drivers/usb/usbip/vhci_sysfs.c - arm/linux - Git at Google

 /*
  * Copyright (C) 2003-2008 Takahiro Hirofuchi
  * Copyright (C) 2015-2016 Nobuo Iwata
  *
  * 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/file.h>
 #include <linux/net.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

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

 /* TODO: refine locking ?*/

 /*
  * output example:
  * hub port sta spd dev      socket           local_busid
  * hs  0000 004 000 00000000         c5a7bb80 1-2.3
  * ................................................
  * ss  0008 004 000 00000000         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.
  */
 static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev)
 {
 	if (hub == HUB_SPEED_HIGH)
 		*out += sprintf(*out, "hs  %04u %03u ",
 				      port, vdev->ud.status);
 	else /* hub == HUB_SPEED_SUPER */
 		*out += sprintf(*out, "ss  %04u %03u ",
 				      port, vdev->ud.status);

 	if (vdev->ud.status == VDEV_ST_USED) {
 		*out += sprintf(*out, "%03u %08x ",
 				      vdev->speed, vdev->devid);
 		*out += sprintf(*out, "%16p %s",
 				      vdev->ud.tcp_socket,
 				      dev_name(&vdev->udev->dev));

 	} else {
 		*out += sprintf(*out, "000 00000000 ");
 		*out += sprintf(*out, "0000000000000000 0-0");
 	}

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

 /* Sysfs entry to show port status */
 static ssize_t status_show_vhci(int pdev_nr, char *out)
 {
 	struct platform_device *pdev = vhcis[pdev_nr].pdev;
 	struct vhci *vhci;
 	struct usb_hcd *hcd;
 	struct vhci_hcd *vhci_hcd;
 	char *s = out;
 	int i;
 	unsigned long flags;

 	if (!pdev || !out) {
 		usbip_dbg_vhci_sysfs("show status error\n");
 		return 0;
 	}

 	hcd = platform_get_drvdata(pdev);
 	vhci_hcd = hcd_to_vhci_hcd(hcd);
 	vhci = vhci_hcd->vhci;

 	spin_lock_irqsave(&vhci->lock, flags);

 	for (i = 0; i < VHCI_HC_PORTS; i++) {
 		struct vhci_device *vdev = &vhci->vhci_hcd_hs->vdev[i];

 		spin_lock(&vdev->ud.lock);
 		port_show_vhci(&out, HUB_SPEED_HIGH,
 			       pdev_nr * VHCI_PORTS + i, vdev);
 		spin_unlock(&vdev->ud.lock);
 	}

 	for (i = 0; i < VHCI_HC_PORTS; i++) {
 		struct vhci_device *vdev = &vhci->vhci_hcd_ss->vdev[i];

 		spin_lock(&vdev->ud.lock);
 		port_show_vhci(&out, HUB_SPEED_SUPER,
 			       pdev_nr * VHCI_PORTS + VHCI_HC_PORTS + i, vdev);
 		spin_unlock(&vdev->ud.lock);
 	}

 	spin_unlock_irqrestore(&vhci->lock, flags);

 	return out - s;
 }

 static ssize_t status_show_not_ready(int pdev_nr, char *out)
 {
 	char *s = out;
 	int i = 0;

 	for (i = 0; i < VHCI_HC_PORTS; i++) {
 		out += sprintf(out, "hs  %04u %03u ",
 				    (pdev_nr * VHCI_PORTS) + i,
 				    VDEV_ST_NOTASSIGNED);
 		out += sprintf(out, "000 00000000 0000000000000000 0-0");
 		out += sprintf(out, "\n");
 	}

 	for (i = 0; i < VHCI_HC_PORTS; i++) {
 		out += sprintf(out, "ss  %04u %03u ",
 				    (pdev_nr * VHCI_PORTS) + VHCI_HC_PORTS + i,
 				    VDEV_ST_NOTASSIGNED);
 		out += sprintf(out, "000 00000000 0000000000000000 0-0");
 		out += sprintf(out, "\n");
 	}
 	return out - s;
 }

 static int status_name_to_id(const char *name)
 {
 	char *c;
 	long val;
 	int ret;

 	c = strchr(name, '.');
 	if (c == NULL)
 		return 0;

 	ret = kstrtol(c+1, 10, &val);
 	if (ret < 0)
 		return ret;

 	return val;
 }

 static ssize_t status_show(struct device *dev,
 			   struct device_attribute *attr, char *out)
 {
 	char *s = out;
 	int pdev_nr;

 	out += sprintf(out,
 		       "hub port sta spd dev      socket           local_busid\n");

 	pdev_nr = status_name_to_id(attr->attr.name);
 	if (pdev_nr < 0)
 		out += status_show_not_ready(pdev_nr, out);
 	else
 		out += status_show_vhci(pdev_nr, out);

 	return out - s;
 }

 static ssize_t nports_show(struct device *dev, struct device_attribute *attr,
 			   char *out)
 {
 	char *s = out;

 	/*
 	 * Half the ports are for SPEED_HIGH and half for SPEED_SUPER, thus the * 2.
 	 */
 	out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers);
 	return out - s;
 }
 static DEVICE_ATTR_RO(nports);

 /* Sysfs entry to shutdown a virtual connection */
 static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
 {
 	struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
 	struct vhci *vhci = vhci_hcd->vhci;
 	unsigned long flags;

 	usbip_dbg_vhci_sysfs("enter\n");

 	/* lock */
 	spin_lock_irqsave(&vhci->lock, flags);
 	spin_lock(&vdev->ud.lock);

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

 		/* unlock */
 		spin_unlock(&vdev->ud.lock);
 		spin_unlock_irqrestore(&vhci->lock, flags);

 		return -EINVAL;
 	}

 	/* unlock */
 	spin_unlock(&vdev->ud.lock);
 	spin_unlock_irqrestore(&vhci->lock, flags);

 	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);

 	return 0;
 }

 static int valid_port(__u32 pdev_nr, __u32 rhport)
 {
 	if (pdev_nr >= vhci_num_controllers) {
 		pr_err("pdev %u\n", pdev_nr);
 		return 0;
 	}
 	if (rhport >= VHCI_HC_PORTS) {
 		pr_err("rhport %u\n", rhport);
 		return 0;
 	}
 	return 1;
 }

 static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
 	__u32 port = 0, pdev_nr = 0, rhport = 0;
 	struct usb_hcd *hcd;
 	struct vhci_hcd *vhci_hcd;
 	int ret;

 	if (kstrtoint(buf, 10, &port) < 0)
 		return -EINVAL;

 	pdev_nr = port_to_pdev_nr(port);
 	rhport = port_to_rhport(port);

 	if (!valid_port(pdev_nr, rhport))
 		return -EINVAL;

 	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
 	if (hcd == NULL) {
 		dev_err(dev, "port is not ready %u\n", port);
 		return -EAGAIN;
 	}

 	usbip_dbg_vhci_sysfs("rhport %d\n", rhport);

 	if ((port / VHCI_HC_PORTS) % 2)
 		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_ss;
 	else
 		vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_hs;

 	ret = vhci_port_disconnect(vhci_hcd, rhport);
 	if (ret < 0)
 		return -EINVAL;

 	usbip_dbg_vhci_sysfs("Leave\n");

 	return count;
 }
 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);

 static int valid_args(__u32 pdev_nr, __u32 rhport, enum usb_device_speed speed)
 {
 	if (!valid_port(pdev_nr, rhport)) {
 		return 0;
 	}

 	switch (speed) {
 	case USB_SPEED_LOW:
 	case USB_SPEED_FULL:
 	case USB_SPEED_HIGH:
 	case USB_SPEED_WIRELESS:
 	case USB_SPEED_SUPER:
 		break;
 	default:
 		pr_err("Failed attach request for unsupported USB speed: %s\n",
 			usb_speed_string(speed));
 		return 0;
 	}

 	return 1;
 }

 /* Sysfs entry to establish a virtual connection */
 /*
  * 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. @devid is embedded into a request to specify the remote device in 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 socket *socket;
 	int sockfd = 0;
 	__u32 port = 0, pdev_nr = 0, rhport = 0, devid = 0, speed = 0;
 	struct usb_hcd *hcd;
 	struct vhci_hcd *vhci_hcd;
 	struct vhci_device *vdev;
 	struct vhci *vhci;
 	int err;
 	unsigned long flags;

 	/*
 	 * @rhport: port number of vhci_hcd
 	 * @sockfd: socket descriptor of an established TCP connection
 	 * @devid: unique device identifier in a remote host
 	 * @speed: usb device speed in a remote host
 	 */
 	if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
 		return -EINVAL;
 	pdev_nr = port_to_pdev_nr(port);
 	rhport = port_to_rhport(port);

 	usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
 			     port, pdev_nr, rhport);
 	usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
 			     sockfd, devid, speed);

 	/* check received parameters */
 	if (!valid_args(pdev_nr, rhport, speed))
 		return -EINVAL;

 	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
 	if (hcd == NULL) {
 		dev_err(dev, "port %d is not ready\n", port);
 		return -EAGAIN;
 	}

 	vhci_hcd = hcd_to_vhci_hcd(hcd);
 	vhci = vhci_hcd->vhci;

 	if (speed == USB_SPEED_SUPER)
 		vdev = &vhci->vhci_hcd_ss->vdev[rhport];
 	else
 		vdev = &vhci->vhci_hcd_hs->vdev[rhport];

 	/* Extract socket from fd. */
 	socket = sockfd_lookup(sockfd, &err);
 	if (!socket)
 		return -EINVAL;

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

 	/* begin a lock */
 	spin_lock_irqsave(&vhci->lock, flags);
 	spin_lock(&vdev->ud.lock);

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

 		sockfd_put(socket);

 		dev_err(dev, "port %d already used\n", rhport);
 		/*
 		 * Will be retried from userspace
 		 * if there's another free port.
 		 */
 		return -EBUSY;
 	}

 	dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
 		 pdev_nr, rhport, sockfd);
 	dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
 		 devid, speed, usb_speed_string(speed));

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

 	spin_unlock(&vdev->ud.lock);
 	spin_unlock_irqrestore(&vhci->lock, flags);
 	/* end the lock */

 	vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
 	vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");

 	rh_port_connect(vdev, speed);

 	return count;
 }
 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);

 #define MAX_STATUS_NAME 16

 struct status_attr {
 	struct device_attribute attr;
 	char name[MAX_STATUS_NAME+1];
 };

 static struct status_attr *status_attrs;

 static void set_status_attr(int id)
 {
 	struct status_attr *status;

 	status = status_attrs + id;
 	if (id == 0)
 		strcpy(status->name, "status");
 	else
 		snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
 	status->attr.attr.name = status->name;
 	status->attr.attr.mode = S_IRUGO;
 	status->attr.show = status_show;
 	sysfs_attr_init(&status->attr.attr);
 }

 static int init_status_attrs(void)
 {
 	int id;

 	status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
 			       GFP_KERNEL);
 	if (status_attrs == NULL)
 		return -ENOMEM;

 	for (id = 0; id < vhci_num_controllers; id++)
 		set_status_attr(id);

 	return 0;
 }

 static void finish_status_attrs(void)
 {
 	kfree(status_attrs);
 }

 struct attribute_group vhci_attr_group = {
 	.attrs = NULL,
 };

 int vhci_init_attr_group(void)
 {
 	struct attribute **attrs;
 	int ret, i;

 	attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
 			GFP_KERNEL);
 	if (attrs == NULL)
 		return -ENOMEM;

 	ret = init_status_attrs();
 	if (ret) {
 		kfree(attrs);
 		return ret;
 	}
 	*attrs = &dev_attr_nports.attr;
 	*(attrs + 1) = &dev_attr_detach.attr;
 	*(attrs + 2) = &dev_attr_attach.attr;
 	*(attrs + 3) = &dev_attr_usbip_debug.attr;
 	for (i = 0; i < vhci_num_controllers; i++)
 		*(attrs + i + 4) = &((status_attrs + i)->attr.attr);
 	vhci_attr_group.attrs = attrs;
 	return 0;
 }

 void vhci_finish_attr_group(void)
 {
 	finish_status_attrs();
 	kfree(vhci_attr_group.attrs);
 }
	/*
	* Copyright (C) 2003-2008 Takahiro Hirofuchi
	* Copyright (C) 2015-2016 Nobuo Iwata
	*
	* 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/file.h>
	#include <linux/net.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

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

	/* TODO: refine locking ?*/

	/*
	* output example:
	* hub port sta spd dev socket local_busid
	* hs 0000 004 000 00000000 c5a7bb80 1-2.3
	* ................................................
	* ss 0008 004 000 00000000 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.
	*/
	static void port_show_vhci(char *out, int hub, int port, struct vhci_device vdev)
	{
	if (hub == HUB_SPEED_HIGH)
	out += sprintf(out, "hs %04u %03u ",
	port, vdev->ud.status);
	else /* hub == HUB_SPEED_SUPER */
	out += sprintf(out, "ss %04u %03u ",
	port, vdev->ud.status);

	if (vdev->ud.status == VDEV_ST_USED) {
	out += sprintf(out, "%03u %08x ",
	vdev->speed, vdev->devid);
	out += sprintf(out, "%16p %s",
	vdev->ud.tcp_socket,
	dev_name(&vdev->udev->dev));

	} else {
	out += sprintf(out, "000 00000000 ");
	out += sprintf(out, "0000000000000000 0-0");
	}

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

	/* Sysfs entry to show port status */
	static ssize_t status_show_vhci(int pdev_nr, char *out)
	{
	struct platform_device *pdev = vhcis[pdev_nr].pdev;
	struct vhci *vhci;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	char *s = out;
	int i;
	unsigned long flags;

	if (!pdev \|\| !out) {
	usbip_dbg_vhci_sysfs("show status error\n");
	return 0;
	}

	hcd = platform_get_drvdata(pdev);
	vhci_hcd = hcd_to_vhci_hcd(hcd);
	vhci = vhci_hcd->vhci;

	spin_lock_irqsave(&vhci->lock, flags);

	for (i = 0; i < VHCI_HC_PORTS; i++) {
	struct vhci_device *vdev = &vhci->vhci_hcd_hs->vdev[i];

	spin_lock(&vdev->ud.lock);
	port_show_vhci(&out, HUB_SPEED_HIGH,
	pdev_nr * VHCI_PORTS + i, vdev);
	spin_unlock(&vdev->ud.lock);
	}

	for (i = 0; i < VHCI_HC_PORTS; i++) {
	struct vhci_device *vdev = &vhci->vhci_hcd_ss->vdev[i];

	spin_lock(&vdev->ud.lock);
	port_show_vhci(&out, HUB_SPEED_SUPER,
	pdev_nr * VHCI_PORTS + VHCI_HC_PORTS + i, vdev);
	spin_unlock(&vdev->ud.lock);
	}

	spin_unlock_irqrestore(&vhci->lock, flags);

	return out - s;
	}

	static ssize_t status_show_not_ready(int pdev_nr, char *out)
	{
	char *s = out;
	int i = 0;

	for (i = 0; i < VHCI_HC_PORTS; i++) {
	out += sprintf(out, "hs %04u %03u ",
	(pdev_nr * VHCI_PORTS) + i,
	VDEV_ST_NOTASSIGNED);
	out += sprintf(out, "000 00000000 0000000000000000 0-0");
	out += sprintf(out, "\n");
	}

	for (i = 0; i < VHCI_HC_PORTS; i++) {
	out += sprintf(out, "ss %04u %03u ",
	(pdev_nr * VHCI_PORTS) + VHCI_HC_PORTS + i,
	VDEV_ST_NOTASSIGNED);
	out += sprintf(out, "000 00000000 0000000000000000 0-0");
	out += sprintf(out, "\n");
	}
	return out - s;
	}

	static int status_name_to_id(const char *name)
	{
	char *c;
	long val;
	int ret;

	c = strchr(name, '.');
	if (c == NULL)
	return 0;

	ret = kstrtol(c+1, 10, &val);
	if (ret < 0)
	return ret;

	return val;
	}

	static ssize_t status_show(struct device *dev,
	struct device_attribute attr, char out)
	{
	char *s = out;
	int pdev_nr;

	out += sprintf(out,
	"hub port sta spd dev socket local_busid\n");

	pdev_nr = status_name_to_id(attr->attr.name);
	if (pdev_nr < 0)
	out += status_show_not_ready(pdev_nr, out);
	else
	out += status_show_vhci(pdev_nr, out);

	return out - s;
	}

	static ssize_t nports_show(struct device dev, struct device_attribute attr,
	char *out)
	{
	char *s = out;

	/*
	* Half the ports are for SPEED_HIGH and half for SPEED_SUPER, thus the * 2.
	*/
	out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers);
	return out - s;
	}
	static DEVICE_ATTR_RO(nports);

	/* Sysfs entry to shutdown a virtual connection */
	static int vhci_port_disconnect(struct vhci_hcd *vhci_hcd, __u32 rhport)
	{
	struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
	struct vhci *vhci = vhci_hcd->vhci;
	unsigned long flags;

	usbip_dbg_vhci_sysfs("enter\n");

	/* lock */
	spin_lock_irqsave(&vhci->lock, flags);
	spin_lock(&vdev->ud.lock);

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

	/* unlock */
	spin_unlock(&vdev->ud.lock);
	spin_unlock_irqrestore(&vhci->lock, flags);

	return -EINVAL;
	}

	/* unlock */
	spin_unlock(&vdev->ud.lock);
	spin_unlock_irqrestore(&vhci->lock, flags);

	usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);

	return 0;
	}

	static int valid_port(__u32 pdev_nr, __u32 rhport)
	{
	if (pdev_nr >= vhci_num_controllers) {
	pr_err("pdev %u\n", pdev_nr);
	return 0;
	}
	if (rhport >= VHCI_HC_PORTS) {
	pr_err("rhport %u\n", rhport);
	return 0;
	}
	return 1;
	}

	static ssize_t store_detach(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	__u32 port = 0, pdev_nr = 0, rhport = 0;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	int ret;

	if (kstrtoint(buf, 10, &port) < 0)
	return -EINVAL;

	pdev_nr = port_to_pdev_nr(port);
	rhport = port_to_rhport(port);

	if (!valid_port(pdev_nr, rhport))
	return -EINVAL;

	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
	if (hcd == NULL) {
	dev_err(dev, "port is not ready %u\n", port);
	return -EAGAIN;
	}

	usbip_dbg_vhci_sysfs("rhport %d\n", rhport);

	if ((port / VHCI_HC_PORTS) % 2)
	vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_ss;
	else
	vhci_hcd = hcd_to_vhci_hcd(hcd)->vhci->vhci_hcd_hs;

	ret = vhci_port_disconnect(vhci_hcd, rhport);
	if (ret < 0)
	return -EINVAL;

	usbip_dbg_vhci_sysfs("Leave\n");

	return count;
	}
	static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);

	static int valid_args(__u32 pdev_nr, __u32 rhport, enum usb_device_speed speed)
	{
	if (!valid_port(pdev_nr, rhport)) {
	return 0;
	}

	switch (speed) {
	case USB_SPEED_LOW:
	case USB_SPEED_FULL:
	case USB_SPEED_HIGH:
	case USB_SPEED_WIRELESS:
	case USB_SPEED_SUPER:
	break;
	default:
	pr_err("Failed attach request for unsupported USB speed: %s\n",
	usb_speed_string(speed));
	return 0;
	}

	return 1;
	}

	/* Sysfs entry to establish a virtual connection */
	/*
	* 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. @devid is embedded into a request to specify the remote device in 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 socket *socket;
	int sockfd = 0;
	__u32 port = 0, pdev_nr = 0, rhport = 0, devid = 0, speed = 0;
	struct usb_hcd *hcd;
	struct vhci_hcd *vhci_hcd;
	struct vhci_device *vdev;
	struct vhci *vhci;
	int err;
	unsigned long flags;

	/*
	* @rhport: port number of vhci_hcd
	* @sockfd: socket descriptor of an established TCP connection
	* @devid: unique device identifier in a remote host
	* @speed: usb device speed in a remote host
	*/
	if (sscanf(buf, "%u %u %u %u", &port, &sockfd, &devid, &speed) != 4)
	return -EINVAL;
	pdev_nr = port_to_pdev_nr(port);
	rhport = port_to_rhport(port);

	usbip_dbg_vhci_sysfs("port(%u) pdev(%d) rhport(%u)\n",
	port, pdev_nr, rhport);
	usbip_dbg_vhci_sysfs("sockfd(%u) devid(%u) speed(%u)\n",
	sockfd, devid, speed);

	/* check received parameters */
	if (!valid_args(pdev_nr, rhport, speed))
	return -EINVAL;

	hcd = platform_get_drvdata(vhcis[pdev_nr].pdev);
	if (hcd == NULL) {
	dev_err(dev, "port %d is not ready\n", port);
	return -EAGAIN;
	}

	vhci_hcd = hcd_to_vhci_hcd(hcd);
	vhci = vhci_hcd->vhci;

	if (speed == USB_SPEED_SUPER)
	vdev = &vhci->vhci_hcd_ss->vdev[rhport];
	else
	vdev = &vhci->vhci_hcd_hs->vdev[rhport];

	/* Extract socket from fd. */
	socket = sockfd_lookup(sockfd, &err);
	if (!socket)
	return -EINVAL;

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

	/* begin a lock */
	spin_lock_irqsave(&vhci->lock, flags);
	spin_lock(&vdev->ud.lock);

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

	sockfd_put(socket);

	dev_err(dev, "port %d already used\n", rhport);
	/*
	* Will be retried from userspace
	* if there's another free port.
	*/
	return -EBUSY;
	}

	dev_info(dev, "pdev(%u) rhport(%u) sockfd(%d)\n",
	pdev_nr, rhport, sockfd);
	dev_info(dev, "devid(%u) speed(%u) speed_str(%s)\n",
	devid, speed, usb_speed_string(speed));

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

	spin_unlock(&vdev->ud.lock);
	spin_unlock_irqrestore(&vhci->lock, flags);
	/* end the lock */

	vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
	vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");

	rh_port_connect(vdev, speed);

	return count;
	}
	static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);

	#define MAX_STATUS_NAME 16

	struct status_attr {
	struct device_attribute attr;
	char name[MAX_STATUS_NAME+1];
	};

	static struct status_attr *status_attrs;

	static void set_status_attr(int id)
	{
	struct status_attr *status;

	status = status_attrs + id;
	if (id == 0)
	strcpy(status->name, "status");
	else
	snprintf(status->name, MAX_STATUS_NAME+1, "status.%d", id);
	status->attr.attr.name = status->name;
	status->attr.attr.mode = S_IRUGO;
	status->attr.show = status_show;
	sysfs_attr_init(&status->attr.attr);
	}

	static int init_status_attrs(void)
	{
	int id;

	status_attrs = kcalloc(vhci_num_controllers, sizeof(struct status_attr),
	GFP_KERNEL);
	if (status_attrs == NULL)
	return -ENOMEM;

	for (id = 0; id < vhci_num_controllers; id++)
	set_status_attr(id);

	return 0;
	}

	static void finish_status_attrs(void)
	{
	kfree(status_attrs);
	}

	struct attribute_group vhci_attr_group = {
	.attrs = NULL,
	};

	int vhci_init_attr_group(void)
	{
	struct attribute **attrs;
	int ret, i;

	attrs = kcalloc((vhci_num_controllers + 5), sizeof(struct attribute *),
	GFP_KERNEL);
	if (attrs == NULL)
	return -ENOMEM;

	ret = init_status_attrs();
	if (ret) {
	kfree(attrs);
	return ret;
	}
	*attrs = &dev_attr_nports.attr;
	*(attrs + 1) = &dev_attr_detach.attr;
	*(attrs + 2) = &dev_attr_attach.attr;
	*(attrs + 3) = &dev_attr_usbip_debug.attr;
	for (i = 0; i < vhci_num_controllers; i++)
	*(attrs + i + 4) = &((status_attrs + i)->attr.attr);
	vhci_attr_group.attrs = attrs;
	return 0;
	}

	void vhci_finish_attr_group(void)
	{
	finish_status_attrs();
	kfree(vhci_attr_group.attrs);
	}