1027 lines
32 KiB
C
1027 lines
32 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* fscrypt.h: declarations for per-file encryption
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*
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* Filesystems that implement per-file encryption must include this header
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* file.
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*
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* Copyright (C) 2015, Google, Inc.
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*
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* Written by Michael Halcrow, 2015.
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* Modified by Jaegeuk Kim, 2015.
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*/
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#ifndef _LINUX_FSCRYPT_H
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#define _LINUX_FSCRYPT_H
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <uapi/linux/fscrypt.h>
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/*
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* The lengths of all file contents blocks must be divisible by this value.
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* This is needed to ensure that all contents encryption modes will work, as
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* some of the supported modes don't support arbitrarily byte-aligned messages.
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*
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* Since the needed alignment is 16 bytes, most filesystems will meet this
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* requirement naturally, as typical block sizes are powers of 2. However, if a
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* filesystem can generate arbitrarily byte-aligned block lengths (e.g., via
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* compression), then it will need to pad to this alignment before encryption.
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*/
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#define FSCRYPT_CONTENTS_ALIGNMENT 16
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union fscrypt_policy;
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struct fscrypt_info;
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struct fs_parameter;
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struct seq_file;
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struct fscrypt_str {
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unsigned char *name;
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u32 len;
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};
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struct fscrypt_name {
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const struct qstr *usr_fname;
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struct fscrypt_str disk_name;
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u32 hash;
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u32 minor_hash;
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struct fscrypt_str crypto_buf;
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bool is_nokey_name;
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};
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#define FSTR_INIT(n, l) { .name = n, .len = l }
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#define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
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#define fname_name(p) ((p)->disk_name.name)
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#define fname_len(p) ((p)->disk_name.len)
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/* Maximum value for the third parameter of fscrypt_operations.set_context(). */
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#define FSCRYPT_SET_CONTEXT_MAX_SIZE 40
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#ifdef CONFIG_FS_ENCRYPTION
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/*
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* If set, the fscrypt bounce page pool won't be allocated (unless another
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* filesystem needs it). Set this if the filesystem always uses its own bounce
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* pages for writes and therefore won't need the fscrypt bounce page pool.
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*/
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#define FS_CFLG_OWN_PAGES (1U << 1)
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/* Crypto operations for filesystems */
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struct fscrypt_operations {
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/* Set of optional flags; see above for allowed flags */
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unsigned int flags;
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/*
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* If set, this is a filesystem-specific key description prefix that
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* will be accepted for "logon" keys for v1 fscrypt policies, in
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* addition to the generic prefix "fscrypt:". This functionality is
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* deprecated, so new filesystems shouldn't set this field.
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*/
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const char *key_prefix;
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/*
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* Get the fscrypt context of the given inode.
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*
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* @inode: the inode whose context to get
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* @ctx: the buffer into which to get the context
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* @len: length of the @ctx buffer in bytes
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*
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* Return: On success, returns the length of the context in bytes; this
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* may be less than @len. On failure, returns -ENODATA if the
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* inode doesn't have a context, -ERANGE if the context is
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* longer than @len, or another -errno code.
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*/
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int (*get_context)(struct inode *inode, void *ctx, size_t len);
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/*
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* Set an fscrypt context on the given inode.
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*
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* @inode: the inode whose context to set. The inode won't already have
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* an fscrypt context.
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* @ctx: the context to set
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* @len: length of @ctx in bytes (at most FSCRYPT_SET_CONTEXT_MAX_SIZE)
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* @fs_data: If called from fscrypt_set_context(), this will be the
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* value the filesystem passed to fscrypt_set_context().
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* Otherwise (i.e. when called from
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* FS_IOC_SET_ENCRYPTION_POLICY) this will be NULL.
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*
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* i_rwsem will be held for write.
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*
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* Return: 0 on success, -errno on failure.
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*/
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int (*set_context)(struct inode *inode, const void *ctx, size_t len,
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void *fs_data);
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/*
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* Get the dummy fscrypt policy in use on the filesystem (if any).
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*
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* Filesystems only need to implement this function if they support the
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* test_dummy_encryption mount option.
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*
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* Return: A pointer to the dummy fscrypt policy, if the filesystem is
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* mounted with test_dummy_encryption; otherwise NULL.
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*/
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const union fscrypt_policy *(*get_dummy_policy)(struct super_block *sb);
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/*
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* Check whether a directory is empty. i_rwsem will be held for write.
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*/
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bool (*empty_dir)(struct inode *inode);
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/*
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* Check whether the filesystem's inode numbers and UUID are stable,
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* meaning that they will never be changed even by offline operations
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* such as filesystem shrinking and therefore can be used in the
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* encryption without the possibility of files becoming unreadable.
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*
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* Filesystems only need to implement this function if they want to
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* support the FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags. These
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* flags are designed to work around the limitations of UFS and eMMC
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* inline crypto hardware, and they shouldn't be used in scenarios where
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* such hardware isn't being used.
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*
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* Leaving this NULL is equivalent to always returning false.
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*/
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bool (*has_stable_inodes)(struct super_block *sb);
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/*
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* Get the number of bits that the filesystem uses to represent inode
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* numbers and file logical block numbers.
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*
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* By default, both of these are assumed to be 64-bit. This function
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* can be implemented to declare that either or both of these numbers is
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* shorter, which may allow the use of the
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* FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags and/or the use of
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* inline crypto hardware whose maximum DUN length is less than 64 bits
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* (e.g., eMMC v5.2 spec compliant hardware). This function only needs
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* to be implemented if support for one of these features is needed.
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*/
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void (*get_ino_and_lblk_bits)(struct super_block *sb,
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int *ino_bits_ret, int *lblk_bits_ret);
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/*
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* Return an array of pointers to the block devices to which the
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* filesystem may write encrypted file contents, NULL if the filesystem
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* only has a single such block device, or an ERR_PTR() on error.
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*
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* On successful non-NULL return, *num_devs is set to the number of
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* devices in the returned array. The caller must free the returned
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* array using kfree().
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*
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* If the filesystem can use multiple block devices (other than block
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* devices that aren't used for encrypted file contents, such as
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* external journal devices), and wants to support inline encryption,
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* then it must implement this function. Otherwise it's not needed.
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*/
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struct block_device **(*get_devices)(struct super_block *sb,
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unsigned int *num_devs);
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};
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static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
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{
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/*
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* Pairs with the cmpxchg_release() in fscrypt_setup_encryption_info().
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* I.e., another task may publish ->i_crypt_info concurrently, executing
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* a RELEASE barrier. We need to use smp_load_acquire() here to safely
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* ACQUIRE the memory the other task published.
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*/
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return smp_load_acquire(&inode->i_crypt_info);
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}
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/**
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* fscrypt_needs_contents_encryption() - check whether an inode needs
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* contents encryption
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* @inode: the inode to check
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*
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* Return: %true iff the inode is an encrypted regular file and the kernel was
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* built with fscrypt support.
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*
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* If you need to know whether the encrypt bit is set even when the kernel was
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* built without fscrypt support, you must use IS_ENCRYPTED() directly instead.
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*/
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static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
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{
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return IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode);
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}
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/*
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* When d_splice_alias() moves a directory's no-key alias to its plaintext alias
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* as a result of the encryption key being added, DCACHE_NOKEY_NAME must be
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* cleared. Note that we don't have to support arbitrary moves of this flag
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* because fscrypt doesn't allow no-key names to be the source or target of a
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* rename().
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*/
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static inline void fscrypt_handle_d_move(struct dentry *dentry)
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{
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dentry->d_flags &= ~DCACHE_NOKEY_NAME;
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}
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/**
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* fscrypt_is_nokey_name() - test whether a dentry is a no-key name
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* @dentry: the dentry to check
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*
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* This returns true if the dentry is a no-key dentry. A no-key dentry is a
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* dentry that was created in an encrypted directory that hasn't had its
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* encryption key added yet. Such dentries may be either positive or negative.
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*
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* When a filesystem is asked to create a new filename in an encrypted directory
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* and the new filename's dentry is a no-key dentry, it must fail the operation
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* with ENOKEY. This includes ->create(), ->mkdir(), ->mknod(), ->symlink(),
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* ->rename(), and ->link(). (However, ->rename() and ->link() are already
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* handled by fscrypt_prepare_rename() and fscrypt_prepare_link().)
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*
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* This is necessary because creating a filename requires the directory's
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* encryption key, but just checking for the key on the directory inode during
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* the final filesystem operation doesn't guarantee that the key was available
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* during the preceding dentry lookup. And the key must have already been
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* available during the dentry lookup in order for it to have been checked
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* whether the filename already exists in the directory and for the new file's
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* dentry not to be invalidated due to it incorrectly having the no-key flag.
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*
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* Return: %true if the dentry is a no-key name
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*/
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static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
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{
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return dentry->d_flags & DCACHE_NOKEY_NAME;
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}
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/* crypto.c */
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void fscrypt_enqueue_decrypt_work(struct work_struct *);
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struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
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unsigned int len,
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unsigned int offs,
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gfp_t gfp_flags);
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int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page,
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unsigned int len, unsigned int offs,
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u64 lblk_num, gfp_t gfp_flags);
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int fscrypt_decrypt_pagecache_blocks(struct folio *folio, size_t len,
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size_t offs);
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int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
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unsigned int len, unsigned int offs,
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u64 lblk_num);
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static inline bool fscrypt_is_bounce_page(struct page *page)
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{
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return page->mapping == NULL;
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}
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static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
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{
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return (struct page *)page_private(bounce_page);
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}
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void fscrypt_free_bounce_page(struct page *bounce_page);
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/* policy.c */
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int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg);
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int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg);
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int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *arg);
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int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg);
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int fscrypt_has_permitted_context(struct inode *parent, struct inode *child);
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int fscrypt_context_for_new_inode(void *ctx, struct inode *inode);
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int fscrypt_set_context(struct inode *inode, void *fs_data);
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struct fscrypt_dummy_policy {
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const union fscrypt_policy *policy;
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};
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int fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
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struct fscrypt_dummy_policy *dummy_policy);
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bool fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
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const struct fscrypt_dummy_policy *p2);
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void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
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struct super_block *sb);
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static inline bool
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fscrypt_is_dummy_policy_set(const struct fscrypt_dummy_policy *dummy_policy)
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{
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return dummy_policy->policy != NULL;
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}
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static inline void
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fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
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{
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kfree(dummy_policy->policy);
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dummy_policy->policy = NULL;
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}
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/* keyring.c */
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void fscrypt_destroy_keyring(struct super_block *sb);
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int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
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int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg);
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int fscrypt_ioctl_remove_key_all_users(struct file *filp, void __user *arg);
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int fscrypt_ioctl_get_key_status(struct file *filp, void __user *arg);
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/* keysetup.c */
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int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode,
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bool *encrypt_ret);
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void fscrypt_put_encryption_info(struct inode *inode);
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void fscrypt_free_inode(struct inode *inode);
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int fscrypt_drop_inode(struct inode *inode);
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/* fname.c */
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int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
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u8 *out, unsigned int olen);
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bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len,
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u32 max_len, u32 *encrypted_len_ret);
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int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname,
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int lookup, struct fscrypt_name *fname);
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static inline void fscrypt_free_filename(struct fscrypt_name *fname)
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{
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kfree(fname->crypto_buf.name);
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}
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int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
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struct fscrypt_str *crypto_str);
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void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str);
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int fscrypt_fname_disk_to_usr(const struct inode *inode,
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||
|
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u32 hash, u32 minor_hash,
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const struct fscrypt_str *iname,
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||
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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 */
|
||
|
|
bool 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);
|
||
|
|
int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat);
|
||
|
|
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 folio *folio,
|
||
|
|
size_t len, size_t 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 int
|
||
|
|
fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
|
||
|
|
struct fscrypt_dummy_policy *dummy_policy)
|
||
|
|
{
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool
|
||
|
|
fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
|
||
|
|
const struct fscrypt_dummy_policy *p2)
|
||
|
|
{
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void fscrypt_show_test_dummy_encryption(struct seq_file *seq,
|
||
|
|
char sep,
|
||
|
|
struct super_block *sb)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool
|
||
|
|
fscrypt_is_dummy_policy_set(const struct fscrypt_dummy_policy *dummy_policy)
|
||
|
|
{
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void
|
||
|
|
fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
/* keyring.c */
|
||
|
|
static inline void fscrypt_destroy_keyring(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 bool fscrypt_decrypt_bio(struct bio *bio)
|
||
|
|
{
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
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 int fscrypt_symlink_getattr(const struct path *path,
|
||
|
|
struct kstat *stat)
|
||
|
|
{
|
||
|
|
return -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);
|
||
|
|
|
||
|
|
bool fscrypt_dio_supported(struct inode *inode);
|
||
|
|
|
||
|
|
u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks);
|
||
|
|
|
||
|
|
#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;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool fscrypt_dio_supported(struct inode *inode)
|
||
|
|
{
|
||
|
|
return !fscrypt_needs_contents_encryption(inode);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk,
|
||
|
|
u64 nr_blocks)
|
||
|
|
{
|
||
|
|
return nr_blocks;
|
||
|
|
}
|
||
|
|
#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 */
|