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, __u8 proto, __wsum csum)
15 __u32 sum = (__force u32)csum;
17 sum += (__force u32)saddr->s6_addr32[0];
18 carry = (sum < (__force u32)saddr->s6_addr32[0]);
21 sum += (__force u32)saddr->s6_addr32[1];
22 carry = (sum < (__force u32)saddr->s6_addr32[1]);
25 sum += (__force u32)saddr->s6_addr32[2];
26 carry = (sum < (__force u32)saddr->s6_addr32[2]);
29 sum += (__force u32)saddr->s6_addr32[3];
30 carry = (sum < (__force u32)saddr->s6_addr32[3]);
33 sum += (__force u32)daddr->s6_addr32[0];
34 carry = (sum < (__force u32)daddr->s6_addr32[0]);
37 sum += (__force u32)daddr->s6_addr32[1];
38 carry = (sum < (__force u32)daddr->s6_addr32[1]);
41 sum += (__force u32)daddr->s6_addr32[2];
42 carry = (sum < (__force u32)daddr->s6_addr32[2]);
45 sum += (__force u32)daddr->s6_addr32[3];
46 carry = (sum < (__force u32)daddr->s6_addr32[3]);
49 ulen = (__force u32)htonl((__u32) len);
54 uproto = (__force u32)htonl(proto);
56 carry = (sum < uproto);
59 return csum_fold((__force __wsum)sum);
61 EXPORT_SYMBOL(csum_ipv6_magic);
64 int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
68 UDP_SKB_CB(skb)->partial_cov = 0;
69 UDP_SKB_CB(skb)->cscov = skb->len;
71 if (proto == IPPROTO_UDPLITE) {
72 err = udplite_checksum_init(skb, uh);
76 if (UDP_SKB_CB(skb)->partial_cov) {
77 skb->csum = ip6_compute_pseudo(skb, proto);
82 /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)
83 * we accept a checksum of zero here. When we find the socket
84 * for the UDP packet we'll check if that socket allows zero checksum
85 * for IPv6 (set by socket option).
87 * Note, we are only interested in != 0 or == 0, thus the
90 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
95 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
96 /* If SW calculated the value, we know it's bad */
97 if (skb->csum_complete_sw)
100 /* HW says the value is bad. Let's validate that.
101 * skb->csum is no longer the full packet checksum,
102 * so don't treat is as such.
104 skb_checksum_complete_unset(skb);
109 EXPORT_SYMBOL(udp6_csum_init);
111 /* Function to set UDP checksum for an IPv6 UDP packet. This is intended
112 * for the simple case like when setting the checksum for a UDP tunnel.
114 void udp6_set_csum(bool nocheck, struct sk_buff *skb,
115 const struct in6_addr *saddr,
116 const struct in6_addr *daddr, int len)
118 struct udphdr *uh = udp_hdr(skb);
122 else if (skb_is_gso(skb))
123 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
124 else if (skb->ip_summed == CHECKSUM_PARTIAL) {
126 uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
128 uh->check = CSUM_MANGLED_0;
130 skb->ip_summed = CHECKSUM_PARTIAL;
131 skb->csum_start = skb_transport_header(skb) - skb->head;
132 skb->csum_offset = offsetof(struct udphdr, check);
133 uh->check = ~udp_v6_check(len, saddr, daddr, 0);
136 EXPORT_SYMBOL(udp6_set_csum);