sys/dev/usb/usb_handle_request.c

   1 /* $FreeBSD$ */
   2 /*-
   3  * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/stdint.h>
  28 #include <sys/stddef.h>
  29 #include <sys/param.h>
  30 #include <sys/queue.h>
  31 #include <sys/types.h>
  32 #include <sys/systm.h>
  33 #include <sys/kernel.h>
  34 #include <sys/bus.h>
  35 #include <sys/module.h>
  36 #include <sys/lock.h>
  37 #include <sys/mutex.h>
  38 #include <sys/condvar.h>
  39 #include <sys/sysctl.h>
  40 #include <sys/sx.h>
  41 #include <sys/unistd.h>
  42 #include <sys/callout.h>
  43 #include <sys/malloc.h>
  44 #include <sys/priv.h>
  45
  46 #include <dev/usb/usb.h>
  47 #include <dev/usb/usbdi.h>
  48 #include <dev/usb/usbdi_util.h>
  49 #include "usb_if.h"
  50
  51 #define USB_DEBUG_VAR usb_debug
  52
  53 #include <dev/usb/usb_core.h>
  54 #include <dev/usb/usb_process.h>
  55 #include <dev/usb/usb_busdma.h>
  56 #include <dev/usb/usb_transfer.h>
  57 #include <dev/usb/usb_device.h>
  58 #include <dev/usb/usb_debug.h>
  59 #include <dev/usb/usb_dynamic.h>
  60 #include <dev/usb/usb_hub.h>
  61
  62 #include <dev/usb/usb_controller.h>
  63 #include <dev/usb/usb_bus.h>
  64
  65 /* function prototypes */
  66
  67 static uint8_t usb_handle_get_stall(struct usb_device *, uint8_t);
  68 static usb_error_t       usb_handle_remote_wakeup(struct usb_xfer *, uint8_t);
  69 static usb_error_t       usb_handle_request(struct usb_xfer *);
  70 static usb_error_t       usb_handle_set_config(struct usb_xfer *, uint8_t);
  71 static usb_error_t       usb_handle_set_stall(struct usb_xfer *, uint8_t,
  72                             uint8_t);
  73 static usb_error_t       usb_handle_iface_request(struct usb_xfer *, void **,
  74                             uint16_t *, struct usb_device_request, uint16_t,
  75                             uint8_t);
  76
  77 /*------------------------------------------------------------------------*
  78  *      usb_handle_request_callback
  79  *
  80  * This function is the USB callback for generic USB Device control
  81  * transfers.
  82  *------------------------------------------------------------------------*/
  83 void
  84 usb_handle_request_callback(struct usb_xfer *xfer, usb_error_t error)
  85 {
  86         usb_error_t err;
  87
  88         /* check the current transfer state */
  89
  90         switch (USB_GET_STATE(xfer)) {
  91         case USB_ST_SETUP:
  92         case USB_ST_TRANSFERRED:
  93
  94                 /* handle the request */
  95                 err = usb_handle_request(xfer);
  96
  97                 if (err) {
  98
  99                         if (err == USB_ERR_BAD_CONTEXT) {
 100                                 /* we need to re-setup the control transfer */
 101                                 usb_needs_explore(xfer->xroot->bus, 0);
 102                                 break;
 103                         }
 104                         goto tr_restart;
 105                 }
 106                 usbd_transfer_submit(xfer);
 107                 break;
 108
 109         default:
 110                 /* check if a control transfer is active */
 111                 if (xfer->flags_int.control_rem != 0xFFFF) {
 112                         /* handle the request */
 113                         err = usb_handle_request(xfer);
 114                 }
 115                 if (xfer->error != USB_ERR_CANCELLED) {
 116                         /* should not happen - try stalling */
 117                         goto tr_restart;
 118                 }
 119                 break;
 120         }
 121         return;
 122
 123 tr_restart:
 124         /*
 125          * If a control transfer is active, stall it, and wait for the
 126          * next control transfer.
 127          */
 128         usbd_xfer_set_frame_len(xfer, 0, sizeof(struct usb_device_request));
 129         xfer->nframes = 1;
 130         xfer->flags.manual_status = 1;
 131         xfer->flags.force_short_xfer = 0;
 132         usbd_xfer_set_stall(xfer);      /* cancel previous transfer, if any */
 133         usbd_transfer_submit(xfer);
 134 }
 135
 136 /*------------------------------------------------------------------------*
 137  *      usb_handle_set_config
 138  *
 139  * Returns:
 140  *    0: Success
 141  * Else: Failure
 142  *------------------------------------------------------------------------*/
 143 static usb_error_t
 144 usb_handle_set_config(struct usb_xfer *xfer, uint8_t conf_no)
 145 {
 146         struct usb_device *udev = xfer->xroot->udev;
 147         usb_error_t err = 0;
 148
 149         /*
 150          * We need to protect against other threads doing probe and
 151          * attach:
 152          */
 153         USB_XFER_UNLOCK(xfer);
 154
 155         usbd_enum_lock(udev);
 156
 157         if (conf_no == USB_UNCONFIG_NO) {
 158                 conf_no = USB_UNCONFIG_INDEX;
 159         } else {
 160                 /*
 161                  * The relationship between config number and config index
 162                  * is very simple in our case:
 163                  */
 164                 conf_no--;
 165         }
 166
 167         if (usbd_set_config_index(udev, conf_no)) {
 168                 DPRINTF("set config %d failed\n", conf_no);
 169                 err = USB_ERR_STALLED;
 170                 goto done;
 171         }
 172         if (usb_probe_and_attach(udev, USB_IFACE_INDEX_ANY)) {
 173                 DPRINTF("probe and attach failed\n");
 174                 err = USB_ERR_STALLED;
 175                 goto done;
 176         }
 177 done:
 178         usbd_enum_unlock(udev);
 179         USB_XFER_LOCK(xfer);
 180         return (err);
 181 }
 182
 183 static usb_error_t
 184 usb_check_alt_setting(struct usb_device *udev,
 185      struct usb_interface *iface, uint8_t alt_index)
 186 {
 187         uint8_t do_unlock;
 188         usb_error_t err = 0;
 189
 190         /* automatic locking */
 191         if (usbd_enum_is_locked(udev)) {
 192                 do_unlock = 0;
 193         } else {
 194                 do_unlock = 1;
 195                 usbd_enum_lock(udev);
 196         }
 197
 198         if (alt_index >= usbd_get_no_alts(udev->cdesc, iface->idesc))
 199                 err = USB_ERR_INVAL;
 200
 201         if (do_unlock)
 202                 usbd_enum_unlock(udev);
 203
 204         return (err);
 205 }
 206
 207 /*------------------------------------------------------------------------*
 208  *      usb_handle_iface_request
 209  *
 210  * Returns:
 211  *    0: Success
 212  * Else: Failure
 213  *------------------------------------------------------------------------*/
 214 static usb_error_t
 215 usb_handle_iface_request(struct usb_xfer *xfer,
 216     void **ppdata, uint16_t *plen,
 217     struct usb_device_request req, uint16_t off, uint8_t state)
 218 {
 219         struct usb_interface *iface;
 220         struct usb_interface *iface_parent;     /* parent interface */
 221         struct usb_device *udev = xfer->xroot->udev;
 222         int error;
 223         uint8_t iface_index;
 224         uint8_t temp_state;
 225
 226         if ((req.bmRequestType & 0x1F) == UT_INTERFACE) {
 227                 iface_index = req.wIndex[0];    /* unicast */
 228         } else {
 229                 iface_index = 0;        /* broadcast */
 230         }
 231
 232         /*
 233          * We need to protect against other threads doing probe and
 234          * attach:
 235          */
 236         USB_XFER_UNLOCK(xfer);
 237
 238         usbd_enum_lock(udev);
 239
 240         error = ENXIO;
 241
 242 tr_repeat:
 243         iface = usbd_get_iface(udev, iface_index);
 244         if ((iface == NULL) ||
 245             (iface->idesc == NULL)) {
 246                 /* end of interfaces non-existing interface */
 247                 goto tr_stalled;
 248         }
 249         /* set initial state */
 250
 251         temp_state = state;
 252
 253         /* forward request to interface, if any */
 254
 255         if ((error != 0) &&
 256             (error != ENOTTY) &&
 257             (iface->subdev != NULL) &&
 258             device_is_attached(iface->subdev)) {
 259 #if 0
 260                 DEVMETHOD(usb_handle_request, NULL);    /* dummy */
 261 #endif
 262                 error = USB_HANDLE_REQUEST(iface->subdev,
 263                     &req, ppdata, plen,
 264                     off, &temp_state);
 265         }
 266         iface_parent = usbd_get_iface(udev, iface->parent_iface_index);
 267
 268         if ((iface_parent == NULL) ||
 269             (iface_parent->idesc == NULL)) {
 270                 /* non-existing interface */
 271                 iface_parent = NULL;
 272         }
 273         /* forward request to parent interface, if any */
 274
 275         if ((error != 0) &&
 276             (error != ENOTTY) &&
 277             (iface_parent != NULL) &&
 278             (iface_parent->subdev != NULL) &&
 279             ((req.bmRequestType & 0x1F) == UT_INTERFACE) &&
 280             (iface_parent->subdev != iface->subdev) &&
 281             device_is_attached(iface_parent->subdev)) {
 282                 error = USB_HANDLE_REQUEST(iface_parent->subdev,
 283                     &req, ppdata, plen, off, &temp_state);
 284         }
 285         if (error == 0) {
 286                 /* negativly adjust pointer and length */
 287                 *ppdata = ((uint8_t *)(*ppdata)) - off;
 288                 *plen += off;
 289
 290                 if ((state == USB_HR_NOT_COMPLETE) &&
 291                     (temp_state == USB_HR_COMPLETE_OK))
 292                         goto tr_short;
 293                 else
 294                         goto tr_valid;
 295         } else if (error == ENOTTY) {
 296                 goto tr_stalled;
 297         }
 298         if ((req.bmRequestType & 0x1F) != UT_INTERFACE) {
 299                 iface_index++;          /* iterate */
 300                 goto tr_repeat;
 301         }
 302         if (state != USB_HR_NOT_COMPLETE) {
 303                 /* we are complete */
 304                 goto tr_valid;
 305         }
 306         switch (req.bmRequestType) {
 307         case UT_WRITE_INTERFACE:
 308                 switch (req.bRequest) {
 309                 case UR_SET_INTERFACE:
 310                         /*
 311                          * We assume that the endpoints are the same
 312                          * accross the alternate settings.
 313                          *
 314                          * Reset the endpoints, because re-attaching
 315                          * only a part of the device is not possible.
 316                          */
 317                         error = usb_check_alt_setting(udev,
 318                             iface, req.wValue[0]);
 319                         if (error) {
 320                                 DPRINTF("alt setting does not exist %s\n",
 321                                     usbd_errstr(error));
 322                                 goto tr_stalled;
 323                         }
 324                         error = usb_reset_iface_endpoints(udev, iface_index);
 325                         if (error) {
 326                                 DPRINTF("alt setting failed %s\n",
 327                                     usbd_errstr(error));
 328                                 goto tr_stalled;
 329                         }
 330                         /* update the current alternate setting */
 331                         iface->alt_index = req.wValue[0];
 332                         break;
 333
 334                 default:
 335                         goto tr_stalled;
 336                 }
 337                 break;
 338
 339         case UT_READ_INTERFACE:
 340                 switch (req.bRequest) {
 341                 case UR_GET_INTERFACE:
 342                         *ppdata = &iface->alt_index;
 343                         *plen = 1;
 344                         break;
 345
 346                 default:
 347                         goto tr_stalled;
 348                 }
 349                 break;
 350         default:
 351                 goto tr_stalled;
 352         }
 353 tr_valid:
 354         usbd_enum_unlock(udev);
 355         USB_XFER_LOCK(xfer);
 356         return (0);
 357
 358 tr_short:
 359         usbd_enum_unlock(udev);
 360         USB_XFER_LOCK(xfer);
 361         return (USB_ERR_SHORT_XFER);
 362
 363 tr_stalled:
 364         usbd_enum_unlock(udev);
 365         USB_XFER_LOCK(xfer);
 366         return (USB_ERR_STALLED);
 367 }
 368
 369 /*------------------------------------------------------------------------*
 370  *      usb_handle_stall
 371  *
 372  * Returns:
 373  *    0: Success
 374  * Else: Failure
 375  *------------------------------------------------------------------------*/
 376 static usb_error_t
 377 usb_handle_set_stall(struct usb_xfer *xfer, uint8_t ep, uint8_t do_stall)
 378 {
 379         struct usb_device *udev = xfer->xroot->udev;
 380         usb_error_t err;
 381
 382         USB_XFER_UNLOCK(xfer);
 383         err = usbd_set_endpoint_stall(udev,
 384             usbd_get_ep_by_addr(udev, ep), do_stall);
 385         USB_XFER_LOCK(xfer);
 386         return (err);
 387 }
 388
 389 /*------------------------------------------------------------------------*
 390  *      usb_handle_get_stall
 391  *
 392  * Returns:
 393  *    0: Success
 394  * Else: Failure
 395  *------------------------------------------------------------------------*/
 396 static uint8_t
 397 usb_handle_get_stall(struct usb_device *udev, uint8_t ea_val)
 398 {
 399         struct usb_endpoint *ep;
 400         uint8_t halted;
 401
 402         ep = usbd_get_ep_by_addr(udev, ea_val);
 403         if (ep == NULL) {
 404                 /* nothing to do */
 405                 return (0);
 406         }
 407         USB_BUS_LOCK(udev->bus);
 408         halted = ep->is_stalled;
 409         USB_BUS_UNLOCK(udev->bus);
 410
 411         return (halted);
 412 }
 413
 414 /*------------------------------------------------------------------------*
 415  *      usb_handle_remote_wakeup
 416  *
 417  * Returns:
 418  *    0: Success
 419  * Else: Failure
 420  *------------------------------------------------------------------------*/
 421 static usb_error_t
 422 usb_handle_remote_wakeup(struct usb_xfer *xfer, uint8_t is_on)
 423 {
 424         struct usb_device *udev;
 425         struct usb_bus *bus;
 426
 427         udev = xfer->xroot->udev;
 428         bus = udev->bus;
 429
 430         USB_BUS_LOCK(bus);
 431
 432         if (is_on) {
 433                 udev->flags.remote_wakeup = 1;
 434         } else {
 435                 udev->flags.remote_wakeup = 0;
 436         }
 437
 438         USB_BUS_UNLOCK(bus);
 439
 440 #if USB_HAVE_POWERD
 441         /* In case we are out of sync, update the power state. */
 442         usb_bus_power_update(udev->bus);
 443 #endif
 444         return (0);                     /* success */
 445 }
 446
 447 /*------------------------------------------------------------------------*
 448  *      usb_handle_request
 449  *
 450  * Internal state sequence:
 451  *
 452  * USB_HR_NOT_COMPLETE -> USB_HR_COMPLETE_OK v USB_HR_COMPLETE_ERR
 453  *
 454  * Returns:
 455  * 0: Ready to start hardware
 456  * Else: Stall current transfer, if any
 457  *------------------------------------------------------------------------*/
 458 static usb_error_t
 459 usb_handle_request(struct usb_xfer *xfer)
 460 {
 461         struct usb_device_request req;
 462         struct usb_device *udev;
 463         const void *src_zcopy;          /* zero-copy source pointer */
 464         const void *src_mcopy;          /* non zero-copy source pointer */
 465         uint16_t off;                   /* data offset */
 466         uint16_t rem;                   /* data remainder */
 467         uint16_t max_len;               /* max fragment length */
 468         uint16_t wValue;
 469         uint8_t state;
 470         uint8_t is_complete = 1;
 471         usb_error_t err;
 472         union {
 473                 uWord   wStatus;
 474                 uint8_t buf[2];
 475         }     temp;
 476
 477         /*
 478          * Filter the USB transfer state into
 479          * something which we understand:
 480          */
 481
 482         switch (USB_GET_STATE(xfer)) {
 483         case USB_ST_SETUP:
 484                 state = USB_HR_NOT_COMPLETE;
 485
 486                 if (!xfer->flags_int.control_act) {
 487                         /* nothing to do */
 488                         goto tr_stalled;
 489                 }
 490                 break;
 491         case USB_ST_TRANSFERRED:
 492                 if (!xfer->flags_int.control_act) {
 493                         state = USB_HR_COMPLETE_OK;
 494                 } else {
 495                         state = USB_HR_NOT_COMPLETE;
 496                 }
 497                 break;
 498         default:
 499                 state = USB_HR_COMPLETE_ERR;
 500                 break;
 501         }
 502
 503         /* reset frame stuff */
 504
 505         usbd_xfer_set_frame_len(xfer, 0, 0);
 506
 507         usbd_xfer_set_frame_offset(xfer, 0, 0);
 508         usbd_xfer_set_frame_offset(xfer, sizeof(req), 1);
 509
 510         /* get the current request, if any */
 511
 512         usbd_copy_out(xfer->frbuffers, 0, &req, sizeof(req));
 513
 514         if (xfer->flags_int.control_rem == 0xFFFF) {
 515                 /* first time - not initialised */
 516                 rem = UGETW(req.wLength);
 517                 off = 0;
 518         } else {
 519                 /* not first time - initialised */
 520                 rem = xfer->flags_int.control_rem;
 521                 off = UGETW(req.wLength) - rem;
 522         }
 523
 524         /* set some defaults */
 525
 526         max_len = 0;
 527         src_zcopy = NULL;
 528         src_mcopy = NULL;
 529         udev = xfer->xroot->udev;
 530
 531         /* get some request fields decoded */
 532
 533         wValue = UGETW(req.wValue);
 534
 535         DPRINTF("req 0x%02x 0x%02x 0x%04x 0x%04x "
 536             "off=0x%x rem=0x%x, state=%d\n", req.bmRequestType,
 537             req.bRequest, wValue, UGETW(req.wIndex), off, rem, state);
 538
 539         /* demultiplex the control request */
 540
 541         switch (req.bmRequestType) {
 542         case UT_READ_DEVICE:
 543                 if (state != USB_HR_NOT_COMPLETE) {
 544                         break;
 545                 }
 546                 switch (req.bRequest) {
 547                 case UR_GET_DESCRIPTOR:
 548                         goto tr_handle_get_descriptor;
 549                 case UR_GET_CONFIG:
 550                         goto tr_handle_get_config;
 551                 case UR_GET_STATUS:
 552                         goto tr_handle_get_status;
 553                 default:
 554                         goto tr_stalled;
 555                 }
 556                 break;
 557
 558         case UT_WRITE_DEVICE:
 559                 switch (req.bRequest) {
 560                 case UR_SET_ADDRESS:
 561                         goto tr_handle_set_address;
 562                 case UR_SET_CONFIG:
 563                         goto tr_handle_set_config;
 564                 case UR_CLEAR_FEATURE:
 565                         switch (wValue) {
 566                         case UF_DEVICE_REMOTE_WAKEUP:
 567                                 goto tr_handle_clear_wakeup;
 568                         default:
 569                                 goto tr_stalled;
 570                         }
 571                         break;
 572                 case UR_SET_FEATURE:
 573                         switch (wValue) {
 574                         case UF_DEVICE_REMOTE_WAKEUP:
 575                                 goto tr_handle_set_wakeup;
 576                         default:
 577                                 goto tr_stalled;
 578                         }
 579                         break;
 580                 default:
 581                         goto tr_stalled;
 582                 }
 583                 break;
 584
 585         case UT_WRITE_ENDPOINT:
 586                 switch (req.bRequest) {
 587                 case UR_CLEAR_FEATURE:
 588                         switch (wValue) {
 589                         case UF_ENDPOINT_HALT:
 590                                 goto tr_handle_clear_halt;
 591                         default:
 592                                 goto tr_stalled;
 593                         }
 594                         break;
 595                 case UR_SET_FEATURE:
 596                         switch (wValue) {
 597                         case UF_ENDPOINT_HALT:
 598                                 goto tr_handle_set_halt;
 599                         default:
 600                                 goto tr_stalled;
 601                         }
 602                         break;
 603                 default:
 604                         goto tr_stalled;
 605                 }
 606                 break;
 607
 608         case UT_READ_ENDPOINT:
 609                 switch (req.bRequest) {
 610                 case UR_GET_STATUS:
 611                         goto tr_handle_get_ep_status;
 612                 default:
 613                         goto tr_stalled;
 614                 }
 615                 break;
 616         default:
 617                 /* we use "USB_ADD_BYTES" to de-const the src_zcopy */
 618                 err = usb_handle_iface_request(xfer,
 619                     USB_ADD_BYTES(&src_zcopy, 0),
 620                     &max_len, req, off, state);
 621                 if (err == 0) {
 622                         is_complete = 0;
 623                         goto tr_valid;
 624                 } else if (err == USB_ERR_SHORT_XFER) {
 625                         goto tr_valid;
 626                 }
 627                 /*
 628                  * Reset zero-copy pointer and max length
 629                  * variable in case they were unintentionally
 630                  * set:
 631                  */
 632                 src_zcopy = NULL;
 633                 max_len = 0;
 634
 635                 /*
 636                  * Check if we have a vendor specific
 637                  * descriptor:
 638                  */
 639                 goto tr_handle_get_descriptor;
 640         }
 641         goto tr_valid;
 642
 643 tr_handle_get_descriptor:
 644         err = (usb_temp_get_desc_p) (udev, &req, &src_zcopy, &max_len);
 645         if (err)
 646                 goto tr_stalled;
 647         if (src_zcopy == NULL)
 648                 goto tr_stalled;
 649         goto tr_valid;
 650
 651 tr_handle_get_config:
 652         temp.buf[0] = udev->curr_config_no;
 653         src_mcopy = temp.buf;
 654         max_len = 1;
 655         goto tr_valid;
 656
 657 tr_handle_get_status:
 658
 659         wValue = 0;
 660
 661         USB_BUS_LOCK(udev->bus);
 662         if (udev->flags.remote_wakeup) {
 663                 wValue |= UDS_REMOTE_WAKEUP;
 664         }
 665         if (udev->flags.self_powered) {
 666                 wValue |= UDS_SELF_POWERED;
 667         }
 668         USB_BUS_UNLOCK(udev->bus);
 669
 670         USETW(temp.wStatus, wValue);
 671         src_mcopy = temp.wStatus;
 672         max_len = sizeof(temp.wStatus);
 673         goto tr_valid;
 674
 675 tr_handle_set_address:
 676         if (state == USB_HR_NOT_COMPLETE) {
 677                 if (wValue >= 0x80) {
 678                         /* invalid value */
 679                         goto tr_stalled;
 680                 } else if (udev->curr_config_no != 0) {
 681                         /* we are configured ! */
 682                         goto tr_stalled;
 683                 }
 684         } else if (state != USB_HR_NOT_COMPLETE) {
 685                 udev->address = (wValue & 0x7F);
 686                 goto tr_bad_context;
 687         }
 688         goto tr_valid;
 689
 690 tr_handle_set_config:
 691         if (state == USB_HR_NOT_COMPLETE) {
 692                 if (usb_handle_set_config(xfer, req.wValue[0])) {
 693                         goto tr_stalled;
 694                 }
 695         }
 696         goto tr_valid;
 697
 698 tr_handle_clear_halt:
 699         if (state == USB_HR_NOT_COMPLETE) {
 700                 if (usb_handle_set_stall(xfer, req.wIndex[0], 0)) {
 701                         goto tr_stalled;
 702                 }
 703         }
 704         goto tr_valid;
 705
 706 tr_handle_clear_wakeup:
 707         if (state == USB_HR_NOT_COMPLETE) {
 708                 if (usb_handle_remote_wakeup(xfer, 0)) {
 709                         goto tr_stalled;
 710                 }
 711         }
 712         goto tr_valid;
 713
 714 tr_handle_set_halt:
 715         if (state == USB_HR_NOT_COMPLETE) {
 716                 if (usb_handle_set_stall(xfer, req.wIndex[0], 1)) {
 717                         goto tr_stalled;
 718                 }
 719         }
 720         goto tr_valid;
 721
 722 tr_handle_set_wakeup:
 723         if (state == USB_HR_NOT_COMPLETE) {
 724                 if (usb_handle_remote_wakeup(xfer, 1)) {
 725                         goto tr_stalled;
 726                 }
 727         }
 728         goto tr_valid;
 729
 730 tr_handle_get_ep_status:
 731         if (state == USB_HR_NOT_COMPLETE) {
 732                 temp.wStatus[0] =
 733                     usb_handle_get_stall(udev, req.wIndex[0]);
 734                 temp.wStatus[1] = 0;
 735                 src_mcopy = temp.wStatus;
 736                 max_len = sizeof(temp.wStatus);
 737         }
 738         goto tr_valid;
 739
 740 tr_valid:
 741         if (state != USB_HR_NOT_COMPLETE) {
 742                 goto tr_stalled;
 743         }
 744         /* subtract offset from length */
 745
 746         max_len -= off;
 747
 748         /* Compute the real maximum data length */
 749
 750         if (max_len > xfer->max_data_length) {
 751                 max_len = usbd_xfer_max_len(xfer);
 752         }
 753         if (max_len > rem) {
 754                 max_len = rem;
 755         }
 756         /*
 757          * If the remainder is greater than the maximum data length,
 758          * we need to truncate the value for the sake of the
 759          * comparison below:
 760          */
 761         if (rem > xfer->max_data_length) {
 762                 rem = usbd_xfer_max_len(xfer);
 763         }
 764         if ((rem != max_len) && (is_complete != 0)) {
 765                 /*
 766                  * If we don't transfer the data we can transfer, then
 767                  * the transfer is short !
 768                  */
 769                 xfer->flags.force_short_xfer = 1;
 770                 xfer->nframes = 2;
 771         } else {
 772                 /*
 773                  * Default case
 774                  */
 775                 xfer->flags.force_short_xfer = 0;
 776                 xfer->nframes = max_len ? 2 : 1;
 777         }
 778         if (max_len > 0) {
 779                 if (src_mcopy) {
 780                         src_mcopy = USB_ADD_BYTES(src_mcopy, off);
 781                         usbd_copy_in(xfer->frbuffers + 1, 0,
 782                             src_mcopy, max_len);
 783                         usbd_xfer_set_frame_len(xfer, 1, max_len);
 784                 } else {
 785                         usbd_xfer_set_frame_data(xfer, 1,
 786                             USB_ADD_BYTES(src_zcopy, off), max_len);
 787                 }
 788         } else {
 789                 /* the end is reached, send status */
 790                 xfer->flags.manual_status = 0;
 791                 usbd_xfer_set_frame_len(xfer, 1, 0);
 792         }
 793         DPRINTF("success\n");
 794         return (0);                     /* success */
 795
 796 tr_stalled:
 797         DPRINTF("%s\n", (state != USB_HR_NOT_COMPLETE) ?
 798             "complete" : "stalled");
 799         return (USB_ERR_STALLED);
 800
 801 tr_bad_context:
 802         DPRINTF("bad context\n");
 803         return (USB_ERR_BAD_CONTEXT);
 804 }