gvn/tun/netutil_windows.go

/*
Copyright © 2022 lilo <luolee.me@gmail.com>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package tun

import (
	"fmt"
	"io/ioutil"
	"net"
	"os"

	"github.com/sirupsen/logrus"
)

var (
	VIP string
)

func ConfigAddr(dev Device) error {
	VIP = dev.Ip
	tmpfile, err := ioutil.TempFile("", "ConfigureAddr-*.bat")
	if err != nil {
		logrus.WithFields(logrus.Fields{
			"File": tmpfile,
		}).Error("ConfigureAddr error when create tmp file")
	}
	logrus.WithFields(logrus.Fields{
		"File": tmpfile.Name(),
	}).Info("bat file to be executed")
	// cidr -> 10.30.20.0/24,172.16.1.1/23 and etc
	ipv4Addr, ipv4Net, err := net.ParseCIDR(VIP)
	if err != nil {
		logrus.WithFields(logrus.Fields{
			"ERROR": err,
		}).Error("Parse VIP error")
	}
	vip := ipv4Addr.String()
	mask := ipv4MaskString(ipv4Net.Mask)
	serverVIP, _, _ := net.ParseCIDR(dev.ServerVIP)
	content := fmt.Sprintf("netsh interface ip set address name=%s source=static addr=%s mask=%s gateway=%s gwmetric=1", dev.Name, vip, mask, serverVIP.String())
	for _, route := range dev.Subnets {
		content = fmt.Sprintf("%s\nroute delete %s\nroute add -p %s %s metric 1", content, route, route, vip)
	}
	content = fmt.Sprintf("%s\nroute delete 0.0.0.0 %s\n", content, serverVIP)
	if _, err := tmpfile.Write([]byte(content)); err != nil {
		return err
	}
	if err := tmpfile.Close(); err != nil {
		logrus.WithFields(logrus.Fields{
			"ERROR": err,
			"File":  tmpfile.Name(),
		}).Error("AddRoute - Close tmp file error")
		return err
	}

	logrus.WithFields(logrus.Fields{
		"COMMAND": content,
	}).Debug("Execute command")

	if err := RunCommand(tmpfile.Name()); err != nil {
		return err
	}
	// remove if success otherwise for debug
	defer os.Remove(tmpfile.Name())
	return nil
}

func UnloadFirewall(dev Device) error {
	return RemoveRoute(dev.Subnets)
}

func RemoveRoute(subnets []string) error {
	logrus.WithFields(logrus.Fields{
		"subnets": subnets,
		"VIP":     VIP,
	}).Debug("Subnets to be removed")
	tmpfile, err := ioutil.TempFile("", "RemoveRoute-*.bat")
	if err != nil {
		logrus.WithFields(logrus.Fields{
			"File": tmpfile,
		}).Error("RemoveRoute error when create tmp file")
	}
	content := ""
	for _, route := range subnets {
		content = fmt.Sprintf("%s\nroute delete %s\n", content, route)
	}
	if _, err := tmpfile.Write([]byte(content)); err != nil {
		return err
	}

	logrus.WithFields(logrus.Fields{
		"COMMAND": content,
	}).Debug("Execute command")

	if err := tmpfile.Close(); err != nil {
		logrus.WithFields(logrus.Fields{
			"ERROR": err,
			"File":  tmpfile.Name(),
		}).Error("RemoveRoute - Close tmp file error")
		return err
	}

	if err := RunCommand(tmpfile.Name()); err != nil {
		return err
	}
	defer os.Remove(tmpfile.Name())
	return nil
}

func AddRoute(subnets []string) error {
	logrus.WithFields(logrus.Fields{
		"subnets": subnets,
		"VIP":     VIP,
	}).Debug("Subnets to be added")
	tmpfile, err := ioutil.TempFile("", "AddRoute-*.bat")
	if err != nil {
		logrus.WithFields(logrus.Fields{
			"File": tmpfile,
		}).Error("AddRoute error when create tmp file")
	}
	// cidr -> 10.30.20.0/24,172.16.1.1/23 and etc
	ipv4Addr, _, err := net.ParseCIDR(VIP)
	if err != nil {
		logrus.WithFields(logrus.Fields{
			"ERROR": err,
		}).Error("Parse VIP error")
	}
	vipWithoutMask := ipv4Addr.String()
	content := ""
	for _, route := range subnets {
		content = fmt.Sprintf("%s\nroute delete %s\nroute add -p %s %s metric 1", content, route, route, vipWithoutMask)
	}

	if _, err := tmpfile.Write([]byte(content)); err != nil {
		return err
	}

	logrus.WithFields(logrus.Fields{
		"COMMAND": content,
	}).Debug("Execute command")

	if err := tmpfile.Close(); err != nil {
		logrus.WithFields(logrus.Fields{
			"ERROR": err,
			"File":  tmpfile.Name(),
		}).Error("AddRoute - Close tmp file error")
		return err
	}

	if err := RunCommand(tmpfile.Name()); err != nil {
		return err
	}
	defer os.Remove(tmpfile.Name())
	return nil
}

func RefreshRoute(subnets []string) {
	RemoveRoute(subnets)
	AddRoute(subnets)
}