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         ssize_t err = -EINVAL;
  90
  91         if (!sdev) {
  92                 dev_err(dev, "sdev is null\n");
  93                 return -ENODEV;
  94         }
  95
  96         sscanf(buf, "%d", &sockfd);
  97
  98         if (sockfd != -1) {
  99                 dev_info(dev, "stub up\n");
 100
 101                 spin_lock_irq(&sdev->ud.lock);
 102
 103                 if (sdev->ud.status != SDEV_ST_AVAILABLE) {
 104                         dev_err(dev, "not ready\n");
 105                         goto err;
 106                 }
 107
 108                 socket = sockfd_to_socket(sockfd);
 109                 if (!socket)
 110                         goto err;
 111
 112                 sdev->ud.tcp_socket = socket;
 113
 114                 spin_unlock_irq(&sdev->ud.lock);
 115
 116                 sdev->ud.tcp_rx = kthread_get_run(stub_rx_loop, &sdev->ud,
 117                                                   "stub_rx");
 118                 sdev->ud.tcp_tx = kthread_get_run(stub_tx_loop, &sdev->ud,
 119                                                   "stub_tx");
 120
 121                 spin_lock_irq(&sdev->ud.lock);
 122                 sdev->ud.status = SDEV_ST_USED;
 123                 spin_unlock_irq(&sdev->ud.lock);
 124
 125         } else {
 126                 dev_info(dev, "stub down\n");
 127
 128                 spin_lock_irq(&sdev->ud.lock);
 129                 if (sdev->ud.status != SDEV_ST_USED)
 130                         goto err;
 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 err:
 140         spin_unlock_irq(&sdev->ud.lock);
 141         return err;
 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) {
 196                 kthread_stop_put(ud->tcp_rx);
 197                 ud->tcp_rx = NULL;
 198         }
 199         if (ud->tcp_tx) {
 200                 kthread_stop_put(ud->tcp_tx);
 201                 ud->tcp_tx = NULL;
 202         }
 203
 204         /*
 205          * 2. close the socket
 206          *
 207          * tcp_socket is freed after threads are killed so that usbip_xmit does
 208          * not touch NULL socket.
 209          */
 210         if (ud->tcp_socket) {
 211                 fput(ud->tcp_socket->file);
 212                 ud->tcp_socket = NULL;
 213         }
 214
 215         /* 3. free used data */
 216         stub_device_cleanup_urbs(sdev);
 217
 218         /* 4. free stub_unlink */
 219         {
 220                 unsigned long flags;
 221                 struct stub_unlink *unlink, *tmp;
 222
 223                 spin_lock_irqsave(&sdev->priv_lock, flags);
 224                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 225                         list_del(&unlink->list);
 226                         kfree(unlink);
 227                 }
 228                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
 229                                          list) {
 230                         list_del(&unlink->list);
 231                         kfree(unlink);
 232                 }
 233                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 234         }
 235 }
 236
 237 static void stub_device_reset(struct usbip_device *ud)
 238 {
 239         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 240         struct usb_device *udev = sdev->udev;
 241         int ret;
 242
 243         dev_dbg(&udev->dev, "device reset");
 244
 245         ret = usb_lock_device_for_reset(udev, sdev->interface);
 246         if (ret < 0) {
 247                 dev_err(&udev->dev, "lock for reset\n");
 248                 spin_lock_irq(&ud->lock);
 249                 ud->status = SDEV_ST_ERROR;
 250                 spin_unlock_irq(&ud->lock);
 251                 return;
 252         }
 253
 254         /* try to reset the device */
 255         ret = usb_reset_device(udev);
 256         usb_unlock_device(udev);
 257
 258         spin_lock_irq(&ud->lock);
 259         if (ret) {
 260                 dev_err(&udev->dev, "device reset\n");
 261                 ud->status = SDEV_ST_ERROR;
 262         } else {
 263                 dev_info(&udev->dev, "device reset\n");
 264                 ud->status = SDEV_ST_AVAILABLE;
 265         }
 266         spin_unlock_irq(&ud->lock);
 267 }
 268
 269 static void stub_device_unusable(struct usbip_device *ud)
 270 {
 271         spin_lock_irq(&ud->lock);
 272         ud->status = SDEV_ST_ERROR;
 273         spin_unlock_irq(&ud->lock);
 274 }
 275
 276 /**
 277  * stub_device_alloc - allocate a new stub_device struct
 278  * @interface: usb_interface of a new device
 279  *
 280  * Allocates and initializes a new stub_device struct.
 281  */
 282 static struct stub_device *stub_device_alloc(struct usb_device *udev,
 283                                              struct usb_interface *interface)
 284 {
 285         struct stub_device *sdev;
 286         int busnum = interface_to_busnum(interface);
 287         int devnum = interface_to_devnum(interface);
 288
 289         dev_dbg(&interface->dev, "allocating stub device");
 290
 291         /* yes, it's a new device */
 292         sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
 293         if (!sdev)
 294                 return NULL;
 295
 296         sdev->interface = usb_get_intf(interface);
 297         sdev->udev = usb_get_dev(udev);
 298
 299         /*
 300          * devid is defined with devnum when this driver is first allocated.
 301          * devnum may change later if a device is reset. However, devid never
 302          * changes during a usbip connection.
 303          */
 304         sdev->devid             = (busnum << 16) | devnum;
 305         sdev->ud.side           = USBIP_STUB;
 306         sdev->ud.status         = SDEV_ST_AVAILABLE;
 307         spin_lock_init(&sdev->ud.lock);
 308         sdev->ud.tcp_socket     = NULL;
 309
 310         INIT_LIST_HEAD(&sdev->priv_init);
 311         INIT_LIST_HEAD(&sdev->priv_tx);
 312         INIT_LIST_HEAD(&sdev->priv_free);
 313         INIT_LIST_HEAD(&sdev->unlink_free);
 314         INIT_LIST_HEAD(&sdev->unlink_tx);
 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 void stub_device_free(struct stub_device *sdev)
 331 {
 332         kfree(sdev);
 333 }
 334
 335 /*
 336  * If a usb device has multiple active interfaces, this driver is bound to all
 337  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 338  * active interface). Currently, a userland program must ensure that it
 339  * looks at the usbip's sysfs entries of only the first active interface.
 340  *
 341  * TODO: use "struct usb_device_driver" to bind a usb device.
 342  * However, it seems it is not fully supported in mainline kernel yet
 343  * (2.6.19.2).
 344  */
 345 static int stub_probe(struct usb_interface *interface,
 346                       const struct usb_device_id *id)
 347 {
 348         struct usb_device *udev = interface_to_usbdev(interface);
 349         struct stub_device *sdev = NULL;
 350         const char *udev_busid = dev_name(interface->dev.parent);
 351         int err = 0;
 352         struct bus_id_priv *busid_priv;
 353
 354         dev_dbg(&interface->dev, "Enter\n");
 355
 356         /* check we should claim or not by busid_table */
 357         busid_priv = get_busid_priv(udev_busid);
 358         if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
 359             (busid_priv->status == STUB_BUSID_OTHER)) {
 360                 dev_info(&interface->dev, "%s is not in match_busid table... "
 361                          "skip!\n", udev_busid);
 362
 363                 /*
 364                  * Return value should be ENODEV or ENOXIO to continue trying
 365                  * other matched drivers by the driver core.
 366                  * See driver_probe_device() in driver/base/dd.c
 367                  */
 368                 return -ENODEV;
 369         }
 370
 371         if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 372                 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 373                          udev_busid);
 374                 return -ENODEV;
 375         }
 376
 377         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 378                 dev_dbg(&udev->dev, "%s is attached on vhci_hcd... skip!\n",
 379                          udev_busid);
 380                 return -ENODEV;
 381         }
 382
 383         if (busid_priv->status == STUB_BUSID_ALLOC) {
 384                 sdev = busid_priv->sdev;
 385                 if (!sdev)
 386                         return -ENODEV;
 387
 388                 busid_priv->interf_count++;
 389                 dev_info(&interface->dev, "usbip-host: register new interface "
 390                          "(bus %u dev %u ifn %u)\n",
 391                          udev->bus->busnum, udev->devnum,
 392                          interface->cur_altsetting->desc.bInterfaceNumber);
 393
 394                 /* set private data to usb_interface */
 395                 usb_set_intfdata(interface, sdev);
 396
 397                 err = stub_add_files(&interface->dev);
 398                 if (err) {
 399                         dev_err(&interface->dev, "stub_add_files for %s\n",
 400                                 udev_busid);
 401                         usb_set_intfdata(interface, NULL);
 402                         busid_priv->interf_count--;
 403                         return err;
 404                 }
 405
 406                 usb_get_intf(interface);
 407                 return 0;
 408         }
 409
 410         /* ok, this is my device */
 411         sdev = stub_device_alloc(udev, interface);
 412         if (!sdev)
 413                 return -ENOMEM;
 414
 415         dev_info(&interface->dev, "usbip-host: register new device "
 416                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 417                  interface->cur_altsetting->desc.bInterfaceNumber);
 418
 419         busid_priv->interf_count = 0;
 420         busid_priv->shutdown_busid = 0;
 421
 422         /* set private data to usb_interface */
 423         usb_set_intfdata(interface, sdev);
 424         busid_priv->interf_count++;
 425         busid_priv->sdev = sdev;
 426
 427         err = stub_add_files(&interface->dev);
 428         if (err) {
 429                 dev_err(&interface->dev, "stub_add_files for %s\n", udev_busid);
 430                 usb_set_intfdata(interface, NULL);
 431                 usb_put_intf(interface);
 432                 usb_put_dev(udev);
 433                 kthread_stop_put(sdev->ud.eh);
 434
 435                 busid_priv->interf_count = 0;
 436                 busid_priv->sdev = NULL;
 437                 stub_device_free(sdev);
 438                 return err;
 439         }
 440         busid_priv->status = STUB_BUSID_ALLOC;
 441
 442         return 0;
 443 }
 444
 445 static void shutdown_busid(struct bus_id_priv *busid_priv)
 446 {
 447         if (busid_priv->sdev && !busid_priv->shutdown_busid) {
 448                 busid_priv->shutdown_busid = 1;
 449                 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 450
 451                 /* wait for the stop of the event handler */
 452                 usbip_stop_eh(&busid_priv->sdev->ud);
 453         }
 454 }
 455
 456 /*
 457  * called in usb_disconnect() or usb_deregister()
 458  * but only if actconfig(active configuration) exists
 459  */
 460 static void stub_disconnect(struct usb_interface *interface)
 461 {
 462         struct stub_device *sdev;
 463         const char *udev_busid = dev_name(interface->dev.parent);
 464         struct bus_id_priv *busid_priv;
 465
 466         dev_dbg(&interface->dev, "Enter\n");
 467
 468         busid_priv = get_busid_priv(udev_busid);
 469         if (!busid_priv) {
 470                 BUG();
 471                 return;
 472         }
 473
 474         sdev = usb_get_intfdata(interface);
 475
 476         /* get stub_device */
 477         if (!sdev) {
 478                 dev_err(&interface->dev, "could not get device");
 479                 return;
 480         }
 481
 482         usb_set_intfdata(interface, NULL);
 483
 484         /*
 485          * NOTE: rx/tx threads are invoked for each usb_device.
 486          */
 487         stub_remove_files(&interface->dev);
 488
 489         /* If usb reset is called from event handler */
 490         if (busid_priv->sdev->ud.eh == current) {
 491                 busid_priv->interf_count--;
 492                 return;
 493         }
 494
 495         if (busid_priv->interf_count > 1) {
 496                 busid_priv->interf_count--;
 497                 shutdown_busid(busid_priv);
 498                 usb_put_intf(interface);
 499                 return;
 500         }
 501
 502         busid_priv->interf_count = 0;
 503
 504         /* shutdown the current connection */
 505         shutdown_busid(busid_priv);
 506
 507         usb_put_dev(sdev->udev);
 508         usb_put_intf(interface);
 509
 510         /* free sdev */
 511         busid_priv->sdev = NULL;
 512         stub_device_free(sdev);
 513
 514         if (busid_priv->status == STUB_BUSID_ALLOC) {
 515                 busid_priv->status = STUB_BUSID_ADDED;
 516         } else {
 517                 busid_priv->status = STUB_BUSID_OTHER;
 518                 del_match_busid((char *)udev_busid);
 519         }
 520 }
 521
 522 /*
 523  * Presence of pre_reset and post_reset prevents the driver from being unbound
 524  * when the device is being reset
 525  */
 526
 527 static int stub_pre_reset(struct usb_interface *interface)
 528 {
 529         dev_dbg(&interface->dev, "pre_reset\n");
 530         return 0;
 531 }
 532
 533 static int stub_post_reset(struct usb_interface *interface)
 534 {
 535         dev_dbg(&interface->dev, "post_reset\n");
 536         return 0;
 537 }
 538
 539 struct usb_driver stub_driver = {
 540         .name           = "usbip-host",
 541         .probe          = stub_probe,
 542         .disconnect     = stub_disconnect,
 543         .id_table       = stub_table,
 544         .pre_reset      = stub_pre_reset,
 545         .post_reset     = stub_post_reset,
 546 };