/*
   * 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/file.h>

  #include <linux/net.h>

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

  /* TODO: refine locking ?*/
  
  /* Sysfs entry to show port status */

  static ssize_t status_show(struct device *dev, struct device_attribute *attr,

  			   char *out)
  {
  	char *s = out;
  	int i = 0;

  	BUG_ON(!the_controller || !out);

  
  	spin_lock(&the_controller->lock);
  
  	/*
  	 * output example:
  	 * prt sta spd 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
  ");

  
  	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 %08x ",

  				       vdev->speed, vdev->devid);

  			out += sprintf(out, "%16p ", vdev->ud.tcp_socket);

  			out += sprintf(out, "%s", dev_name(&vdev->udev->dev));

  		} else {

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

  		}

  
  		out += sprintf(out, "
  ");

  		spin_unlock(&vdev->ud.lock);
  	}
  
  	spin_unlock(&the_controller->lock);
  
  	return out - s;
  }

  static DEVICE_ATTR_RO(status);

  
  /* Sysfs entry to shutdown a virtual connection */
  static int vhci_port_disconnect(__u32 rhport)
  {
  	struct vhci_device *vdev;

  	usbip_dbg_vhci_sysfs("enter
  ");

  
  	/* lock */
  	spin_lock(&the_controller->lock);
  
  	vdev = port_to_vdev(rhport);
  
  	spin_lock(&vdev->ud.lock);
  	if (vdev->ud.status == VDEV_ST_NULL) {

  		pr_err("not connected %d
  ", 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;

  	if (sscanf(buf, "%u", &rhport) != 1)
  		return -EINVAL;

  
  	/* check rhport */
  	if (rhport >= VHCI_NPORTS) {

  		dev_err(dev, "invalid port %u
  ", rhport);

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

  	usbip_dbg_vhci_sysfs("Leave
  ");

  	return count;
  }
  static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
  
  /* Sysfs entry to establish a virtual connection */
  static int valid_args(__u32 rhport, enum usb_device_speed speed)
  {
  	/* check rhport */

  	if (rhport >= VHCI_NPORTS) {

  		pr_err("port %u
  ", rhport);

  		return -EINVAL;
  	}
  
  	/* check speed */
  	switch (speed) {
  	case USB_SPEED_LOW:
  	case USB_SPEED_FULL:
  	case USB_SPEED_HIGH:

  	case USB_SPEED_WIRELESS:

  		break;
  	default:

  		pr_err("Failed attach request for unsupported USB speed: %s
  ",
  			usb_speed_string(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. @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 vhci_device *vdev;
  	struct socket *socket;
  	int sockfd = 0;
  	__u32 rhport = 0, devid = 0, speed = 0;

  	int err;

  
  	/*
  	 * @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", &rhport, &sockfd, &devid, &speed) != 4)

  		return -EINVAL;

  	usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)
  ",

  			     rhport, sockfd, devid, speed);

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

  	/* 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(&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);

  		sockfd_put(socket);

  		dev_err(dev, "port %d already used
  ", rhport);

  		return -EINVAL;
  	}

  	dev_info(dev,
  		 "rhport(%u) sockfd(%d) devid(%u) speed(%u) speed_str(%s)
  ",
  		 rhport, sockfd, 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(&the_controller->lock);
  	/* 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(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,
  };

  const struct attribute_group dev_attr_group = {

  	.attrs = dev_attrs,
  };