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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/usb/usbip/stub_rx.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/usb/usbip/stub_rx.c')
-rw-r--r--drivers/usb/usbip/stub_rx.c688
1 files changed, 688 insertions, 0 deletions
diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
new file mode 100644
index 000000000..fc01b31bb
--- /dev/null
+++ b/drivers/usb/usbip/stub_rx.c
@@ -0,0 +1,688 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#include <asm/byteorder.h>
+#include <linux/kthread.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/scatterlist.h>
+
+#include "usbip_common.h"
+#include "stub.h"
+
+static int is_clear_halt_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+ return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
+ (req->bRequestType == USB_RECIP_ENDPOINT) &&
+ (req->wValue == USB_ENDPOINT_HALT);
+}
+
+static int is_set_interface_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+ return (req->bRequest == USB_REQ_SET_INTERFACE) &&
+ (req->bRequestType == USB_RECIP_INTERFACE);
+}
+
+static int is_set_configuration_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+ return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
+ (req->bRequestType == USB_RECIP_DEVICE);
+}
+
+static int is_reset_device_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+ __u16 value;
+ __u16 index;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+ value = le16_to_cpu(req->wValue);
+ index = le16_to_cpu(req->wIndex);
+
+ if ((req->bRequest == USB_REQ_SET_FEATURE) &&
+ (req->bRequestType == USB_RT_PORT) &&
+ (value == USB_PORT_FEAT_RESET)) {
+ usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
+ return 1;
+ } else
+ return 0;
+}
+
+static int tweak_clear_halt_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+ int target_endp;
+ int target_dir;
+ int target_pipe;
+ int ret;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+ /*
+ * The stalled endpoint is specified in the wIndex value. The endpoint
+ * of the urb is the target of this clear_halt request (i.e., control
+ * endpoint).
+ */
+ target_endp = le16_to_cpu(req->wIndex) & 0x000f;
+
+ /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80. */
+ target_dir = le16_to_cpu(req->wIndex) & 0x0080;
+
+ if (target_dir)
+ target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
+ else
+ target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
+
+ ret = usb_clear_halt(urb->dev, target_pipe);
+ if (ret < 0)
+ dev_err(&urb->dev->dev,
+ "usb_clear_halt error: devnum %d endp %d ret %d\n",
+ urb->dev->devnum, target_endp, ret);
+ else
+ dev_info(&urb->dev->dev,
+ "usb_clear_halt done: devnum %d endp %d\n",
+ urb->dev->devnum, target_endp);
+
+ return ret;
+}
+
+static int tweak_set_interface_cmd(struct urb *urb)
+{
+ struct usb_ctrlrequest *req;
+ __u16 alternate;
+ __u16 interface;
+ int ret;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+ alternate = le16_to_cpu(req->wValue);
+ interface = le16_to_cpu(req->wIndex);
+
+ usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
+ interface, alternate);
+
+ ret = usb_set_interface(urb->dev, interface, alternate);
+ if (ret < 0)
+ dev_err(&urb->dev->dev,
+ "usb_set_interface error: inf %u alt %u ret %d\n",
+ interface, alternate, ret);
+ else
+ dev_info(&urb->dev->dev,
+ "usb_set_interface done: inf %u alt %u\n",
+ interface, alternate);
+
+ return ret;
+}
+
+static int tweak_set_configuration_cmd(struct urb *urb)
+{
+ struct stub_priv *priv = (struct stub_priv *) urb->context;
+ struct stub_device *sdev = priv->sdev;
+ struct usb_ctrlrequest *req;
+ __u16 config;
+ int err;
+
+ req = (struct usb_ctrlrequest *) urb->setup_packet;
+ config = le16_to_cpu(req->wValue);
+
+ usb_lock_device(sdev->udev);
+ err = usb_set_configuration(sdev->udev, config);
+ usb_unlock_device(sdev->udev);
+ if (err && err != -ENODEV)
+ dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
+ config, err);
+ return 0;
+}
+
+static int tweak_reset_device_cmd(struct urb *urb)
+{
+ struct stub_priv *priv = (struct stub_priv *) urb->context;
+ struct stub_device *sdev = priv->sdev;
+
+ dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
+
+ if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
+ dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
+ return 0;
+ }
+ usb_reset_device(sdev->udev);
+ usb_unlock_device(sdev->udev);
+
+ return 0;
+}
+
+/*
+ * clear_halt, set_interface, and set_configuration require special tricks.
+ */
+static void tweak_special_requests(struct urb *urb)
+{
+ if (!urb || !urb->setup_packet)
+ return;
+
+ if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
+ return;
+
+ if (is_clear_halt_cmd(urb))
+ /* tweak clear_halt */
+ tweak_clear_halt_cmd(urb);
+
+ else if (is_set_interface_cmd(urb))
+ /* tweak set_interface */
+ tweak_set_interface_cmd(urb);
+
+ else if (is_set_configuration_cmd(urb))
+ /* tweak set_configuration */
+ tweak_set_configuration_cmd(urb);
+
+ else if (is_reset_device_cmd(urb))
+ tweak_reset_device_cmd(urb);
+ else
+ usbip_dbg_stub_rx("no need to tweak\n");
+}
+
+/*
+ * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
+ * By unlinking the urb asynchronously, stub_rx can continuously
+ * process coming urbs. Even if the urb is unlinked, its completion
+ * handler will be called and stub_tx will send a return pdu.
+ *
+ * See also comments about unlinking strategy in vhci_hcd.c.
+ */
+static int stub_recv_cmd_unlink(struct stub_device *sdev,
+ struct usbip_header *pdu)
+{
+ int ret, i;
+ unsigned long flags;
+ struct stub_priv *priv;
+
+ spin_lock_irqsave(&sdev->priv_lock, flags);
+
+ list_for_each_entry(priv, &sdev->priv_init, list) {
+ if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
+ continue;
+
+ /*
+ * This matched urb is not completed yet (i.e., be in
+ * flight in usb hcd hardware/driver). Now we are
+ * cancelling it. The unlinking flag means that we are
+ * now not going to return the normal result pdu of a
+ * submission request, but going to return a result pdu
+ * of the unlink request.
+ */
+ priv->unlinking = 1;
+
+ /*
+ * In the case that unlinking flag is on, prev->seqnum
+ * is changed from the seqnum of the cancelling urb to
+ * the seqnum of the unlink request. This will be used
+ * to make the result pdu of the unlink request.
+ */
+ priv->seqnum = pdu->base.seqnum;
+
+ spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+ /*
+ * usb_unlink_urb() is now out of spinlocking to avoid
+ * spinlock recursion since stub_complete() is
+ * sometimes called in this context but not in the
+ * interrupt context. If stub_complete() is executed
+ * before we call usb_unlink_urb(), usb_unlink_urb()
+ * will return an error value. In this case, stub_tx
+ * will return the result pdu of this unlink request
+ * though submission is completed and actual unlinking
+ * is not executed. OK?
+ */
+ /* In the above case, urb->status is not -ECONNRESET,
+ * so a driver in a client host will know the failure
+ * of the unlink request ?
+ */
+ for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
+ ret = usb_unlink_urb(priv->urbs[i]);
+ if (ret != -EINPROGRESS)
+ dev_err(&priv->urbs[i]->dev->dev,
+ "failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
+ i + 1, priv->num_urbs,
+ priv->seqnum, ret);
+ }
+ return 0;
+ }
+
+ usbip_dbg_stub_rx("seqnum %d is not pending\n",
+ pdu->u.cmd_unlink.seqnum);
+
+ /*
+ * The urb of the unlink target is not found in priv_init queue. It was
+ * already completed and its results is/was going to be sent by a
+ * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
+ * return the completeness of this unlink request to vhci_hcd.
+ */
+ stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
+
+ spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+ return 0;
+}
+
+static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
+{
+ struct usbip_device *ud = &sdev->ud;
+ int valid = 0;
+
+ if (pdu->base.devid == sdev->devid) {
+ spin_lock_irq(&ud->lock);
+ if (ud->status == SDEV_ST_USED) {
+ /* A request is valid. */
+ valid = 1;
+ }
+ spin_unlock_irq(&ud->lock);
+ }
+
+ return valid;
+}
+
+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_zalloc(stub_priv_cache, GFP_ATOMIC);
+ if (!priv) {
+ dev_err(&sdev->udev->dev, "alloc stub_priv\n");
+ spin_unlock_irqrestore(&sdev->priv_lock, flags);
+ usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+ return NULL;
+ }
+
+ 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;
+}
+
+static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
+{
+ struct usb_device *udev = sdev->udev;
+ struct usb_host_endpoint *ep;
+ struct usb_endpoint_descriptor *epd = NULL;
+ int epnum = pdu->base.ep;
+ int dir = pdu->base.direction;
+
+ if (epnum < 0 || epnum > 15)
+ goto err_ret;
+
+ if (dir == USBIP_DIR_IN)
+ ep = udev->ep_in[epnum & 0x7f];
+ else
+ ep = udev->ep_out[epnum & 0x7f];
+ if (!ep)
+ goto err_ret;
+
+ epd = &ep->desc;
+
+ 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)) {
+ /* validate number of packets */
+ if (pdu->u.cmd_submit.number_of_packets < 0 ||
+ pdu->u.cmd_submit.number_of_packets >
+ USBIP_MAX_ISO_PACKETS) {
+ dev_err(&sdev->udev->dev,
+ "CMD_SUBMIT: isoc invalid num packets %d\n",
+ pdu->u.cmd_submit.number_of_packets);
+ return -1;
+ }
+ if (dir == USBIP_DIR_OUT)
+ return usb_sndisocpipe(udev, epnum);
+ else
+ return usb_rcvisocpipe(udev, epnum);
+ }
+
+err_ret:
+ /* NOT REACHED */
+ dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
+ return -1;
+}
+
+static void masking_bogus_flags(struct urb *urb)
+{
+ int xfertype;
+ struct usb_device *dev;
+ struct usb_host_endpoint *ep;
+ int is_out;
+ unsigned int allowed;
+
+ if (!urb || urb->hcpriv || !urb->complete)
+ return;
+ dev = urb->dev;
+ if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
+ return;
+
+ ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
+ [usb_pipeendpoint(urb->pipe)];
+ if (!ep)
+ return;
+
+ xfertype = usb_endpoint_type(&ep->desc);
+ if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
+ struct usb_ctrlrequest *setup =
+ (struct usb_ctrlrequest *) urb->setup_packet;
+
+ if (!setup)
+ return;
+ is_out = !(setup->bRequestType & USB_DIR_IN) ||
+ !setup->wLength;
+ } else {
+ is_out = usb_endpoint_dir_out(&ep->desc);
+ }
+
+ /* enforce simple/standard policy */
+ allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
+ URB_DIR_MASK | URB_FREE_BUFFER);
+ switch (xfertype) {
+ case USB_ENDPOINT_XFER_BULK:
+ if (is_out)
+ allowed |= URB_ZERO_PACKET;
+ fallthrough;
+ default: /* all non-iso endpoints */
+ if (!is_out)
+ allowed |= URB_SHORT_NOT_OK;
+ break;
+ case USB_ENDPOINT_XFER_ISOC:
+ allowed |= URB_ISO_ASAP;
+ break;
+ }
+ urb->transfer_flags &= allowed;
+}
+
+static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
+{
+ int ret;
+ int i;
+
+ for (i = 0; i < priv->num_urbs; i++) {
+ ret = usbip_recv_xbuff(ud, priv->urbs[i]);
+ if (ret < 0)
+ break;
+ }
+
+ return ret;
+}
+
+static void stub_recv_cmd_submit(struct stub_device *sdev,
+ struct usbip_header *pdu)
+{
+ struct stub_priv *priv;
+ struct usbip_device *ud = &sdev->ud;
+ struct usb_device *udev = sdev->udev;
+ struct scatterlist *sgl = NULL, *sg;
+ void *buffer = NULL;
+ unsigned long long buf_len;
+ int nents;
+ int num_urbs = 1;
+ int pipe = get_pipe(sdev, pdu);
+ int use_sg = pdu->u.cmd_submit.transfer_flags & USBIP_URB_DMA_MAP_SG;
+ int support_sg = 1;
+ int np = 0;
+ int ret, i;
+
+ if (pipe == -1)
+ return;
+
+ /*
+ * Smatch reported the error case where use_sg is true and buf_len is 0.
+ * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
+ * released by stub event handler and connection will be shut down.
+ */
+ priv = stub_priv_alloc(sdev, pdu);
+ if (!priv)
+ return;
+
+ buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
+
+ if (use_sg && !buf_len) {
+ dev_err(&udev->dev, "sg buffer with zero length\n");
+ goto err_malloc;
+ }
+
+ /* allocate urb transfer buffer, if needed */
+ if (buf_len) {
+ if (use_sg) {
+ sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
+ if (!sgl)
+ goto err_malloc;
+
+ /* Check if the server's HCD supports SG */
+ if (!udev->bus->sg_tablesize) {
+ /*
+ * If the server's HCD doesn't support SG, break
+ * a single SG request into several URBs and map
+ * each SG list entry to corresponding URB
+ * buffer. The previously allocated SG list is
+ * stored in priv->sgl (If the server's HCD
+ * support SG, SG list is stored only in
+ * urb->sg) and it is used as an indicator that
+ * the server split single SG request into
+ * several URBs. Later, priv->sgl is used by
+ * stub_complete() and stub_send_ret_submit() to
+ * reassemble the divied URBs.
+ */
+ support_sg = 0;
+ num_urbs = nents;
+ priv->completed_urbs = 0;
+ pdu->u.cmd_submit.transfer_flags &=
+ ~USBIP_URB_DMA_MAP_SG;
+ }
+ } else {
+ buffer = kzalloc(buf_len, GFP_KERNEL);
+ if (!buffer)
+ goto err_malloc;
+ }
+ }
+
+ /* allocate urb array */
+ priv->num_urbs = num_urbs;
+ priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
+ if (!priv->urbs)
+ goto err_urbs;
+
+ /* setup a urb */
+ if (support_sg) {
+ if (usb_pipeisoc(pipe))
+ np = pdu->u.cmd_submit.number_of_packets;
+
+ priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
+ if (!priv->urbs[0])
+ goto err_urb;
+
+ if (buf_len) {
+ if (use_sg) {
+ priv->urbs[0]->sg = sgl;
+ priv->urbs[0]->num_sgs = nents;
+ priv->urbs[0]->transfer_buffer = NULL;
+ } else {
+ priv->urbs[0]->transfer_buffer = buffer;
+ }
+ }
+
+ /* copy urb setup packet */
+ priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
+ 8, GFP_KERNEL);
+ if (!priv->urbs[0]->setup_packet) {
+ usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+ return;
+ }
+
+ usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
+ } else {
+ for_each_sg(sgl, sg, nents, i) {
+ priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+ /* The URBs which is previously allocated will be freed
+ * in stub_device_cleanup_urbs() if error occurs.
+ */
+ if (!priv->urbs[i])
+ goto err_urb;
+
+ usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
+ priv->urbs[i]->transfer_buffer = sg_virt(sg);
+ priv->urbs[i]->transfer_buffer_length = sg->length;
+ }
+ priv->sgl = sgl;
+ }
+
+ for (i = 0; i < num_urbs; i++) {
+ /* set other members from the base header of pdu */
+ priv->urbs[i]->context = (void *) priv;
+ priv->urbs[i]->dev = udev;
+ priv->urbs[i]->pipe = pipe;
+ priv->urbs[i]->complete = stub_complete;
+
+ /* no need to submit an intercepted request, but harmless? */
+ tweak_special_requests(priv->urbs[i]);
+
+ masking_bogus_flags(priv->urbs[i]);
+ }
+
+ if (stub_recv_xbuff(ud, priv) < 0)
+ return;
+
+ if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
+ return;
+
+ /* urb is now ready to submit */
+ for (i = 0; i < priv->num_urbs; i++) {
+ ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
+
+ if (ret == 0)
+ usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
+ pdu->base.seqnum);
+ else {
+ dev_err(&udev->dev, "submit_urb error, %d\n", ret);
+ usbip_dump_header(pdu);
+ usbip_dump_urb(priv->urbs[i]);
+
+ /*
+ * Pessimistic.
+ * This connection will be discarded.
+ */
+ usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+ break;
+ }
+ }
+
+ usbip_dbg_stub_rx("Leave\n");
+ return;
+
+err_urb:
+ kfree(priv->urbs);
+err_urbs:
+ kfree(buffer);
+ sgl_free(sgl);
+err_malloc:
+ usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+}
+
+/* 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);
+ struct device *dev = &sdev->udev->dev;
+
+ usbip_dbg_stub_rx("Enter\n");
+
+ memset(&pdu, 0, sizeof(pdu));
+
+ /* receive a pdu header */
+ ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
+ if (ret != sizeof(pdu)) {
+ dev_err(dev, "recv a header, %d\n", ret);
+ usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+ return;
+ }
+
+ usbip_header_correct_endian(&pdu, 0);
+
+ if (usbip_dbg_flag_stub_rx)
+ usbip_dump_header(&pdu);
+
+ if (!valid_request(sdev, &pdu)) {
+ dev_err(dev, "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 */
+ dev_err(dev, "unknown pdu\n");
+ usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+ break;
+ }
+}
+
+int stub_rx_loop(void *data)
+{
+ struct usbip_device *ud = data;
+
+ while (!kthread_should_stop()) {
+ if (usbip_event_happened(ud))
+ break;
+
+ stub_rx_pdu(ud);
+ }
+
+ return 0;
+}