summaryrefslogtreecommitdiffhomepage
path: root/tunnel/tools/libwg-go/api-android.go
blob: d47c5d76cfdef368ae1cdacf805c53acc553a023 (plain)
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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/* SPDX-License-Identifier: Apache-2.0
 *
 * Copyright © 2017-2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 */

package main

// #cgo LDFLAGS: -llog
// #include <android/log.h>
import "C"

import (
	"fmt"
	"math"
	"net"
	"os"
	"os/signal"
	"runtime"
	"runtime/debug"
	"strings"
	"unsafe"

	"golang.org/x/sys/unix"
	"golang.zx2c4.com/wireguard/conn"
	"golang.zx2c4.com/wireguard/device"
	"golang.zx2c4.com/wireguard/ipc"
	"golang.zx2c4.com/wireguard/tun"
)

type AndroidLogger struct {
	level C.int
	tag   *C.char
}

func cstring(s string) *C.char {
	b, err := unix.BytePtrFromString(s)
	if err != nil {
		b := [1]C.char{}
		return &b[0]
	}
	return (*C.char)(unsafe.Pointer(b))
}

func (l AndroidLogger) Printf(format string, args ...interface{}) {
	C.__android_log_write(l.level, l.tag, cstring(fmt.Sprintf(format, args...)))
}

type TunnelHandle struct {
	device *device.Device
	uapi   net.Listener
}

var tunnelHandles map[int32]TunnelHandle

func init() {
	tunnelHandles = make(map[int32]TunnelHandle)
	signals := make(chan os.Signal)
	signal.Notify(signals, unix.SIGUSR2)
	go func() {
		buf := make([]byte, os.Getpagesize())
		for {
			select {
			case <-signals:
				n := runtime.Stack(buf, true)
				if n == len(buf) {
					n--
				}
				buf[n] = 0
				C.__android_log_write(C.ANDROID_LOG_ERROR, cstring("WireGuard/GoBackend/Stacktrace"), (*C.char)(unsafe.Pointer(&buf[0])))
			}
		}
	}()
}

//export wgTurnOn
func wgTurnOn(interfaceName string, tunFd int32, settings string) int32 {
	tag := cstring("WireGuard/GoBackend/" + interfaceName)
	logger := &device.Logger{
		Verbosef: AndroidLogger{level: C.ANDROID_LOG_DEBUG, tag: tag}.Printf,
		Errorf:   AndroidLogger{level: C.ANDROID_LOG_ERROR, tag: tag}.Printf,
	}

	tun, name, err := tun.CreateUnmonitoredTUNFromFD(int(tunFd))
	if err != nil {
		unix.Close(int(tunFd))
		logger.Errorf("CreateUnmonitoredTUNFromFD: %v", err)
		return -1
	}

	logger.Verbosef("Attaching to interface %v", name)
	device := device.NewDevice(tun, conn.NewStdNetBind(), logger)

	err = device.IpcSet(settings)
	if err != nil {
		unix.Close(int(tunFd))
		logger.Errorf("IpcSet: %v", err)
		return -1
	}
	device.DisableSomeRoamingForBrokenMobileSemantics()

	var uapi net.Listener

	uapiFile, err := ipc.UAPIOpen(name)
	if err != nil {
		logger.Errorf("UAPIOpen: %v", err)
	} else {
		uapi, err = ipc.UAPIListen(name, uapiFile)
		if err != nil {
			uapiFile.Close()
			logger.Errorf("UAPIListen: %v", err)
		} else {
			go func() {
				for {
					conn, err := uapi.Accept()
					if err != nil {
						return
					}
					go device.IpcHandle(conn)
				}
			}()
		}
	}

	err = device.Up()
	if err != nil {
		logger.Errorf("Unable to bring up device: %v", err)
		uapiFile.Close()
		device.Close()
		return -1
	}
	logger.Verbosef("Device started")

	var i int32
	for i = 0; i < math.MaxInt32; i++ {
		if _, exists := tunnelHandles[i]; !exists {
			break
		}
	}
	if i == math.MaxInt32 {
		logger.Errorf("Unable to find empty handle")
		uapiFile.Close()
		device.Close()
		return -1
	}
	tunnelHandles[i] = TunnelHandle{device: device, uapi: uapi}
	return i
}

//export wgTurnOff
func wgTurnOff(tunnelHandle int32) {
	handle, ok := tunnelHandles[tunnelHandle]
	if !ok {
		return
	}
	delete(tunnelHandles, tunnelHandle)
	if handle.uapi != nil {
		handle.uapi.Close()
	}
	handle.device.Close()
}

//export wgGetSocketV4
func wgGetSocketV4(tunnelHandle int32) int32 {
	handle, ok := tunnelHandles[tunnelHandle]
	if !ok {
		return -1
	}
	bind, _ := handle.device.Bind().(conn.PeekLookAtSocketFd)
	if bind == nil {
		return -1
	}
	fd, err := bind.PeekLookAtSocketFd4()
	if err != nil {
		return -1
	}
	return int32(fd)
}

//export wgGetSocketV6
func wgGetSocketV6(tunnelHandle int32) int32 {
	handle, ok := tunnelHandles[tunnelHandle]
	if !ok {
		return -1
	}
	bind, _ := handle.device.Bind().(conn.PeekLookAtSocketFd)
	if bind == nil {
		return -1
	}
	fd, err := bind.PeekLookAtSocketFd6()
	if err != nil {
		return -1
	}
	return int32(fd)
}

//export wgGetConfig
func wgGetConfig(tunnelHandle int32) *C.char {
	handle, ok := tunnelHandles[tunnelHandle]
	if !ok {
		return nil
	}
	settings, err := handle.device.IpcGet()
	if err != nil {
		return nil
	}
	return C.CString(settings)
}

//export wgVersion
func wgVersion() *C.char {
	info, ok := debug.ReadBuildInfo()
	if !ok {
		return C.CString("unknown")
	}
	for _, dep := range info.Deps {
		if dep.Path == "golang.zx2c4.com/wireguard" {
			parts := strings.Split(dep.Version, "-")
			if len(parts) == 3 && len(parts[2]) == 12 {
				return C.CString(parts[2][:7])
			}
			return C.CString(dep.Version)
		}
	}
	return C.CString("unknown")
}

func main() {}