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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 <[email protected]>
9 * Michael C. Thompson <[email protected]>
10 * Tyler Hicks <[email protected]>
11 */
12
13#include <linux/dcache.h>
14#include <linux/file.h>
15#include <linux/fips.h>
16#include <linux/module.h>
17#include <linux/namei.h>
18#include <linux/skbuff.h>
19#include <linux/pagemap.h>
20#include <linux/key.h>
21#include <linux/fs_context.h>
22#include <linux/fs_parser.h>
23#include <linux/fs_stack.h>
24#include <linux/sysfs.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/magic.h>
28#include "ecryptfs_kernel.h"
29
30/*
31 * Module parameter that defines the ecryptfs_verbosity level.
32 */
33int ecryptfs_verbosity = 0;
34
35module_param(ecryptfs_verbosity, int, 0);
36MODULE_PARM_DESC(ecryptfs_verbosity,
37 "Initial verbosity level (0 or 1; defaults to "
38 "0, which is Quiet)");
39
40/*
41 * Module parameter that defines the number of message buffer elements
42 */
43unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
44
45module_param(ecryptfs_message_buf_len, uint, 0);
46MODULE_PARM_DESC(ecryptfs_message_buf_len,
47 "Number of message buffer elements");
48
49/*
50 * Module parameter that defines the maximum guaranteed amount of time to wait
51 * for a response from ecryptfsd. The actual sleep time will be, more than
52 * likely, a small amount greater than this specified value, but only less if
53 * the message successfully arrives.
54 */
55signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
56
57module_param(ecryptfs_message_wait_timeout, long, 0);
58MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
59 "Maximum number of seconds that an operation will "
60 "sleep while waiting for a message response from "
61 "userspace");
62
63/*
64 * Module parameter that is an estimate of the maximum number of users
65 * that will be concurrently using eCryptfs. Set this to the right
66 * value to balance performance and memory use.
67 */
68unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
69
70module_param(ecryptfs_number_of_users, uint, 0);
71MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
72 "concurrent users of eCryptfs");
73
74void __ecryptfs_printk(const char *fmt, ...)
75{
76 va_list args;
77 va_start(args, fmt);
78 if (fmt[1] == '7') { /* KERN_DEBUG */
79 if (ecryptfs_verbosity >= 1)
80 vprintk(fmt, args);
81 } else
82 vprintk(fmt, args);
83 va_end(args);
84}
85
86/*
87 * ecryptfs_init_lower_file
88 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
89 * the lower dentry and the lower mount set
90 *
91 * eCryptfs only ever keeps a single open file for every lower
92 * inode. All I/O operations to the lower inode occur through that
93 * file. When the first eCryptfs dentry that interposes with the first
94 * lower dentry for that inode is created, this function creates the
95 * lower file struct and associates it with the eCryptfs
96 * inode. When all eCryptfs files associated with the inode are released, the
97 * file is closed.
98 *
99 * The lower file will be opened with read/write permissions, if
100 * possible. Otherwise, it is opened read-only.
101 *
102 * This function does nothing if a lower file is already
103 * associated with the eCryptfs inode.
104 *
105 * Returns zero on success; non-zero otherwise
106 */
107static int ecryptfs_init_lower_file(struct dentry *dentry,
108 struct file **lower_file)
109{
110 const struct cred *cred = current_cred();
111 struct path path = ecryptfs_lower_path(dentry);
112 int rc;
113
114 rc = ecryptfs_privileged_open(lower_file, path.dentry, path.mnt, cred);
115 if (rc) {
116 printk(KERN_ERR "Error opening lower file "
117 "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
118 "rc = [%d]\n", path.dentry, path.mnt, rc);
119 (*lower_file) = NULL;
120 }
121 return rc;
122}
123
124int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode)
125{
126 struct ecryptfs_inode_info *inode_info;
127 int count, rc = 0;
128
129 inode_info = ecryptfs_inode_to_private(inode);
130 mutex_lock(&inode_info->lower_file_mutex);
131 count = atomic_inc_return(&inode_info->lower_file_count);
132 if (WARN_ON_ONCE(count < 1))
133 rc = -EINVAL;
134 else if (count == 1) {
135 rc = ecryptfs_init_lower_file(dentry,
136 &inode_info->lower_file);
137 if (rc)
138 atomic_set(&inode_info->lower_file_count, 0);
139 }
140 mutex_unlock(&inode_info->lower_file_mutex);
141 return rc;
142}
143
144void ecryptfs_put_lower_file(struct inode *inode)
145{
146 struct ecryptfs_inode_info *inode_info;
147
148 inode_info = ecryptfs_inode_to_private(inode);
149 if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count,
150 &inode_info->lower_file_mutex)) {
151 filemap_write_and_wait(inode->i_mapping);
152 fput(inode_info->lower_file);
153 inode_info->lower_file = NULL;
154 mutex_unlock(&inode_info->lower_file_mutex);
155 }
156}
157
158enum {
159 Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher,
160 Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata,
161 Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher,
162 Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only,
163 Opt_check_dev_ruid
164};
165
166static const struct fs_parameter_spec ecryptfs_fs_param_spec[] = {
167 fsparam_string ("sig", Opt_sig),
168 fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig),
169 fsparam_string ("cipher", Opt_cipher),
170 fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher),
171 fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes),
172 fsparam_flag ("ecryptfs_passthrough", Opt_passthrough),
173 fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata),
174 fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view),
175 fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig),
176 fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher),
177 fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes),
178 fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs),
179 fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only),
180 fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid),
181 {}
182};
183
184static int ecryptfs_init_global_auth_toks(
185 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
186{
187 struct ecryptfs_global_auth_tok *global_auth_tok;
188 struct ecryptfs_auth_tok *auth_tok;
189 int rc = 0;
190
191 list_for_each_entry(global_auth_tok,
192 &mount_crypt_stat->global_auth_tok_list,
193 mount_crypt_stat_list) {
194 rc = ecryptfs_keyring_auth_tok_for_sig(
195 &global_auth_tok->global_auth_tok_key, &auth_tok,
196 global_auth_tok->sig);
197 if (rc) {
198 printk(KERN_ERR "Could not find valid key in user "
199 "session keyring for sig specified in mount "
200 "option: [%s]\n", global_auth_tok->sig);
201 global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
202 goto out;
203 } else {
204 global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
205 up_write(&(global_auth_tok->global_auth_tok_key)->sem);
206 }
207 }
208out:
209 return rc;
210}
211
212static void ecryptfs_init_mount_crypt_stat(
213 struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
214{
215 memset((void *)mount_crypt_stat, 0,
216 sizeof(struct ecryptfs_mount_crypt_stat));
217 INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
218 mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
219 mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
220}
221
222struct ecryptfs_fs_context {
223 /* Mount option status trackers */
224 bool check_ruid;
225 bool sig_set;
226 bool cipher_name_set;
227 bool cipher_key_bytes_set;
228 bool fn_cipher_name_set;
229 bool fn_cipher_key_bytes_set;
230};
231
232/**
233 * ecryptfs_parse_param
234 * @fc: The ecryptfs filesystem context
235 * @param: The mount parameter to parse
236 *
237 * The signature of the key to use must be the description of a key
238 * already in the keyring. Mounting will fail if the key can not be
239 * found.
240 *
241 * Returns zero on success; non-zero on error
242 */
243static int ecryptfs_parse_param(
244 struct fs_context *fc,
245 struct fs_parameter *param)
246{
247 int rc;
248 int opt;
249 struct fs_parse_result result;
250 struct ecryptfs_fs_context *ctx = fc->fs_private;
251 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
252 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
253 &sbi->mount_crypt_stat;
254
255 opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result);
256 if (opt < 0)
257 return opt;
258
259 switch (opt) {
260 case Opt_sig:
261 case Opt_ecryptfs_sig:
262 rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
263 param->string, 0);
264 if (rc) {
265 printk(KERN_ERR "Error attempting to register "
266 "global sig; rc = [%d]\n", rc);
267 return rc;
268 }
269 ctx->sig_set = 1;
270 break;
271 case Opt_cipher:
272 case Opt_ecryptfs_cipher:
273 strscpy(mount_crypt_stat->global_default_cipher_name,
274 param->string);
275 ctx->cipher_name_set = 1;
276 break;
277 case Opt_ecryptfs_key_bytes:
278 mount_crypt_stat->global_default_cipher_key_size =
279 result.uint_32;
280 ctx->cipher_key_bytes_set = 1;
281 break;
282 case Opt_passthrough:
283 mount_crypt_stat->flags |=
284 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
285 break;
286 case Opt_xattr_metadata:
287 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
288 break;
289 case Opt_encrypted_view:
290 mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
291 mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
292 break;
293 case Opt_fnek_sig:
294 strscpy(mount_crypt_stat->global_default_fnek_sig,
295 param->string);
296 rc = ecryptfs_add_global_auth_tok(
297 mount_crypt_stat,
298 mount_crypt_stat->global_default_fnek_sig,
299 ECRYPTFS_AUTH_TOK_FNEK);
300 if (rc) {
301 printk(KERN_ERR "Error attempting to register "
302 "global fnek sig [%s]; rc = [%d]\n",
303 mount_crypt_stat->global_default_fnek_sig, rc);
304 return rc;
305 }
306 mount_crypt_stat->flags |=
307 (ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
308 | ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
309 break;
310 case Opt_fn_cipher:
311 strscpy(mount_crypt_stat->global_default_fn_cipher_name,
312 param->string);
313 ctx->fn_cipher_name_set = 1;
314 break;
315 case Opt_fn_cipher_key_bytes:
316 mount_crypt_stat->global_default_fn_cipher_key_bytes =
317 result.uint_32;
318 ctx->fn_cipher_key_bytes_set = 1;
319 break;
320 case Opt_unlink_sigs:
321 mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
322 break;
323 case Opt_mount_auth_tok_only:
324 mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
325 break;
326 case Opt_check_dev_ruid:
327 ctx->check_ruid = 1;
328 break;
329 default:
330 return -EINVAL;
331 }
332
333 return 0;
334}
335
336static int ecryptfs_validate_options(struct fs_context *fc)
337{
338 int rc = 0;
339 u8 cipher_code;
340 struct ecryptfs_fs_context *ctx = fc->fs_private;
341 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
342 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
343
344
345 mount_crypt_stat = &sbi->mount_crypt_stat;
346
347 if (!ctx->sig_set) {
348 rc = -EINVAL;
349 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
350 "auth tok signature as a mount "
351 "parameter; see the eCryptfs README\n");
352 goto out;
353 }
354 if (!ctx->cipher_name_set) {
355 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
356
357 BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
358 strscpy(mount_crypt_stat->global_default_cipher_name,
359 ECRYPTFS_DEFAULT_CIPHER);
360 }
361 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
362 && !ctx->fn_cipher_name_set)
363 strscpy(mount_crypt_stat->global_default_fn_cipher_name,
364 mount_crypt_stat->global_default_cipher_name);
365 if (!ctx->cipher_key_bytes_set)
366 mount_crypt_stat->global_default_cipher_key_size = 0;
367 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
368 && !ctx->fn_cipher_key_bytes_set)
369 mount_crypt_stat->global_default_fn_cipher_key_bytes =
370 mount_crypt_stat->global_default_cipher_key_size;
371
372 cipher_code = ecryptfs_code_for_cipher_string(
373 mount_crypt_stat->global_default_cipher_name,
374 mount_crypt_stat->global_default_cipher_key_size);
375 if (!cipher_code) {
376 ecryptfs_printk(KERN_ERR,
377 "eCryptfs doesn't support cipher: %s\n",
378 mount_crypt_stat->global_default_cipher_name);
379 rc = -EINVAL;
380 goto out;
381 }
382
383 mutex_lock(&key_tfm_list_mutex);
384 if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
385 NULL)) {
386 rc = ecryptfs_add_new_key_tfm(
387 NULL, mount_crypt_stat->global_default_cipher_name,
388 mount_crypt_stat->global_default_cipher_key_size);
389 if (rc) {
390 printk(KERN_ERR "Error attempting to initialize "
391 "cipher with name = [%s] and key size = [%td]; "
392 "rc = [%d]\n",
393 mount_crypt_stat->global_default_cipher_name,
394 mount_crypt_stat->global_default_cipher_key_size,
395 rc);
396 rc = -EINVAL;
397 mutex_unlock(&key_tfm_list_mutex);
398 goto out;
399 }
400 }
401 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
402 && !ecryptfs_tfm_exists(
403 mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
404 rc = ecryptfs_add_new_key_tfm(
405 NULL, mount_crypt_stat->global_default_fn_cipher_name,
406 mount_crypt_stat->global_default_fn_cipher_key_bytes);
407 if (rc) {
408 printk(KERN_ERR "Error attempting to initialize "
409 "cipher with name = [%s] and key size = [%td]; "
410 "rc = [%d]\n",
411 mount_crypt_stat->global_default_fn_cipher_name,
412 mount_crypt_stat->global_default_fn_cipher_key_bytes,
413 rc);
414 rc = -EINVAL;
415 mutex_unlock(&key_tfm_list_mutex);
416 goto out;
417 }
418 }
419 mutex_unlock(&key_tfm_list_mutex);
420 rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
421 if (rc)
422 printk(KERN_WARNING "One or more global auth toks could not "
423 "properly register; rc = [%d]\n", rc);
424out:
425 return rc;
426}
427
428struct kmem_cache *ecryptfs_sb_info_cache;
429static struct file_system_type ecryptfs_fs_type;
430
431/*
432 * ecryptfs_get_tree
433 * @fc: The filesystem context
434 */
435static int ecryptfs_get_tree(struct fs_context *fc)
436{
437 struct super_block *s;
438 struct ecryptfs_fs_context *ctx = fc->fs_private;
439 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
440 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
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 if (fips_enabled) {
460 rc = -EINVAL;
461 err = "eCryptfs support is disabled due to FIPS";
462 goto out;
463 }
464
465 s = sget_fc(fc, NULL, set_anon_super_fc);
466 if (IS_ERR(s)) {
467 rc = PTR_ERR(s);
468 goto out;
469 }
470
471 rc = super_setup_bdi(s);
472 if (rc)
473 goto out1;
474
475 ecryptfs_set_superblock_private(s, sbi);
476
477 /* ->kill_sb() will take care of sbi after that point */
478 sbi = NULL;
479 s->s_op = &ecryptfs_sops;
480 s->s_xattr = ecryptfs_xattr_handlers;
481 set_default_d_op(s, &ecryptfs_dops);
482
483 err = "Reading sb failed";
484 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
485 if (rc) {
486 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
487 goto out1;
488 }
489 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
490 rc = -EINVAL;
491 printk(KERN_ERR "Mount on filesystem of type "
492 "eCryptfs explicitly disallowed due to "
493 "known incompatibilities\n");
494 goto out_free;
495 }
496
497 if (is_idmapped_mnt(path.mnt)) {
498 rc = -EINVAL;
499 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n");
500 goto out_free;
501 }
502
503 if (ctx->check_ruid &&
504 !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
505 rc = -EPERM;
506 printk(KERN_ERR "Mount of device (uid: %d) not owned by "
507 "requested user (uid: %d)\n",
508 i_uid_read(d_inode(path.dentry)),
509 from_kuid(&init_user_ns, current_uid()));
510 goto out_free;
511 }
512
513 ecryptfs_set_superblock_lower(s, path.dentry->d_sb);
514
515 /**
516 * Set the POSIX ACL flag based on whether they're enabled in the lower
517 * mount.
518 */
519 s->s_flags = fc->sb_flags & ~SB_POSIXACL;
520 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
521
522 /**
523 * Force a read-only eCryptfs mount when:
524 * 1) The lower mount is ro
525 * 2) The ecryptfs_encrypted_view mount option is specified
526 */
527 if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
528 s->s_flags |= SB_RDONLY;
529
530 s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
531 s->s_blocksize = path.dentry->d_sb->s_blocksize;
532 s->s_magic = ECRYPTFS_SUPER_MAGIC;
533 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
534 s->s_time_gran = path.dentry->d_sb->s_time_gran;
535
536 rc = -EINVAL;
537 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
538 pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
539 goto out_free;
540 }
541
542 inode = ecryptfs_get_inode(d_inode(path.dentry), s);
543 rc = PTR_ERR(inode);
544 if (IS_ERR(inode))
545 goto out_free;
546
547 s->s_root = d_make_root(inode);
548 if (!s->s_root) {
549 rc = -ENOMEM;
550 goto out_free;
551 }
552
553 ecryptfs_set_dentry_lower(s->s_root, path.dentry);
554 ecryptfs_superblock_to_private(s)->lower_mnt = path.mnt;
555
556 s->s_flags |= SB_ACTIVE;
557 fc->root = dget(s->s_root);
558 return 0;
559
560out_free:
561 path_put(&path);
562out1:
563 deactivate_locked_super(s);
564out:
565 if (sbi)
566 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
567
568 printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
569 return rc;
570}
571
572/**
573 * ecryptfs_kill_block_super
574 * @sb: The ecryptfs super block
575 *
576 * Used to bring the superblock down and free the private data.
577 */
578static void ecryptfs_kill_block_super(struct super_block *sb)
579{
580 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
581 kill_anon_super(sb);
582 if (!sb_info)
583 return;
584 mntput(sb_info->lower_mnt);
585 ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
586 kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
587}
588
589static void ecryptfs_free_fc(struct fs_context *fc)
590{
591 struct ecryptfs_fs_context *ctx = fc->fs_private;
592 struct ecryptfs_sb_info *sbi = fc->s_fs_info;
593
594 kfree(ctx);
595
596 if (sbi) {
597 ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
598 kmem_cache_free(ecryptfs_sb_info_cache, sbi);
599 }
600}
601
602static const struct fs_context_operations ecryptfs_context_ops = {
603 .free = ecryptfs_free_fc,
604 .parse_param = ecryptfs_parse_param,
605 .get_tree = ecryptfs_get_tree,
606 .reconfigure = NULL,
607};
608
609static int ecryptfs_init_fs_context(struct fs_context *fc)
610{
611 struct ecryptfs_fs_context *ctx;
612 struct ecryptfs_sb_info *sbi = NULL;
613
614 ctx = kzalloc_obj(struct ecryptfs_fs_context);
615 if (!ctx)
616 return -ENOMEM;
617 sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
618 if (!sbi) {
619 kfree(ctx);
620 ctx = NULL;
621 return -ENOMEM;
622 }
623
624 ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat);
625
626 fc->fs_private = ctx;
627 fc->s_fs_info = sbi;
628 fc->ops = &ecryptfs_context_ops;
629 return 0;
630}
631
632static struct file_system_type ecryptfs_fs_type = {
633 .owner = THIS_MODULE,
634 .name = "ecryptfs",
635 .init_fs_context = ecryptfs_init_fs_context,
636 .parameters = ecryptfs_fs_param_spec,
637 .kill_sb = ecryptfs_kill_block_super,
638 .fs_flags = 0
639};
640MODULE_ALIAS_FS("ecryptfs");
641
642/*
643 * inode_info_init_once
644 *
645 * Initializes the ecryptfs_inode_info_cache when it is created
646 */
647static void
648inode_info_init_once(void *vptr)
649{
650 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
651
652 inode_init_once(&ei->vfs_inode);
653}
654
655static struct ecryptfs_cache_info {
656 struct kmem_cache **cache;
657 const char *name;
658 size_t size;
659 slab_flags_t flags;
660 void (*ctor)(void *obj);
661} ecryptfs_cache_infos[] = {
662 {
663 .cache = &ecryptfs_auth_tok_list_item_cache,
664 .name = "ecryptfs_auth_tok_list_item",
665 .size = sizeof(struct ecryptfs_auth_tok_list_item),
666 },
667 {
668 .cache = &ecryptfs_file_info_cache,
669 .name = "ecryptfs_file_cache",
670 .size = sizeof(struct ecryptfs_file_info),
671 },
672 {
673 .cache = &ecryptfs_inode_info_cache,
674 .name = "ecryptfs_inode_cache",
675 .size = sizeof(struct ecryptfs_inode_info),
676 .flags = SLAB_ACCOUNT,
677 .ctor = inode_info_init_once,
678 },
679 {
680 .cache = &ecryptfs_sb_info_cache,
681 .name = "ecryptfs_sb_cache",
682 .size = sizeof(struct ecryptfs_sb_info),
683 },
684 {
685 .cache = &ecryptfs_header_cache,
686 .name = "ecryptfs_headers",
687 .size = PAGE_SIZE,
688 },
689 {
690 .cache = &ecryptfs_xattr_cache,
691 .name = "ecryptfs_xattr_cache",
692 .size = PAGE_SIZE,
693 },
694 {
695 .cache = &ecryptfs_key_record_cache,
696 .name = "ecryptfs_key_record_cache",
697 .size = sizeof(struct ecryptfs_key_record),
698 },
699 {
700 .cache = &ecryptfs_key_sig_cache,
701 .name = "ecryptfs_key_sig_cache",
702 .size = sizeof(struct ecryptfs_key_sig),
703 },
704 {
705 .cache = &ecryptfs_global_auth_tok_cache,
706 .name = "ecryptfs_global_auth_tok_cache",
707 .size = sizeof(struct ecryptfs_global_auth_tok),
708 },
709 {
710 .cache = &ecryptfs_key_tfm_cache,
711 .name = "ecryptfs_key_tfm_cache",
712 .size = sizeof(struct ecryptfs_key_tfm),
713 },
714};
715
716static void ecryptfs_free_kmem_caches(void)
717{
718 int i;
719
720 /*
721 * Make sure all delayed rcu free inodes are flushed before we
722 * destroy cache.
723 */
724 rcu_barrier();
725
726 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
727 struct ecryptfs_cache_info *info;
728
729 info = &ecryptfs_cache_infos[i];
730 kmem_cache_destroy(*(info->cache));
731 }
732}
733
734/**
735 * ecryptfs_init_kmem_caches
736 *
737 * Returns zero on success; non-zero otherwise
738 */
739static int ecryptfs_init_kmem_caches(void)
740{
741 int i;
742
743 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
744 struct ecryptfs_cache_info *info;
745
746 info = &ecryptfs_cache_infos[i];
747 *(info->cache) = kmem_cache_create(info->name, info->size, 0,
748 SLAB_HWCACHE_ALIGN | info->flags, info->ctor);
749 if (!*(info->cache)) {
750 ecryptfs_free_kmem_caches();
751 ecryptfs_printk(KERN_WARNING, "%s: "
752 "kmem_cache_create failed\n",
753 info->name);
754 return -ENOMEM;
755 }
756 }
757 return 0;
758}
759
760static struct kobject *ecryptfs_kobj;
761
762static ssize_t version_show(struct kobject *kobj,
763 struct kobj_attribute *attr, char *buff)
764{
765 return sysfs_emit(buff, "%d\n", ECRYPTFS_VERSIONING_MASK);
766}
767
768static struct kobj_attribute version_attr = __ATTR_RO(version);
769
770static struct attribute *attributes[] = {
771 &version_attr.attr,
772 NULL,
773};
774
775static const struct attribute_group attr_group = {
776 .attrs = attributes,
777};
778
779static int do_sysfs_registration(void)
780{
781 int rc;
782
783 ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
784 if (!ecryptfs_kobj) {
785 printk(KERN_ERR "Unable to create ecryptfs kset\n");
786 rc = -ENOMEM;
787 goto out;
788 }
789 rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
790 if (rc) {
791 printk(KERN_ERR
792 "Unable to create ecryptfs version attributes\n");
793 kobject_put(ecryptfs_kobj);
794 }
795out:
796 return rc;
797}
798
799static void do_sysfs_unregistration(void)
800{
801 sysfs_remove_group(ecryptfs_kobj, &attr_group);
802 kobject_put(ecryptfs_kobj);
803}
804
805static int __init ecryptfs_init(void)
806{
807 int rc;
808
809 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
810 rc = -EINVAL;
811 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
812 "larger than the host's page size, and so "
813 "eCryptfs cannot run on this system. The "
814 "default eCryptfs extent size is [%u] bytes; "
815 "the page size is [%lu] bytes.\n",
816 ECRYPTFS_DEFAULT_EXTENT_SIZE,
817 (unsigned long)PAGE_SIZE);
818 goto out;
819 }
820 rc = ecryptfs_init_kmem_caches();
821 if (rc) {
822 printk(KERN_ERR
823 "Failed to allocate one or more kmem_cache objects\n");
824 goto out;
825 }
826 rc = do_sysfs_registration();
827 if (rc) {
828 printk(KERN_ERR "sysfs registration failed\n");
829 goto out_free_kmem_caches;
830 }
831 rc = ecryptfs_init_kthread();
832 if (rc) {
833 printk(KERN_ERR "%s: kthread initialization failed; "
834 "rc = [%d]\n", __func__, rc);
835 goto out_do_sysfs_unregistration;
836 }
837 rc = ecryptfs_init_messaging();
838 if (rc) {
839 printk(KERN_ERR "Failure occurred while attempting to "
840 "initialize the communications channel to "
841 "ecryptfsd\n");
842 goto out_destroy_kthread;
843 }
844 rc = ecryptfs_init_crypto();
845 if (rc) {
846 printk(KERN_ERR "Failure whilst attempting to init crypto; "
847 "rc = [%d]\n", rc);
848 goto out_release_messaging;
849 }
850 rc = register_filesystem(&ecryptfs_fs_type);
851 if (rc) {
852 printk(KERN_ERR "Failed to register filesystem\n");
853 goto out_destroy_crypto;
854 }
855 if (ecryptfs_verbosity > 0)
856 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
857 "will be written to the syslog!\n", ecryptfs_verbosity);
858
859 goto out;
860out_destroy_crypto:
861 ecryptfs_destroy_crypto();
862out_release_messaging:
863 ecryptfs_release_messaging();
864out_destroy_kthread:
865 ecryptfs_destroy_kthread();
866out_do_sysfs_unregistration:
867 do_sysfs_unregistration();
868out_free_kmem_caches:
869 ecryptfs_free_kmem_caches();
870out:
871 return rc;
872}
873
874static void __exit ecryptfs_exit(void)
875{
876 int rc;
877
878 rc = ecryptfs_destroy_crypto();
879 if (rc)
880 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
881 "rc = [%d]\n", rc);
882 ecryptfs_release_messaging();
883 ecryptfs_destroy_kthread();
884 do_sysfs_unregistration();
885 unregister_filesystem(&ecryptfs_fs_type);
886 ecryptfs_free_kmem_caches();
887}
888
889MODULE_AUTHOR("Michael A. Halcrow <[email protected]>");
890MODULE_DESCRIPTION("eCryptfs");
891
892MODULE_LICENSE("GPL");
893
894module_init(ecryptfs_init)
895module_exit(ecryptfs_exit)