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 
ip6_compute_pseudo(struct sk_buff * skb,int proto)39 static 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 
ip6_gro_compute_pseudo(struct sk_buff * skb,int proto)46 static 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 
tcp_v6_check(int len,const struct in6_addr * saddr,const struct in6_addr * daddr,__wsum base)54 static __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 
__tcp_v6_send_check(struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr)62 static 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 
tcp_v6_gso_csum_prep(struct sk_buff * skb)79 static 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 
udp_v6_check(int len,const struct in6_addr * saddr,const struct in6_addr * daddr,__wsum base)88 static 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 
96 void udp6_set_csum(bool nocheck, struct sk_buff *skb,
97 		   const struct in6_addr *saddr,
98 		   const struct in6_addr *daddr, int len);
99 
100 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto);
101 #endif
102