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