1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
4 *		operating system.  INET is implemented using the  BSD Socket
5 *		interface as the means of communication with the user level.
6 *
7 *		Checksumming functions for IPv6
8 *
9 * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
10 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 *		Borrows very liberally from tcp.c and ip.c, see those
12 *		files for more names.
13 */
14
15/*
16 *	Fixes:
17 *
18 *	Ralf Baechle			:	generic ipv6 checksum
19 *	<ralf@waldorf-gmbh.de>
20 */
21
22#ifndef _CHECKSUM_IPV6_H
23#define _CHECKSUM_IPV6_H
24
25#include <asm/types.h>
26#include <asm/byteorder.h>
27#include <net/ip.h>
28#include <asm/checksum.h>
29#include <linux/in6.h>
30#include <linux/tcp.h>
31#include <linux/ipv6.h>
32
33#ifndef _HAVE_ARCH_IPV6_CSUM
34__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
35			const struct in6_addr *daddr,
36			__u32 len, __u8 proto, __wsum csum);
37#endif
38
39static inline __wsum ip6_compute_pseudo(struct sk_buff *skb, int proto)
40{
41	return ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
42					    &ipv6_hdr(skb)->daddr,
43					    skb->len, proto, 0));
44}
45
46static inline __wsum ip6_gro_compute_pseudo(struct sk_buff *skb, int proto)
47{
48	const struct ipv6hdr *iph = skb_gro_network_header(skb);
49
50	return ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr,
51					    skb_gro_len(skb), proto, 0));
52}
53
54static __inline__ __sum16 tcp_v6_check(int len,
55				   const struct in6_addr *saddr,
56				   const struct in6_addr *daddr,
57				   __wsum base)
58{
59	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
60}
61
62static inline void __tcp_v6_send_check(struct sk_buff *skb,
63				       const struct in6_addr *saddr,
64				       const struct in6_addr *daddr)
65{
66	struct tcphdr *th = tcp_hdr(skb);
67
68	if (skb->ip_summed == CHECKSUM_PARTIAL) {
69		th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
70		skb->csum_start = skb_transport_header(skb) - skb->head;
71		skb->csum_offset = offsetof(struct tcphdr, check);
72	} else {
73		th->check = tcp_v6_check(skb->len, saddr, daddr,
74					 csum_partial(th, th->doff << 2,
75						      skb->csum));
76	}
77}
78
79static inline void tcp_v6_gso_csum_prep(struct sk_buff *skb)
80{
81	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
82	struct tcphdr *th = tcp_hdr(skb);
83
84	ipv6h->payload_len = 0;
85	th->check = ~tcp_v6_check(0, &ipv6h->saddr, &ipv6h->daddr, 0);
86}
87
88static inline __sum16 udp_v6_check(int len,
89				   const struct in6_addr *saddr,
90				   const struct in6_addr *daddr,
91				   __wsum base)
92{
93	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, base);
94}
95
96void udp6_set_csum(bool nocheck, struct sk_buff *skb,
97		   const struct in6_addr *saddr,
98		   const struct in6_addr *daddr, int len);
99
100int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
101#endif
102