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Commit cde4de12 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs crypto: declare some definitions for f2fs encryption feature 



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

Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 7f63eb77

fs/f2fs/f2fs.h

+55 −0
Original line number Diff line number Diff line
@@ -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

fs/f2fs/f2fs_crypto.h

0 → 100644
+147 −0
Original line number Diff line number Diff line 
/*

 * 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 */

include/linux/f2fs_fs.h

+3 −1
Original line number Diff line number Diff line
@@ -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;



/*