include/asm-sh64/checksum.h

   1 #ifndef __ASM_SH64_CHECKSUM_H
   2 #define __ASM_SH64_CHECKSUM_H
   3
   4 /*
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  *
   9  * include/asm-sh64/checksum.h
  10  *
  11  * Copyright (C) 2000, 2001  Paolo Alberelli
  12  *
  13  */
  14
  15 #include <asm/registers.h>
  16
  17 /*
  18  * computes the checksum of a memory block at buff, length len,
  19  * and adds in "sum" (32-bit)
  20  *
  21  * returns a 32-bit number suitable for feeding into itself
  22  * or csum_tcpudp_magic
  23  *
  24  * this function must be called with even lengths, except
  25  * for the last fragment, which may be odd
  26  *
  27  * it's best to have buff aligned on a 32-bit boundary
  28  */
  29 asmlinkage unsigned int csum_partial(const unsigned char *buff, int len,
  30                                      unsigned int sum);
  31
  32 /*
  33  *      Note: when you get a NULL pointer exception here this means someone
  34  *      passed in an incorrect kernel address to one of these functions.
  35  *
  36  *      If you use these functions directly please don't forget the
  37  *      access_ok().
  38  */
  39
  40
  41 unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len,
  42                                        unsigned int sum);
  43
  44 unsigned int csum_partial_copy_from_user(const char *src, char *dst,
  45                                          int len, int sum, int *err_ptr);
  46
  47 /*
  48  * These are the old (and unsafe) way of doing checksums, a warning message will be
  49  * printed if they are used and an exeption occurs.
  50  *
  51  * these functions should go away after some time.
  52  */
  53
  54 #define csum_partial_copy_fromuser csum_partial_copy
  55
  56 unsigned int csum_partial_copy(const char *src, char *dst, int len,
  57                                unsigned int sum);
  58
  59 static inline unsigned short csum_fold(unsigned int sum)
  60 {
  61         sum = (sum & 0xffff) + (sum >> 16);
  62         sum = (sum & 0xffff) + (sum >> 16);
  63         return ~(sum);
  64 }
  65
  66 unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
  67
  68 unsigned long csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
  69                                  unsigned short len, unsigned short proto,
  70                                  unsigned int sum);
  71
  72 /*
  73  * computes the checksum of the TCP/UDP pseudo-header
  74  * returns a 16-bit checksum, already complemented
  75  */
  76 static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
  77                                                    unsigned long daddr,
  78                                                    unsigned short len,
  79                                                    unsigned short proto,
  80                                                    unsigned int sum)
  81 {
  82         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  83 }
  84
  85 /*
  86  * this routine is used for miscellaneous IP-like checksums, mainly
  87  * in icmp.c
  88  */
  89 static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
  90 {
  91         return csum_fold(csum_partial(buff, len, 0));
  92 }
  93
  94 #endif /* __ASM_SH64_CHECKSUM_H */
  95