
177 /* Written on a bigendian machine with old fetch_int code. Save as le. */
178
179 if (dbwrap_store_int32(share_db, vstring,
180 SHARE_DATABASE_VERSION_V2) != 0) {
181 DEBUG(0, ("dbwrap_store_int32 failed\n"));
182 goto cancel;
183 }
184 vers_id = SHARE_DATABASE_VERSION_V2;
185 }
186
187 if (vers_id != SHARE_DATABASE_VERSION_V2) {
188 ret = share_db->traverse(share_db, delete_fn, NULL);
189 if (ret < 0) {
190 DEBUG(0, ("traverse failed\n"));
191 goto cancel;
192 }
193 if (dbwrap_store_int32(share_db, vstring,
194 SHARE_DATABASE_VERSION_V2) != 0) {
195 DEBUG(0, ("dbwrap_store_int32 failed\n"));
196 goto cancel;
197 }
198 }
199
200 /* Finally upgrade to version 3, with canonicalized sharenames. */
201
202 ret = share_db->traverse(share_db, upgrade_v2_to_v3, &upgrade_ok);
203 if (ret < 0 || upgrade_ok == false) {
204 DEBUG(0, ("traverse failed\n"));
205 goto cancel;
206 }
207 if (dbwrap_store_int32(share_db, vstring,
208 SHARE_DATABASE_VERSION_V3) != 0) {
209 DEBUG(0, ("dbwrap_store_int32 failed\n"));
210 goto cancel;
211 }
212
213 if (share_db->transaction_commit(share_db) != 0) {
214 DEBUG(0, ("transaction_commit failed\n"));
215 return false;
216 }
217
218 return true;
219
220 cancel:
221 if (share_db->transaction_cancel(share_db)) {
222 smb_panic("transaction_cancel failed");
223 }
224
225 return false;
226}
227
228/*******************************************************************
229 Fake up a Everyone, default access as a default.
230 def_access is a GENERIC_XXX access mode.
231 ********************************************************************/
232
233struct security_descriptor *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access)
234{
235 uint32_t sa;
236 struct security_ace ace;
237 struct security_acl *psa = NULL;
238 struct security_descriptor *psd = NULL;
239 uint32 spec_access = def_access;
240
241 se_map_generic(&spec_access, &file_generic_mapping);
242
243 sa = (def_access | spec_access );
244 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
245
246 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
247 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
248 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
249 psa, psize);
250 }
251
252 if (!psd) {
253 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
254 return NULL;
255 }
256
257 return psd;
258}
259
260/*******************************************************************
261 Pull a security descriptor from the share tdb.
262 ********************************************************************/
263
264struct security_descriptor *get_share_security( TALLOC_CTX *ctx, const char *servicename,
265 size_t *psize)
266{
267 char *key;
268 struct security_descriptor *psd = NULL;
269 TDB_DATA data;
270 char *c_servicename = canonicalize_servicename(talloc_tos(), servicename);
271 NTSTATUS status;
272
273 if (!c_servicename) {
274 return NULL;
275 }
276
277 if (!share_info_db_init()) {
278 TALLOC_FREE(c_servicename);
279 return NULL;
280 }
281
282 if (!(key = talloc_asprintf(ctx, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_servicename))) {
283 TALLOC_FREE(c_servicename);
284 DEBUG(0, ("talloc_asprintf failed\n"));
285 return NULL;
286 }
287
288 TALLOC_FREE(c_servicename);
289
290 data = dbwrap_fetch_bystring(share_db, talloc_tos(), key);
291
292 TALLOC_FREE(key);
293
294 if (data.dptr == NULL) {
295 return get_share_security_default(ctx, psize,
296 GENERIC_ALL_ACCESS);
297 }
298
299 status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd);
300
301 TALLOC_FREE(data.dptr);
302
303 if (!NT_STATUS_IS_OK(status)) {
304 DEBUG(0, ("unmarshall_sec_desc failed: %s\n",
305 nt_errstr(status)));
306 return get_share_security_default(ctx, psize,
307 GENERIC_ALL_ACCESS);
308 }
309
310 if (psd) {
311 *psize = ndr_size_security_descriptor(psd, 0);
312 } else {
313 return get_share_security_default(ctx, psize,
314 GENERIC_ALL_ACCESS);
315 }
316
317 return psd;
318}
319
320/*******************************************************************
321 Store a security descriptor in the share db.
322 ********************************************************************/
323
324bool set_share_security(const char *share_name, struct security_descriptor *psd)
325{
326 TALLOC_CTX *frame = talloc_stackframe();
327 char *key;
328 bool ret = False;
329 TDB_DATA blob;
330 NTSTATUS status;
331 char *c_share_name = canonicalize_servicename(frame, share_name);
332
333 if (!c_share_name) {
334 goto out;
335 }
336
337 if (!share_info_db_init()) {
338 goto out;
339 }
340
341 status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize);
342
343 if (!NT_STATUS_IS_OK(status)) {
344 DEBUG(0, ("marshall_sec_desc failed: %s\n",
345 nt_errstr(status)));
346 goto out;
347 }
348
349 if (!(key = talloc_asprintf(frame, SHARE_SECURITY_DB_KEY_PREFIX_STR "%s", c_share_name))) {
350 DEBUG(0, ("talloc_asprintf failed\n"));
351 goto out;
352 }
353
354 status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob,
355 TDB_REPLACE);
356 if (!NT_STATUS_IS_OK(status)) {
357 DEBUG(1, ("set_share_security: Failed to store secdesc for "
358 "%s: %s\n", share_name, nt_errstr(status)));
359 goto out;
360 }
361
362 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
363 ret = True;
364
365 out:
366 TALLOC_FREE(frame);
367 return ret;
368}
369
370/*******************************************************************
371 Delete a security descriptor.
372********************************************************************/
373
374bool delete_share_security(const char *servicename)
375{
376 TDB_DATA kbuf;
377 char *key;
378 NTSTATUS status;
379 char *c_servicename = canonicalize_servicename(talloc_tos(), servicename);
380
381 if (!c_servicename) {
382 return NULL;
383 }
384
385 if (!share_info_db_init()) {
386 TALLOC_FREE(c_servicename);
387 return False;
388 }
389
390 if (!(key = talloc_asprintf(talloc_tos(), SHARE_SECURITY_DB_KEY_PREFIX_STR "%s",
391 c_servicename))) {
392 TALLOC_FREE(c_servicename);
393 return False;
394 }
395 kbuf = string_term_tdb_data(key);
396
397 status = dbwrap_trans_delete(share_db, kbuf);
398 if (!NT_STATUS_IS_OK(status)) {
399 DEBUG(0, ("delete_share_security: Failed to delete entry for "
400 "share %s: %s\n", c_servicename, nt_errstr(status)));
401 TALLOC_FREE(c_servicename);
402 return False;
403 }
404
405 TALLOC_FREE(c_servicename);
406 return True;
407}
408
409/*******************************************************************
410 Can this user access with share with the required permissions ?
411********************************************************************/
412
413bool share_access_check(const struct security_token *token,
414 const char *sharename,
415 uint32 desired_access,
416 uint32_t *pgranted)
417{
418 uint32 granted;
419 NTSTATUS status;
420 struct security_descriptor *psd = NULL;
421 size_t sd_size;
422
423 psd = get_share_security(talloc_tos(), sharename, &sd_size);
424
425 if (!psd) {
426 return True;
427 }
428
429 status = se_access_check(psd, token, desired_access, &granted);
430
431 TALLOC_FREE(psd);
432
433 if (pgranted != NULL) {
434 *pgranted = granted;
435 }
436
437 return NT_STATUS_IS_OK(status);
438}
439
440/***************************************************************************
441 Parse the contents of an acl string from a usershare file.
442***************************************************************************/
443
444bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, struct security_descriptor **ppsd)
445{
446 size_t s_size = 0;
447 const char *pacl = acl_str;
448 int num_aces = 0;
449 struct security_ace *ace_list = NULL;
450 struct security_acl *psa = NULL;
451 struct security_descriptor *psd = NULL;
452 size_t sd_size = 0;
453 int i;
454
455 *ppsd = NULL;
456
457 /* If the acl string is blank return "Everyone:R" */
458 if (!*acl_str) {
459 struct security_descriptor *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
460 if (!default_psd) {
461 return False;
462 }
463 *ppsd = default_psd;
464 return True;
465 }
466
467 num_aces = 1;
468
469 /* Add the number of ',' characters to get the number of aces. */
470 num_aces += count_chars(pacl,',');
471
472 ace_list = TALLOC_ARRAY(ctx, struct security_ace, num_aces);
473 if (!ace_list) {
474 return False;
475 }
476
477 for (i = 0; i < num_aces; i++) {
478 uint32_t sa;
479 uint32 g_access;
480 uint32 s_access;
481 struct dom_sid sid;
482 char *sidstr;
483 enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED;
484
485 if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) {
486 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
487 "for ':' in string '%s'\n", pacl));
488 return False;
489 }
490
491 if (!string_to_sid(&sid, sidstr)) {
492 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
493 sidstr ));
494 return False;
495 }
496
497 switch (*pacl) {
498 case 'F': /* Full Control, ie. R+W */
499 case 'f': /* Full Control, ie. R+W */
500 s_access = g_access = GENERIC_ALL_ACCESS;
501 break;
502 case 'R': /* Read only. */
503 case 'r': /* Read only. */
504 s_access = g_access = GENERIC_READ_ACCESS;
505 break;
506 case 'D': /* Deny all to this SID. */
507 case 'd': /* Deny all to this SID. */
508 type = SEC_ACE_TYPE_ACCESS_DENIED;
509 s_access = g_access = GENERIC_ALL_ACCESS;
510 break;
511 default:
512 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
513 pacl ));
514 return False;
515 }
516
517 pacl++;
518 if (*pacl && *pacl != ',') {
519 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
520 pacl ));
521 return False;
522 }
523 pacl++; /* Go past any ',' */
524
525 se_map_generic(&s_access, &file_generic_mapping);
526 sa = (g_access | s_access);
527 init_sec_ace(&ace_list[i], &sid, type, sa, 0);
528 }
529
530 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
531 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
532 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
533 psa, &sd_size);
534 }
535
536 if (!psd) {
537 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
538 return False;
539 }
540
541 *ppsd = psd;
542 return True;
543}
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