1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5 *
6 */
7
8#include <linux/fs.h>
9#include <linux/posix_acl.h>
10#include <linux/posix_acl_xattr.h>
11#include <linux/xattr.h>
12
13#include "debug.h"
14#include "ntfs.h"
15#include "ntfs_fs.h"
16
17// clang-format off
18#define SYSTEM_DOS_ATTRIB "system.dos_attrib"
19#define SYSTEM_NTFS_ATTRIB "system.ntfs_attrib"
20#define SYSTEM_NTFS_ATTRIB_BE "system.ntfs_attrib_be"
21#define SYSTEM_NTFS_SECURITY "system.ntfs_security"
22// clang-format on
23
24static inline size_t unpacked_ea_size(const struct EA_FULL *ea)
25{
26 return ea->size ? le32_to_cpu(ea->size) :
27 ALIGN(struct_size(ea, name,
28 1 + ea->name_len +
29 le16_to_cpu(ea->elength)),
30 4);
31}
32
33static inline size_t packed_ea_size(const struct EA_FULL *ea)
34{
35 return struct_size(ea, name,
36 1 + ea->name_len + le16_to_cpu(ea->elength)) -
37 offsetof(struct EA_FULL, flags);
38}
39
40/*
41 * find_ea
42 *
43 * Assume there is at least one xattr in the list.
44 */
45static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
46 const char *name, u8 name_len, u32 *off, u32 *ea_sz)
47{
48 u32 ea_size;
49
50 *off = 0;
51 if (!ea_all)
52 return false;
53
54 for (; *off < bytes; *off += ea_size) {
55 const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
56 ea_size = unpacked_ea_size(ea);
57 if (ea->name_len == name_len &&
58 !memcmp(p: ea->name, q: name, size: name_len)) {
59 if (ea_sz)
60 *ea_sz = ea_size;
61 return true;
62 }
63 }
64
65 return false;
66}
67
68/*
69 * ntfs_read_ea - Read all extended attributes.
70 * @ea: New allocated memory.
71 * @info: Pointer into resident data.
72 */
73static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
74 size_t add_bytes, const struct EA_INFO **info)
75{
76 int err = -EINVAL;
77 struct ntfs_sb_info *sbi = ni->mi.sbi;
78 struct ATTR_LIST_ENTRY *le = NULL;
79 struct ATTRIB *attr_info, *attr_ea;
80 void *ea_p;
81 u32 size, off, ea_size;
82
83 static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
84
85 *ea = NULL;
86 *info = NULL;
87
88 attr_info =
89 ni_find_attr(ni, NULL, entry_o: &le, type: ATTR_EA_INFO, NULL, name_len: 0, NULL, NULL);
90 attr_ea =
91 ni_find_attr(ni, attr: attr_info, entry_o: &le, type: ATTR_EA, NULL, name_len: 0, NULL, NULL);
92
93 if (!attr_ea || !attr_info)
94 return 0;
95
96 *info = resident_data_ex(attr: attr_info, datasize: sizeof(struct EA_INFO));
97 if (!*info)
98 goto out;
99
100 /* Check Ea limit. */
101 size = le32_to_cpu((*info)->size);
102 if (size > sbi->ea_max_size) {
103 err = -EFBIG;
104 goto out;
105 }
106
107 if (attr_size(attr: attr_ea) > sbi->ea_max_size) {
108 err = -EFBIG;
109 goto out;
110 }
111
112 if (!size) {
113 /* EA info persists, but xattr is empty. Looks like EA problem. */
114 goto out;
115 }
116
117 /* Allocate memory for packed Ea. */
118 ea_p = kmalloc(size_add(size, add_bytes), GFP_NOFS);
119 if (!ea_p)
120 return -ENOMEM;
121
122 if (attr_ea->non_res) {
123 struct runs_tree run;
124
125 run_init(run: &run);
126
127 err = attr_load_runs_range(ni, type: ATTR_EA, NULL, name_len: 0, run: &run, from: 0, to: size);
128 if (!err)
129 err = ntfs_read_run_nb(sbi, run: &run, vbo: 0, buf: ea_p, bytes: size, NULL);
130 run_close(run: &run);
131
132 if (err)
133 goto out1;
134 } else {
135 void *p = resident_data_ex(attr: attr_ea, datasize: size);
136
137 if (!p)
138 goto out1;
139 memcpy(ea_p, p, size);
140 }
141
142 memset(Add2Ptr(ea_p, size), 0, add_bytes);
143
144 err = -EINVAL;
145 /* Check all attributes for consistency. */
146 for (off = 0; off < size; off += ea_size) {
147 const struct EA_FULL *ef = Add2Ptr(ea_p, off);
148 u32 bytes = size - off;
149
150 /* Check if we can use field ea->size. */
151 if (bytes < sizeof(ef->size))
152 goto out1;
153
154 if (ef->size) {
155 ea_size = le32_to_cpu(ef->size);
156 if (ea_size > bytes)
157 goto out1;
158 continue;
159 }
160
161 /* Check if we can use fields ef->name_len and ef->elength. */
162 if (bytes < offsetof(struct EA_FULL, name))
163 goto out1;
164
165 ea_size = ALIGN(struct_size(ef, name,
166 1 + ef->name_len +
167 le16_to_cpu(ef->elength)),
168 4);
169 if (ea_size > bytes)
170 goto out1;
171 }
172
173 *ea = ea_p;
174 return 0;
175
176out1:
177 kfree(objp: ea_p);
178out:
179 ntfs_set_state(sbi, dirty: NTFS_DIRTY_DIRTY);
180 return err;
181}
182
183/*
184 * ntfs_list_ea
185 *
186 * Copy a list of xattrs names into the buffer
187 * provided, or compute the buffer size required.
188 *
189 * Return:
190 * * Number of bytes used / required on
191 * * -ERRNO - on failure
192 */
193static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
194 size_t bytes_per_buffer)
195{
196 const struct EA_INFO *info;
197 struct EA_FULL *ea_all = NULL;
198 u32 off, size;
199 int err;
200 size_t ret;
201
202 err = ntfs_read_ea(ni, ea: &ea_all, add_bytes: 0, info: &info);
203 if (err)
204 return err;
205
206 if (!info || !ea_all)
207 return 0;
208
209 size = le32_to_cpu(info->size);
210
211 /* Enumerate all xattrs. */
212 ret = 0;
213 off = 0;
214 while (off + sizeof(struct EA_FULL) < size) {
215 const struct EA_FULL *ea = Add2Ptr(ea_all, off);
216 int ea_size = unpacked_ea_size(ea);
217 u8 name_len = ea->name_len;
218
219 if (!name_len)
220 break;
221
222 if (name_len > ea_size) {
223 ntfs_set_state(sbi: ni->mi.sbi, dirty: NTFS_DIRTY_ERROR);
224 err = -EINVAL; /* corrupted fs. */
225 break;
226 }
227
228 if (buffer) {
229 /* Check if we can use field ea->name */
230 if (off + ea_size > size)
231 break;
232
233 if (ret + name_len + 1 > bytes_per_buffer) {
234 err = -ERANGE;
235 goto out;
236 }
237
238 memcpy(buffer + ret, ea->name, name_len);
239 buffer[ret + name_len] = 0;
240 }
241
242 ret += name_len + 1;
243 off += ea_size;
244 }
245
246out:
247 kfree(objp: ea_all);
248 return err ? err : ret;
249}
250
251static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
252 void *buffer, size_t size, size_t *required)
253{
254 struct ntfs_inode *ni = ntfs_i(inode);
255 const struct EA_INFO *info;
256 struct EA_FULL *ea_all = NULL;
257 const struct EA_FULL *ea;
258 u32 off, len;
259 int err;
260
261 if (!(ni->ni_flags & NI_FLAG_EA))
262 return -ENODATA;
263
264 if (!required)
265 ni_lock(ni);
266
267 len = 0;
268
269 if (name_len > 255) {
270 err = -ENAMETOOLONG;
271 goto out;
272 }
273
274 err = ntfs_read_ea(ni, ea: &ea_all, add_bytes: 0, info: &info);
275 if (err)
276 goto out;
277
278 if (!info)
279 goto out;
280
281 /* Enumerate all xattrs. */
282 if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, off: &off,
283 NULL)) {
284 err = -ENODATA;
285 goto out;
286 }
287 ea = Add2Ptr(ea_all, off);
288
289 len = le16_to_cpu(ea->elength);
290 if (!buffer) {
291 err = 0;
292 goto out;
293 }
294
295 if (len > size) {
296 err = -ERANGE;
297 if (required)
298 *required = len;
299 goto out;
300 }
301
302 memcpy(buffer, ea->name + ea->name_len + 1, len);
303 err = 0;
304
305out:
306 kfree(objp: ea_all);
307 if (!required)
308 ni_unlock(ni);
309
310 return err ? err : len;
311}
312
313static noinline int ntfs_set_ea(struct inode *inode, const char *name,
314 size_t name_len, const void *value,
315 size_t val_size, int flags, bool locked,
316 __le32 *ea_size)
317{
318 struct ntfs_inode *ni = ntfs_i(inode);
319 struct ntfs_sb_info *sbi = ni->mi.sbi;
320 int err;
321 struct EA_INFO ea_info;
322 const struct EA_INFO *info;
323 struct EA_FULL *new_ea;
324 struct EA_FULL *ea_all = NULL;
325 size_t add, new_pack;
326 u32 off, size, ea_sz;
327 __le16 size_pack;
328 struct ATTRIB *attr;
329 struct ATTR_LIST_ENTRY *le;
330 struct mft_inode *mi;
331 struct runs_tree ea_run;
332 u64 new_sz;
333 void *p;
334
335 if (!locked)
336 ni_lock(ni);
337
338 run_init(run: &ea_run);
339
340 if (name_len > 255) {
341 err = -ENAMETOOLONG;
342 goto out;
343 }
344
345 add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
346
347 err = ntfs_read_ea(ni, ea: &ea_all, add_bytes: add, info: &info);
348 if (err)
349 goto out;
350
351 if (!info) {
352 memset(&ea_info, 0, sizeof(ea_info));
353 size = 0;
354 size_pack = 0;
355 } else {
356 memcpy(&ea_info, info, sizeof(ea_info));
357 size = le32_to_cpu(ea_info.size);
358 size_pack = ea_info.size_pack;
359 }
360
361 if (info && find_ea(ea_all, bytes: size, name, name_len, off: &off, ea_sz: &ea_sz)) {
362 struct EA_FULL *ea;
363
364 if (flags & XATTR_CREATE) {
365 err = -EEXIST;
366 goto out;
367 }
368
369 ea = Add2Ptr(ea_all, off);
370
371 /*
372 * Check simple case when we try to insert xattr with the same value
373 * e.g. ntfs_save_wsl_perm
374 */
375 if (val_size && le16_to_cpu(ea->elength) == val_size &&
376 !memcmp(p: ea->name + ea->name_len + 1, q: value, size: val_size)) {
377 /* xattr already contains the required value. */
378 goto out;
379 }
380
381 /* Remove current xattr. */
382 if (ea->flags & FILE_NEED_EA)
383 le16_add_cpu(var: &ea_info.count, val: -1);
384
385 le16_add_cpu(var: &ea_info.size_pack, val: 0 - packed_ea_size(ea));
386
387 memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
388
389 size -= ea_sz;
390 memset(Add2Ptr(ea_all, size), 0, ea_sz);
391
392 ea_info.size = cpu_to_le32(size);
393
394 if ((flags & XATTR_REPLACE) && !val_size) {
395 /* Remove xattr. */
396 goto update_ea;
397 }
398 } else {
399 if (flags & XATTR_REPLACE) {
400 err = -ENODATA;
401 goto out;
402 }
403
404 if (!ea_all) {
405 ea_all = kzalloc(add, GFP_NOFS);
406 if (!ea_all) {
407 err = -ENOMEM;
408 goto out;
409 }
410 }
411 }
412
413 /* Append new xattr. */
414 new_ea = Add2Ptr(ea_all, size);
415 new_ea->size = cpu_to_le32(add);
416 new_ea->flags = 0;
417 new_ea->name_len = name_len;
418 new_ea->elength = cpu_to_le16(val_size);
419 memcpy(new_ea->name, name, name_len);
420 new_ea->name[name_len] = 0;
421 memcpy(new_ea->name + name_len + 1, value, val_size);
422 new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(ea: new_ea);
423 ea_info.size_pack = cpu_to_le16(new_pack);
424 /* New size of ATTR_EA. */
425 size += add;
426 ea_info.size = cpu_to_le32(size);
427
428 /*
429 * 1. Check ea_info.size_pack for overflow.
430 * 2. New attribute size must fit value from $AttrDef
431 */
432 if (new_pack > 0xffff || size > sbi->ea_max_size) {
433 ntfs_inode_warn(
434 inode,
435 "The size of extended attributes must not exceed 64KiB");
436 err = -EFBIG; // -EINVAL?
437 goto out;
438 }
439
440update_ea:
441
442 if (!info) {
443 /* Create xattr. */
444 if (!size) {
445 err = 0;
446 goto out;
447 }
448
449 err = ni_insert_resident(ni, data_size: sizeof(struct EA_INFO),
450 type: ATTR_EA_INFO, NULL, name_len: 0, NULL, NULL,
451 NULL);
452 if (err)
453 goto out;
454
455 err = ni_insert_resident(ni, data_size: 0, type: ATTR_EA, NULL, name_len: 0, NULL, NULL,
456 NULL);
457 if (err)
458 goto out;
459 }
460
461 new_sz = size;
462 err = attr_set_size(ni, type: ATTR_EA, NULL, name_len: 0, run: &ea_run, new_size: new_sz, new_valid: &new_sz,
463 keep_prealloc: false, NULL);
464 if (err)
465 goto out;
466
467 le = NULL;
468 attr = ni_find_attr(ni, NULL, entry_o: &le, type: ATTR_EA_INFO, NULL, name_len: 0, NULL, mi: &mi);
469 if (!attr) {
470 err = -EINVAL;
471 goto out;
472 }
473
474 if (!size) {
475 /* Delete xattr, ATTR_EA_INFO */
476 ni_remove_attr_le(ni, attr, mi, le);
477 } else {
478 p = resident_data_ex(attr, datasize: sizeof(struct EA_INFO));
479 if (!p) {
480 err = -EINVAL;
481 goto out;
482 }
483 memcpy(p, &ea_info, sizeof(struct EA_INFO));
484 mi->dirty = true;
485 }
486
487 le = NULL;
488 attr = ni_find_attr(ni, NULL, entry_o: &le, type: ATTR_EA, NULL, name_len: 0, NULL, mi: &mi);
489 if (!attr) {
490 err = -EINVAL;
491 goto out;
492 }
493
494 if (!size) {
495 /* Delete xattr, ATTR_EA */
496 ni_remove_attr_le(ni, attr, mi, le);
497 } else if (attr->non_res) {
498 err = attr_load_runs_range(ni, type: ATTR_EA, NULL, name_len: 0, run: &ea_run, from: 0,
499 to: size);
500 if (err)
501 goto out;
502
503 err = ntfs_sb_write_run(sbi, run: &ea_run, vbo: 0, buf: ea_all, bytes: size, sync: 0);
504 if (err)
505 goto out;
506 } else {
507 p = resident_data_ex(attr, datasize: size);
508 if (!p) {
509 err = -EINVAL;
510 goto out;
511 }
512 memcpy(p, ea_all, size);
513 mi->dirty = true;
514 }
515
516 /* Check if we delete the last xattr. */
517 if (size)
518 ni->ni_flags |= NI_FLAG_EA;
519 else
520 ni->ni_flags &= ~NI_FLAG_EA;
521
522 if (ea_info.size_pack != size_pack)
523 ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
524 if (ea_size)
525 *ea_size = ea_info.size;
526 mark_inode_dirty(inode: &ni->vfs_inode);
527
528out:
529 if (!locked)
530 ni_unlock(ni);
531
532 run_close(run: &ea_run);
533 kfree(objp: ea_all);
534
535 return err;
536}
537
538#ifdef CONFIG_NTFS3_FS_POSIX_ACL
539
540/*
541 * ntfs_get_acl - inode_operations::get_acl
542 */
543struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
544 int type)
545{
546 struct inode *inode = d_inode(dentry);
547 struct ntfs_inode *ni = ntfs_i(inode);
548 const char *name;
549 size_t name_len;
550 struct posix_acl *acl;
551 size_t req;
552 int err;
553 void *buf;
554
555 /* Avoid any operation if inode is bad. */
556 if (unlikely(is_bad_ni(ni)))
557 return ERR_PTR(error: -EINVAL);
558
559 /* Allocate PATH_MAX bytes. */
560 buf = __getname();
561 if (!buf)
562 return ERR_PTR(error: -ENOMEM);
563
564 /* Possible values of 'type' was already checked above. */
565 if (type == ACL_TYPE_ACCESS) {
566 name = XATTR_NAME_POSIX_ACL_ACCESS;
567 name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
568 } else {
569 name = XATTR_NAME_POSIX_ACL_DEFAULT;
570 name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
571 }
572
573 ni_lock(ni);
574
575 err = ntfs_get_ea(inode, name, name_len, buffer: buf, PATH_MAX, required: &req);
576
577 ni_unlock(ni);
578
579 /* Translate extended attribute to acl. */
580 if (err >= 0) {
581 acl = posix_acl_from_xattr(user_ns: &init_user_ns, value: buf, size: err);
582 } else if (err == -ENODATA) {
583 acl = NULL;
584 } else {
585 acl = ERR_PTR(error: err);
586 }
587
588 if (!IS_ERR(ptr: acl))
589 set_cached_acl(inode, type, acl);
590
591 __putname(buf);
592
593 return acl;
594}
595
596static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
597 struct inode *inode, struct posix_acl *acl,
598 int type, bool init_acl)
599{
600 const char *name;
601 size_t size, name_len;
602 void *value;
603 int err;
604 int flags;
605 umode_t mode;
606
607 /* Avoid any operation if inode is bad. */
608 if (unlikely(is_bad_ni(ntfs_i(inode))))
609 return -EINVAL;
610
611 if (S_ISLNK(inode->i_mode))
612 return -EOPNOTSUPP;
613
614 mode = inode->i_mode;
615 switch (type) {
616 case ACL_TYPE_ACCESS:
617 /* Do not change i_mode if we are in init_acl */
618 if (acl && !init_acl) {
619 err = posix_acl_update_mode(idmap, inode, &mode, &acl);
620 if (err)
621 return err;
622 }
623 name = XATTR_NAME_POSIX_ACL_ACCESS;
624 name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
625 break;
626
627 case ACL_TYPE_DEFAULT:
628 if (!S_ISDIR(inode->i_mode))
629 return acl ? -EACCES : 0;
630 name = XATTR_NAME_POSIX_ACL_DEFAULT;
631 name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
632 break;
633
634 default:
635 return -EINVAL;
636 }
637
638 if (!acl) {
639 /* Remove xattr if it can be presented via mode. */
640 size = 0;
641 value = NULL;
642 flags = XATTR_REPLACE;
643 } else {
644 size = posix_acl_xattr_size(count: acl->a_count);
645 value = kmalloc(size, GFP_NOFS);
646 if (!value)
647 return -ENOMEM;
648 err = posix_acl_to_xattr(user_ns: &init_user_ns, acl, buffer: value, size);
649 if (err < 0)
650 goto out;
651 flags = 0;
652 }
653
654 err = ntfs_set_ea(inode, name, name_len, value, val_size: size, flags, locked: 0, NULL);
655 if (err == -ENODATA && !size)
656 err = 0; /* Removing non existed xattr. */
657 if (err)
658 goto out;
659
660 if (inode->i_mode != mode) {
661 umode_t old_mode = inode->i_mode;
662 inode->i_mode = mode;
663 err = ntfs_save_wsl_perm(inode, NULL);
664 if (err) {
665 inode->i_mode = old_mode;
666 goto out;
667 }
668 inode->i_mode = mode;
669 }
670 set_cached_acl(inode, type, acl);
671 inode_set_ctime_current(inode);
672 mark_inode_dirty(inode);
673
674out:
675 kfree(objp: value);
676
677 return err;
678}
679
680/*
681 * ntfs_set_acl - inode_operations::set_acl
682 */
683int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
684 struct posix_acl *acl, int type)
685{
686 return ntfs_set_acl_ex(idmap, inode: d_inode(dentry), acl, type, init_acl: false);
687}
688
689/*
690 * ntfs_init_acl - Initialize the ACLs of a new inode.
691 *
692 * Called from ntfs_create_inode().
693 */
694int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
695 struct inode *dir)
696{
697 struct posix_acl *default_acl, *acl;
698 int err;
699
700 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
701 if (err)
702 return err;
703
704 if (default_acl) {
705 err = ntfs_set_acl_ex(idmap, inode, acl: default_acl,
706 ACL_TYPE_DEFAULT, init_acl: true);
707 posix_acl_release(acl: default_acl);
708 } else {
709 inode->i_default_acl = NULL;
710 }
711
712 if (acl) {
713 if (!err)
714 err = ntfs_set_acl_ex(idmap, inode, acl,
715 ACL_TYPE_ACCESS, init_acl: true);
716 posix_acl_release(acl);
717 } else {
718 inode->i_acl = NULL;
719 }
720
721 return err;
722}
723#endif
724
725/*
726 * ntfs_acl_chmod - Helper for ntfs_setattr().
727 */
728int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
729{
730 struct inode *inode = d_inode(dentry);
731 struct super_block *sb = inode->i_sb;
732
733 if (!(sb->s_flags & SB_POSIXACL))
734 return 0;
735
736 if (S_ISLNK(inode->i_mode))
737 return -EOPNOTSUPP;
738
739 return posix_acl_chmod(idmap, dentry, inode->i_mode);
740}
741
742/*
743 * ntfs_listxattr - inode_operations::listxattr
744 */
745ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
746{
747 struct inode *inode = d_inode(dentry);
748 struct ntfs_inode *ni = ntfs_i(inode);
749 ssize_t ret;
750
751 /* Avoid any operation if inode is bad. */
752 if (unlikely(is_bad_ni(ni)))
753 return -EINVAL;
754
755 if (!(ni->ni_flags & NI_FLAG_EA)) {
756 /* no xattr in file */
757 return 0;
758 }
759
760 ni_lock(ni);
761
762 ret = ntfs_list_ea(ni, buffer, bytes_per_buffer: size);
763
764 ni_unlock(ni);
765
766 return ret;
767}
768
769static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
770 struct inode *inode, const char *name, void *buffer,
771 size_t size)
772{
773 int err;
774 struct ntfs_inode *ni = ntfs_i(inode);
775
776 /* Avoid any operation if inode is bad. */
777 if (unlikely(is_bad_ni(ni)))
778 return -EINVAL;
779
780 if (unlikely(ntfs3_forced_shutdown(inode->i_sb)))
781 return -EIO;
782
783 /* Dispatch request. */
784 if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
785 /* system.dos_attrib */
786 if (!buffer) {
787 err = sizeof(u8);
788 } else if (size < sizeof(u8)) {
789 err = -ENODATA;
790 } else {
791 err = sizeof(u8);
792 *(u8 *)buffer = le32_to_cpu(ni->std_fa);
793 }
794 goto out;
795 }
796
797 if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
798 !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
799 /* system.ntfs_attrib */
800 if (!buffer) {
801 err = sizeof(u32);
802 } else if (size < sizeof(u32)) {
803 err = -ENODATA;
804 } else {
805 err = sizeof(u32);
806 *(u32 *)buffer = le32_to_cpu(ni->std_fa);
807 if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
808 *(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
809 }
810 goto out;
811 }
812
813 if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
814 /* system.ntfs_security*/
815 struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
816 size_t sd_size = 0;
817
818 if (!is_ntfs3(sbi: ni->mi.sbi)) {
819 /* We should get nt4 security. */
820 err = -EINVAL;
821 goto out;
822 } else if (le32_to_cpu(ni->std_security_id) <
823 SECURITY_ID_FIRST) {
824 err = -ENOENT;
825 goto out;
826 }
827
828 err = ntfs_get_security_by_id(sbi: ni->mi.sbi, security_id: ni->std_security_id,
829 sd: &sd, size: &sd_size);
830 if (err)
831 goto out;
832
833 if (!is_sd_valid(sd, len: sd_size)) {
834 ntfs_inode_warn(
835 inode,
836 "looks like you get incorrect security descriptor id=%u",
837 ni->std_security_id);
838 }
839
840 if (!buffer) {
841 err = sd_size;
842 } else if (size < sd_size) {
843 err = -ENODATA;
844 } else {
845 err = sd_size;
846 memcpy(buffer, sd, sd_size);
847 }
848 kfree(objp: sd);
849 goto out;
850 }
851
852 /* Deal with NTFS extended attribute. */
853 err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
854
855out:
856 return err;
857}
858
859/*
860 * ntfs_setxattr - inode_operations::setxattr
861 */
862static noinline int ntfs_setxattr(const struct xattr_handler *handler,
863 struct mnt_idmap *idmap, struct dentry *de,
864 struct inode *inode, const char *name,
865 const void *value, size_t size, int flags)
866{
867 int err = -EINVAL;
868 struct ntfs_inode *ni = ntfs_i(inode);
869 enum FILE_ATTRIBUTE new_fa;
870
871 /* Dispatch request. */
872 if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
873 if (sizeof(u8) != size)
874 goto out;
875 new_fa = cpu_to_le32(*(u8 *)value);
876 goto set_new_fa;
877 }
878
879 if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
880 !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
881 if (size != sizeof(u32))
882 goto out;
883 if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
884 new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
885 else
886 new_fa = cpu_to_le32(*(u32 *)value);
887
888 if (S_ISREG(inode->i_mode)) {
889 /* Process compressed/sparsed in special way. */
890 ni_lock(ni);
891 err = ni_new_attr_flags(ni, new_fa);
892 ni_unlock(ni);
893 if (err)
894 goto out;
895 }
896set_new_fa:
897 /*
898 * Thanks Mark Harmstone:
899 * Keep directory bit consistency.
900 */
901 if (S_ISDIR(inode->i_mode))
902 new_fa |= FILE_ATTRIBUTE_DIRECTORY;
903 else
904 new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
905
906 if (ni->std_fa != new_fa) {
907 ni->std_fa = new_fa;
908 if (new_fa & FILE_ATTRIBUTE_READONLY)
909 inode->i_mode &= ~0222;
910 else
911 inode->i_mode |= 0222;
912 /* Std attribute always in primary record. */
913 ni->mi.dirty = true;
914 mark_inode_dirty(inode);
915 }
916 err = 0;
917
918 goto out;
919 }
920
921 if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
922 /* system.ntfs_security*/
923 __le32 security_id;
924 bool inserted;
925 struct ATTR_STD_INFO5 *std;
926
927 if (!is_ntfs3(sbi: ni->mi.sbi)) {
928 /*
929 * We should replace ATTR_SECURE.
930 * Skip this way cause it is nt4 feature.
931 */
932 err = -EINVAL;
933 goto out;
934 }
935
936 if (!is_sd_valid(sd: value, len: size)) {
937 err = -EINVAL;
938 ntfs_inode_warn(
939 inode,
940 "you try to set invalid security descriptor");
941 goto out;
942 }
943
944 err = ntfs_insert_security(sbi: ni->mi.sbi, sd: value, size,
945 security_id: &security_id, inserted: &inserted);
946 if (err)
947 goto out;
948
949 ni_lock(ni);
950 std = ni_std5(ni);
951 if (!std) {
952 err = -EINVAL;
953 } else if (std->security_id != security_id) {
954 std->security_id = ni->std_security_id = security_id;
955 /* Std attribute always in primary record. */
956 ni->mi.dirty = true;
957 mark_inode_dirty(inode: &ni->vfs_inode);
958 }
959 ni_unlock(ni);
960 goto out;
961 }
962
963 /* Deal with NTFS extended attribute. */
964 err = ntfs_set_ea(inode, name, strlen(name), value, val_size: size, flags, locked: 0,
965 NULL);
966
967out:
968 inode_set_ctime_current(inode);
969 mark_inode_dirty(inode);
970
971 return err;
972}
973
974/*
975 * ntfs_save_wsl_perm
976 *
977 * save uid/gid/mode in xattr
978 */
979int ntfs_save_wsl_perm(struct inode *inode, __le32 *ea_size)
980{
981 int err;
982 __le32 value;
983 struct ntfs_inode *ni = ntfs_i(inode);
984
985 ni_lock(ni);
986 value = cpu_to_le32(i_uid_read(inode));
987 err = ntfs_set_ea(inode, name: "$LXUID", name_len: sizeof("$LXUID") - 1, value: &value,
988 val_size: sizeof(value), flags: 0, locked: true, ea_size);
989 if (err)
990 goto out;
991
992 value = cpu_to_le32(i_gid_read(inode));
993 err = ntfs_set_ea(inode, name: "$LXGID", name_len: sizeof("$LXGID") - 1, value: &value,
994 val_size: sizeof(value), flags: 0, locked: true, ea_size);
995 if (err)
996 goto out;
997
998 value = cpu_to_le32(inode->i_mode);
999 err = ntfs_set_ea(inode, name: "$LXMOD", name_len: sizeof("$LXMOD") - 1, value: &value,
1000 val_size: sizeof(value), flags: 0, locked: true, ea_size);
1001 if (err)
1002 goto out;
1003
1004 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1005 value = cpu_to_le32(inode->i_rdev);
1006 err = ntfs_set_ea(inode, name: "$LXDEV", name_len: sizeof("$LXDEV") - 1, value: &value,
1007 val_size: sizeof(value), flags: 0, locked: true, ea_size);
1008 if (err)
1009 goto out;
1010 }
1011
1012out:
1013 ni_unlock(ni);
1014 /* In case of error should we delete all WSL xattr? */
1015 return err;
1016}
1017
1018/*
1019 * ntfs_get_wsl_perm
1020 *
1021 * get uid/gid/mode from xattr
1022 * it is called from ntfs_iget5->ntfs_read_mft
1023 */
1024void ntfs_get_wsl_perm(struct inode *inode)
1025{
1026 size_t sz;
1027 __le32 value[3];
1028
1029 if (ntfs_get_ea(inode, name: "$LXUID", name_len: sizeof("$LXUID") - 1, buffer: &value[0],
1030 size: sizeof(value[0]), required: &sz) == sizeof(value[0]) &&
1031 ntfs_get_ea(inode, name: "$LXGID", name_len: sizeof("$LXGID") - 1, buffer: &value[1],
1032 size: sizeof(value[1]), required: &sz) == sizeof(value[1]) &&
1033 ntfs_get_ea(inode, name: "$LXMOD", name_len: sizeof("$LXMOD") - 1, buffer: &value[2],
1034 size: sizeof(value[2]), required: &sz) == sizeof(value[2])) {
1035 i_uid_write(inode, uid: (uid_t)le32_to_cpu(value[0]));
1036 i_gid_write(inode, gid: (gid_t)le32_to_cpu(value[1]));
1037 inode->i_mode = le32_to_cpu(value[2]);
1038
1039 if (ntfs_get_ea(inode, name: "$LXDEV", name_len: sizeof("$$LXDEV") - 1,
1040 buffer: &value[0], size: sizeof(value),
1041 required: &sz) == sizeof(value[0])) {
1042 inode->i_rdev = le32_to_cpu(value[0]);
1043 }
1044 }
1045}
1046
1047static bool ntfs_xattr_user_list(struct dentry *dentry)
1048{
1049 return true;
1050}
1051
1052// clang-format off
1053static const struct xattr_handler ntfs_other_xattr_handler = {
1054 .prefix = "",
1055 .get = ntfs_getxattr,
1056 .set = ntfs_setxattr,
1057 .list = ntfs_xattr_user_list,
1058};
1059
1060const struct xattr_handler * const ntfs_xattr_handlers[] = {
1061 &ntfs_other_xattr_handler,
1062 NULL,
1063};
1064// clang-format on
1065

source code of linux/fs/ntfs3/xattr.c