fs/ecryptfs/ecryptfs_kernel.h

   1 /**
   2  * eCryptfs: Linux filesystem encryption layer
   3  * Kernel declarations.
   4  *
   5  * Copyright (C) 1997-2003 Erez Zadok
   6  * Copyright (C) 2001-2003 Stony Brook University
   7  * Copyright (C) 2004-2006 International Business Machines Corp.
   8  *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of the
  13  * License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  23  * 02111-1307, USA.
  24  */
  25
  26 #ifndef ECRYPTFS_KERNEL_H
  27 #define ECRYPTFS_KERNEL_H
  28
  29 #include <keys/user-type.h>
  30 #include <linux/fs.h>
  31 #include <linux/scatterlist.h>
  32
  33 /* Version verification for shared data structures w/ userspace */
  34 #define ECRYPTFS_VERSION_MAJOR 0x00
  35 #define ECRYPTFS_VERSION_MINOR 0x04
  36 #define ECRYPTFS_SUPPORTED_FILE_VERSION 0x01
  37 /* These flags indicate which features are supported by the kernel
  38  * module; userspace tools such as the mount helper read
  39  * ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine
  40  * how to behave. */
  41 #define ECRYPTFS_VERSIONING_PASSPHRASE 0x00000001
  42 #define ECRYPTFS_VERSIONING_PUBKEY 0x00000002
  43 #define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004
  44 #define ECRYPTFS_VERSIONING_POLICY 0x00000008
  45 #define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
  46                                   | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH)
  47
  48 #define ECRYPTFS_MAX_PASSWORD_LENGTH 64
  49 #define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH
  50 #define ECRYPTFS_SALT_SIZE 8
  51 #define ECRYPTFS_SALT_SIZE_HEX (ECRYPTFS_SALT_SIZE*2)
  52 /* The original signature size is only for what is stored on disk; all
  53  * in-memory representations are expanded hex, so it better adapted to
  54  * be passed around or referenced on the command line */
  55 #define ECRYPTFS_SIG_SIZE 8
  56 #define ECRYPTFS_SIG_SIZE_HEX (ECRYPTFS_SIG_SIZE*2)
  57 #define ECRYPTFS_PASSWORD_SIG_SIZE ECRYPTFS_SIG_SIZE_HEX
  58 #define ECRYPTFS_MAX_KEY_BYTES 64
  59 #define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
  60 #define ECRYPTFS_DEFAULT_IV_BYTES 16
  61 #define ECRYPTFS_FILE_VERSION 0x01
  62 #define ECRYPTFS_DEFAULT_HEADER_EXTENT_SIZE 8192
  63 #define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
  64 #define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
  65
  66 #define RFC2440_CIPHER_DES3_EDE 0x02
  67 #define RFC2440_CIPHER_CAST_5 0x03
  68 #define RFC2440_CIPHER_BLOWFISH 0x04
  69 #define RFC2440_CIPHER_AES_128 0x07
  70 #define RFC2440_CIPHER_AES_192 0x08
  71 #define RFC2440_CIPHER_AES_256 0x09
  72 #define RFC2440_CIPHER_TWOFISH 0x0a
  73 #define RFC2440_CIPHER_CAST_6 0x0b
  74
  75 #define ECRYPTFS_SET_FLAG(flag_bit_vector, flag) (flag_bit_vector |= (flag))
  76 #define ECRYPTFS_CLEAR_FLAG(flag_bit_vector, flag) (flag_bit_vector &= ~(flag))
  77 #define ECRYPTFS_CHECK_FLAG(flag_bit_vector, flag) (flag_bit_vector & (flag))
  78
  79 /**
  80  * For convenience, we may need to pass around the encrypted session
  81  * key between kernel and userspace because the authentication token
  82  * may not be extractable.  For example, the TPM may not release the
  83  * private key, instead requiring the encrypted data and returning the
  84  * decrypted data.
  85  */
  86 struct ecryptfs_session_key {
  87 #define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT 0x00000001
  88 #define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT 0x00000002
  89 #define ECRYPTFS_CONTAINS_DECRYPTED_KEY 0x00000004
  90 #define ECRYPTFS_CONTAINS_ENCRYPTED_KEY 0x00000008
  91         u32 flags;
  92         u32 encrypted_key_size;
  93         u32 decrypted_key_size;
  94         u8 encrypted_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
  95         u8 decrypted_key[ECRYPTFS_MAX_KEY_BYTES];
  96 };
  97
  98 struct ecryptfs_password {
  99         u32 password_bytes;
 100         s32 hash_algo;
 101         u32 hash_iterations;
 102         u32 session_key_encryption_key_bytes;
 103 #define ECRYPTFS_PERSISTENT_PASSWORD 0x01
 104 #define ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET 0x02
 105         u32 flags;
 106         /* Iterated-hash concatenation of salt and passphrase */
 107         u8 session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
 108         u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
 109         /* Always in expanded hex */
 110         u8 salt[ECRYPTFS_SALT_SIZE];
 111 };
 112
 113 enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY};
 114
 115 /* May be a password or a private key */
 116 struct ecryptfs_auth_tok {
 117         u16 version; /* 8-bit major and 8-bit minor */
 118         u16 token_type;
 119         u32 flags;
 120         struct ecryptfs_session_key session_key;
 121         u8 reserved[32];
 122         union {
 123                 struct ecryptfs_password password;
 124                 /* Private key is in future eCryptfs releases */
 125         } token;
 126 } __attribute__ ((packed));
 127
 128 void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
 129 extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size);
 130 extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
 131
 132 struct ecryptfs_key_record {
 133         unsigned char type;
 134         size_t enc_key_size;
 135         unsigned char sig[ECRYPTFS_SIG_SIZE];
 136         unsigned char enc_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
 137 };
 138
 139 struct ecryptfs_auth_tok_list {
 140         struct ecryptfs_auth_tok *auth_tok;
 141         struct list_head list;
 142 };
 143
 144 struct ecryptfs_crypt_stat;
 145 struct ecryptfs_mount_crypt_stat;
 146
 147 struct ecryptfs_page_crypt_context {
 148         struct page *page;
 149 #define ECRYPTFS_PREPARE_COMMIT_MODE 0
 150 #define ECRYPTFS_WRITEPAGE_MODE      1
 151         unsigned int mode;
 152         union {
 153                 struct file *lower_file;
 154                 struct writeback_control *wbc;
 155         } param;
 156 };
 157
 158 static inline struct ecryptfs_auth_tok *
 159 ecryptfs_get_key_payload_data(struct key *key)
 160 {
 161         return (struct ecryptfs_auth_tok *)
 162                 (((struct user_key_payload*)key->payload.data)->data);
 163 }
 164
 165 #define ECRYPTFS_SUPER_MAGIC 0xf15f
 166 #define ECRYPTFS_MAX_KEYSET_SIZE 1024
 167 #define ECRYPTFS_MAX_CIPHER_NAME_SIZE 32
 168 #define ECRYPTFS_MAX_NUM_ENC_KEYS 64
 169 #define ECRYPTFS_MAX_NUM_KEYSIGS 2 /* TODO: Make this a linked list */
 170 #define ECRYPTFS_MAX_IV_BYTES 16        /* 128 bits */
 171 #define ECRYPTFS_SALT_BYTES 2
 172 #define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
 173 #define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8      /* 4*2 */
 174 #define ECRYPTFS_FILE_SIZE_BYTES 8
 175 #define ECRYPTFS_DEFAULT_CIPHER "aes"
 176 #define ECRYPTFS_DEFAULT_KEY_BYTES 16
 177 #define ECRYPTFS_DEFAULT_CHAINING_MODE CRYPTO_TFM_MODE_CBC
 178 #define ECRYPTFS_DEFAULT_HASH "md5"
 179 #define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
 180 #define ECRYPTFS_TAG_11_PACKET_TYPE 0xED
 181 #define MD5_DIGEST_SIZE 16
 182
 183 /**
 184  * This is the primary struct associated with each encrypted file.
 185  *
 186  * TODO: cache align/pack?
 187  */
 188 struct ecryptfs_crypt_stat {
 189 #define ECRYPTFS_STRUCT_INITIALIZED 0x00000001
 190 #define ECRYPTFS_POLICY_APPLIED     0x00000002
 191 #define ECRYPTFS_NEW_FILE           0x00000004
 192 #define ECRYPTFS_ENCRYPTED          0x00000008
 193 #define ECRYPTFS_SECURITY_WARNING   0x00000010
 194 #define ECRYPTFS_ENABLE_HMAC        0x00000020
 195 #define ECRYPTFS_ENCRYPT_IV_PAGES   0x00000040
 196 #define ECRYPTFS_KEY_VALID          0x00000080
 197         u32 flags;
 198         unsigned int file_version;
 199         size_t iv_bytes;
 200         size_t num_keysigs;
 201         size_t header_extent_size;
 202         size_t num_header_extents_at_front;
 203         size_t extent_size; /* Data extent size; default is 4096 */
 204         size_t key_size;
 205         size_t extent_shift;
 206         unsigned int extent_mask;
 207         struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 208         struct crypto_blkcipher *tfm;
 209         struct crypto_hash *hash_tfm; /* Crypto context for generating
 210                                        * the initialization vectors */
 211         unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
 212         unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
 213         unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];
 214         unsigned char keysigs[ECRYPTFS_MAX_NUM_KEYSIGS][ECRYPTFS_SIG_SIZE_HEX];
 215         struct mutex cs_tfm_mutex;
 216         struct mutex cs_hash_tfm_mutex;
 217         struct mutex cs_mutex;
 218 };
 219
 220 /* inode private data. */
 221 struct ecryptfs_inode_info {
 222         struct inode vfs_inode;
 223         struct inode *wii_inode;
 224         struct ecryptfs_crypt_stat crypt_stat;
 225 };
 226
 227 /* dentry private data. Each dentry must keep track of a lower
 228  * vfsmount too. */
 229 struct ecryptfs_dentry_info {
 230         struct dentry *wdi_dentry;
 231         struct vfsmount *lower_mnt;
 232         struct ecryptfs_crypt_stat *crypt_stat;
 233 };
 234
 235 /**
 236  * This struct is to enable a mount-wide passphrase/salt combo. This
 237  * is more or less a stopgap to provide similar functionality to other
 238  * crypto filesystems like EncFS or CFS until full policy support is
 239  * implemented in eCryptfs.
 240  */
 241 struct ecryptfs_mount_crypt_stat {
 242         /* Pointers to memory we do not own, do not free these */
 243 #define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001
 244         u32 flags;
 245         struct ecryptfs_auth_tok *global_auth_tok;
 246         struct key *global_auth_tok_key;
 247         size_t global_default_cipher_key_size;
 248         struct crypto_blkcipher *global_key_tfm;
 249         struct mutex global_key_tfm_mutex;
 250         unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
 251                                                  + 1];
 252         unsigned char global_auth_tok_sig[ECRYPTFS_SIG_SIZE_HEX + 1];
 253 };
 254
 255 /* superblock private data. */
 256 struct ecryptfs_sb_info {
 257         struct super_block *wsi_sb;
 258         struct ecryptfs_mount_crypt_stat mount_crypt_stat;
 259 };
 260
 261 /* file private data. */
 262 struct ecryptfs_file_info {
 263         struct file *wfi_file;
 264         struct ecryptfs_crypt_stat *crypt_stat;
 265 };
 266
 267 /* auth_tok <=> encrypted_session_key mappings */
 268 struct ecryptfs_auth_tok_list_item {
 269         unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
 270         struct list_head list;
 271         struct ecryptfs_auth_tok auth_tok;
 272 };
 273
 274 static inline struct ecryptfs_file_info *
 275 ecryptfs_file_to_private(struct file *file)
 276 {
 277         return (struct ecryptfs_file_info *)file->private_data;
 278 }
 279
 280 static inline void
 281 ecryptfs_set_file_private(struct file *file,
 282                           struct ecryptfs_file_info *file_info)
 283 {
 284         file->private_data = file_info;
 285 }
 286
 287 static inline struct file *ecryptfs_file_to_lower(struct file *file)
 288 {
 289         return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
 290 }
 291
 292 static inline void
 293 ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
 294 {
 295         ((struct ecryptfs_file_info *)file->private_data)->wfi_file =
 296                 lower_file;
 297 }
 298
 299 static inline struct ecryptfs_inode_info *
 300 ecryptfs_inode_to_private(struct inode *inode)
 301 {
 302         return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
 303 }
 304
 305 static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
 306 {
 307         return ecryptfs_inode_to_private(inode)->wii_inode;
 308 }
 309
 310 static inline void
 311 ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
 312 {
 313         ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
 314 }
 315
 316 static inline struct ecryptfs_sb_info *
 317 ecryptfs_superblock_to_private(struct super_block *sb)
 318 {
 319         return (struct ecryptfs_sb_info *)sb->s_fs_info;
 320 }
 321
 322 static inline void
 323 ecryptfs_set_superblock_private(struct super_block *sb,
 324                                 struct ecryptfs_sb_info *sb_info)
 325 {
 326         sb->s_fs_info = sb_info;
 327 }
 328
 329 static inline struct super_block *
 330 ecryptfs_superblock_to_lower(struct super_block *sb)
 331 {
 332         return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
 333 }
 334
 335 static inline void
 336 ecryptfs_set_superblock_lower(struct super_block *sb,
 337                               struct super_block *lower_sb)
 338 {
 339         ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
 340 }
 341
 342 static inline struct ecryptfs_dentry_info *
 343 ecryptfs_dentry_to_private(struct dentry *dentry)
 344 {
 345         return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
 346 }
 347
 348 static inline void
 349 ecryptfs_set_dentry_private(struct dentry *dentry,
 350                             struct ecryptfs_dentry_info *dentry_info)
 351 {
 352         dentry->d_fsdata = dentry_info;
 353 }
 354
 355 static inline struct dentry *
 356 ecryptfs_dentry_to_lower(struct dentry *dentry)
 357 {
 358         return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->wdi_dentry;
 359 }
 360
 361 static inline void
 362 ecryptfs_set_dentry_lower(struct dentry *dentry, struct dentry *lower_dentry)
 363 {
 364         ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->wdi_dentry =
 365                 lower_dentry;
 366 }
 367
 368 static inline struct vfsmount *
 369 ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
 370 {
 371         return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_mnt;
 372 }
 373
 374 static inline void
 375 ecryptfs_set_dentry_lower_mnt(struct dentry *dentry, struct vfsmount *lower_mnt)
 376 {
 377         ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_mnt =
 378                 lower_mnt;
 379 }
 380
 381 #define ecryptfs_printk(type, fmt, arg...) \
 382         __ecryptfs_printk(type "%s: " fmt, __FUNCTION__, ## arg);
 383 void __ecryptfs_printk(const char *fmt, ...);
 384
 385 extern const struct file_operations ecryptfs_main_fops;
 386 extern const struct file_operations ecryptfs_dir_fops;
 387 extern struct inode_operations ecryptfs_main_iops;
 388 extern struct inode_operations ecryptfs_dir_iops;
 389 extern struct inode_operations ecryptfs_symlink_iops;
 390 extern struct super_operations ecryptfs_sops;
 391 extern struct dentry_operations ecryptfs_dops;
 392 extern struct address_space_operations ecryptfs_aops;
 393 extern int ecryptfs_verbosity;
 394
 395 extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
 396 extern struct kmem_cache *ecryptfs_file_info_cache;
 397 extern struct kmem_cache *ecryptfs_dentry_info_cache;
 398 extern struct kmem_cache *ecryptfs_inode_info_cache;
 399 extern struct kmem_cache *ecryptfs_sb_info_cache;
 400 extern struct kmem_cache *ecryptfs_header_cache_0;
 401 extern struct kmem_cache *ecryptfs_header_cache_1;
 402 extern struct kmem_cache *ecryptfs_header_cache_2;
 403 extern struct kmem_cache *ecryptfs_lower_page_cache;
 404
 405 int ecryptfs_interpose(struct dentry *hidden_dentry,
 406                        struct dentry *this_dentry, struct super_block *sb,
 407                        int flag);
 408 int ecryptfs_fill_zeros(struct file *file, loff_t new_length);
 409 int ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat,
 410                              const char *name, int length,
 411                              char **decrypted_name);
 412 int ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat,
 413                              const char *name, int length,
 414                              char **encoded_name);
 415 struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);
 416 void ecryptfs_copy_attr_atime(struct inode *dest, const struct inode *src);
 417 void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src);
 418 void ecryptfs_copy_inode_size(struct inode *dst, const struct inode *src);
 419 void ecryptfs_dump_hex(char *data, int bytes);
 420 int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
 421                         int sg_size);
 422 int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
 423 void ecryptfs_rotate_iv(unsigned char *iv);
 424 void ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
 425 void ecryptfs_destruct_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
 426 void ecryptfs_destruct_mount_crypt_stat(
 427         struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
 428 int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
 429 int ecryptfs_crypto_api_algify_cipher_name(char **algified_name,
 430                                            char *cipher_name,
 431                                            char *chaining_modifier);
 432 int ecryptfs_write_inode_size_to_header(struct file *lower_file,
 433                                         struct inode *lower_inode,
 434                                         struct inode *inode);
 435 int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
 436                             struct file *lower_file,
 437                             unsigned long lower_page_index, int byte_offset,
 438                             int region_bytes);
 439 int
 440 ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
 441                            struct file *lower_file, int byte_offset,
 442                            int region_size);
 443 int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
 444                                 struct file *lower_file);
 445 int ecryptfs_do_readpage(struct file *file, struct page *page,
 446                          pgoff_t lower_page_index);
 447 int ecryptfs_grab_and_map_lower_page(struct page **lower_page,
 448                                      char **lower_virt,
 449                                      struct inode *lower_inode,
 450                                      unsigned long lower_page_index);
 451 int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
 452                                               struct inode *lower_inode,
 453                                               struct writeback_control *wbc);
 454 int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx);
 455 int ecryptfs_decrypt_page(struct file *file, struct page *page);
 456 int ecryptfs_write_headers(struct dentry *ecryptfs_dentry,
 457                            struct file *lower_file);
 458 int ecryptfs_write_headers_virt(char *page_virt,
 459                                 struct ecryptfs_crypt_stat *crypt_stat,
 460                                 struct dentry *ecryptfs_dentry);
 461 int ecryptfs_read_headers(struct dentry *ecryptfs_dentry,
 462                           struct file *lower_file);
 463 int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry);
 464 int contains_ecryptfs_marker(char *data);
 465 int ecryptfs_read_header_region(char *data, struct dentry *dentry,
 466                                 struct vfsmount *mnt);
 467 u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat);
 468 int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code);
 469 void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
 470 int ecryptfs_generate_key_packet_set(char *dest_base,
 471                                      struct ecryptfs_crypt_stat *crypt_stat,
 472                                      struct dentry *ecryptfs_dentry,
 473                                      size_t *len, size_t max);
 474 int process_request_key_err(long err_code);
 475 int
 476 ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
 477                           unsigned char *src, struct dentry *ecryptfs_dentry);
 478 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
 479 int
 480 ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name,
 481                         size_t *key_size);
 482 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode);
 483 int ecryptfs_inode_set(struct inode *inode, void *lower_inode);
 484 void ecryptfs_init_inode(struct inode *inode, struct inode *lower_inode);
 485 int ecryptfs_open_lower_file(struct file **lower_file,
 486                              struct dentry *lower_dentry,
 487                              struct vfsmount *lower_mnt, int flags);
 488 int ecryptfs_close_lower_file(struct file *lower_file);
 489
 490 #endif /* #ifndef ECRYPTFS_KERNEL_H */