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