import PULS_20180308
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / jffs2 / acl.c
CommitLineData
652ecc20
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1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
aa98d7cf 3 *
c00c310e 4 * Copyright © 2006 NEC Corporation
aa98d7cf 5 *
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6 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 */
c00c310e 11
5a528957
JP
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
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14#include <linux/kernel.h>
15#include <linux/slab.h>
16#include <linux/fs.h>
914e2637 17#include <linux/sched.h>
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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) {
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29 return sizeof(struct jffs2_acl_header)
30 + count * sizeof(struct jffs2_acl_entry_short);
aa98d7cf 31 } else {
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32 return sizeof(struct jffs2_acl_header)
33 + 4 * sizeof(struct jffs2_acl_entry_short)
34 + (count - 4) * sizeof(struct jffs2_acl_entry);
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35 }
36}
37
38static int jffs2_acl_count(size_t size)
39{
40 size_t s;
41
de1f72fa 42 size -= sizeof(struct jffs2_acl_header);
fc371a25 43 if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
de1f72fa 44 if (size % sizeof(struct jffs2_acl_entry_short))
aa98d7cf 45 return -1;
de1f72fa 46 return size / sizeof(struct jffs2_acl_entry_short);
aa98d7cf 47 } else {
fc371a25 48 s = size - 4 * sizeof(struct jffs2_acl_entry_short);
de1f72fa 49 if (s % sizeof(struct jffs2_acl_entry))
aa98d7cf 50 return -1;
de1f72fa 51 return s / sizeof(struct jffs2_acl_entry) + 4;
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52 }
53}
54
dea80134 55static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
aa98d7cf 56{
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57 void *end = value + size;
58 struct jffs2_acl_header *header = value;
59 struct jffs2_acl_entry *entry;
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60 struct posix_acl *acl;
61 uint32_t ver;
62 int i, count;
63
64 if (!value)
65 return NULL;
de1f72fa 66 if (size < sizeof(struct jffs2_acl_header))
aa98d7cf 67 return ERR_PTR(-EINVAL);
dea80134 68 ver = je32_to_cpu(header->a_version);
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69 if (ver != JFFS2_ACL_VERSION) {
70 JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
71 return ERR_PTR(-EINVAL);
72 }
73
dea80134 74 value += sizeof(struct jffs2_acl_header);
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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++) {
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86 entry = value;
87 if (value + sizeof(struct jffs2_acl_entry_short) > end)
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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:
dea80134 96 value += sizeof(struct jffs2_acl_entry_short);
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97 break;
98
99 case ACL_USER:
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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;
aa98d7cf 107 case ACL_GROUP:
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108 value += sizeof(struct jffs2_acl_entry);
109 if (value > end)
aa98d7cf 110 goto fail;
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111 acl->a_entries[i].e_gid =
112 make_kgid(&init_user_ns,
113 je32_to_cpu(entry->e_id));
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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{
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130 struct jffs2_acl_header *header;
131 struct jffs2_acl_entry *entry;
132 void *e;
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133 size_t i;
134
135 *size = jffs2_acl_size(acl->a_count);
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136 header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
137 if (!header)
aa98d7cf 138 return ERR_PTR(-ENOMEM);
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139 header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
140 e = header + 1;
aa98d7cf 141 for (i=0; i < acl->a_count; i++) {
0cfe53d3 142 const struct posix_acl_entry *acl_e = &acl->a_entries[i];
dea80134 143 entry = e;
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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) {
aa98d7cf 147 case ACL_USER:
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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;
aa98d7cf 152 case ACL_GROUP:
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153 entry->e_id = cpu_to_je32(
154 from_kgid(&init_user_ns, acl_e->e_gid));
de1f72fa 155 e += sizeof(struct jffs2_acl_entry);
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156 break;
157
158 case ACL_USER_OBJ:
159 case ACL_GROUP_OBJ:
160 case ACL_MASK:
161 case ACL_OTHER:
de1f72fa 162 e += sizeof(struct jffs2_acl_entry_short);
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163 break;
164
165 default:
166 goto fail;
167 }
168 }
dea80134 169 return header;
aa98d7cf 170 fail:
dea80134 171 kfree(header);
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172 return ERR_PTR(-EINVAL);
173}
174
4e34e719 175struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
aa98d7cf 176{
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177 struct posix_acl *acl;
178 char *value = NULL;
179 int rc, xprefix;
180
073aaa1b
AV
181 acl = get_cached_acl(inode, type);
182 if (acl != ACL_NOT_CACHED)
183 return acl;
184
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185 switch (type) {
186 case ACL_TYPE_ACCESS:
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187 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
188 break;
189 case ACL_TYPE_DEFAULT:
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190 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
191 break;
192 default:
073aaa1b 193 BUG();
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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);
073aaa1b
AV
211 if (!IS_ERR(acl))
212 set_cached_acl(inode, type, acl);
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213 return acl;
214}
215
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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
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235static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
236{
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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) {
4b9e9796
S
246 umode_t mode;
247
248 rc = posix_acl_update_mode(inode, &mode, &acl);
249 if (rc)
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250 return rc;
251 if (inode->i_mode != mode) {
9ed437c5
DW
252 struct iattr attr;
253
1c24d06f 254 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
9ed437c5 255 attr.ia_mode = mode;
1c24d06f 256 attr.ia_ctime = CURRENT_TIME_SEC;
9ed437c5
DW
257 rc = jffs2_do_setattr(inode, &attr);
258 if (rc < 0)
259 return rc;
aa98d7cf 260 }
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261 }
262 break;
263 case ACL_TYPE_DEFAULT:
264 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
265 if (!S_ISDIR(inode->i_mode))
266 return acl ? -EACCES : 0;
267 break;
268 default:
269 return -EINVAL;
270 }
cfc8dc6f 271 rc = __jffs2_set_acl(inode, xprefix, acl);
073aaa1b
AV
272 if (!rc)
273 set_cached_acl(inode, type, acl);
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274 return rc;
275}
276
d3fb6120 277int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
aa98d7cf 278{
826cae2f 279 struct posix_acl *acl;
cfc8dc6f 280 int rc;
aa98d7cf 281
72c04902 282 cache_no_acl(inode);
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283
284 if (S_ISLNK(*i_mode))
285 return 0; /* Symlink always has no-ACL */
286
287 acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
288 if (IS_ERR(acl))
289 return PTR_ERR(acl);
290
291 if (!acl) {
ce3b0f8d 292 *i_mode &= ~current_umask();
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293 } else {
294 if (S_ISDIR(*i_mode))
073aaa1b 295 set_cached_acl(inode, ACL_TYPE_DEFAULT, acl);
9ed437c5 296
826cae2f
AV
297 rc = posix_acl_create(&acl, GFP_KERNEL, i_mode);
298 if (rc < 0)
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299 return rc;
300 if (rc > 0)
826cae2f 301 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
cfc8dc6f 302
826cae2f 303 posix_acl_release(acl);
aa98d7cf 304 }
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305 return 0;
306}
307
308int jffs2_init_acl_post(struct inode *inode)
309{
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310 int rc;
311
290c263b
AV
312 if (inode->i_default_acl) {
313 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
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KK
314 if (rc)
315 return rc;
316 }
317
290c263b
AV
318 if (inode->i_acl) {
319 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
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320 if (rc)
321 return rc;
322 }
323
8d6ea587 324 return 0;
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325}
326
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327int jffs2_acl_chmod(struct inode *inode)
328{
bc26ab5f 329 struct posix_acl *acl;
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330 int rc;
331
332 if (S_ISLNK(inode->i_mode))
333 return -EOPNOTSUPP;
334 acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
335 if (IS_ERR(acl) || !acl)
336 return PTR_ERR(acl);
bc26ab5f
AV
337 rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
338 if (rc)
339 return rc;
340 rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, acl);
aa98d7cf 341 posix_acl_release(acl);
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342 return rc;
343}
344
431547b3
CH
345static size_t jffs2_acl_access_listxattr(struct dentry *dentry, char *list,
346 size_t list_size, const char *name, size_t name_len, int type)
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347{
348 const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
349
350 if (list && retlen <= list_size)
351 strcpy(list, POSIX_ACL_XATTR_ACCESS);
352 return retlen;
353}
354
431547b3
CH
355static size_t jffs2_acl_default_listxattr(struct dentry *dentry, char *list,
356 size_t list_size, const char *name, size_t name_len, int type)
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357{
358 const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
359
360 if (list && retlen <= list_size)
361 strcpy(list, POSIX_ACL_XATTR_DEFAULT);
362 return retlen;
363}
364
431547b3
CH
365static int jffs2_acl_getxattr(struct dentry *dentry, const char *name,
366 void *buffer, size_t size, int type)
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KK
367{
368 struct posix_acl *acl;
369 int rc;
370
431547b3
CH
371 if (name[0] != '\0')
372 return -EINVAL;
373
374 acl = jffs2_get_acl(dentry->d_inode, type);
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375 if (IS_ERR(acl))
376 return PTR_ERR(acl);
377 if (!acl)
378 return -ENODATA;
5f3a4a28 379 rc = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
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380 posix_acl_release(acl);
381
382 return rc;
383}
384
431547b3
CH
385static int jffs2_acl_setxattr(struct dentry *dentry, const char *name,
386 const void *value, size_t size, int flags, int type)
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KK
387{
388 struct posix_acl *acl;
389 int rc;
390
431547b3
CH
391 if (name[0] != '\0')
392 return -EINVAL;
2e149670 393 if (!inode_owner_or_capable(dentry->d_inode))
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394 return -EPERM;
395
396 if (value) {
5f3a4a28 397 acl = posix_acl_from_xattr(&init_user_ns, value, size);
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398 if (IS_ERR(acl))
399 return PTR_ERR(acl);
400 if (acl) {
401 rc = posix_acl_valid(acl);
402 if (rc)
403 goto out;
404 }
405 } else {
406 acl = NULL;
407 }
431547b3 408 rc = jffs2_set_acl(dentry->d_inode, type, acl);
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409 out:
410 posix_acl_release(acl);
411 return rc;
412}
413
365f0cb9 414const struct xattr_handler jffs2_acl_access_xattr_handler = {
aa98d7cf 415 .prefix = POSIX_ACL_XATTR_ACCESS,
431547b3 416 .flags = ACL_TYPE_DEFAULT,
aa98d7cf 417 .list = jffs2_acl_access_listxattr,
431547b3
CH
418 .get = jffs2_acl_getxattr,
419 .set = jffs2_acl_setxattr,
aa98d7cf
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420};
421
365f0cb9 422const struct xattr_handler jffs2_acl_default_xattr_handler = {
aa98d7cf 423 .prefix = POSIX_ACL_XATTR_DEFAULT,
431547b3 424 .flags = ACL_TYPE_DEFAULT,
aa98d7cf 425 .list = jffs2_acl_default_listxattr,
431547b3
CH
426 .get = jffs2_acl_getxattr,
427 .set = jffs2_acl_setxattr,
aa98d7cf 428};