Move tun to subpackage

1 files changed, 0 insertions, 472 deletions

diff --git a/tun_linux.go b/tun_linux.go
deleted file mode 100644
index db9cb51..0000000
--- a/tun_linux.go
+++ /dev/null
@@ -1,472 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
- * Copyright (C) 2017-2018 Mathias N. Hall-Andersen <mathias@hall-andersen.dk>.
- */
-
-/* Copyright 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
-
-package main
-
-/* Implementation of the TUN device interface for linux
- */
-
-import (
-	"./rwcancel"
-	"bytes"
-	"encoding/binary"
-	"errors"
-	"fmt"
-	"golang.org/x/net/ipv6"
-	"golang.org/x/sys/unix"
-	"net"
-	"os"
-	"strconv"
-	"sync"
-	"time"
-	"unsafe"
-)
-
-const (
-	cloneDevicePath = "/dev/net/tun"
-	ifReqSize       = unix.IFNAMSIZ + 64
-)
-
-type NativeTun struct {
-	fd                      *os.File
-	fdCancel                *rwcancel.RWCancel
-	index                   int32         // if index
-	name                    string        // name of interface
-	errors                  chan error    // async error handling
-	events                  chan TUNEvent // device related events
-	nopi                    bool          // the device was pased IFF_NO_PI
-	netlinkSock             int
-	netlinkCancel           *rwcancel.RWCancel
-	hackListenerClosed      sync.Mutex
-	statusListenersShutdown chan struct{}
-}
-
-func (tun *NativeTun) File() *os.File {
-	return tun.fd
-}
-
-func (tun *NativeTun) RoutineHackListener() {
-	defer tun.hackListenerClosed.Unlock()
-	/* This is needed for the detection to work across network namespaces
-	 * If you are reading this and know a better method, please get in touch.
-	 */
-	fd := int(tun.fd.Fd())
-	for {
-		_, err := unix.Write(fd, nil)
-		switch err {
-		case unix.EINVAL:
-			tun.events <- TUNEventUp
-		case unix.EIO:
-			tun.events <- TUNEventDown
-		default:
-			return
-		}
-		select {
-		case <-time.After(time.Second):
-		case <-tun.statusListenersShutdown:
-			return
-		}
-	}
-}
-
-func createNetlinkSocket() (int, error) {
-	sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE)
-	if err != nil {
-		return -1, err
-	}
-	saddr := &unix.SockaddrNetlink{
-		Family: unix.AF_NETLINK,
-		Groups: uint32((1 << (unix.RTNLGRP_LINK - 1)) | (1 << (unix.RTNLGRP_IPV4_IFADDR - 1)) | (1 << (unix.RTNLGRP_IPV6_IFADDR - 1))),
-	}
-	err = unix.Bind(sock, saddr)
-	if err != nil {
-		return -1, err
-	}
-	return sock, nil
-}
-
-func (tun *NativeTun) RoutineNetlinkListener() {
-	defer func() {
-		unix.Close(tun.netlinkSock)
-		tun.hackListenerClosed.Lock()
-		close(tun.events)
-	}()
-
-	for msg := make([]byte, 1<<16); ; {
-
-		var err error
-		var msgn int
-		for {
-			msgn, _, _, _, err = unix.Recvmsg(tun.netlinkSock, msg[:], nil, 0)
-			if err == nil || !rwcancel.ErrorIsEAGAIN(err) {
-				break
-			}
-			if !tun.netlinkCancel.ReadyRead() {
-				tun.errors <- fmt.Errorf("netlink socket closed: %s", err.Error())
-				return
-			}
-		}
-		if err != nil {
-			tun.errors <- fmt.Errorf("failed to receive netlink message: %s", err.Error())
-			return
-		}
-
-		select {
-		case <-tun.statusListenersShutdown:
-			return
-		default:
-		}
-
-		for remain := msg[:msgn]; len(remain) >= unix.SizeofNlMsghdr; {
-
-			hdr := *(*unix.NlMsghdr)(unsafe.Pointer(&remain[0]))
-
-			if int(hdr.Len) > len(remain) {
-				break
-			}
-
-			switch hdr.Type {
-			case unix.NLMSG_DONE:
-				remain = []byte{}
-
-			case unix.RTM_NEWLINK:
-				info := *(*unix.IfInfomsg)(unsafe.Pointer(&remain[unix.SizeofNlMsghdr]))
-				remain = remain[hdr.Len:]
-
-				if info.Index != tun.index {
-					// not our interface
-					continue
-				}
-
-				if info.Flags&unix.IFF_RUNNING != 0 {
-					tun.events <- TUNEventUp
-				}
-
-				if info.Flags&unix.IFF_RUNNING == 0 {
-					tun.events <- TUNEventDown
-				}
-
-				tun.events <- TUNEventMTUUpdate
-
-			default:
-				remain = remain[hdr.Len:]
-			}
-		}
-	}
-}
-
-func (tun *NativeTun) isUp() (bool, error) {
-	inter, err := net.InterfaceByName(tun.name)
-	return inter.Flags&net.FlagUp != 0, err
-}
-
-func getDummySock() (int, error) {
-	return unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM,
-		0,
-	)
-}
-
-func getIFIndex(name string) (int32, error) {
-	fd, err := getDummySock()
-	if err != nil {
-		return 0, err
-	}
-
-	defer unix.Close(fd)
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], name)
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCGIFINDEX),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return 0, errno
-	}
-
-	index := binary.LittleEndian.Uint32(ifr[unix.IFNAMSIZ:])
-	return toInt32(index), nil
-}
-
-func (tun *NativeTun) setMTU(n int) error {
-
-	// open datagram socket
-
-	fd, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM,
-		0,
-	)
-
-	if err != nil {
-		return err
-	}
-
-	defer unix.Close(fd)
-
-	// do ioctl call
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], tun.name)
-	binary.LittleEndian.PutUint32(ifr[16:20], uint32(n))
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCSIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-
-	if errno != 0 {
-		return errors.New("failed to set MTU of TUN device")
-	}
-
-	return nil
-}
-
-func (tun *NativeTun) MTU() (int, error) {
-
-	// open datagram socket
-
-	fd, err := unix.Socket(
-		unix.AF_INET,
-		unix.SOCK_DGRAM,
-		0,
-	)
-
-	if err != nil {
-		return 0, err
-	}
-
-	defer unix.Close(fd)
-
-	// do ioctl call
-
-	var ifr [ifReqSize]byte
-	copy(ifr[:], tun.name)
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		uintptr(fd),
-		uintptr(unix.SIOCGIFMTU),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-	if errno != 0 {
-		return 0, errors.New("failed to get MTU of TUN device: " + strconv.FormatInt(int64(errno), 10))
-	}
-
-	return int(*(*int32)(unsafe.Pointer(&ifr[16]))), nil
-}
-
-func (tun *NativeTun) Name() (string, error) {
-
-	var ifr [ifReqSize]byte
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		tun.fd.Fd(),
-		uintptr(unix.TUNGETIFF),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-	if errno != 0 {
-		return "", errors.New("failed to get name of TUN device: " + strconv.FormatInt(int64(errno), 10))
-	}
-	nullStr := ifr[:]
-	i := bytes.IndexByte(nullStr, 0)
-	if i != -1 {
-		nullStr = nullStr[:i]
-	}
-	tun.name = string(nullStr)
-	return tun.name, nil
-}
-
-func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
-
-	if tun.nopi {
-		buff = buff[offset:]
-	} else {
-		// reserve space for header
-
-		buff = buff[offset-4:]
-
-		// add packet information header
-
-		buff[0] = 0x00
-		buff[1] = 0x00
-
-		if buff[4]>>4 == ipv6.Version {
-			buff[2] = 0x86
-			buff[3] = 0xdd
-		} else {
-			buff[2] = 0x08
-			buff[3] = 0x00
-		}
-	}
-
-	// write
-
-	return tun.fd.Write(buff)
-}
-
-func (tun *NativeTun) doRead(buff []byte, offset int) (int, error) {
-	select {
-	case err := <-tun.errors:
-		return 0, err
-	default:
-		if tun.nopi {
-			return tun.fd.Read(buff[offset:])
-		} else {
-			buff := buff[offset-4:]
-			n, err := tun.fd.Read(buff[:])
-			if n < 4 {
-				return 0, err
-			}
-			return n - 4, err
-		}
-	}
-}
-
-func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
-	for {
-		n, err := tun.doRead(buff, offset)
-		if err == nil || !rwcancel.ErrorIsEAGAIN(err) {
-			return n, err
-		}
-		if !tun.fdCancel.ReadyRead() {
-			return 0, errors.New("tun device closed")
-		}
-	}
-}
-
-func (tun *NativeTun) Events() chan TUNEvent {
-	return tun.events
-}
-
-func (tun *NativeTun) Close() error {
-	var err1 error
-	if tun.statusListenersShutdown != nil {
-		close(tun.statusListenersShutdown)
-		if tun.netlinkCancel != nil {
-			err1 = tun.netlinkCancel.Cancel()
-		}
-	} else if tun.events != nil {
-		close(tun.events)
-	}
-	err2 := tun.fd.Close()
-	err3 := tun.fdCancel.Cancel()
-
-	if err1 != nil {
-		return err1
-	}
-	if err2 != nil {
-		return err2
-	}
-	return err3
-}
-
-func CreateTUN(name string) (TUNDevice, error) {
-
-	// open clone device
-
-	// HACK: we open it as a raw Fd first, so that f.nonblock=false
-	// when we make it into a file object.
-	nfd, err := unix.Open(cloneDevicePath, os.O_RDWR, 0)
-	if err != nil {
-		return nil, err
-	}
-
-	err = unix.SetNonblock(nfd, true)
-	if err != nil {
-		return nil, err
-	}
-
-	fd := os.NewFile(uintptr(nfd), cloneDevicePath)
-	if err != nil {
-		return nil, err
-	}
-
-	// create new device
-
-	var ifr [ifReqSize]byte
-	var flags uint16 = unix.IFF_TUN // | unix.IFF_NO_PI (disabled for TUN status hack)
-	nameBytes := []byte(name)
-	if len(nameBytes) >= unix.IFNAMSIZ {
-		return nil, errors.New("interface name too long")
-	}
-	copy(ifr[:], nameBytes)
-	binary.LittleEndian.PutUint16(ifr[16:], flags)
-
-	_, _, errno := unix.Syscall(
-		unix.SYS_IOCTL,
-		fd.Fd(),
-		uintptr(unix.TUNSETIFF),
-		uintptr(unsafe.Pointer(&ifr[0])),
-	)
-	if errno != 0 {
-		return nil, errno
-	}
-
-	return CreateTUNFromFile(fd)
-}
-
-func CreateTUNFromFile(fd *os.File) (TUNDevice, error) {
-	tun := &NativeTun{
-		fd:                      fd,
-		events:                  make(chan TUNEvent, 5),
-		errors:                  make(chan error, 5),
-		statusListenersShutdown: make(chan struct{}),
-		nopi: false,
-	}
-	var err error
-
-	tun.fdCancel, err = rwcancel.NewRWCancel(int(fd.Fd()))
-	if err != nil {
-		tun.fd.Close()
-		return nil, err
-	}
-
-	_, err = tun.Name()
-	if err != nil {
-		tun.fd.Close()
-		return nil, err
-	}
-
-	// start event listener
-
-	tun.index, err = getIFIndex(tun.name)
-	if err != nil {
-		return nil, err
-	}
-
-	tun.netlinkSock, err = createNetlinkSocket()
-	if err != nil {
-		tun.fd.Close()
-		return nil, err
-	}
-	tun.netlinkCancel, err = rwcancel.NewRWCancel(tun.netlinkSock)
-	if err != nil {
-		tun.fd.Close()
-		return nil, err
-	}
-
-	tun.hackListenerClosed.Lock()
-	go tun.RoutineNetlinkListener()
-	go tun.RoutineHackListener() // cross namespace
-
-	// set default MTU
-
-	err = tun.setMTU(DefaultMTU)
-	if err != nil {
-		tun.Close()
-		return nil, err
-	}
-
-	return tun, nil
-}