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1/*
2 * linux/fs/ext4/acl.c
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 */
6
7#include "ext4_jbd2.h"
8#include "ext4.h"
9#include "xattr.h"
10#include "acl.h"
11
12/*
13 * Convert from filesystem to in-memory representation.
14 */
15static struct posix_acl *
16ext4_acl_from_disk(const void *value, size_t size)
17{
18 const char *end = (char *)value + size;
19 int n, count;
20 struct posix_acl *acl;
21
22 if (!value)
23 return NULL;
24 if (size < sizeof(ext4_acl_header))
25 return ERR_PTR(-EINVAL);
26 if (((ext4_acl_header *)value)->a_version !=
27 cpu_to_le32(EXT4_ACL_VERSION))
28 return ERR_PTR(-EINVAL);
29 value = (char *)value + sizeof(ext4_acl_header);
30 count = ext4_acl_count(size);
31 if (count < 0)
32 return ERR_PTR(-EINVAL);
33 if (count == 0)
34 return NULL;
35 acl = posix_acl_alloc(count, GFP_NOFS);
36 if (!acl)
37 return ERR_PTR(-ENOMEM);
38 for (n = 0; n < count; n++) {
39 ext4_acl_entry *entry =
40 (ext4_acl_entry *)value;
41 if ((char *)value + sizeof(ext4_acl_entry_short) > end)
42 goto fail;
43 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
44 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
45
46 switch (acl->a_entries[n].e_tag) {
47 case ACL_USER_OBJ:
48 case ACL_GROUP_OBJ:
49 case ACL_MASK:
50 case ACL_OTHER:
51 value = (char *)value +
52 sizeof(ext4_acl_entry_short);
53 break;
54
55 case ACL_USER:
56 value = (char *)value + sizeof(ext4_acl_entry);
57 if ((char *)value > end)
58 goto fail;
59 acl->a_entries[n].e_uid =
60 make_kuid(&init_user_ns,
61 le32_to_cpu(entry->e_id));
62 break;
63 case ACL_GROUP:
64 value = (char *)value + sizeof(ext4_acl_entry);
65 if ((char *)value > end)
66 goto fail;
67 acl->a_entries[n].e_gid =
68 make_kgid(&init_user_ns,
69 le32_to_cpu(entry->e_id));
70 break;
71
72 default:
73 goto fail;
74 }
75 }
76 if (value != end)
77 goto fail;
78 return acl;
79
80fail:
81 posix_acl_release(acl);
82 return ERR_PTR(-EINVAL);
83}
84
85/*
86 * Convert from in-memory to filesystem representation.
87 */
88static void *
89ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
90{
91 ext4_acl_header *ext_acl;
92 char *e;
93 size_t n;
94
95 *size = ext4_acl_size(acl->a_count);
96 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
97 sizeof(ext4_acl_entry), GFP_NOFS);
98 if (!ext_acl)
99 return ERR_PTR(-ENOMEM);
100 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
101 e = (char *)ext_acl + sizeof(ext4_acl_header);
102 for (n = 0; n < acl->a_count; n++) {
103 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
104 ext4_acl_entry *entry = (ext4_acl_entry *)e;
105 entry->e_tag = cpu_to_le16(acl_e->e_tag);
106 entry->e_perm = cpu_to_le16(acl_e->e_perm);
107 switch (acl_e->e_tag) {
108 case ACL_USER:
109 entry->e_id = cpu_to_le32(
110 from_kuid(&init_user_ns, acl_e->e_uid));
111 e += sizeof(ext4_acl_entry);
112 break;
113 case ACL_GROUP:
114 entry->e_id = cpu_to_le32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
116 e += sizeof(ext4_acl_entry);
117 break;
118
119 case ACL_USER_OBJ:
120 case ACL_GROUP_OBJ:
121 case ACL_MASK:
122 case ACL_OTHER:
123 e += sizeof(ext4_acl_entry_short);
124 break;
125
126 default:
127 goto fail;
128 }
129 }
130 return (char *)ext_acl;
131
132fail:
133 kfree(ext_acl);
134 return ERR_PTR(-EINVAL);
135}
136
137/*
138 * Inode operation get_posix_acl().
139 *
140 * inode->i_mutex: don't care
141 */
142struct posix_acl *
143ext4_get_acl(struct inode *inode, int type)
144{
145 int name_index;
146 char *value = NULL;
147 struct posix_acl *acl;
148 int retval;
149
150 switch (type) {
151 case ACL_TYPE_ACCESS:
152 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
153 break;
154 case ACL_TYPE_DEFAULT:
155 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
156 break;
157 default:
158 BUG();
159 }
160 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
161 if (retval > 0) {
162 value = kmalloc(retval, GFP_NOFS);
163 if (!value)
164 return ERR_PTR(-ENOMEM);
165 retval = ext4_xattr_get(inode, name_index, "", value, retval);
166 }
167 if (retval > 0)
168 acl = ext4_acl_from_disk(value, retval);
169 else if (retval == -ENODATA || retval == -ENOSYS)
170 acl = NULL;
171 else
172 acl = ERR_PTR(retval);
173 kfree(value);
174
175 if (!IS_ERR(acl))
176 set_cached_acl(inode, type, acl);
177
178 return acl;
179}
180
181/*
182 * Set the access or default ACL of an inode.
183 *
184 * inode->i_mutex: down unless called from ext4_new_inode
185 */
186static int
187__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
188 struct posix_acl *acl)
189{
190 int name_index;
191 void *value = NULL;
192 size_t size = 0;
193 int error;
194
195 switch (type) {
196 case ACL_TYPE_ACCESS:
197 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
198 if (acl) {
199 error = posix_acl_equiv_mode(acl, &inode->i_mode);
200 if (error < 0)
201 return error;
202 else {
203 inode->i_ctime = ext4_current_time(inode);
204 ext4_mark_inode_dirty(handle, inode);
205 if (error == 0)
206 acl = NULL;
207 }
208 }
209 break;
210
211 case ACL_TYPE_DEFAULT:
212 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
213 if (!S_ISDIR(inode->i_mode))
214 return acl ? -EACCES : 0;
215 break;
216
217 default:
218 return -EINVAL;
219 }
220 if (acl) {
221 value = ext4_acl_to_disk(acl, &size);
222 if (IS_ERR(value))
223 return (int)PTR_ERR(value);
224 }
225
226 error = ext4_xattr_set_handle(handle, inode, name_index, "",
227 value, size, 0);
228
229 kfree(value);
230 if (!error)
231 set_cached_acl(inode, type, acl);
232
233 return error;
234}
235
236int
237ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
238{
239 handle_t *handle;
240 int error, retries = 0;
241
242retry:
243 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
244 ext4_jbd2_credits_xattr(inode));
245 if (IS_ERR(handle))
246 return PTR_ERR(handle);
247
248 error = __ext4_set_acl(handle, inode, type, acl);
249 ext4_journal_stop(handle);
250 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
251 goto retry;
252 return error;
253}
254
255/*
256 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
257 *
258 * dir->i_mutex: down
259 * inode->i_mutex: up (access to inode is still exclusive)
260 */
261int
262ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
263{
264 struct posix_acl *default_acl, *acl;
265 int error;
266
267 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
268 if (error)
269 return error;
270
271 if (default_acl) {
272 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
273 default_acl);
274 posix_acl_release(default_acl);
275 }
276 if (acl) {
277 if (!error)
278 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
279 acl);
280 posix_acl_release(acl);
281 }
282 return error;
283}
1/*
2 * linux/fs/ext4/acl.c
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 */
6
7#include <linux/init.h>
8#include <linux/sched.h>
9#include <linux/slab.h>
10#include <linux/capability.h>
11#include <linux/fs.h>
12#include "ext4_jbd2.h"
13#include "ext4.h"
14#include "xattr.h"
15#include "acl.h"
16
17/*
18 * Convert from filesystem to in-memory representation.
19 */
20static struct posix_acl *
21ext4_acl_from_disk(const void *value, size_t size)
22{
23 const char *end = (char *)value + size;
24 int n, count;
25 struct posix_acl *acl;
26
27 if (!value)
28 return NULL;
29 if (size < sizeof(ext4_acl_header))
30 return ERR_PTR(-EINVAL);
31 if (((ext4_acl_header *)value)->a_version !=
32 cpu_to_le32(EXT4_ACL_VERSION))
33 return ERR_PTR(-EINVAL);
34 value = (char *)value + sizeof(ext4_acl_header);
35 count = ext4_acl_count(size);
36 if (count < 0)
37 return ERR_PTR(-EINVAL);
38 if (count == 0)
39 return NULL;
40 acl = posix_acl_alloc(count, GFP_NOFS);
41 if (!acl)
42 return ERR_PTR(-ENOMEM);
43 for (n = 0; n < count; n++) {
44 ext4_acl_entry *entry =
45 (ext4_acl_entry *)value;
46 if ((char *)value + sizeof(ext4_acl_entry_short) > end)
47 goto fail;
48 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
49 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
50
51 switch (acl->a_entries[n].e_tag) {
52 case ACL_USER_OBJ:
53 case ACL_GROUP_OBJ:
54 case ACL_MASK:
55 case ACL_OTHER:
56 value = (char *)value +
57 sizeof(ext4_acl_entry_short);
58 break;
59
60 case ACL_USER:
61 value = (char *)value + sizeof(ext4_acl_entry);
62 if ((char *)value > end)
63 goto fail;
64 acl->a_entries[n].e_uid =
65 make_kuid(&init_user_ns,
66 le32_to_cpu(entry->e_id));
67 break;
68 case ACL_GROUP:
69 value = (char *)value + sizeof(ext4_acl_entry);
70 if ((char *)value > end)
71 goto fail;
72 acl->a_entries[n].e_gid =
73 make_kgid(&init_user_ns,
74 le32_to_cpu(entry->e_id));
75 break;
76
77 default:
78 goto fail;
79 }
80 }
81 if (value != end)
82 goto fail;
83 return acl;
84
85fail:
86 posix_acl_release(acl);
87 return ERR_PTR(-EINVAL);
88}
89
90/*
91 * Convert from in-memory to filesystem representation.
92 */
93static void *
94ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
95{
96 ext4_acl_header *ext_acl;
97 char *e;
98 size_t n;
99
100 *size = ext4_acl_size(acl->a_count);
101 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
102 sizeof(ext4_acl_entry), GFP_NOFS);
103 if (!ext_acl)
104 return ERR_PTR(-ENOMEM);
105 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
106 e = (char *)ext_acl + sizeof(ext4_acl_header);
107 for (n = 0; n < acl->a_count; n++) {
108 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
109 ext4_acl_entry *entry = (ext4_acl_entry *)e;
110 entry->e_tag = cpu_to_le16(acl_e->e_tag);
111 entry->e_perm = cpu_to_le16(acl_e->e_perm);
112 switch (acl_e->e_tag) {
113 case ACL_USER:
114 entry->e_id = cpu_to_le32(
115 from_kuid(&init_user_ns, acl_e->e_uid));
116 e += sizeof(ext4_acl_entry);
117 break;
118 case ACL_GROUP:
119 entry->e_id = cpu_to_le32(
120 from_kgid(&init_user_ns, acl_e->e_gid));
121 e += sizeof(ext4_acl_entry);
122 break;
123
124 case ACL_USER_OBJ:
125 case ACL_GROUP_OBJ:
126 case ACL_MASK:
127 case ACL_OTHER:
128 e += sizeof(ext4_acl_entry_short);
129 break;
130
131 default:
132 goto fail;
133 }
134 }
135 return (char *)ext_acl;
136
137fail:
138 kfree(ext_acl);
139 return ERR_PTR(-EINVAL);
140}
141
142/*
143 * Inode operation get_posix_acl().
144 *
145 * inode->i_mutex: don't care
146 */
147struct posix_acl *
148ext4_get_acl(struct inode *inode, int type)
149{
150 int name_index;
151 char *value = NULL;
152 struct posix_acl *acl;
153 int retval;
154
155 switch (type) {
156 case ACL_TYPE_ACCESS:
157 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
158 break;
159 case ACL_TYPE_DEFAULT:
160 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
161 break;
162 default:
163 BUG();
164 }
165 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
166 if (retval > 0) {
167 value = kmalloc(retval, GFP_NOFS);
168 if (!value)
169 return ERR_PTR(-ENOMEM);
170 retval = ext4_xattr_get(inode, name_index, "", value, retval);
171 }
172 if (retval > 0)
173 acl = ext4_acl_from_disk(value, retval);
174 else if (retval == -ENODATA || retval == -ENOSYS)
175 acl = NULL;
176 else
177 acl = ERR_PTR(retval);
178 kfree(value);
179
180 if (!IS_ERR(acl))
181 set_cached_acl(inode, type, acl);
182
183 return acl;
184}
185
186/*
187 * Set the access or default ACL of an inode.
188 *
189 * inode->i_mutex: down unless called from ext4_new_inode
190 */
191static int
192__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
193 struct posix_acl *acl)
194{
195 int name_index;
196 void *value = NULL;
197 size_t size = 0;
198 int error;
199
200 switch (type) {
201 case ACL_TYPE_ACCESS:
202 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
203 if (acl) {
204 error = posix_acl_equiv_mode(acl, &inode->i_mode);
205 if (error < 0)
206 return error;
207 else {
208 inode->i_ctime = ext4_current_time(inode);
209 ext4_mark_inode_dirty(handle, inode);
210 if (error == 0)
211 acl = NULL;
212 }
213 }
214 break;
215
216 case ACL_TYPE_DEFAULT:
217 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
218 if (!S_ISDIR(inode->i_mode))
219 return acl ? -EACCES : 0;
220 break;
221
222 default:
223 return -EINVAL;
224 }
225 if (acl) {
226 value = ext4_acl_to_disk(acl, &size);
227 if (IS_ERR(value))
228 return (int)PTR_ERR(value);
229 }
230
231 error = ext4_xattr_set_handle(handle, inode, name_index, "",
232 value, size, 0);
233
234 kfree(value);
235 if (!error)
236 set_cached_acl(inode, type, acl);
237
238 return error;
239}
240
241int
242ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
243{
244 handle_t *handle;
245 int error, retries = 0;
246
247retry:
248 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
249 ext4_jbd2_credits_xattr(inode));
250 if (IS_ERR(handle))
251 return PTR_ERR(handle);
252
253 error = __ext4_set_acl(handle, inode, type, acl);
254 ext4_journal_stop(handle);
255 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
256 goto retry;
257 return error;
258}
259
260/*
261 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
262 *
263 * dir->i_mutex: down
264 * inode->i_mutex: up (access to inode is still exclusive)
265 */
266int
267ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
268{
269 struct posix_acl *default_acl, *acl;
270 int error;
271
272 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
273 if (error)
274 return error;
275
276 if (default_acl) {
277 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
278 default_acl);
279 posix_acl_release(default_acl);
280 }
281 if (acl) {
282 if (!error)
283 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
284 acl);
285 posix_acl_release(acl);
286 }
287 return error;
288}