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                 rc = ecryptfs_privileged_open(&inode_info->lower_file,
 134                                                      lower_dentry, lower_mnt);
 135                 if (rc || IS_ERR(inode_info->lower_file)) {
 136                         printk(KERN_ERR "Error opening lower persistent file "
 137                                "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
 138                                "rc = [%d]\n", lower_dentry, lower_mnt, rc);
 139                         rc = PTR_ERR(inode_info->lower_file);
 140                         inode_info->lower_file = NULL;
 141                 }
 142         }
 143         mutex_unlock(&inode_info->lower_file_mutex);
 144         return rc;
 145 }
 146
 147 /**
 148  * ecryptfs_interpose
 149  * @lower_dentry: Existing dentry in the lower filesystem
 150  * @dentry: ecryptfs' dentry
 151  * @sb: ecryptfs's super_block
 152  * @flags: flags to govern behavior of interpose procedure
 153  *
 154  * Interposes upper and lower dentries.
 155  *
 156  * Returns zero on success; non-zero otherwise
 157  */
 158 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 159                        struct super_block *sb, u32 flags)
 160 {
 161         struct inode *lower_inode;
 162         struct inode *inode;
 163         int rc = 0;
 164
 165         lower_inode = lower_dentry->d_inode;
 166         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 167                 rc = -EXDEV;
 168                 goto out;
 169         }
 170         if (!igrab(lower_inode)) {
 171                 rc = -ESTALE;
 172                 goto out;
 173         }
 174         inode = iget5_locked(sb, (unsigned long)lower_inode,
 175                              ecryptfs_inode_test, ecryptfs_inode_set,
 176                              lower_inode);
 177         if (!inode) {
 178                 rc = -EACCES;
 179                 iput(lower_inode);
 180                 goto out;
 181         }
 182         if (inode->i_state & I_NEW)
 183                 unlock_new_inode(inode);
 184         else
 185                 iput(lower_inode);
 186         if (S_ISLNK(lower_inode->i_mode))
 187                 inode->i_op = &ecryptfs_symlink_iops;
 188         else if (S_ISDIR(lower_inode->i_mode))
 189                 inode->i_op = &ecryptfs_dir_iops;
 190         if (S_ISDIR(lower_inode->i_mode))
 191                 inode->i_fop = &ecryptfs_dir_fops;
 192         if (special_file(lower_inode->i_mode))
 193                 init_special_inode(inode, lower_inode->i_mode,
 194                                    lower_inode->i_rdev);
 195         dentry->d_op = &ecryptfs_dops;
 196         if (flags & ECRYPTFS_INTERPOSE_FLAG_D_ADD)
 197                 d_add(dentry, inode);
 198         else
 199                 d_instantiate(dentry, inode);
 200         fsstack_copy_attr_all(inode, lower_inode, NULL);
 201         /* This size will be overwritten for real files w/ headers and
 202          * other metadata */
 203         fsstack_copy_inode_size(inode, lower_inode);
 204 out:
 205         return rc;
 206 }
 207
 208 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig,
 209        ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher,
 210        ecryptfs_opt_ecryptfs_key_bytes,
 211        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 212        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
 213
 214 static match_table_t tokens = {
 215         {ecryptfs_opt_sig, "sig=%s"},
 216         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 217         {ecryptfs_opt_cipher, "cipher=%s"},
 218         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 219         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 220         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 221         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 222         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 223         {ecryptfs_opt_err, NULL}
 224 };
 225
 226 static int ecryptfs_init_global_auth_toks(
 227         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 228 {
 229         struct ecryptfs_global_auth_tok *global_auth_tok;
 230         int rc = 0;
 231
 232         list_for_each_entry(global_auth_tok,
 233                             &mount_crypt_stat->global_auth_tok_list,
 234                             mount_crypt_stat_list) {
 235                 rc = ecryptfs_keyring_auth_tok_for_sig(
 236                         &global_auth_tok->global_auth_tok_key,
 237                         &global_auth_tok->global_auth_tok,
 238                         global_auth_tok->sig);
 239                 if (rc) {
 240                         printk(KERN_ERR "Could not find valid key in user "
 241                                "session keyring for sig specified in mount "
 242                                "option: [%s]\n", global_auth_tok->sig);
 243                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 244                         goto out;
 245                 } else
 246                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 247         }
 248 out:
 249         return rc;
 250 }
 251
 252 static void ecryptfs_init_mount_crypt_stat(
 253         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 254 {
 255         memset((void *)mount_crypt_stat, 0,
 256                sizeof(struct ecryptfs_mount_crypt_stat));
 257         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 258         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 259         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 260 }
 261
 262 /**
 263  * ecryptfs_parse_options
 264  * @sb: The ecryptfs super block
 265  * @options: The options pased to the kernel
 266  *
 267  * Parse mount options:
 268  * debug=N         - ecryptfs_verbosity level for debug output
 269  * sig=XXX         - description(signature) of the key to use
 270  *
 271  * Returns the dentry object of the lower-level (lower/interposed)
 272  * directory; We want to mount our stackable file system on top of
 273  * that lower directory.
 274  *
 275  * The signature of the key to use must be the description of a key
 276  * already in the keyring. Mounting will fail if the key can not be
 277  * found.
 278  *
 279  * Returns zero on success; non-zero on error
 280  */
 281 static int ecryptfs_parse_options(struct super_block *sb, char *options)
 282 {
 283         char *p;
 284         int rc = 0;
 285         int sig_set = 0;
 286         int cipher_name_set = 0;
 287         int cipher_key_bytes;
 288         int cipher_key_bytes_set = 0;
 289         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 290                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
 291         substring_t args[MAX_OPT_ARGS];
 292         int token;
 293         char *sig_src;
 294         char *cipher_name_dst;
 295         char *cipher_name_src;
 296         char *cipher_key_bytes_src;
 297
 298         if (!options) {
 299                 rc = -EINVAL;
 300                 goto out;
 301         }
 302         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 303         while ((p = strsep(&options, ",")) != NULL) {
 304                 if (!*p)
 305                         continue;
 306                 token = match_token(p, tokens, args);
 307                 switch (token) {
 308                 case ecryptfs_opt_sig:
 309                 case ecryptfs_opt_ecryptfs_sig:
 310                         sig_src = args[0].from;
 311                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 312                                                           sig_src);
 313                         if (rc) {
 314                                 printk(KERN_ERR "Error attempting to register "
 315                                        "global sig; rc = [%d]\n", rc);
 316                                 goto out;
 317                         }
 318                         sig_set = 1;
 319                         break;
 320                 case ecryptfs_opt_cipher:
 321                 case ecryptfs_opt_ecryptfs_cipher:
 322                         cipher_name_src = args[0].from;
 323                         cipher_name_dst =
 324                                 mount_crypt_stat->
 325                                 global_default_cipher_name;
 326                         strncpy(cipher_name_dst, cipher_name_src,
 327                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 328                         ecryptfs_printk(KERN_DEBUG,
 329                                         "The mount_crypt_stat "
 330                                         "global_default_cipher_name set to: "
 331                                         "[%s]\n", cipher_name_dst);
 332                         cipher_name_set = 1;
 333                         break;
 334                 case ecryptfs_opt_ecryptfs_key_bytes:
 335                         cipher_key_bytes_src = args[0].from;
 336                         cipher_key_bytes =
 337                                 (int)simple_strtol(cipher_key_bytes_src,
 338                                                    &cipher_key_bytes_src, 0);
 339                         mount_crypt_stat->global_default_cipher_key_size =
 340                                 cipher_key_bytes;
 341                         ecryptfs_printk(KERN_DEBUG,
 342                                         "The mount_crypt_stat "
 343                                         "global_default_cipher_key_size "
 344                                         "set to: [%d]\n", mount_crypt_stat->
 345                                         global_default_cipher_key_size);
 346                         cipher_key_bytes_set = 1;
 347                         break;
 348                 case ecryptfs_opt_passthrough:
 349                         mount_crypt_stat->flags |=
 350                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 351                         break;
 352                 case ecryptfs_opt_xattr_metadata:
 353                         mount_crypt_stat->flags |=
 354                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 355                         break;
 356                 case ecryptfs_opt_encrypted_view:
 357                         mount_crypt_stat->flags |=
 358                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 359                         mount_crypt_stat->flags |=
 360                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 361                         break;
 362                 case ecryptfs_opt_err:
 363                 default:
 364                         ecryptfs_printk(KERN_WARNING,
 365                                         "eCryptfs: unrecognized option '%s'\n",
 366                                         p);
 367                 }
 368         }
 369         if (!sig_set) {
 370                 rc = -EINVAL;
 371                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 372                                 "auth tok signature as a mount "
 373                                 "parameter; see the eCryptfs README\n");
 374                 goto out;
 375         }
 376         if (!cipher_name_set) {
 377                 int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 378
 379                 BUG_ON(cipher_name_len >= ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 380
 381                 strcpy(mount_crypt_stat->global_default_cipher_name,
 382                        ECRYPTFS_DEFAULT_CIPHER);
 383         }
 384         if (!cipher_key_bytes_set) {
 385                 mount_crypt_stat->global_default_cipher_key_size = 0;
 386         }
 387         mutex_lock(&key_tfm_list_mutex);
 388         if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name,
 389                                  NULL))
 390                 rc = ecryptfs_add_new_key_tfm(
 391                         NULL, mount_crypt_stat->global_default_cipher_name,
 392                         mount_crypt_stat->global_default_cipher_key_size);
 393         mutex_unlock(&key_tfm_list_mutex);
 394         if (rc) {
 395                 printk(KERN_ERR "Error attempting to initialize cipher with "
 396                        "name = [%s] and key size = [%td]; rc = [%d]\n",
 397                        mount_crypt_stat->global_default_cipher_name,
 398                        mount_crypt_stat->global_default_cipher_key_size, rc);
 399                 rc = -EINVAL;
 400                 goto out;
 401         }
 402         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 403         if (rc) {
 404                 printk(KERN_WARNING "One or more global auth toks could not "
 405                        "properly register; rc = [%d]\n", rc);
 406         }
 407 out:
 408         return rc;
 409 }
 410
 411 struct kmem_cache *ecryptfs_sb_info_cache;
 412
 413 /**
 414  * ecryptfs_fill_super
 415  * @sb: The ecryptfs super block
 416  * @raw_data: The options passed to mount
 417  * @silent: Not used but required by function prototype
 418  *
 419  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 420  *
 421  * Returns zero on success; non-zero otherwise
 422  */
 423 static int
 424 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
 425 {
 426         int rc = 0;
 427
 428         /* Released in ecryptfs_put_super() */
 429         ecryptfs_set_superblock_private(sb,
 430                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
 431                                                          GFP_KERNEL));
 432         if (!ecryptfs_superblock_to_private(sb)) {
 433                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
 434                 rc = -ENOMEM;
 435                 goto out;
 436         }
 437         sb->s_op = &ecryptfs_sops;
 438         /* Released through deactivate_super(sb) from get_sb_nodev */
 439         sb->s_root = d_alloc(NULL, &(const struct qstr) {
 440                              .hash = 0,.name = "/",.len = 1});
 441         if (!sb->s_root) {
 442                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
 443                 rc = -ENOMEM;
 444                 goto out;
 445         }
 446         sb->s_root->d_op = &ecryptfs_dops;
 447         sb->s_root->d_sb = sb;
 448         sb->s_root->d_parent = sb->s_root;
 449         /* Released in d_release when dput(sb->s_root) is called */
 450         /* through deactivate_super(sb) from get_sb_nodev() */
 451         ecryptfs_set_dentry_private(sb->s_root,
 452                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
 453                                                      GFP_KERNEL));
 454         if (!ecryptfs_dentry_to_private(sb->s_root)) {
 455                 ecryptfs_printk(KERN_ERR,
 456                                 "dentry_info_cache alloc failed\n");
 457                 rc = -ENOMEM;
 458                 goto out;
 459         }
 460         rc = 0;
 461 out:
 462         /* Should be able to rely on deactivate_super called from
 463          * get_sb_nodev */
 464         return rc;
 465 }
 466
 467 /**
 468  * ecryptfs_read_super
 469  * @sb: The ecryptfs super block
 470  * @dev_name: The path to mount over
 471  *
 472  * Read the super block of the lower filesystem, and use
 473  * ecryptfs_interpose to create our initial inode and super block
 474  * struct.
 475  */
 476 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 477 {
 478         int rc;
 479         struct nameidata nd;
 480         struct dentry *lower_root;
 481         struct vfsmount *lower_mnt;
 482
 483         memset(&nd, 0, sizeof(struct nameidata));
 484         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
 485         if (rc) {
 486                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
 487                 goto out;
 488         }
 489         lower_root = nd.path.dentry;
 490         lower_mnt = nd.path.mnt;
 491         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
 492         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
 493         sb->s_blocksize = lower_root->d_sb->s_blocksize;
 494         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
 495         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
 496         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
 497         if (rc)
 498                 goto out_free;
 499         rc = 0;
 500         goto out;
 501 out_free:
 502         path_put(&nd.path);
 503 out:
 504         return rc;
 505 }
 506
 507 /**
 508  * ecryptfs_get_sb
 509  * @fs_type
 510  * @flags
 511  * @dev_name: The path to mount over
 512  * @raw_data: The options passed into the kernel
 513  *
 514  * The whole ecryptfs_get_sb process is broken into 4 functions:
 515  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 516  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 517  *                        with as much information as it can before needing
 518  *                        the lower filesystem.
 519  * ecryptfs_read_super(): this accesses the lower filesystem and uses
 520  *                        ecryptfs_interpolate to perform most of the linking
 521  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 522  */
 523 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 524                         const char *dev_name, void *raw_data,
 525                         struct vfsmount *mnt)
 526 {
 527         int rc;
 528         struct super_block *sb;
 529
 530         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
 531         if (rc < 0) {
 532                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
 533                 goto out;
 534         }
 535         sb = mnt->mnt_sb;
 536         rc = ecryptfs_parse_options(sb, raw_data);
 537         if (rc) {
 538                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
 539                 goto out_abort;
 540         }
 541         rc = ecryptfs_read_super(sb, dev_name);
 542         if (rc) {
 543                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
 544                 goto out_abort;
 545         }
 546         goto out;
 547 out_abort:
 548         dput(sb->s_root);
 549         up_write(&sb->s_umount);
 550         deactivate_super(sb);
 551 out:
 552         return rc;
 553 }
 554
 555 /**
 556  * ecryptfs_kill_block_super
 557  * @sb: The ecryptfs super block
 558  *
 559  * Used to bring the superblock down and free the private data.
 560  * Private data is free'd in ecryptfs_put_super()
 561  */
 562 static void ecryptfs_kill_block_super(struct super_block *sb)
 563 {
 564         generic_shutdown_super(sb);
 565 }
 566
 567 static struct file_system_type ecryptfs_fs_type = {
 568         .owner = THIS_MODULE,
 569         .name = "ecryptfs",
 570         .get_sb = ecryptfs_get_sb,
 571         .kill_sb = ecryptfs_kill_block_super,
 572         .fs_flags = 0
 573 };
 574
 575 /**
 576  * inode_info_init_once
 577  *
 578  * Initializes the ecryptfs_inode_info_cache when it is created
 579  */
 580 static void
 581 inode_info_init_once(void *vptr)
 582 {
 583         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 584
 585         inode_init_once(&ei->vfs_inode);
 586 }
 587
 588 static struct ecryptfs_cache_info {
 589         struct kmem_cache **cache;
 590         const char *name;
 591         size_t size;
 592         void (*ctor)(void *obj);
 593 } ecryptfs_cache_infos[] = {
 594         {
 595                 .cache = &ecryptfs_auth_tok_list_item_cache,
 596                 .name = "ecryptfs_auth_tok_list_item",
 597                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 598         },
 599         {
 600                 .cache = &ecryptfs_file_info_cache,
 601                 .name = "ecryptfs_file_cache",
 602                 .size = sizeof(struct ecryptfs_file_info),
 603         },
 604         {
 605                 .cache = &ecryptfs_dentry_info_cache,
 606                 .name = "ecryptfs_dentry_info_cache",
 607                 .size = sizeof(struct ecryptfs_dentry_info),
 608         },
 609         {
 610                 .cache = &ecryptfs_inode_info_cache,
 611                 .name = "ecryptfs_inode_cache",
 612                 .size = sizeof(struct ecryptfs_inode_info),
 613                 .ctor = inode_info_init_once,
 614         },
 615         {
 616                 .cache = &ecryptfs_sb_info_cache,
 617                 .name = "ecryptfs_sb_cache",
 618                 .size = sizeof(struct ecryptfs_sb_info),
 619         },
 620         {
 621                 .cache = &ecryptfs_header_cache_1,
 622                 .name = "ecryptfs_headers_1",
 623                 .size = PAGE_CACHE_SIZE,
 624         },
 625         {
 626                 .cache = &ecryptfs_header_cache_2,
 627                 .name = "ecryptfs_headers_2",
 628                 .size = PAGE_CACHE_SIZE,
 629         },
 630         {
 631                 .cache = &ecryptfs_xattr_cache,
 632                 .name = "ecryptfs_xattr_cache",
 633                 .size = PAGE_CACHE_SIZE,
 634         },
 635         {
 636                 .cache = &ecryptfs_key_record_cache,
 637                 .name = "ecryptfs_key_record_cache",
 638                 .size = sizeof(struct ecryptfs_key_record),
 639         },
 640         {
 641                 .cache = &ecryptfs_key_sig_cache,
 642                 .name = "ecryptfs_key_sig_cache",
 643                 .size = sizeof(struct ecryptfs_key_sig),
 644         },
 645         {
 646                 .cache = &ecryptfs_global_auth_tok_cache,
 647                 .name = "ecryptfs_global_auth_tok_cache",
 648                 .size = sizeof(struct ecryptfs_global_auth_tok),
 649         },
 650         {
 651                 .cache = &ecryptfs_key_tfm_cache,
 652                 .name = "ecryptfs_key_tfm_cache",
 653                 .size = sizeof(struct ecryptfs_key_tfm),
 654         },
 655         {
 656                 .cache = &ecryptfs_open_req_cache,
 657                 .name = "ecryptfs_open_req_cache",
 658                 .size = sizeof(struct ecryptfs_open_req),
 659         },
 660 };
 661
 662 static void ecryptfs_free_kmem_caches(void)
 663 {
 664         int i;
 665
 666         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 667                 struct ecryptfs_cache_info *info;
 668
 669                 info = &ecryptfs_cache_infos[i];
 670                 if (*(info->cache))
 671                         kmem_cache_destroy(*(info->cache));
 672         }
 673 }
 674
 675 /**
 676  * ecryptfs_init_kmem_caches
 677  *
 678  * Returns zero on success; non-zero otherwise
 679  */
 680 static int ecryptfs_init_kmem_caches(void)
 681 {
 682         int i;
 683
 684         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 685                 struct ecryptfs_cache_info *info;
 686
 687                 info = &ecryptfs_cache_infos[i];
 688                 *(info->cache) = kmem_cache_create(info->name, info->size,
 689                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 690                 if (!*(info->cache)) {
 691                         ecryptfs_free_kmem_caches();
 692                         ecryptfs_printk(KERN_WARNING, "%s: "
 693                                         "kmem_cache_create failed\n",
 694                                         info->name);
 695                         return -ENOMEM;
 696                 }
 697         }
 698         return 0;
 699 }
 700
 701 static struct kobject *ecryptfs_kobj;
 702
 703 static ssize_t version_show(struct kobject *kobj,
 704                             struct kobj_attribute *attr, char *buff)
 705 {
 706         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 707 }
 708
 709 static struct kobj_attribute version_attr = __ATTR_RO(version);
 710
 711 static struct attribute *attributes[] = {
 712         &version_attr.attr,
 713         NULL,
 714 };
 715
 716 static struct attribute_group attr_group = {
 717         .attrs = attributes,
 718 };
 719
 720 static int do_sysfs_registration(void)
 721 {
 722         int rc;
 723
 724         ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj);
 725         if (!ecryptfs_kobj) {
 726                 printk(KERN_ERR "Unable to create ecryptfs kset\n");
 727                 rc = -ENOMEM;
 728                 goto out;
 729         }
 730         rc = sysfs_create_group(ecryptfs_kobj, &attr_group);
 731         if (rc) {
 732                 printk(KERN_ERR
 733                        "Unable to create ecryptfs version attributes\n");
 734                 kobject_put(ecryptfs_kobj);
 735         }
 736 out:
 737         return rc;
 738 }
 739
 740 static void do_sysfs_unregistration(void)
 741 {
 742         sysfs_remove_group(ecryptfs_kobj, &attr_group);
 743         kobject_put(ecryptfs_kobj);
 744 }
 745
 746 static int __init ecryptfs_init(void)
 747 {
 748         int rc;
 749
 750         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 751                 rc = -EINVAL;
 752                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 753                                 "larger than the host's page size, and so "
 754                                 "eCryptfs cannot run on this system. The "
 755                                 "default eCryptfs extent size is [%d] bytes; "
 756                                 "the page size is [%d] bytes.\n",
 757                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 758                 goto out;
 759         }
 760         rc = ecryptfs_init_kmem_caches();
 761         if (rc) {
 762                 printk(KERN_ERR
 763                        "Failed to allocate one or more kmem_cache objects\n");
 764                 goto out;
 765         }
 766         rc = register_filesystem(&ecryptfs_fs_type);
 767         if (rc) {
 768                 printk(KERN_ERR "Failed to register filesystem\n");
 769                 goto out_free_kmem_caches;
 770         }
 771         rc = do_sysfs_registration();
 772         if (rc) {
 773                 printk(KERN_ERR "sysfs registration failed\n");
 774                 goto out_unregister_filesystem;
 775         }
 776         rc = ecryptfs_init_kthread();
 777         if (rc) {
 778                 printk(KERN_ERR "%s: kthread initialization failed; "
 779                        "rc = [%d]\n", __func__, rc);
 780                 goto out_do_sysfs_unregistration;
 781         }
 782         rc = ecryptfs_init_messaging(ecryptfs_transport);
 783         if (rc) {
 784                 printk(KERN_ERR "Failure occured while attempting to "
 785                                 "initialize the eCryptfs netlink socket\n");
 786                 goto out_destroy_kthread;
 787         }
 788         rc = ecryptfs_init_crypto();
 789         if (rc) {
 790                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 791                        "rc = [%d]\n", rc);
 792                 goto out_release_messaging;
 793         }
 794         if (ecryptfs_verbosity > 0)
 795                 printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values "
 796                         "will be written to the syslog!\n", ecryptfs_verbosity);
 797
 798         goto out;
 799 out_release_messaging:
 800         ecryptfs_release_messaging(ecryptfs_transport);
 801 out_destroy_kthread:
 802         ecryptfs_destroy_kthread();
 803 out_do_sysfs_unregistration:
 804         do_sysfs_unregistration();
 805 out_unregister_filesystem:
 806         unregister_filesystem(&ecryptfs_fs_type);
 807 out_free_kmem_caches:
 808         ecryptfs_free_kmem_caches();
 809 out:
 810         return rc;
 811 }
 812
 813 static void __exit ecryptfs_exit(void)
 814 {
 815         int rc;
 816
 817         rc = ecryptfs_destroy_crypto();
 818         if (rc)
 819                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 820                        "rc = [%d]\n", rc);
 821         ecryptfs_release_messaging(ecryptfs_transport);
 822         ecryptfs_destroy_kthread();
 823         do_sysfs_unregistration();
 824         unregister_filesystem(&ecryptfs_fs_type);
 825         ecryptfs_free_kmem_caches();
 826 }
 827
 828 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 829 MODULE_DESCRIPTION("eCryptfs");
 830
 831 MODULE_LICENSE("GPL");
 832
 833 module_init(ecryptfs_init)
 834 module_exit(ecryptfs_exit)