wireguard-go-bridge: take fd instead of fnptr

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

wireguard-go-bridge/src/api-ios.go

@@ -15,6 +15,7 @@ import "C"
 
 import (
 	"bufio"
+	"errors"
 	"git.zx2c4.com/wireguard-go/tun"
 	"golang.org/x/sys/unix"
 	"io/ioutil"
@@ -25,7 +26,6 @@ import (
 	"runtime"
 	"strings"
 	"unsafe"
-	"errors"
 )
 
 var loggerFunc unsafe.Pointer
@@ -75,7 +75,7 @@ func wgSetLogger(loggerFn uintptr) {
 }
 
 //export wgTurnOn
-func wgTurnOn(ifnameRef string, settings string, mtu uint16, readFn uintptr, writeFn uintptr, ctx uintptr) int32 {
+func wgTurnOn(ifnameRef string, settings string, tunFd int32) int32 {
 	interfaceName := string([]byte(ifnameRef))
 
 	logger := &Logger{
@@ -86,12 +86,14 @@ func wgTurnOn(ifnameRef string, settings string, mtu uint16, readFn uintptr, wri
 
 	logger.Debug.Println("Debug log enabled")
 
-	tun := tun.CreateTUN(mtu, unsafe.Pointer(readFn), unsafe.Pointer(writeFn), unsafe.Pointer(ctx))
+	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)
 
-	logger.Debug.Println("Interface has MTU", device.tun.mtu)
-
 	bufferedSettings := bufio.NewReadWriter(bufio.NewReader(strings.NewReader(settings)), bufio.NewWriter(ioutil.Discard))
 	setError := ipcSetOperation(device, bufferedSettings)
 	if setError != nil {

wireguard-go-bridge/src/queueconstants.go

@@ -8,9 +8,9 @@ package main
 /* Fit within memory limits for iOS */
 
 const (
-        QueueOutboundSize          = 1024
-        QueueInboundSize           = 1024
-        QueueHandshakeSize         = 1024
-        MaxSegmentSize             = 1700
-        PreallocatedBuffersPerPool = 1024
+	QueueOutboundSize          = 1024
+	QueueInboundSize           = 1024
+	QueueHandshakeSize         = 1024
+	MaxSegmentSize             = 1700
+	PreallocatedBuffersPerPool = 1024
 )

wireguard-go-bridge/src/tun/api-ios.go

@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+package tun
+
+import (
+	"git.zx2c4.com/wireguard-go/rwcancel"
+	"golang.org/x/sys/unix"
+	"net"
+	"os"
+)
+
+func CreateTUNFromFD(tunFd int) (TUNDevice, string, error) {
+	file := os.NewFile(uintptr(tunFd), "/dev/tun")
+	tun := &nativeTun{
+		tunFile: file,
+		fd:      file.Fd(),
+		events:  make(chan TUNEvent, 5),
+		errors:  make(chan error, 5),
+	}
+	var err error
+	tun.rwcancel, err = rwcancel.NewRWCancel(tunFd)
+	if err != nil {
+		return nil, "", err
+	}
+	name, err := tun.Name()
+	if err != nil {
+		tun.rwcancel.Cancel()
+		return nil, "", err
+	}
+	tunIfindex, err := func() (int, error) {
+		iface, err := net.InterfaceByName(name)
+		if err != nil {
+			return -1, err
+		}
+		return iface.Index, nil
+	}()
+	if err != nil {
+		tun.tunFile.Close()
+		return nil, "", err
+	}
+	tun.routeSocket, err = unix.Socket(unix.AF_ROUTE, unix.SOCK_RAW, unix.AF_UNSPEC)
+	if err != nil {
+		tun.tunFile.Close()
+		return nil, "", err
+	}
+	go tun.routineRouteListener(tunIfindex)
+
+	return tun, name, nil
+}

wireguard-go-bridge/src/tun/tun_ios.go

@@ -1,90 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
- */
-
-package tun
-
-// #include <sys/types.h>
-// static ssize_t callFnWithCtx(const void *func, const void *ctx, const void *buffer, size_t len)
-// {
-// 	return ((ssize_t(*)(const void *, const unsigned char *, size_t))func)(ctx, buffer, len);
-// }
-import "C"
-
-import (
-	"os"
-	"syscall"
-	"unsafe"
-)
-
-type nativeTun struct {
-	events  chan TUNEvent
-	mtu     int
-	readFn  unsafe.Pointer
-	writeFn unsafe.Pointer
-	ctx     unsafe.Pointer
-}
-
-func CreateTUN(mtu uint16, readFn unsafe.Pointer, writeFn unsafe.Pointer, ctx unsafe.Pointer) TUNDevice {
-	if mtu == 0 {
-		/* 0 means automatic MTU, which iOS makes outerMTU-80-15. The 80 is for
-		 * WireGuard and the 15 ensures our padding will work. Therefore, it's
-		 * safe to have this code assume a massive MTU.
-		 */
-		mtu = ^mtu
-	}
-	tun := &nativeTun{
-		events:  make(chan TUNEvent, 10),
-		mtu:     int(mtu),
-		readFn:  readFn,
-		writeFn: writeFn,
-		ctx:     ctx,
-	}
-	tun.events <- TUNEventUp
-	return tun
-}
-
-func (tun *nativeTun) Name() (string, error) {
-	return "tun", nil
-}
-
-func (tun *nativeTun) File() *os.File {
-	return nil
-}
-
-func (tun *nativeTun) Events() chan TUNEvent {
-	return tun.events
-}
-
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
-	ret := C.callFnWithCtx(tun.readFn, tun.ctx, unsafe.Pointer(&buff[offset]), C.size_t(len(buff) - offset))
-	if ret < 0 {
-		return 0, syscall.Errno(-ret)
-	}
-	return int(ret), nil
-}
-
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
-	ret := C.callFnWithCtx(tun.writeFn, tun.ctx, unsafe.Pointer(&buff[offset]), C.size_t(len(buff) - offset))
-	if ret < 0 {
-		return 0, syscall.Errno(-ret)
-	}
-	return int(ret), nil
-}
-
-func (tun *nativeTun) Close() error {
-	if tun.events != nil {
-		close(tun.events)
-	}
-	return nil
-}
-
-func (tun *nativeTun) setMTU(n int) error {
-	tun.mtu = n
-	return nil
-}
-
-func (tun *nativeTun) MTU() (int, error) {
-	return tun.mtu, nil
-}