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#ifndef _OR32_CHECKSUM_H

#define _OR32_CHECKSUM_H

#include <linux/config.h>

/*

 * computes the checksum of a memory block at buff, length len,

 * and adds in "sum" (32-bit)

 *

 * returns a 32-bit number suitable for feeding into itself

 * or csum_tcpudp_magic

 *

 * this function must be called with even lengths, except

 * for the last fragment, which may be odd

 *

 * it's best to have buff aligned on a 32-bit boundary

 */

unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);

/*

 * the same as csum_partial_copy, but copies from src while it

 * checksums

 *

 * here even more important to align src and dst on a 32-bit (or even

 * better 64-bit) boundary

 */

unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);

/*

 * the same as csum_partial_copy, but copies from user space.

 *

 * here even more important to align src and dst on a 32-bit (or even

 * better 64-bit) boundary

 */

unsigned int csum_partial_copy_fromuser(const char *src, char *dst, int len, int sum);

unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl);

/*

 *      Fold a partial checksum without adding pseudo headers

 */

static inline unsigned short

csum_fold(unsigned int sum)

{

        sum = (sum & 0xffff) + (sum >> 16);

        sum = (sum & 0xffff) + (sum >> 16);

        return ~sum;

}

/*

 * computes the checksum of the TCP/UDP pseudo-header

 * returns a 16-bit checksum, already complemented

 */

static inline unsigned short int

csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,

                  unsigned short proto, unsigned int sum)

{

        unsigned long result = saddr;

        result += daddr;

        result += (daddr > result);

        result += len;

        result += (len > result);

        result += proto;

        result += (proto > result);

        result += sum;

        result += (sum > result);

        result = (result >> 16) + (result & 0xffff);

        result = (result >> 16) + (result & 0xffff);

        return ~result;

}

extern unsigned short

ip_compute_csum(const unsigned char * buff, int len);

#endif /* _OR32_CHECKSUM_H */