wireguard-go/main.go
Jason A. Donenfeld da9d300cf8 main: now that we're upstreamed, relax Linux warning
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-05-02 02:20:47 -06:00

270 lines
6.1 KiB
Go

// +build !windows
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2020 WireGuard LLC. All Rights Reserved.
*/
package main
import (
"fmt"
"os"
"os/signal"
"runtime"
"strconv"
"syscall"
"golang.zx2c4.com/wireguard/device"
"golang.zx2c4.com/wireguard/ipc"
"golang.zx2c4.com/wireguard/tun"
)
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
}
fmt.Fprintln(os.Stderr, "┌───────────────────────────────────────────────────┐")
fmt.Fprintln(os.Stderr, "│ │")
fmt.Fprintln(os.Stderr, "│ Running this software on Linux is unnecessary, │")
fmt.Fprintln(os.Stderr, "│ because the Linux kernel has built-in first │")
fmt.Fprintln(os.Stderr, "│ class support for WireGuard, which will be │")
fmt.Fprintln(os.Stderr, "│ faster, slicker, and better integrated. For │")
fmt.Fprintln(os.Stderr, "│ information on installing the kernel module, │")
fmt.Fprintln(os.Stderr, "│ please visit: <https://wireguard.com/install>. │")
fmt.Fprintln(os.Stderr, "│ │")
fmt.Fprintln(os.Stderr, "└───────────────────────────────────────────────────┘")
}
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()
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.Device, 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")
}