blob: 101fe4c7b1ee6db074eecdd56adf459736c271c3 [file] [log] [blame]
Michael Halcrow237fead2006-10-04 02:16:22 -07001/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2003 Erez Zadok
5 * Copyright (C) 2001-2003 Stony Brook University
Michael Halcrowdd2a3b72007-02-12 00:53:46 -08006 * Copyright (C) 2004-2007 International Business Machines Corp.
Michael Halcrow237fead2006-10-04 02:16:22 -07007 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompson <mcthomps@us.ibm.com>
Michael Halcrowdddfa462007-02-12 00:53:44 -08009 * Tyler Hicks <tyhicks@ou.edu>
Michael Halcrow237fead2006-10-04 02:16:22 -070010 *
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>
Michael Halcrow237fead2006-10-04 02:16:22 -070033#include <linux/mount.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070034#include <linux/pagemap.h>
35#include <linux/key.h>
36#include <linux/parser.h>
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -080037#include <linux/fs_stack.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070038#include "ecryptfs_kernel.h"
39
40/**
41 * Module parameter that defines the ecryptfs_verbosity level.
42 */
43int ecryptfs_verbosity = 0;
44
45module_param(ecryptfs_verbosity, int, 0);
46MODULE_PARM_DESC(ecryptfs_verbosity,
47 "Initial verbosity level (0 or 1; defaults to "
48 "0, which is Quiet)");
49
Michael Halcrowdddfa462007-02-12 00:53:44 -080050/**
Tyler Hicks624ae522008-10-15 22:02:51 -070051 * Module parameter that defines the number of message buffer elements
Michael Halcrowdddfa462007-02-12 00:53:44 -080052 */
53unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
54
55module_param(ecryptfs_message_buf_len, uint, 0);
56MODULE_PARM_DESC(ecryptfs_message_buf_len,
57 "Number of message buffer elements");
58
59/**
60 * Module parameter that defines the maximum guaranteed amount of time to wait
Tyler Hicks624ae522008-10-15 22:02:51 -070061 * for a response from ecryptfsd. The actual sleep time will be, more than
Michael Halcrowdddfa462007-02-12 00:53:44 -080062 * likely, a small amount greater than this specified value, but only less if
Tyler Hicks624ae522008-10-15 22:02:51 -070063 * the message successfully arrives.
Michael Halcrowdddfa462007-02-12 00:53:44 -080064 */
65signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
66
67module_param(ecryptfs_message_wait_timeout, long, 0);
68MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
69 "Maximum number of seconds that an operation will "
70 "sleep while waiting for a message response from "
71 "userspace");
72
73/**
74 * Module parameter that is an estimate of the maximum number of users
75 * that will be concurrently using eCryptfs. Set this to the right
76 * value to balance performance and memory use.
77 */
78unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
79
80module_param(ecryptfs_number_of_users, uint, 0);
81MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
82 "concurrent users of eCryptfs");
83
Michael Halcrow237fead2006-10-04 02:16:22 -070084void __ecryptfs_printk(const char *fmt, ...)
85{
86 va_list args;
87 va_start(args, fmt);
88 if (fmt[1] == '7') { /* KERN_DEBUG */
89 if (ecryptfs_verbosity >= 1)
90 vprintk(fmt, args);
91 } else
92 vprintk(fmt, args);
93 va_end(args);
94}
95
96/**
Michael Halcrow4981e082007-10-16 01:28:09 -070097 * ecryptfs_init_persistent_file
98 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
99 * the lower dentry and the lower mount set
100 *
101 * eCryptfs only ever keeps a single open file for every lower
102 * inode. All I/O operations to the lower inode occur through that
103 * file. When the first eCryptfs dentry that interposes with the first
104 * lower dentry for that inode is created, this function creates the
105 * persistent file struct and associates it with the eCryptfs
106 * inode. When the eCryptfs inode is destroyed, the file is closed.
107 *
108 * The persistent file will be opened with read/write permissions, if
109 * possible. Otherwise, it is opened read-only.
110 *
111 * This function does nothing if a lower persistent file is already
112 * associated with the eCryptfs inode.
113 *
114 * Returns zero on success; non-zero otherwise
115 */
Michael Halcrow72b55ff2008-07-23 21:30:07 -0700116int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
Michael Halcrow4981e082007-10-16 01:28:09 -0700117{
David Howells745ca242008-11-14 10:39:22 +1100118 const struct cred *cred = current_cred();
Michael Halcrow4981e082007-10-16 01:28:09 -0700119 struct ecryptfs_inode_info *inode_info =
120 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
121 int rc = 0;
122
123 mutex_lock(&inode_info->lower_file_mutex);
124 if (!inode_info->lower_file) {
125 struct dentry *lower_dentry;
126 struct vfsmount *lower_mnt =
127 ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
128
129 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
Michael Halcrow746f1e52008-07-23 21:30:02 -0700130 rc = ecryptfs_privileged_open(&inode_info->lower_file,
David Howells745ca242008-11-14 10:39:22 +1100131 lower_dentry, lower_mnt, cred);
Tyler Hicksac22ba22009-08-12 01:06:54 -0500132 if (rc) {
Michael Halcrow4981e082007-10-16 01:28:09 -0700133 printk(KERN_ERR "Error opening lower persistent file "
Michael Halcrow746f1e52008-07-23 21:30:02 -0700134 "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
135 "rc = [%d]\n", lower_dentry, lower_mnt, rc);
Michael Halcrow4981e082007-10-16 01:28:09 -0700136 inode_info->lower_file = NULL;
137 }
138 }
139 mutex_unlock(&inode_info->lower_file_mutex);
140 return rc;
141}
142
143/**
Michael Halcrow237fead2006-10-04 02:16:22 -0700144 * ecryptfs_interpose
145 * @lower_dentry: Existing dentry in the lower filesystem
146 * @dentry: ecryptfs' dentry
147 * @sb: ecryptfs's super_block
Michael Halcrow72b55ff2008-07-23 21:30:07 -0700148 * @flags: flags to govern behavior of interpose procedure
Michael Halcrow237fead2006-10-04 02:16:22 -0700149 *
150 * Interposes upper and lower dentries.
151 *
152 * Returns zero on success; non-zero otherwise
153 */
154int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
Michael Halcrow72b55ff2008-07-23 21:30:07 -0700155 struct super_block *sb, u32 flags)
Michael Halcrow237fead2006-10-04 02:16:22 -0700156{
157 struct inode *lower_inode;
158 struct inode *inode;
159 int rc = 0;
160
161 lower_inode = lower_dentry->d_inode;
162 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
163 rc = -EXDEV;
164 goto out;
165 }
166 if (!igrab(lower_inode)) {
167 rc = -ESTALE;
168 goto out;
169 }
170 inode = iget5_locked(sb, (unsigned long)lower_inode,
171 ecryptfs_inode_test, ecryptfs_inode_set,
172 lower_inode);
173 if (!inode) {
174 rc = -EACCES;
175 iput(lower_inode);
176 goto out;
177 }
178 if (inode->i_state & I_NEW)
179 unlock_new_inode(inode);
180 else
181 iput(lower_inode);
182 if (S_ISLNK(lower_inode->i_mode))
183 inode->i_op = &ecryptfs_symlink_iops;
184 else if (S_ISDIR(lower_inode->i_mode))
185 inode->i_op = &ecryptfs_dir_iops;
186 if (S_ISDIR(lower_inode->i_mode))
187 inode->i_fop = &ecryptfs_dir_fops;
Pekka Enberg26da8202006-10-19 23:28:14 -0700188 if (special_file(lower_inode->i_mode))
Michael Halcrow237fead2006-10-04 02:16:22 -0700189 init_special_inode(inode, lower_inode->i_mode,
190 lower_inode->i_rdev);
191 dentry->d_op = &ecryptfs_dops;
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800192 fsstack_copy_attr_all(inode, lower_inode, NULL);
Michael Halcrow237fead2006-10-04 02:16:22 -0700193 /* This size will be overwritten for real files w/ headers and
194 * other metadata */
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -0800195 fsstack_copy_inode_size(inode, lower_inode);
Tyler Hicksae6e8452009-03-12 00:19:46 -0500196 if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
197 d_add(dentry, inode);
198 else
199 d_instantiate(dentry, inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700200out:
201 return rc;
202}
203
Eric Sandeen2830bfd2008-02-06 01:38:34 -0800204enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
205 ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
206 ecryptfs_opt_ecryptfs_key_bytes,
Michael Halcrow17398952007-02-12 00:53:45 -0800207 ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
Michael Halcrow87c94c42009-01-06 14:42:01 -0800208 ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig,
209 ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes,
Tyler Hickse77cc8d2009-04-22 04:08:46 -0500210 ecryptfs_opt_unlink_sigs, ecryptfs_opt_err };
Michael Halcrow237fead2006-10-04 02:16:22 -0700211
Steven Whitehousea447c092008-10-13 10:46:57 +0100212static const match_table_t tokens = {
Michael Halcrow237fead2006-10-04 02:16:22 -0700213 {ecryptfs_opt_sig, "sig=%s"},
214 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
Michael Halcrow237fead2006-10-04 02:16:22 -0700215 {ecryptfs_opt_cipher, "cipher=%s"},
216 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
217 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
218 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
Michael Halcrow17398952007-02-12 00:53:45 -0800219 {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
220 {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
Michael Halcrow87c94c42009-01-06 14:42:01 -0800221 {ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"},
222 {ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"},
223 {ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"},
Tyler Hickse77cc8d2009-04-22 04:08:46 -0500224 {ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"},
Michael Halcrow237fead2006-10-04 02:16:22 -0700225 {ecryptfs_opt_err, NULL}
226};
227
Michael Halcrowf4aad162007-10-16 01:27:53 -0700228static int ecryptfs_init_global_auth_toks(
229 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -0700230{
Michael Halcrowf4aad162007-10-16 01:27:53 -0700231 struct ecryptfs_global_auth_tok *global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -0700232 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700233
Michael Halcrowf4aad162007-10-16 01:27:53 -0700234 list_for_each_entry(global_auth_tok,
235 &mount_crypt_stat->global_auth_tok_list,
236 mount_crypt_stat_list) {
Michael Halcrow5dda6992007-10-16 01:28:06 -0700237 rc = ecryptfs_keyring_auth_tok_for_sig(
238 &global_auth_tok->global_auth_tok_key,
239 &global_auth_tok->global_auth_tok,
240 global_auth_tok->sig);
241 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -0700242 printk(KERN_ERR "Could not find valid key in user "
243 "session keyring for sig specified in mount "
244 "option: [%s]\n", global_auth_tok->sig);
245 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
Eric Sandeen982363c2008-07-23 21:30:04 -0700246 goto out;
Michael Halcrowf4aad162007-10-16 01:27:53 -0700247 } else
248 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
Michael Halcrow237fead2006-10-04 02:16:22 -0700249 }
Eric Sandeen982363c2008-07-23 21:30:04 -0700250out:
Michael Halcrow237fead2006-10-04 02:16:22 -0700251 return rc;
252}
253
Michael Halcrowf4aad162007-10-16 01:27:53 -0700254static void ecryptfs_init_mount_crypt_stat(
255 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
256{
257 memset((void *)mount_crypt_stat, 0,
258 sizeof(struct ecryptfs_mount_crypt_stat));
259 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
260 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
261 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
262}
263
Michael Halcrow237fead2006-10-04 02:16:22 -0700264/**
265 * ecryptfs_parse_options
266 * @sb: The ecryptfs super block
267 * @options: The options pased to the kernel
268 *
269 * Parse mount options:
270 * debug=N - ecryptfs_verbosity level for debug output
271 * sig=XXX - description(signature) of the key to use
272 *
273 * Returns the dentry object of the lower-level (lower/interposed)
274 * directory; We want to mount our stackable file system on top of
275 * that lower directory.
276 *
277 * The signature of the key to use must be the description of a key
278 * already in the keyring. Mounting will fail if the key can not be
279 * found.
280 *
281 * Returns zero on success; non-zero on error
282 */
283static int ecryptfs_parse_options(struct super_block *sb, char *options)
284{
285 char *p;
286 int rc = 0;
287 int sig_set = 0;
288 int cipher_name_set = 0;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800289 int fn_cipher_name_set = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700290 int cipher_key_bytes;
291 int cipher_key_bytes_set = 0;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800292 int fn_cipher_key_bytes;
293 int fn_cipher_key_bytes_set = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -0700294 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
295 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
296 substring_t args[MAX_OPT_ARGS];
297 int token;
298 char *sig_src;
Michael Halcrow237fead2006-10-04 02:16:22 -0700299 char *cipher_name_dst;
300 char *cipher_name_src;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800301 char *fn_cipher_name_dst;
302 char *fn_cipher_name_src;
303 char *fnek_dst;
304 char *fnek_src;
Michael Halcrow237fead2006-10-04 02:16:22 -0700305 char *cipher_key_bytes_src;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800306 char *fn_cipher_key_bytes_src;
Michael Halcrow237fead2006-10-04 02:16:22 -0700307
308 if (!options) {
309 rc = -EINVAL;
310 goto out;
311 }
Michael Halcrow956159c2007-10-16 01:27:55 -0700312 ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -0700313 while ((p = strsep(&options, ",")) != NULL) {
314 if (!*p)
315 continue;
316 token = match_token(p, tokens, args);
317 switch (token) {
318 case ecryptfs_opt_sig:
319 case ecryptfs_opt_ecryptfs_sig:
320 sig_src = args[0].from;
Michael Halcrowf4aad162007-10-16 01:27:53 -0700321 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -0700322 sig_src, 0);
Michael Halcrowf4aad162007-10-16 01:27:53 -0700323 if (rc) {
324 printk(KERN_ERR "Error attempting to register "
325 "global sig; rc = [%d]\n", rc);
326 goto out;
327 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700328 sig_set = 1;
329 break;
Michael Halcrow237fead2006-10-04 02:16:22 -0700330 case ecryptfs_opt_cipher:
331 case ecryptfs_opt_ecryptfs_cipher:
332 cipher_name_src = args[0].from;
333 cipher_name_dst =
334 mount_crypt_stat->
335 global_default_cipher_name;
336 strncpy(cipher_name_dst, cipher_name_src,
337 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
Michael Halcrow87c94c42009-01-06 14:42:01 -0800338 cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
Michael Halcrow237fead2006-10-04 02:16:22 -0700339 cipher_name_set = 1;
340 break;
341 case ecryptfs_opt_ecryptfs_key_bytes:
342 cipher_key_bytes_src = args[0].from;
343 cipher_key_bytes =
344 (int)simple_strtol(cipher_key_bytes_src,
345 &cipher_key_bytes_src, 0);
346 mount_crypt_stat->global_default_cipher_key_size =
347 cipher_key_bytes;
Michael Halcrow237fead2006-10-04 02:16:22 -0700348 cipher_key_bytes_set = 1;
349 break;
350 case ecryptfs_opt_passthrough:
351 mount_crypt_stat->flags |=
352 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
353 break;
Michael Halcrow17398952007-02-12 00:53:45 -0800354 case ecryptfs_opt_xattr_metadata:
355 mount_crypt_stat->flags |=
356 ECRYPTFS_XATTR_METADATA_ENABLED;
357 break;
358 case ecryptfs_opt_encrypted_view:
359 mount_crypt_stat->flags |=
360 ECRYPTFS_XATTR_METADATA_ENABLED;
361 mount_crypt_stat->flags |=
362 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
363 break;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800364 case ecryptfs_opt_fnek_sig:
365 fnek_src = args[0].from;
366 fnek_dst =
367 mount_crypt_stat->global_default_fnek_sig;
368 strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
369 mount_crypt_stat->global_default_fnek_sig[
370 ECRYPTFS_SIG_SIZE_HEX] = '\0';
371 rc = ecryptfs_add_global_auth_tok(
372 mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -0700373 mount_crypt_stat->global_default_fnek_sig,
374 ECRYPTFS_AUTH_TOK_FNEK);
Michael Halcrow87c94c42009-01-06 14:42:01 -0800375 if (rc) {
376 printk(KERN_ERR "Error attempting to register "
377 "global fnek sig [%s]; rc = [%d]\n",
378 mount_crypt_stat->global_default_fnek_sig,
379 rc);
380 goto out;
381 }
382 mount_crypt_stat->flags |=
383 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
384 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
385 break;
386 case ecryptfs_opt_fn_cipher:
387 fn_cipher_name_src = args[0].from;
388 fn_cipher_name_dst =
389 mount_crypt_stat->global_default_fn_cipher_name;
390 strncpy(fn_cipher_name_dst, fn_cipher_name_src,
391 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
392 mount_crypt_stat->global_default_fn_cipher_name[
393 ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
394 fn_cipher_name_set = 1;
395 break;
396 case ecryptfs_opt_fn_cipher_key_bytes:
397 fn_cipher_key_bytes_src = args[0].from;
398 fn_cipher_key_bytes =
399 (int)simple_strtol(fn_cipher_key_bytes_src,
400 &fn_cipher_key_bytes_src, 0);
401 mount_crypt_stat->global_default_fn_cipher_key_bytes =
402 fn_cipher_key_bytes;
403 fn_cipher_key_bytes_set = 1;
404 break;
Tyler Hickse77cc8d2009-04-22 04:08:46 -0500405 case ecryptfs_opt_unlink_sigs:
406 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
407 break;
Michael Halcrow237fead2006-10-04 02:16:22 -0700408 case ecryptfs_opt_err:
409 default:
Michael Halcrow87c94c42009-01-06 14:42:01 -0800410 printk(KERN_WARNING
411 "%s: eCryptfs: unrecognized option [%s]\n",
412 __func__, p);
Michael Halcrow237fead2006-10-04 02:16:22 -0700413 }
414 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700415 if (!sig_set) {
416 rc = -EINVAL;
Michael Halcrow956159c2007-10-16 01:27:55 -0700417 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
418 "auth tok signature as a mount "
Michael Halcrow237fead2006-10-04 02:16:22 -0700419 "parameter; see the eCryptfs README\n");
420 goto out;
421 }
422 if (!cipher_name_set) {
Miklos Szeredi8f236802008-07-23 21:30:05 -0700423 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
424
425 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
Miklos Szeredi8f236802008-07-23 21:30:05 -0700426 strcpy(mount_crypt_stat->global_default_cipher_name,
427 ECRYPTFS_DEFAULT_CIPHER);
Michael Halcrow237fead2006-10-04 02:16:22 -0700428 }
Michael Halcrow87c94c42009-01-06 14:42:01 -0800429 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
430 && !fn_cipher_name_set)
431 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
432 mount_crypt_stat->global_default_cipher_name);
433 if (!cipher_key_bytes_set)
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -0800434 mount_crypt_stat->global_default_cipher_key_size = 0;
Michael Halcrow87c94c42009-01-06 14:42:01 -0800435 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
436 && !fn_cipher_key_bytes_set)
437 mount_crypt_stat->global_default_fn_cipher_key_bytes =
438 mount_crypt_stat->global_default_cipher_key_size;
Eric Sandeenaf440f52008-02-06 01:38:37 -0800439 mutex_lock(&key_tfm_list_mutex);
440 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
Michael Halcrow87c94c42009-01-06 14:42:01 -0800441 NULL)) {
Eric Sandeenaf440f52008-02-06 01:38:37 -0800442 rc = ecryptfs_add_new_key_tfm(
443 NULL, mount_crypt_stat->global_default_cipher_name,
444 mount_crypt_stat->global_default_cipher_key_size);
Michael Halcrow87c94c42009-01-06 14:42:01 -0800445 if (rc) {
446 printk(KERN_ERR "Error attempting to initialize "
447 "cipher with name = [%s] and key size = [%td]; "
448 "rc = [%d]\n",
449 mount_crypt_stat->global_default_cipher_name,
450 mount_crypt_stat->global_default_cipher_key_size,
451 rc);
452 rc = -EINVAL;
453 mutex_unlock(&key_tfm_list_mutex);
454 goto out;
455 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700456 }
Michael Halcrow87c94c42009-01-06 14:42:01 -0800457 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
458 && !ecryptfs_tfm_exists(
459 mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
460 rc = ecryptfs_add_new_key_tfm(
461 NULL, mount_crypt_stat->global_default_fn_cipher_name,
462 mount_crypt_stat->global_default_fn_cipher_key_bytes);
463 if (rc) {
464 printk(KERN_ERR "Error attempting to initialize "
465 "cipher with name = [%s] and key size = [%td]; "
466 "rc = [%d]\n",
467 mount_crypt_stat->global_default_fn_cipher_name,
468 mount_crypt_stat->global_default_fn_cipher_key_bytes,
469 rc);
470 rc = -EINVAL;
471 mutex_unlock(&key_tfm_list_mutex);
472 goto out;
473 }
474 }
475 mutex_unlock(&key_tfm_list_mutex);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700476 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
Michael Halcrow87c94c42009-01-06 14:42:01 -0800477 if (rc)
Michael Halcrowf4aad162007-10-16 01:27:53 -0700478 printk(KERN_WARNING "One or more global auth toks could not "
479 "properly register; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -0700480out:
481 return rc;
482}
483
484struct kmem_cache *ecryptfs_sb_info_cache;
485
486/**
487 * ecryptfs_fill_super
488 * @sb: The ecryptfs super block
489 * @raw_data: The options passed to mount
490 * @silent: Not used but required by function prototype
491 *
492 * Sets up what we can of the sb, rest is done in ecryptfs_read_super
493 *
494 * Returns zero on success; non-zero otherwise
495 */
496static int
497ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
498{
499 int rc = 0;
500
501 /* Released in ecryptfs_put_super() */
502 ecryptfs_set_superblock_private(sb,
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800503 kmem_cache_zalloc(ecryptfs_sb_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800504 GFP_KERNEL));
Michael Halcrow237fead2006-10-04 02:16:22 -0700505 if (!ecryptfs_superblock_to_private(sb)) {
506 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
507 rc = -ENOMEM;
508 goto out;
509 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700510 sb->s_op = &ecryptfs_sops;
511 /* Released through deactivate_super(sb) from get_sb_nodev */
512 sb->s_root = d_alloc(NULL, &(const struct qstr) {
513 .hash = 0,.name = "/",.len = 1});
514 if (!sb->s_root) {
515 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
516 rc = -ENOMEM;
517 goto out;
518 }
519 sb->s_root->d_op = &ecryptfs_dops;
520 sb->s_root->d_sb = sb;
521 sb->s_root->d_parent = sb->s_root;
522 /* Released in d_release when dput(sb->s_root) is called */
523 /* through deactivate_super(sb) from get_sb_nodev() */
524 ecryptfs_set_dentry_private(sb->s_root,
Robert P. J. Dayc3762222007-02-10 01:45:03 -0800525 kmem_cache_zalloc(ecryptfs_dentry_info_cache,
Christoph Lametere94b1762006-12-06 20:33:17 -0800526 GFP_KERNEL));
Michael Halcrow237fead2006-10-04 02:16:22 -0700527 if (!ecryptfs_dentry_to_private(sb->s_root)) {
528 ecryptfs_printk(KERN_ERR,
529 "dentry_info_cache alloc failed\n");
530 rc = -ENOMEM;
531 goto out;
532 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700533 rc = 0;
534out:
535 /* Should be able to rely on deactivate_super called from
536 * get_sb_nodev */
537 return rc;
538}
539
540/**
541 * ecryptfs_read_super
542 * @sb: The ecryptfs super block
543 * @dev_name: The path to mount over
544 *
545 * Read the super block of the lower filesystem, and use
546 * ecryptfs_interpose to create our initial inode and super block
547 * struct.
548 */
549static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
550{
Al Viro421748e2008-08-02 01:04:36 -0400551 struct path path;
Michael Halcrow237fead2006-10-04 02:16:22 -0700552 int rc;
Michael Halcrow237fead2006-10-04 02:16:22 -0700553
Al Viro421748e2008-08-02 01:04:36 -0400554 rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
Michael Halcrow237fead2006-10-04 02:16:22 -0700555 if (rc) {
556 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
Michael Halcrow65dc8142007-02-28 20:12:57 -0800557 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -0700558 }
Al Viro421748e2008-08-02 01:04:36 -0400559 ecryptfs_set_superblock_lower(sb, path.dentry->d_sb);
560 sb->s_maxbytes = path.dentry->d_sb->s_maxbytes;
561 sb->s_blocksize = path.dentry->d_sb->s_blocksize;
562 ecryptfs_set_dentry_lower(sb->s_root, path.dentry);
563 ecryptfs_set_dentry_lower_mnt(sb->s_root, path.mnt);
564 rc = ecryptfs_interpose(path.dentry, sb->s_root, sb, 0);
Michael Halcrow5dda6992007-10-16 01:28:06 -0700565 if (rc)
Michael Halcrow237fead2006-10-04 02:16:22 -0700566 goto out_free;
567 rc = 0;
568 goto out;
569out_free:
Al Viro421748e2008-08-02 01:04:36 -0400570 path_put(&path);
Michael Halcrow237fead2006-10-04 02:16:22 -0700571out:
572 return rc;
573}
574
575/**
576 * ecryptfs_get_sb
577 * @fs_type
578 * @flags
579 * @dev_name: The path to mount over
580 * @raw_data: The options passed into the kernel
581 *
582 * The whole ecryptfs_get_sb process is broken into 4 functions:
583 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
584 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
585 * with as much information as it can before needing
586 * the lower filesystem.
587 * ecryptfs_read_super(): this accesses the lower filesystem and uses
588 * ecryptfs_interpolate to perform most of the linking
589 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
590 */
591static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
592 const char *dev_name, void *raw_data,
593 struct vfsmount *mnt)
594{
595 int rc;
596 struct super_block *sb;
597
598 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
599 if (rc < 0) {
600 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
601 goto out;
602 }
603 sb = mnt->mnt_sb;
604 rc = ecryptfs_parse_options(sb, raw_data);
605 if (rc) {
606 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
607 goto out_abort;
608 }
609 rc = ecryptfs_read_super(sb, dev_name);
610 if (rc) {
611 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
612 goto out_abort;
613 }
614 goto out;
615out_abort:
Al Viro6f5bbff2009-05-06 01:34:22 -0400616 dput(sb->s_root); /* aka mnt->mnt_root, as set by get_sb_nodev() */
617 deactivate_locked_super(sb);
Michael Halcrow237fead2006-10-04 02:16:22 -0700618out:
619 return rc;
620}
621
622/**
623 * ecryptfs_kill_block_super
624 * @sb: The ecryptfs super block
625 *
626 * Used to bring the superblock down and free the private data.
627 * Private data is free'd in ecryptfs_put_super()
628 */
629static void ecryptfs_kill_block_super(struct super_block *sb)
630{
631 generic_shutdown_super(sb);
632}
633
634static struct file_system_type ecryptfs_fs_type = {
635 .owner = THIS_MODULE,
636 .name = "ecryptfs",
637 .get_sb = ecryptfs_get_sb,
638 .kill_sb = ecryptfs_kill_block_super,
639 .fs_flags = 0
640};
641
642/**
643 * inode_info_init_once
644 *
645 * Initializes the ecryptfs_inode_info_cache when it is created
646 */
647static void
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700648inode_info_init_once(void *vptr)
Michael Halcrow237fead2006-10-04 02:16:22 -0700649{
650 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
651
Christoph Lametera35afb82007-05-16 22:10:57 -0700652 inode_init_once(&ei->vfs_inode);
Michael Halcrow237fead2006-10-04 02:16:22 -0700653}
654
655static struct ecryptfs_cache_info {
Christoph Lametere18b8902006-12-06 20:33:20 -0800656 struct kmem_cache **cache;
Michael Halcrow237fead2006-10-04 02:16:22 -0700657 const char *name;
658 size_t size;
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700659 void (*ctor)(void *obj);
Michael Halcrow237fead2006-10-04 02:16:22 -0700660} ecryptfs_cache_infos[] = {
661 {
662 .cache = &ecryptfs_auth_tok_list_item_cache,
663 .name = "ecryptfs_auth_tok_list_item",
664 .size = sizeof(struct ecryptfs_auth_tok_list_item),
665 },
666 {
667 .cache = &ecryptfs_file_info_cache,
668 .name = "ecryptfs_file_cache",
669 .size = sizeof(struct ecryptfs_file_info),
670 },
671 {
672 .cache = &ecryptfs_dentry_info_cache,
673 .name = "ecryptfs_dentry_info_cache",
674 .size = sizeof(struct ecryptfs_dentry_info),
675 },
676 {
677 .cache = &ecryptfs_inode_info_cache,
678 .name = "ecryptfs_inode_cache",
679 .size = sizeof(struct ecryptfs_inode_info),
680 .ctor = inode_info_init_once,
681 },
682 {
683 .cache = &ecryptfs_sb_info_cache,
684 .name = "ecryptfs_sb_cache",
685 .size = sizeof(struct ecryptfs_sb_info),
686 },
687 {
Michael Halcrow237fead2006-10-04 02:16:22 -0700688 .cache = &ecryptfs_header_cache_1,
689 .name = "ecryptfs_headers_1",
690 .size = PAGE_CACHE_SIZE,
691 },
692 {
693 .cache = &ecryptfs_header_cache_2,
694 .name = "ecryptfs_headers_2",
695 .size = PAGE_CACHE_SIZE,
696 },
697 {
Michael Halcrowdd2a3b72007-02-12 00:53:46 -0800698 .cache = &ecryptfs_xattr_cache,
699 .name = "ecryptfs_xattr_cache",
700 .size = PAGE_CACHE_SIZE,
701 },
702 {
Michael Halcroweb95e7f2007-02-16 01:28:40 -0800703 .cache = &ecryptfs_key_record_cache,
704 .name = "ecryptfs_key_record_cache",
705 .size = sizeof(struct ecryptfs_key_record),
706 },
Michael Halcrow956159c2007-10-16 01:27:55 -0700707 {
708 .cache = &ecryptfs_key_sig_cache,
709 .name = "ecryptfs_key_sig_cache",
710 .size = sizeof(struct ecryptfs_key_sig),
711 },
712 {
713 .cache = &ecryptfs_global_auth_tok_cache,
714 .name = "ecryptfs_global_auth_tok_cache",
715 .size = sizeof(struct ecryptfs_global_auth_tok),
716 },
717 {
718 .cache = &ecryptfs_key_tfm_cache,
719 .name = "ecryptfs_key_tfm_cache",
720 .size = sizeof(struct ecryptfs_key_tfm),
721 },
Michael Halcrow746f1e52008-07-23 21:30:02 -0700722 {
723 .cache = &ecryptfs_open_req_cache,
724 .name = "ecryptfs_open_req_cache",
725 .size = sizeof(struct ecryptfs_open_req),
726 },
Michael Halcrow237fead2006-10-04 02:16:22 -0700727};
728
729static void ecryptfs_free_kmem_caches(void)
730{
731 int i;
732
733 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
734 struct ecryptfs_cache_info *info;
735
736 info = &ecryptfs_cache_infos[i];
737 if (*(info->cache))
738 kmem_cache_destroy(*(info->cache));
739 }
740}
741
742/**
743 * ecryptfs_init_kmem_caches
744 *
745 * Returns zero on success; non-zero otherwise
746 */
747static int ecryptfs_init_kmem_caches(void)
748{
749 int i;
750
751 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
752 struct ecryptfs_cache_info *info;
753
754 info = &ecryptfs_cache_infos[i];
755 *(info->cache) = kmem_cache_create(info->name, info->size,
Paul Mundt20c2df82007-07-20 10:11:58 +0900756 0, SLAB_HWCACHE_ALIGN, info->ctor);
Michael Halcrow237fead2006-10-04 02:16:22 -0700757 if (!*(info->cache)) {
758 ecryptfs_free_kmem_caches();
759 ecryptfs_printk(KERN_WARNING, "%s: "
760 "kmem_cache_create failed\n",
761 info->name);
762 return -ENOMEM;
763 }
764 }
765 return 0;
766}
767
Greg Kroah-Hartman6e90aa92007-11-06 15:08:08 -0800768static struct kobject *ecryptfs_kobj;
Michael Halcrow237fead2006-10-04 02:16:22 -0700769
Kay Sievers386f2752007-11-02 13:47:53 +0100770static ssize_t version_show(struct kobject *kobj,
771 struct kobj_attribute *attr, char *buff)
Michael Halcrow237fead2006-10-04 02:16:22 -0700772{
773 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
774}
775
Kay Sievers386f2752007-11-02 13:47:53 +0100776static struct kobj_attribute version_attr = __ATTR_RO(version);
Michael Halcrow237fead2006-10-04 02:16:22 -0700777
Greg Kroah-Hartman30a468b2007-10-15 15:01:24 -0700778static struct attribute *attributes[] = {
779 &version_attr.attr,
Greg Kroah-Hartman30a468b2007-10-15 15:01:24 -0700780 NULL,
781};
782
783static struct attribute_group attr_group = {
784 .attrs = attributes,
785};
Michael Halcrow237fead2006-10-04 02:16:22 -0700786
787static int do_sysfs_registration(void)
788{
789 int rc;
790
Greg Kroah-Hartman6e90aa92007-11-06 15:08:08 -0800791 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
792 if (!ecryptfs_kobj) {
Greg Kroah-Hartman917e8652007-10-29 20:13:17 +0100793 printk(KERN_ERR "Unable to create ecryptfs kset\n");
794 rc = -ENOMEM;
Michael Halcrow237fead2006-10-04 02:16:22 -0700795 goto out;
796 }
Greg Kroah-Hartman6e90aa92007-11-06 15:08:08 -0800797 rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
Michael Halcrow237fead2006-10-04 02:16:22 -0700798 if (rc) {
799 printk(KERN_ERR
Greg Kroah-Hartman30a468b2007-10-15 15:01:24 -0700800 "Unable to create ecryptfs version attributes\n");
Greg Kroah-Hartman197b12d2007-12-20 08:13:05 -0800801 kobject_put(ecryptfs_kobj);
Michael Halcrow237fead2006-10-04 02:16:22 -0700802 }
803out:
804 return rc;
805}
806
Ryusuke Konishia75de1b2007-08-10 13:00:56 -0700807static void do_sysfs_unregistration(void)
808{
Greg Kroah-Hartman6e90aa92007-11-06 15:08:08 -0800809 sysfs_remove_group(ecryptfs_kobj, &attr_group);
Greg Kroah-Hartman197b12d2007-12-20 08:13:05 -0800810 kobject_put(ecryptfs_kobj);
Ryusuke Konishia75de1b2007-08-10 13:00:56 -0700811}
812
Michael Halcrow237fead2006-10-04 02:16:22 -0700813static int __init ecryptfs_init(void)
814{
815 int rc;
816
817 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
818 rc = -EINVAL;
819 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
820 "larger than the host's page size, and so "
821 "eCryptfs cannot run on this system. The "
822 "default eCryptfs extent size is [%d] bytes; "
823 "the page size is [%d] bytes.\n",
824 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
825 goto out;
826 }
827 rc = ecryptfs_init_kmem_caches();
828 if (rc) {
829 printk(KERN_ERR
830 "Failed to allocate one or more kmem_cache objects\n");
831 goto out;
832 }
833 rc = register_filesystem(&ecryptfs_fs_type);
834 if (rc) {
835 printk(KERN_ERR "Failed to register filesystem\n");
Michael Halcrowcf81f892007-10-16 01:28:07 -0700836 goto out_free_kmem_caches;
Michael Halcrow237fead2006-10-04 02:16:22 -0700837 }
Michael Halcrow237fead2006-10-04 02:16:22 -0700838 rc = do_sysfs_registration();
839 if (rc) {
840 printk(KERN_ERR "sysfs registration failed\n");
Michael Halcrowcf81f892007-10-16 01:28:07 -0700841 goto out_unregister_filesystem;
Michael Halcrow237fead2006-10-04 02:16:22 -0700842 }
Michael Halcrow746f1e52008-07-23 21:30:02 -0700843 rc = ecryptfs_init_kthread();
844 if (rc) {
845 printk(KERN_ERR "%s: kthread initialization failed; "
846 "rc = [%d]\n", __func__, rc);
847 goto out_do_sysfs_unregistration;
848 }
Tyler Hicks624ae522008-10-15 22:02:51 -0700849 rc = ecryptfs_init_messaging();
Michael Halcrowdddfa462007-02-12 00:53:44 -0800850 if (rc) {
Michael Halcrow746f1e52008-07-23 21:30:02 -0700851 printk(KERN_ERR "Failure occured while attempting to "
Tyler Hicks624ae522008-10-15 22:02:51 -0700852 "initialize the communications channel to "
853 "ecryptfsd\n");
Michael Halcrow746f1e52008-07-23 21:30:02 -0700854 goto out_destroy_kthread;
Michael Halcrow956159c2007-10-16 01:27:55 -0700855 }
856 rc = ecryptfs_init_crypto();
857 if (rc) {
858 printk(KERN_ERR "Failure whilst attempting to init crypto; "
859 "rc = [%d]\n", rc);
Michael Halcrowcf81f892007-10-16 01:28:07 -0700860 goto out_release_messaging;
Michael Halcrowdddfa462007-02-12 00:53:44 -0800861 }
Eric Sandeen2830bfd2008-02-06 01:38:34 -0800862 if (ecryptfs_verbosity > 0)
863 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
864 "will be written to the syslog!\n", ecryptfs_verbosity);
865
Michael Halcrowcf81f892007-10-16 01:28:07 -0700866 goto out;
867out_release_messaging:
Tyler Hicks624ae522008-10-15 22:02:51 -0700868 ecryptfs_release_messaging();
Michael Halcrow746f1e52008-07-23 21:30:02 -0700869out_destroy_kthread:
870 ecryptfs_destroy_kthread();
Michael Halcrowcf81f892007-10-16 01:28:07 -0700871out_do_sysfs_unregistration:
872 do_sysfs_unregistration();
873out_unregister_filesystem:
874 unregister_filesystem(&ecryptfs_fs_type);
875out_free_kmem_caches:
876 ecryptfs_free_kmem_caches();
Michael Halcrow237fead2006-10-04 02:16:22 -0700877out:
878 return rc;
879}
880
881static void __exit ecryptfs_exit(void)
882{
Michael Halcrowcf81f892007-10-16 01:28:07 -0700883 int rc;
884
885 rc = ecryptfs_destroy_crypto();
886 if (rc)
887 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
888 "rc = [%d]\n", rc);
Tyler Hicks624ae522008-10-15 22:02:51 -0700889 ecryptfs_release_messaging();
Michael Halcrow746f1e52008-07-23 21:30:02 -0700890 ecryptfs_destroy_kthread();
Michael Halcrowcf81f892007-10-16 01:28:07 -0700891 do_sysfs_unregistration();
Michael Halcrow237fead2006-10-04 02:16:22 -0700892 unregister_filesystem(&ecryptfs_fs_type);
893 ecryptfs_free_kmem_caches();
894}
895
896MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
897MODULE_DESCRIPTION("eCryptfs");
898
899MODULE_LICENSE("GPL");
900
901module_init(ecryptfs_init)
902module_exit(ecryptfs_exit)