1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/capability.h> |
3 | #include <linux/fs.h> |
4 | #include <linux/posix_acl.h> |
5 | #include "reiserfs.h" |
6 | #include <linux/errno.h> |
7 | #include <linux/pagemap.h> |
8 | #include <linux/xattr.h> |
9 | #include <linux/slab.h> |
10 | #include <linux/posix_acl_xattr.h> |
11 | #include "xattr.h" |
12 | #include "acl.h" |
13 | #include <linux/uaccess.h> |
14 | |
15 | static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, |
16 | struct inode *inode, int type, |
17 | struct posix_acl *acl); |
18 | |
19 | |
20 | int |
21 | reiserfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, |
22 | struct posix_acl *acl, int type) |
23 | { |
24 | int error, error2; |
25 | struct reiserfs_transaction_handle th; |
26 | size_t jcreate_blocks; |
27 | int size = acl ? posix_acl_xattr_size(count: acl->a_count) : 0; |
28 | int update_mode = 0; |
29 | struct inode *inode = d_inode(dentry); |
30 | umode_t mode = inode->i_mode; |
31 | |
32 | /* |
33 | * Pessimism: We can't assume that anything from the xattr root up |
34 | * has been created. |
35 | */ |
36 | |
37 | jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + |
38 | reiserfs_xattr_nblocks(inode, size) * 2; |
39 | |
40 | reiserfs_write_lock(s: inode->i_sb); |
41 | error = journal_begin(&th, sb: inode->i_sb, jcreate_blocks); |
42 | reiserfs_write_unlock(s: inode->i_sb); |
43 | if (error == 0) { |
44 | if (type == ACL_TYPE_ACCESS && acl) { |
45 | error = posix_acl_update_mode(&nop_mnt_idmap, inode, |
46 | &mode, &acl); |
47 | if (error) |
48 | goto unlock; |
49 | update_mode = 1; |
50 | } |
51 | error = __reiserfs_set_acl(th: &th, inode, type, acl); |
52 | if (!error && update_mode) |
53 | inode->i_mode = mode; |
54 | unlock: |
55 | reiserfs_write_lock(s: inode->i_sb); |
56 | error2 = journal_end(&th); |
57 | reiserfs_write_unlock(s: inode->i_sb); |
58 | if (error2) |
59 | error = error2; |
60 | } |
61 | |
62 | return error; |
63 | } |
64 | |
65 | /* |
66 | * Convert from filesystem to in-memory representation. |
67 | */ |
68 | static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) |
69 | { |
70 | const char *end = (char *)value + size; |
71 | int n, count; |
72 | struct posix_acl *acl; |
73 | |
74 | if (!value) |
75 | return NULL; |
76 | if (size < sizeof(reiserfs_acl_header)) |
77 | return ERR_PTR(error: -EINVAL); |
78 | if (((reiserfs_acl_header *) value)->a_version != |
79 | cpu_to_le32(REISERFS_ACL_VERSION)) |
80 | return ERR_PTR(error: -EINVAL); |
81 | value = (char *)value + sizeof(reiserfs_acl_header); |
82 | count = reiserfs_acl_count(size); |
83 | if (count < 0) |
84 | return ERR_PTR(error: -EINVAL); |
85 | if (count == 0) |
86 | return NULL; |
87 | acl = posix_acl_alloc(count, GFP_NOFS); |
88 | if (!acl) |
89 | return ERR_PTR(error: -ENOMEM); |
90 | for (n = 0; n < count; n++) { |
91 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; |
92 | if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) |
93 | goto fail; |
94 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); |
95 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); |
96 | switch (acl->a_entries[n].e_tag) { |
97 | case ACL_USER_OBJ: |
98 | case ACL_GROUP_OBJ: |
99 | case ACL_MASK: |
100 | case ACL_OTHER: |
101 | value = (char *)value + |
102 | sizeof(reiserfs_acl_entry_short); |
103 | break; |
104 | |
105 | case ACL_USER: |
106 | value = (char *)value + sizeof(reiserfs_acl_entry); |
107 | if ((char *)value > end) |
108 | goto fail; |
109 | acl->a_entries[n].e_uid = |
110 | make_kuid(from: &init_user_ns, |
111 | le32_to_cpu(entry->e_id)); |
112 | break; |
113 | case ACL_GROUP: |
114 | value = (char *)value + sizeof(reiserfs_acl_entry); |
115 | if ((char *)value > end) |
116 | goto fail; |
117 | acl->a_entries[n].e_gid = |
118 | make_kgid(from: &init_user_ns, |
119 | le32_to_cpu(entry->e_id)); |
120 | break; |
121 | |
122 | default: |
123 | goto fail; |
124 | } |
125 | } |
126 | if (value != end) |
127 | goto fail; |
128 | return acl; |
129 | |
130 | fail: |
131 | posix_acl_release(acl); |
132 | return ERR_PTR(error: -EINVAL); |
133 | } |
134 | |
135 | /* |
136 | * Convert from in-memory to filesystem representation. |
137 | */ |
138 | static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) |
139 | { |
140 | reiserfs_acl_header *ext_acl; |
141 | char *e; |
142 | int n; |
143 | |
144 | *size = reiserfs_acl_size(count: acl->a_count); |
145 | ext_acl = kmalloc(size: sizeof(reiserfs_acl_header) + |
146 | acl->a_count * |
147 | sizeof(reiserfs_acl_entry), |
148 | GFP_NOFS); |
149 | if (!ext_acl) |
150 | return ERR_PTR(error: -ENOMEM); |
151 | ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); |
152 | e = (char *)ext_acl + sizeof(reiserfs_acl_header); |
153 | for (n = 0; n < acl->a_count; n++) { |
154 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; |
155 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; |
156 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); |
157 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); |
158 | switch (acl->a_entries[n].e_tag) { |
159 | case ACL_USER: |
160 | entry->e_id = cpu_to_le32( |
161 | from_kuid(&init_user_ns, acl_e->e_uid)); |
162 | e += sizeof(reiserfs_acl_entry); |
163 | break; |
164 | case ACL_GROUP: |
165 | entry->e_id = cpu_to_le32( |
166 | from_kgid(&init_user_ns, acl_e->e_gid)); |
167 | e += sizeof(reiserfs_acl_entry); |
168 | break; |
169 | |
170 | case ACL_USER_OBJ: |
171 | case ACL_GROUP_OBJ: |
172 | case ACL_MASK: |
173 | case ACL_OTHER: |
174 | e += sizeof(reiserfs_acl_entry_short); |
175 | break; |
176 | |
177 | default: |
178 | goto fail; |
179 | } |
180 | } |
181 | return (char *)ext_acl; |
182 | |
183 | fail: |
184 | kfree(objp: ext_acl); |
185 | return ERR_PTR(error: -EINVAL); |
186 | } |
187 | |
188 | /* |
189 | * Inode operation get_posix_acl(). |
190 | * |
191 | * inode->i_mutex: down |
192 | * BKL held [before 2.5.x] |
193 | */ |
194 | struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, bool rcu) |
195 | { |
196 | char *name, *value; |
197 | struct posix_acl *acl; |
198 | int size; |
199 | int retval; |
200 | |
201 | if (rcu) |
202 | return ERR_PTR(error: -ECHILD); |
203 | |
204 | switch (type) { |
205 | case ACL_TYPE_ACCESS: |
206 | name = XATTR_NAME_POSIX_ACL_ACCESS; |
207 | break; |
208 | case ACL_TYPE_DEFAULT: |
209 | name = XATTR_NAME_POSIX_ACL_DEFAULT; |
210 | break; |
211 | default: |
212 | BUG(); |
213 | } |
214 | |
215 | size = reiserfs_xattr_get(inode, name, NULL, 0); |
216 | if (size < 0) { |
217 | if (size == -ENODATA || size == -ENOSYS) |
218 | return NULL; |
219 | return ERR_PTR(error: size); |
220 | } |
221 | |
222 | value = kmalloc(size, GFP_NOFS); |
223 | if (!value) |
224 | return ERR_PTR(error: -ENOMEM); |
225 | |
226 | retval = reiserfs_xattr_get(inode, name, value, size); |
227 | if (retval == -ENODATA || retval == -ENOSYS) { |
228 | /* |
229 | * This shouldn't actually happen as it should have |
230 | * been caught above.. but just in case |
231 | */ |
232 | acl = NULL; |
233 | } else if (retval < 0) { |
234 | acl = ERR_PTR(error: retval); |
235 | } else { |
236 | acl = reiserfs_posix_acl_from_disk(value, size: retval); |
237 | } |
238 | |
239 | kfree(objp: value); |
240 | return acl; |
241 | } |
242 | |
243 | /* |
244 | * Inode operation set_posix_acl(). |
245 | * |
246 | * inode->i_mutex: down |
247 | * BKL held [before 2.5.x] |
248 | */ |
249 | static int |
250 | __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, |
251 | int type, struct posix_acl *acl) |
252 | { |
253 | char *name; |
254 | void *value = NULL; |
255 | size_t size = 0; |
256 | int error; |
257 | |
258 | switch (type) { |
259 | case ACL_TYPE_ACCESS: |
260 | name = XATTR_NAME_POSIX_ACL_ACCESS; |
261 | break; |
262 | case ACL_TYPE_DEFAULT: |
263 | name = XATTR_NAME_POSIX_ACL_DEFAULT; |
264 | if (!S_ISDIR(inode->i_mode)) |
265 | return acl ? -EACCES : 0; |
266 | break; |
267 | default: |
268 | return -EINVAL; |
269 | } |
270 | |
271 | if (acl) { |
272 | value = reiserfs_posix_acl_to_disk(acl, size: &size); |
273 | if (IS_ERR(ptr: value)) |
274 | return (int)PTR_ERR(ptr: value); |
275 | } |
276 | |
277 | error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); |
278 | |
279 | /* |
280 | * Ensure that the inode gets dirtied if we're only using |
281 | * the mode bits and an old ACL didn't exist. We don't need |
282 | * to check if the inode is hashed here since we won't get |
283 | * called by reiserfs_inherit_default_acl(). |
284 | */ |
285 | if (error == -ENODATA) { |
286 | error = 0; |
287 | if (type == ACL_TYPE_ACCESS) { |
288 | inode_set_ctime_current(inode); |
289 | mark_inode_dirty(inode); |
290 | } |
291 | } |
292 | |
293 | kfree(objp: value); |
294 | |
295 | if (!error) |
296 | set_cached_acl(inode, type, acl); |
297 | |
298 | return error; |
299 | } |
300 | |
301 | /* |
302 | * dir->i_mutex: locked, |
303 | * inode is new and not released into the wild yet |
304 | */ |
305 | int |
306 | reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, |
307 | struct inode *dir, struct dentry *dentry, |
308 | struct inode *inode) |
309 | { |
310 | struct posix_acl *default_acl, *acl; |
311 | int err = 0; |
312 | |
313 | /* ACLs only get applied to files and directories */ |
314 | if (S_ISLNK(inode->i_mode)) |
315 | return 0; |
316 | |
317 | /* |
318 | * ACLs can only be used on "new" objects, so if it's an old object |
319 | * there is nothing to inherit from |
320 | */ |
321 | if (get_inode_sd_version(dir) == STAT_DATA_V1) |
322 | goto apply_umask; |
323 | |
324 | /* |
325 | * Don't apply ACLs to objects in the .reiserfs_priv tree.. This |
326 | * would be useless since permissions are ignored, and a pain because |
327 | * it introduces locking cycles |
328 | */ |
329 | if (IS_PRIVATE(inode)) |
330 | goto apply_umask; |
331 | |
332 | err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); |
333 | if (err) |
334 | return err; |
335 | |
336 | if (default_acl) { |
337 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, |
338 | acl: default_acl); |
339 | posix_acl_release(acl: default_acl); |
340 | } |
341 | if (acl) { |
342 | if (!err) |
343 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, |
344 | acl); |
345 | posix_acl_release(acl); |
346 | } |
347 | |
348 | return err; |
349 | |
350 | apply_umask: |
351 | /* no ACL, apply umask */ |
352 | inode->i_mode &= ~current_umask(); |
353 | return err; |
354 | } |
355 | |
356 | /* This is used to cache the default acl before a new object is created. |
357 | * The biggest reason for this is to get an idea of how many blocks will |
358 | * actually be required for the create operation if we must inherit an ACL. |
359 | * An ACL write can add up to 3 object creations and an additional file write |
360 | * so we'd prefer not to reserve that many blocks in the journal if we can. |
361 | * It also has the advantage of not loading the ACL with a transaction open, |
362 | * this may seem silly, but if the owner of the directory is doing the |
363 | * creation, the ACL may not be loaded since the permissions wouldn't require |
364 | * it. |
365 | * We return the number of blocks required for the transaction. |
366 | */ |
367 | int reiserfs_cache_default_acl(struct inode *inode) |
368 | { |
369 | struct posix_acl *acl; |
370 | int nblocks = 0; |
371 | |
372 | if (IS_PRIVATE(inode)) |
373 | return 0; |
374 | |
375 | acl = get_inode_acl(inode, ACL_TYPE_DEFAULT); |
376 | |
377 | if (acl && !IS_ERR(ptr: acl)) { |
378 | int size = reiserfs_acl_size(count: acl->a_count); |
379 | |
380 | /* Other xattrs can be created during inode creation. We don't |
381 | * want to claim too many blocks, so we check to see if we |
382 | * need to create the tree to the xattrs, and then we |
383 | * just want two files. */ |
384 | nblocks = reiserfs_xattr_jcreate_nblocks(inode); |
385 | nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); |
386 | |
387 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; |
388 | |
389 | /* We need to account for writes + bitmaps for two files */ |
390 | nblocks += reiserfs_xattr_nblocks(inode, size) * 4; |
391 | posix_acl_release(acl); |
392 | } |
393 | |
394 | return nblocks; |
395 | } |
396 | |
397 | /* |
398 | * Called under i_mutex |
399 | */ |
400 | int reiserfs_acl_chmod(struct dentry *dentry) |
401 | { |
402 | struct inode *inode = d_inode(dentry); |
403 | |
404 | if (IS_PRIVATE(inode)) |
405 | return 0; |
406 | if (get_inode_sd_version(inode) == STAT_DATA_V1 || |
407 | !reiserfs_posixacl(inode->i_sb)) |
408 | return 0; |
409 | |
410 | return posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode); |
411 | } |
412 | |