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1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2010
5 * Phillip Lougher <phillip@squashfs.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 * xattr.c
22 */
23
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/string.h>
27#include <linux/fs.h>
28#include <linux/vfs.h>
29#include <linux/xattr.h>
30#include <linux/slab.h>
31
32#include "squashfs_fs.h"
33#include "squashfs_fs_sb.h"
34#include "squashfs_fs_i.h"
35#include "squashfs.h"
36
37static const struct xattr_handler *squashfs_xattr_handler(int);
38
39ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
40 size_t buffer_size)
41{
42 struct inode *inode = d_inode(d);
43 struct super_block *sb = inode->i_sb;
44 struct squashfs_sb_info *msblk = sb->s_fs_info;
45 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
46 + msblk->xattr_table;
47 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
48 int count = squashfs_i(inode)->xattr_count;
49 size_t rest = buffer_size;
50 int err;
51
52 /* check that the file system has xattrs */
53 if (msblk->xattr_id_table == NULL)
54 return -EOPNOTSUPP;
55
56 /* loop reading each xattr name */
57 while (count--) {
58 struct squashfs_xattr_entry entry;
59 struct squashfs_xattr_val val;
60 const struct xattr_handler *handler;
61 int name_size;
62
63 err = squashfs_read_metadata(sb, &entry, &start, &offset,
64 sizeof(entry));
65 if (err < 0)
66 goto failed;
67
68 name_size = le16_to_cpu(entry.size);
69 handler = squashfs_xattr_handler(le16_to_cpu(entry.type));
70 if (handler && (!handler->list || handler->list(d))) {
71 const char *prefix = handler->prefix ?: handler->name;
72 size_t prefix_size = strlen(prefix);
73
74 if (buffer) {
75 if (prefix_size + name_size + 1 > rest) {
76 err = -ERANGE;
77 goto failed;
78 }
79 memcpy(buffer, prefix, prefix_size);
80 buffer += prefix_size;
81 }
82 err = squashfs_read_metadata(sb, buffer, &start,
83 &offset, name_size);
84 if (err < 0)
85 goto failed;
86 if (buffer) {
87 buffer[name_size] = '\0';
88 buffer += name_size + 1;
89 }
90 rest -= prefix_size + name_size + 1;
91 } else {
92 /* no handler or insuffficient privileges, so skip */
93 err = squashfs_read_metadata(sb, NULL, &start,
94 &offset, name_size);
95 if (err < 0)
96 goto failed;
97 }
98
99
100 /* skip remaining xattr entry */
101 err = squashfs_read_metadata(sb, &val, &start, &offset,
102 sizeof(val));
103 if (err < 0)
104 goto failed;
105
106 err = squashfs_read_metadata(sb, NULL, &start, &offset,
107 le32_to_cpu(val.vsize));
108 if (err < 0)
109 goto failed;
110 }
111 err = buffer_size - rest;
112
113failed:
114 return err;
115}
116
117
118static int squashfs_xattr_get(struct inode *inode, int name_index,
119 const char *name, void *buffer, size_t buffer_size)
120{
121 struct super_block *sb = inode->i_sb;
122 struct squashfs_sb_info *msblk = sb->s_fs_info;
123 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
124 + msblk->xattr_table;
125 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
126 int count = squashfs_i(inode)->xattr_count;
127 int name_len = strlen(name);
128 int err, vsize;
129 char *target = kmalloc(name_len, GFP_KERNEL);
130
131 if (target == NULL)
132 return -ENOMEM;
133
134 /* loop reading each xattr name */
135 for (; count; count--) {
136 struct squashfs_xattr_entry entry;
137 struct squashfs_xattr_val val;
138 int type, prefix, name_size;
139
140 err = squashfs_read_metadata(sb, &entry, &start, &offset,
141 sizeof(entry));
142 if (err < 0)
143 goto failed;
144
145 name_size = le16_to_cpu(entry.size);
146 type = le16_to_cpu(entry.type);
147 prefix = type & SQUASHFS_XATTR_PREFIX_MASK;
148
149 if (prefix == name_index && name_size == name_len)
150 err = squashfs_read_metadata(sb, target, &start,
151 &offset, name_size);
152 else
153 err = squashfs_read_metadata(sb, NULL, &start,
154 &offset, name_size);
155 if (err < 0)
156 goto failed;
157
158 if (prefix == name_index && name_size == name_len &&
159 strncmp(target, name, name_size) == 0) {
160 /* found xattr */
161 if (type & SQUASHFS_XATTR_VALUE_OOL) {
162 __le64 xattr_val;
163 u64 xattr;
164 /* val is a reference to the real location */
165 err = squashfs_read_metadata(sb, &val, &start,
166 &offset, sizeof(val));
167 if (err < 0)
168 goto failed;
169 err = squashfs_read_metadata(sb, &xattr_val,
170 &start, &offset, sizeof(xattr_val));
171 if (err < 0)
172 goto failed;
173 xattr = le64_to_cpu(xattr_val);
174 start = SQUASHFS_XATTR_BLK(xattr) +
175 msblk->xattr_table;
176 offset = SQUASHFS_XATTR_OFFSET(xattr);
177 }
178 /* read xattr value */
179 err = squashfs_read_metadata(sb, &val, &start, &offset,
180 sizeof(val));
181 if (err < 0)
182 goto failed;
183
184 vsize = le32_to_cpu(val.vsize);
185 if (buffer) {
186 if (vsize > buffer_size) {
187 err = -ERANGE;
188 goto failed;
189 }
190 err = squashfs_read_metadata(sb, buffer, &start,
191 &offset, vsize);
192 if (err < 0)
193 goto failed;
194 }
195 break;
196 }
197
198 /* no match, skip remaining xattr entry */
199 err = squashfs_read_metadata(sb, &val, &start, &offset,
200 sizeof(val));
201 if (err < 0)
202 goto failed;
203 err = squashfs_read_metadata(sb, NULL, &start, &offset,
204 le32_to_cpu(val.vsize));
205 if (err < 0)
206 goto failed;
207 }
208 err = count ? vsize : -ENODATA;
209
210failed:
211 kfree(target);
212 return err;
213}
214
215
216static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
217 struct dentry *d, const char *name,
218 void *buffer, size_t size)
219{
220 return squashfs_xattr_get(d_inode(d), handler->flags, name,
221 buffer, size);
222}
223
224/*
225 * User namespace support
226 */
227static const struct xattr_handler squashfs_xattr_user_handler = {
228 .prefix = XATTR_USER_PREFIX,
229 .flags = SQUASHFS_XATTR_USER,
230 .get = squashfs_xattr_handler_get
231};
232
233/*
234 * Trusted namespace support
235 */
236static bool squashfs_trusted_xattr_handler_list(struct dentry *d)
237{
238 return capable(CAP_SYS_ADMIN);
239}
240
241static const struct xattr_handler squashfs_xattr_trusted_handler = {
242 .prefix = XATTR_TRUSTED_PREFIX,
243 .flags = SQUASHFS_XATTR_TRUSTED,
244 .list = squashfs_trusted_xattr_handler_list,
245 .get = squashfs_xattr_handler_get
246};
247
248/*
249 * Security namespace support
250 */
251static const struct xattr_handler squashfs_xattr_security_handler = {
252 .prefix = XATTR_SECURITY_PREFIX,
253 .flags = SQUASHFS_XATTR_SECURITY,
254 .get = squashfs_xattr_handler_get
255};
256
257static const struct xattr_handler *squashfs_xattr_handler(int type)
258{
259 if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
260 /* ignore unrecognised type */
261 return NULL;
262
263 switch (type & SQUASHFS_XATTR_PREFIX_MASK) {
264 case SQUASHFS_XATTR_USER:
265 return &squashfs_xattr_user_handler;
266 case SQUASHFS_XATTR_TRUSTED:
267 return &squashfs_xattr_trusted_handler;
268 case SQUASHFS_XATTR_SECURITY:
269 return &squashfs_xattr_security_handler;
270 default:
271 /* ignore unrecognised type */
272 return NULL;
273 }
274}
275
276const struct xattr_handler *squashfs_xattr_handlers[] = {
277 &squashfs_xattr_user_handler,
278 &squashfs_xattr_trusted_handler,
279 &squashfs_xattr_security_handler,
280 NULL
281};
282
1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2010
5 * Phillip Lougher <phillip@squashfs.org.uk>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 *
21 * xattr.c
22 */
23
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/string.h>
27#include <linux/fs.h>
28#include <linux/vfs.h>
29#include <linux/xattr.h>
30#include <linux/slab.h>
31
32#include "squashfs_fs.h"
33#include "squashfs_fs_sb.h"
34#include "squashfs_fs_i.h"
35#include "squashfs.h"
36
37static const struct xattr_handler *squashfs_xattr_handler(int);
38
39ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
40 size_t buffer_size)
41{
42 struct inode *inode = d->d_inode;
43 struct super_block *sb = inode->i_sb;
44 struct squashfs_sb_info *msblk = sb->s_fs_info;
45 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
46 + msblk->xattr_table;
47 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
48 int count = squashfs_i(inode)->xattr_count;
49 size_t rest = buffer_size;
50 int err;
51
52 /* check that the file system has xattrs */
53 if (msblk->xattr_id_table == NULL)
54 return -EOPNOTSUPP;
55
56 /* loop reading each xattr name */
57 while (count--) {
58 struct squashfs_xattr_entry entry;
59 struct squashfs_xattr_val val;
60 const struct xattr_handler *handler;
61 int name_size, prefix_size = 0;
62
63 err = squashfs_read_metadata(sb, &entry, &start, &offset,
64 sizeof(entry));
65 if (err < 0)
66 goto failed;
67
68 name_size = le16_to_cpu(entry.size);
69 handler = squashfs_xattr_handler(le16_to_cpu(entry.type));
70 if (handler)
71 prefix_size = handler->list(d, buffer, rest, NULL,
72 name_size, handler->flags);
73 if (prefix_size) {
74 if (buffer) {
75 if (prefix_size + name_size + 1 > rest) {
76 err = -ERANGE;
77 goto failed;
78 }
79 buffer += prefix_size;
80 }
81 err = squashfs_read_metadata(sb, buffer, &start,
82 &offset, name_size);
83 if (err < 0)
84 goto failed;
85 if (buffer) {
86 buffer[name_size] = '\0';
87 buffer += name_size + 1;
88 }
89 rest -= prefix_size + name_size + 1;
90 } else {
91 /* no handler or insuffficient privileges, so skip */
92 err = squashfs_read_metadata(sb, NULL, &start,
93 &offset, name_size);
94 if (err < 0)
95 goto failed;
96 }
97
98
99 /* skip remaining xattr entry */
100 err = squashfs_read_metadata(sb, &val, &start, &offset,
101 sizeof(val));
102 if (err < 0)
103 goto failed;
104
105 err = squashfs_read_metadata(sb, NULL, &start, &offset,
106 le32_to_cpu(val.vsize));
107 if (err < 0)
108 goto failed;
109 }
110 err = buffer_size - rest;
111
112failed:
113 return err;
114}
115
116
117static int squashfs_xattr_get(struct inode *inode, int name_index,
118 const char *name, void *buffer, size_t buffer_size)
119{
120 struct super_block *sb = inode->i_sb;
121 struct squashfs_sb_info *msblk = sb->s_fs_info;
122 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
123 + msblk->xattr_table;
124 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
125 int count = squashfs_i(inode)->xattr_count;
126 int name_len = strlen(name);
127 int err, vsize;
128 char *target = kmalloc(name_len, GFP_KERNEL);
129
130 if (target == NULL)
131 return -ENOMEM;
132
133 /* loop reading each xattr name */
134 for (; count; count--) {
135 struct squashfs_xattr_entry entry;
136 struct squashfs_xattr_val val;
137 int type, prefix, name_size;
138
139 err = squashfs_read_metadata(sb, &entry, &start, &offset,
140 sizeof(entry));
141 if (err < 0)
142 goto failed;
143
144 name_size = le16_to_cpu(entry.size);
145 type = le16_to_cpu(entry.type);
146 prefix = type & SQUASHFS_XATTR_PREFIX_MASK;
147
148 if (prefix == name_index && name_size == name_len)
149 err = squashfs_read_metadata(sb, target, &start,
150 &offset, name_size);
151 else
152 err = squashfs_read_metadata(sb, NULL, &start,
153 &offset, name_size);
154 if (err < 0)
155 goto failed;
156
157 if (prefix == name_index && name_size == name_len &&
158 strncmp(target, name, name_size) == 0) {
159 /* found xattr */
160 if (type & SQUASHFS_XATTR_VALUE_OOL) {
161 __le64 xattr_val;
162 u64 xattr;
163 /* val is a reference to the real location */
164 err = squashfs_read_metadata(sb, &val, &start,
165 &offset, sizeof(val));
166 if (err < 0)
167 goto failed;
168 err = squashfs_read_metadata(sb, &xattr_val,
169 &start, &offset, sizeof(xattr_val));
170 if (err < 0)
171 goto failed;
172 xattr = le64_to_cpu(xattr_val);
173 start = SQUASHFS_XATTR_BLK(xattr) +
174 msblk->xattr_table;
175 offset = SQUASHFS_XATTR_OFFSET(xattr);
176 }
177 /* read xattr value */
178 err = squashfs_read_metadata(sb, &val, &start, &offset,
179 sizeof(val));
180 if (err < 0)
181 goto failed;
182
183 vsize = le32_to_cpu(val.vsize);
184 if (buffer) {
185 if (vsize > buffer_size) {
186 err = -ERANGE;
187 goto failed;
188 }
189 err = squashfs_read_metadata(sb, buffer, &start,
190 &offset, vsize);
191 if (err < 0)
192 goto failed;
193 }
194 break;
195 }
196
197 /* no match, skip remaining xattr entry */
198 err = squashfs_read_metadata(sb, &val, &start, &offset,
199 sizeof(val));
200 if (err < 0)
201 goto failed;
202 err = squashfs_read_metadata(sb, NULL, &start, &offset,
203 le32_to_cpu(val.vsize));
204 if (err < 0)
205 goto failed;
206 }
207 err = count ? vsize : -ENODATA;
208
209failed:
210 kfree(target);
211 return err;
212}
213
214
215/*
216 * User namespace support
217 */
218static size_t squashfs_user_list(struct dentry *d, char *list, size_t list_size,
219 const char *name, size_t name_len, int type)
220{
221 if (list && XATTR_USER_PREFIX_LEN <= list_size)
222 memcpy(list, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
223 return XATTR_USER_PREFIX_LEN;
224}
225
226static int squashfs_user_get(struct dentry *d, const char *name, void *buffer,
227 size_t size, int type)
228{
229 if (name[0] == '\0')
230 return -EINVAL;
231
232 return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_USER, name,
233 buffer, size);
234}
235
236static const struct xattr_handler squashfs_xattr_user_handler = {
237 .prefix = XATTR_USER_PREFIX,
238 .list = squashfs_user_list,
239 .get = squashfs_user_get
240};
241
242/*
243 * Trusted namespace support
244 */
245static size_t squashfs_trusted_list(struct dentry *d, char *list,
246 size_t list_size, const char *name, size_t name_len, int type)
247{
248 if (!capable(CAP_SYS_ADMIN))
249 return 0;
250
251 if (list && XATTR_TRUSTED_PREFIX_LEN <= list_size)
252 memcpy(list, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
253 return XATTR_TRUSTED_PREFIX_LEN;
254}
255
256static int squashfs_trusted_get(struct dentry *d, const char *name,
257 void *buffer, size_t size, int type)
258{
259 if (name[0] == '\0')
260 return -EINVAL;
261
262 return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_TRUSTED, name,
263 buffer, size);
264}
265
266static const struct xattr_handler squashfs_xattr_trusted_handler = {
267 .prefix = XATTR_TRUSTED_PREFIX,
268 .list = squashfs_trusted_list,
269 .get = squashfs_trusted_get
270};
271
272/*
273 * Security namespace support
274 */
275static size_t squashfs_security_list(struct dentry *d, char *list,
276 size_t list_size, const char *name, size_t name_len, int type)
277{
278 if (list && XATTR_SECURITY_PREFIX_LEN <= list_size)
279 memcpy(list, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN);
280 return XATTR_SECURITY_PREFIX_LEN;
281}
282
283static int squashfs_security_get(struct dentry *d, const char *name,
284 void *buffer, size_t size, int type)
285{
286 if (name[0] == '\0')
287 return -EINVAL;
288
289 return squashfs_xattr_get(d->d_inode, SQUASHFS_XATTR_SECURITY, name,
290 buffer, size);
291}
292
293static const struct xattr_handler squashfs_xattr_security_handler = {
294 .prefix = XATTR_SECURITY_PREFIX,
295 .list = squashfs_security_list,
296 .get = squashfs_security_get
297};
298
299static const struct xattr_handler *squashfs_xattr_handler(int type)
300{
301 if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
302 /* ignore unrecognised type */
303 return NULL;
304
305 switch (type & SQUASHFS_XATTR_PREFIX_MASK) {
306 case SQUASHFS_XATTR_USER:
307 return &squashfs_xattr_user_handler;
308 case SQUASHFS_XATTR_TRUSTED:
309 return &squashfs_xattr_trusted_handler;
310 case SQUASHFS_XATTR_SECURITY:
311 return &squashfs_xattr_security_handler;
312 default:
313 /* ignore unrecognised type */
314 return NULL;
315 }
316}
317
318const struct xattr_handler *squashfs_xattr_handlers[] = {
319 &squashfs_xattr_user_handler,
320 &squashfs_xattr_trusted_handler,
321 &squashfs_xattr_security_handler,
322 NULL
323};
324