drivers/staging/usbip/stub_dev.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/slab.h>
  21
  22 #include "usbip_common.h"
  23 #include "stub.h"
  24
  25
  26
  27 static int stub_probe(struct usb_interface *interface,
  28                                 const struct usb_device_id *id);
  29 static void stub_disconnect(struct usb_interface *interface);
  30
  31
  32 /*
  33  * Define device IDs here if you want to explicitly limit exportable devices.
  34  * In the most cases, wild card matching will be ok because driver binding can
  35  * be changed dynamically by a userland program.
  36  */
  37 static struct usb_device_id stub_table[] = {
  38 #if 0
  39         /* just an example */
  40         { USB_DEVICE(0x05ac, 0x0301) },   /* Mac 1 button mouse */
  41         { USB_DEVICE(0x0430, 0x0009) },   /* Plat Home Keyboard */
  42         { USB_DEVICE(0x059b, 0x0001) },   /* Iomega USB Zip 100 */
  43         { USB_DEVICE(0x04b3, 0x4427) },   /* IBM USB CD-ROM */
  44         { USB_DEVICE(0x05a9, 0xa511) },   /* LifeView USB cam */
  45         { USB_DEVICE(0x55aa, 0x0201) },   /* Imation card reader */
  46         { USB_DEVICE(0x046d, 0x0870) },   /* Qcam Express(QV-30) */
  47         { USB_DEVICE(0x04bb, 0x0101) },   /* IO-DATA HD 120GB */
  48         { USB_DEVICE(0x04bb, 0x0904) },   /* IO-DATA USB-ET/TX */
  49         { USB_DEVICE(0x04bb, 0x0201) },   /* IO-DATA USB-ET/TX */
  50         { USB_DEVICE(0x08bb, 0x2702) },   /* ONKYO USB Speaker */
  51         { USB_DEVICE(0x046d, 0x08b2) },   /* Logicool Qcam 4000 Pro */
  52 #endif
  53         /* magic for wild card */
  54         { .driver_info = 1 },
  55         { 0, }                                     /* Terminating entry */
  56 };
  57 MODULE_DEVICE_TABLE(usb, stub_table);
  58
  59 struct usb_driver stub_driver = {
  60         .name           = "usbip",
  61         .probe          = stub_probe,
  62         .disconnect     = stub_disconnect,
  63         .id_table       = stub_table,
  64 };
  65
  66
  67 /*-------------------------------------------------------------------------*/
  68
  69 /* Define sysfs entries for a usbip-bound device */
  70
  71
  72 /*
  73  * usbip_status shows status of usbip as long as this driver is bound to the
  74  * target device.
  75  */
  76 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  77                            char *buf)
  78 {
  79         struct stub_device *sdev = dev_get_drvdata(dev);
  80         int status;
  81
  82         if (!sdev) {
  83                 dev_err(dev, "sdev is null\n");
  84                 return -ENODEV;
  85         }
  86
  87         spin_lock(&sdev->ud.lock);
  88         status = sdev->ud.status;
  89         spin_unlock(&sdev->ud.lock);
  90
  91         return snprintf(buf, PAGE_SIZE, "%d\n", status);
  92 }
  93 static DEVICE_ATTR(usbip_status, S_IRUGO, show_status, NULL);
  94
  95 /*
  96  * usbip_sockfd gets a socket descriptor of an established TCP connection that
  97  * is used to transfer usbip requests by kernel threads. -1 is a magic number
  98  * by which usbip connection is finished.
  99  */
 100 static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
 101                             const char *buf, size_t count)
 102 {
 103         struct stub_device *sdev = dev_get_drvdata(dev);
 104         int sockfd = 0;
 105         struct socket *socket;
 106
 107         if (!sdev) {
 108                 dev_err(dev, "sdev is null\n");
 109                 return -ENODEV;
 110         }
 111
 112         sscanf(buf, "%d", &sockfd);
 113
 114         if (sockfd != -1) {
 115                 dev_info(dev, "stub up\n");
 116
 117                 spin_lock(&sdev->ud.lock);
 118
 119                 if (sdev->ud.status != SDEV_ST_AVAILABLE) {
 120                         dev_err(dev, "not ready\n");
 121                         spin_unlock(&sdev->ud.lock);
 122                         return -EINVAL;
 123                 }
 124
 125                 socket = sockfd_to_socket(sockfd);
 126                 if (!socket) {
 127                         spin_unlock(&sdev->ud.lock);
 128                         return -EINVAL;
 129                 }
 130
 131 #if 0
 132                 setnodelay(socket);
 133                 setkeepalive(socket);
 134                 setreuse(socket);
 135 #endif
 136
 137                 sdev->ud.tcp_socket = socket;
 138
 139                 spin_unlock(&sdev->ud.lock);
 140
 141                 usbip_start_threads(&sdev->ud);
 142
 143                 spin_lock(&sdev->ud.lock);
 144                 sdev->ud.status = SDEV_ST_USED;
 145                 spin_unlock(&sdev->ud.lock);
 146
 147         } else {
 148                 dev_info(dev, "stub down\n");
 149
 150                 spin_lock(&sdev->ud.lock);
 151                 if (sdev->ud.status != SDEV_ST_USED) {
 152                         spin_unlock(&sdev->ud.lock);
 153                         return -EINVAL;
 154                 }
 155                 spin_unlock(&sdev->ud.lock);
 156
 157                 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
 158         }
 159
 160         return count;
 161 }
 162 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 163
 164 static int stub_add_files(struct device *dev)
 165 {
 166         int err = 0;
 167
 168         err = device_create_file(dev, &dev_attr_usbip_status);
 169         if (err)
 170                 goto err_status;
 171
 172         err = device_create_file(dev, &dev_attr_usbip_sockfd);
 173         if (err)
 174                 goto err_sockfd;
 175
 176         err = device_create_file(dev, &dev_attr_usbip_debug);
 177         if (err)
 178                 goto err_debug;
 179
 180         return 0;
 181
 182 err_debug:
 183         device_remove_file(dev, &dev_attr_usbip_sockfd);
 184
 185 err_sockfd:
 186         device_remove_file(dev, &dev_attr_usbip_status);
 187
 188 err_status:
 189         return err;
 190 }
 191
 192 static void stub_remove_files(struct device *dev)
 193 {
 194         device_remove_file(dev, &dev_attr_usbip_status);
 195         device_remove_file(dev, &dev_attr_usbip_sockfd);
 196         device_remove_file(dev, &dev_attr_usbip_debug);
 197 }
 198
 199
 200
 201 /*-------------------------------------------------------------------------*/
 202
 203 /* Event handler functions called by an event handler thread */
 204
 205 static void stub_shutdown_connection(struct usbip_device *ud)
 206 {
 207         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 208
 209         /*
 210          * When removing an exported device, kernel panic sometimes occurred
 211          * and then EIP was sk_wait_data of stub_rx thread. Is this because
 212          * sk_wait_data returned though stub_rx thread was already finished by
 213          * step 1?
 214          */
 215         if (ud->tcp_socket) {
 216                 usbip_udbg("shutdown tcp_socket %p\n", ud->tcp_socket);
 217                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 218         }
 219
 220         /* 1. stop threads */
 221         usbip_stop_threads(ud);
 222
 223         /* 2. close the socket */
 224         /*
 225          * tcp_socket is freed after threads are killed.
 226          * So usbip_xmit do not touch NULL socket.
 227          */
 228         if (ud->tcp_socket) {
 229                 sock_release(ud->tcp_socket);
 230                 ud->tcp_socket = NULL;
 231         }
 232
 233         /* 3. free used data */
 234         stub_device_cleanup_urbs(sdev);
 235
 236         /* 4. free stub_unlink */
 237         {
 238                 unsigned long flags;
 239                 struct stub_unlink *unlink, *tmp;
 240
 241                 spin_lock_irqsave(&sdev->priv_lock, flags);
 242
 243                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 244                         list_del(&unlink->list);
 245                         kfree(unlink);
 246                 }
 247
 248                 list_for_each_entry_safe(unlink, tmp,
 249                                                  &sdev->unlink_free, list) {
 250                         list_del(&unlink->list);
 251                         kfree(unlink);
 252                 }
 253
 254                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 255         }
 256 }
 257
 258 static void stub_device_reset(struct usbip_device *ud)
 259 {
 260         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 261         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 262         int ret;
 263
 264         usbip_udbg("device reset");
 265         ret = usb_lock_device_for_reset(udev, sdev->interface);
 266         if (ret < 0) {
 267                 dev_err(&udev->dev, "lock for reset\n");
 268
 269                 spin_lock(&ud->lock);
 270                 ud->status = SDEV_ST_ERROR;
 271                 spin_unlock(&ud->lock);
 272
 273                 return;
 274         }
 275
 276         /* try to reset the device */
 277         ret = usb_reset_device(udev);
 278
 279         usb_unlock_device(udev);
 280
 281         spin_lock(&ud->lock);
 282         if (ret) {
 283                 dev_err(&udev->dev, "device reset\n");
 284                 ud->status = SDEV_ST_ERROR;
 285
 286         } else {
 287                 dev_info(&udev->dev, "device reset\n");
 288                 ud->status = SDEV_ST_AVAILABLE;
 289
 290         }
 291         spin_unlock(&ud->lock);
 292
 293         return;
 294 }
 295
 296 static void stub_device_unusable(struct usbip_device *ud)
 297 {
 298         spin_lock(&ud->lock);
 299         ud->status = SDEV_ST_ERROR;
 300         spin_unlock(&ud->lock);
 301 }
 302
 303
 304 /*-------------------------------------------------------------------------*/
 305
 306 /**
 307  * stub_device_alloc - allocate a new stub_device struct
 308  * @interface: usb_interface of a new device
 309  *
 310  * Allocates and initializes a new stub_device struct.
 311  */
 312 static struct stub_device *stub_device_alloc(struct usb_interface *interface)
 313 {
 314         struct stub_device *sdev;
 315         int busnum = interface_to_busnum(interface);
 316         int devnum = interface_to_devnum(interface);
 317
 318         dev_dbg(&interface->dev, "allocating stub device");
 319
 320         /* yes, it's a new device */
 321         sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
 322         if (!sdev) {
 323                 dev_err(&interface->dev, "no memory for stub_device\n");
 324                 return NULL;
 325         }
 326
 327         sdev->interface = interface;
 328
 329         /*
 330          * devid is defined with devnum when this driver is first allocated.
 331          * devnum may change later if a device is reset. However, devid never
 332          * changes during a usbip connection.
 333          */
 334         sdev->devid     = (busnum << 16) | devnum;
 335
 336         usbip_task_init(&sdev->ud.tcp_rx, "stub_rx", stub_rx_loop);
 337         usbip_task_init(&sdev->ud.tcp_tx, "stub_tx", stub_tx_loop);
 338
 339         sdev->ud.side = USBIP_STUB;
 340         sdev->ud.status = SDEV_ST_AVAILABLE;
 341         /* sdev->ud.lock = SPIN_LOCK_UNLOCKED; */
 342         spin_lock_init(&sdev->ud.lock);
 343         sdev->ud.tcp_socket = NULL;
 344
 345         INIT_LIST_HEAD(&sdev->priv_init);
 346         INIT_LIST_HEAD(&sdev->priv_tx);
 347         INIT_LIST_HEAD(&sdev->priv_free);
 348         INIT_LIST_HEAD(&sdev->unlink_free);
 349         INIT_LIST_HEAD(&sdev->unlink_tx);
 350         /* sdev->priv_lock = SPIN_LOCK_UNLOCKED; */
 351         spin_lock_init(&sdev->priv_lock);
 352
 353         init_waitqueue_head(&sdev->tx_waitq);
 354
 355         sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
 356         sdev->ud.eh_ops.reset    = stub_device_reset;
 357         sdev->ud.eh_ops.unusable = stub_device_unusable;
 358
 359         usbip_start_eh(&sdev->ud);
 360
 361         usbip_udbg("register new interface\n");
 362         return sdev;
 363 }
 364
 365 static int stub_device_free(struct stub_device *sdev)
 366 {
 367         if (!sdev)
 368                 return -EINVAL;
 369
 370         kfree(sdev);
 371         usbip_udbg("kfree udev ok\n");
 372
 373         return 0;
 374 }
 375
 376
 377 /*-------------------------------------------------------------------------*/
 378
 379 /*
 380  * If a usb device has multiple active interfaces, this driver is bound to all
 381  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 382  * active interface). Currently, a userland program must ensure that it
 383  * looks at the usbip's sysfs entries of only the first active interface.
 384  *
 385  * TODO: use "struct usb_device_driver" to bind a usb device.
 386  * However, it seems it is not fully supported in mainline kernel yet
 387  * (2.6.19.2).
 388  */
 389 static int stub_probe(struct usb_interface *interface,
 390                       const struct usb_device_id *id)
 391 {
 392         struct usb_device *udev = interface_to_usbdev(interface);
 393         struct stub_device *sdev = NULL;
 394         const char *udev_busid = dev_name(interface->dev.parent);
 395         int err = 0;
 396
 397         dev_dbg(&interface->dev, "Enter\n");
 398
 399         /* check we should claim or not by busid_table */
 400         if (match_busid(udev_busid)) {
 401                 dev_info(&interface->dev,
 402                          "this device %s is not in match_busid table. skip!\n",
 403                          udev_busid);
 404
 405                 /*
 406                  * Return value should be ENODEV or ENOXIO to continue trying
 407                  * other matched drivers by the driver core.
 408                  * See driver_probe_device() in driver/base/dd.c
 409                  */
 410                 return -ENODEV;
 411         }
 412
 413         if (udev->descriptor.bDeviceClass ==  USB_CLASS_HUB) {
 414                 usbip_udbg("this device %s is a usb hub device. skip!\n",
 415                                                                 udev_busid);
 416                 return -ENODEV;
 417         }
 418
 419         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 420                 usbip_udbg("this device %s is attached on vhci_hcd. skip!\n",
 421                                                                 udev_busid);
 422                 return -ENODEV;
 423         }
 424
 425         /* ok. this is my device. */
 426         sdev = stub_device_alloc(interface);
 427         if (!sdev)
 428                 return -ENOMEM;
 429
 430         dev_info(&interface->dev, "USB/IP Stub: register a new interface "
 431                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 432                  interface->cur_altsetting->desc.bInterfaceNumber);
 433
 434         /* set private data to usb_interface */
 435         usb_set_intfdata(interface, sdev);
 436
 437         err = stub_add_files(&interface->dev);
 438         if (err) {
 439                 dev_err(&interface->dev, "create sysfs files for %s\n",
 440                         udev_busid);
 441                 return err;
 442         }
 443
 444         return 0;
 445 }
 446
 447
 448 /*
 449  * called in usb_disconnect() or usb_deregister()
 450  * but only if actconfig(active configuration) exists
 451  */
 452 static void stub_disconnect(struct usb_interface *interface)
 453 {
 454         struct stub_device *sdev = usb_get_intfdata(interface);
 455
 456         usbip_udbg("Enter\n");
 457
 458         /* get stub_device */
 459         if (!sdev) {
 460                 err(" could not get device from inteface data");
 461                 /* BUG(); */
 462                 return;
 463         }
 464
 465         usb_set_intfdata(interface, NULL);
 466
 467
 468         /*
 469          * NOTE:
 470          * rx/tx threads are invoked for each usb_device.
 471          */
 472         stub_remove_files(&interface->dev);
 473
 474         /* 1. shutdown the current connection */
 475         usbip_event_add(&sdev->ud, SDEV_EVENT_REMOVED);
 476
 477         /* 2. wait for the stop of the event handler */
 478         usbip_stop_eh(&sdev->ud);
 479
 480         /* 3. free sdev */
 481         stub_device_free(sdev);
 482
 483
 484         usbip_udbg("bye\n");
 485 }