stub_rx.c

linux virtual usb host source

/*
 * $Id: stub_rx.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 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);
}

#if 0
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)) {
		dbg_stub_rx("reset_device_cmd, port %u\n", index);
		return 1;
	} else 
		return 0;
}
#endif

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)
		uinfo("clear_halt error: devnum %d endp %d, %d\n",
				urb->dev->devnum, target_endp, ret);
	else
		uinfo("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);

	dbg_stub_rx("set_interface: inf %u alt %u\n", interface, alternate);

	ret = usb_set_interface(urb->dev, interface, alternate);
	if (ret < 0)
		uinfo("set_interface error: inf %u alt %u, %d\n",
				interface, alternate, ret);
	else
		uinfo("set_interface done: inf %u alt %u\n", interface, alternate);

	return ret;
}

static int tweak_set_configuration_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;
	__u16 config;

	req = (struct usb_ctrlrequest *) urb->setup_packet;
	config = le16_to_cpu(req->wValue);

	/*
	 * I have never seen a multi-config device. Very rare.
	 * For most devices, this will be called to choose a default
	 * configuration only once in an initialization phase.
	 *
	 * set_configuration may change a device configuration and its device
	 * drivers will be unbound and assigned for a new device configuration.
	 * This means this usbip driver will be also unbound when called, then
	 * eventually reassigned to the device as far as driver matching
	 * condition is kept.
	 *
	 * Unfortunatelly, an existing usbip connection will be dropped
	 * due to this driver unbinding. So, skip here.
	 * A user may need to set a special configuration value before
	 * exporting the device.
	 */
	uinfo("set_configuration (%d) to %s\n", config, urb->dev->dev.bus_id);
	uinfo("but, skip!\n");

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)
	return 0;
	//return usb_driver_set_configuration(urb->dev, config);
#else
	//uinfo("no support of set_config in 2.6.18\n");
	return 0;
#endif
}

#if 0
static int tweak_reset_device_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;
	__u16 value;
	__u16 index;
	int ret;

	req = (struct usb_ctrlrequest *) urb->setup_packet;
	value = le16_to_cpu(req->wValue);
	index = le16_to_cpu(req->wIndex);

	uinfo("reset_device (port %d) to %s\n", index, urb->dev->dev.bus_id);

	/* all interfaces should be owned by usbip driver, so just reset it. */
	ret = usb_lock_device_for_reset(urb->dev, NULL);
	if (ret < 0) {
		uerr("lock for reset\n");
		return ret;
	}

	/* try to reset the device */
	ret = usb_reset_composite_device(urb->dev, NULL);
	if (ret < 0)
		uerr("device reset\n");

	usb_unlock_device(urb->dev);

	return ret;
}
#endif


/*
 * 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);

#if 0
	else if (is_reset_device_cmd(urb))
		tweak_reset_device_cmd(urb);
#endif

	else
		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)
{
	struct list_head *listhead = &sdev->priv_init;
	struct list_head *ptr;
	unsigned long flags;

	struct stub_priv *priv;


	spin_lock_irqsave(&sdev->priv_lock, flags);

	for (ptr = listhead->next; ptr != listhead; ptr = ptr->next) {
		priv = list_entry(ptr, struct stub_priv, list);
		if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
			int ret;

			uinfo("unlink urb %p\n", priv->urb);

			/*
			 * 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 ?
			 */
			ret = usb_unlink_urb(priv->urb);
			if (ret != -EINPROGRESS)
				uerr("faild to unlink a urb %p, ret %d\n", priv->urb, ret);

			return 0;
		}
	}

	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;