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