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#include <linux/tcp.h>
35#include <linux/ipv6.h>
36
37#ifndef _HAVE_ARCH_IPV6_CSUM
38__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
39			const struct in6_addr *daddr,
40			__u32 len, unsigned short proto,
41			__wsum csum);
42#endif
43
44static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
45{
46	return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
47					    &ipv6_hdr(skb)->daddr,
48					    skb->len, proto, 0));
49}
50
51static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
52{
53	const struct ipv6hdr *iph = skb_gro_network_header(skb);
54
55	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
56					    skb_gro_len(skb), proto, 0));
57}
58
59static __inline__ __sum16 tcp_v6_check(int len,
60				   const struct in6_addr *saddr,
61				   const struct in6_addr *daddr,
62				   __wsum base)
63{
64	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
65}
66
67static inline void __tcp_v6_send_check(struct sk_buff *skb,
68				       const struct in6_addr *saddr,
69				       const struct in6_addr *daddr)
70{
71	struct tcphdr *th = tcp_hdr(skb);
72
73	if (skb->ip_summed == CHECKSUM_PARTIAL) {
74		th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
75		skb->csum_start = skb_transport_header(skb) - skb->head;
76		skb->csum_offset = offsetof(struct tcphdr, check);
77	} else {
78		th->check = tcp_v6_check(skb->len, saddr, daddr,
79					 csum_partial(th, th->doff << 2,
80						      skb->csum));
81	}
82}
83
84#if IS_ENABLED(CONFIG_IPV6)
85static inline void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
86{
87	struct ipv6_pinfo *np = inet6_sk(sk);
88
89	__tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
90}
91#endif
92
93static inline __sum16 udp_v6_check(int len,
94				   const struct in6_addr *saddr,
95				   const struct in6_addr *daddr,
96				   __wsum base)
97{
98	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base);
99}
100
101void udp6_set_csum(bool nocheck, struct sk_buff *skb,
102		   const struct in6_addr *saddr,
103		   const struct in6_addr *daddr, int len);
104
105int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
106#endif
107