mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
866 lines
26 KiB
866 lines
26 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
|
/* |
|
* fscrypt.h: declarations for per-file encryption |
|
* |
|
* Filesystems that implement per-file encryption must include this header |
|
* file. |
|
* |
|
* Copyright (C) 2015, Google, Inc. |
|
* |
|
* Written by Michael Halcrow, 2015. |
|
* Modified by Jaegeuk Kim, 2015. |
|
*/ |
|
#ifndef _LINUX_FSCRYPT_H |
|
#define _LINUX_FSCRYPT_H |
|
|
|
#include <linux/fs.h> |
|
#include <linux/mm.h> |
|
#include <linux/slab.h> |
|
#include <uapi/linux/fscrypt.h> |
|
|
|
#define FS_CRYPTO_BLOCK_SIZE 16 |
|
|
|
union fscrypt_policy; |
|
struct fscrypt_info; |
|
struct seq_file; |
|
|
|
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; |
|
bool is_nokey_name; |
|
}; |
|
|
|
#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) |
|
|
|
/* Maximum value for the third parameter of fscrypt_operations.set_context(). */ |
|
#define FSCRYPT_SET_CONTEXT_MAX_SIZE 40 |
|
|
|
#ifdef CONFIG_FS_ENCRYPTION |
|
/* |
|
* 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 *inode, void *ctx, size_t len); |
|
int (*set_context)(struct inode *inode, const void *ctx, size_t len, |
|
void *fs_data); |
|
const union fscrypt_policy *(*get_dummy_policy)(struct super_block *sb); |
|
bool (*empty_dir)(struct inode *inode); |
|
unsigned int max_namelen; |
|
bool (*has_stable_inodes)(struct super_block *sb); |
|
void (*get_ino_and_lblk_bits)(struct super_block *sb, |
|
int *ino_bits_ret, int *lblk_bits_ret); |
|
int (*get_num_devices)(struct super_block *sb); |
|
void (*get_devices)(struct super_block *sb, |
|
struct request_queue **devs); |
|
}; |
|
|
|
static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode) |
|
{ |
|
/* |
|
* Pairs with the cmpxchg_release() in fscrypt_setup_encryption_info(). |
|
* I.e., another task may publish ->i_crypt_info concurrently, executing |
|
* a RELEASE barrier. We need to use smp_load_acquire() here to safely |
|
* ACQUIRE the memory the other task published. |
|
*/ |
|
return smp_load_acquire(&inode->i_crypt_info); |
|
} |
|
|
|
/** |
|
* fscrypt_needs_contents_encryption() - check whether an inode needs |
|
* contents encryption |
|
* @inode: the inode to check |
|
* |
|
* Return: %true iff the inode is an encrypted regular file and the kernel was |
|
* built with fscrypt support. |
|
* |
|
* If you need to know whether the encrypt bit is set even when the kernel was |
|
* built without fscrypt support, you must use IS_ENCRYPTED() directly instead. |
|
*/ |
|
static inline bool fscrypt_needs_contents_encryption(const struct inode *inode) |
|
{ |
|
return IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode); |
|
} |
|
|
|
/* |
|
* When d_splice_alias() moves a directory's no-key alias to its plaintext alias |
|
* as a result of the encryption key being added, DCACHE_NOKEY_NAME must be |
|
* cleared. Note that we don't have to support arbitrary moves of this flag |
|
* because fscrypt doesn't allow no-key names to be the source or target of a |
|
* rename(). |
|
*/ |
|
static inline void fscrypt_handle_d_move(struct dentry *dentry) |
|
{ |
|
dentry->d_flags &= ~DCACHE_NOKEY_NAME; |
|
} |
|
|
|
/** |
|
* fscrypt_is_nokey_name() - test whether a dentry is a no-key name |
|
* @dentry: the dentry to check |
|
* |
|
* This returns true if the dentry is a no-key dentry. A no-key dentry is a |
|
* dentry that was created in an encrypted directory that hasn't had its |
|
* encryption key added yet. Such dentries may be either positive or negative. |
|
* |
|
* When a filesystem is asked to create a new filename in an encrypted directory |
|
* and the new filename's dentry is a no-key dentry, it must fail the operation |
|
* with ENOKEY. This includes ->create(), ->mkdir(), ->mknod(), ->symlink(), |
|
* ->rename(), and ->link(). (However, ->rename() and ->link() are already |
|
* handled by fscrypt_prepare_rename() and fscrypt_prepare_link().) |
|
* |
|
* This is necessary because creating a filename requires the directory's |
|
* encryption key, but just checking for the key on the directory inode during |
|
* the final filesystem operation doesn't guarantee that the key was available |
|
* during the preceding dentry lookup. And the key must have already been |
|
* available during the dentry lookup in order for it to have been checked |
|
* whether the filename already exists in the directory and for the new file's |
|
* dentry not to be invalidated due to it incorrectly having the no-key flag. |
|
* |
|
* Return: %true if the dentry is a no-key name |
|
*/ |
|
static inline bool fscrypt_is_nokey_name(const struct dentry *dentry) |
|
{ |
|
return dentry->d_flags & DCACHE_NOKEY_NAME; |
|
} |
|
|
|
/* crypto.c */ |
|
void fscrypt_enqueue_decrypt_work(struct work_struct *); |
|
|
|
struct page *fscrypt_encrypt_pagecache_blocks(struct page *page, |
|
unsigned int len, |
|
unsigned int offs, |
|
gfp_t gfp_flags); |
|
int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page, |
|
unsigned int len, unsigned int offs, |
|
u64 lblk_num, gfp_t gfp_flags); |
|
|
|
int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len, |
|
unsigned int offs); |
|
int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page, |
|
unsigned int len, unsigned int offs, |
|
u64 lblk_num); |
|
|
|
static inline bool fscrypt_is_bounce_page(struct page *page) |
|
{ |
|
return page->mapping == NULL; |
|
} |
|
|
|
static inline struct page *fscrypt_pagecache_page(struct page *bounce_page) |
|
{ |
|
return (struct page *)page_private(bounce_page); |
|
} |
|
|
|
void fscrypt_free_bounce_page(struct page *bounce_page); |
|
|
|
/* policy.c */ |
|
int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg); |
|
int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg); |
|
int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *arg); |
|
int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg); |
|
int fscrypt_has_permitted_context(struct inode *parent, struct inode *child); |
|
int fscrypt_set_context(struct inode *inode, void *fs_data); |
|
|
|
struct fscrypt_dummy_policy { |
|
const union fscrypt_policy *policy; |
|
}; |
|
|
|
int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg, |
|
struct fscrypt_dummy_policy *dummy_policy); |
|
void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep, |
|
struct super_block *sb); |
|
static inline void |
|
fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy) |
|
{ |
|
kfree(dummy_policy->policy); |
|
dummy_policy->policy = NULL; |
|
} |
|
|
|
/* keyring.c */ |
|
void fscrypt_sb_free(struct super_block *sb); |
|
int fscrypt_ioctl_add_key(struct file *filp, void __user *arg); |
|
int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg); |
|
int fscrypt_ioctl_remove_key_all_users(struct file *filp, void __user *arg); |
|
int fscrypt_ioctl_get_key_status(struct file *filp, void __user *arg); |
|
|
|
/* keysetup.c */ |
|
int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode, |
|
bool *encrypt_ret); |
|
void fscrypt_put_encryption_info(struct inode *inode); |
|
void fscrypt_free_inode(struct inode *inode); |
|
int fscrypt_drop_inode(struct inode *inode); |
|
|
|
/* fname.c */ |
|
int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname, |
|
int lookup, struct fscrypt_name *fname); |
|
|
|
static inline void fscrypt_free_filename(struct fscrypt_name *fname) |
|
{ |
|
kfree(fname->crypto_buf.name); |
|
} |
|
|
|
int fscrypt_fname_alloc_buffer(u32 max_encrypted_len, |
|
struct fscrypt_str *crypto_str); |
|
void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str); |
|
int fscrypt_fname_disk_to_usr(const struct inode *inode, |
|
u32 hash, u32 minor_hash, |
|
const struct fscrypt_str *iname, |
|
struct fscrypt_str *oname); |
|
bool fscrypt_match_name(const struct fscrypt_name *fname, |
|
const u8 *de_name, u32 de_name_len); |
|
u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name); |
|
int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags); |
|
|
|
/* bio.c */ |
|
void fscrypt_decrypt_bio(struct bio *bio); |
|
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, |
|
sector_t pblk, unsigned int len); |
|
|
|
/* hooks.c */ |
|
int fscrypt_file_open(struct inode *inode, struct file *filp); |
|
int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, |
|
struct dentry *dentry); |
|
int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry, |
|
struct inode *new_dir, struct dentry *new_dentry, |
|
unsigned int flags); |
|
int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, |
|
struct fscrypt_name *fname); |
|
int __fscrypt_prepare_readdir(struct inode *dir); |
|
int __fscrypt_prepare_setattr(struct dentry *dentry, struct iattr *attr); |
|
int fscrypt_prepare_setflags(struct inode *inode, |
|
unsigned int oldflags, unsigned int flags); |
|
int fscrypt_prepare_symlink(struct inode *dir, const char *target, |
|
unsigned int len, unsigned int max_len, |
|
struct fscrypt_str *disk_link); |
|
int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, |
|
unsigned int len, struct fscrypt_str *disk_link); |
|
const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, |
|
unsigned int max_size, |
|
struct delayed_call *done); |
|
static inline void fscrypt_set_ops(struct super_block *sb, |
|
const struct fscrypt_operations *s_cop) |
|
{ |
|
sb->s_cop = s_cop; |
|
} |
|
#else /* !CONFIG_FS_ENCRYPTION */ |
|
|
|
static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static inline bool fscrypt_needs_contents_encryption(const struct inode *inode) |
|
{ |
|
return false; |
|
} |
|
|
|
static inline void fscrypt_handle_d_move(struct dentry *dentry) |
|
{ |
|
} |
|
|
|
static inline bool fscrypt_is_nokey_name(const struct dentry *dentry) |
|
{ |
|
return false; |
|
} |
|
|
|
/* crypto.c */ |
|
static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work) |
|
{ |
|
} |
|
|
|
static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page, |
|
unsigned int len, |
|
unsigned int offs, |
|
gfp_t gfp_flags) |
|
{ |
|
return ERR_PTR(-EOPNOTSUPP); |
|
} |
|
|
|
static inline int fscrypt_encrypt_block_inplace(const struct inode *inode, |
|
struct page *page, |
|
unsigned int len, |
|
unsigned int offs, u64 lblk_num, |
|
gfp_t gfp_flags) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_decrypt_pagecache_blocks(struct page *page, |
|
unsigned int len, |
|
unsigned int offs) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_decrypt_block_inplace(const struct inode *inode, |
|
struct page *page, |
|
unsigned int len, |
|
unsigned int offs, u64 lblk_num) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline bool fscrypt_is_bounce_page(struct page *page) |
|
{ |
|
return false; |
|
} |
|
|
|
static inline struct page *fscrypt_pagecache_page(struct page *bounce_page) |
|
{ |
|
WARN_ON_ONCE(1); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
static inline void fscrypt_free_bounce_page(struct page *bounce_page) |
|
{ |
|
} |
|
|
|
/* policy.c */ |
|
static inline int fscrypt_ioctl_set_policy(struct file *filp, |
|
const void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_get_policy_ex(struct file *filp, |
|
void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_has_permitted_context(struct inode *parent, |
|
struct inode *child) |
|
{ |
|
return 0; |
|
} |
|
|
|
static inline int fscrypt_set_context(struct inode *inode, void *fs_data) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
struct fscrypt_dummy_policy { |
|
}; |
|
|
|
static inline void fscrypt_show_test_dummy_encryption(struct seq_file *seq, |
|
char sep, |
|
struct super_block *sb) |
|
{ |
|
} |
|
|
|
static inline void |
|
fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy) |
|
{ |
|
} |
|
|
|
/* keyring.c */ |
|
static inline void fscrypt_sb_free(struct super_block *sb) |
|
{ |
|
} |
|
|
|
static inline int fscrypt_ioctl_add_key(struct file *filp, void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_remove_key_all_users(struct file *filp, |
|
void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_ioctl_get_key_status(struct file *filp, |
|
void __user *arg) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
/* keysetup.c */ |
|
|
|
static inline int fscrypt_prepare_new_inode(struct inode *dir, |
|
struct inode *inode, |
|
bool *encrypt_ret) |
|
{ |
|
if (IS_ENCRYPTED(dir)) |
|
return -EOPNOTSUPP; |
|
return 0; |
|
} |
|
|
|
static inline void fscrypt_put_encryption_info(struct inode *inode) |
|
{ |
|
return; |
|
} |
|
|
|
static inline void fscrypt_free_inode(struct inode *inode) |
|
{ |
|
} |
|
|
|
static inline int fscrypt_drop_inode(struct inode *inode) |
|
{ |
|
return 0; |
|
} |
|
|
|
/* fname.c */ |
|
static inline int fscrypt_setup_filename(struct inode *dir, |
|
const struct qstr *iname, |
|
int lookup, struct fscrypt_name *fname) |
|
{ |
|
if (IS_ENCRYPTED(dir)) |
|
return -EOPNOTSUPP; |
|
|
|
memset(fname, 0, sizeof(*fname)); |
|
fname->usr_fname = iname; |
|
fname->disk_name.name = (unsigned char *)iname->name; |
|
fname->disk_name.len = iname->len; |
|
return 0; |
|
} |
|
|
|
static inline void fscrypt_free_filename(struct fscrypt_name *fname) |
|
{ |
|
return; |
|
} |
|
|
|
static inline int fscrypt_fname_alloc_buffer(u32 max_encrypted_len, |
|
struct fscrypt_str *crypto_str) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str) |
|
{ |
|
return; |
|
} |
|
|
|
static inline int fscrypt_fname_disk_to_usr(const struct inode *inode, |
|
u32 hash, u32 minor_hash, |
|
const struct fscrypt_str *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) |
|
{ |
|
/* Encryption support disabled; use standard comparison */ |
|
if (de_name_len != fname->disk_name.len) |
|
return false; |
|
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len); |
|
} |
|
|
|
static inline u64 fscrypt_fname_siphash(const struct inode *dir, |
|
const struct qstr *name) |
|
{ |
|
WARN_ON_ONCE(1); |
|
return 0; |
|
} |
|
|
|
static inline int fscrypt_d_revalidate(struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
return 1; |
|
} |
|
|
|
/* bio.c */ |
|
static inline void fscrypt_decrypt_bio(struct bio *bio) |
|
{ |
|
} |
|
|
|
static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, |
|
sector_t pblk, unsigned int len) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
/* hooks.c */ |
|
|
|
static inline int fscrypt_file_open(struct inode *inode, struct file *filp) |
|
{ |
|
if (IS_ENCRYPTED(inode)) |
|
return -EOPNOTSUPP; |
|
return 0; |
|
} |
|
|
|
static inline int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, |
|
struct dentry *dentry) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int __fscrypt_prepare_rename(struct inode *old_dir, |
|
struct dentry *old_dentry, |
|
struct inode *new_dir, |
|
struct dentry *new_dentry, |
|
unsigned int flags) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int __fscrypt_prepare_lookup(struct inode *dir, |
|
struct dentry *dentry, |
|
struct fscrypt_name *fname) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int __fscrypt_prepare_readdir(struct inode *dir) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int __fscrypt_prepare_setattr(struct dentry *dentry, |
|
struct iattr *attr) |
|
{ |
|
return -EOPNOTSUPP; |
|
} |
|
|
|
static inline int fscrypt_prepare_setflags(struct inode *inode, |
|
unsigned int oldflags, |
|
unsigned int flags) |
|
{ |
|
return 0; |
|
} |
|
|
|
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)) |
|
return -EOPNOTSUPP; |
|
disk_link->name = (unsigned char *)target; |
|
disk_link->len = len + 1; |
|
if (disk_link->len > max_len) |
|
return -ENAMETOOLONG; |
|
return 0; |
|
} |
|
|
|
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); |
|
} |
|
|
|
static inline void fscrypt_set_ops(struct super_block *sb, |
|
const struct fscrypt_operations *s_cop) |
|
{ |
|
} |
|
|
|
#endif /* !CONFIG_FS_ENCRYPTION */ |
|
|
|
/* inline_crypt.c */ |
|
#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT |
|
|
|
bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode); |
|
|
|
void fscrypt_set_bio_crypt_ctx(struct bio *bio, |
|
const struct inode *inode, u64 first_lblk, |
|
gfp_t gfp_mask); |
|
|
|
void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio, |
|
const struct buffer_head *first_bh, |
|
gfp_t gfp_mask); |
|
|
|
bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, |
|
u64 next_lblk); |
|
|
|
bool fscrypt_mergeable_bio_bh(struct bio *bio, |
|
const struct buffer_head *next_bh); |
|
|
|
#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ |
|
|
|
static inline bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode) |
|
{ |
|
return false; |
|
} |
|
|
|
static inline void fscrypt_set_bio_crypt_ctx(struct bio *bio, |
|
const struct inode *inode, |
|
u64 first_lblk, gfp_t gfp_mask) { } |
|
|
|
static inline void fscrypt_set_bio_crypt_ctx_bh( |
|
struct bio *bio, |
|
const struct buffer_head *first_bh, |
|
gfp_t gfp_mask) { } |
|
|
|
static inline bool fscrypt_mergeable_bio(struct bio *bio, |
|
const struct inode *inode, |
|
u64 next_lblk) |
|
{ |
|
return true; |
|
} |
|
|
|
static inline bool fscrypt_mergeable_bio_bh(struct bio *bio, |
|
const struct buffer_head *next_bh) |
|
{ |
|
return true; |
|
} |
|
#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ |
|
|
|
/** |
|
* fscrypt_inode_uses_inline_crypto() - test whether an inode uses inline |
|
* encryption |
|
* @inode: an inode. If encrypted, its key must be set up. |
|
* |
|
* Return: true if the inode requires file contents encryption and if the |
|
* encryption should be done in the block layer via blk-crypto rather |
|
* than in the filesystem layer. |
|
*/ |
|
static inline bool fscrypt_inode_uses_inline_crypto(const struct inode *inode) |
|
{ |
|
return fscrypt_needs_contents_encryption(inode) && |
|
__fscrypt_inode_uses_inline_crypto(inode); |
|
} |
|
|
|
/** |
|
* fscrypt_inode_uses_fs_layer_crypto() - test whether an inode uses fs-layer |
|
* encryption |
|
* @inode: an inode. If encrypted, its key must be set up. |
|
* |
|
* Return: true if the inode requires file contents encryption and if the |
|
* encryption should be done in the filesystem layer rather than in the |
|
* block layer via blk-crypto. |
|
*/ |
|
static inline bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode) |
|
{ |
|
return fscrypt_needs_contents_encryption(inode) && |
|
!__fscrypt_inode_uses_inline_crypto(inode); |
|
} |
|
|
|
/** |
|
* fscrypt_has_encryption_key() - check whether an inode has had its key set up |
|
* @inode: the inode to check |
|
* |
|
* Return: %true if the inode has had its encryption key set up, else %false. |
|
* |
|
* Usually this should be preceded by fscrypt_get_encryption_info() to try to |
|
* set up the key first. |
|
*/ |
|
static inline bool fscrypt_has_encryption_key(const struct inode *inode) |
|
{ |
|
return fscrypt_get_info(inode) != NULL; |
|
} |
|
|
|
/** |
|
* fscrypt_prepare_link() - prepare to link an inode into a possibly-encrypted |
|
* directory |
|
* @old_dentry: an existing dentry for the inode being linked |
|
* @dir: the target directory |
|
* @dentry: negative dentry for the target filename |
|
* |
|
* A new link can only be added to an encrypted directory if the directory's |
|
* encryption key is available --- since otherwise we'd have no way to encrypt |
|
* the filename. |
|
* |
|
* We also verify that the link will not violate the constraint that all files |
|
* in an encrypted directory tree use the same encryption policy. |
|
* |
|
* Return: 0 on success, -ENOKEY if the directory's encryption key is missing, |
|
* -EXDEV if the link would result in an inconsistent encryption policy, or |
|
* another -errno code. |
|
*/ |
|
static inline int fscrypt_prepare_link(struct dentry *old_dentry, |
|
struct inode *dir, |
|
struct dentry *dentry) |
|
{ |
|
if (IS_ENCRYPTED(dir)) |
|
return __fscrypt_prepare_link(d_inode(old_dentry), dir, dentry); |
|
return 0; |
|
} |
|
|
|
/** |
|
* fscrypt_prepare_rename() - prepare for a rename between possibly-encrypted |
|
* directories |
|
* @old_dir: source directory |
|
* @old_dentry: dentry for source file |
|
* @new_dir: target directory |
|
* @new_dentry: dentry for target location (may be negative unless exchanging) |
|
* @flags: rename flags (we care at least about %RENAME_EXCHANGE) |
|
* |
|
* Prepare for ->rename() where the source and/or target directories may be |
|
* encrypted. A new link can only be added to an encrypted directory if the |
|
* directory's encryption key is available --- since otherwise we'd have no way |
|
* to encrypt the filename. A rename to an existing name, on the other hand, |
|
* *is* cryptographically possible without the key. However, we take the more |
|
* conservative approach and just forbid all no-key renames. |
|
* |
|
* We also verify that the rename will not violate the constraint that all files |
|
* in an encrypted directory tree use the same encryption policy. |
|
* |
|
* Return: 0 on success, -ENOKEY if an encryption key is missing, -EXDEV if the |
|
* rename would cause inconsistent encryption policies, or another -errno code. |
|
*/ |
|
static inline int fscrypt_prepare_rename(struct inode *old_dir, |
|
struct dentry *old_dentry, |
|
struct inode *new_dir, |
|
struct dentry *new_dentry, |
|
unsigned int flags) |
|
{ |
|
if (IS_ENCRYPTED(old_dir) || IS_ENCRYPTED(new_dir)) |
|
return __fscrypt_prepare_rename(old_dir, old_dentry, |
|
new_dir, new_dentry, flags); |
|
return 0; |
|
} |
|
|
|
/** |
|
* fscrypt_prepare_lookup() - prepare to lookup a name in a possibly-encrypted |
|
* directory |
|
* @dir: directory being searched |
|
* @dentry: filename being looked up |
|
* @fname: (output) the name to use to search the on-disk directory |
|
* |
|
* Prepare for ->lookup() in a directory which may be encrypted by determining |
|
* the name that will actually be used to search the directory on-disk. If the |
|
* directory's encryption policy is supported by this kernel and its encryption |
|
* key is available, then the lookup is assumed to be by plaintext name; |
|
* otherwise, it is assumed to be by no-key name. |
|
* |
|
* This will set DCACHE_NOKEY_NAME on the dentry if the lookup is by no-key |
|
* name. In this case the filesystem must assign the dentry a dentry_operations |
|
* which contains fscrypt_d_revalidate (or contains a d_revalidate method that |
|
* calls fscrypt_d_revalidate), so that the dentry will be invalidated if the |
|
* directory's encryption key is later added. |
|
* |
|
* Return: 0 on success; -ENOENT if the directory's key is unavailable but the |
|
* filename isn't a valid no-key name, so a negative dentry should be created; |
|
* or another -errno code. |
|
*/ |
|
static inline int fscrypt_prepare_lookup(struct inode *dir, |
|
struct dentry *dentry, |
|
struct fscrypt_name *fname) |
|
{ |
|
if (IS_ENCRYPTED(dir)) |
|
return __fscrypt_prepare_lookup(dir, dentry, fname); |
|
|
|
memset(fname, 0, sizeof(*fname)); |
|
fname->usr_fname = &dentry->d_name; |
|
fname->disk_name.name = (unsigned char *)dentry->d_name.name; |
|
fname->disk_name.len = dentry->d_name.len; |
|
return 0; |
|
} |
|
|
|
/** |
|
* fscrypt_prepare_readdir() - prepare to read a possibly-encrypted directory |
|
* @dir: the directory inode |
|
* |
|
* If the directory is encrypted and it doesn't already have its encryption key |
|
* set up, try to set it up so that the filenames will be listed in plaintext |
|
* form rather than in no-key form. |
|
* |
|
* Return: 0 on success; -errno on error. Note that the encryption key being |
|
* unavailable is not considered an error. It is also not an error if |
|
* the encryption policy is unsupported by this kernel; that is treated |
|
* like the key being unavailable, so that files can still be deleted. |
|
*/ |
|
static inline int fscrypt_prepare_readdir(struct inode *dir) |
|
{ |
|
if (IS_ENCRYPTED(dir)) |
|
return __fscrypt_prepare_readdir(dir); |
|
return 0; |
|
} |
|
|
|
/** |
|
* fscrypt_prepare_setattr() - prepare to change a possibly-encrypted inode's |
|
* attributes |
|
* @dentry: dentry through which the inode is being changed |
|
* @attr: attributes to change |
|
* |
|
* Prepare for ->setattr() on a possibly-encrypted inode. On an encrypted file, |
|
* most attribute changes are allowed even without the encryption key. However, |
|
* without the encryption key we do have to forbid truncates. This is needed |
|
* because the size being truncated to may not be a multiple of the filesystem |
|
* block size, and in that case we'd have to decrypt the final block, zero the |
|
* portion past i_size, and re-encrypt it. (We *could* allow truncating to a |
|
* filesystem block boundary, but it's simpler to just forbid all truncates --- |
|
* and we already forbid all other contents modifications without the key.) |
|
* |
|
* Return: 0 on success, -ENOKEY if the key is missing, or another -errno code |
|
* if a problem occurred while setting up the encryption key. |
|
*/ |
|
static inline int fscrypt_prepare_setattr(struct dentry *dentry, |
|
struct iattr *attr) |
|
{ |
|
if (IS_ENCRYPTED(d_inode(dentry))) |
|
return __fscrypt_prepare_setattr(dentry, attr); |
|
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; |
|
} |
|
|
|
/* If *pagep is a bounce page, free it and set *pagep to the pagecache page */ |
|
static inline void fscrypt_finalize_bounce_page(struct page **pagep) |
|
{ |
|
struct page *page = *pagep; |
|
|
|
if (fscrypt_is_bounce_page(page)) { |
|
*pagep = fscrypt_pagecache_page(page); |
|
fscrypt_free_bounce_page(page); |
|
} |
|
} |
|
|
|
#endif /* _LINUX_FSCRYPT_H */
|
|
|