From a0f54cbe5ac2cd8b8296c2c57c30029dd349cff0 Mon Sep 17 00:00:00 2001
From: Mathias Hall-Andersen <mathias@hall-andersen.dk>
Date: Sun, 4 Feb 2018 16:08:26 +0100
Subject: Align with go library layout

---
 main.go | 196 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 196 insertions(+)
 create mode 100644 main.go

(limited to 'main.go')

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..b12bb09
--- /dev/null
+++ b/main.go
@@ -0,0 +1,196 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"runtime"
+	"strconv"
+)
+
+const (
+	ExitSetupSuccess = 0
+	ExitSetupFailed  = 1
+)
+
+const (
+	ENV_WG_TUN_FD  = "WG_TUN_FD"
+	ENV_WG_UAPI_FD = "WG_UAPI_FD"
+)
+
+func printUsage() {
+	fmt.Printf("usage:\n")
+	fmt.Printf("%s [-f/--foreground] INTERFACE-NAME\n", os.Args[0])
+}
+
+func main() {
+
+	// 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]
+	}
+
+	// get log level (default: info)
+
+	logLevel := func() int {
+		switch os.Getenv("LOG_LEVEL") {
+		case "debug":
+			return LogLevelDebug
+		case "info":
+			return LogLevelInfo
+		case "error":
+			return LogLevelError
+		}
+		return LogLevelInfo
+	}()
+
+	logger := NewLogger(
+		logLevel,
+		fmt.Sprintf("(%s) ", interfaceName),
+	)
+
+	logger.Debug.Println("Debug log enabled")
+
+	// open TUN device (or use supplied fd)
+
+	tun, err := func() (TUNDevice, error) {
+		tunFdStr := os.Getenv(ENV_WG_TUN_FD)
+		if tunFdStr == "" {
+			return CreateTUN(interfaceName)
+		}
+
+		// construct tun device from supplied fd
+
+		fd, err := strconv.ParseUint(tunFdStr, 10, 32)
+		if err != nil {
+			return nil, err
+		}
+
+		file := os.NewFile(uintptr(fd), "")
+		return CreateTUNFromFile(interfaceName, file)
+	}()
+
+	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 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))
+		attr := &os.ProcAttr{
+			Files: []*os.File{
+				nil, // stdin
+				nil, // stdout
+				nil, // stderr
+				tun.File(),
+				fileUAPI,
+			},
+			Dir: ".",
+			Env: env,
+		}
+		err = Daemonize(attr)
+		if err != nil {
+			logger.Error.Println("Failed to daemonize:", err)
+			os.Exit(ExitSetupFailed)
+		}
+		return
+	}
+
+	// increase number of go workers (for Go <1.5)
+
+	runtime.GOMAXPROCS(runtime.NumCPU())
+
+	// create wireguard device
+
+	device := NewDevice(tun, logger)
+
+	logger.Info.Println("Device started")
+
+	// start uapi listener
+
+	errs := make(chan error)
+	term := make(chan os.Signal)
+
+	uapi, err := UAPIListen(interfaceName, fileUAPI)
+
+	go func() {
+		for {
+			conn, err := uapi.Accept()
+			if err != nil {
+				errs <- err
+				return
+			}
+			go ipcHandle(device, conn)
+		}
+	}()
+
+	logger.Info.Println("UAPI listener started")
+
+	// wait for program to terminate
+
+	signal.Notify(term, os.Kill)
+	signal.Notify(term, os.Interrupt)
+
+	select {
+	case <-term:
+	case <-errs:
+	case <-device.Wait():
+	}
+
+	// clean up
+
+	uapi.Close()
+	device.Close()
+
+	logger.Info.Println("Shutting down")
+}
-- 
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