/**
   * eCryptfs: Linux filesystem encryption layer
   * Kernel declarations.
   *
   * Copyright (C) 1997-2003 Erez Zadok
   * Copyright (C) 2001-2003 Stony Brook University

   * Copyright (C) 2004-2008 International Business Machines Corp.

   *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>

   *              Trevor S. Highland <trevor.highland@gmail.com>
   *              Tyler Hicks <tyhicks@ou.edu>

   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation; either version 2 of the
   * License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   * 02111-1307, USA.
   */
  
  #ifndef ECRYPTFS_KERNEL_H
  #define ECRYPTFS_KERNEL_H

  #include <crypto/skcipher.h>

  #include <keys/user-type.h>

  #include <keys/encrypted-type.h>

  #include <linux/fs.h>

  #include <linux/fs_stack.h>

  #include <linux/namei.h>

  #include <linux/scatterlist.h>

  #include <linux/hash.h>

  #include <linux/nsproxy.h>

  #include <linux/backing-dev.h>

  #include <linux/ecryptfs.h>

  #define ECRYPTFS_DEFAULT_IV_BYTES 16

  #define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
  #define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192

  #define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
  #define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ
  #define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3)

  #define ECRYPTFS_DEFAULT_NUM_USERS 4
  #define ECRYPTFS_MAX_NUM_USERS 32768

  #define ECRYPTFS_XATTR_NAME "user.ecryptfs"

  void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
  extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size);
  extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
  
  struct ecryptfs_key_record {
  	unsigned char type;
  	size_t enc_key_size;
  	unsigned char sig[ECRYPTFS_SIG_SIZE];
  	unsigned char enc_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
  };
  
  struct ecryptfs_auth_tok_list {
  	struct ecryptfs_auth_tok *auth_tok;
  	struct list_head list;
  };
  
  struct ecryptfs_crypt_stat;
  struct ecryptfs_mount_crypt_stat;
  
  struct ecryptfs_page_crypt_context {
  	struct page *page;
  #define ECRYPTFS_PREPARE_COMMIT_MODE 0
  #define ECRYPTFS_WRITEPAGE_MODE      1
  	unsigned int mode;
  	union {
  		struct file *lower_file;
  		struct writeback_control *wbc;
  	} param;
  };

  #if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE)
  static inline struct ecryptfs_auth_tok *
  ecryptfs_get_encrypted_key_payload_data(struct key *key)
  {
  	if (key->type == &key_type_encrypted)
  		return (struct ecryptfs_auth_tok *)

  			(&((struct encrypted_key_payload *)key->payload.data[0])->payload_data);

  	else
  		return NULL;
  }
  
  static inline struct key *ecryptfs_get_encrypted_key(char *sig)
  {
  	return request_key(&key_type_encrypted, sig, NULL);
  }
  
  #else
  static inline struct ecryptfs_auth_tok *
  ecryptfs_get_encrypted_key_payload_data(struct key *key)
  {
  	return NULL;
  }
  
  static inline struct key *ecryptfs_get_encrypted_key(char *sig)
  {
  	return ERR_PTR(-ENOKEY);
  }
  
  #endif /* CONFIG_ENCRYPTED_KEYS */

  static inline struct ecryptfs_auth_tok *
  ecryptfs_get_key_payload_data(struct key *key)
  {

  	struct ecryptfs_auth_tok *auth_tok;
  
  	auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
  	if (!auth_tok)

  		return (struct ecryptfs_auth_tok *)user_key_payload(key)->data;

  	else
  		return auth_tok;

  }

  #define ECRYPTFS_MAX_KEYSET_SIZE 1024

  #define ECRYPTFS_MAX_CIPHER_NAME_SIZE 31

  #define ECRYPTFS_MAX_NUM_ENC_KEYS 64

  #define ECRYPTFS_MAX_IV_BYTES 16	/* 128 bits */
  #define ECRYPTFS_SALT_BYTES 2
  #define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
  #define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8	/* 4*2 */

  #define ECRYPTFS_FILE_SIZE_BYTES (sizeof(u64))

  #define ECRYPTFS_SIZE_AND_MARKER_BYTES (ECRYPTFS_FILE_SIZE_BYTES \
  					+ MAGIC_ECRYPTFS_MARKER_SIZE_BYTES)

  #define ECRYPTFS_DEFAULT_CIPHER "aes"
  #define ECRYPTFS_DEFAULT_KEY_BYTES 16

  #define ECRYPTFS_DEFAULT_HASH "md5"

  #define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH

  #define ECRYPTFS_TAG_1_PACKET_TYPE 0x01

  #define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C
  #define ECRYPTFS_TAG_11_PACKET_TYPE 0xED

  #define ECRYPTFS_TAG_64_PACKET_TYPE 0x40
  #define ECRYPTFS_TAG_65_PACKET_TYPE 0x41
  #define ECRYPTFS_TAG_66_PACKET_TYPE 0x42
  #define ECRYPTFS_TAG_67_PACKET_TYPE 0x43

  #define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename
  					  * as dentry name */
  #define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in
  					  * metadata */
  #define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as
  					  * dentry name */
  #define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as
  					  * metadata */

  #define ECRYPTFS_MIN_PKT_LEN_SIZE 1 /* Min size to specify packet length */
  #define ECRYPTFS_MAX_PKT_LEN_SIZE 2 /* Pass at least this many bytes to
  				     * ecryptfs_parse_packet_length() and
  				     * ecryptfs_write_packet_length()
  				     */

  /* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >=
   * ECRYPTFS_MAX_IV_BYTES */
  #define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16
  #define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */

  #define MD5_DIGEST_SIZE 16

  #define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE

  #define ECRYPTFS_TAG_70_MIN_METADATA_SIZE (1 + ECRYPTFS_MIN_PKT_LEN_SIZE \
  					   + ECRYPTFS_SIG_SIZE + 1 + 1)
  #define ECRYPTFS_TAG_70_MAX_METADATA_SIZE (1 + ECRYPTFS_MAX_PKT_LEN_SIZE \
  					   + ECRYPTFS_SIG_SIZE + 1 + 1)

  #define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED."
  #define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23
  #define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED."
  #define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24
  #define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32)

  #ifdef CONFIG_ECRYPT_FS_MESSAGING
  # define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \
  					     | ECRYPTFS_VERSIONING_PUBKEY)
  #else
  # define ECRYPTFS_VERSIONING_MASK_MESSAGING 0
  #endif
  
  #define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
  				  | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
  				  | ECRYPTFS_VERSIONING_XATTR \
  				  | ECRYPTFS_VERSIONING_MULTKEY \
  				  | ECRYPTFS_VERSIONING_MASK_MESSAGING \
  				  | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)

  struct ecryptfs_key_sig {
  	struct list_head crypt_stat_list;

  	char keysig[ECRYPTFS_SIG_SIZE_HEX + 1];

  };

  struct ecryptfs_filename {
  	struct list_head crypt_stat_list;
  #define ECRYPTFS_FILENAME_CONTAINS_DECRYPTED 0x00000001
  	u32 flags;
  	u32 seq_no;
  	char *filename;
  	char *encrypted_filename;
  	size_t filename_size;
  	size_t encrypted_filename_size;
  	char fnek_sig[ECRYPTFS_SIG_SIZE_HEX];
  	char dentry_name[ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN + 1];
  };

  /**
   * This is the primary struct associated with each encrypted file.
   *
   * TODO: cache align/pack?
   */
  struct ecryptfs_crypt_stat {

  #define ECRYPTFS_STRUCT_INITIALIZED   0x00000001
  #define ECRYPTFS_POLICY_APPLIED       0x00000002

  #define ECRYPTFS_ENCRYPTED            0x00000004
  #define ECRYPTFS_SECURITY_WARNING     0x00000008
  #define ECRYPTFS_ENABLE_HMAC          0x00000010
  #define ECRYPTFS_ENCRYPT_IV_PAGES     0x00000020
  #define ECRYPTFS_KEY_VALID            0x00000040
  #define ECRYPTFS_METADATA_IN_XATTR    0x00000080
  #define ECRYPTFS_VIEW_AS_ENCRYPTED    0x00000100
  #define ECRYPTFS_KEY_SET              0x00000200
  #define ECRYPTFS_ENCRYPT_FILENAMES    0x00000400
  #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
  #define ECRYPTFS_ENCFN_USE_FEK        0x00001000
  #define ECRYPTFS_UNLINK_SIGS          0x00002000

  #define ECRYPTFS_I_SIZE_INITIALIZED   0x00004000

  	u32 flags;
  	unsigned int file_version;
  	size_t iv_bytes;

  	size_t metadata_size;

  	size_t extent_size; /* Data extent size; default is 4096 */
  	size_t key_size;
  	size_t extent_shift;
  	unsigned int extent_mask;
  	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;

  	struct crypto_skcipher *tfm;
  	struct crypto_shash *hash_tfm; /* Crypto context for generating
  					* the initialization vectors */

  	unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];

  	unsigned char key[ECRYPTFS_MAX_KEY_BYTES];
  	unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES];

  	struct list_head keysig_list;
  	struct mutex keysig_list_mutex;

  	struct mutex cs_tfm_mutex;

  	struct mutex cs_mutex;
  };
  
  /* inode private data. */
  struct ecryptfs_inode_info {
  	struct inode vfs_inode;
  	struct inode *wii_inode;

  	struct mutex lower_file_mutex;
  	atomic_t lower_file_count;

  	struct file *lower_file;

  	struct ecryptfs_crypt_stat crypt_stat;
  };
  
  /* dentry private data. Each dentry must keep track of a lower
   * vfsmount too. */
  struct ecryptfs_dentry_info {

  	struct path lower_path;

  	union {
  		struct ecryptfs_crypt_stat *crypt_stat;
  		struct rcu_head rcu;
  	};

  };

  /**

   * ecryptfs_global_auth_tok - A key used to encrypt all new files under the mountpoint
   * @flags: Status flags
   * @mount_crypt_stat_list: These auth_toks hang off the mount-wide
   *                         cryptographic context. Every time a new
   *                         inode comes into existence, eCryptfs copies
   *                         the auth_toks on that list to the set of
   *                         auth_toks on the inode's crypt_stat
   * @global_auth_tok_key: The key from the user's keyring for the sig
   * @global_auth_tok: The key contents
   * @sig: The key identifier
   *

   * ecryptfs_global_auth_tok structs refer to authentication token keys
   * in the user keyring that apply to newly created files. A list of
   * these objects hangs off of the mount_crypt_stat struct for any
   * given eCryptfs mount. This struct maintains a reference to both the
   * key contents and the key itself so that the key can be put on
   * unmount.
   */

  struct ecryptfs_global_auth_tok {
  #define ECRYPTFS_AUTH_TOK_INVALID 0x00000001

  #define ECRYPTFS_AUTH_TOK_FNEK    0x00000002

  	u32 flags;

  	struct list_head mount_crypt_stat_list;
  	struct key *global_auth_tok_key;

  	unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];

  };

  /**

   * ecryptfs_key_tfm - Persistent key tfm
   * @key_tfm: crypto API handle to the key
   * @key_size: Key size in bytes
   * @key_tfm_mutex: Mutex to ensure only one operation in eCryptfs is
   *                 using the persistent TFM at any point in time
   * @key_tfm_list: Handle to hang this off the module-wide TFM list
   * @cipher_name: String name for the cipher for this TFM
   *

   * Typically, eCryptfs will use the same ciphers repeatedly throughout
   * the course of its operations. In order to avoid unnecessarily
   * destroying and initializing the same cipher repeatedly, eCryptfs
   * keeps a list of crypto API contexts around to use when needed.
   */

  struct ecryptfs_key_tfm {

  	struct crypto_skcipher *key_tfm;

  	size_t key_size;
  	struct mutex key_tfm_mutex;

  	struct list_head key_tfm_list;

  	unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
  };

  extern struct mutex key_tfm_list_mutex;

  /**
   * This struct is to enable a mount-wide passphrase/salt combo. This
   * is more or less a stopgap to provide similar functionality to other
   * crypto filesystems like EncFS or CFS until full policy support is
   * implemented in eCryptfs.
   */
  struct ecryptfs_mount_crypt_stat {
  	/* Pointers to memory we do not own, do not free these */
  #define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001

  #define ECRYPTFS_XATTR_METADATA_ENABLED        0x00000002
  #define ECRYPTFS_ENCRYPTED_VIEW_ENABLED        0x00000004

  #define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED  0x00000008

  #define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES      0x00000010
  #define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK   0x00000020
  #define ECRYPTFS_GLOBAL_ENCFN_USE_FEK          0x00000040

  #define ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY    0x00000080

  	u32 flags;

  	struct list_head global_auth_tok_list;
  	struct mutex global_auth_tok_list_mutex;

  	size_t global_default_cipher_key_size;

  	size_t global_default_fn_cipher_key_bytes;

  	unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
  						 + 1];

  	unsigned char global_default_fn_cipher_name[
  		ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
  	char global_default_fnek_sig[ECRYPTFS_SIG_SIZE_HEX + 1];

  };
  
  /* superblock private data. */
  struct ecryptfs_sb_info {
  	struct super_block *wsi_sb;
  	struct ecryptfs_mount_crypt_stat mount_crypt_stat;

  	struct backing_dev_info bdi;

  };
  
  /* file private data. */
  struct ecryptfs_file_info {
  	struct file *wfi_file;
  	struct ecryptfs_crypt_stat *crypt_stat;
  };
  
  /* auth_tok <=> encrypted_session_key mappings */
  struct ecryptfs_auth_tok_list_item {
  	unsigned char encrypted_session_key[ECRYPTFS_MAX_KEY_BYTES];
  	struct list_head list;
  	struct ecryptfs_auth_tok auth_tok;
  };

  struct ecryptfs_message {

  	/* Can never be greater than ecryptfs_message_buf_len */
  	/* Used to find the parent msg_ctx */
  	/* Inherits from msg_ctx->index */

  	u32 index;
  	u32 data_len;
  	u8 data[];
  };
  
  struct ecryptfs_msg_ctx {

  #define ECRYPTFS_MSG_CTX_STATE_FREE     0x01
  #define ECRYPTFS_MSG_CTX_STATE_PENDING  0x02
  #define ECRYPTFS_MSG_CTX_STATE_DONE     0x03
  #define ECRYPTFS_MSG_CTX_STATE_NO_REPLY 0x04
  	u8 state;
  #define ECRYPTFS_MSG_HELO 100
  #define ECRYPTFS_MSG_QUIT 101
  #define ECRYPTFS_MSG_REQUEST 102
  #define ECRYPTFS_MSG_RESPONSE 103
  	u8 type;
  	u32 index;
  	/* Counter converts to a sequence number. Each message sent
  	 * out for which we expect a response has an associated
  	 * sequence number. The response must have the same sequence
  	 * number as the counter for the msg_stc for the message to be
  	 * valid. */
  	u32 counter;
  	size_t msg_size;

  	struct ecryptfs_message *msg;
  	struct task_struct *task;
  	struct list_head node;

  	struct list_head daemon_out_list;

  	struct mutex mux;
  };

  struct ecryptfs_daemon {
  #define ECRYPTFS_DAEMON_IN_READ      0x00000001
  #define ECRYPTFS_DAEMON_IN_POLL      0x00000002
  #define ECRYPTFS_DAEMON_ZOMBIE       0x00000004
  #define ECRYPTFS_DAEMON_MISCDEV_OPEN 0x00000008
  	u32 flags;
  	u32 num_queued_msg_ctx;

  	struct file *file;

  	struct mutex mux;
  	struct list_head msg_ctx_out_queue;
  	wait_queue_head_t wait;
  	struct hlist_node euid_chain;

  };

  #ifdef CONFIG_ECRYPT_FS_MESSAGING

  extern struct mutex ecryptfs_daemon_hash_mux;

  #endif

  static inline size_t
  ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat)
  {
  	if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
  		return 0;

  	return crypt_stat->metadata_size;

  }

  static inline struct ecryptfs_file_info *
  ecryptfs_file_to_private(struct file *file)
  {

  	return file->private_data;

  }
  
  static inline void
  ecryptfs_set_file_private(struct file *file,
  			  struct ecryptfs_file_info *file_info)
  {
  	file->private_data = file_info;
  }
  
  static inline struct file *ecryptfs_file_to_lower(struct file *file)
  {
  	return ((struct ecryptfs_file_info *)file->private_data)->wfi_file;
  }
  
  static inline void
  ecryptfs_set_file_lower(struct file *file, struct file *lower_file)
  {
  	((struct ecryptfs_file_info *)file->private_data)->wfi_file =
  		lower_file;
  }
  
  static inline struct ecryptfs_inode_info *
  ecryptfs_inode_to_private(struct inode *inode)
  {
  	return container_of(inode, struct ecryptfs_inode_info, vfs_inode);
  }
  
  static inline struct inode *ecryptfs_inode_to_lower(struct inode *inode)
  {
  	return ecryptfs_inode_to_private(inode)->wii_inode;
  }
  
  static inline void
  ecryptfs_set_inode_lower(struct inode *inode, struct inode *lower_inode)
  {
  	ecryptfs_inode_to_private(inode)->wii_inode = lower_inode;
  }
  
  static inline struct ecryptfs_sb_info *
  ecryptfs_superblock_to_private(struct super_block *sb)
  {
  	return (struct ecryptfs_sb_info *)sb->s_fs_info;
  }
  
  static inline void
  ecryptfs_set_superblock_private(struct super_block *sb,
  				struct ecryptfs_sb_info *sb_info)
  {
  	sb->s_fs_info = sb_info;
  }
  
  static inline struct super_block *
  ecryptfs_superblock_to_lower(struct super_block *sb)
  {
  	return ((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb;
  }
  
  static inline void
  ecryptfs_set_superblock_lower(struct super_block *sb,
  			      struct super_block *lower_sb)
  {
  	((struct ecryptfs_sb_info *)sb->s_fs_info)->wsi_sb = lower_sb;
  }
  
  static inline struct ecryptfs_dentry_info *
  ecryptfs_dentry_to_private(struct dentry *dentry)
  {
  	return (struct ecryptfs_dentry_info *)dentry->d_fsdata;
  }
  
  static inline void
  ecryptfs_set_dentry_private(struct dentry *dentry,
  			    struct ecryptfs_dentry_info *dentry_info)
  {
  	dentry->d_fsdata = dentry_info;
  }
  
  static inline struct dentry *
  ecryptfs_dentry_to_lower(struct dentry *dentry)
  {

  	return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.dentry;

  }

  static inline struct vfsmount *
  ecryptfs_dentry_to_lower_mnt(struct dentry *dentry)
  {

  	return ((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path.mnt;

  }

  static inline struct path *
  ecryptfs_dentry_to_lower_path(struct dentry *dentry)
  {
  	return &((struct ecryptfs_dentry_info *)dentry->d_fsdata)->lower_path;
  }

  #define ecryptfs_printk(type, fmt, arg...) \

          __ecryptfs_printk(type "%s: " fmt, __func__, ## arg);

  __printf(1, 2)

  void __ecryptfs_printk(const char *fmt, ...);
  
  extern const struct file_operations ecryptfs_main_fops;
  extern const struct file_operations ecryptfs_dir_fops;

  extern const struct inode_operations ecryptfs_main_iops;
  extern const struct inode_operations ecryptfs_dir_iops;
  extern const struct inode_operations ecryptfs_symlink_iops;

  extern const struct super_operations ecryptfs_sops;

  extern const struct dentry_operations ecryptfs_dops;

  extern const struct address_space_operations ecryptfs_aops;

  extern int ecryptfs_verbosity;

  extern unsigned int ecryptfs_message_buf_len;
  extern signed long ecryptfs_message_wait_timeout;
  extern unsigned int ecryptfs_number_of_users;

  
  extern struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
  extern struct kmem_cache *ecryptfs_file_info_cache;
  extern struct kmem_cache *ecryptfs_dentry_info_cache;
  extern struct kmem_cache *ecryptfs_inode_info_cache;
  extern struct kmem_cache *ecryptfs_sb_info_cache;

  extern struct kmem_cache *ecryptfs_header_cache;

  extern struct kmem_cache *ecryptfs_xattr_cache;

  extern struct kmem_cache *ecryptfs_key_record_cache;

  extern struct kmem_cache *ecryptfs_key_sig_cache;
  extern struct kmem_cache *ecryptfs_global_auth_tok_cache;
  extern struct kmem_cache *ecryptfs_key_tfm_cache;

  struct inode *ecryptfs_get_inode(struct inode *lower_inode,
  				 struct super_block *sb);

  void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);

  int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
  			     struct inode *ecryptfs_inode);

  int ecryptfs_decode_and_decrypt_filename(char **decrypted_name,
  					 size_t *decrypted_name_size,

  					 struct super_block *sb,

  					 const char *name, size_t name_size);

  int ecryptfs_fill_zeros(struct file *file, loff_t new_length);

  int ecryptfs_encrypt_and_encode_filename(
  	char **encoded_name,
  	size_t *encoded_name_size,

  	struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
  	const char *name, size_t name_size);

  struct dentry *ecryptfs_lower_dentry(struct dentry *this_dentry);

  void ecryptfs_dump_hex(char *data, int bytes);
  int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg,
  			int sg_size);
  int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat);
  void ecryptfs_rotate_iv(unsigned char *iv);

  int ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);

  void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat);
  void ecryptfs_destroy_mount_crypt_stat(

  	struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
  int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);

  int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode);

  int ecryptfs_encrypt_page(struct page *page);
  int ecryptfs_decrypt_page(struct page *page);

  int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
  			    struct inode *ecryptfs_inode);

  int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);

  int ecryptfs_new_file_context(struct inode *ecryptfs_inode);

  void ecryptfs_write_crypt_stat_flags(char *page_virt,
  				     struct ecryptfs_crypt_stat *crypt_stat,
  				     size_t *written);

  int ecryptfs_read_and_validate_header_region(struct inode *inode);
  int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,

  					    struct inode *inode);

  u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes);

  int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code);

  void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat);
  int ecryptfs_generate_key_packet_set(char *dest_base,
  				     struct ecryptfs_crypt_stat *crypt_stat,
  				     struct dentry *ecryptfs_dentry,
  				     size_t *len, size_t max);

  int
  ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
  			  unsigned char *src, struct dentry *ecryptfs_dentry);
  int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);

  ssize_t

  ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
  			const char *name, void *value, size_t size);

  int

  ecryptfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
  		  const void *value, size_t size, int flags);

  int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode);

  #ifdef CONFIG_ECRYPT_FS_MESSAGING

  int ecryptfs_process_response(struct ecryptfs_daemon *daemon,
  			      struct ecryptfs_message *msg, u32 seq);

  int ecryptfs_send_message(char *data, int data_len,

  			  struct ecryptfs_msg_ctx **msg_ctx);
  int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
  			       struct ecryptfs_message **emsg);

  int ecryptfs_init_messaging(void);
  void ecryptfs_release_messaging(void);

  #else
  static inline int ecryptfs_init_messaging(void)
  {
  	return 0;
  }
  static inline void ecryptfs_release_messaging(void)
  { }
  static inline int ecryptfs_send_message(char *data, int data_len,
  					struct ecryptfs_msg_ctx **msg_ctx)
  {
  	return -ENOTCONN;
  }
  static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
  					     struct ecryptfs_message **emsg)
  {
  	return -ENOMSG;
  }
  #endif

  void
  ecryptfs_write_header_metadata(char *virt,
  			       struct ecryptfs_crypt_stat *crypt_stat,
  			       size_t *written);

  int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig);
  int
  ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,

  			   char *sig, u32 global_auth_tok_flags);

  int ecryptfs_get_global_auth_tok_for_sig(
  	struct ecryptfs_global_auth_tok **global_auth_tok,
  	struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig);
  int
  ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
  			 size_t key_size);
  int ecryptfs_init_crypto(void);

  int ecryptfs_destroy_crypto(void);

  int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm);

  int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_skcipher **tfm,

  					       struct mutex **tfm_mutex,
  					       char *cipher_name);
  int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
  				      struct ecryptfs_auth_tok **auth_tok,
  				      char *sig);

  int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data,
  			 loff_t offset, size_t size);
  int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode,
  				      struct page *page_for_lower,
  				      size_t offset_in_page, size_t size);

  int ecryptfs_write(struct inode *inode, char *data, loff_t offset, size_t size);

  int ecryptfs_read_lower(char *data, loff_t offset, size_t size,
  			struct inode *ecryptfs_inode);
  int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
  				     pgoff_t page_index,
  				     size_t offset_in_page, size_t size,
  				     struct inode *ecryptfs_inode);

  struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index);

  int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
  				 size_t *length_size);
  int ecryptfs_write_packet_length(char *dest, size_t size,
  				 size_t *packet_size_length);

  #ifdef CONFIG_ECRYPT_FS_MESSAGING

  int ecryptfs_init_ecryptfs_miscdev(void);
  void ecryptfs_destroy_ecryptfs_miscdev(void);
  int ecryptfs_send_miscdev(char *data, size_t data_size,
  			  struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type,
  			  u16 msg_flags, struct ecryptfs_daemon *daemon);
  void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx);
  int

  ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file);

  int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon);
  int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon);
  #endif

  int ecryptfs_init_kthread(void);
  void ecryptfs_destroy_kthread(void);
  int ecryptfs_privileged_open(struct file **lower_file,
  			     struct dentry *lower_dentry,

  			     struct vfsmount *lower_mnt,
  			     const struct cred *cred);

  int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode);

  void ecryptfs_put_lower_file(struct inode *inode);

  int
  ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
  			     size_t *packet_size,
  			     struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
  			     char *filename, size_t filename_size);
  int
  ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
  			     size_t *packet_size,
  			     struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
  			     char *data, size_t max_packet_size);

  int ecryptfs_set_f_namelen(long *namelen, long lower_namelen,
  			   struct ecryptfs_mount_crypt_stat *mount_crypt_stat);

  int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat,
  		       loff_t offset);

  extern const struct xattr_handler *ecryptfs_xattr_handlers[];

  #endif /* #ifndef ECRYPTFS_KERNEL_H */