include/asm-sh/checksum.h

   1 #ifndef __ASM_SH_CHECKSUM_H
   2 #define __ASM_SH_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 /*
  22  * computes the checksum of a memory block at buff, length len,
  23  * and adds in "sum" (32-bit)
  24  *
  25  * returns a 32-bit number suitable for feeding into itself
  26  * or csum_tcpudp_magic
  27  *
  28  * this function must be called with even lengths, except
  29  * for the last fragment, which may be odd
  30  *
  31  * it's best to have buff aligned on a 32-bit boundary
  32  */
  33 extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
  34
  35 /*
  36  * the same as csum_partial, but copies from src while it
  37  * checksums
  38  *
  39  * here even more important to align src and dst on a 32-bit (or even
  40  * better 64-bit) boundary
  41  */
  42 unsigned int csum_partial_copy(const char *src, char *dst, int len, unsigned int sum);
  43
  44 /*
  45  * the same as csum_partial, but copies from user space (but on the alpha
  46  * we have just one address space, so this is identical to the above)
  47  *
  48  * this is obsolete and will go away.
  49  */
  50 #define csum_partial_copy_fromuser csum_partial_copy
  51
  52 /*
  53  * this is a new version of the above that records errors it finds in *errp,
  54  * but continues and zeros the rest of the buffer.
  55  */
  56 unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp);
  57
  58 /*
  59  * this routine is used for miscellaneous IP-like checksums, mainly
  60  * in icmp.c
  61  */
  62
  63 extern unsigned short ip_compute_csum(unsigned char * buff, int len);
  64
  65 /*
  66  *      Fold a partial checksum without adding pseudo headers
  67  */
  68
  69 static inline unsigned short csum_fold(unsigned int sum)
  70 {
  71         sum = (sum & 0xffff) + (sum >> 16);
  72         sum = (sum & 0xffff) + (sum >> 16);
  73         return ~sum;
  74 }
  75
  76 #define _HAVE_ARCH_IPV6_CSUM
  77 /*
  78 extern unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
  79                                           struct in6_addr *daddr,
  80                                           __u16 len,
  81                                           unsigned short proto,
  82                                           unsigned int sum);
  83 */
  84 #endif /* __ASM_SH_CHECKSUM_H */