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gerrit-public.fairphone.software / kernel / msm-4.9 / da7a26af4ae7192e63103aaaf0941a1fd42723df / . / net / ipv6 / ip6_checksum.c
blob: c0cbcb259f5a9acf9157d4626c61f532d8077855 [file] [log] [blame]
Cong Wangacb3e042013-01-07 20:52:40 +0000[diff] [blame]1#include <net/ip.h>
2#include <net/udp.h>
3#include <net/udplite.h>
4#include <asm/checksum.h>
5
6#ifndef _HAVE_ARCH_IPV6_CSUM
7__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
8 const struct in6_addr *daddr,
Alexander Duyck1e940822016-03-11 14:05:41 -0800[diff] [blame]9 __u32 len, __u8 proto, __wsum csum)
Cong Wangacb3e042013-01-07 20:52:40 +0000[diff] [blame]10{
11
12 int carry;
13 __u32 ulen;
14 __u32 uproto;
15 __u32 sum = (__force u32)csum;
16
17 sum += (__force u32)saddr->s6_addr32[0];
18 carry = (sum < (__force u32)saddr->s6_addr32[0]);
19 sum += carry;
20
21 sum += (__force u32)saddr->s6_addr32[1];
22 carry = (sum < (__force u32)saddr->s6_addr32[1]);
23 sum += carry;
24
25 sum += (__force u32)saddr->s6_addr32[2];
26 carry = (sum < (__force u32)saddr->s6_addr32[2]);
27 sum += carry;
28
29 sum += (__force u32)saddr->s6_addr32[3];
30 carry = (sum < (__force u32)saddr->s6_addr32[3]);
31 sum += carry;
32
33 sum += (__force u32)daddr->s6_addr32[0];
34 carry = (sum < (__force u32)daddr->s6_addr32[0]);
35 sum += carry;
36
37 sum += (__force u32)daddr->s6_addr32[1];
38 carry = (sum < (__force u32)daddr->s6_addr32[1]);
39 sum += carry;
40
41 sum += (__force u32)daddr->s6_addr32[2];
42 carry = (sum < (__force u32)daddr->s6_addr32[2]);
43 sum += carry;
44
45 sum += (__force u32)daddr->s6_addr32[3];
46 carry = (sum < (__force u32)daddr->s6_addr32[3]);
47 sum += carry;
48
49 ulen = (__force u32)htonl((__u32) len);
50 sum += ulen;
51 carry = (sum < ulen);
52 sum += carry;
53
54 uproto = (__force u32)htonl(proto);
55 sum += uproto;
56 carry = (sum < uproto);
57 sum += carry;
58
59 return csum_fold((__force __wsum)sum);
60}
61EXPORT_SYMBOL(csum_ipv6_magic);
62#endif
63
64int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
65{
66 int err;
67
68 UDP_SKB_CB(skb)->partial_cov = 0;
69 UDP_SKB_CB(skb)->cscov = skb->len;
70
71 if (proto == IPPROTO_UDPLITE) {
72 err = udplite_checksum_init(skb, uh);
73 if (err)
74 return err;
75 }
76
Tom Herbert40685792014-05-02 16:29:58 -0700[diff] [blame]77 /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
78 * we accept a checksum of zero here. When we find the socket
79 * for the UDP packet we'll check if that socket allows zero checksum
80 * for IPv6 (set by socket option).
Hannes Frederic Sowac148d162016-06-11 21:15:37 +0200[diff] [blame]81 *
82 * Note, we are only interested in != 0 or == 0, thus the
83 * force to int.
Tom Herbert40685792014-05-02 16:29:58 -0700[diff] [blame]84 */
Hannes Frederic Sowac148d162016-06-11 21:15:37 +0200[diff] [blame]85 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
86 ip6_compute_pseudo);
Cong Wangacb3e042013-01-07 20:52:40 +0000[diff] [blame]87}
88EXPORT_SYMBOL(udp6_csum_init);
Tom Herbertaf5fcba2014-06-04 17:19:48 -0700[diff] [blame]89
90/* Function to set UDP checksum for an IPv6 UDP packet. This is intended
91 * for the simple case like when setting the checksum for a UDP tunnel.
92 */
93void udp6_set_csum(bool nocheck, struct sk_buff *skb,
94 const struct in6_addr *saddr,
95 const struct in6_addr *daddr, int len)
96{
97 struct udphdr *uh = udp_hdr(skb);
98
99 if (nocheck)
100 uh->check = 0;
101 else if (skb_is_gso(skb))
102 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
Edward Cree179bc672016-02-11 20:48:04 +0000[diff] [blame]103 else if (skb->ip_summed == CHECKSUM_PARTIAL) {
104 uh->check = 0;
105 uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
106 if (uh->check == 0)
107 uh->check = CSUM_MANGLED_0;
Edward Creed75f1302016-02-11 20:49:40 +0000[diff] [blame]108 } else {
Tom Herbertaf5fcba2014-06-04 17:19:48 -0700[diff] [blame]109 skb->ip_summed = CHECKSUM_PARTIAL;
110 skb->csum_start = skb_transport_header(skb) - skb->head;
111 skb->csum_offset = offsetof(struct udphdr, check);
112 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
Tom Herbertaf5fcba2014-06-04 17:19:48 -0700[diff] [blame]113 }
114}
115EXPORT_SYMBOL(udp6_set_csum);