drivers/usb/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 <asm/byteorder.h>
  21 #include <linux/kthread.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/hcd.h>
  24
  25 #include "usbip_common.h"
  26 #include "stub.h"
  27
  28 static int is_clear_halt_cmd(struct urb *urb)
  29 {
  30         struct usb_ctrlrequest *req;
  31
  32         req = (struct usb_ctrlrequest *) urb->setup_packet;
  33
  34          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  35                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  36                  (req->wValue == USB_ENDPOINT_HALT);
  37 }
  38
  39 static int is_set_interface_cmd(struct urb *urb)
  40 {
  41         struct usb_ctrlrequest *req;
  42
  43         req = (struct usb_ctrlrequest *) urb->setup_packet;
  44
  45         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
  46                 (req->bRequestType == USB_RECIP_INTERFACE);
  47 }
  48
  49 static int is_set_configuration_cmd(struct urb *urb)
  50 {
  51         struct usb_ctrlrequest *req;
  52
  53         req = (struct usb_ctrlrequest *) urb->setup_packet;
  54
  55         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  56                 (req->bRequestType == USB_RECIP_DEVICE);
  57 }
  58
  59 static int is_reset_device_cmd(struct urb *urb)
  60 {
  61         struct usb_ctrlrequest *req;
  62         __u16 value;
  63         __u16 index;
  64
  65         req = (struct usb_ctrlrequest *) urb->setup_packet;
  66         value = le16_to_cpu(req->wValue);
  67         index = le16_to_cpu(req->wIndex);
  68
  69         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  70             (req->bRequestType == USB_RT_PORT) &&
  71             (value == USB_PORT_FEAT_RESET)) {
  72                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  73                 return 1;
  74         } else
  75                 return 0;
  76 }
  77
  78 static int tweak_clear_halt_cmd(struct urb *urb)
  79 {
  80         struct usb_ctrlrequest *req;
  81         int target_endp;
  82         int target_dir;
  83         int target_pipe;
  84         int ret;
  85
  86         req = (struct usb_ctrlrequest *) urb->setup_packet;
  87
  88         /*
  89          * The stalled endpoint is specified in the wIndex value. The endpoint
  90          * of the urb is the target of this clear_halt request (i.e., control
  91          * endpoint).
  92          */
  93         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  94
  95         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  96         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  97
  98         if (target_dir)
  99                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
 100         else
 101                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
 102
 103         ret = usb_clear_halt(urb->dev, target_pipe);
 104         if (ret < 0)
 105                 dev_err(&urb->dev->dev,
 106                         "usb_clear_halt error: devnum %d endp %d ret %d\n",
 107                         urb->dev->devnum, target_endp, ret);
 108         else
 109                 dev_info(&urb->dev->dev,
 110                          "usb_clear_halt done: devnum %d endp %d\n",
 111                          urb->dev->devnum, target_endp);
 112
 113         return ret;
 114 }
 115
 116 static int tweak_set_interface_cmd(struct urb *urb)
 117 {
 118         struct usb_ctrlrequest *req;
 119         __u16 alternate;
 120         __u16 interface;
 121         int ret;
 122
 123         req = (struct usb_ctrlrequest *) urb->setup_packet;
 124         alternate = le16_to_cpu(req->wValue);
 125         interface = le16_to_cpu(req->wIndex);
 126
 127         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
 128                           interface, alternate);
 129
 130         ret = usb_set_interface(urb->dev, interface, alternate);
 131         if (ret < 0)
 132                 dev_err(&urb->dev->dev,
 133                         "usb_set_interface error: inf %u alt %u ret %d\n",
 134                         interface, alternate, ret);
 135         else
 136                 dev_info(&urb->dev->dev,
 137                         "usb_set_interface done: inf %u alt %u\n",
 138                         interface, alternate);
 139
 140         return ret;
 141 }
 142
 143 static int tweak_set_configuration_cmd(struct urb *urb)
 144 {
 145         struct stub_priv *priv = (struct stub_priv *) urb->context;
 146         struct stub_device *sdev = priv->sdev;
 147         struct usb_ctrlrequest *req;
 148         __u16 config;
 149         int err;
 150
 151         req = (struct usb_ctrlrequest *) urb->setup_packet;
 152         config = le16_to_cpu(req->wValue);
 153
 154         err = usb_set_configuration(sdev->udev, config);
 155         if (err && err != -ENODEV)
 156                 dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
 157                         config, err);
 158         return 0;
 159 }
 160
 161 static int tweak_reset_device_cmd(struct urb *urb)
 162 {
 163         struct stub_priv *priv = (struct stub_priv *) urb->context;
 164         struct stub_device *sdev = priv->sdev;
 165
 166         dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 167
 168         /*
 169          * With the implementation of pre_reset and post_reset the driver no
 170          * longer unbinds. This allows the use of synchronous reset.
 171          */
 172
 173         if (usb_lock_device_for_reset(sdev->udev, sdev->interface) < 0) {
 174                 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
 175                 return 0;
 176         }
 177         usb_reset_device(sdev->udev);
 178         usb_unlock_device(sdev->udev);
 179
 180         return 0;
 181 }
 182
 183 /*
 184  * clear_halt, set_interface, and set_configuration require special tricks.
 185  */
 186 static void tweak_special_requests(struct urb *urb)
 187 {
 188         if (!urb || !urb->setup_packet)
 189                 return;
 190
 191         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 192                 return;
 193
 194         if (is_clear_halt_cmd(urb))
 195                 /* tweak clear_halt */
 196                  tweak_clear_halt_cmd(urb);
 197
 198         else if (is_set_interface_cmd(urb))
 199                 /* tweak set_interface */
 200                 tweak_set_interface_cmd(urb);
 201
 202         else if (is_set_configuration_cmd(urb))
 203                 /* tweak set_configuration */
 204                 tweak_set_configuration_cmd(urb);
 205
 206         else if (is_reset_device_cmd(urb))
 207                 tweak_reset_device_cmd(urb);
 208         else
 209                 usbip_dbg_stub_rx("no need to tweak\n");
 210 }
 211
 212 /*
 213  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 214  * By unlinking the urb asynchronously, stub_rx can continuously
 215  * process coming urbs.  Even if the urb is unlinked, its completion
 216  * handler will be called and stub_tx will send a return pdu.
 217  *
 218  * See also comments about unlinking strategy in vhci_hcd.c.
 219  */
 220 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 221                                 struct usbip_header *pdu)
 222 {
 223         int ret;
 224         unsigned long flags;
 225         struct stub_priv *priv;
 226
 227         spin_lock_irqsave(&sdev->priv_lock, flags);
 228
 229         list_for_each_entry(priv, &sdev->priv_init, list) {
 230                 if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
 231                         continue;
 232
 233                 /*
 234                  * This matched urb is not completed yet (i.e., be in
 235                  * flight in usb hcd hardware/driver). Now we are
 236                  * cancelling it. The unlinking flag means that we are
 237                  * now not going to return the normal result pdu of a
 238                  * submission request, but going to return a result pdu
 239                  * of the unlink request.
 240                  */
 241                 priv->unlinking = 1;
 242
 243                 /*
 244                  * In the case that unlinking flag is on, prev->seqnum
 245                  * is changed from the seqnum of the cancelling urb to
 246                  * the seqnum of the unlink request. This will be used
 247                  * to make the result pdu of the unlink request.
 248                  */
 249                 priv->seqnum = pdu->base.seqnum;
 250
 251                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 252
 253                 /*
 254                  * usb_unlink_urb() is now out of spinlocking to avoid
 255                  * spinlock recursion since stub_complete() is
 256                  * sometimes called in this context but not in the
 257                  * interrupt context.  If stub_complete() is executed
 258                  * before we call usb_unlink_urb(), usb_unlink_urb()
 259                  * will return an error value. In this case, stub_tx
 260                  * will return the result pdu of this unlink request
 261                  * though submission is completed and actual unlinking
 262                  * is not executed. OK?
 263                  */
 264                 /* In the above case, urb->status is not -ECONNRESET,
 265                  * so a driver in a client host will know the failure
 266                  * of the unlink request ?
 267                  */
 268                 ret = usb_unlink_urb(priv->urb);
 269                 if (ret != -EINPROGRESS)
 270                         dev_err(&priv->urb->dev->dev,
 271                                 "failed to unlink a urb # %lu, ret %d\n",
 272                                 priv->seqnum, ret);
 273
 274                 return 0;
 275         }
 276
 277         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 278                           pdu->u.cmd_unlink.seqnum);
 279
 280         /*
 281          * The urb of the unlink target is not found in priv_init queue. It was
 282          * already completed and its results is/was going to be sent by a
 283          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 284          * return the completeness of this unlink request to vhci_hcd.
 285          */
 286         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 287
 288         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 289
 290         return 0;
 291 }
 292
 293 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 294 {
 295         struct usbip_device *ud = &sdev->ud;
 296         int valid = 0;
 297
 298         if (pdu->base.devid == sdev->devid) {
 299                 spin_lock_irq(&ud->lock);
 300                 if (ud->status == SDEV_ST_USED) {
 301                         /* A request is valid. */
 302                         valid = 1;
 303                 }
 304                 spin_unlock_irq(&ud->lock);
 305         }
 306
 307         return valid;
 308 }
 309
 310 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 311                                          struct usbip_header *pdu)
 312 {
 313         struct stub_priv *priv;
 314         struct usbip_device *ud = &sdev->ud;
 315         unsigned long flags;
 316
 317         spin_lock_irqsave(&sdev->priv_lock, flags);
 318
 319         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 320         if (!priv) {
 321                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 322                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 323                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 324                 return NULL;
 325         }
 326
 327         priv->seqnum = pdu->base.seqnum;
 328         priv->sdev = sdev;
 329
 330         /*
 331          * After a stub_priv is linked to a list_head,
 332          * our error handler can free allocated data.
 333          */
 334         list_add_tail(&priv->list, &sdev->priv_init);
 335
 336         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 337
 338         return priv;
 339 }
 340
 341 static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
 342 {
 343         struct usb_device *udev = sdev->udev;
 344         struct usb_host_endpoint *ep;
 345         struct usb_endpoint_descriptor *epd = NULL;
 346         int epnum = pdu->base.ep;
 347         int dir = pdu->base.direction;
 348
 349         if (epnum < 0 || epnum > 15)
 350                 goto err_ret;
 351
 352         if (dir == USBIP_DIR_IN)
 353                 ep = udev->ep_in[epnum & 0x7f];
 354         else
 355                 ep = udev->ep_out[epnum & 0x7f];
 356         if (!ep)
 357                 goto err_ret;
 358
 359         epd = &ep->desc;
 360
 361         if (usb_endpoint_xfer_control(epd)) {
 362                 if (dir == USBIP_DIR_OUT)
 363                         return usb_sndctrlpipe(udev, epnum);
 364                 else
 365                         return usb_rcvctrlpipe(udev, epnum);
 366         }
 367
 368         if (usb_endpoint_xfer_bulk(epd)) {
 369                 if (dir == USBIP_DIR_OUT)
 370                         return usb_sndbulkpipe(udev, epnum);
 371                 else
 372                         return usb_rcvbulkpipe(udev, epnum);
 373         }
 374
 375         if (usb_endpoint_xfer_int(epd)) {
 376                 if (dir == USBIP_DIR_OUT)
 377                         return usb_sndintpipe(udev, epnum);
 378                 else
 379                         return usb_rcvintpipe(udev, epnum);
 380         }
 381
 382         if (usb_endpoint_xfer_isoc(epd)) {
 383                 /* validate number of packets */
 384                 if (pdu->u.cmd_submit.number_of_packets < 0 ||
 385                     pdu->u.cmd_submit.number_of_packets >
 386                     USBIP_MAX_ISO_PACKETS) {
 387                         dev_err(&sdev->udev->dev,
 388                                 "CMD_SUBMIT: isoc invalid num packets %d\n",
 389                                 pdu->u.cmd_submit.number_of_packets);
 390                         return -1;
 391                 }
 392                 if (dir == USBIP_DIR_OUT)
 393                         return usb_sndisocpipe(udev, epnum);
 394                 else
 395                         return usb_rcvisocpipe(udev, epnum);
 396         }
 397
 398 err_ret:
 399         /* NOT REACHED */
 400         dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
 401         return -1;
 402 }
 403
 404 static void masking_bogus_flags(struct urb *urb)
 405 {
 406         int                             xfertype;
 407         struct usb_device               *dev;
 408         struct usb_host_endpoint        *ep;
 409         int                             is_out;
 410         unsigned int    allowed;
 411
 412         if (!urb || urb->hcpriv || !urb->complete)
 413                 return;
 414         dev = urb->dev;
 415         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 416                 return;
 417
 418         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 419                 [usb_pipeendpoint(urb->pipe)];
 420         if (!ep)
 421                 return;
 422
 423         xfertype = usb_endpoint_type(&ep->desc);
 424         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 425                 struct usb_ctrlrequest *setup =
 426                         (struct usb_ctrlrequest *) urb->setup_packet;
 427
 428                 if (!setup)
 429                         return;
 430                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 431                         !setup->wLength;
 432         } else {
 433                 is_out = usb_endpoint_dir_out(&ep->desc);
 434         }
 435
 436         /* enforce simple/standard policy */
 437         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 438                    URB_DIR_MASK | URB_FREE_BUFFER);
 439         switch (xfertype) {
 440         case USB_ENDPOINT_XFER_BULK:
 441                 if (is_out)
 442                         allowed |= URB_ZERO_PACKET;
 443                 /* FALLTHROUGH */
 444         case USB_ENDPOINT_XFER_CONTROL:
 445                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 446                 /* FALLTHROUGH */
 447         default:                        /* all non-iso endpoints */
 448                 if (!is_out)
 449                         allowed |= URB_SHORT_NOT_OK;
 450                 break;
 451         case USB_ENDPOINT_XFER_ISOC:
 452                 allowed |= URB_ISO_ASAP;
 453                 break;
 454         }
 455         urb->transfer_flags &= allowed;
 456 }
 457
 458 static void stub_recv_cmd_submit(struct stub_device *sdev,
 459                                  struct usbip_header *pdu)
 460 {
 461         int ret;
 462         struct stub_priv *priv;
 463         struct usbip_device *ud = &sdev->ud;
 464         struct usb_device *udev = sdev->udev;
 465         int pipe = get_pipe(sdev, pdu);
 466
 467         if (pipe == -1)
 468                 return;
 469
 470         priv = stub_priv_alloc(sdev, pdu);
 471         if (!priv)
 472                 return;
 473
 474         /* setup a urb */
 475         if (usb_pipeisoc(pipe))
 476                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 477                                           GFP_KERNEL);
 478         else
 479                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 480
 481         if (!priv->urb) {
 482                 dev_err(&sdev->interface->dev, "malloc urb\n");
 483                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 484                 return;
 485         }
 486
 487         /* allocate urb transfer buffer, if needed */
 488         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 489                 priv->urb->transfer_buffer =
 490                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 491                                 GFP_KERNEL);
 492                 if (!priv->urb->transfer_buffer) {
 493                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 494                         return;
 495                 }
 496         }
 497
 498         /* copy urb setup packet */
 499         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 500                                           GFP_KERNEL);
 501         if (!priv->urb->setup_packet) {
 502                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 503                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 504                 return;
 505         }
 506
 507         /* set other members from the base header of pdu */
 508         priv->urb->context                = (void *) priv;
 509         priv->urb->dev                    = udev;
 510         priv->urb->pipe                   = pipe;
 511         priv->urb->complete               = stub_complete;
 512
 513         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 514
 515
 516         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 517                 return;
 518
 519         if (usbip_recv_iso(ud, priv->urb) < 0)
 520                 return;
 521
 522         /* no need to submit an intercepted request, but harmless? */
 523         tweak_special_requests(priv->urb);
 524
 525         masking_bogus_flags(priv->urb);
 526         /* urb is now ready to submit */
 527         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 528
 529         if (ret == 0)
 530                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 531                                   pdu->base.seqnum);
 532         else {
 533                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 534                 usbip_dump_header(pdu);
 535                 usbip_dump_urb(priv->urb);
 536
 537                 /*
 538                  * Pessimistic.
 539                  * This connection will be discarded.
 540                  */
 541                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 542         }
 543
 544         usbip_dbg_stub_rx("Leave\n");
 545 }
 546
 547 /* recv a pdu */
 548 static void stub_rx_pdu(struct usbip_device *ud)
 549 {
 550         int ret;
 551         struct usbip_header pdu;
 552         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 553         struct device *dev = &sdev->udev->dev;
 554
 555         usbip_dbg_stub_rx("Enter\n");
 556
 557         memset(&pdu, 0, sizeof(pdu));
 558
 559         /* receive a pdu header */
 560         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 561         if (ret != sizeof(pdu)) {
 562                 dev_err(dev, "recv a header, %d\n", ret);
 563                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 564                 return;
 565         }
 566
 567         usbip_header_correct_endian(&pdu, 0);
 568
 569         if (usbip_dbg_flag_stub_rx)
 570                 usbip_dump_header(&pdu);
 571
 572         if (!valid_request(sdev, &pdu)) {
 573                 dev_err(dev, "recv invalid request\n");
 574                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 575                 return;
 576         }
 577
 578         switch (pdu.base.command) {
 579         case USBIP_CMD_UNLINK:
 580                 stub_recv_cmd_unlink(sdev, &pdu);
 581                 break;
 582
 583         case USBIP_CMD_SUBMIT:
 584                 stub_recv_cmd_submit(sdev, &pdu);
 585                 break;
 586
 587         default:
 588                 /* NOTREACHED */
 589                 dev_err(dev, "unknown pdu\n");
 590                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 591                 break;
 592         }
 593 }
 594
 595 int stub_rx_loop(void *data)
 596 {
 597         struct usbip_device *ud = data;
 598
 599         while (!kthread_should_stop()) {
 600                 if (usbip_event_happened(ud))
 601                         break;
 602
 603                 stub_rx_pdu(ud);
 604         }
 605
 606         return 0;
 607 }