blob: a5303b871b13874d574edb6dec5642cf2286e7cb [file] [log] [blame]
Josef Bacik5103e942007-11-16 11:45:54 -05001/*
2 * Copyright (C) 2007 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/init.h>
20#include <linux/fs.h>
21#include <linux/slab.h>
22#include <linux/rwsem.h>
23#include <linux/xattr.h>
Jim Owens0279b4c2009-02-04 09:29:13 -050024#include <linux/security.h>
Josef Bacik5103e942007-11-16 11:45:54 -050025#include "ctree.h"
26#include "btrfs_inode.h"
27#include "transaction.h"
28#include "xattr.h"
29#include "disk-io.h"
Josef Bacik33268ea2008-07-24 12:16:36 -040030
Josef Bacik33268ea2008-07-24 12:16:36 -040031
Christoph Hellwig95819c02008-08-28 06:21:17 -040032ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
33 void *buffer, size_t size)
Josef Bacik5103e942007-11-16 11:45:54 -050034{
35 struct btrfs_dir_item *di;
36 struct btrfs_root *root = BTRFS_I(inode)->root;
37 struct btrfs_path *path;
38 struct extent_buffer *leaf;
Josef Bacik5103e942007-11-16 11:45:54 -050039 int ret = 0;
40 unsigned long data_ptr;
Josef Bacik5103e942007-11-16 11:45:54 -050041
42 path = btrfs_alloc_path();
Christoph Hellwig95819c02008-08-28 06:21:17 -040043 if (!path)
Josef Bacik5103e942007-11-16 11:45:54 -050044 return -ENOMEM;
Josef Bacik5103e942007-11-16 11:45:54 -050045
Josef Bacik5103e942007-11-16 11:45:54 -050046 /* lookup the xattr by name */
47 di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
48 strlen(name), 0);
Josef Bacik07060402009-01-21 10:49:16 -050049 if (!di) {
Josef Bacik5103e942007-11-16 11:45:54 -050050 ret = -ENODATA;
51 goto out;
Josef Bacik07060402009-01-21 10:49:16 -050052 } else if (IS_ERR(di)) {
53 ret = PTR_ERR(di);
54 goto out;
Josef Bacik5103e942007-11-16 11:45:54 -050055 }
56
57 leaf = path->nodes[0];
58 /* if size is 0, that means we want the size of the attr */
59 if (!size) {
60 ret = btrfs_dir_data_len(leaf, di);
61 goto out;
62 }
63
64 /* now get the data out of our dir_item */
65 if (btrfs_dir_data_len(leaf, di) > size) {
66 ret = -ERANGE;
67 goto out;
68 }
Josef Bacik07060402009-01-21 10:49:16 -050069
70 /*
71 * The way things are packed into the leaf is like this
72 * |struct btrfs_dir_item|name|data|
73 * where name is the xattr name, so security.foo, and data is the
74 * content of the xattr. data_ptr points to the location in memory
75 * where the data starts in the in memory leaf
76 */
Josef Bacik5103e942007-11-16 11:45:54 -050077 data_ptr = (unsigned long)((char *)(di + 1) +
78 btrfs_dir_name_len(leaf, di));
79 read_extent_buffer(leaf, buffer, data_ptr,
Josef Bacik3acd7ee2007-11-19 10:18:19 -050080 btrfs_dir_data_len(leaf, di));
Josef Bacik5103e942007-11-16 11:45:54 -050081 ret = btrfs_dir_data_len(leaf, di);
82
83out:
Josef Bacik5103e942007-11-16 11:45:54 -050084 btrfs_free_path(path);
85 return ret;
86}
87
Yan, Zhengf34f57a2009-11-12 09:35:27 +000088static int do_setxattr(struct btrfs_trans_handle *trans,
89 struct inode *inode, const char *name,
90 const void *value, size_t size, int flags)
Josef Bacik5103e942007-11-16 11:45:54 -050091{
92 struct btrfs_dir_item *di;
93 struct btrfs_root *root = BTRFS_I(inode)->root;
Josef Bacik5103e942007-11-16 11:45:54 -050094 struct btrfs_path *path;
Yan, Zhengf34f57a2009-11-12 09:35:27 +000095 size_t name_len = strlen(name);
96 int ret = 0;
97
98 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
99 return -ENOSPC;
Josef Bacik5103e942007-11-16 11:45:54 -0500100
101 path = btrfs_alloc_path();
Christoph Hellwig95819c02008-08-28 06:21:17 -0400102 if (!path)
Josef Bacik5103e942007-11-16 11:45:54 -0500103 return -ENOMEM;
Josef Bacik5103e942007-11-16 11:45:54 -0500104
Josef Bacik5103e942007-11-16 11:45:54 -0500105 /* first lets see if we already have this xattr */
106 di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
107 strlen(name), -1);
108 if (IS_ERR(di)) {
109 ret = PTR_ERR(di);
110 goto out;
111 }
112
113 /* ok we already have this xattr, lets remove it */
114 if (di) {
115 /* if we want create only exit */
116 if (flags & XATTR_CREATE) {
117 ret = -EEXIST;
118 goto out;
119 }
120
121 ret = btrfs_delete_one_dir_name(trans, root, path, di);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000122 BUG_ON(ret);
Josef Bacik5103e942007-11-16 11:45:54 -0500123 btrfs_release_path(root, path);
124
125 /* if we don't have a value then we are removing the xattr */
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000126 if (!value)
Josef Bacik5103e942007-11-16 11:45:54 -0500127 goto out;
Josef Bacik33268ea2008-07-24 12:16:36 -0400128 } else {
129 btrfs_release_path(root, path);
130
131 if (flags & XATTR_REPLACE) {
132 /* we couldn't find the attr to replace */
133 ret = -ENODATA;
134 goto out;
135 }
Josef Bacik5103e942007-11-16 11:45:54 -0500136 }
137
138 /* ok we have to create a completely new xattr */
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000139 ret = btrfs_insert_xattr_item(trans, root, path, inode->i_ino,
140 name, name_len, value, size);
141 BUG_ON(ret);
142out:
143 btrfs_free_path(path);
144 return ret;
145}
146
147int __btrfs_setxattr(struct btrfs_trans_handle *trans,
148 struct inode *inode, const char *name,
149 const void *value, size_t size, int flags)
150{
151 struct btrfs_root *root = BTRFS_I(inode)->root;
152 int ret;
153
154 if (trans)
155 return do_setxattr(trans, inode, name, value, size, flags);
156
Yan, Zhenga22285a2010-05-16 10:48:46 -0400157 trans = btrfs_start_transaction(root, 2);
158 if (IS_ERR(trans))
159 return PTR_ERR(trans);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000160
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000161 btrfs_set_trans_block_group(trans, inode);
162
163 ret = do_setxattr(trans, inode, name, value, size, flags);
Josef Bacik5103e942007-11-16 11:45:54 -0500164 if (ret)
165 goto out;
Josef Bacik5103e942007-11-16 11:45:54 -0500166
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000167 inode->i_ctime = CURRENT_TIME;
168 ret = btrfs_update_inode(trans, root, inode);
169 BUG_ON(ret);
Josef Bacik5103e942007-11-16 11:45:54 -0500170out:
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000171 btrfs_end_transaction_throttle(trans, root);
Josef Bacik5103e942007-11-16 11:45:54 -0500172 return ret;
173}
174
175ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
176{
177 struct btrfs_key key, found_key;
178 struct inode *inode = dentry->d_inode;
179 struct btrfs_root *root = BTRFS_I(inode)->root;
180 struct btrfs_path *path;
Josef Bacik5103e942007-11-16 11:45:54 -0500181 struct extent_buffer *leaf;
182 struct btrfs_dir_item *di;
Josef Bacik5103e942007-11-16 11:45:54 -0500183 int ret = 0, slot, advance;
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400184 size_t total_size = 0, size_left = size;
Josef Bacik5103e942007-11-16 11:45:54 -0500185 unsigned long name_ptr;
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400186 size_t name_len;
Josef Bacik5103e942007-11-16 11:45:54 -0500187 u32 nritems;
188
189 /*
190 * ok we want all objects associated with this id.
191 * NOTE: we set key.offset = 0; because we want to start with the
192 * first xattr that we find and walk forward
193 */
194 key.objectid = inode->i_ino;
195 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
196 key.offset = 0;
197
198 path = btrfs_alloc_path();
Josef Bacik5103e942007-11-16 11:45:54 -0500199 if (!path)
200 return -ENOMEM;
Josef Bacik1caf9342007-11-19 10:18:17 -0500201 path->reada = 2;
Josef Bacik5103e942007-11-16 11:45:54 -0500202
Josef Bacik5103e942007-11-16 11:45:54 -0500203 /* search for our xattrs */
204 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
205 if (ret < 0)
206 goto err;
Josef Bacik5103e942007-11-16 11:45:54 -0500207 advance = 0;
208 while (1) {
209 leaf = path->nodes[0];
210 nritems = btrfs_header_nritems(leaf);
211 slot = path->slots[0];
212
213 /* this is where we start walking through the path */
214 if (advance || slot >= nritems) {
215 /*
216 * if we've reached the last slot in this leaf we need
217 * to go to the next leaf and reset everything
218 */
219 if (slot >= nritems-1) {
220 ret = btrfs_next_leaf(root, path);
221 if (ret)
222 break;
223 leaf = path->nodes[0];
224 nritems = btrfs_header_nritems(leaf);
225 slot = path->slots[0];
226 } else {
227 /*
228 * just walking through the slots on this leaf
229 */
230 slot++;
231 path->slots[0]++;
232 }
233 }
234 advance = 1;
235
Josef Bacik5103e942007-11-16 11:45:54 -0500236 btrfs_item_key_to_cpu(leaf, &found_key, slot);
237
238 /* check to make sure this item is what we want */
239 if (found_key.objectid != key.objectid)
240 break;
241 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
242 break;
243
244 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
Josef Bacik22a94d42011-03-16 16:47:17 -0400245 if (verify_dir_item(root, leaf, di))
246 continue;
Josef Bacik5103e942007-11-16 11:45:54 -0500247
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400248 name_len = btrfs_dir_name_len(leaf, di);
249 total_size += name_len + 1;
Josef Bacik5103e942007-11-16 11:45:54 -0500250
251 /* we are just looking for how big our buffer needs to be */
252 if (!size)
253 continue;
254
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400255 if (!buffer || (name_len + 1) > size_left) {
Josef Bacik5103e942007-11-16 11:45:54 -0500256 ret = -ERANGE;
Yehuda Sadeh Weinraubb16281c2008-12-17 10:21:26 -0500257 goto err;
Josef Bacik5103e942007-11-16 11:45:54 -0500258 }
259
Christoph Hellwigeaa47d82008-08-28 06:21:16 -0400260 name_ptr = (unsigned long)(di + 1);
261 read_extent_buffer(leaf, buffer, name_ptr, name_len);
262 buffer[name_len] = '\0';
263
264 size_left -= name_len + 1;
265 buffer += name_len + 1;
Josef Bacik5103e942007-11-16 11:45:54 -0500266 }
267 ret = total_size;
268
269err:
Josef Bacik5103e942007-11-16 11:45:54 -0500270 btrfs_free_path(path);
271
272 return ret;
273}
274
275/*
Christoph Hellwig95819c02008-08-28 06:21:17 -0400276 * List of handlers for synthetic system.* attributes. All real ondisk
277 * attributes are handled directly.
Josef Bacik5103e942007-11-16 11:45:54 -0500278 */
Stephen Hemmingerf01cbd32010-05-13 17:53:15 -0700279const struct xattr_handler *btrfs_xattr_handlers[] = {
Chris Mason0eda2942009-10-13 13:50:18 -0400280#ifdef CONFIG_BTRFS_FS_POSIX_ACL
Christoph Hellwig95819c02008-08-28 06:21:17 -0400281 &btrfs_xattr_acl_access_handler,
282 &btrfs_xattr_acl_default_handler,
283#endif
284 NULL,
285};
286
287/*
288 * Check if the attribute is in a supported namespace.
289 *
290 * This applied after the check for the synthetic attributes in the system
291 * namespace.
292 */
293static bool btrfs_is_valid_xattr(const char *name)
294{
Chris Masond3977122009-01-05 21:25:51 -0500295 return !strncmp(name, XATTR_SECURITY_PREFIX,
296 XATTR_SECURITY_PREFIX_LEN) ||
Christoph Hellwig95819c02008-08-28 06:21:17 -0400297 !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
298 !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
299 !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
Chris Mason69a32ac2008-01-14 14:33:35 -0500300}
301
Christoph Hellwig95819c02008-08-28 06:21:17 -0400302ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
303 void *buffer, size_t size)
304{
305 /*
306 * If this is a request for a synthetic attribute in the system.*
307 * namespace use the generic infrastructure to resolve a handler
308 * for it via sb->s_xattr.
309 */
310 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
311 return generic_getxattr(dentry, name, buffer, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500312
Christoph Hellwig95819c02008-08-28 06:21:17 -0400313 if (!btrfs_is_valid_xattr(name))
314 return -EOPNOTSUPP;
315 return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
316}
Josef Bacik5103e942007-11-16 11:45:54 -0500317
Christoph Hellwig95819c02008-08-28 06:21:17 -0400318int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
319 size_t size, int flags)
320{
Li Zefanb83cc962010-12-20 16:04:08 +0800321 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
322
323 /*
324 * The permission on security.* and system.* is not checked
325 * in permission().
326 */
327 if (btrfs_root_readonly(root))
328 return -EROFS;
329
Christoph Hellwig95819c02008-08-28 06:21:17 -0400330 /*
331 * If this is a request for a synthetic attribute in the system.*
332 * namespace use the generic infrastructure to resolve a handler
333 * for it via sb->s_xattr.
334 */
335 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
336 return generic_setxattr(dentry, name, value, size, flags);
Josef Bacik5103e942007-11-16 11:45:54 -0500337
Christoph Hellwig95819c02008-08-28 06:21:17 -0400338 if (!btrfs_is_valid_xattr(name))
339 return -EOPNOTSUPP;
Josef Bacik5103e942007-11-16 11:45:54 -0500340
Christoph Hellwig95819c02008-08-28 06:21:17 -0400341 if (size == 0)
342 value = ""; /* empty EA, do not remove */
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000343
344 return __btrfs_setxattr(NULL, dentry->d_inode, name, value, size,
345 flags);
Christoph Hellwig95819c02008-08-28 06:21:17 -0400346}
347
348int btrfs_removexattr(struct dentry *dentry, const char *name)
349{
Li Zefanb83cc962010-12-20 16:04:08 +0800350 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
351
352 /*
353 * The permission on security.* and system.* is not checked
354 * in permission().
355 */
356 if (btrfs_root_readonly(root))
357 return -EROFS;
358
Christoph Hellwig95819c02008-08-28 06:21:17 -0400359 /*
360 * If this is a request for a synthetic attribute in the system.*
361 * namespace use the generic infrastructure to resolve a handler
362 * for it via sb->s_xattr.
363 */
364 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
365 return generic_removexattr(dentry, name);
366
367 if (!btrfs_is_valid_xattr(name))
368 return -EOPNOTSUPP;
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000369
370 return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
371 XATTR_REPLACE);
Christoph Hellwig95819c02008-08-28 06:21:17 -0400372}
Jim Owens0279b4c2009-02-04 09:29:13 -0500373
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000374int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
Eric Paris2a7dba32011-02-01 11:05:39 -0500375 struct inode *inode, struct inode *dir,
376 const struct qstr *qstr)
Jim Owens0279b4c2009-02-04 09:29:13 -0500377{
378 int err;
379 size_t len;
380 void *value;
381 char *suffix;
382 char *name;
383
Eric Paris2a7dba32011-02-01 11:05:39 -0500384 err = security_inode_init_security(inode, dir, qstr, &suffix, &value,
385 &len);
Jim Owens0279b4c2009-02-04 09:29:13 -0500386 if (err) {
387 if (err == -EOPNOTSUPP)
388 return 0;
389 return err;
390 }
391
392 name = kmalloc(XATTR_SECURITY_PREFIX_LEN + strlen(suffix) + 1,
393 GFP_NOFS);
394 if (!name) {
395 err = -ENOMEM;
396 } else {
397 strcpy(name, XATTR_SECURITY_PREFIX);
398 strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
Yan, Zhengf34f57a2009-11-12 09:35:27 +0000399 err = __btrfs_setxattr(trans, inode, name, value, len, 0);
Jim Owens0279b4c2009-02-04 09:29:13 -0500400 kfree(name);
401 }
402
403 kfree(suffix);
404 kfree(value);
405 return err;
406}