146 lines
3.2 KiB
C
146 lines
3.2 KiB
C
/*
|
|
* 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;
|
|
|
|
/**
|
|
* This function is used to calculate the disk space required to
|
|
* store a filename of length l in encrypted symlink format.
|
|
*/
|
|
static inline u32 fscrypt_symlink_data_len(u32 l)
|
|
{
|
|
if (l < FS_CRYPTO_BLOCK_SIZE)
|
|
l = FS_CRYPTO_BLOCK_SIZE;
|
|
return (l + sizeof(struct fscrypt_symlink_data) - 1);
|
|
}
|
|
|
|
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 *);
|
|
int (*dummy_context)(struct inode *);
|
|
bool (*is_encrypted)(struct inode *);
|
|
bool (*empty_dir)(struct inode *);
|
|
unsigned (*max_namelen)(struct inode *);
|
|
};
|
|
|
|
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_contents_enc_mode(u32 mode)
|
|
{
|
|
return (mode == FS_ENCRYPTION_MODE_AES_256_XTS);
|
|
}
|
|
|
|
static inline bool fscrypt_valid_filenames_enc_mode(u32 mode)
|
|
{
|
|
return (mode == FS_ENCRYPTION_MODE_AES_256_CTS);
|
|
}
|
|
|
|
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 */
|