[linux-2.6-block.git] / include / linux / fscrypt_common.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * fscrypt_common.h: common declarations for per-file encryption
 *
 * Copyright (C) 2015, Google, Inc.
 *
 * Written by Michael Halcrow, 2015.
 * Modified by Jaegeuk Kim, 2015.
 */

#ifndef _LINUX_FSCRYPT_COMMON_H
#define _LINUX_FSCRYPT_COMMON_H

#include <linux/key.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/dcache.h>
#include <crypto/skcipher.h>
#include <uapi/linux/fs.h>

#define FS_CRYPTO_BLOCK_SIZE		16

struct fscrypt_info;

struct fscrypt_ctx {
	union {
		struct {
			struct page *bounce_page;	/* Ciphertext page */
			struct page *control_page;	/* Original page  */
		} w;
		struct {
			struct bio *bio;
			struct work_struct work;
		} r;
		struct list_head free_list;	/* Free list */
	};
	u8 flags;				/* Flags */
};

/**
 * For encrypted symlinks, the ciphertext length is stored at the beginning
 * of the string in little-endian format.
 */
struct fscrypt_symlink_data {
	__le16 len;
	char encrypted_path[1];
} __packed;

struct fscrypt_str {
	unsigned char *name;
	u32 len;
};

struct fscrypt_name {
	const struct qstr *usr_fname;
	struct fscrypt_str disk_name;
	u32 hash;
	u32 minor_hash;
	struct fscrypt_str crypto_buf;
};

#define FSTR_INIT(n, l)		{ .name = n, .len = l }
#define FSTR_TO_QSTR(f)		QSTR_INIT((f)->name, (f)->len)
#define fname_name(p)		((p)->disk_name.name)
#define fname_len(p)		((p)->disk_name.len)

/*
 * fscrypt superblock flags
 */
#define FS_CFLG_OWN_PAGES (1U << 1)

/*
 * crypto opertions for filesystems
 */
struct fscrypt_operations {
	unsigned int flags;
	const char *key_prefix;
	int (*get_context)(struct inode *, void *, size_t);
	int (*set_context)(struct inode *, const void *, size_t, void *);
	bool (*dummy_context)(struct inode *);
	bool (*is_encrypted)(struct inode *);
	bool (*empty_dir)(struct inode *);
	unsigned (*max_namelen)(struct inode *);
};

/* Maximum value for the third parameter of fscrypt_operations.set_context(). */
#define FSCRYPT_SET_CONTEXT_MAX_SIZE	28

static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
{
	if (inode->i_sb->s_cop->dummy_context &&
				inode->i_sb->s_cop->dummy_context(inode))
		return true;
	return false;
}

static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
					u32 filenames_mode)
{
	if (contents_mode == FS_ENCRYPTION_MODE_AES_128_CBC &&
	    filenames_mode == FS_ENCRYPTION_MODE_AES_128_CTS)
		return true;

	if (contents_mode == FS_ENCRYPTION_MODE_AES_256_XTS &&
	    filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS)
		return true;

	return false;
}

static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
{
	if (str->len == 1 && str->name[0] == '.')
		return true;

	if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
		return true;

	return false;
}

static inline struct page *fscrypt_control_page(struct page *page)
{
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
#else
	WARN_ON_ONCE(1);
	return ERR_PTR(-EINVAL);
#endif
}

static inline int fscrypt_has_encryption_key(const struct inode *inode)
{
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	return (inode->i_crypt_info != NULL);
#else
	return 0;
#endif
}

#endif	/* _LINUX_FSCRYPT_COMMON_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
46f47e48 EB	2	/*
	3	* fscrypt_common.h: common declarations for per-file encryption
	4	*
	5	* Copyright (C) 2015, Google, Inc.
	6	*
	7	* Written by Michael Halcrow, 2015.
	8	* Modified by Jaegeuk Kim, 2015.
	9	*/
	10
	11	#ifndef _LINUX_FSCRYPT_COMMON_H
	12	#define _LINUX_FSCRYPT_COMMON_H
	13
	14	#include <linux/key.h>
	15	#include <linux/fs.h>
	16	#include <linux/mm.h>
	17	#include <linux/bio.h>
	18	#include <linux/dcache.h>
	19	#include <crypto/skcipher.h>
	20	#include <uapi/linux/fs.h>
	21
	22	#define FS_CRYPTO_BLOCK_SIZE 16
	23
	24	struct fscrypt_info;
	25
	26	struct fscrypt_ctx {
	27	union {
	28	struct {
	29	struct page bounce_page; / Ciphertext page */
	30	struct page control_page; / Original page */
	31	} w;
	32	struct {
	33	struct bio *bio;
	34	struct work_struct work;
	35	} r;
	36	struct list_head free_list; /* Free list */
	37	};
	38	u8 flags; /* Flags */
	39	};
	40
	41	/**
	42	* For encrypted symlinks, the ciphertext length is stored at the beginning
	43	* of the string in little-endian format.
	44	*/
	45	struct fscrypt_symlink_data {
	46	__le16 len;
	47	char encrypted_path[1];
	48	} __packed;
	49
46f47e48 EB	50	struct fscrypt_str {
	51	unsigned char *name;
	52	u32 len;
	53	};
	54
	55	struct fscrypt_name {
	56	const struct qstr *usr_fname;
	57	struct fscrypt_str disk_name;
	58	u32 hash;
	59	u32 minor_hash;
	60	struct fscrypt_str crypto_buf;
	61	};
	62
	63	#define FSTR_INIT(n, l) { .name = n, .len = l }
	64	#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
	65	#define fname_name(p) ((p)->disk_name.name)
	66	#define fname_len(p) ((p)->disk_name.len)
	67
	68	/*
	69	* fscrypt superblock flags
	70	*/
	71	#define FS_CFLG_OWN_PAGES (1U << 1)
	72
	73	/*
	74	* crypto opertions for filesystems
	75	*/
	76	struct fscrypt_operations {
	77	unsigned int flags;
	78	const char *key_prefix;
	79	int (get_context)(struct inode , void *, size_t);
46f47e48	80	int (set_context)(struct inode , const void , size_t, void );
c250b7dd	81	bool (dummy_context)(struct inode );
46f47e48 EB	82	bool (is_encrypted)(struct inode );
	83	bool (empty_dir)(struct inode );
	84	unsigned (max_namelen)(struct inode );
	85	};
	86
af65207c TE	87	/* Maximum value for the third parameter of fscrypt_operations.set_context(). */
	88	#define FSCRYPT_SET_CONTEXT_MAX_SIZE 28
	89
46f47e48 EB	90	static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
	91	{
	92	if (inode->i_sb->s_cop->dummy_context &&
	93	inode->i_sb->s_cop->dummy_context(inode))
	94	return true;
	95	return false;
	96	}
	97
b7e7cf7a DW	98	static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
b7e7cf7a DW	99	u32 filenames_mode)
46f47e48	100	{
b7e7cf7a DW	101	if (contents_mode == FS_ENCRYPTION_MODE_AES_128_CBC &&
	102	filenames_mode == FS_ENCRYPTION_MODE_AES_128_CTS)
	103	return true;
46f47e48	104
b7e7cf7a DW	105	if (contents_mode == FS_ENCRYPTION_MODE_AES_256_XTS &&
	106	filenames_mode == FS_ENCRYPTION_MODE_AES_256_CTS)
	107	return true;
	108
	109	return false;
46f47e48 EB	110	}
	111
	112	static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
	113	{
	114	if (str->len == 1 && str->name[0] == '.')
	115	return true;
	116
	117	if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
	118	return true;
	119
	120	return false;
	121	}
	122
	123	static inline struct page fscrypt_control_page(struct page page)
	124	{
	125	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	126	return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
	127	#else
	128	WARN_ON_ONCE(1);
	129	return ERR_PTR(-EINVAL);
	130	#endif
	131	}
	132
	133	static inline int fscrypt_has_encryption_key(const struct inode *inode)
	134	{
	135	#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	136	return (inode->i_crypt_info != NULL);
	137	#else
	138	return 0;
	139	#endif
	140	}
	141
	142	#endif /* _LINUX_FSCRYPT_COMMON_H */