1 // SPDX-License-Identifier: GPL-2.0 2 #include <net/ip.h> 3 #include <net/ip6_checksum.h> 4 #include <net/udp.h> 5 #include <asm/checksum.h> 6 7 #ifndef _HAVE_ARCH_IPV6_CSUM 8 __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 9 const struct in6_addr *daddr, 10 __u32 len, __u8 proto, __wsum csum) 11 { 12 13 int carry; 14 __u32 ulen; 15 __u32 uproto; 16 __u32 sum = (__force u32)csum; 17 18 sum += (__force u32)saddr->s6_addr32[0]; 19 carry = (sum < (__force u32)saddr->s6_addr32[0]); 20 sum += carry; 21 22 sum += (__force u32)saddr->s6_addr32[1]; 23 carry = (sum < (__force u32)saddr->s6_addr32[1]); 24 sum += carry; 25 26 sum += (__force u32)saddr->s6_addr32[2]; 27 carry = (sum < (__force u32)saddr->s6_addr32[2]); 28 sum += carry; 29 30 sum += (__force u32)saddr->s6_addr32[3]; 31 carry = (sum < (__force u32)saddr->s6_addr32[3]); 32 sum += carry; 33 34 sum += (__force u32)daddr->s6_addr32[0]; 35 carry = (sum < (__force u32)daddr->s6_addr32[0]); 36 sum += carry; 37 38 sum += (__force u32)daddr->s6_addr32[1]; 39 carry = (sum < (__force u32)daddr->s6_addr32[1]); 40 sum += carry; 41 42 sum += (__force u32)daddr->s6_addr32[2]; 43 carry = (sum < (__force u32)daddr->s6_addr32[2]); 44 sum += carry; 45 46 sum += (__force u32)daddr->s6_addr32[3]; 47 carry = (sum < (__force u32)daddr->s6_addr32[3]); 48 sum += carry; 49 50 ulen = (__force u32)htonl((__u32) len); 51 sum += ulen; 52 carry = (sum < ulen); 53 sum += carry; 54 55 uproto = (__force u32)htonl(proto); 56 sum += uproto; 57 carry = (sum < uproto); 58 sum += carry; 59 60 return csum_fold((__force __wsum)sum); 61 } 62 EXPORT_SYMBOL(csum_ipv6_magic); 63 #endif 64 65 /* Function to set UDP checksum for an IPv6 UDP packet. This is intended 66 * for the simple case like when setting the checksum for a UDP tunnel. 67 */ 68 void udp6_set_csum(bool nocheck, struct sk_buff *skb, 69 const struct in6_addr *saddr, 70 const struct in6_addr *daddr, int len) 71 { 72 struct udphdr *uh = udp_hdr(skb); 73 74 if (nocheck) 75 uh->check = 0; 76 else if (skb_is_gso(skb)) 77 uh->check = ~udp_v6_check(len, saddr, daddr, 0); 78 else if (skb->ip_summed == CHECKSUM_PARTIAL) { 79 uh->check = 0; 80 uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb)); 81 if (uh->check == 0) 82 uh->check = CSUM_MANGLED_0; 83 } else { 84 skb->ip_summed = CHECKSUM_PARTIAL; 85 skb->csum_start = skb_transport_header(skb) - skb->head; 86 skb->csum_offset = offsetof(struct udphdr, check); 87 uh->check = ~udp_v6_check(len, saddr, daddr, 0); 88 } 89 } 90 EXPORT_SYMBOL(udp6_set_csum); 91