nfp: flower: reject tunnel encap with ipv6 outer headers for offloading

This fixes a bug where ipv6 tunnels would report that it is
getting offloaded to hardware but would actually be rejected
by hardware.

Fixes: b27d6a95 ("nfp: compile flower vxlan tunnel set actions")
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/action.c

@@ -52,6 +52,7 @@
 #define NFP_FL_TUNNEL_CSUM			cpu_to_be16(0x01)
 #define NFP_FL_TUNNEL_KEY			cpu_to_be16(0x04)
 #define NFP_FL_TUNNEL_GENEVE_OPT		cpu_to_be16(0x0800)
+#define NFP_FL_SUPPORTED_TUNNEL_INFO_FLAGS	IP_TUNNEL_INFO_TX
 #define NFP_FL_SUPPORTED_IPV4_UDP_TUN_FLAGS	(NFP_FL_TUNNEL_CSUM | \
 						 NFP_FL_TUNNEL_KEY | \
 						 NFP_FL_TUNNEL_GENEVE_OPT)
@@ -741,11 +742,16 @@ nfp_flower_loop_action(struct nfp_app *app, const struct tc_action *a,
 		nfp_fl_push_vlan(psh_v, a);
 		*a_len += sizeof(struct nfp_fl_push_vlan);
 	} else if (is_tcf_tunnel_set(a)) {
+		struct ip_tunnel_info *ip_tun = tcf_tunnel_info(a);
 		struct nfp_repr *repr = netdev_priv(netdev);
+
 		*tun_type = nfp_fl_get_tun_from_act_l4_port(repr->app, a);
 		if (*tun_type == NFP_FL_TUNNEL_NONE)
 			return -EOPNOTSUPP;
 
+		if (ip_tun->mode & ~NFP_FL_SUPPORTED_TUNNEL_INFO_FLAGS)
+			return -EOPNOTSUPP;
+
 		/* Pre-tunnel action is required for tunnel encap.
 		 * This checks for next hop entries on NFP.
 		 * If none, the packet falls back before applying other actions.