Orange Pi5 kernel

// 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);
 
<------>err = usb_set_configuration(sdev->udev, config);
<------>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 & 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 &=
<------><------><------><------><------><------><------><------>~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;
}