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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-04 21:43:12 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-04 21:43:12 +0300 |
commit | 3462ac57033e79a87dbae2497773f22b9c536fbc (patch) | |
tree | 08d0b98ac665ad0cd0e85bde0342fd2650424db5 /include/linux | |
parent | 617aebe6a97efa539cc4b8a52adccd89596e6be0 (diff) | |
parent | 0b1dfa4cc6c60052b2c30ead316fa84c46d3c43c (diff) | |
download | linux-3462ac57033e79a87dbae2497773f22b9c536fbc.tar.xz |
Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt
Pull fscrypt updates from Ted Ts'o:
"Refactor support for encrypted symlinks to move common code to fscrypt"
Ted also points out about the merge:
"This makes the f2fs symlink code use the fscrypt_encrypt_symlink()
from the fscrypt tree. This will end up dropping the kzalloc() ->
f2fs_kzalloc() change, which means the fscrypt-specific allocation
won't get tested by f2fs's kmalloc error injection system; which is
fine"
* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: (26 commits)
fscrypt: fix build with pre-4.6 gcc versions
fscrypt: remove 'ci' parameter from fscrypt_put_encryption_info()
fscrypt: document symlink length restriction
fscrypt: fix up fscrypt_fname_encrypted_size() for internal use
fscrypt: define fscrypt_fname_alloc_buffer() to be for presented names
fscrypt: calculate NUL-padding length in one place only
fscrypt: move fscrypt_symlink_data to fscrypt_private.h
fscrypt: remove fscrypt_fname_usr_to_disk()
ubifs: switch to fscrypt_get_symlink()
ubifs: switch to fscrypt ->symlink() helper functions
ubifs: free the encrypted symlink target
f2fs: switch to fscrypt_get_symlink()
f2fs: switch to fscrypt ->symlink() helper functions
ext4: switch to fscrypt_get_symlink()
ext4: switch to fscrypt ->symlink() helper functions
fscrypt: new helper function - fscrypt_get_symlink()
fscrypt: new helper functions for ->symlink()
fscrypt: trim down fscrypt.h includes
fscrypt: move fscrypt_is_dot_dotdot() to fs/crypto/fname.c
fscrypt: move fscrypt_valid_enc_modes() to fscrypt_private.h
...
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/fscrypt.h | 174 | ||||
-rw-r--r-- | include/linux/fscrypt_notsupp.h | 59 | ||||
-rw-r--r-- | include/linux/fscrypt_supp.h | 68 |
3 files changed, 171 insertions, 130 deletions
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 08b4b40c5aa8..952ab97af325 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -14,42 +14,13 @@ #ifndef _LINUX_FSCRYPT_H #define _LINUX_FSCRYPT_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_ctx; 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; @@ -68,89 +39,14 @@ struct fscrypt_name { #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 (*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; -} - #if __FS_HAS_ENCRYPTION - -static inline struct page *fscrypt_control_page(struct page *page) -{ - return ((struct fscrypt_ctx *)page_private(page))->w.control_page; -} - -static inline bool fscrypt_has_encryption_key(const struct inode *inode) -{ - return (inode->i_crypt_info != NULL); -} - #include <linux/fscrypt_supp.h> - -#else /* !__FS_HAS_ENCRYPTION */ - -static inline struct page *fscrypt_control_page(struct page *page) -{ - WARN_ON_ONCE(1); - return ERR_PTR(-EINVAL); -} - -static inline bool fscrypt_has_encryption_key(const struct inode *inode) -{ - return 0; -} - +#else #include <linux/fscrypt_notsupp.h> -#endif /* __FS_HAS_ENCRYPTION */ +#endif /** * fscrypt_require_key - require an inode's encryption key @@ -291,4 +187,68 @@ static inline int fscrypt_prepare_setattr(struct dentry *dentry, return 0; } +/** + * fscrypt_prepare_symlink - prepare to create a possibly-encrypted symlink + * @dir: directory in which the symlink is being created + * @target: plaintext symlink target + * @len: length of @target excluding null terminator + * @max_len: space the filesystem has available to store the symlink target + * @disk_link: (out) the on-disk symlink target being prepared + * + * This function computes the size the symlink target will require on-disk, + * stores it in @disk_link->len, and validates it against @max_len. An + * encrypted symlink may be longer than the original. + * + * Additionally, @disk_link->name is set to @target if the symlink will be + * unencrypted, but left NULL if the symlink will be encrypted. For encrypted + * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the + * on-disk target later. (The reason for the two-step process is that some + * filesystems need to know the size of the symlink target before creating the + * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.) + * + * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long, + * -ENOKEY if the encryption key is missing, or another -errno code if a problem + * occurred while setting up the encryption key. + */ +static inline int fscrypt_prepare_symlink(struct inode *dir, + const char *target, + unsigned int len, + unsigned int max_len, + struct fscrypt_str *disk_link) +{ + if (IS_ENCRYPTED(dir) || fscrypt_dummy_context_enabled(dir)) + return __fscrypt_prepare_symlink(dir, len, max_len, disk_link); + + disk_link->name = (unsigned char *)target; + disk_link->len = len + 1; + if (disk_link->len > max_len) + return -ENAMETOOLONG; + return 0; +} + +/** + * fscrypt_encrypt_symlink - encrypt the symlink target if needed + * @inode: symlink inode + * @target: plaintext symlink target + * @len: length of @target excluding null terminator + * @disk_link: (in/out) the on-disk symlink target being prepared + * + * If the symlink target needs to be encrypted, then this function encrypts it + * into @disk_link->name. fscrypt_prepare_symlink() must have been called + * previously to compute @disk_link->len. If the filesystem did not allocate a + * buffer for @disk_link->name after calling fscrypt_prepare_link(), then one + * will be kmalloc()'ed and the filesystem will be responsible for freeing it. + * + * Return: 0 on success, -errno on failure + */ +static inline int fscrypt_encrypt_symlink(struct inode *inode, + const char *target, + unsigned int len, + struct fscrypt_str *disk_link) +{ + if (IS_ENCRYPTED(inode)) + return __fscrypt_encrypt_symlink(inode, target, len, disk_link); + return 0; +} + #endif /* _LINUX_FSCRYPT_H */ diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index 63e58808519a..44b50c04bae9 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -14,6 +14,16 @@ #ifndef _LINUX_FSCRYPT_NOTSUPP_H #define _LINUX_FSCRYPT_NOTSUPP_H +static inline bool fscrypt_has_encryption_key(const struct inode *inode) +{ + return false; +} + +static inline bool fscrypt_dummy_context_enabled(struct inode *inode) +{ + return false; +} + /* crypto.c */ static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags) @@ -43,6 +53,11 @@ static inline int fscrypt_decrypt_page(const struct inode *inode, return -EOPNOTSUPP; } +static inline struct page *fscrypt_control_page(struct page *page) +{ + WARN_ON_ONCE(1); + return ERR_PTR(-EINVAL); +} static inline void fscrypt_restore_control_page(struct page *page) { @@ -90,8 +105,7 @@ static inline int fscrypt_get_encryption_info(struct inode *inode) return -EOPNOTSUPP; } -static inline void fscrypt_put_encryption_info(struct inode *inode, - struct fscrypt_info *ci) +static inline void fscrypt_put_encryption_info(struct inode *inode) { return; } @@ -116,16 +130,8 @@ static inline void fscrypt_free_filename(struct fscrypt_name *fname) return; } -static inline u32 fscrypt_fname_encrypted_size(const struct inode *inode, - u32 ilen) -{ - /* never happens */ - WARN_ON(1); - return 0; -} - static inline int fscrypt_fname_alloc_buffer(const struct inode *inode, - u32 ilen, + u32 max_encrypted_len, struct fscrypt_str *crypto_str) { return -EOPNOTSUPP; @@ -144,13 +150,6 @@ static inline int fscrypt_fname_disk_to_usr(struct inode *inode, return -EOPNOTSUPP; } -static inline int fscrypt_fname_usr_to_disk(struct inode *inode, - const struct qstr *iname, - struct fscrypt_str *oname) -{ - return -EOPNOTSUPP; -} - static inline bool fscrypt_match_name(const struct fscrypt_name *fname, const u8 *de_name, u32 de_name_len) { @@ -208,4 +207,28 @@ static inline int __fscrypt_prepare_lookup(struct inode *dir, return -EOPNOTSUPP; } +static inline int __fscrypt_prepare_symlink(struct inode *dir, + unsigned int len, + unsigned int max_len, + struct fscrypt_str *disk_link) +{ + return -EOPNOTSUPP; +} + +static inline int __fscrypt_encrypt_symlink(struct inode *inode, + const char *target, + unsigned int len, + struct fscrypt_str *disk_link) +{ + return -EOPNOTSUPP; +} + +static inline const char *fscrypt_get_symlink(struct inode *inode, + const void *caddr, + unsigned int max_size, + struct delayed_call *done) +{ + return ERR_PTR(-EOPNOTSUPP); +} + #endif /* _LINUX_FSCRYPT_NOTSUPP_H */ diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h index cf9e9fc02f0a..477a7a6504d2 100644 --- a/include/linux/fscrypt_supp.h +++ b/include/linux/fscrypt_supp.h @@ -11,8 +11,54 @@ #ifndef _LINUX_FSCRYPT_SUPP_H #define _LINUX_FSCRYPT_SUPP_H +#include <linux/mm.h> +#include <linux/slab.h> + +/* + * fscrypt superblock flags + */ +#define FS_CFLG_OWN_PAGES (1U << 1) + +/* + * crypto operations 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 (*empty_dir)(struct inode *); + unsigned (*max_namelen)(struct inode *); +}; + +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 */ +}; + +static inline bool fscrypt_has_encryption_key(const struct inode *inode) +{ + return (inode->i_crypt_info != NULL); +} + +static inline bool fscrypt_dummy_context_enabled(struct inode *inode) +{ + return inode->i_sb->s_cop->dummy_context && + inode->i_sb->s_cop->dummy_context(inode); +} + /* crypto.c */ -extern struct kmem_cache *fscrypt_info_cachep; extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t); extern void fscrypt_release_ctx(struct fscrypt_ctx *); extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, @@ -20,6 +66,12 @@ extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, u64, gfp_t); extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, u64); + +static inline struct page *fscrypt_control_page(struct page *page) +{ + return ((struct fscrypt_ctx *)page_private(page))->w.control_page; +} + extern void fscrypt_restore_control_page(struct page *); extern const struct dentry_operations fscrypt_d_ops; @@ -44,7 +96,7 @@ extern int fscrypt_inherit_context(struct inode *, struct inode *, void *, bool); /* keyinfo.c */ extern int fscrypt_get_encryption_info(struct inode *); -extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *); +extern void fscrypt_put_encryption_info(struct inode *); /* fname.c */ extern int fscrypt_setup_filename(struct inode *, const struct qstr *, @@ -55,14 +107,11 @@ static inline void fscrypt_free_filename(struct fscrypt_name *fname) kfree(fname->crypto_buf.name); } -extern u32 fscrypt_fname_encrypted_size(const struct inode *, u32); extern int fscrypt_fname_alloc_buffer(const struct inode *, u32, struct fscrypt_str *); extern void fscrypt_fname_free_buffer(struct fscrypt_str *); extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32, const struct fscrypt_str *, struct fscrypt_str *); -extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *, - struct fscrypt_str *); #define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE 32 @@ -153,5 +202,14 @@ extern int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *new_dentry, unsigned int flags); extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry); +extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, + unsigned int max_len, + struct fscrypt_str *disk_link); +extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, + unsigned int len, + struct fscrypt_str *disk_link); +extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, + unsigned int max_size, + struct delayed_call *done); #endif /* _LINUX_FSCRYPT_SUPP_H */ |