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                 sdev->ud.tcp_socket = socket;
 113
 114                 spin_unlock(&sdev->ud.lock);
 115
 116                 sdev->ud.tcp_rx = kthread_run(stub_rx_loop, &sdev->ud, "stub_rx");
 117                 sdev->ud.tcp_tx = kthread_run(stub_tx_loop, &sdev->ud, "stub_tx");
 118
 119                 spin_lock(&sdev->ud.lock);
 120                 sdev->ud.status = SDEV_ST_USED;
 121                 spin_unlock(&sdev->ud.lock);
 122
 123         } else {
 124                 dev_info(dev, "stub down\n");
 125
 126                 spin_lock(&sdev->ud.lock);
 127                 if (sdev->ud.status != SDEV_ST_USED) {
 128                         spin_unlock(&sdev->ud.lock);
 129                         return -EINVAL;
 130                 }
 131                 spin_unlock(&sdev->ud.lock);
 132
 133                 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
 134         }
 135
 136         return count;
 137 }
 138 static DEVICE_ATTR(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
 139
 140 static int stub_add_files(struct device *dev)
 141 {
 142         int err = 0;
 143
 144         err = device_create_file(dev, &dev_attr_usbip_status);
 145         if (err)
 146                 goto err_status;
 147
 148         err = device_create_file(dev, &dev_attr_usbip_sockfd);
 149         if (err)
 150                 goto err_sockfd;
 151
 152         err = device_create_file(dev, &dev_attr_usbip_debug);
 153         if (err)
 154                 goto err_debug;
 155
 156         return 0;
 157
 158 err_debug:
 159         device_remove_file(dev, &dev_attr_usbip_sockfd);
 160 err_sockfd:
 161         device_remove_file(dev, &dev_attr_usbip_status);
 162 err_status:
 163         return err;
 164 }
 165
 166 static void stub_remove_files(struct device *dev)
 167 {
 168         device_remove_file(dev, &dev_attr_usbip_status);
 169         device_remove_file(dev, &dev_attr_usbip_sockfd);
 170         device_remove_file(dev, &dev_attr_usbip_debug);
 171 }
 172
 173 static void stub_shutdown_connection(struct usbip_device *ud)
 174 {
 175         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 176
 177         /*
 178          * When removing an exported device, kernel panic sometimes occurred
 179          * and then EIP was sk_wait_data of stub_rx thread. Is this because
 180          * sk_wait_data returned though stub_rx thread was already finished by
 181          * step 1?
 182          */
 183         if (ud->tcp_socket) {
 184                 dev_dbg(&sdev->udev->dev, "shutdown tcp_socket %p\n",
 185                         ud->tcp_socket);
 186                 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 187         }
 188
 189         /* 1. stop threads */
 190         if (ud->tcp_rx && !task_is_dead(ud->tcp_rx))
 191                 kthread_stop(ud->tcp_rx);
 192         if (ud->tcp_tx && !task_is_dead(ud->tcp_tx))
 193                 kthread_stop(ud->tcp_tx);
 194
 195         /*
 196          * 2. close the socket
 197          *
 198          * tcp_socket is freed after threads are killed so that usbip_xmit does
 199          * not touch NULL socket.
 200          */
 201         if (ud->tcp_socket) {
 202                 sock_release(ud->tcp_socket);
 203                 ud->tcp_socket = NULL;
 204         }
 205
 206         /* 3. free used data */
 207         stub_device_cleanup_urbs(sdev);
 208
 209         /* 4. free stub_unlink */
 210         {
 211                 unsigned long flags;
 212                 struct stub_unlink *unlink, *tmp;
 213
 214                 spin_lock_irqsave(&sdev->priv_lock, flags);
 215                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
 216                         list_del(&unlink->list);
 217                         kfree(unlink);
 218                 }
 219                 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
 220                                          list) {
 221                         list_del(&unlink->list);
 222                         kfree(unlink);
 223                 }
 224                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 225         }
 226 }
 227
 228 static void stub_device_reset(struct usbip_device *ud)
 229 {
 230         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 231         struct usb_device *udev = sdev->udev;
 232         int ret;
 233
 234         dev_dbg(&udev->dev, "device reset");
 235
 236         ret = usb_lock_device_for_reset(udev, sdev->interface);
 237         if (ret < 0) {
 238                 dev_err(&udev->dev, "lock for reset\n");
 239                 spin_lock(&ud->lock);
 240                 ud->status = SDEV_ST_ERROR;
 241                 spin_unlock(&ud->lock);
 242                 return;
 243         }
 244
 245         /* try to reset the device */
 246         ret = usb_reset_device(udev);
 247         usb_unlock_device(udev);
 248
 249         spin_lock(&ud->lock);
 250         if (ret) {
 251                 dev_err(&udev->dev, "device reset\n");
 252                 ud->status = SDEV_ST_ERROR;
 253         } else {
 254                 dev_info(&udev->dev, "device reset\n");
 255                 ud->status = SDEV_ST_AVAILABLE;
 256         }
 257         spin_unlock(&ud->lock);
 258 }
 259
 260 static void stub_device_unusable(struct usbip_device *ud)
 261 {
 262         spin_lock(&ud->lock);
 263         ud->status = SDEV_ST_ERROR;
 264         spin_unlock(&ud->lock);
 265 }
 266
 267 /**
 268  * stub_device_alloc - allocate a new stub_device struct
 269  * @interface: usb_interface of a new device
 270  *
 271  * Allocates and initializes a new stub_device struct.
 272  */
 273 static struct stub_device *stub_device_alloc(struct usb_device *udev,
 274                                              struct usb_interface *interface)
 275 {
 276         struct stub_device *sdev;
 277         int busnum = interface_to_busnum(interface);
 278         int devnum = interface_to_devnum(interface);
 279
 280         dev_dbg(&interface->dev, "allocating stub device");
 281
 282         /* yes, it's a new device */
 283         sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
 284         if (!sdev) {
 285                 dev_err(&interface->dev, "no memory for stub_device\n");
 286                 return NULL;
 287         }
 288
 289         sdev->interface = usb_get_intf(interface);
 290         sdev->udev = usb_get_dev(udev);
 291
 292         /*
 293          * devid is defined with devnum when this driver is first allocated.
 294          * devnum may change later if a device is reset. However, devid never
 295          * changes during a usbip connection.
 296          */
 297         sdev->devid             = (busnum << 16) | devnum;
 298         sdev->ud.side           = USBIP_STUB;
 299         sdev->ud.status         = SDEV_ST_AVAILABLE;
 300         /* sdev->ud.lock = SPIN_LOCK_UNLOCKED; */
 301         spin_lock_init(&sdev->ud.lock);
 302         sdev->ud.tcp_socket     = NULL;
 303
 304         INIT_LIST_HEAD(&sdev->priv_init);
 305         INIT_LIST_HEAD(&sdev->priv_tx);
 306         INIT_LIST_HEAD(&sdev->priv_free);
 307         INIT_LIST_HEAD(&sdev->unlink_free);
 308         INIT_LIST_HEAD(&sdev->unlink_tx);
 309         /* sdev->priv_lock = SPIN_LOCK_UNLOCKED; */
 310         spin_lock_init(&sdev->priv_lock);
 311
 312         init_waitqueue_head(&sdev->tx_waitq);
 313
 314         sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
 315         sdev->ud.eh_ops.reset    = stub_device_reset;
 316         sdev->ud.eh_ops.unusable = stub_device_unusable;
 317
 318         usbip_start_eh(&sdev->ud);
 319
 320         dev_dbg(&interface->dev, "register new interface\n");
 321
 322         return sdev;
 323 }
 324
 325 static int stub_device_free(struct stub_device *sdev)
 326 {
 327         if (!sdev)
 328                 return -EINVAL;
 329
 330         kfree(sdev);
 331         pr_debug("kfree udev ok\n");
 332
 333         return 0;
 334 }
 335
 336 /*
 337  * If a usb device has multiple active interfaces, this driver is bound to all
 338  * the active interfaces. However, usbip exports *a* usb device (i.e., not *an*
 339  * active interface). Currently, a userland program must ensure that it
 340  * looks at the usbip's sysfs entries of only the first active interface.
 341  *
 342  * TODO: use "struct usb_device_driver" to bind a usb device.
 343  * However, it seems it is not fully supported in mainline kernel yet
 344  * (2.6.19.2).
 345  */
 346 static int stub_probe(struct usb_interface *interface,
 347                       const struct usb_device_id *id)
 348 {
 349         struct usb_device *udev = interface_to_usbdev(interface);
 350         struct stub_device *sdev = NULL;
 351         const char *udev_busid = dev_name(interface->dev.parent);
 352         int err = 0;
 353         struct bus_id_priv *busid_priv;
 354
 355         dev_dbg(&interface->dev, "Enter\n");
 356
 357         /* check we should claim or not by busid_table */
 358         busid_priv = get_busid_priv(udev_busid);
 359         if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
 360             (busid_priv->status == STUB_BUSID_OTHER)) {
 361                 dev_info(&interface->dev, "%s is not in match_busid table... "
 362                          "skip!\n", udev_busid);
 363
 364                 /*
 365                  * Return value should be ENODEV or ENOXIO to continue trying
 366                  * other matched drivers by the driver core.
 367                  * See driver_probe_device() in driver/base/dd.c
 368                  */
 369                 return -ENODEV;
 370         }
 371
 372         if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 373                 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 374                          udev_busid);
 375                 return -ENODEV;
 376         }
 377
 378         if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
 379                 dev_dbg(&udev->dev, "%s is attached on vhci_hcd... skip!\n",
 380                          udev_busid);
 381                 return -ENODEV;
 382         }
 383
 384         if (busid_priv->status == STUB_BUSID_ALLOC) {
 385                 sdev = busid_priv->sdev;
 386                 if (!sdev)
 387                         return -ENODEV;
 388
 389                 busid_priv->interf_count++;
 390                 dev_info(&interface->dev, "usbip-host: register new interface "
 391                          "(bus %u dev %u ifn %u)\n",
 392                          udev->bus->busnum, udev->devnum,
 393                          interface->cur_altsetting->desc.bInterfaceNumber);
 394
 395                 /* set private data to usb_interface */
 396                 usb_set_intfdata(interface, sdev);
 397
 398                 err = stub_add_files(&interface->dev);
 399                 if (err) {
 400                         dev_err(&interface->dev, "stub_add_files for %s\n",
 401                                 udev_busid);
 402                         usb_set_intfdata(interface, NULL);
 403                         busid_priv->interf_count--;
 404                         return err;
 405                 }
 406
 407                 usb_get_intf(interface);
 408                 return 0;
 409         }
 410
 411         /* ok, this is my device */
 412         sdev = stub_device_alloc(udev, interface);
 413         if (!sdev)
 414                 return -ENOMEM;
 415
 416         dev_info(&interface->dev, "usbip-host: register new device "
 417                  "(bus %u dev %u ifn %u)\n", udev->bus->busnum, udev->devnum,
 418                  interface->cur_altsetting->desc.bInterfaceNumber);
 419
 420         busid_priv->interf_count = 0;
 421         busid_priv->shutdown_busid = 0;
 422
 423         /* set private data to usb_interface */
 424         usb_set_intfdata(interface, sdev);
 425         busid_priv->interf_count++;
 426         busid_priv->sdev = sdev;
 427
 428         err = stub_add_files(&interface->dev);
 429         if (err) {
 430                 dev_err(&interface->dev, "stub_add_files for %s\n", udev_busid);
 431                 usb_set_intfdata(interface, NULL);
 432                 usb_put_intf(interface);
 433
 434                 busid_priv->interf_count = 0;
 435                 busid_priv->sdev = NULL;
 436                 stub_device_free(sdev);
 437                 return err;
 438         }
 439         busid_priv->status = STUB_BUSID_ALLOC;
 440
 441         return 0;
 442 }
 443
 444 static void shutdown_busid(struct bus_id_priv *busid_priv)
 445 {
 446         if (busid_priv->sdev && !busid_priv->shutdown_busid) {
 447                 busid_priv->shutdown_busid = 1;
 448                 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 449
 450                 /* 2. wait for the stop of the event handler */
 451                 usbip_stop_eh(&busid_priv->sdev->ud);
 452         }
 453 }
 454
 455 /*
 456  * called in usb_disconnect() or usb_deregister()
 457  * but only if actconfig(active configuration) exists
 458  */
 459 static void stub_disconnect(struct usb_interface *interface)
 460 {
 461         struct stub_device *sdev;
 462         const char *udev_busid = dev_name(interface->dev.parent);
 463         struct bus_id_priv *busid_priv;
 464
 465         dev_dbg(&interface->dev, "Enter\n");
 466
 467         busid_priv = get_busid_priv(udev_busid);
 468         if (!busid_priv) {
 469                 BUG();
 470                 return;
 471         }
 472
 473         sdev = usb_get_intfdata(interface);
 474
 475         /* get stub_device */
 476         if (!sdev) {
 477                 dev_err(&interface->dev, "could not get device");
 478                 /* BUG(); */
 479                 return;
 480         }
 481
 482         usb_set_intfdata(interface, NULL);
 483
 484         /*
 485          * NOTE:
 486          * rx/tx threads are invoked for each usb_device.
 487          */
 488         stub_remove_files(&interface->dev);
 489
 490         /*If usb reset called from event handler*/
 491         if (busid_priv->sdev->ud.eh == current) {
 492                 busid_priv->interf_count--;
 493                 return;
 494         }
 495
 496         if (busid_priv->interf_count > 1) {
 497                 busid_priv->interf_count--;
 498                 shutdown_busid(busid_priv);
 499                 usb_put_intf(interface);
 500                 return;
 501         }
 502
 503         busid_priv->interf_count = 0;
 504
 505         /* 1. shutdown the current connection */
 506         shutdown_busid(busid_priv);
 507
 508         usb_put_dev(sdev->udev);
 509         usb_put_intf(interface);
 510
 511         /* 3. free sdev */
 512         busid_priv->sdev = NULL;
 513         stub_device_free(sdev);
 514
 515         if (busid_priv->status == STUB_BUSID_ALLOC) {
 516                 busid_priv->status = STUB_BUSID_ADDED;
 517         } else {
 518                 busid_priv->status = STUB_BUSID_OTHER;
 519                 del_match_busid((char *)udev_busid);
 520         }
 521 }
 522
 523 /*
 524  * Presence of pre_reset and post_reset prevents the driver from being unbound
 525  * when the device is being reset
 526  */
 527
 528 int stub_pre_reset(struct usb_interface *interface)
 529 {
 530         dev_dbg(&interface->dev, "pre_reset\n");
 531         return 0;
 532 }
 533
 534 int stub_post_reset(struct usb_interface *interface)
 535 {
 536         dev_dbg(&interface->dev, "post_reset\n");
 537         return 0;
 538 }
 539
 540 struct usb_driver stub_driver = {
 541         .name           = "usbip-host",
 542         .probe          = stub_probe,
 543         .disconnect     = stub_disconnect,
 544         .id_table       = stub_table,
 545         .pre_reset      = stub_pre_reset,
 546         .post_reset     = stub_post_reset,
 547 };