Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi...
[linux-2.6.git] / include / net / ip6_checksum.h
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
37 static __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