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f2fs crypto: declare some definitions for f2fs encryption feature

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This definitions will be used by inode and superblock for encyption.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2015-04-20 13:57:51 -07:00
parent 7f63eb77af
commit cde4de1205
3 changed files with 205 additions and 1 deletions
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55
fs/f2fs/f2fs.h
View File

@ -70,6 +70,8 @@ struct f2fs_mount_info {
unsigned int opt;
};
#define F2FS_FEATURE_ENCRYPT 0x0001
#define F2FS_HAS_FEATURE(sb, mask) \
((F2FS_SB(sb)->raw_super->feature & cpu_to_le32(mask)) != 0)
#define F2FS_SET_FEATURE(sb, mask) \
@ -346,6 +348,7 @@ struct f2fs_map_blocks {
*/
#define FADVISE_COLD_BIT 0x01
#define FADVISE_LOST_PINO_BIT 0x02
#define FADVISE_ENCRYPT_BIT 0x04
#define file_is_cold(inode) is_file(inode, FADVISE_COLD_BIT)
#define file_wrong_pino(inode) is_file(inode, FADVISE_LOST_PINO_BIT)
@ -353,6 +356,16 @@ struct f2fs_map_blocks {
#define file_lost_pino(inode) set_file(inode, FADVISE_LOST_PINO_BIT)
#define file_clear_cold(inode) clear_file(inode, FADVISE_COLD_BIT)
#define file_got_pino(inode) clear_file(inode, FADVISE_LOST_PINO_BIT)
#define file_is_encrypt(inode) is_file(inode, FADVISE_ENCRYPT_BIT)
#define file_set_encrypt(inode) set_file(inode, FADVISE_ENCRYPT_BIT)
#define file_clear_encrypt(inode) clear_file(inode, FADVISE_ENCRYPT_BIT)
/* Encryption algorithms */
#define F2FS_ENCRYPTION_MODE_INVALID 0
#define F2FS_ENCRYPTION_MODE_AES_256_XTS 1
#define F2FS_ENCRYPTION_MODE_AES_256_GCM 2
#define F2FS_ENCRYPTION_MODE_AES_256_CBC 3
#define F2FS_ENCRYPTION_MODE_AES_256_CTS 4
#define DEF_DIR_LEVEL 0
@ -380,6 +393,11 @@ struct f2fs_inode_info {
struct radix_tree_root inmem_root; /* radix tree for inmem pages */
struct list_head inmem_pages; /* inmemory pages managed by f2fs */
struct mutex inmem_lock; /* lock for inmemory pages */
#ifdef CONFIG_F2FS_FS_ENCRYPTION
/* Encryption params */
struct f2fs_crypt_info *i_crypt_info;
#endif
};
static inline void get_extent_info(struct extent_info *ext,
@ -1891,4 +1909,41 @@ void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *,
struct inode *, struct inode *);
bool f2fs_empty_inline_dir(struct inode *);
int f2fs_read_inline_dir(struct file *, struct dir_context *);
/*
* crypto support
*/
static inline int f2fs_encrypted_inode(struct inode *inode)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
return file_is_encrypt(inode);
#else
return 0;
#endif
}
static inline void f2fs_set_encrypted_inode(struct inode *inode)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
file_set_encrypt(inode);
#endif
}
static inline bool f2fs_bio_encrypted(struct bio *bio)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
return unlikely(bio->bi_private != NULL);
#else
return false;
#endif
}
static inline int f2fs_sb_has_crypto(struct super_block *sb)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
return F2FS_HAS_FEATURE(sb, F2FS_FEATURE_ENCRYPT);
#else
return 0;
#endif
}
#endif

147
fs/f2fs/f2fs_crypto.h Normal file
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@ -0,0 +1,147 @@
/*
* linux/fs/f2fs/f2fs_crypto.h
*
* Copied from linux/fs/ext4/ext4_crypto.h
*
* Copyright (C) 2015, Google, Inc.
*
* This contains encryption header content for f2fs
*
* Written by Michael Halcrow, 2015.
* Modified by Jaegeuk Kim, 2015.
*/
#ifndef _F2FS_CRYPTO_H
#define _F2FS_CRYPTO_H
#include <linux/fs.h>
#define F2FS_KEY_DESCRIPTOR_SIZE 8
/* Policy provided via an ioctl on the topmost directory */
struct f2fs_encryption_policy {
char version;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
} __attribute__((__packed__));
#define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
#define F2FS_KEY_DERIVATION_NONCE_SIZE 16
#define F2FS_POLICY_FLAGS_PAD_4 0x00
#define F2FS_POLICY_FLAGS_PAD_8 0x01
#define F2FS_POLICY_FLAGS_PAD_16 0x02
#define F2FS_POLICY_FLAGS_PAD_32 0x03
#define F2FS_POLICY_FLAGS_PAD_MASK 0x03
#define F2FS_POLICY_FLAGS_VALID 0x03
/**
* Encryption context for inode
*
* Protector format:
* 1 byte: Protector format (1 = this version)
* 1 byte: File contents encryption mode
* 1 byte: File names encryption mode
* 1 byte: Flags
* 8 bytes: Master Key descriptor
* 16 bytes: Encryption Key derivation nonce
*/
struct f2fs_encryption_context {
char format;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE];
} __attribute__((__packed__));
/* Encryption parameters */
#define F2FS_XTS_TWEAK_SIZE 16
#define F2FS_AES_128_ECB_KEY_SIZE 16
#define F2FS_AES_256_GCM_KEY_SIZE 32
#define F2FS_AES_256_CBC_KEY_SIZE 32
#define F2FS_AES_256_CTS_KEY_SIZE 32
#define F2FS_AES_256_XTS_KEY_SIZE 64
#define F2FS_MAX_KEY_SIZE 64
struct f2fs_encryption_key {
__u32 mode;
char raw[F2FS_MAX_KEY_SIZE];
__u32 size;
} __attribute__((__packed__));
struct f2fs_crypt_info {
unsigned char ci_mode;
unsigned char ci_size;
char ci_data_mode;
char ci_filename_mode;
char ci_flags;
struct crypto_ablkcipher *ci_ctfm;
struct key *ci_keyring_key;
char ci_raw[F2FS_MAX_KEY_SIZE];
char ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE];
};
#define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define F2FS_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002
struct f2fs_crypto_ctx {
struct crypto_tfm *tfm; /* Crypto API context */
struct page *bounce_page; /* Ciphertext page on write path */
struct page *control_page; /* Original page on write path */
struct bio *bio; /* The bio for this context */
struct work_struct work; /* Work queue for read complete path */
struct list_head free_list; /* Free list */
int flags; /* Flags */
int mode; /* Encryption mode for tfm */
};
struct f2fs_completion_result {
struct completion completion;
int res;
};
#define DECLARE_F2FS_COMPLETION_RESULT(ecr) \
struct f2fs_completion_result ecr = { \
COMPLETION_INITIALIZER((ecr).completion), 0 }
static inline int f2fs_encryption_key_size(int mode)
{
switch (mode) {
case F2FS_ENCRYPTION_MODE_AES_256_XTS:
return F2FS_AES_256_XTS_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_GCM:
return F2FS_AES_256_GCM_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_CBC:
return F2FS_AES_256_CBC_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_CTS:
return F2FS_AES_256_CTS_KEY_SIZE;
default:
BUG();
}
return 0;
}
#define F2FS_FNAME_NUM_SCATTER_ENTRIES 4
#define F2FS_CRYPTO_BLOCK_SIZE 16
#define F2FS_FNAME_CRYPTO_DIGEST_SIZE 32
/**
* For encrypted symlinks, the ciphertext length is stored at the beginning
* of the string in little-endian format.
*/
struct f2fs_encrypted_symlink_data {
__le16 len;
char encrypted_path[1];
} __attribute__((__packed__));
/**
* This function is used to calculate the disk space required to
* store a filename of length l in encrypted symlink format.
*/
static inline u32 encrypted_symlink_data_len(u32 l)
{
return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1);
}
#endif /* _F2FS_CRYPTO_H */

4
include/linux/f2fs_fs.h
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@ -91,7 +91,9 @@ struct f2fs_super_block {
__u8 version[VERSION_LEN]; /* the kernel version */
__u8 init_version[VERSION_LEN]; /* the initial kernel version */
__le32 feature; /* defined features */
__u8 reserved[888]; /* valid reserved region */
__u8 encryption_level; /* versioning level for encryption */
__u8 encrypt_pw_salt[16]; /* Salt used for string2key algorithm */
__u8 reserved[871]; /* valid reserved region */
} __packed;
/*