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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 | */ | |
120 | int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) | |
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); | |
133 | /* Corresponding dput() and mntput() are done when the | |
134 | * persistent file is fput() when the eCryptfs inode | |
135 | * is destroyed. */ | |
136 | dget(lower_dentry); | |
137 | mntget(lower_mnt); | |
138 | inode_info->lower_file = dentry_open(lower_dentry, | |
139 | lower_mnt, | |
140 | (O_RDWR | O_LARGEFILE)); | |
141 | if (IS_ERR(inode_info->lower_file)) | |
142 | inode_info->lower_file = dentry_open(lower_dentry, | |
143 | lower_mnt, | |
144 | (O_RDONLY | |
145 | | O_LARGEFILE)); | |
146 | if (IS_ERR(inode_info->lower_file)) { | |
147 | printk(KERN_ERR "Error opening lower persistent file " | |
148 | "for lower_dentry [0x%p] and lower_mnt [0x%p]\n", | |
149 | lower_dentry, lower_mnt); | |
150 | rc = PTR_ERR(inode_info->lower_file); | |
151 | inode_info->lower_file = NULL; | |
152 | } | |
153 | } | |
154 | mutex_unlock(&inode_info->lower_file_mutex); | |
155 | return rc; | |
156 | } | |
157 | ||
237fead6 MH |
158 | /** |
159 | * ecryptfs_interpose | |
160 | * @lower_dentry: Existing dentry in the lower filesystem | |
161 | * @dentry: ecryptfs' dentry | |
162 | * @sb: ecryptfs's super_block | |
163 | * @flag: If set to true, then d_add is called, else d_instantiate is called | |
164 | * | |
165 | * Interposes upper and lower dentries. | |
166 | * | |
167 | * Returns zero on success; non-zero otherwise | |
168 | */ | |
169 | int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry, | |
170 | struct super_block *sb, int flag) | |
171 | { | |
172 | struct inode *lower_inode; | |
173 | struct inode *inode; | |
174 | int rc = 0; | |
175 | ||
176 | lower_inode = lower_dentry->d_inode; | |
177 | if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) { | |
178 | rc = -EXDEV; | |
179 | goto out; | |
180 | } | |
181 | if (!igrab(lower_inode)) { | |
182 | rc = -ESTALE; | |
183 | goto out; | |
184 | } | |
185 | inode = iget5_locked(sb, (unsigned long)lower_inode, | |
186 | ecryptfs_inode_test, ecryptfs_inode_set, | |
187 | lower_inode); | |
188 | if (!inode) { | |
189 | rc = -EACCES; | |
190 | iput(lower_inode); | |
191 | goto out; | |
192 | } | |
193 | if (inode->i_state & I_NEW) | |
194 | unlock_new_inode(inode); | |
195 | else | |
196 | iput(lower_inode); | |
197 | if (S_ISLNK(lower_inode->i_mode)) | |
198 | inode->i_op = &ecryptfs_symlink_iops; | |
199 | else if (S_ISDIR(lower_inode->i_mode)) | |
200 | inode->i_op = &ecryptfs_dir_iops; | |
201 | if (S_ISDIR(lower_inode->i_mode)) | |
202 | inode->i_fop = &ecryptfs_dir_fops; | |
26da8205 | 203 | if (special_file(lower_inode->i_mode)) |
237fead6 MH |
204 | init_special_inode(inode, lower_inode->i_mode, |
205 | lower_inode->i_rdev); | |
206 | dentry->d_op = &ecryptfs_dops; | |
207 | if (flag) | |
208 | d_add(dentry, inode); | |
209 | else | |
210 | d_instantiate(dentry, inode); | |
0cc72dc7 | 211 | fsstack_copy_attr_all(inode, lower_inode, NULL); |
237fead6 MH |
212 | /* This size will be overwritten for real files w/ headers and |
213 | * other metadata */ | |
0cc72dc7 | 214 | fsstack_copy_inode_size(inode, lower_inode); |
4981e081 MH |
215 | rc = ecryptfs_init_persistent_file(dentry); |
216 | if (rc) { | |
217 | printk(KERN_ERR "%s: Error attempting to initialize the " | |
218 | "persistent file for the dentry with name [%s]; " | |
219 | "rc = [%d]\n", __FUNCTION__, dentry->d_name.name, rc); | |
220 | goto out; | |
221 | } | |
237fead6 MH |
222 | out: |
223 | return rc; | |
224 | } | |
225 | ||
226 | enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug, | |
227 | ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher, | |
228 | ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes, | |
17398957 MH |
229 | ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, |
230 | ecryptfs_opt_encrypted_view, ecryptfs_opt_err }; | |
237fead6 MH |
231 | |
232 | static match_table_t tokens = { | |
233 | {ecryptfs_opt_sig, "sig=%s"}, | |
234 | {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, | |
235 | {ecryptfs_opt_debug, "debug=%u"}, | |
236 | {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"}, | |
237 | {ecryptfs_opt_cipher, "cipher=%s"}, | |
238 | {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, | |
239 | {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, | |
240 | {ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, | |
17398957 MH |
241 | {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, |
242 | {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, | |
237fead6 MH |
243 | {ecryptfs_opt_err, NULL} |
244 | }; | |
245 | ||
f4aad16a MH |
246 | static int ecryptfs_init_global_auth_toks( |
247 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
237fead6 | 248 | { |
f4aad16a | 249 | struct ecryptfs_global_auth_tok *global_auth_tok; |
237fead6 | 250 | int rc = 0; |
237fead6 | 251 | |
f4aad16a MH |
252 | list_for_each_entry(global_auth_tok, |
253 | &mount_crypt_stat->global_auth_tok_list, | |
254 | mount_crypt_stat_list) { | |
5dda6992 MH |
255 | rc = ecryptfs_keyring_auth_tok_for_sig( |
256 | &global_auth_tok->global_auth_tok_key, | |
257 | &global_auth_tok->global_auth_tok, | |
258 | global_auth_tok->sig); | |
259 | if (rc) { | |
f4aad16a MH |
260 | printk(KERN_ERR "Could not find valid key in user " |
261 | "session keyring for sig specified in mount " | |
262 | "option: [%s]\n", global_auth_tok->sig); | |
263 | global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
264 | rc = 0; | |
265 | } else | |
266 | global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; | |
237fead6 | 267 | } |
237fead6 MH |
268 | return rc; |
269 | } | |
270 | ||
f4aad16a MH |
271 | static void ecryptfs_init_mount_crypt_stat( |
272 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
273 | { | |
274 | memset((void *)mount_crypt_stat, 0, | |
275 | sizeof(struct ecryptfs_mount_crypt_stat)); | |
276 | INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); | |
277 | mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); | |
278 | mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; | |
279 | } | |
280 | ||
237fead6 MH |
281 | /** |
282 | * ecryptfs_parse_options | |
283 | * @sb: The ecryptfs super block | |
284 | * @options: The options pased to the kernel | |
285 | * | |
286 | * Parse mount options: | |
287 | * debug=N - ecryptfs_verbosity level for debug output | |
288 | * sig=XXX - description(signature) of the key to use | |
289 | * | |
290 | * Returns the dentry object of the lower-level (lower/interposed) | |
291 | * directory; We want to mount our stackable file system on top of | |
292 | * that lower directory. | |
293 | * | |
294 | * The signature of the key to use must be the description of a key | |
295 | * already in the keyring. Mounting will fail if the key can not be | |
296 | * found. | |
297 | * | |
298 | * Returns zero on success; non-zero on error | |
299 | */ | |
300 | static int ecryptfs_parse_options(struct super_block *sb, char *options) | |
301 | { | |
302 | char *p; | |
303 | int rc = 0; | |
304 | int sig_set = 0; | |
305 | int cipher_name_set = 0; | |
306 | int cipher_key_bytes; | |
307 | int cipher_key_bytes_set = 0; | |
237fead6 MH |
308 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
309 | &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; | |
310 | substring_t args[MAX_OPT_ARGS]; | |
311 | int token; | |
312 | char *sig_src; | |
237fead6 MH |
313 | char *debug_src; |
314 | char *cipher_name_dst; | |
315 | char *cipher_name_src; | |
316 | char *cipher_key_bytes_src; | |
237fead6 MH |
317 | int cipher_name_len; |
318 | ||
319 | if (!options) { | |
320 | rc = -EINVAL; | |
321 | goto out; | |
322 | } | |
956159c3 | 323 | ecryptfs_init_mount_crypt_stat(mount_crypt_stat); |
237fead6 MH |
324 | while ((p = strsep(&options, ",")) != NULL) { |
325 | if (!*p) | |
326 | continue; | |
327 | token = match_token(p, tokens, args); | |
328 | switch (token) { | |
329 | case ecryptfs_opt_sig: | |
330 | case ecryptfs_opt_ecryptfs_sig: | |
331 | sig_src = args[0].from; | |
f4aad16a MH |
332 | rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, |
333 | sig_src); | |
334 | if (rc) { | |
335 | printk(KERN_ERR "Error attempting to register " | |
336 | "global sig; rc = [%d]\n", rc); | |
337 | goto out; | |
338 | } | |
237fead6 MH |
339 | sig_set = 1; |
340 | break; | |
341 | case ecryptfs_opt_debug: | |
342 | case ecryptfs_opt_ecryptfs_debug: | |
343 | debug_src = args[0].from; | |
344 | ecryptfs_verbosity = | |
345 | (int)simple_strtol(debug_src, &debug_src, | |
346 | 0); | |
347 | ecryptfs_printk(KERN_DEBUG, | |
348 | "Verbosity set to [%d]" "\n", | |
349 | ecryptfs_verbosity); | |
350 | break; | |
351 | case ecryptfs_opt_cipher: | |
352 | case ecryptfs_opt_ecryptfs_cipher: | |
353 | cipher_name_src = args[0].from; | |
354 | cipher_name_dst = | |
355 | mount_crypt_stat-> | |
356 | global_default_cipher_name; | |
357 | strncpy(cipher_name_dst, cipher_name_src, | |
358 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
359 | ecryptfs_printk(KERN_DEBUG, | |
360 | "The mount_crypt_stat " | |
361 | "global_default_cipher_name set to: " | |
362 | "[%s]\n", cipher_name_dst); | |
363 | cipher_name_set = 1; | |
364 | break; | |
365 | case ecryptfs_opt_ecryptfs_key_bytes: | |
366 | cipher_key_bytes_src = args[0].from; | |
367 | cipher_key_bytes = | |
368 | (int)simple_strtol(cipher_key_bytes_src, | |
369 | &cipher_key_bytes_src, 0); | |
370 | mount_crypt_stat->global_default_cipher_key_size = | |
371 | cipher_key_bytes; | |
372 | ecryptfs_printk(KERN_DEBUG, | |
373 | "The mount_crypt_stat " | |
374 | "global_default_cipher_key_size " | |
375 | "set to: [%d]\n", mount_crypt_stat-> | |
376 | global_default_cipher_key_size); | |
377 | cipher_key_bytes_set = 1; | |
378 | break; | |
379 | case ecryptfs_opt_passthrough: | |
380 | mount_crypt_stat->flags |= | |
381 | ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; | |
382 | break; | |
17398957 MH |
383 | case ecryptfs_opt_xattr_metadata: |
384 | mount_crypt_stat->flags |= | |
385 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
386 | break; | |
387 | case ecryptfs_opt_encrypted_view: | |
388 | mount_crypt_stat->flags |= | |
389 | ECRYPTFS_XATTR_METADATA_ENABLED; | |
390 | mount_crypt_stat->flags |= | |
391 | ECRYPTFS_ENCRYPTED_VIEW_ENABLED; | |
392 | break; | |
237fead6 MH |
393 | case ecryptfs_opt_err: |
394 | default: | |
395 | ecryptfs_printk(KERN_WARNING, | |
396 | "eCryptfs: unrecognized option '%s'\n", | |
397 | p); | |
398 | } | |
399 | } | |
237fead6 MH |
400 | if (!sig_set) { |
401 | rc = -EINVAL; | |
956159c3 MH |
402 | ecryptfs_printk(KERN_ERR, "You must supply at least one valid " |
403 | "auth tok signature as a mount " | |
237fead6 MH |
404 | "parameter; see the eCryptfs README\n"); |
405 | goto out; | |
406 | } | |
407 | if (!cipher_name_set) { | |
408 | cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); | |
409 | if (unlikely(cipher_name_len | |
410 | >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) { | |
411 | rc = -EINVAL; | |
412 | BUG(); | |
413 | goto out; | |
414 | } | |
415 | memcpy(mount_crypt_stat->global_default_cipher_name, | |
416 | ECRYPTFS_DEFAULT_CIPHER, cipher_name_len); | |
417 | mount_crypt_stat->global_default_cipher_name[cipher_name_len] | |
418 | = '\0'; | |
419 | } | |
420 | if (!cipher_key_bytes_set) { | |
e5d9cbde | 421 | mount_crypt_stat->global_default_cipher_key_size = 0; |
237fead6 | 422 | } |
5dda6992 MH |
423 | rc = ecryptfs_add_new_key_tfm( |
424 | NULL, mount_crypt_stat->global_default_cipher_name, | |
425 | mount_crypt_stat->global_default_cipher_key_size); | |
426 | if (rc) { | |
f4aad16a | 427 | printk(KERN_ERR "Error attempting to initialize cipher with " |
81acbcd6 | 428 | "name = [%s] and key size = [%td]; rc = [%d]\n", |
237fead6 MH |
429 | mount_crypt_stat->global_default_cipher_name, |
430 | mount_crypt_stat->global_default_cipher_key_size, rc); | |
237fead6 MH |
431 | rc = -EINVAL; |
432 | goto out; | |
433 | } | |
5dda6992 MH |
434 | rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); |
435 | if (rc) { | |
f4aad16a MH |
436 | printk(KERN_WARNING "One or more global auth toks could not " |
437 | "properly register; rc = [%d]\n", rc); | |
237fead6 | 438 | } |
f4aad16a | 439 | rc = 0; |
237fead6 MH |
440 | out: |
441 | return rc; | |
442 | } | |
443 | ||
444 | struct kmem_cache *ecryptfs_sb_info_cache; | |
445 | ||
446 | /** | |
447 | * ecryptfs_fill_super | |
448 | * @sb: The ecryptfs super block | |
449 | * @raw_data: The options passed to mount | |
450 | * @silent: Not used but required by function prototype | |
451 | * | |
452 | * Sets up what we can of the sb, rest is done in ecryptfs_read_super | |
453 | * | |
454 | * Returns zero on success; non-zero otherwise | |
455 | */ | |
456 | static int | |
457 | ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) | |
458 | { | |
459 | int rc = 0; | |
460 | ||
461 | /* Released in ecryptfs_put_super() */ | |
462 | ecryptfs_set_superblock_private(sb, | |
c3762229 | 463 | kmem_cache_zalloc(ecryptfs_sb_info_cache, |
e94b1766 | 464 | GFP_KERNEL)); |
237fead6 MH |
465 | if (!ecryptfs_superblock_to_private(sb)) { |
466 | ecryptfs_printk(KERN_WARNING, "Out of memory\n"); | |
467 | rc = -ENOMEM; | |
468 | goto out; | |
469 | } | |
237fead6 MH |
470 | sb->s_op = &ecryptfs_sops; |
471 | /* Released through deactivate_super(sb) from get_sb_nodev */ | |
472 | sb->s_root = d_alloc(NULL, &(const struct qstr) { | |
473 | .hash = 0,.name = "/",.len = 1}); | |
474 | if (!sb->s_root) { | |
475 | ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); | |
476 | rc = -ENOMEM; | |
477 | goto out; | |
478 | } | |
479 | sb->s_root->d_op = &ecryptfs_dops; | |
480 | sb->s_root->d_sb = sb; | |
481 | sb->s_root->d_parent = sb->s_root; | |
482 | /* Released in d_release when dput(sb->s_root) is called */ | |
483 | /* through deactivate_super(sb) from get_sb_nodev() */ | |
484 | ecryptfs_set_dentry_private(sb->s_root, | |
c3762229 | 485 | kmem_cache_zalloc(ecryptfs_dentry_info_cache, |
e94b1766 | 486 | GFP_KERNEL)); |
237fead6 MH |
487 | if (!ecryptfs_dentry_to_private(sb->s_root)) { |
488 | ecryptfs_printk(KERN_ERR, | |
489 | "dentry_info_cache alloc failed\n"); | |
490 | rc = -ENOMEM; | |
491 | goto out; | |
492 | } | |
237fead6 MH |
493 | rc = 0; |
494 | out: | |
495 | /* Should be able to rely on deactivate_super called from | |
496 | * get_sb_nodev */ | |
497 | return rc; | |
498 | } | |
499 | ||
500 | /** | |
501 | * ecryptfs_read_super | |
502 | * @sb: The ecryptfs super block | |
503 | * @dev_name: The path to mount over | |
504 | * | |
505 | * Read the super block of the lower filesystem, and use | |
506 | * ecryptfs_interpose to create our initial inode and super block | |
507 | * struct. | |
508 | */ | |
509 | static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) | |
510 | { | |
511 | int rc; | |
512 | struct nameidata nd; | |
513 | struct dentry *lower_root; | |
514 | struct vfsmount *lower_mnt; | |
515 | ||
516 | memset(&nd, 0, sizeof(struct nameidata)); | |
82b16528 | 517 | rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd); |
237fead6 MH |
518 | if (rc) { |
519 | ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); | |
65dc8145 | 520 | goto out; |
237fead6 MH |
521 | } |
522 | lower_root = nd.dentry; | |
237fead6 MH |
523 | lower_mnt = nd.mnt; |
524 | ecryptfs_set_superblock_lower(sb, lower_root->d_sb); | |
525 | sb->s_maxbytes = lower_root->d_sb->s_maxbytes; | |
7c9e70ef | 526 | sb->s_blocksize = lower_root->d_sb->s_blocksize; |
237fead6 MH |
527 | ecryptfs_set_dentry_lower(sb->s_root, lower_root); |
528 | ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt); | |
5dda6992 MH |
529 | rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0); |
530 | if (rc) | |
237fead6 MH |
531 | goto out_free; |
532 | rc = 0; | |
533 | goto out; | |
534 | out_free: | |
535 | path_release(&nd); | |
536 | out: | |
537 | return rc; | |
538 | } | |
539 | ||
540 | /** | |
541 | * ecryptfs_get_sb | |
542 | * @fs_type | |
543 | * @flags | |
544 | * @dev_name: The path to mount over | |
545 | * @raw_data: The options passed into the kernel | |
546 | * | |
547 | * The whole ecryptfs_get_sb process is broken into 4 functions: | |
548 | * ecryptfs_parse_options(): handle options passed to ecryptfs, if any | |
549 | * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block | |
550 | * with as much information as it can before needing | |
551 | * the lower filesystem. | |
552 | * ecryptfs_read_super(): this accesses the lower filesystem and uses | |
553 | * ecryptfs_interpolate to perform most of the linking | |
554 | * ecryptfs_interpolate(): links the lower filesystem into ecryptfs | |
555 | */ | |
556 | static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, | |
557 | const char *dev_name, void *raw_data, | |
558 | struct vfsmount *mnt) | |
559 | { | |
560 | int rc; | |
561 | struct super_block *sb; | |
562 | ||
563 | rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); | |
564 | if (rc < 0) { | |
565 | printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); | |
566 | goto out; | |
567 | } | |
568 | sb = mnt->mnt_sb; | |
569 | rc = ecryptfs_parse_options(sb, raw_data); | |
570 | if (rc) { | |
571 | printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); | |
572 | goto out_abort; | |
573 | } | |
574 | rc = ecryptfs_read_super(sb, dev_name); | |
575 | if (rc) { | |
576 | printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); | |
577 | goto out_abort; | |
578 | } | |
579 | goto out; | |
580 | out_abort: | |
581 | dput(sb->s_root); | |
582 | up_write(&sb->s_umount); | |
583 | deactivate_super(sb); | |
584 | out: | |
585 | return rc; | |
586 | } | |
587 | ||
588 | /** | |
589 | * ecryptfs_kill_block_super | |
590 | * @sb: The ecryptfs super block | |
591 | * | |
592 | * Used to bring the superblock down and free the private data. | |
593 | * Private data is free'd in ecryptfs_put_super() | |
594 | */ | |
595 | static void ecryptfs_kill_block_super(struct super_block *sb) | |
596 | { | |
597 | generic_shutdown_super(sb); | |
598 | } | |
599 | ||
600 | static struct file_system_type ecryptfs_fs_type = { | |
601 | .owner = THIS_MODULE, | |
602 | .name = "ecryptfs", | |
603 | .get_sb = ecryptfs_get_sb, | |
604 | .kill_sb = ecryptfs_kill_block_super, | |
605 | .fs_flags = 0 | |
606 | }; | |
607 | ||
608 | /** | |
609 | * inode_info_init_once | |
610 | * | |
611 | * Initializes the ecryptfs_inode_info_cache when it is created | |
612 | */ | |
613 | static void | |
4ba9b9d0 | 614 | inode_info_init_once(struct kmem_cache *cachep, void *vptr) |
237fead6 MH |
615 | { |
616 | struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; | |
617 | ||
a35afb83 | 618 | inode_init_once(&ei->vfs_inode); |
237fead6 MH |
619 | } |
620 | ||
621 | static struct ecryptfs_cache_info { | |
e18b890b | 622 | struct kmem_cache **cache; |
237fead6 MH |
623 | const char *name; |
624 | size_t size; | |
4ba9b9d0 | 625 | void (*ctor)(struct kmem_cache *cache, void *obj); |
237fead6 MH |
626 | } ecryptfs_cache_infos[] = { |
627 | { | |
628 | .cache = &ecryptfs_auth_tok_list_item_cache, | |
629 | .name = "ecryptfs_auth_tok_list_item", | |
630 | .size = sizeof(struct ecryptfs_auth_tok_list_item), | |
631 | }, | |
632 | { | |
633 | .cache = &ecryptfs_file_info_cache, | |
634 | .name = "ecryptfs_file_cache", | |
635 | .size = sizeof(struct ecryptfs_file_info), | |
636 | }, | |
637 | { | |
638 | .cache = &ecryptfs_dentry_info_cache, | |
639 | .name = "ecryptfs_dentry_info_cache", | |
640 | .size = sizeof(struct ecryptfs_dentry_info), | |
641 | }, | |
642 | { | |
643 | .cache = &ecryptfs_inode_info_cache, | |
644 | .name = "ecryptfs_inode_cache", | |
645 | .size = sizeof(struct ecryptfs_inode_info), | |
646 | .ctor = inode_info_init_once, | |
647 | }, | |
648 | { | |
649 | .cache = &ecryptfs_sb_info_cache, | |
650 | .name = "ecryptfs_sb_cache", | |
651 | .size = sizeof(struct ecryptfs_sb_info), | |
652 | }, | |
653 | { | |
654 | .cache = &ecryptfs_header_cache_0, | |
655 | .name = "ecryptfs_headers_0", | |
656 | .size = PAGE_CACHE_SIZE, | |
657 | }, | |
658 | { | |
659 | .cache = &ecryptfs_header_cache_1, | |
660 | .name = "ecryptfs_headers_1", | |
661 | .size = PAGE_CACHE_SIZE, | |
662 | }, | |
663 | { | |
664 | .cache = &ecryptfs_header_cache_2, | |
665 | .name = "ecryptfs_headers_2", | |
666 | .size = PAGE_CACHE_SIZE, | |
667 | }, | |
dd2a3b7a MH |
668 | { |
669 | .cache = &ecryptfs_xattr_cache, | |
670 | .name = "ecryptfs_xattr_cache", | |
671 | .size = PAGE_CACHE_SIZE, | |
672 | }, | |
eb95e7ff MH |
673 | { |
674 | .cache = &ecryptfs_key_record_cache, | |
675 | .name = "ecryptfs_key_record_cache", | |
676 | .size = sizeof(struct ecryptfs_key_record), | |
677 | }, | |
956159c3 MH |
678 | { |
679 | .cache = &ecryptfs_key_sig_cache, | |
680 | .name = "ecryptfs_key_sig_cache", | |
681 | .size = sizeof(struct ecryptfs_key_sig), | |
682 | }, | |
683 | { | |
684 | .cache = &ecryptfs_global_auth_tok_cache, | |
685 | .name = "ecryptfs_global_auth_tok_cache", | |
686 | .size = sizeof(struct ecryptfs_global_auth_tok), | |
687 | }, | |
688 | { | |
689 | .cache = &ecryptfs_key_tfm_cache, | |
690 | .name = "ecryptfs_key_tfm_cache", | |
691 | .size = sizeof(struct ecryptfs_key_tfm), | |
692 | }, | |
237fead6 MH |
693 | }; |
694 | ||
695 | static void ecryptfs_free_kmem_caches(void) | |
696 | { | |
697 | int i; | |
698 | ||
699 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
700 | struct ecryptfs_cache_info *info; | |
701 | ||
702 | info = &ecryptfs_cache_infos[i]; | |
703 | if (*(info->cache)) | |
704 | kmem_cache_destroy(*(info->cache)); | |
705 | } | |
706 | } | |
707 | ||
708 | /** | |
709 | * ecryptfs_init_kmem_caches | |
710 | * | |
711 | * Returns zero on success; non-zero otherwise | |
712 | */ | |
713 | static int ecryptfs_init_kmem_caches(void) | |
714 | { | |
715 | int i; | |
716 | ||
717 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { | |
718 | struct ecryptfs_cache_info *info; | |
719 | ||
720 | info = &ecryptfs_cache_infos[i]; | |
721 | *(info->cache) = kmem_cache_create(info->name, info->size, | |
20c2df83 | 722 | 0, SLAB_HWCACHE_ALIGN, info->ctor); |
237fead6 MH |
723 | if (!*(info->cache)) { |
724 | ecryptfs_free_kmem_caches(); | |
725 | ecryptfs_printk(KERN_WARNING, "%s: " | |
726 | "kmem_cache_create failed\n", | |
727 | info->name); | |
728 | return -ENOMEM; | |
729 | } | |
730 | } | |
731 | return 0; | |
732 | } | |
733 | ||
734 | struct ecryptfs_obj { | |
735 | char *name; | |
736 | struct list_head slot_list; | |
737 | struct kobject kobj; | |
738 | }; | |
739 | ||
740 | struct ecryptfs_attribute { | |
741 | struct attribute attr; | |
742 | ssize_t(*show) (struct ecryptfs_obj *, char *); | |
743 | ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t); | |
744 | }; | |
745 | ||
746 | static ssize_t | |
747 | ecryptfs_attr_store(struct kobject *kobj, | |
748 | struct attribute *attr, const char *buf, size_t len) | |
749 | { | |
750 | struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, | |
751 | kobj); | |
752 | struct ecryptfs_attribute *attribute = | |
753 | container_of(attr, struct ecryptfs_attribute, attr); | |
754 | ||
755 | return (attribute->store ? attribute->store(obj, buf, len) : 0); | |
756 | } | |
757 | ||
758 | static ssize_t | |
759 | ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) | |
760 | { | |
761 | struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj, | |
762 | kobj); | |
763 | struct ecryptfs_attribute *attribute = | |
764 | container_of(attr, struct ecryptfs_attribute, attr); | |
765 | ||
766 | return (attribute->show ? attribute->show(obj, buf) : 0); | |
767 | } | |
768 | ||
769 | static struct sysfs_ops ecryptfs_sysfs_ops = { | |
770 | .show = ecryptfs_attr_show, | |
771 | .store = ecryptfs_attr_store | |
772 | }; | |
773 | ||
774 | static struct kobj_type ecryptfs_ktype = { | |
775 | .sysfs_ops = &ecryptfs_sysfs_ops | |
776 | }; | |
777 | ||
778 | static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL); | |
779 | ||
780 | static ssize_t version_show(struct ecryptfs_obj *obj, char *buff) | |
781 | { | |
782 | return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); | |
783 | } | |
784 | ||
785 | static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version); | |
786 | ||
8487f2e4 | 787 | static struct ecryptfs_version_str_map_elem { |
237fead6 MH |
788 | u32 flag; |
789 | char *str; | |
790 | } ecryptfs_version_str_map[] = { | |
791 | {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"}, | |
792 | {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"}, | |
793 | {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"}, | |
17398957 | 794 | {ECRYPTFS_VERSIONING_POLICY, "policy"}, |
956159c3 MH |
795 | {ECRYPTFS_VERSIONING_XATTR, "metadata in extended attribute"}, |
796 | {ECRYPTFS_VERSIONING_MULTKEY, "multiple keys per file"} | |
237fead6 MH |
797 | }; |
798 | ||
799 | static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff) | |
800 | { | |
801 | int i; | |
802 | int remaining = PAGE_SIZE; | |
803 | int total_written = 0; | |
804 | ||
805 | buff[0] = '\0'; | |
806 | for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) { | |
807 | int entry_size; | |
808 | ||
809 | if (!(ECRYPTFS_VERSIONING_MASK | |
810 | & ecryptfs_version_str_map[i].flag)) | |
811 | continue; | |
812 | entry_size = strlen(ecryptfs_version_str_map[i].str); | |
813 | if ((entry_size + 2) > remaining) | |
814 | goto out; | |
815 | memcpy(buff, ecryptfs_version_str_map[i].str, entry_size); | |
816 | buff[entry_size++] = '\n'; | |
817 | buff[entry_size] = '\0'; | |
818 | buff += entry_size; | |
819 | total_written += entry_size; | |
820 | remaining -= entry_size; | |
821 | } | |
822 | out: | |
823 | return total_written; | |
824 | } | |
825 | ||
826 | static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str); | |
827 | ||
828 | static int do_sysfs_registration(void) | |
829 | { | |
830 | int rc; | |
831 | ||
5dda6992 MH |
832 | rc = subsystem_register(&ecryptfs_subsys); |
833 | if (rc) { | |
237fead6 MH |
834 | printk(KERN_ERR |
835 | "Unable to register ecryptfs sysfs subsystem\n"); | |
836 | goto out; | |
837 | } | |
823bccfc | 838 | rc = sysfs_create_file(&ecryptfs_subsys.kobj, |
237fead6 MH |
839 | &sysfs_attr_version.attr); |
840 | if (rc) { | |
841 | printk(KERN_ERR | |
842 | "Unable to create ecryptfs version attribute\n"); | |
843 | subsystem_unregister(&ecryptfs_subsys); | |
844 | goto out; | |
845 | } | |
823bccfc | 846 | rc = sysfs_create_file(&ecryptfs_subsys.kobj, |
237fead6 MH |
847 | &sysfs_attr_version_str.attr); |
848 | if (rc) { | |
849 | printk(KERN_ERR | |
850 | "Unable to create ecryptfs version_str attribute\n"); | |
823bccfc | 851 | sysfs_remove_file(&ecryptfs_subsys.kobj, |
237fead6 MH |
852 | &sysfs_attr_version.attr); |
853 | subsystem_unregister(&ecryptfs_subsys); | |
854 | goto out; | |
855 | } | |
856 | out: | |
857 | return rc; | |
858 | } | |
859 | ||
a75de1b3 RK |
860 | static void do_sysfs_unregistration(void) |
861 | { | |
862 | sysfs_remove_file(&ecryptfs_subsys.kobj, | |
863 | &sysfs_attr_version.attr); | |
864 | sysfs_remove_file(&ecryptfs_subsys.kobj, | |
865 | &sysfs_attr_version_str.attr); | |
866 | subsystem_unregister(&ecryptfs_subsys); | |
867 | } | |
868 | ||
237fead6 MH |
869 | static int __init ecryptfs_init(void) |
870 | { | |
871 | int rc; | |
872 | ||
873 | if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) { | |
874 | rc = -EINVAL; | |
875 | ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " | |
876 | "larger than the host's page size, and so " | |
877 | "eCryptfs cannot run on this system. The " | |
878 | "default eCryptfs extent size is [%d] bytes; " | |
879 | "the page size is [%d] bytes.\n", | |
880 | ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE); | |
881 | goto out; | |
882 | } | |
883 | rc = ecryptfs_init_kmem_caches(); | |
884 | if (rc) { | |
885 | printk(KERN_ERR | |
886 | "Failed to allocate one or more kmem_cache objects\n"); | |
887 | goto out; | |
888 | } | |
889 | rc = register_filesystem(&ecryptfs_fs_type); | |
890 | if (rc) { | |
891 | printk(KERN_ERR "Failed to register filesystem\n"); | |
cf81f89d | 892 | goto out_free_kmem_caches; |
237fead6 | 893 | } |
823bccfc | 894 | kobj_set_kset_s(&ecryptfs_subsys, fs_subsys); |
237fead6 MH |
895 | rc = do_sysfs_registration(); |
896 | if (rc) { | |
897 | printk(KERN_ERR "sysfs registration failed\n"); | |
cf81f89d | 898 | goto out_unregister_filesystem; |
237fead6 | 899 | } |
dddfa461 MH |
900 | rc = ecryptfs_init_messaging(ecryptfs_transport); |
901 | if (rc) { | |
902 | ecryptfs_printk(KERN_ERR, "Failure occured while attempting to " | |
903 | "initialize the eCryptfs netlink socket\n"); | |
cf81f89d | 904 | goto out_do_sysfs_unregistration; |
956159c3 MH |
905 | } |
906 | rc = ecryptfs_init_crypto(); | |
907 | if (rc) { | |
908 | printk(KERN_ERR "Failure whilst attempting to init crypto; " | |
909 | "rc = [%d]\n", rc); | |
cf81f89d | 910 | goto out_release_messaging; |
dddfa461 | 911 | } |
cf81f89d MH |
912 | goto out; |
913 | out_release_messaging: | |
914 | ecryptfs_release_messaging(ecryptfs_transport); | |
915 | out_do_sysfs_unregistration: | |
916 | do_sysfs_unregistration(); | |
917 | out_unregister_filesystem: | |
918 | unregister_filesystem(&ecryptfs_fs_type); | |
919 | out_free_kmem_caches: | |
920 | ecryptfs_free_kmem_caches(); | |
237fead6 MH |
921 | out: |
922 | return rc; | |
923 | } | |
924 | ||
925 | static void __exit ecryptfs_exit(void) | |
926 | { | |
cf81f89d MH |
927 | int rc; |
928 | ||
929 | rc = ecryptfs_destroy_crypto(); | |
930 | if (rc) | |
931 | printk(KERN_ERR "Failure whilst attempting to destroy crypto; " | |
932 | "rc = [%d]\n", rc); | |
dddfa461 | 933 | ecryptfs_release_messaging(ecryptfs_transport); |
cf81f89d | 934 | do_sysfs_unregistration(); |
237fead6 MH |
935 | unregister_filesystem(&ecryptfs_fs_type); |
936 | ecryptfs_free_kmem_caches(); | |
937 | } | |
938 | ||
939 | MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>"); | |
940 | MODULE_DESCRIPTION("eCryptfs"); | |
941 | ||
942 | MODULE_LICENSE("GPL"); | |
943 | ||
944 | module_init(ecryptfs_init) | |
945 | module_exit(ecryptfs_exit) |