nfp: flower: Allow ipv6gretap interface for offloading

The tunnel_type check only allows for "netif_is_gretap", but for
OVS the port is actually "netif_is_ip6gretap" when setting up GRE
for ipv6, which means offloading request was rejected before.

Therefore, adding "netif_is_ip6gretap" allow ipv6gretap interface
for offloading.
Signed-off-by: Yu Xiao <yu.xiao@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -272,7 +272,8 @@ nfp_flower_tun_is_gre(struct flow_rule *rule, int start_idx)
 	for (act_idx = start_idx + 1; act_idx < num_act; act_idx++)
 		if (act[act_idx].id == FLOW_ACTION_REDIRECT ||
 		    act[act_idx].id == FLOW_ACTION_MIRRED)
-			return netif_is_gretap(act[act_idx].dev);
+			return netif_is_gretap(act[act_idx].dev) ||
+			       netif_is_ip6gretap(act[act_idx].dev);
 
 	return false;
 }

drivers/net/ethernet/netronome/nfp/flower/cmsg.h

@@ -703,7 +703,7 @@ nfp_fl_netdev_is_tunnel_type(struct net_device *netdev,
 {
 	if (netif_is_vxlan(netdev))
 		return tun_type == NFP_FL_TUNNEL_VXLAN;
-	if (netif_is_gretap(netdev))
+	if (netif_is_gretap(netdev) || netif_is_ip6gretap(netdev))
 		return tun_type == NFP_FL_TUNNEL_GRE;
 	if (netif_is_geneve(netdev))
 		return tun_type == NFP_FL_TUNNEL_GENEVE;

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

@@ -360,7 +360,7 @@ nfp_flower_calculate_key_layers(struct nfp_app *app,
 
 		if (!flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 			/* check if GRE, which has no enc_ports */
-			if (!netif_is_gretap(netdev)) {
+			if (!netif_is_gretap(netdev) && !netif_is_ip6gretap(netdev)) {
 				NL_SET_ERR_MSG_MOD(extack, "unsupported offload: an exact match on L4 destination port is required for non-GRE tunnels");
 				return -EOPNOTSUPP;
 			}