diff options
Diffstat (limited to 'tun/tun_windows.go')
| -rw-r--r-- | tun/tun_windows.go | 125 |
1 files changed, 39 insertions, 86 deletions
diff --git a/tun/tun_windows.go b/tun/tun_windows.go index 684d6f0..63eb812 100644 --- a/tun/tun_windows.go +++ b/tun/tun_windows.go @@ -9,10 +9,9 @@ import ( "errors" "fmt" "os" - "sync" "sync/atomic" "time" - "unsafe" + _ "unsafe" "golang.org/x/sys/windows" @@ -40,8 +39,8 @@ type NativeTun struct { errors chan error forcedMTU int rate rateJuggler - rings *wintun.RingDescriptor - writeLock sync.Mutex + session wintun.Session + readWait windows.Handle } var WintunPool *wintun.Pool @@ -103,17 +102,13 @@ func CreateTUNWithRequestedGUID(ifname string, requestedGUID *windows.GUID, mtu forcedMTU: forcedMTU, } - tun.rings, err = wintun.NewRingDescriptor() + tun.session, err = wt.StartSession(0x800000) // Ring capacity, 8 MiB if err != nil { - tun.Close() - return nil, fmt.Errorf("Error creating events: %v", err) - } - - tun.handle, err = tun.wt.Register(tun.rings) - if err != nil { - tun.Close() - return nil, fmt.Errorf("Error registering rings: %v", err) + _, err = tun.wt.Delete(false) + close(tun.events) + return nil, fmt.Errorf("Error starting session: %v", err) } + tun.readWait = tun.session.ReadWaitEvent() return tun, nil } @@ -131,13 +126,7 @@ func (tun *NativeTun) Events() chan Event { func (tun *NativeTun) Close() error { tun.close = true - if tun.rings.Send.TailMoved != 0 { - windows.SetEvent(tun.rings.Send.TailMoved) // wake the reader if it's sleeping - } - if tun.handle != windows.InvalidHandle { - windows.CloseHandle(tun.handle) - } - tun.rings.Close() + tun.session.End() var err error if tun.wt != nil { _, err = tun.wt.Delete(false) @@ -164,56 +153,34 @@ retry: return 0, err default: } - if tun.close { - return 0, os.ErrClosed - } - - buffHead := atomic.LoadUint32(&tun.rings.Send.Ring.Head) - if buffHead >= wintun.PacketCapacity { - return 0, os.ErrClosed - } - start := nanotime() shouldSpin := atomic.LoadUint64(&tun.rate.current) >= spinloopRateThreshold && uint64(start-atomic.LoadInt64(&tun.rate.nextStartTime)) <= rateMeasurementGranularity*2 - var buffTail uint32 for { - buffTail = atomic.LoadUint32(&tun.rings.Send.Ring.Tail) - if buffHead != buffTail { - break - } if tun.close { return 0, os.ErrClosed } - if !shouldSpin || uint64(nanotime()-start) >= spinloopDuration { - windows.WaitForSingleObject(tun.rings.Send.TailMoved, windows.INFINITE) - goto retry + packet, err := tun.session.ReceivePacket() + switch err { + case nil: + packetSize := len(packet) + copy(buff[offset:], packet) + tun.session.ReleaseReceivePacket(packet) + tun.rate.update(uint64(packetSize)) + return packetSize, nil + case windows.ERROR_NO_MORE_ITEMS: + if !shouldSpin || uint64(nanotime()-start) >= spinloopDuration { + windows.WaitForSingleObject(tun.readWait, windows.INFINITE) + goto retry + } + procyield(1) + continue + case windows.ERROR_HANDLE_EOF: + return 0, os.ErrClosed + case windows.ERROR_INVALID_DATA: + return 0, errors.New("Send ring corrupt") } - procyield(1) - } - if buffTail >= wintun.PacketCapacity { - return 0, os.ErrClosed - } - - buffContent := tun.rings.Send.Ring.Wrap(buffTail - buffHead) - if buffContent < uint32(unsafe.Sizeof(wintun.PacketHeader{})) { - return 0, errors.New("incomplete packet header in send ring") - } - - packet := (*wintun.Packet)(unsafe.Pointer(&tun.rings.Send.Ring.Data[buffHead])) - if packet.Size > wintun.PacketSizeMax { - return 0, errors.New("packet too big in send ring") - } - - alignedPacketSize := wintun.PacketAlign(uint32(unsafe.Sizeof(wintun.PacketHeader{})) + packet.Size) - if alignedPacketSize > buffContent { - return 0, errors.New("incomplete packet in send ring") + return 0, fmt.Errorf("Read failed: %v", err) } - - copy(buff[offset:], packet.Data[:packet.Size]) - buffHead = tun.rings.Send.Ring.Wrap(buffHead + alignedPacketSize) - atomic.StoreUint32(&tun.rings.Send.Ring.Head, buffHead) - tun.rate.update(uint64(packet.Size)) - return int(packet.Size), nil } func (tun *NativeTun) Flush() error { @@ -225,36 +192,22 @@ func (tun *NativeTun) Write(buff []byte, offset int) (int, error) { return 0, os.ErrClosed } - packetSize := uint32(len(buff) - offset) + packetSize := len(buff) - offset tun.rate.update(uint64(packetSize)) - alignedPacketSize := wintun.PacketAlign(uint32(unsafe.Sizeof(wintun.PacketHeader{})) + packetSize) - tun.writeLock.Lock() - defer tun.writeLock.Unlock() - - buffHead := atomic.LoadUint32(&tun.rings.Receive.Ring.Head) - if buffHead >= wintun.PacketCapacity { - return 0, os.ErrClosed + packet, err := tun.session.AllocateSendPacket(packetSize) + if err == nil { + copy(packet, buff[offset:]) + tun.session.SendPacket(packet) + return packetSize, nil } - - buffTail := atomic.LoadUint32(&tun.rings.Receive.Ring.Tail) - if buffTail >= wintun.PacketCapacity { + switch err { + case windows.ERROR_HANDLE_EOF: return 0, os.ErrClosed - } - - buffSpace := tun.rings.Receive.Ring.Wrap(buffHead - buffTail - wintun.PacketAlignment) - if alignedPacketSize > buffSpace { + case windows.ERROR_BUFFER_OVERFLOW: return 0, nil // Dropping when ring is full. } - - packet := (*wintun.Packet)(unsafe.Pointer(&tun.rings.Receive.Ring.Data[buffTail])) - packet.Size = packetSize - copy(packet.Data[:packetSize], buff[offset:]) - atomic.StoreUint32(&tun.rings.Receive.Ring.Tail, tun.rings.Receive.Ring.Wrap(buffTail+alignedPacketSize)) - if atomic.LoadInt32(&tun.rings.Receive.Ring.Alertable) != 0 { - windows.SetEvent(tun.rings.Receive.TailMoved) - } - return int(packetSize), nil + return 0, fmt.Errorf("Write failed: %v", err) } // LUID returns Windows interface instance ID. |