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 <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, "usb_clear_halt error: devnum %d endp "
 106                         "%d ret %d\n", urb->dev->devnum, target_endp, ret);
 107         else
 108                 dev_info(&urb->dev->dev, "usb_clear_halt done: devnum %d endp "
 109                          "%d\n", urb->dev->devnum, target_endp);
 110
 111         return ret;
 112 }
 113
 114 static int tweak_set_interface_cmd(struct urb *urb)
 115 {
 116         struct usb_ctrlrequest *req;
 117         __u16 alternate;
 118         __u16 interface;
 119         int ret;
 120
 121         req = (struct usb_ctrlrequest *) urb->setup_packet;
 122         alternate = le16_to_cpu(req->wValue);
 123         interface = le16_to_cpu(req->wIndex);
 124
 125         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
 126                           interface, alternate);
 127
 128         ret = usb_set_interface(urb->dev, interface, alternate);
 129         if (ret < 0)
 130                 dev_err(&urb->dev->dev, "usb_set_interface error: inf %u alt "
 131                         "%u ret %d\n", interface, alternate, ret);
 132         else
 133                 dev_info(&urb->dev->dev, "usb_set_interface done: inf %u alt "
 134                          "%u\n", interface, alternate);
 135
 136         return ret;
 137 }
 138
 139 static int tweak_set_configuration_cmd(struct urb *urb)
 140 {
 141         struct usb_ctrlrequest *req;
 142         __u16 config;
 143
 144         req = (struct usb_ctrlrequest *) urb->setup_packet;
 145         config = le16_to_cpu(req->wValue);
 146
 147         /*
 148          * I have never seen a multi-config device. Very rare.
 149          * For most devices, this will be called to choose a default
 150          * configuration only once in an initialization phase.
 151          *
 152          * set_configuration may change a device configuration and its device
 153          * drivers will be unbound and assigned for a new device configuration.
 154          * This means this usbip driver will be also unbound when called, then
 155          * eventually reassigned to the device as far as driver matching
 156          * condition is kept.
 157          *
 158          * Unfortunately, an existing usbip connection will be dropped
 159          * due to this driver unbinding. So, skip here.
 160          * A user may need to set a special configuration value before
 161          * exporting the device.
 162          */
 163         dev_info(&urb->dev->dev, "usb_set_configuration %d to %s... skip!\n",
 164                  config, dev_name(&urb->dev->dev));
 165
 166         return 0;
 167 }
 168
 169 static int tweak_reset_device_cmd(struct urb *urb)
 170 {
 171         struct stub_priv *priv = (struct stub_priv *) urb->context;
 172         struct stub_device *sdev = priv->sdev;
 173
 174         dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 175
 176         /*
 177          * With the implementation of pre_reset and post_reset the driver no
 178          * longer unbinds. This allows the use of synchronous reset.
 179          */
 180
 181         if (usb_lock_device_for_reset(sdev->udev, sdev->interface) < 0) {
 182                 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
 183                 return 0;
 184         }
 185         usb_reset_device(sdev->udev);
 186         usb_unlock_device(sdev->udev);
 187
 188         return 0;
 189 }
 190
 191 /*
 192  * clear_halt, set_interface, and set_configuration require special tricks.
 193  */
 194 static void tweak_special_requests(struct urb *urb)
 195 {
 196         if (!urb || !urb->setup_packet)
 197                 return;
 198
 199         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 200                 return;
 201
 202         if (is_clear_halt_cmd(urb))
 203                 /* tweak clear_halt */
 204                  tweak_clear_halt_cmd(urb);
 205
 206         else if (is_set_interface_cmd(urb))
 207                 /* tweak set_interface */
 208                 tweak_set_interface_cmd(urb);
 209
 210         else if (is_set_configuration_cmd(urb))
 211                 /* tweak set_configuration */
 212                 tweak_set_configuration_cmd(urb);
 213
 214         else if (is_reset_device_cmd(urb))
 215                 tweak_reset_device_cmd(urb);
 216         else
 217                 usbip_dbg_stub_rx("no need to tweak\n");
 218 }
 219
 220 /*
 221  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 222  * By unlinking the urb asynchronously, stub_rx can continuously
 223  * process coming urbs.  Even if the urb is unlinked, its completion
 224  * handler will be called and stub_tx will send a return pdu.
 225  *
 226  * See also comments about unlinking strategy in vhci_hcd.c.
 227  */
 228 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 229                                 struct usbip_header *pdu)
 230 {
 231         int ret;
 232         unsigned long flags;
 233         struct stub_priv *priv;
 234
 235         spin_lock_irqsave(&sdev->priv_lock, flags);
 236
 237         list_for_each_entry(priv, &sdev->priv_init, list) {
 238                 if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
 239                         continue;
 240
 241                 dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 242                          priv->urb);
 243
 244                 /*
 245                  * This matched urb is not completed yet (i.e., be in
 246                  * flight in usb hcd hardware/driver). Now we are
 247                  * cancelling it. The unlinking flag means that we are
 248                  * now not going to return the normal result pdu of a
 249                  * submission request, but going to return a result pdu
 250                  * of the unlink request.
 251                  */
 252                 priv->unlinking = 1;
 253
 254                 /*
 255                  * In the case that unlinking flag is on, prev->seqnum
 256                  * is changed from the seqnum of the cancelling urb to
 257                  * the seqnum of the unlink request. This will be used
 258                  * to make the result pdu of the unlink request.
 259                  */
 260                 priv->seqnum = pdu->base.seqnum;
 261
 262                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 263
 264                 /*
 265                  * usb_unlink_urb() is now out of spinlocking to avoid
 266                  * spinlock recursion since stub_complete() is
 267                  * sometimes called in this context but not in the
 268                  * interrupt context.  If stub_complete() is executed
 269                  * before we call usb_unlink_urb(), usb_unlink_urb()
 270                  * will return an error value. In this case, stub_tx
 271                  * will return the result pdu of this unlink request
 272                  * though submission is completed and actual unlinking
 273                  * is not executed. OK?
 274                  */
 275                 /* In the above case, urb->status is not -ECONNRESET,
 276                  * so a driver in a client host will know the failure
 277                  * of the unlink request ?
 278                  */
 279                 ret = usb_unlink_urb(priv->urb);
 280                 if (ret != -EINPROGRESS)
 281                         dev_err(&priv->urb->dev->dev,
 282                                 "failed to unlink a urb %p, ret %d\n",
 283                                 priv->urb, ret);
 284
 285                 return 0;
 286         }
 287
 288         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 289                           pdu->u.cmd_unlink.seqnum);
 290
 291         /*
 292          * The urb of the unlink target is not found in priv_init queue. It was
 293          * already completed and its results is/was going to be sent by a
 294          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 295          * return the completeness of this unlink request to vhci_hcd.
 296          */
 297         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 298
 299         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 300
 301         return 0;
 302 }
 303
 304 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 305 {
 306         struct usbip_device *ud = &sdev->ud;
 307         int valid = 0;
 308
 309         if (pdu->base.devid == sdev->devid) {
 310                 spin_lock_irq(&ud->lock);
 311                 if (ud->status == SDEV_ST_USED) {
 312                         /* A request is valid. */
 313                         valid = 1;
 314                 }
 315                 spin_unlock_irq(&ud->lock);
 316         }
 317
 318         return valid;
 319 }
 320
 321 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 322                                          struct usbip_header *pdu)
 323 {
 324         struct stub_priv *priv;
 325         struct usbip_device *ud = &sdev->ud;
 326         unsigned long flags;
 327
 328         spin_lock_irqsave(&sdev->priv_lock, flags);
 329
 330         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 331         if (!priv) {
 332                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 333                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 334                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 335                 return NULL;
 336         }
 337
 338         priv->seqnum = pdu->base.seqnum;
 339         priv->sdev = sdev;
 340
 341         /*
 342          * After a stub_priv is linked to a list_head,
 343          * our error handler can free allocated data.
 344          */
 345         list_add_tail(&priv->list, &sdev->priv_init);
 346
 347         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 348
 349         return priv;
 350 }
 351
 352 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 353 {
 354         struct usb_device *udev = sdev->udev;
 355         struct usb_host_endpoint *ep;
 356         struct usb_endpoint_descriptor *epd = NULL;
 357
 358         if (dir == USBIP_DIR_IN)
 359                 ep = udev->ep_in[epnum & 0x7f];
 360         else
 361                 ep = udev->ep_out[epnum & 0x7f];
 362         if (!ep) {
 363                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 364                         epnum);
 365                 BUG();
 366         }
 367
 368         epd = &ep->desc;
 369         if (usb_endpoint_xfer_control(epd)) {
 370                 if (dir == USBIP_DIR_OUT)
 371                         return usb_sndctrlpipe(udev, epnum);
 372                 else
 373                         return usb_rcvctrlpipe(udev, epnum);
 374         }
 375
 376         if (usb_endpoint_xfer_bulk(epd)) {
 377                 if (dir == USBIP_DIR_OUT)
 378                         return usb_sndbulkpipe(udev, epnum);
 379                 else
 380                         return usb_rcvbulkpipe(udev, epnum);
 381         }
 382
 383         if (usb_endpoint_xfer_int(epd)) {
 384                 if (dir == USBIP_DIR_OUT)
 385                         return usb_sndintpipe(udev, epnum);
 386                 else
 387                         return usb_rcvintpipe(udev, epnum);
 388         }
 389
 390         if (usb_endpoint_xfer_isoc(epd)) {
 391                 if (dir == USBIP_DIR_OUT)
 392                         return usb_sndisocpipe(udev, epnum);
 393                 else
 394                         return usb_rcvisocpipe(udev, epnum);
 395         }
 396
 397         /* NOT REACHED */
 398         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 399         return 0;
 400 }
 401
 402 static void masking_bogus_flags(struct urb *urb)
 403 {
 404         int                             xfertype;
 405         struct usb_device               *dev;
 406         struct usb_host_endpoint        *ep;
 407         int                             is_out;
 408         unsigned int    allowed;
 409
 410         if (!urb || urb->hcpriv || !urb->complete)
 411                 return;
 412         dev = urb->dev;
 413         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 414                 return;
 415
 416         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 417                 [usb_pipeendpoint(urb->pipe)];
 418         if (!ep)
 419                 return;
 420
 421         xfertype = usb_endpoint_type(&ep->desc);
 422         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 423                 struct usb_ctrlrequest *setup =
 424                         (struct usb_ctrlrequest *) urb->setup_packet;
 425
 426                 if (!setup)
 427                         return;
 428                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 429                         !setup->wLength;
 430         } else {
 431                 is_out = usb_endpoint_dir_out(&ep->desc);
 432         }
 433
 434         /* enforce simple/standard policy */
 435         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 436                    URB_DIR_MASK | URB_FREE_BUFFER);
 437         switch (xfertype) {
 438         case USB_ENDPOINT_XFER_BULK:
 439                 if (is_out)
 440                         allowed |= URB_ZERO_PACKET;
 441                 /* FALLTHROUGH */
 442         case USB_ENDPOINT_XFER_CONTROL:
 443                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 444                 /* FALLTHROUGH */
 445         default:                        /* all non-iso endpoints */
 446                 if (!is_out)
 447                         allowed |= URB_SHORT_NOT_OK;
 448                 break;
 449         case USB_ENDPOINT_XFER_ISOC:
 450                 allowed |= URB_ISO_ASAP;
 451                 break;
 452         }
 453         urb->transfer_flags &= allowed;
 454 }
 455
 456 static void stub_recv_cmd_submit(struct stub_device *sdev,
 457                                  struct usbip_header *pdu)
 458 {
 459         int ret;
 460         struct stub_priv *priv;
 461         struct usbip_device *ud = &sdev->ud;
 462         struct usb_device *udev = sdev->udev;
 463         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 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                 dev_err(&sdev->interface->dev, "malloc urb\n");
 478                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 479                 return;
 480         }
 481
 482         /* allocate urb transfer buffer, if needed */
 483         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 484                 priv->urb->transfer_buffer =
 485                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 486                                 GFP_KERNEL);
 487                 if (!priv->urb->transfer_buffer) {
 488                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 489                         return;
 490                 }
 491         }
 492
 493         /* copy urb setup packet */
 494         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 495                                           GFP_KERNEL);
 496         if (!priv->urb->setup_packet) {
 497                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 498                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 499                 return;
 500         }
 501
 502         /* set other members from the base header of pdu */
 503         priv->urb->context                = (void *) priv;
 504         priv->urb->dev                    = udev;
 505         priv->urb->pipe                   = pipe;
 506         priv->urb->complete               = stub_complete;
 507
 508         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 509
 510
 511         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 512                 return;
 513
 514         if (usbip_recv_iso(ud, priv->urb) < 0)
 515                 return;
 516
 517         /* no need to submit an intercepted request, but harmless? */
 518         tweak_special_requests(priv->urb);
 519
 520         masking_bogus_flags(priv->urb);
 521         /* urb is now ready to submit */
 522         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 523
 524         if (ret == 0)
 525                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 526                                   pdu->base.seqnum);
 527         else {
 528                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 529                 usbip_dump_header(pdu);
 530                 usbip_dump_urb(priv->urb);
 531
 532                 /*
 533                  * Pessimistic.
 534                  * This connection will be discarded.
 535                  */
 536                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 537         }
 538
 539         usbip_dbg_stub_rx("Leave\n");
 540         return;
 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->interface->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 }