vxlan: tun_id is 64bit, not 32bit

The tun_id field in struct ip_tunnel_key is __be64, not __be32. We need to
convert the vni to tun_id correctly.

Fixes: 54bfd872 ("vxlan: keep flags and vni in network byte order")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -1310,9 +1310,10 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 
 	if (vxlan_collect_metadata(vs)) {
+		__be32 vni = vxlan_vni(vxlan_hdr(skb)->vx_vni);
+
 		tun_dst = udp_tun_rx_dst(skb, vxlan_get_sk_family(vs), TUNNEL_KEY,
-					 vxlan_vni(vxlan_hdr(skb)->vx_vni),
-					 sizeof(*md));
+					 vxlan_vni_to_tun_id(vni), sizeof(*md));
 
 		if (!tun_dst)
 			goto drop;

include/net/vxlan.h

@@ -294,6 +294,15 @@ static inline __be32 vxlan_tun_id_to_vni(__be64 tun_id)
 #endif
 }
 
+static inline __be64 vxlan_vni_to_tun_id(__be32 vni)
+{
+#if defined(__BIG_ENDIAN)
+	return (__be64)vni;
+#else
+	return (__be64)vni << 32;
+#endif
+}
+
 static inline size_t vxlan_rco_start(__be32 vni_field)
 {
 	return be32_to_cpu(vni_field & VXLAN_RCO_MASK) << VXLAN_RCO_SHIFT;