mlxsw: spectrum: Prevent RIF access outside of routing code

There are currently 5 users of mlxsw_sp_rif_find_by_dev() outside of the
routing code. Only one call site actually needs to dereference the
router interface (RIF). The rest merely need to know if a RIF exists for
the provided netdev.

Convert this call site to query the needed information directly from the
routing code instead of dereferencing the RIF.

This will later allow us to replace mlxsw_sp_rif_find_by_dev() with a
function that checks if a RIF exist.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -565,8 +565,8 @@ void mlxsw_sp_rif_destroy_by_dev(struct mlxsw_sp *mlxsw_sp,
 				 struct net_device *dev);
 struct mlxsw_sp_rif *mlxsw_sp_rif_find_by_dev(const struct mlxsw_sp *mlxsw_sp,
 					      const struct net_device *dev);
+u16 mlxsw_sp_rif_vid(struct mlxsw_sp *mlxsw_sp, const struct net_device *dev);
 u8 mlxsw_sp_router_port(const struct mlxsw_sp *mlxsw_sp);
-struct mlxsw_sp_fid *mlxsw_sp_rif_fid(const struct mlxsw_sp_rif *rif);
 int mlxsw_sp_router_nve_promote_decap(struct mlxsw_sp *mlxsw_sp, u32 ul_tb_id,
 				      enum mlxsw_sp_l3proto ul_proto,
 				      const union mlxsw_sp_l3addr *ul_sip,

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -6270,6 +6270,27 @@ mlxsw_sp_rif_find_by_dev(const struct mlxsw_sp *mlxsw_sp,
 	return NULL;
 }
 
+u16 mlxsw_sp_rif_vid(struct mlxsw_sp *mlxsw_sp, const struct net_device *dev)
+{
+	struct mlxsw_sp_rif *rif;
+	u16 vid = 0;
+
+	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
+	if (!rif)
+		goto out;
+
+	/* We only return the VID for VLAN RIFs. Otherwise we return an
+	 * invalid value (0).
+	 */
+	if (rif->ops->type != MLXSW_SP_RIF_TYPE_VLAN)
+		goto out;
+
+	vid = mlxsw_sp_fid_8021q_vid(rif->fid);
+
+out:
+	return vid;
+}
+
 static int mlxsw_sp_router_rif_disable(struct mlxsw_sp *mlxsw_sp, u16 rif)
 {
 	char ritr_pl[MLXSW_REG_RITR_LEN];
@@ -6436,11 +6457,6 @@ const struct net_device *mlxsw_sp_rif_dev(const struct mlxsw_sp_rif *rif)
 	return rif->dev;
 }
 
-struct mlxsw_sp_fid *mlxsw_sp_rif_fid(const struct mlxsw_sp_rif *rif)
-{
-	return rif->fid;
-}
-
 static struct mlxsw_sp_rif *
 mlxsw_sp_rif_create(struct mlxsw_sp *mlxsw_sp,
 		    const struct mlxsw_sp_rif_params *params,

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -1173,16 +1173,12 @@ mlxsw_sp_br_ban_rif_pvid_change(struct mlxsw_sp *mlxsw_sp,
 				const struct net_device *br_dev,
 				const struct switchdev_obj_port_vlan *vlan)
 {
-	struct mlxsw_sp_rif *rif;
-	struct mlxsw_sp_fid *fid;
 	u16 pvid;
 	u16 vid;
 
-	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, br_dev);
-	if (!rif)
+	pvid = mlxsw_sp_rif_vid(mlxsw_sp, br_dev);
+	if (!pvid)
 		return 0;
-	fid = mlxsw_sp_rif_fid(rif);
-	pvid = mlxsw_sp_fid_8021q_vid(fid);
 
 	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
 		if (vlan->flags & BRIDGE_VLAN_INFO_PVID) {