root/arch/ia64/include/asm/checksum.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. csum_fold

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_IA64_CHECKSUM_H
   3 #define _ASM_IA64_CHECKSUM_H
   4 
   5 /*
   6  * Modified 1998, 1999
   7  *      David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
   8  */
   9 
  10 /*
  11  * This is a version of ip_compute_csum() optimized for IP headers,
  12  * which always checksum on 4 octet boundaries.
  13  */
  14 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  15 
  16 /*
  17  * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit
  18  * checksum, already complemented
  19  */
  20 extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  21                                  __u32 len, __u8 proto, __wsum sum);
  22 
  23 extern __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  24                                  __u32 len, __u8 proto, __wsum 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 __wsum csum_partial(const void *buff, int len, __wsum sum);
  39 
  40 /*
  41  * Same as csum_partial, but copies from src while it checksums.
  42  *
  43  * Here it is even more important to align src and dst on a 32-bit (or
  44  * even better 64-bit) boundary.
  45  */
  46 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  47                                                  int len, __wsum sum,
  48                                                  int *errp);
  49 
  50 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  51                                                int len, __wsum sum);
  52 
  53 /*
  54  * This routine is used for miscellaneous IP-like checksums, mainly in
  55  * icmp.c
  56  */
  57 extern __sum16 ip_compute_csum(const void *buff, int len);
  58 
  59 /*
  60  * Fold a partial checksum without adding pseudo headers.
  61  */
  62 static inline __sum16 csum_fold(__wsum csum)
  63 {
  64         u32 sum = (__force u32)csum;
  65         sum = (sum & 0xffff) + (sum >> 16);
  66         sum = (sum & 0xffff) + (sum >> 16);
  67         return (__force __sum16)~sum;
  68 }
  69 
  70 #define _HAVE_ARCH_IPV6_CSUM    1
  71 struct in6_addr;
  72 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
  73                                const struct in6_addr *daddr,
  74                                __u32 len, __u8 proto, __wsum csum);
  75 
  76 #endif /* _ASM_IA64_CHECKSUM_H */

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