LXR linux/arch/alpha/include/asm/checksum.h

   1#ifndef _ALPHA_CHECKSUM_H
   2#define _ALPHA_CHECKSUM_H
   3
   4#include <linux/in6.h>
   5
   6/*
   7 *      This is a version of ip_compute_csum() optimized for IP headers,
   8 *      which always checksum on 4 octet boundaries.
   9 */
  10extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  11
  12/*
  13 * computes the checksum of the TCP/UDP pseudo-header
  14 * returns a 16-bit checksum, already complemented
  15 */
  16extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  17                                           unsigned short len,
  18                                           unsigned short proto,
  19                                           __wsum sum);
  20
  21__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  22                                unsigned short len, unsigned short proto,
  23                                __wsum sum);
  24
  25/*
  26 * computes the checksum of a memory block at buff, length len,
  27 * and adds in "sum" (32-bit)
  28 *
  29 * returns a 32-bit number suitable for feeding into itself
  30 * or csum_tcpudp_magic
  31 *
  32 * this function must be called with even lengths, except
  33 * for the last fragment, which may be odd
  34 *
  35 * it's best to have buff aligned on a 32-bit boundary
  36 */
  37extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  38
  39/*
  40 * the same as csum_partial, but copies from src while it
  41 * checksums
  42 *
  43 * here even more important to align src and dst on a 32-bit (or even
  44 * better 64-bit) boundary
  45 */
  46__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
  47
  48__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
  49
  50
  51/*
  52 * this routine is used for miscellaneous IP-like checksums, mainly
  53 * in icmp.c
  54 */
  55
  56extern __sum16 ip_compute_csum(const void *buff, int len);
  57
  58/*
  59 *      Fold a partial checksum without adding pseudo headers
  60 */
  61
  62static inline __sum16 csum_fold(__wsum csum)
  63{
  64        u32 sum = (__force u32)csum;
  65        sum = (sum & 0xffff) + (sum >> 16);
  66        sum = (sum & 0xffff) + (sum >> 16);
  67        return (__force __sum16)~sum;
  68}
  69
  70#define _HAVE_ARCH_IPV6_CSUM
  71extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  72                               const struct in6_addr *daddr,
  73                               __u32 len, unsigned short proto,
  74                               __wsum sum);
  75#endif
  76