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                         inode_info->lower_file = dentry_open(lower_dentry,
 143                                                              lower_mnt,
 144                                                              (O_RDONLY
 145                                                               | O_LARGEFILE));
 146                 if (IS_ERR(inode_info->lower_file)) {
 147                         printk(KERN_ERR "Error opening lower persistent file "
 148                                "for lower_dentry [0x%p] and lower_mnt [0x%p]\n",
 149                                lower_dentry, lower_mnt);
 150                         rc = PTR_ERR(inode_info->lower_file);
 151                         inode_info->lower_file = NULL;
 152                 }
 153         }
 154         mutex_unlock(&inode_info->lower_file_mutex);
 155         return rc;
 156 }
 157
 158 /**
 159  * ecryptfs_interpose
 160  * @lower_dentry: Existing dentry in the lower filesystem
 161  * @dentry: ecryptfs' dentry
 162  * @sb: ecryptfs's super_block
 163  * @flag: If set to true, then d_add is called, else d_instantiate is called
 164  *
 165  * Interposes upper and lower dentries.
 166  *
 167  * Returns zero on success; non-zero otherwise
 168  */
 169 int ecryptfs_interpose(struct dentry *lower_dentry, struct dentry *dentry,
 170                        struct super_block *sb, int flag)
 171 {
 172         struct inode *lower_inode;
 173         struct inode *inode;
 174         int rc = 0;
 175
 176         lower_inode = lower_dentry->d_inode;
 177         if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb)) {
 178                 rc = -EXDEV;
 179                 goto out;
 180         }
 181         if (!igrab(lower_inode)) {
 182                 rc = -ESTALE;
 183                 goto out;
 184         }
 185         inode = iget5_locked(sb, (unsigned long)lower_inode,
 186                              ecryptfs_inode_test, ecryptfs_inode_set,
 187                              lower_inode);
 188         if (!inode) {
 189                 rc = -EACCES;
 190                 iput(lower_inode);
 191                 goto out;
 192         }
 193         if (inode->i_state & I_NEW)
 194                 unlock_new_inode(inode);
 195         else
 196                 iput(lower_inode);
 197         if (S_ISLNK(lower_inode->i_mode))
 198                 inode->i_op = &ecryptfs_symlink_iops;
 199         else if (S_ISDIR(lower_inode->i_mode))
 200                 inode->i_op = &ecryptfs_dir_iops;
 201         if (S_ISDIR(lower_inode->i_mode))
 202                 inode->i_fop = &ecryptfs_dir_fops;
 203         if (special_file(lower_inode->i_mode))
 204                 init_special_inode(inode, lower_inode->i_mode,
 205                                    lower_inode->i_rdev);
 206         dentry->d_op = &ecryptfs_dops;
 207         if (flag)
 208                 d_add(dentry, inode);
 209         else
 210                 d_instantiate(dentry, inode);
 211         fsstack_copy_attr_all(inode, lower_inode, NULL);
 212         /* This size will be overwritten for real files w/ headers and
 213          * other metadata */
 214         fsstack_copy_inode_size(inode, lower_inode);
 215         rc = ecryptfs_init_persistent_file(dentry);
 216         if (rc) {
 217                 printk(KERN_ERR "%s: Error attempting to initialize the "
 218                        "persistent file for the dentry with name [%s]; "
 219                        "rc = [%d]\n", __FUNCTION__, dentry->d_name.name, rc);
 220                 goto out;
 221         }
 222 out:
 223         return rc;
 224 }
 225
 226 enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, ecryptfs_opt_debug,
 227        ecryptfs_opt_ecryptfs_debug, ecryptfs_opt_cipher,
 228        ecryptfs_opt_ecryptfs_cipher, ecryptfs_opt_ecryptfs_key_bytes,
 229        ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata,
 230        ecryptfs_opt_encrypted_view, ecryptfs_opt_err };
 231
 232 static match_table_t tokens = {
 233         {ecryptfs_opt_sig, "sig=%s"},
 234         {ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"},
 235         {ecryptfs_opt_debug, "debug=%u"},
 236         {ecryptfs_opt_ecryptfs_debug, "ecryptfs_debug=%u"},
 237         {ecryptfs_opt_cipher, "cipher=%s"},
 238         {ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"},
 239         {ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"},
 240         {ecryptfs_opt_passthrough, "ecryptfs_passthrough"},
 241         {ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"},
 242         {ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"},
 243         {ecryptfs_opt_err, NULL}
 244 };
 245
 246 static int ecryptfs_init_global_auth_toks(
 247         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 248 {
 249         struct ecryptfs_global_auth_tok *global_auth_tok;
 250         int rc = 0;
 251
 252         list_for_each_entry(global_auth_tok,
 253                             &mount_crypt_stat->global_auth_tok_list,
 254                             mount_crypt_stat_list) {
 255                 rc = ecryptfs_keyring_auth_tok_for_sig(
 256                         &global_auth_tok->global_auth_tok_key,
 257                         &global_auth_tok->global_auth_tok,
 258                         global_auth_tok->sig);
 259                 if (rc) {
 260                         printk(KERN_ERR "Could not find valid key in user "
 261                                "session keyring for sig specified in mount "
 262                                "option: [%s]\n", global_auth_tok->sig);
 263                         global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID;
 264                         rc = 0;
 265                 } else
 266                         global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID;
 267         }
 268         return rc;
 269 }
 270
 271 static void ecryptfs_init_mount_crypt_stat(
 272         struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 273 {
 274         memset((void *)mount_crypt_stat, 0,
 275                sizeof(struct ecryptfs_mount_crypt_stat));
 276         INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list);
 277         mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex);
 278         mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
 279 }
 280
 281 /**
 282  * ecryptfs_parse_options
 283  * @sb: The ecryptfs super block
 284  * @options: The options pased to the kernel
 285  *
 286  * Parse mount options:
 287  * debug=N         - ecryptfs_verbosity level for debug output
 288  * sig=XXX         - description(signature) of the key to use
 289  *
 290  * Returns the dentry object of the lower-level (lower/interposed)
 291  * directory; We want to mount our stackable file system on top of
 292  * that lower directory.
 293  *
 294  * The signature of the key to use must be the description of a key
 295  * already in the keyring. Mounting will fail if the key can not be
 296  * found.
 297  *
 298  * Returns zero on success; non-zero on error
 299  */
 300 static int ecryptfs_parse_options(struct super_block *sb, char *options)
 301 {
 302         char *p;
 303         int rc = 0;
 304         int sig_set = 0;
 305         int cipher_name_set = 0;
 306         int cipher_key_bytes;
 307         int cipher_key_bytes_set = 0;
 308         struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
 309                 &ecryptfs_superblock_to_private(sb)->mount_crypt_stat;
 310         substring_t args[MAX_OPT_ARGS];
 311         int token;
 312         char *sig_src;
 313         char *debug_src;
 314         char *cipher_name_dst;
 315         char *cipher_name_src;
 316         char *cipher_key_bytes_src;
 317         int cipher_name_len;
 318
 319         if (!options) {
 320                 rc = -EINVAL;
 321                 goto out;
 322         }
 323         ecryptfs_init_mount_crypt_stat(mount_crypt_stat);
 324         while ((p = strsep(&options, ",")) != NULL) {
 325                 if (!*p)
 326                         continue;
 327                 token = match_token(p, tokens, args);
 328                 switch (token) {
 329                 case ecryptfs_opt_sig:
 330                 case ecryptfs_opt_ecryptfs_sig:
 331                         sig_src = args[0].from;
 332                         rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
 333                                                           sig_src);
 334                         if (rc) {
 335                                 printk(KERN_ERR "Error attempting to register "
 336                                        "global sig; rc = [%d]\n", rc);
 337                                 goto out;
 338                         }
 339                         sig_set = 1;
 340                         break;
 341                 case ecryptfs_opt_debug:
 342                 case ecryptfs_opt_ecryptfs_debug:
 343                         debug_src = args[0].from;
 344                         ecryptfs_verbosity =
 345                                 (int)simple_strtol(debug_src, &debug_src,
 346                                                    0);
 347                         ecryptfs_printk(KERN_DEBUG,
 348                                         "Verbosity set to [%d]" "\n",
 349                                         ecryptfs_verbosity);
 350                         break;
 351                 case ecryptfs_opt_cipher:
 352                 case ecryptfs_opt_ecryptfs_cipher:
 353                         cipher_name_src = args[0].from;
 354                         cipher_name_dst =
 355                                 mount_crypt_stat->
 356                                 global_default_cipher_name;
 357                         strncpy(cipher_name_dst, cipher_name_src,
 358                                 ECRYPTFS_MAX_CIPHER_NAME_SIZE);
 359                         ecryptfs_printk(KERN_DEBUG,
 360                                         "The mount_crypt_stat "
 361                                         "global_default_cipher_name set to: "
 362                                         "[%s]\n", cipher_name_dst);
 363                         cipher_name_set = 1;
 364                         break;
 365                 case ecryptfs_opt_ecryptfs_key_bytes:
 366                         cipher_key_bytes_src = args[0].from;
 367                         cipher_key_bytes =
 368                                 (int)simple_strtol(cipher_key_bytes_src,
 369                                                    &cipher_key_bytes_src, 0);
 370                         mount_crypt_stat->global_default_cipher_key_size =
 371                                 cipher_key_bytes;
 372                         ecryptfs_printk(KERN_DEBUG,
 373                                         "The mount_crypt_stat "
 374                                         "global_default_cipher_key_size "
 375                                         "set to: [%d]\n", mount_crypt_stat->
 376                                         global_default_cipher_key_size);
 377                         cipher_key_bytes_set = 1;
 378                         break;
 379                 case ecryptfs_opt_passthrough:
 380                         mount_crypt_stat->flags |=
 381                                 ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
 382                         break;
 383                 case ecryptfs_opt_xattr_metadata:
 384                         mount_crypt_stat->flags |=
 385                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 386                         break;
 387                 case ecryptfs_opt_encrypted_view:
 388                         mount_crypt_stat->flags |=
 389                                 ECRYPTFS_XATTR_METADATA_ENABLED;
 390                         mount_crypt_stat->flags |=
 391                                 ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
 392                         break;
 393                 case ecryptfs_opt_err:
 394                 default:
 395                         ecryptfs_printk(KERN_WARNING,
 396                                         "eCryptfs: unrecognized option '%s'\n",
 397                                         p);
 398                 }
 399         }
 400         if (!sig_set) {
 401                 rc = -EINVAL;
 402                 ecryptfs_printk(KERN_ERR, "You must supply at least one valid "
 403                                 "auth tok signature as a mount "
 404                                 "parameter; see the eCryptfs README\n");
 405                 goto out;
 406         }
 407         if (!cipher_name_set) {
 408                 cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
 409                 if (unlikely(cipher_name_len
 410                              >= ECRYPTFS_MAX_CIPHER_NAME_SIZE)) {
 411                         rc = -EINVAL;
 412                         BUG();
 413                         goto out;
 414                 }
 415                 memcpy(mount_crypt_stat->global_default_cipher_name,
 416                        ECRYPTFS_DEFAULT_CIPHER, cipher_name_len);
 417                 mount_crypt_stat->global_default_cipher_name[cipher_name_len]
 418                     = '\0';
 419         }
 420         if (!cipher_key_bytes_set) {
 421                 mount_crypt_stat->global_default_cipher_key_size = 0;
 422         }
 423         rc = ecryptfs_add_new_key_tfm(
 424                 NULL, mount_crypt_stat->global_default_cipher_name,
 425                 mount_crypt_stat->global_default_cipher_key_size);
 426         if (rc) {
 427                 printk(KERN_ERR "Error attempting to initialize cipher with "
 428                        "name = [%s] and key size = [%td]; rc = [%d]\n",
 429                        mount_crypt_stat->global_default_cipher_name,
 430                        mount_crypt_stat->global_default_cipher_key_size, rc);
 431                 rc = -EINVAL;
 432                 goto out;
 433         }
 434         rc = ecryptfs_init_global_auth_toks(mount_crypt_stat);
 435         if (rc) {
 436                 printk(KERN_WARNING "One or more global auth toks could not "
 437                        "properly register; rc = [%d]\n", rc);
 438         }
 439         rc = 0;
 440 out:
 441         return rc;
 442 }
 443
 444 struct kmem_cache *ecryptfs_sb_info_cache;
 445
 446 /**
 447  * ecryptfs_fill_super
 448  * @sb: The ecryptfs super block
 449  * @raw_data: The options passed to mount
 450  * @silent: Not used but required by function prototype
 451  *
 452  * Sets up what we can of the sb, rest is done in ecryptfs_read_super
 453  *
 454  * Returns zero on success; non-zero otherwise
 455  */
 456 static int
 457 ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent)
 458 {
 459         int rc = 0;
 460
 461         /* Released in ecryptfs_put_super() */
 462         ecryptfs_set_superblock_private(sb,
 463                                         kmem_cache_zalloc(ecryptfs_sb_info_cache,
 464                                                          GFP_KERNEL));
 465         if (!ecryptfs_superblock_to_private(sb)) {
 466                 ecryptfs_printk(KERN_WARNING, "Out of memory\n");
 467                 rc = -ENOMEM;
 468                 goto out;
 469         }
 470         sb->s_op = &ecryptfs_sops;
 471         /* Released through deactivate_super(sb) from get_sb_nodev */
 472         sb->s_root = d_alloc(NULL, &(const struct qstr) {
 473                              .hash = 0,.name = "/",.len = 1});
 474         if (!sb->s_root) {
 475                 ecryptfs_printk(KERN_ERR, "d_alloc failed\n");
 476                 rc = -ENOMEM;
 477                 goto out;
 478         }
 479         sb->s_root->d_op = &ecryptfs_dops;
 480         sb->s_root->d_sb = sb;
 481         sb->s_root->d_parent = sb->s_root;
 482         /* Released in d_release when dput(sb->s_root) is called */
 483         /* through deactivate_super(sb) from get_sb_nodev() */
 484         ecryptfs_set_dentry_private(sb->s_root,
 485                                     kmem_cache_zalloc(ecryptfs_dentry_info_cache,
 486                                                      GFP_KERNEL));
 487         if (!ecryptfs_dentry_to_private(sb->s_root)) {
 488                 ecryptfs_printk(KERN_ERR,
 489                                 "dentry_info_cache alloc failed\n");
 490                 rc = -ENOMEM;
 491                 goto out;
 492         }
 493         rc = 0;
 494 out:
 495         /* Should be able to rely on deactivate_super called from
 496          * get_sb_nodev */
 497         return rc;
 498 }
 499
 500 /**
 501  * ecryptfs_read_super
 502  * @sb: The ecryptfs super block
 503  * @dev_name: The path to mount over
 504  *
 505  * Read the super block of the lower filesystem, and use
 506  * ecryptfs_interpose to create our initial inode and super block
 507  * struct.
 508  */
 509 static int ecryptfs_read_super(struct super_block *sb, const char *dev_name)
 510 {
 511         int rc;
 512         struct nameidata nd;
 513         struct dentry *lower_root;
 514         struct vfsmount *lower_mnt;
 515
 516         memset(&nd, 0, sizeof(struct nameidata));
 517         rc = path_lookup(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &nd);
 518         if (rc) {
 519                 ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n");
 520                 goto out;
 521         }
 522         lower_root = nd.dentry;
 523         lower_mnt = nd.mnt;
 524         ecryptfs_set_superblock_lower(sb, lower_root->d_sb);
 525         sb->s_maxbytes = lower_root->d_sb->s_maxbytes;
 526         ecryptfs_set_dentry_lower(sb->s_root, lower_root);
 527         ecryptfs_set_dentry_lower_mnt(sb->s_root, lower_mnt);
 528         rc = ecryptfs_interpose(lower_root, sb->s_root, sb, 0);
 529         if (rc)
 530                 goto out_free;
 531         rc = 0;
 532         goto out;
 533 out_free:
 534         path_release(&nd);
 535 out:
 536         return rc;
 537 }
 538
 539 /**
 540  * ecryptfs_get_sb
 541  * @fs_type
 542  * @flags
 543  * @dev_name: The path to mount over
 544  * @raw_data: The options passed into the kernel
 545  *
 546  * The whole ecryptfs_get_sb process is broken into 4 functions:
 547  * ecryptfs_parse_options(): handle options passed to ecryptfs, if any
 548  * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block
 549  *                        with as much information as it can before needing
 550  *                        the lower filesystem.
 551  * ecryptfs_read_super(): this accesses the lower filesystem and uses
 552  *                        ecryptfs_interpolate to perform most of the linking
 553  * ecryptfs_interpolate(): links the lower filesystem into ecryptfs
 554  */
 555 static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags,
 556                         const char *dev_name, void *raw_data,
 557                         struct vfsmount *mnt)
 558 {
 559         int rc;
 560         struct super_block *sb;
 561
 562         rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt);
 563         if (rc < 0) {
 564                 printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc);
 565                 goto out;
 566         }
 567         sb = mnt->mnt_sb;
 568         rc = ecryptfs_parse_options(sb, raw_data);
 569         if (rc) {
 570                 printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc);
 571                 goto out_abort;
 572         }
 573         rc = ecryptfs_read_super(sb, dev_name);
 574         if (rc) {
 575                 printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc);
 576                 goto out_abort;
 577         }
 578         goto out;
 579 out_abort:
 580         dput(sb->s_root);
 581         up_write(&sb->s_umount);
 582         deactivate_super(sb);
 583 out:
 584         return rc;
 585 }
 586
 587 /**
 588  * ecryptfs_kill_block_super
 589  * @sb: The ecryptfs super block
 590  *
 591  * Used to bring the superblock down and free the private data.
 592  * Private data is free'd in ecryptfs_put_super()
 593  */
 594 static void ecryptfs_kill_block_super(struct super_block *sb)
 595 {
 596         generic_shutdown_super(sb);
 597 }
 598
 599 static struct file_system_type ecryptfs_fs_type = {
 600         .owner = THIS_MODULE,
 601         .name = "ecryptfs",
 602         .get_sb = ecryptfs_get_sb,
 603         .kill_sb = ecryptfs_kill_block_super,
 604         .fs_flags = 0
 605 };
 606
 607 /**
 608  * inode_info_init_once
 609  *
 610  * Initializes the ecryptfs_inode_info_cache when it is created
 611  */
 612 static void
 613 inode_info_init_once(struct kmem_cache *cachep, void *vptr)
 614 {
 615         struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr;
 616
 617         inode_init_once(&ei->vfs_inode);
 618 }
 619
 620 static struct ecryptfs_cache_info {
 621         struct kmem_cache **cache;
 622         const char *name;
 623         size_t size;
 624         void (*ctor)(struct kmem_cache *cache, void *obj);
 625 } ecryptfs_cache_infos[] = {
 626         {
 627                 .cache = &ecryptfs_auth_tok_list_item_cache,
 628                 .name = "ecryptfs_auth_tok_list_item",
 629                 .size = sizeof(struct ecryptfs_auth_tok_list_item),
 630         },
 631         {
 632                 .cache = &ecryptfs_file_info_cache,
 633                 .name = "ecryptfs_file_cache",
 634                 .size = sizeof(struct ecryptfs_file_info),
 635         },
 636         {
 637                 .cache = &ecryptfs_dentry_info_cache,
 638                 .name = "ecryptfs_dentry_info_cache",
 639                 .size = sizeof(struct ecryptfs_dentry_info),
 640         },
 641         {
 642                 .cache = &ecryptfs_inode_info_cache,
 643                 .name = "ecryptfs_inode_cache",
 644                 .size = sizeof(struct ecryptfs_inode_info),
 645                 .ctor = inode_info_init_once,
 646         },
 647         {
 648                 .cache = &ecryptfs_sb_info_cache,
 649                 .name = "ecryptfs_sb_cache",
 650                 .size = sizeof(struct ecryptfs_sb_info),
 651         },
 652         {
 653                 .cache = &ecryptfs_header_cache_0,
 654                 .name = "ecryptfs_headers_0",
 655                 .size = PAGE_CACHE_SIZE,
 656         },
 657         {
 658                 .cache = &ecryptfs_header_cache_1,
 659                 .name = "ecryptfs_headers_1",
 660                 .size = PAGE_CACHE_SIZE,
 661         },
 662         {
 663                 .cache = &ecryptfs_header_cache_2,
 664                 .name = "ecryptfs_headers_2",
 665                 .size = PAGE_CACHE_SIZE,
 666         },
 667         {
 668                 .cache = &ecryptfs_xattr_cache,
 669                 .name = "ecryptfs_xattr_cache",
 670                 .size = PAGE_CACHE_SIZE,
 671         },
 672         {
 673                 .cache = &ecryptfs_key_record_cache,
 674                 .name = "ecryptfs_key_record_cache",
 675                 .size = sizeof(struct ecryptfs_key_record),
 676         },
 677         {
 678                 .cache = &ecryptfs_key_sig_cache,
 679                 .name = "ecryptfs_key_sig_cache",
 680                 .size = sizeof(struct ecryptfs_key_sig),
 681         },
 682         {
 683                 .cache = &ecryptfs_global_auth_tok_cache,
 684                 .name = "ecryptfs_global_auth_tok_cache",
 685                 .size = sizeof(struct ecryptfs_global_auth_tok),
 686         },
 687         {
 688                 .cache = &ecryptfs_key_tfm_cache,
 689                 .name = "ecryptfs_key_tfm_cache",
 690                 .size = sizeof(struct ecryptfs_key_tfm),
 691         },
 692 };
 693
 694 static void ecryptfs_free_kmem_caches(void)
 695 {
 696         int i;
 697
 698         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 699                 struct ecryptfs_cache_info *info;
 700
 701                 info = &ecryptfs_cache_infos[i];
 702                 if (*(info->cache))
 703                         kmem_cache_destroy(*(info->cache));
 704         }
 705 }
 706
 707 /**
 708  * ecryptfs_init_kmem_caches
 709  *
 710  * Returns zero on success; non-zero otherwise
 711  */
 712 static int ecryptfs_init_kmem_caches(void)
 713 {
 714         int i;
 715
 716         for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) {
 717                 struct ecryptfs_cache_info *info;
 718
 719                 info = &ecryptfs_cache_infos[i];
 720                 *(info->cache) = kmem_cache_create(info->name, info->size,
 721                                 0, SLAB_HWCACHE_ALIGN, info->ctor);
 722                 if (!*(info->cache)) {
 723                         ecryptfs_free_kmem_caches();
 724                         ecryptfs_printk(KERN_WARNING, "%s: "
 725                                         "kmem_cache_create failed\n",
 726                                         info->name);
 727                         return -ENOMEM;
 728                 }
 729         }
 730         return 0;
 731 }
 732
 733 struct ecryptfs_obj {
 734         char *name;
 735         struct list_head slot_list;
 736         struct kobject kobj;
 737 };
 738
 739 struct ecryptfs_attribute {
 740         struct attribute attr;
 741         ssize_t(*show) (struct ecryptfs_obj *, char *);
 742         ssize_t(*store) (struct ecryptfs_obj *, const char *, size_t);
 743 };
 744
 745 static ssize_t
 746 ecryptfs_attr_store(struct kobject *kobj,
 747                     struct attribute *attr, const char *buf, size_t len)
 748 {
 749         struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
 750                                                 kobj);
 751         struct ecryptfs_attribute *attribute =
 752                 container_of(attr, struct ecryptfs_attribute, attr);
 753
 754         return (attribute->store ? attribute->store(obj, buf, len) : 0);
 755 }
 756
 757 static ssize_t
 758 ecryptfs_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
 759 {
 760         struct ecryptfs_obj *obj = container_of(kobj, struct ecryptfs_obj,
 761                                                 kobj);
 762         struct ecryptfs_attribute *attribute =
 763                 container_of(attr, struct ecryptfs_attribute, attr);
 764
 765         return (attribute->show ? attribute->show(obj, buf) : 0);
 766 }
 767
 768 static struct sysfs_ops ecryptfs_sysfs_ops = {
 769         .show = ecryptfs_attr_show,
 770         .store = ecryptfs_attr_store
 771 };
 772
 773 static struct kobj_type ecryptfs_ktype = {
 774         .sysfs_ops = &ecryptfs_sysfs_ops
 775 };
 776
 777 static decl_subsys(ecryptfs, &ecryptfs_ktype, NULL);
 778
 779 static ssize_t version_show(struct ecryptfs_obj *obj, char *buff)
 780 {
 781         return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK);
 782 }
 783
 784 static struct ecryptfs_attribute sysfs_attr_version = __ATTR_RO(version);
 785
 786 static struct ecryptfs_version_str_map_elem {
 787         u32 flag;
 788         char *str;
 789 } ecryptfs_version_str_map[] = {
 790         {ECRYPTFS_VERSIONING_PASSPHRASE, "passphrase"},
 791         {ECRYPTFS_VERSIONING_PUBKEY, "pubkey"},
 792         {ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH, "plaintext passthrough"},
 793         {ECRYPTFS_VERSIONING_POLICY, "policy"},
 794         {ECRYPTFS_VERSIONING_XATTR, "metadata in extended attribute"},
 795         {ECRYPTFS_VERSIONING_MULTKEY, "multiple keys per file"}
 796 };
 797
 798 static ssize_t version_str_show(struct ecryptfs_obj *obj, char *buff)
 799 {
 800         int i;
 801         int remaining = PAGE_SIZE;
 802         int total_written = 0;
 803
 804         buff[0] = '\0';
 805         for (i = 0; i < ARRAY_SIZE(ecryptfs_version_str_map); i++) {
 806                 int entry_size;
 807
 808                 if (!(ECRYPTFS_VERSIONING_MASK
 809                       & ecryptfs_version_str_map[i].flag))
 810                         continue;
 811                 entry_size = strlen(ecryptfs_version_str_map[i].str);
 812                 if ((entry_size + 2) > remaining)
 813                         goto out;
 814                 memcpy(buff, ecryptfs_version_str_map[i].str, entry_size);
 815                 buff[entry_size++] = '\n';
 816                 buff[entry_size] = '\0';
 817                 buff += entry_size;
 818                 total_written += entry_size;
 819                 remaining -= entry_size;
 820         }
 821 out:
 822         return total_written;
 823 }
 824
 825 static struct ecryptfs_attribute sysfs_attr_version_str = __ATTR_RO(version_str);
 826
 827 static int do_sysfs_registration(void)
 828 {
 829         int rc;
 830
 831         rc = subsystem_register(&ecryptfs_subsys);
 832         if (rc) {
 833                 printk(KERN_ERR
 834                        "Unable to register ecryptfs sysfs subsystem\n");
 835                 goto out;
 836         }
 837         rc = sysfs_create_file(&ecryptfs_subsys.kobj,
 838                                &sysfs_attr_version.attr);
 839         if (rc) {
 840                 printk(KERN_ERR
 841                        "Unable to create ecryptfs version attribute\n");
 842                 subsystem_unregister(&ecryptfs_subsys);
 843                 goto out;
 844         }
 845         rc = sysfs_create_file(&ecryptfs_subsys.kobj,
 846                                &sysfs_attr_version_str.attr);
 847         if (rc) {
 848                 printk(KERN_ERR
 849                        "Unable to create ecryptfs version_str attribute\n");
 850                 sysfs_remove_file(&ecryptfs_subsys.kobj,
 851                                   &sysfs_attr_version.attr);
 852                 subsystem_unregister(&ecryptfs_subsys);
 853                 goto out;
 854         }
 855 out:
 856         return rc;
 857 }
 858
 859 static void do_sysfs_unregistration(void)
 860 {
 861         sysfs_remove_file(&ecryptfs_subsys.kobj,
 862                           &sysfs_attr_version.attr);
 863         sysfs_remove_file(&ecryptfs_subsys.kobj,
 864                           &sysfs_attr_version_str.attr);
 865         subsystem_unregister(&ecryptfs_subsys);
 866 }
 867
 868 static int __init ecryptfs_init(void)
 869 {
 870         int rc;
 871
 872         if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_CACHE_SIZE) {
 873                 rc = -EINVAL;
 874                 ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is "
 875                                 "larger than the host's page size, and so "
 876                                 "eCryptfs cannot run on this system. The "
 877                                 "default eCryptfs extent size is [%d] bytes; "
 878                                 "the page size is [%d] bytes.\n",
 879                                 ECRYPTFS_DEFAULT_EXTENT_SIZE, PAGE_CACHE_SIZE);
 880                 goto out;
 881         }
 882         rc = ecryptfs_init_kmem_caches();
 883         if (rc) {
 884                 printk(KERN_ERR
 885                        "Failed to allocate one or more kmem_cache objects\n");
 886                 goto out;
 887         }
 888         rc = register_filesystem(&ecryptfs_fs_type);
 889         if (rc) {
 890                 printk(KERN_ERR "Failed to register filesystem\n");
 891                 goto out_free_kmem_caches;
 892         }
 893         kobj_set_kset_s(&ecryptfs_subsys, fs_subsys);
 894         rc = do_sysfs_registration();
 895         if (rc) {
 896                 printk(KERN_ERR "sysfs registration failed\n");
 897                 goto out_unregister_filesystem;
 898         }
 899         rc = ecryptfs_init_messaging(ecryptfs_transport);
 900         if (rc) {
 901                 ecryptfs_printk(KERN_ERR, "Failure occured while attempting to "
 902                                 "initialize the eCryptfs netlink socket\n");
 903                 goto out_do_sysfs_unregistration;
 904         }
 905         rc = ecryptfs_init_crypto();
 906         if (rc) {
 907                 printk(KERN_ERR "Failure whilst attempting to init crypto; "
 908                        "rc = [%d]\n", rc);
 909                 goto out_release_messaging;
 910         }
 911         goto out;
 912 out_release_messaging:
 913         ecryptfs_release_messaging(ecryptfs_transport);
 914 out_do_sysfs_unregistration:
 915         do_sysfs_unregistration();
 916 out_unregister_filesystem:
 917         unregister_filesystem(&ecryptfs_fs_type);
 918 out_free_kmem_caches:
 919         ecryptfs_free_kmem_caches();
 920 out:
 921         return rc;
 922 }
 923
 924 static void __exit ecryptfs_exit(void)
 925 {
 926         int rc;
 927
 928         rc = ecryptfs_destroy_crypto();
 929         if (rc)
 930                 printk(KERN_ERR "Failure whilst attempting to destroy crypto; "
 931                        "rc = [%d]\n", rc);
 932         ecryptfs_release_messaging(ecryptfs_transport);
 933         do_sysfs_unregistration();
 934         unregister_filesystem(&ecryptfs_fs_type);
 935         ecryptfs_free_kmem_caches();
 936 }
 937
 938 MODULE_AUTHOR("Michael A. Halcrow <mhalcrow@us.ibm.com>");
 939 MODULE_DESCRIPTION("eCryptfs");
 940
 941 MODULE_LICENSE("GPL");
 942
 943 module_init(ecryptfs_init)
 944 module_exit(ecryptfs_exit)