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 "usbip_common.h"
  21 #include "stub.h"
  22 #include "../../usb/core/hcd.h"
  23
  24
  25 static int is_clear_halt_cmd(struct urb *urb)
  26 {
  27         struct usb_ctrlrequest *req;
  28
  29         req = (struct usb_ctrlrequest *) urb->setup_packet;
  30
  31          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  32                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  33                  (req->wValue == USB_ENDPOINT_HALT);
  34 }
  35
  36 static int is_set_interface_cmd(struct urb *urb)
  37 {
  38         struct usb_ctrlrequest *req;
  39
  40         req = (struct usb_ctrlrequest *) urb->setup_packet;
  41
  42         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
  43                    (req->bRequestType == USB_RECIP_INTERFACE);
  44 }
  45
  46 static int is_set_configuration_cmd(struct urb *urb)
  47 {
  48         struct usb_ctrlrequest *req;
  49
  50         req = (struct usb_ctrlrequest *) urb->setup_packet;
  51
  52         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  53                    (req->bRequestType == USB_RECIP_DEVICE);
  54 }
  55
  56 static int is_reset_device_cmd(struct urb *urb)
  57 {
  58         struct usb_ctrlrequest *req;
  59         __u16 value;
  60         __u16 index;
  61
  62         req = (struct usb_ctrlrequest *) urb->setup_packet;
  63         value = le16_to_cpu(req->wValue);
  64         index = le16_to_cpu(req->wIndex);
  65
  66         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  67                         (req->bRequestType == USB_RT_PORT) &&
  68                         (value == USB_PORT_FEAT_RESET)) {
  69                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  70                 return 1;
  71         } else
  72                 return 0;
  73 }
  74
  75 static int tweak_clear_halt_cmd(struct urb *urb)
  76 {
  77         struct usb_ctrlrequest *req;
  78         int target_endp;
  79         int target_dir;
  80         int target_pipe;
  81         int ret;
  82
  83         req = (struct usb_ctrlrequest *) urb->setup_packet;
  84
  85         /*
  86          * The stalled endpoint is specified in the wIndex value. The endpoint
  87          * of the urb is the target of this clear_halt request (i.e., control
  88          * endpoint).
  89          */
  90         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  91
  92         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  93         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  94
  95         if (target_dir)
  96                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
  97         else
  98                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
  99
 100         ret = usb_clear_halt(urb->dev, target_pipe);
 101         if (ret < 0)
 102                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
 103                                         urb->dev->devnum, target_endp, ret);
 104         else
 105                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
 106                                         urb->dev->devnum, target_endp);
 107
 108         return ret;
 109 }
 110
 111 static int tweak_set_interface_cmd(struct urb *urb)
 112 {
 113         struct usb_ctrlrequest *req;
 114         __u16 alternate;
 115         __u16 interface;
 116         int ret;
 117
 118         req = (struct usb_ctrlrequest *) urb->setup_packet;
 119         alternate = le16_to_cpu(req->wValue);
 120         interface = le16_to_cpu(req->wIndex);
 121
 122         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n", interface,
 123                                                                 alternate);
 124
 125         ret = usb_set_interface(urb->dev, interface, alternate);
 126         if (ret < 0)
 127                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
 128                                         interface, alternate, ret);
 129         else
 130                 usbip_uinfo("set_interface done: inf %u alt %u\n",
 131                                                         interface,
 132                                                         alternate);
 133
 134         return ret;
 135 }
 136
 137 static int tweak_set_configuration_cmd(struct urb *urb)
 138 {
 139         struct usb_ctrlrequest *req;
 140         __u16 config;
 141
 142         req = (struct usb_ctrlrequest *) urb->setup_packet;
 143         config = le16_to_cpu(req->wValue);
 144
 145         /*
 146          * I have never seen a multi-config device. Very rare.
 147          * For most devices, this will be called to choose a default
 148          * configuration only once in an initialization phase.
 149          *
 150          * set_configuration may change a device configuration and its device
 151          * drivers will be unbound and assigned for a new device configuration.
 152          * This means this usbip driver will be also unbound when called, then
 153          * eventually reassigned to the device as far as driver matching
 154          * condition is kept.
 155          *
 156          * Unfortunatelly, an existing usbip connection will be dropped
 157          * due to this driver unbinding. So, skip here.
 158          * A user may need to set a special configuration value before
 159          * exporting the device.
 160          */
 161         usbip_uinfo("set_configuration (%d) to %s\n", config,
 162                                                 dev_name(&urb->dev->dev));
 163         usbip_uinfo("but, skip!\n");
 164
 165         return 0;
 166         /* return usb_driver_set_configuration(urb->dev, config); */
 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         usbip_uinfo("reset_device %s\n", dev_name(&urb->dev->dev));
 175
 176         /*
 177          * usb_lock_device_for_reset caused a deadlock: it causes the driver
 178          * to unbind. In the shutdown the rx thread is signalled to shut down
 179          * but this thread is pending in the usb_lock_device_for_reset.
 180          *
 181          * Instead queue the reset.
 182          *
 183          * Unfortunatly an existing usbip connection will be dropped due to
 184          * driver unbinding.
 185          */
 186         usb_queue_reset_device(sdev->interface);
 187         return 0;
 188 }
 189
 190 /*
 191  * clear_halt, set_interface, and set_configuration require special tricks.
 192  */
 193 static void tweak_special_requests(struct urb *urb)
 194 {
 195         if (!urb || !urb->setup_packet)
 196                 return;
 197
 198         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 199                 return;
 200
 201         if (is_clear_halt_cmd(urb))
 202                 /* tweak clear_halt */
 203                  tweak_clear_halt_cmd(urb);
 204
 205         else if (is_set_interface_cmd(urb))
 206                 /* tweak set_interface */
 207                 tweak_set_interface_cmd(urb);
 208
 209         else if (is_set_configuration_cmd(urb))
 210                 /* tweak set_configuration */
 211                 tweak_set_configuration_cmd(urb);
 212
 213         else if (is_reset_device_cmd(urb))
 214                 tweak_reset_device_cmd(urb);
 215         else
 216                 usbip_dbg_stub_rx("no need to tweak\n");
 217 }
 218
 219 /*
 220  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 221  * By unlinking the urb asynchronously, stub_rx can continuously
 222  * process coming urbs.  Even if the urb is unlinked, its completion
 223  * handler will be called and stub_tx will send a return pdu.
 224  *
 225  * See also comments about unlinking strategy in vhci_hcd.c.
 226  */
 227 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 228                                                 struct usbip_header *pdu)
 229 {
 230         unsigned long flags;
 231
 232         struct stub_priv *priv;
 233
 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                         int ret;
 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                         return 0;
 285                 }
 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
 302         return 0;
 303 }
 304
 305 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 306 {
 307         struct usbip_device *ud = &sdev->ud;
 308
 309         if (pdu->base.devid == sdev->devid) {
 310                 spin_lock(&ud->lock);
 311                 if (ud->status == SDEV_ST_USED) {
 312                         /* A request is valid. */
 313                         spin_unlock(&ud->lock);
 314                         return 1;
 315                 }
 316                 spin_unlock(&ud->lock);
 317         }
 318
 319         return 0;
 320 }
 321
 322 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 323                                          struct usbip_header *pdu)
 324 {
 325         struct stub_priv *priv;
 326         struct usbip_device *ud = &sdev->ud;
 327         unsigned long flags;
 328
 329         spin_lock_irqsave(&sdev->priv_lock, flags);
 330
 331         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 332         if (!priv) {
 333                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 334                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 335                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 336                 return NULL;
 337         }
 338
 339         priv->seqnum = pdu->base.seqnum;
 340         priv->sdev = sdev;
 341
 342         /*
 343          * After a stub_priv is linked to a list_head,
 344          * our error handler can free allocated data.
 345          */
 346         list_add_tail(&priv->list, &sdev->priv_init);
 347
 348         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 349
 350         return priv;
 351 }
 352
 353
 354 static struct usb_host_endpoint *get_ep_from_epnum(struct usb_device *udev,
 355                 int epnum0)
 356 {
 357         struct usb_host_config *config;
 358         int i = 0, j = 0;
 359         struct usb_host_endpoint *ep = NULL;
 360         int epnum;
 361         int found = 0;
 362
 363         if (epnum0 == 0)
 364                 return &udev->ep0;
 365
 366         config = udev->actconfig;
 367         if (!config)
 368                 return NULL;
 369
 370         for (i = 0; i < config->desc.bNumInterfaces; i++) {
 371                 struct usb_host_interface *setting;
 372
 373                 setting = config->interface[i]->cur_altsetting;
 374
 375                 for (j = 0; j < setting->desc.bNumEndpoints; j++) {
 376                         ep = &setting->endpoint[j];
 377                         epnum = (ep->desc.bEndpointAddress & 0x7f);
 378
 379                         if (epnum == epnum0) {
 380                                 /* usbip_uinfo("found epnum %d\n", epnum0);*/
 381                                 found = 1;
 382                                 break;
 383                         }
 384                 }
 385         }
 386
 387         if (found)
 388                 return ep;
 389         else
 390                 return NULL;
 391 }
 392
 393
 394 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 395 {
 396         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 397         struct usb_host_endpoint *ep;
 398         struct usb_endpoint_descriptor *epd = NULL;
 399
 400         ep = get_ep_from_epnum(udev, epnum);
 401         if (!ep) {
 402                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 403                         epnum);
 404                 BUG();
 405         }
 406
 407         epd = &ep->desc;
 408
 409
 410 #if 0
 411         /* epnum 0 is always control */
 412         if (epnum == 0) {
 413                 if (dir == USBIP_DIR_OUT)
 414                         return usb_sndctrlpipe(udev, 0);
 415                 else
 416                         return usb_rcvctrlpipe(udev, 0);
 417         }
 418 #endif
 419
 420         if (usb_endpoint_xfer_control(epd)) {
 421                 if (dir == USBIP_DIR_OUT)
 422                         return usb_sndctrlpipe(udev, epnum);
 423                 else
 424                         return usb_rcvctrlpipe(udev, epnum);
 425         }
 426
 427         if (usb_endpoint_xfer_bulk(epd)) {
 428                 if (dir == USBIP_DIR_OUT)
 429                         return usb_sndbulkpipe(udev, epnum);
 430                 else
 431                         return usb_rcvbulkpipe(udev, epnum);
 432         }
 433
 434         if (usb_endpoint_xfer_int(epd)) {
 435                 if (dir == USBIP_DIR_OUT)
 436                         return usb_sndintpipe(udev, epnum);
 437                 else
 438                         return usb_rcvintpipe(udev, epnum);
 439         }
 440
 441         if (usb_endpoint_xfer_isoc(epd)) {
 442                 if (dir == USBIP_DIR_OUT)
 443                         return usb_sndisocpipe(udev, epnum);
 444                 else
 445                         return usb_rcvisocpipe(udev, epnum);
 446         }
 447
 448         /* NOT REACHED */
 449         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 450         return 0;
 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 = interface_to_usbdev(sdev->interface);
 460         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 461
 462
 463         priv = stub_priv_alloc(sdev, pdu);
 464         if (!priv)
 465                 return;
 466
 467         /* setup a urb */
 468         if (usb_pipeisoc(pipe))
 469                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 470                                                                 GFP_KERNEL);
 471         else
 472                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 473
 474         if (!priv->urb) {
 475                 dev_err(&sdev->interface->dev, "malloc urb\n");
 476                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 477                 return;
 478         }
 479
 480         /* set priv->urb->transfer_buffer */
 481         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 482                 priv->urb->transfer_buffer =
 483                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 484                                                                 GFP_KERNEL);
 485                 if (!priv->urb->transfer_buffer) {
 486                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 487                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 488                         return;
 489                 }
 490         }
 491
 492         /* set priv->urb->setup_packet */
 493         priv->urb->setup_packet = kzalloc(8, GFP_KERNEL);
 494         if (!priv->urb->setup_packet) {
 495                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 496                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 497                 return;
 498         }
 499         memcpy(priv->urb->setup_packet, &pdu->u.cmd_submit.setup, 8);
 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         /* urb is now ready to submit */
 520         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 521
 522         if (ret == 0)
 523                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 524                                                         pdu->base.seqnum);
 525         else {
 526                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 527                 usbip_dump_header(pdu);
 528                 usbip_dump_urb(priv->urb);
 529
 530                 /*
 531                  * Pessimistic.
 532                  * This connection will be discarded.
 533                  */
 534                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 535         }
 536
 537         usbip_dbg_stub_rx("Leave\n");
 538         return;
 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->interface->dev;
 548
 549         usbip_dbg_stub_rx("Enter\n");
 550
 551         memset(&pdu, 0, sizeof(pdu));
 552
 553         /* 1. receive a pdu header */
 554         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 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                 return;
 586         }
 587
 588 }
 589
 590 void stub_rx_loop(struct usbip_task *ut)
 591 {
 592         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 593
 594         while (1) {
 595                 if (signal_pending(current)) {
 596                         usbip_dbg_stub_rx("signal caught!\n");
 597                         break;
 598                 }
 599
 600                 if (usbip_event_happened(ud))
 601                         break;
 602
 603                 stub_rx_pdu(ud);
 604         }
 605 }