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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(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
137 if (!header)
138 return ERR_PTR(-ENOMEM);
139 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
140 e = header + 1;
141 for (i=0; i < acl->a_count; i++) {
142 const struct posix_acl_entry *acl_e = &acl->a_entries[i];
143 entry = e;
144 entry->e_tag = cpu_to_je16(acl_e->e_tag);
145 entry->e_perm = cpu_to_je16(acl_e->e_perm);
146 switch(acl_e->e_tag) {
147 case ACL_USER:
148 entry->e_id = cpu_to_je32(
149 from_kuid(&init_user_ns, acl_e->e_uid));
150 e += sizeof(struct jffs2_acl_entry);
151 break;
152 case ACL_GROUP:
153 entry->e_id = cpu_to_je32(
154 from_kgid(&init_user_ns, acl_e->e_gid));
155 e += sizeof(struct jffs2_acl_entry);
156 break;
157
158 case ACL_USER_OBJ:
159 case ACL_GROUP_OBJ:
160 case ACL_MASK:
161 case ACL_OTHER:
162 e += sizeof(struct jffs2_acl_entry_short);
163 break;
164
165 default:
166 goto fail;
167 }
168 }
169 return header;
170 fail:
171 kfree(header);
172 return ERR_PTR(-EINVAL);
173}
174
175struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
176{
177 struct posix_acl *acl;
178 char *value = NULL;
179 int rc, xprefix;
180
181 switch (type) {
182 case ACL_TYPE_ACCESS:
183 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
184 break;
185 case ACL_TYPE_DEFAULT:
186 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
187 break;
188 default:
189 BUG();
190 }
191 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
192 if (rc > 0) {
193 value = kmalloc(rc, GFP_KERNEL);
194 if (!value)
195 return ERR_PTR(-ENOMEM);
196 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
197 }
198 if (rc > 0) {
199 acl = jffs2_acl_from_medium(value, rc);
200 } else if (rc == -ENODATA || rc == -ENOSYS) {
201 acl = NULL;
202 } else {
203 acl = ERR_PTR(rc);
204 }
205 kfree(value);
206 if (!IS_ERR(acl))
207 set_cached_acl(inode, type, acl);
208 return acl;
209}
210
211static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
212{
213 char *value = NULL;
214 size_t size = 0;
215 int rc;
216
217 if (acl) {
218 value = jffs2_acl_to_medium(acl, &size);
219 if (IS_ERR(value))
220 return PTR_ERR(value);
221 }
222 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
223 if (!value && rc == -ENODATA)
224 rc = 0;
225 kfree(value);
226
227 return rc;
228}
229
230int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
231{
232 int rc, xprefix;
233
234 switch (type) {
235 case ACL_TYPE_ACCESS:
236 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
237 if (acl) {
238 umode_t mode = inode->i_mode;
239 rc = posix_acl_equiv_mode(acl, &mode);
240 if (rc < 0)
241 return rc;
242 if (inode->i_mode != mode) {
243 struct iattr attr;
244
245 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
246 attr.ia_mode = mode;
247 attr.ia_ctime = CURRENT_TIME_SEC;
248 rc = jffs2_do_setattr(inode, &attr);
249 if (rc < 0)
250 return rc;
251 }
252 if (rc == 0)
253 acl = NULL;
254 }
255 break;
256 case ACL_TYPE_DEFAULT:
257 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
258 if (!S_ISDIR(inode->i_mode))
259 return acl ? -EACCES : 0;
260 break;
261 default:
262 return -EINVAL;
263 }
264 rc = __jffs2_set_acl(inode, xprefix, acl);
265 if (!rc)
266 set_cached_acl(inode, type, acl);
267 return rc;
268}
269
270int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
271{
272 struct posix_acl *default_acl, *acl;
273 int rc;
274
275 cache_no_acl(inode);
276
277 rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl);
278 if (rc)
279 return rc;
280
281 if (default_acl) {
282 set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
283 posix_acl_release(default_acl);
284 }
285 if (acl) {
286 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
287 posix_acl_release(acl);
288 }
289 return 0;
290}
291
292int jffs2_init_acl_post(struct inode *inode)
293{
294 int rc;
295
296 if (inode->i_default_acl) {
297 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
298 if (rc)
299 return rc;
300 }
301
302 if (inode->i_acl) {
303 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
304 if (rc)
305 return rc;
306 }
307
308 return 0;
309}
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 acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
98 break;
99
100 case ACL_USER:
101 case ACL_GROUP:
102 value += sizeof(struct jffs2_acl_entry);
103 if (value > end)
104 goto fail;
105 acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
106 break;
107
108 default:
109 goto fail;
110 }
111 }
112 if (value != end)
113 goto fail;
114 return acl;
115 fail:
116 posix_acl_release(acl);
117 return ERR_PTR(-EINVAL);
118}
119
120static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
121{
122 struct jffs2_acl_header *header;
123 struct jffs2_acl_entry *entry;
124 void *e;
125 size_t i;
126
127 *size = jffs2_acl_size(acl->a_count);
128 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
129 if (!header)
130 return ERR_PTR(-ENOMEM);
131 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
132 e = header + 1;
133 for (i=0; i < acl->a_count; i++) {
134 entry = e;
135 entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
136 entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
137 switch(acl->a_entries[i].e_tag) {
138 case ACL_USER:
139 case ACL_GROUP:
140 entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
141 e += sizeof(struct jffs2_acl_entry);
142 break;
143
144 case ACL_USER_OBJ:
145 case ACL_GROUP_OBJ:
146 case ACL_MASK:
147 case ACL_OTHER:
148 e += sizeof(struct jffs2_acl_entry_short);
149 break;
150
151 default:
152 goto fail;
153 }
154 }
155 return header;
156 fail:
157 kfree(header);
158 return ERR_PTR(-EINVAL);
159}
160
161struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
162{
163 struct posix_acl *acl;
164 char *value = NULL;
165 int rc, xprefix;
166
167 acl = get_cached_acl(inode, type);
168 if (acl != ACL_NOT_CACHED)
169 return acl;
170
171 switch (type) {
172 case ACL_TYPE_ACCESS:
173 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
174 break;
175 case ACL_TYPE_DEFAULT:
176 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
177 break;
178 default:
179 BUG();
180 }
181 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
182 if (rc > 0) {
183 value = kmalloc(rc, GFP_KERNEL);
184 if (!value)
185 return ERR_PTR(-ENOMEM);
186 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
187 }
188 if (rc > 0) {
189 acl = jffs2_acl_from_medium(value, rc);
190 } else if (rc == -ENODATA || rc == -ENOSYS) {
191 acl = NULL;
192 } else {
193 acl = ERR_PTR(rc);
194 }
195 if (value)
196 kfree(value);
197 if (!IS_ERR(acl))
198 set_cached_acl(inode, type, acl);
199 return acl;
200}
201
202static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
203{
204 char *value = NULL;
205 size_t size = 0;
206 int rc;
207
208 if (acl) {
209 value = jffs2_acl_to_medium(acl, &size);
210 if (IS_ERR(value))
211 return PTR_ERR(value);
212 }
213 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
214 if (!value && rc == -ENODATA)
215 rc = 0;
216 kfree(value);
217
218 return rc;
219}
220
221static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
222{
223 int rc, xprefix;
224
225 if (S_ISLNK(inode->i_mode))
226 return -EOPNOTSUPP;
227
228 switch (type) {
229 case ACL_TYPE_ACCESS:
230 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
231 if (acl) {
232 umode_t mode = inode->i_mode;
233 rc = posix_acl_equiv_mode(acl, &mode);
234 if (rc < 0)
235 return rc;
236 if (inode->i_mode != mode) {
237 struct iattr attr;
238
239 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
240 attr.ia_mode = mode;
241 attr.ia_ctime = CURRENT_TIME_SEC;
242 rc = jffs2_do_setattr(inode, &attr);
243 if (rc < 0)
244 return rc;
245 }
246 if (rc == 0)
247 acl = NULL;
248 }
249 break;
250 case ACL_TYPE_DEFAULT:
251 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
252 if (!S_ISDIR(inode->i_mode))
253 return acl ? -EACCES : 0;
254 break;
255 default:
256 return -EINVAL;
257 }
258 rc = __jffs2_set_acl(inode, xprefix, acl);
259 if (!rc)
260 set_cached_acl(inode, type, acl);
261 return rc;
262}
263
264int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
265{
266 struct posix_acl *acl;
267 int rc;
268
269 cache_no_acl(inode);
270
271 if (S_ISLNK(*i_mode))
272 return 0; /* Symlink always has no-ACL */
273
274 acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
275 if (IS_ERR(acl))
276 return PTR_ERR(acl);
277
278 if (!acl) {
279 *i_mode &= ~current_umask();
280 } else {
281 if (S_ISDIR(*i_mode))
282 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);
283
284 rc = posix_acl_create(&acl, GFP_KERNEL, i_mode);
285 if (rc < 0)
286 return rc;
287 if (rc > 0)
288 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
289
290 posix_acl_release(acl);
291 }
292 return 0;
293}
294
295int jffs2_init_acl_post(struct inode *inode)
296{
297 int rc;
298
299 if (inode->i_default_acl) {
300 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
301 if (rc)
302 return rc;
303 }
304
305 if (inode->i_acl) {
306 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
307 if (rc)
308 return rc;
309 }
310
311 return 0;
312}
313
314int jffs2_acl_chmod(struct inode *inode)
315{
316 struct posix_acl *acl;
317 int rc;
318
319 if (S_ISLNK(inode->i_mode))
320 return -EOPNOTSUPP;
321 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
322 if (IS_ERR(acl) || !acl)
323 return PTR_ERR(acl);
324 rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
325 if (rc)
326 return rc;
327 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, acl);
328 posix_acl_release(acl);
329 return rc;
330}
331
332static size_t jffs2_acl_access_listxattr(struct dentry *dentry, char *list,
333 size_t list_size, const char *name, size_t name_len, int type)
334{
335 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
336
337 if (list && retlen <= list_size)
338 strcpy(list, POSIX_ACL_XATTR_ACCESS);
339 return retlen;
340}
341
342static size_t jffs2_acl_default_listxattr(struct dentry *dentry, char *list,
343 size_t list_size, const char *name, size_t name_len, int type)
344{
345 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
346
347 if (list && retlen <= list_size)
348 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
349 return retlen;
350}
351
352static int jffs2_acl_getxattr(struct dentry *dentry, const char *name,
353 void *buffer, size_t size, int type)
354{
355 struct posix_acl *acl;
356 int rc;
357
358 if (name[0] != '\0')
359 return -EINVAL;
360
361 acl = jffs2_get_acl(dentry->d_inode, type);
362 if (IS_ERR(acl))
363 return PTR_ERR(acl);
364 if (!acl)
365 return -ENODATA;
366 rc = posix_acl_to_xattr(acl, buffer, size);
367 posix_acl_release(acl);
368
369 return rc;
370}
371
372static int jffs2_acl_setxattr(struct dentry *dentry, const char *name,
373 const void *value, size_t size, int flags, int type)
374{
375 struct posix_acl *acl;
376 int rc;
377
378 if (name[0] != '\0')
379 return -EINVAL;
380 if (!inode_owner_or_capable(dentry->d_inode))
381 return -EPERM;
382
383 if (value) {
384 acl = posix_acl_from_xattr(value, size);
385 if (IS_ERR(acl))
386 return PTR_ERR(acl);
387 if (acl) {
388 rc = posix_acl_valid(acl);
389 if (rc)
390 goto out;
391 }
392 } else {
393 acl = NULL;
394 }
395 rc = jffs2_set_acl(dentry->d_inode, type, acl);
396 out:
397 posix_acl_release(acl);
398 return rc;
399}
400
401const struct xattr_handler jffs2_acl_access_xattr_handler = {
402 .prefix = POSIX_ACL_XATTR_ACCESS,
403 .flags = ACL_TYPE_DEFAULT,
404 .list = jffs2_acl_access_listxattr,
405 .get = jffs2_acl_getxattr,
406 .set = jffs2_acl_setxattr,
407};
408
409const struct xattr_handler jffs2_acl_default_xattr_handler = {
410 .prefix = POSIX_ACL_XATTR_DEFAULT,
411 .flags = ACL_TYPE_DEFAULT,
412 .list = jffs2_acl_default_listxattr,
413 .get = jffs2_acl_getxattr,
414 .set = jffs2_acl_setxattr,
415};