add router interface

router/router.go

@@ -0,0 +1,24 @@
+package router
+
+import (
+	"context"
+	"net"
+)
+
+type Options struct{}
+
+type Option func(opts *Options)
+
+type Route struct {
+	// Net is the destination network, e.g. 192.168.0.0/16, 172.10.10.0/24.
+	Net *net.IPNet
+	// Gateway is the gateway for the destination network.
+	Gateway net.IP
+}
+
+type Router interface {
+	// SetRoute adds or updates a route for the router.
+	SetRoute(ctx context.Context, route *Route, opts ...Option) bool
+	// GetRoute queries a route by destination IP address.
+	GetRoute(ctx context.Context, dst net.IP, opts ...Option) *Route
+}