Add FreeBSD support

Signed-off-by: Brady OBrien <brady.obrien128@gmail.com>
This commit is contained in:
Brady OBrien 2018-05-17 17:58:54 -05:00 committed by Jason A. Donenfeld
parent 837a12c841
commit b962d7d791
8 changed files with 792 additions and 20 deletions

24
rwcancel/fdset_default.go Normal file
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@ -0,0 +1,24 @@
// +build !freebsd
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package rwcancel
import "golang.org/x/sys/unix"
type fdSet struct {
fdset unix.FdSet
}
func (fdset *fdSet) set(i int) {
bits := 32 << (^uint(0) >> 63)
fdset.fdset.Bits[i/bits] |= 1 << uint(i%bits)
}
func (fdset *fdSet) check(i int) bool {
bits := 32 << (^uint(0) >> 63)
return (fdset.fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
}

22
rwcancel/fdset_freebsd.go Normal file
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@ -0,0 +1,22 @@
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package rwcancel
import "golang.org/x/sys/unix"
type fdSet struct {
fdset unix.FdSet
}
func (fdset *fdSet) set(i int) {
bits := 32 << (^uint(0) >> 63)
fdset.fdset.X__fds_bits[i/bits] |= 1 << uint(i%bits)
}
func (fdset *fdSet) check(i int) bool {
bits := 32 << (^uint(0) >> 63)
return (fdset.fdset.X__fds_bits[i/bits] & (1 << uint(i%bits))) != 0
}

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@ -12,26 +12,6 @@ import (
"syscall"
)
type RWCancel struct {
fd int
closingReader *os.File
closingWriter *os.File
}
type fdSet struct {
fdset unix.FdSet
}
func (fdset *fdSet) set(i int) {
bits := 32 << (^uint(0) >> 63)
fdset.fdset.Bits[i/bits] |= 1 << uint(i%bits)
}
func (fdset *fdSet) check(i int) bool {
bits := 32 << (^uint(0) >> 63)
return (fdset.fdset.Bits[i/bits] & (1 << uint(i%bits))) != 0
}
func max(a, b int) int {
if a > b {
return a
@ -39,6 +19,12 @@ func max(a, b int) int {
return b
}
type RWCancel struct {
fd int
closingReader *os.File
closingWriter *os.File
}
func NewRWCancel(fd int) (*RWCancel, error) {
err := unix.SetNonblock(fd, true)
if err != nil {

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@ -3,6 +3,8 @@
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
// +build !linux
package rwcancel
import "golang.org/x/sys/unix"

507
tun_freebsd.go Normal file
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@ -0,0 +1,507 @@
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package main
import (
"./rwcancel"
"bytes"
"errors"
"fmt"
"golang.org/x/net/ipv6"
"golang.org/x/sys/unix"
"io/ioutil"
"net"
"os"
"path/filepath"
"time"
"unsafe"
)
// _TUNSIFHEAD, value derived from sys/net/{if_tun,ioccom}.h
// const _TUNSIFHEAD = ((0x80000000) | (((4) & ((1 << 13) - 1) ) << 16) | (uint32(byte('t')) << 8) | (96))
const _TUNSIFHEAD = 0x80047460
const _TUNSIFMODE = 0x8004745e
const _TUNSIFPID = 0x2000745f
// Iface status string max len
const _IFSTATMAX = 800
// Structure for iface mtu get/set ioctls
type ifreq_mtu struct {
Name [_IFNAMESIZ]byte
MTU uint32
Pad0 [12]byte
}
// Structure for interface status request ioctl
type ifstat struct {
IfsName [_IFNAMESIZ]byte
Ascii [_IFSTATMAX]byte
}
// NativeTun is a hack to work around the first 4 bytes "packet
// information" because there doesn't seem to be an IFF_NO_PI for darwin.
type NativeTun struct {
name string
fd *os.File
rwcancel *rwcancel.RWCancel
mtu int
events chan TUNEvent
errors chan error
statusListenersShutdown chan struct{}
}
// Figure out the interface name for an open tun device file descriptor
func TunIfaceName(f *os.File) (string, error) {
//Terrible hack to make up for freebsd not having a TUNGIFNAME
fd := f.Fd()
//First, make sure the tun pid matches this proc's pid
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(fd),
uintptr(_TUNSIFPID),
uintptr(0),
)
if errno != 0 {
return "", fmt.Errorf("Failed to set tun device PID: %s", errno.Error())
}
// Open iface control socket
confd, err := unix.Socket(
unix.AF_INET,
unix.SOCK_DGRAM,
0,
)
defer unix.Close(confd)
if err != nil {
return "", err
}
procPid := os.Getpid()
//Try to find interface with matching PID
for i := 1; ; i++ {
iface, _ := net.InterfaceByIndex(i)
if err != nil || iface == nil {
break
}
// Structs for getting data in and out of SIOCGIFSTATUS ioctl
var ifstatus ifstat
ifname := iface.Name
copy(ifstatus.IfsName[:], ifname)
// Make the syscall to get the status string
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(confd),
uintptr(unix.SIOCGIFSTATUS),
uintptr(unsafe.Pointer(&ifstatus)),
)
if errno != 0 {
continue
}
nullStr := ifstatus.Ascii[:]
i := bytes.IndexByte(nullStr, 0)
if i < 1 {
continue
}
if i != -1 {
nullStr = nullStr[:i]
}
statStr := string(nullStr)
var pidNum int = 0
// Finally get the owning PID
// Format string taken from sys/net/if_tun.c
_, err := fmt.Sscanf(statStr, "\tOpened by PID %d\n", &pidNum)
if err != nil {
return "", err
}
if pidNum == procPid {
return ifname, nil
}
}
return "", nil
}
// Destroy a named system interface
func DestroyIface(name string) error {
// open control socket
var fd int
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 [32]byte
copy(ifr[:], name)
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(fd),
uintptr(unix.SIOCIFDESTROY),
uintptr(unsafe.Pointer(&ifr[0])),
)
if errno != 0 {
return fmt.Errorf("Failed to destroy interface %s: %s", name, errno.Error())
}
return nil
}
func CreateTUN(name string) (TUNDevice, error) {
if len(name) > _IFNAMESIZ-1 {
return nil, errors.New("Interface name too long")
}
// See if interface already exists
iface, _ := net.InterfaceByName(name)
if iface != nil {
return nil, fmt.Errorf("Interface %s already exists", name)
}
tunfile, err := os.OpenFile("/dev/tun", unix.O_RDWR, 0)
if err != nil {
return nil, err
}
nameif, err := TunIfaceName(tunfile)
if err != nil {
tunfile.Close()
return nil, err
}
tunfd := tunfile.Fd()
// Enable ifhead mode, otherwise tun will complain if it gets a non-AF_INET packet
ifheadmode := 1
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(tunfd),
uintptr(_TUNSIFHEAD),
uintptr(unsafe.Pointer(&ifheadmode)),
)
if errno != 0 {
return nil, fmt.Errorf("Error %s", errno.Error())
}
/* Set TUN iface to broadcast mode. TUN inferfaces on freebsd come up
* point to point by default */
ifmodemode := unix.IFF_BROADCAST
_, _, errno = unix.Syscall(
unix.SYS_IOCTL,
uintptr(tunfd),
uintptr(_TUNSIFMODE),
uintptr(unsafe.Pointer(&ifmodemode)),
)
if errno != 0 {
return nil, fmt.Errorf("Error %s", errno.Error())
}
// Rename tun interface
// Open control socket
ctfd, err := unix.Socket(
unix.AF_INET,
unix.SOCK_DGRAM,
0,
)
if err != nil {
return nil, err
}
defer unix.Close(ctfd)
// set up struct for iface rename
var newnp [_IFNAMESIZ]byte
copy(newnp[:], name)
var ifr ifreq_ptr
copy(ifr.Name[:], nameif)
ifr.Data = uintptr(unsafe.Pointer(&newnp[0]))
//do actual ioctl to rename iface
_, _, errno = unix.Syscall(
unix.SYS_IOCTL,
uintptr(ctfd),
uintptr(unix.SIOCSIFNAME),
uintptr(unsafe.Pointer(&ifr)),
)
if errno != 0 {
tunfile.Close()
DestroyIface(name)
return nil, fmt.Errorf("Failed to rename %s to %s: %s", nameif, name, errno.Error())
}
tun, err := CreateTUNFromFile(tunfile)
if err != nil {
return nil, err
}
if err == nil && name == "tun" {
fname := os.Getenv("WG_FREEBSD_TUN_NAME_FILE")
if fname != "" {
os.MkdirAll(filepath.Dir(fname), 0700)
ioutil.WriteFile(fname, []byte(tun.(*NativeTun).name+"\n"), 0400)
}
}
return tun, err
}
func CreateTUNFromFile(file *os.File) (TUNDevice, error) {
tun := &NativeTun{
fd: file,
mtu: 1500,
events: make(chan TUNEvent, 10),
errors: make(chan error, 1),
statusListenersShutdown: make(chan struct{}),
}
_, err := tun.Name()
if err != nil {
tun.fd.Close()
return nil, err
}
tun.rwcancel, err = rwcancel.NewRWCancel(int(file.Fd()))
if err != nil {
tun.fd.Close()
return nil, err
}
// TODO: Fix this very naive implementation
go func(tun *NativeTun) {
var (
statusUp bool
statusMTU int
)
for {
intr, err := net.InterfaceByName(tun.name)
if err != nil {
tun.errors <- err
return
}
// Up / Down event
up := (intr.Flags & net.FlagUp) != 0
if up != statusUp && up {
tun.events <- TUNEventUp
}
if up != statusUp && !up {
tun.events <- TUNEventDown
}
statusUp = up
// MTU changes
if intr.MTU != statusMTU {
tun.events <- TUNEventMTUUpdate
}
statusMTU = intr.MTU
select {
case <-time.After(time.Second / 10):
case <-tun.statusListenersShutdown:
return
}
}
}(tun)
// set default MTU
err = tun.setMTU(DefaultMTU)
if err != nil {
tun.Close()
return nil, err
}
return tun, nil
}
func (tun *NativeTun) Name() (string, error) {
name, err := TunIfaceName(tun.fd)
if err != nil {
return "", err
}
tun.name = name
return name, nil
}
func (tun *NativeTun) File() *os.File {
return tun.fd
}
func (tun *NativeTun) Events() chan TUNEvent {
return tun.events
}
func (tun *NativeTun) doRead(buff []byte, offset int) (int, error) {
select {
case err := <-tun.errors:
return 0, err
default:
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.rwcancel.ReadyRead() {
return 0, errors.New("tun device closed")
}
}
}
func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
// reserve space for header
buff = buff[offset-4:]
// add packet information header
buff[0] = 0x00
buff[1] = 0x00
buff[2] = 0x00
if buff[4]>>4 == ipv6.Version {
buff[3] = unix.AF_INET6
} else {
buff[3] = unix.AF_INET
}
// write
return tun.fd.Write(buff)
}
func (tun *NativeTun) Close() error {
close(tun.statusListenersShutdown)
err1 := tun.rwcancel.Cancel()
err2 := tun.fd.Close()
err3 := DestroyIface(tun.name)
close(tun.events)
if err1 != nil {
return err1
}
if err2 != nil {
return err2
}
return err3
}
func (tun *NativeTun) setMTU(n int) error {
// open datagram socket
var fd int
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 ifreq_mtu
copy(ifr.Name[:], tun.name)
ifr.MTU = uint32(n)
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(fd),
uintptr(unix.SIOCSIFMTU),
uintptr(unsafe.Pointer(&ifr)),
)
if errno != 0 {
return fmt.Errorf("Failed to set MTU on %s", tun.name)
}
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 ifreq_mtu
copy(ifr.Name[:], tun.name)
_, _, errno := unix.Syscall(
unix.SYS_IOCTL,
uintptr(fd),
uintptr(unix.SIOCGIFMTU),
uintptr(unsafe.Pointer(&ifr)),
)
if errno != 0 {
return 0, fmt.Errorf("Failed to get MTU on %s", tun.name)
}
// convert result to signed 32-bit int
mtu := ifr.MTU
if mtu >= (1 << 31) {
return int(mtu-(1<<31)) - (1 << 31), nil
}
return int(mtu), nil
}

18
tun_freebsd_386.go Normal file
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@ -0,0 +1,18 @@
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
/* Types to deal with FreeBSD fdiogname ioctl for determining tun device name */
package main
// Iface name max len
const _IFNAMESIZ = 16
// structure for iface requests with a pointer
type ifreq_ptr struct {
Name [_IFNAMESIZ]byte
Data uintptr
Pad0 [20]byte
}

18
tun_freebsd_amd64.go Normal file
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@ -0,0 +1,18 @@
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
/* Types to deal with FreeBSD fdiogname ioctl for determining tun device name */
package main
// Iface name max len
const _IFNAMESIZ = 16
// structure for iface requests with a pointer
type ifreq_ptr struct {
Name [_IFNAMESIZ]byte
Data uintptr
Pad0 [16]byte
}

195
uapi_freebsd.go Normal file
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@ -0,0 +1,195 @@
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
package main
import (
"errors"
"fmt"
"golang.org/x/sys/unix"
"net"
"os"
"path"
)
const (
ipcErrorIO = -int64(unix.EIO)
ipcErrorProtocol = -int64(unix.EPROTO)
ipcErrorInvalid = -int64(unix.EINVAL)
ipcErrorPortInUse = -int64(unix.EADDRINUSE)
socketDirectory = "/var/run/wireguard"
socketName = "%s.sock"
)
type UAPIListener struct {
listener net.Listener // unix socket listener
connNew chan net.Conn
connErr chan error
kqueueFd int
keventFd int
}
func (l *UAPIListener) Accept() (net.Conn, error) {
for {
select {
case conn := <-l.connNew:
return conn, nil
case err := <-l.connErr:
return nil, err
}
}
}
func (l *UAPIListener) Close() error {
err1 := unix.Close(l.kqueueFd)
err2 := unix.Close(l.keventFd)
err3 := l.listener.Close()
if err1 != nil {
return err1
}
if err2 != nil {
return err2
}
return err3
}
func (l *UAPIListener) Addr() net.Addr {
return l.listener.Addr()
}
func UAPIListen(name string, file *os.File) (net.Listener, error) {
// wrap file in listener
listener, err := net.FileListener(file)
if err != nil {
return nil, err
}
uapi := &UAPIListener{
listener: listener,
connNew: make(chan net.Conn, 1),
connErr: make(chan error, 1),
}
if unixListener, ok := listener.(*net.UnixListener); ok {
unixListener.SetUnlinkOnClose(true)
}
socketPath := path.Join(
socketDirectory,
fmt.Sprintf(socketName, name),
)
// watch for deletion of socket
uapi.kqueueFd, err = unix.Kqueue()
if err != nil {
return nil, err
}
// TODO: Double check socket deletion logic port from MacOS
uapi.keventFd, err = unix.Open(socketDirectory, unix.O_RDONLY, 0)
if err != nil {
unix.Close(uapi.kqueueFd)
return nil, err
}
go func(l *UAPIListener) {
event := unix.Kevent_t{
Ident: uint64(uapi.keventFd),
Filter: unix.EVFILT_VNODE,
Flags: unix.EV_ADD | unix.EV_ENABLE | unix.EV_ONESHOT,
Fflags: unix.NOTE_WRITE,
}
events := make([]unix.Kevent_t, 1)
n := 1
var kerr error
for {
// start with lstat to avoid race condition
if _, err := os.Lstat(socketPath); os.IsNotExist(err) {
l.connErr <- err
return
}
if kerr != nil || n != 1 {
if kerr != nil {
l.connErr <- kerr
} else {
l.connErr <- errors.New("kqueue returned empty")
}
return
}
n, kerr = unix.Kevent(uapi.kqueueFd, []unix.Kevent_t{event}, events, nil)
}
}(uapi)
// watch for new connections
go func(l *UAPIListener) {
for {
conn, err := l.listener.Accept()
if err != nil {
l.connErr <- err
break
}
l.connNew <- conn
}
}(uapi)
return uapi, nil
}
func UAPIOpen(name string) (*os.File, error) {
// check if path exist
err := os.MkdirAll(socketDirectory, 0700)
if err != nil && !os.IsExist(err) {
return nil, err
}
// open UNIX socket
socketPath := path.Join(
socketDirectory,
fmt.Sprintf(socketName, name),
)
addr, err := net.ResolveUnixAddr("unix", socketPath)
if err != nil {
return nil, err
}
listener, err := func() (*net.UnixListener, error) {
// initial connection attempt
listener, err := net.ListenUnix("unix", addr)
if err == nil {
return listener, nil
}
// check if socket already active
_, err = net.Dial("unix", socketPath)
if err == nil {
return nil, errors.New("unix socket in use")
}
// cleanup & attempt again
err = os.Remove(socketPath)
if err != nil {
return nil, err
}
return net.ListenUnix("unix", addr)
}()
if err != nil {
return nil, err
}
return listener.File()
}