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/device.h>
  21 #include <linux/file.h>
  22 #include <linux/kthread.h>
  23 #include <linux/module.h>
  24
  25 #include "usbip_common.h"
  26 #include "stub.h"
  27
  28 /*
  29  * Define device IDs here if you want to explicitly limit exportable devices.
  30  * In most cases, wildcard matching will be okay because driver binding can be
  31  * changed dynamically by a userland program.
  32  */
  33 static struct usb_device_id stub_table[] = {
  34 #if 0
  35         /* just an example */
  36         { USB_DEVICE(0x05ac, 0x0301) },   /* Mac 1 button mouse */
  37         { USB_DEVICE(0x0430, 0x0009) },   /* Plat Home Keyboard */
  38         { USB_DEVICE(0x059b, 0x0001) },   /* Iomega USB Zip 100 */
  39         { USB_DEVICE(0x04b3, 0x4427) },   /* IBM USB CD-ROM */
  40         { USB_DEVICE(0x05a9, 0xa511) },   /* LifeView USB cam */
  41         { USB_DEVICE(0x55aa, 0x0201) },   /* Imation card reader */
  42         { USB_DEVICE(0x046d, 0x0870) },   /* Qcam Express(QV-30) */
  43         { USB_DEVICE(0x04bb, 0x0101) },   /* IO-DATA HD 120GB */
  44         { USB_DEVICE(0x04bb, 0x0904) },   /* IO-DATA USB-ET/TX */
  45         { USB_DEVICE(0x04bb, 0x0201) },   /* IO-DATA USB-ET/TX */
  46         { USB_DEVICE(0x08bb, 0x2702) },   /* ONKYO USB Speaker */
  47         { USB_DEVICE(0x046d, 0x08b2) },   /* Logicool Qcam 4000 Pro */
  48 #endif
  49         /* magic for wild card */
  50         { .driver_info = 1 },
  51         { 0, }                                     /* Terminating entry */
  52 };
  53 MODULE_DEVICE_TABLE(usb, stub_table);
  54
  55 /*
  56  * usbip_status shows the status of usbip-host as long as this driver is bound
  57  * to the target device.
  58  */
  59 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  60                            char *buf)
  61 {
  62         struct stub_device *sdev = dev_get_drvdata(dev);
  63         int status;
  64
  65         if (!sdev) {
  66                 dev_err(dev, "sdev is null\n");
  67                 return -ENODEV;
  68         }
  69
  70         spin_lock_irq(&sdev->ud.lock);
  71         status = sdev->ud.status;
  72         spin_unlock_irq(&sdev->ud.lock);
  73
  74         return snprintf(buf, PAGE_SIZE, "%d\n", status);
  75 }
  76 static DEVICE_ATTR(usbip_status, S_IRUGO, show_status, NULL);
  77
  78 /*
  79  * usbip_sockfd gets a socket descriptor of an established TCP connection that
  80  * is used to transfer usbip requests by kernel threads. -1 is a magic number
  81  * by which usbip connection is finished.
  82  */
  83 static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
  84                             const char *buf, size_t count)
  85 {
  86         struct stub_device *sdev = dev_get_drvdata(dev);
  87         int sockfd = 0;
  88         struct socket *socket;
  89
  90         if (!sdev) {
  91                 dev_err(dev, "sdev is null\n");
  92                 return -ENODEV;
  93         }
  94
  95         sscanf(buf, "%d", &sockfd);
  96
  97         if (sockfd != -1) {
  98                 dev_info(dev, "stub up\n");
  99
 100                 spin_lock_irq(&sdev->ud.lock);
 101
 102                 if (sdev->ud.status != SDEV_ST_AVAILABLE) {
 103                         dev_err(dev, "not ready\n");
 104                         spin_unlock_irq(&sdev->ud.lock);
 105                         return -EINVAL;
 106                 }
 107
 108                 socket = sockfd_to_socket(sockfd);
 109                 if (!socket) {
 110                         spin_unlock_irq(&sdev->ud.lock);
 111                         return -EINVAL;
 112                 }
 113                 sdev->ud.tcp_socket = socket;
 114
 115                 spin_unlock_irq(&sdev->ud.lock);
 116
 117                 sdev->ud.tcp_rx = kthread_get_run(stub_rx_loop, &sdev->ud, "stub_rx");
 118                 sdev->ud.tcp_tx = kthread_get_run(stub_tx_loop, &sdev->ud, "stub_tx");
 119
 120                 spin_lock_irq(&sdev->ud.lock);
 121                 sdev->ud.status = SDEV_ST_USED;
 122                 spin_unlock_irq(&sdev->ud.lock);
 123
 124         } else {
 125                 dev_info(dev, "stub down\n");
 126
 127                 spin_lock_irq(&sdev->ud.lock);
 128                 if (sdev->ud.status != SDEV_ST_USED) {
 129                         spin_unlock_irq(&sdev->ud.lock);
 130                         return -EINVAL;
 131                 }
 132                 spin_unlock_irq(&sdev->ud.lock);
 133
 134                 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
 135         }
 136
 137         return count;
 138 }
 139 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 140
 141 static int stub_add_files(struct device *dev)
 142 {
 143         int err = 0;
 144
 145         err = device_create_file(dev, &dev_attr_usbip_status);
 146         if (err)
 147                 goto err_status;
 148
 149         err = device_create_file(dev, &dev_attr_usbip_sockfd);
 150         if (err)
 151                 goto err_sockfd;
 152
 153         err = device_create_file(dev, &dev_attr_usbip_debug);
 154         if (err)
 155                 goto err_debug;
 156
 157         return 0;
 158
 159 err_debug:
 160         device_remove_file(dev, &dev_attr_usbip_sockfd);
 161 err_sockfd:
 162         device_remove_file(dev, &dev_attr_usbip_status);
 163 err_status:
 164         return err;
 165 }
 166
 167 static void stub_remove_files(struct device *dev)
 168 {
 169         device_remove_file(dev, &dev_attr_usbip_status);
 170         device_remove_file(dev, &dev_attr_usbip_sockfd);
 171         device_remove_file(dev, &dev_attr_usbip_debug);
 172 }
 173
 174 static void stub_shutdown_connection(struct usbip_device *ud)
 175 {
 176         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 177
 178         /*
 179          * When removing an exported device, kernel panic sometimes occurred
 180          * and then EIP was sk_wait_data of stub_rx thread. Is this because
 181          * sk_wait_data returned though stub_rx thread was already finished by
 182          * step 1?
 183          */
 184         if (ud->tcp_socket) {
 185                 dev_dbg(&sdev->udev->dev, "shutdown tcp_socket %p\n",
 186                         ud->tcp_socket);
 187                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 188         }
 189
 190         /* 1. stop threads */
 191         if (ud->tcp_rx) {
 192                 kthread_stop_put(ud->tcp_rx);
 193                 ud->tcp_rx = NULL;
 194         }
 195         if (ud->tcp_tx) {
 196                 kthread_stop_put(ud->tcp_tx);
 197                 ud->tcp_tx = NULL;
 198         }
 199
 200         /*
 201          * 2. close the socket
 202          *
 203          * tcp_socket is freed after threads are killed so that usbip_xmit does
 204          * not touch NULL socket.
 205          */
 206         if (ud->tcp_socket) {
 207                 fput(ud->tcp_socket->file);
 208                 ud->tcp_socket = NULL;
 209         }
 210
 211         /* 3. free used data */
 212         stub_device_cleanup_urbs(sdev);
 213
 214         /* 4. free stub_unlink */
 215         {
 216                 unsigned long flags;
 217                 struct stub_unlink *unlink, *tmp;
 218
 219                 spin_lock_irqsave(&sdev->priv_lock, flags);
 220                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 221                         list_del(&unlink->list);
 222                         kfree(unlink);
 223                 }
 224                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
 225                                          list) {
 226                         list_del(&unlink->list);
 227                         kfree(unlink);
 228                 }
 229                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 230         }
 231 }
 232
 233 static void stub_device_reset(struct usbip_device *ud)
 234 {
 235         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 236         struct usb_device *udev = sdev->udev;
 237         int ret;
 238
 239         dev_dbg(&udev->dev, "device reset");
 240
 241         ret = usb_lock_device_for_reset(udev, sdev->interface);
 242         if (ret < 0) {
 243                 dev_err(&udev->dev, "lock for reset\n");
 244                 spin_lock_irq(&ud->lock);
 245                 ud->status = SDEV_ST_ERROR;
 246                 spin_unlock_irq(&ud->lock);
 247                 return;
 248         }
 249
 250         /* try to reset the device */
 251         ret = usb_reset_device(udev);
 252         usb_unlock_device(udev);
 253
 254         spin_lock_irq(&ud->lock);
 255         if (ret) {
 256                 dev_err(&udev->dev, "device reset\n");
 257                 ud->status = SDEV_ST_ERROR;
 258         } else {
 259                 dev_info(&udev->dev, "device reset\n");
 260                 ud->status = SDEV_ST_AVAILABLE;
 261         }
 262         spin_unlock_irq(&ud->lock);
 263 }
 264
 265 static void stub_device_unusable(struct usbip_device *ud)
 266 {
 267         spin_lock_irq(&ud->lock);
 268         ud->status = SDEV_ST_ERROR;
 269         spin_unlock_irq(&ud->lock);
 270 }
 271
 272 /**
 273  * stub_device_alloc - allocate a new stub_device struct
 274  * @interface: usb_interface of a new device
 275  *
 276  * Allocates and initializes a new stub_device struct.
 277  */
 278 static struct stub_device *stub_device_alloc(struct usb_device *udev,
 279                                              struct usb_interface *interface)
 280 {
 281         struct stub_device *sdev;
 282         int busnum = interface_to_busnum(interface);
 283         int devnum = interface_to_devnum(interface);
 284
 285         dev_dbg(&interface->dev, "allocating stub device");
 286
 287         /* yes, it's a new device */
 288         sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
 289         if (!sdev)
 290                 return NULL;
 291
 292         sdev->interface = usb_get_intf(interface);
 293         sdev->udev = usb_get_dev(udev);
 294
 295         /*
 296          * devid is defined with devnum when this driver is first allocated.
 297          * devnum may change later if a device is reset. However, devid never
 298          * changes during a usbip connection.
 299          */
 300         sdev->devid             = (busnum << 16) | devnum;
 301         sdev->ud.side           = USBIP_STUB;
 302         sdev->ud.status         = SDEV_ST_AVAILABLE;
 303         spin_lock_init(&sdev->ud.lock);
 304         sdev->ud.tcp_socket     = NULL;
 305
 306         INIT_LIST_HEAD(&sdev->priv_init);
 307         INIT_LIST_HEAD(&sdev->priv_tx);
 308         INIT_LIST_HEAD(&sdev->priv_free);
 309         INIT_LIST_HEAD(&sdev->unlink_free);
 310         INIT_LIST_HEAD(&sdev->unlink_tx);
 311         spin_lock_init(&sdev->priv_lock);
 312
 313         init_waitqueue_head(&sdev->tx_waitq);
 314
 315         sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
 316         sdev->ud.eh_ops.reset    = stub_device_reset;
 317         sdev->ud.eh_ops.unusable = stub_device_unusable;
 318
 319         usbip_start_eh(&sdev->ud);
 320
 321         dev_dbg(&interface->dev, "register new interface\n");
 322
 323         return sdev;
 324 }
 325
 326 static int stub_device_free(struct stub_device *sdev)
 327 {
 328         if (!sdev)
 329                 return -EINVAL;
 330
 331         kfree(sdev);
 332         pr_debug("kfree udev ok\n");
 333
 334         return 0;
 335 }
 336
 337 /*
 338  * If a usb device has multiple active interfaces, this driver is bound to all
 339  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 340  * active interface). Currently, a userland program must ensure that it
 341  * looks at the usbip's sysfs entries of only the first active interface.
 342  *
 343  * TODO: use "struct usb_device_driver" to bind a usb device.
 344  * However, it seems it is not fully supported in mainline kernel yet
 345  * (2.6.19.2).
 346  */
 347 static int stub_probe(struct usb_interface *interface,
 348                       const struct usb_device_id *id)
 349 {
 350         struct usb_device *udev = interface_to_usbdev(interface);
 351         struct stub_device *sdev = NULL;
 352         const char *udev_busid = dev_name(interface->dev.parent);
 353         int err = 0;
 354         struct bus_id_priv *busid_priv;
 355
 356         dev_dbg(&interface->dev, "Enter\n");
 357
 358         /* check we should claim or not by busid_table */
 359         busid_priv = get_busid_priv(udev_busid);
 360         if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
 361             (busid_priv->status == STUB_BUSID_OTHER)) {
 362                 dev_info(&interface->dev, "%s is not in match_busid table... "
 363                          "skip!\n", udev_busid);
 364
 365                 /*
 366                  * Return value should be ENODEV or ENOXIO to continue trying
 367                  * other matched drivers by the driver core.
 368                  * See driver_probe_device() in driver/base/dd.c
 369                  */
 370                 return -ENODEV;
 371         }
 372
 373         if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 374                 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 375                          udev_busid);
 376                 return -ENODEV;
 377         }
 378
 379         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 380                 dev_dbg(&udev->dev, "%s is attached on vhci_hcd... skip!\n",
 381                          udev_busid);
 382                 return -ENODEV;
 383         }
 384
 385         if (busid_priv->status == STUB_BUSID_ALLOC) {
 386                 sdev = busid_priv->sdev;
 387                 if (!sdev)
 388                         return -ENODEV;
 389
 390                 busid_priv->interf_count++;
 391                 dev_info(&interface->dev, "usbip-host: register new interface "
 392                          "(bus %u dev %u ifn %u)\n",
 393                          udev->bus->busnum, udev->devnum,
 394                          interface->cur_altsetting->desc.bInterfaceNumber);
 395
 396                 /* set private data to usb_interface */
 397                 usb_set_intfdata(interface, sdev);
 398
 399                 err = stub_add_files(&interface->dev);
 400                 if (err) {
 401                         dev_err(&interface->dev, "stub_add_files for %s\n",
 402                                 udev_busid);
 403                         usb_set_intfdata(interface, NULL);
 404                         busid_priv->interf_count--;
 405                         return err;
 406                 }
 407
 408                 usb_get_intf(interface);
 409                 return 0;
 410         }
 411
 412         /* ok, this is my device */
 413         sdev = stub_device_alloc(udev, interface);
 414         if (!sdev)
 415                 return -ENOMEM;
 416
 417         dev_info(&interface->dev, "usbip-host: register new device "
 418                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 419                  interface->cur_altsetting->desc.bInterfaceNumber);
 420
 421         busid_priv->interf_count = 0;
 422         busid_priv->shutdown_busid = 0;
 423
 424         /* set private data to usb_interface */
 425         usb_set_intfdata(interface, sdev);
 426         busid_priv->interf_count++;
 427         busid_priv->sdev = sdev;
 428
 429         err = stub_add_files(&interface->dev);
 430         if (err) {
 431                 dev_err(&interface->dev, "stub_add_files for %s\n", udev_busid);
 432                 usb_set_intfdata(interface, NULL);
 433                 usb_put_intf(interface);
 434                 usb_put_dev(udev);
 435                 kthread_stop_put(sdev->ud.eh);
 436
 437                 busid_priv->interf_count = 0;
 438                 busid_priv->sdev = NULL;
 439                 stub_device_free(sdev);
 440                 return err;
 441         }
 442         busid_priv->status = STUB_BUSID_ALLOC;
 443
 444         return 0;
 445 }
 446
 447 static void shutdown_busid(struct bus_id_priv *busid_priv)
 448 {
 449         if (busid_priv->sdev && !busid_priv->shutdown_busid) {
 450                 busid_priv->shutdown_busid = 1;
 451                 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 452
 453                 /* 2. wait for the stop of the event handler */
 454                 usbip_stop_eh(&busid_priv->sdev->ud);
 455         }
 456 }
 457
 458 /*
 459  * called in usb_disconnect() or usb_deregister()
 460  * but only if actconfig(active configuration) exists
 461  */
 462 static void stub_disconnect(struct usb_interface *interface)
 463 {
 464         struct stub_device *sdev;
 465         const char *udev_busid = dev_name(interface->dev.parent);
 466         struct bus_id_priv *busid_priv;
 467
 468         dev_dbg(&interface->dev, "Enter\n");
 469
 470         busid_priv = get_busid_priv(udev_busid);
 471         if (!busid_priv) {
 472                 BUG();
 473                 return;
 474         }
 475
 476         sdev = usb_get_intfdata(interface);
 477
 478         /* get stub_device */
 479         if (!sdev) {
 480                 dev_err(&interface->dev, "could not get device");
 481                 return;
 482         }
 483
 484         usb_set_intfdata(interface, NULL);
 485
 486         /*
 487          * NOTE: rx/tx threads are invoked for each usb_device.
 488          */
 489         stub_remove_files(&interface->dev);
 490
 491         /* If usb reset is called from event handler */
 492         if (busid_priv->sdev->ud.eh == current) {
 493                 busid_priv->interf_count--;
 494                 return;
 495         }
 496
 497         if (busid_priv->interf_count > 1) {
 498                 busid_priv->interf_count--;
 499                 shutdown_busid(busid_priv);
 500                 usb_put_intf(interface);
 501                 return;
 502         }
 503
 504         busid_priv->interf_count = 0;
 505
 506         /* shutdown the current connection */
 507         shutdown_busid(busid_priv);
 508
 509         usb_put_dev(sdev->udev);
 510         usb_put_intf(interface);
 511
 512         /* free sdev */
 513         busid_priv->sdev = NULL;
 514         stub_device_free(sdev);
 515
 516         if (busid_priv->status == STUB_BUSID_ALLOC) {
 517                 busid_priv->status = STUB_BUSID_ADDED;
 518         } else {
 519                 busid_priv->status = STUB_BUSID_OTHER;
 520                 del_match_busid((char *)udev_busid);
 521         }
 522 }
 523
 524 /*
 525  * Presence of pre_reset and post_reset prevents the driver from being unbound
 526  * when the device is being reset
 527  */
 528
 529 static int stub_pre_reset(struct usb_interface *interface)
 530 {
 531         dev_dbg(&interface->dev, "pre_reset\n");
 532         return 0;
 533 }
 534
 535 static int stub_post_reset(struct usb_interface *interface)
 536 {
 537         dev_dbg(&interface->dev, "post_reset\n");
 538         return 0;
 539 }
 540
 541 struct usb_driver stub_driver = {
 542         .name           = "usbip-host",
 543         .probe          = stub_probe,
 544         .disconnect     = stub_disconnect,
 545         .id_table       = stub_table,
 546         .pre_reset      = stub_pre_reset,
 547         .post_reset     = stub_post_reset,
 548 };