ecryptfs: clean up attribute mess
[linux-2.6.git] / fs / ecryptfs / main.c
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) 2004-2007 International Business Machines Corp.
7  *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8  *              Michael C. Thompson <mcthomps@us.ibm.com>
9  *              Tyler Hicks <tyhicks@ou.edu>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of the
14  * License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
24  * 02111-1307, USA.
25  */
26
27 #include <linux/dcache.h>
28 #include <linux/file.h>
29 #include <linux/module.h>
30 #include <linux/namei.h>
31 #include <linux/skbuff.h>
32 #include <linux/crypto.h>
33 #include <linux/netlink.h>
34 #include <linux/mount.h>
35 #include <linux/pagemap.h>
36 #include <linux/key.h>
37 #include <linux/parser.h>
38 #include <linux/fs_stack.h>
39 #include "ecryptfs_kernel.h"
40
41 /**
42  * Module parameter that defines the ecryptfs_verbosity level.
43  */
44 int ecryptfs_verbosity = 0;
45
46 module_param(ecryptfs_verbosity, int, 0);
47 MODULE_PARM_DESC(ecryptfs_verbosity,
48                  "Initial verbosity level (0 or 1; defaults to "
49                  "0, which is Quiet)");
50
51 /**
52  * Module parameter that defines the number of netlink message buffer
53  * elements
54  */
55 unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS;
56
57 module_param(ecryptfs_message_buf_len, uint, 0);
58 MODULE_PARM_DESC(ecryptfs_message_buf_len,
59                  "Number of message buffer elements");
60
61 /**
62  * Module parameter that defines the maximum guaranteed amount of time to wait
63  * for a response through netlink.  The actual sleep time will be, more than
64  * likely, a small amount greater than this specified value, but only less if
65  * the netlink message successfully arrives.
66  */
67 signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ;
68
69 module_param(ecryptfs_message_wait_timeout, long, 0);
70 MODULE_PARM_DESC(ecryptfs_message_wait_timeout,
71                  "Maximum number of seconds that an operation will "
72                  "sleep while waiting for a message response from "
73                  "userspace");
74
75 /**
76  * Module parameter that is an estimate of the maximum number of users
77  * that will be concurrently using eCryptfs. Set this to the right
78  * value to balance performance and memory use.
79  */
80 unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS;
81
82 module_param(ecryptfs_number_of_users, uint, 0);
83 MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of "
84                  "concurrent users of eCryptfs");
85
86 unsigned int ecryptfs_transport = ECRYPTFS_DEFAULT_TRANSPORT;
87
88 void __ecryptfs_printk(const char *fmt, ...)
89 {
90         va_list args;
91         va_start(args, fmt);
92         if (fmt[1] == '7') { /* KERN_DEBUG */
93                 if (ecryptfs_verbosity >= 1)
94                         vprintk(fmt, args);
95         } else
96                 vprintk(fmt, args);
97         va_end(args);
98 }
99
100 /**
101  * ecryptfs_init_persistent_file
102  * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with
103  *                   the lower dentry and the lower mount set
104  *
105  * eCryptfs only ever keeps a single open file for every lower
106  * inode. All I/O operations to the lower inode occur through that
107  * file. When the first eCryptfs dentry that interposes with the first
108  * lower dentry for that inode is created, this function creates the
109  * persistent file struct and associates it with the eCryptfs
110  * inode. When the eCryptfs inode is destroyed, the file is closed.
111  *
112  * The persistent file will be opened with read/write permissions, if
113  * possible. Otherwise, it is opened read-only.
114  *
115  * This function does nothing if a lower persistent file is already
116  * associated with the eCryptfs inode.
117  *
118  * Returns zero on success; non-zero otherwise
119  */
120 int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry)
121 {
122         struct ecryptfs_inode_info *inode_info =
123                 ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
124         int rc = 0;
125
126         mutex_lock(&inode_info->lower_file_mutex);
127         if (!inode_info->lower_file) {
128                 struct dentry *lower_dentry;
129                 struct vfsmount *lower_mnt =
130                         ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
131
132                 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
133                 /* Corresponding dput() and mntput() are done when the
134                  * persistent file is fput() when the eCryptfs inode
135                  * is destroyed. */
136                 dget(lower_dentry);
137                 mntget(lower_mnt);
138                 inode_info->lower_file = dentry_open(lower_dentry,
139                                                      lower_mnt,
140                                                      (O_RDWR | O_LARGEFILE));
141                 if (IS_ERR(inode_info->lower_file)) {
142                         dget(lower_dentry);
143                         mntget(lower_mnt);
144                         inode_info->lower_file = dentry_open(lower_dentry,
145                                                              lower_mnt,
146                                                              (O_RDONLY
147                                                               | O_LARGEFILE));
148                 }
149                 if (IS_ERR(inode_info->lower_file)) {
150                         printk(KERN_ERR "Error opening lower persistent file "
151                                "for lower_dentry [0x%p] and lower_mnt [0x%p]\n",
152                                lower_dentry, lower_mnt);
153                         rc = PTR_ERR(inode_info->lower_file);
154                         inode_info->lower_file = NULL;
155                 }
156         }
157         mutex_unlock(&inode_info->lower_file_mutex);
158         return rc;
159 }
160
161 /**
162  * ecryptfs_interpose
163  * @lower_dentry: Existing dentry in the lower filesystem
164  * @dentry: ecryptfs' dentry
165  * @sb: ecryptfs's super_block
166  * @flag: If set to true, then d_add is called, else d_instantiate is called
167  *
168  * Interposes upper and lower dentries.
169  *
170  * Returns zero on success; non-zero otherwise
171  */
172 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
173                        struct super_block *sb, int flag)
174 {
175         struct inode *lower_inode;
176         struct inode *inode;
177         int rc = 0;
178
179         lower_inode = lower_dentry->d_inode;
180         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
181                 rc = -EXDEV;
182                 goto out;
183         }
184         if (!igrab(lower_inode)) {
185                 rc = -ESTALE;
186                 goto out;
187         }
188         inode = iget5_locked(sb, (unsigned long)lower_inode,
189                              ecryptfs_inode_test, ecryptfs_inode_set,
190                              lower_inode);
191         if (!inode) {
192                 rc = -EACCES;
193                 iput(lower_inode);
194                 goto out;
195         }
196         if (inode->i_state & I_NEW)
197                 unlock_new_inode(inode);
198         else
199                 iput(lower_inode);
200         if (S_ISLNK(lower_inode->i_mode))
201                 inode->i_op = &ecryptfs_symlink_iops;
202         else if (S_ISDIR(lower_inode->i_mode))
203                 inode->i_op = &ecryptfs_dir_iops;
204         if (S_ISDIR(lower_inode->i_mode))
205                 inode->i_fop = &ecryptfs_dir_fops;
206         if (special_file(lower_inode->i_mode))
207                 init_special_inode(inode, lower_inode->i_mode,
208                                    lower_inode->i_rdev);
209         dentry->d_op = &ecryptfs_dops;
210         if (flag)
211                 d_add(dentry, inode);
212         else
213                 d_instantiate(dentry, inode);
214         fsstack_copy_attr_all(inode, lower_inode, NULL);
215         /* This size will be overwritten for real files w/ headers and
216          * other metadata */
217         fsstack_copy_inode_size(inode, lower_inode);
218         rc = ecryptfs_init_persistent_file(dentry);
219         if (rc) {
220                 printk(KERN_ERR "%s: Error attempting to initialize the "
221                        "persistent file for the dentry with name [%s]; "
222                        "rc = [%d]\n", __FUNCTION__, dentry->d_name.name, rc);
223                 goto out;
224         }
225 out:
226         return rc;
227 }
228
229 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
230        ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
231        ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
232        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
233        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
234
235 static match_table_t tokens = {
236         {ecryptfs_opt_sig, "sig=%s"},
237         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
238         {ecryptfs_opt_debug, "debug=%u"},
239         {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
240         {ecryptfs_opt_cipher, "cipher=%s"},
241         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
242         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
243         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
244         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
245         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
246         {ecryptfs_opt_err, NULL}
247 };
248
249 static int ecryptfs_init_global_auth_toks(
250         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
251 {
252         struct ecryptfs_global_auth_tok *global_auth_tok;
253         int rc = 0;
254
255         list_for_each_entry(global_auth_tok,
256                             &mount_crypt_stat->global_auth_tok_list,
257                             mount_crypt_stat_list) {
258                 rc = ecryptfs_keyring_auth_tok_for_sig(
259                         &global_auth_tok->global_auth_tok_key,
260                         &global_auth_tok->global_auth_tok,
261                         global_auth_tok->sig);
262                 if (rc) {
263                         printk(KERN_ERR "Could not find valid key in user "
264                                "session keyring for sig specified in mount "
265                                "option: [%s]\n", global_auth_tok->sig);
266                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
267                         rc = 0;
268                 } else
269                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
270         }
271         return rc;
272 }
273
274 static void ecryptfs_init_mount_crypt_stat(
275         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
276 {
277         memset((void *)mount_crypt_stat, 0,
278                sizeof(struct ecryptfs_mount_crypt_stat));
279         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
280         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
281         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
282 }
283
284 /**
285  * ecryptfs_parse_options
286  * @sb: The ecryptfs super block
287  * @options: The options pased to the kernel
288  *
289  * Parse mount options:
290  * debug=N         - ecryptfs_verbosity level for debug output
291  * sig=XXX         - description(signature) of the key to use
292  *
293  * Returns the dentry object of the lower-level (lower/interposed)
294  * directory; We want to mount our stackable file system on top of
295  * that lower directory.
296  *
297  * The signature of the key to use must be the description of a key
298  * already in the keyring. Mounting will fail if the key can not be
299  * found.
300  *
301  * Returns zero on success; non-zero on error
302  */
303 static int ecryptfs_parse_options(struct super_block *sb, char *options)
304 {
305         char *p;
306         int rc = 0;
307         int sig_set = 0;
308         int cipher_name_set = 0;
309         int cipher_key_bytes;
310         int cipher_key_bytes_set = 0;
311         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
312                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
313         substring_t args[MAX_OPT_ARGS];
314         int token;
315         char *sig_src;
316         char *debug_src;
317         char *cipher_name_dst;
318         char *cipher_name_src;
319         char *cipher_key_bytes_src;
320         int cipher_name_len;
321
322         if (!options) {
323                 rc = -EINVAL;
324                 goto out;
325         }
326         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
327         while ((p = strsep(&options, ",")) != NULL) {
328                 if (!*p)
329                         continue;
330                 token = match_token(p, tokens, args);
331                 switch (token) {
332                 case ecryptfs_opt_sig:
333                 case ecryptfs_opt_ecryptfs_sig:
334                         sig_src = args[0].from;
335                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
336                                                           sig_src);
337                         if (rc) {
338                                 printk(KERN_ERR "Error attempting to register "
339                                        "global sig; rc = [%d]\n", rc);
340                                 goto out;
341                         }
342                         sig_set = 1;
343                         break;
344                 case ecryptfs_opt_debug:
345                 case ecryptfs_opt_ecryptfs_debug:
346                         debug_src = args[0].from;
347                         ecryptfs_verbosity =
348                                 (int)simple_strtol(debug_src, &debug_src,
349                                                    0);
350                         ecryptfs_printk(KERN_DEBUG,
351                                         "Verbosity set to [%d]" "\n",
352                                         ecryptfs_verbosity);
353                         break;
354                 case ecryptfs_opt_cipher:
355                 case ecryptfs_opt_ecryptfs_cipher:
356                         cipher_name_src = args[0].from;
357                         cipher_name_dst =
358                                 mount_crypt_stat->
359                                 global_default_cipher_name;
360                         strncpy(cipher_name_dst, cipher_name_src,
361                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
362                         ecryptfs_printk(KERN_DEBUG,
363                                         "The mount_crypt_stat "
364                                         "global_default_cipher_name set to: "
365                                         "[%s]\n", cipher_name_dst);
366                         cipher_name_set = 1;
367                         break;
368                 case ecryptfs_opt_ecryptfs_key_bytes:
369                         cipher_key_bytes_src = args[0].from;
370                         cipher_key_bytes =
371                                 (int)simple_strtol(cipher_key_bytes_src,
372                                                    &cipher_key_bytes_src, 0);
373                         mount_crypt_stat->global_default_cipher_key_size =
374                                 cipher_key_bytes;
375                         ecryptfs_printk(KERN_DEBUG,
376                                         "The mount_crypt_stat "
377                                         "global_default_cipher_key_size "
378                                         "set to: [%d]\n", mount_crypt_stat->
379                                         global_default_cipher_key_size);
380                         cipher_key_bytes_set = 1;
381                         break;
382                 case ecryptfs_opt_passthrough:
383                         mount_crypt_stat->flags |=
384                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
385                         break;
386                 case ecryptfs_opt_xattr_metadata:
387                         mount_crypt_stat->flags |=
388                                 ECRYPTFS_XATTR_METADATA_ENABLED;
389                         break;
390                 case ecryptfs_opt_encrypted_view:
391                         mount_crypt_stat->flags |=
392                                 ECRYPTFS_XATTR_METADATA_ENABLED;
393                         mount_crypt_stat->flags |=
394                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
395                         break;
396                 case ecryptfs_opt_err:
397                 default:
398                         ecryptfs_printk(KERN_WARNING,
399                                         "eCryptfs: unrecognized option '%s'\n",
400                                         p);
401                 }
402         }
403         if (!sig_set) {
404                 rc = -EINVAL;
405                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
406                                 "auth tok signature as a mount "
407                                 "parameter; see the eCryptfs README\n");
408                 goto out;
409         }
410         if (!cipher_name_set) {
411                 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
412                 if (unlikely(cipher_name_len
413                              >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
414                         rc = -EINVAL;
415                         BUG();
416                         goto out;
417                 }
418                 memcpy(mount_crypt_stat->global_default_cipher_name,
419                        ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
420                 mount_crypt_stat->global_default_cipher_name[cipher_name_len]
421                     = '\0';
422         }
423         if (!cipher_key_bytes_set) {
424                 mount_crypt_stat->global_default_cipher_key_size = 0;
425         }
426         rc = ecryptfs_add_new_key_tfm(
427                 NULL, mount_crypt_stat->global_default_cipher_name,
428                 mount_crypt_stat->global_default_cipher_key_size);
429         if (rc) {
430                 printk(KERN_ERR "Error attempting to initialize cipher with "
431                        "name = [%s] and key size = [%td]; rc = [%d]\n",
432                        mount_crypt_stat->global_default_cipher_name,
433                        mount_crypt_stat->global_default_cipher_key_size, rc);
434                 rc = -EINVAL;
435                 goto out;
436         }
437         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
438         if (rc) {
439                 printk(KERN_WARNING "One or more global auth toks could not "
440                        "properly register; rc = [%d]\n", rc);
441         }
442         rc = 0;
443 out:
444         return rc;
445 }
446
447 struct kmem_cache *ecryptfs_sb_info_cache;
448
449 /**
450  * ecryptfs_fill_super
451  * @sb: The ecryptfs super block
452  * @raw_data: The options passed to mount
453  * @silent: Not used but required by function prototype
454  *
455  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
456  *
457  * Returns zero on success; non-zero otherwise
458  */
459 static int
460 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
461 {
462         int rc = 0;
463
464         /* Released in ecryptfs_put_super() */
465         ecryptfs_set_superblock_private(sb,
466                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
467                                                          GFP_KERNEL));
468         if (!ecryptfs_superblock_to_private(sb)) {
469                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
470                 rc = -ENOMEM;
471                 goto out;
472         }
473         sb->s_op = &ecryptfs_sops;
474         /* Released through deactivate_super(sb) from get_sb_nodev */
475         sb->s_root = d_alloc(NULL, &(const struct qstr) {
476                              .hash = 0,.name = "/",.len = 1});
477         if (!sb->s_root) {
478                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
479                 rc = -ENOMEM;
480                 goto out;
481         }
482         sb->s_root->d_op = &ecryptfs_dops;
483         sb->s_root->d_sb = sb;
484         sb->s_root->d_parent = sb->s_root;
485         /* Released in d_release when dput(sb->s_root) is called */
486         /* through deactivate_super(sb) from get_sb_nodev() */
487         ecryptfs_set_dentry_private(sb->s_root,
488                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
489                                                      GFP_KERNEL));
490         if (!ecryptfs_dentry_to_private(sb->s_root)) {
491                 ecryptfs_printk(KERN_ERR,
492                                 "dentry_info_cache alloc failed\n");
493                 rc = -ENOMEM;
494                 goto out;
495         }
496         rc = 0;
497 out:
498         /* Should be able to rely on deactivate_super called from
499          * get_sb_nodev */
500         return rc;
501 }
502
503 /**
504  * ecryptfs_read_super
505  * @sb: The ecryptfs super block
506  * @dev_name: The path to mount over
507  *
508  * Read the super block of the lower filesystem, and use
509  * ecryptfs_interpose to create our initial inode and super block
510  * struct.
511  */
512 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
513 {
514         int rc;
515         struct nameidata nd;
516         struct dentry *lower_root;
517         struct vfsmount *lower_mnt;
518
519         memset(&nd, 0, sizeof(struct nameidata));
520         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
521         if (rc) {
522                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
523                 goto out;
524         }
525         lower_root = nd.dentry;
526         lower_mnt = nd.mnt;
527         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
528         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
529         sb->s_blocksize = lower_root->d_sb->s_blocksize;
530         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
531         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
532         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
533         if (rc)
534                 goto out_free;
535         rc = 0;
536         goto out;
537 out_free:
538         path_release(&nd);
539 out:
540         return rc;
541 }
542
543 /**
544  * ecryptfs_get_sb
545  * @fs_type
546  * @flags
547  * @dev_name: The path to mount over
548  * @raw_data: The options passed into the kernel
549  *
550  * The whole ecryptfs_get_sb process is broken into 4 functions:
551  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
552  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
553  *                        with as much information as it can before needing
554  *                        the lower filesystem.
555  * ecryptfs_read_super(): this accesses the lower filesystem and uses
556  *                        ecryptfs_interpolate to perform most of the linking
557  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
558  */
559 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
560                         const char *dev_name, void *raw_data,
561                         struct vfsmount *mnt)
562 {
563         int rc;
564         struct super_block *sb;
565
566         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
567         if (rc < 0) {
568                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
569                 goto out;
570         }
571         sb = mnt->mnt_sb;
572         rc = ecryptfs_parse_options(sb, raw_data);
573         if (rc) {
574                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
575                 goto out_abort;
576         }
577         rc = ecryptfs_read_super(sb, dev_name);
578         if (rc) {
579                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
580                 goto out_abort;
581         }
582         goto out;
583 out_abort:
584         dput(sb->s_root);
585         up_write(&sb->s_umount);
586         deactivate_super(sb);
587 out:
588         return rc;
589 }
590
591 /**
592  * ecryptfs_kill_block_super
593  * @sb: The ecryptfs super block
594  *
595  * Used to bring the superblock down and free the private data.
596  * Private data is free'd in ecryptfs_put_super()
597  */
598 static void ecryptfs_kill_block_super(struct super_block *sb)
599 {
600         generic_shutdown_super(sb);
601 }
602
603 static struct file_system_type ecryptfs_fs_type = {
604         .owner = THIS_MODULE,
605         .name = "ecryptfs",
606         .get_sb = ecryptfs_get_sb,
607         .kill_sb = ecryptfs_kill_block_super,
608         .fs_flags = 0
609 };
610
611 /**
612  * inode_info_init_once
613  *
614  * Initializes the ecryptfs_inode_info_cache when it is created
615  */
616 static void
617 inode_info_init_once(struct kmem_cache *cachep, void *vptr)
618 {
619         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
620
621         inode_init_once(&ei->vfs_inode);
622 }
623
624 static struct ecryptfs_cache_info {
625         struct kmem_cache **cache;
626         const char *name;
627         size_t size;
628         void (*ctor)(struct kmem_cache *cache, void *obj);
629 } ecryptfs_cache_infos[] = {
630         {
631                 .cache = &ecryptfs_auth_tok_list_item_cache,
632                 .name = "ecryptfs_auth_tok_list_item",
633                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
634         },
635         {
636                 .cache = &ecryptfs_file_info_cache,
637                 .name = "ecryptfs_file_cache",
638                 .size = sizeof(struct ecryptfs_file_info),
639         },
640         {
641                 .cache = &ecryptfs_dentry_info_cache,
642                 .name = "ecryptfs_dentry_info_cache",
643                 .size = sizeof(struct ecryptfs_dentry_info),
644         },
645         {
646                 .cache = &ecryptfs_inode_info_cache,
647                 .name = "ecryptfs_inode_cache",
648                 .size = sizeof(struct ecryptfs_inode_info),
649                 .ctor = inode_info_init_once,
650         },
651         {
652                 .cache = &ecryptfs_sb_info_cache,
653                 .name = "ecryptfs_sb_cache",
654                 .size = sizeof(struct ecryptfs_sb_info),
655         },
656         {
657                 .cache = &ecryptfs_header_cache_0,
658                 .name = "ecryptfs_headers_0",
659                 .size = PAGE_CACHE_SIZE,
660         },
661         {
662                 .cache = &ecryptfs_header_cache_1,
663                 .name = "ecryptfs_headers_1",
664                 .size = PAGE_CACHE_SIZE,
665         },
666         {
667                 .cache = &ecryptfs_header_cache_2,
668                 .name = "ecryptfs_headers_2",
669                 .size = PAGE_CACHE_SIZE,
670         },
671         {
672                 .cache = &ecryptfs_xattr_cache,
673                 .name = "ecryptfs_xattr_cache",
674                 .size = PAGE_CACHE_SIZE,
675         },
676         {
677                 .cache = &ecryptfs_key_record_cache,
678                 .name = "ecryptfs_key_record_cache",
679                 .size = sizeof(struct ecryptfs_key_record),
680         },
681         {
682                 .cache = &ecryptfs_key_sig_cache,
683                 .name = "ecryptfs_key_sig_cache",
684                 .size = sizeof(struct ecryptfs_key_sig),
685         },
686         {
687                 .cache = &ecryptfs_global_auth_tok_cache,
688                 .name = "ecryptfs_global_auth_tok_cache",
689                 .size = sizeof(struct ecryptfs_global_auth_tok),
690         },
691         {
692                 .cache = &ecryptfs_key_tfm_cache,
693                 .name = "ecryptfs_key_tfm_cache",
694                 .size = sizeof(struct ecryptfs_key_tfm),
695         },
696 };
697
698 static void ecryptfs_free_kmem_caches(void)
699 {
700         int i;
701
702         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
703                 struct ecryptfs_cache_info *info;
704
705                 info = &ecryptfs_cache_infos[i];
706                 if (*(info->cache))
707                         kmem_cache_destroy(*(info->cache));
708         }
709 }
710
711 /**
712  * ecryptfs_init_kmem_caches
713  *
714  * Returns zero on success; non-zero otherwise
715  */
716 static int ecryptfs_init_kmem_caches(void)
717 {
718         int i;
719
720         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
721                 struct ecryptfs_cache_info *info;
722
723                 info = &ecryptfs_cache_infos[i];
724                 *(info->cache) = kmem_cache_create(info->name, info->size,
725                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
726                 if (!*(info->cache)) {
727                         ecryptfs_free_kmem_caches();
728                         ecryptfs_printk(KERN_WARNING, "%s: "
729                                         "kmem_cache_create failed\n",
730                                         info->name);
731                         return -ENOMEM;
732                 }
733         }
734         return 0;
735 }
736
737 static decl_subsys(ecryptfs, NULL, NULL);
738
739 static ssize_t version_show(struct kset *kset, char *buff)
740 {
741         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
742 }
743
744 static struct subsys_attribute version_attr = __ATTR_RO(version);
745
746 static struct ecryptfs_version_str_map_elem {
747         u32 flag;
748         char *str;
749 } ecryptfs_version_str_map[] = {
750         {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"},
751         {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"},
752         {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"},
753         {ECRYPTFS_VERSIONING_POLICY, "policy"},
754         {ECRYPTFS_VERSIONING_XATTR, "metadata in extended attribute"},
755         {ECRYPTFS_VERSIONING_MULTKEY, "multiple keys per file"}
756 };
757
758 static ssize_t version_str_show(struct kset *kset, char *buff)
759 {
760         int i;
761         int remaining = PAGE_SIZE;
762         int total_written = 0;
763
764         buff[0] = '\0';
765         for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) {
766                 int entry_size;
767
768                 if (!(ECRYPTFS_VERSIONING_MASK
769                       & ecryptfs_version_str_map[i].flag))
770                         continue;
771                 entry_size = strlen(ecryptfs_version_str_map[i].str);
772                 if ((entry_size + 2) > remaining)
773                         goto out;
774                 memcpy(buff, ecryptfs_version_str_map[i].str, entry_size);
775                 buff[entry_size++] = '\n';
776                 buff[entry_size] = '\0';
777                 buff += entry_size;
778                 total_written += entry_size;
779                 remaining -= entry_size;
780         }
781 out:
782         return total_written;
783 }
784
785 static struct subsys_attribute version_attr_str = __ATTR_RO(version_str);
786
787 static struct attribute *attributes[] = {
788         &version_attr.attr,
789         &version_attr_str.attr,
790         NULL,
791 };
792
793 static struct attribute_group attr_group = {
794         .attrs = attributes,
795 };
796
797 static int do_sysfs_registration(void)
798 {
799         int rc;
800
801         rc = subsystem_register(&ecryptfs_subsys);
802         if (rc) {
803                 printk(KERN_ERR
804                        "Unable to register ecryptfs sysfs subsystem\n");
805                 goto out;
806         }
807         rc = sysfs_create_group(&ecryptfs_subsys.kobj, &attr_group);
808         if (rc) {
809                 printk(KERN_ERR
810                        "Unable to create ecryptfs version attributes\n");
811                 subsystem_unregister(&ecryptfs_subsys);
812         }
813 out:
814         return rc;
815 }
816
817 static void do_sysfs_unregistration(void)
818 {
819         sysfs_remove_group(&ecryptfs_subsys.kobj, &attr_group);
820         subsystem_unregister(&ecryptfs_subsys);
821 }
822
823 static int __init ecryptfs_init(void)
824 {
825         int rc;
826
827         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
828                 rc = -EINVAL;
829                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
830                                 "larger than the host's page size, and so "
831                                 "eCryptfs cannot run on this system. The "
832                                 "default eCryptfs extent size is [%d] bytes; "
833                                 "the page size is [%d] bytes.\n",
834                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
835                 goto out;
836         }
837         rc = ecryptfs_init_kmem_caches();
838         if (rc) {
839                 printk(KERN_ERR
840                        "Failed to allocate one or more kmem_cache objects\n");
841                 goto out;
842         }
843         rc = register_filesystem(&ecryptfs_fs_type);
844         if (rc) {
845                 printk(KERN_ERR "Failed to register filesystem\n");
846                 goto out_free_kmem_caches;
847         }
848         kobj_set_kset_s(&ecryptfs_subsys, fs_subsys);
849         rc = do_sysfs_registration();
850         if (rc) {
851                 printk(KERN_ERR "sysfs registration failed\n");
852                 goto out_unregister_filesystem;
853         }
854         rc = ecryptfs_init_messaging(ecryptfs_transport);
855         if (rc) {
856                 ecryptfs_printk(KERN_ERR, "Failure occured while attempting to "
857                                 "initialize the eCryptfs netlink socket\n");
858                 goto out_do_sysfs_unregistration;
859         }
860         rc = ecryptfs_init_crypto();
861         if (rc) {
862                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
863                        "rc = [%d]\n", rc);
864                 goto out_release_messaging;
865         }
866         goto out;
867 out_release_messaging:
868         ecryptfs_release_messaging(ecryptfs_transport);
869 out_do_sysfs_unregistration:
870         do_sysfs_unregistration();
871 out_unregister_filesystem:
872         unregister_filesystem(&ecryptfs_fs_type);
873 out_free_kmem_caches:
874         ecryptfs_free_kmem_caches();
875 out:
876         return rc;
877 }
878
879 static void __exit ecryptfs_exit(void)
880 {
881         int rc;
882
883         rc = ecryptfs_destroy_crypto();
884         if (rc)
885                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
886                        "rc = [%d]\n", rc);
887         ecryptfs_release_messaging(ecryptfs_transport);
888         do_sysfs_unregistration();
889         unregister_filesystem(&ecryptfs_fs_type);
890         ecryptfs_free_kmem_caches();
891 }
892
893 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
894 MODULE_DESCRIPTION("eCryptfs");
895
896 MODULE_LICENSE("GPL");
897
898 module_init(ecryptfs_init)
899 module_exit(ecryptfs_exit)