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/kthread.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25
  26 /*
  27  * Define device IDs here if you want to explicitly limit exportable devices.
  28  * In most cases, wildcard matching will be okay because driver binding can be
  29  * changed dynamically by a userland program.
  30  */
  31 static struct usb_device_id stub_table[] = {
  32 #if 0
  33         /* just an example */
  34         { USB_DEVICE(0x05ac, 0x0301) },   /* Mac 1 button mouse */
  35         { USB_DEVICE(0x0430, 0x0009) },   /* Plat Home Keyboard */
  36         { USB_DEVICE(0x059b, 0x0001) },   /* Iomega USB Zip 100 */
  37         { USB_DEVICE(0x04b3, 0x4427) },   /* IBM USB CD-ROM */
  38         { USB_DEVICE(0x05a9, 0xa511) },   /* LifeView USB cam */
  39         { USB_DEVICE(0x55aa, 0x0201) },   /* Imation card reader */
  40         { USB_DEVICE(0x046d, 0x0870) },   /* Qcam Express(QV-30) */
  41         { USB_DEVICE(0x04bb, 0x0101) },   /* IO-DATA HD 120GB */
  42         { USB_DEVICE(0x04bb, 0x0904) },   /* IO-DATA USB-ET/TX */
  43         { USB_DEVICE(0x04bb, 0x0201) },   /* IO-DATA USB-ET/TX */
  44         { USB_DEVICE(0x08bb, 0x2702) },   /* ONKYO USB Speaker */
  45         { USB_DEVICE(0x046d, 0x08b2) },   /* Logicool Qcam 4000 Pro */
  46 #endif
  47         /* magic for wild card */
  48         { .driver_info = 1 },
  49         { 0, }                                     /* Terminating entry */
  50 };
  51 MODULE_DEVICE_TABLE(usb, stub_table);
  52
  53 /*
  54  * usbip_status shows the status of usbip-host as long as this driver is bound
  55  * to the target device.
  56  */
  57 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  58                            char *buf)
  59 {
  60         struct stub_device *sdev = dev_get_drvdata(dev);
  61         int status;
  62
  63         if (!sdev) {
  64                 dev_err(dev, "sdev is null\n");
  65                 return -ENODEV;
  66         }
  67
  68         spin_lock(&sdev->ud.lock);
  69         status = sdev->ud.status;
  70         spin_unlock(&sdev->ud.lock);
  71
  72         return snprintf(buf, PAGE_SIZE, "%d\n", status);
  73 }
  74 static DEVICE_ATTR(usbip_status, S_IRUGO, show_status, NULL);
  75
  76 /*
  77  * usbip_sockfd gets a socket descriptor of an established TCP connection that
  78  * is used to transfer usbip requests by kernel threads. -1 is a magic number
  79  * by which usbip connection is finished.
  80  */
  81 static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
  82                             const char *buf, size_t count)
  83 {
  84         struct stub_device *sdev = dev_get_drvdata(dev);
  85         int sockfd = 0;
  86         struct socket *socket;
  87
  88         if (!sdev) {
  89                 dev_err(dev, "sdev is null\n");
  90                 return -ENODEV;
  91         }
  92
  93         sscanf(buf, "%d", &sockfd);
  94
  95         if (sockfd != -1) {
  96                 dev_info(dev, "stub up\n");
  97
  98                 spin_lock(&sdev->ud.lock);
  99
 100                 if (sdev->ud.status != SDEV_ST_AVAILABLE) {
 101                         dev_err(dev, "not ready\n");
 102                         spin_unlock(&sdev->ud.lock);
 103                         return -EINVAL;
 104                 }
 105
 106                 socket = sockfd_to_socket(sockfd);
 107                 if (!socket) {
 108                         spin_unlock(&sdev->ud.lock);
 109                         return -EINVAL;
 110                 }
 111 #if 0
 112                 setnodelay(socket);
 113                 setkeepalive(socket);
 114                 setreuse(socket);
 115 #endif
 116                 sdev->ud.tcp_socket = socket;
 117
 118                 spin_unlock(&sdev->ud.lock);
 119
 120                 sdev->ud.tcp_rx = kthread_run(stub_rx_loop, &sdev->ud, "stub_rx");
 121                 sdev->ud.tcp_tx = kthread_run(stub_tx_loop, &sdev->ud, "stub_tx");
 122
 123                 spin_lock(&sdev->ud.lock);
 124                 sdev->ud.status = SDEV_ST_USED;
 125                 spin_unlock(&sdev->ud.lock);
 126
 127         } else {
 128                 dev_info(dev, "stub down\n");
 129
 130                 spin_lock(&sdev->ud.lock);
 131                 if (sdev->ud.status != SDEV_ST_USED) {
 132                         spin_unlock(&sdev->ud.lock);
 133                         return -EINVAL;
 134                 }
 135                 spin_unlock(&sdev->ud.lock);
 136
 137                 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
 138         }
 139
 140         return count;
 141 }
 142 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 143
 144 static int stub_add_files(struct device *dev)
 145 {
 146         int err = 0;
 147
 148         err = device_create_file(dev, &dev_attr_usbip_status);
 149         if (err)
 150                 goto err_status;
 151
 152         err = device_create_file(dev, &dev_attr_usbip_sockfd);
 153         if (err)
 154                 goto err_sockfd;
 155
 156         err = device_create_file(dev, &dev_attr_usbip_debug);
 157         if (err)
 158                 goto err_debug;
 159
 160         return 0;
 161
 162 err_debug:
 163         device_remove_file(dev, &dev_attr_usbip_sockfd);
 164 err_sockfd:
 165         device_remove_file(dev, &dev_attr_usbip_status);
 166 err_status:
 167         return err;
 168 }
 169
 170 static void stub_remove_files(struct device *dev)
 171 {
 172         device_remove_file(dev, &dev_attr_usbip_status);
 173         device_remove_file(dev, &dev_attr_usbip_sockfd);
 174         device_remove_file(dev, &dev_attr_usbip_debug);
 175 }
 176
 177 static void stub_shutdown_connection(struct usbip_device *ud)
 178 {
 179         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 180
 181         /*
 182          * When removing an exported device, kernel panic sometimes occurred
 183          * and then EIP was sk_wait_data of stub_rx thread. Is this because
 184          * sk_wait_data returned though stub_rx thread was already finished by
 185          * step 1?
 186          */
 187         if (ud->tcp_socket) {
 188                 dev_dbg(&sdev->udev->dev, "shutdown tcp_socket %p\n",
 189                         ud->tcp_socket);
 190                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 191         }
 192
 193         /* 1. stop threads */
 194         if (ud->tcp_rx && !task_is_dead(ud->tcp_rx))
 195                 kthread_stop(ud->tcp_rx);
 196         if (ud->tcp_tx && !task_is_dead(ud->tcp_tx))
 197                 kthread_stop(ud->tcp_tx);
 198
 199         /*
 200          * 2. close the socket
 201          *
 202          * tcp_socket is freed after threads are killed so that usbip_xmit does
 203          * not touch NULL socket.
 204          */
 205         if (ud->tcp_socket) {
 206                 sock_release(ud->tcp_socket);
 207                 ud->tcp_socket = NULL;
 208         }
 209
 210         /* 3. free used data */
 211         stub_device_cleanup_urbs(sdev);
 212
 213         /* 4. free stub_unlink */
 214         {
 215                 unsigned long flags;
 216                 struct stub_unlink *unlink, *tmp;
 217
 218                 spin_lock_irqsave(&sdev->priv_lock, flags);
 219                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 220                         list_del(&unlink->list);
 221                         kfree(unlink);
 222                 }
 223                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
 224                                          list) {
 225                         list_del(&unlink->list);
 226                         kfree(unlink);
 227                 }
 228                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 229         }
 230 }
 231
 232 static void stub_device_reset(struct usbip_device *ud)
 233 {
 234         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 235         struct usb_device *udev = sdev->udev;
 236         int ret;
 237
 238         dev_dbg(&udev->dev, "device reset");
 239
 240         ret = usb_lock_device_for_reset(udev, sdev->interface);
 241         if (ret < 0) {
 242                 dev_err(&udev->dev, "lock for reset\n");
 243                 spin_lock(&ud->lock);
 244                 ud->status = SDEV_ST_ERROR;
 245                 spin_unlock(&ud->lock);
 246                 return;
 247         }
 248
 249         /* try to reset the device */
 250         ret = usb_reset_device(udev);
 251         usb_unlock_device(udev);
 252
 253         spin_lock(&ud->lock);
 254         if (ret) {
 255                 dev_err(&udev->dev, "device reset\n");
 256                 ud->status = SDEV_ST_ERROR;
 257         } else {
 258                 dev_info(&udev->dev, "device reset\n");
 259                 ud->status = SDEV_ST_AVAILABLE;
 260         }
 261         spin_unlock(&ud->lock);
 262 }
 263
 264 static void stub_device_unusable(struct usbip_device *ud)
 265 {
 266         spin_lock(&ud->lock);
 267         ud->status = SDEV_ST_ERROR;
 268         spin_unlock(&ud->lock);
 269 }
 270
 271 /**
 272  * stub_device_alloc - allocate a new stub_device struct
 273  * @interface: usb_interface of a new device
 274  *
 275  * Allocates and initializes a new stub_device struct.
 276  */
 277 static struct stub_device *stub_device_alloc(struct usb_device *udev,
 278                                              struct usb_interface *interface)
 279 {
 280         struct stub_device *sdev;
 281         int busnum = interface_to_busnum(interface);
 282         int devnum = interface_to_devnum(interface);
 283
 284         dev_dbg(&interface->dev, "allocating stub device");
 285
 286         /* yes, it's a new device */
 287         sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
 288         if (!sdev) {
 289                 dev_err(&interface->dev, "no memory for stub_device\n");
 290                 return NULL;
 291         }
 292
 293         sdev->interface = usb_get_intf(interface);
 294         sdev->udev = usb_get_dev(udev);
 295
 296         /*
 297          * devid is defined with devnum when this driver is first allocated.
 298          * devnum may change later if a device is reset. However, devid never
 299          * changes during a usbip connection.
 300          */
 301         sdev->devid             = (busnum << 16) | devnum;
 302         sdev->ud.side           = USBIP_STUB;
 303         sdev->ud.status         = SDEV_ST_AVAILABLE;
 304         /* sdev->ud.lock = SPIN_LOCK_UNLOCKED; */
 305         spin_lock_init(&sdev->ud.lock);
 306         sdev->ud.tcp_socket     = NULL;
 307
 308         INIT_LIST_HEAD(&sdev->priv_init);
 309         INIT_LIST_HEAD(&sdev->priv_tx);
 310         INIT_LIST_HEAD(&sdev->priv_free);
 311         INIT_LIST_HEAD(&sdev->unlink_free);
 312         INIT_LIST_HEAD(&sdev->unlink_tx);
 313         /* sdev->priv_lock = SPIN_LOCK_UNLOCKED; */
 314         spin_lock_init(&sdev->priv_lock);
 315
 316         init_waitqueue_head(&sdev->tx_waitq);
 317
 318         sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
 319         sdev->ud.eh_ops.reset    = stub_device_reset;
 320         sdev->ud.eh_ops.unusable = stub_device_unusable;
 321
 322         usbip_start_eh(&sdev->ud);
 323
 324         dev_dbg(&interface->dev, "register new interface\n");
 325
 326         return sdev;
 327 }
 328
 329 static int stub_device_free(struct stub_device *sdev)
 330 {
 331         if (!sdev)
 332                 return -EINVAL;
 333
 334         kfree(sdev);
 335         pr_debug("kfree udev ok\n");
 336
 337         return 0;
 338 }
 339
 340 /*
 341  * If a usb device has multiple active interfaces, this driver is bound to all
 342  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 343  * active interface). Currently, a userland program must ensure that it
 344  * looks at the usbip's sysfs entries of only the first active interface.
 345  *
 346  * TODO: use "struct usb_device_driver" to bind a usb device.
 347  * However, it seems it is not fully supported in mainline kernel yet
 348  * (2.6.19.2).
 349  */
 350 static int stub_probe(struct usb_interface *interface,
 351                       const struct usb_device_id *id)
 352 {
 353         struct usb_device *udev = interface_to_usbdev(interface);
 354         struct stub_device *sdev = NULL;
 355         const char *udev_busid = dev_name(interface->dev.parent);
 356         int err = 0;
 357         struct bus_id_priv *busid_priv;
 358
 359         dev_dbg(&interface->dev, "Enter\n");
 360
 361         /* check we should claim or not by busid_table */
 362         busid_priv = get_busid_priv(udev_busid);
 363         if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
 364             (busid_priv->status == STUB_BUSID_OTHER)) {
 365                 dev_info(&interface->dev, "%s is not in match_busid table... "
 366                          "skip!\n", udev_busid);
 367
 368                 /*
 369                  * Return value should be ENODEV or ENOXIO to continue trying
 370                  * other matched drivers by the driver core.
 371                  * See driver_probe_device() in driver/base/dd.c
 372                  */
 373                 return -ENODEV;
 374         }
 375
 376         if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 377                 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 378                          udev_busid);
 379                 return -ENODEV;
 380         }
 381
 382         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 383                 dev_dbg(&udev->dev, "%s is attached on vhci_hcd... skip!\n",
 384                          udev_busid);
 385                 return -ENODEV;
 386         }
 387
 388         if (busid_priv->status == STUB_BUSID_ALLOC) {
 389                 sdev = busid_priv->sdev;
 390                 if (!sdev)
 391                         return -ENODEV;
 392
 393                 busid_priv->interf_count++;
 394                 dev_info(&interface->dev, "usbip-host: register new interface "
 395                          "(bus %u dev %u ifn %u)\n",
 396                          udev->bus->busnum, udev->devnum,
 397                          interface->cur_altsetting->desc.bInterfaceNumber);
 398
 399                 /* set private data to usb_interface */
 400                 usb_set_intfdata(interface, sdev);
 401
 402                 err = stub_add_files(&interface->dev);
 403                 if (err) {
 404                         dev_err(&interface->dev, "stub_add_files for %s\n",
 405                                 udev_busid);
 406                         usb_set_intfdata(interface, NULL);
 407                         busid_priv->interf_count--;
 408                         return err;
 409                 }
 410
 411                 usb_get_intf(interface);
 412                 return 0;
 413         }
 414
 415         /* ok, this is my device */
 416         sdev = stub_device_alloc(udev, interface);
 417         if (!sdev)
 418                 return -ENOMEM;
 419
 420         dev_info(&interface->dev, "usbip-host: register new device "
 421                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 422                  interface->cur_altsetting->desc.bInterfaceNumber);
 423
 424         busid_priv->interf_count = 0;
 425         busid_priv->shutdown_busid = 0;
 426
 427         /* set private data to usb_interface */
 428         usb_set_intfdata(interface, sdev);
 429         busid_priv->interf_count++;
 430         busid_priv->sdev = sdev;
 431
 432         err = stub_add_files(&interface->dev);
 433         if (err) {
 434                 dev_err(&interface->dev, "stub_add_files for %s\n", udev_busid);
 435                 usb_set_intfdata(interface, NULL);
 436                 usb_put_intf(interface);
 437
 438                 busid_priv->interf_count = 0;
 439                 busid_priv->sdev = NULL;
 440                 stub_device_free(sdev);
 441                 return err;
 442         }
 443         busid_priv->status = STUB_BUSID_ALLOC;
 444
 445         return 0;
 446 }
 447
 448 static void shutdown_busid(struct bus_id_priv *busid_priv)
 449 {
 450         if (busid_priv->sdev && !busid_priv->shutdown_busid) {
 451                 busid_priv->shutdown_busid = 1;
 452                 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 453
 454                 /* 2. wait for the stop of the event handler */
 455                 usbip_stop_eh(&busid_priv->sdev->ud);
 456         }
 457 }
 458
 459 /*
 460  * called in usb_disconnect() or usb_deregister()
 461  * but only if actconfig(active configuration) exists
 462  */
 463 static void stub_disconnect(struct usb_interface *interface)
 464 {
 465         struct stub_device *sdev;
 466         const char *udev_busid = dev_name(interface->dev.parent);
 467         struct bus_id_priv *busid_priv;
 468
 469         dev_dbg(&interface->dev, "Enter\n");
 470
 471         busid_priv = get_busid_priv(udev_busid);
 472         if (!busid_priv) {
 473                 BUG();
 474                 return;
 475         }
 476
 477         sdev = usb_get_intfdata(interface);
 478
 479         /* get stub_device */
 480         if (!sdev) {
 481                 dev_err(&interface->dev, "could not get device");
 482                 /* BUG(); */
 483                 return;
 484         }
 485
 486         usb_set_intfdata(interface, NULL);
 487
 488         /*
 489          * NOTE:
 490          * rx/tx threads are invoked for each usb_device.
 491          */
 492         stub_remove_files(&interface->dev);
 493
 494         /*If usb reset called from event handler*/
 495         if (busid_priv->sdev->ud.eh == current) {
 496                 busid_priv->interf_count--;
 497                 return;
 498         }
 499
 500         if (busid_priv->interf_count > 1) {
 501                 busid_priv->interf_count--;
 502                 shutdown_busid(busid_priv);
 503                 usb_put_intf(interface);
 504                 return;
 505         }
 506
 507         busid_priv->interf_count = 0;
 508
 509         /* 1. shutdown the current connection */
 510         shutdown_busid(busid_priv);
 511
 512         usb_put_dev(sdev->udev);
 513         usb_put_intf(interface);
 514
 515         /* 3. free sdev */
 516         busid_priv->sdev = NULL;
 517         stub_device_free(sdev);
 518
 519         if (busid_priv->status == STUB_BUSID_ALLOC) {
 520                 busid_priv->status = STUB_BUSID_ADDED;
 521         } else {
 522                 busid_priv->status = STUB_BUSID_OTHER;
 523                 del_match_busid((char *)udev_busid);
 524         }
 525 }
 526
 527 /*
 528  * Presence of pre_reset and post_reset prevents the driver from being unbound
 529  * when the device is being reset
 530  */
 531
 532 int stub_pre_reset(struct usb_interface *interface)
 533 {
 534         dev_dbg(&interface->dev, "pre_reset\n");
 535         return 0;
 536 }
 537
 538 int stub_post_reset(struct usb_interface *interface)
 539 {
 540         dev_dbg(&interface->dev, "post_reset\n");
 541         return 0;
 542 }
 543
 544 struct usb_driver stub_driver = {
 545         .name           = "usbip-host",
 546         .probe          = stub_probe,
 547         .disconnect     = stub_disconnect,
 548         .id_table       = stub_table,
 549         .pre_reset      = stub_pre_reset,
 550         .post_reset     = stub_post_reset,
 551  };