vxlan: allow setting ipv6 traffic class

We can already do that for IPv4, but IPv6 support was missing. Add
it for vxlan, so it can be used with collect metadata frontends.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -1789,7 +1789,7 @@ static struct rtable *vxlan_get_route(struct vxlan_dev *vxlan,
 
 #if IS_ENABLED(CONFIG_IPV6)
 static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
-					  struct sk_buff *skb, int oif,
+					  struct sk_buff *skb, int oif, u8 tos,
 					  const struct in6_addr *daddr,
 					  struct in6_addr *saddr,
 					  struct dst_cache *dst_cache,
@@ -1800,6 +1800,8 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
 	struct flowi6 fl6;
 	int err;
 
+	if (tos && !info)
+		use_cache = false;
 	if (use_cache) {
 		ndst = dst_cache_get_ip6(dst_cache, saddr);
 		if (ndst)
@@ -1808,6 +1810,7 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
 
 	memset(&fl6, 0, sizeof(fl6));
 	fl6.flowi6_oif = oif;
+	fl6.flowi6_tos = RT_TOS(tos);
 	fl6.daddr = *daddr;
 	fl6.saddr = vxlan->cfg.saddr.sin6.sin6_addr;
 	fl6.flowi6_mark = skb->mark;
@@ -2016,7 +2019,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		sk = vxlan->vn6_sock->sock->sk;
 
 		ndst = vxlan6_get_route(vxlan, skb,
-					rdst ? rdst->remote_ifindex : 0,
+					rdst ? rdst->remote_ifindex : 0, tos,
 					&dst->sin6.sin6_addr, &saddr,
 					dst_cache, info);
 		if (IS_ERR(ndst)) {
@@ -2053,6 +2056,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		if (!info)
 			udp_sum = !(flags & VXLAN_F_UDP_ZERO_CSUM6_TX);
 
+		tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
 		ttl = ttl ? : ip6_dst_hoplimit(ndst);
 		skb_scrub_packet(skb, xnet);
 		err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr),
@@ -2062,8 +2066,8 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 			return;
 		}
 		udp_tunnel6_xmit_skb(ndst, sk, skb, dev,
-				     &saddr, &dst->sin6.sin6_addr,
-				     0, ttl, src_port, dst_port, !udp_sum);
+				     &saddr, &dst->sin6.sin6_addr, tos, ttl,
+				     src_port, dst_port, !udp_sum);
 #endif
 	}
 
@@ -2385,7 +2389,7 @@ static int vxlan_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 
 		if (!vxlan->vn6_sock)
 			return -EINVAL;
-		ndst = vxlan6_get_route(vxlan, skb, 0,
+		ndst = vxlan6_get_route(vxlan, skb, 0, info->key.tos,
 					&info->key.u.ipv6.dst,
 					&info->key.u.ipv6.src, NULL, info);
 		if (IS_ERR(ndst))