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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 switch (type) {
182 case ACL_TYPE_ACCESS:
183 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
184 break;
185 case ACL_TYPE_DEFAULT:
186 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
187 break;
188 default:
189 BUG();
190 }
191 rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
192 if (rc > 0) {
193 value = kmalloc(rc, GFP_KERNEL);
194 if (!value)
195 return ERR_PTR(-ENOMEM);
196 rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
197 }
198 if (rc > 0) {
199 acl = jffs2_acl_from_medium(value, rc);
200 } else if (rc == -ENODATA || rc == -ENOSYS) {
201 acl = NULL;
202 } else {
203 acl = ERR_PTR(rc);
204 }
205 kfree(value);
206 return acl;
207}
208
209static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
210{
211 char *value = NULL;
212 size_t size = 0;
213 int rc;
214
215 if (acl) {
216 value = jffs2_acl_to_medium(acl, &size);
217 if (IS_ERR(value))
218 return PTR_ERR(value);
219 }
220 rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
221 if (!value && rc == -ENODATA)
222 rc = 0;
223 kfree(value);
224
225 return rc;
226}
227
228int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
229{
230 int rc, xprefix;
231
232 switch (type) {
233 case ACL_TYPE_ACCESS:
234 xprefix = JFFS2_XPREFIX_ACL_ACCESS;
235 if (acl) {
236 umode_t mode;
237
238 rc = posix_acl_update_mode(inode, &mode, &acl);
239 if (rc)
240 return rc;
241 if (inode->i_mode != mode) {
242 struct iattr attr;
243
244 attr.ia_valid = ATTR_MODE | ATTR_CTIME;
245 attr.ia_mode = mode;
246 attr.ia_ctime = current_time(inode);
247 rc = jffs2_do_setattr(inode, &attr);
248 if (rc < 0)
249 return rc;
250 }
251 }
252 break;
253 case ACL_TYPE_DEFAULT:
254 xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
255 if (!S_ISDIR(inode->i_mode))
256 return acl ? -EACCES : 0;
257 break;
258 default:
259 return -EINVAL;
260 }
261 rc = __jffs2_set_acl(inode, xprefix, acl);
262 if (!rc)
263 set_cached_acl(inode, type, acl);
264 return rc;
265}
266
267int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
268{
269 struct posix_acl *default_acl, *acl;
270 int rc;
271
272 cache_no_acl(inode);
273
274 rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl);
275 if (rc)
276 return rc;
277
278 if (default_acl) {
279 set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
280 posix_acl_release(default_acl);
281 }
282 if (acl) {
283 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
284 posix_acl_release(acl);
285 }
286 return 0;
287}
288
289int jffs2_init_acl_post(struct inode *inode)
290{
291 int rc;
292
293 if (inode->i_default_acl) {
294 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
295 if (rc)
296 return rc;
297 }
298
299 if (inode->i_acl) {
300 rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
301 if (rc)
302 return rc;
303 }
304
305 return 0;
306}
307
