@@ -107,6 +107,8 @@ module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
static struct rtnl_link_ops ipgre_link_ops __read_mostly;
+static const struct header_ops ipgre_header_ops;
+
static int ipgre_tunnel_init(struct net_device *dev);
static void erspan_build_header(struct sk_buff *skb,
u32 id, u32 index,
@@ -364,7 +366,10 @@ static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
raw_proto, false) < 0)
goto drop;
- if (tunnel->dev->type != ARPHRD_NONE)
+ /* Special case for ipgre_header_parse(), which expects the
+ * mac_header to point to the outer IP header.
+ */
+ if (tunnel->dev->header_ops == &ipgre_header_ops)
skb_pop_mac_header(skb);
else
skb_reset_mac_header(skb);
Commit e271c7b4420d ("gre: do not keep the GRE header around in collect medata mode") did reset the mac_header for the collect_md case. Let's extend this behaviour to classical gre devices as well. ipgre_header_parse() seems to be the only case that requires mac_header to point to the outer header. We can detect this case accurately by checking ->header_ops. For all other cases, we can reset mac_header. This allows to push an Ethernet header to ipgre packets and redirect them to an Ethernet device: $ tc filter add dev gre0 ingress matchall \ action vlan push_eth dst_mac 00:00:5e:00:53:01 \ src_mac 00:00:5e:00:53:00 \ action mirred egress redirect dev eth0 Before this patch, this worked only for collect_md gre devices. Now this works for regular gre devices as well. Only the special case of gre devices that use ipgre_header_ops isn't supported. Signed-off-by: Guillaume Nault <gnault@redhat.com> --- net/ipv4/ip_gre.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)