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Sourcecode: usbip version File versions

stub_tx.c

/*
 * $Id: stub_tx.c 66 2008-04-20 13:19:42Z hirofuchi $
 *
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include "usbip_common.h"
#include "stub.h"


static void stub_free_priv_and_urb(struct stub_priv *priv)
{
      struct urb *urb = priv->urb;

      if (urb->setup_packet)
            kfree(urb->setup_packet);

      if (urb->transfer_buffer)
            kfree(urb->transfer_buffer);

      list_del(&priv->list);
      kmem_cache_free(stub_priv_cache, priv);

      usb_free_urb(urb);
}

/* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum, __u32 status)
{
      struct stub_unlink *unlink;

      unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
      if (!unlink) {
            uerr("alloc stub_unlink\n");
            usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
            return;
      }

      unlink->seqnum = seqnum;
      unlink->status = status;

      list_add_tail(&unlink->list, &sdev->unlink_tx);
}

/**
 * stub_complete - completion handler of a usbip urb
 * @urb: pointer to the urb completed
 * @regs:
 *
 * When a urb has completed, the USB core driver calls this function mostly in
 * the interrupt context. To return the result of a urb, the completed urb is
 * linked to the pending list of returning.
 *
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
void stub_complete(struct urb *urb)
#else
void stub_complete(struct urb *urb, struct pt_regs *regs)
#endif
{
      struct stub_priv *priv = (struct stub_priv *) urb->context;
      struct stub_device *sdev = priv->sdev;
      unsigned long flags;

      dbg_stub_tx("complete! status %d\n", urb->status);


      switch (urb->status) {
            case 0:
                  /* OK */
                  break;
            case -ENOENT:
                  uinfo("stopped by a call of usb_kill_urb()"
                              "because of cleaning up a virtual connection\n");
                  return;
            case -ECONNRESET:
                  uinfo("unlinked by a call of usb_unlink_urb()\n");
                  break;
            case -EPIPE:
                  uinfo("endpoint %d is stalled\n", usb_pipeendpoint(urb->pipe));
                  break;
            case -ESHUTDOWN:
                  uinfo("device removed?\n");
                  break;
            default:
                  uinfo("urb completion with non-zero status %d\n", urb->status);
      }

      /* link a urb to the queue of tx. */
      spin_lock_irqsave(&sdev->priv_lock, flags);

      if (priv->unlinking) {
            stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
            stub_free_priv_and_urb(priv);
      } else
            list_move_tail(&priv->list, &sdev->priv_tx);


      spin_unlock_irqrestore(&sdev->priv_lock, flags);

      /* wake up tx_thread */
      wake_up(&sdev->tx_waitq);
}


/*-------------------------------------------------------------------------*/
/* fill PDU */

static inline void setup_base_pdu(struct usbip_header_basic *base,
            __u32 command, __u32 seqnum)
{
      base->command = command;
      base->seqnum  = seqnum;
      base->devid   = 0;
      base->ep      = 0;
      base->direction   = 0;
}

static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
{
      struct stub_priv *priv = (struct stub_priv *) urb->context;

      setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);

      usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
}

static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
            struct stub_unlink *unlink)
{
      setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);

      rpdu->u.ret_unlink.status = unlink->status;
}


/*-------------------------------------------------------------------------*/
/* send RET_SUBMIT */

static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
{
      unsigned long flags;
      struct stub_priv *priv, *tmp;

      spin_lock_irqsave(&sdev->priv_lock, flags);

      list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
            list_move_tail(&priv->list, &sdev->priv_free);
            spin_unlock_irqrestore(&sdev->priv_lock, flags);
            return priv;
      }

      spin_unlock_irqrestore(&sdev->priv_lock, flags);

      return NULL;
}

static int stub_send_ret_submit(struct stub_device *sdev)
{
      unsigned long flags;
      struct stub_priv *priv, *tmp;

      struct msghdr msg;
      struct kvec iov[3];
      size_t txsize;

      size_t total_size = 0;

      while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
            int ret;
            struct urb *urb = priv->urb;
            struct usbip_header pdu_header;
            void *iso_buffer = NULL;

            txsize = 0;
            memset(&pdu_header, 0, sizeof(pdu_header));
            memset(&msg, 0, sizeof(msg));
            memset(&iov, 0, sizeof(iov));

            dbg_stub_tx("setup txdata urb %p\n", urb);


            /* 1. setup usbip_header */
            setup_ret_submit_pdu(&pdu_header, urb);
            usbip_header_correct_endian(&pdu_header, 1);

            iov[0].iov_base = &pdu_header;
            iov[0].iov_len  = sizeof(pdu_header);
            txsize += sizeof(pdu_header);

            /* 2. setup transfer buffer */
            if (usb_pipein(urb->pipe) && urb->actual_length > 0) {
                  iov[1].iov_base = urb->transfer_buffer;
                  iov[1].iov_len  = urb->actual_length;
                  txsize += urb->actual_length;
            }

            /* 3. setup iso_packet_descriptor */
            if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
                  ssize_t len = 0;

                  iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
                  if (!iso_buffer) {
                        usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_MALLOC);
                        return -1;
                  }

                  iov[2].iov_base = iso_buffer;
                  iov[2].iov_len  = len;
                  txsize += len;
            }

            ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov, 3, txsize);
            if (ret != txsize) {
                  uerr("sendmsg failed!, retval %d for %zd\n", ret, txsize);
                  if (iso_buffer)
                        kfree(iso_buffer);
                  usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
                  return -1;
            }

            if (iso_buffer)
                  kfree(iso_buffer);

            dbg_stub_tx("send txdata\n");

            total_size += txsize;
      }


      spin_lock_irqsave(&sdev->priv_lock, flags);

      list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
            stub_free_priv_and_urb(priv);
      }

      spin_unlock_irqrestore(&sdev->priv_lock, flags);

      return total_size;
}


/*-------------------------------------------------------------------------*/
/* send RET_UNLINK */

static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
{
      unsigned long flags;
      struct stub_unlink *unlink, *tmp;

      spin_lock_irqsave(&sdev->priv_lock, flags);

      list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
            list_move_tail(&unlink->list, &sdev->unlink_free);
            spin_unlock_irqrestore(&sdev->priv_lock, flags);
            return unlink;
      }

      spin_unlock_irqrestore(&sdev->priv_lock, flags);

      return NULL;
}


static int stub_send_ret_unlink(struct stub_device *sdev)
{
      unsigned long flags;
      struct stub_unlink *unlink, *tmp;

      struct msghdr msg;
      struct kvec iov[1];
      size_t txsize;

      size_t total_size = 0;

      while ((unlink = dequeue_from_unlink_tx(sdev)) != NULL) {
            int ret;
            struct usbip_header pdu_header;

            txsize = 0;
            memset(&pdu_header, 0, sizeof(pdu_header));
            memset(&msg, 0, sizeof(msg));
            memset(&iov, 0, sizeof(iov));

            dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);

            /* 1. setup usbip_header */
            setup_ret_unlink_pdu(&pdu_header, unlink);
            usbip_header_correct_endian(&pdu_header, 1);

            iov[0].iov_base = &pdu_header;
            iov[0].iov_len  = sizeof(pdu_header);
            txsize += sizeof(pdu_header);

            ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov, 1, txsize);
            if (ret != txsize) {
                  uerr("sendmsg failed!, retval %d for %zd\n", ret, txsize);
                  usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
                  return -1;
            }


            dbg_stub_tx("send txdata\n");

            total_size += txsize;
      }


      spin_lock_irqsave(&sdev->priv_lock, flags);

      list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
            list_del(&unlink->list);
            kfree(unlink);
      }

      spin_unlock_irqrestore(&sdev->priv_lock, flags);

      return total_size;
}


/*-------------------------------------------------------------------------*/

void stub_tx_loop(struct usbip_task *ut)
{
      struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
      struct stub_device *sdev = container_of(ud, struct stub_device, ud);

      while (1) {
            if (signal_pending(current)) {
                  dbg_stub_tx("signal catched\n");
                  break;
            }

            if (usbip_event_happend(ud))
                  break;

            /*
             * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
             * looks at only priv_init queue. If the completion of a URB is
             * earlier than the receive of CMD_UNLINK, priv is moved to
             * priv_tx queue and stub_rx does not find the target priv. In
             * this case, vhci_rx receives the result of the submit request
             * and then receives the result of the unlink request. The
             * result of the submit is given back to the usbcore as the
             * completion of the unlink request. The request of the
             * unlink is ignored. This is ok because a driver who calls
             * usb_unlink_urb() understands the unlink was too late by
             * getting the status of the given-backed URB which has the
             * status of usb_submit_urb().
             */
            if (stub_send_ret_submit(sdev) < 0)
                  break;

            if (stub_send_ret_unlink(sdev) < 0)
                  break;

            wait_event_interruptible(sdev->tx_waitq,
                        (!list_empty(&sdev->priv_tx) ||
                         !list_empty(&sdev->unlink_tx)));
      }
}

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