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/*
* crc32.h for early Linux 2.4.19pre kernel inclusion
* This defines ether_crc_le() and ether_crc() as inline functions
* This is slated to change to using the library crc32 functions
* as kernel 2.5.2 included at some future date.
*/
#ifndef _LINUX_CRC32_H
#define _LINUX_CRC32_H
#include <linux/types.h>
/* The little-endian AUTODIN II ethernet CRC calculation.
N.B. Do not use for bulk data, use a table-based routine instead.
This is common code and should be moved to net/core/crc.c */
static unsigned const ethernet_polynomial_le = 0xedb88320U;
static inline unsigned ether_crc_le(int length, unsigned char *data)
{
unsigned int crc = 0xffffffff; /* Initial value. */
while(--length >= 0) {
unsigned char current_octet = *data++;
int bit;
for (bit = 8; --bit >= 0; current_octet >>= 1) {
if ((crc ^ current_octet) & 1) {
crc >>= 1;
crc ^= ethernet_polynomial_le;
} else
crc >>= 1;
}
}
return crc;
}
static unsigned const ethernet_polynomial = 0x04c11db7U;
static inline u32 ether_crc(int length, unsigned char *data)
{
int crc = -1;
while (--length >= 0) {
unsigned char current_octet = *data++;
int bit;
for (bit = 0; bit < 8; bit++, current_octet >>= 1) {
crc = (crc << 1) ^
((crc < 0) ^ (current_octet & 1) ?
ethernet_polynomial : 0);
}
}
return crc;
}
#endif /* _LINUX_CRC32_H */
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