Subversion Repositories or1k

#ifndef _ALPHA_CHECKSUM_H

#define _ALPHA_CHECKSUM_H

/*

 *      This is a version of ip_compute_csum() optimized for IP headers,

 *      which always checksum on 4 octet boundaries.

 */

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

/*

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

 * returns a 16-bit checksum, already complemented

 */

extern unsigned short int csum_tcpudp_magic(unsigned long saddr,

                                           unsigned long daddr,

                                           unsigned short len,

                                           unsigned short proto,

                                           unsigned int sum);

/*

 * 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

 */

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

/*

 * the same as csum_partial, 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, but copies from user space (but on the alpha

 * we have just one address space, so this is identical to the above)

 */

#define csum_partial_copy_fromuser csum_partial_copy

/*

 * this routine is used for miscellaneous IP-like checksums, mainly

 * in icmp.c

 */

extern unsigned short ip_compute_csum(unsigned char * buff, int len);

/*

 *      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;

}

#endif