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