ip_vti/ip6_vti: Do not touch skb->mark on xmit

Instead of modifying skb->mark we can simply modify the flowi_mark that is
generated as a result of the xfrm_decode_session.  By doing this we don't
need to actually touch the skb->mark and it can be preserved as it passes
out through the tunnel.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/ipv4/ip_vti.c

@@ -216,8 +216,6 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	memset(&fl, 0, sizeof(fl));
 
-	skb->mark = be32_to_cpu(tunnel->parms.o_key);
-
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
 		xfrm_decode_session(skb, &fl, AF_INET);
@@ -233,6 +231,9 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_OK;
 	}
 
+	/* override mark with tunnel output key */
+	fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
+
 	return vti_xmit(skb, dev, &fl);
 }
 

net/ipv6/ip6_vti.c

@@ -495,7 +495,6 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 	int ret;
 
 	memset(&fl, 0, sizeof(fl));
-	skb->mark = be32_to_cpu(t->parms.o_key);
 
 	switch (skb->protocol) {
 	case htons(ETH_P_IPV6):
@@ -516,6 +515,9 @@ vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto tx_err;
 	}
 
+	/* override mark with tunnel output key */
+	fl.flowi_mark = be32_to_cpu(t->parms.o_key);
+
 	ret = vti6_xmit(skb, dev, &fl);
 	if (ret < 0)
 		goto tx_err;