1/*
2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
3 *		operating system.  INET is implemented using the  BSD Socket
4 *		interface as the means of communication with the user level.
5 *
6 *		Checksumming functions for IPv6
7 *
8 * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
9 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
10 *		Borrows very liberally from tcp.c and ip.c, see those
11 *		files for more names.
12 *
13 *		This program is free software; you can redistribute it and/or
14 *		modify it under the terms of the GNU General Public License
15 *		as published by the Free Software Foundation; either version
16 *		2 of the License, or (at your option) any later version.
17 */
18
19/*
20 *	Fixes:
21 *
22 *	Ralf Baechle			:	generic ipv6 checksum
23 *	<ralf@waldorf-gmbh.de>
24 */
25
26#ifndef _CHECKSUM_IPV6_H
27#define _CHECKSUM_IPV6_H
28
29#include <asm/types.h>
30#include <asm/byteorder.h>
31#include <net/ip.h>
32#include <asm/checksum.h>
33#include <linux/in6.h>
34
35#ifndef _HAVE_ARCH_IPV6_CSUM
36
37static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
38					  const struct in6_addr *daddr,
39					  __u32 len, unsigned short proto,
40					  __wsum csum)
41{
42
43	int carry;
44	__u32 ulen;
45	__u32 uproto;
46	__u32 sum = (__force u32)csum;
47
48	sum += (__force u32)saddr->s6_addr32[0];
49	carry = (sum < (__force u32)saddr->s6_addr32[0]);
50	sum += carry;
51
52	sum += (__force u32)saddr->s6_addr32[1];
53	carry = (sum < (__force u32)saddr->s6_addr32[1]);
54	sum += carry;
55
56	sum += (__force u32)saddr->s6_addr32[2];
57	carry = (sum < (__force u32)saddr->s6_addr32[2]);
58	sum += carry;
59
60	sum += (__force u32)saddr->s6_addr32[3];
61	carry = (sum < (__force u32)saddr->s6_addr32[3]);
62	sum += carry;
63
64	sum += (__force u32)daddr->s6_addr32[0];
65	carry = (sum < (__force u32)daddr->s6_addr32[0]);
66	sum += carry;
67
68	sum += (__force u32)daddr->s6_addr32[1];
69	carry = (sum < (__force u32)daddr->s6_addr32[1]);
70	sum += carry;
71
72	sum += (__force u32)daddr->s6_addr32[2];
73	carry = (sum < (__force u32)daddr->s6_addr32[2]);
74	sum += carry;
75
76	sum += (__force u32)daddr->s6_addr32[3];
77	carry = (sum < (__force u32)daddr->s6_addr32[3]);
78	sum += carry;
79
80	ulen = (__force u32)htonl((__u32) len);
81	sum += ulen;
82	carry = (sum < ulen);
83	sum += carry;
84
85	uproto = (__force u32)htonl(proto);
86	sum += uproto;
87	carry = (sum < uproto);
88	sum += carry;
89
90	return csum_fold((__force __wsum)sum);
91}
92
93#endif
94#endif
95