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         unsigned long flags;
  36
  37         BUG_ON(!the_controller || !out);
  38
  39         spin_lock_irqsave(&the_controller->lock, flags);
  40
  41         /*
  42          * output example:
  43          * prt sta spd dev socket           local_busid
  44          * 000 004 000 000         c5a7bb80 1-2.3
  45          * 001 004 000 000         d8cee980 2-3.4
  46          *
  47          * IP address can be retrieved from a socket pointer address by looking
  48          * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
  49          * port number and its peer IP address.
  50          */
  51         out += sprintf(out,
  52                        "prt sta spd bus dev socket           local_busid\n");
  53
  54         for (i = 0; i < VHCI_NPORTS; i++) {
  55                 struct vhci_device *vdev = port_to_vdev(i);
  56
  57                 spin_lock(&vdev->ud.lock);
  58                 out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
  59
  60                 if (vdev->ud.status == VDEV_ST_USED) {
  61                         out += sprintf(out, "%03u %08x ",
  62                                        vdev->speed, vdev->devid);
  63                         out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
  64                         out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
  65
  66                 } else {
  67                         out += sprintf(out, "000 000 000 0000000000000000 0-0");
  68                 }
  69
  70                 out += sprintf(out, "\n");
  71                 spin_unlock(&vdev->ud.lock);
  72         }
  73
  74         spin_unlock_irqrestore(&the_controller->lock, flags);
  75
  76         return out - s;
  77 }
  78 static DEVICE_ATTR_RO(status);
  79
  80 /* Sysfs entry to shutdown a virtual connection */
  81 static int vhci_port_disconnect(__u32 rhport)
  82 {
  83         struct vhci_device *vdev;
  84         unsigned long flags;
  85
  86         usbip_dbg_vhci_sysfs("enter\n");
  87
  88         /* lock */
  89         spin_lock_irqsave(&the_controller->lock, flags);
  90
  91         vdev = port_to_vdev(rhport);
  92
  93         spin_lock(&vdev->ud.lock);
  94         if (vdev->ud.status == VDEV_ST_NULL) {
  95                 pr_err("not connected %d\n", vdev->ud.status);
  96
  97                 /* unlock */
  98                 spin_unlock(&vdev->ud.lock);
  99                 spin_unlock_irqrestore(&the_controller->lock, flags);
 100
 101                 return -EINVAL;
 102         }
 103
 104         /* unlock */
 105         spin_unlock(&vdev->ud.lock);
 106         spin_unlock_irqrestore(&the_controller->lock, flags);
 107
 108         usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
 109
 110         return 0;
 111 }
 112
 113 static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
 114                             const char *buf, size_t count)
 115 {
 116         int err;
 117         __u32 rhport = 0;
 118
 119         if (sscanf(buf, "%u", &rhport) != 1)
 120                 return -EINVAL;
 121
 122         /* check rhport */
 123         if (rhport >= VHCI_NPORTS) {
 124                 dev_err(dev, "invalid port %u\n", rhport);
 125                 return -EINVAL;
 126         }
 127
 128         err = vhci_port_disconnect(rhport);
 129         if (err < 0)
 130                 return -EINVAL;
 131
 132         usbip_dbg_vhci_sysfs("Leave\n");
 133
 134         return count;
 135 }
 136 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
 137
 138 /* Sysfs entry to establish a virtual connection */
 139 static int valid_args(__u32 rhport, enum usb_device_speed speed)
 140 {
 141         /* check rhport */
 142         if (rhport >= VHCI_NPORTS) {
 143                 pr_err("port %u\n", rhport);
 144                 return -EINVAL;
 145         }
 146
 147         /* check speed */
 148         switch (speed) {
 149         case USB_SPEED_LOW:
 150         case USB_SPEED_FULL:
 151         case USB_SPEED_HIGH:
 152         case USB_SPEED_WIRELESS:
 153                 break;
 154         default:
 155                 pr_err("Failed attach request for unsupported USB speed: %s\n",
 156                         usb_speed_string(speed));
 157                 return -EINVAL;
 158         }
 159
 160         return 0;
 161 }
 162
 163 /*
 164  * To start a new USB/IP attachment, a userland program needs to setup a TCP
 165  * connection and then write its socket descriptor with remote device
 166  * information into this sysfs file.
 167  *
 168  * A remote device is virtually attached to the root-hub port of @rhport with
 169  * @speed. @devid is embedded into a request to specify the remote device in a
 170  * server host.
 171  *
 172  * write() returns 0 on success, else negative errno.
 173  */
 174 static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
 175                             const char *buf, size_t count)
 176 {
 177         struct vhci_device *vdev;
 178         struct socket *socket;
 179         int sockfd = 0;
 180         __u32 rhport = 0, devid = 0, speed = 0;
 181         int err;
 182         unsigned long flags;
 183
 184         /*
 185          * @rhport: port number of vhci_hcd
 186          * @sockfd: socket descriptor of an established TCP connection
 187          * @devid: unique device identifier in a remote host
 188          * @speed: usb device speed in a remote host
 189          */
 190         if (sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed) != 4)
 191                 return -EINVAL;
 192
 193         usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
 194                              rhport, sockfd, devid, speed);
 195
 196         /* check received parameters */
 197         if (valid_args(rhport, speed) < 0)
 198                 return -EINVAL;
 199
 200         /* Extract socket from fd. */
 201         socket = sockfd_lookup(sockfd, &err);
 202         if (!socket)
 203                 return -EINVAL;
 204
 205         /* now need lock until setting vdev status as used */
 206
 207         /* begin a lock */
 208         spin_lock_irqsave(&the_controller->lock, flags);
 209         vdev = port_to_vdev(rhport);
 210         spin_lock(&vdev->ud.lock);
 211
 212         if (vdev->ud.status != VDEV_ST_NULL) {
 213                 /* end of the lock */
 214                 spin_unlock(&vdev->ud.lock);
 215                 spin_unlock_irqrestore(&the_controller->lock, flags);
 216
 217                 sockfd_put(socket);
 218
 219                 dev_err(dev, "port %d already used\n", rhport);
 220                 return -EINVAL;
 221         }
 222
 223         dev_info(dev,
 224                  "rhport(%u) sockfd(%d) devid(%u) speed(%u) speed_str(%s)\n",
 225                  rhport, sockfd, devid, speed, usb_speed_string(speed));
 226
 227         vdev->devid         = devid;
 228         vdev->speed         = speed;
 229         vdev->ud.tcp_socket = socket;
 230         vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 231
 232         spin_unlock(&vdev->ud.lock);
 233         spin_unlock_irqrestore(&the_controller->lock, flags);
 234         /* end the lock */
 235
 236         vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
 237         vdev->ud.tcp_tx = kthread_get_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
 238
 239         rh_port_connect(rhport, speed);
 240
 241         return count;
 242 }
 243 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
 244
 245 static struct attribute *dev_attrs[] = {
 246         &dev_attr_status.attr,
 247         &dev_attr_detach.attr,
 248         &dev_attr_attach.attr,
 249         &dev_attr_usbip_debug.attr,
 250         NULL,
 251 };
 252
 253 const struct attribute_group dev_attr_group = {
 254         .attrs = dev_attrs,
 255 };