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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2003 Erez Zadok | |
5 | * Copyright (C) 2001-2003 Stony Brook University | |
dd2a3b7a | 6 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
8 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
dddfa461 | 9 | * Tyler Hicks <tyhicks@ou.edu> |
237fead6 MH |
10 | * |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License as | |
13 | * published by the Free Software Foundation; either version 2 of the | |
14 | * License, or (at your option) any later version. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but | |
17 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License | |
22 | * along with this program; if not, write to the Free Software | |
23 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
24 | * 02111-1307, USA. | |
25 | */ | |
26 | ||
27 | #include <linux/dcache.h> | |
28 | #include <linux/file.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/namei.h> | |
31 | #include <linux/skbuff.h> | |
32 | #include <linux/crypto.h> | |
33 | #include <linux/netlink.h> | |
34 | #include <linux/mount.h> | |
237fead6 MH |
35 | #include <linux/pagemap.h> |
36 | #include <linux/key.h> | |
37 | #include <linux/parser.h> | |
0cc72dc7 | 38 | #include <linux/fs_stack.h> |
237fead6 MH |
39 | #include "ecryptfs_kernel.h" |
40 | ||
41 | /** | |
42 | * Module parameter that defines the ecryptfs_verbosity level. | |
43 | */ | |
44 | int ecryptfs_verbosity = 0; | |
45 | ||
46 | module_param(ecryptfs_verbosity, int, 0); | |
47 | MODULE_PARM_DESC(ecryptfs_verbosity, | |
48 | "Initial verbosity level (0 or 1; defaults to " | |
49 | "0, which is Quiet)"); | |
50 | ||
dddfa461 MH |
51 | /** |
52 | * Module parameter that defines the number of netlink message buffer | |
53 | * elements | |
54 | */ | |
55 | unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; | |
56 | ||
57 | module_param(ecryptfs_message_buf_len, uint, 0); | |
58 | MODULE_PARM_DESC(ecryptfs_message_buf_len, | |
59 | "Number of message buffer elements"); | |
60 | ||
61 | /** | |
62 | * Module parameter that defines the maximum guaranteed amount of time to wait | |
63 | * for a response through netlink. The actual sleep time will be, more than | |
64 | * likely, a small amount greater than this specified value, but only less if | |
65 | * the netlink message successfully arrives. | |
66 | */ | |
67 | signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; | |
68 | ||
69 | module_param(ecryptfs_message_wait_timeout, long, 0); | |
70 | MODULE_PARM_DESC(ecryptfs_message_wait_timeout, | |
71 | "Maximum number of seconds that an operation will " | |
72 | "sleep while waiting for a message response from " | |
73 | "userspace"); | |
74 | ||
75 | /** | |
76 | * Module parameter that is an estimate of the maximum number of users | |
77 | * that will be concurrently using eCryptfs. Set this to the right | |
78 | * value to balance performance and memory use. | |
79 | */ | |
80 | unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; | |
81 | ||
82 | module_param(ecryptfs_number_of_users, uint, 0); | |
83 | MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " | |
84 | "concurrent users of eCryptfs"); | |
85 | ||
86 | unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT; | |
87 | ||
237fead6 MH |
88 | void __ecryptfs_printk(const char *fmt, ...) |
89 | { | |
90 | va_list args; | |
91 | va_start(args, fmt); | |
92 | if (fmt[1] == '7') { /* KERN_DEBUG */ | |
93 | if (ecryptfs_verbosity >= 1) | |
94 | vprintk(fmt, args); | |
95 | } else | |
96 | vprintk(fmt, args); | |
97 | va_end(args); | |
98 | } | |
99 | ||
4981e081 MH |
100 | /** |
101 | * ecryptfs_init_persistent_file | |
102 | * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with | |
103 | * the lower dentry and the lower mount set | |
104 | * | |
105 | * eCryptfs only ever keeps a single open file for every lower | |
106 | * inode. All I/O operations to the lower inode occur through that | |
107 | * file. When the first eCryptfs dentry that interposes with the first | |
108 | * lower dentry for that inode is created, this function creates the | |
109 | * persistent file struct and associates it with the eCryptfs | |
110 | * inode. When the eCryptfs inode is destroyed, the file is closed. | |
111 | * | |
112 | * The persistent file will be opened with read/write permissions, if | |
113 | * possible. Otherwise, it is opened read-only. | |
114 | * | |
115 | * This function does nothing if a lower persistent file is already | |
116 | * associated with the eCryptfs inode. | |
117 | * | |
118 | * Returns zero on success; non-zero otherwise | |
119 | */ | |
72b55fff | 120 | int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) |
4981e081 MH |
121 | { |
122 | struct ecryptfs_inode_info *inode_info = | |
123 | ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); | |
124 | int rc = 0; | |
125 | ||
126 | mutex_lock(&inode_info->lower_file_mutex); | |
127 | if (!inode_info->lower_file) { | |
128 | struct dentry *lower_dentry; | |
129 | struct vfsmount *lower_mnt = | |
130 | ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); | |
131 | ||
132 | lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); | |
746f1e55 MH |
133 | rc = ecryptfs_privileged_open(&inode_info->lower_file, |
134 | lower_dentry, lower_mnt); | |
135 | if (rc || IS_ERR(inode_info->lower_file)) { | |
4981e081 | 136 | printk(KERN_ERR "Error opening lower persistent file " |
746f1e55 MH |
137 | "for lower_dentry [0x%p] and lower_mnt [0x%p]; " |
138 | "rc = [%d]\n", lower_dentry, lower_mnt, rc); | |
4981e081 MH |
139 | rc = PTR_ERR(inode_info->lower_file); |
140 | inode_info->lower_file = NULL; | |
141 | } | |
142 | } | |
143 | mutex_unlock(&inode_info->lower_file_mutex); | |
144 | return rc; | |
145 | } | |
146 | ||
237fead6 MH |
147 | /** |
148 | * ecryptfs_interpose | |
149 | * @lower_dentry: Existing dentry in the lower filesystem | |
150 | * @dentry: ecryptfs' dentry | |
151 | * @sb: ecryptfs's super_block | |
72b55fff | 152 | * @flags: flags to govern behavior of interpose procedure |
237fead6 MH |
153 | * |
154 | * Interposes upper and lower dentries. | |
155 | * | |
156 | * Returns zero on success; non-zero otherwise | |
157 | */ | |
158 | int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, | |
72b55fff | 159 | struct super_block *sb, u32 flags) |
237fead6 MH |
160 | { |
161 | struct inode *lower_inode; | |
162 | struct inode *inode; | |
163 | int rc = 0; | |
164 | ||
165 | lower_inode = lower_dentry->d_inode; | |
166 | if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { | |
167 | rc = -EXDEV; | |
168 | goto out; | |
169 | } | |
170 | if (!igrab(lower_inode)) { | |
171 | rc = -ESTALE; | |
172 | goto out; | |
173 | } | |
174 | inode = iget5_locked(sb, (unsigned long)lower_inode, | |
175 | ecryptfs_inode_test, ecryptfs_inode_set, | |
176 | lower_inode); | |
177 | if (!inode) { | |
178 | rc = -EACCES; | |
179 | iput(lower_inode); | |
180 | goto out; | |
181 | } | |
182 | if (inode->i_state & I_NEW) | |
183 | unlock_new_inode(inode); | |
184 | else | |
185 | iput(lower_inode); | |
186 | if (S_ISLNK(lower_inode->i_mode)) | |
187 | inode->i_op = &ecryptfs_symlink_iops; | |
188 | else if (S_ISDIR(lower_inode->i_mode)) | |
189 | inode->i_op = &ecryptfs_dir_iops; | |
190 | if (S_ISDIR(lower_inode->i_mode)) | |
191 | inode->i_fop = &ecryptfs_dir_fops; | |
26da8205 | 192 | if (special_file(lower_inode->i_mode)) |
237fead6 MH |
193 | init_special_inode(inode, lower_inode->i_mode, |
194 | lower_inode->i_rdev); | |
195 | dentry->d_op = &ecryptfs_dops; | |
72b55fff | 196 | if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD) |
237fead6 MH |
197 | d_add(dentry, inode); |
198 | else | |
199 | d_instantiate(dentry, inode); | |
0cc72dc7 | 200 | fsstack_copy_attr_all(inode, lower_inode, NULL); |
237fead6 MH |
201 | /* This size will be overwritten for real files w/ headers and |
202 | * other metadata */ | |
0cc72dc7 | 203 | fsstack_copy_inode_size(inode, lower_inode); |
237fead6 MH |
204 | out: |
205 | return rc; | |
206 | } | |
207 | ||
2830bfd6 ES |
208 | enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, |
209 | ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, | |
210 | ecryptfs_opt_ecryptfs_key_bytes, | |
17398957 MH |
211 | ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, |
212 | ecryptfs_opt_encrypted_view, ecryptfs_opt_err }; | |
237fead6 MH |
213 | |
214 | static match_table_t tokens = { | |
215 | {ecryptfs_opt_sig, "sig=%s"}, | |
216 | {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, | |
237fead6 MH |
217 | {ecryptfs_opt_cipher, "cipher=%s"}, |
218 | {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, | |
219 | {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, | |
220 | {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, | |
17398957 MH |
221 | {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, |
222 | {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, | |
237fead6 MH |
223 | {ecryptfs_opt_err, NULL} |
224 | }; | |
225 | ||
f4aad16a MH |
226 | static int ecryptfs_init_global_auth_toks( |
227 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
237fead6 | 228 | { |
f4aad16a | 229 | struct ecryptfs_global_auth_tok *global_auth_tok; |
237fead6 | 230 | int rc = 0; |
237fead6 | 231 | |
f4aad16a MH |
232 | list_for_each_entry(global_auth_tok, |
233 | &mount_crypt_stat->global_auth_tok_list, | |
234 | mount_crypt_stat_list) { | |
5dda6992 MH |
235 | rc = ecryptfs_keyring_auth_tok_for_sig( |
236 | &global_auth_tok->global_auth_tok_key, | |
237 | &global_auth_tok->global_auth_tok, | |
238 | global_auth_tok->sig); | |
239 | if (rc) { | |
f4aad16a MH |
240 | printk(KERN_ERR "Could not find valid key in user " |
241 | "session keyring for sig specified in mount " | |
242 | "option: [%s]\n", global_auth_tok->sig); | |
243 | global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
982363c9 | 244 | goto out; |
f4aad16a MH |
245 | } else |
246 | global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; | |
237fead6 | 247 | } |
982363c9 | 248 | out: |
237fead6 MH |
249 | return rc; |
250 | } | |
251 | ||
f4aad16a MH |
252 | static void ecryptfs_init_mount_crypt_stat( |
253 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
254 | { | |
255 | memset((void *)mount_crypt_stat, 0, | |
256 | sizeof(struct ecryptfs_mount_crypt_stat)); | |
257 | INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); | |
258 | mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); | |
259 | mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; | |
260 | } | |
261 | ||
237fead6 MH |
262 | /** |
263 | * ecryptfs_parse_options | |
264 | * @sb: The ecryptfs super block | |
265 | * @options: The options pased to the kernel | |
266 | * | |
267 | * Parse mount options: | |
268 | * debug=N - ecryptfs_verbosity level for debug output | |
269 | * sig=XXX - description(signature) of the key to use | |
270 | * | |
271 | * Returns the dentry object of the lower-level (lower/interposed) | |
272 | * directory; We want to mount our stackable file system on top of | |
273 | * that lower directory. | |
274 | * | |
275 | * The signature of the key to use must be the description of a key | |
276 | * already in the keyring. Mounting will fail if the key can not be | |
277 | * found. | |
278 | * | |
279 | * Returns zero on success; non-zero on error | |
280 | */ | |
281 | static int ecryptfs_parse_options(struct super_block *sb, char *options) | |
282 | { | |
283 | char *p; | |
284 | int rc = 0; | |
285 | int sig_set = 0; | |
286 | int cipher_name_set = 0; | |
287 | int cipher_key_bytes; | |
288 | int cipher_key_bytes_set = 0; | |
237fead6 MH |
289 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
290 | &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; | |
291 | substring_t args[MAX_OPT_ARGS]; | |
292 | int token; | |
293 | char *sig_src; | |
237fead6 MH |
294 | char *cipher_name_dst; |
295 | char *cipher_name_src; | |
296 | char *cipher_key_bytes_src; | |
237fead6 MH |
297 | |
298 | if (!options) { | |
299 | rc = -EINVAL; | |
300 | goto out; | |
301 | } | |
956159c3 | 302 | ecryptfs_init_mount_crypt_stat(mount_crypt_stat); |
237fead6 MH |
303 | while ((p = strsep(&options, ",")) != NULL) { |
304 | if (!*p) | |
305 | continue; | |
306 | token = match_token(p, tokens, args); | |
307 | switch (token) { | |
308 | case ecryptfs_opt_sig: | |
309 | case ecryptfs_opt_ecryptfs_sig: | |
310 | sig_src = args[0].from; | |
f4aad16a MH |
311 | rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, |
312 | sig_src); | |
313 | if (rc) { | |
314 | printk(KERN_ERR "Error attempting to register " | |
315 | "global sig; rc = [%d]\n", rc); | |
316 | goto out; | |
317 | } | |
237fead6 MH |
318 | sig_set = 1; |
319 | break; | |
237fead6 MH |
320 | case ecryptfs_opt_cipher: |
321 | case ecryptfs_opt_ecryptfs_cipher: | |
322 | cipher_name_src = args[0].from; | |
323 | cipher_name_dst = | |
324 | mount_crypt_stat-> | |
325 | global_default_cipher_name; | |
326 | strncpy(cipher_name_dst, cipher_name_src, | |
327 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
328 | ecryptfs_printk(KERN_DEBUG, | |
329 | "The mount_crypt_stat " | |
330 | "global_default_cipher_name set to: " | |
331 | "[%s]\n", cipher_name_dst); | |
332 | cipher_name_set = 1; | |
333 | break; | |
334 | case ecryptfs_opt_ecryptfs_key_bytes: | |
335 | cipher_key_bytes_src = args[0].from; | |
336 | cipher_key_bytes = | |
337 | (int)simple_strtol(cipher_key_bytes_src, | |
338 | &cipher_key_bytes_src, 0); | |
339 | mount_crypt_stat->global_default_cipher_key_size = | |
340 | cipher_key_bytes; | |
341 | ecryptfs_printk(KERN_DEBUG, | |
342 | "The mount_crypt_stat " | |
343 | "global_default_cipher_key_size " | |
344 | "set to: [%d]\n", mount_crypt_stat-> | |
345 | global_default_cipher_key_size); | |
346 | cipher_key_bytes_set = 1; | |
347 | break; | |
348 | case ecryptfs_opt_passthrough: | |
349 | mount_crypt_stat->flags |= | |
350 | ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; | |
351 | break; | |
17398957 MH |
352 | case ecryptfs_opt_xattr_metadata: |
353 | mount_crypt_stat->flags |= | |
354 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
355 | break; | |
356 | case ecryptfs_opt_encrypted_view: | |
357 | mount_crypt_stat->flags |= | |
358 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
359 | mount_crypt_stat->flags |= | |
360 | ECRYPTFS_ENCRYPTED_VIEW_ENABLED; | |
361 | break; | |
237fead6 MH |
362 | case ecryptfs_opt_err: |
363 | default: | |
364 | ecryptfs_printk(KERN_WARNING, | |
365 | "eCryptfs: unrecognized option '%s'\n", | |
366 | p); | |
367 | } | |
368 | } | |
237fead6 MH |
369 | if (!sig_set) { |
370 | rc = -EINVAL; | |
956159c3 MH |
371 | ecryptfs_printk(KERN_ERR, "You must supply at least one valid " |
372 | "auth tok signature as a mount " | |
237fead6 MH |
373 | "parameter; see the eCryptfs README\n"); |
374 | goto out; | |
375 | } | |
376 | if (!cipher_name_set) { | |
8f236809 MS |
377 | int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); |
378 | ||
379 | BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
380 | ||
381 | strcpy(mount_crypt_stat->global_default_cipher_name, | |
382 | ECRYPTFS_DEFAULT_CIPHER); | |
237fead6 MH |
383 | } |
384 | if (!cipher_key_bytes_set) { | |
e5d9cbde | 385 | mount_crypt_stat->global_default_cipher_key_size = 0; |
237fead6 | 386 | } |
af440f52 ES |
387 | mutex_lock(&key_tfm_list_mutex); |
388 | if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, | |
389 | NULL)) | |
390 | rc = ecryptfs_add_new_key_tfm( | |
391 | NULL, mount_crypt_stat->global_default_cipher_name, | |
392 | mount_crypt_stat->global_default_cipher_key_size); | |
393 | mutex_unlock(&key_tfm_list_mutex); | |
5dda6992 | 394 | if (rc) { |
f4aad16a | 395 | printk(KERN_ERR "Error attempting to initialize cipher with " |
81acbcd6 | 396 | "name = [%s] and key size = [%td]; rc = [%d]\n", |
237fead6 MH |
397 | mount_crypt_stat->global_default_cipher_name, |
398 | mount_crypt_stat->global_default_cipher_key_size, rc); | |
237fead6 MH |
399 | rc = -EINVAL; |
400 | goto out; | |
401 | } | |
5dda6992 MH |
402 | rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); |
403 | if (rc) { | |
f4aad16a MH |
404 | printk(KERN_WARNING "One or more global auth toks could not " |
405 | "properly register; rc = [%d]\n", rc); | |
237fead6 | 406 | } |
237fead6 MH |
407 | out: |
408 | return rc; | |
409 | } | |
410 | ||
411 | struct kmem_cache *ecryptfs_sb_info_cache; | |
412 | ||
413 | /** | |
414 | * ecryptfs_fill_super | |
415 | * @sb: The ecryptfs super block | |
416 | * @raw_data: The options passed to mount | |
417 | * @silent: Not used but required by function prototype | |
418 | * | |
419 | * Sets up what we can of the sb, rest is done in ecryptfs_read_super | |
420 | * | |
421 | * Returns zero on success; non-zero otherwise | |
422 | */ | |
423 | static int | |
424 | ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) | |
425 | { | |
426 | int rc = 0; | |
427 | ||
428 | /* Released in ecryptfs_put_super() */ | |
429 | ecryptfs_set_superblock_private(sb, | |
c3762229 | 430 | kmem_cache_zalloc(ecryptfs_sb_info_cache, |
e94b1766 | 431 | GFP_KERNEL)); |
237fead6 MH |
432 | if (!ecryptfs_superblock_to_private(sb)) { |
433 | ecryptfs_printk(KERN_WARNING, "Out of memory\n"); | |
434 | rc = -ENOMEM; | |
435 | goto out; | |
436 | } | |
237fead6 MH |
437 | sb->s_op = &ecryptfs_sops; |
438 | /* Released through deactivate_super(sb) from get_sb_nodev */ | |
439 | sb->s_root = d_alloc(NULL, &(const struct qstr) { | |
440 | .hash = 0,.name = "/",.len = 1}); | |
441 | if (!sb->s_root) { | |
442 | ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); | |
443 | rc = -ENOMEM; | |
444 | goto out; | |
445 | } | |
446 | sb->s_root->d_op = &ecryptfs_dops; | |
447 | sb->s_root->d_sb = sb; | |
448 | sb->s_root->d_parent = sb->s_root; | |
449 | /* Released in d_release when dput(sb->s_root) is called */ | |
450 | /* through deactivate_super(sb) from get_sb_nodev() */ | |
451 | ecryptfs_set_dentry_private(sb->s_root, | |
c3762229 | 452 | kmem_cache_zalloc(ecryptfs_dentry_info_cache, |
e94b1766 | 453 | GFP_KERNEL)); |
237fead6 MH |
454 | if (!ecryptfs_dentry_to_private(sb->s_root)) { |
455 | ecryptfs_printk(KERN_ERR, | |
456 | "dentry_info_cache alloc failed\n"); | |
457 | rc = -ENOMEM; | |
458 | goto out; | |
459 | } | |
237fead6 MH |
460 | rc = 0; |
461 | out: | |
462 | /* Should be able to rely on deactivate_super called from | |
463 | * get_sb_nodev */ | |
464 | return rc; | |
465 | } | |
466 | ||
467 | /** | |
468 | * ecryptfs_read_super | |
469 | * @sb: The ecryptfs super block | |
470 | * @dev_name: The path to mount over | |
471 | * | |
472 | * Read the super block of the lower filesystem, and use | |
473 | * ecryptfs_interpose to create our initial inode and super block | |
474 | * struct. | |
475 | */ | |
476 | static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) | |
477 | { | |
478 | int rc; | |
479 | struct nameidata nd; | |
480 | struct dentry *lower_root; | |
481 | struct vfsmount *lower_mnt; | |
482 | ||
483 | memset(&nd, 0, sizeof(struct nameidata)); | |
82b16528 | 484 | rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd); |
237fead6 MH |
485 | if (rc) { |
486 | ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); | |
65dc8145 | 487 | goto out; |
237fead6 | 488 | } |
4ac91378 JB |
489 | lower_root = nd.path.dentry; |
490 | lower_mnt = nd.path.mnt; | |
237fead6 MH |
491 | ecryptfs_set_superblock_lower(sb, lower_root->d_sb); |
492 | sb->s_maxbytes = lower_root->d_sb->s_maxbytes; | |
7c9e70ef | 493 | sb->s_blocksize = lower_root->d_sb->s_blocksize; |
237fead6 MH |
494 | ecryptfs_set_dentry_lower(sb->s_root, lower_root); |
495 | ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt); | |
5dda6992 MH |
496 | rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0); |
497 | if (rc) | |
237fead6 MH |
498 | goto out_free; |
499 | rc = 0; | |
500 | goto out; | |
501 | out_free: | |
1d957f9b | 502 | path_put(&nd.path); |
237fead6 MH |
503 | out: |
504 | return rc; | |
505 | } | |
506 | ||
507 | /** | |
508 | * ecryptfs_get_sb | |
509 | * @fs_type | |
510 | * @flags | |
511 | * @dev_name: The path to mount over | |
512 | * @raw_data: The options passed into the kernel | |
513 | * | |
514 | * The whole ecryptfs_get_sb process is broken into 4 functions: | |
515 | * ecryptfs_parse_options(): handle options passed to ecryptfs, if any | |
516 | * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block | |
517 | * with as much information as it can before needing | |
518 | * the lower filesystem. | |
519 | * ecryptfs_read_super(): this accesses the lower filesystem and uses | |
520 | * ecryptfs_interpolate to perform most of the linking | |
521 | * ecryptfs_interpolate(): links the lower filesystem into ecryptfs | |
522 | */ | |
523 | static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, | |
524 | const char *dev_name, void *raw_data, | |
525 | struct vfsmount *mnt) | |
526 | { | |
527 | int rc; | |
528 | struct super_block *sb; | |
529 | ||
530 | rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); | |
531 | if (rc < 0) { | |
532 | printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); | |
533 | goto out; | |
534 | } | |
535 | sb = mnt->mnt_sb; | |
536 | rc = ecryptfs_parse_options(sb, raw_data); | |
537 | if (rc) { | |
538 | printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); | |
539 | goto out_abort; | |
540 | } | |
541 | rc = ecryptfs_read_super(sb, dev_name); | |
542 | if (rc) { | |
543 | printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); | |
544 | goto out_abort; | |
545 | } | |
546 | goto out; | |
547 | out_abort: | |
548 | dput(sb->s_root); | |
549 | up_write(&sb->s_umount); | |
550 | deactivate_super(sb); | |
551 | out: | |
552 | return rc; | |
553 | } | |
554 | ||
555 | /** | |
556 | * ecryptfs_kill_block_super | |
557 | * @sb: The ecryptfs super block | |
558 | * | |
559 | * Used to bring the superblock down and free the private data. | |
560 | * Private data is free'd in ecryptfs_put_super() | |
561 | */ | |
562 | static void ecryptfs_kill_block_super(struct super_block *sb) | |
563 | { | |
564 | generic_shutdown_super(sb); | |
565 | } | |
566 | ||
567 | static struct file_system_type ecryptfs_fs_type = { | |
568 | .owner = THIS_MODULE, | |
569 | .name = "ecryptfs", | |
570 | .get_sb = ecryptfs_get_sb, | |
571 | .kill_sb = ecryptfs_kill_block_super, | |
572 | .fs_flags = 0 | |
573 | }; | |
574 | ||
575 | /** | |
576 | * inode_info_init_once | |
577 | * | |
578 | * Initializes the ecryptfs_inode_info_cache when it is created | |
579 | */ | |
580 | static void | |
4ba9b9d0 | 581 | inode_info_init_once(struct kmem_cache *cachep, void *vptr) |
237fead6 MH |
582 | { |
583 | struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; | |
584 | ||
a35afb83 | 585 | inode_init_once(&ei->vfs_inode); |
237fead6 MH |
586 | } |
587 | ||
588 | static struct ecryptfs_cache_info { | |
e18b890b | 589 | struct kmem_cache **cache; |
237fead6 MH |
590 | const char *name; |
591 | size_t size; | |
4ba9b9d0 | 592 | void (*ctor)(struct kmem_cache *cache, void *obj); |
237fead6 MH |
593 | } ecryptfs_cache_infos[] = { |
594 | { | |
595 | .cache = &ecryptfs_auth_tok_list_item_cache, | |
596 | .name = "ecryptfs_auth_tok_list_item", | |
597 | .size = sizeof(struct ecryptfs_auth_tok_list_item), | |
598 | }, | |
599 | { | |
600 | .cache = &ecryptfs_file_info_cache, | |
601 | .name = "ecryptfs_file_cache", | |
602 | .size = sizeof(struct ecryptfs_file_info), | |
603 | }, | |
604 | { | |
605 | .cache = &ecryptfs_dentry_info_cache, | |
606 | .name = "ecryptfs_dentry_info_cache", | |
607 | .size = sizeof(struct ecryptfs_dentry_info), | |
608 | }, | |
609 | { | |
610 | .cache = &ecryptfs_inode_info_cache, | |
611 | .name = "ecryptfs_inode_cache", | |
612 | .size = sizeof(struct ecryptfs_inode_info), | |
613 | .ctor = inode_info_init_once, | |
614 | }, | |
615 | { | |
616 | .cache = &ecryptfs_sb_info_cache, | |
617 | .name = "ecryptfs_sb_cache", | |
618 | .size = sizeof(struct ecryptfs_sb_info), | |
619 | }, | |
237fead6 MH |
620 | { |
621 | .cache = &ecryptfs_header_cache_1, | |
622 | .name = "ecryptfs_headers_1", | |
623 | .size = PAGE_CACHE_SIZE, | |
624 | }, | |
625 | { | |
626 | .cache = &ecryptfs_header_cache_2, | |
627 | .name = "ecryptfs_headers_2", | |
628 | .size = PAGE_CACHE_SIZE, | |
629 | }, | |
dd2a3b7a MH |
630 | { |
631 | .cache = &ecryptfs_xattr_cache, | |
632 | .name = "ecryptfs_xattr_cache", | |
633 | .size = PAGE_CACHE_SIZE, | |
634 | }, | |
eb95e7ff MH |
635 | { |
636 | .cache = &ecryptfs_key_record_cache, | |
637 | .name = "ecryptfs_key_record_cache", | |
638 | .size = sizeof(struct ecryptfs_key_record), | |
639 | }, | |
956159c3 MH |
640 | { |
641 | .cache = &ecryptfs_key_sig_cache, | |
642 | .name = "ecryptfs_key_sig_cache", | |
643 | .size = sizeof(struct ecryptfs_key_sig), | |
644 | }, | |
645 | { | |
646 | .cache = &ecryptfs_global_auth_tok_cache, | |
647 | .name = "ecryptfs_global_auth_tok_cache", | |
648 | .size = sizeof(struct ecryptfs_global_auth_tok), | |
649 | }, | |
650 | { | |
651 | .cache = &ecryptfs_key_tfm_cache, | |
652 | .name = "ecryptfs_key_tfm_cache", | |
653 | .size = sizeof(struct ecryptfs_key_tfm), | |
654 | }, | |
746f1e55 MH |
655 | { |
656 | .cache = &ecryptfs_open_req_cache, | |
657 | .name = "ecryptfs_open_req_cache", | |
658 | .size = sizeof(struct ecryptfs_open_req), | |
659 | }, | |
237fead6 MH |
660 | }; |
661 | ||
662 | static void ecryptfs_free_kmem_caches(void) | |
663 | { | |
664 | int i; | |
665 | ||
666 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
667 | struct ecryptfs_cache_info *info; | |
668 | ||
669 | info = &ecryptfs_cache_infos[i]; | |
670 | if (*(info->cache)) | |
671 | kmem_cache_destroy(*(info->cache)); | |
672 | } | |
673 | } | |
674 | ||
675 | /** | |
676 | * ecryptfs_init_kmem_caches | |
677 | * | |
678 | * Returns zero on success; non-zero otherwise | |
679 | */ | |
680 | static int ecryptfs_init_kmem_caches(void) | |
681 | { | |
682 | int i; | |
683 | ||
684 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
685 | struct ecryptfs_cache_info *info; | |
686 | ||
687 | info = &ecryptfs_cache_infos[i]; | |
688 | *(info->cache) = kmem_cache_create(info->name, info->size, | |
20c2df83 | 689 | 0, SLAB_HWCACHE_ALIGN, info->ctor); |
237fead6 MH |
690 | if (!*(info->cache)) { |
691 | ecryptfs_free_kmem_caches(); | |
692 | ecryptfs_printk(KERN_WARNING, "%s: " | |
693 | "kmem_cache_create failed\n", | |
694 | info->name); | |
695 | return -ENOMEM; | |
696 | } | |
697 | } | |
698 | return 0; | |
699 | } | |
700 | ||
6e90aa97 | 701 | static struct kobject *ecryptfs_kobj; |
237fead6 | 702 | |
386f275f KS |
703 | static ssize_t version_show(struct kobject *kobj, |
704 | struct kobj_attribute *attr, char *buff) | |
237fead6 MH |
705 | { |
706 | return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); | |
707 | } | |
708 | ||
386f275f | 709 | static struct kobj_attribute version_attr = __ATTR_RO(version); |
237fead6 | 710 | |
30a468b1 GKH |
711 | static struct attribute *attributes[] = { |
712 | &version_attr.attr, | |
30a468b1 GKH |
713 | NULL, |
714 | }; | |
715 | ||
716 | static struct attribute_group attr_group = { | |
717 | .attrs = attributes, | |
718 | }; | |
237fead6 MH |
719 | |
720 | static int do_sysfs_registration(void) | |
721 | { | |
722 | int rc; | |
723 | ||
6e90aa97 GKH |
724 | ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); |
725 | if (!ecryptfs_kobj) { | |
917e865d GKH |
726 | printk(KERN_ERR "Unable to create ecryptfs kset\n"); |
727 | rc = -ENOMEM; | |
237fead6 MH |
728 | goto out; |
729 | } | |
6e90aa97 | 730 | rc = sysfs_create_group(ecryptfs_kobj, &attr_group); |
237fead6 MH |
731 | if (rc) { |
732 | printk(KERN_ERR | |
30a468b1 | 733 | "Unable to create ecryptfs version attributes\n"); |
197b12d6 | 734 | kobject_put(ecryptfs_kobj); |
237fead6 MH |
735 | } |
736 | out: | |
737 | return rc; | |
738 | } | |
739 | ||
a75de1b3 RK |
740 | static void do_sysfs_unregistration(void) |
741 | { | |
6e90aa97 | 742 | sysfs_remove_group(ecryptfs_kobj, &attr_group); |
197b12d6 | 743 | kobject_put(ecryptfs_kobj); |
a75de1b3 RK |
744 | } |
745 | ||
237fead6 MH |
746 | static int __init ecryptfs_init(void) |
747 | { | |
748 | int rc; | |
749 | ||
750 | if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { | |
751 | rc = -EINVAL; | |
752 | ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " | |
753 | "larger than the host's page size, and so " | |
754 | "eCryptfs cannot run on this system. The " | |
755 | "default eCryptfs extent size is [%d] bytes; " | |
756 | "the page size is [%d] bytes.\n", | |
757 | ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); | |
758 | goto out; | |
759 | } | |
760 | rc = ecryptfs_init_kmem_caches(); | |
761 | if (rc) { | |
762 | printk(KERN_ERR | |
763 | "Failed to allocate one or more kmem_cache objects\n"); | |
764 | goto out; | |
765 | } | |
766 | rc = register_filesystem(&ecryptfs_fs_type); | |
767 | if (rc) { | |
768 | printk(KERN_ERR "Failed to register filesystem\n"); | |
cf81f89d | 769 | goto out_free_kmem_caches; |
237fead6 | 770 | } |
237fead6 MH |
771 | rc = do_sysfs_registration(); |
772 | if (rc) { | |
773 | printk(KERN_ERR "sysfs registration failed\n"); | |
cf81f89d | 774 | goto out_unregister_filesystem; |
237fead6 | 775 | } |
746f1e55 MH |
776 | rc = ecryptfs_init_kthread(); |
777 | if (rc) { | |
778 | printk(KERN_ERR "%s: kthread initialization failed; " | |
779 | "rc = [%d]\n", __func__, rc); | |
780 | goto out_do_sysfs_unregistration; | |
781 | } | |
dddfa461 MH |
782 | rc = ecryptfs_init_messaging(ecryptfs_transport); |
783 | if (rc) { | |
746f1e55 | 784 | printk(KERN_ERR "Failure occured while attempting to " |
dddfa461 | 785 | "initialize the eCryptfs netlink socket\n"); |
746f1e55 | 786 | goto out_destroy_kthread; |
956159c3 MH |
787 | } |
788 | rc = ecryptfs_init_crypto(); | |
789 | if (rc) { | |
790 | printk(KERN_ERR "Failure whilst attempting to init crypto; " | |
791 | "rc = [%d]\n", rc); | |
cf81f89d | 792 | goto out_release_messaging; |
dddfa461 | 793 | } |
2830bfd6 ES |
794 | if (ecryptfs_verbosity > 0) |
795 | printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " | |
796 | "will be written to the syslog!\n", ecryptfs_verbosity); | |
797 | ||
cf81f89d MH |
798 | goto out; |
799 | out_release_messaging: | |
800 | ecryptfs_release_messaging(ecryptfs_transport); | |
746f1e55 MH |
801 | out_destroy_kthread: |
802 | ecryptfs_destroy_kthread(); | |
cf81f89d MH |
803 | out_do_sysfs_unregistration: |
804 | do_sysfs_unregistration(); | |
805 | out_unregister_filesystem: | |
806 | unregister_filesystem(&ecryptfs_fs_type); | |
807 | out_free_kmem_caches: | |
808 | ecryptfs_free_kmem_caches(); | |
237fead6 MH |
809 | out: |
810 | return rc; | |
811 | } | |
812 | ||
813 | static void __exit ecryptfs_exit(void) | |
814 | { | |
cf81f89d MH |
815 | int rc; |
816 | ||
817 | rc = ecryptfs_destroy_crypto(); | |
818 | if (rc) | |
819 | printk(KERN_ERR "Failure whilst attempting to destroy crypto; " | |
820 | "rc = [%d]\n", rc); | |
dddfa461 | 821 | ecryptfs_release_messaging(ecryptfs_transport); |
746f1e55 | 822 | ecryptfs_destroy_kthread(); |
cf81f89d | 823 | do_sysfs_unregistration(); |
237fead6 MH |
824 | unregister_filesystem(&ecryptfs_fs_type); |
825 | ecryptfs_free_kmem_caches(); | |
826 | } | |
827 | ||
828 | MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); | |
829 | MODULE_DESCRIPTION("eCryptfs"); | |
830 | ||
831 | MODULE_LICENSE("GPL"); | |
832 | ||
833 | module_init(ecryptfs_init) | |
834 | module_exit(ecryptfs_exit) |