drivers/usb/usbip/vhci_sysfs.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  *
   4  * This is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  */
  19
  20 #include <linux/kthread.h>
  21 #include <linux/file.h>
  22 #include <linux/net.h>
  23
  24 #include "usbip_common.h"
  25 #include "vhci.h"
  26
  27 /* TODO: refine locking ?*/
  28
  29 /* Sysfs entry to show port status */
  30 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
  31                            char *out)
  32 {
  33         char *s = out;
  34         int i = 0;
  35
  36         BUG_ON(!the_controller || !out);
  37
  38         spin_lock(&the_controller->lock);
  39
  40         /*
  41          * output example:
  42          * prt sta spd dev socket           local_busid
  43          * 000 004 000 000         c5a7bb80 1-2.3
  44          * 001 004 000 000         d8cee980 2-3.4
  45          *
  46          * IP address can be retrieved from a socket pointer address by looking
  47          * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
  48          * port number and its peer IP address.
  49          */
  50         out += sprintf(out,
  51                        "prt sta spd bus dev socket           local_busid\n");
  52
  53         for (i = 0; i < VHCI_NPORTS; i++) {
  54                 struct vhci_device *vdev = port_to_vdev(i);
  55
  56                 spin_lock(&vdev->ud.lock);
  57                 out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
  58
  59                 if (vdev->ud.status == VDEV_ST_USED) {
  60                         out += sprintf(out, "%03u %08x ",
  61                                        vdev->speed, vdev->devid);
  62                         out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
  63                         out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
  64
  65                 } else {
  66                         out += sprintf(out, "000 000 000 0000000000000000 0-0");
  67                 }
  68
  69                 out += sprintf(out, "\n");
  70                 spin_unlock(&vdev->ud.lock);
  71         }
  72
  73         spin_unlock(&the_controller->lock);
  74
  75         return out - s;
  76 }
  77 static DEVICE_ATTR_RO(status);
  78
  79 /* Sysfs entry to shutdown a virtual connection */
  80 static int vhci_port_disconnect(__u32 rhport)
  81 {
  82         struct vhci_device *vdev;
  83
  84         usbip_dbg_vhci_sysfs("enter\n");
  85
  86         /* lock */
  87         spin_lock(&the_controller->lock);
  88
  89         vdev = port_to_vdev(rhport);
  90
  91         spin_lock(&vdev->ud.lock);
  92         if (vdev->ud.status == VDEV_ST_NULL) {
  93                 pr_err("not connected %d\n", vdev->ud.status);
  94
  95                 /* unlock */
  96                 spin_unlock(&vdev->ud.lock);
  97                 spin_unlock(&the_controller->lock);
  98
  99                 return -EINVAL;
 100         }
 101
 102         /* unlock */
 103         spin_unlock(&vdev->ud.lock);
 104         spin_unlock(&the_controller->lock);
 105
 106         usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
 107
 108         return 0;
 109 }
 110
 111 static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
 112                             const char *buf, size_t count)
 113 {
 114         int err;
 115         __u32 rhport = 0;
 116
 117         if (sscanf(buf, "%u", &rhport) != 1)
 118                 return -EINVAL;
 119
 120         /* check rhport */
 121         if (rhport >= VHCI_NPORTS) {
 122                 dev_err(dev, "invalid port %u\n", rhport);
 123                 return -EINVAL;
 124         }
 125
 126         err = vhci_port_disconnect(rhport);
 127         if (err < 0)
 128                 return -EINVAL;
 129
 130         usbip_dbg_vhci_sysfs("Leave\n");
 131
 132         return count;
 133 }
 134 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
 135
 136 /* Sysfs entry to establish a virtual connection */
 137 static int valid_args(__u32 rhport, enum usb_device_speed speed)
 138 {
 139         /* check rhport */
 140         if (rhport >= VHCI_NPORTS) {
 141                 pr_err("port %u\n", rhport);
 142                 return -EINVAL;
 143         }
 144
 145         /* check speed */
 146         switch (speed) {
 147         case USB_SPEED_LOW:
 148         case USB_SPEED_FULL:
 149         case USB_SPEED_HIGH:
 150         case USB_SPEED_WIRELESS:
 151                 break;
 152         default:
 153                 pr_err("Failed attach request for unsupported USB speed: %s\n",
 154                         usb_speed_string(speed));
 155                 return -EINVAL;
 156         }
 157
 158         return 0;
 159 }
 160
 161 /*
 162  * To start a new USB/IP attachment, a userland program needs to setup a TCP
 163  * connection and then write its socket descriptor with remote device
 164  * information into this sysfs file.
 165  *
 166  * A remote device is virtually attached to the root-hub port of @rhport with
 167  * @speed. @devid is embedded into a request to specify the remote device in a
 168  * server host.
 169  *
 170  * write() returns 0 on success, else negative errno.
 171  */
 172 static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
 173                             const char *buf, size_t count)
 174 {
 175         struct vhci_device *vdev;
 176         struct socket *socket;
 177         int sockfd = 0;
 178         __u32 rhport = 0, devid = 0, speed = 0;
 179         int err;
 180
 181         /*
 182          * @rhport: port number of vhci_hcd
 183          * @sockfd: socket descriptor of an established TCP connection
 184          * @devid: unique device identifier in a remote host
 185          * @speed: usb device speed in a remote host
 186          */
 187         if (sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed) != 4)
 188                 return -EINVAL;
 189
 190         usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
 191                              rhport, sockfd, devid, speed);
 192
 193         /* check received parameters */
 194         if (valid_args(rhport, speed) < 0)
 195                 return -EINVAL;
 196
 197         /* Extract socket from fd. */
 198         socket = sockfd_lookup(sockfd, &err);
 199         if (!socket)
 200                 return -EINVAL;
 201
 202         /* now need lock until setting vdev status as used */
 203
 204         /* begin a lock */
 205         spin_lock(&the_controller->lock);
 206         vdev = port_to_vdev(rhport);
 207         spin_lock(&vdev->ud.lock);
 208
 209         if (vdev->ud.status != VDEV_ST_NULL) {
 210                 /* end of the lock */
 211                 spin_unlock(&vdev->ud.lock);
 212                 spin_unlock(&the_controller->lock);
 213
 214                 sockfd_put(socket);
 215
 216                 dev_err(dev, "port %d already used\n", rhport);
 217                 return -EINVAL;
 218         }
 219
 220         dev_info(dev,
 221                  "rhport(%u) sockfd(%d) devid(%u) speed(%u) speed_str(%s)\n",
 222                  rhport, sockfd, devid, speed, usb_speed_string(speed));
 223
 224         vdev->devid         = devid;
 225         vdev->speed         = speed;
 226         vdev->ud.tcp_socket = socket;
 227         vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 228
 229         spin_unlock(&vdev->ud.lock);
 230         spin_unlock(&the_controller->lock);
 231         /* end the lock */
 232
 233         vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
 234         vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
 235
 236         rh_port_connect(rhport, speed);
 237
 238         return count;
 239 }
 240 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
 241
 242 static struct attribute *dev_attrs[] = {
 243         &dev_attr_status.attr,
 244         &dev_attr_detach.attr,
 245         &dev_attr_attach.attr,
 246         &dev_attr_usbip_debug.attr,
 247         NULL,
 248 };
 249
 250 const struct attribute_group dev_attr_group = {
 251         .attrs = dev_attrs,
 252 };