crc32.h (2894B)
1/* 2 * crc32.h 3 * See linux/lib/crc32.c for license and changes 4 */ 5#ifndef _LINUX_CRC32_H 6#define _LINUX_CRC32_H 7 8#include <linux/types.h> 9#include <linux/bitrev.h> 10 11u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len); 12u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len); 13 14/** 15 * crc32_le_combine - Combine two crc32 check values into one. For two 16 * sequences of bytes, seq1 and seq2 with lengths len1 17 * and len2, crc32_le() check values were calculated 18 * for each, crc1 and crc2. 19 * 20 * @crc1: crc32 of the first block 21 * @crc2: crc32 of the second block 22 * @len2: length of the second block 23 * 24 * Return: The crc32_le() check value of seq1 and seq2 concatenated, 25 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 26 * the concatenated memory area of seq1 with seq2, and crc_full 27 * the crc32_le() value of seq_full, then crc_full == 28 * crc32_le_combine(crc1, crc2, len2) when crc_full was seeded 29 * with the same initializer as crc1, and crc2 seed was 0. See 30 * also crc32_combine_test(). 31 */ 32u32 __attribute_const__ crc32_le_shift(u32 crc, size_t len); 33 34static inline u32 crc32_le_combine(u32 crc1, u32 crc2, size_t len2) 35{ 36 return crc32_le_shift(crc1, len2) ^ crc2; 37} 38 39u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len); 40 41/** 42 * __crc32c_le_combine - Combine two crc32c check values into one. For two 43 * sequences of bytes, seq1 and seq2 with lengths len1 44 * and len2, __crc32c_le() check values were calculated 45 * for each, crc1 and crc2. 46 * 47 * @crc1: crc32c of the first block 48 * @crc2: crc32c of the second block 49 * @len2: length of the second block 50 * 51 * Return: The __crc32c_le() check value of seq1 and seq2 concatenated, 52 * requiring only crc1, crc2, and len2. Note: If seq_full denotes 53 * the concatenated memory area of seq1 with seq2, and crc_full 54 * the __crc32c_le() value of seq_full, then crc_full == 55 * __crc32c_le_combine(crc1, crc2, len2) when crc_full was 56 * seeded with the same initializer as crc1, and crc2 seed 57 * was 0. See also crc32c_combine_test(). 58 */ 59u32 __attribute_const__ __crc32c_le_shift(u32 crc, size_t len); 60 61static inline u32 __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2) 62{ 63 return __crc32c_le_shift(crc1, len2) ^ crc2; 64} 65 66#define crc32(seed, data, length) crc32_le(seed, (unsigned char const *)(data), length) 67 68/* 69 * Helpers for hash table generation of ethernet nics: 70 * 71 * Ethernet sends the least significant bit of a byte first, thus crc32_le 72 * is used. The output of crc32_le is bit reversed [most significant bit 73 * is in bit nr 0], thus it must be reversed before use. Except for 74 * nics that bit swap the result internally... 75 */ 76#define ether_crc(length, data) bitrev32(crc32_le(~0, data, length)) 77#define ether_crc_le(length, data) crc32_le(~0, data, length) 78 79#endif /* _LINUX_CRC32_H */