vhci_rx.c

Realize the usbip function, which could be simulate usb port through net

/*
 * $Id: vhci_rx.c 15 2007-06-18 12:22:03Z hirofuchi $
 *
 * Copyright (C) 2003-2007 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 "vhci.h"



/* get URB from transmitted urb queue */
static struct urb *pickup_urb_and_free_priv(struct vhci_device *vdev, __u32 seqnum)
{
	struct vhci_priv *priv, *tmp;
	struct urb *urb = NULL;


	spin_lock(&vdev->priv_lock);


	list_for_each_entry_safe(priv, tmp, &vdev->priv_rx, list) {
		if (priv->seqnum == seqnum) {
			urb = priv->urb;
			dbg_vhci_rx("find urb %p vurb %p seqnum %u\n", urb, priv, seqnum);


			if (urb->status != -EINPROGRESS) {
				 if (urb->status == -ENOENT || urb->status == -ECONNRESET) {
					 uinfo("urb %p was unlinked %ssynchronuously.\n",
							 urb, urb->status == -ENOENT ? "" : "a");
				 } else {
					 uinfo("urb %p may be in a error, status %d\n",
							 urb, urb->status);
				 }
			}


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


			break;
		}
	}

	spin_unlock(&vdev->priv_lock);


	return urb;
}

static void vhci_recv_ret_submit(struct vhci_device *vdev, struct usbip_header *pdu)
{
	struct usbip_device *ud = &vdev->ud;
	struct urb *urb;


	urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);


	if (!urb) {
		uerr("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
		uinfo("max seqnum %d\n", atomic_read(&the_controller->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;


	if (dbg_flag_vhci_rx)
		usbip_dump_urb(urb);


	dbg_vhci_rx("now giveback urb %p\n", urb);



	usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb);


	dbg_vhci_rx("Leave\n");

	return;
}


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

	spin_lock(&vdev->priv_lock);

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

			spin_unlock(&vdev->priv_lock);
			return unlink;
		}
	}

	spin_unlock(&vdev->priv_lock);

	return NULL;
}


static void vhci_recv_ret_unlink(struct vhci_device *vdev, struct usbip_header *pdu)
{
	struct vhci_unlink *unlink;
	struct urb *urb;

	usbip_dump_header(pdu);

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

	urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
	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.
		 */
		uinfo("the urb (seqnum %d) was already given backed\n", pdu->base.seqnum);
	} else {
		dbg_vhci_rx("now giveback urb %p\n", urb);

		/* If unlink is succeed, status is -ECONNRESET */
		urb->status = pdu->u.ret_unlink.status;
		uinfo("%d\n", urb->status);
		usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb);
	}

	kfree(unlink);

	return;
}

/* 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);


	dbg_vhci_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("receiving pdu failed! size is %d, should be %d\n",
				ret, sizeof(pdu));
		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
		return;
	}

	usbip_header_correct_endian(&pdu, 0);

	if (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:
			/* NOTREACHED */
			uerr("unknown pdu %u\n", pdu.base.command);
			usbip_dump_header(&pdu);
			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
	}
}


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

void vhci_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_vhci_rx("signal catched!\n");
			break;
		}


		if (usbip_event_happend(ud)) break;

		vhci_rx_pdu(ud);
	}
}