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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/f2fs/acl.c
4 *
5 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6 * http://www.samsung.com/
7 *
8 * Portions of this code from linux/fs/ext2/acl.c
9 *
10 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
11 */
12#include <linux/fs_struct.h>
13#include <linux/f2fs_fs.h>
14#include "f2fs.h"
15#include "xattr.h"
16#include "acl.h"
17
18static inline size_t f2fs_acl_size(int count)
19{
20 if (count <= 4) {
21 return sizeof(struct f2fs_acl_header) +
22 count * sizeof(struct f2fs_acl_entry_short);
23 } else {
24 return sizeof(struct f2fs_acl_header) +
25 4 * sizeof(struct f2fs_acl_entry_short) +
26 (count - 4) * sizeof(struct f2fs_acl_entry);
27 }
28}
29
30static inline int f2fs_acl_count(size_t size)
31{
32 ssize_t s;
33
34 size -= sizeof(struct f2fs_acl_header);
35 s = size - 4 * sizeof(struct f2fs_acl_entry_short);
36 if (s < 0) {
37 if (size % sizeof(struct f2fs_acl_entry_short))
38 return -1;
39 return size / sizeof(struct f2fs_acl_entry_short);
40 } else {
41 if (s % sizeof(struct f2fs_acl_entry))
42 return -1;
43 return s / sizeof(struct f2fs_acl_entry) + 4;
44 }
45}
46
47static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
48{
49 int i, count;
50 struct posix_acl *acl;
51 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
52 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
53 const char *end = value + size;
54
55 if (size < sizeof(struct f2fs_acl_header))
56 return ERR_PTR(error: -EINVAL);
57
58 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
59 return ERR_PTR(error: -EINVAL);
60
61 count = f2fs_acl_count(size);
62 if (count < 0)
63 return ERR_PTR(error: -EINVAL);
64 if (count == 0)
65 return NULL;
66
67 acl = posix_acl_alloc(count, GFP_NOFS);
68 if (!acl)
69 return ERR_PTR(error: -ENOMEM);
70
71 for (i = 0; i < count; i++) {
72
73 if ((char *)entry > end)
74 goto fail;
75
76 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
77 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
78
79 switch (acl->a_entries[i].e_tag) {
80 case ACL_USER_OBJ:
81 case ACL_GROUP_OBJ:
82 case ACL_MASK:
83 case ACL_OTHER:
84 entry = (struct f2fs_acl_entry *)((char *)entry +
85 sizeof(struct f2fs_acl_entry_short));
86 break;
87
88 case ACL_USER:
89 acl->a_entries[i].e_uid =
90 make_kuid(from: &init_user_ns,
91 le32_to_cpu(entry->e_id));
92 entry = (struct f2fs_acl_entry *)((char *)entry +
93 sizeof(struct f2fs_acl_entry));
94 break;
95 case ACL_GROUP:
96 acl->a_entries[i].e_gid =
97 make_kgid(from: &init_user_ns,
98 le32_to_cpu(entry->e_id));
99 entry = (struct f2fs_acl_entry *)((char *)entry +
100 sizeof(struct f2fs_acl_entry));
101 break;
102 default:
103 goto fail;
104 }
105 }
106 if ((char *)entry != end)
107 goto fail;
108 return acl;
109fail:
110 posix_acl_release(acl);
111 return ERR_PTR(error: -EINVAL);
112}
113
114static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi,
115 const struct posix_acl *acl, size_t *size)
116{
117 struct f2fs_acl_header *f2fs_acl;
118 struct f2fs_acl_entry *entry;
119 int i;
120
121 f2fs_acl = f2fs_kmalloc(sbi, size: sizeof(struct f2fs_acl_header) +
122 acl->a_count * sizeof(struct f2fs_acl_entry),
123 GFP_NOFS);
124 if (!f2fs_acl)
125 return ERR_PTR(error: -ENOMEM);
126
127 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
128 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
129
130 for (i = 0; i < acl->a_count; i++) {
131
132 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
133 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
134
135 switch (acl->a_entries[i].e_tag) {
136 case ACL_USER:
137 entry->e_id = cpu_to_le32(
138 from_kuid(&init_user_ns,
139 acl->a_entries[i].e_uid));
140 entry = (struct f2fs_acl_entry *)((char *)entry +
141 sizeof(struct f2fs_acl_entry));
142 break;
143 case ACL_GROUP:
144 entry->e_id = cpu_to_le32(
145 from_kgid(&init_user_ns,
146 acl->a_entries[i].e_gid));
147 entry = (struct f2fs_acl_entry *)((char *)entry +
148 sizeof(struct f2fs_acl_entry));
149 break;
150 case ACL_USER_OBJ:
151 case ACL_GROUP_OBJ:
152 case ACL_MASK:
153 case ACL_OTHER:
154 entry = (struct f2fs_acl_entry *)((char *)entry +
155 sizeof(struct f2fs_acl_entry_short));
156 break;
157 default:
158 goto fail;
159 }
160 }
161 *size = f2fs_acl_size(count: acl->a_count);
162 return (void *)f2fs_acl;
163
164fail:
165 kfree(objp: f2fs_acl);
166 return ERR_PTR(error: -EINVAL);
167}
168
169static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
170 struct folio *dfolio)
171{
172 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
173 void *value = NULL;
174 struct posix_acl *acl;
175 int retval;
176
177 if (type == ACL_TYPE_ACCESS)
178 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
179
180 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dfolio);
181 if (retval > 0) {
182 value = f2fs_kmalloc(sbi: F2FS_I_SB(inode), size: retval, GFP_F2FS_ZERO);
183 if (!value)
184 return ERR_PTR(error: -ENOMEM);
185 retval = f2fs_getxattr(inode, name_index, "", value,
186 retval, dfolio);
187 }
188
189 if (retval > 0)
190 acl = f2fs_acl_from_disk(value, size: retval);
191 else if (retval == -ENODATA)
192 acl = NULL;
193 else
194 acl = ERR_PTR(error: retval);
195 kfree(objp: value);
196
197 return acl;
198}
199
200struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu)
201{
202 if (rcu)
203 return ERR_PTR(error: -ECHILD);
204
205 return __f2fs_get_acl(inode, type, NULL);
206}
207
208static int f2fs_acl_update_mode(struct mnt_idmap *idmap,
209 struct inode *inode, umode_t *mode_p,
210 struct posix_acl **acl)
211{
212 umode_t mode = inode->i_mode;
213 int error;
214
215 if (is_inode_flag_set(inode, flag: FI_ACL_MODE))
216 mode = F2FS_I(inode)->i_acl_mode;
217
218 error = posix_acl_equiv_mode(*acl, &mode);
219 if (error < 0)
220 return error;
221 if (error == 0)
222 *acl = NULL;
223 if (!in_group_or_capable(idmap, inode, vfsgid: i_gid_into_vfsgid(idmap, inode)))
224 mode &= ~S_ISGID;
225 *mode_p = mode;
226 return 0;
227}
228
229static int __f2fs_set_acl(struct mnt_idmap *idmap,
230 struct inode *inode, int type,
231 struct posix_acl *acl, struct folio *ifolio)
232{
233 int name_index;
234 void *value = NULL;
235 size_t size = 0;
236 int error;
237 umode_t mode = inode->i_mode;
238
239 switch (type) {
240 case ACL_TYPE_ACCESS:
241 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
242 if (acl && !ifolio) {
243 error = f2fs_acl_update_mode(idmap, inode, mode_p: &mode, acl: &acl);
244 if (error)
245 return error;
246 set_acl_inode(inode, mode);
247 }
248 break;
249
250 case ACL_TYPE_DEFAULT:
251 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
252 if (!S_ISDIR(inode->i_mode))
253 return acl ? -EACCES : 0;
254 break;
255
256 default:
257 return -EINVAL;
258 }
259
260 if (acl) {
261 value = f2fs_acl_to_disk(sbi: F2FS_I_SB(inode), acl, size: &size);
262 if (IS_ERR(ptr: value)) {
263 clear_inode_flag(inode, flag: FI_ACL_MODE);
264 return PTR_ERR(ptr: value);
265 }
266 }
267
268 error = f2fs_setxattr(inode, name_index, "", value, size, ifolio, 0);
269
270 kfree(objp: value);
271 if (!error)
272 set_cached_acl(inode, type, acl);
273
274 clear_inode_flag(inode, flag: FI_ACL_MODE);
275 return error;
276}
277
278int f2fs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
279 struct posix_acl *acl, int type)
280{
281 struct inode *inode = d_inode(dentry);
282
283 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
284 return -EIO;
285
286 return __f2fs_set_acl(idmap, inode, type, acl, NULL);
287}
288
289/*
290 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
291 * are copied from posix_acl.c
292 */
293static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
294 gfp_t flags)
295{
296 struct posix_acl *clone = NULL;
297
298 if (acl) {
299 clone = kmemdup(acl, struct_size(acl, a_entries, acl->a_count),
300 flags);
301 if (clone)
302 refcount_set(r: &clone->a_refcount, n: 1);
303 }
304 return clone;
305}
306
307static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
308{
309 struct posix_acl_entry *pa, *pe;
310 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
311 umode_t mode = *mode_p;
312 int not_equiv = 0;
313
314 /* assert(atomic_read(acl->a_refcount) == 1); */
315
316 FOREACH_ACL_ENTRY(pa, acl, pe) {
317 switch (pa->e_tag) {
318 case ACL_USER_OBJ:
319 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
320 mode &= (pa->e_perm << 6) | ~S_IRWXU;
321 break;
322
323 case ACL_USER:
324 case ACL_GROUP:
325 not_equiv = 1;
326 break;
327
328 case ACL_GROUP_OBJ:
329 group_obj = pa;
330 break;
331
332 case ACL_OTHER:
333 pa->e_perm &= mode | ~S_IRWXO;
334 mode &= pa->e_perm | ~S_IRWXO;
335 break;
336
337 case ACL_MASK:
338 mask_obj = pa;
339 not_equiv = 1;
340 break;
341
342 default:
343 return -EIO;
344 }
345 }
346
347 if (mask_obj) {
348 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
349 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
350 } else {
351 if (!group_obj)
352 return -EIO;
353 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
354 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
355 }
356
357 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
358 return not_equiv;
359}
360
361static int f2fs_acl_create(struct inode *dir, umode_t *mode,
362 struct posix_acl **default_acl, struct posix_acl **acl,
363 struct folio *dfolio)
364{
365 struct posix_acl *p;
366 struct posix_acl *clone;
367 int ret;
368
369 *acl = NULL;
370 *default_acl = NULL;
371
372 if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
373 return 0;
374
375 p = __f2fs_get_acl(inode: dir, ACL_TYPE_DEFAULT, dfolio);
376 if (!p || p == ERR_PTR(error: -EOPNOTSUPP)) {
377 *mode &= ~current_umask();
378 return 0;
379 }
380 if (IS_ERR(ptr: p))
381 return PTR_ERR(ptr: p);
382
383 clone = f2fs_acl_clone(acl: p, GFP_NOFS);
384 if (!clone) {
385 ret = -ENOMEM;
386 goto release_acl;
387 }
388
389 ret = f2fs_acl_create_masq(acl: clone, mode_p: mode);
390 if (ret < 0)
391 goto release_clone;
392
393 if (ret == 0)
394 posix_acl_release(acl: clone);
395 else
396 *acl = clone;
397
398 if (!S_ISDIR(*mode))
399 posix_acl_release(acl: p);
400 else
401 *default_acl = p;
402
403 return 0;
404
405release_clone:
406 posix_acl_release(acl: clone);
407release_acl:
408 posix_acl_release(acl: p);
409 return ret;
410}
411
412int f2fs_init_acl(struct inode *inode, struct inode *dir, struct folio *ifolio,
413 struct folio *dfolio)
414{
415 struct posix_acl *default_acl = NULL, *acl = NULL;
416 int error;
417
418 error = f2fs_acl_create(dir, mode: &inode->i_mode, default_acl: &default_acl, acl: &acl, dfolio);
419 if (error)
420 return error;
421
422 f2fs_mark_inode_dirty_sync(inode, sync: true);
423
424 if (default_acl) {
425 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_DEFAULT,
426 acl: default_acl, ifolio);
427 posix_acl_release(acl: default_acl);
428 } else {
429 inode->i_default_acl = NULL;
430 }
431 if (acl) {
432 if (!error)
433 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_ACCESS,
434 acl, ifolio);
435 posix_acl_release(acl);
436 } else {
437 inode->i_acl = NULL;
438 }
439
440 return error;
441}
442

source code of linux/fs/f2fs/acl.c