wireguard-go/main.go
2019-04-19 07:48:09 +09:00

285 lines
6.6 KiB
Go

// +build !windows
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
*/
package main
import (
"fmt"
"golang.zx2c4.com/wireguard/device"
"golang.zx2c4.com/wireguard/ipc"
"golang.zx2c4.com/wireguard/tun"
"os"
"os/signal"
"runtime"
"strconv"
"syscall"
)
const (
ExitSetupSuccess = 0
ExitSetupFailed = 1
)
const (
ENV_WG_TUN_FD = "WG_TUN_FD"
ENV_WG_UAPI_FD = "WG_UAPI_FD"
ENV_WG_PROCESS_FOREGROUND = "WG_PROCESS_FOREGROUND"
)
func printUsage() {
fmt.Printf("usage:\n")
fmt.Printf("%s [-f/--foreground] INTERFACE-NAME\n", os.Args[0])
}
func warning() {
if runtime.GOOS != "linux" || os.Getenv(ENV_WG_PROCESS_FOREGROUND) == "1" {
return
}
shouldQuit := os.Getenv("WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD") != "1"
fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
fmt.Fprintln(os.Stderr, "W G")
fmt.Fprintln(os.Stderr, "W You are running this software on a Linux kernel, G")
fmt.Fprintln(os.Stderr, "W which is probably unnecessary and foolish. This G")
fmt.Fprintln(os.Stderr, "W is because the Linux kernel has built-in first G")
fmt.Fprintln(os.Stderr, "W class support for WireGuard, and this support is G")
fmt.Fprintln(os.Stderr, "W much more refined than this slower userspace G")
fmt.Fprintln(os.Stderr, "W implementation. For more information on G")
fmt.Fprintln(os.Stderr, "W installing the kernel module, please visit: G")
fmt.Fprintln(os.Stderr, "W https://www.wireguard.com/install G")
if shouldQuit {
fmt.Fprintln(os.Stderr, "W G")
fmt.Fprintln(os.Stderr, "W If you still want to use this program, against G")
fmt.Fprintln(os.Stderr, "W the advice here, please first export this G")
fmt.Fprintln(os.Stderr, "W environment variable: G")
fmt.Fprintln(os.Stderr, "W WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD=1 G")
}
fmt.Fprintln(os.Stderr, "W G")
fmt.Fprintln(os.Stderr, "WARNING WARNING WARNING WARNING WARNING WARNING WARNING")
if shouldQuit {
os.Exit(1)
}
}
func main() {
if len(os.Args) == 2 && os.Args[1] == "--version" {
fmt.Printf("wireguard-go v%s\n\nUserspace WireGuard daemon for %s-%s.\nInformation available at https://www.wireguard.com.\nCopyright (C) Jason A. Donenfeld <Jason@zx2c4.com>.\n", device.WireGuardGoVersion, runtime.GOOS, runtime.GOARCH)
return
}
warning()
// parse arguments
var foreground bool
var interfaceName string
if len(os.Args) < 2 || len(os.Args) > 3 {
printUsage()
return
}
switch os.Args[1] {
case "-f", "--foreground":
foreground = true
if len(os.Args) != 3 {
printUsage()
return
}
interfaceName = os.Args[2]
default:
foreground = false
if len(os.Args) != 2 {
printUsage()
return
}
interfaceName = os.Args[1]
}
if !foreground {
foreground = os.Getenv(ENV_WG_PROCESS_FOREGROUND) == "1"
}
// get log level (default: info)
logLevel := func() int {
switch os.Getenv("LOG_LEVEL") {
case "debug":
return device.LogLevelDebug
case "info":
return device.LogLevelInfo
case "error":
return device.LogLevelError
case "silent":
return device.LogLevelSilent
}
return device.LogLevelInfo
}()
// open TUN device (or use supplied fd)
tun, err := func() (tun.TUNDevice, error) {
tunFdStr := os.Getenv(ENV_WG_TUN_FD)
if tunFdStr == "" {
return tun.CreateTUN(interfaceName, device.DefaultMTU)
}
// construct tun device from supplied fd
fd, err := strconv.ParseUint(tunFdStr, 10, 32)
if err != nil {
return nil, err
}
err = syscall.SetNonblock(int(fd), true)
if err != nil {
return nil, err
}
file := os.NewFile(uintptr(fd), "")
return tun.CreateTUNFromFile(file, device.DefaultMTU)
}()
if err == nil {
realInterfaceName, err2 := tun.Name()
if err2 == nil {
interfaceName = realInterfaceName
}
}
logger := device.NewLogger(
logLevel,
fmt.Sprintf("(%s) ", interfaceName),
)
logger.Info.Println("Starting wireguard-go version", device.WireGuardGoVersion)
logger.Debug.Println("Debug log enabled")
if err != nil {
logger.Error.Println("Failed to create TUN device:", err)
os.Exit(ExitSetupFailed)
}
// open UAPI file (or use supplied fd)
fileUAPI, err := func() (*os.File, error) {
uapiFdStr := os.Getenv(ENV_WG_UAPI_FD)
if uapiFdStr == "" {
return ipc.UAPIOpen(interfaceName)
}
// use supplied fd
fd, err := strconv.ParseUint(uapiFdStr, 10, 32)
if err != nil {
return nil, err
}
return os.NewFile(uintptr(fd), ""), nil
}()
if err != nil {
logger.Error.Println("UAPI listen error:", err)
os.Exit(ExitSetupFailed)
return
}
// daemonize the process
if !foreground {
env := os.Environ()
env = append(env, fmt.Sprintf("%s=3", ENV_WG_TUN_FD))
env = append(env, fmt.Sprintf("%s=4", ENV_WG_UAPI_FD))
env = append(env, fmt.Sprintf("%s=1", ENV_WG_PROCESS_FOREGROUND))
files := [3]*os.File{}
if os.Getenv("LOG_LEVEL") != "" && logLevel != device.LogLevelSilent {
files[0], _ = os.Open(os.DevNull)
files[1] = os.Stdout
files[2] = os.Stderr
} else {
files[0], _ = os.Open(os.DevNull)
files[1], _ = os.Open(os.DevNull)
files[2], _ = os.Open(os.DevNull)
}
attr := &os.ProcAttr{
Files: []*os.File{
files[0], // stdin
files[1], // stdout
files[2], // stderr
tun.File(),
fileUAPI,
},
Dir: ".",
Env: env,
}
path, err := os.Executable()
if err != nil {
logger.Error.Println("Failed to determine executable:", err)
os.Exit(ExitSetupFailed)
}
process, err := os.StartProcess(
path,
os.Args,
attr,
)
if err != nil {
logger.Error.Println("Failed to daemonize:", err)
os.Exit(ExitSetupFailed)
}
process.Release()
return
}
device := device.NewDevice(tun, logger)
logger.Info.Println("Device started")
errs := make(chan error)
term := make(chan os.Signal, 1)
uapi, err := ipc.UAPIListen(interfaceName, fileUAPI)
if err != nil {
logger.Error.Println("Failed to listen on uapi socket:", err)
os.Exit(ExitSetupFailed)
}
go func() {
for {
conn, err := uapi.Accept()
if err != nil {
errs <- err
return
}
go device.IpcHandle(conn)
}
}()
logger.Info.Println("UAPI listener started")
// wait for program to terminate
signal.Notify(term, syscall.SIGTERM)
signal.Notify(term, os.Interrupt)
select {
case <-term:
case <-errs:
case <-device.Wait():
}
// clean up
uapi.Close()
device.Close()
logger.Info.Println("Shutting down")
}