linux/fs/ext4/hash.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/ext4/hash.c
 *
 * Copyright (C) 2002 by Theodore Ts'o
 */

#include <linux/fs.h>
#include <linux/unicode.h>
#include <linux/compiler.h>
#include <linux/bitops.h>
#include "ext4.h"

#define DELTA …

static void TEA_transform(__u32 buf[4], __u32 const in[])
{ … }

/* F, G and H are basic MD4 functions: selection, majority, parity */
#define F …
#define G …
#define H …

/*
 * The generic round function.  The application is so specific that
 * we don't bother protecting all the arguments with parens, as is generally
 * good macro practice, in favor of extra legibility.
 * Rotation is separate from addition to prevent recomputation
 */
#define ROUND …
#define K1 …
#define K2 …
#define K3 …

/*
 * Basic cut-down MD4 transform.  Returns only 32 bits of result.
 */
static __u32 half_md4_transform(__u32 buf[4], __u32 const in[8])
{ … }
#undef ROUND
#undef K1
#undef K2
#undef K3
#undef F
#undef G
#undef H

/* The old legacy hash */
static __u32 dx_hack_hash_unsigned(const char *name, int len)
{ … }

static __u32 dx_hack_hash_signed(const char *name, int len)
{ … }

static void str2hashbuf_signed(const char *msg, int len, __u32 *buf, int num)
{ … }

static void str2hashbuf_unsigned(const char *msg, int len, __u32 *buf, int num)
{ … }

/*
 * Returns the hash of a filename.  If len is 0 and name is NULL, then
 * this function can be used to test whether or not a hash version is
 * supported.
 *
 * The seed is an 4 longword (32 bits) "secret" which can be used to
 * uniquify a hash.  If the seed is all zero's, then some default seed
 * may be used.
 *
 * A particular hash version specifies whether or not the seed is
 * represented, and whether or not the returned hash is 32 bits or 64
 * bits.  32 bit hashes will return 0 for the minor hash.
 */
static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len,
			    struct dx_hash_info *hinfo)
{ … }

int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
		   struct dx_hash_info *hinfo)
{ … }