1 files changed, 38 insertions, 10 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 1e586d92260e..7edf096867c4 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -634,6 +634,10 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
 			int ret;
 
+			/* Verify checksum before giving to encap */
+			if (udp_lib_checksum_complete(skb))
+				goto csum_error;
+
 			ret = encap_rcv(sk, skb);
 			if (ret <= 0) {
 				UDP_INC_STATS_BH(sock_net(sk),
@@ -760,6 +764,17 @@ static void flush_stack(struct sock **stack, unsigned int count,
 	if (unlikely(skb1))
 		kfree_skb(skb1);
 }
+
+static void udp6_csum_zero_error(struct sk_buff *skb)
+{
+	/* 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 for [%pI6c]:%u->[%pI6c]:%u\n",
+		       &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
+		       &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
+}
+
 /*
  * Note: called only from the BH handler context,
  * so we don't need to lock the hashes.
@@ -779,7 +794,12 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 	dif = inet6_iif(skb);
 	sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
 	while (sk) {
-		stack[count++] = sk;
+		/* If zero checksum and sk_no_check is not on for
+		 * the socket then skip it.
+		 */
+		if (uh->check || sk->sk_no_check)
+			stack[count++] = sk;
+
 		sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
 				       uh->source, saddr, dif);
 		if (unlikely(count == ARRAY_SIZE(stack))) {
@@ -867,6 +887,12 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 	if (sk != NULL) {
 		int ret;
 
+		if (!uh->check && !sk->sk_no_check) {
+			sock_put(sk);
+			udp6_csum_zero_error(skb);
+			goto csum_error;
+		}
+
 		ret = udpv6_queue_rcv_skb(sk, skb);
 		sock_put(sk);
 
@@ -879,6 +905,11 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 		return 0;
 	}
 
+	if (!uh->check) {
+		udp6_csum_zero_error(skb);
+		goto csum_error;
+	}
+
 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 		goto discard;
 
@@ -1006,7 +1037,10 @@ static int udp_v6_push_pending_frames(struct sock *sk)
 
 	if (is_udplite)
 		csum = udplite_csum_outgoing(sk, skb);
-	else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
+	else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */
+		skb->ip_summed = CHECKSUM_NONE;
+		goto send;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
 				     up->len);
 		goto send;
@@ -1232,14 +1266,8 @@ do_udp_sendmsg:
 		goto out;
 	}
 
-	if (hlimit < 0) {
-		if (ipv6_addr_is_multicast(&fl6.daddr))
-			hlimit = np->mcast_hops;
-		else
-			hlimit = np->hop_limit;
-		if (hlimit < 0)
-			hlimit = ip6_dst_hoplimit(dst);
-	}
+	if (hlimit < 0)
+		hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 
 	if (tclass < 0)
 		tclass = np->tclass;