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 "usbip_common.h"
  21 #include "vhci.h"
  22
  23 #include <linux/in.h>
  24
  25 /* TODO: refine locking ?*/
  26
  27 /* Sysfs entry to show port status */
  28 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  29                            char *out)
  30 {
  31         char *s = out;
  32         int i = 0;
  33
  34         BUG_ON(!the_controller || !out);
  35
  36         spin_lock(&the_controller->lock);
  37
  38         /*
  39          * output example:
  40          * prt sta spd dev socket           local_busid
  41          * 000 004 000 000         c5a7bb80 1-2.3
  42          * 001 004 000 000         d8cee980 2-3.4
  43          *
  44          * IP address can be retrieved from a socket pointer address by looking
  45          * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a
  46          * port number and its peer IP address.
  47          */
  48         out += sprintf(out, "prt sta spd bus dev socket           "
  49                        "local_busid\n");
  50
  51         for (i = 0; i < VHCI_NPORTS; i++) {
  52                 struct vhci_device *vdev = port_to_vdev(i);
  53
  54                 spin_lock(&vdev->ud.lock);
  55
  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                 out += sprintf(out, "\n");
  68
  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                 usbip_uerr("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                 usbip_uerr("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         return count;
 130 }
 131 static DEVICE_ATTR(detach, S_IWUSR, NULL, store_detach);
 132
 133 /* Sysfs entry to establish a virtual connection */
 134 static int valid_args(__u32 rhport, enum usb_device_speed speed)
 135 {
 136         /* check rhport */
 137         if ((rhport < 0) || (rhport >= VHCI_NPORTS)) {
 138                 usbip_uerr("port %u\n", rhport);
 139                 return -EINVAL;
 140         }
 141
 142         /* check speed */
 143         switch (speed) {
 144         case USB_SPEED_LOW:
 145         case USB_SPEED_FULL:
 146         case USB_SPEED_HIGH:
 147         case USB_SPEED_VARIABLE:
 148                 break;
 149         default:
 150                 usbip_uerr("speed %d\n", speed);
 151                 return -EINVAL;
 152         }
 153
 154         return 0;
 155 }
 156
 157 /*
 158  * To start a new USB/IP attachment, a userland program needs to setup a TCP
 159  * connection and then write its socket descriptor with remote device
 160  * information into this sysfs file.
 161  *
 162  * A remote device is virtually attached to the root-hub port of @rhport with
 163  * @speed. @devid is embedded into a request to specify the remote device in a
 164  * server host.
 165  *
 166  * write() returns 0 on success, else negative errno.
 167  */
 168 static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
 169                             const char *buf, size_t count)
 170 {
 171         struct vhci_device *vdev;
 172         struct socket *socket;
 173         int sockfd = 0;
 174         __u32 rhport = 0, devid = 0, speed = 0;
 175
 176         /*
 177          * @rhport: port number of vhci_hcd
 178          * @sockfd: socket descriptor of an established TCP connection
 179          * @devid: unique device identifier in a remote host
 180          * @speed: usb device speed in a remote host
 181          */
 182         sscanf(buf, "%u %u %u %u", &rhport, &sockfd, &devid, &speed);
 183
 184         usbip_dbg_vhci_sysfs("rhport(%u) sockfd(%u) devid(%u) speed(%u)\n",
 185                                 rhport, sockfd, devid, speed);
 186
 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
 202         vdev = port_to_vdev(rhport);
 203
 204         spin_lock(&vdev->ud.lock);
 205
 206         if (vdev->ud.status != VDEV_ST_NULL) {
 207                 /* end of the lock */
 208                 spin_unlock(&vdev->ud.lock);
 209                 spin_unlock(&the_controller->lock);
 210
 211                 usbip_uerr("port %d already used\n", rhport);
 212                 return -EINVAL;
 213         }
 214
 215         usbip_uinfo("rhport(%u) sockfd(%d) devid(%u) speed(%u)\n",
 216                                 rhport, sockfd, devid, speed);
 217
 218         vdev->devid         = devid;
 219         vdev->speed         = speed;
 220         vdev->ud.tcp_socket = socket;
 221         vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 222
 223         spin_unlock(&vdev->ud.lock);
 224         spin_unlock(&the_controller->lock);
 225         /* end the lock */
 226
 227         /*
 228          * this function will sleep, so should be out of the lock. but, it's ok
 229          * because we already marked vdev as being used. really?
 230          */
 231         usbip_start_threads(&vdev->ud);
 232
 233         rh_port_connect(rhport, speed);
 234
 235         return count;
 236 }
 237 static DEVICE_ATTR(attach, S_IWUSR, NULL, store_attach);
 238
 239 static struct attribute *dev_attrs[] = {
 240         &dev_attr_status.attr,
 241         &dev_attr_detach.attr,
 242         &dev_attr_attach.attr,
 243         &dev_attr_usbip_debug.attr,
 244         NULL,
 245 };
 246
 247 struct attribute_group dev_attr_group = {
 248         .attrs = dev_attrs,
 249 };