xref: /linux/fs/ntfs/ea.c (revision 1fc5a74b108fc90951890ec513ac81869f5eaff1)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Pocessing of EA's
4  *
5  * Part of this file is based on code from the NTFS-3G.
6  *
7  * Copyright (c) 2014-2021 Jean-Pierre Andre
8  * Copyright (c) 2025 LG Electronics Co., Ltd.
9  */
10 
11 #include <linux/fs.h>
12 #include <linux/posix_acl.h>
13 #include <linux/posix_acl_xattr.h>
14 #include <linux/xattr.h>
15 
16 #include "layout.h"
17 #include "attrib.h"
18 #include "index.h"
19 #include "dir.h"
20 #include "ea.h"
21 
ntfs_write_ea(struct ntfs_inode * ni,__le32 type,char * value,s64 ea_off,s64 ea_size,bool need_truncate)22 static int ntfs_write_ea(struct ntfs_inode *ni, __le32 type, char *value, s64 ea_off,
23 		s64 ea_size, bool need_truncate)
24 {
25 	struct inode *ea_vi;
26 	int err = 0;
27 	s64 written;
28 
29 	ea_vi = ntfs_attr_iget(VFS_I(ni), type, AT_UNNAMED, 0);
30 	if (IS_ERR(ea_vi))
31 		return PTR_ERR(ea_vi);
32 
33 	written = ntfs_inode_attr_pwrite(ea_vi, ea_off, ea_size, value, false);
34 	if (written != ea_size)
35 		err = -EIO;
36 	else {
37 		struct ntfs_inode *ea_ni = NTFS_I(ea_vi);
38 
39 		if (need_truncate && ea_ni->data_size > ea_off + ea_size)
40 			ntfs_attr_truncate(ea_ni, ea_off + ea_size);
41 		mark_mft_record_dirty(ni);
42 	}
43 
44 	iput(ea_vi);
45 	return err;
46 }
47 
ntfs_ea_lookup(char * ea_buf,s64 ea_buf_size,const char * name,int name_len,s64 * ea_offset,s64 * ea_size)48 static int ntfs_ea_lookup(char *ea_buf, s64 ea_buf_size, const char *name,
49 			  int name_len, s64 *ea_offset, s64 *ea_size)
50 {
51 	const struct ea_attr *p_ea;
52 	size_t actual_size;
53 	loff_t offset, p_ea_size;
54 	unsigned int next;
55 
56 	offset = 0;
57 	do {
58 		if (ea_buf_size - offset < sizeof(struct ea_attr))
59 			break;
60 
61 		p_ea = (const struct ea_attr *)&ea_buf[offset];
62 		next = le32_to_cpu(p_ea->next_entry_offset);
63 		p_ea_size = next ? next : (ea_buf_size - offset);
64 
65 		if (p_ea_size < sizeof(struct ea_attr) ||
66 		    offset + p_ea_size > ea_buf_size)
67 			break;
68 
69 		if ((s64)p_ea->ea_name_length + 1 >
70 		    p_ea_size - offsetof(struct ea_attr, ea_name))
71 			break;
72 
73 		actual_size = ALIGN(struct_size(p_ea, ea_name, 1 + p_ea->ea_name_length +
74 					le16_to_cpu(p_ea->ea_value_length)), 4);
75 		if (actual_size > p_ea_size)
76 			break;
77 
78 		if (p_ea->ea_name_length == name_len &&
79 		    !memcmp(p_ea->ea_name, name, name_len)) {
80 			*ea_offset = offset;
81 			*ea_size = next ? next : actual_size;
82 
83 			if (ea_buf_size < *ea_offset + *ea_size)
84 				goto out;
85 
86 			return 0;
87 		}
88 		offset += next;
89 	} while (next > 0 && offset < ea_buf_size);
90 
91 out:
92 	return -ENOENT;
93 }
94 
95 /*
96  * Return the existing EA
97  *
98  * The EA_INFORMATION is not examined and the consistency of the
99  * existing EA is not checked.
100  *
101  * If successful, the full attribute is returned unchanged
102  * and its size is returned.
103  * If the designated buffer is too small, the needed size is
104  * returned, and the buffer is left unchanged.
105  * If there is an error, a negative value is returned and errno
106  * is set according to the error.
107  */
ntfs_get_ea(struct inode * inode,const char * name,size_t name_len,void * buffer,size_t size)108 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
109 		void *buffer, size_t size)
110 {
111 	struct ntfs_inode *ni = NTFS_I(inode);
112 	const struct ea_attr *p_ea;
113 	char *ea_buf;
114 	s64 ea_off, ea_size, all_ea_size, ea_info_size;
115 	int err;
116 	u32 ea_info_qlen;
117 	u16 ea_value_len;
118 	struct ea_information *p_ea_info;
119 
120 	if (!NInoHasEA(ni))
121 		return -ENODATA;
122 
123 	p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
124 			&ea_info_size);
125 	if (IS_ERR(p_ea_info))
126 		return PTR_ERR(p_ea_info);
127 	if (ea_info_size != sizeof(struct ea_information)) {
128 		kvfree(p_ea_info);
129 		return -EIO;
130 	}
131 
132 	ea_info_qlen = le32_to_cpu(p_ea_info->ea_query_length);
133 	kvfree(p_ea_info);
134 
135 	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
136 	if (IS_ERR(ea_buf))
137 		return PTR_ERR(ea_buf);
138 
139 	if (ea_info_qlen > all_ea_size) {
140 		err = -EIO;
141 		goto free_ea_buf;
142 	}
143 
144 	err = ntfs_ea_lookup(ea_buf, ea_info_qlen, name, name_len, &ea_off,
145 			&ea_size);
146 	if (!err) {
147 		p_ea = (struct ea_attr *)&ea_buf[ea_off];
148 		ea_value_len = le16_to_cpu(p_ea->ea_value_length);
149 		if (!buffer) {
150 			kvfree(ea_buf);
151 			return ea_value_len;
152 		}
153 
154 		if (ea_value_len > size) {
155 			err = -ERANGE;
156 			goto free_ea_buf;
157 		}
158 
159 		memcpy(buffer, &p_ea->ea_name[p_ea->ea_name_length + 1],
160 				ea_value_len);
161 		kvfree(ea_buf);
162 		return ea_value_len;
163 	}
164 
165 	err = -ENODATA;
166 free_ea_buf:
167 	kvfree(ea_buf);
168 	return err;
169 }
170 
ea_packed_size(const struct ea_attr * p_ea)171 static inline int ea_packed_size(const struct ea_attr *p_ea)
172 {
173 	/*
174 	 * 4 bytes for header (flags and lengths) + name length + 1 +
175 	 * value length.
176 	 */
177 	return 5 + p_ea->ea_name_length + le16_to_cpu(p_ea->ea_value_length);
178 }
179 
180 /*
181  * Set a new EA, and set EA_INFORMATION accordingly
182  *
183  * This is roughly the same as ZwSetEaFile() on Windows, however
184  * the "offset to next" of the last EA should not be cleared.
185  *
186  * Consistency of the new EA is first checked.
187  *
188  * EA_INFORMATION is set first, and it is restored to its former
189  * state if setting EA fails.
190  */
ntfs_set_ea(struct inode * inode,const char * name,size_t name_len,const void * value,size_t val_size,int flags,__le16 * packed_ea_size)191 static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
192 		const void *value, size_t val_size, int flags,
193 		__le16 *packed_ea_size)
194 {
195 	struct ntfs_inode *ni = NTFS_I(inode);
196 	struct ea_information *p_ea_info = NULL;
197 	int ea_packed, err = 0;
198 	struct ea_attr *p_ea;
199 	u32 ea_info_qsize = 0;
200 	char *ea_buf = NULL;
201 	char *new_ea_buf;
202 	char *old_ea_buf = NULL;
203 	struct ea_information old_ea_info;
204 	size_t new_ea_size = ALIGN(struct_size(p_ea, ea_name, 1 + name_len + val_size), 4);
205 	s64 ea_off, ea_info_size, all_ea_size, ea_size;
206 
207 	if (name_len > 255)
208 		return -ENAMETOOLONG;
209 
210 	if (ntfs_attr_exist(ni, AT_EA_INFORMATION, AT_UNNAMED, 0)) {
211 		p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
212 						&ea_info_size);
213 		if (IS_ERR(p_ea_info)) {
214 			err = PTR_ERR(p_ea_info);
215 			p_ea_info = NULL;
216 			goto out;
217 		}
218 		if (ea_info_size != sizeof(struct ea_information)) {
219 			err = -EIO;
220 			goto out;
221 		}
222 
223 		ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
224 		if (IS_ERR(ea_buf)) {
225 			err = PTR_ERR(ea_buf);
226 			ea_buf = NULL;
227 			goto out;
228 		}
229 		if (!ea_buf) {
230 			ea_info_qsize = 0;
231 			kvfree(p_ea_info);
232 			goto create_ea_info;
233 		}
234 
235 		ea_info_qsize = le32_to_cpu(p_ea_info->ea_query_length);
236 	} else {
237 create_ea_info:
238 		p_ea_info = kzalloc_obj(struct ea_information, GFP_NOFS);
239 		if (!p_ea_info)
240 			return -ENOMEM;
241 
242 		ea_info_qsize = 0;
243 		err = ntfs_attr_add(ni, AT_EA_INFORMATION, AT_UNNAMED, 0,
244 				(char *)p_ea_info, sizeof(struct ea_information));
245 		if (err)
246 			goto out;
247 
248 		if (ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
249 			err = ntfs_attr_remove(ni, AT_EA, AT_UNNAMED, 0);
250 			if (err)
251 				goto out;
252 		}
253 
254 		goto alloc_new_ea;
255 	}
256 
257 	if (ea_info_qsize > all_ea_size) {
258 		err = -EIO;
259 		goto out;
260 	}
261 
262 	err = ntfs_ea_lookup(ea_buf, ea_info_qsize, name, name_len, &ea_off,
263 			&ea_size);
264 	if (ea_info_qsize && !err) {
265 		if (flags & XATTR_CREATE) {
266 			err = -EEXIST;
267 			goto out;
268 		}
269 		if ((flags & XATTR_REPLACE) && !val_size) {
270 			old_ea_info = *p_ea_info;
271 			old_ea_buf = kvmemdup(ea_buf, all_ea_size, GFP_NOFS);
272 			if (!old_ea_buf) {
273 				err = -ENOMEM;
274 				goto out;
275 			}
276 		}
277 
278 		/* Check the final $EA size before removing the old entry. */
279 		if (val_size &&
280 		    ntfs_attr_size_bounds_check(ni->vol, AT_EA,
281 					ea_info_qsize - ea_size + new_ea_size)) {
282 			err = -EFBIG;
283 			goto out;
284 		}
285 
286 		p_ea = (struct ea_attr *)(ea_buf + ea_off);
287 
288 		if (val_size &&
289 		    le16_to_cpu(p_ea->ea_value_length) == val_size &&
290 		    !memcmp(p_ea->ea_name + p_ea->ea_name_length + 1, value,
291 			    val_size))
292 			goto out;
293 
294 		le16_add_cpu(&p_ea_info->ea_length, 0 - ea_packed_size(p_ea));
295 
296 		if (p_ea->flags & NEED_EA)
297 			le16_add_cpu(&p_ea_info->need_ea_count, -1);
298 
299 		memmove((char *)p_ea, (char *)p_ea + ea_size, ea_info_qsize - (ea_off + ea_size));
300 		ea_info_qsize -= ea_size;
301 		p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize);
302 
303 		if ((flags & XATTR_REPLACE) && !val_size && !ea_info_qsize) {
304 			err = ntfs_attr_remove(ni, AT_EA, AT_UNNAMED, 0);
305 			if (err)
306 				goto out;
307 
308 			err = ntfs_attr_remove(ni, AT_EA_INFORMATION, AT_UNNAMED, 0);
309 			if (err) {
310 				/* Restore the original $EA if $EA_INFORMATION removal failed. */
311 				ntfs_attr_add(ni, AT_EA, AT_UNNAMED, 0, old_ea_buf,
312 					      all_ea_size);
313 				ea_info_qsize = le32_to_cpu(old_ea_info.ea_query_length);
314 			}
315 			goto out;
316 		}
317 
318 		if ((flags & XATTR_REPLACE) && !val_size) {
319 			err = ntfs_write_ea(ni, AT_EA, ea_buf, 0, ea_info_qsize,
320 					true);
321 			if (err) {
322 				ntfs_write_ea(ni, AT_EA, old_ea_buf, 0,
323 					      all_ea_size, false);
324 				goto out;
325 			}
326 
327 			err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info,
328 					0, sizeof(struct ea_information), false);
329 			if (err) {
330 				ntfs_write_ea(ni, AT_EA, old_ea_buf, 0,
331 					      all_ea_size, false);
332 				ntfs_write_ea(ni, AT_EA_INFORMATION,
333 					      (char *)&old_ea_info, 0,
334 					      sizeof(old_ea_info), false);
335 			}
336 			goto out;
337 		}
338 	} else {
339 		if (flags & XATTR_REPLACE) {
340 			err = -ENODATA;
341 			goto out;
342 		}
343 
344 		if (ntfs_attr_size_bounds_check(ni->vol, AT_EA,
345 					ea_info_qsize + new_ea_size)) {
346 			err = -EFBIG;
347 			goto out;
348 		}
349 	}
350 alloc_new_ea:
351 	new_ea_buf = kvzalloc(ea_info_qsize + new_ea_size, GFP_NOFS);
352 	if (!new_ea_buf) {
353 		err = -ENOMEM;
354 		goto out;
355 	}
356 	if (ea_info_qsize)
357 		memcpy(new_ea_buf, ea_buf, ea_info_qsize);
358 	kvfree(ea_buf);
359 	ea_buf = new_ea_buf;
360 	p_ea = (struct ea_attr *)(ea_buf + ea_info_qsize);
361 
362 	/*
363 	 * EA and REPARSE_POINT compatibility not checked any more,
364 	 * required by Windows 10, but having both may lead to
365 	 * problems with earlier versions.
366 	 */
367 	memcpy(p_ea->ea_name, name, name_len);
368 	p_ea->ea_name_length = name_len;
369 	p_ea->ea_name[name_len] = 0;
370 	memcpy(p_ea->ea_name + name_len + 1, value, val_size);
371 	p_ea->ea_value_length = cpu_to_le16(val_size);
372 	p_ea->next_entry_offset = cpu_to_le32(new_ea_size);
373 
374 	ea_packed = le16_to_cpu(p_ea_info->ea_length) + ea_packed_size(p_ea);
375 	p_ea_info->ea_length = cpu_to_le16(ea_packed);
376 	p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize + new_ea_size);
377 
378 	if (ea_packed > 0xffff) {
379 		err = -EFBIG;
380 		goto out;
381 	}
382 
383 	/*
384 	 * no EA or EA_INFORMATION : add them
385 	 */
386 	if (!ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
387 		err = ntfs_attr_add(ni, AT_EA, AT_UNNAMED, 0, ea_buf,
388 				ea_info_qsize + new_ea_size);
389 		if (err)
390 			goto out;
391 	} else {
392 		err = ntfs_write_ea(ni, AT_EA, ea_buf, 0,
393 				ea_info_qsize + new_ea_size, true);
394 		if (err)
395 			goto out;
396 	}
397 
398 	err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info, 0,
399 			sizeof(struct ea_information), false);
400 	if (err)
401 		goto out;
402 
403 	if (packed_ea_size)
404 		*packed_ea_size = p_ea_info->ea_length;
405 	mark_mft_record_dirty(ni);
406 out:
407 	if (!err) {
408 		if (ea_info_qsize > 0)
409 			NInoSetHasEA(ni);
410 		else
411 			NInoClearHasEA(ni);
412 	}
413 
414 	kvfree(ea_buf);
415 	kvfree(old_ea_buf);
416 	kvfree(p_ea_info);
417 
418 	return err;
419 }
420 
421 /*
422  * Check for the presence of an EA "$LXDEV" (used by WSL)
423  * and return its value as a device address
424  */
ntfs_ea_get_wsl_inode(struct inode * inode,dev_t * rdevp,unsigned int flags,bool * has_lxmod)425 int ntfs_ea_get_wsl_inode(struct inode *inode, dev_t *rdevp, unsigned int flags,
426 			  bool *has_lxmod)
427 {
428 	int err;
429 	__le32 v;
430 
431 	*has_lxmod = false;
432 
433 	if (!(flags & NTFS_VOL_UID)) {
434 		/* Load uid to lxuid EA */
435 		err = ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
436 				sizeof(v));
437 		if (err == sizeof(v))
438 			i_uid_write(inode, le32_to_cpu(v));
439 	}
440 
441 	if (!(flags & NTFS_VOL_GID)) {
442 		/* Load gid to lxgid EA */
443 		err = ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
444 				sizeof(v));
445 		if (err == sizeof(v))
446 			i_gid_write(inode, le32_to_cpu(v));
447 	}
448 
449 	/* Load mode to lxmod EA */
450 	err = ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v, sizeof(v));
451 	if (err == sizeof(v)) {
452 		inode->i_mode = le32_to_cpu(v);
453 		*has_lxmod = true;
454 	} else {
455 		/* Everyone gets all permissions. */
456 		inode->i_mode |= 0777;
457 	}
458 
459 	/* Load mode to lxdev EA */
460 	err = ntfs_get_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v));
461 	if (err == sizeof(v))
462 		*rdevp = le32_to_cpu(v);
463 	err = 0;
464 
465 	return err;
466 }
467 
ntfs_ea_set_wsl_inode(struct inode * inode,dev_t rdev,__le16 * ea_size,unsigned int flags)468 int ntfs_ea_set_wsl_inode(struct inode *inode, dev_t rdev, __le16 *ea_size,
469 		unsigned int flags)
470 {
471 	__le32 v;
472 	int err = 0;
473 
474 	if (ea_size)
475 		*ea_size = 0;
476 
477 	if (flags & NTFS_EA_UID) {
478 		/* Store uid to lxuid EA */
479 		v = cpu_to_le32(i_uid_read(inode));
480 		err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
481 				sizeof(v), 0, ea_size);
482 		if (err)
483 			return err;
484 	}
485 
486 	if (flags & NTFS_EA_GID) {
487 		/* Store gid to lxgid EA */
488 		v = cpu_to_le32(i_gid_read(inode));
489 		err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
490 				sizeof(v), 0, ea_size);
491 		if (err)
492 			return err;
493 	}
494 
495 	if (flags & NTFS_EA_MODE) {
496 		/* Store mode to lxmod EA */
497 		v = cpu_to_le32(inode->i_mode);
498 		err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v,
499 				sizeof(v), 0, ea_size);
500 		if (err)
501 			return err;
502 	}
503 
504 	if (rdev) {
505 		v = cpu_to_le32(rdev);
506 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v),
507 				0, ea_size);
508 	}
509 
510 	return err;
511 }
512 
ntfs_listxattr(struct dentry * dentry,char * buffer,size_t size)513 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
514 {
515 	struct inode *inode = d_inode(dentry);
516 	struct ntfs_inode *ni = NTFS_I(inode);
517 	const struct ea_attr *p_ea;
518 	s64 offset, ea_buf_size, ea_info_size;
519 	s64 ea_size;
520 	u32 next;
521 	int err = 0;
522 	u32 ea_info_qsize;
523 	char *ea_buf = NULL;
524 	ssize_t ret = 0;
525 	struct ea_information *ea_info;
526 
527 	if (!NInoHasEA(ni))
528 		return 0;
529 
530 	mutex_lock(&NTFS_I(inode)->mrec_lock);
531 	ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
532 			&ea_info_size);
533 	if (IS_ERR(ea_info)) {
534 		err = PTR_ERR(ea_info);
535 		ea_info = NULL;
536 		goto out;
537 	}
538 	if (ea_info_size != sizeof(struct ea_information)) {
539 		err = -EIO;
540 		goto out;
541 	}
542 
543 	ea_info_qsize = le32_to_cpu(ea_info->ea_query_length);
544 
545 	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &ea_buf_size);
546 	if (IS_ERR(ea_buf)) {
547 		err = PTR_ERR(ea_buf);
548 		ea_buf = NULL;
549 		goto out;
550 	}
551 
552 	if (ea_info_qsize > ea_buf_size || ea_info_qsize == 0)
553 		goto out;
554 
555 	offset = 0;
556 	do {
557 		if (ea_info_qsize - offset < sizeof(struct ea_attr)) {
558 			err = -EIO;
559 			goto out;
560 		}
561 
562 		p_ea = (const struct ea_attr *)&ea_buf[offset];
563 		next = le32_to_cpu(p_ea->next_entry_offset);
564 		ea_size = next ? next : (ea_info_qsize - offset);
565 
566 		if (ea_size < sizeof(struct ea_attr) ||
567 		    offset + ea_size > ea_info_qsize) {
568 			err = -EIO;
569 			goto out;
570 		}
571 
572 		if ((int)p_ea->ea_name_length + 1 >
573 			ea_size - offsetof(struct ea_attr, ea_name)) {
574 			err = -EIO;
575 			goto out;
576 		}
577 
578 		if (buffer) {
579 			if (ret + p_ea->ea_name_length + 1 > size) {
580 				err = -ERANGE;
581 				goto out;
582 			}
583 
584 			memcpy(buffer + ret, p_ea->ea_name, p_ea->ea_name_length);
585 			buffer[ret + p_ea->ea_name_length] = 0;
586 		}
587 
588 		ret += p_ea->ea_name_length + 1;
589 		offset += ea_size;
590 	} while (next > 0 && offset < ea_info_qsize);
591 
592 out:
593 	mutex_unlock(&NTFS_I(inode)->mrec_lock);
594 	kvfree(ea_info);
595 	kvfree(ea_buf);
596 
597 	return err ? err : ret;
598 }
599 
600 // clang-format off
601 #define SYSTEM_DOS_ATTRIB     "system.dos_attrib"
602 #define SYSTEM_NTFS_ATTRIB    "system.ntfs_attrib"
603 #define SYSTEM_NTFS_ATTRIB_BE "system.ntfs_attrib_be"
604 // clang-format on
605 
ntfs_getxattr(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * buffer,size_t size)606 static int ntfs_getxattr(const struct xattr_handler *handler,
607 		struct dentry *unused, struct inode *inode, const char *name,
608 		void *buffer, size_t size)
609 {
610 	struct ntfs_inode *ni = NTFS_I(inode);
611 	int err;
612 
613 	if (NVolShutdown(ni->vol))
614 		return -EIO;
615 
616 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
617 		if (!buffer) {
618 			err = sizeof(u8);
619 		} else if (size < sizeof(u8)) {
620 			err = -ERANGE;
621 		} else {
622 			err = sizeof(u8);
623 			*(u8 *)buffer = (u8)(le32_to_cpu(ni->flags) & 0x3F);
624 		}
625 		goto out;
626 	}
627 
628 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
629 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
630 		if (!buffer) {
631 			err = sizeof(u32);
632 		} else if (size < sizeof(u32)) {
633 			err = -ERANGE;
634 		} else {
635 			err = sizeof(u32);
636 			*(u32 *)buffer = le32_to_cpu(ni->flags);
637 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
638 				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
639 		}
640 		goto out;
641 	}
642 
643 	mutex_lock(&ni->mrec_lock);
644 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size);
645 	mutex_unlock(&ni->mrec_lock);
646 
647 out:
648 	return err;
649 }
650 
ntfs_new_attr_flags(struct ntfs_inode * ni,__le32 fattr)651 static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
652 {
653 	struct ntfs_attr_search_ctx *ctx;
654 	struct mft_record *m;
655 	struct attr_record *a;
656 	__le16 new_aflags;
657 	u16 old_name_ofs, old_mp_ofs;
658 	int mp_size, mp_ofs, name_ofs, old_arec_size, arec_size, err;
659 
660 	m = map_mft_record(ni);
661 	if (IS_ERR(m))
662 		return PTR_ERR(m);
663 
664 	ctx = ntfs_attr_get_search_ctx(ni, m);
665 	if (!ctx) {
666 		err = -ENOMEM;
667 		goto err_out;
668 	}
669 
670 	err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
671 			CASE_SENSITIVE, 0, NULL, 0, ctx);
672 	if (err) {
673 		err = -EINVAL;
674 		goto err_out;
675 	}
676 
677 	a = ctx->attr;
678 	new_aflags = ctx->attr->flags;
679 
680 	if (fattr & FILE_ATTR_SPARSE_FILE)
681 		new_aflags |= ATTR_IS_SPARSE;
682 	else
683 		new_aflags &= ~ATTR_IS_SPARSE;
684 
685 	if (fattr & FILE_ATTR_COMPRESSED)
686 		new_aflags |= ATTR_IS_COMPRESSED;
687 	else
688 		new_aflags &= ~ATTR_IS_COMPRESSED;
689 
690 	if (new_aflags == a->flags) {
691 		err = 0;
692 		goto err_out;
693 	}
694 
695 	if ((new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) ==
696 			  (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
697 		pr_err("file can't be sparsed and compressed\n");
698 		err = -EOPNOTSUPP;
699 		goto err_out;
700 	}
701 
702 	if (!a->non_resident) {
703 		if (!(new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))) {
704 			err = 0;
705 			goto err_out;
706 		}
707 
708 		if (le32_to_cpu(a->data.resident.value_length)) {
709 			pr_err("Can't change sparse/compressed for non-empty file");
710 			err = -EOPNOTSUPP;
711 			goto err_out;
712 		}
713 
714 		err = ntfs_attr_make_non_resident(ni, 0);
715 		if (err)
716 			goto err_out;
717 
718 		ntfs_attr_reinit_search_ctx(ctx);
719 		err = ntfs_attr_lookup(ni->type, ni->name,
720 				ni->name_len, CASE_SENSITIVE,
721 				0, NULL, 0, ctx);
722 		if (err) {
723 			err = -EINVAL;
724 			goto err_out;
725 		}
726 		a = ctx->attr;
727 	} else {
728 		if (a->data.non_resident.data_size) {
729 			pr_err("Can't change sparsed/compressed for non-empty file");
730 			err = -EOPNOTSUPP;
731 			goto err_out;
732 		}
733 	}
734 
735 	old_name_ofs = le16_to_cpu(a->name_offset);
736 	old_mp_ofs = le16_to_cpu(a->data.non_resident.mapping_pairs_offset);
737 
738 	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))
739 		name_ofs = (offsetof(struct attr_record,
740 				     data.non_resident.compressed_size) +
741 					sizeof(a->data.non_resident.compressed_size) + 7) & ~7;
742 	else
743 		name_ofs = (offsetof(struct attr_record,
744 				     data.non_resident.compressed_size) + 7) & ~7;
745 
746 	mp_size = ntfs_get_size_for_mapping_pairs(ni->vol, ni->runlist.rl, 0, -1, -1);
747 	if (unlikely(mp_size < 0)) {
748 		err = mp_size;
749 		ntfs_debug("Failed to get size for mapping pairs array, error code %i.\n", err);
750 		goto err_out;
751 	}
752 
753 	mp_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
754 	arec_size = (mp_ofs + mp_size + 7) & ~7;
755 	old_arec_size = le32_to_cpu(a->length);
756 
757 	/*
758 	 * Move payloads before shrinking the record. Otherwise resizing moves
759 	 * the following attribute over the old payload before it can be copied.
760 	 *
761 	 * When offsets increase, move mapping_pairs first to avoid name
762 	 * overwriting the start of mapping_pairs.
763 	 */
764 	if (arec_size < old_arec_size) {
765 		if (name_ofs > old_name_ofs) {
766 			/* Payload offsets increased: move mapping pairs first. */
767 			if (mp_ofs != old_mp_ofs)
768 				memmove((u8 *)a + mp_ofs,
769 						(u8 *)a + old_mp_ofs,
770 						mp_size);
771 			if (a->name_length && name_ofs != old_name_ofs)
772 				memmove((u8 *)a + name_ofs,
773 						(u8 *)a + old_name_ofs,
774 						a->name_length *
775 							sizeof(__le16));
776 		} else {
777 			/* Payload offsets decreased or unchanged: move name first. */
778 			if (a->name_length && name_ofs != old_name_ofs)
779 				memmove((u8 *)a + name_ofs,
780 						(u8 *)a + old_name_ofs,
781 						a->name_length *
782 							sizeof(__le16));
783 			if (mp_ofs != old_mp_ofs)
784 				memmove((u8 *)a + mp_ofs,
785 						(u8 *)a + old_mp_ofs,
786 						mp_size);
787 		}
788 	}
789 
790 	err = ntfs_attr_record_resize(ctx->mrec, a, arec_size);
791 	if (unlikely(err))
792 		goto err_out;
793 
794 	/*
795 	 * When compressed/sparse state changes, the non-resident header grows or
796 	 * shrinks by the compressed_size field. Update the in-record payload layout
797 	 * to match the new offsets before exposing the new mapping_pairs_offset.
798 	 */
799 	if (arec_size > old_arec_size) {
800 		if (mp_ofs != old_mp_ofs)
801 			memmove((u8 *)a + mp_ofs, (u8 *)a + old_mp_ofs, mp_size);
802 		if (a->name_length)
803 			memmove((u8 *)a + name_ofs, (u8 *)a + old_name_ofs,
804 				a->name_length * sizeof(__le16));
805 	}
806 
807 	if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
808 		a->data.non_resident.compression_unit = 0;
809 		if (new_aflags & ATTR_IS_COMPRESSED || ni->vol->major_ver < 3)
810 			a->data.non_resident.compression_unit = 4;
811 		a->data.non_resident.compressed_size = 0;
812 		ni->itype.compressed.size = 0;
813 		if (a->data.non_resident.compression_unit) {
814 			ni->itype.compressed.block_size = 1U <<
815 				(a->data.non_resident.compression_unit +
816 				 ni->vol->cluster_size_bits);
817 			ni->itype.compressed.block_size_bits =
818 					ffs(ni->itype.compressed.block_size) -
819 					1;
820 			ni->itype.compressed.block_clusters = 1U <<
821 					a->data.non_resident.compression_unit;
822 		} else {
823 			ni->itype.compressed.block_size = 0;
824 			ni->itype.compressed.block_size_bits = 0;
825 			ni->itype.compressed.block_clusters = 0;
826 		}
827 	} else {
828 		a->data.non_resident.compression_unit = 0;
829 	}
830 
831 	a->name_offset = cpu_to_le16(name_ofs);
832 	a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
833 
834 	a->flags = new_aflags;
835 
836 	if (new_aflags & ATTR_IS_SPARSE) {
837 		NInoSetSparse(ni);
838 		ni->flags |= FILE_ATTR_SPARSE_FILE;
839 	} else {
840 		NInoClearSparse(ni);
841 		ni->flags &= ~FILE_ATTR_SPARSE_FILE;
842 	}
843 
844 	if (new_aflags & ATTR_IS_COMPRESSED) {
845 		NInoSetCompressed(ni);
846 		ni->flags |= FILE_ATTR_COMPRESSED;
847 	} else {
848 		NInoClearCompressed(ni);
849 		ni->flags &= ~FILE_ATTR_COMPRESSED;
850 	}
851 
852 	mark_mft_record_dirty(ctx->ntfs_ino);
853 err_out:
854 	if (ctx)
855 		ntfs_attr_put_search_ctx(ctx);
856 	unmap_mft_record(ni);
857 	return err;
858 }
859 
ntfs_is_reserved_lxattr(const char * name)860 static bool ntfs_is_reserved_lxattr(const char *name)
861 {
862 	return !strcmp(name, "$LXUID") || !strcmp(name, "$LXGID") ||
863 	       !strcmp(name, "$LXMOD") || !strcmp(name, "$LXDEV");
864 }
865 
ntfs_validate_fattr(struct ntfs_inode * ni,__le32 fattr)866 static int ntfs_validate_fattr(struct ntfs_inode *ni, __le32 fattr)
867 {
868 	const __le32 wof_flags = FILE_ATTR_SPARSE_FILE |
869 				 FILE_ATTR_REPARSE_POINT;
870 
871 	if (NInoWofCompressed(ni) && ((ni->flags ^ fattr) & wof_flags))
872 		return -EPERM;
873 
874 	return 0;
875 }
876 
ntfs_setxattr(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * unused,struct inode * inode,const char * name,const void * value,size_t size,int flags)877 static int ntfs_setxattr(const struct xattr_handler *handler,
878 		struct mnt_idmap *idmap, struct dentry *unused,
879 		struct inode *inode, const char *name, const void *value,
880 		size_t size, int flags)
881 {
882 	struct ntfs_inode *ni = NTFS_I(inode);
883 	int err;
884 	__le32 fattr;
885 
886 	if (NVolShutdown(ni->vol))
887 		return -EIO;
888 
889 	if (ntfs_is_reserved_lxattr(name) && !capable(CAP_SYS_ADMIN))
890 		return -EPERM;
891 
892 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
893 		if (sizeof(u8) != size) {
894 			err = -EINVAL;
895 			goto out;
896 		}
897 		fattr = cpu_to_le32((le32_to_cpu(ni->flags) & ~0xffU) |
898 				    *(u8 *)value);
899 		goto set_fattr;
900 	}
901 
902 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
903 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
904 		if (size != sizeof(u32)) {
905 			err = -EINVAL;
906 			goto out;
907 		}
908 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
909 			fattr = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
910 		else
911 			fattr = cpu_to_le32(*(u32 *)value);
912 
913 		err = ntfs_validate_fattr(ni, fattr);
914 		if (err)
915 			goto out;
916 
917 		if (S_ISREG(inode->i_mode)) {
918 			mutex_lock(&ni->mrec_lock);
919 			err = ntfs_new_attr_flags(ni, fattr);
920 			mutex_unlock(&ni->mrec_lock);
921 			if (err)
922 				goto out;
923 		}
924 
925 set_fattr:
926 		if (S_ISDIR(inode->i_mode))
927 			fattr |= FILE_ATTR_DIRECTORY;
928 		else
929 			fattr &= ~FILE_ATTR_DIRECTORY;
930 
931 		err = ntfs_validate_fattr(ni, fattr);
932 		if (err)
933 			goto out;
934 
935 		if (ni->flags != fattr) {
936 			ni->flags = fattr;
937 			if (fattr & FILE_ATTR_READONLY)
938 				inode->i_mode &= ~0222;
939 			else
940 				inode->i_mode |= 0222;
941 			NInoSetFileNameDirty(ni);
942 			mark_inode_dirty(inode);
943 		}
944 		err = 0;
945 		goto out;
946 	}
947 
948 	mutex_lock(&ni->mrec_lock);
949 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, NULL);
950 	mutex_unlock(&ni->mrec_lock);
951 
952 out:
953 	if (!err) {
954 		inode_set_ctime_current(inode);
955 		mark_inode_dirty(inode);
956 	}
957 	return err;
958 }
959 
ntfs_xattr_user_list(struct dentry * dentry)960 static bool ntfs_xattr_user_list(struct dentry *dentry)
961 {
962 	return true;
963 }
964 
965 // clang-format off
966 static const struct xattr_handler ntfs_other_xattr_handler = {
967 	.prefix	= "",
968 	.get	= ntfs_getxattr,
969 	.set	= ntfs_setxattr,
970 	.list	= ntfs_xattr_user_list,
971 };
972 
973 const struct xattr_handler * const ntfs_xattr_handlers[] = {
974 	&ntfs_other_xattr_handler,
975 	NULL,
976 };
977 // clang-format on
978 
979 #ifdef CONFIG_NTFS_FS_POSIX_ACL
ntfs_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,int type)980 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
981 			       int type)
982 {
983 	struct inode *inode = d_inode(dentry);
984 	struct ntfs_inode *ni = NTFS_I(inode);
985 	const char *name;
986 	size_t name_len;
987 	struct posix_acl *acl;
988 	int err;
989 	void *buf;
990 
991 	buf = kmalloc(PATH_MAX, GFP_KERNEL);
992 	if (!buf)
993 		return ERR_PTR(-ENOMEM);
994 
995 	/* Possible values of 'type' was already checked above. */
996 	if (type == ACL_TYPE_ACCESS) {
997 		name = XATTR_NAME_POSIX_ACL_ACCESS;
998 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
999 	} else {
1000 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
1001 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
1002 	}
1003 
1004 	mutex_lock(&ni->mrec_lock);
1005 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX);
1006 	mutex_unlock(&ni->mrec_lock);
1007 
1008 	/* Translate extended attribute to acl. */
1009 	if (err >= 0)
1010 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
1011 	else if (err == -ENODATA)
1012 		acl = NULL;
1013 	else
1014 		acl = ERR_PTR(err);
1015 
1016 	if (!IS_ERR(acl))
1017 		set_cached_acl(inode, type, acl);
1018 
1019 	kfree(buf);
1020 
1021 	return acl;
1022 }
1023 
ntfs_set_acl_ex(struct mnt_idmap * idmap,struct inode * inode,struct posix_acl * acl,int type,bool init_acl)1024 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
1025 				    struct inode *inode, struct posix_acl *acl,
1026 				    int type, bool init_acl)
1027 {
1028 	const char *name;
1029 	size_t size, name_len;
1030 	void *value;
1031 	int err;
1032 	int flags;
1033 	umode_t mode;
1034 
1035 	if (S_ISLNK(inode->i_mode))
1036 		return -EOPNOTSUPP;
1037 
1038 	mode = inode->i_mode;
1039 	switch (type) {
1040 	case ACL_TYPE_ACCESS:
1041 		/* Do not change i_mode if we are in init_acl */
1042 		if (acl && !init_acl) {
1043 			err = posix_acl_update_mode(idmap, inode, &mode, &acl);
1044 			if (err)
1045 				return err;
1046 		}
1047 		name = XATTR_NAME_POSIX_ACL_ACCESS;
1048 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
1049 		break;
1050 
1051 	case ACL_TYPE_DEFAULT:
1052 		if (!S_ISDIR(inode->i_mode))
1053 			return acl ? -EACCES : 0;
1054 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
1055 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
1056 		break;
1057 
1058 	default:
1059 		return -EINVAL;
1060 	}
1061 
1062 	if (!acl) {
1063 		/* Remove xattr if it can be presented via mode. */
1064 		size = 0;
1065 		value = NULL;
1066 		flags = XATTR_REPLACE;
1067 	} else {
1068 		value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS);
1069 		if (!value)
1070 			return -ENOMEM;
1071 		flags = 0;
1072 	}
1073 
1074 	mutex_lock(&NTFS_I(inode)->mrec_lock);
1075 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, NULL);
1076 	mutex_unlock(&NTFS_I(inode)->mrec_lock);
1077 	if (err == -ENODATA && !size)
1078 		err = 0; /* Removing non existed xattr. */
1079 	if (!err) {
1080 		__le16 ea_size = 0;
1081 		umode_t old_mode = inode->i_mode;
1082 
1083 		inode->i_mode = mode;
1084 		mutex_lock(&NTFS_I(inode)->mrec_lock);
1085 		err = ntfs_ea_set_wsl_inode(inode, 0, &ea_size, NTFS_EA_MODE);
1086 		if (err) {
1087 			ntfs_set_ea(inode, name, name_len, NULL, 0,
1088 				    XATTR_REPLACE, NULL);
1089 			mutex_unlock(&NTFS_I(inode)->mrec_lock);
1090 			inode->i_mode = old_mode;
1091 			goto out;
1092 		}
1093 		mutex_unlock(&NTFS_I(inode)->mrec_lock);
1094 
1095 		set_cached_acl(inode, type, acl);
1096 		inode_set_ctime_current(inode);
1097 		mark_inode_dirty(inode);
1098 	}
1099 
1100 out:
1101 	kfree(value);
1102 
1103 	return err;
1104 }
1105 
ntfs_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,struct posix_acl * acl,int type)1106 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
1107 		 struct posix_acl *acl, int type)
1108 {
1109 	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
1110 }
1111 
ntfs_init_acl(struct mnt_idmap * idmap,struct inode * inode,struct inode * dir)1112 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
1113 		  struct inode *dir)
1114 {
1115 	struct posix_acl *default_acl, *acl;
1116 	int err;
1117 
1118 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
1119 	if (err)
1120 		return err;
1121 
1122 	if (default_acl) {
1123 		err = ntfs_set_acl_ex(idmap, inode, default_acl,
1124 				      ACL_TYPE_DEFAULT, true);
1125 		posix_acl_release(default_acl);
1126 	} else {
1127 		inode->i_default_acl = NULL;
1128 	}
1129 
1130 	if (acl) {
1131 		if (!err)
1132 			err = ntfs_set_acl_ex(idmap, inode, acl,
1133 					      ACL_TYPE_ACCESS, true);
1134 		posix_acl_release(acl);
1135 	} else {
1136 		inode->i_acl = NULL;
1137 	}
1138 
1139 	return err;
1140 }
1141 #endif
1142