drivers/usb/usbip/vhci_rx.c - linux-imx - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * 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 <linux/kthread.h>
 #include <linux/slab.h>

 #include "usbip_common.h"
 #include "vhci.h"

 /* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
 struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev, __u32 seqnum)
 {
 	struct vhci_priv *priv, *tmp;
 	struct urb *urb = NULL;
 	int status;

 	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
 		if (priv->seqnum != seqnum)
 			continue;

 		urb = priv->urb;
 		status = urb->status;

 		usbip_dbg_vhci_rx("find urb seqnum %u\n", seqnum);

 		switch (status) {
 		case -ENOENT:
 			/* fall through */
 		case -ECONNRESET:
 			dev_dbg(&urb->dev->dev,
 				 "urb seq# %u was unlinked %ssynchronuously\n",
 				 seqnum, status == -ENOENT ? "" : "a");
 			break;
 		case -EINPROGRESS:
 			/* no info output */
 			break;
 		default:
 			dev_dbg(&urb->dev->dev,
 				 "urb seq# %u may be in a error, status %d\n",
 				 seqnum, status);
 		}

 		list_del(&priv->list);
 		kfree(priv);
 		urb->hcpriv = NULL;

 		break;
 	}

 	return urb;
 }

 static void vhci_recv_ret_submit(struct vhci_device *vdev,
 				 struct usbip_header *pdu)
 {
 	struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
 	struct vhci *vhci = vhci_hcd->vhci;
 	struct usbip_device *ud = &vdev->ud;
 	struct urb *urb;
 	unsigned long flags;

 	spin_lock_irqsave(&vdev->priv_lock, flags);
 	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
 	spin_unlock_irqrestore(&vdev->priv_lock, flags);

 	if (!urb) {
 		pr_err("cannot find a urb of seqnum %u max seqnum %d\n",
 			pdu->base.seqnum,
 			atomic_read(&vhci_hcd->seqnum));
 		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 		return;
 	}

 	/* unpack the pdu to a urb */
 	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);

 	/* recv transfer buffer */
 	if (usbip_recv_xbuff(ud, urb) < 0)
 		return;

 	/* recv iso_packet_descriptor */
 	if (usbip_recv_iso(ud, urb) < 0)
 		return;

 	/* restore the padding in iso packets */
 	usbip_pad_iso(ud, urb);

 	if (usbip_dbg_flag_vhci_rx)
 		usbip_dump_urb(urb);

 	usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);

 	spin_lock_irqsave(&vhci->lock, flags);
 	usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
 	spin_unlock_irqrestore(&vhci->lock, flags);

 	usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);

 	usbip_dbg_vhci_rx("Leave\n");
 }

 static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
 						  struct usbip_header *pdu)
 {
 	struct vhci_unlink *unlink, *tmp;
 	unsigned long flags;

 	spin_lock_irqsave(&vdev->priv_lock, flags);

 	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
 		pr_info("unlink->seqnum %lu\n", unlink->seqnum);
 		if (unlink->seqnum == pdu->base.seqnum) {
 			usbip_dbg_vhci_rx("found pending unlink, %lu\n",
 					  unlink->seqnum);
 			list_del(&unlink->list);

 			spin_unlock_irqrestore(&vdev->priv_lock, flags);
 			return unlink;
 		}
 	}

 	spin_unlock_irqrestore(&vdev->priv_lock, flags);

 	return NULL;
 }

 static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 				 struct usbip_header *pdu)
 {
 	struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
 	struct vhci *vhci = vhci_hcd->vhci;
 	struct vhci_unlink *unlink;
 	struct urb *urb;
 	unsigned long flags;

 	usbip_dump_header(pdu);

 	unlink = dequeue_pending_unlink(vdev, pdu);
 	if (!unlink) {
 		pr_info("cannot find the pending unlink %u\n",
 			pdu->base.seqnum);
 		return;
 	}

 	spin_lock_irqsave(&vdev->priv_lock, flags);
 	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
 	spin_unlock_irqrestore(&vdev->priv_lock, flags);

 	if (!urb) {
 		/*
 		 * I get the result of a unlink request. But, it seems that I
 		 * already received the result of its submit result and gave
 		 * back the URB.
 		 */
 		pr_info("the urb (seqnum %d) was already given back\n",
 			pdu->base.seqnum);
 	} else {
 		usbip_dbg_vhci_rx("now giveback urb %d\n", pdu->base.seqnum);

 		/* If unlink is successful, status is -ECONNRESET */
 		urb->status = pdu->u.ret_unlink.status;
 		pr_info("urb->status %d\n", urb->status);

 		spin_lock_irqsave(&vhci->lock, flags);
 		usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
 		spin_unlock_irqrestore(&vhci->lock, flags);

 		usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
 	}

 	kfree(unlink);
 }

 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 {
 	int empty = 0;
 	unsigned long flags;

 	spin_lock_irqsave(&vdev->priv_lock, flags);
 	empty = list_empty(&vdev->priv_rx);
 	spin_unlock_irqrestore(&vdev->priv_lock, flags);

 	return empty;
 }

 /* recv a pdu */
 static void vhci_rx_pdu(struct usbip_device *ud)
 {
 	int ret;
 	struct usbip_header pdu;
 	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);

 	usbip_dbg_vhci_rx("Enter\n");

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

 	/* receive a pdu header */
 	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 	if (ret < 0) {
 		if (ret == -ECONNRESET)
 			pr_info("connection reset by peer\n");
 		else if (ret == -EAGAIN) {
 			/* ignore if connection was idle */
 			if (vhci_priv_tx_empty(vdev))
 				return;
 			pr_info("connection timed out with pending urbs\n");
 		} else if (ret != -ERESTARTSYS)
 			pr_info("xmit failed %d\n", ret);

 		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 		return;
 	}
 	if (ret == 0) {
 		pr_info("connection closed");
 		usbip_event_add(ud, VDEV_EVENT_DOWN);
 		return;
 	}
 	if (ret != sizeof(pdu)) {
 		pr_err("received pdu size is %d, should be %d\n", ret,
 		       (unsigned int)sizeof(pdu));
 		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 		return;
 	}

 	usbip_header_correct_endian(&pdu, 0);

 	if (usbip_dbg_flag_vhci_rx)
 		usbip_dump_header(&pdu);

 	switch (pdu.base.command) {
 	case USBIP_RET_SUBMIT:
 		vhci_recv_ret_submit(vdev, &pdu);
 		break;
 	case USBIP_RET_UNLINK:
 		vhci_recv_ret_unlink(vdev, &pdu);
 		break;
 	default:
 		/* NOT REACHED */
 		pr_err("unknown pdu %u\n", pdu.base.command);
 		usbip_dump_header(&pdu);
 		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 		break;
 	}
 }

 int vhci_rx_loop(void *data)
 {
 	struct usbip_device *ud = data;

 	while (!kthread_should_stop()) {
 		if (usbip_event_happened(ud))
 			break;

 		vhci_rx_pdu(ud);
 	}

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* 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 <linux/kthread.h>
	#include <linux/slab.h>

	#include "usbip_common.h"
	#include "vhci.h"

	/* get URB from transmitted urb queue. caller must hold vdev->priv_lock */
	struct urb pickup_urb_and_free_priv(struct vhci_device vdev, __u32 seqnum)
	{
	struct vhci_priv priv, tmp;
	struct urb *urb = NULL;
	int status;

	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
	if (priv->seqnum != seqnum)
	continue;

	urb = priv->urb;
	status = urb->status;

	usbip_dbg_vhci_rx("find urb seqnum %u\n", seqnum);

	switch (status) {
	case -ENOENT:
	/* fall through */
	case -ECONNRESET:
	dev_dbg(&urb->dev->dev,
	"urb seq# %u was unlinked %ssynchronuously\n",
	seqnum, status == -ENOENT ? "" : "a");
	break;
	case -EINPROGRESS:
	/* no info output */
	break;
	default:
	dev_dbg(&urb->dev->dev,
	"urb seq# %u may be in a error, status %d\n",
	seqnum, status);
	}

	list_del(&priv->list);
	kfree(priv);
	urb->hcpriv = NULL;

	break;
	}

	return urb;
	}

	static void vhci_recv_ret_submit(struct vhci_device *vdev,
	struct usbip_header *pdu)
	{
	struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	struct usbip_device *ud = &vdev->ud;
	struct urb *urb;
	unsigned long flags;

	spin_lock_irqsave(&vdev->priv_lock, flags);
	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	if (!urb) {
	pr_err("cannot find a urb of seqnum %u max seqnum %d\n",
	pdu->base.seqnum,
	atomic_read(&vhci_hcd->seqnum));
	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	return;
	}

	/* unpack the pdu to a urb */
	usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);

	/* recv transfer buffer */
	if (usbip_recv_xbuff(ud, urb) < 0)
	return;

	/* recv iso_packet_descriptor */
	if (usbip_recv_iso(ud, urb) < 0)
	return;

	/* restore the padding in iso packets */
	usbip_pad_iso(ud, urb);

	if (usbip_dbg_flag_vhci_rx)
	usbip_dump_urb(urb);

	usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);

	spin_lock_irqsave(&vhci->lock, flags);
	usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
	spin_unlock_irqrestore(&vhci->lock, flags);

	usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);

	usbip_dbg_vhci_rx("Leave\n");
	}

	static struct vhci_unlink dequeue_pending_unlink(struct vhci_device vdev,
	struct usbip_header *pdu)
	{
	struct vhci_unlink unlink, tmp;
	unsigned long flags;

	spin_lock_irqsave(&vdev->priv_lock, flags);

	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
	pr_info("unlink->seqnum %lu\n", unlink->seqnum);
	if (unlink->seqnum == pdu->base.seqnum) {
	usbip_dbg_vhci_rx("found pending unlink, %lu\n",
	unlink->seqnum);
	list_del(&unlink->list);

	spin_unlock_irqrestore(&vdev->priv_lock, flags);
	return unlink;
	}
	}

	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	return NULL;
	}

	static void vhci_recv_ret_unlink(struct vhci_device *vdev,
	struct usbip_header *pdu)
	{
	struct vhci_hcd *vhci_hcd = vdev_to_vhci_hcd(vdev);
	struct vhci *vhci = vhci_hcd->vhci;
	struct vhci_unlink *unlink;
	struct urb *urb;
	unsigned long flags;

	usbip_dump_header(pdu);

	unlink = dequeue_pending_unlink(vdev, pdu);
	if (!unlink) {
	pr_info("cannot find the pending unlink %u\n",
	pdu->base.seqnum);
	return;
	}

	spin_lock_irqsave(&vdev->priv_lock, flags);
	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	if (!urb) {
	/*
	* I get the result of a unlink request. But, it seems that I
	* already received the result of its submit result and gave
	* back the URB.
	*/
	pr_info("the urb (seqnum %d) was already given back\n",
	pdu->base.seqnum);
	} else {
	usbip_dbg_vhci_rx("now giveback urb %d\n", pdu->base.seqnum);

	/* If unlink is successful, status is -ECONNRESET */
	urb->status = pdu->u.ret_unlink.status;
	pr_info("urb->status %d\n", urb->status);

	spin_lock_irqsave(&vhci->lock, flags);
	usb_hcd_unlink_urb_from_ep(vhci_hcd_to_hcd(vhci_hcd), urb);
	spin_unlock_irqrestore(&vhci->lock, flags);

	usb_hcd_giveback_urb(vhci_hcd_to_hcd(vhci_hcd), urb, urb->status);
	}

	kfree(unlink);
	}

	static int vhci_priv_tx_empty(struct vhci_device *vdev)
	{
	int empty = 0;
	unsigned long flags;

	spin_lock_irqsave(&vdev->priv_lock, flags);
	empty = list_empty(&vdev->priv_rx);
	spin_unlock_irqrestore(&vdev->priv_lock, flags);

	return empty;
	}

	/* recv a pdu */
	static void vhci_rx_pdu(struct usbip_device *ud)
	{
	int ret;
	struct usbip_header pdu;
	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);

	usbip_dbg_vhci_rx("Enter\n");

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

	/* receive a pdu header */
	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
	if (ret < 0) {
	if (ret == -ECONNRESET)
	pr_info("connection reset by peer\n");
	else if (ret == -EAGAIN) {
	/* ignore if connection was idle */
	if (vhci_priv_tx_empty(vdev))
	return;
	pr_info("connection timed out with pending urbs\n");
	} else if (ret != -ERESTARTSYS)
	pr_info("xmit failed %d\n", ret);

	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	return;
	}
	if (ret == 0) {
	pr_info("connection closed");
	usbip_event_add(ud, VDEV_EVENT_DOWN);
	return;
	}
	if (ret != sizeof(pdu)) {
	pr_err("received pdu size is %d, should be %d\n", ret,
	(unsigned int)sizeof(pdu));
	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	return;
	}

	usbip_header_correct_endian(&pdu, 0);

	if (usbip_dbg_flag_vhci_rx)
	usbip_dump_header(&pdu);

	switch (pdu.base.command) {
	case USBIP_RET_SUBMIT:
	vhci_recv_ret_submit(vdev, &pdu);
	break;
	case USBIP_RET_UNLINK:
	vhci_recv_ret_unlink(vdev, &pdu);
	break;
	default:
	/* NOT REACHED */
	pr_err("unknown pdu %u\n", pdu.base.command);
	usbip_dump_header(&pdu);
	usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	break;
	}
	}

	int vhci_rx_loop(void *data)
	{
	struct usbip_device *ud = data;

	while (!kthread_should_stop()) {
	if (usbip_event_happened(ud))
	break;

	vhci_rx_pdu(ud);
	}

	return 0;
	}