add all files from Hong

plugins/router/plugin.go

@@ -0,0 +1,49 @@
+// Copyright 2018-present the CoreDHCP Authors. All rights reserved
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package router
+
+import (
+	"errors"
+	"net"
+
+	"github.com/coredhcp/coredhcp/handler"
+	"github.com/coredhcp/coredhcp/logger"
+	"github.com/coredhcp/coredhcp/plugins"
+	"github.com/insomniacslk/dhcp/dhcpv4"
+)
+
+var log = logger.GetLogger("plugins/router")
+
+// Plugin wraps plugin registration information
+var Plugin = plugins.Plugin{
+	Name:   "router",
+	Setup4: setup4,
+}
+
+var (
+	routers []net.IP
+)
+
+func setup4(args ...string) (handler.Handler4, error) {
+	log.Printf("Loaded plugin for DHCPv4.")
+	if len(args) < 1 {
+		return nil, errors.New("need at least one router IP address")
+	}
+	for _, arg := range args {
+		router := net.ParseIP(arg)
+		if router.To4() == nil {
+			return Handler4, errors.New("expected an router IP address, got: " + arg)
+		}
+		routers = append(routers, router)
+	}
+	log.Infof("loaded %d router IP addresses.", len(routers))
+	return Handler4, nil
+}
+
+//Handler4 handles DHCPv4 packets for the router plugin
+func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
+	resp.Options.Update(dhcpv4.OptRouter(routers...))
+	return resp, false
+}