1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * eCryptfs: Linux filesystem encryption layer
4 *
5 * Copyright (C) 1997-2003 Erez Zadok
6 * Copyright (C) 2001-2003 Stony Brook University
7 * Copyright (C) 2004-2007 International Business Machines Corp.
8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
9 * Michael C. Thompson <mcthomps@us.ibm.com>
10 * Tyler Hicks <code@tyhicks.com>
11 */
12
13 #include <linux/dcache.h>
14 #include <linux/file.h>
15 #include <linux/module.h>
16 #include <linux/namei.h>
17 #include <linux/skbuff.h>
18 #include <linux/pagemap.h>
19 #include <linux/key.h>
20 #include <linux/fs_context.h>
21 #include <linux/fs_parser.h>
22 #include <linux/fs_stack.h>
23 #include <linux/sysfs.h>
24 #include <linux/slab.h>
25 #include <linux/magic.h>
26 #include "ecryptfs_kernel.h"
27
28 /*
29 * Module parameter that defines the ecryptfs_verbosity level.
30 */
31 int ecryptfs_verbosity = 0;
32
33 module_param(ecryptfs_verbosity, int, 0);
34 MODULE_PARM_DESC(ecryptfs_verbosity,
35 "Initial verbosity level (0 or 1; defaults to "
36 "0, which is Quiet)");
37
38 /*
39 * Module parameter that defines the number of message buffer elements
40 */
41 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
42
43 module_param(ecryptfs_message_buf_len, uint, 0);
44 MODULE_PARM_DESC(ecryptfs_message_buf_len,
45 "Number of message buffer elements");
46
47 /*
48 * Module parameter that defines the maximum guaranteed amount of time to wait
49 * for a response from ecryptfsd. The actual sleep time will be, more than
50 * likely, a small amount greater than this specified value, but only less if
51 * the message successfully arrives.
52 */
53 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
54
55 module_param(ecryptfs_message_wait_timeout, long, 0);
56 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
57 "Maximum number of seconds that an operation will "
58 "sleep while waiting for a message response from "
59 "userspace");
60
61 /*
62 * Module parameter that is an estimate of the maximum number of users
63 * that will be concurrently using eCryptfs. Set this to the right
64 * value to balance performance and memory use.
65 */
66 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
67
68 module_param(ecryptfs_number_of_users, uint, 0);
69 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
70 "concurrent users of eCryptfs");
71
__ecryptfs_printk(const char * fmt,...)72 void __ecryptfs_printk(const char *fmt, ...)
73 {
74 va_list args;
75 va_start(args, fmt);
76 if (fmt[1] == '7') { /* KERN_DEBUG */
77 if (ecryptfs_verbosity >= 1)
78 vprintk(fmt, args);
79 } else
80 vprintk(fmt, args);
81 va_end(args);
82 }
83
84 /*
85 * ecryptfs_init_lower_file
86 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
87 * the lower dentry and the lower mount set
88 *
89 * eCryptfs only ever keeps a single open file for every lower
90 * inode. All I/O operations to the lower inode occur through that
91 * file. When the first eCryptfs dentry that interposes with the first
92 * lower dentry for that inode is created, this function creates the
93 * lower file struct and associates it with the eCryptfs
94 * inode. When all eCryptfs files associated with the inode are released, the
95 * file is closed.
96 *
97 * The lower file will be opened with read/write permissions, if
98 * possible. Otherwise, it is opened read-only.
99 *
100 * This function does nothing if a lower file is already
101 * associated with the eCryptfs inode.
102 *
103 * Returns zero on success; non-zero otherwise
104 */
ecryptfs_init_lower_file(struct dentry * dentry,struct file ** lower_file)105 static int ecryptfs_init_lower_file(struct dentry *dentry,
106 struct file **lower_file)
107 {
108 const struct cred *cred = current_cred();
109 const struct path *path = ecryptfs_dentry_to_lower_path(dentry);
110 int rc;
111
112 rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt,
113 cred);
114 if (rc) {
115 printk(KERN_ERR "Error opening lower file "
116 "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
117 "rc = [%d]\n", path->dentry, path->mnt, rc);
118 (*lower_file) = NULL;
119 }
120 return rc;
121 }
122
ecryptfs_get_lower_file(struct dentry * dentry,struct inode * inode)123 int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
124 {
125 struct ecryptfs_inode_info *inode_info;
126 int count, rc = 0;
127
128 inode_info = ecryptfs_inode_to_private(inode);
129 mutex_lock(&inode_info->lower_file_mutex);
130 count = atomic_inc_return(&inode_info->lower_file_count);
131 if (WARN_ON_ONCE(count < 1))
132 rc = -EINVAL;
133 else if (count == 1) {
134 rc = ecryptfs_init_lower_file(dentry,
135 &inode_info->lower_file);
136 if (rc)
137 atomic_set(&inode_info->lower_file_count, 0);
138 }
139 mutex_unlock(&inode_info->lower_file_mutex);
140 return rc;
141 }
142
ecryptfs_put_lower_file(struct inode * inode)143 void ecryptfs_put_lower_file(struct inode *inode)
144 {
145 struct ecryptfs_inode_info *inode_info;
146
147 inode_info = ecryptfs_inode_to_private(inode);
148 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
149 &inode_info->lower_file_mutex)) {
150 filemap_write_and_wait(inode->i_mapping);
151 fput(inode_info->lower_file);
152 inode_info->lower_file = NULL;
153 mutex_unlock(&inode_info->lower_file_mutex);
154 }
155 }
156
157 enum {
158 Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher,
159 Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata,
160 Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher,
161 Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only,
162 Opt_check_dev_ruid
163 };
164
165 static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = {
166 fsparam_string ("sig", Opt_sig),
167 fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig),
168 fsparam_string ("cipher", Opt_cipher),
169 fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher),
170 fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes),
171 fsparam_flag ("ecryptfs_passthrough", Opt_passthrough),
172 fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata),
173 fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view),
174 fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig),
175 fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher),
176 fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes),
177 fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs),
178 fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only),
179 fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid),
180 {}
181 };
182
ecryptfs_init_global_auth_toks(struct ecryptfs_mount_crypt_stat * mount_crypt_stat)183 static int ecryptfs_init_global_auth_toks(
184 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
185 {
186 struct ecryptfs_global_auth_tok *global_auth_tok;
187 struct ecryptfs_auth_tok *auth_tok;
188 int rc = 0;
189
190 list_for_each_entry(global_auth_tok,
191 &mount_crypt_stat->global_auth_tok_list,
192 mount_crypt_stat_list) {
193 rc = ecryptfs_keyring_auth_tok_for_sig(
194 &global_auth_tok->global_auth_tok_key, &auth_tok,
195 global_auth_tok->sig);
196 if (rc) {
197 printk(KERN_ERR "Could not find valid key in user "
198 "session keyring for sig specified in mount "
199 "option: [%s]\n", global_auth_tok->sig);
200 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
201 goto out;
202 } else {
203 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
204 up_write(&(global_auth_tok->global_auth_tok_key)->sem);
205 }
206 }
207 out:
208 return rc;
209 }
210
ecryptfs_init_mount_crypt_stat(struct ecryptfs_mount_crypt_stat * mount_crypt_stat)211 static void ecryptfs_init_mount_crypt_stat(
212 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
213 {
214 memset((void *)mount_crypt_stat, 0,
215 sizeof(struct ecryptfs_mount_crypt_stat));
216 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
217 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
218 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
219 }
220
221 struct ecryptfs_fs_context {
222 /* Mount option status trackers */
223 bool check_ruid;
224 bool sig_set;
225 bool cipher_name_set;
226 bool cipher_key_bytes_set;
227 bool fn_cipher_name_set;
228 bool fn_cipher_key_bytes_set;
229 };
230
231 /**
232 * ecryptfs_parse_param
233 * @fc: The ecryptfs filesystem context
234 * @param: The mount parameter to parse
235 *
236 * The signature of the key to use must be the description of a key
237 * already in the keyring. Mounting will fail if the key can not be
238 * found.
239 *
240 * Returns zero on success; non-zero on error
241 */
ecryptfs_parse_param(struct fs_context * fc,struct fs_parameter * param)242 static int ecryptfs_parse_param(
243 struct fs_context *fc,
244 struct fs_parameter *param)
245 {
246 int rc;
247 int opt;
248 struct fs_parse_result result;
249 struct ecryptfs_fs_context *ctx = fc->fs_private;
250 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
251 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
252 &sbi->mount_crypt_stat;
253
254 opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result);
255 if (opt < 0)
256 return opt;
257
258 switch (opt) {
259 case Opt_sig:
260 case Opt_ecryptfs_sig:
261 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
262 param->string, 0);
263 if (rc) {
264 printk(KERN_ERR "Error attempting to register "
265 "global sig; rc = [%d]\n", rc);
266 return rc;
267 }
268 ctx->sig_set = 1;
269 break;
270 case Opt_cipher:
271 case Opt_ecryptfs_cipher:
272 strscpy(mount_crypt_stat->global_default_cipher_name,
273 param->string);
274 ctx->cipher_name_set = 1;
275 break;
276 case Opt_ecryptfs_key_bytes:
277 mount_crypt_stat->global_default_cipher_key_size =
278 result.uint_32;
279 ctx->cipher_key_bytes_set = 1;
280 break;
281 case Opt_passthrough:
282 mount_crypt_stat->flags |=
283 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
284 break;
285 case Opt_xattr_metadata:
286 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
287 break;
288 case Opt_encrypted_view:
289 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
290 mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
291 break;
292 case Opt_fnek_sig:
293 strscpy(mount_crypt_stat->global_default_fnek_sig,
294 param->string);
295 rc = ecryptfs_add_global_auth_tok(
296 mount_crypt_stat,
297 mount_crypt_stat->global_default_fnek_sig,
298 ECRYPTFS_AUTH_TOK_FNEK);
299 if (rc) {
300 printk(KERN_ERR "Error attempting to register "
301 "global fnek sig [%s]; rc = [%d]\n",
302 mount_crypt_stat->global_default_fnek_sig, rc);
303 return rc;
304 }
305 mount_crypt_stat->flags |=
306 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
307 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
308 break;
309 case Opt_fn_cipher:
310 strscpy(mount_crypt_stat->global_default_fn_cipher_name,
311 param->string);
312 ctx->fn_cipher_name_set = 1;
313 break;
314 case Opt_fn_cipher_key_bytes:
315 mount_crypt_stat->global_default_fn_cipher_key_bytes =
316 result.uint_32;
317 ctx->fn_cipher_key_bytes_set = 1;
318 break;
319 case Opt_unlink_sigs:
320 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
321 break;
322 case Opt_mount_auth_tok_only:
323 mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
324 break;
325 case Opt_check_dev_ruid:
326 ctx->check_ruid = 1;
327 break;
328 default:
329 return -EINVAL;
330 }
331
332 return 0;
333 }
334
ecryptfs_validate_options(struct fs_context * fc)335 static int ecryptfs_validate_options(struct fs_context *fc)
336 {
337 int rc = 0;
338 u8 cipher_code;
339 struct ecryptfs_fs_context *ctx = fc->fs_private;
340 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
341 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
342
343
344 mount_crypt_stat = &sbi->mount_crypt_stat;
345
346 if (!ctx->sig_set) {
347 rc = -EINVAL;
348 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
349 "auth tok signature as a mount "
350 "parameter; see the eCryptfs README\n");
351 goto out;
352 }
353 if (!ctx->cipher_name_set) {
354 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
355
356 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
357 strcpy(mount_crypt_stat->global_default_cipher_name,
358 ECRYPTFS_DEFAULT_CIPHER);
359 }
360 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
361 && !ctx->fn_cipher_name_set)
362 strcpy(mount_crypt_stat->global_default_fn_cipher_name,
363 mount_crypt_stat->global_default_cipher_name);
364 if (!ctx->cipher_key_bytes_set)
365 mount_crypt_stat->global_default_cipher_key_size = 0;
366 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
367 && !ctx->fn_cipher_key_bytes_set)
368 mount_crypt_stat->global_default_fn_cipher_key_bytes =
369 mount_crypt_stat->global_default_cipher_key_size;
370
371 cipher_code = ecryptfs_code_for_cipher_string(
372 mount_crypt_stat->global_default_cipher_name,
373 mount_crypt_stat->global_default_cipher_key_size);
374 if (!cipher_code) {
375 ecryptfs_printk(KERN_ERR,
376 "eCryptfs doesn't support cipher: %s\n",
377 mount_crypt_stat->global_default_cipher_name);
378 rc = -EINVAL;
379 goto out;
380 }
381
382 mutex_lock(&key_tfm_list_mutex);
383 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
384 NULL)) {
385 rc = ecryptfs_add_new_key_tfm(
386 NULL, mount_crypt_stat->global_default_cipher_name,
387 mount_crypt_stat->global_default_cipher_key_size);
388 if (rc) {
389 printk(KERN_ERR "Error attempting to initialize "
390 "cipher with name = [%s] and key size = [%td]; "
391 "rc = [%d]\n",
392 mount_crypt_stat->global_default_cipher_name,
393 mount_crypt_stat->global_default_cipher_key_size,
394 rc);
395 rc = -EINVAL;
396 mutex_unlock(&key_tfm_list_mutex);
397 goto out;
398 }
399 }
400 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
401 && !ecryptfs_tfm_exists(
402 mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
403 rc = ecryptfs_add_new_key_tfm(
404 NULL, mount_crypt_stat->global_default_fn_cipher_name,
405 mount_crypt_stat->global_default_fn_cipher_key_bytes);
406 if (rc) {
407 printk(KERN_ERR "Error attempting to initialize "
408 "cipher with name = [%s] and key size = [%td]; "
409 "rc = [%d]\n",
410 mount_crypt_stat->global_default_fn_cipher_name,
411 mount_crypt_stat->global_default_fn_cipher_key_bytes,
412 rc);
413 rc = -EINVAL;
414 mutex_unlock(&key_tfm_list_mutex);
415 goto out;
416 }
417 }
418 mutex_unlock(&key_tfm_list_mutex);
419 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
420 if (rc)
421 printk(KERN_WARNING "One or more global auth toks could not "
422 "properly register; rc = [%d]\n", rc);
423 out:
424 return rc;
425 }
426
427 struct kmem_cache *ecryptfs_sb_info_cache;
428 static struct file_system_type ecryptfs_fs_type;
429
430 /*
431 * ecryptfs_get_tree
432 * @fc: The filesystem context
433 */
ecryptfs_get_tree(struct fs_context * fc)434 static int ecryptfs_get_tree(struct fs_context *fc)
435 {
436 struct super_block *s;
437 struct ecryptfs_fs_context *ctx = fc->fs_private;
438 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
439 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
440 struct ecryptfs_dentry_info *root_info;
441 const char *err = "Getting sb failed";
442 struct inode *inode;
443 struct path path;
444 int rc;
445
446 if (!fc->source) {
447 rc = -EINVAL;
448 err = "Device name cannot be null";
449 goto out;
450 }
451
452 mount_crypt_stat = &sbi->mount_crypt_stat;
453 rc = ecryptfs_validate_options(fc);
454 if (rc) {
455 err = "Error validating options";
456 goto out;
457 }
458
459 s = sget_fc(fc, NULL, set_anon_super_fc);
460 if (IS_ERR(s)) {
461 rc = PTR_ERR(s);
462 goto out;
463 }
464
465 rc = super_setup_bdi(s);
466 if (rc)
467 goto out1;
468
469 ecryptfs_set_superblock_private(s, sbi);
470
471 /* ->kill_sb() will take care of sbi after that point */
472 sbi = NULL;
473 s->s_op = &ecryptfs_sops;
474 s->s_xattr = ecryptfs_xattr_handlers;
475 set_default_d_op(s, &ecryptfs_dops);
476
477 err = "Reading sb failed";
478 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
479 if (rc) {
480 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
481 goto out1;
482 }
483 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
484 rc = -EINVAL;
485 printk(KERN_ERR "Mount on filesystem of type "
486 "eCryptfs explicitly disallowed due to "
487 "known incompatibilities\n");
488 goto out_free;
489 }
490
491 if (is_idmapped_mnt(path.mnt)) {
492 rc = -EINVAL;
493 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n");
494 goto out_free;
495 }
496
497 if (ctx->check_ruid &&
498 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
499 rc = -EPERM;
500 printk(KERN_ERR "Mount of device (uid: %d) not owned by "
501 "requested user (uid: %d)\n",
502 i_uid_read(d_inode(path.dentry)),
503 from_kuid(&init_user_ns, current_uid()));
504 goto out_free;
505 }
506
507 ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
508
509 /**
510 * Set the POSIX ACL flag based on whether they're enabled in the lower
511 * mount.
512 */
513 s->s_flags = fc->sb_flags & ~SB_POSIXACL;
514 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
515
516 /**
517 * Force a read-only eCryptfs mount when:
518 * 1) The lower mount is ro
519 * 2) The ecryptfs_encrypted_view mount option is specified
520 */
521 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
522 s->s_flags |= SB_RDONLY;
523
524 s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
525 s->s_blocksize = path.dentry->d_sb->s_blocksize;
526 s->s_magic = ECRYPTFS_SUPER_MAGIC;
527 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
528
529 rc = -EINVAL;
530 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
531 pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
532 goto out_free;
533 }
534
535 inode = ecryptfs_get_inode(d_inode(path.dentry), s);
536 rc = PTR_ERR(inode);
537 if (IS_ERR(inode))
538 goto out_free;
539
540 s->s_root = d_make_root(inode);
541 if (!s->s_root) {
542 rc = -ENOMEM;
543 goto out_free;
544 }
545
546 rc = -ENOMEM;
547 root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
548 if (!root_info)
549 goto out_free;
550
551 /* ->kill_sb() will take care of root_info */
552 ecryptfs_set_dentry_private(s->s_root, root_info);
553 root_info->lower_path = path;
554
555 s->s_flags |= SB_ACTIVE;
556 fc->root = dget(s->s_root);
557 return 0;
558
559 out_free:
560 path_put(&path);
561 out1:
562 deactivate_locked_super(s);
563 out:
564 if (sbi)
565 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
566
567 printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
568 return rc;
569 }
570
571 /**
572 * ecryptfs_kill_block_super
573 * @sb: The ecryptfs super block
574 *
575 * Used to bring the superblock down and free the private data.
576 */
ecryptfs_kill_block_super(struct super_block * sb)577 static void ecryptfs_kill_block_super(struct super_block *sb)
578 {
579 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
580 kill_anon_super(sb);
581 if (!sb_info)
582 return;
583 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
584 kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
585 }
586
ecryptfs_free_fc(struct fs_context * fc)587 static void ecryptfs_free_fc(struct fs_context *fc)
588 {
589 struct ecryptfs_fs_context *ctx = fc->fs_private;
590 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
591
592 kfree(ctx);
593
594 if (sbi) {
595 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
596 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
597 }
598 }
599
600 static const struct fs_context_operations ecryptfs_context_ops = {
601 .free = ecryptfs_free_fc,
602 .parse_param = ecryptfs_parse_param,
603 .get_tree = ecryptfs_get_tree,
604 .reconfigure = NULL,
605 };
606
ecryptfs_init_fs_context(struct fs_context * fc)607 static int ecryptfs_init_fs_context(struct fs_context *fc)
608 {
609 struct ecryptfs_fs_context *ctx;
610 struct ecryptfs_sb_info *sbi = NULL;
611
612 ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL);
613 if (!ctx)
614 return -ENOMEM;
615 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
616 if (!sbi) {
617 kfree(ctx);
618 ctx = NULL;
619 return -ENOMEM;
620 }
621
622 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat);
623
624 fc->fs_private = ctx;
625 fc->s_fs_info = sbi;
626 fc->ops = &ecryptfs_context_ops;
627 return 0;
628 }
629
630 static struct file_system_type ecryptfs_fs_type = {
631 .owner = THIS_MODULE,
632 .name = "ecryptfs",
633 .init_fs_context = ecryptfs_init_fs_context,
634 .parameters = ecryptfs_fs_param_spec,
635 .kill_sb = ecryptfs_kill_block_super,
636 .fs_flags = 0
637 };
638 MODULE_ALIAS_FS("ecryptfs");
639
640 /*
641 * inode_info_init_once
642 *
643 * Initializes the ecryptfs_inode_info_cache when it is created
644 */
645 static void
inode_info_init_once(void * vptr)646 inode_info_init_once(void *vptr)
647 {
648 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
649
650 inode_init_once(&ei->vfs_inode);
651 }
652
653 static struct ecryptfs_cache_info {
654 struct kmem_cache **cache;
655 const char *name;
656 size_t size;
657 slab_flags_t flags;
658 void (*ctor)(void *obj);
659 } ecryptfs_cache_infos[] = {
660 {
661 .cache = &ecryptfs_auth_tok_list_item_cache,
662 .name = "ecryptfs_auth_tok_list_item",
663 .size = sizeof(struct ecryptfs_auth_tok_list_item),
664 },
665 {
666 .cache = &ecryptfs_file_info_cache,
667 .name = "ecryptfs_file_cache",
668 .size = sizeof(struct ecryptfs_file_info),
669 },
670 {
671 .cache = &ecryptfs_dentry_info_cache,
672 .name = "ecryptfs_dentry_info_cache",
673 .size = sizeof(struct ecryptfs_dentry_info),
674 },
675 {
676 .cache = &ecryptfs_inode_info_cache,
677 .name = "ecryptfs_inode_cache",
678 .size = sizeof(struct ecryptfs_inode_info),
679 .flags = SLAB_ACCOUNT,
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 {
688 .cache = &ecryptfs_header_cache,
689 .name = "ecryptfs_headers",
690 .size = PAGE_SIZE,
691 },
692 {
693 .cache = &ecryptfs_xattr_cache,
694 .name = "ecryptfs_xattr_cache",
695 .size = PAGE_SIZE,
696 },
697 {
698 .cache = &ecryptfs_key_record_cache,
699 .name = "ecryptfs_key_record_cache",
700 .size = sizeof(struct ecryptfs_key_record),
701 },
702 {
703 .cache = &ecryptfs_key_sig_cache,
704 .name = "ecryptfs_key_sig_cache",
705 .size = sizeof(struct ecryptfs_key_sig),
706 },
707 {
708 .cache = &ecryptfs_global_auth_tok_cache,
709 .name = "ecryptfs_global_auth_tok_cache",
710 .size = sizeof(struct ecryptfs_global_auth_tok),
711 },
712 {
713 .cache = &ecryptfs_key_tfm_cache,
714 .name = "ecryptfs_key_tfm_cache",
715 .size = sizeof(struct ecryptfs_key_tfm),
716 },
717 };
718
ecryptfs_free_kmem_caches(void)719 static void ecryptfs_free_kmem_caches(void)
720 {
721 int i;
722
723 /*
724 * Make sure all delayed rcu free inodes are flushed before we
725 * destroy cache.
726 */
727 rcu_barrier();
728
729 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
730 struct ecryptfs_cache_info *info;
731
732 info = &ecryptfs_cache_infos[i];
733 kmem_cache_destroy(*(info->cache));
734 }
735 }
736
737 /**
738 * ecryptfs_init_kmem_caches
739 *
740 * Returns zero on success; non-zero otherwise
741 */
ecryptfs_init_kmem_caches(void)742 static int ecryptfs_init_kmem_caches(void)
743 {
744 int i;
745
746 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
747 struct ecryptfs_cache_info *info;
748
749 info = &ecryptfs_cache_infos[i];
750 *(info->cache) = kmem_cache_create(info->name, info->size, 0,
751 SLAB_HWCACHE_ALIGN | info->flags, info->ctor);
752 if (!*(info->cache)) {
753 ecryptfs_free_kmem_caches();
754 ecryptfs_printk(KERN_WARNING, "%s: "
755 "kmem_cache_create failed\n",
756 info->name);
757 return -ENOMEM;
758 }
759 }
760 return 0;
761 }
762
763 static struct kobject *ecryptfs_kobj;
764
version_show(struct kobject * kobj,struct kobj_attribute * attr,char * buff)765 static ssize_t version_show(struct kobject *kobj,
766 struct kobj_attribute *attr, char *buff)
767 {
768 return sysfs_emit(buff, "%d\n", ECRYPTFS_VERSIONING_MASK);
769 }
770
771 static struct kobj_attribute version_attr = __ATTR_RO(version);
772
773 static struct attribute *attributes[] = {
774 &version_attr.attr,
775 NULL,
776 };
777
778 static const struct attribute_group attr_group = {
779 .attrs = attributes,
780 };
781
do_sysfs_registration(void)782 static int do_sysfs_registration(void)
783 {
784 int rc;
785
786 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
787 if (!ecryptfs_kobj) {
788 printk(KERN_ERR "Unable to create ecryptfs kset\n");
789 rc = -ENOMEM;
790 goto out;
791 }
792 rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
793 if (rc) {
794 printk(KERN_ERR
795 "Unable to create ecryptfs version attributes\n");
796 kobject_put(ecryptfs_kobj);
797 }
798 out:
799 return rc;
800 }
801
do_sysfs_unregistration(void)802 static void do_sysfs_unregistration(void)
803 {
804 sysfs_remove_group(ecryptfs_kobj, &attr_group);
805 kobject_put(ecryptfs_kobj);
806 }
807
ecryptfs_init(void)808 static int __init ecryptfs_init(void)
809 {
810 int rc;
811
812 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
813 rc = -EINVAL;
814 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
815 "larger than the host's page size, and so "
816 "eCryptfs cannot run on this system. The "
817 "default eCryptfs extent size is [%u] bytes; "
818 "the page size is [%lu] bytes.\n",
819 ECRYPTFS_DEFAULT_EXTENT_SIZE,
820 (unsigned long)PAGE_SIZE);
821 goto out;
822 }
823 rc = ecryptfs_init_kmem_caches();
824 if (rc) {
825 printk(KERN_ERR
826 "Failed to allocate one or more kmem_cache objects\n");
827 goto out;
828 }
829 rc = do_sysfs_registration();
830 if (rc) {
831 printk(KERN_ERR "sysfs registration failed\n");
832 goto out_free_kmem_caches;
833 }
834 rc = ecryptfs_init_kthread();
835 if (rc) {
836 printk(KERN_ERR "%s: kthread initialization failed; "
837 "rc = [%d]\n", __func__, rc);
838 goto out_do_sysfs_unregistration;
839 }
840 rc = ecryptfs_init_messaging();
841 if (rc) {
842 printk(KERN_ERR "Failure occurred while attempting to "
843 "initialize the communications channel to "
844 "ecryptfsd\n");
845 goto out_destroy_kthread;
846 }
847 rc = ecryptfs_init_crypto();
848 if (rc) {
849 printk(KERN_ERR "Failure whilst attempting to init crypto; "
850 "rc = [%d]\n", rc);
851 goto out_release_messaging;
852 }
853 rc = register_filesystem(&ecryptfs_fs_type);
854 if (rc) {
855 printk(KERN_ERR "Failed to register filesystem\n");
856 goto out_destroy_crypto;
857 }
858 if (ecryptfs_verbosity > 0)
859 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
860 "will be written to the syslog!\n", ecryptfs_verbosity);
861
862 goto out;
863 out_destroy_crypto:
864 ecryptfs_destroy_crypto();
865 out_release_messaging:
866 ecryptfs_release_messaging();
867 out_destroy_kthread:
868 ecryptfs_destroy_kthread();
869 out_do_sysfs_unregistration:
870 do_sysfs_unregistration();
871 out_free_kmem_caches:
872 ecryptfs_free_kmem_caches();
873 out:
874 return rc;
875 }
876
ecryptfs_exit(void)877 static void __exit ecryptfs_exit(void)
878 {
879 int rc;
880
881 rc = ecryptfs_destroy_crypto();
882 if (rc)
883 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
884 "rc = [%d]\n", rc);
885 ecryptfs_release_messaging();
886 ecryptfs_destroy_kthread();
887 do_sysfs_unregistration();
888 unregister_filesystem(&ecryptfs_fs_type);
889 ecryptfs_free_kmem_caches();
890 }
891
892 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
893 MODULE_DESCRIPTION("eCryptfs");
894
895 MODULE_LICENSE("GPL");
896
897 module_init(ecryptfs_init)
898 module_exit(ecryptfs_exit)
899