include/linux/crc32.h

   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
  11 extern u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
  12 extern u32  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  */
  32 extern u32  crc32_le_combine(u32 crc1, u32 crc2, size_t len2);
  33
  34 extern u32  __crc32c_le(u32 crc, unsigned char const *p, size_t len);
  35
  36 /**
  37  * __crc32c_le_combine - Combine two crc32c check values into one. For two
  38  *                       sequences of bytes, seq1 and seq2 with lengths len1
  39  *                       and len2, __crc32c_le() check values were calculated
  40  *                       for each, crc1 and crc2.
  41  *
  42  * @crc1: crc32c of the first block
  43  * @crc2: crc32c of the second block
  44  * @len2: length of the second block
  45  *
  46  * Return: The __crc32c_le() check value of seq1 and seq2 concatenated,
  47  *         requiring only crc1, crc2, and len2. Note: If seq_full denotes
  48  *         the concatenated memory area of seq1 with seq2, and crc_full
  49  *         the __crc32c_le() value of seq_full, then crc_full ==
  50  *         __crc32c_le_combine(crc1, crc2, len2) when crc_full was
  51  *         seeded with the same initializer as crc1, and crc2 seed
  52  *         was 0. See also crc32c_combine_test().
  53  */
  54 extern u32  __crc32c_le_combine(u32 crc1, u32 crc2, size_t len2);
  55
  56 #define crc32(seed, data, length)  crc32_le(seed, (unsigned char const *)(data), length)
  57
  58 /*
  59  * Helpers for hash table generation of ethernet nics:
  60  *
  61  * Ethernet sends the least significant bit of a byte first, thus crc32_le
  62  * is used. The output of crc32_le is bit reversed [most significant bit
  63  * is in bit nr 0], thus it must be reversed before use. Except for
  64  * nics that bit swap the result internally...
  65  */
  66 #define ether_crc(length, data)    bitrev32(crc32_le(~0, data, length))
  67 #define ether_crc_le(length, data) crc32_le(~0, data, length)
  68
  69 #endif /* _LINUX_CRC32_H */