vxlan: fix tos value before xmit

[ Upstream commit 71130f29979c7c7956b040673e6b9d5643003176 ]

Before ip_tunnel_ecn_encap() and udp_tunnel_xmit_skb() we should filter
tos value by RT_TOS() instead of using config tos directly.

vxlan_get_route() would filter the tos to fl4.flowi4_tos but we didn't
return it back, as geneve_get_v4_rt() did. So we have to use RT_TOS()
directly in function ip_tunnel_ecn_encap().

Fixes: 206aaafc ("VXLAN: Use IP Tunnels tunnel ENC encap API")
Fixes: 1400615d ("vxlan: allow setting ipv6 traffic class")
Signed-off-by: NHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/vxlan.c

@@ -2217,7 +2217,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		ndst = &rt->dst;
 		skb_tunnel_check_pmtu(skb, ndst, VXLAN_HEADROOM);
 
-		tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
+		tos = ip_tunnel_ecn_encap(RT_TOS(tos), old_iph, skb);
 		ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
 		err = vxlan_build_skb(skb, ndst, sizeof(struct iphdr),
 				      vni, md, flags, udp_sum);
@@ -2254,7 +2254,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 
 		skb_tunnel_check_pmtu(skb, ndst, VXLAN6_HEADROOM);
 
-		tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
+		tos = ip_tunnel_ecn_encap(RT_TOS(tos), old_iph, skb);
 		ttl = ttl ? : ip6_dst_hoplimit(ndst);
 		skb_scrub_packet(skb, xnet);
 		err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr),