| Cong Wang | acb3e04 | 2013-01-07 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, |
| 9 | __u32 len, unsigned short proto, |
| 10 | __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 | int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto) |
| 66 | { |
| 67 | int err; |
| 68 | |
| 69 | UDP_SKB_CB(skb)->partial_cov = 0; |
| 70 | UDP_SKB_CB(skb)->cscov = skb->len; |
| 71 | |
| 72 | if (proto == IPPROTO_UDPLITE) { |
| 73 | err = udplite_checksum_init(skb, uh); |
| 74 | if (err) |
| 75 | return err; |
| 76 | } |
| 77 | |
| 78 | if (uh->check == 0) { |
| 79 | /* RFC 2460 section 8.1 says that we SHOULD log |
| 80 | this error. Well, it is reasonable. |
| 81 | */ |
| 82 | LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n"); |
| 83 | return 1; |
| 84 | } |
| 85 | if (skb->ip_summed == CHECKSUM_COMPLETE && |
| 86 | !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr, |
| 87 | skb->len, proto, skb->csum)) |
| 88 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 89 | |
| 90 | if (!skb_csum_unnecessary(skb)) |
| 91 | skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr, |
| 92 | &ipv6_hdr(skb)->daddr, |
| 93 | skb->len, proto, 0)); |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | EXPORT_SYMBOL(udp6_csum_init); |