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/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package main
// #include <stdlib.h>
// #include <sys/types.h>
// static void callLogger(void *func, int level, const char *msg)
// {
// ((void(*)(int, const char *))func)(level, msg);
// }
import "C"
import (
"bufio"
"errors"
"git.zx2c4.com/wireguard-go/tun"
"golang.org/x/sys/unix"
"io/ioutil"
"log"
"math"
"os"
"os/signal"
"runtime"
"strings"
"syscall"
"time"
"unsafe"
)
var loggerFunc unsafe.Pointer
var versionString *C.char
type CLogger struct {
level C.int
interfaceName string
}
func (l *CLogger) Write(p []byte) (int, error) {
if uintptr(loggerFunc) == 0 {
return 0, errors.New("No logger initialized")
}
message := C.CString(l.interfaceName + ": " + string(p))
C.callLogger(loggerFunc, l.level, message)
C.free(unsafe.Pointer(message))
return len(p), nil
}
type DeviceState struct {
device *Device
logger *Logger
endpointsTimer *time.Timer
endpointsSettings string
}
var tunnelHandles map[int32]*DeviceState
func listenForRouteChanges() {
//TODO: replace with NWPathMonitor
data := make([]byte, os.Getpagesize())
routeSocket, err := unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
if err != nil {
return
}
for {
n, err := unix.Read(routeSocket, data)
if err != nil {
if errno, ok := err.(syscall.Errno); ok && errno == syscall.EINTR {
continue
}
return
}
if n < 4 {
continue
}
for _, deviceState := range tunnelHandles {
if deviceState.endpointsTimer == nil {
deviceState.endpointsTimer = time.AfterFunc(time.Second, func() {
deviceState.endpointsTimer = nil
bufferedSettings := bufio.NewReadWriter(bufio.NewReader(strings.NewReader(deviceState.endpointsSettings)), bufio.NewWriter(ioutil.Discard))
deviceState.logger.Info.Println("Setting endpoints for re-resolution due to network change")
err := ipcSetOperation(deviceState.device, bufferedSettings)
if err != nil {
deviceState.logger.Error.Println(err)
}
})
}
}
}
}
func init() {
versionString = C.CString(WireGuardGoVersion)
roamingDisabled = true
tunnelHandles = make(map[int32]*DeviceState)
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)
buf[n] = 0
if uintptr(loggerFunc) != 0 {
C.callLogger(loggerFunc, 0, (*_Ctype_char)(unsafe.Pointer(&buf[0])))
}
}
}
}()
go listenForRouteChanges()
}
//export wgSetLogger
func wgSetLogger(loggerFn uintptr) {
loggerFunc = unsafe.Pointer(loggerFn)
}
func extractEndpointFromSettings(settings string) string {
var b strings.Builder
pubkey := ""
endpoint := ""
listenPort := "listen_port=0"
for _, line := range strings.Split(settings, "\n") {
if strings.HasPrefix(line, "listen_port=") {
listenPort = line
} else if strings.HasPrefix(line, "public_key=") {
if pubkey != "" && endpoint != "" {
b.WriteString(pubkey + "\n" + endpoint + "\n")
}
pubkey = line
} else if strings.HasPrefix(line, "endpoint=") {
endpoint = line
} else if line == "remove=true" {
pubkey = ""
endpoint = ""
}
}
if pubkey != "" && endpoint != "" {
b.WriteString(pubkey + "\n" + endpoint + "\n")
}
return listenPort + "\n" + b.String()
}
//export wgTurnOn
func wgTurnOn(ifnameRef string, settings string, tunFd int32) int32 {
interfaceName := string([]byte(ifnameRef))
logger := &Logger{
Debug: log.New(&CLogger{level: 0, interfaceName: interfaceName}, "", 0),
Info: log.New(&CLogger{level: 1, interfaceName: interfaceName}, "", 0),
Error: log.New(&CLogger{level: 2, interfaceName: interfaceName}, "", 0),
}
logger.Debug.Println("Debug log enabled")
tun, _, err := tun.CreateTUNFromFD(int(tunFd))
if err != nil {
logger.Error.Println(err)
return -1
}
logger.Info.Println("Attaching to interface")
device := NewDevice(tun, logger)
bufferedSettings := bufio.NewReadWriter(bufio.NewReader(strings.NewReader(settings)), bufio.NewWriter(ioutil.Discard))
setError := ipcSetOperation(device, bufferedSettings)
if setError != nil {
logger.Error.Println(setError)
return -1
}
device.Up()
logger.Info.Println("Device started")
var i int32
for i = 0; i < math.MaxInt32; i++ {
if _, exists := tunnelHandles[i]; !exists {
break
}
}
if i == math.MaxInt32 {
return -1
}
tunnelHandles[i] = &DeviceState{
device: device,
logger: logger,
endpointsSettings: extractEndpointFromSettings(settings),
}
return i
}
//export wgTurnOff
func wgTurnOff(tunnelHandle int32) {
deviceState, ok := tunnelHandles[tunnelHandle]
if !ok {
return
}
delete(tunnelHandles, tunnelHandle)
t := deviceState.endpointsTimer
if t != nil {
deviceState.endpointsTimer = nil
t.Stop()
}
deviceState.device.Close()
}
//export wgVersion
func wgVersion() *C.char {
return versionString
}
func main() {}
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