1 files changed, 97 insertions, 0 deletions

diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
new file mode 100644
index 000000000000..72d198b8e4d2
--- /dev/null
+++ b/net/ipv6/ip6_checksum.c
@@ -0,0 +1,97 @@
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <asm/checksum.h>
+
+#ifndef _HAVE_ARCH_IPV6_CSUM
+__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+                        const struct in6_addr *daddr,
+                        __u32 len, unsigned short proto,
+                        __wsum csum)
+{
+
+        int carry;
+        __u32 ulen;
+        __u32 uproto;
+        __u32 sum = (__force u32)csum;
+
+        sum += (__force u32)saddr->s6_addr32[0];
+        carry = (sum < (__force u32)saddr->s6_addr32[0]);
+        sum += carry;
+
+        sum += (__force u32)saddr->s6_addr32[1];
+        carry = (sum < (__force u32)saddr->s6_addr32[1]);
+        sum += carry;
+
+        sum += (__force u32)saddr->s6_addr32[2];
+        carry = (sum < (__force u32)saddr->s6_addr32[2]);
+        sum += carry;
+
+        sum += (__force u32)saddr->s6_addr32[3];
+        carry = (sum < (__force u32)saddr->s6_addr32[3]);
+        sum += carry;
+
+        sum += (__force u32)daddr->s6_addr32[0];
+        carry = (sum < (__force u32)daddr->s6_addr32[0]);
+        sum += carry;
+
+        sum += (__force u32)daddr->s6_addr32[1];
+        carry = (sum < (__force u32)daddr->s6_addr32[1]);
+        sum += carry;
+
+        sum += (__force u32)daddr->s6_addr32[2];
+        carry = (sum < (__force u32)daddr->s6_addr32[2]);
+        sum += carry;
+
+        sum += (__force u32)daddr->s6_addr32[3];
+        carry = (sum < (__force u32)daddr->s6_addr32[3]);
+        sum += carry;
+
+        ulen = (__force u32)htonl((__u32) len);
+        sum += ulen;
+        carry = (sum < ulen);
+        sum += carry;
+
+        uproto = (__force u32)htonl(proto);
+        sum += uproto;
+        carry = (sum < uproto);
+        sum += carry;
+
+        return csum_fold((__force __wsum)sum);
+}
+EXPORT_SYMBOL(csum_ipv6_magic);
+#endif
+
+int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto)
+{
+        int err;
+
+        UDP_SKB_CB(skb)->partial_cov = 0;
+        UDP_SKB_CB(skb)->cscov = skb->len;
+
+        if (proto == IPPROTO_UDPLITE) {
+                err = udplite_checksum_init(skb, uh);
+                if (err)
+                        return err;
+        }
+
+        if (uh->check == 0) {
+                /* RFC 2460 section 8.1 says that we SHOULD log
+                   this error. Well, it is reasonable.
+                 */
+                LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
+                return 1;
+        }
+        if (skb->ip_summed == CHECKSUM_COMPLETE &&
+            !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
+                             skb->len, proto, skb->csum))
+                skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+        if (!skb_csum_unnecessary(skb))
+                skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+                                                         &ipv6_hdr(skb)->daddr,
+                                                         skb->len, proto, 0));
+
+        return 0;
+}
+EXPORT_SYMBOL(udp6_csum_init);