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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Squashfs - a compressed read only filesystem for Linux
4 *
5 * Copyright (c) 2010
6 * Phillip Lougher <phillip@squashfs.org.uk>
7 *
8 * xattr.c
9 */
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/string.h>
14#include <linux/fs.h>
15#include <linux/vfs.h>
16#include <linux/xattr.h>
17#include <linux/slab.h>
18
19#include "squashfs_fs.h"
20#include "squashfs_fs_sb.h"
21#include "squashfs_fs_i.h"
22#include "squashfs.h"
23
24static const struct xattr_handler *squashfs_xattr_handler(int);
25
26ssize_t squashfs_listxattr(struct dentry *d, char *buffer,
27 size_t buffer_size)
28{
29 struct inode *inode = d_inode(d);
30 struct super_block *sb = inode->i_sb;
31 struct squashfs_sb_info *msblk = sb->s_fs_info;
32 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
33 + msblk->xattr_table;
34 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
35 int count = squashfs_i(inode)->xattr_count;
36 size_t rest = buffer_size;
37 int err;
38
39 /* check that the file system has xattrs */
40 if (msblk->xattr_id_table == NULL)
41 return -EOPNOTSUPP;
42
43 /* loop reading each xattr name */
44 while (count--) {
45 struct squashfs_xattr_entry entry;
46 struct squashfs_xattr_val val;
47 const struct xattr_handler *handler;
48 int name_size;
49
50 err = squashfs_read_metadata(sb, &entry, &start, &offset,
51 sizeof(entry));
52 if (err < 0)
53 goto failed;
54
55 name_size = le16_to_cpu(entry.size);
56 handler = squashfs_xattr_handler(le16_to_cpu(entry.type));
57 if (handler && (!handler->list || handler->list(d))) {
58 const char *prefix = handler->prefix ?: handler->name;
59 size_t prefix_size = strlen(prefix);
60
61 if (buffer) {
62 if (prefix_size + name_size + 1 > rest) {
63 err = -ERANGE;
64 goto failed;
65 }
66 memcpy(buffer, prefix, prefix_size);
67 buffer += prefix_size;
68 }
69 err = squashfs_read_metadata(sb, buffer, &start,
70 &offset, name_size);
71 if (err < 0)
72 goto failed;
73 if (buffer) {
74 buffer[name_size] = '\0';
75 buffer += name_size + 1;
76 }
77 rest -= prefix_size + name_size + 1;
78 } else {
79 /* no handler or insuffficient privileges, so skip */
80 err = squashfs_read_metadata(sb, NULL, &start,
81 &offset, name_size);
82 if (err < 0)
83 goto failed;
84 }
85
86
87 /* skip remaining xattr entry */
88 err = squashfs_read_metadata(sb, &val, &start, &offset,
89 sizeof(val));
90 if (err < 0)
91 goto failed;
92
93 err = squashfs_read_metadata(sb, NULL, &start, &offset,
94 le32_to_cpu(val.vsize));
95 if (err < 0)
96 goto failed;
97 }
98 err = buffer_size - rest;
99
100failed:
101 return err;
102}
103
104
105static int squashfs_xattr_get(struct inode *inode, int name_index,
106 const char *name, void *buffer, size_t buffer_size)
107{
108 struct super_block *sb = inode->i_sb;
109 struct squashfs_sb_info *msblk = sb->s_fs_info;
110 u64 start = SQUASHFS_XATTR_BLK(squashfs_i(inode)->xattr)
111 + msblk->xattr_table;
112 int offset = SQUASHFS_XATTR_OFFSET(squashfs_i(inode)->xattr);
113 int count = squashfs_i(inode)->xattr_count;
114 int name_len = strlen(name);
115 int err, vsize;
116 char *target = kmalloc(name_len, GFP_KERNEL);
117
118 if (target == NULL)
119 return -ENOMEM;
120
121 /* loop reading each xattr name */
122 for (; count; count--) {
123 struct squashfs_xattr_entry entry;
124 struct squashfs_xattr_val val;
125 int type, prefix, name_size;
126
127 err = squashfs_read_metadata(sb, &entry, &start, &offset,
128 sizeof(entry));
129 if (err < 0)
130 goto failed;
131
132 name_size = le16_to_cpu(entry.size);
133 type = le16_to_cpu(entry.type);
134 prefix = type & SQUASHFS_XATTR_PREFIX_MASK;
135
136 if (prefix == name_index && name_size == name_len)
137 err = squashfs_read_metadata(sb, target, &start,
138 &offset, name_size);
139 else
140 err = squashfs_read_metadata(sb, NULL, &start,
141 &offset, name_size);
142 if (err < 0)
143 goto failed;
144
145 if (prefix == name_index && name_size == name_len &&
146 strncmp(target, name, name_size) == 0) {
147 /* found xattr */
148 if (type & SQUASHFS_XATTR_VALUE_OOL) {
149 __le64 xattr_val;
150 u64 xattr;
151 /* val is a reference to the real location */
152 err = squashfs_read_metadata(sb, &val, &start,
153 &offset, sizeof(val));
154 if (err < 0)
155 goto failed;
156 err = squashfs_read_metadata(sb, &xattr_val,
157 &start, &offset, sizeof(xattr_val));
158 if (err < 0)
159 goto failed;
160 xattr = le64_to_cpu(xattr_val);
161 start = SQUASHFS_XATTR_BLK(xattr) +
162 msblk->xattr_table;
163 offset = SQUASHFS_XATTR_OFFSET(xattr);
164 }
165 /* read xattr value */
166 err = squashfs_read_metadata(sb, &val, &start, &offset,
167 sizeof(val));
168 if (err < 0)
169 goto failed;
170
171 vsize = le32_to_cpu(val.vsize);
172 if (buffer) {
173 if (vsize > buffer_size) {
174 err = -ERANGE;
175 goto failed;
176 }
177 err = squashfs_read_metadata(sb, buffer, &start,
178 &offset, vsize);
179 if (err < 0)
180 goto failed;
181 }
182 break;
183 }
184
185 /* no match, skip remaining xattr entry */
186 err = squashfs_read_metadata(sb, &val, &start, &offset,
187 sizeof(val));
188 if (err < 0)
189 goto failed;
190 err = squashfs_read_metadata(sb, NULL, &start, &offset,
191 le32_to_cpu(val.vsize));
192 if (err < 0)
193 goto failed;
194 }
195 err = count ? vsize : -ENODATA;
196
197failed:
198 kfree(target);
199 return err;
200}
201
202
203static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
204 struct dentry *unused,
205 struct inode *inode,
206 const char *name,
207 void *buffer, size_t size)
208{
209 return squashfs_xattr_get(inode, handler->flags, name,
210 buffer, size);
211}
212
213/*
214 * User namespace support
215 */
216static const struct xattr_handler squashfs_xattr_user_handler = {
217 .prefix = XATTR_USER_PREFIX,
218 .flags = SQUASHFS_XATTR_USER,
219 .get = squashfs_xattr_handler_get
220};
221
222/*
223 * Trusted namespace support
224 */
225static bool squashfs_trusted_xattr_handler_list(struct dentry *d)
226{
227 return capable(CAP_SYS_ADMIN);
228}
229
230static const struct xattr_handler squashfs_xattr_trusted_handler = {
231 .prefix = XATTR_TRUSTED_PREFIX,
232 .flags = SQUASHFS_XATTR_TRUSTED,
233 .list = squashfs_trusted_xattr_handler_list,
234 .get = squashfs_xattr_handler_get
235};
236
237/*
238 * Security namespace support
239 */
240static const struct xattr_handler squashfs_xattr_security_handler = {
241 .prefix = XATTR_SECURITY_PREFIX,
242 .flags = SQUASHFS_XATTR_SECURITY,
243 .get = squashfs_xattr_handler_get
244};
245
246static const struct xattr_handler *squashfs_xattr_handler(int type)
247{
248 if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
249 /* ignore unrecognised type */
250 return NULL;
251
252 switch (type & SQUASHFS_XATTR_PREFIX_MASK) {
253 case SQUASHFS_XATTR_USER:
254 return &squashfs_xattr_user_handler;
255 case SQUASHFS_XATTR_TRUSTED:
256 return &squashfs_xattr_trusted_handler;
257 case SQUASHFS_XATTR_SECURITY:
258 return &squashfs_xattr_security_handler;
259 default:
260 /* ignore unrecognised type */
261 return NULL;
262 }
263}
264
265const struct xattr_handler *squashfs_xattr_handlers[] = {
266 &squashfs_xattr_user_handler,
267 &squashfs_xattr_trusted_handler,
268 &squashfs_xattr_security_handler,
269 NULL
270};
271