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vfs_io_uring: move error handling out of vfs_io_uring_pread_recv()
[Samba.git] / source3 / modules / vfs_acl_common.c
blob35dc82ee11d6e6dad57011e4ba9d69451ee50cae
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 * Copyright (C) Ralph Böhme, 2016
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 3 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "vfs_acl_common.h"
25 #include "smbd/smbd.h"
26 #include "system/filesys.h"
27 #include "librpc/gen_ndr/ndr_xattr.h"
28 #include "../libcli/security/security.h"
29 #include "../librpc/gen_ndr/ndr_security.h"
30 #include "../lib/util/bitmap.h"
31 #include "passdb/lookup_sid.h"
32
33 #include <gnutls/gnutls.h>
34 #include <gnutls/crypto.h>
35
36 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
37 DATA_BLOB *pblob,
38 uint16_t hash_type,
39 uint8_t hash[XATTR_SD_HASH_SIZE]);
40
41 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
42 SECINFO_GROUP | \
43 SECINFO_DACL | \
44 SECINFO_SACL)
45
46 bool init_acl_common_config(vfs_handle_struct *handle,
47 const char *module_name)
48 {
49 struct acl_common_config *config = NULL;
50 const struct enum_list *default_acl_style_list = NULL;
51
52 default_acl_style_list = get_default_acl_style_list();
53
54 config = talloc_zero(handle->conn, struct acl_common_config);
55 if (config == NULL) {
56 DBG_ERR("talloc_zero() failed\n");
57 errno = ENOMEM;
58 return false;
59 }
60
61 config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn),
62 module_name,
63 "ignore system acls",
64 false);
65 config->default_acl_style = lp_parm_enum(SNUM(handle->conn),
66 module_name,
67 "default acl style",
68 default_acl_style_list,
69 DEFAULT_ACL_POSIX);
70
71 SMB_VFS_HANDLE_SET_DATA(handle, config, NULL,
72 struct acl_common_config,
73 return false);
74
75 return true;
76 }
77
78
79 /*******************************************************************
80 Hash a security descriptor.
81 *******************************************************************/
82
83 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
84 uint8_t *hash)
85 {
86 int rc;
87
88 ZERO_ARRAY_LEN(hash, XATTR_SD_HASH_SIZE);
89
90 rc = gnutls_hash_fast(GNUTLS_DIG_SHA256,
91 blob.data,
92 blob.length,
93 hash);
94 if (rc < 0) {
95 return NT_STATUS_INTERNAL_ERROR;
96 }
97
98 return NT_STATUS_OK;
99 }
100
101 /*******************************************************************
102 Hash a security descriptor.
103 *******************************************************************/
104
105 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
106 uint8_t *hash)
107 {
108 DATA_BLOB blob;
109 NTSTATUS status;
110
111 memset(hash, '\0', XATTR_SD_HASH_SIZE);
112 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
113 if (!NT_STATUS_IS_OK(status)) {
114 return status;
115 }
116 return hash_blob_sha256(blob, hash);
117 }
118
119 /*******************************************************************
120 Parse out a struct security_descriptor from a DATA_BLOB.
121 *******************************************************************/
122
123 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
124 TALLOC_CTX *mem_ctx,
125 struct security_descriptor **ppdesc,
126 uint16_t *p_hash_type,
127 uint16_t *p_version,
128 uint8_t hash[XATTR_SD_HASH_SIZE],
129 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
130 {
131 struct xattr_NTACL xacl;
132 enum ndr_err_code ndr_err;
133 size_t sd_size;
134 TALLOC_CTX *frame = talloc_stackframe();
135
136 ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
137 (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
138
139 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
140 DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n",
141 ndr_errstr(ndr_err));
142 TALLOC_FREE(frame);
143 return ndr_map_error2ntstatus(ndr_err);
144 }
145
146 *p_version = xacl.version;
147
148 switch (xacl.version) {
149 case 1:
150 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
151 xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
152 xacl.info.sd->owner_sid,
153 xacl.info.sd->group_sid,
154 xacl.info.sd->sacl,
155 xacl.info.sd->dacl,
156 &sd_size);
157 /* No hash - null out. */
158 *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
159 memset(hash, '\0', XATTR_SD_HASH_SIZE);
160 break;
161 case 2:
162 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
163 xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
164 xacl.info.sd_hs2->sd->owner_sid,
165 xacl.info.sd_hs2->sd->group_sid,
166 xacl.info.sd_hs2->sd->sacl,
167 xacl.info.sd_hs2->sd->dacl,
168 &sd_size);
169 /* No hash - null out. */
170 *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
171 memset(hash, '\0', XATTR_SD_HASH_SIZE);
172 break;
173 case 3:
174 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
175 xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
176 xacl.info.sd_hs3->sd->owner_sid,
177 xacl.info.sd_hs3->sd->group_sid,
178 xacl.info.sd_hs3->sd->sacl,
179 xacl.info.sd_hs3->sd->dacl,
180 &sd_size);
181 *p_hash_type = xacl.info.sd_hs3->hash_type;
182 /* Current version 3 (if no sys acl hash available). */
183 memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
184 break;
185 case 4:
186 *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
187 xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
188 xacl.info.sd_hs4->sd->owner_sid,
189 xacl.info.sd_hs4->sd->group_sid,
190 xacl.info.sd_hs4->sd->sacl,
191 xacl.info.sd_hs4->sd->dacl,
192 &sd_size);
193 *p_hash_type = xacl.info.sd_hs4->hash_type;
194 /* Current version 4. */
195 memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
196 memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
197 break;
198 default:
199 TALLOC_FREE(frame);
200 return NT_STATUS_REVISION_MISMATCH;
201 }
202
203 TALLOC_FREE(frame);
204
205 return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
206 }
207
208 /*******************************************************************
209 Create a DATA_BLOB from a hash of the security descriptor storead at
210 the system layer and the NT ACL we wish to preserve
211 *******************************************************************/
212
213 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
214 DATA_BLOB *pblob,
215 uint16_t hash_type,
216 uint8_t hash[XATTR_SD_HASH_SIZE])
217 {
218 struct xattr_NTACL xacl;
219 struct security_descriptor_hash_v3 sd_hs3;
220 enum ndr_err_code ndr_err;
221 TALLOC_CTX *ctx = talloc_tos();
222
223 ZERO_STRUCT(xacl);
224 ZERO_STRUCT(sd_hs3);
225
226 xacl.version = 3;
227 xacl.info.sd_hs3 = &sd_hs3;
228 xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
229 xacl.info.sd_hs3->hash_type = hash_type;
230 memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
231
232 ndr_err = ndr_push_struct_blob(
233 pblob, ctx, &xacl,
234 (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
235
236 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
237 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
238 ndr_errstr(ndr_err));
239 return ndr_map_error2ntstatus(ndr_err);
240 }
241
242 return NT_STATUS_OK;
243 }
244
245 /*******************************************************************
246 Create a DATA_BLOB from a hash of the security descriptors
247 (system and NT) stored at the system layer and the NT ACL we wish
248 to preserve.
249 *******************************************************************/
250
251 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
252 DATA_BLOB *pblob,
253 uint16_t hash_type,
254 uint8_t hash[XATTR_SD_HASH_SIZE],
255 const char *description,
256 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
257 {
258 struct xattr_NTACL xacl;
259 struct security_descriptor_hash_v4 sd_hs4;
260 enum ndr_err_code ndr_err;
261 TALLOC_CTX *ctx = talloc_tos();
262 NTTIME nttime_now;
263 struct timeval now = timeval_current();
264 nttime_now = timeval_to_nttime(&now);
265
266 ZERO_STRUCT(xacl);
267 ZERO_STRUCT(sd_hs4);
268
269 xacl.version = 4;
270 xacl.info.sd_hs4 = &sd_hs4;
271 xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
272 xacl.info.sd_hs4->hash_type = hash_type;
273 memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
274 xacl.info.sd_hs4->description = description;
275 xacl.info.sd_hs4->time = nttime_now;
276 memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
277
278 ndr_err = ndr_push_struct_blob(
279 pblob, ctx, &xacl,
280 (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
281
282 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
283 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
284 ndr_errstr(ndr_err));
285 return ndr_map_error2ntstatus(ndr_err);
286 }
287
288 return NT_STATUS_OK;
289 }
290
291 /*******************************************************************
292 Add in 3 inheritable components for a non-inheritable directory ACL.
293 CREATOR_OWNER/CREATOR_GROUP/WORLD.
294 *******************************************************************/
295
296 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
297 const char *name,
298 SMB_STRUCT_STAT *psbuf,
299 struct security_descriptor *psd)
300 {
301 struct connection_struct *conn = handle->conn;
302 int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
303 struct smb_filename smb_fname;
304 enum security_ace_type acltype;
305 uint32_t access_mask;
306 mode_t dir_mode;
307 mode_t file_mode;
308 mode_t mode;
309 struct security_ace *new_ace_list;
310
311 if (psd->dacl) {
312 new_ace_list = talloc_zero_array(psd->dacl,
313 struct security_ace,
314 num_aces + 3);
315 } else {
316 /*
317 * make_sec_acl() at the bottom of this function
318 * dupliates new_ace_list
319 */
320 new_ace_list = talloc_zero_array(talloc_tos(),
321 struct security_ace,
322 num_aces + 3);
323 }
324
325 if (new_ace_list == NULL) {
326 return NT_STATUS_NO_MEMORY;
327 }
328
329 /* Fake a quick smb_filename. */
330 ZERO_STRUCT(smb_fname);
331 smb_fname.st = *psbuf;
332 smb_fname.base_name = discard_const_p(char, name);
333
334 dir_mode = unix_mode(conn,
335 FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
336 file_mode = unix_mode(conn,
337 FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
338
339 mode = dir_mode | file_mode;
340
341 DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode);
342
343 if (num_aces) {
344 memcpy(new_ace_list, psd->dacl->aces,
345 num_aces * sizeof(struct security_ace));
346 }
347 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
348 mode & 0700, false);
349
350 init_sec_ace(&new_ace_list[num_aces],
351 &global_sid_Creator_Owner,
352 acltype,
353 access_mask,
354 SEC_ACE_FLAG_CONTAINER_INHERIT|
355 SEC_ACE_FLAG_OBJECT_INHERIT|
356 SEC_ACE_FLAG_INHERIT_ONLY);
357 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
358 (mode << 3) & 0700, false);
359 init_sec_ace(&new_ace_list[num_aces+1],
360 &global_sid_Creator_Group,
361 acltype,
362 access_mask,
363 SEC_ACE_FLAG_CONTAINER_INHERIT|
364 SEC_ACE_FLAG_OBJECT_INHERIT|
365 SEC_ACE_FLAG_INHERIT_ONLY);
366 access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
367 (mode << 6) & 0700, false);
368 init_sec_ace(&new_ace_list[num_aces+2],
369 &global_sid_World,
370 acltype,
371 access_mask,
372 SEC_ACE_FLAG_CONTAINER_INHERIT|
373 SEC_ACE_FLAG_OBJECT_INHERIT|
374 SEC_ACE_FLAG_INHERIT_ONLY);
375 if (psd->dacl) {
376 psd->dacl->aces = new_ace_list;
377 psd->dacl->num_aces += 3;
378 psd->dacl->size += new_ace_list[num_aces].size +
379 new_ace_list[num_aces+1].size +
380 new_ace_list[num_aces+2].size;
381 } else {
382 psd->dacl = make_sec_acl(psd,
383 NT4_ACL_REVISION,
384 3,
385 new_ace_list);
386 if (psd->dacl == NULL) {
387 return NT_STATUS_NO_MEMORY;
388 }
389 }
390 return NT_STATUS_OK;
391 }
392
393 /**
394 * Validate an ACL blob
395 *
396 * This validates an ACL blob against the underlying filesystem ACL. If this
397 * function returns NT_STATUS_OK ppsd can be
398 *
399 * 1. the ACL from the blob (psd_from_fs=false), or
400 * 2. the ACL from the fs (psd_from_fs=true), or
401 * 3. NULL (!)
402 *
403 * If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL
404 * and psd_from_fs set to false.
405 *
406 * Returning the underlying filesystem ACL in case no. 2 is really just an
407 * optimisation, because some validations have to fetch the filesytem ACL as
408 * part of the validation, so we already have it available and callers might
409 * need it as well.
410 **/
411 static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx,
412 vfs_handle_struct *handle,
413 files_struct *fsp,
414 const struct smb_filename *smb_fname,
415 const DATA_BLOB *blob,
416 struct security_descriptor **ppsd,
417 bool *psd_is_from_fs)
418 {
419 NTSTATUS status;
420 uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
421 uint16_t xattr_version = 0;
422 uint8_t hash[XATTR_SD_HASH_SIZE];
423 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
424 uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
425 uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
426 struct security_descriptor *psd = NULL;
427 struct security_descriptor *psd_blob = NULL;
428 struct security_descriptor *psd_fs = NULL;
429 char *sys_acl_blob_description = NULL;
430 DATA_BLOB sys_acl_blob = { 0 };
431 struct acl_common_config *config = NULL;
432
433 *ppsd = NULL;
434 *psd_is_from_fs = false;
435
436 SMB_VFS_HANDLE_GET_DATA(handle, config,
437 struct acl_common_config,
438 return NT_STATUS_UNSUCCESSFUL);
439
440 status = parse_acl_blob(blob,
441 mem_ctx,
442 &psd_blob,
443 &hash_type,
444 &xattr_version,
445 &hash[0],
446 &sys_acl_hash[0]);
447 if (!NT_STATUS_IS_OK(status)) {
448 DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status));
449 goto fail;
450 }
451
452 /* determine which type of xattr we got */
453 switch (xattr_version) {
454 case 1:
455 case 2:
456 /* These xattr types are unilatteral, they do not
457 * require confirmation of the hash. In particular,
458 * the NTVFS file server uses version 1, but
459 * 'samba-tool ntacl' can set these as well */
460 *ppsd = psd_blob;
461 return NT_STATUS_OK;
462 case 3:
463 case 4:
464 if (config->ignore_system_acls) {
465 *ppsd = psd_blob;
466 return NT_STATUS_OK;
467 }
468
469 break;
470 default:
471 DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n",
472 (unsigned int)hash_type, smb_fname->base_name);
473 TALLOC_FREE(psd_blob);
474 return NT_STATUS_OK;
475 }
476
477 /* determine which type of xattr we got */
478 if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
479 DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n",
480 (unsigned int)hash_type, smb_fname->base_name);
481 TALLOC_FREE(psd_blob);
482 return NT_STATUS_OK;
483 }
484
485 /* determine which type of xattr we got */
486 switch (xattr_version) {
487 case 4:
488 {
489 int ret;
490 if (fsp) {
491 /* Get the full underlying sd, then hash. */
492 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
493 fsp,
494 mem_ctx,
495 &sys_acl_blob_description,
496 &sys_acl_blob);
497 } else {
498 /* Get the full underlying sd, then hash. */
499 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
500 smb_fname,
501 mem_ctx,
502 &sys_acl_blob_description,
503 &sys_acl_blob);
504 }
505
506 /* If we fail to get the ACL blob (for some reason) then this
507 * is not fatal, we just work based on the NT ACL only */
508 if (ret == 0) {
509 status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
510 if (!NT_STATUS_IS_OK(status)) {
511 goto fail;
512 }
513
514 TALLOC_FREE(sys_acl_blob_description);
515 TALLOC_FREE(sys_acl_blob.data);
516
517 if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
518 XATTR_SD_HASH_SIZE) == 0) {
519 /* Hash matches, return blob sd. */
520 DBG_DEBUG("blob hash matches for file %s\n",
521 smb_fname->base_name);
522 *ppsd = psd_blob;
523 return NT_STATUS_OK;
524 }
525 }
526
527 /* Otherwise, fall though and see if the NT ACL hash matches */
528 FALL_THROUGH;
529 }
530 case 3:
531 /* Get the full underlying sd for the hash
532 or to return as backup. */
533 if (fsp) {
534 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
535 fsp,
536 HASH_SECURITY_INFO,
537 mem_ctx,
538 &psd_fs);
539 } else {
540 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
541 smb_fname,
542 HASH_SECURITY_INFO,
543 mem_ctx,
544 &psd_fs);
545 }
546
547 if (!NT_STATUS_IS_OK(status)) {
548 DBG_DEBUG("get_next_acl for file %s returned %s\n",
549 smb_fname->base_name, nt_errstr(status));
550 goto fail;
551 }
552
553 status = hash_sd_sha256(psd_fs, hash_tmp);
554 if (!NT_STATUS_IS_OK(status)) {
555 TALLOC_FREE(psd_blob);
556 *ppsd = psd_fs;
557 *psd_is_from_fs = true;
558 return NT_STATUS_OK;
559 }
560
561 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
562 /* Hash matches, return blob sd. */
563 DBG_DEBUG("blob hash matches for file %s\n",
564 smb_fname->base_name);
565 *ppsd = psd_blob;
566 return NT_STATUS_OK;
567 }
568
569 /* Hash doesn't match, return underlying sd. */
570 DBG_DEBUG("blob hash does not match for file %s - returning "
571 "file system SD mapping.\n",
572 smb_fname->base_name);
573
574 if (DEBUGLEVEL >= 10) {
575 DBG_DEBUG("acl for blob hash for %s is:\n",
576 smb_fname->base_name);
577 NDR_PRINT_DEBUG(security_descriptor, psd_fs);
578 }
579
580 TALLOC_FREE(psd_blob);
581 *ppsd = psd_fs;
582 *psd_is_from_fs = true;
583 }
584
585 return NT_STATUS_OK;
586
587 fail:
588 TALLOC_FREE(psd);
589 TALLOC_FREE(psd_blob);
590 TALLOC_FREE(psd_fs);
591 TALLOC_FREE(sys_acl_blob_description);
592 TALLOC_FREE(sys_acl_blob.data);
593 return status;
594 }
595
596 static NTSTATUS stat_fsp_or_smb_fname(vfs_handle_struct *handle,
597 files_struct *fsp,
598 const struct smb_filename *smb_fname,
599 SMB_STRUCT_STAT *sbuf,
600 SMB_STRUCT_STAT **psbuf)
601 {
602 NTSTATUS status;
603 int ret;
604
605 if (fsp) {
606 status = vfs_stat_fsp(fsp);
607 if (!NT_STATUS_IS_OK(status)) {
608 return status;
609 }
610 *psbuf = &fsp->fsp_name->st;
611 } else {
612 /*
613 * https://bugzilla.samba.org/show_bug.cgi?id=11249
614 *
615 * We are currently guaranteed that 'name' here is a
616 * smb_fname->base_name, which *cannot* contain a stream name
617 * (':'). vfs_stat_smb_fname() splits a name into a base name +
618 * stream name, which when we get here we know we've already
619 * done. So we have to call the stat or lstat VFS calls
620 * directly here. Else, a base_name that contains a ':' (from a
621 * demangled name) will get split again.
622 *
623 * FIXME.
624 * This uglyness will go away once smb_fname is fully plumbed
625 * through the VFS.
626 */
627 ret = vfs_stat_smb_basename(handle->conn,
628 smb_fname,
629 sbuf);
630 if (ret == -1) {
631 return map_nt_error_from_unix(errno);
632 }
633 }
634
635 return NT_STATUS_OK;
636 }
637
638 /*******************************************************************
639 Pull a DATA_BLOB from an xattr given a pathname.
640 If the hash doesn't match, or doesn't exist - return the underlying
641 filesystem sd.
642 *******************************************************************/
643
644 NTSTATUS get_nt_acl_common(
645 NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
646 vfs_handle_struct *handle,
647 files_struct *fsp,
648 const struct smb_filename *smb_fname,
649 DATA_BLOB *pblob),
650 vfs_handle_struct *handle,
651 files_struct *fsp,
652 const struct smb_filename *smb_fname_in,
653 uint32_t security_info,
654 TALLOC_CTX *mem_ctx,
655 struct security_descriptor **ppdesc)
656 {
657 DATA_BLOB blob = data_blob_null;
658 NTSTATUS status;
659 struct security_descriptor *psd = NULL;
660 const struct smb_filename *smb_fname = NULL;
661 bool psd_is_from_fs = false;
662 struct acl_common_config *config = NULL;
663
664 SMB_VFS_HANDLE_GET_DATA(handle, config,
665 struct acl_common_config,
666 return NT_STATUS_UNSUCCESSFUL);
667
668 if (fsp && smb_fname_in == NULL) {
669 smb_fname = fsp->fsp_name;
670 } else {
671 smb_fname = smb_fname_in;
672 }
673
674 DBG_DEBUG("name=%s\n", smb_fname->base_name);
675
676 status = get_acl_blob_fn(mem_ctx, handle, fsp, smb_fname, &blob);
677 if (NT_STATUS_IS_OK(status)) {
678 status = validate_nt_acl_blob(mem_ctx,
679 handle,
680 fsp,
681 smb_fname,
682 &blob,
683 &psd,
684 &psd_is_from_fs);
685 TALLOC_FREE(blob.data);
686 if (!NT_STATUS_IS_OK(status)) {
687 DBG_DEBUG("ACL validation for [%s] failed\n",
688 smb_fname->base_name);
689 goto fail;
690 }
691 }
692
693 if (psd == NULL) {
694 /* Get the full underlying sd, as we failed to get the
695 * blob for the hash, or the revision/hash type wasn't
696 * known */
697
698 if (config->ignore_system_acls) {
699 SMB_STRUCT_STAT sbuf;
700 SMB_STRUCT_STAT *psbuf = &sbuf;
701
702 status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
703 &sbuf, &psbuf);
704 if (!NT_STATUS_IS_OK(status)) {
705 goto fail;
706 }
707
708 status = make_default_filesystem_acl(
709 mem_ctx,
710 config->default_acl_style,
711 smb_fname->base_name,
712 psbuf,
713 &psd);
714 if (!NT_STATUS_IS_OK(status)) {
715 goto fail;
716 }
717 } else {
718 if (fsp) {
719 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
720 fsp,
721 security_info,
722 mem_ctx,
723 &psd);
724 } else {
725 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
726 smb_fname,
727 security_info,
728 mem_ctx,
729 &psd);
730 }
731
732 if (!NT_STATUS_IS_OK(status)) {
733 DBG_DEBUG("get_next_acl for file %s "
734 "returned %s\n",
735 smb_fname->base_name,
736 nt_errstr(status));
737 goto fail;
738 }
739
740 psd_is_from_fs = true;
741 }
742 }
743
744 if (psd_is_from_fs) {
745 SMB_STRUCT_STAT sbuf;
746 SMB_STRUCT_STAT *psbuf = &sbuf;
747 bool is_directory = false;
748
749 /*
750 * We're returning the underlying ACL from the
751 * filesystem. If it's a directory, and has no
752 * inheritable ACE entries we have to fake them.
753 */
754
755 status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
756 &sbuf, &psbuf);
757 if (!NT_STATUS_IS_OK(status)) {
758 goto fail;
759 }
760
761 is_directory = S_ISDIR(psbuf->st_ex_mode);
762
763 if (is_directory && !sd_has_inheritable_components(psd, true)) {
764 status = add_directory_inheritable_components(
765 handle,
766 smb_fname->base_name,
767 psbuf,
768 psd);
769 if (!NT_STATUS_IS_OK(status)) {
770 goto fail;
771 }
772 }
773
774 /*
775 * The underlying POSIX module always sets the
776 * ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in
777 * this way under POSIX. Remove it for Windows-style ACLs.
778 */
779 psd->type &= ~SEC_DESC_DACL_PROTECTED;
780 }
781
782 if (!(security_info & SECINFO_OWNER)) {
783 psd->owner_sid = NULL;
784 }
785 if (!(security_info & SECINFO_GROUP)) {
786 psd->group_sid = NULL;
787 }
788 if (!(security_info & SECINFO_DACL)) {
789 psd->type &= ~SEC_DESC_DACL_PRESENT;
790 psd->dacl = NULL;
791 }
792 if (!(security_info & SECINFO_SACL)) {
793 psd->type &= ~SEC_DESC_SACL_PRESENT;
794 psd->sacl = NULL;
795 }
796
797 if (DEBUGLEVEL >= 10) {
798 DBG_DEBUG("returning acl for %s is:\n",
799 smb_fname->base_name);
800 NDR_PRINT_DEBUG(security_descriptor, psd);
801 }
802
803 *ppdesc = psd;
804
805 return NT_STATUS_OK;
806
807 fail:
808 TALLOC_FREE(psd);
809 return status;
810 }
811
812 /*********************************************************************
813 Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc)
814 *********************************************************************/
815 static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp,
816 struct security_descriptor *psd,
817 uint32_t security_info_sent,
818 bool chown_needed)
819 {
820 NTSTATUS status;
821 const struct security_token *token = NULL;
822 struct dom_sid_buf buf;
823
824 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
825 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
826 return status;
827 }
828
829 /* We got access denied here. If we're already root,
830 or we didn't need to do a chown, or the fsp isn't
831 open with WRITE_OWNER access, just return. */
832 if (get_current_uid(handle->conn) == 0 || chown_needed == false ||
833 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
834 return NT_STATUS_ACCESS_DENIED;
835 }
836
837 /*
838 * Only allow take-ownership, not give-ownership. That's the way Windows
839 * implements SEC_STD_WRITE_OWNER. MS-FSA 2.1.5.16 just states: If
840 * InputBuffer.OwnerSid is not a valid owner SID for a file in the
841 * objectstore, as determined in an implementation specific manner, the
842 * object store MUST return STATUS_INVALID_OWNER.
843 */
844 token = get_current_nttok(fsp->conn);
845 if (!security_token_is_sid(token, psd->owner_sid)) {
846 return NT_STATUS_INVALID_OWNER;
847 }
848
849 DBG_DEBUG("overriding chown on file %s for sid %s\n",
850 fsp_str_dbg(fsp),
851 dom_sid_str_buf(psd->owner_sid, &buf));
852
853 /* Ok, we failed to chown and we have
854 SEC_STD_WRITE_OWNER access - override. */
855 become_root();
856 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
857 unbecome_root();
858
859 return status;
860 }
861
862 /*********************************************************************
863 Store a v3 security descriptor
864 *********************************************************************/
865 static NTSTATUS store_v3_blob(
866 NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
867 files_struct *fsp,
868 DATA_BLOB *pblob),
869 vfs_handle_struct *handle, files_struct *fsp,
870 struct security_descriptor *psd,
871 struct security_descriptor *pdesc_next,
872 uint8_t hash[XATTR_SD_HASH_SIZE])
873 {
874 NTSTATUS status;
875 DATA_BLOB blob;
876
877 if (DEBUGLEVEL >= 10) {
878 DBG_DEBUG("storing xattr sd for file %s\n",
879 fsp_str_dbg(fsp));
880 NDR_PRINT_DEBUG(
881 security_descriptor,
882 discard_const_p(struct security_descriptor, psd));
883
884 if (pdesc_next != NULL) {
885 DBG_DEBUG("storing xattr sd based on \n");
886 NDR_PRINT_DEBUG(
887 security_descriptor,
888 discard_const_p(struct security_descriptor,
889 pdesc_next));
890 } else {
891 DBG_DEBUG("ignoring underlying sd\n");
892 }
893 }
894 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
895 if (!NT_STATUS_IS_OK(status)) {
896 DBG_DEBUG("create_acl_blob failed\n");
897 return status;
898 }
899
900 status = store_acl_blob_fsp_fn(handle, fsp, &blob);
901 return status;
902 }
903
904 /*********************************************************************
905 Store a security descriptor given an fsp.
906 *********************************************************************/
907
908 NTSTATUS fset_nt_acl_common(
909 NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
910 vfs_handle_struct *handle,
911 files_struct *fsp,
912 const struct smb_filename *smb_fname,
913 DATA_BLOB *pblob),
914 NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
915 files_struct *fsp,
916 DATA_BLOB *pblob),
917 const char *module_name,
918 vfs_handle_struct *handle, files_struct *fsp,
919 uint32_t security_info_sent,
920 const struct security_descriptor *orig_psd)
921 {
922 NTSTATUS status;
923 int ret;
924 DATA_BLOB blob, sys_acl_blob;
925 struct security_descriptor *pdesc_next = NULL;
926 struct security_descriptor *psd = NULL;
927 uint8_t hash[XATTR_SD_HASH_SIZE];
928 uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
929 bool chown_needed = false;
930 char *sys_acl_description;
931 TALLOC_CTX *frame = talloc_stackframe();
932 bool ignore_file_system_acl = lp_parm_bool(
933 SNUM(handle->conn), module_name, "ignore system acls", false);
934
935 if (DEBUGLEVEL >= 10) {
936 DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp));
937 NDR_PRINT_DEBUG(security_descriptor,
938 discard_const_p(struct security_descriptor, orig_psd));
939 }
940
941 status = get_nt_acl_common(get_acl_blob_fn, handle, fsp,
942 NULL,
943 SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
944 frame,
945 &psd);
946
947 if (!NT_STATUS_IS_OK(status)) {
948 TALLOC_FREE(frame);
949 return status;
950 }
951
952 psd->revision = orig_psd->revision;
953 if (security_info_sent & SECINFO_DACL) {
954 psd->type = orig_psd->type;
955 /* All our SD's are self relative. */
956 psd->type |= SEC_DESC_SELF_RELATIVE;
957 }
958
959 if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
960 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
961 /* We're changing the owner. */
962 chown_needed = true;
963 }
964 psd->owner_sid = orig_psd->owner_sid;
965 }
966 if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
967 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
968 /* We're changing the group. */
969 chown_needed = true;
970 }
971 psd->group_sid = orig_psd->group_sid;
972 }
973 if (security_info_sent & SECINFO_DACL) {
974 if (security_descriptor_with_ms_nfs(orig_psd)) {
975 /*
976 * If the sd contains a MS NFS SID, do
977 * nothing, it's a chmod() request from OS X
978 * with AAPL context.
979 */
980 TALLOC_FREE(frame);
981 return NT_STATUS_OK;
982 }
983 psd->dacl = orig_psd->dacl;
984 psd->type |= SEC_DESC_DACL_PRESENT;
985 }
986 if (security_info_sent & SECINFO_SACL) {
987 psd->sacl = orig_psd->sacl;
988 psd->type |= SEC_DESC_SACL_PRESENT;
989 }
990
991 if (ignore_file_system_acl) {
992 if (chown_needed) {
993 /* send only ownership stuff to lower layer */
994 security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP);
995 status = set_underlying_acl(handle, fsp, psd,
996 security_info_sent, true);
997 if (!NT_STATUS_IS_OK(status)) {
998 TALLOC_FREE(frame);
999 return status;
1000 }
1001 }
1002 ZERO_ARRAY(hash);
1003 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
1004 NULL, hash);
1005
1006 TALLOC_FREE(frame);
1007 return status;
1008 }
1009
1010 status = set_underlying_acl(handle, fsp, psd, security_info_sent,
1011 chown_needed);
1012 if (!NT_STATUS_IS_OK(status)) {
1013 TALLOC_FREE(frame);
1014 return status;
1015 }
1016
1017 /* Get the full underlying sd, then hash. */
1018 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
1019 fsp,
1020 HASH_SECURITY_INFO,
1021 frame,
1022 &pdesc_next);
1023
1024 if (!NT_STATUS_IS_OK(status)) {
1025 TALLOC_FREE(frame);
1026 return status;
1027 }
1028
1029 status = hash_sd_sha256(pdesc_next, hash);
1030 if (!NT_STATUS_IS_OK(status)) {
1031 TALLOC_FREE(frame);
1032 return status;
1033 }
1034
1035 /* Get the full underlying sd, then hash. */
1036 ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
1037 fsp,
1038 frame,
1039 &sys_acl_description,
1040 &sys_acl_blob);
1041
1042 /* If we fail to get the ACL blob (for some reason) then this
1043 * is not fatal, we just work based on the NT ACL only */
1044 if (ret != 0) {
1045 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
1046 pdesc_next, hash);
1047
1048 TALLOC_FREE(frame);
1049 return status;
1050 }
1051
1052 status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
1053 if (!NT_STATUS_IS_OK(status)) {
1054 TALLOC_FREE(frame);
1055 return status;
1056 }
1057
1058 if (DEBUGLEVEL >= 10) {
1059 DBG_DEBUG("storing xattr sd for file %s based on system ACL\n",
1060 fsp_str_dbg(fsp));
1061 NDR_PRINT_DEBUG(security_descriptor,
1062 discard_const_p(struct security_descriptor, psd));
1063
1064 DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n");
1065 NDR_PRINT_DEBUG(security_descriptor,
1066 discard_const_p(struct security_descriptor, pdesc_next));
1067 }
1068
1069 /* We store hashes of both the sys ACL blob and the NT
1070 * security desciptor mapped from that ACL so as to improve
1071 * our chances against some inadvertant change breaking the
1072 * hash used */
1073 status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
1074 sys_acl_description, sys_acl_hash);
1075 if (!NT_STATUS_IS_OK(status)) {
1076 DBG_DEBUG("create_sys_acl_blob failed\n");
1077 TALLOC_FREE(frame);
1078 return status;
1079 }
1080
1081 status = store_acl_blob_fsp_fn(handle, fsp, &blob);
1082
1083 TALLOC_FREE(frame);
1084 return status;
1085 }
1086
1087 static int acl_common_remove_object(vfs_handle_struct *handle,
1088 const struct smb_filename *smb_fname,
1089 bool is_directory)
1090 {
1091 connection_struct *conn = handle->conn;
1092 struct file_id id;
1093 files_struct *fsp = NULL;
1094 int ret = 0;
1095 char *parent_dir = NULL;
1096 const char *final_component = NULL;
1097 struct smb_filename local_fname = {0};
1098 struct smb_filename parent_dir_fname = {0};
1099 int saved_errno = 0;
1100 struct smb_filename *saved_dir_fname = NULL;
1101
1102 saved_dir_fname = vfs_GetWd(talloc_tos(),conn);
1103 if (saved_dir_fname == NULL) {
1104 saved_errno = errno;
1105 goto out;
1106 }
1107
1108 if (!parent_dirname(talloc_tos(), smb_fname->base_name,
1109 &parent_dir, &final_component)) {
1110 saved_errno = ENOMEM;
1111 goto out;
1112 }
1113
1114 DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file",
1115 parent_dir, final_component);
1116
1117 parent_dir_fname = (struct smb_filename) { .base_name = parent_dir };
1118
1119 /* cd into the parent dir to pin it. */
1120 ret = vfs_ChDir(conn, &parent_dir_fname);
1121 if (ret == -1) {
1122 saved_errno = errno;
1123 goto out;
1124 }
1125
1126 local_fname.base_name = discard_const_p(char, final_component);
1127
1128 /* Must use lstat here. */
1129 ret = SMB_VFS_LSTAT(conn, &local_fname);
1130 if (ret == -1) {
1131 saved_errno = errno;
1132 goto out;
1133 }
1134
1135 /* Ensure we have this file open with DELETE access. */
1136 id = vfs_file_id_from_sbuf(conn, &local_fname.st);
1137 for (fsp = file_find_di_first(conn->sconn, id); fsp;
1138 fsp = file_find_di_next(fsp)) {
1139 if (fsp->access_mask & DELETE_ACCESS &&
1140 fsp->delete_on_close) {
1141 /* We did open this for delete,
1142 * allow the delete as root.
1143 */
1144 break;
1145 }
1146 }
1147
1148 if (!fsp) {
1149 DBG_DEBUG("%s %s/%s not an open file\n",
1150 is_directory ? "directory" : "file",
1151 parent_dir, final_component);
1152 saved_errno = EACCES;
1153 goto out;
1154 }
1155
1156 become_root();
1157 if (is_directory) {
1158 ret = SMB_VFS_NEXT_UNLINKAT(handle,
1159 conn->cwd_fsp,
1160 &local_fname,
1161 AT_REMOVEDIR);
1162 } else {
1163 ret = SMB_VFS_NEXT_UNLINKAT(handle,
1164 conn->cwd_fsp,
1165 &local_fname,
1166 0);
1167 }
1168 unbecome_root();
1169
1170 if (ret == -1) {
1171 saved_errno = errno;
1172 }
1173
1174 out:
1175
1176 TALLOC_FREE(parent_dir);
1177
1178 if (saved_dir_fname) {
1179 vfs_ChDir(conn, saved_dir_fname);
1180 TALLOC_FREE(saved_dir_fname);
1181 }
1182 if (saved_errno) {
1183 errno = saved_errno;
1184 }
1185 return ret;
1186 }
1187
1188 int rmdir_acl_common(struct vfs_handle_struct *handle,
1189 struct files_struct *dirfsp,
1190 const struct smb_filename *smb_fname)
1191 {
1192 int ret;
1193
1194 /* Try the normal rmdir first. */
1195 ret = SMB_VFS_NEXT_UNLINKAT(handle,
1196 dirfsp,
1197 smb_fname,
1198 AT_REMOVEDIR);
1199 if (ret == 0) {
1200 return 0;
1201 }
1202 if (errno == EACCES || errno == EPERM) {
1203 /* Failed due to access denied,
1204 see if we need to root override. */
1205 return acl_common_remove_object(handle,
1206 smb_fname,
1207 true);
1208 }
1209
1210 DBG_DEBUG("unlink of %s failed %s\n",
1211 smb_fname->base_name,
1212 strerror(errno));
1213 return -1;
1214 }
1215
1216 int unlink_acl_common(struct vfs_handle_struct *handle,
1217 struct files_struct *dirfsp,
1218 const struct smb_filename *smb_fname,
1219 int flags)
1220 {
1221 int ret;
1222
1223 /* Try the normal unlink first. */
1224 ret = SMB_VFS_NEXT_UNLINKAT(handle,
1225 dirfsp,
1226 smb_fname,
1227 flags);
1228 if (ret == 0) {
1229 return 0;
1230 }
1231 if (errno == EACCES || errno == EPERM) {
1232 /* Failed due to access denied,
1233 see if we need to root override. */
1234
1235 /* Don't do anything fancy for streams. */
1236 if (smb_fname->stream_name) {
1237 return -1;
1238 }
1239 return acl_common_remove_object(handle,
1240 smb_fname,
1241 false);
1242 }
1243
1244 DBG_DEBUG("unlink of %s failed %s\n",
1245 smb_fname->base_name,
1246 strerror(errno));
1247 return -1;
1248 }
1249
1250 int chmod_acl_module_common(struct vfs_handle_struct *handle,
1251 const struct smb_filename *smb_fname,
1252 mode_t mode)
1253 {
1254 if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1255 /* Only allow this on POSIX pathnames. */
1256 return SMB_VFS_NEXT_CHMOD(handle, smb_fname, mode);
1257 }
1258 return 0;
1259 }
1260
1261 int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1262 struct files_struct *fsp, mode_t mode)
1263 {
1264 if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1265 /* Only allow this on POSIX opens. */
1266 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1267 }
1268 return 0;
1269 }
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