Subversion Repositories or1k

/*

 * based on ppc, cris

 *

 *

 */

#ifdef __KERNEL__

#ifndef _OR32_CHECKSUM_H

#define _OR32_CHECKSUM_H

#include <asm/spr_defs.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

 */

extern unsigned int csum_partial(const unsigned char * buff, int len,

                                 unsigned int sum);

/*

 * Computes the checksum of a memory block at src, length len,

 * and adds in "sum" (32-bit), while copying the block to dst.

 * If an access exception occurs on src or dst, it stores -EFAULT

 * to *src_err or *dst_err respectively (if that pointer is not

 * NULL), and, for an error on src, zeroes the rest of dst.

 *

 * Like csum_partial, this must be called with even lengths,

 * except for the last fragment.

 */

unsigned int csum_partial_copy_from_user (const char *src, char *dst,

                                          int len, unsigned int sum,

                                          int *err_ptr);

unsigned int csum_partial_copy_nocheck(const char *src, char *dst,

                                       int len, unsigned int sum);

/*

 * Old versions which ignore errors.

 */

#define csum_partial_copy(src, dst, len, sum)   \

        csum_partial_copy_nocheck((src), (dst), (len), (sum))

/*

 * turns a 32-bit partial checksum (e.g. from csum_partial) into a

 * 1's complement 16-bit checksum.

 */

static inline unsigned int csum_fold(unsigned int sum)

{

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

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

        return ~sum;

}

static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,

                                               unsigned long daddr,

                                               unsigned short len,

                                               unsigned short proto,

                                               unsigned int sum)

{

        sum += saddr;

        sum += (saddr > sum) ? 1 : 0;

        sum += daddr;

        sum += (daddr > sum) ? 1 : 0;

        sum += ((proto<<16)+len);

        sum += (((proto<<16)+len) > sum) ? 1 : 0;

        return sum;

}

/*

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

 *  which always checksum on 4 octet boundaries.

 */

static inline unsigned short ip_fast_csum(unsigned char * iph,

                                          unsigned int ihl)

{

        return csum_fold(csum_partial(iph, ihl * 4, 0));

}

/*

 * 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)

{

        return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));

}

/*

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

 * in icmp.c

 */

static inline unsigned short ip_compute_csum(unsigned char * buff, int len)

{

        return csum_fold (csum_partial(buff, len, 0));

}

#endif /* __KERNEL__ */

#endif /* _OR32_CHECKSUM_H */