gre: do not keep the GRE header around in collect medata mode

Jiri Benc · davem330 · commit e271c7b4420d · 2016-05-11T15:16:32.000-04:00
For ipgre interface in collect metadata mode, it doesn't make sense for the interface to be of ARPHRD_IPGRE type. The outer header of received packets is not needed, as all the information from it is present in metadata_dst. We already don't set ipgre_header_ops for collect metadata interfaces, which is the only consumer of mac_header pointing to the outer IP header. Just set the interface type to ARPHRD_NONE in collect metadata mode for ipgre (not gretap, that still correctly stays ARPHRD_ETHER) and reset mac_header. Fixes: a64b04d ("gre: do not assign header_ops in collect metadata mode") Fixes: 2e15ea3 ("ip_gre: Add support to collect tunnel metadata.") Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
@@ -398,7 +398,10 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 				  iph->saddr, iph->daddr, tpi->key);
 
 	if (tunnel) {
-		skb_pop_mac_header(skb);
+		if (tunnel->dev->type != ARPHRD_NONE)
+			skb_pop_mac_header(skb);
+		else
+			skb_reset_mac_header(skb);
 		if (tunnel->collect_md) {
 			__be16 flags;
 			__be64 tun_id;
@@ -1031,6 +1034,8 @@ static void ipgre_netlink_parms(struct net_device *dev,
 		struct ip_tunnel *t = netdev_priv(dev);
 
 		t->collect_md = true;
+		if (dev->type == ARPHRD_IPGRE)
+			dev->type = ARPHRD_NONE;
 	}
 }
 
