include/asm-ia64/checksum.h

   1 #ifndef _ASM_IA64_CHECKSUM_H
   2 #define _ASM_IA64_CHECKSUM_H
   3
   4 /*
   5  * Modified 1998, 1999
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
   7  */
   8
   9 /*
  10  * This is a version of ip_compute_csum() optimized for IP headers,
  11  * which always checksum on 4 octet boundaries.
  12  */
  13 extern unsigned short ip_fast_csum (unsigned char * iph, unsigned int ihl);
  14
  15 /*
  16  * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit
  17  * checksum, already complemented
  18  */
  19 extern unsigned short int csum_tcpudp_magic (unsigned long saddr,
  20                                              unsigned long daddr,
  21                                              unsigned short len,
  22                                              unsigned short proto,
  23                                              unsigned int sum);
  24
  25 extern unsigned int csum_tcpudp_nofold (unsigned long saddr,
  26                                         unsigned long daddr,
  27                                         unsigned short len,
  28                                         unsigned short proto,
  29                                         unsigned int sum);
  30
  31 /*
  32  * Computes the checksum of a memory block at buff, length len,
  33  * and adds in "sum" (32-bit)
  34  *
  35  * returns a 32-bit number suitable for feeding into itself
  36  * or csum_tcpudp_magic
  37  *
  38  * this function must be called with even lengths, except
  39  * for the last fragment, which may be odd
  40  *
  41  * it's best to have buff aligned on a 32-bit boundary
  42  */
  43 extern unsigned int csum_partial (const unsigned char * buff, int len,
  44                                   unsigned int sum);
  45
  46 /*
  47  * Same as csum_partial, but copies from src while it checksums.
  48  *
  49  * Here it is even more important to align src and dst on a 32-bit (or
  50  * even better 64-bit) boundary.
  51  */
  52 extern unsigned int csum_partial_copy_from_user (const char *src, char *dst,
  53                                                  int len, unsigned int sum,
  54                                                  int *errp);
  55
  56 extern unsigned int csum_partial_copy_nocheck (const char *src, char *dst,
  57                                                int len, unsigned int sum);
  58
  59 /*
  60  * This routine is used for miscellaneous IP-like checksums, mainly in
  61  * icmp.c
  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 static inline unsigned short
  69 csum_fold (unsigned int sum)
  70 {
  71         sum = (sum & 0xffff) + (sum >> 16);
  72         sum = (sum & 0xffff) + (sum >> 16);
  73         return ~sum;
  74 }
  75
  76 #endif /* _ASM_IA64_CHECKSUM_H */