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