vhci_sysfs.c

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

/*
 * $Id: vhci_sysfs.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"


/* TODO: refine locking ?*/


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

/* Sysfs entry to show port status */

static ssize_t show_status(struct device *dev, struct device_attribute *attr,
		char *out)
{
	char *s = out;
	int i = 0;

	if (!the_controller || !out) {
		if(!the_controller) 
			err("'the_controller' is undefined");
		if(!out)
			err("'out' is undefined");

		//BUG();
		return -1;
	}

	spin_lock(&the_controller->lock);

	/*
	 * output example:
	 * prt sta bus dev socket           local_busid
	 * 000 004 000 000         c5a7bb80 1-2.3
	 * 001 004 000 000         d8cee980 2-3.4
	 *
	 * IP address can be retrieved from a socket pointer address by looking
	 * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
	 * port number and its peer IP address.
	 */
	out += sprintf(out, "prt sta spd bus dev socket           local_busid\n");

	for (i=0; i < VHCI_NPORTS; i++) {
		struct vhci_device *vdev = port_to_vdev(i);

		spin_lock(&vdev->ud.lock);

		out += sprintf(out, "%03u %03u ", i, vdev->ud.status);

		if (vdev->ud.status == VDEV_ST_USED) {
			out += sprintf(out, "%03u %03u %03u ",
					vdev->speed, vdev->busnum, vdev->devnum);
			out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
			out += sprintf(out, "%s", vdev->udev->dev.bus_id);

		} else
			out += sprintf(out, "000 000 000 0000000000000000 0-0");

		out += sprintf(out, "\n");

		spin_unlock(&vdev->ud.lock);
	}

	spin_unlock(&the_controller->lock);

	return out - s ;
}

static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);



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

/* Sysfs entry to shutdown a virtual connection */

static int vhci_port_disconnect(__u32 rhport)
{
	struct vhci_device *vdev;

	dbg_vhci_sysfs("enter\n");

	/* lock */
	spin_lock(&the_controller->lock);

	vdev = port_to_vdev(rhport);

	spin_lock(&vdev->ud.lock);
	if (vdev->ud.status == VDEV_ST_NULL) {
		uerr("not connected %d\n", vdev->ud.status);

		/* unlock */
		spin_unlock(&vdev->ud.lock);
		spin_unlock(&the_controller->lock);

		return -EINVAL;
	}

	/* unlock */
	spin_unlock(&vdev->ud.lock);
	spin_unlock(&the_controller->lock);

	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);

	return 0;
}

static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count) {
	int err;
	__u32 rhport = 0;

	sscanf(buf, "%u", &rhport);

	/* check rhport */
	if (rhport >= VHCI_NPORTS) {
		uerr("invalid port %u\n", rhport);
		return -EINVAL;
	}

	err = vhci_port_disconnect(rhport);
	if (err < 0) {
		return -EINVAL;
	}

	dbg_vhci_sysfs("Leave\n");
	return count;
}

static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);



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

/* Sysfs entry to establish a virtual connection */

static int valid_args(__u32 rhport, __u32 busnum, __u32 devnum,
		enum usb_device_speed speed)
{
	/* check rhport */
	if ((rhport < 0) || (rhport >= VHCI_NPORTS)) {
		uerr("port %u\n", rhport);
		return -EINVAL;
	}

	/* check busnum & devnum */
	if ((busnum <= 0) || (busnum >= 128) || (devnum <= 0) || (devnum >= 128)) {
		uerr("busnum %u devnum %u\n", busnum, devnum);
		return -EINVAL;
	}

	/* check speed */
	switch(speed) {
		case USB_SPEED_LOW:
		case USB_SPEED_FULL:
		case USB_SPEED_HIGH:
		case USB_SPEED_VARIABLE:
			break;

		default:
			uerr("speed %d\n", speed);
			return -EINVAL;
	}

	return 0;
}

/*
 * To start a new USB/IP attachment, a userland program needs to setup a TCP
 * connection and then write its socket descriptor with remote device
 * information into this sysfs file.
 *
 * A remote device is virtually attached to the root-hub port of @rhport with
 * @speed. @busnum and @devnum are used to convert URBs between a client host
 * and a server host.
 *
 * write() returns 0 on success, else negative errno.
 */
static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct vhci_device *vdev;
	struct socket *socket;
	int sockfd = 0;
	__u32 rhport=0, busnum=0, devnum=0, speed=0;


	/*
	 * @rhport: port number of vhci_hcd
	 * @sockfd: socket descriptor of an established TCP connection
	 * @busnum: usb bus number in a remote host
	 * @devnum: usb device number in a remote host
	 * @speed: usb device speed in a remote host
	 */
	sscanf(buf, "%u %u %u %u %u", &rhport, &sockfd, &busnum, &devnum, &speed);

	dbg_vhci_sysfs("rhport(%u) sockfd(%u) busnum(%u) devnum(%u) speed(%u)\n",
			rhport, sockfd, busnum, devnum, speed);


	/* check received parameters */
	if (valid_args(rhport, busnum, devnum, speed) < 0)
		return -EINVAL;

	/* check sockfd */
	socket = sockfd_to_socket(sockfd);
	if (!socket)
		return  -EINVAL;

#if 0
	setnodelay(socket);
#endif

	/* now need lock until setting vdev status as used */

	/* begin a lock */
	spin_lock(&the_controller->lock);

	vdev = port_to_vdev(rhport);

	spin_lock(&vdev->ud.lock);

	if (vdev->ud.status != VDEV_ST_NULL) {
		/* end of the lock */
		spin_unlock(&vdev->ud.lock);
		spin_unlock(&the_controller->lock);

		uerr("port %d already used\n", rhport);
		return -EINVAL;
	}

	uinfo("rhport(%u) sockfd(%d) busnum(%u) devnum(%u) speed(%u)\n",
			rhport, sockfd, busnum, devnum, speed);

	vdev->busnum        = busnum;
	vdev->devnum        = devnum;
	vdev->speed         = speed;
	vdev->ud.tcp_socket = socket;
	vdev->ud.status     = VDEV_ST_NOTASSIGNED;

	spin_unlock(&vdev->ud.lock);
	spin_unlock(&the_controller->lock);
	/* end the lock */

	/*
	 * this function will sleep, so should be out of the lock. but, it's ok
	 * because we already marked vdev as being used. really?
	 */
	usbip_start_threads(&vdev->ud);

	rh_port_connect(rhport, speed);

	return count;
}

static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);



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

static struct attribute *dev_attrs[] = {
	&dev_attr_status.attr,
	&dev_attr_detach.attr,
	&dev_attr_attach.attr,
	&dev_attr_usbip_debug.attr,
	NULL,
};

struct attribute_group dev_attr_group = {
	.attrs = dev_attrs,
};