feat(internal/wireguard): opportunistic kernelspace

- Auto detect if kernelspace implementation is available
- Fallback to Go userspace implementation if kernel is not available

internal/netlink/family.go

@@ -1,6 +1,10 @@
 package netlink
 
-import "github.com/vishvananda/netlink"
+import (
+	"fmt"
+
+	"github.com/vishvananda/netlink"
+)
 
 //nolint:revive
 const (
@@ -8,3 +12,20 @@ const (
 	FAMILY_V4  = netlink.FAMILY_V4
 	FAMILY_V6  = netlink.FAMILY_V6
 )
+
+type WireguardChecker interface {
+	IsWireguardSupported() (ok bool, err error)
+}
+
+func (n *NetLink) IsWireguardSupported() (ok bool, err error) {
+	families, err := netlink.GenlFamilyList()
+	if err != nil {
+		return false, fmt.Errorf("cannot list gen 1 families: %w", err)
+	}
+	for _, family := range families {
+		if family.Name == "wireguard" {
+			return true, nil
+		}
+	}
+	return false, nil
+}