drivers/staging/usbip/stub_rx.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 "usbip_common.h"
  21 #include "stub.h"
  22 #include "../../usb/core/hcd.h"
  23
  24
  25 static int is_clear_halt_cmd(struct urb *urb)
  26 {
  27         struct usb_ctrlrequest *req;
  28
  29         req = (struct usb_ctrlrequest *) urb->setup_packet;
  30
  31          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  32                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  33                  (req->wValue == USB_ENDPOINT_HALT);
  34 }
  35
  36 static int is_set_interface_cmd(struct urb *urb)
  37 {
  38         struct usb_ctrlrequest *req;
  39
  40         req = (struct usb_ctrlrequest *) urb->setup_packet;
  41
  42         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
  43                    (req->bRequestType == USB_RECIP_INTERFACE);
  44 }
  45
  46 static int is_set_configuration_cmd(struct urb *urb)
  47 {
  48         struct usb_ctrlrequest *req;
  49
  50         req = (struct usb_ctrlrequest *) urb->setup_packet;
  51
  52         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  53                    (req->bRequestType == USB_RECIP_DEVICE);
  54 }
  55
  56 static int is_reset_device_cmd(struct urb *urb)
  57 {
  58         struct usb_ctrlrequest *req;
  59         __u16 value;
  60         __u16 index;
  61
  62         req = (struct usb_ctrlrequest *) urb->setup_packet;
  63         value = le16_to_cpu(req->wValue);
  64         index = le16_to_cpu(req->wIndex);
  65
  66         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  67                         (req->bRequestType == USB_RT_PORT) &&
  68                         (value == USB_PORT_FEAT_RESET)) {
  69                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  70                 return 1;
  71         } else
  72                 return 0;
  73 }
  74
  75 static int tweak_clear_halt_cmd(struct urb *urb)
  76 {
  77         struct usb_ctrlrequest *req;
  78         int target_endp;
  79         int target_dir;
  80         int target_pipe;
  81         int ret;
  82
  83         req = (struct usb_ctrlrequest *) urb->setup_packet;
  84
  85         /*
  86          * The stalled endpoint is specified in the wIndex value. The endpoint
  87          * of the urb is the target of this clear_halt request (i.e., control
  88          * endpoint).
  89          */
  90         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  91
  92         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  93         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  94
  95         if (target_dir)
  96                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
  97         else
  98                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
  99
 100         ret = usb_clear_halt(urb->dev, target_pipe);
 101         if (ret < 0)
 102                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
 103                                         urb->dev->devnum, target_endp, ret);
 104         else
 105                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
 106                                         urb->dev->devnum, target_endp);
 107
 108         return ret;
 109 }
 110
 111 static int tweak_set_interface_cmd(struct urb *urb)
 112 {
 113         struct usb_ctrlrequest *req;
 114         __u16 alternate;
 115         __u16 interface;
 116         int ret;
 117
 118         req = (struct usb_ctrlrequest *) urb->setup_packet;
 119         alternate = le16_to_cpu(req->wValue);
 120         interface = le16_to_cpu(req->wIndex);
 121
 122         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n", interface,
 123                                                                 alternate);
 124
 125         ret = usb_set_interface(urb->dev, interface, alternate);
 126         if (ret < 0)
 127                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
 128                                         interface, alternate, ret);
 129         else
 130                 usbip_uinfo("set_interface done: inf %u alt %u\n",
 131                                                         interface,
 132                                                         alternate);
 133
 134         return ret;
 135 }
 136
 137 static int tweak_set_configuration_cmd(struct urb *urb)
 138 {
 139         struct usb_ctrlrequest *req;
 140         __u16 config;
 141
 142         req = (struct usb_ctrlrequest *) urb->setup_packet;
 143         config = le16_to_cpu(req->wValue);
 144
 145         /*
 146          * I have never seen a multi-config device. Very rare.
 147          * For most devices, this will be called to choose a default
 148          * configuration only once in an initialization phase.
 149          *
 150          * set_configuration may change a device configuration and its device
 151          * drivers will be unbound and assigned for a new device configuration.
 152          * This means this usbip driver will be also unbound when called, then
 153          * eventually reassigned to the device as far as driver matching
 154          * condition is kept.
 155          *
 156          * Unfortunatelly, an existing usbip connection will be dropped
 157          * due to this driver unbinding. So, skip here.
 158          * A user may need to set a special configuration value before
 159          * exporting the device.
 160          */
 161         usbip_uinfo("set_configuration (%d) to %s\n", config,
 162                                                 dev_name(&urb->dev->dev));
 163         usbip_uinfo("but, skip!\n");
 164
 165         return 0;
 166         /* return usb_driver_set_configuration(urb->dev, config); */
 167 }
 168
 169 static int tweak_reset_device_cmd(struct urb *urb)
 170 {
 171         struct usb_ctrlrequest *req;
 172         __u16 value;
 173         __u16 index;
 174         int ret;
 175
 176         req = (struct usb_ctrlrequest *) urb->setup_packet;
 177         value = le16_to_cpu(req->wValue);
 178         index = le16_to_cpu(req->wIndex);
 179
 180         usbip_uinfo("reset_device (port %d) to %s\n", index,
 181                                                 dev_name(&urb->dev->dev));
 182
 183         /* all interfaces should be owned by usbip driver, so just reset it.  */
 184         ret = usb_lock_device_for_reset(urb->dev, NULL);
 185         if (ret < 0) {
 186                 dev_err(&urb->dev->dev, "lock for reset\n");
 187                 return ret;
 188         }
 189
 190         /* try to reset the device */
 191         ret = usb_reset_device(urb->dev);
 192         if (ret < 0)
 193                 dev_err(&urb->dev->dev, "device reset\n");
 194
 195         usb_unlock_device(urb->dev);
 196
 197         return ret;
 198 }
 199
 200 /*
 201  * clear_halt, set_interface, and set_configuration require special tricks.
 202  */
 203 static void tweak_special_requests(struct urb *urb)
 204 {
 205         if (!urb || !urb->setup_packet)
 206                 return;
 207
 208         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 209                 return;
 210
 211         if (is_clear_halt_cmd(urb))
 212                 /* tweak clear_halt */
 213                  tweak_clear_halt_cmd(urb);
 214
 215         else if (is_set_interface_cmd(urb))
 216                 /* tweak set_interface */
 217                 tweak_set_interface_cmd(urb);
 218
 219         else if (is_set_configuration_cmd(urb))
 220                 /* tweak set_configuration */
 221                 tweak_set_configuration_cmd(urb);
 222
 223         else if (is_reset_device_cmd(urb))
 224                 tweak_reset_device_cmd(urb);
 225         else
 226                 usbip_dbg_stub_rx("no need to tweak\n");
 227 }
 228
 229 /*
 230  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 231  * By unlinking the urb asynchronously, stub_rx can continuously
 232  * process coming urbs.  Even if the urb is unlinked, its completion
 233  * handler will be called and stub_tx will send a return pdu.
 234  *
 235  * See also comments about unlinking strategy in vhci_hcd.c.
 236  */
 237 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 238                                                 struct usbip_header *pdu)
 239 {
 240         unsigned long flags;
 241
 242         struct stub_priv *priv;
 243
 244
 245         spin_lock_irqsave(&sdev->priv_lock, flags);
 246
 247         list_for_each_entry(priv, &sdev->priv_init, list) {
 248                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 249                         int ret;
 250
 251                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 252                                  priv->urb);
 253
 254                         /*
 255                          * This matched urb is not completed yet (i.e., be in
 256                          * flight in usb hcd hardware/driver). Now we are
 257                          * cancelling it. The unlinking flag means that we are
 258                          * now not going to return the normal result pdu of a
 259                          * submission request, but going to return a result pdu
 260                          * of the unlink request.
 261                          */
 262                         priv->unlinking = 1;
 263
 264                         /*
 265                          * In the case that unlinking flag is on, prev->seqnum
 266                          * is changed from the seqnum of the cancelling urb to
 267                          * the seqnum of the unlink request. This will be used
 268                          * to make the result pdu of the unlink request.
 269                          */
 270                         priv->seqnum = pdu->base.seqnum;
 271
 272                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 273
 274                         /*
 275                          * usb_unlink_urb() is now out of spinlocking to avoid
 276                          * spinlock recursion since stub_complete() is
 277                          * sometimes called in this context but not in the
 278                          * interrupt context.  If stub_complete() is executed
 279                          * before we call usb_unlink_urb(), usb_unlink_urb()
 280                          * will return an error value. In this case, stub_tx
 281                          * will return the result pdu of this unlink request
 282                          * though submission is completed and actual unlinking
 283                          * is not executed. OK?
 284                          */
 285                         /* In the above case, urb->status is not -ECONNRESET,
 286                          * so a driver in a client host will know the failure
 287                          * of the unlink request ?
 288                          */
 289                         ret = usb_unlink_urb(priv->urb);
 290                         if (ret != -EINPROGRESS)
 291                                 dev_err(&priv->urb->dev->dev,
 292                                         "failed to unlink a urb %p, ret %d\n",
 293                                         priv->urb, ret);
 294                         return 0;
 295                 }
 296         }
 297
 298         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 299                                                 pdu->u.cmd_unlink.seqnum);
 300
 301         /*
 302          * The urb of the unlink target is not found in priv_init queue. It was
 303          * already completed and its results is/was going to be sent by a
 304          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 305          * return the completeness of this unlink request to vhci_hcd.
 306          */
 307         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 308
 309         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 310
 311
 312         return 0;
 313 }
 314
 315 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 316 {
 317         struct usbip_device *ud = &sdev->ud;
 318
 319         if (pdu->base.devid == sdev->devid) {
 320                 spin_lock(&ud->lock);
 321                 if (ud->status == SDEV_ST_USED) {
 322                         /* A request is valid. */
 323                         spin_unlock(&ud->lock);
 324                         return 1;
 325                 }
 326                 spin_unlock(&ud->lock);
 327         }
 328
 329         return 0;
 330 }
 331
 332 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 333                                          struct usbip_header *pdu)
 334 {
 335         struct stub_priv *priv;
 336         struct usbip_device *ud = &sdev->ud;
 337         unsigned long flags;
 338
 339         spin_lock_irqsave(&sdev->priv_lock, flags);
 340
 341         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 342         if (!priv) {
 343                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 344                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 345                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 346                 return NULL;
 347         }
 348
 349         priv->seqnum = pdu->base.seqnum;
 350         priv->sdev = sdev;
 351
 352         /*
 353          * After a stub_priv is linked to a list_head,
 354          * our error handler can free allocated data.
 355          */
 356         list_add_tail(&priv->list, &sdev->priv_init);
 357
 358         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 359
 360         return priv;
 361 }
 362
 363
 364 static struct usb_host_endpoint *get_ep_from_epnum(struct usb_device *udev,
 365                 int epnum0)
 366 {
 367         struct usb_host_config *config;
 368         int i = 0, j = 0;
 369         struct usb_host_endpoint *ep = NULL;
 370         int epnum;
 371         int found = 0;
 372
 373         if (epnum0 == 0)
 374                 return &udev->ep0;
 375
 376         config = udev->actconfig;
 377         if (!config)
 378                 return NULL;
 379
 380         for (i = 0; i < config->desc.bNumInterfaces; i++) {
 381                 struct usb_host_interface *setting;
 382
 383                 setting = config->interface[i]->cur_altsetting;
 384
 385                 for (j = 0; j < setting->desc.bNumEndpoints; j++) {
 386                         ep = &setting->endpoint[j];
 387                         epnum = (ep->desc.bEndpointAddress & 0x7f);
 388
 389                         if (epnum == epnum0) {
 390                                 /* usbip_uinfo("found epnum %d\n", epnum0);*/
 391                                 found = 1;
 392                                 break;
 393                         }
 394                 }
 395         }
 396
 397         if (found)
 398                 return ep;
 399         else
 400                 return NULL;
 401 }
 402
 403
 404 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 405 {
 406         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 407         struct usb_host_endpoint *ep;
 408         struct usb_endpoint_descriptor *epd = NULL;
 409
 410         ep = get_ep_from_epnum(udev, epnum);
 411         if (!ep) {
 412                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 413                         epnum);
 414                 BUG();
 415         }
 416
 417         epd = &ep->desc;
 418
 419
 420 #if 0
 421         /* epnum 0 is always control */
 422         if (epnum == 0) {
 423                 if (dir == USBIP_DIR_OUT)
 424                         return usb_sndctrlpipe(udev, 0);
 425                 else
 426                         return usb_rcvctrlpipe(udev, 0);
 427         }
 428 #endif
 429
 430         if (usb_endpoint_xfer_control(epd)) {
 431                 if (dir == USBIP_DIR_OUT)
 432                         return usb_sndctrlpipe(udev, epnum);
 433                 else
 434                         return usb_rcvctrlpipe(udev, epnum);
 435         }
 436
 437         if (usb_endpoint_xfer_bulk(epd)) {
 438                 if (dir == USBIP_DIR_OUT)
 439                         return usb_sndbulkpipe(udev, epnum);
 440                 else
 441                         return usb_rcvbulkpipe(udev, epnum);
 442         }
 443
 444         if (usb_endpoint_xfer_int(epd)) {
 445                 if (dir == USBIP_DIR_OUT)
 446                         return usb_sndintpipe(udev, epnum);
 447                 else
 448                         return usb_rcvintpipe(udev, epnum);
 449         }
 450
 451         if (usb_endpoint_xfer_isoc(epd)) {
 452                 if (dir == USBIP_DIR_OUT)
 453                         return usb_sndisocpipe(udev, epnum);
 454                 else
 455                         return usb_rcvisocpipe(udev, epnum);
 456         }
 457
 458         /* NOT REACHED */
 459         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 460         return 0;
 461 }
 462
 463 static void stub_recv_cmd_submit(struct stub_device *sdev,
 464                                  struct usbip_header *pdu)
 465 {
 466         int ret;
 467         struct stub_priv *priv;
 468         struct usbip_device *ud = &sdev->ud;
 469         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 470         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 471
 472
 473         priv = stub_priv_alloc(sdev, pdu);
 474         if (!priv)
 475                 return;
 476
 477         /* setup a urb */
 478         if (usb_pipeisoc(pipe))
 479                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 480                                                                 GFP_KERNEL);
 481         else
 482                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 483
 484         if (!priv->urb) {
 485                 dev_err(&sdev->interface->dev, "malloc urb\n");
 486                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 487                 return;
 488         }
 489
 490         /* set priv->urb->transfer_buffer */
 491         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 492                 priv->urb->transfer_buffer =
 493                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 494                                                                 GFP_KERNEL);
 495                 if (!priv->urb->transfer_buffer) {
 496                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 497                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 498                         return;
 499                 }
 500         }
 501
 502         /* set priv->urb->setup_packet */
 503         priv->urb->setup_packet = kzalloc(8, GFP_KERNEL);
 504         if (!priv->urb->setup_packet) {
 505                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 506                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 507                 return;
 508         }
 509         memcpy(priv->urb->setup_packet, &pdu->u.cmd_submit.setup, 8);
 510
 511         /* set other members from the base header of pdu */
 512         priv->urb->context                = (void *) priv;
 513         priv->urb->dev                    = udev;
 514         priv->urb->pipe                   = pipe;
 515         priv->urb->complete               = stub_complete;
 516
 517         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 518
 519
 520         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 521                 return;
 522
 523         if (usbip_recv_iso(ud, priv->urb) < 0)
 524                 return;
 525
 526         /* no need to submit an intercepted request, but harmless? */
 527         tweak_special_requests(priv->urb);
 528
 529         /* urb is now ready to submit */
 530         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 531
 532         if (ret == 0)
 533                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 534                                                         pdu->base.seqnum);
 535         else {
 536                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 537                 usbip_dump_header(pdu);
 538                 usbip_dump_urb(priv->urb);
 539
 540                 /*
 541                  * Pessimistic.
 542                  * This connection will be discarded.
 543                  */
 544                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 545         }
 546
 547         usbip_dbg_stub_rx("Leave\n");
 548         return;
 549 }
 550
 551 /* recv a pdu */
 552 static void stub_rx_pdu(struct usbip_device *ud)
 553 {
 554         int ret;
 555         struct usbip_header pdu;
 556         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 557         struct device *dev = &sdev->interface->dev;
 558
 559         usbip_dbg_stub_rx("Enter\n");
 560
 561         memset(&pdu, 0, sizeof(pdu));
 562
 563         /* 1. receive a pdu header */
 564         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 565         if (ret != sizeof(pdu)) {
 566                 dev_err(dev, "recv a header, %d\n", ret);
 567                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 568                 return;
 569         }
 570
 571         usbip_header_correct_endian(&pdu, 0);
 572
 573         if (usbip_dbg_flag_stub_rx)
 574                 usbip_dump_header(&pdu);
 575
 576         if (!valid_request(sdev, &pdu)) {
 577                 dev_err(dev, "recv invalid request\n");
 578                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 579                 return;
 580         }
 581
 582         switch (pdu.base.command) {
 583         case USBIP_CMD_UNLINK:
 584                 stub_recv_cmd_unlink(sdev, &pdu);
 585                 break;
 586
 587         case USBIP_CMD_SUBMIT:
 588                 stub_recv_cmd_submit(sdev, &pdu);
 589                 break;
 590
 591         default:
 592                 /* NOTREACHED */
 593                 dev_err(dev, "unknown pdu\n");
 594                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 595                 return;
 596         }
 597
 598 }
 599
 600 void stub_rx_loop(struct usbip_task *ut)
 601 {
 602         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 603
 604         while (1) {
 605                 if (signal_pending(current)) {
 606                         usbip_dbg_stub_rx("signal caught!\n");
 607                         break;
 608                 }
 609
 610                 if (usbip_event_happened(ud))
 611                         break;
 612
 613                 stub_rx_pdu(ud);
 614         }
 615 }