drivers/staging/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/net.h>
  22
  23 #include "usbip_common.h"
  24 #include "vhci.h"
  25
  26 /* TODO: refine locking ?*/
  27
  28 /* Sysfs entry to show port status */
  29 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  30                            char *out)
  31 {
  32         char *s = out;
  33         int i = 0;
  34
  35         BUG_ON(!the_controller || !out);
  36
  37         spin_lock(&the_controller->lock);
  38
  39         /*
  40          * output example:
  41          * prt sta spd dev socket           local_busid
  42          * 000 004 000 000         c5a7bb80 1-2.3
  43          * 001 004 000 000         d8cee980 2-3.4
  44          *
  45          * IP address can be retrieved from a socket pointer address by looking
  46          * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
  47          * port number and its peer IP address.
  48          */
  49         out += sprintf(out, "prt sta spd bus dev socket           "
  50                        "local_busid\n");
  51
  52         for (i = 0; i < VHCI_NPORTS; i++) {
  53                 struct vhci_device *vdev = port_to_vdev(i);
  54
  55                 spin_lock(&vdev->ud.lock);
  56                 out += sprintf(out, "%03u %03u ", i, vdev->ud.status);
  57
  58                 if (vdev->ud.status == VDEV_ST_USED) {
  59                         out += sprintf(out, "%03u %08x ",
  60                                        vdev->speed, vdev->devid);
  61                         out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
  62                         out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
  63
  64                 } else {
  65                         out += sprintf(out, "000 000 000 0000000000000000 0-0");
  66                 }
  67
  68                 out += sprintf(out, "\n");
  69                 spin_unlock(&vdev->ud.lock);
  70         }
  71
  72         spin_unlock(&the_controller->lock);
  73
  74         return out - s;
  75 }
  76 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
  77
  78 /* Sysfs entry to shutdown a virtual connection */
  79 static int vhci_port_disconnect(__u32 rhport)
  80 {
  81         struct vhci_device *vdev;
  82
  83         usbip_dbg_vhci_sysfs("enter\n");
  84
  85         /* lock */
  86         spin_lock(&the_controller->lock);
  87
  88         vdev = port_to_vdev(rhport);
  89
  90         spin_lock(&vdev->ud.lock);
  91         if (vdev->ud.status == VDEV_ST_NULL) {
  92                 pr_err("not connected %d\n", vdev->ud.status);
  93
  94                 /* unlock */
  95                 spin_unlock(&vdev->ud.lock);
  96                 spin_unlock(&the_controller->lock);
  97
  98                 return -EINVAL;
  99         }
 100
 101         /* unlock */
 102         spin_unlock(&vdev->ud.lock);
 103         spin_unlock(&the_controller->lock);
 104
 105         usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
 106
 107         return 0;
 108 }
 109
 110 static ssize_t store_detach(struct device *dev, struct device_attribute *attr,
 111                             const char *buf, size_t count)
 112 {
 113         int err;
 114         __u32 rhport = 0;
 115
 116         sscanf(buf, "%u", &rhport);
 117
 118         /* check rhport */
 119         if (rhport >= VHCI_NPORTS) {
 120                 dev_err(dev, "invalid port %u\n", rhport);
 121                 return -EINVAL;
 122         }
 123
 124         err = vhci_port_disconnect(rhport);
 125         if (err < 0)
 126                 return -EINVAL;
 127
 128         usbip_dbg_vhci_sysfs("Leave\n");
 129
 130         return count;
 131 }
 132 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
 133
 134 /* Sysfs entry to establish a virtual connection */
 135 static int valid_args(__u32 rhport, enum usb_device_speed speed)
 136 {
 137         /* check rhport */
 138         if (rhport >= VHCI_NPORTS) {
 139                 pr_err("port %u\n", rhport);
 140                 return -EINVAL;
 141         }
 142
 143         /* check speed */
 144         switch (speed) {
 145         case USB_SPEED_LOW:
 146         case USB_SPEED_FULL:
 147         case USB_SPEED_HIGH:
 148         case USB_SPEED_WIRELESS:
 149                 break;
 150         default:
 151                 pr_err("speed %d\n", speed);
 152                 return -EINVAL;
 153         }
 154
 155         return 0;
 156 }
 157
 158 /*
 159  * To start a new USB/IP attachment, a userland program needs to setup a TCP
 160  * connection and then write its socket descriptor with remote device
 161  * information into this sysfs file.
 162  *
 163  * A remote device is virtually attached to the root-hub port of @rhport with
 164  * @speed. @devid is embedded into a request to specify the remote device in a
 165  * server host.
 166  *
 167  * write() returns 0 on success, else negative errno.
 168  */
 169 static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
 170                             const char *buf, size_t count)
 171 {
 172         struct vhci_device *vdev;
 173         struct socket *socket;
 174         int sockfd = 0;
 175         __u32 rhport = 0, devid = 0, speed = 0;
 176
 177         /*
 178          * @rhport: port number of vhci_hcd
 179          * @sockfd: socket descriptor of an established TCP connection
 180          * @devid: unique device identifier in a remote host
 181          * @speed: usb device speed in a remote host
 182          */
 183         sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed);
 184
 185         usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
 186                              rhport, sockfd, devid, speed);
 187
 188         /* check received parameters */
 189         if (valid_args(rhport, speed) < 0)
 190                 return -EINVAL;
 191
 192         /* check sockfd */
 193         socket = sockfd_to_socket(sockfd);
 194         if (!socket)
 195                 return -EINVAL;
 196
 197         /* now need lock until setting vdev status as used */
 198
 199         /* begin a lock */
 200         spin_lock(&the_controller->lock);
 201         vdev = port_to_vdev(rhport);
 202         spin_lock(&vdev->ud.lock);
 203
 204         if (vdev->ud.status != VDEV_ST_NULL) {
 205                 /* end of the lock */
 206                 spin_unlock(&vdev->ud.lock);
 207                 spin_unlock(&the_controller->lock);
 208
 209                 dev_err(dev, "port %d already used\n", rhport);
 210                 return -EINVAL;
 211         }
 212
 213         dev_info(dev, "rhport(%u) sockfd(%d) devid(%u) speed(%u)\n",
 214                  rhport, sockfd, devid, speed);
 215
 216         vdev->devid         = devid;
 217         vdev->speed         = speed;
 218         vdev->ud.tcp_socket = socket;
 219         vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 220
 221         spin_unlock(&vdev->ud.lock);
 222         spin_unlock(&the_controller->lock);
 223         /* end the lock */
 224
 225         vdev->ud.tcp_rx = kthread_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
 226         vdev->ud.tcp_tx = kthread_run(vhci_tx_loop, &vdev->ud, "vhci_tx");
 227
 228         rh_port_connect(rhport, speed);
 229
 230         return count;
 231 }
 232 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
 233
 234 static struct attribute *dev_attrs[] = {
 235         &dev_attr_status.attr,
 236         &dev_attr_detach.attr,
 237         &dev_attr_attach.attr,
 238         &dev_attr_usbip_debug.attr,
 239         NULL,
 240 };
 241
 242 const struct attribute_group dev_attr_group = {
 243         .attrs = dev_attrs,
 244 };