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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 acl = get_cached_acl(inode, type);
182 if (acl != ACL_NOT_CACHED)
183 return acl;
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 if (value)
210 kfree(value);
211 if (!IS_ERR(acl))
212 set_cached_acl(inode, type, acl);
213 return acl;
214}
215
216static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
217{
218 char *value = NULL;
219 size_t size = 0;
220 int rc;
221
222 if (acl) {
223 value = jffs2_acl_to_medium(acl, &size);
224 if (IS_ERR(value))
225 return PTR_ERR(value);
226 }
227 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
228 if (!value && rc == -ENODATA)
229 rc = 0;
230 kfree(value);
231
232 return rc;
233}
234
235static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
236{
237 int rc, xprefix;
238
239 if (S_ISLNK(inode->i_mode))
240 return -EOPNOTSUPP;
241
242 switch (type) {
243 case ACL_TYPE_ACCESS:
244 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
245 if (acl) {
246 umode_t mode = inode->i_mode;
247 rc = posix_acl_equiv_mode(acl, &mode);
248 if (rc < 0)
249 return rc;
250 if (inode->i_mode != mode) {
251 struct iattr attr;
252
253 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
254 attr.ia_mode = mode;
255 attr.ia_ctime = CURRENT_TIME_SEC;
256 rc = jffs2_do_setattr(inode, &attr);
257 if (rc < 0)
258 return rc;
259 }
260 if (rc == 0)
261 acl = NULL;
262 }
263 break;
264 case ACL_TYPE_DEFAULT:
265 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
266 if (!S_ISDIR(inode->i_mode))
267 return acl ? -EACCES : 0;
268 break;
269 default:
270 return -EINVAL;
271 }
272 rc = __jffs2_set_acl(inode, xprefix, acl);
273 if (!rc)
274 set_cached_acl(inode, type, acl);
275 return rc;
276}
277
278int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
279{
280 struct posix_acl *acl;
281 int rc;
282
283 cache_no_acl(inode);
284
285 if (S_ISLNK(*i_mode))
286 return 0;
287
288 acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
289 if (IS_ERR(acl))
290 return PTR_ERR(acl);
291
292 if (!acl) {
293 *i_mode &= ~current_umask();
294 } else {
295 if (S_ISDIR(*i_mode))
296 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);
297
298 rc = posix_acl_create(&acl, GFP_KERNEL, i_mode);
299 if (rc < 0)
300 return rc;
301 if (rc > 0)
302 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
303
304 posix_acl_release(acl);
305 }
306 return 0;
307}
308
309int jffs2_init_acl_post(struct inode *inode)
310{
311 int rc;
312
313 if (inode->i_default_acl) {
314 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
315 if (rc)
316 return rc;
317 }
318
319 if (inode->i_acl) {
320 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
321 if (rc)
322 return rc;
323 }
324
325 return 0;
326}
327
328int jffs2_acl_chmod(struct inode *inode)
329{
330 struct posix_acl *acl;
331 int rc;
332
333 if (S_ISLNK(inode->i_mode))
334 return -EOPNOTSUPP;
335 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
336 if (IS_ERR(acl) || !acl)
337 return PTR_ERR(acl);
338 rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
339 if (rc)
340 return rc;
341 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, acl);
342 posix_acl_release(acl);
343 return rc;
344}
345
346static size_t jffs2_acl_access_listxattr(struct dentry *dentry, char *list,
347 size_t list_size, const char *name, size_t name_len, int type)
348{
349 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
350
351 if (list && retlen <= list_size)
352 strcpy(list, POSIX_ACL_XATTR_ACCESS);
353 return retlen;
354}
355
356static size_t jffs2_acl_default_listxattr(struct dentry *dentry, char *list,
357 size_t list_size, const char *name, size_t name_len, int type)
358{
359 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
360
361 if (list && retlen <= list_size)
362 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
363 return retlen;
364}
365
366static int jffs2_acl_getxattr(struct dentry *dentry, const char *name,
367 void *buffer, size_t size, int type)
368{
369 struct posix_acl *acl;
370 int rc;
371
372 if (name[0] != '\0')
373 return -EINVAL;
374
375 acl = jffs2_get_acl(dentry->d_inode, type);
376 if (IS_ERR(acl))
377 return PTR_ERR(acl);
378 if (!acl)
379 return -ENODATA;
380 rc = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
381 posix_acl_release(acl);
382
383 return rc;
384}
385
386static int jffs2_acl_setxattr(struct dentry *dentry, const char *name,
387 const void *value, size_t size, int flags, int type)
388{
389 struct posix_acl *acl;
390 int rc;
391
392 if (name[0] != '\0')
393 return -EINVAL;
394 if (!inode_owner_or_capable(dentry->d_inode))
395 return -EPERM;
396
397 if (value) {
398 acl = posix_acl_from_xattr(&init_user_ns, value, size);
399 if (IS_ERR(acl))
400 return PTR_ERR(acl);
401 if (acl) {
402 rc = posix_acl_valid(dentry->d_inode->i_sb->s_user_ns, acl);
403 if (rc)
404 goto out;
405 }
406 } else {
407 acl = NULL;
408 }
409 rc = jffs2_set_acl(dentry->d_inode, type, acl);
410 out:
411 posix_acl_release(acl);
412 return rc;
413}
414
415const struct xattr_handler jffs2_acl_access_xattr_handler = {
416 .prefix = POSIX_ACL_XATTR_ACCESS,
417 .flags = ACL_TYPE_DEFAULT,
418 .list = jffs2_acl_access_listxattr,
419 .get = jffs2_acl_getxattr,
420 .set = jffs2_acl_setxattr,
421};
422
423const struct xattr_handler jffs2_acl_default_xattr_handler = {
424 .prefix = POSIX_ACL_XATTR_DEFAULT,
425 .flags = ACL_TYPE_DEFAULT,
426 .list = jffs2_acl_default_listxattr,
427 .get = jffs2_acl_getxattr,
428 .set = jffs2_acl_setxattr,
429};
430
