stub_rx.c

linux virtual usb host source

	if (pdu->base.devid == sdev->devid) {
		spin_lock(&ud->lock);
		if (ud->status == SDEV_ST_USED) {
			/* A request is valid. */
			spin_unlock(&ud->lock);
			return 1;
		}
		spin_unlock(&ud->lock);
	}

	return 0;
}

static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
		struct usbip_header *pdu)
{
	struct stub_priv *priv;
	struct usbip_device *ud = &sdev->ud;
	unsigned long flags;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	priv = kmem_cache_alloc(stub_priv_cache, GFP_ATOMIC);
	if (!priv) {
		uerr("alloc stub_priv\n");
		spin_unlock_irqrestore(&sdev->priv_lock, flags);
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return NULL;
	}

	memset(priv, 0, sizeof(struct stub_priv));

	priv->seqnum = pdu->base.seqnum;
	priv->sdev = sdev;

	/*
	 * After a stub_priv is linked to a list_head,
	 * our error handler can free allocated data.
	 */
	list_add_tail(&priv->list, &sdev->priv_init);

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return priv;
}

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)
static inline int usb_endpoint_xfer_bulk(
		const struct usb_endpoint_descriptor *epd)
{
	return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
			USB_ENDPOINT_XFER_BULK);
}
static inline int usb_endpoint_xfer_control(
		const struct usb_endpoint_descriptor *epd)
{
	return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
			USB_ENDPOINT_XFER_CONTROL);
}
static inline int usb_endpoint_xfer_int(
		const struct usb_endpoint_descriptor *epd)
{
	return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
			USB_ENDPOINT_XFER_INT);
}
static inline int usb_endpoint_xfer_isoc(
		const struct usb_endpoint_descriptor *epd)
{
	return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
			USB_ENDPOINT_XFER_ISOC);
}
#endif


static struct usb_host_endpoint *get_ep_from_epnum(struct usb_device *udev,
		int epnum0)
{
	struct usb_host_config *config;
	int i = 0, j = 0;
	struct usb_host_endpoint *ep = NULL;
	int epnum;
	int found = 0;

	if (epnum0 == 0)
		return &udev->ep0;

	config = udev->actconfig;
	if (!config)
		return NULL;

	for (i = 0; i < config->desc.bNumInterfaces; i++) {
		struct usb_host_interface *setting;

		setting = config->interface[i]->cur_altsetting;

		for (j = 0; j < setting->desc.bNumEndpoints; j++) {
			ep = &setting->endpoint[j];
			epnum = (ep->desc.bEndpointAddress & 0x7f);

			if (epnum == epnum0) {
				//uinfo("found epnum %d\n", epnum0);
				found = 1;
				break;
			}
		}
	}

	if (found)
		return ep;
	else
		return NULL;
}


static int get_pipe(struct stub_device *sdev, int epnum, int dir)
{
	struct usb_device *udev = interface_to_usbdev(sdev->interface);
	struct usb_host_endpoint *ep;
	struct usb_endpoint_descriptor *epd = NULL;

	ep = get_ep_from_epnum(udev, epnum);
	if (!ep) {
		uerr("no such endpoint?, %d", epnum);
		BUG();
	}

	epd = &ep->desc;


#if 0
	/* epnum 0 is always control */
	if (epnum == 0) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndctrlpipe(udev, 0);
		else
			return usb_rcvctrlpipe(udev, 0);
	}
#endif

	if (usb_endpoint_xfer_control(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndctrlpipe(udev, epnum);
		else
			return usb_rcvctrlpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_bulk(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndbulkpipe(udev, epnum);
		else
			return usb_rcvbulkpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_int(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndintpipe(udev, epnum);
		else
			return usb_rcvintpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_isoc(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndisocpipe(udev, epnum);
		else
			return usb_rcvisocpipe(udev, epnum);
	}

	/* NOT REACHED */
	uerr("get pipe, epnum %d\n", epnum);
	return 0;
}


static void stub_recv_cmd_submit(struct stub_device *sdev, struct usbip_header *pdu)
{
	int ret;
	struct stub_priv *priv;
	struct usbip_device *ud = &sdev->ud;
	struct usb_device *udev = interface_to_usbdev(sdev->interface);
	int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);


	priv = stub_priv_alloc(sdev, pdu);
	if (!priv)
		return;

	/* setup a urb */
	if (usb_pipeisoc(pipe))
		priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets, GFP_KERNEL);
	else
		priv->urb = usb_alloc_urb(0, GFP_KERNEL);

	if (!priv->urb) {
		uerr("malloc urb\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return;
	}

	/* set priv->urb->transfer_buffer */
	if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
		priv->urb->transfer_buffer =
			kzalloc(pdu->u.cmd_submit.transfer_buffer_length, GFP_KERNEL);
		if (!priv->urb->transfer_buffer) {
			uerr("malloc x_buff\n");
			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
			return;
		}
	}

	/* set priv->urb->setup_packet */
	priv->urb->setup_packet = kzalloc(8, GFP_KERNEL);
	if (!priv->urb->setup_packet) {
		uerr("allocate setup_packet\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return;
	}
	memcpy(priv->urb->setup_packet, &pdu->u.cmd_submit.setup, 8);

	/* set other members from the base header of pdu */
	priv->urb->context                = (void *) priv;
	priv->urb->dev                    = udev;
	priv->urb->pipe                   = pipe;
	priv->urb->complete               = stub_complete;

	usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);


	if (usbip_recv_xbuff(ud, priv->urb) < 0)
		return;

	if (usbip_recv_iso(ud, priv->urb) < 0)
		return;

	/* no need to submit an intercepted request, but harmless? */
	tweak_special_requests(priv->urb);

	/* urb is now ready to submit */
	ret = usb_submit_urb(priv->urb, GFP_KERNEL);

	if (ret == 0)
		dbg_stub_rx("submit urb ok, seqnum %u\n", pdu->base.seqnum);
	else {
		uerr("submit_urb error, %d\n", ret);
		usbip_dump_header(pdu);
		usbip_dump_urb(priv->urb);

		/*
		 * Pessimistic.
		 * This connection will be discarded.
		 */
		usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
	}

	dbg_stub_rx("Leave\n");
	return;
}

/* recv a pdu */
static void stub_rx_pdu(struct usbip_device *ud)
{
	int ret;
	struct usbip_header pdu;
	struct stub_device *sdev = container_of(ud, struct stub_device, ud);


	dbg_stub_rx("Enter\n");

	memset(&pdu, 0, sizeof(pdu));


	/* 1. receive a pdu header */
	ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu),0);
	if (ret != sizeof(pdu)) {
		uerr("recv a header, %d\n", ret);
		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		return;
	}

	usbip_header_correct_endian(&pdu, 0);

	if (dbg_flag_stub_rx)
		usbip_dump_header(&pdu);

	if (!valid_request(sdev, &pdu)) {
		uerr("recv invalid request\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		return;
	}

	switch (pdu.base.command) {
		case USBIP_CMD_UNLINK:
			stub_recv_cmd_unlink(sdev, &pdu);
			break;

		case USBIP_CMD_SUBMIT:
			stub_recv_cmd_submit(sdev, &pdu);
			break;

		default:
			/* NOTREACHED */
			uerr("unknown pdu\n");
			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
			return;
	}

}

void stub_rx_loop(struct usbip_task *ut)
{
	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);

	while (1) {
		if (signal_pending(current)) {
			dbg_stub_rx("signal caught!\n");
			break;
		}

		if (usbip_event_happend(ud))
			break;

		stub_rx_pdu(ud);
	}
}