2 * General per-file encryption definition
4 * Copyright (C) 2015, Google, Inc.
6 * Written by Michael Halcrow, 2015.
7 * Modified by Jaegeuk Kim, 2015.
10 #ifndef _LINUX_FSCRYPTO_H
11 #define _LINUX_FSCRYPTO_H
13 #include <linux/key.h>
16 #include <linux/bio.h>
17 #include <linux/dcache.h>
18 #include <crypto/skcipher.h>
19 #include <uapi/linux/fs.h>
21 #define FS_CRYPTO_BLOCK_SIZE 16
28 struct page
*bounce_page
; /* Ciphertext page */
29 struct page
*control_page
; /* Original page */
33 struct work_struct work
;
35 struct list_head free_list
; /* Free list */
38 u8 mode
; /* Encryption mode for tfm */
42 * For encrypted symlinks, the ciphertext length is stored at the beginning
43 * of the string in little-endian format.
45 struct fscrypt_symlink_data
{
47 char encrypted_path
[1];
51 * This function is used to calculate the disk space required to
52 * store a filename of length l in encrypted symlink format.
54 static inline u32
fscrypt_symlink_data_len(u32 l
)
56 if (l
< FS_CRYPTO_BLOCK_SIZE
)
57 l
= FS_CRYPTO_BLOCK_SIZE
;
58 return (l
+ sizeof(struct fscrypt_symlink_data
) - 1);
67 const struct qstr
*usr_fname
;
68 struct fscrypt_str disk_name
;
71 struct fscrypt_str crypto_buf
;
74 #define FSTR_INIT(n, l) { .name = n, .len = l }
75 #define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
76 #define fname_name(p) ((p)->disk_name.name)
77 #define fname_len(p) ((p)->disk_name.len)
80 * fscrypt superblock flags
82 #define FS_CFLG_OWN_PAGES (1U << 1)
85 * crypto opertions for filesystems
87 struct fscrypt_operations
{
89 int (*get_context
)(struct inode
*, void *, size_t);
90 int (*key_prefix
)(struct inode
*, u8
**);
91 int (*prepare_context
)(struct inode
*);
92 int (*set_context
)(struct inode
*, const void *, size_t, void *);
93 int (*dummy_context
)(struct inode
*);
94 bool (*is_encrypted
)(struct inode
*);
95 bool (*empty_dir
)(struct inode
*);
96 unsigned (*max_namelen
)(struct inode
*);
99 static inline bool fscrypt_dummy_context_enabled(struct inode
*inode
)
101 if (inode
->i_sb
->s_cop
->dummy_context
&&
102 inode
->i_sb
->s_cop
->dummy_context(inode
))
107 static inline bool fscrypt_valid_contents_enc_mode(u32 mode
)
109 return (mode
== FS_ENCRYPTION_MODE_AES_256_XTS
);
112 static inline bool fscrypt_valid_filenames_enc_mode(u32 mode
)
114 return (mode
== FS_ENCRYPTION_MODE_AES_256_CTS
);
117 static inline bool fscrypt_is_dot_dotdot(const struct qstr
*str
)
119 if (str
->len
== 1 && str
->name
[0] == '.')
122 if (str
->len
== 2 && str
->name
[0] == '.' && str
->name
[1] == '.')
128 static inline struct page
*fscrypt_control_page(struct page
*page
)
130 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
131 return ((struct fscrypt_ctx
*)page_private(page
))->w
.control_page
;
134 return ERR_PTR(-EINVAL
);
138 static inline int fscrypt_has_encryption_key(const struct inode
*inode
)
140 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
141 return (inode
->i_crypt_info
!= NULL
);
147 static inline void fscrypt_set_encrypted_dentry(struct dentry
*dentry
)
149 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
150 spin_lock(&dentry
->d_lock
);
151 dentry
->d_flags
|= DCACHE_ENCRYPTED_WITH_KEY
;
152 spin_unlock(&dentry
->d_lock
);
156 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
157 extern const struct dentry_operations fscrypt_d_ops
;
160 static inline void fscrypt_set_d_op(struct dentry
*dentry
)
162 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
163 d_set_d_op(dentry
, &fscrypt_d_ops
);
167 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
169 extern struct kmem_cache
*fscrypt_info_cachep
;
170 extern struct fscrypt_ctx
*fscrypt_get_ctx(const struct inode
*, gfp_t
);
171 extern void fscrypt_release_ctx(struct fscrypt_ctx
*);
172 extern struct page
*fscrypt_encrypt_page(const struct inode
*, struct page
*,
173 unsigned int, unsigned int,
175 extern int fscrypt_decrypt_page(const struct inode
*, struct page
*, unsigned int,
177 extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx
*, struct bio
*);
178 extern void fscrypt_pullback_bio_page(struct page
**, bool);
179 extern void fscrypt_restore_control_page(struct page
*);
180 extern int fscrypt_zeroout_range(const struct inode
*, pgoff_t
, sector_t
,
183 extern int fscrypt_ioctl_set_policy(struct file
*, const void __user
*);
184 extern int fscrypt_ioctl_get_policy(struct file
*, void __user
*);
185 extern int fscrypt_has_permitted_context(struct inode
*, struct inode
*);
186 extern int fscrypt_inherit_context(struct inode
*, struct inode
*,
189 extern int fscrypt_get_encryption_info(struct inode
*);
190 extern void fscrypt_put_encryption_info(struct inode
*, struct fscrypt_info
*);
193 extern int fscrypt_setup_filename(struct inode
*, const struct qstr
*,
194 int lookup
, struct fscrypt_name
*);
195 extern void fscrypt_free_filename(struct fscrypt_name
*);
196 extern u32
fscrypt_fname_encrypted_size(const struct inode
*, u32
);
197 extern int fscrypt_fname_alloc_buffer(const struct inode
*, u32
,
198 struct fscrypt_str
*);
199 extern void fscrypt_fname_free_buffer(struct fscrypt_str
*);
200 extern int fscrypt_fname_disk_to_usr(struct inode
*, u32
, u32
,
201 const struct fscrypt_str
*, struct fscrypt_str
*);
202 extern int fscrypt_fname_usr_to_disk(struct inode
*, const struct qstr
*,
203 struct fscrypt_str
*);
207 static inline struct fscrypt_ctx
*fscrypt_notsupp_get_ctx(const struct inode
*i
,
210 return ERR_PTR(-EOPNOTSUPP
);
213 static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx
*c
)
218 static inline struct page
*fscrypt_notsupp_encrypt_page(const struct inode
*i
,
222 u64 lblk_num
, gfp_t f
)
224 return ERR_PTR(-EOPNOTSUPP
);
227 static inline int fscrypt_notsupp_decrypt_page(const struct inode
*i
, struct page
*p
,
228 unsigned int len
, unsigned int offs
,
234 static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx
*c
,
240 static inline void fscrypt_notsupp_pullback_bio_page(struct page
**p
, bool b
)
245 static inline void fscrypt_notsupp_restore_control_page(struct page
*p
)
250 static inline int fscrypt_notsupp_zeroout_range(const struct inode
*i
, pgoff_t p
,
251 sector_t s
, unsigned int f
)
257 static inline int fscrypt_notsupp_ioctl_set_policy(struct file
*f
,
258 const void __user
*arg
)
263 static inline int fscrypt_notsupp_ioctl_get_policy(struct file
*f
,
269 static inline int fscrypt_notsupp_has_permitted_context(struct inode
*p
,
275 static inline int fscrypt_notsupp_inherit_context(struct inode
*p
,
276 struct inode
*i
, void *v
, bool b
)
282 static inline int fscrypt_notsupp_get_encryption_info(struct inode
*i
)
287 static inline void fscrypt_notsupp_put_encryption_info(struct inode
*i
,
288 struct fscrypt_info
*f
)
294 static inline int fscrypt_notsupp_setup_filename(struct inode
*dir
,
295 const struct qstr
*iname
,
296 int lookup
, struct fscrypt_name
*fname
)
298 if (dir
->i_sb
->s_cop
->is_encrypted(dir
))
301 memset(fname
, 0, sizeof(struct fscrypt_name
));
302 fname
->usr_fname
= iname
;
303 fname
->disk_name
.name
= (unsigned char *)iname
->name
;
304 fname
->disk_name
.len
= iname
->len
;
308 static inline void fscrypt_notsupp_free_filename(struct fscrypt_name
*fname
)
313 static inline u32
fscrypt_notsupp_fname_encrypted_size(struct inode
*i
, u32 s
)
320 static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode
*inode
,
321 u32 ilen
, struct fscrypt_str
*crypto_str
)
326 static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str
*c
)
331 static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode
*inode
,
332 u32 hash
, u32 minor_hash
,
333 const struct fscrypt_str
*iname
,
334 struct fscrypt_str
*oname
)
339 static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode
*inode
,
340 const struct qstr
*iname
,
341 struct fscrypt_str
*oname
)
345 #endif /* _LINUX_FSCRYPTO_H */