tunnels: harmonize cleanup done on skb on xmit path

The goal of this patch is to harmonize cleanup done on a skbuff on xmit path.
Before this patch, behaviors were different depending of the tunnel type.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index b0e74e1..88d7d7d 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -614,9 +614,6 @@
 		goto tx_error;
 	}
 
-	if (!net_eq(tunnel->net, dev_net(dev)))
-		skb_scrub_packet(skb, true);
-
 	if (tunnel->err_count > 0) {
 		if (time_before(jiffies,
 				tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
@@ -655,7 +652,8 @@
 	}
 
 	err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, protocol,
-			    ip_tunnel_ecn_encap(tos, inner_iph, skb), ttl, df);
+			    ip_tunnel_ecn_encap(tos, inner_iph, skb), ttl, df,
+			    !net_eq(tunnel->net, dev_net(dev)));
 	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 
 	return;
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index e820458..d6c856b 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -48,16 +48,15 @@
 
 int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
 		  __be32 src, __be32 dst, __u8 proto,
-		  __u8 tos, __u8 ttl, __be16 df)
+		  __u8 tos, __u8 ttl, __be16 df, bool xnet)
 {
 	int pkt_len = skb->len;
 	struct iphdr *iph;
 	int err;
 
-	nf_reset(skb);
-	secpath_reset(skb);
+	skb_scrub_packet(skb, xnet);
+
 	skb->rxhash = 0;
-	skb_dst_drop(skb);
 	skb_dst_set(skb, &rt->dst);
 	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index f2d0a42..f179ff1 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -694,6 +694,8 @@
 			tunnel->err_count = 0;
 	}
 
+	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
+
 	max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 
 	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
@@ -710,8 +712,6 @@
 		skb = new_skb;
 	}
 
-	skb_dst_drop(skb);
-
 	if (fl6->flowi6_mark) {
 		skb_dst_set(skb, dst);
 		ndst = NULL;
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 72372ac..ecbcdbd 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1001,8 +1001,7 @@
 		goto tx_err_dst_release;
 	}
 
-	if (!net_eq(t->net, dev_net(dev)))
-		skb_scrub_packet(skb, true);
+	skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
 
 	/*
 	 * Okay, now see if we can stuff it in the buffer as-is.
@@ -1021,7 +1020,6 @@
 		consume_skb(skb);
 		skb = new_skb;
 	}
-	skb_dst_drop(skb);
 	if (fl6->flowi6_mark) {
 		skb_dst_set(skb, dst);
 		ndst = NULL;
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index b2e44f4..82b425b 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -860,9 +860,6 @@
 			tunnel->err_count = 0;
 	}
 
-	if (!net_eq(tunnel->net, dev_net(dev)))
-		skb_scrub_packet(skb, true);
-
 	/*
 	 * Okay, now see if we can stuff it in the buffer as-is.
 	 */
@@ -889,7 +886,7 @@
 	tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 
 	err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos,
-			    ttl, df);
+			    ttl, df, !net_eq(tunnel->net, dev_net(dev)));
 	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 	return NETDEV_TX_OK;
 
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index 9b3713ef..c99dea5 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -179,7 +179,7 @@
 	return iptunnel_xmit(rt, skb, fl.saddr,
 			     OVS_CB(skb)->tun_key->ipv4_dst, IPPROTO_GRE,
 			     OVS_CB(skb)->tun_key->ipv4_tos,
-			     OVS_CB(skb)->tun_key->ipv4_ttl, df);
+			     OVS_CB(skb)->tun_key->ipv4_ttl, df, false);
 err_free_rt:
 	ip_rt_put(rt);
 error: