1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2018 Netronome Systems, Inc.
3 * All rights reserved.
4 */
5
6 #include <stdio.h>
7 #include <inttypes.h>
8
9 #include "nfp_crc.h"
10
11 static inline uint32_t
nfp_crc32_be_generic(uint32_t crc,unsigned char const * p,size_t len,uint32_t polynomial)12 nfp_crc32_be_generic(uint32_t crc, unsigned char const *p, size_t len,
13 uint32_t polynomial)
14 {
15 int i;
16 while (len--) {
17 crc ^= *p++ << 24;
18 for (i = 0; i < 8; i++)
19 crc = (crc << 1) ^ ((crc & 0x80000000) ? polynomial :
20 0);
21 }
22 return crc;
23 }
24
25 static inline uint32_t
nfp_crc32_be(uint32_t crc,unsigned char const * p,size_t len)26 nfp_crc32_be(uint32_t crc, unsigned char const *p, size_t len)
27 {
28 return nfp_crc32_be_generic(crc, p, len, CRCPOLY_BE);
29 }
30
31 static uint32_t
nfp_crc32_posix_end(uint32_t crc,size_t total_len)32 nfp_crc32_posix_end(uint32_t crc, size_t total_len)
33 {
34 /* Extend with the length of the string. */
35 while (total_len != 0) {
36 uint8_t c = total_len & 0xff;
37
38 crc = nfp_crc32_be(crc, &c, 1);
39 total_len >>= 8;
40 }
41
42 return ~crc;
43 }
44
45 uint32_t
nfp_crc32_posix(const void * buff,size_t len)46 nfp_crc32_posix(const void *buff, size_t len)
47 {
48 return nfp_crc32_posix_end(nfp_crc32_be(0, buff, len), len);
49 }
50