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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 "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 return acl;
176}
177
178/*
179 * Set the access or default ACL of an inode.
180 *
181 * inode->i_mutex: down unless called from ext4_new_inode
182 */
183static int
184__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
185 struct posix_acl *acl)
186{
187 int name_index;
188 void *value = NULL;
189 size_t size = 0;
190 int error;
191
192 switch (type) {
193 case ACL_TYPE_ACCESS:
194 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
195 if (acl) {
196 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
197 if (error)
198 return error;
199 inode->i_ctime = current_time(inode);
200 ext4_mark_inode_dirty(handle, inode);
201 }
202 break;
203
204 case ACL_TYPE_DEFAULT:
205 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
206 if (!S_ISDIR(inode->i_mode))
207 return acl ? -EACCES : 0;
208 break;
209
210 default:
211 return -EINVAL;
212 }
213 if (acl) {
214 value = ext4_acl_to_disk(acl, &size);
215 if (IS_ERR(value))
216 return (int)PTR_ERR(value);
217 }
218
219 error = ext4_xattr_set_handle(handle, inode, name_index, "",
220 value, size, 0);
221
222 kfree(value);
223 if (!error)
224 set_cached_acl(inode, type, acl);
225
226 return error;
227}
228
229int
230ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
231{
232 handle_t *handle;
233 int error, retries = 0;
234
235retry:
236 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
237 ext4_jbd2_credits_xattr(inode));
238 if (IS_ERR(handle))
239 return PTR_ERR(handle);
240
241 error = __ext4_set_acl(handle, inode, type, acl);
242 ext4_journal_stop(handle);
243 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
244 goto retry;
245 return error;
246}
247
248/*
249 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
250 *
251 * dir->i_mutex: down
252 * inode->i_mutex: up (access to inode is still exclusive)
253 */
254int
255ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
256{
257 struct posix_acl *default_acl, *acl;
258 int error;
259
260 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
261 if (error)
262 return error;
263
264 if (default_acl) {
265 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
266 default_acl);
267 posix_acl_release(default_acl);
268 }
269 if (acl) {
270 if (!error)
271 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
272 acl);
273 posix_acl_release(acl);
274 }
275 return error;
276}