ieee802154: 6lowpan: Drop PACKET_OTHERHOST skbs in 6lowpan

There is no point processing pkts which are PACKET_OTHERHOST
in 6lowpan as they are discarded as soon as they reach the
ipv6 layer. Therefore we should drop them in the 6lowpan layer.
Signed-off-by: NSimon Vincent <simon.vincent@xsilon.com>
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/ieee802154/6lowpan_rtnl.c

@@ -515,6 +515,9 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (!netif_running(dev))
 		goto drop_skb;
 
+	if (skb->pkt_type == PACKET_OTHERHOST)
+		goto drop_skb;
+
 	if (dev->type != ARPHRD_IEEE802154)
 		goto drop_skb;