/* * xxHash - Extremely Fast Hash algorithm * Copyright (C) 2012-2016, Yann Collet. * * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * *   * Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. *   * Redistributions in binary form must reproduce the above *     copyright notice, this list of conditions and the following disclaimer *     in the documentation and/or other materials provided with the *     distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. This program is dual-licensed; you may select * either version 2 of the GNU General Public License ("GPL") or BSD license * ("BSD"). * * You can contact the author at: * - xxHash homepage: https://cyan4973.github.io/xxHash/ * - xxHash source repository: https://github.com/Cyan4973/xxHash */ #include <linux/unaligned.h>#include <linux/errno.h>#include <linux/compiler.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/string.h>#include <linux/xxhash.h> /*-************************************* * Macros **************************************/#define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r)))#define xxh_rotl64(x, r) ((x << r) | (x >> (64 - r))) #ifdef __LITTLE_ENDIAN# define XXH_CPU_LITTLE_ENDIAN 1#else# define XXH_CPU_LITTLE_ENDIAN 0#endif /*-************************************* * Constants **************************************/static const uint32_t PRIME32_1 = 2654435761U;static const uint32_t PRIME32_2 = 2246822519U;static const uint32_t PRIME32_3 = 3266489917U;static const uint32_t PRIME32_4 =  668265263U;static const uint32_t PRIME32_5 =  374761393U; static const uint64_t PRIME64_1 = 11400714785074694791ULL;static const uint64_t PRIME64_2 = 14029467366897019727ULL;static const uint64_t PRIME64_3 =  1609587929392839161ULL;static const uint64_t PRIME64_4 =  9650029242287828579ULL;static const uint64_t PRIME64_5 =  2870177450012600261ULL; /*-*************************** * Simple Hash Functions ****************************/static uint32_t xxh32_round(uint32_t seed, const uint32_t input){	seed += input * PRIME32_2;	seed = xxh_rotl32(seed, 13);	seed *= PRIME32_1;	return seed;} uint32_t xxh32(const void *input, const size_t len, const uint32_t seed){	const uint8_t *p = (const uint8_t *)input;	const uint8_t *b_end = p + len;	uint32_t h32; 	if (len >= 16) {		const uint8_t *const limit = b_end - 16;		uint32_t v1 = seed + PRIME32_1 + PRIME32_2;		uint32_t v2 = seed + PRIME32_2;		uint32_t v3 = seed + 0;		uint32_t v4 = seed - PRIME32_1; 		do {			v1 = xxh32_round(v1, get_unaligned_le32(p));			p += 4;			v2 = xxh32_round(v2, get_unaligned_le32(p));			p += 4;			v3 = xxh32_round(v3, get_unaligned_le32(p));			p += 4;			v4 = xxh32_round(v4, get_unaligned_le32(p));			p += 4;		} while (p <= limit); 		h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +			xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);	} else {		h32 = seed + PRIME32_5;	} 	h32 += (uint32_t)len; 	while (p + 4 <= b_end) {		h32 += get_unaligned_le32(p) * PRIME32_3;		h32 = xxh_rotl32(h32, 17) * PRIME32_4;		p += 4;	} 	while (p < b_end) {		h32 += (*p) * PRIME32_5;		h32 = xxh_rotl32(h32, 11) * PRIME32_1;		p++;	} 	h32 ^= h32 >> 15;	h32 *= PRIME32_2;	h32 ^= h32 >> 13;	h32 *= PRIME32_3;	h32 ^= h32 >> 16; 	return h32;}EXPORT_SYMBOL(xxh32); static uint64_t xxh64_round(uint64_t acc, const uint64_t input){	acc += input * PRIME64_2;	acc = xxh_rotl64(acc, 31);	acc *= PRIME64_1;	return acc;} static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val){	val = xxh64_round(0, val);	acc ^= val;	acc = acc * PRIME64_1 + PRIME64_4;	return acc;} uint64_t xxh64(const void *input, const size_t len, const uint64_t seed){	const uint8_t *p = (const uint8_t *)input;	const uint8_t *const b_end = p + len;	uint64_t h64; 	if (len >= 32) {		const uint8_t *const limit = b_end - 32;		uint64_t v1 = seed + PRIME64_1 + PRIME64_2;		uint64_t v2 = seed + PRIME64_2;		uint64_t v3 = seed + 0;		uint64_t v4 = seed - PRIME64_1; 		do {			v1 = xxh64_round(v1, get_unaligned_le64(p));			p += 8;			v2 = xxh64_round(v2, get_unaligned_le64(p));			p += 8;			v3 = xxh64_round(v3, get_unaligned_le64(p));			p += 8;			v4 = xxh64_round(v4, get_unaligned_le64(p));			p += 8;		} while (p <= limit); 		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);		h64 = xxh64_merge_round(h64, v1);		h64 = xxh64_merge_round(h64, v2);		h64 = xxh64_merge_round(h64, v3);		h64 = xxh64_merge_round(h64, v4); 	} else {		h64  = seed + PRIME64_5;	} 	h64 += (uint64_t)len; 	while (p + 8 <= b_end) {		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); 		h64 ^= k1;		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;		p += 8;	} 	if (p + 4 <= b_end) {		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;		p += 4;	} 	while (p < b_end) {		h64 ^= (*p) * PRIME64_5;		h64 = xxh_rotl64(h64, 11) * PRIME64_1;		p++;	} 	h64 ^= h64 >> 33;	h64 *= PRIME64_2;	h64 ^= h64 >> 29;	h64 *= PRIME64_3;	h64 ^= h64 >> 32; 	return h64;}EXPORT_SYMBOL(xxh64); /*-************************************************** * Advanced Hash Functions ***************************************************/void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed){	/* use a local state for memcpy() to avoid strict-aliasing warnings */	struct xxh64_state state; 	memset(&state, 0, sizeof(state));	state.v1 = seed + PRIME64_1 + PRIME64_2;	state.v2 = seed + PRIME64_2;	state.v3 = seed + 0;	state.v4 = seed - PRIME64_1;	memcpy(statePtr, &state, sizeof(state));}EXPORT_SYMBOL(xxh64_reset); int xxh64_update(struct xxh64_state *state, const void *input, const size_t len){	const uint8_t *p = (const uint8_t *)input;	const uint8_t *const b_end = p + len; 	if (input == NULL)		return -EINVAL; 	state->total_len += len; 	if (state->memsize + len < 32) { /* fill in tmp buffer */		memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);		state->memsize += (uint32_t)len;		return 0;	} 	if (state->memsize) { /* tmp buffer is full */		uint64_t *p64 = state->mem64; 		memcpy(((uint8_t *)p64) + state->memsize, input,			32 - state->memsize); 		state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));		p64++;		state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));		p64++;		state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));		p64++;		state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64)); 		p += 32 - state->memsize;		state->memsize = 0;	} 	if (p + 32 <= b_end) {		const uint8_t *const limit = b_end - 32;		uint64_t v1 = state->v1;		uint64_t v2 = state->v2;		uint64_t v3 = state->v3;		uint64_t v4 = state->v4; 		do {			v1 = xxh64_round(v1, get_unaligned_le64(p));			p += 8;			v2 = xxh64_round(v2, get_unaligned_le64(p));			p += 8;			v3 = xxh64_round(v3, get_unaligned_le64(p));			p += 8;			v4 = xxh64_round(v4, get_unaligned_le64(p));			p += 8;		} while (p <= limit); 		state->v1 = v1;		state->v2 = v2;		state->v3 = v3;		state->v4 = v4;	} 	if (p < b_end) {		memcpy(state->mem64, p, (size_t)(b_end-p));		state->memsize = (uint32_t)(b_end - p);	} 	return 0;}EXPORT_SYMBOL(xxh64_update); uint64_t xxh64_digest(const struct xxh64_state *state){	const uint8_t *p = (const uint8_t *)state->mem64;	const uint8_t *const b_end = (const uint8_t *)state->mem64 +		state->memsize;	uint64_t h64; 	if (state->total_len >= 32) {		const uint64_t v1 = state->v1;		const uint64_t v2 = state->v2;		const uint64_t v3 = state->v3;		const uint64_t v4 = state->v4; 		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);		h64 = xxh64_merge_round(h64, v1);		h64 = xxh64_merge_round(h64, v2);		h64 = xxh64_merge_round(h64, v3);		h64 = xxh64_merge_round(h64, v4);	} else {		h64  = state->v3 + PRIME64_5;	} 	h64 += (uint64_t)state->total_len; 	while (p + 8 <= b_end) {		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p)); 		h64 ^= k1;		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;		p += 8;	} 	if (p + 4 <= b_end) {		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;		p += 4;	} 	while (p < b_end) {		h64 ^= (*p) * PRIME64_5;		h64 = xxh_rotl64(h64, 11) * PRIME64_1;		p++;	} 	h64 ^= h64 >> 33;	h64 *= PRIME64_2;	h64 ^= h64 >> 29;	h64 *= PRIME64_3;	h64 ^= h64 >> 32; 	return h64;}EXPORT_SYMBOL(xxh64_digest); MODULE_LICENSE("Dual BSD/GPL");MODULE_DESCRIPTION("xxHash");