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vfs: Implement an improved vfs_acl_common that uses the hash of the system ACL
[Samba.git] / source3 / modules / vfs_acl_common.c
blob5d4327a62891bed088d519206f8b95854ca0f2de
1 /*
2 * Store Windows ACLs in data store - common functions.
3 * #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
4 *
5 * Copyright (C) Volker Lendecke, 2008
6 * Copyright (C) Jeremy Allison, 2009
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "smbd/smbd.h"
23 #include "system/filesys.h"
24 #include "../libcli/security/security.h"
25 #include "../librpc/gen_ndr/ndr_security.h"
26 #include "../lib/util/bitmap.h"
27
28 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
29 DATA_BLOB *pblob,
30 uint16_t hash_type,
31 uint8_t hash[XATTR_SD_HASH_SIZE]);
32
33 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
34 vfs_handle_struct *handle,
35 files_struct *fsp,
36 const char *name,
37 DATA_BLOB *pblob);
38
39 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
40 files_struct *fsp,
41 DATA_BLOB *pblob);
42
43 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
44 SECINFO_GROUP | \
45 SECINFO_DACL | \
46 SECINFO_SACL)
47
48 /*******************************************************************
49 Hash a security descriptor.
50 *******************************************************************/
51
52 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
53 uint8_t *hash)
54 {
55 SHA256_CTX tctx;
56
57 memset(hash, '\0', XATTR_SD_HASH_SIZE);
58
59 samba_SHA256_Init(&tctx);
60 samba_SHA256_Update(&tctx, blob.data, blob.length);
61 samba_SHA256_Final(hash, &tctx);
62
63 return NT_STATUS_OK;
64 }
65
66 /*******************************************************************
67 Hash a security descriptor.
68 *******************************************************************/
69
70 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
71 uint8_t *hash)
72 {
73 DATA_BLOB blob;
74 NTSTATUS status;
75
76 memset(hash, '\0', XATTR_SD_HASH_SIZE);
77 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
78 if (!NT_STATUS_IS_OK(status)) {
79 return status;
80 }
81 return hash_blob_sha256(blob, hash);
82 }
83
84 /*******************************************************************
85 Parse out a struct security_descriptor from a DATA_BLOB.
86 *******************************************************************/
87
88 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
89 TALLOC_CTX *mem_ctx,
90 struct security_descriptor **ppdesc,
91 uint16_t *p_hash_type,
92 uint16_t *p_version,
93 uint8_t hash[XATTR_SD_HASH_SIZE],
94 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
95 {
96 struct xattr_NTACL xacl;
97 enum ndr_err_code ndr_err;
98 size_t sd_size;
99 TALLOC_CTX *frame = talloc_stackframe();
100
101 ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
102 (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
103
104 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
105 DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
106 ndr_errstr(ndr_err)));
107 TALLOC_FREE(frame);
108 return ndr_map_error2ntstatus(ndr_err);
109 }
110
111 *p_version = xacl.version;
112
113 switch (xacl.version) {
114 case 1:
115 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
116 xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
117 xacl.info.sd->owner_sid,
118 xacl.info.sd->group_sid,
119 xacl.info.sd->sacl,
120 xacl.info.sd->dacl,
121 &sd_size);
122 /* No hash - null out. */
123 *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
124 memset(hash, '\0', XATTR_SD_HASH_SIZE);
125 break;
126 case 2:
127 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
128 xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
129 xacl.info.sd_hs2->sd->owner_sid,
130 xacl.info.sd_hs2->sd->group_sid,
131 xacl.info.sd_hs2->sd->sacl,
132 xacl.info.sd_hs2->sd->dacl,
133 &sd_size);
134 /* No hash - null out. */
135 *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
136 memset(hash, '\0', XATTR_SD_HASH_SIZE);
137 break;
138 case 3:
139 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
140 xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
141 xacl.info.sd_hs3->sd->owner_sid,
142 xacl.info.sd_hs3->sd->group_sid,
143 xacl.info.sd_hs3->sd->sacl,
144 xacl.info.sd_hs3->sd->dacl,
145 &sd_size);
146 *p_hash_type = xacl.info.sd_hs3->hash_type;
147 /* Current version 3 (if no sys acl hash available). */
148 memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
149 break;
150 case 4:
151 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
152 xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
153 xacl.info.sd_hs4->sd->owner_sid,
154 xacl.info.sd_hs4->sd->group_sid,
155 xacl.info.sd_hs4->sd->sacl,
156 xacl.info.sd_hs4->sd->dacl,
157 &sd_size);
158 *p_hash_type = xacl.info.sd_hs4->hash_type;
159 /* Current version 4. */
160 memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
161 memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
162 break;
163 default:
164 TALLOC_FREE(frame);
165 return NT_STATUS_REVISION_MISMATCH;
166 }
167
168 TALLOC_FREE(frame);
169
170 return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
171 }
172
173 /*******************************************************************
174 Create a DATA_BLOB from a hash of the security descriptor storead at
175 the system layer and the NT ACL we wish to preserve
176 *******************************************************************/
177
178 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
179 DATA_BLOB *pblob,
180 uint16_t hash_type,
181 uint8_t hash[XATTR_SD_HASH_SIZE])
182 {
183 struct xattr_NTACL xacl;
184 struct security_descriptor_hash_v3 sd_hs3;
185 enum ndr_err_code ndr_err;
186 TALLOC_CTX *ctx = talloc_tos();
187
188 ZERO_STRUCT(xacl);
189 ZERO_STRUCT(sd_hs3);
190
191 xacl.version = 3;
192 xacl.info.sd_hs3 = &sd_hs3;
193 xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
194 xacl.info.sd_hs3->hash_type = hash_type;
195 memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
196
197 ndr_err = ndr_push_struct_blob(
198 pblob, ctx, &xacl,
199 (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
200
201 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
202 DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
203 ndr_errstr(ndr_err)));
204 return ndr_map_error2ntstatus(ndr_err);
205 }
206
207 return NT_STATUS_OK;
208 }
209
210 /*******************************************************************
211 Create a DATA_BLOB from a hash of the security descriptors
212 (system and NT) stored at the system layer and the NT ACL we wish
213 to preserve.
214 *******************************************************************/
215
216 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
217 DATA_BLOB *pblob,
218 uint16_t hash_type,
219 uint8_t hash[XATTR_SD_HASH_SIZE],
220 const char *description,
221 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
222 {
223 struct xattr_NTACL xacl;
224 struct security_descriptor_hash_v4 sd_hs4;
225 enum ndr_err_code ndr_err;
226 TALLOC_CTX *ctx = talloc_tos();
227 NTTIME nttime_now;
228 struct timeval now = timeval_current();
229 nttime_now = timeval_to_nttime(&now);
230
231 ZERO_STRUCT(xacl);
232 ZERO_STRUCT(sd_hs4);
233
234 xacl.version = 4;
235 xacl.info.sd_hs4 = &sd_hs4;
236 xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
237 xacl.info.sd_hs4->hash_type = hash_type;
238 memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
239 xacl.info.sd_hs4->description = description;
240 xacl.info.sd_hs4->time = nttime_now;
241 memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
242
243 ndr_err = ndr_push_struct_blob(
244 pblob, ctx, &xacl,
245 (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
246
247 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
248 DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
249 ndr_errstr(ndr_err)));
250 return ndr_map_error2ntstatus(ndr_err);
251 }
252
253 return NT_STATUS_OK;
254 }
255
256 /*******************************************************************
257 Add in 3 inheritable components for a non-inheritable directory ACL.
258 CREATOR_OWNER/CREATOR_GROUP/WORLD.
259 *******************************************************************/
260
261 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
262 const char *name,
263 SMB_STRUCT_STAT *psbuf,
264 struct security_descriptor *psd)
265 {
266 struct connection_struct *conn = handle->conn;
267 int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
268 struct smb_filename smb_fname;
269 enum security_ace_type acltype;
270 uint32_t access_mask;
271 mode_t dir_mode;
272 mode_t file_mode;
273 mode_t mode;
274 struct security_ace *new_ace_list;
275
276 if (psd->dacl) {
277 new_ace_list = talloc_zero_array(psd->dacl,
278 struct security_ace,
279 num_aces + 3);
280 } else {
281 /*
282 * make_sec_acl() at the bottom of this function
283 * dupliates new_ace_list
284 */
285 new_ace_list = talloc_zero_array(talloc_tos(),
286 struct security_ace,
287 num_aces + 3);
288 }
289
290 if (new_ace_list == NULL) {
291 return NT_STATUS_NO_MEMORY;
292 }
293
294 /* Fake a quick smb_filename. */
295 ZERO_STRUCT(smb_fname);
296 smb_fname.st = *psbuf;
297 smb_fname.base_name = discard_const_p(char, name);
298
299 dir_mode = unix_mode(conn,
300 FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
301 file_mode = unix_mode(conn,
302 FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
303
304 mode = dir_mode | file_mode;
305
306 DEBUG(10, ("add_directory_inheritable_components: directory %s, "
307 "mode = 0%o\n",
308 name,
309 (unsigned int)mode ));
310
311 if (num_aces) {
312 memcpy(new_ace_list, psd->dacl->aces,
313 num_aces * sizeof(struct security_ace));
314 }
315 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
316 mode & 0700, false);
317
318 init_sec_ace(&new_ace_list[num_aces],
319 &global_sid_Creator_Owner,
320 acltype,
321 access_mask,
322 SEC_ACE_FLAG_CONTAINER_INHERIT|
323 SEC_ACE_FLAG_OBJECT_INHERIT|
324 SEC_ACE_FLAG_INHERIT_ONLY);
325 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
326 (mode << 3) & 0700, false);
327 init_sec_ace(&new_ace_list[num_aces+1],
328 &global_sid_Creator_Group,
329 acltype,
330 access_mask,
331 SEC_ACE_FLAG_CONTAINER_INHERIT|
332 SEC_ACE_FLAG_OBJECT_INHERIT|
333 SEC_ACE_FLAG_INHERIT_ONLY);
334 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
335 (mode << 6) & 0700, false);
336 init_sec_ace(&new_ace_list[num_aces+2],
337 &global_sid_World,
338 acltype,
339 access_mask,
340 SEC_ACE_FLAG_CONTAINER_INHERIT|
341 SEC_ACE_FLAG_OBJECT_INHERIT|
342 SEC_ACE_FLAG_INHERIT_ONLY);
343 if (psd->dacl) {
344 psd->dacl->aces = new_ace_list;
345 psd->dacl->num_aces += 3;
346 } else {
347 psd->dacl = make_sec_acl(psd,
348 NT4_ACL_REVISION,
349 3,
350 new_ace_list);
351 if (psd->dacl == NULL) {
352 return NT_STATUS_NO_MEMORY;
353 }
354 }
355 return NT_STATUS_OK;
356 }
357
358 /*******************************************************************
359 Pull a DATA_BLOB from an xattr given a pathname.
360 If the hash doesn't match, or doesn't exist - return the underlying
361 filesystem sd.
362 *******************************************************************/
363
364 static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
365 files_struct *fsp,
366 const char *name,
367 uint32_t security_info,
368 TALLOC_CTX *mem_ctx,
369 struct security_descriptor **ppdesc)
370 {
371 DATA_BLOB blob = data_blob_null;
372 NTSTATUS status;
373 uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
374 uint16_t xattr_version = 0;
375 uint8_t hash[XATTR_SD_HASH_SIZE];
376 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
377 uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
378 uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
379 struct security_descriptor *psd = NULL;
380 struct security_descriptor *pdesc_next = NULL;
381 bool ignore_file_system_acl = lp_parm_bool(SNUM(handle->conn),
382 ACL_MODULE_NAME,
383 "ignore system acls",
384 false);
385 TALLOC_CTX *frame = talloc_stackframe();
386
387 if (fsp && name == NULL) {
388 name = fsp->fsp_name->base_name;
389 }
390
391 DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
392
393 /* Get the full underlying sd for the hash
394 or to return as backup. */
395 if (fsp) {
396 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
397 fsp,
398 HASH_SECURITY_INFO,
399 mem_ctx,
400 &pdesc_next);
401 } else {
402 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
403 name,
404 HASH_SECURITY_INFO,
405 mem_ctx,
406 &pdesc_next);
407 }
408
409 if (!NT_STATUS_IS_OK(status)) {
410 DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
411 "returned %s\n",
412 name,
413 nt_errstr(status)));
414 TALLOC_FREE(frame);
415 return status;
416 }
417
418 /* Ensure we don't leak psd_next if we don't choose it.
419 *
420 * We don't allocate it onto frame as it is preferred not to
421 * steal from a talloc pool.
422 */
423 talloc_steal(frame, pdesc_next);
424
425 status = get_acl_blob(frame, handle, fsp, name, &blob);
426 if (!NT_STATUS_IS_OK(status)) {
427 DEBUG(10, ("get_nt_acl_internal: get_acl_blob returned %s\n",
428 nt_errstr(status)));
429 psd = pdesc_next;
430 goto out;
431 }
432
433 status = parse_acl_blob(&blob, mem_ctx, &psd,
434 &hash_type, &xattr_version, &hash[0], &sys_acl_hash[0]);
435 if (!NT_STATUS_IS_OK(status)) {
436 DEBUG(10, ("parse_acl_blob returned %s\n",
437 nt_errstr(status)));
438 psd = pdesc_next;
439 goto out;
440 }
441
442 /* Ensure we don't leak psd if we don't choose it.
443 *
444 * We don't allocate it onto frame as it is preferred not to
445 * steal from a talloc pool.
446 */
447 talloc_steal(frame, psd);
448
449 /* determine which type of xattr we got */
450 switch (xattr_version) {
451 case 1:
452 case 2:
453 /* These xattr types are unilatteral, they do not
454 * require confirmation of the hash. In particular,
455 * the NTVFS file server uses version 1, but
456 * 'samba-tool ntacl' can set these as well */
457 goto out;
458 case 3:
459 case 4:
460 if (ignore_file_system_acl) {
461 goto out;
462 }
463
464 break;
465 default:
466 DEBUG(10, ("get_nt_acl_internal: ACL blob revision "
467 "mismatch (%u) for file %s\n",
468 (unsigned int)hash_type,
469 name));
470 TALLOC_FREE(psd);
471 psd = pdesc_next;
472 goto out;
473 }
474
475 /* determine which type of xattr we got */
476 if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
477 DEBUG(10, ("get_nt_acl_internal: ACL blob hash type "
478 "(%u) unexpected for file %s\n",
479 (unsigned int)hash_type,
480 name));
481 TALLOC_FREE(psd);
482 psd = pdesc_next;
483 goto out;
484 }
485
486 /* determine which type of xattr we got */
487 switch (xattr_version) {
488 case 4:
489 {
490 int ret;
491 char *sys_acl_blob_description;
492 DATA_BLOB sys_acl_blob;
493 if (fsp) {
494 /* Get the full underlying sd, then hash. */
495 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
496 fsp,
497 frame,
498 &sys_acl_blob_description,
499 &sys_acl_blob);
500 } else {
501 /* Get the full underlying sd, then hash. */
502 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
503 name,
504 frame,
505 &sys_acl_blob_description,
506 &sys_acl_blob);
507 }
508
509 /* If we fail to get the ACL blob (for some reason) then this
510 * is not fatal, we just work based on the NT ACL only */
511 if (ret == 0) {
512 status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
513 if (!NT_STATUS_IS_OK(status)) {
514 TALLOC_FREE(frame);
515 return status;
516 }
517
518 if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
519 XATTR_SD_HASH_SIZE) == 0) {
520 /* Hash matches, return blob sd. */
521 DEBUG(10, ("get_nt_acl_internal: blob hash "
522 "matches for file %s\n",
523 name ));
524 goto out;
525 }
526 }
527
528 /* Otherwise, fall though and see if the NT ACL hash matches */
529 }
530 case 3:
531 status = hash_sd_sha256(pdesc_next, hash_tmp);
532 if (!NT_STATUS_IS_OK(status)) {
533 TALLOC_FREE(psd);
534 psd = pdesc_next;
535 goto out;
536 }
537
538 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
539 /* Hash matches, return blob sd. */
540 DEBUG(10, ("get_nt_acl_internal: blob hash "
541 "matches for file %s\n",
542 name ));
543 goto out;
544 }
545
546 /* Hash doesn't match, return underlying sd. */
547 DEBUG(10, ("get_nt_acl_internal: blob hash "
548 "does not match for file %s - returning "
549 "file system SD mapping.\n",
550 name ));
551
552 if (DEBUGLEVEL >= 10) {
553 DEBUG(10,("get_nt_acl_internal: acl for blob hash for %s is:\n",
554 name ));
555 NDR_PRINT_DEBUG(security_descriptor, pdesc_next);
556 }
557
558 TALLOC_FREE(psd);
559 psd = pdesc_next;
560 }
561 out:
562
563 if (psd != pdesc_next) {
564 /* We're returning the blob, throw
565 * away the filesystem SD. */
566 TALLOC_FREE(pdesc_next);
567 } else {
568 SMB_STRUCT_STAT sbuf;
569 SMB_STRUCT_STAT *psbuf = &sbuf;
570 bool is_directory = false;
571 /*
572 * We're returning the underlying ACL from the
573 * filesystem. If it's a directory, and has no
574 * inheritable ACE entries we have to fake them.
575 */
576 if (fsp) {
577 status = vfs_stat_fsp(fsp);
578 if (!NT_STATUS_IS_OK(status)) {
579 TALLOC_FREE(frame);
580 return status;
581 }
582 psbuf = &fsp->fsp_name->st;
583 } else {
584 int ret = vfs_stat_smb_fname(handle->conn,
585 name,
586 &sbuf);
587 if (ret == -1) {
588 TALLOC_FREE(frame);
589 return map_nt_error_from_unix(errno);
590 }
591 }
592 is_directory = S_ISDIR(psbuf->st_ex_mode);
593
594 if (ignore_file_system_acl) {
595 TALLOC_FREE(pdesc_next);
596 status = make_default_filesystem_acl(mem_ctx,
597 name,
598 psbuf,
599 &psd);
600 if (!NT_STATUS_IS_OK(status)) {
601 TALLOC_FREE(frame);
602 return status;
603 }
604 } else {
605 if (is_directory &&
606 !sd_has_inheritable_components(psd,
607 true)) {
608 status = add_directory_inheritable_components(
609 handle,
610 name,
611 psbuf,
612 psd);
613 if (!NT_STATUS_IS_OK(status)) {
614 TALLOC_FREE(frame);
615 return status;
616 }
617 }
618 /* The underlying POSIX module always sets
619 the ~SEC_DESC_DACL_PROTECTED bit, as ACLs
620 can't be inherited in this way under POSIX.
621 Remove it for Windows-style ACLs. */
622 psd->type &= ~SEC_DESC_DACL_PROTECTED;
623 }
624 }
625
626 if (!(security_info & SECINFO_OWNER)) {
627 psd->owner_sid = NULL;
628 }
629 if (!(security_info & SECINFO_GROUP)) {
630 psd->group_sid = NULL;
631 }
632 if (!(security_info & SECINFO_DACL)) {
633 psd->type &= ~SEC_DESC_DACL_PRESENT;
634 psd->dacl = NULL;
635 }
636 if (!(security_info & SECINFO_SACL)) {
637 psd->type &= ~SEC_DESC_SACL_PRESENT;
638 psd->sacl = NULL;
639 }
640
641 TALLOC_FREE(blob.data);
642
643 if (DEBUGLEVEL >= 10) {
644 DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
645 name ));
646 NDR_PRINT_DEBUG(security_descriptor, psd);
647 }
648
649 /* The VFS API is that the ACL is expected to be on mem_ctx */
650 *ppdesc = talloc_move(mem_ctx, &psd);
651
652 TALLOC_FREE(frame);
653 return NT_STATUS_OK;
654 }
655
656 /*********************************************************************
657 Fetch a security descriptor given an fsp.
658 *********************************************************************/
659
660 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
661 files_struct *fsp,
662 uint32_t security_info,
663 TALLOC_CTX *mem_ctx,
664 struct security_descriptor **ppdesc)
665 {
666 return get_nt_acl_internal(handle, fsp,
667 NULL, security_info, mem_ctx, ppdesc);
668 }
669
670 /*********************************************************************
671 Fetch a security descriptor given a pathname.
672 *********************************************************************/
673
674 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
675 const char *name,
676 uint32_t security_info,
677 TALLOC_CTX *mem_ctx,
678 struct security_descriptor **ppdesc)
679 {
680 return get_nt_acl_internal(handle, NULL,
681 name, security_info, mem_ctx, ppdesc);
682 }
683
684 /*********************************************************************
685 Store a security descriptor given an fsp.
686 *********************************************************************/
687
688 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
689 uint32_t security_info_sent, const struct security_descriptor *orig_psd)
690 {
691 NTSTATUS status;
692 int ret;
693 DATA_BLOB blob, sys_acl_blob;
694 struct security_descriptor *pdesc_next = NULL;
695 struct security_descriptor *psd = NULL;
696 uint8_t hash[XATTR_SD_HASH_SIZE];
697 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
698 bool chown_needed = false;
699 char *sys_acl_description;
700 TALLOC_CTX *frame = talloc_stackframe();
701
702 if (DEBUGLEVEL >= 10) {
703 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
704 fsp_str_dbg(fsp)));
705 NDR_PRINT_DEBUG(security_descriptor,
706 discard_const_p(struct security_descriptor, orig_psd));
707 }
708
709 status = get_nt_acl_internal(handle, fsp,
710 NULL,
711 SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
712 frame,
713 &psd);
714
715 if (!NT_STATUS_IS_OK(status)) {
716 TALLOC_FREE(frame);
717 return status;
718 }
719
720 psd->revision = orig_psd->revision;
721 /* All our SD's are self relative. */
722 psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
723
724 if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
725 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
726 /* We're changing the owner. */
727 chown_needed = true;
728 }
729 psd->owner_sid = orig_psd->owner_sid;
730 }
731 if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
732 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
733 /* We're changing the group. */
734 chown_needed = true;
735 }
736 psd->group_sid = orig_psd->group_sid;
737 }
738 if (security_info_sent & SECINFO_DACL) {
739 psd->dacl = orig_psd->dacl;
740 psd->type |= SEC_DESC_DACL_PRESENT;
741 }
742 if (security_info_sent & SECINFO_SACL) {
743 psd->sacl = orig_psd->sacl;
744 psd->type |= SEC_DESC_SACL_PRESENT;
745 }
746
747 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
748 if (!NT_STATUS_IS_OK(status)) {
749 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
750 TALLOC_FREE(frame);
751 return status;
752 }
753 /* We got access denied here. If we're already root,
754 or we didn't need to do a chown, or the fsp isn't
755 open with WRITE_OWNER access, just return. */
756 if (get_current_uid(handle->conn) == 0 ||
757 chown_needed == false ||
758 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
759 TALLOC_FREE(frame);
760 return NT_STATUS_ACCESS_DENIED;
761 }
762
763 DEBUG(10,("fset_nt_acl_common: overriding chown on file %s "
764 "for sid %s\n",
765 fsp_str_dbg(fsp),
766 sid_string_tos(psd->owner_sid)
767 ));
768
769 /* Ok, we failed to chown and we have
770 SEC_STD_WRITE_OWNER access - override. */
771 become_root();
772 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp,
773 security_info_sent, psd);
774 unbecome_root();
775 if (!NT_STATUS_IS_OK(status)) {
776 TALLOC_FREE(frame);
777 return status;
778 }
779 }
780
781 /* Get the full underlying sd, then hash. */
782 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
783 fsp,
784 HASH_SECURITY_INFO,
785 frame,
786 &pdesc_next);
787
788 if (!NT_STATUS_IS_OK(status)) {
789 TALLOC_FREE(frame);
790 return status;
791 }
792
793 status = hash_sd_sha256(pdesc_next, hash);
794 if (!NT_STATUS_IS_OK(status)) {
795 TALLOC_FREE(frame);
796 return status;
797 }
798
799 /* Get the full underlying sd, then hash. */
800 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
801 fsp,
802 frame,
803 &sys_acl_description,
804 &sys_acl_blob);
805
806 /* If we fail to get the ACL blob (for some reason) then this
807 * is not fatal, we just work based on the NT ACL only */
808 if (ret != 0) {
809 if (DEBUGLEVEL >= 10) {
810 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
811 fsp_str_dbg(fsp)));
812 NDR_PRINT_DEBUG(security_descriptor,
813 discard_const_p(struct security_descriptor, psd));
814
815 DEBUG(10,("fset_nt_acl_xattr: storing has in xattr sd based on \n"));
816 NDR_PRINT_DEBUG(security_descriptor,
817 discard_const_p(struct security_descriptor, pdesc_next));
818 }
819 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
820 if (!NT_STATUS_IS_OK(status)) {
821 DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
822 TALLOC_FREE(frame);
823 return status;
824 }
825
826 status = store_acl_blob_fsp(handle, fsp, &blob);
827
828 TALLOC_FREE(frame);
829 return status;
830 }
831
832 status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
833 if (!NT_STATUS_IS_OK(status)) {
834 TALLOC_FREE(frame);
835 return status;
836 }
837
838 if (DEBUGLEVEL >= 10) {
839 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s based on system ACL\n",
840 fsp_str_dbg(fsp)));
841 NDR_PRINT_DEBUG(security_descriptor,
842 discard_const_p(struct security_descriptor, psd));
843
844 DEBUG(10,("fset_nt_acl_xattr: storing hash in xattr sd based on system ACL and:\n"));
845 NDR_PRINT_DEBUG(security_descriptor,
846 discard_const_p(struct security_descriptor, pdesc_next));
847 }
848
849 /* We store hashes of both the sys ACL blob and the NT
850 * security desciptor mapped from that ACL so as to improve
851 * our chances against some inadvertant change breaking the
852 * hash used */
853 status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
854 sys_acl_description, sys_acl_hash);
855 if (!NT_STATUS_IS_OK(status)) {
856 DEBUG(10, ("fset_nt_acl_xattr: create_sys_acl_blob failed\n"));
857 TALLOC_FREE(frame);
858 return status;
859 }
860
861 status = store_acl_blob_fsp(handle, fsp, &blob);
862
863 TALLOC_FREE(frame);
864 return status;
865 }
866
867 static int acl_common_remove_object(vfs_handle_struct *handle,
868 const char *path,
869 bool is_directory)
870 {
871 connection_struct *conn = handle->conn;
872 struct file_id id;
873 files_struct *fsp = NULL;
874 int ret = 0;
875 char *parent_dir = NULL;
876 const char *final_component = NULL;
877 struct smb_filename local_fname;
878 int saved_errno = 0;
879 char *saved_dir = NULL;
880
881 saved_dir = vfs_GetWd(talloc_tos(),conn);
882 if (!saved_dir) {
883 saved_errno = errno;
884 goto out;
885 }
886
887 if (!parent_dirname(talloc_tos(), path,
888 &parent_dir, &final_component)) {
889 saved_errno = ENOMEM;
890 goto out;
891 }
892
893 DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
894 is_directory ? "directory" : "file",
895 parent_dir, final_component ));
896
897 /* cd into the parent dir to pin it. */
898 ret = vfs_ChDir(conn, parent_dir);
899 if (ret == -1) {
900 saved_errno = errno;
901 goto out;
902 }
903
904 ZERO_STRUCT(local_fname);
905 local_fname.base_name = discard_const_p(char, final_component);
906
907 /* Must use lstat here. */
908 ret = SMB_VFS_LSTAT(conn, &local_fname);
909 if (ret == -1) {
910 saved_errno = errno;
911 goto out;
912 }
913
914 /* Ensure we have this file open with DELETE access. */
915 id = vfs_file_id_from_sbuf(conn, &local_fname.st);
916 for (fsp = file_find_di_first(conn->sconn, id); fsp;
917 fsp = file_find_di_next(fsp)) {
918 if (fsp->access_mask & DELETE_ACCESS &&
919 fsp->delete_on_close) {
920 /* We did open this for delete,
921 * allow the delete as root.
922 */
923 break;
924 }
925 }
926
927 if (!fsp) {
928 DEBUG(10,("acl_common_remove_object: %s %s/%s "
929 "not an open file\n",
930 is_directory ? "directory" : "file",
931 parent_dir, final_component ));
932 saved_errno = EACCES;
933 goto out;
934 }
935
936 become_root();
937 if (is_directory) {
938 ret = SMB_VFS_NEXT_RMDIR(handle, final_component);
939 } else {
940 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
941 }
942 unbecome_root();
943
944 if (ret == -1) {
945 saved_errno = errno;
946 }
947
948 out:
949
950 TALLOC_FREE(parent_dir);
951
952 if (saved_dir) {
953 vfs_ChDir(conn, saved_dir);
954 }
955 if (saved_errno) {
956 errno = saved_errno;
957 }
958 return ret;
959 }
960
961 static int rmdir_acl_common(struct vfs_handle_struct *handle,
962 const char *path)
963 {
964 int ret;
965
966 /* Try the normal rmdir first. */
967 ret = SMB_VFS_NEXT_RMDIR(handle, path);
968 if (ret == 0) {
969 return 0;
970 }
971 if (errno == EACCES || errno == EPERM) {
972 /* Failed due to access denied,
973 see if we need to root override. */
974 return acl_common_remove_object(handle,
975 path,
976 true);
977 }
978
979 DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
980 path,
981 strerror(errno) ));
982 return -1;
983 }
984
985 static int unlink_acl_common(struct vfs_handle_struct *handle,
986 const struct smb_filename *smb_fname)
987 {
988 int ret;
989
990 /* Try the normal unlink first. */
991 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
992 if (ret == 0) {
993 return 0;
994 }
995 if (errno == EACCES || errno == EPERM) {
996 /* Failed due to access denied,
997 see if we need to root override. */
998
999 /* Don't do anything fancy for streams. */
1000 if (smb_fname->stream_name) {
1001 return -1;
1002 }
1003 return acl_common_remove_object(handle,
1004 smb_fname->base_name,
1005 false);
1006 }
1007
1008 DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
1009 smb_fname->base_name,
1010 strerror(errno) ));
1011 return -1;
1012 }
1013
1014 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1015 const char *path, mode_t mode)
1016 {
1017 if (lp_posix_pathnames()) {
1018 /* Only allow this on POSIX pathnames. */
1019 return SMB_VFS_NEXT_CHMOD(handle, path, mode);
1020 }
1021 return 0;
1022 }
1023
1024 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1025 struct files_struct *fsp, mode_t mode)
1026 {
1027 if (fsp->posix_open) {
1028 /* Only allow this on POSIX opens. */
1029 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1030 }
1031 return 0;
1032 }
1033
1034 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1035 const char *name, mode_t mode)
1036 {
1037 if (lp_posix_pathnames()) {
1038 /* Only allow this on POSIX pathnames. */
1039 return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
1040 }
1041 return 0;
1042 }
1043
1044 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1045 struct files_struct *fsp, mode_t mode)
1046 {
1047 if (fsp->posix_open) {
1048 /* Only allow this on POSIX opens. */
1049 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1050 }
1051 return 0;
1052 }
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