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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Vlad Yasevich8663e022012-11-15 08:49:17 +000034#include <linux/tcp.h>
35#include <linux/ipv6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#ifndef _HAVE_ARCH_IPV6_CSUM
38
Al Viro56649d52006-11-14 21:23:59 -080039static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
40 const struct in6_addr *daddr,
41 __u32 len, unsigned short proto,
42 __wsum csum)
Linus Torvalds1da177e2005-04-16 15:20:36 -070043{
44
45 int carry;
46 __u32 ulen;
47 __u32 uproto;
Al Viro56649d52006-11-14 21:23:59 -080048 __u32 sum = (__force u32)csum;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Al Viro56649d52006-11-14 21:23:59 -080050 sum += (__force u32)saddr->s6_addr32[0];
51 carry = (sum < (__force u32)saddr->s6_addr32[0]);
52 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Al Viro56649d52006-11-14 21:23:59 -080054 sum += (__force u32)saddr->s6_addr32[1];
55 carry = (sum < (__force u32)saddr->s6_addr32[1]);
56 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Al Viro56649d52006-11-14 21:23:59 -080058 sum += (__force u32)saddr->s6_addr32[2];
59 carry = (sum < (__force u32)saddr->s6_addr32[2]);
60 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Al Viro56649d52006-11-14 21:23:59 -080062 sum += (__force u32)saddr->s6_addr32[3];
63 carry = (sum < (__force u32)saddr->s6_addr32[3]);
64 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
Al Viro56649d52006-11-14 21:23:59 -080066 sum += (__force u32)daddr->s6_addr32[0];
67 carry = (sum < (__force u32)daddr->s6_addr32[0]);
68 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Al Viro56649d52006-11-14 21:23:59 -080070 sum += (__force u32)daddr->s6_addr32[1];
71 carry = (sum < (__force u32)daddr->s6_addr32[1]);
72 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Al Viro56649d52006-11-14 21:23:59 -080074 sum += (__force u32)daddr->s6_addr32[2];
75 carry = (sum < (__force u32)daddr->s6_addr32[2]);
76 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Al Viro56649d52006-11-14 21:23:59 -080078 sum += (__force u32)daddr->s6_addr32[3];
79 carry = (sum < (__force u32)daddr->s6_addr32[3]);
80 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Al Viro56649d52006-11-14 21:23:59 -080082 ulen = (__force u32)htonl((__u32) len);
83 sum += ulen;
84 carry = (sum < ulen);
85 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Al Viro56649d52006-11-14 21:23:59 -080087 uproto = (__force u32)htonl(proto);
88 sum += uproto;
89 carry = (sum < uproto);
90 sum += carry;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Al Virob23e3532006-12-21 13:15:18 -080092 return csum_fold((__force __wsum)sum);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
95#endif
Vlad Yasevich8663e022012-11-15 08:49:17 +000096
97static __inline__ __sum16 tcp_v6_check(int len,
98 const struct in6_addr *saddr,
99 const struct in6_addr *daddr,
100 __wsum base)
101{
102 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
103}
104
105static inline void __tcp_v6_send_check(struct sk_buff *skb,
106 const struct in6_addr *saddr,
107 const struct in6_addr *daddr)
108{
109 struct tcphdr *th = tcp_hdr(skb);
110
111 if (skb->ip_summed == CHECKSUM_PARTIAL) {
112 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
113 skb->csum_start = skb_transport_header(skb) - skb->head;
114 skb->csum_offset = offsetof(struct tcphdr, check);
115 } else {
116 th->check = tcp_v6_check(skb->len, saddr, daddr,
117 csum_partial(th, th->doff << 2,
118 skb->csum));
119 }
120}
121
122static inline void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
123{
124 struct ipv6_pinfo *np = inet6_sk(sk);
125
126 __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
127}
128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129#endif