[PATCH 4.4 037/137] vxlan: fix missing options_len update on RX with collect metadata

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniel Borkmann <daniel@xxxxxxxxxxxxx>

[ Upstream commit 4024fcf70556311521e7b6cf79fa50e16f31013a ]

When signalling to metadata consumers that the metadata_dst entry
carries additional GBP extension data for vxlan (TUNNEL_VXLAN_OPT),
the dst's vxlan_metadata information is populated, but options_len
is left to zero. F.e. in ovs, ovs_flow_key_extract() checks for
options_len before extracting the data through ip_tunnel_info_opts_get().

Geneve uses ip_tunnel_info_opts_set() helper in receive path, which
sets options_len internally, vxlan however uses ip_tunnel_info_opts(),
so when filling vxlan_metadata, we do need to update options_len.

Fixes: 4c22279848c5 ("ip-tunnel: Use API to access tunnel metadata options.")
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Thomas Graf <tgraf@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/vxlan.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1306,8 +1306,10 @@ static int vxlan_udp_encap_recv(struct s
 		gbp = (struct vxlanhdr_gbp *)vxh;
 		md->gbp = ntohs(gbp->policy_id);
 
-		if (tun_dst)
+		if (tun_dst) {
 			tun_dst->u.tun_info.key.tun_flags |= TUNNEL_VXLAN_OPT;
+			tun_dst->u.tun_info.options_len = sizeof(*md);
+		}
 
 		if (gbp->dont_learn)
 			md->gbp |= VXLAN_GBP_DONT_LEARN;