ieee1394: merge from Linus
[linux-2.6] / 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__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
38                                                      struct in6_addr *daddr,
39                                                      __u16 len,
40                                                      unsigned short proto,
41                                                      unsigned int csum) 
42 {
43
44         int carry;
45         __u32 ulen;
46         __u32 uproto;
47
48         csum += saddr->s6_addr32[0];
49         carry = (csum < saddr->s6_addr32[0]);
50         csum += carry;
51
52         csum += saddr->s6_addr32[1];
53         carry = (csum < saddr->s6_addr32[1]);
54         csum += carry;
55
56         csum += saddr->s6_addr32[2];
57         carry = (csum < saddr->s6_addr32[2]);
58         csum += carry;
59
60         csum += saddr->s6_addr32[3];
61         carry = (csum < saddr->s6_addr32[3]);
62         csum += carry;
63
64         csum += daddr->s6_addr32[0];
65         carry = (csum < daddr->s6_addr32[0]);
66         csum += carry;
67
68         csum += daddr->s6_addr32[1];
69         carry = (csum < daddr->s6_addr32[1]);
70         csum += carry;
71
72         csum += daddr->s6_addr32[2];
73         carry = (csum < daddr->s6_addr32[2]);
74         csum += carry;
75
76         csum += daddr->s6_addr32[3];
77         carry = (csum < daddr->s6_addr32[3]);
78         csum += carry;
79
80         ulen = htonl((__u32) len);
81         csum += ulen;
82         carry = (csum < ulen);
83         csum += carry;
84
85         uproto = htonl(proto);
86         csum += uproto;
87         carry = (csum < uproto);
88         csum += carry;
89
90         return csum_fold(csum);
91 }
92
93 #endif
94 #endif