[IPV6] RAW: Add checksum default defines for MH.

Add checksum default defines for mobility header(MH) which
goes through raw socket. As the result kernel's behavior is
to handle MH checksum as default.

This patch also removes verifying inbound MH checksum at
mip6_mh_filter() since it did not consider user specified
checksum offset and was redundant check with raw socket code.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/mip6.c

@@ -89,7 +89,6 @@ static int mip6_mh_len(int type)
 int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 {
 	struct ip6_mh *mh;
-	int mhlen;
 
 	if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) ||
 	    !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3)))
@@ -103,31 +102,6 @@ int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 		mip6_param_prob(skb, 0, (&mh->ip6mh_hdrlen) - skb->nh.raw);
 		return -1;
 	}
-	mhlen = (mh->ip6mh_hdrlen + 1) << 3;
-
-	if (skb->ip_summed == CHECKSUM_COMPLETE) {
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb->csum)) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH hw checksum failed\n");
-			skb->ip_summed = CHECKSUM_NONE;
-		}
-	}
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb_checksum(skb, 0, mhlen, 0))) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH checksum failed "
-				       "[" NIP6_FMT " > " NIP6_FMT "]\n",
-				       NIP6(skb->nh.ipv6h->saddr),
-				       NIP6(skb->nh.ipv6h->daddr));
-			return -1;
-		}
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	}
 
 	if (mh->ip6mh_proto != IPPROTO_NONE) {
 		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",

net/ipv6/raw.c

@@ -1094,10 +1094,19 @@ static void rawv6_close(struct sock *sk, long timeout)
 
 static int rawv6_init_sk(struct sock *sk)
 {
-	if (inet_sk(sk)->num == IPPROTO_ICMPV6) {
-		struct raw6_sock *rp = raw6_sk(sk);
+	struct raw6_sock *rp = raw6_sk(sk);
+
+	switch (inet_sk(sk)->num) {
+	case IPPROTO_ICMPV6:
 		rp->checksum = 1;
 		rp->offset   = 2;
+		break;
+	case IPPROTO_MH:
+		rp->checksum = 1;
+		rp->offset   = 4;
+		break;
+	default:
+		break;
 	}
 	return(0);
 }