xref: /openbmc/linux/fs/hfsplus/xattr.c (revision bc000245)
1 /*
2  * linux/fs/hfsplus/xattr.c
3  *
4  * Vyacheslav Dubeyko <slava@dubeyko.com>
5  *
6  * Logic of processing extended attributes
7  */
8 
9 #include "hfsplus_fs.h"
10 #include "xattr.h"
11 #include "acl.h"
12 
13 const struct xattr_handler *hfsplus_xattr_handlers[] = {
14 	&hfsplus_xattr_osx_handler,
15 	&hfsplus_xattr_user_handler,
16 	&hfsplus_xattr_trusted_handler,
17 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
18 	&hfsplus_xattr_acl_access_handler,
19 	&hfsplus_xattr_acl_default_handler,
20 #endif
21 	&hfsplus_xattr_security_handler,
22 	NULL
23 };
24 
25 static int strcmp_xattr_finder_info(const char *name)
26 {
27 	if (name) {
28 		return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
29 				sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
30 	}
31 	return -1;
32 }
33 
34 static int strcmp_xattr_acl(const char *name)
35 {
36 	if (name) {
37 		return strncmp(name, HFSPLUS_XATTR_ACL_NAME,
38 				sizeof(HFSPLUS_XATTR_ACL_NAME));
39 	}
40 	return -1;
41 }
42 
43 static inline int is_known_namespace(const char *name)
44 {
45 	if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
46 	    strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
47 	    strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
48 	    strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
49 		return false;
50 
51 	return true;
52 }
53 
54 static int can_set_system_xattr(struct inode *inode, const char *name,
55 				const void *value, size_t size)
56 {
57 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
58 	struct posix_acl *acl;
59 	int err;
60 
61 	if (!inode_owner_or_capable(inode))
62 		return -EPERM;
63 
64 	/*
65 	 * POSIX_ACL_XATTR_ACCESS is tied to i_mode
66 	 */
67 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
68 		acl = posix_acl_from_xattr(&init_user_ns, value, size);
69 		if (IS_ERR(acl))
70 			return PTR_ERR(acl);
71 		if (acl) {
72 			err = posix_acl_equiv_mode(acl, &inode->i_mode);
73 			posix_acl_release(acl);
74 			if (err < 0)
75 				return err;
76 			mark_inode_dirty(inode);
77 		}
78 		/*
79 		 * We're changing the ACL.  Get rid of the cached one
80 		 */
81 		forget_cached_acl(inode, ACL_TYPE_ACCESS);
82 
83 		return 0;
84 	} else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
85 		acl = posix_acl_from_xattr(&init_user_ns, value, size);
86 		if (IS_ERR(acl))
87 			return PTR_ERR(acl);
88 		posix_acl_release(acl);
89 
90 		/*
91 		 * We're changing the default ACL.  Get rid of the cached one
92 		 */
93 		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
94 
95 		return 0;
96 	}
97 #endif /* CONFIG_HFSPLUS_FS_POSIX_ACL */
98 	return -EOPNOTSUPP;
99 }
100 
101 static int can_set_xattr(struct inode *inode, const char *name,
102 				const void *value, size_t value_len)
103 {
104 	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
105 		return can_set_system_xattr(inode, name, value, value_len);
106 
107 	if (!strncmp(name, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN)) {
108 		/*
109 		 * This makes sure that we aren't trying to set an
110 		 * attribute in a different namespace by prefixing it
111 		 * with "osx."
112 		 */
113 		if (is_known_namespace(name + XATTR_MAC_OSX_PREFIX_LEN))
114 			return -EOPNOTSUPP;
115 
116 		return 0;
117 	}
118 
119 	/*
120 	 * Don't allow setting an attribute in an unknown namespace.
121 	 */
122 	if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
123 	    strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
124 	    strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
125 		return -EOPNOTSUPP;
126 
127 	return 0;
128 }
129 
130 static void hfsplus_init_header_node(struct inode *attr_file,
131 					u32 clump_size,
132 					char *buf, u16 node_size)
133 {
134 	struct hfs_bnode_desc *desc;
135 	struct hfs_btree_header_rec *head;
136 	u16 offset;
137 	__be16 *rec_offsets;
138 	u32 hdr_node_map_rec_bits;
139 	char *bmp;
140 	u32 used_nodes;
141 	u32 used_bmp_bytes;
142 	loff_t tmp;
143 
144 	hfs_dbg(ATTR_MOD, "init_hdr_attr_file: clump %u, node_size %u\n",
145 				clump_size, node_size);
146 
147 	/* The end of the node contains list of record offsets */
148 	rec_offsets = (__be16 *)(buf + node_size);
149 
150 	desc = (struct hfs_bnode_desc *)buf;
151 	desc->type = HFS_NODE_HEADER;
152 	desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
153 	offset = sizeof(struct hfs_bnode_desc);
154 	*--rec_offsets = cpu_to_be16(offset);
155 
156 	head = (struct hfs_btree_header_rec *)(buf + offset);
157 	head->node_size = cpu_to_be16(node_size);
158 	tmp = i_size_read(attr_file);
159 	do_div(tmp, node_size);
160 	head->node_count = cpu_to_be32(tmp);
161 	head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
162 	head->clump_size = cpu_to_be32(clump_size);
163 	head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
164 	head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
165 	offset += sizeof(struct hfs_btree_header_rec);
166 	*--rec_offsets = cpu_to_be16(offset);
167 	offset += HFSPLUS_BTREE_HDR_USER_BYTES;
168 	*--rec_offsets = cpu_to_be16(offset);
169 
170 	hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
171 	if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
172 		u32 map_node_bits;
173 		u32 map_nodes;
174 
175 		desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
176 		map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
177 					(2 * sizeof(u16)) - 2);
178 		map_nodes = (be32_to_cpu(head->node_count) -
179 				hdr_node_map_rec_bits +
180 				(map_node_bits - 1)) / map_node_bits;
181 		be32_add_cpu(&head->free_nodes, 0 - map_nodes);
182 	}
183 
184 	bmp = buf + offset;
185 	used_nodes =
186 		be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
187 	used_bmp_bytes = used_nodes / 8;
188 	if (used_bmp_bytes) {
189 		memset(bmp, 0xFF, used_bmp_bytes);
190 		bmp += used_bmp_bytes;
191 		used_nodes %= 8;
192 	}
193 	*bmp = ~(0xFF >> used_nodes);
194 	offset += hdr_node_map_rec_bits / 8;
195 	*--rec_offsets = cpu_to_be16(offset);
196 }
197 
198 static int hfsplus_create_attributes_file(struct super_block *sb)
199 {
200 	int err = 0;
201 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
202 	struct inode *attr_file;
203 	struct hfsplus_inode_info *hip;
204 	u32 clump_size;
205 	u16 node_size = HFSPLUS_ATTR_TREE_NODE_SIZE;
206 	char *buf;
207 	int index, written;
208 	struct address_space *mapping;
209 	struct page *page;
210 	int old_state = HFSPLUS_EMPTY_ATTR_TREE;
211 
212 	hfs_dbg(ATTR_MOD, "create_attr_file: ino %d\n", HFSPLUS_ATTR_CNID);
213 
214 check_attr_tree_state_again:
215 	switch (atomic_read(&sbi->attr_tree_state)) {
216 	case HFSPLUS_EMPTY_ATTR_TREE:
217 		if (old_state != atomic_cmpxchg(&sbi->attr_tree_state,
218 						old_state,
219 						HFSPLUS_CREATING_ATTR_TREE))
220 			goto check_attr_tree_state_again;
221 		break;
222 	case HFSPLUS_CREATING_ATTR_TREE:
223 		/*
224 		 * This state means that another thread is in process
225 		 * of AttributesFile creation. Theoretically, it is
226 		 * possible to be here. But really __setxattr() method
227 		 * first of all calls hfs_find_init() for lookup in
228 		 * B-tree of CatalogFile. This method locks mutex of
229 		 * CatalogFile's B-tree. As a result, if some thread
230 		 * is inside AttributedFile creation operation then
231 		 * another threads will be waiting unlocking of
232 		 * CatalogFile's B-tree's mutex. However, if code will
233 		 * change then we will return error code (-EAGAIN) from
234 		 * here. Really, it means that first try to set of xattr
235 		 * fails with error but second attempt will have success.
236 		 */
237 		return -EAGAIN;
238 	case HFSPLUS_VALID_ATTR_TREE:
239 		return 0;
240 	case HFSPLUS_FAILED_ATTR_TREE:
241 		return -EOPNOTSUPP;
242 	default:
243 		BUG();
244 	}
245 
246 	attr_file = hfsplus_iget(sb, HFSPLUS_ATTR_CNID);
247 	if (IS_ERR(attr_file)) {
248 		pr_err("failed to load attributes file\n");
249 		return PTR_ERR(attr_file);
250 	}
251 
252 	BUG_ON(i_size_read(attr_file) != 0);
253 
254 	hip = HFSPLUS_I(attr_file);
255 
256 	clump_size = hfsplus_calc_btree_clump_size(sb->s_blocksize,
257 						    node_size,
258 						    sbi->sect_count,
259 						    HFSPLUS_ATTR_CNID);
260 
261 	mutex_lock(&hip->extents_lock);
262 	hip->clump_blocks = clump_size >> sbi->alloc_blksz_shift;
263 	mutex_unlock(&hip->extents_lock);
264 
265 	if (sbi->free_blocks <= (hip->clump_blocks << 1)) {
266 		err = -ENOSPC;
267 		goto end_attr_file_creation;
268 	}
269 
270 	while (hip->alloc_blocks < hip->clump_blocks) {
271 		err = hfsplus_file_extend(attr_file);
272 		if (unlikely(err)) {
273 			pr_err("failed to extend attributes file\n");
274 			goto end_attr_file_creation;
275 		}
276 		hip->phys_size = attr_file->i_size =
277 			(loff_t)hip->alloc_blocks << sbi->alloc_blksz_shift;
278 		hip->fs_blocks = hip->alloc_blocks << sbi->fs_shift;
279 		inode_set_bytes(attr_file, attr_file->i_size);
280 	}
281 
282 	buf = kzalloc(node_size, GFP_NOFS);
283 	if (!buf) {
284 		pr_err("failed to allocate memory for header node\n");
285 		err = -ENOMEM;
286 		goto end_attr_file_creation;
287 	}
288 
289 	hfsplus_init_header_node(attr_file, clump_size, buf, node_size);
290 
291 	mapping = attr_file->i_mapping;
292 
293 	index = 0;
294 	written = 0;
295 	for (; written < node_size; index++, written += PAGE_CACHE_SIZE) {
296 		void *kaddr;
297 
298 		page = read_mapping_page(mapping, index, NULL);
299 		if (IS_ERR(page)) {
300 			err = PTR_ERR(page);
301 			goto failed_header_node_init;
302 		}
303 
304 		kaddr = kmap_atomic(page);
305 		memcpy(kaddr, buf + written,
306 			min_t(size_t, PAGE_CACHE_SIZE, node_size - written));
307 		kunmap_atomic(kaddr);
308 
309 		set_page_dirty(page);
310 		page_cache_release(page);
311 	}
312 
313 	hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
314 
315 	sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
316 	if (!sbi->attr_tree)
317 		pr_err("failed to load attributes file\n");
318 
319 failed_header_node_init:
320 	kfree(buf);
321 
322 end_attr_file_creation:
323 	iput(attr_file);
324 
325 	if (!err)
326 		atomic_set(&sbi->attr_tree_state, HFSPLUS_VALID_ATTR_TREE);
327 	else if (err == -ENOSPC)
328 		atomic_set(&sbi->attr_tree_state, HFSPLUS_EMPTY_ATTR_TREE);
329 	else
330 		atomic_set(&sbi->attr_tree_state, HFSPLUS_FAILED_ATTR_TREE);
331 
332 	return err;
333 }
334 
335 int __hfsplus_setxattr(struct inode *inode, const char *name,
336 			const void *value, size_t size, int flags)
337 {
338 	int err = 0;
339 	struct hfs_find_data cat_fd;
340 	hfsplus_cat_entry entry;
341 	u16 cat_entry_flags, cat_entry_type;
342 	u16 folder_finderinfo_len = sizeof(struct DInfo) +
343 					sizeof(struct DXInfo);
344 	u16 file_finderinfo_len = sizeof(struct FInfo) +
345 					sizeof(struct FXInfo);
346 
347 	if ((!S_ISREG(inode->i_mode) &&
348 			!S_ISDIR(inode->i_mode)) ||
349 				HFSPLUS_IS_RSRC(inode))
350 		return -EOPNOTSUPP;
351 
352 	err = can_set_xattr(inode, name, value, size);
353 	if (err)
354 		return err;
355 
356 	if (strncmp(name, XATTR_MAC_OSX_PREFIX,
357 				XATTR_MAC_OSX_PREFIX_LEN) == 0)
358 		name += XATTR_MAC_OSX_PREFIX_LEN;
359 
360 	if (value == NULL) {
361 		value = "";
362 		size = 0;
363 	}
364 
365 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
366 	if (err) {
367 		pr_err("can't init xattr find struct\n");
368 		return err;
369 	}
370 
371 	err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
372 	if (err) {
373 		pr_err("catalog searching failed\n");
374 		goto end_setxattr;
375 	}
376 
377 	if (!strcmp_xattr_finder_info(name)) {
378 		if (flags & XATTR_CREATE) {
379 			pr_err("xattr exists yet\n");
380 			err = -EOPNOTSUPP;
381 			goto end_setxattr;
382 		}
383 		hfs_bnode_read(cat_fd.bnode, &entry, cat_fd.entryoffset,
384 					sizeof(hfsplus_cat_entry));
385 		if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {
386 			if (size == folder_finderinfo_len) {
387 				memcpy(&entry.folder.user_info, value,
388 						folder_finderinfo_len);
389 				hfs_bnode_write(cat_fd.bnode, &entry,
390 					cat_fd.entryoffset,
391 					sizeof(struct hfsplus_cat_folder));
392 				hfsplus_mark_inode_dirty(inode,
393 						HFSPLUS_I_CAT_DIRTY);
394 			} else {
395 				err = -ERANGE;
396 				goto end_setxattr;
397 			}
398 		} else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {
399 			if (size == file_finderinfo_len) {
400 				memcpy(&entry.file.user_info, value,
401 						file_finderinfo_len);
402 				hfs_bnode_write(cat_fd.bnode, &entry,
403 					cat_fd.entryoffset,
404 					sizeof(struct hfsplus_cat_file));
405 				hfsplus_mark_inode_dirty(inode,
406 						HFSPLUS_I_CAT_DIRTY);
407 			} else {
408 				err = -ERANGE;
409 				goto end_setxattr;
410 			}
411 		} else {
412 			err = -EOPNOTSUPP;
413 			goto end_setxattr;
414 		}
415 		goto end_setxattr;
416 	}
417 
418 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree) {
419 		err = hfsplus_create_attributes_file(inode->i_sb);
420 		if (unlikely(err))
421 			goto end_setxattr;
422 	}
423 
424 	if (hfsplus_attr_exists(inode, name)) {
425 		if (flags & XATTR_CREATE) {
426 			pr_err("xattr exists yet\n");
427 			err = -EOPNOTSUPP;
428 			goto end_setxattr;
429 		}
430 		err = hfsplus_delete_attr(inode, name);
431 		if (err)
432 			goto end_setxattr;
433 		err = hfsplus_create_attr(inode, name, value, size);
434 		if (err)
435 			goto end_setxattr;
436 	} else {
437 		if (flags & XATTR_REPLACE) {
438 			pr_err("cannot replace xattr\n");
439 			err = -EOPNOTSUPP;
440 			goto end_setxattr;
441 		}
442 		err = hfsplus_create_attr(inode, name, value, size);
443 		if (err)
444 			goto end_setxattr;
445 	}
446 
447 	cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
448 	if (cat_entry_type == HFSPLUS_FOLDER) {
449 		cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
450 				    cat_fd.entryoffset +
451 				    offsetof(struct hfsplus_cat_folder, flags));
452 		cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
453 		if (!strcmp_xattr_acl(name))
454 			cat_entry_flags |= HFSPLUS_ACL_EXISTS;
455 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
456 				offsetof(struct hfsplus_cat_folder, flags),
457 				cat_entry_flags);
458 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
459 	} else if (cat_entry_type == HFSPLUS_FILE) {
460 		cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
461 				    cat_fd.entryoffset +
462 				    offsetof(struct hfsplus_cat_file, flags));
463 		cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
464 		if (!strcmp_xattr_acl(name))
465 			cat_entry_flags |= HFSPLUS_ACL_EXISTS;
466 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
467 				    offsetof(struct hfsplus_cat_file, flags),
468 				    cat_entry_flags);
469 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
470 	} else {
471 		pr_err("invalid catalog entry type\n");
472 		err = -EIO;
473 		goto end_setxattr;
474 	}
475 
476 end_setxattr:
477 	hfs_find_exit(&cat_fd);
478 	return err;
479 }
480 
481 static inline int is_osx_xattr(const char *xattr_name)
482 {
483 	return !is_known_namespace(xattr_name);
484 }
485 
486 static int name_len(const char *xattr_name, int xattr_name_len)
487 {
488 	int len = xattr_name_len + 1;
489 
490 	if (is_osx_xattr(xattr_name))
491 		len += XATTR_MAC_OSX_PREFIX_LEN;
492 
493 	return len;
494 }
495 
496 static int copy_name(char *buffer, const char *xattr_name, int name_len)
497 {
498 	int len = name_len;
499 	int offset = 0;
500 
501 	if (is_osx_xattr(xattr_name)) {
502 		strncpy(buffer, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN);
503 		offset += XATTR_MAC_OSX_PREFIX_LEN;
504 		len += XATTR_MAC_OSX_PREFIX_LEN;
505 	}
506 
507 	strncpy(buffer + offset, xattr_name, name_len);
508 	memset(buffer + offset + name_len, 0, 1);
509 	len += 1;
510 
511 	return len;
512 }
513 
514 static ssize_t hfsplus_getxattr_finder_info(struct inode *inode,
515 						void *value, size_t size)
516 {
517 	ssize_t res = 0;
518 	struct hfs_find_data fd;
519 	u16 entry_type;
520 	u16 folder_rec_len = sizeof(struct DInfo) + sizeof(struct DXInfo);
521 	u16 file_rec_len = sizeof(struct FInfo) + sizeof(struct FXInfo);
522 	u16 record_len = max(folder_rec_len, file_rec_len);
523 	u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
524 	u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
525 
526 	if (size >= record_len) {
527 		res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
528 		if (res) {
529 			pr_err("can't init xattr find struct\n");
530 			return res;
531 		}
532 		res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
533 		if (res)
534 			goto end_getxattr_finder_info;
535 		entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
536 
537 		if (entry_type == HFSPLUS_FOLDER) {
538 			hfs_bnode_read(fd.bnode, folder_finder_info,
539 				fd.entryoffset +
540 				offsetof(struct hfsplus_cat_folder, user_info),
541 				folder_rec_len);
542 			memcpy(value, folder_finder_info, folder_rec_len);
543 			res = folder_rec_len;
544 		} else if (entry_type == HFSPLUS_FILE) {
545 			hfs_bnode_read(fd.bnode, file_finder_info,
546 				fd.entryoffset +
547 				offsetof(struct hfsplus_cat_file, user_info),
548 				file_rec_len);
549 			memcpy(value, file_finder_info, file_rec_len);
550 			res = file_rec_len;
551 		} else {
552 			res = -EOPNOTSUPP;
553 			goto end_getxattr_finder_info;
554 		}
555 	} else
556 		res = size ? -ERANGE : record_len;
557 
558 end_getxattr_finder_info:
559 	if (size >= record_len)
560 		hfs_find_exit(&fd);
561 	return res;
562 }
563 
564 ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
565 			 void *value, size_t size)
566 {
567 	struct hfs_find_data fd;
568 	hfsplus_attr_entry *entry;
569 	__be32 xattr_record_type;
570 	u32 record_type;
571 	u16 record_length = 0;
572 	ssize_t res = 0;
573 
574 	if ((!S_ISREG(inode->i_mode) &&
575 			!S_ISDIR(inode->i_mode)) ||
576 				HFSPLUS_IS_RSRC(inode))
577 		return -EOPNOTSUPP;
578 
579 	if (strncmp(name, XATTR_MAC_OSX_PREFIX,
580 				XATTR_MAC_OSX_PREFIX_LEN) == 0) {
581 		/* skip "osx." prefix */
582 		name += XATTR_MAC_OSX_PREFIX_LEN;
583 		/*
584 		 * Don't allow retrieving properly prefixed attributes
585 		 * by prepending them with "osx."
586 		 */
587 		if (is_known_namespace(name))
588 			return -EOPNOTSUPP;
589 	}
590 
591 	if (!strcmp_xattr_finder_info(name))
592 		return hfsplus_getxattr_finder_info(inode, value, size);
593 
594 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
595 		return -EOPNOTSUPP;
596 
597 	entry = hfsplus_alloc_attr_entry();
598 	if (!entry) {
599 		pr_err("can't allocate xattr entry\n");
600 		return -ENOMEM;
601 	}
602 
603 	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
604 	if (res) {
605 		pr_err("can't init xattr find struct\n");
606 		goto failed_getxattr_init;
607 	}
608 
609 	res = hfsplus_find_attr(inode->i_sb, inode->i_ino, name, &fd);
610 	if (res) {
611 		if (res == -ENOENT)
612 			res = -ENODATA;
613 		else
614 			pr_err("xattr searching failed\n");
615 		goto out;
616 	}
617 
618 	hfs_bnode_read(fd.bnode, &xattr_record_type,
619 			fd.entryoffset, sizeof(xattr_record_type));
620 	record_type = be32_to_cpu(xattr_record_type);
621 	if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
622 		record_length = hfs_bnode_read_u16(fd.bnode,
623 				fd.entryoffset +
624 				offsetof(struct hfsplus_attr_inline_data,
625 				length));
626 		if (record_length > HFSPLUS_MAX_INLINE_DATA_SIZE) {
627 			pr_err("invalid xattr record size\n");
628 			res = -EIO;
629 			goto out;
630 		}
631 	} else if (record_type == HFSPLUS_ATTR_FORK_DATA ||
632 			record_type == HFSPLUS_ATTR_EXTENTS) {
633 		pr_err("only inline data xattr are supported\n");
634 		res = -EOPNOTSUPP;
635 		goto out;
636 	} else {
637 		pr_err("invalid xattr record\n");
638 		res = -EIO;
639 		goto out;
640 	}
641 
642 	if (size) {
643 		hfs_bnode_read(fd.bnode, entry, fd.entryoffset,
644 				offsetof(struct hfsplus_attr_inline_data,
645 					raw_bytes) + record_length);
646 	}
647 
648 	if (size >= record_length) {
649 		memcpy(value, entry->inline_data.raw_bytes, record_length);
650 		res = record_length;
651 	} else
652 		res = size ? -ERANGE : record_length;
653 
654 out:
655 	hfs_find_exit(&fd);
656 
657 failed_getxattr_init:
658 	hfsplus_destroy_attr_entry(entry);
659 	return res;
660 }
661 
662 static inline int can_list(const char *xattr_name)
663 {
664 	if (!xattr_name)
665 		return 0;
666 
667 	return strncmp(xattr_name, XATTR_TRUSTED_PREFIX,
668 			XATTR_TRUSTED_PREFIX_LEN) ||
669 				capable(CAP_SYS_ADMIN);
670 }
671 
672 static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry,
673 						char *buffer, size_t size)
674 {
675 	ssize_t res = 0;
676 	struct inode *inode = dentry->d_inode;
677 	struct hfs_find_data fd;
678 	u16 entry_type;
679 	u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
680 	u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
681 	unsigned long len, found_bit;
682 	int xattr_name_len, symbols_count;
683 
684 	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
685 	if (res) {
686 		pr_err("can't init xattr find struct\n");
687 		return res;
688 	}
689 
690 	res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
691 	if (res)
692 		goto end_listxattr_finder_info;
693 
694 	entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
695 	if (entry_type == HFSPLUS_FOLDER) {
696 		len = sizeof(struct DInfo) + sizeof(struct DXInfo);
697 		hfs_bnode_read(fd.bnode, folder_finder_info,
698 				fd.entryoffset +
699 				offsetof(struct hfsplus_cat_folder, user_info),
700 				len);
701 		found_bit = find_first_bit((void *)folder_finder_info, len*8);
702 	} else if (entry_type == HFSPLUS_FILE) {
703 		len = sizeof(struct FInfo) + sizeof(struct FXInfo);
704 		hfs_bnode_read(fd.bnode, file_finder_info,
705 				fd.entryoffset +
706 				offsetof(struct hfsplus_cat_file, user_info),
707 				len);
708 		found_bit = find_first_bit((void *)file_finder_info, len*8);
709 	} else {
710 		res = -EOPNOTSUPP;
711 		goto end_listxattr_finder_info;
712 	}
713 
714 	if (found_bit >= (len*8))
715 		res = 0;
716 	else {
717 		symbols_count = sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME) - 1;
718 		xattr_name_len =
719 			name_len(HFSPLUS_XATTR_FINDER_INFO_NAME, symbols_count);
720 		if (!buffer || !size) {
721 			if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME))
722 				res = xattr_name_len;
723 		} else if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME)) {
724 			if (size < xattr_name_len)
725 				res = -ERANGE;
726 			else {
727 				res = copy_name(buffer,
728 						HFSPLUS_XATTR_FINDER_INFO_NAME,
729 						symbols_count);
730 			}
731 		}
732 	}
733 
734 end_listxattr_finder_info:
735 	hfs_find_exit(&fd);
736 
737 	return res;
738 }
739 
740 ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
741 {
742 	ssize_t err;
743 	ssize_t res = 0;
744 	struct inode *inode = dentry->d_inode;
745 	struct hfs_find_data fd;
746 	u16 key_len = 0;
747 	struct hfsplus_attr_key attr_key;
748 	char strbuf[HFSPLUS_ATTR_MAX_STRLEN +
749 			XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
750 	int xattr_name_len;
751 
752 	if ((!S_ISREG(inode->i_mode) &&
753 			!S_ISDIR(inode->i_mode)) ||
754 				HFSPLUS_IS_RSRC(inode))
755 		return -EOPNOTSUPP;
756 
757 	res = hfsplus_listxattr_finder_info(dentry, buffer, size);
758 	if (res < 0)
759 		return res;
760 	else if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
761 		return (res == 0) ? -EOPNOTSUPP : res;
762 
763 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
764 	if (err) {
765 		pr_err("can't init xattr find struct\n");
766 		return err;
767 	}
768 
769 	err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd);
770 	if (err) {
771 		if (err == -ENOENT) {
772 			if (res == 0)
773 				res = -ENODATA;
774 			goto end_listxattr;
775 		} else {
776 			res = err;
777 			goto end_listxattr;
778 		}
779 	}
780 
781 	for (;;) {
782 		key_len = hfs_bnode_read_u16(fd.bnode, fd.keyoffset);
783 		if (key_len == 0 || key_len > fd.tree->max_key_len) {
784 			pr_err("invalid xattr key length: %d\n", key_len);
785 			res = -EIO;
786 			goto end_listxattr;
787 		}
788 
789 		hfs_bnode_read(fd.bnode, &attr_key,
790 				fd.keyoffset, key_len + sizeof(key_len));
791 
792 		if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
793 			goto end_listxattr;
794 
795 		xattr_name_len = HFSPLUS_ATTR_MAX_STRLEN;
796 		if (hfsplus_uni2asc(inode->i_sb,
797 			(const struct hfsplus_unistr *)&fd.key->attr.key_name,
798 					strbuf, &xattr_name_len)) {
799 			pr_err("unicode conversion failed\n");
800 			res = -EIO;
801 			goto end_listxattr;
802 		}
803 
804 		if (!buffer || !size) {
805 			if (can_list(strbuf))
806 				res += name_len(strbuf, xattr_name_len);
807 		} else if (can_list(strbuf)) {
808 			if (size < (res + name_len(strbuf, xattr_name_len))) {
809 				res = -ERANGE;
810 				goto end_listxattr;
811 			} else
812 				res += copy_name(buffer + res,
813 						strbuf, xattr_name_len);
814 		}
815 
816 		if (hfs_brec_goto(&fd, 1))
817 			goto end_listxattr;
818 	}
819 
820 end_listxattr:
821 	hfs_find_exit(&fd);
822 	return res;
823 }
824 
825 int hfsplus_removexattr(struct dentry *dentry, const char *name)
826 {
827 	int err = 0;
828 	struct inode *inode = dentry->d_inode;
829 	struct hfs_find_data cat_fd;
830 	u16 flags;
831 	u16 cat_entry_type;
832 	int is_xattr_acl_deleted = 0;
833 	int is_all_xattrs_deleted = 0;
834 
835 	if ((!S_ISREG(inode->i_mode) &&
836 			!S_ISDIR(inode->i_mode)) ||
837 				HFSPLUS_IS_RSRC(inode))
838 		return -EOPNOTSUPP;
839 
840 	if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
841 		return -EOPNOTSUPP;
842 
843 	err = can_set_xattr(inode, name, NULL, 0);
844 	if (err)
845 		return err;
846 
847 	if (strncmp(name, XATTR_MAC_OSX_PREFIX,
848 				XATTR_MAC_OSX_PREFIX_LEN) == 0)
849 		name += XATTR_MAC_OSX_PREFIX_LEN;
850 
851 	if (!strcmp_xattr_finder_info(name))
852 		return -EOPNOTSUPP;
853 
854 	err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
855 	if (err) {
856 		pr_err("can't init xattr find struct\n");
857 		return err;
858 	}
859 
860 	err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
861 	if (err) {
862 		pr_err("catalog searching failed\n");
863 		goto end_removexattr;
864 	}
865 
866 	err = hfsplus_delete_attr(inode, name);
867 	if (err)
868 		goto end_removexattr;
869 
870 	is_xattr_acl_deleted = !strcmp_xattr_acl(name);
871 	is_all_xattrs_deleted = !hfsplus_attr_exists(inode, NULL);
872 
873 	if (!is_xattr_acl_deleted && !is_all_xattrs_deleted)
874 		goto end_removexattr;
875 
876 	cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
877 
878 	if (cat_entry_type == HFSPLUS_FOLDER) {
879 		flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
880 				offsetof(struct hfsplus_cat_folder, flags));
881 		if (is_xattr_acl_deleted)
882 			flags &= ~HFSPLUS_ACL_EXISTS;
883 		if (is_all_xattrs_deleted)
884 			flags &= ~HFSPLUS_XATTR_EXISTS;
885 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
886 				offsetof(struct hfsplus_cat_folder, flags),
887 				flags);
888 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
889 	} else if (cat_entry_type == HFSPLUS_FILE) {
890 		flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
891 				offsetof(struct hfsplus_cat_file, flags));
892 		if (is_xattr_acl_deleted)
893 			flags &= ~HFSPLUS_ACL_EXISTS;
894 		if (is_all_xattrs_deleted)
895 			flags &= ~HFSPLUS_XATTR_EXISTS;
896 		hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
897 				offsetof(struct hfsplus_cat_file, flags),
898 				flags);
899 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
900 	} else {
901 		pr_err("invalid catalog entry type\n");
902 		err = -EIO;
903 		goto end_removexattr;
904 	}
905 
906 end_removexattr:
907 	hfs_find_exit(&cat_fd);
908 	return err;
909 }
910 
911 static int hfsplus_osx_getxattr(struct dentry *dentry, const char *name,
912 					void *buffer, size_t size, int type)
913 {
914 	char xattr_name[HFSPLUS_ATTR_MAX_STRLEN +
915 				XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
916 	size_t len = strlen(name);
917 
918 	if (!strcmp(name, ""))
919 		return -EINVAL;
920 
921 	if (len > HFSPLUS_ATTR_MAX_STRLEN)
922 		return -EOPNOTSUPP;
923 
924 	strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
925 	strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
926 
927 	return hfsplus_getxattr(dentry, xattr_name, buffer, size);
928 }
929 
930 static int hfsplus_osx_setxattr(struct dentry *dentry, const char *name,
931 		const void *buffer, size_t size, int flags, int type)
932 {
933 	char xattr_name[HFSPLUS_ATTR_MAX_STRLEN +
934 				XATTR_MAC_OSX_PREFIX_LEN + 1] = {0};
935 	size_t len = strlen(name);
936 
937 	if (!strcmp(name, ""))
938 		return -EINVAL;
939 
940 	if (len > HFSPLUS_ATTR_MAX_STRLEN)
941 		return -EOPNOTSUPP;
942 
943 	strcpy(xattr_name, XATTR_MAC_OSX_PREFIX);
944 	strcpy(xattr_name + XATTR_MAC_OSX_PREFIX_LEN, name);
945 
946 	return hfsplus_setxattr(dentry, xattr_name, buffer, size, flags);
947 }
948 
949 static size_t hfsplus_osx_listxattr(struct dentry *dentry, char *list,
950 		size_t list_size, const char *name, size_t name_len, int type)
951 {
952 	/*
953 	 * This method is not used.
954 	 * It is used hfsplus_listxattr() instead of generic_listxattr().
955 	 */
956 	return -EOPNOTSUPP;
957 }
958 
959 const struct xattr_handler hfsplus_xattr_osx_handler = {
960 	.prefix	= XATTR_MAC_OSX_PREFIX,
961 	.list	= hfsplus_osx_listxattr,
962 	.get	= hfsplus_osx_getxattr,
963 	.set	= hfsplus_osx_setxattr,
964 };
965