release/src-rt-6.x.4708/linux/linux-2.6.36/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  */
  10 extern __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  */
  16 extern __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  */
  37 extern __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
  56 extern __sum16 ip_compute_csum(const void *buff, int len);
  57
  58 /*
  59  *      Fold a partial checksum without adding pseudo headers
  60  */
  61
  62 static 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
  71 extern __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