xref: /openbmc/linux/fs/ntfs3/xattr.c (revision 13e83a4923bea7c4f2f6714030cb7e56d20ef7e5)
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 {
301 	struct ntfs_inode *ni = ntfs_i(inode);
302 	struct ntfs_sb_info *sbi = ni->mi.sbi;
303 	int err;
304 	struct EA_INFO ea_info;
305 	const struct EA_INFO *info;
306 	struct EA_FULL *new_ea;
307 	struct EA_FULL *ea_all = NULL;
308 	size_t add, new_pack;
309 	u32 off, size, ea_sz;
310 	__le16 size_pack;
311 	struct ATTRIB *attr;
312 	struct ATTR_LIST_ENTRY *le;
313 	struct mft_inode *mi;
314 	struct runs_tree ea_run;
315 	u64 new_sz;
316 	void *p;
317 
318 	if (!locked)
319 		ni_lock(ni);
320 
321 	run_init(&ea_run);
322 
323 	if (name_len > 255) {
324 		err = -ENAMETOOLONG;
325 		goto out;
326 	}
327 
328 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
329 
330 	err = ntfs_read_ea(ni, &ea_all, add, &info);
331 	if (err)
332 		goto out;
333 
334 	if (!info) {
335 		memset(&ea_info, 0, sizeof(ea_info));
336 		size = 0;
337 		size_pack = 0;
338 	} else {
339 		memcpy(&ea_info, info, sizeof(ea_info));
340 		size = le32_to_cpu(ea_info.size);
341 		size_pack = ea_info.size_pack;
342 	}
343 
344 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
345 		struct EA_FULL *ea;
346 
347 		if (flags & XATTR_CREATE) {
348 			err = -EEXIST;
349 			goto out;
350 		}
351 
352 		ea = Add2Ptr(ea_all, off);
353 
354 		/*
355 		 * Check simple case when we try to insert xattr with the same value
356 		 * e.g. ntfs_save_wsl_perm
357 		 */
358 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
359 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
360 			/* xattr already contains the required value. */
361 			goto out;
362 		}
363 
364 		/* Remove current xattr. */
365 		if (ea->flags & FILE_NEED_EA)
366 			le16_add_cpu(&ea_info.count, -1);
367 
368 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
369 
370 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
371 
372 		size -= ea_sz;
373 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
374 
375 		ea_info.size = cpu_to_le32(size);
376 
377 		if ((flags & XATTR_REPLACE) && !val_size) {
378 			/* Remove xattr. */
379 			goto update_ea;
380 		}
381 	} else {
382 		if (flags & XATTR_REPLACE) {
383 			err = -ENODATA;
384 			goto out;
385 		}
386 
387 		if (!ea_all) {
388 			ea_all = kzalloc(add, GFP_NOFS);
389 			if (!ea_all) {
390 				err = -ENOMEM;
391 				goto out;
392 			}
393 		}
394 	}
395 
396 	/* Append new xattr. */
397 	new_ea = Add2Ptr(ea_all, size);
398 	new_ea->size = cpu_to_le32(add);
399 	new_ea->flags = 0;
400 	new_ea->name_len = name_len;
401 	new_ea->elength = cpu_to_le16(val_size);
402 	memcpy(new_ea->name, name, name_len);
403 	new_ea->name[name_len] = 0;
404 	memcpy(new_ea->name + name_len + 1, value, val_size);
405 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
406 	ea_info.size_pack = cpu_to_le16(new_pack);
407 	/* New size of ATTR_EA. */
408 	size += add;
409 	ea_info.size = cpu_to_le32(size);
410 
411 	/*
412 	 * 1. Check ea_info.size_pack for overflow.
413 	 * 2. New attibute size must fit value from $AttrDef
414 	 */
415 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
416 		ntfs_inode_warn(
417 			inode,
418 			"The size of extended attributes must not exceed 64KiB");
419 		err = -EFBIG; // -EINVAL?
420 		goto out;
421 	}
422 
423 update_ea:
424 
425 	if (!info) {
426 		/* Create xattr. */
427 		if (!size) {
428 			err = 0;
429 			goto out;
430 		}
431 
432 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
433 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
434 					 NULL);
435 		if (err)
436 			goto out;
437 
438 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
439 					 NULL);
440 		if (err)
441 			goto out;
442 	}
443 
444 	new_sz = size;
445 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
446 			    false, NULL);
447 	if (err)
448 		goto out;
449 
450 	le = NULL;
451 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
452 	if (!attr) {
453 		err = -EINVAL;
454 		goto out;
455 	}
456 
457 	if (!size) {
458 		/* Delete xattr, ATTR_EA_INFO */
459 		ni_remove_attr_le(ni, attr, mi, le);
460 	} else {
461 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
462 		if (!p) {
463 			err = -EINVAL;
464 			goto out;
465 		}
466 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
467 		mi->dirty = true;
468 	}
469 
470 	le = NULL;
471 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
472 	if (!attr) {
473 		err = -EINVAL;
474 		goto out;
475 	}
476 
477 	if (!size) {
478 		/* Delete xattr, ATTR_EA */
479 		ni_remove_attr_le(ni, attr, mi, le);
480 	} else if (attr->non_res) {
481 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
482 					   size);
483 		if (err)
484 			goto out;
485 
486 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
487 		if (err)
488 			goto out;
489 	} else {
490 		p = resident_data_ex(attr, size);
491 		if (!p) {
492 			err = -EINVAL;
493 			goto out;
494 		}
495 		memcpy(p, ea_all, size);
496 		mi->dirty = true;
497 	}
498 
499 	/* Check if we delete the last xattr. */
500 	if (size)
501 		ni->ni_flags |= NI_FLAG_EA;
502 	else
503 		ni->ni_flags &= ~NI_FLAG_EA;
504 
505 	if (ea_info.size_pack != size_pack)
506 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
507 	mark_inode_dirty(&ni->vfs_inode);
508 
509 out:
510 	if (!locked)
511 		ni_unlock(ni);
512 
513 	run_close(&ea_run);
514 	kfree(ea_all);
515 
516 	return err;
517 }
518 
519 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
520 static struct posix_acl *ntfs_get_acl_ex(struct inode *inode, int type,
521 					 int locked)
522 {
523 	struct ntfs_inode *ni = ntfs_i(inode);
524 	const char *name;
525 	size_t name_len;
526 	struct posix_acl *acl;
527 	size_t req;
528 	int err;
529 	void *buf;
530 
531 	/* Allocate PATH_MAX bytes. */
532 	buf = __getname();
533 	if (!buf)
534 		return ERR_PTR(-ENOMEM);
535 
536 	/* Possible values of 'type' was already checked above. */
537 	if (type == ACL_TYPE_ACCESS) {
538 		name = XATTR_NAME_POSIX_ACL_ACCESS;
539 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
540 	} else {
541 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
542 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
543 	}
544 
545 	if (!locked)
546 		ni_lock(ni);
547 
548 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
549 
550 	if (!locked)
551 		ni_unlock(ni);
552 
553 	/* Translate extended attribute to acl. */
554 	if (err >= 0) {
555 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
556 	} else if (err == -ENODATA) {
557 		acl = NULL;
558 	} else {
559 		acl = ERR_PTR(err);
560 	}
561 
562 	if (!IS_ERR(acl))
563 		set_cached_acl(inode, type, acl);
564 
565 	__putname(buf);
566 
567 	return acl;
568 }
569 
570 /*
571  * ntfs_get_acl - inode_operations::get_acl
572  */
573 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
574 {
575 	if (rcu)
576 		return ERR_PTR(-ECHILD);
577 
578 	return ntfs_get_acl_ex(inode, type, 0);
579 }
580 
581 static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
582 				    struct inode *inode, struct posix_acl *acl,
583 				    int type, bool init_acl)
584 {
585 	const char *name;
586 	size_t size, name_len;
587 	void *value;
588 	int err;
589 	int flags;
590 	umode_t mode;
591 
592 	if (S_ISLNK(inode->i_mode))
593 		return -EOPNOTSUPP;
594 
595 	mode = inode->i_mode;
596 	switch (type) {
597 	case ACL_TYPE_ACCESS:
598 		/* Do not change i_mode if we are in init_acl */
599 		if (acl && !init_acl) {
600 			err = posix_acl_update_mode(mnt_userns, inode, &mode,
601 						    &acl);
602 			if (err)
603 				return err;
604 		}
605 		name = XATTR_NAME_POSIX_ACL_ACCESS;
606 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
607 		break;
608 
609 	case ACL_TYPE_DEFAULT:
610 		if (!S_ISDIR(inode->i_mode))
611 			return acl ? -EACCES : 0;
612 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
613 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
614 		break;
615 
616 	default:
617 		return -EINVAL;
618 	}
619 
620 	if (!acl) {
621 		/* Remove xattr if it can be presented via mode. */
622 		size = 0;
623 		value = NULL;
624 		flags = XATTR_REPLACE;
625 	} else {
626 		size = posix_acl_xattr_size(acl->a_count);
627 		value = kmalloc(size, GFP_NOFS);
628 		if (!value)
629 			return -ENOMEM;
630 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
631 		if (err < 0)
632 			goto out;
633 		flags = 0;
634 	}
635 
636 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
637 	if (err == -ENODATA && !size)
638 		err = 0; /* Removing non existed xattr. */
639 	if (!err) {
640 		set_cached_acl(inode, type, acl);
641 		inode->i_mode = mode;
642 		inode->i_ctime = current_time(inode);
643 		mark_inode_dirty(inode);
644 	}
645 
646 out:
647 	kfree(value);
648 
649 	return err;
650 }
651 
652 /*
653  * ntfs_set_acl - inode_operations::set_acl
654  */
655 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
656 		 struct posix_acl *acl, int type)
657 {
658 	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
659 
660 	return ntfs_set_acl_ex(mnt_userns, d_inode(dentry), acl, type, false);
661 }
662 
663 /*
664  * ntfs_init_acl - Initialize the ACLs of a new inode.
665  *
666  * Called from ntfs_create_inode().
667  */
668 int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
669 		  struct inode *dir)
670 {
671 	struct posix_acl *default_acl, *acl;
672 	int err;
673 
674 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
675 	if (err)
676 		return err;
677 
678 	if (default_acl) {
679 		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
680 				      ACL_TYPE_DEFAULT, true);
681 		posix_acl_release(default_acl);
682 	} else {
683 		inode->i_default_acl = NULL;
684 	}
685 
686 	if (acl) {
687 		if (!err)
688 			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
689 					      ACL_TYPE_ACCESS, true);
690 		posix_acl_release(acl);
691 	} else {
692 		inode->i_acl = NULL;
693 	}
694 
695 	return err;
696 }
697 #endif
698 
699 /*
700  * ntfs_acl_chmod - Helper for ntfs3_setattr().
701  */
702 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
703 {
704 	struct inode *inode = d_inode(dentry);
705 	struct super_block *sb = inode->i_sb;
706 
707 	if (!(sb->s_flags & SB_POSIXACL))
708 		return 0;
709 
710 	if (S_ISLNK(inode->i_mode))
711 		return -EOPNOTSUPP;
712 
713 	return posix_acl_chmod(idmap, dentry, inode->i_mode);
714 }
715 
716 /*
717  * ntfs_permission - inode_operations::permission
718  */
719 int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
720 		    int mask)
721 {
722 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
723 		/* "No access rules" mode - Allow all changes. */
724 		return 0;
725 	}
726 
727 	return generic_permission(mnt_userns, inode, mask);
728 }
729 
730 /*
731  * ntfs_listxattr - inode_operations::listxattr
732  */
733 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
734 {
735 	struct inode *inode = d_inode(dentry);
736 	struct ntfs_inode *ni = ntfs_i(inode);
737 	ssize_t ret;
738 
739 	if (!(ni->ni_flags & NI_FLAG_EA)) {
740 		/* no xattr in file */
741 		return 0;
742 	}
743 
744 	ni_lock(ni);
745 
746 	ret = ntfs_list_ea(ni, buffer, size);
747 
748 	ni_unlock(ni);
749 
750 	return ret;
751 }
752 
753 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
754 			 struct inode *inode, const char *name, void *buffer,
755 			 size_t size)
756 {
757 	int err;
758 	struct ntfs_inode *ni = ntfs_i(inode);
759 
760 	/* Dispatch request. */
761 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
762 		/* system.dos_attrib */
763 		if (!buffer) {
764 			err = sizeof(u8);
765 		} else if (size < sizeof(u8)) {
766 			err = -ENODATA;
767 		} else {
768 			err = sizeof(u8);
769 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
770 		}
771 		goto out;
772 	}
773 
774 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
775 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
776 		/* system.ntfs_attrib */
777 		if (!buffer) {
778 			err = sizeof(u32);
779 		} else if (size < sizeof(u32)) {
780 			err = -ENODATA;
781 		} else {
782 			err = sizeof(u32);
783 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
784 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
785 				*(u32 *)buffer = cpu_to_be32(*(u32 *)buffer);
786 		}
787 		goto out;
788 	}
789 
790 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
791 		/* system.ntfs_security*/
792 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
793 		size_t sd_size = 0;
794 
795 		if (!is_ntfs3(ni->mi.sbi)) {
796 			/* We should get nt4 security. */
797 			err = -EINVAL;
798 			goto out;
799 		} else if (le32_to_cpu(ni->std_security_id) <
800 			   SECURITY_ID_FIRST) {
801 			err = -ENOENT;
802 			goto out;
803 		}
804 
805 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
806 					      &sd, &sd_size);
807 		if (err)
808 			goto out;
809 
810 		if (!is_sd_valid(sd, sd_size)) {
811 			ntfs_inode_warn(
812 				inode,
813 				"looks like you get incorrect security descriptor id=%u",
814 				ni->std_security_id);
815 		}
816 
817 		if (!buffer) {
818 			err = sd_size;
819 		} else if (size < sd_size) {
820 			err = -ENODATA;
821 		} else {
822 			err = sd_size;
823 			memcpy(buffer, sd, sd_size);
824 		}
825 		kfree(sd);
826 		goto out;
827 	}
828 
829 	/* Deal with NTFS extended attribute. */
830 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
831 
832 out:
833 	return err;
834 }
835 
836 /*
837  * ntfs_setxattr - inode_operations::setxattr
838  */
839 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
840 				  struct user_namespace *mnt_userns,
841 				  struct dentry *de, struct inode *inode,
842 				  const char *name, const void *value,
843 				  size_t size, int flags)
844 {
845 	int err = -EINVAL;
846 	struct ntfs_inode *ni = ntfs_i(inode);
847 	enum FILE_ATTRIBUTE new_fa;
848 
849 	/* Dispatch request. */
850 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
851 		if (sizeof(u8) != size)
852 			goto out;
853 		new_fa = cpu_to_le32(*(u8 *)value);
854 		goto set_new_fa;
855 	}
856 
857 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
858 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
859 		if (size != sizeof(u32))
860 			goto out;
861 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
862 			new_fa = cpu_to_le32(be32_to_cpu(*(u32 *)value));
863 		else
864 			new_fa = cpu_to_le32(*(u32 *)value);
865 
866 		if (S_ISREG(inode->i_mode)) {
867 			/* Process compressed/sparsed in special way. */
868 			ni_lock(ni);
869 			err = ni_new_attr_flags(ni, new_fa);
870 			ni_unlock(ni);
871 			if (err)
872 				goto out;
873 		}
874 set_new_fa:
875 		/*
876 		 * Thanks Mark Harmstone:
877 		 * Keep directory bit consistency.
878 		 */
879 		if (S_ISDIR(inode->i_mode))
880 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
881 		else
882 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
883 
884 		if (ni->std_fa != new_fa) {
885 			ni->std_fa = new_fa;
886 			if (new_fa & FILE_ATTRIBUTE_READONLY)
887 				inode->i_mode &= ~0222;
888 			else
889 				inode->i_mode |= 0222;
890 			/* Std attribute always in primary record. */
891 			ni->mi.dirty = true;
892 			mark_inode_dirty(inode);
893 		}
894 		err = 0;
895 
896 		goto out;
897 	}
898 
899 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
900 		/* system.ntfs_security*/
901 		__le32 security_id;
902 		bool inserted;
903 		struct ATTR_STD_INFO5 *std;
904 
905 		if (!is_ntfs3(ni->mi.sbi)) {
906 			/*
907 			 * We should replace ATTR_SECURE.
908 			 * Skip this way cause it is nt4 feature.
909 			 */
910 			err = -EINVAL;
911 			goto out;
912 		}
913 
914 		if (!is_sd_valid(value, size)) {
915 			err = -EINVAL;
916 			ntfs_inode_warn(
917 				inode,
918 				"you try to set invalid security descriptor");
919 			goto out;
920 		}
921 
922 		err = ntfs_insert_security(ni->mi.sbi, value, size,
923 					   &security_id, &inserted);
924 		if (err)
925 			goto out;
926 
927 		ni_lock(ni);
928 		std = ni_std5(ni);
929 		if (!std) {
930 			err = -EINVAL;
931 		} else if (std->security_id != security_id) {
932 			std->security_id = ni->std_security_id = security_id;
933 			/* Std attribute always in primary record. */
934 			ni->mi.dirty = true;
935 			mark_inode_dirty(&ni->vfs_inode);
936 		}
937 		ni_unlock(ni);
938 		goto out;
939 	}
940 
941 	/* Deal with NTFS extended attribute. */
942 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0);
943 
944 out:
945 	inode->i_ctime = current_time(inode);
946 	mark_inode_dirty(inode);
947 
948 	return err;
949 }
950 
951 /*
952  * ntfs_save_wsl_perm
953  *
954  * save uid/gid/mode in xattr
955  */
956 int ntfs_save_wsl_perm(struct inode *inode)
957 {
958 	int err;
959 	__le32 value;
960 	struct ntfs_inode *ni = ntfs_i(inode);
961 
962 	ni_lock(ni);
963 	value = cpu_to_le32(i_uid_read(inode));
964 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
965 			  sizeof(value), 0, true); /* true == already locked. */
966 	if (err)
967 		goto out;
968 
969 	value = cpu_to_le32(i_gid_read(inode));
970 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
971 			  sizeof(value), 0, true);
972 	if (err)
973 		goto out;
974 
975 	value = cpu_to_le32(inode->i_mode);
976 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
977 			  sizeof(value), 0, true);
978 	if (err)
979 		goto out;
980 
981 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
982 		value = cpu_to_le32(inode->i_rdev);
983 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
984 				  sizeof(value), 0, true);
985 		if (err)
986 			goto out;
987 	}
988 
989 out:
990 	ni_unlock(ni);
991 	/* In case of error should we delete all WSL xattr? */
992 	return err;
993 }
994 
995 /*
996  * ntfs_get_wsl_perm
997  *
998  * get uid/gid/mode from xattr
999  * it is called from ntfs_iget5->ntfs_read_mft
1000  */
1001 void ntfs_get_wsl_perm(struct inode *inode)
1002 {
1003 	size_t sz;
1004 	__le32 value[3];
1005 
1006 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1007 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1008 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1009 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1010 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1011 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1012 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1013 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1014 		inode->i_mode = le32_to_cpu(value[2]);
1015 
1016 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1017 				&value[0], sizeof(value),
1018 				&sz) == sizeof(value[0])) {
1019 			inode->i_rdev = le32_to_cpu(value[0]);
1020 		}
1021 	}
1022 }
1023 
1024 static bool ntfs_xattr_user_list(struct dentry *dentry)
1025 {
1026 	return true;
1027 }
1028 
1029 // clang-format off
1030 static const struct xattr_handler ntfs_other_xattr_handler = {
1031 	.prefix	= "",
1032 	.get	= ntfs_getxattr,
1033 	.set	= ntfs_setxattr,
1034 	.list	= ntfs_xattr_user_list,
1035 };
1036 
1037 const struct xattr_handler *ntfs_xattr_handlers[] = {
1038 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
1039 	&posix_acl_access_xattr_handler,
1040 	&posix_acl_default_xattr_handler,
1041 #endif
1042 	&ntfs_other_xattr_handler,
1043 	NULL,
1044 };
1045 // clang-format on
1046