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