net: dsa: resolve forwarding path for dsa slave ports

Add .ndo_fill_forward_path for dsa slave port devices

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -853,6 +853,7 @@ enum net_device_path_type {
 	DEV_PATH_VLAN,
 	DEV_PATH_BRIDGE,
 	DEV_PATH_PPPOE,
+	DEV_PATH_DSA,
 };
 
 struct net_device_path {
@@ -873,6 +874,10 @@ struct net_device_path {
 			u16		vlan_id;
 			__be16		vlan_proto;
 		} bridge;
+		struct {
+			int port;
+			u16 proto;
+		} dsa;
 	};
 };
 

net/dsa/slave.c

@@ -1654,6 +1654,21 @@ static void dsa_slave_get_stats64(struct net_device *dev,
 		dev_get_tstats64(dev, s);
 }
 
+static int dsa_slave_fill_forward_path(struct net_device_path_ctx *ctx,
+				       struct net_device_path *path)
+{
+	struct dsa_port *dp = dsa_slave_to_port(ctx->dev);
+	struct dsa_port *cpu_dp = dp->cpu_dp;
+
+	path->dev = ctx->dev;
+	path->type = DEV_PATH_DSA;
+	path->dsa.proto = cpu_dp->tag_ops->proto;
+	path->dsa.port = dp->index;
+	ctx->dev = cpu_dp->master;
+
+	return 0;
+}
+
 static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_open	 	= dsa_slave_open,
 	.ndo_stop		= dsa_slave_close,
@@ -1679,6 +1694,7 @@ static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_vlan_rx_kill_vid	= dsa_slave_vlan_rx_kill_vid,
 	.ndo_get_devlink_port	= dsa_slave_get_devlink_port,
 	.ndo_change_mtu		= dsa_slave_change_mtu,
+	.ndo_fill_forward_path	= dsa_slave_fill_forward_path,
 };
 
 static struct device_type dsa_type = {