forked from Minki/linux
aec992aab8
In order to support a new dirhash method that is a secret-keyed hash over the plaintext filenames (which will be used by encrypted+casefolded directories on ext4 and f2fs), fscrypt will be switching to a new no-key name format that always encodes the dirhash in the name. UBIFS isn't happy with this because it has assertions that verify that either the hash or the disk name is provided, not both. Change it to use the disk name if one is provided, even if a hash is available too; else use the hash. Link: https://lore.kernel.org/r/20200120223201.241390-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
544 lines
14 KiB
C
544 lines
14 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* This file is part of UBIFS.
|
|
*
|
|
* Copyright (C) 2006-2008 Nokia Corporation.
|
|
*
|
|
* Authors: Artem Bityutskiy (Битюцкий Артём)
|
|
* Adrian Hunter
|
|
*/
|
|
|
|
/*
|
|
* This header contains various key-related definitions and helper function.
|
|
* UBIFS allows several key schemes, so we access key fields only via these
|
|
* helpers. At the moment only one key scheme is supported.
|
|
*
|
|
* Simple key scheme
|
|
* ~~~~~~~~~~~~~~~~~
|
|
*
|
|
* Keys are 64-bits long. First 32-bits are inode number (parent inode number
|
|
* in case of direntry key). Next 3 bits are node type. The last 29 bits are
|
|
* 4KiB offset in case of inode node, and direntry hash in case of a direntry
|
|
* node. We use "r5" hash borrowed from reiserfs.
|
|
*/
|
|
|
|
/*
|
|
* Lot's of the key helpers require a struct ubifs_info *c as the first parameter.
|
|
* But we are not using it at all currently. That's designed for future extensions of
|
|
* different c->key_format. But right now, there is only one key type, UBIFS_SIMPLE_KEY_FMT.
|
|
*/
|
|
|
|
#ifndef __UBIFS_KEY_H__
|
|
#define __UBIFS_KEY_H__
|
|
|
|
/**
|
|
* key_mask_hash - mask a valid hash value.
|
|
* @val: value to be masked
|
|
*
|
|
* We use hash values as offset in directories, so values %0 and %1 are
|
|
* reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
|
|
* function makes sure the reserved values are not used.
|
|
*/
|
|
static inline uint32_t key_mask_hash(uint32_t hash)
|
|
{
|
|
hash &= UBIFS_S_KEY_HASH_MASK;
|
|
if (unlikely(hash <= 2))
|
|
hash += 3;
|
|
return hash;
|
|
}
|
|
|
|
/**
|
|
* key_r5_hash - R5 hash function (borrowed from reiserfs).
|
|
* @s: direntry name
|
|
* @len: name length
|
|
*/
|
|
static inline uint32_t key_r5_hash(const char *s, int len)
|
|
{
|
|
uint32_t a = 0;
|
|
const signed char *str = (const signed char *)s;
|
|
|
|
while (len--) {
|
|
a += *str << 4;
|
|
a += *str >> 4;
|
|
a *= 11;
|
|
str++;
|
|
}
|
|
|
|
return key_mask_hash(a);
|
|
}
|
|
|
|
/**
|
|
* key_test_hash - testing hash function.
|
|
* @str: direntry name
|
|
* @len: name length
|
|
*/
|
|
static inline uint32_t key_test_hash(const char *str, int len)
|
|
{
|
|
uint32_t a = 0;
|
|
|
|
len = min_t(uint32_t, len, 4);
|
|
memcpy(&a, str, len);
|
|
return key_mask_hash(a);
|
|
}
|
|
|
|
/**
|
|
* ino_key_init - initialize inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void ino_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* ino_key_init_flash - initialize on-flash inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum)
|
|
{
|
|
union ubifs_key *key = k;
|
|
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_ino_key - get the lowest possible inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void lowest_ino_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = 0;
|
|
}
|
|
|
|
/**
|
|
* highest_ino_key - get the highest possible inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void highest_ino_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = 0xffffffff;
|
|
}
|
|
|
|
/**
|
|
* dent_key_init - initialize directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: parent inode number
|
|
* @nm: direntry name and length. Not a string when encrypted!
|
|
*/
|
|
static inline void dent_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
const struct fscrypt_name *nm)
|
|
{
|
|
uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
|
|
|
|
ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* dent_key_init_hash - initialize directory entry key without re-calculating
|
|
* hash function.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: parent inode number
|
|
* @hash: direntry name hash
|
|
*/
|
|
static inline void dent_key_init_hash(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
uint32_t hash)
|
|
{
|
|
ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* dent_key_init_flash - initialize on-flash directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: parent inode number
|
|
* @nm: direntry name and length
|
|
*/
|
|
static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum,
|
|
const struct fscrypt_name *nm)
|
|
{
|
|
union ubifs_key *key = k;
|
|
uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
|
|
|
|
ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(hash |
|
|
(UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_dent_key - get the lowest possible directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: where to store the lowest key
|
|
* @inum: parent inode number
|
|
*/
|
|
static inline void lowest_dent_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
|
|
}
|
|
|
|
/**
|
|
* xent_key_init - initialize extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: host inode number
|
|
* @nm: extended attribute entry name and length
|
|
*/
|
|
static inline void xent_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
const struct fscrypt_name *nm)
|
|
{
|
|
uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
|
|
|
|
ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* xent_key_init_flash - initialize on-flash extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: host inode number
|
|
* @nm: extended attribute entry name and length
|
|
*/
|
|
static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum, const struct fscrypt_name *nm)
|
|
{
|
|
union ubifs_key *key = k;
|
|
uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
|
|
|
|
ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(hash |
|
|
(UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_xent_key - get the lowest possible extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: where to store the lowest key
|
|
* @inum: host inode number
|
|
*/
|
|
static inline void lowest_xent_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
|
|
}
|
|
|
|
/**
|
|
* data_key_init - initialize data key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
* @block: block number
|
|
*/
|
|
static inline void data_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
unsigned int block)
|
|
{
|
|
ubifs_assert(c, !(block & ~UBIFS_S_KEY_BLOCK_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
|
|
}
|
|
|
|
/**
|
|
* highest_data_key - get the highest possible data key for an inode.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void highest_data_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK);
|
|
}
|
|
|
|
/**
|
|
* trun_key_init - initialize truncation node key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*
|
|
* Note, UBIFS does not have truncation keys on the media and this function is
|
|
* only used for purposes of replay.
|
|
*/
|
|
static inline void trun_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* invalid_key_init - initialize invalid node key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
*
|
|
* This is a helper function which marks a @key object as invalid.
|
|
*/
|
|
static inline void invalid_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key)
|
|
{
|
|
key->u32[0] = 0xDEADBEAF;
|
|
key->u32[1] = UBIFS_INVALID_KEY;
|
|
}
|
|
|
|
/**
|
|
* key_type - get key type.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to get type of
|
|
*/
|
|
static inline int key_type(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* key_type_flash - get type of a on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to get type of
|
|
*/
|
|
static inline int key_type_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* key_inum - fetch inode number from key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to fetch inode number from
|
|
*/
|
|
static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return key->u32[0];
|
|
}
|
|
|
|
/**
|
|
* key_inum_flash - fetch inode number from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to fetch inode number from
|
|
*/
|
|
static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[0]);
|
|
}
|
|
|
|
/**
|
|
* key_hash - get directory entry hash.
|
|
* @c: UBIFS file-system description object
|
|
* @key: the key to get hash from
|
|
*/
|
|
static inline uint32_t key_hash(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_hash_flash - get directory entry hash from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: the key to get hash from
|
|
*/
|
|
static inline uint32_t key_hash_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_block - get data block number.
|
|
* @c: UBIFS file-system description object
|
|
* @key: the key to get the block number from
|
|
*/
|
|
static inline unsigned int key_block(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_block_flash - get data block number from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: the key to get the block number from
|
|
*/
|
|
static inline unsigned int key_block_flash(const struct ubifs_info *c,
|
|
const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_read - transform a key to in-memory format.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_read(const struct ubifs_info *c, const void *from,
|
|
union ubifs_key *to)
|
|
{
|
|
const union ubifs_key *f = from;
|
|
|
|
to->u32[0] = le32_to_cpu(f->j32[0]);
|
|
to->u32[1] = le32_to_cpu(f->j32[1]);
|
|
}
|
|
|
|
/**
|
|
* key_write - transform a key from in-memory format.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_write(const struct ubifs_info *c,
|
|
const union ubifs_key *from, void *to)
|
|
{
|
|
union ubifs_key *t = to;
|
|
|
|
t->j32[0] = cpu_to_le32(from->u32[0]);
|
|
t->j32[1] = cpu_to_le32(from->u32[1]);
|
|
memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* key_write_idx - transform a key from in-memory format for the index.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_write_idx(const struct ubifs_info *c,
|
|
const union ubifs_key *from, void *to)
|
|
{
|
|
union ubifs_key *t = to;
|
|
|
|
t->j32[0] = cpu_to_le32(from->u32[0]);
|
|
t->j32[1] = cpu_to_le32(from->u32[1]);
|
|
}
|
|
|
|
/**
|
|
* key_copy - copy a key.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to copy from
|
|
* @to: the key to copy to
|
|
*/
|
|
static inline void key_copy(const struct ubifs_info *c,
|
|
const union ubifs_key *from, union ubifs_key *to)
|
|
{
|
|
to->u64[0] = from->u64[0];
|
|
}
|
|
|
|
/**
|
|
* keys_cmp - compare keys.
|
|
* @c: UBIFS file-system description object
|
|
* @key1: the first key to compare
|
|
* @key2: the second key to compare
|
|
*
|
|
* This function compares 2 keys and returns %-1 if @key1 is less than
|
|
* @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
|
|
*/
|
|
static inline int keys_cmp(const struct ubifs_info *c,
|
|
const union ubifs_key *key1,
|
|
const union ubifs_key *key2)
|
|
{
|
|
if (key1->u32[0] < key2->u32[0])
|
|
return -1;
|
|
if (key1->u32[0] > key2->u32[0])
|
|
return 1;
|
|
if (key1->u32[1] < key2->u32[1])
|
|
return -1;
|
|
if (key1->u32[1] > key2->u32[1])
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* keys_eq - determine if keys are equivalent.
|
|
* @c: UBIFS file-system description object
|
|
* @key1: the first key to compare
|
|
* @key2: the second key to compare
|
|
*
|
|
* This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
|
|
* %0 if not.
|
|
*/
|
|
static inline int keys_eq(const struct ubifs_info *c,
|
|
const union ubifs_key *key1,
|
|
const union ubifs_key *key2)
|
|
{
|
|
if (key1->u32[0] != key2->u32[0])
|
|
return 0;
|
|
if (key1->u32[1] != key2->u32[1])
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* is_hash_key - is a key vulnerable to hash collisions.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key
|
|
*
|
|
* This function returns %1 if @key is a hashed key or %0 otherwise.
|
|
*/
|
|
static inline int is_hash_key(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
int type = key_type(c, key);
|
|
|
|
return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
|
|
}
|
|
|
|
/**
|
|
* key_max_inode_size - get maximum file size allowed by current key format.
|
|
* @c: UBIFS file-system description object
|
|
*/
|
|
static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
|
|
{
|
|
switch (c->key_fmt) {
|
|
case UBIFS_SIMPLE_KEY_FMT:
|
|
return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#endif /* !__UBIFS_KEY_H__ */
|