add all files from Hong

plugins/leasetime/plugin.go

@@ -0,0 +1,57 @@
+// 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 leasetime
+
+import (
+	"errors"
+	"time"
+
+	"github.com/coredhcp/coredhcp/handler"
+	"github.com/coredhcp/coredhcp/logger"
+	"github.com/coredhcp/coredhcp/plugins"
+	"github.com/insomniacslk/dhcp/dhcpv4"
+)
+
+// Plugin wraps plugin registration information
+var Plugin = plugins.Plugin{
+	Name: "lease_time",
+	// currently not supported for DHCPv6
+	Setup6: nil,
+	Setup4: setup4,
+}
+
+var (
+	log         = logger.GetLogger("plugins/lease_time")
+	v4LeaseTime time.Duration
+)
+
+// Handler4 handles DHCPv4 packets for the lease_time plugin.
+func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
+	if req.OpCode != dhcpv4.OpcodeBootRequest {
+		return resp, false
+	}
+	// Set lease time unless it has already been set
+	if !resp.Options.Has(dhcpv4.OptionIPAddressLeaseTime) {
+		resp.Options.Update(dhcpv4.OptIPAddressLeaseTime(v4LeaseTime))
+	}
+	return resp, false
+}
+
+func setup4(args ...string) (handler.Handler4, error) {
+	log.Print("loading `lease_time` plugin for DHCPv4")
+	if len(args) < 1 {
+		log.Error("No default lease time provided")
+		return nil, errors.New("lease_time failed to initialize")
+	}
+
+	leaseTime, err := time.ParseDuration(args[0])
+	if err != nil {
+		log.Errorf("invalid duration: %v", args[0])
+		return nil, errors.New("lease_time failed to initialize")
+	}
+	v4LeaseTime = leaseTime
+
+	return Handler4, nil
+}