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7#include "ext3.h"
8#include "xattr.h"
9#include "acl.h"
10
11
12
13
14static struct posix_acl *
15ext3_acl_from_disk(const void *value, size_t size)
16{
17 const char *end = (char *)value + size;
18 int n, count;
19 struct posix_acl *acl;
20
21 if (!value)
22 return NULL;
23 if (size < sizeof(ext3_acl_header))
24 return ERR_PTR(-EINVAL);
25 if (((ext3_acl_header *)value)->a_version !=
26 cpu_to_le32(EXT3_ACL_VERSION))
27 return ERR_PTR(-EINVAL);
28 value = (char *)value + sizeof(ext3_acl_header);
29 count = ext3_acl_count(size);
30 if (count < 0)
31 return ERR_PTR(-EINVAL);
32 if (count == 0)
33 return NULL;
34 acl = posix_acl_alloc(count, GFP_NOFS);
35 if (!acl)
36 return ERR_PTR(-ENOMEM);
37 for (n=0; n < count; n++) {
38 ext3_acl_entry *entry =
39 (ext3_acl_entry *)value;
40 if ((char *)value + sizeof(ext3_acl_entry_short) > end)
41 goto fail;
42 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
43 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
44 switch(acl->a_entries[n].e_tag) {
45 case ACL_USER_OBJ:
46 case ACL_GROUP_OBJ:
47 case ACL_MASK:
48 case ACL_OTHER:
49 value = (char *)value +
50 sizeof(ext3_acl_entry_short);
51 break;
52
53 case ACL_USER:
54 value = (char *)value + sizeof(ext3_acl_entry);
55 if ((char *)value > end)
56 goto fail;
57 acl->a_entries[n].e_uid =
58 make_kuid(&init_user_ns,
59 le32_to_cpu(entry->e_id));
60 break;
61 case ACL_GROUP:
62 value = (char *)value + sizeof(ext3_acl_entry);
63 if ((char *)value > end)
64 goto fail;
65 acl->a_entries[n].e_gid =
66 make_kgid(&init_user_ns,
67 le32_to_cpu(entry->e_id));
68 break;
69
70 default:
71 goto fail;
72 }
73 }
74 if (value != end)
75 goto fail;
76 return acl;
77
78fail:
79 posix_acl_release(acl);
80 return ERR_PTR(-EINVAL);
81}
82
83
84
85
86static void *
87ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
88{
89 ext3_acl_header *ext_acl;
90 char *e;
91 size_t n;
92
93 *size = ext3_acl_size(acl->a_count);
94 ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
95 sizeof(ext3_acl_entry), GFP_NOFS);
96 if (!ext_acl)
97 return ERR_PTR(-ENOMEM);
98 ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
99 e = (char *)ext_acl + sizeof(ext3_acl_header);
100 for (n=0; n < acl->a_count; n++) {
101 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
102 ext3_acl_entry *entry = (ext3_acl_entry *)e;
103 entry->e_tag = cpu_to_le16(acl_e->e_tag);
104 entry->e_perm = cpu_to_le16(acl_e->e_perm);
105 switch(acl_e->e_tag) {
106 case ACL_USER:
107 entry->e_id = cpu_to_le32(
108 from_kuid(&init_user_ns, acl_e->e_uid));
109 e += sizeof(ext3_acl_entry);
110 break;
111 case ACL_GROUP:
112 entry->e_id = cpu_to_le32(
113 from_kgid(&init_user_ns, acl_e->e_gid));
114 e += sizeof(ext3_acl_entry);
115 break;
116
117 case ACL_USER_OBJ:
118 case ACL_GROUP_OBJ:
119 case ACL_MASK:
120 case ACL_OTHER:
121 e += sizeof(ext3_acl_entry_short);
122 break;
123
124 default:
125 goto fail;
126 }
127 }
128 return (char *)ext_acl;
129
130fail:
131 kfree(ext_acl);
132 return ERR_PTR(-EINVAL);
133}
134
135
136
137
138
139
140struct posix_acl *
141ext3_get_acl(struct inode *inode, int type)
142{
143 int name_index;
144 char *value = NULL;
145 struct posix_acl *acl;
146 int retval;
147
148 switch (type) {
149 case ACL_TYPE_ACCESS:
150 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
151 break;
152 case ACL_TYPE_DEFAULT:
153 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
154 break;
155 default:
156 BUG();
157 }
158
159 retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
160 if (retval > 0) {
161 value = kmalloc(retval, GFP_NOFS);
162 if (!value)
163 return ERR_PTR(-ENOMEM);
164 retval = ext3_xattr_get(inode, name_index, "", value, retval);
165 }
166 if (retval > 0)
167 acl = ext3_acl_from_disk(value, retval);
168 else if (retval == -ENODATA || retval == -ENOSYS)
169 acl = NULL;
170 else
171 acl = ERR_PTR(retval);
172 kfree(value);
173
174 if (!IS_ERR(acl))
175 set_cached_acl(inode, type, acl);
176
177 return acl;
178}
179
180
181
182
183
184
185static int
186__ext3_set_acl(handle_t *handle, struct inode *inode, int type,
187 struct posix_acl *acl)
188{
189 int name_index;
190 void *value = NULL;
191 size_t size = 0;
192 int error;
193
194 switch(type) {
195 case ACL_TYPE_ACCESS:
196 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
197 if (acl) {
198 error = posix_acl_equiv_mode(acl, &inode->i_mode);
199 if (error < 0)
200 return error;
201 else {
202 inode->i_ctime = CURRENT_TIME_SEC;
203 ext3_mark_inode_dirty(handle, inode);
204 if (error == 0)
205 acl = NULL;
206 }
207 }
208 break;
209
210 case ACL_TYPE_DEFAULT:
211 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
212 if (!S_ISDIR(inode->i_mode))
213 return acl ? -EACCES : 0;
214 break;
215
216 default:
217 return -EINVAL;
218 }
219 if (acl) {
220 value = ext3_acl_to_disk(acl, &size);
221 if (IS_ERR(value))
222 return (int)PTR_ERR(value);
223 }
224
225 error = ext3_xattr_set_handle(handle, inode, name_index, "",
226 value, size, 0);
227
228 kfree(value);
229
230 if (!error)
231 set_cached_acl(inode, type, acl);
232
233 return error;
234}
235
236int
237ext3_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 = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
244 if (IS_ERR(handle))
245 return PTR_ERR(handle);
246 error = __ext3_set_acl(handle, inode, type, acl);
247 ext3_journal_stop(handle);
248 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
249 goto retry;
250 return error;
251}
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257
258
259int
260ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
261{
262 struct posix_acl *default_acl, *acl;
263 int error;
264
265 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
266 if (error)
267 return error;
268
269 if (default_acl) {
270 error = __ext3_set_acl(handle, inode, ACL_TYPE_DEFAULT,
271 default_acl);
272 posix_acl_release(default_acl);
273 }
274 if (acl) {
275 if (!error)
276 error = __ext3_set_acl(handle, inode, ACL_TYPE_ACCESS,
277 acl);
278 posix_acl_release(acl);
279 }
280 return error;
281}
282
