xref: /openbmc/linux/fs/ntfs3/xattr.c (revision 7c2435ef)
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 
24 static 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 
33 static 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  */
45 static 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(ea->name, name, 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  */
73 static 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, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
90 	attr_ea =
91 		ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
92 
93 	if (!attr_ea || !attr_info)
94 		return 0;
95 
96 	*info = resident_data_ex(attr_info, 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_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);
126 
127 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &run, 0, size);
128 		if (!err)
129 			err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
130 		run_close(&run);
131 
132 		if (err)
133 			goto out1;
134 	} else {
135 		void *p = resident_data_ex(attr_ea, 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 	/* Check all attributes for consistency. */
145 	for (off = 0; off < size; off += ea_size) {
146 		const struct EA_FULL *ef = Add2Ptr(ea_p, off);
147 		u32 bytes = size - off;
148 
149 		/* Check if we can use field ea->size. */
150 		if (bytes < sizeof(ef->size))
151 			goto out1;
152 
153 		if (ef->size) {
154 			ea_size = le32_to_cpu(ef->size);
155 			if (ea_size > bytes)
156 				goto out1;
157 			continue;
158 		}
159 
160 		/* Check if we can use fields ef->name_len and ef->elength. */
161 		if (bytes < offsetof(struct EA_FULL, name))
162 			goto out1;
163 
164 		ea_size = ALIGN(struct_size(ef, name,
165 					    1 + ef->name_len +
166 						    le16_to_cpu(ef->elength)),
167 				4);
168 		if (ea_size > bytes)
169 			goto out1;
170 	}
171 
172 	*ea = ea_p;
173 	return 0;
174 
175 out1:
176 	kfree(ea_p);
177 out:
178 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
179 	return err;
180 }
181 
182 /*
183  * ntfs_list_ea
184  *
185  * Copy a list of xattrs names into the buffer
186  * provided, or compute the buffer size required.
187  *
188  * Return:
189  * * Number of bytes used / required on
190  * * -ERRNO - on failure
191  */
192 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
193 			    size_t bytes_per_buffer)
194 {
195 	const struct EA_INFO *info;
196 	struct EA_FULL *ea_all = NULL;
197 	const struct EA_FULL *ea;
198 	u32 off, size;
199 	int err;
200 	int ea_size;
201 	size_t ret;
202 
203 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
204 	if (err)
205 		return err;
206 
207 	if (!info || !ea_all)
208 		return 0;
209 
210 	size = le32_to_cpu(info->size);
211 
212 	/* Enumerate all xattrs. */
213 	for (ret = 0, off = 0; off < size; off += ea_size) {
214 		ea = Add2Ptr(ea_all, off);
215 		ea_size = unpacked_ea_size(ea);
216 
217 		if (buffer) {
218 			if (ret + ea->name_len + 1 > bytes_per_buffer) {
219 				err = -ERANGE;
220 				goto out;
221 			}
222 
223 			memcpy(buffer + ret, ea->name, ea->name_len);
224 			buffer[ret + ea->name_len] = 0;
225 		}
226 
227 		ret += ea->name_len + 1;
228 	}
229 
230 out:
231 	kfree(ea_all);
232 	return err ? err : ret;
233 }
234 
235 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
236 		       void *buffer, size_t size, size_t *required)
237 {
238 	struct ntfs_inode *ni = ntfs_i(inode);
239 	const struct EA_INFO *info;
240 	struct EA_FULL *ea_all = NULL;
241 	const struct EA_FULL *ea;
242 	u32 off, len;
243 	int err;
244 
245 	if (!(ni->ni_flags & NI_FLAG_EA))
246 		return -ENODATA;
247 
248 	if (!required)
249 		ni_lock(ni);
250 
251 	len = 0;
252 
253 	if (name_len > 255) {
254 		err = -ENAMETOOLONG;
255 		goto out;
256 	}
257 
258 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
259 	if (err)
260 		goto out;
261 
262 	if (!info)
263 		goto out;
264 
265 	/* Enumerate all xattrs. */
266 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
267 		     NULL)) {
268 		err = -ENODATA;
269 		goto out;
270 	}
271 	ea = Add2Ptr(ea_all, off);
272 
273 	len = le16_to_cpu(ea->elength);
274 	if (!buffer) {
275 		err = 0;
276 		goto out;
277 	}
278 
279 	if (len > size) {
280 		err = -ERANGE;
281 		if (required)
282 			*required = len;
283 		goto out;
284 	}
285 
286 	memcpy(buffer, ea->name + ea->name_len + 1, len);
287 	err = 0;
288 
289 out:
290 	kfree(ea_all);
291 	if (!required)
292 		ni_unlock(ni);
293 
294 	return err ? err : len;
295 }
296 
297 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
298 				size_t name_len, const void *value,
299 				size_t val_size, int flags, bool locked,
300 				__le16 *ea_size)
301 {
302 	struct ntfs_inode *ni = ntfs_i(inode);
303 	struct ntfs_sb_info *sbi = ni->mi.sbi;
304 	int err;
305 	struct EA_INFO ea_info;
306 	const struct EA_INFO *info;
307 	struct EA_FULL *new_ea;
308 	struct EA_FULL *ea_all = NULL;
309 	size_t add, new_pack;
310 	u32 off, size, ea_sz;
311 	__le16 size_pack;
312 	struct ATTRIB *attr;
313 	struct ATTR_LIST_ENTRY *le;
314 	struct mft_inode *mi;
315 	struct runs_tree ea_run;
316 	u64 new_sz;
317 	void *p;
318 
319 	if (!locked)
320 		ni_lock(ni);
321 
322 	run_init(&ea_run);
323 
324 	if (name_len > 255) {
325 		err = -ENAMETOOLONG;
326 		goto out;
327 	}
328 
329 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
330 
331 	err = ntfs_read_ea(ni, &ea_all, add, &info);
332 	if (err)
333 		goto out;
334 
335 	if (!info) {
336 		memset(&ea_info, 0, sizeof(ea_info));
337 		size = 0;
338 		size_pack = 0;
339 	} else {
340 		memcpy(&ea_info, info, sizeof(ea_info));
341 		size = le32_to_cpu(ea_info.size);
342 		size_pack = ea_info.size_pack;
343 	}
344 
345 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
346 		struct EA_FULL *ea;
347 
348 		if (flags & XATTR_CREATE) {
349 			err = -EEXIST;
350 			goto out;
351 		}
352 
353 		ea = Add2Ptr(ea_all, off);
354 
355 		/*
356 		 * Check simple case when we try to insert xattr with the same value
357 		 * e.g. ntfs_save_wsl_perm
358 		 */
359 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
360 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
361 			/* xattr already contains the required value. */
362 			goto out;
363 		}
364 
365 		/* Remove current xattr. */
366 		if (ea->flags & FILE_NEED_EA)
367 			le16_add_cpu(&ea_info.count, -1);
368 
369 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
370 
371 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
372 
373 		size -= ea_sz;
374 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
375 
376 		ea_info.size = cpu_to_le32(size);
377 
378 		if ((flags & XATTR_REPLACE) && !val_size) {
379 			/* Remove xattr. */
380 			goto update_ea;
381 		}
382 	} else {
383 		if (flags & XATTR_REPLACE) {
384 			err = -ENODATA;
385 			goto out;
386 		}
387 
388 		if (!ea_all) {
389 			ea_all = kzalloc(add, GFP_NOFS);
390 			if (!ea_all) {
391 				err = -ENOMEM;
392 				goto out;
393 			}
394 		}
395 	}
396 
397 	/* Append new xattr. */
398 	new_ea = Add2Ptr(ea_all, size);
399 	new_ea->size = cpu_to_le32(add);
400 	new_ea->flags = 0;
401 	new_ea->name_len = name_len;
402 	new_ea->elength = cpu_to_le16(val_size);
403 	memcpy(new_ea->name, name, name_len);
404 	new_ea->name[name_len] = 0;
405 	memcpy(new_ea->name + name_len + 1, value, val_size);
406 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
407 	ea_info.size_pack = cpu_to_le16(new_pack);
408 	/* New size of ATTR_EA. */
409 	size += add;
410 	ea_info.size = cpu_to_le32(size);
411 
412 	/*
413 	 * 1. Check ea_info.size_pack for overflow.
414 	 * 2. New attribute size must fit value from $AttrDef
415 	 */
416 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
417 		ntfs_inode_warn(
418 			inode,
419 			"The size of extended attributes must not exceed 64KiB");
420 		err = -EFBIG; // -EINVAL?
421 		goto out;
422 	}
423 
424 update_ea:
425 
426 	if (!info) {
427 		/* Create xattr. */
428 		if (!size) {
429 			err = 0;
430 			goto out;
431 		}
432 
433 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
434 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
435 					 NULL);
436 		if (err)
437 			goto out;
438 
439 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
440 					 NULL);
441 		if (err)
442 			goto out;
443 	}
444 
445 	new_sz = size;
446 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
447 			    false, NULL);
448 	if (err)
449 		goto out;
450 
451 	le = NULL;
452 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
453 	if (!attr) {
454 		err = -EINVAL;
455 		goto out;
456 	}
457 
458 	if (!size) {
459 		/* Delete xattr, ATTR_EA_INFO */
460 		ni_remove_attr_le(ni, attr, mi, le);
461 	} else {
462 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
463 		if (!p) {
464 			err = -EINVAL;
465 			goto out;
466 		}
467 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
468 		mi->dirty = true;
469 	}
470 
471 	le = NULL;
472 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
473 	if (!attr) {
474 		err = -EINVAL;
475 		goto out;
476 	}
477 
478 	if (!size) {
479 		/* Delete xattr, ATTR_EA */
480 		ni_remove_attr_le(ni, attr, mi, le);
481 	} else if (attr->non_res) {
482 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
483 					   size);
484 		if (err)
485 			goto out;
486 
487 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
488 		if (err)
489 			goto out;
490 	} else {
491 		p = resident_data_ex(attr, size);
492 		if (!p) {
493 			err = -EINVAL;
494 			goto out;
495 		}
496 		memcpy(p, ea_all, size);
497 		mi->dirty = true;
498 	}
499 
500 	/* Check if we delete the last xattr. */
501 	if (size)
502 		ni->ni_flags |= NI_FLAG_EA;
503 	else
504 		ni->ni_flags &= ~NI_FLAG_EA;
505 
506 	if (ea_info.size_pack != size_pack)
507 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
508 	if (ea_size)
509 		*ea_size = ea_info.size_pack;
510 	mark_inode_dirty(&ni->vfs_inode);
511 
512 out:
513 	if (!locked)
514 		ni_unlock(ni);
515 
516 	run_close(&ea_run);
517 	kfree(ea_all);
518 
519 	return err;
520 }
521 
522 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
523 
524 /*
525  * ntfs_get_acl - inode_operations::get_acl
526  */
527 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap,
528 			       struct dentry *dentry, int type)
529 {
530 	struct inode *inode = d_inode(dentry);
531 	struct ntfs_inode *ni = ntfs_i(inode);
532 	const char *name;
533 	size_t name_len;
534 	struct posix_acl *acl;
535 	size_t req;
536 	int err;
537 	void *buf;
538 
539 	/* Allocate PATH_MAX bytes. */
540 	buf = __getname();
541 	if (!buf)
542 		return ERR_PTR(-ENOMEM);
543 
544 	/* Possible values of 'type' was already checked above. */
545 	if (type == ACL_TYPE_ACCESS) {
546 		name = XATTR_NAME_POSIX_ACL_ACCESS;
547 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
548 	} else {
549 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
550 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
551 	}
552 
553 	ni_lock(ni);
554 
555 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
556 
557 	ni_unlock(ni);
558 
559 	/* Translate extended attribute to acl. */
560 	if (err >= 0) {
561 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
562 	} else if (err == -ENODATA) {
563 		acl = NULL;
564 	} else {
565 		acl = ERR_PTR(err);
566 	}
567 
568 	if (!IS_ERR(acl))
569 		set_cached_acl(inode, type, acl);
570 
571 	__putname(buf);
572 
573 	return acl;
574 }
575 
576 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
577 				    struct inode *inode, struct posix_acl *acl,
578 				    int type, bool init_acl)
579 {
580 	const char *name;
581 	size_t size, name_len;
582 	void *value;
583 	int err;
584 	int flags;
585 	umode_t mode;
586 
587 	if (S_ISLNK(inode->i_mode))
588 		return -EOPNOTSUPP;
589 
590 	mode = inode->i_mode;
591 	switch (type) {
592 	case ACL_TYPE_ACCESS:
593 		/* Do not change i_mode if we are in init_acl */
594 		if (acl && !init_acl) {
595 			err = posix_acl_update_mode(idmap, inode, &mode,
596 						    &acl);
597 			if (err)
598 				return err;
599 		}
600 		name = XATTR_NAME_POSIX_ACL_ACCESS;
601 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
602 		break;
603 
604 	case ACL_TYPE_DEFAULT:
605 		if (!S_ISDIR(inode->i_mode))
606 			return acl ? -EACCES : 0;
607 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
608 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
609 		break;
610 
611 	default:
612 		return -EINVAL;
613 	}
614 
615 	if (!acl) {
616 		/* Remove xattr if it can be presented via mode. */
617 		size = 0;
618 		value = NULL;
619 		flags = XATTR_REPLACE;
620 	} else {
621 		size = posix_acl_xattr_size(acl->a_count);
622 		value = kmalloc(size, GFP_NOFS);
623 		if (!value)
624 			return -ENOMEM;
625 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
626 		if (err < 0)
627 			goto out;
628 		flags = 0;
629 	}
630 
631 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
632 	if (err == -ENODATA && !size)
633 		err = 0; /* Removing non existed xattr. */
634 	if (!err) {
635 		set_cached_acl(inode, type, acl);
636 		inode->i_mode = mode;
637 		inode->i_ctime = current_time(inode);
638 		mark_inode_dirty(inode);
639 	}
640 
641 out:
642 	kfree(value);
643 
644 	return err;
645 }
646 
647 /*
648  * ntfs_set_acl - inode_operations::set_acl
649  */
650 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
651 		 struct posix_acl *acl, int type)
652 {
653 	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
654 }
655 
656 /*
657  * ntfs_init_acl - Initialize the ACLs of a new inode.
658  *
659  * Called from ntfs_create_inode().
660  */
661 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
662 		  struct inode *dir)
663 {
664 	struct posix_acl *default_acl, *acl;
665 	int err;
666 
667 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
668 	if (err)
669 		return err;
670 
671 	if (default_acl) {
672 		err = ntfs_set_acl_ex(idmap, inode, default_acl,
673 				      ACL_TYPE_DEFAULT, true);
674 		posix_acl_release(default_acl);
675 	} else {
676 		inode->i_default_acl = NULL;
677 	}
678 
679 	if (acl) {
680 		if (!err)
681 			err = ntfs_set_acl_ex(idmap, inode, acl,
682 					      ACL_TYPE_ACCESS, true);
683 		posix_acl_release(acl);
684 	} else {
685 		inode->i_acl = NULL;
686 	}
687 
688 	return err;
689 }
690 #endif
691 
692 /*
693  * ntfs_acl_chmod - Helper for ntfs3_setattr().
694  */
695 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
696 {
697 	struct inode *inode = d_inode(dentry);
698 	struct super_block *sb = inode->i_sb;
699 
700 	if (!(sb->s_flags & SB_POSIXACL))
701 		return 0;
702 
703 	if (S_ISLNK(inode->i_mode))
704 		return -EOPNOTSUPP;
705 
706 	return posix_acl_chmod(idmap, dentry, inode->i_mode);
707 }
708 
709 /*
710  * ntfs_listxattr - inode_operations::listxattr
711  */
712 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
713 {
714 	struct inode *inode = d_inode(dentry);
715 	struct ntfs_inode *ni = ntfs_i(inode);
716 	ssize_t ret;
717 
718 	if (!(ni->ni_flags & NI_FLAG_EA)) {
719 		/* no xattr in file */
720 		return 0;
721 	}
722 
723 	ni_lock(ni);
724 
725 	ret = ntfs_list_ea(ni, buffer, size);
726 
727 	ni_unlock(ni);
728 
729 	return ret;
730 }
731 
732 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
733 			 struct inode *inode, const char *name, void *buffer,
734 			 size_t size)
735 {
736 	int err;
737 	struct ntfs_inode *ni = ntfs_i(inode);
738 
739 	/* Dispatch request. */
740 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
741 		/* system.dos_attrib */
742 		if (!buffer) {
743 			err = sizeof(u8);
744 		} else if (size < sizeof(u8)) {
745 			err = -ENODATA;
746 		} else {
747 			err = sizeof(u8);
748 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
749 		}
750 		goto out;
751 	}
752 
753 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
754 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
755 		/* system.ntfs_attrib */
756 		if (!buffer) {
757 			err = sizeof(u32);
758 		} else if (size < sizeof(u32)) {
759 			err = -ENODATA;
760 		} else {
761 			err = sizeof(u32);
762 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
763 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
764 				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
765 		}
766 		goto out;
767 	}
768 
769 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
770 		/* system.ntfs_security*/
771 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
772 		size_t sd_size = 0;
773 
774 		if (!is_ntfs3(ni->mi.sbi)) {
775 			/* We should get nt4 security. */
776 			err = -EINVAL;
777 			goto out;
778 		} else if (le32_to_cpu(ni->std_security_id) <
779 			   SECURITY_ID_FIRST) {
780 			err = -ENOENT;
781 			goto out;
782 		}
783 
784 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
785 					      &sd, &sd_size);
786 		if (err)
787 			goto out;
788 
789 		if (!is_sd_valid(sd, sd_size)) {
790 			ntfs_inode_warn(
791 				inode,
792 				"looks like you get incorrect security descriptor id=%u",
793 				ni->std_security_id);
794 		}
795 
796 		if (!buffer) {
797 			err = sd_size;
798 		} else if (size < sd_size) {
799 			err = -ENODATA;
800 		} else {
801 			err = sd_size;
802 			memcpy(buffer, sd, sd_size);
803 		}
804 		kfree(sd);
805 		goto out;
806 	}
807 
808 	/* Deal with NTFS extended attribute. */
809 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
810 
811 out:
812 	return err;
813 }
814 
815 /*
816  * ntfs_setxattr - inode_operations::setxattr
817  */
818 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
819 				  struct mnt_idmap *idmap,
820 				  struct dentry *de, struct inode *inode,
821 				  const char *name, const void *value,
822 				  size_t size, int flags)
823 {
824 	int err = -EINVAL;
825 	struct ntfs_inode *ni = ntfs_i(inode);
826 	enum FILE_ATTRIBUTE new_fa;
827 
828 	/* Dispatch request. */
829 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
830 		if (sizeof(u8) != size)
831 			goto out;
832 		new_fa = cpu_to_le32(*(u8 *)value);
833 		goto set_new_fa;
834 	}
835 
836 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
837 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
838 		if (size != sizeof(u32))
839 			goto out;
840 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
841 			new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
842 		else
843 			new_fa = cpu_to_le32(*(u32 *)value);
844 
845 		if (S_ISREG(inode->i_mode)) {
846 			/* Process compressed/sparsed in special way. */
847 			ni_lock(ni);
848 			err = ni_new_attr_flags(ni, new_fa);
849 			ni_unlock(ni);
850 			if (err)
851 				goto out;
852 		}
853 set_new_fa:
854 		/*
855 		 * Thanks Mark Harmstone:
856 		 * Keep directory bit consistency.
857 		 */
858 		if (S_ISDIR(inode->i_mode))
859 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
860 		else
861 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
862 
863 		if (ni->std_fa != new_fa) {
864 			ni->std_fa = new_fa;
865 			if (new_fa & FILE_ATTRIBUTE_READONLY)
866 				inode->i_mode &= ~0222;
867 			else
868 				inode->i_mode |= 0222;
869 			/* Std attribute always in primary record. */
870 			ni->mi.dirty = true;
871 			mark_inode_dirty(inode);
872 		}
873 		err = 0;
874 
875 		goto out;
876 	}
877 
878 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
879 		/* system.ntfs_security*/
880 		__le32 security_id;
881 		bool inserted;
882 		struct ATTR_STD_INFO5 *std;
883 
884 		if (!is_ntfs3(ni->mi.sbi)) {
885 			/*
886 			 * We should replace ATTR_SECURE.
887 			 * Skip this way cause it is nt4 feature.
888 			 */
889 			err = -EINVAL;
890 			goto out;
891 		}
892 
893 		if (!is_sd_valid(value, size)) {
894 			err = -EINVAL;
895 			ntfs_inode_warn(
896 				inode,
897 				"you try to set invalid security descriptor");
898 			goto out;
899 		}
900 
901 		err = ntfs_insert_security(ni->mi.sbi, value, size,
902 					   &security_id, &inserted);
903 		if (err)
904 			goto out;
905 
906 		ni_lock(ni);
907 		std = ni_std5(ni);
908 		if (!std) {
909 			err = -EINVAL;
910 		} else if (std->security_id != security_id) {
911 			std->security_id = ni->std_security_id = security_id;
912 			/* Std attribute always in primary record. */
913 			ni->mi.dirty = true;
914 			mark_inode_dirty(&ni->vfs_inode);
915 		}
916 		ni_unlock(ni);
917 		goto out;
918 	}
919 
920 	/* Deal with NTFS extended attribute. */
921 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0,
922 			  NULL);
923 
924 out:
925 	inode->i_ctime = current_time(inode);
926 	mark_inode_dirty(inode);
927 
928 	return err;
929 }
930 
931 /*
932  * ntfs_save_wsl_perm
933  *
934  * save uid/gid/mode in xattr
935  */
936 int ntfs_save_wsl_perm(struct inode *inode, __le16 *ea_size)
937 {
938 	int err;
939 	__le32 value;
940 	struct ntfs_inode *ni = ntfs_i(inode);
941 
942 	ni_lock(ni);
943 	value = cpu_to_le32(i_uid_read(inode));
944 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
945 			  sizeof(value), 0, true, ea_size);
946 	if (err)
947 		goto out;
948 
949 	value = cpu_to_le32(i_gid_read(inode));
950 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
951 			  sizeof(value), 0, true, ea_size);
952 	if (err)
953 		goto out;
954 
955 	value = cpu_to_le32(inode->i_mode);
956 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
957 			  sizeof(value), 0, true, ea_size);
958 	if (err)
959 		goto out;
960 
961 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
962 		value = cpu_to_le32(inode->i_rdev);
963 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
964 				  sizeof(value), 0, true, ea_size);
965 		if (err)
966 			goto out;
967 	}
968 
969 out:
970 	ni_unlock(ni);
971 	/* In case of error should we delete all WSL xattr? */
972 	return err;
973 }
974 
975 /*
976  * ntfs_get_wsl_perm
977  *
978  * get uid/gid/mode from xattr
979  * it is called from ntfs_iget5->ntfs_read_mft
980  */
981 void ntfs_get_wsl_perm(struct inode *inode)
982 {
983 	size_t sz;
984 	__le32 value[3];
985 
986 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
987 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
988 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
989 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
990 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
991 			sizeof(value[2]), &sz) == sizeof(value[2])) {
992 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
993 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
994 		inode->i_mode = le32_to_cpu(value[2]);
995 
996 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
997 				&value[0], sizeof(value),
998 				&sz) == sizeof(value[0])) {
999 			inode->i_rdev = le32_to_cpu(value[0]);
1000 		}
1001 	}
1002 }
1003 
1004 static bool ntfs_xattr_user_list(struct dentry *dentry)
1005 {
1006 	return true;
1007 }
1008 
1009 // clang-format off
1010 static const struct xattr_handler ntfs_other_xattr_handler = {
1011 	.prefix	= "",
1012 	.get	= ntfs_getxattr,
1013 	.set	= ntfs_setxattr,
1014 	.list	= ntfs_xattr_user_list,
1015 };
1016 
1017 const struct xattr_handler *ntfs_xattr_handlers[] = {
1018 	&ntfs_other_xattr_handler,
1019 	NULL,
1020 };
1021 // clang-format on
1022