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
  10 extern u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
  11 extern u32  crc32_be(u32 crc, unsigned char const *p, size_t len);
  12 extern u32  bitreverse(u32 in);
  13
  14 #define crc32(seed, data, length)  crc32_le(seed, (unsigned char const *)data, length)
  15
  16 /*
  17  * Helpers for hash table generation of ethernet nics:
  18  *
  19  * Ethernet sends the least significant bit of a byte first, thus crc32_le
  20  * is used. The output of crc32_le is bit reversed [most significant bit
  21  * is in bit nr 0], thus it must be reversed before use. Except for
  22  * nics that bit swap the result internally...
  23  */
  24 #define ether_crc(length, data)    bitreverse(crc32_le(~0, data, length))
  25 #define ether_crc_le(length, data) crc32_le(~0, data, length)
  26
  27 #endif /* _LINUX_CRC32_H */