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(n: csum_ipv6_magic(saddr: &ipv6_hdr(skb)->saddr,
42 daddr: &ipv6_hdr(skb)->daddr,
43 len: skb->len, proto, csum: 0));
44}
45
46static __inline__ __sum16 tcp_v6_check(int len,
47 const struct in6_addr *saddr,
48 const struct in6_addr *daddr,
49 __wsum base)
50{
51 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, csum: base);
52}
53
54static inline void __tcp_v6_send_check(struct sk_buff *skb,
55 const struct in6_addr *saddr,
56 const struct in6_addr *daddr)
57{
58 struct tcphdr *th = tcp_hdr(skb);
59
60 th->check = ~tcp_v6_check(len: skb->len, saddr, daddr, base: 0);
61 skb->csum_start = skb_transport_header(skb) - skb->head;
62 skb->csum_offset = offsetof(struct tcphdr, check);
63}
64
65static inline void tcp_v6_gso_csum_prep(struct sk_buff *skb)
66{
67 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
68 struct tcphdr *th = tcp_hdr(skb);
69
70 ipv6h->payload_len = 0;
71 th->check = ~tcp_v6_check(len: 0, saddr: &ipv6h->saddr, daddr: &ipv6h->daddr, base: 0);
72}
73
74static inline __sum16 udp_v6_check(int len,
75 const struct in6_addr *saddr,
76 const struct in6_addr *daddr,
77 __wsum base)
78{
79 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, csum: base);
80}
81
82void udp6_set_csum(bool nocheck, struct sk_buff *skb,
83 const struct in6_addr *saddr,
84 const struct in6_addr *daddr, int len);
85
86int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
87#endif
88

source code of linux/include/net/ip6_checksum.h