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-rw-r--r--fs/ecryptfs/main.c831
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diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
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1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2003 Erez Zadok
5 * Copyright (C) 2001-2003 Stony Brook University
6 * Copyright (C) 2004-2006 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompson <mcthomps@us.ibm.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
23 * 02111-1307, USA.
24 */
25
26#include <linux/dcache.h>
27#include <linux/file.h>
28#include <linux/module.h>
29#include <linux/namei.h>
30#include <linux/skbuff.h>
31#include <linux/crypto.h>
32#include <linux/netlink.h>
33#include <linux/mount.h>
34#include <linux/dcache.h>
35#include <linux/pagemap.h>
36#include <linux/key.h>
37#include <linux/parser.h>
38#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
50void __ecryptfs_printk(const char *fmt, ...)
51{
52 va_list args;
53 va_start(args, fmt);
54 if (fmt[1] == '7') { /* KERN_DEBUG */
55 if (ecryptfs_verbosity >= 1)
56 vprintk(fmt, args);
57 } else
58 vprintk(fmt, args);
59 va_end(args);
60}
61
62/**
63 * ecryptfs_interpose
64 * @lower_dentry: Existing dentry in the lower filesystem
65 * @dentry: ecryptfs' dentry
66 * @sb: ecryptfs's super_block
67 * @flag: If set to true, then d_add is called, else d_instantiate is called
68 *
69 * Interposes upper and lower dentries.
70 *
71 * Returns zero on success; non-zero otherwise
72 */
73int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
74 struct super_block *sb, int flag)
75{
76 struct inode *lower_inode;
77 struct inode *inode;
78 int rc = 0;
79
80 lower_inode = lower_dentry->d_inode;
81 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
82 rc = -EXDEV;
83 goto out;
84 }
85 if (!igrab(lower_inode)) {
86 rc = -ESTALE;
87 goto out;
88 }
89 inode = iget5_locked(sb, (unsigned long)lower_inode,
90 ecryptfs_inode_test, ecryptfs_inode_set,
91 lower_inode);
92 if (!inode) {
93 rc = -EACCES;
94 iput(lower_inode);
95 goto out;
96 }
97 if (inode->i_state & I_NEW)
98 unlock_new_inode(inode);
99 else
100 iput(lower_inode);
101 if (S_ISLNK(lower_inode->i_mode))
102 inode->i_op = &ecryptfs_symlink_iops;
103 else if (S_ISDIR(lower_inode->i_mode))
104 inode->i_op = &ecryptfs_dir_iops;
105 if (S_ISDIR(lower_inode->i_mode))
106 inode->i_fop = &ecryptfs_dir_fops;
107 /* TODO: Is there a better way to identify if the inode is
108 * special? */
109 if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) ||
110 S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(lower_inode->i_mode))
111 init_special_inode(inode, lower_inode->i_mode,
112 lower_inode->i_rdev);
113 dentry->d_op = &ecryptfs_dops;
114 if (flag)
115 d_add(dentry, inode);
116 else
117 d_instantiate(dentry, inode);
118 ecryptfs_copy_attr_all(inode, lower_inode);
119 /* This size will be overwritten for real files w/ headers and
120 * other metadata */
121 ecryptfs_copy_inode_size(inode, lower_inode);
122out:
123 return rc;
124}
125
126enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
127 ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
128 ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
129 ecryptfs_opt_passthrough, ecryptfs_opt_err };
130
131static match_table_t tokens = {
132 {ecryptfs_opt_sig, "sig=%s"},
133 {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
134 {ecryptfs_opt_debug, "debug=%u"},
135 {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
136 {ecryptfs_opt_cipher, "cipher=%s"},
137 {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
138 {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
139 {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
140 {ecryptfs_opt_err, NULL}
141};
142
143/**
144 * ecryptfs_verify_version
145 * @version: The version number to confirm
146 *
147 * Returns zero on good version; non-zero otherwise
148 */
149static int ecryptfs_verify_version(u16 version)
150{
151 int rc = 0;
152 unsigned char major;
153 unsigned char minor;
154
155 major = ((version >> 8) & 0xFF);
156 minor = (version & 0xFF);
157 if (major != ECRYPTFS_VERSION_MAJOR) {
158 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
159 "Expected [%d]; got [%d]\n",
160 ECRYPTFS_VERSION_MAJOR, major);
161 rc = -EINVAL;
162 goto out;
163 }
164 if (minor != ECRYPTFS_VERSION_MINOR) {
165 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
166 "Expected [%d]; got [%d]\n",
167 ECRYPTFS_VERSION_MINOR, minor);
168 rc = -EINVAL;
169 goto out;
170 }
171out:
172 return rc;
173}
174
175/**
176 * ecryptfs_parse_options
177 * @sb: The ecryptfs super block
178 * @options: The options pased to the kernel
179 *
180 * Parse mount options:
181 * debug=N - ecryptfs_verbosity level for debug output
182 * sig=XXX - description(signature) of the key to use
183 *
184 * Returns the dentry object of the lower-level (lower/interposed)
185 * directory; We want to mount our stackable file system on top of
186 * that lower directory.
187 *
188 * The signature of the key to use must be the description of a key
189 * already in the keyring. Mounting will fail if the key can not be
190 * found.
191 *
192 * Returns zero on success; non-zero on error
193 */
194static int ecryptfs_parse_options(struct super_block *sb, char *options)
195{
196 char *p;
197 int rc = 0;
198 int sig_set = 0;
199 int cipher_name_set = 0;
200 int cipher_key_bytes;
201 int cipher_key_bytes_set = 0;
202 struct key *auth_tok_key = NULL;
203 struct ecryptfs_auth_tok *auth_tok = NULL;
204 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
205 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
206 substring_t args[MAX_OPT_ARGS];
207 int token;
208 char *sig_src;
209 char *sig_dst;
210 char *debug_src;
211 char *cipher_name_dst;
212 char *cipher_name_src;
213 char *cipher_key_bytes_src;
214 struct crypto_tfm *tmp_tfm;
215 int cipher_name_len;
216
217 if (!options) {
218 rc = -EINVAL;
219 goto out;
220 }
221 while ((p = strsep(&options, ",")) != NULL) {
222 if (!*p)
223 continue;
224 token = match_token(p, tokens, args);
225 switch (token) {
226 case ecryptfs_opt_sig:
227 case ecryptfs_opt_ecryptfs_sig:
228 sig_src = args[0].from;
229 sig_dst =
230 mount_crypt_stat->global_auth_tok_sig;
231 memcpy(sig_dst, sig_src, ECRYPTFS_SIG_SIZE_HEX);
232 sig_dst[ECRYPTFS_SIG_SIZE_HEX] = '\0';
233 ecryptfs_printk(KERN_DEBUG,
234 "The mount_crypt_stat "
235 "global_auth_tok_sig set to: "
236 "[%s]\n", sig_dst);
237 sig_set = 1;
238 break;
239 case ecryptfs_opt_debug:
240 case ecryptfs_opt_ecryptfs_debug:
241 debug_src = args[0].from;
242 ecryptfs_verbosity =
243 (int)simple_strtol(debug_src, &debug_src,
244 0);
245 ecryptfs_printk(KERN_DEBUG,
246 "Verbosity set to [%d]" "\n",
247 ecryptfs_verbosity);
248 break;
249 case ecryptfs_opt_cipher:
250 case ecryptfs_opt_ecryptfs_cipher:
251 cipher_name_src = args[0].from;
252 cipher_name_dst =
253 mount_crypt_stat->
254 global_default_cipher_name;
255 strncpy(cipher_name_dst, cipher_name_src,
256 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
257 ecryptfs_printk(KERN_DEBUG,
258 "The mount_crypt_stat "
259 "global_default_cipher_name set to: "
260 "[%s]\n", cipher_name_dst);
261 cipher_name_set = 1;
262 break;
263 case ecryptfs_opt_ecryptfs_key_bytes:
264 cipher_key_bytes_src = args[0].from;
265 cipher_key_bytes =
266 (int)simple_strtol(cipher_key_bytes_src,
267 &cipher_key_bytes_src, 0);
268 mount_crypt_stat->global_default_cipher_key_size =
269 cipher_key_bytes;
270 ecryptfs_printk(KERN_DEBUG,
271 "The mount_crypt_stat "
272 "global_default_cipher_key_size "
273 "set to: [%d]\n", mount_crypt_stat->
274 global_default_cipher_key_size);
275 cipher_key_bytes_set = 1;
276 break;
277 case ecryptfs_opt_passthrough:
278 mount_crypt_stat->flags |=
279 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
280 break;
281 case ecryptfs_opt_err:
282 default:
283 ecryptfs_printk(KERN_WARNING,
284 "eCryptfs: unrecognized option '%s'\n",
285 p);
286 }
287 }
288 /* Do not support lack of mount-wide signature in 0.1
289 * release */
290 if (!sig_set) {
291 rc = -EINVAL;
292 ecryptfs_printk(KERN_ERR, "You must supply a valid "
293 "passphrase auth tok signature as a mount "
294 "parameter; see the eCryptfs README\n");
295 goto out;
296 }
297 if (!cipher_name_set) {
298 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
299 if (unlikely(cipher_name_len
300 >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
301 rc = -EINVAL;
302 BUG();
303 goto out;
304 }
305 memcpy(mount_crypt_stat->global_default_cipher_name,
306 ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
307 mount_crypt_stat->global_default_cipher_name[cipher_name_len]
308 = '\0';
309 }
310 if (!cipher_key_bytes_set) {
311 mount_crypt_stat->global_default_cipher_key_size =
312 ECRYPTFS_DEFAULT_KEY_BYTES;
313 ecryptfs_printk(KERN_DEBUG, "Cipher key size was not "
314 "specified. Defaulting to [%d]\n",
315 mount_crypt_stat->
316 global_default_cipher_key_size);
317 }
318 rc = ecryptfs_process_cipher(
319 &tmp_tfm,
320 &mount_crypt_stat->global_key_tfm,
321 mount_crypt_stat->global_default_cipher_name,
322 mount_crypt_stat->global_default_cipher_key_size);
323 if (tmp_tfm)
324 crypto_free_tfm(tmp_tfm);
325 if (rc) {
326 printk(KERN_ERR "Error attempting to initialize cipher [%s] "
327 "with key size [%Zd] bytes; rc = [%d]\n",
328 mount_crypt_stat->global_default_cipher_name,
329 mount_crypt_stat->global_default_cipher_key_size, rc);
330 rc = -EINVAL;
331 goto out;
332 }
333 mutex_init(&mount_crypt_stat->global_key_tfm_mutex);
334 ecryptfs_printk(KERN_DEBUG, "Requesting the key with description: "
335 "[%s]\n", mount_crypt_stat->global_auth_tok_sig);
336 /* The reference to this key is held until umount is done The
337 * call to key_put is done in ecryptfs_put_super() */
338 auth_tok_key = request_key(&key_type_user,
339 mount_crypt_stat->global_auth_tok_sig,
340 NULL);
341 if (!auth_tok_key || IS_ERR(auth_tok_key)) {
342 ecryptfs_printk(KERN_ERR, "Could not find key with "
343 "description: [%s]\n",
344 mount_crypt_stat->global_auth_tok_sig);
345 process_request_key_err(PTR_ERR(auth_tok_key));
346 rc = -EINVAL;
347 goto out;
348 }
349 auth_tok = ecryptfs_get_key_payload_data(auth_tok_key);
350 if (ecryptfs_verify_version(auth_tok->version)) {
351 ecryptfs_printk(KERN_ERR, "Data structure version mismatch. "
352 "Userspace tools must match eCryptfs kernel "
353 "module with major version [%d] and minor "
354 "version [%d]\n", ECRYPTFS_VERSION_MAJOR,
355 ECRYPTFS_VERSION_MINOR);
356 rc = -EINVAL;
357 goto out;
358 }
359 if (auth_tok->token_type != ECRYPTFS_PASSWORD) {
360 ecryptfs_printk(KERN_ERR, "Invalid auth_tok structure "
361 "returned from key\n");
362 rc = -EINVAL;
363 goto out;
364 }
365 mount_crypt_stat->global_auth_tok_key = auth_tok_key;
366 mount_crypt_stat->global_auth_tok = auth_tok;
367out:
368 return rc;
369}
370
371struct kmem_cache *ecryptfs_sb_info_cache;
372
373/**
374 * ecryptfs_fill_super
375 * @sb: The ecryptfs super block
376 * @raw_data: The options passed to mount
377 * @silent: Not used but required by function prototype
378 *
379 * Sets up what we can of the sb, rest is done in ecryptfs_read_super
380 *
381 * Returns zero on success; non-zero otherwise
382 */
383static int
384ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
385{
386 int rc = 0;
387
388 /* Released in ecryptfs_put_super() */
389 ecryptfs_set_superblock_private(sb,
390 kmem_cache_alloc(ecryptfs_sb_info_cache,
391 SLAB_KERNEL));
392 if (!ecryptfs_superblock_to_private(sb)) {
393 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
394 rc = -ENOMEM;
395 goto out;
396 }
397 memset(ecryptfs_superblock_to_private(sb), 0,
398 sizeof(struct ecryptfs_sb_info));
399 sb->s_op = &ecryptfs_sops;
400 /* Released through deactivate_super(sb) from get_sb_nodev */
401 sb->s_root = d_alloc(NULL, &(const struct qstr) {
402 .hash = 0,.name = "/",.len = 1});
403 if (!sb->s_root) {
404 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
405 rc = -ENOMEM;
406 goto out;
407 }
408 sb->s_root->d_op = &ecryptfs_dops;
409 sb->s_root->d_sb = sb;
410 sb->s_root->d_parent = sb->s_root;
411 /* Released in d_release when dput(sb->s_root) is called */
412 /* through deactivate_super(sb) from get_sb_nodev() */
413 ecryptfs_set_dentry_private(sb->s_root,
414 kmem_cache_alloc(ecryptfs_dentry_info_cache,
415 SLAB_KERNEL));
416 if (!ecryptfs_dentry_to_private(sb->s_root)) {
417 ecryptfs_printk(KERN_ERR,
418 "dentry_info_cache alloc failed\n");
419 rc = -ENOMEM;
420 goto out;
421 }
422 memset(ecryptfs_dentry_to_private(sb->s_root), 0,
423 sizeof(struct ecryptfs_dentry_info));
424 rc = 0;
425out:
426 /* Should be able to rely on deactivate_super called from
427 * get_sb_nodev */
428 return rc;
429}
430
431/**
432 * ecryptfs_read_super
433 * @sb: The ecryptfs super block
434 * @dev_name: The path to mount over
435 *
436 * Read the super block of the lower filesystem, and use
437 * ecryptfs_interpose to create our initial inode and super block
438 * struct.
439 */
440static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
441{
442 int rc;
443 struct nameidata nd;
444 struct dentry *lower_root;
445 struct vfsmount *lower_mnt;
446
447 memset(&nd, 0, sizeof(struct nameidata));
448 rc = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
449 if (rc) {
450 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
451 goto out_free;
452 }
453 lower_root = nd.dentry;
454 if (!lower_root->d_inode) {
455 ecryptfs_printk(KERN_WARNING,
456 "No directory to interpose on\n");
457 rc = -ENOENT;
458 goto out_free;
459 }
460 lower_mnt = nd.mnt;
461 ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
462 sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
463 ecryptfs_set_dentry_lower(sb->s_root, lower_root);
464 ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
465 if ((rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0)))
466 goto out_free;
467 rc = 0;
468 goto out;
469out_free:
470 path_release(&nd);
471out:
472 return rc;
473}
474
475/**
476 * ecryptfs_get_sb
477 * @fs_type
478 * @flags
479 * @dev_name: The path to mount over
480 * @raw_data: The options passed into the kernel
481 *
482 * The whole ecryptfs_get_sb process is broken into 4 functions:
483 * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
484 * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
485 * with as much information as it can before needing
486 * the lower filesystem.
487 * ecryptfs_read_super(): this accesses the lower filesystem and uses
488 * ecryptfs_interpolate to perform most of the linking
489 * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
490 */
491static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
492 const char *dev_name, void *raw_data,
493 struct vfsmount *mnt)
494{
495 int rc;
496 struct super_block *sb;
497
498 rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
499 if (rc < 0) {
500 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
501 goto out;
502 }
503 sb = mnt->mnt_sb;
504 rc = ecryptfs_parse_options(sb, raw_data);
505 if (rc) {
506 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
507 goto out_abort;
508 }
509 rc = ecryptfs_read_super(sb, dev_name);
510 if (rc) {
511 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
512 goto out_abort;
513 }
514 goto out;
515out_abort:
516 dput(sb->s_root);
517 up_write(&sb->s_umount);
518 deactivate_super(sb);
519out:
520 return rc;
521}
522
523/**
524 * ecryptfs_kill_block_super
525 * @sb: The ecryptfs super block
526 *
527 * Used to bring the superblock down and free the private data.
528 * Private data is free'd in ecryptfs_put_super()
529 */
530static void ecryptfs_kill_block_super(struct super_block *sb)
531{
532 generic_shutdown_super(sb);
533}
534
535static struct file_system_type ecryptfs_fs_type = {
536 .owner = THIS_MODULE,
537 .name = "ecryptfs",
538 .get_sb = ecryptfs_get_sb,
539 .kill_sb = ecryptfs_kill_block_super,
540 .fs_flags = 0
541};
542
543/**
544 * inode_info_init_once
545 *
546 * Initializes the ecryptfs_inode_info_cache when it is created
547 */
548static void
549inode_info_init_once(void *vptr, struct kmem_cache *cachep, unsigned long flags)
550{
551 struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
552
553 if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
554 SLAB_CTOR_CONSTRUCTOR)
555 inode_init_once(&ei->vfs_inode);
556}
557
558static struct ecryptfs_cache_info {
559 kmem_cache_t **cache;
560 const char *name;
561 size_t size;
562 void (*ctor)(void*, struct kmem_cache *, unsigned long);
563} ecryptfs_cache_infos[] = {
564 {
565 .cache = &ecryptfs_auth_tok_list_item_cache,
566 .name = "ecryptfs_auth_tok_list_item",
567 .size = sizeof(struct ecryptfs_auth_tok_list_item),
568 },
569 {
570 .cache = &ecryptfs_file_info_cache,
571 .name = "ecryptfs_file_cache",
572 .size = sizeof(struct ecryptfs_file_info),
573 },
574 {
575 .cache = &ecryptfs_dentry_info_cache,
576 .name = "ecryptfs_dentry_info_cache",
577 .size = sizeof(struct ecryptfs_dentry_info),
578 },
579 {
580 .cache = &ecryptfs_inode_info_cache,
581 .name = "ecryptfs_inode_cache",
582 .size = sizeof(struct ecryptfs_inode_info),
583 .ctor = inode_info_init_once,
584 },
585 {
586 .cache = &ecryptfs_sb_info_cache,
587 .name = "ecryptfs_sb_cache",
588 .size = sizeof(struct ecryptfs_sb_info),
589 },
590 {
591 .cache = &ecryptfs_header_cache_0,
592 .name = "ecryptfs_headers_0",
593 .size = PAGE_CACHE_SIZE,
594 },
595 {
596 .cache = &ecryptfs_header_cache_1,
597 .name = "ecryptfs_headers_1",
598 .size = PAGE_CACHE_SIZE,
599 },
600 {
601 .cache = &ecryptfs_header_cache_2,
602 .name = "ecryptfs_headers_2",
603 .size = PAGE_CACHE_SIZE,
604 },
605 {
606 .cache = &ecryptfs_lower_page_cache,
607 .name = "ecryptfs_lower_page_cache",
608 .size = PAGE_CACHE_SIZE,
609 },
610};
611
612static void ecryptfs_free_kmem_caches(void)
613{
614 int i;
615
616 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
617 struct ecryptfs_cache_info *info;
618
619 info = &ecryptfs_cache_infos[i];
620 if (*(info->cache))
621 kmem_cache_destroy(*(info->cache));
622 }
623}
624
625/**
626 * ecryptfs_init_kmem_caches
627 *
628 * Returns zero on success; non-zero otherwise
629 */
630static int ecryptfs_init_kmem_caches(void)
631{
632 int i;
633
634 for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
635 struct ecryptfs_cache_info *info;
636
637 info = &ecryptfs_cache_infos[i];
638 *(info->cache) = kmem_cache_create(info->name, info->size,
639 0, SLAB_HWCACHE_ALIGN, info->ctor, NULL);
640 if (!*(info->cache)) {
641 ecryptfs_free_kmem_caches();
642 ecryptfs_printk(KERN_WARNING, "%s: "
643 "kmem_cache_create failed\n",
644 info->name);
645 return -ENOMEM;
646 }
647 }
648 return 0;
649}
650
651struct ecryptfs_obj {
652 char *name;
653 struct list_head slot_list;
654 struct kobject kobj;
655};
656
657struct ecryptfs_attribute {
658 struct attribute attr;
659 ssize_t(*show) (struct ecryptfs_obj *, char *);
660 ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t);
661};
662
663static ssize_t
664ecryptfs_attr_store(struct kobject *kobj,
665 struct attribute *attr, const char *buf, size_t len)
666{
667 struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
668 kobj);
669 struct ecryptfs_attribute *attribute =
670 container_of(attr, struct ecryptfs_attribute, attr);
671
672 return (attribute->store ? attribute->store(obj, buf, len) : 0);
673}
674
675static ssize_t
676ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
677{
678 struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
679 kobj);
680 struct ecryptfs_attribute *attribute =
681 container_of(attr, struct ecryptfs_attribute, attr);
682
683 return (attribute->show ? attribute->show(obj, buf) : 0);
684}
685
686static struct sysfs_ops ecryptfs_sysfs_ops = {
687 .show = ecryptfs_attr_show,
688 .store = ecryptfs_attr_store
689};
690
691static struct kobj_type ecryptfs_ktype = {
692 .sysfs_ops = &ecryptfs_sysfs_ops
693};
694
695static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL);
696
697static ssize_t version_show(struct ecryptfs_obj *obj, char *buff)
698{
699 return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
700}
701
702static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version);
703
704struct ecryptfs_version_str_map_elem {
705 u32 flag;
706 char *str;
707} ecryptfs_version_str_map[] = {
708 {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"},
709 {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"},
710 {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"},
711 {ECRYPTFS_VERSIONING_POLICY, "policy"}
712};
713
714static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff)
715{
716 int i;
717 int remaining = PAGE_SIZE;
718 int total_written = 0;
719
720 buff[0] = '\0';
721 for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) {
722 int entry_size;
723
724 if (!(ECRYPTFS_VERSIONING_MASK
725 & ecryptfs_version_str_map[i].flag))
726 continue;
727 entry_size = strlen(ecryptfs_version_str_map[i].str);
728 if ((entry_size + 2) > remaining)
729 goto out;
730 memcpy(buff, ecryptfs_version_str_map[i].str, entry_size);
731 buff[entry_size++] = '\n';
732 buff[entry_size] = '\0';
733 buff += entry_size;
734 total_written += entry_size;
735 remaining -= entry_size;
736 }
737out:
738 return total_written;
739}
740
741static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str);
742
743static int do_sysfs_registration(void)
744{
745 int rc;
746
747 if ((rc = subsystem_register(&ecryptfs_subsys))) {
748 printk(KERN_ERR
749 "Unable to register ecryptfs sysfs subsystem\n");
750 goto out;
751 }
752 rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj,
753 &sysfs_attr_version.attr);
754 if (rc) {
755 printk(KERN_ERR
756 "Unable to create ecryptfs version attribute\n");
757 subsystem_unregister(&ecryptfs_subsys);
758 goto out;
759 }
760 rc = sysfs_create_file(&ecryptfs_subsys.kset.kobj,
761 &sysfs_attr_version_str.attr);
762 if (rc) {
763 printk(KERN_ERR
764 "Unable to create ecryptfs version_str attribute\n");
765 sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
766 &sysfs_attr_version.attr);
767 subsystem_unregister(&ecryptfs_subsys);
768 goto out;
769 }
770out:
771 return rc;
772}
773
774static int __init ecryptfs_init(void)
775{
776 int rc;
777
778 if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
779 rc = -EINVAL;
780 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
781 "larger than the host's page size, and so "
782 "eCryptfs cannot run on this system. The "
783 "default eCryptfs extent size is [%d] bytes; "
784 "the page size is [%d] bytes.\n",
785 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
786 goto out;
787 }
788 rc = ecryptfs_init_kmem_caches();
789 if (rc) {
790 printk(KERN_ERR
791 "Failed to allocate one or more kmem_cache objects\n");
792 goto out;
793 }
794 rc = register_filesystem(&ecryptfs_fs_type);
795 if (rc) {
796 printk(KERN_ERR "Failed to register filesystem\n");
797 ecryptfs_free_kmem_caches();
798 goto out;
799 }
800 kset_set_kset_s(&ecryptfs_subsys, fs_subsys);
801 sysfs_attr_version.attr.owner = THIS_MODULE;
802 sysfs_attr_version_str.attr.owner = THIS_MODULE;
803 rc = do_sysfs_registration();
804 if (rc) {
805 printk(KERN_ERR "sysfs registration failed\n");
806 unregister_filesystem(&ecryptfs_fs_type);
807 ecryptfs_free_kmem_caches();
808 goto out;
809 }
810out:
811 return rc;
812}
813
814static void __exit ecryptfs_exit(void)
815{
816 sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
817 &sysfs_attr_version.attr);
818 sysfs_remove_file(&ecryptfs_subsys.kset.kobj,
819 &sysfs_attr_version_str.attr);
820 subsystem_unregister(&ecryptfs_subsys);
821 unregister_filesystem(&ecryptfs_fs_type);
822 ecryptfs_free_kmem_caches();
823}
824
825MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
826MODULE_DESCRIPTION("eCryptfs");
827
828MODULE_LICENSE("GPL");
829
830module_init(ecryptfs_init)
831module_exit(ecryptfs_exit)
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-26 11:38:41 -0500