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/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/magic.h>
27#include "ecryptfs_kernel.h"
28
29/*
30 * Module parameter that defines the ecryptfs_verbosity level.
31 */
32int ecryptfs_verbosity = 0;
33
34module_param(ecryptfs_verbosity, int, 0);
35MODULE_PARM_DESC(ecryptfs_verbosity,
36 "Initial verbosity level (0 or 1; defaults to "
37 "0, which is Quiet)");
38
39/*
40 * Module parameter that defines the number of message buffer elements
41 */
42unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
43
44module_param(ecryptfs_message_buf_len, uint, 0);
45MODULE_PARM_DESC(ecryptfs_message_buf_len,
46 "Number of message buffer elements");
47
48/*
49 * Module parameter that defines the maximum guaranteed amount of time to wait
50 * for a response from ecryptfsd. The actual sleep time will be, more than
51 * likely, a small amount greater than this specified value, but only less if
52 * the message successfully arrives.
53 */
54signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
55
56module_param(ecryptfs_message_wait_timeout, long, 0);
57MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
58 "Maximum number of seconds that an operation will "
59 "sleep while waiting for a message response from "
60 "userspace");
61
62/*
63 * Module parameter that is an estimate of the maximum number of users
64 * that will be concurrently using eCryptfs. Set this to the right
65 * value to balance performance and memory use.
66 */
67unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
68
69module_param(ecryptfs_number_of_users, uint, 0);
70MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
71 "concurrent users of eCryptfs");
72
73void __ecryptfs_printk(const char *fmt, ...)
74{
75 va_list args;
76 va_start(args, fmt);
77 if (fmt[1] == '7') { /* KERN_DEBUG */
78 if (ecryptfs_verbosity >= 1)
79 vprintk(fmt, args);
80 } else
81 vprintk(fmt, args);
82 va_end(args);
83}
84
85/*
86 * ecryptfs_init_lower_file
87 * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
88 * the lower dentry and the lower mount set
89 *
90 * eCryptfs only ever keeps a single open file for every lower
91 * inode. All I/O operations to the lower inode occur through that
92 * file. When the first eCryptfs dentry that interposes with the first
93 * lower dentry for that inode is created, this function creates the
94 * lower file struct and associates it with the eCryptfs
95 * inode. When all eCryptfs files associated with the inode are released, the
96 * file is closed.
97 *
98 * The lower file will be opened with read/write permissions, if
99 * possible. Otherwise, it is opened read-only.
100 *
101 * This function does nothing if a lower file is already
102 * associated with the eCryptfs inode.
103 *
104 * Returns zero on success; non-zero otherwise
105 */
106static int ecryptfs_init_lower_file(struct dentry *dentry,
107 struct file **lower_file)
108{
109 const struct cred *cred = current_cred();
110 struct path path = ecryptfs_lower_path(dentry);
111 int rc;
112
113 rc = ecryptfs_privileged_open(lower_file, lower_dentry: path.dentry, lower_mnt: path.mnt, 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
123int 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(v: &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 lower_file: &inode_info->lower_file);
136 if (rc)
137 atomic_set(v: &inode_info->lower_file_count, i: 0);
138 }
139 mutex_unlock(lock: &inode_info->lower_file_mutex);
140 return rc;
141}
142
143void 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(cnt: &inode_info->lower_file_count,
149 lock: &inode_info->lower_file_mutex)) {
150 filemap_write_and_wait(mapping: inode->i_mapping);
151 fput(inode_info->lower_file);
152 inode_info->lower_file = NULL;
153 mutex_unlock(lock: &inode_info->lower_file_mutex);
154 }
155}
156
157enum {
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
165static 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
183static 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 auth_tok_key: &global_auth_tok->global_auth_tok_key, auth_tok: &auth_tok,
195 sig: 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(sem: &(global_auth_tok->global_auth_tok_key)->sem);
205 }
206 }
207out:
208 return rc;
209}
210
211static 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(list: &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
221struct 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 */
242static 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, desc: ecryptfs_fs_param_spec, param, result: &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 sig: param->string, global_auth_tok_flags: 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 sig: 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
335static 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(p: 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(p: mount_crypt_stat->global_default_fn_cipher_name,
363 q: 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 cipher_name: mount_crypt_stat->global_default_cipher_name,
373 key_bytes: 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(cipher_name: mount_crypt_stat->global_default_cipher_name,
384 NULL)) {
385 rc = ecryptfs_add_new_key_tfm(
386 NULL, cipher_name: mount_crypt_stat->global_default_cipher_name,
387 key_size: 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(lock: &key_tfm_list_mutex);
397 goto out;
398 }
399 }
400 if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
401 && !ecryptfs_tfm_exists(
402 cipher_name: mount_crypt_stat->global_default_fn_cipher_name, NULL)) {
403 rc = ecryptfs_add_new_key_tfm(
404 NULL, cipher_name: mount_crypt_stat->global_default_fn_cipher_name,
405 key_size: 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(lock: &key_tfm_list_mutex);
415 goto out;
416 }
417 }
418 mutex_unlock(lock: &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);
423out:
424 return rc;
425}
426
427struct kmem_cache *ecryptfs_sb_info_cache;
428static struct file_system_type ecryptfs_fs_type;
429
430/*
431 * ecryptfs_get_tree
432 * @fc: The filesystem context
433 */
434static 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 const char *err = "Getting sb failed";
441 struct inode *inode;
442 struct path path;
443 int rc;
444
445 if (!fc->source) {
446 rc = -EINVAL;
447 err = "Device name cannot be null";
448 goto out;
449 }
450
451 mount_crypt_stat = &sbi->mount_crypt_stat;
452 rc = ecryptfs_validate_options(fc);
453 if (rc) {
454 err = "Error validating options";
455 goto out;
456 }
457
458 if (fips_enabled) {
459 rc = -EINVAL;
460 err = "eCryptfs support is disabled due to FIPS";
461 goto out;
462 }
463
464 s = sget_fc(fc, NULL, set: set_anon_super_fc);
465 if (IS_ERR(ptr: s)) {
466 rc = PTR_ERR(ptr: s);
467 goto out;
468 }
469
470 rc = super_setup_bdi(sb: s);
471 if (rc)
472 goto out1;
473
474 ecryptfs_set_superblock_private(sb: s, sb_info: sbi);
475
476 /* ->kill_sb() will take care of sbi after that point */
477 sbi = NULL;
478 s->s_op = &ecryptfs_sops;
479 s->s_xattr = ecryptfs_xattr_handlers;
480 set_default_d_op(s, &ecryptfs_dops);
481
482 err = "Reading sb failed";
483 rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
484 if (rc) {
485 ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
486 goto out1;
487 }
488 if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) {
489 rc = -EINVAL;
490 printk(KERN_ERR "Mount on filesystem of type "
491 "eCryptfs explicitly disallowed due to "
492 "known incompatibilities\n");
493 goto out_free;
494 }
495
496 if (is_idmapped_mnt(mnt: path.mnt)) {
497 rc = -EINVAL;
498 printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n");
499 goto out_free;
500 }
501
502 if (ctx->check_ruid &&
503 !uid_eq(left: d_inode(dentry: path.dentry)->i_uid, current_uid())) {
504 rc = -EPERM;
505 printk(KERN_ERR "Mount of device (uid: %d) not owned by "
506 "requested user (uid: %d)\n",
507 i_uid_read(d_inode(path.dentry)),
508 from_kuid(&init_user_ns, current_uid()));
509 goto out_free;
510 }
511
512 ecryptfs_set_superblock_lower(sb: s, lower_sb: path.dentry->d_sb);
513
514 /**
515 * Set the POSIX ACL flag based on whether they're enabled in the lower
516 * mount.
517 */
518 s->s_flags = fc->sb_flags & ~SB_POSIXACL;
519 s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
520
521 /**
522 * Force a read-only eCryptfs mount when:
523 * 1) The lower mount is ro
524 * 2) The ecryptfs_encrypted_view mount option is specified
525 */
526 if (sb_rdonly(sb: path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
527 s->s_flags |= SB_RDONLY;
528
529 s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
530 s->s_blocksize = path.dentry->d_sb->s_blocksize;
531 s->s_magic = ECRYPTFS_SUPER_MAGIC;
532 s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
533
534 rc = -EINVAL;
535 if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
536 pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
537 goto out_free;
538 }
539
540 inode = ecryptfs_get_inode(lower_inode: d_inode(dentry: path.dentry), sb: s);
541 rc = PTR_ERR(ptr: inode);
542 if (IS_ERR(ptr: inode))
543 goto out_free;
544
545 s->s_root = d_make_root(inode);
546 if (!s->s_root) {
547 rc = -ENOMEM;
548 goto out_free;
549 }
550
551 ecryptfs_set_dentry_lower(dentry: s->s_root, lower_dentry: path.dentry);
552 ecryptfs_superblock_to_private(sb: s)->lower_mnt = path.mnt;
553
554 s->s_flags |= SB_ACTIVE;
555 fc->root = dget(dentry: s->s_root);
556 return 0;
557
558out_free:
559 path_put(&path);
560out1:
561 deactivate_locked_super(sb: s);
562out:
563 if (sbi)
564 ecryptfs_destroy_mount_crypt_stat(mount_crypt_stat: &sbi->mount_crypt_stat);
565
566 printk(KERN_ERR "%s; rc = [%d]\n", err, rc);
567 return rc;
568}
569
570/**
571 * ecryptfs_kill_block_super
572 * @sb: The ecryptfs super block
573 *
574 * Used to bring the superblock down and free the private data.
575 */
576static void ecryptfs_kill_block_super(struct super_block *sb)
577{
578 struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
579 kill_anon_super(sb);
580 if (!sb_info)
581 return;
582 mntput(mnt: sb_info->lower_mnt);
583 ecryptfs_destroy_mount_crypt_stat(mount_crypt_stat: &sb_info->mount_crypt_stat);
584 kmem_cache_free(s: ecryptfs_sb_info_cache, objp: sb_info);
585}
586
587static 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(objp: ctx);
593
594 if (sbi) {
595 ecryptfs_destroy_mount_crypt_stat(mount_crypt_stat: &sbi->mount_crypt_stat);
596 kmem_cache_free(s: ecryptfs_sb_info_cache, objp: sbi);
597 }
598}
599
600static 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
607static 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(objp: ctx);
618 ctx = NULL;
619 return -ENOMEM;
620 }
621
622 ecryptfs_init_mount_crypt_stat(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
630static 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};
638MODULE_ALIAS_FS("ecryptfs");
639
640/*
641 * inode_info_init_once
642 *
643 * Initializes the ecryptfs_inode_info_cache when it is created
644 */
645static void
646inode_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
653static 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_inode_info_cache,
672 .name = "ecryptfs_inode_cache",
673 .size = sizeof(struct ecryptfs_inode_info),
674 .flags = SLAB_ACCOUNT,
675 .ctor = inode_info_init_once,
676 },
677 {
678 .cache = &ecryptfs_sb_info_cache,
679 .name = "ecryptfs_sb_cache",
680 .size = sizeof(struct ecryptfs_sb_info),
681 },
682 {
683 .cache = &ecryptfs_header_cache,
684 .name = "ecryptfs_headers",
685 .size = PAGE_SIZE,
686 },
687 {
688 .cache = &ecryptfs_xattr_cache,
689 .name = "ecryptfs_xattr_cache",
690 .size = PAGE_SIZE,
691 },
692 {
693 .cache = &ecryptfs_key_record_cache,
694 .name = "ecryptfs_key_record_cache",
695 .size = sizeof(struct ecryptfs_key_record),
696 },
697 {
698 .cache = &ecryptfs_key_sig_cache,
699 .name = "ecryptfs_key_sig_cache",
700 .size = sizeof(struct ecryptfs_key_sig),
701 },
702 {
703 .cache = &ecryptfs_global_auth_tok_cache,
704 .name = "ecryptfs_global_auth_tok_cache",
705 .size = sizeof(struct ecryptfs_global_auth_tok),
706 },
707 {
708 .cache = &ecryptfs_key_tfm_cache,
709 .name = "ecryptfs_key_tfm_cache",
710 .size = sizeof(struct ecryptfs_key_tfm),
711 },
712};
713
714static void ecryptfs_free_kmem_caches(void)
715{
716 int i;
717
718 /*
719 * Make sure all delayed rcu free inodes are flushed before we
720 * destroy cache.
721 */
722 rcu_barrier();
723
724 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
725 struct ecryptfs_cache_info *info;
726
727 info = &ecryptfs_cache_infos[i];
728 kmem_cache_destroy(s: *(info->cache));
729 }
730}
731
732/**
733 * ecryptfs_init_kmem_caches
734 *
735 * Returns zero on success; non-zero otherwise
736 */
737static int ecryptfs_init_kmem_caches(void)
738{
739 int i;
740
741 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
742 struct ecryptfs_cache_info *info;
743
744 info = &ecryptfs_cache_infos[i];
745 *(info->cache) = kmem_cache_create(info->name, info->size, 0,
746 SLAB_HWCACHE_ALIGN | info->flags, info->ctor);
747 if (!*(info->cache)) {
748 ecryptfs_free_kmem_caches();
749 ecryptfs_printk(KERN_WARNING, "%s: "
750 "kmem_cache_create failed\n",
751 info->name);
752 return -ENOMEM;
753 }
754 }
755 return 0;
756}
757
758static struct kobject *ecryptfs_kobj;
759
760static ssize_t version_show(struct kobject *kobj,
761 struct kobj_attribute *attr, char *buff)
762{
763 return sysfs_emit(buf: buff, fmt: "%d\n", ECRYPTFS_VERSIONING_MASK);
764}
765
766static struct kobj_attribute version_attr = __ATTR_RO(version);
767
768static struct attribute *attributes[] = {
769 &version_attr.attr,
770 NULL,
771};
772
773static const struct attribute_group attr_group = {
774 .attrs = attributes,
775};
776
777static int do_sysfs_registration(void)
778{
779 int rc;
780
781 ecryptfs_kobj = kobject_create_and_add(name: "ecryptfs", parent: fs_kobj);
782 if (!ecryptfs_kobj) {
783 printk(KERN_ERR "Unable to create ecryptfs kset\n");
784 rc = -ENOMEM;
785 goto out;
786 }
787 rc = sysfs_create_group(kobj: ecryptfs_kobj, grp: &attr_group);
788 if (rc) {
789 printk(KERN_ERR
790 "Unable to create ecryptfs version attributes\n");
791 kobject_put(kobj: ecryptfs_kobj);
792 }
793out:
794 return rc;
795}
796
797static void do_sysfs_unregistration(void)
798{
799 sysfs_remove_group(kobj: ecryptfs_kobj, grp: &attr_group);
800 kobject_put(kobj: ecryptfs_kobj);
801}
802
803static int __init ecryptfs_init(void)
804{
805 int rc;
806
807 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) {
808 rc = -EINVAL;
809 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
810 "larger than the host's page size, and so "
811 "eCryptfs cannot run on this system. The "
812 "default eCryptfs extent size is [%u] bytes; "
813 "the page size is [%lu] bytes.\n",
814 ECRYPTFS_DEFAULT_EXTENT_SIZE,
815 (unsigned long)PAGE_SIZE);
816 goto out;
817 }
818 rc = ecryptfs_init_kmem_caches();
819 if (rc) {
820 printk(KERN_ERR
821 "Failed to allocate one or more kmem_cache objects\n");
822 goto out;
823 }
824 rc = do_sysfs_registration();
825 if (rc) {
826 printk(KERN_ERR "sysfs registration failed\n");
827 goto out_free_kmem_caches;
828 }
829 rc = ecryptfs_init_kthread();
830 if (rc) {
831 printk(KERN_ERR "%s: kthread initialization failed; "
832 "rc = [%d]\n", __func__, rc);
833 goto out_do_sysfs_unregistration;
834 }
835 rc = ecryptfs_init_messaging();
836 if (rc) {
837 printk(KERN_ERR "Failure occurred while attempting to "
838 "initialize the communications channel to "
839 "ecryptfsd\n");
840 goto out_destroy_kthread;
841 }
842 rc = ecryptfs_init_crypto();
843 if (rc) {
844 printk(KERN_ERR "Failure whilst attempting to init crypto; "
845 "rc = [%d]\n", rc);
846 goto out_release_messaging;
847 }
848 rc = register_filesystem(&ecryptfs_fs_type);
849 if (rc) {
850 printk(KERN_ERR "Failed to register filesystem\n");
851 goto out_destroy_crypto;
852 }
853 if (ecryptfs_verbosity > 0)
854 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
855 "will be written to the syslog!\n", ecryptfs_verbosity);
856
857 goto out;
858out_destroy_crypto:
859 ecryptfs_destroy_crypto();
860out_release_messaging:
861 ecryptfs_release_messaging();
862out_destroy_kthread:
863 ecryptfs_destroy_kthread();
864out_do_sysfs_unregistration:
865 do_sysfs_unregistration();
866out_free_kmem_caches:
867 ecryptfs_free_kmem_caches();
868out:
869 return rc;
870}
871
872static void __exit ecryptfs_exit(void)
873{
874 int rc;
875
876 rc = ecryptfs_destroy_crypto();
877 if (rc)
878 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
879 "rc = [%d]\n", rc);
880 ecryptfs_release_messaging();
881 ecryptfs_destroy_kthread();
882 do_sysfs_unregistration();
883 unregister_filesystem(&ecryptfs_fs_type);
884 ecryptfs_free_kmem_caches();
885}
886
887MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
888MODULE_DESCRIPTION("eCryptfs");
889
890MODULE_LICENSE("GPL");
891
892module_init(ecryptfs_init)
893module_exit(ecryptfs_exit)
894

source code of linux/fs/ecryptfs/main.c