3 #include <net/udplite.h>
4 #include <asm/checksum.h>
6 #ifndef _HAVE_ARCH_IPV6_CSUM
7 __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
8 const struct in6_addr *daddr,
9 __u32 len, unsigned short proto,
16 __u32 sum = (__force u32)csum;
18 sum += (__force u32)saddr->s6_addr32[0];
19 carry = (sum < (__force u32)saddr->s6_addr32[0]);
22 sum += (__force u32)saddr->s6_addr32[1];
23 carry = (sum < (__force u32)saddr->s6_addr32[1]);
26 sum += (__force u32)saddr->s6_addr32[2];
27 carry = (sum < (__force u32)saddr->s6_addr32[2]);
30 sum += (__force u32)saddr->s6_addr32[3];
31 carry = (sum < (__force u32)saddr->s6_addr32[3]);
34 sum += (__force u32)daddr->s6_addr32[0];
35 carry = (sum < (__force u32)daddr->s6_addr32[0]);
38 sum += (__force u32)daddr->s6_addr32[1];
39 carry = (sum < (__force u32)daddr->s6_addr32[1]);
42 sum += (__force u32)daddr->s6_addr32[2];
43 carry = (sum < (__force u32)daddr->s6_addr32[2]);
46 sum += (__force u32)daddr->s6_addr32[3];
47 carry = (sum < (__force u32)daddr->s6_addr32[3]);
50 ulen = (__force u32)htonl((__u32) len);
55 uproto = (__force u32)htonl(proto);
57 carry = (sum < uproto);
60 return csum_fold((__force __wsum)sum);
62 EXPORT_SYMBOL(csum_ipv6_magic);
65 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
69 UDP_SKB_CB(skb)->partial_cov = 0;
70 UDP_SKB_CB(skb)->cscov = skb->len;
72 if (proto == IPPROTO_UDPLITE) {
73 err = udplite_checksum_init(skb, uh);
78 /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
79 * we accept a checksum of zero here. When we find the socket
80 * for the UDP packet we'll check if that socket allows zero checksum
81 * for IPv6 (set by socket option).
83 return skb_checksum_init_zero_check(skb, proto, uh->check,
86 EXPORT_SYMBOL(udp6_csum_init);
88 /* Function to set UDP checksum for an IPv6 UDP packet. This is intended
89 * for the simple case like when setting the checksum for a UDP tunnel.
91 void udp6_set_csum(bool nocheck, struct sk_buff *skb,
92 const struct in6_addr *saddr,
93 const struct in6_addr *daddr, int len)
95 struct udphdr *uh = udp_hdr(skb);
99 else if (skb_is_gso(skb))
100 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
101 else if (skb_dst(skb) && skb_dst(skb)->dev &&
102 (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
104 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
106 skb->ip_summed = CHECKSUM_PARTIAL;
107 skb->csum_start = skb_transport_header(skb) - skb->head;
108 skb->csum_offset = offsetof(struct udphdr, check);
109 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
113 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
116 csum = skb_checksum(skb, 0, len, 0);
117 uh->check = udp_v6_check(len, saddr, daddr, csum);
119 uh->check = CSUM_MANGLED_0;
121 skb->ip_summed = CHECKSUM_UNNECESSARY;
124 EXPORT_SYMBOL(udp6_set_csum);