1/*
2 * xxHash - Extremely Fast Hash algorithm
3 * Copyright (C) 2012-2016, Yann Collet.
4 *
5 * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
11 *   * Redistributions of source code must retain the above copyright
12 *     notice, this list of conditions and the following disclaimer.
13 *   * Redistributions in binary form must reproduce the above
14 *     copyright notice, this list of conditions and the following disclaimer
15 *     in the documentation and/or other materials provided with the
16 *     distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * This program is free software; you can redistribute it and/or modify it under
31 * the terms of the GNU General Public License version 2 as published by the
32 * Free Software Foundation. This program is dual-licensed; you may select
33 * either version 2 of the GNU General Public License ("GPL") or BSD license
34 * ("BSD").
35 *
36 * You can contact the author at:
37 * - xxHash homepage: https://cyan4973.github.io/xxHash/
38 * - xxHash source repository: https://github.com/Cyan4973/xxHash
39 */
40
41#include <asm/unaligned.h>
42#include <linux/errno.h>
43#include <linux/compiler.h>
44#include <linux/kernel.h>
45#include <linux/module.h>
46#include <linux/string.h>
47#include <linux/xxhash.h>
48
49/*-*************************************
50 * Macros
51 **************************************/
52#define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r)))
53#define xxh_rotl64(x, r) ((x << r) | (x >> (64 - r)))
54
55#ifdef __LITTLE_ENDIAN
56# define XXH_CPU_LITTLE_ENDIAN 1
57#else
58# define XXH_CPU_LITTLE_ENDIAN 0
59#endif
60
61/*-*************************************
62 * Constants
63 **************************************/
64static const uint32_t PRIME32_1 = 2654435761U;
65static const uint32_t PRIME32_2 = 2246822519U;
66static const uint32_t PRIME32_3 = 3266489917U;
67static const uint32_t PRIME32_4 =  668265263U;
68static const uint32_t PRIME32_5 =  374761393U;
69
70static const uint64_t PRIME64_1 = 11400714785074694791ULL;
71static const uint64_t PRIME64_2 = 14029467366897019727ULL;
72static const uint64_t PRIME64_3 =  1609587929392839161ULL;
73static const uint64_t PRIME64_4 =  9650029242287828579ULL;
74static const uint64_t PRIME64_5 =  2870177450012600261ULL;
75
76/*-**************************
77 *  Utils
78 ***************************/
79void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src)
80{
81	memcpy(dst, src, sizeof(*dst));
82}
83EXPORT_SYMBOL(xxh32_copy_state);
84
85void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src)
86{
87	memcpy(dst, src, sizeof(*dst));
88}
89EXPORT_SYMBOL(xxh64_copy_state);
90
91/*-***************************
92 * Simple Hash Functions
93 ****************************/
94static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
95{
96	seed += input * PRIME32_2;
97	seed = xxh_rotl32(seed, 13);
98	seed *= PRIME32_1;
99	return seed;
100}
101
102uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
103{
104	const uint8_t *p = (const uint8_t *)input;
105	const uint8_t *b_end = p + len;
106	uint32_t h32;
107
108	if (len >= 16) {
109		const uint8_t *const limit = b_end - 16;
110		uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
111		uint32_t v2 = seed + PRIME32_2;
112		uint32_t v3 = seed + 0;
113		uint32_t v4 = seed - PRIME32_1;
114
115		do {
116			v1 = xxh32_round(v1, get_unaligned_le32(p));
117			p += 4;
118			v2 = xxh32_round(v2, get_unaligned_le32(p));
119			p += 4;
120			v3 = xxh32_round(v3, get_unaligned_le32(p));
121			p += 4;
122			v4 = xxh32_round(v4, get_unaligned_le32(p));
123			p += 4;
124		} while (p <= limit);
125
126		h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
127			xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
128	} else {
129		h32 = seed + PRIME32_5;
130	}
131
132	h32 += (uint32_t)len;
133
134	while (p + 4 <= b_end) {
135		h32 += get_unaligned_le32(p) * PRIME32_3;
136		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
137		p += 4;
138	}
139
140	while (p < b_end) {
141		h32 += (*p) * PRIME32_5;
142		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
143		p++;
144	}
145
146	h32 ^= h32 >> 15;
147	h32 *= PRIME32_2;
148	h32 ^= h32 >> 13;
149	h32 *= PRIME32_3;
150	h32 ^= h32 >> 16;
151
152	return h32;
153}
154EXPORT_SYMBOL(xxh32);
155
156static uint64_t xxh64_round(uint64_t acc, const uint64_t input)
157{
158	acc += input * PRIME64_2;
159	acc = xxh_rotl64(acc, 31);
160	acc *= PRIME64_1;
161	return acc;
162}
163
164static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val)
165{
166	val = xxh64_round(0, val);
167	acc ^= val;
168	acc = acc * PRIME64_1 + PRIME64_4;
169	return acc;
170}
171
172uint64_t xxh64(const void *input, const size_t len, const uint64_t seed)
173{
174	const uint8_t *p = (const uint8_t *)input;
175	const uint8_t *const b_end = p + len;
176	uint64_t h64;
177
178	if (len >= 32) {
179		const uint8_t *const limit = b_end - 32;
180		uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
181		uint64_t v2 = seed + PRIME64_2;
182		uint64_t v3 = seed + 0;
183		uint64_t v4 = seed - PRIME64_1;
184
185		do {
186			v1 = xxh64_round(v1, get_unaligned_le64(p));
187			p += 8;
188			v2 = xxh64_round(v2, get_unaligned_le64(p));
189			p += 8;
190			v3 = xxh64_round(v3, get_unaligned_le64(p));
191			p += 8;
192			v4 = xxh64_round(v4, get_unaligned_le64(p));
193			p += 8;
194		} while (p <= limit);
195
196		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
197			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
198		h64 = xxh64_merge_round(h64, v1);
199		h64 = xxh64_merge_round(h64, v2);
200		h64 = xxh64_merge_round(h64, v3);
201		h64 = xxh64_merge_round(h64, v4);
202
203	} else {
204		h64  = seed + PRIME64_5;
205	}
206
207	h64 += (uint64_t)len;
208
209	while (p + 8 <= b_end) {
210		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));
211
212		h64 ^= k1;
213		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
214		p += 8;
215	}
216
217	if (p + 4 <= b_end) {
218		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
219		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
220		p += 4;
221	}
222
223	while (p < b_end) {
224		h64 ^= (*p) * PRIME64_5;
225		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
226		p++;
227	}
228
229	h64 ^= h64 >> 33;
230	h64 *= PRIME64_2;
231	h64 ^= h64 >> 29;
232	h64 *= PRIME64_3;
233	h64 ^= h64 >> 32;
234
235	return h64;
236}
237EXPORT_SYMBOL(xxh64);
238
239/*-**************************************************
240 * Advanced Hash Functions
241 ***************************************************/
242void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
243{
244	/* use a local state for memcpy() to avoid strict-aliasing warnings */
245	struct xxh32_state state;
246
247	memset(&state, 0, sizeof(state));
248	state.v1 = seed + PRIME32_1 + PRIME32_2;
249	state.v2 = seed + PRIME32_2;
250	state.v3 = seed + 0;
251	state.v4 = seed - PRIME32_1;
252	memcpy(statePtr, &state, sizeof(state));
253}
254EXPORT_SYMBOL(xxh32_reset);
255
256void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
257{
258	/* use a local state for memcpy() to avoid strict-aliasing warnings */
259	struct xxh64_state state;
260
261	memset(&state, 0, sizeof(state));
262	state.v1 = seed + PRIME64_1 + PRIME64_2;
263	state.v2 = seed + PRIME64_2;
264	state.v3 = seed + 0;
265	state.v4 = seed - PRIME64_1;
266	memcpy(statePtr, &state, sizeof(state));
267}
268EXPORT_SYMBOL(xxh64_reset);
269
270int xxh32_update(struct xxh32_state *state, const void *input, const size_t len)
271{
272	const uint8_t *p = (const uint8_t *)input;
273	const uint8_t *const b_end = p + len;
274
275	if (input == NULL)
276		return -EINVAL;
277
278	state->total_len_32 += (uint32_t)len;
279	state->large_len |= (len >= 16) | (state->total_len_32 >= 16);
280
281	if (state->memsize + len < 16) { /* fill in tmp buffer */
282		memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
283		state->memsize += (uint32_t)len;
284		return 0;
285	}
286
287	if (state->memsize) { /* some data left from previous update */
288		const uint32_t *p32 = state->mem32;
289
290		memcpy((uint8_t *)(state->mem32) + state->memsize, input,
291			16 - state->memsize);
292
293		state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
294		p32++;
295		state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
296		p32++;
297		state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
298		p32++;
299		state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
300		p32++;
301
302		p += 16-state->memsize;
303		state->memsize = 0;
304	}
305
306	if (p <= b_end - 16) {
307		const uint8_t *const limit = b_end - 16;
308		uint32_t v1 = state->v1;
309		uint32_t v2 = state->v2;
310		uint32_t v3 = state->v3;
311		uint32_t v4 = state->v4;
312
313		do {
314			v1 = xxh32_round(v1, get_unaligned_le32(p));
315			p += 4;
316			v2 = xxh32_round(v2, get_unaligned_le32(p));
317			p += 4;
318			v3 = xxh32_round(v3, get_unaligned_le32(p));
319			p += 4;
320			v4 = xxh32_round(v4, get_unaligned_le32(p));
321			p += 4;
322		} while (p <= limit);
323
324		state->v1 = v1;
325		state->v2 = v2;
326		state->v3 = v3;
327		state->v4 = v4;
328	}
329
330	if (p < b_end) {
331		memcpy(state->mem32, p, (size_t)(b_end-p));
332		state->memsize = (uint32_t)(b_end-p);
333	}
334
335	return 0;
336}
337EXPORT_SYMBOL(xxh32_update);
338
339uint32_t xxh32_digest(const struct xxh32_state *state)
340{
341	const uint8_t *p = (const uint8_t *)state->mem32;
342	const uint8_t *const b_end = (const uint8_t *)(state->mem32) +
343		state->memsize;
344	uint32_t h32;
345
346	if (state->large_len) {
347		h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
348			xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
349	} else {
350		h32 = state->v3 /* == seed */ + PRIME32_5;
351	}
352
353	h32 += state->total_len_32;
354
355	while (p + 4 <= b_end) {
356		h32 += get_unaligned_le32(p) * PRIME32_3;
357		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
358		p += 4;
359	}
360
361	while (p < b_end) {
362		h32 += (*p) * PRIME32_5;
363		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
364		p++;
365	}
366
367	h32 ^= h32 >> 15;
368	h32 *= PRIME32_2;
369	h32 ^= h32 >> 13;
370	h32 *= PRIME32_3;
371	h32 ^= h32 >> 16;
372
373	return h32;
374}
375EXPORT_SYMBOL(xxh32_digest);
376
377int xxh64_update(struct xxh64_state *state, const void *input, const size_t len)
378{
379	const uint8_t *p = (const uint8_t *)input;
380	const uint8_t *const b_end = p + len;
381
382	if (input == NULL)
383		return -EINVAL;
384
385	state->total_len += len;
386
387	if (state->memsize + len < 32) { /* fill in tmp buffer */
388		memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);
389		state->memsize += (uint32_t)len;
390		return 0;
391	}
392
393	if (state->memsize) { /* tmp buffer is full */
394		uint64_t *p64 = state->mem64;
395
396		memcpy(((uint8_t *)p64) + state->memsize, input,
397			32 - state->memsize);
398
399		state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));
400		p64++;
401		state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));
402		p64++;
403		state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));
404		p64++;
405		state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64));
406
407		p += 32 - state->memsize;
408		state->memsize = 0;
409	}
410
411	if (p + 32 <= b_end) {
412		const uint8_t *const limit = b_end - 32;
413		uint64_t v1 = state->v1;
414		uint64_t v2 = state->v2;
415		uint64_t v3 = state->v3;
416		uint64_t v4 = state->v4;
417
418		do {
419			v1 = xxh64_round(v1, get_unaligned_le64(p));
420			p += 8;
421			v2 = xxh64_round(v2, get_unaligned_le64(p));
422			p += 8;
423			v3 = xxh64_round(v3, get_unaligned_le64(p));
424			p += 8;
425			v4 = xxh64_round(v4, get_unaligned_le64(p));
426			p += 8;
427		} while (p <= limit);
428
429		state->v1 = v1;
430		state->v2 = v2;
431		state->v3 = v3;
432		state->v4 = v4;
433	}
434
435	if (p < b_end) {
436		memcpy(state->mem64, p, (size_t)(b_end-p));
437		state->memsize = (uint32_t)(b_end - p);
438	}
439
440	return 0;
441}
442EXPORT_SYMBOL(xxh64_update);
443
444uint64_t xxh64_digest(const struct xxh64_state *state)
445{
446	const uint8_t *p = (const uint8_t *)state->mem64;
447	const uint8_t *const b_end = (const uint8_t *)state->mem64 +
448		state->memsize;
449	uint64_t h64;
450
451	if (state->total_len >= 32) {
452		const uint64_t v1 = state->v1;
453		const uint64_t v2 = state->v2;
454		const uint64_t v3 = state->v3;
455		const uint64_t v4 = state->v4;
456
457		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
458			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
459		h64 = xxh64_merge_round(h64, v1);
460		h64 = xxh64_merge_round(h64, v2);
461		h64 = xxh64_merge_round(h64, v3);
462		h64 = xxh64_merge_round(h64, v4);
463	} else {
464		h64  = state->v3 + PRIME64_5;
465	}
466
467	h64 += (uint64_t)state->total_len;
468
469	while (p + 8 <= b_end) {
470		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));
471
472		h64 ^= k1;
473		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
474		p += 8;
475	}
476
477	if (p + 4 <= b_end) {
478		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
479		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
480		p += 4;
481	}
482
483	while (p < b_end) {
484		h64 ^= (*p) * PRIME64_5;
485		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
486		p++;
487	}
488
489	h64 ^= h64 >> 33;
490	h64 *= PRIME64_2;
491	h64 ^= h64 >> 29;
492	h64 *= PRIME64_3;
493	h64 ^= h64 >> 32;
494
495	return h64;
496}
497EXPORT_SYMBOL(xxh64_digest);
498
499MODULE_LICENSE("Dual BSD/GPL");
500MODULE_DESCRIPTION("xxHash");
501