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 */