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 <linux/slab.h>
  21 #include <linux/kthread.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25 #include <linux/usb/hcd.h>
  26
  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                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
 106                                         urb->dev->devnum, target_endp, ret);
 107         else
 108                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
 109                                         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", interface,
 126                                                                 alternate);
 127
 128         ret = usb_set_interface(urb->dev, interface, alternate);
 129         if (ret < 0)
 130                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
 131                                         interface, alternate, ret);
 132         else
 133                 usbip_uinfo("set_interface done: inf %u alt %u\n",
 134                                                         interface,
 135                                                         alternate);
 136
 137         return ret;
 138 }
 139
 140 static int tweak_set_configuration_cmd(struct urb *urb)
 141 {
 142         struct usb_ctrlrequest *req;
 143         __u16 config;
 144
 145         req = (struct usb_ctrlrequest *) urb->setup_packet;
 146         config = le16_to_cpu(req->wValue);
 147
 148         /*
 149          * I have never seen a multi-config device. Very rare.
 150          * For most devices, this will be called to choose a default
 151          * configuration only once in an initialization phase.
 152          *
 153          * set_configuration may change a device configuration and its device
 154          * drivers will be unbound and assigned for a new device configuration.
 155          * This means this usbip driver will be also unbound when called, then
 156          * eventually reassigned to the device as far as driver matching
 157          * condition is kept.
 158          *
 159          * Unfortunatelly, an existing usbip connection will be dropped
 160          * due to this driver unbinding. So, skip here.
 161          * A user may need to set a special configuration value before
 162          * exporting the device.
 163          */
 164         usbip_uinfo("set_configuration (%d) to %s\n", config,
 165                                                 dev_name(&urb->dev->dev));
 166         usbip_uinfo("but, skip!\n");
 167
 168         return 0;
 169         /* return usb_driver_set_configuration(urb->dev, config); */
 170 }
 171
 172 static int tweak_reset_device_cmd(struct urb *urb)
 173 {
 174         struct usb_ctrlrequest *req;
 175         __u16 value;
 176         __u16 index;
 177         int ret;
 178
 179         req = (struct usb_ctrlrequest *) urb->setup_packet;
 180         value = le16_to_cpu(req->wValue);
 181         index = le16_to_cpu(req->wIndex);
 182
 183         usbip_uinfo("reset_device (port %d) to %s\n", index,
 184                                                 dev_name(&urb->dev->dev));
 185
 186         /* all interfaces should be owned by usbip driver, so just reset it.  */
 187         ret = usb_lock_device_for_reset(urb->dev, NULL);
 188         if (ret < 0) {
 189                 dev_err(&urb->dev->dev, "lock for reset\n");
 190                 return ret;
 191         }
 192
 193         /* try to reset the device */
 194         ret = usb_reset_device(urb->dev);
 195         if (ret < 0)
 196                 dev_err(&urb->dev->dev, "device reset\n");
 197
 198         usb_unlock_device(urb->dev);
 199
 200         return ret;
 201 }
 202
 203 /*
 204  * clear_halt, set_interface, and set_configuration require special tricks.
 205  */
 206 static void tweak_special_requests(struct urb *urb)
 207 {
 208         if (!urb || !urb->setup_packet)
 209                 return;
 210
 211         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 212                 return;
 213
 214         if (is_clear_halt_cmd(urb))
 215                 /* tweak clear_halt */
 216                  tweak_clear_halt_cmd(urb);
 217
 218         else if (is_set_interface_cmd(urb))
 219                 /* tweak set_interface */
 220                 tweak_set_interface_cmd(urb);
 221
 222         else if (is_set_configuration_cmd(urb))
 223                 /* tweak set_configuration */
 224                 tweak_set_configuration_cmd(urb);
 225
 226         else if (is_reset_device_cmd(urb))
 227                 tweak_reset_device_cmd(urb);
 228         else
 229                 usbip_dbg_stub_rx("no need to tweak\n");
 230 }
 231
 232 /*
 233  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 234  * By unlinking the urb asynchronously, stub_rx can continuously
 235  * process coming urbs.  Even if the urb is unlinked, its completion
 236  * handler will be called and stub_tx will send a return pdu.
 237  *
 238  * See also comments about unlinking strategy in vhci_hcd.c.
 239  */
 240 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 241                                                 struct usbip_header *pdu)
 242 {
 243         unsigned long flags;
 244
 245         struct stub_priv *priv;
 246
 247
 248         spin_lock_irqsave(&sdev->priv_lock, flags);
 249
 250         list_for_each_entry(priv, &sdev->priv_init, list) {
 251                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 252                         int ret;
 253
 254                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 255                                  priv->urb);
 256
 257                         /*
 258                          * This matched urb is not completed yet (i.e., be in
 259                          * flight in usb hcd hardware/driver). Now we are
 260                          * cancelling it. The unlinking flag means that we are
 261                          * now not going to return the normal result pdu of a
 262                          * submission request, but going to return a result pdu
 263                          * of the unlink request.
 264                          */
 265                         priv->unlinking = 1;
 266
 267                         /*
 268                          * In the case that unlinking flag is on, prev->seqnum
 269                          * is changed from the seqnum of the cancelling urb to
 270                          * the seqnum of the unlink request. This will be used
 271                          * to make the result pdu of the unlink request.
 272                          */
 273                         priv->seqnum = pdu->base.seqnum;
 274
 275                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 276
 277                         /*
 278                          * usb_unlink_urb() is now out of spinlocking to avoid
 279                          * spinlock recursion since stub_complete() is
 280                          * sometimes called in this context but not in the
 281                          * interrupt context.  If stub_complete() is executed
 282                          * before we call usb_unlink_urb(), usb_unlink_urb()
 283                          * will return an error value. In this case, stub_tx
 284                          * will return the result pdu of this unlink request
 285                          * though submission is completed and actual unlinking
 286                          * is not executed. OK?
 287                          */
 288                         /* In the above case, urb->status is not -ECONNRESET,
 289                          * so a driver in a client host will know the failure
 290                          * of the unlink request ?
 291                          */
 292                         ret = usb_unlink_urb(priv->urb);
 293                         if (ret != -EINPROGRESS)
 294                                 dev_err(&priv->urb->dev->dev,
 295                                         "failed to unlink a urb %p, ret %d\n",
 296                                         priv->urb, ret);
 297                         return 0;
 298                 }
 299         }
 300
 301         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 302                                                 pdu->u.cmd_unlink.seqnum);
 303
 304         /*
 305          * The urb of the unlink target is not found in priv_init queue. It was
 306          * already completed and its results is/was going to be sent by a
 307          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 308          * return the completeness of this unlink request to vhci_hcd.
 309          */
 310         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 311
 312         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 313
 314
 315         return 0;
 316 }
 317
 318 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 319 {
 320         struct usbip_device *ud = &sdev->ud;
 321
 322         if (pdu->base.devid == sdev->devid) {
 323                 spin_lock(&ud->lock);
 324                 if (ud->status == SDEV_ST_USED) {
 325                         /* A request is valid. */
 326                         spin_unlock(&ud->lock);
 327                         return 1;
 328                 }
 329                 spin_unlock(&ud->lock);
 330         }
 331
 332         return 0;
 333 }
 334
 335 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 336                                          struct usbip_header *pdu)
 337 {
 338         struct stub_priv *priv;
 339         struct usbip_device *ud = &sdev->ud;
 340         unsigned long flags;
 341
 342         spin_lock_irqsave(&sdev->priv_lock, flags);
 343
 344         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 345         if (!priv) {
 346                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 347                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 348                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 349                 return NULL;
 350         }
 351
 352         priv->seqnum = pdu->base.seqnum;
 353         priv->sdev = sdev;
 354
 355         /*
 356          * After a stub_priv is linked to a list_head,
 357          * our error handler can free allocated data.
 358          */
 359         list_add_tail(&priv->list, &sdev->priv_init);
 360
 361         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 362
 363         return priv;
 364 }
 365
 366 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 367 {
 368         struct usb_device *udev = sdev->udev;
 369         struct usb_host_endpoint *ep;
 370         struct usb_endpoint_descriptor *epd = NULL;
 371
 372         if (dir == USBIP_DIR_IN)
 373                 ep = udev->ep_in[epnum & 0x7f];
 374         else
 375                 ep = udev->ep_out[epnum & 0x7f];
 376         if (!ep) {
 377                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 378                         epnum);
 379                 BUG();
 380         }
 381
 382         epd = &ep->desc;
 383
 384
 385 #if 0
 386         /* epnum 0 is always control */
 387         if (epnum == 0) {
 388                 if (dir == USBIP_DIR_OUT)
 389                         return usb_sndctrlpipe(udev, 0);
 390                 else
 391                         return usb_rcvctrlpipe(udev, 0);
 392         }
 393 #endif
 394
 395         if (usb_endpoint_xfer_control(epd)) {
 396                 if (dir == USBIP_DIR_OUT)
 397                         return usb_sndctrlpipe(udev, epnum);
 398                 else
 399                         return usb_rcvctrlpipe(udev, epnum);
 400         }
 401
 402         if (usb_endpoint_xfer_bulk(epd)) {
 403                 if (dir == USBIP_DIR_OUT)
 404                         return usb_sndbulkpipe(udev, epnum);
 405                 else
 406                         return usb_rcvbulkpipe(udev, epnum);
 407         }
 408
 409         if (usb_endpoint_xfer_int(epd)) {
 410                 if (dir == USBIP_DIR_OUT)
 411                         return usb_sndintpipe(udev, epnum);
 412                 else
 413                         return usb_rcvintpipe(udev, epnum);
 414         }
 415
 416         if (usb_endpoint_xfer_isoc(epd)) {
 417                 if (dir == USBIP_DIR_OUT)
 418                         return usb_sndisocpipe(udev, epnum);
 419                 else
 420                         return usb_rcvisocpipe(udev, epnum);
 421         }
 422
 423         /* NOT REACHED */
 424         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 425         return 0;
 426 }
 427
 428 static void masking_bogus_flags(struct urb *urb)
 429 {
 430         int                             xfertype;
 431         struct usb_device               *dev;
 432         struct usb_host_endpoint        *ep;
 433         int                             is_out;
 434         unsigned int    allowed;
 435
 436         if (!urb || urb->hcpriv || !urb->complete)
 437                 return;
 438         dev = urb->dev;
 439         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 440                 return;
 441
 442         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 443                         [usb_pipeendpoint(urb->pipe)];
 444         if (!ep)
 445                 return;
 446
 447         xfertype = usb_endpoint_type(&ep->desc);
 448         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 449                 struct usb_ctrlrequest *setup =
 450                                 (struct usb_ctrlrequest *) urb->setup_packet;
 451
 452                 if (!setup)
 453                         return;
 454                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 455                                 !setup->wLength;
 456         } else {
 457                 is_out = usb_endpoint_dir_out(&ep->desc);
 458         }
 459
 460         /* enforce simple/standard policy */
 461         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 462                    URB_DIR_MASK | URB_FREE_BUFFER);
 463         switch (xfertype) {
 464         case USB_ENDPOINT_XFER_BULK:
 465                 if (is_out)
 466                         allowed |= URB_ZERO_PACKET;
 467                 /* FALLTHROUGH */
 468         case USB_ENDPOINT_XFER_CONTROL:
 469                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 470                 /* FALLTHROUGH */
 471         default:                        /* all non-iso endpoints */
 472                 if (!is_out)
 473                         allowed |= URB_SHORT_NOT_OK;
 474                 break;
 475         case USB_ENDPOINT_XFER_ISOC:
 476                 allowed |= URB_ISO_ASAP;
 477                 break;
 478         }
 479         urb->transfer_flags &= allowed;
 480 }
 481
 482 static void stub_recv_cmd_submit(struct stub_device *sdev,
 483                                  struct usbip_header *pdu)
 484 {
 485         int ret;
 486         struct stub_priv *priv;
 487         struct usbip_device *ud = &sdev->ud;
 488         struct usb_device *udev = sdev->udev;
 489         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 490
 491
 492         priv = stub_priv_alloc(sdev, pdu);
 493         if (!priv)
 494                 return;
 495
 496         /* setup a urb */
 497         if (usb_pipeisoc(pipe))
 498                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 499                                                                 GFP_KERNEL);
 500         else
 501                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 502
 503         if (!priv->urb) {
 504                 dev_err(&sdev->interface->dev, "malloc urb\n");
 505                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 506                 return;
 507         }
 508
 509         /* set priv->urb->transfer_buffer */
 510         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 511                 priv->urb->transfer_buffer =
 512                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 513                                                                 GFP_KERNEL);
 514                 if (!priv->urb->transfer_buffer) {
 515                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 516                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 517                         return;
 518                 }
 519         }
 520
 521         /* set priv->urb->setup_packet */
 522         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 523                                           GFP_KERNEL);
 524         if (!priv->urb->setup_packet) {
 525                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 526                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 527                 return;
 528         }
 529
 530         /* set other members from the base header of pdu */
 531         priv->urb->context                = (void *) priv;
 532         priv->urb->dev                    = udev;
 533         priv->urb->pipe                   = pipe;
 534         priv->urb->complete               = stub_complete;
 535
 536         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 537
 538
 539         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 540                 return;
 541
 542         if (usbip_recv_iso(ud, priv->urb) < 0)
 543                 return;
 544
 545         /* no need to submit an intercepted request, but harmless? */
 546         tweak_special_requests(priv->urb);
 547
 548         masking_bogus_flags(priv->urb);
 549         /* urb is now ready to submit */
 550         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 551
 552         if (ret == 0)
 553                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 554                                                         pdu->base.seqnum);
 555         else {
 556                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 557                 usbip_dump_header(pdu);
 558                 usbip_dump_urb(priv->urb);
 559
 560                 /*
 561                  * Pessimistic.
 562                  * This connection will be discarded.
 563                  */
 564                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 565         }
 566
 567         usbip_dbg_stub_rx("Leave\n");
 568         return;
 569 }
 570
 571 /* recv a pdu */
 572 static void stub_rx_pdu(struct usbip_device *ud)
 573 {
 574         int ret;
 575         struct usbip_header pdu;
 576         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 577         struct device *dev = &sdev->interface->dev;
 578
 579         usbip_dbg_stub_rx("Enter\n");
 580
 581         memset(&pdu, 0, sizeof(pdu));
 582
 583         /* 1. receive a pdu header */
 584         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 585         if (ret != sizeof(pdu)) {
 586                 dev_err(dev, "recv a header, %d\n", ret);
 587                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 588                 return;
 589         }
 590
 591         usbip_header_correct_endian(&pdu, 0);
 592
 593         if (usbip_dbg_flag_stub_rx)
 594                 usbip_dump_header(&pdu);
 595
 596         if (!valid_request(sdev, &pdu)) {
 597                 dev_err(dev, "recv invalid request\n");
 598                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 599                 return;
 600         }
 601
 602         switch (pdu.base.command) {
 603         case USBIP_CMD_UNLINK:
 604                 stub_recv_cmd_unlink(sdev, &pdu);
 605                 break;
 606
 607         case USBIP_CMD_SUBMIT:
 608                 stub_recv_cmd_submit(sdev, &pdu);
 609                 break;
 610
 611         default:
 612                 /* NOTREACHED */
 613                 dev_err(dev, "unknown pdu\n");
 614                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 615                 return;
 616         }
 617
 618 }
 619
 620 int stub_rx_loop(void *data)
 621 {
 622         struct usbip_device *ud = data;
 623
 624         while (!kthread_should_stop()) {
 625                 if (usbip_event_happened(ud))
 626                         break;
 627
 628                 stub_rx_pdu(ud);
 629         }
 630         return 0;
 631 }