Method RoutineReadFromTUN

polyamide/device/send.go:217–280

()

}

func (device *Device) RoutineReadFromTUN() {
	defer func() {
		device.Log.Verbosef("Routine: TUN reader - stopped")
		device.state.stopping.Done()
		device.queue.encryption.wg.Done()
	}()

	device.Log.Verbosef("Routine: TUN reader - started")

	var (
		batchSize = device.BatchSize()
		readErr   error
		rBufs     = make([][]byte, batchSize)
		bufs      = make([]*[MaxMessageSize]byte, batchSize)
		count     = batchSize
		sizes     = make([]int, batchSize)
		tcBufs    = make([]*TCElement, 0, batchSize)
		offset    = MessageTransportHeaderSize
		tcs       = NewTCState()
	)

	for i := 0; i < batchSize; i++ {
		bufs[i] = device.GetMessageBuffer()
		rBufs[i] = bufs[i][:]
	}

	for {
		count, readErr = device.tun.device.Read(rBufs, sizes, offset)

		for i := 0; i < count; i++ {
			if sizes[i] < 1 {
				continue
			}
			tce := device.GetTCElement()
			tce.Buffer = bufs[i]
			tcBufs = append(tcBufs, tce)

			bufs[i] = device.GetMessageBuffer()
			rBufs[i] = bufs[i][:]
		}

		// pass to traffic control
		device.TCBatch(tcBufs, tcs)

		tcBufs = tcBufs[:0]

		if readErr != nil {
			if errors.Is(readErr, tun.ErrTooManySegments) {
				// TODO: record stat for this
				// This will happen if MSS is surprisingly small (< 576)
				// coincident with reasonably high throughput.
				device.Log.Verbosef("Dropped some packets from multi-segment read: %v", readErr)
				continue
			}
			if !device.isClosed() {
				if !errors.Is(readErr, os.ErrClosed) {
					device.Log.Errorf("Failed to read packet from TUN device: %v", readErr)
				}