aboutsummaryrefslogtreecommitdiffstats
path: root/main.go
blob: 7742eef04bd9421cbb5c3a4011de0709f754c4f3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
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(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")
}