include/asm-alpha/checksum.h

   1 #ifndef _ALPHA_CHECKSUM_H
   2 #define _ALPHA_CHECKSUM_H
   3
   4
   5 /*
   6  *      This is a version of ip_compute_csum() optimized for IP headers,
   7  *      which always checksum on 4 octet boundaries.
   8  */
   9 extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
  10
  11 /*
  12  * computes the checksum of the TCP/UDP pseudo-header
  13  * returns a 16-bit checksum, already complemented
  14  */
  15 extern unsigned short int csum_tcpudp_magic(unsigned long saddr,
  16                                            unsigned long daddr,
  17                                            unsigned short len,
  18                                            unsigned short proto,
  19                                            unsigned int sum);
  20
  21 unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
  22                                 unsigned short len, unsigned short proto,
  23                                 unsigned int 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 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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 unsigned int csum_partial_copy(const char *src, char *dst, int len, unsigned int sum);
  47
  48 /*
  49  * the same as csum_partial, but copies from user space (but on the alpha
  50  * we have just one address space, so this is identical to the above)
  51  *
  52  * this is obsolete and will go away.
  53  */
  54 #define csum_partial_copy_fromuser csum_partial_copy
  55
  56 /*
  57  * this is a new version of the above that records errors it finds in *errp,
  58  * but continues and zeros the rest of the buffer.
  59  */
  60 unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp);
  61
  62 unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum);
  63
  64
  65 /*
  66  * this routine is used for miscellaneous IP-like checksums, mainly
  67  * in icmp.c
  68  */
  69
  70 extern unsigned short ip_compute_csum(unsigned char * buff, int len);
  71
  72 /*
  73  *      Fold a partial checksum without adding pseudo headers
  74  */
  75
  76 static inline unsigned short csum_fold(unsigned int sum)
  77 {
  78         sum = (sum & 0xffff) + (sum >> 16);
  79         sum = (sum & 0xffff) + (sum >> 16);
  80         return ~sum;
  81 }
  82
  83 #define _HAVE_ARCH_IPV6_CSUM
  84 extern unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
  85                                           struct in6_addr *daddr,
  86                                           __u16 len,
  87                                           unsigned short proto,
  88                                           unsigned int sum);
  89
  90 #endif