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1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2006 NEC Corporation
5 *
6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/fs.h>
17#include <linux/sched.h>
18#include <linux/time.h>
19#include <linux/crc32.h>
20#include <linux/jffs2.h>
21#include <linux/xattr.h>
22#include <linux/posix_acl_xattr.h>
23#include <linux/mtd/mtd.h>
24#include "nodelist.h"
25
26static size_t jffs2_acl_size(int count)
27{
28 if (count <= 4) {
29 return sizeof(struct jffs2_acl_header)
30 + count * sizeof(struct jffs2_acl_entry_short);
31 } else {
32 return sizeof(struct jffs2_acl_header)
33 + 4 * sizeof(struct jffs2_acl_entry_short)
34 + (count - 4) * sizeof(struct jffs2_acl_entry);
35 }
36}
37
38static int jffs2_acl_count(size_t size)
39{
40 size_t s;
41
42 size -= sizeof(struct jffs2_acl_header);
43 if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
44 if (size % sizeof(struct jffs2_acl_entry_short))
45 return -1;
46 return size / sizeof(struct jffs2_acl_entry_short);
47 } else {
48 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
49 if (s % sizeof(struct jffs2_acl_entry))
50 return -1;
51 return s / sizeof(struct jffs2_acl_entry) + 4;
52 }
53}
54
55static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
56{
57 void *end = value + size;
58 struct jffs2_acl_header *header = value;
59 struct jffs2_acl_entry *entry;
60 struct posix_acl *acl;
61 uint32_t ver;
62 int i, count;
63
64 if (!value)
65 return NULL;
66 if (size < sizeof(struct jffs2_acl_header))
67 return ERR_PTR(-EINVAL);
68 ver = je32_to_cpu(header->a_version);
69 if (ver != JFFS2_ACL_VERSION) {
70 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
71 return ERR_PTR(-EINVAL);
72 }
73
74 value += sizeof(struct jffs2_acl_header);
75 count = jffs2_acl_count(size);
76 if (count < 0)
77 return ERR_PTR(-EINVAL);
78 if (count == 0)
79 return NULL;
80
81 acl = posix_acl_alloc(count, GFP_KERNEL);
82 if (!acl)
83 return ERR_PTR(-ENOMEM);
84
85 for (i=0; i < count; i++) {
86 entry = value;
87 if (value + sizeof(struct jffs2_acl_entry_short) > end)
88 goto fail;
89 acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
90 acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
91 switch (acl->a_entries[i].e_tag) {
92 case ACL_USER_OBJ:
93 case ACL_GROUP_OBJ:
94 case ACL_MASK:
95 case ACL_OTHER:
96 value += sizeof(struct jffs2_acl_entry_short);
97 break;
98
99 case ACL_USER:
100 value += sizeof(struct jffs2_acl_entry);
101 if (value > end)
102 goto fail;
103 acl->a_entries[i].e_uid =
104 make_kuid(&init_user_ns,
105 je32_to_cpu(entry->e_id));
106 break;
107 case ACL_GROUP:
108 value += sizeof(struct jffs2_acl_entry);
109 if (value > end)
110 goto fail;
111 acl->a_entries[i].e_gid =
112 make_kgid(&init_user_ns,
113 je32_to_cpu(entry->e_id));
114 break;
115
116 default:
117 goto fail;
118 }
119 }
120 if (value != end)
121 goto fail;
122 return acl;
123 fail:
124 posix_acl_release(acl);
125 return ERR_PTR(-EINVAL);
126}
127
128static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
129{
130 struct jffs2_acl_header *header;
131 struct jffs2_acl_entry *entry;
132 void *e;
133 size_t i;
134
135 *size = jffs2_acl_size(acl->a_count);
136 header = kmalloc(struct_size(header, a_entries, acl->a_count),
137 GFP_KERNEL);
138 if (!header)
139 return ERR_PTR(-ENOMEM);
140 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
141 e = header + 1;
142 for (i=0; i < acl->a_count; i++) {
143 const struct posix_acl_entry *acl_e = &acl->a_entries[i];
144 entry = e;
145 entry->e_tag = cpu_to_je16(acl_e->e_tag);
146 entry->e_perm = cpu_to_je16(acl_e->e_perm);
147 switch(acl_e->e_tag) {
148 case ACL_USER:
149 entry->e_id = cpu_to_je32(
150 from_kuid(&init_user_ns, acl_e->e_uid));
151 e += sizeof(struct jffs2_acl_entry);
152 break;
153 case ACL_GROUP:
154 entry->e_id = cpu_to_je32(
155 from_kgid(&init_user_ns, acl_e->e_gid));
156 e += sizeof(struct jffs2_acl_entry);
157 break;
158
159 case ACL_USER_OBJ:
160 case ACL_GROUP_OBJ:
161 case ACL_MASK:
162 case ACL_OTHER:
163 e += sizeof(struct jffs2_acl_entry_short);
164 break;
165
166 default:
167 goto fail;
168 }
169 }
170 return header;
171 fail:
172 kfree(header);
173 return ERR_PTR(-EINVAL);
174}
175
176struct posix_acl *jffs2_get_acl(struct inode *inode, int type, bool rcu)
177{
178 struct posix_acl *acl;
179 char *value = NULL;
180 int rc, xprefix;
181
182 if (rcu)
183 return ERR_PTR(-ECHILD);
184
185 switch (type) {
186 case ACL_TYPE_ACCESS:
187 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
188 break;
189 case ACL_TYPE_DEFAULT:
190 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
191 break;
192 default:
193 BUG();
194 }
195 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
196 if (rc > 0) {
197 value = kmalloc(rc, GFP_KERNEL);
198 if (!value)
199 return ERR_PTR(-ENOMEM);
200 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
201 }
202 if (rc > 0) {
203 acl = jffs2_acl_from_medium(value, rc);
204 } else if (rc == -ENODATA || rc == -ENOSYS) {
205 acl = NULL;
206 } else {
207 acl = ERR_PTR(rc);
208 }
209 kfree(value);
210 return acl;
211}
212
213static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
214{
215 char *value = NULL;
216 size_t size = 0;
217 int rc;
218
219 if (acl) {
220 value = jffs2_acl_to_medium(acl, &size);
221 if (IS_ERR(value))
222 return PTR_ERR(value);
223 }
224 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
225 if (!value && rc == -ENODATA)
226 rc = 0;
227 kfree(value);
228
229 return rc;
230}
231
232int jffs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
233 struct posix_acl *acl, int type)
234{
235 int rc, xprefix;
236 struct inode *inode = d_inode(dentry);
237
238 switch (type) {
239 case ACL_TYPE_ACCESS:
240 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
241 if (acl) {
242 umode_t mode;
243
244 rc = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode,
245 &acl);
246 if (rc)
247 return rc;
248 if (inode->i_mode != mode) {
249 struct iattr attr;
250
251 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
252 attr.ia_mode = mode;
253 attr.ia_ctime = current_time(inode);
254 rc = jffs2_do_setattr(inode, &attr);
255 if (rc < 0)
256 return rc;
257 }
258 }
259 break;
260 case ACL_TYPE_DEFAULT:
261 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
262 if (!S_ISDIR(inode->i_mode))
263 return acl ? -EACCES : 0;
264 break;
265 default:
266 return -EINVAL;
267 }
268 rc = __jffs2_set_acl(inode, xprefix, acl);
269 if (!rc)
270 set_cached_acl(inode, type, acl);
271 return rc;
272}
273
274int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
275{
276 struct posix_acl *default_acl, *acl;
277 int rc;
278
279 cache_no_acl(inode);
280
281 rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl);
282 if (rc)
283 return rc;
284
285 if (default_acl) {
286 set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
287 posix_acl_release(default_acl);
288 }
289 if (acl) {
290 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
291 posix_acl_release(acl);
292 }
293 return 0;
294}
295
296int jffs2_init_acl_post(struct inode *inode)
297{
298 int rc;
299
300 if (inode->i_default_acl) {
301 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
302 if (rc)
303 return rc;
304 }
305
306 if (inode->i_acl) {
307 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
308 if (rc)
309 return rc;
310 }
311
312 return 0;
313}
1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright © 2006 NEC Corporation
5 *
6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
11
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/fs.h>
15#include <linux/sched.h>
16#include <linux/time.h>
17#include <linux/crc32.h>
18#include <linux/jffs2.h>
19#include <linux/xattr.h>
20#include <linux/posix_acl_xattr.h>
21#include <linux/mtd/mtd.h>
22#include "nodelist.h"
23
24static size_t jffs2_acl_size(int count)
25{
26 if (count <= 4) {
27 return sizeof(struct jffs2_acl_header)
28 + count * sizeof(struct jffs2_acl_entry_short);
29 } else {
30 return sizeof(struct jffs2_acl_header)
31 + 4 * sizeof(struct jffs2_acl_entry_short)
32 + (count - 4) * sizeof(struct jffs2_acl_entry);
33 }
34}
35
36static int jffs2_acl_count(size_t size)
37{
38 size_t s;
39
40 size -= sizeof(struct jffs2_acl_header);
41 if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
42 if (size % sizeof(struct jffs2_acl_entry_short))
43 return -1;
44 return size / sizeof(struct jffs2_acl_entry_short);
45 } else {
46 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
47 if (s % sizeof(struct jffs2_acl_entry))
48 return -1;
49 return s / sizeof(struct jffs2_acl_entry) + 4;
50 }
51}
52
53static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
54{
55 void *end = value + size;
56 struct jffs2_acl_header *header = value;
57 struct jffs2_acl_entry *entry;
58 struct posix_acl *acl;
59 uint32_t ver;
60 int i, count;
61
62 if (!value)
63 return NULL;
64 if (size < sizeof(struct jffs2_acl_header))
65 return ERR_PTR(-EINVAL);
66 ver = je32_to_cpu(header->a_version);
67 if (ver != JFFS2_ACL_VERSION) {
68 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
69 return ERR_PTR(-EINVAL);
70 }
71
72 value += sizeof(struct jffs2_acl_header);
73 count = jffs2_acl_count(size);
74 if (count < 0)
75 return ERR_PTR(-EINVAL);
76 if (count == 0)
77 return NULL;
78
79 acl = posix_acl_alloc(count, GFP_KERNEL);
80 if (!acl)
81 return ERR_PTR(-ENOMEM);
82
83 for (i=0; i < count; i++) {
84 entry = value;
85 if (value + sizeof(struct jffs2_acl_entry_short) > end)
86 goto fail;
87 acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
88 acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
89 switch (acl->a_entries[i].e_tag) {
90 case ACL_USER_OBJ:
91 case ACL_GROUP_OBJ:
92 case ACL_MASK:
93 case ACL_OTHER:
94 value += sizeof(struct jffs2_acl_entry_short);
95 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
96 break;
97
98 case ACL_USER:
99 case ACL_GROUP:
100 value += sizeof(struct jffs2_acl_entry);
101 if (value > end)
102 goto fail;
103 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
104 break;
105
106 default:
107 goto fail;
108 }
109 }
110 if (value != end)
111 goto fail;
112 return acl;
113 fail:
114 posix_acl_release(acl);
115 return ERR_PTR(-EINVAL);
116}
117
118static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
119{
120 struct jffs2_acl_header *header;
121 struct jffs2_acl_entry *entry;
122 void *e;
123 size_t i;
124
125 *size = jffs2_acl_size(acl->a_count);
126 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
127 if (!header)
128 return ERR_PTR(-ENOMEM);
129 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
130 e = header + 1;
131 for (i=0; i < acl->a_count; i++) {
132 entry = e;
133 entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
134 entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
135 switch(acl->a_entries[i].e_tag) {
136 case ACL_USER:
137 case ACL_GROUP:
138 entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
139 e += sizeof(struct jffs2_acl_entry);
140 break;
141
142 case ACL_USER_OBJ:
143 case ACL_GROUP_OBJ:
144 case ACL_MASK:
145 case ACL_OTHER:
146 e += sizeof(struct jffs2_acl_entry_short);
147 break;
148
149 default:
150 goto fail;
151 }
152 }
153 return header;
154 fail:
155 kfree(header);
156 return ERR_PTR(-EINVAL);
157}
158
159struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
160{
161 struct posix_acl *acl;
162 char *value = NULL;
163 int rc, xprefix;
164
165 acl = get_cached_acl(inode, type);
166 if (acl != ACL_NOT_CACHED)
167 return acl;
168
169 switch (type) {
170 case ACL_TYPE_ACCESS:
171 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
172 break;
173 case ACL_TYPE_DEFAULT:
174 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
175 break;
176 default:
177 BUG();
178 }
179 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
180 if (rc > 0) {
181 value = kmalloc(rc, GFP_KERNEL);
182 if (!value)
183 return ERR_PTR(-ENOMEM);
184 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
185 }
186 if (rc > 0) {
187 acl = jffs2_acl_from_medium(value, rc);
188 } else if (rc == -ENODATA || rc == -ENOSYS) {
189 acl = NULL;
190 } else {
191 acl = ERR_PTR(rc);
192 }
193 if (value)
194 kfree(value);
195 if (!IS_ERR(acl))
196 set_cached_acl(inode, type, acl);
197 return acl;
198}
199
200static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
201{
202 char *value = NULL;
203 size_t size = 0;
204 int rc;
205
206 if (acl) {
207 value = jffs2_acl_to_medium(acl, &size);
208 if (IS_ERR(value))
209 return PTR_ERR(value);
210 }
211 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
212 if (!value && rc == -ENODATA)
213 rc = 0;
214 kfree(value);
215
216 return rc;
217}
218
219static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
220{
221 int rc, xprefix;
222
223 if (S_ISLNK(inode->i_mode))
224 return -EOPNOTSUPP;
225
226 switch (type) {
227 case ACL_TYPE_ACCESS:
228 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
229 if (acl) {
230 umode_t mode = inode->i_mode;
231 rc = posix_acl_equiv_mode(acl, &mode);
232 if (rc < 0)
233 return rc;
234 if (inode->i_mode != mode) {
235 struct iattr attr;
236
237 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
238 attr.ia_mode = mode;
239 attr.ia_ctime = CURRENT_TIME_SEC;
240 rc = jffs2_do_setattr(inode, &attr);
241 if (rc < 0)
242 return rc;
243 }
244 if (rc == 0)
245 acl = NULL;
246 }
247 break;
248 case ACL_TYPE_DEFAULT:
249 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
250 if (!S_ISDIR(inode->i_mode))
251 return acl ? -EACCES : 0;
252 break;
253 default:
254 return -EINVAL;
255 }
256 rc = __jffs2_set_acl(inode, xprefix, acl);
257 if (!rc)
258 set_cached_acl(inode, type, acl);
259 return rc;
260}
261
262int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
263{
264 struct posix_acl *acl;
265 int rc;
266
267 cache_no_acl(inode);
268
269 if (S_ISLNK(*i_mode))
270 return 0; /* Symlink always has no-ACL */
271
272 acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
273 if (IS_ERR(acl))
274 return PTR_ERR(acl);
275
276 if (!acl) {
277 *i_mode &= ~current_umask();
278 } else {
279 if (S_ISDIR(*i_mode))
280 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);
281
282 rc = posix_acl_create(&acl, GFP_KERNEL, i_mode);
283 if (rc < 0)
284 return rc;
285 if (rc > 0)
286 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
287
288 posix_acl_release(acl);
289 }
290 return 0;
291}
292
293int jffs2_init_acl_post(struct inode *inode)
294{
295 int rc;
296
297 if (inode->i_default_acl) {
298 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
299 if (rc)
300 return rc;
301 }
302
303 if (inode->i_acl) {
304 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
305 if (rc)
306 return rc;
307 }
308
309 return 0;
310}
311
312int jffs2_acl_chmod(struct inode *inode)
313{
314 struct posix_acl *acl;
315 int rc;
316
317 if (S_ISLNK(inode->i_mode))
318 return -EOPNOTSUPP;
319 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
320 if (IS_ERR(acl) || !acl)
321 return PTR_ERR(acl);
322 rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
323 if (rc)
324 return rc;
325 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, acl);
326 posix_acl_release(acl);
327 return rc;
328}
329
330static size_t jffs2_acl_access_listxattr(struct dentry *dentry, char *list,
331 size_t list_size, const char *name, size_t name_len, int type)
332{
333 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
334
335 if (list && retlen <= list_size)
336 strcpy(list, POSIX_ACL_XATTR_ACCESS);
337 return retlen;
338}
339
340static size_t jffs2_acl_default_listxattr(struct dentry *dentry, char *list,
341 size_t list_size, const char *name, size_t name_len, int type)
342{
343 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
344
345 if (list && retlen <= list_size)
346 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
347 return retlen;
348}
349
350static int jffs2_acl_getxattr(struct dentry *dentry, const char *name,
351 void *buffer, size_t size, int type)
352{
353 struct posix_acl *acl;
354 int rc;
355
356 if (name[0] != '\0')
357 return -EINVAL;
358
359 acl = jffs2_get_acl(dentry->d_inode, type);
360 if (IS_ERR(acl))
361 return PTR_ERR(acl);
362 if (!acl)
363 return -ENODATA;
364 rc = posix_acl_to_xattr(acl, buffer, size);
365 posix_acl_release(acl);
366
367 return rc;
368}
369
370static int jffs2_acl_setxattr(struct dentry *dentry, const char *name,
371 const void *value, size_t size, int flags, int type)
372{
373 struct posix_acl *acl;
374 int rc;
375
376 if (name[0] != '\0')
377 return -EINVAL;
378 if (!inode_owner_or_capable(dentry->d_inode))
379 return -EPERM;
380
381 if (value) {
382 acl = posix_acl_from_xattr(value, size);
383 if (IS_ERR(acl))
384 return PTR_ERR(acl);
385 if (acl) {
386 rc = posix_acl_valid(acl);
387 if (rc)
388 goto out;
389 }
390 } else {
391 acl = NULL;
392 }
393 rc = jffs2_set_acl(dentry->d_inode, type, acl);
394 out:
395 posix_acl_release(acl);
396 return rc;
397}
398
399const struct xattr_handler jffs2_acl_access_xattr_handler = {
400 .prefix = POSIX_ACL_XATTR_ACCESS,
401 .flags = ACL_TYPE_DEFAULT,
402 .list = jffs2_acl_access_listxattr,
403 .get = jffs2_acl_getxattr,
404 .set = jffs2_acl_setxattr,
405};
406
407const struct xattr_handler jffs2_acl_default_xattr_handler = {
408 .prefix = POSIX_ACL_XATTR_DEFAULT,
409 .flags = ACL_TYPE_DEFAULT,
410 .list = jffs2_acl_default_listxattr,
411 .get = jffs2_acl_getxattr,
412 .set = jffs2_acl_setxattr,
413};