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 #include <linux/module.h>
  23
  24 #include "usbip_common.h"
  25 #include "stub.h"
  26
  27 /*
  28  * Define device IDs here if you want to explicitly limit exportable devices.
  29  * In most cases, wildcard matching will be okay because driver binding can be
  30  * changed dynamically by a userland program.
  31  */
  32 static struct usb_device_id stub_table[] = {
  33 #if 0
  34         /* just an example */
  35         { USB_DEVICE(0x05ac, 0x0301) },   /* Mac 1 button mouse */
  36         { USB_DEVICE(0x0430, 0x0009) },   /* Plat Home Keyboard */
  37         { USB_DEVICE(0x059b, 0x0001) },   /* Iomega USB Zip 100 */
  38         { USB_DEVICE(0x04b3, 0x4427) },   /* IBM USB CD-ROM */
  39         { USB_DEVICE(0x05a9, 0xa511) },   /* LifeView USB cam */
  40         { USB_DEVICE(0x55aa, 0x0201) },   /* Imation card reader */
  41         { USB_DEVICE(0x046d, 0x0870) },   /* Qcam Express(QV-30) */
  42         { USB_DEVICE(0x04bb, 0x0101) },   /* IO-DATA HD 120GB */
  43         { USB_DEVICE(0x04bb, 0x0904) },   /* IO-DATA USB-ET/TX */
  44         { USB_DEVICE(0x04bb, 0x0201) },   /* IO-DATA USB-ET/TX */
  45         { USB_DEVICE(0x08bb, 0x2702) },   /* ONKYO USB Speaker */
  46         { USB_DEVICE(0x046d, 0x08b2) },   /* Logicool Qcam 4000 Pro */
  47 #endif
  48         /* magic for wild card */
  49         { .driver_info = 1 },
  50         { 0, }                                     /* Terminating entry */
  51 };
  52 MODULE_DEVICE_TABLE(usb, stub_table);
  53
  54 /*
  55  * usbip_status shows the status of usbip-host as long as this driver is bound
  56  * to the target device.
  57  */
  58 static ssize_t show_status(struct device *dev, struct device_attribute *attr,
  59                            char *buf)
  60 {
  61         struct stub_device *sdev = dev_get_drvdata(dev);
  62         int status;
  63
  64         if (!sdev) {
  65                 dev_err(dev, "sdev is null\n");
  66                 return -ENODEV;
  67         }
  68
  69         spin_lock(&sdev->ud.lock);
  70         status = sdev->ud.status;
  71         spin_unlock(&sdev->ud.lock);
  72
  73         return snprintf(buf, PAGE_SIZE, "%d\n", status);
  74 }
  75 static DEVICE_ATTR(usbip_status, S_IRUGO, show_status, NULL);
  76
  77 /*
  78  * usbip_sockfd gets a socket descriptor of an established TCP connection that
  79  * is used to transfer usbip requests by kernel threads. -1 is a magic number
  80  * by which usbip connection is finished.
  81  */
  82 static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
  83                             const char *buf, size_t count)
  84 {
  85         struct stub_device *sdev = dev_get_drvdata(dev);
  86         int sockfd = 0;
  87         struct socket *socket;
  88
  89         if (!sdev) {
  90                 dev_err(dev, "sdev is null\n");
  91                 return -ENODEV;
  92         }
  93
  94         sscanf(buf, "%d", &sockfd);
  95
  96         if (sockfd != -1) {
  97                 dev_info(dev, "stub up\n");
  98
  99                 spin_lock(&sdev->ud.lock);
 100
 101                 if (sdev->ud.status != SDEV_ST_AVAILABLE) {
 102                         dev_err(dev, "not ready\n");
 103                         spin_unlock(&sdev->ud.lock);
 104                         return -EINVAL;
 105                 }
 106
 107                 socket = sockfd_to_socket(sockfd);
 108                 if (!socket) {
 109                         spin_unlock(&sdev->ud.lock);
 110                         return -EINVAL;
 111                 }
 112 #if 0
 113                 setnodelay(socket);
 114                 setkeepalive(socket);
 115                 setreuse(socket);
 116 #endif
 117                 sdev->ud.tcp_socket = socket;
 118
 119                 spin_unlock(&sdev->ud.lock);
 120
 121                 sdev->ud.tcp_rx = kthread_run(stub_rx_loop, &sdev->ud, "stub_rx");
 122                 sdev->ud.tcp_tx = kthread_run(stub_tx_loop, &sdev->ud, "stub_tx");
 123
 124                 spin_lock(&sdev->ud.lock);
 125                 sdev->ud.status = SDEV_ST_USED;
 126                 spin_unlock(&sdev->ud.lock);
 127
 128         } else {
 129                 dev_info(dev, "stub down\n");
 130
 131                 spin_lock(&sdev->ud.lock);
 132                 if (sdev->ud.status != SDEV_ST_USED) {
 133                         spin_unlock(&sdev->ud.lock);
 134                         return -EINVAL;
 135                 }
 136                 spin_unlock(&sdev->ud.lock);
 137
 138                 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
 139         }
 140
 141         return count;
 142 }
 143 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 144
 145 static int stub_add_files(struct device *dev)
 146 {
 147         int err = 0;
 148
 149         err = device_create_file(dev, &dev_attr_usbip_status);
 150         if (err)
 151                 goto err_status;
 152
 153         err = device_create_file(dev, &dev_attr_usbip_sockfd);
 154         if (err)
 155                 goto err_sockfd;
 156
 157         err = device_create_file(dev, &dev_attr_usbip_debug);
 158         if (err)
 159                 goto err_debug;
 160
 161         return 0;
 162
 163 err_debug:
 164         device_remove_file(dev, &dev_attr_usbip_sockfd);
 165 err_sockfd:
 166         device_remove_file(dev, &dev_attr_usbip_status);
 167 err_status:
 168         return err;
 169 }
 170
 171 static void stub_remove_files(struct device *dev)
 172 {
 173         device_remove_file(dev, &dev_attr_usbip_status);
 174         device_remove_file(dev, &dev_attr_usbip_sockfd);
 175         device_remove_file(dev, &dev_attr_usbip_debug);
 176 }
 177
 178 static void stub_shutdown_connection(struct usbip_device *ud)
 179 {
 180         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 181
 182         /*
 183          * When removing an exported device, kernel panic sometimes occurred
 184          * and then EIP was sk_wait_data of stub_rx thread. Is this because
 185          * sk_wait_data returned though stub_rx thread was already finished by
 186          * step 1?
 187          */
 188         if (ud->tcp_socket) {
 189                 dev_dbg(&sdev->udev->dev, "shutdown tcp_socket %p\n",
 190                         ud->tcp_socket);
 191                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 192         }
 193
 194         /* 1. stop threads */
 195         if (ud->tcp_rx && !task_is_dead(ud->tcp_rx))
 196                 kthread_stop(ud->tcp_rx);
 197         if (ud->tcp_tx && !task_is_dead(ud->tcp_tx))
 198                 kthread_stop(ud->tcp_tx);
 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                 sock_release(ud->tcp_socket);
 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(&ud->lock);
 245                 ud->status = SDEV_ST_ERROR;
 246                 spin_unlock(&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(&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(&ud->lock);
 263 }
 264
 265 static void stub_device_unusable(struct usbip_device *ud)
 266 {
 267         spin_lock(&ud->lock);
 268         ud->status = SDEV_ST_ERROR;
 269         spin_unlock(&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                 dev_err(&interface->dev, "no memory for stub_device\n");
 291                 return NULL;
 292         }
 293
 294         sdev->interface = usb_get_intf(interface);
 295         sdev->udev = usb_get_dev(udev);
 296
 297         /*
 298          * devid is defined with devnum when this driver is first allocated.
 299          * devnum may change later if a device is reset. However, devid never
 300          * changes during a usbip connection.
 301          */
 302         sdev->devid             = (busnum << 16) | devnum;
 303         sdev->ud.side           = USBIP_STUB;
 304         sdev->ud.status         = SDEV_ST_AVAILABLE;
 305         /* sdev->ud.lock = SPIN_LOCK_UNLOCKED; */
 306         spin_lock_init(&sdev->ud.lock);
 307         sdev->ud.tcp_socket     = NULL;
 308
 309         INIT_LIST_HEAD(&sdev->priv_init);
 310         INIT_LIST_HEAD(&sdev->priv_tx);
 311         INIT_LIST_HEAD(&sdev->priv_free);
 312         INIT_LIST_HEAD(&sdev->unlink_free);
 313         INIT_LIST_HEAD(&sdev->unlink_tx);
 314         /* sdev->priv_lock = SPIN_LOCK_UNLOCKED; */
 315         spin_lock_init(&sdev->priv_lock);
 316
 317         init_waitqueue_head(&sdev->tx_waitq);
 318
 319         sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
 320         sdev->ud.eh_ops.reset    = stub_device_reset;
 321         sdev->ud.eh_ops.unusable = stub_device_unusable;
 322
 323         usbip_start_eh(&sdev->ud);
 324
 325         dev_dbg(&interface->dev, "register new interface\n");
 326
 327         return sdev;
 328 }
 329
 330 static int stub_device_free(struct stub_device *sdev)
 331 {
 332         if (!sdev)
 333                 return -EINVAL;
 334
 335         kfree(sdev);
 336         pr_debug("kfree udev ok\n");
 337
 338         return 0;
 339 }
 340
 341 /*
 342  * If a usb device has multiple active interfaces, this driver is bound to all
 343  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 344  * active interface). Currently, a userland program must ensure that it
 345  * looks at the usbip's sysfs entries of only the first active interface.
 346  *
 347  * TODO: use "struct usb_device_driver" to bind a usb device.
 348  * However, it seems it is not fully supported in mainline kernel yet
 349  * (2.6.19.2).
 350  */
 351 static int stub_probe(struct usb_interface *interface,
 352                       const struct usb_device_id *id)
 353 {
 354         struct usb_device *udev = interface_to_usbdev(interface);
 355         struct stub_device *sdev = NULL;
 356         const char *udev_busid = dev_name(interface->dev.parent);
 357         int err = 0;
 358         struct bus_id_priv *busid_priv;
 359
 360         dev_dbg(&interface->dev, "Enter\n");
 361
 362         /* check we should claim or not by busid_table */
 363         busid_priv = get_busid_priv(udev_busid);
 364         if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
 365             (busid_priv->status == STUB_BUSID_OTHER)) {
 366                 dev_info(&interface->dev, "%s is not in match_busid table... "
 367                          "skip!\n", udev_busid);
 368
 369                 /*
 370                  * Return value should be ENODEV or ENOXIO to continue trying
 371                  * other matched drivers by the driver core.
 372                  * See driver_probe_device() in driver/base/dd.c
 373                  */
 374                 return -ENODEV;
 375         }
 376
 377         if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 378                 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 379                          udev_busid);
 380                 return -ENODEV;
 381         }
 382
 383         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 384                 dev_dbg(&udev->dev, "%s is attached on vhci_hcd... skip!\n",
 385                          udev_busid);
 386                 return -ENODEV;
 387         }
 388
 389         if (busid_priv->status == STUB_BUSID_ALLOC) {
 390                 sdev = busid_priv->sdev;
 391                 if (!sdev)
 392                         return -ENODEV;
 393
 394                 busid_priv->interf_count++;
 395                 dev_info(&interface->dev, "usbip-host: register new interface "
 396                          "(bus %u dev %u ifn %u)\n",
 397                          udev->bus->busnum, udev->devnum,
 398                          interface->cur_altsetting->desc.bInterfaceNumber);
 399
 400                 /* set private data to usb_interface */
 401                 usb_set_intfdata(interface, sdev);
 402
 403                 err = stub_add_files(&interface->dev);
 404                 if (err) {
 405                         dev_err(&interface->dev, "stub_add_files for %s\n",
 406                                 udev_busid);
 407                         usb_set_intfdata(interface, NULL);
 408                         busid_priv->interf_count--;
 409                         return err;
 410                 }
 411
 412                 usb_get_intf(interface);
 413                 return 0;
 414         }
 415
 416         /* ok, this is my device */
 417         sdev = stub_device_alloc(udev, interface);
 418         if (!sdev)
 419                 return -ENOMEM;
 420
 421         dev_info(&interface->dev, "usbip-host: register new device "
 422                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 423                  interface->cur_altsetting->desc.bInterfaceNumber);
 424
 425         busid_priv->interf_count = 0;
 426         busid_priv->shutdown_busid = 0;
 427
 428         /* set private data to usb_interface */
 429         usb_set_intfdata(interface, sdev);
 430         busid_priv->interf_count++;
 431         busid_priv->sdev = sdev;
 432
 433         err = stub_add_files(&interface->dev);
 434         if (err) {
 435                 dev_err(&interface->dev, "stub_add_files for %s\n", udev_busid);
 436                 usb_set_intfdata(interface, NULL);
 437                 usb_put_intf(interface);
 438
 439                 busid_priv->interf_count = 0;
 440                 busid_priv->sdev = NULL;
 441                 stub_device_free(sdev);
 442                 return err;
 443         }
 444         busid_priv->status = STUB_BUSID_ALLOC;
 445
 446         return 0;
 447 }
 448
 449 static void shutdown_busid(struct bus_id_priv *busid_priv)
 450 {
 451         if (busid_priv->sdev && !busid_priv->shutdown_busid) {
 452                 busid_priv->shutdown_busid = 1;
 453                 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 454
 455                 /* 2. wait for the stop of the event handler */
 456                 usbip_stop_eh(&busid_priv->sdev->ud);
 457         }
 458 }
 459
 460 /*
 461  * called in usb_disconnect() or usb_deregister()
 462  * but only if actconfig(active configuration) exists
 463  */
 464 static void stub_disconnect(struct usb_interface *interface)
 465 {
 466         struct stub_device *sdev;
 467         const char *udev_busid = dev_name(interface->dev.parent);
 468         struct bus_id_priv *busid_priv;
 469
 470         dev_dbg(&interface->dev, "Enter\n");
 471
 472         busid_priv = get_busid_priv(udev_busid);
 473         if (!busid_priv) {
 474                 BUG();
 475                 return;
 476         }
 477
 478         sdev = usb_get_intfdata(interface);
 479
 480         /* get stub_device */
 481         if (!sdev) {
 482                 dev_err(&interface->dev, "could not get device");
 483                 /* BUG(); */
 484                 return;
 485         }
 486
 487         usb_set_intfdata(interface, NULL);
 488
 489         /*
 490          * NOTE:
 491          * rx/tx threads are invoked for each usb_device.
 492          */
 493         stub_remove_files(&interface->dev);
 494
 495         /*If usb reset called from event handler*/
 496         if (busid_priv->sdev->ud.eh == current) {
 497                 busid_priv->interf_count--;
 498                 return;
 499         }
 500
 501         if (busid_priv->interf_count > 1) {
 502                 busid_priv->interf_count--;
 503                 shutdown_busid(busid_priv);
 504                 usb_put_intf(interface);
 505                 return;
 506         }
 507
 508         busid_priv->interf_count = 0;
 509
 510         /* 1. shutdown the current connection */
 511         shutdown_busid(busid_priv);
 512
 513         usb_put_dev(sdev->udev);
 514         usb_put_intf(interface);
 515
 516         /* 3. free sdev */
 517         busid_priv->sdev = NULL;
 518         stub_device_free(sdev);
 519
 520         if (busid_priv->status == STUB_BUSID_ALLOC) {
 521                 busid_priv->status = STUB_BUSID_ADDED;
 522         } else {
 523                 busid_priv->status = STUB_BUSID_OTHER;
 524                 del_match_busid((char *)udev_busid);
 525         }
 526 }
 527
 528 /*
 529  * Presence of pre_reset and post_reset prevents the driver from being unbound
 530  * when the device is being reset
 531  */
 532
 533 int stub_pre_reset(struct usb_interface *interface)
 534 {
 535         dev_dbg(&interface->dev, "pre_reset\n");
 536         return 0;
 537 }
 538
 539 int stub_post_reset(struct usb_interface *interface)
 540 {
 541         dev_dbg(&interface->dev, "post_reset\n");
 542         return 0;
 543 }
 544
 545 struct usb_driver stub_driver = {
 546         .name           = "usbip-host",
 547         .probe          = stub_probe,
 548         .disconnect     = stub_disconnect,
 549         .id_table       = stub_table,
 550         .pre_reset      = stub_pre_reset,
 551         .post_reset     = stub_post_reset,
 552 };