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
29 struct page *bounce_page; /* Ciphertext page */
30 struct page *control_page; /* Original page */
34 struct work_struct work;
36 struct list_head free_list; /* Free list */
39 u8 mode; /* Encryption mode for tfm */
43 * For encrypted symlinks, the ciphertext length is stored at the beginning
44 * of the string in little-endian format.
46 struct fscrypt_symlink_data {
48 char encrypted_path[1];
52 * This function is used to calculate the disk space required to
53 * store a filename of length l in encrypted symlink format.
55 static inline u32 fscrypt_symlink_data_len(u32 l)
57 if (l < FS_CRYPTO_BLOCK_SIZE)
58 l = FS_CRYPTO_BLOCK_SIZE;
59 return (l + sizeof(struct fscrypt_symlink_data) - 1);
68 const struct qstr *usr_fname;
69 struct fscrypt_str disk_name;
72 struct fscrypt_str crypto_buf;
75 #define FSTR_INIT(n, l) { .name = n, .len = l }
76 #define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
77 #define fname_name(p) ((p)->disk_name.name)
78 #define fname_len(p) ((p)->disk_name.len)
81 * fscrypt superblock flags
83 #define FS_CFLG_OWN_PAGES (1U << 1)
86 * crypto opertions for filesystems
88 struct fscrypt_operations {
90 int (*get_context)(struct inode *, void *, size_t);
91 int (*key_prefix)(struct inode *, u8 **);
92 int (*prepare_context)(struct inode *);
93 int (*set_context)(struct inode *, const void *, size_t, void *);
94 int (*dummy_context)(struct inode *);
95 bool (*is_encrypted)(struct inode *);
96 bool (*empty_dir)(struct inode *);
97 unsigned (*max_namelen)(struct inode *);
100 static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
102 if (inode->i_sb->s_cop->dummy_context &&
103 inode->i_sb->s_cop->dummy_context(inode))
108 static inline bool fscrypt_valid_contents_enc_mode(u32 mode)
110 return (mode == FS_ENCRYPTION_MODE_AES_256_XTS);
113 static inline bool fscrypt_valid_filenames_enc_mode(u32 mode)
115 return (mode == FS_ENCRYPTION_MODE_AES_256_CTS);
118 static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
120 if (str->len == 1 && str->name[0] == '.')
123 if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
129 static inline struct page *fscrypt_control_page(struct page *page)
131 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
132 return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
135 return ERR_PTR(-EINVAL);
139 static inline int fscrypt_has_encryption_key(const struct inode *inode)
141 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
142 return (inode->i_crypt_info != NULL);
148 static inline void fscrypt_set_encrypted_dentry(struct dentry *dentry)
150 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
151 spin_lock(&dentry->d_lock);
152 dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY;
153 spin_unlock(&dentry->d_lock);
157 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
158 extern const struct dentry_operations fscrypt_d_ops;
161 static inline void fscrypt_set_d_op(struct dentry *dentry)
163 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
164 d_set_d_op(dentry, &fscrypt_d_ops);
168 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
170 extern struct kmem_cache *fscrypt_info_cachep;
171 extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
172 extern void fscrypt_release_ctx(struct fscrypt_ctx *);
173 extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
174 unsigned int, unsigned int,
176 extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
178 extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);
179 extern void fscrypt_pullback_bio_page(struct page **, bool);
180 extern void fscrypt_restore_control_page(struct page *);
181 extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
184 extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
185 extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
186 extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
187 extern int fscrypt_inherit_context(struct inode *, struct inode *,
190 extern int fscrypt_get_encryption_info(struct inode *);
191 extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *);
194 extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
195 int lookup, struct fscrypt_name *);
196 extern void fscrypt_free_filename(struct fscrypt_name *);
197 extern u32 fscrypt_fname_encrypted_size(const struct inode *, u32);
198 extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
199 struct fscrypt_str *);
200 extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
201 extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
202 const struct fscrypt_str *, struct fscrypt_str *);
203 extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *,
204 struct fscrypt_str *);
208 static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(const struct inode *i,
211 return ERR_PTR(-EOPNOTSUPP);
214 static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c)
219 static inline struct page *fscrypt_notsupp_encrypt_page(const struct inode *i,
223 u64 lblk_num, gfp_t f)
225 return ERR_PTR(-EOPNOTSUPP);
228 static inline int fscrypt_notsupp_decrypt_page(const struct inode *i, struct page *p,
229 unsigned int len, unsigned int offs,
235 static inline void fscrypt_notsupp_decrypt_bio_pages(struct fscrypt_ctx *c,
241 static inline void fscrypt_notsupp_pullback_bio_page(struct page **p, bool b)
246 static inline void fscrypt_notsupp_restore_control_page(struct page *p)
251 static inline int fscrypt_notsupp_zeroout_range(const struct inode *i, pgoff_t p,
252 sector_t s, unsigned int f)
258 static inline int fscrypt_notsupp_ioctl_set_policy(struct file *f,
259 const void __user *arg)
264 static inline int fscrypt_notsupp_ioctl_get_policy(struct file *f,
270 static inline int fscrypt_notsupp_has_permitted_context(struct inode *p,
276 static inline int fscrypt_notsupp_inherit_context(struct inode *p,
277 struct inode *i, void *v, bool b)
283 static inline int fscrypt_notsupp_get_encryption_info(struct inode *i)
288 static inline void fscrypt_notsupp_put_encryption_info(struct inode *i,
289 struct fscrypt_info *f)
295 static inline int fscrypt_notsupp_setup_filename(struct inode *dir,
296 const struct qstr *iname,
297 int lookup, struct fscrypt_name *fname)
299 if (dir->i_sb->s_cop->is_encrypted(dir))
302 memset(fname, 0, sizeof(struct fscrypt_name));
303 fname->usr_fname = iname;
304 fname->disk_name.name = (unsigned char *)iname->name;
305 fname->disk_name.len = iname->len;
309 static inline void fscrypt_notsupp_free_filename(struct fscrypt_name *fname)
314 static inline u32 fscrypt_notsupp_fname_encrypted_size(struct inode *i, u32 s)
321 static inline int fscrypt_notsupp_fname_alloc_buffer(struct inode *inode,
322 u32 ilen, struct fscrypt_str *crypto_str)
327 static inline void fscrypt_notsupp_fname_free_buffer(struct fscrypt_str *c)
332 static inline int fscrypt_notsupp_fname_disk_to_usr(struct inode *inode,
333 u32 hash, u32 minor_hash,
334 const struct fscrypt_str *iname,
335 struct fscrypt_str *oname)
340 static inline int fscrypt_notsupp_fname_usr_to_disk(struct inode *inode,
341 const struct qstr *iname,
342 struct fscrypt_str *oname)
346 #endif /* _LINUX_FSCRYPTO_H */