net/mlx4: Fix firmware command timeout during interrupt test
[cascardo/linux.git] / fs / squashfs / xattr.c
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
37 static const struct xattr_handler *squashfs_xattr_handler(int);
38
39 ssize_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
113 failed:
114         return err;
115 }
116
117
118 static 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
210 failed:
211         kfree(target);
212         return err;
213 }
214
215
216 static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
217                                       struct dentry *unused,
218                                       struct inode *inode,
219                                       const char *name,
220                                       void *buffer, size_t size)
221 {
222         return squashfs_xattr_get(inode, handler->flags, name,
223                 buffer, size);
224 }
225
226 /*
227  * User namespace support
228  */
229 static const struct xattr_handler squashfs_xattr_user_handler = {
230         .prefix = XATTR_USER_PREFIX,
231         .flags  = SQUASHFS_XATTR_USER,
232         .get    = squashfs_xattr_handler_get
233 };
234
235 /*
236  * Trusted namespace support
237  */
238 static bool squashfs_trusted_xattr_handler_list(struct dentry *d)
239 {
240         return capable(CAP_SYS_ADMIN);
241 }
242
243 static const struct xattr_handler squashfs_xattr_trusted_handler = {
244         .prefix = XATTR_TRUSTED_PREFIX,
245         .flags  = SQUASHFS_XATTR_TRUSTED,
246         .list   = squashfs_trusted_xattr_handler_list,
247         .get    = squashfs_xattr_handler_get
248 };
249
250 /*
251  * Security namespace support
252  */
253 static const struct xattr_handler squashfs_xattr_security_handler = {
254         .prefix = XATTR_SECURITY_PREFIX,
255         .flags  = SQUASHFS_XATTR_SECURITY,
256         .get    = squashfs_xattr_handler_get
257 };
258
259 static const struct xattr_handler *squashfs_xattr_handler(int type)
260 {
261         if (type & ~(SQUASHFS_XATTR_PREFIX_MASK | SQUASHFS_XATTR_VALUE_OOL))
262                 /* ignore unrecognised type */
263                 return NULL;
264
265         switch (type & SQUASHFS_XATTR_PREFIX_MASK) {
266         case SQUASHFS_XATTR_USER:
267                 return &squashfs_xattr_user_handler;
268         case SQUASHFS_XATTR_TRUSTED:
269                 return &squashfs_xattr_trusted_handler;
270         case SQUASHFS_XATTR_SECURITY:
271                 return &squashfs_xattr_security_handler;
272         default:
273                 /* ignore unrecognised type */
274                 return NULL;
275         }
276 }
277
278 const struct xattr_handler *squashfs_xattr_handlers[] = {
279         &squashfs_xattr_user_handler,
280         &squashfs_xattr_trusted_handler,
281         &squashfs_xattr_security_handler,
282         NULL
283 };
284