drivers/usb/usbip/stub_rx.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   4  */
   5
   6 #include <asm/byteorder.h>
   7 #include <linux/kthread.h>
   8 #include <linux/usb.h>
   9 #include <linux/usb/hcd.h>
  10
  11 #include "usbip_common.h"
  12 #include "stub.h"
  13
  14 static int is_clear_halt_cmd(struct urb *urb)
  15 {
  16         struct usb_ctrlrequest *req;
  17
  18         req = (struct usb_ctrlrequest *) urb->setup_packet;
  19
  20          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  21                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  22                  (req->wValue == USB_ENDPOINT_HALT);
  23 }
  24
  25 static int is_set_interface_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_SET_INTERFACE) &&
  32                 (req->bRequestType == USB_RECIP_INTERFACE);
  33 }
  34
  35 static int is_set_configuration_cmd(struct urb *urb)
  36 {
  37         struct usb_ctrlrequest *req;
  38
  39         req = (struct usb_ctrlrequest *) urb->setup_packet;
  40
  41         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  42                 (req->bRequestType == USB_RECIP_DEVICE);
  43 }
  44
  45 static int is_reset_device_cmd(struct urb *urb)
  46 {
  47         struct usb_ctrlrequest *req;
  48         __u16 value;
  49         __u16 index;
  50
  51         req = (struct usb_ctrlrequest *) urb->setup_packet;
  52         value = le16_to_cpu(req->wValue);
  53         index = le16_to_cpu(req->wIndex);
  54
  55         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  56             (req->bRequestType == USB_RT_PORT) &&
  57             (value == USB_PORT_FEAT_RESET)) {
  58                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  59                 return 1;
  60         } else
  61                 return 0;
  62 }
  63
  64 static int tweak_clear_halt_cmd(struct urb *urb)
  65 {
  66         struct usb_ctrlrequest *req;
  67         int target_endp;
  68         int target_dir;
  69         int target_pipe;
  70         int ret;
  71
  72         req = (struct usb_ctrlrequest *) urb->setup_packet;
  73
  74         /*
  75          * The stalled endpoint is specified in the wIndex value. The endpoint
  76          * of the urb is the target of this clear_halt request (i.e., control
  77          * endpoint).
  78          */
  79         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  80
  81         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  82         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  83
  84         if (target_dir)
  85                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
  86         else
  87                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
  88
  89         ret = usb_clear_halt(urb->dev, target_pipe);
  90         if (ret < 0)
  91                 dev_err(&urb->dev->dev,
  92                         "usb_clear_halt error: devnum %d endp %d ret %d\n",
  93                         urb->dev->devnum, target_endp, ret);
  94         else
  95                 dev_info(&urb->dev->dev,
  96                          "usb_clear_halt done: devnum %d endp %d\n",
  97                          urb->dev->devnum, target_endp);
  98
  99         return ret;
 100 }
 101
 102 static int tweak_set_interface_cmd(struct urb *urb)
 103 {
 104         struct usb_ctrlrequest *req;
 105         __u16 alternate;
 106         __u16 interface;
 107         int ret;
 108
 109         req = (struct usb_ctrlrequest *) urb->setup_packet;
 110         alternate = le16_to_cpu(req->wValue);
 111         interface = le16_to_cpu(req->wIndex);
 112
 113         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
 114                           interface, alternate);
 115
 116         ret = usb_set_interface(urb->dev, interface, alternate);
 117         if (ret < 0)
 118                 dev_err(&urb->dev->dev,
 119                         "usb_set_interface error: inf %u alt %u ret %d\n",
 120                         interface, alternate, ret);
 121         else
 122                 dev_info(&urb->dev->dev,
 123                         "usb_set_interface done: inf %u alt %u\n",
 124                         interface, alternate);
 125
 126         return ret;
 127 }
 128
 129 static int tweak_set_configuration_cmd(struct urb *urb)
 130 {
 131         struct stub_priv *priv = (struct stub_priv *) urb->context;
 132         struct stub_device *sdev = priv->sdev;
 133         struct usb_ctrlrequest *req;
 134         __u16 config;
 135         int err;
 136
 137         req = (struct usb_ctrlrequest *) urb->setup_packet;
 138         config = le16_to_cpu(req->wValue);
 139
 140         err = usb_set_configuration(sdev->udev, config);
 141         if (err && err != -ENODEV)
 142                 dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
 143                         config, err);
 144         return 0;
 145 }
 146
 147 static int tweak_reset_device_cmd(struct urb *urb)
 148 {
 149         struct stub_priv *priv = (struct stub_priv *) urb->context;
 150         struct stub_device *sdev = priv->sdev;
 151
 152         dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 153
 154         if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
 155                 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
 156                 return 0;
 157         }
 158         usb_reset_device(sdev->udev);
 159         usb_unlock_device(sdev->udev);
 160
 161         return 0;
 162 }
 163
 164 /*
 165  * clear_halt, set_interface, and set_configuration require special tricks.
 166  */
 167 static void tweak_special_requests(struct urb *urb)
 168 {
 169         if (!urb || !urb->setup_packet)
 170                 return;
 171
 172         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 173                 return;
 174
 175         if (is_clear_halt_cmd(urb))
 176                 /* tweak clear_halt */
 177                  tweak_clear_halt_cmd(urb);
 178
 179         else if (is_set_interface_cmd(urb))
 180                 /* tweak set_interface */
 181                 tweak_set_interface_cmd(urb);
 182
 183         else if (is_set_configuration_cmd(urb))
 184                 /* tweak set_configuration */
 185                 tweak_set_configuration_cmd(urb);
 186
 187         else if (is_reset_device_cmd(urb))
 188                 tweak_reset_device_cmd(urb);
 189         else
 190                 usbip_dbg_stub_rx("no need to tweak\n");
 191 }
 192
 193 /*
 194  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 195  * By unlinking the urb asynchronously, stub_rx can continuously
 196  * process coming urbs.  Even if the urb is unlinked, its completion
 197  * handler will be called and stub_tx will send a return pdu.
 198  *
 199  * See also comments about unlinking strategy in vhci_hcd.c.
 200  */
 201 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 202                                 struct usbip_header *pdu)
 203 {
 204         int ret;
 205         unsigned long flags;
 206         struct stub_priv *priv;
 207
 208         spin_lock_irqsave(&sdev->priv_lock, flags);
 209
 210         list_for_each_entry(priv, &sdev->priv_init, list) {
 211                 if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
 212                         continue;
 213
 214                 dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 215                          priv->urb);
 216
 217                 /*
 218                  * This matched urb is not completed yet (i.e., be in
 219                  * flight in usb hcd hardware/driver). Now we are
 220                  * cancelling it. The unlinking flag means that we are
 221                  * now not going to return the normal result pdu of a
 222                  * submission request, but going to return a result pdu
 223                  * of the unlink request.
 224                  */
 225                 priv->unlinking = 1;
 226
 227                 /*
 228                  * In the case that unlinking flag is on, prev->seqnum
 229                  * is changed from the seqnum of the cancelling urb to
 230                  * the seqnum of the unlink request. This will be used
 231                  * to make the result pdu of the unlink request.
 232                  */
 233                 priv->seqnum = pdu->base.seqnum;
 234
 235                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 236
 237                 /*
 238                  * usb_unlink_urb() is now out of spinlocking to avoid
 239                  * spinlock recursion since stub_complete() is
 240                  * sometimes called in this context but not in the
 241                  * interrupt context.  If stub_complete() is executed
 242                  * before we call usb_unlink_urb(), usb_unlink_urb()
 243                  * will return an error value. In this case, stub_tx
 244                  * will return the result pdu of this unlink request
 245                  * though submission is completed and actual unlinking
 246                  * is not executed. OK?
 247                  */
 248                 /* In the above case, urb->status is not -ECONNRESET,
 249                  * so a driver in a client host will know the failure
 250                  * of the unlink request ?
 251                  */
 252                 ret = usb_unlink_urb(priv->urb);
 253                 if (ret != -EINPROGRESS)
 254                         dev_err(&priv->urb->dev->dev,
 255                                 "failed to unlink a urb %p, ret %d\n",
 256                                 priv->urb, ret);
 257
 258                 return 0;
 259         }
 260
 261         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 262                           pdu->u.cmd_unlink.seqnum);
 263
 264         /*
 265          * The urb of the unlink target is not found in priv_init queue. It was
 266          * already completed and its results is/was going to be sent by a
 267          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 268          * return the completeness of this unlink request to vhci_hcd.
 269          */
 270         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 271
 272         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 273
 274         return 0;
 275 }
 276
 277 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 278 {
 279         struct usbip_device *ud = &sdev->ud;
 280         int valid = 0;
 281
 282         if (pdu->base.devid == sdev->devid) {
 283                 spin_lock_irq(&ud->lock);
 284                 if (ud->status == SDEV_ST_USED) {
 285                         /* A request is valid. */
 286                         valid = 1;
 287                 }
 288                 spin_unlock_irq(&ud->lock);
 289         }
 290
 291         return valid;
 292 }
 293
 294 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 295                                          struct usbip_header *pdu)
 296 {
 297         struct stub_priv *priv;
 298         struct usbip_device *ud = &sdev->ud;
 299         unsigned long flags;
 300
 301         spin_lock_irqsave(&sdev->priv_lock, flags);
 302
 303         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 304         if (!priv) {
 305                 dev_err(&sdev->udev->dev, "alloc stub_priv\n");
 306                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 307                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 308                 return NULL;
 309         }
 310
 311         priv->seqnum = pdu->base.seqnum;
 312         priv->sdev = sdev;
 313
 314         /*
 315          * After a stub_priv is linked to a list_head,
 316          * our error handler can free allocated data.
 317          */
 318         list_add_tail(&priv->list, &sdev->priv_init);
 319
 320         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 321
 322         return priv;
 323 }
 324
 325 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 326 {
 327         struct usb_device *udev = sdev->udev;
 328         struct usb_host_endpoint *ep;
 329         struct usb_endpoint_descriptor *epd = NULL;
 330
 331         if (dir == USBIP_DIR_IN)
 332                 ep = udev->ep_in[epnum & 0x7f];
 333         else
 334                 ep = udev->ep_out[epnum & 0x7f];
 335         if (!ep) {
 336                 dev_err(&sdev->udev->dev, "no such endpoint?, %d\n",
 337                         epnum);
 338                 BUG();
 339         }
 340
 341         epd = &ep->desc;
 342         if (usb_endpoint_xfer_control(epd)) {
 343                 if (dir == USBIP_DIR_OUT)
 344                         return usb_sndctrlpipe(udev, epnum);
 345                 else
 346                         return usb_rcvctrlpipe(udev, epnum);
 347         }
 348
 349         if (usb_endpoint_xfer_bulk(epd)) {
 350                 if (dir == USBIP_DIR_OUT)
 351                         return usb_sndbulkpipe(udev, epnum);
 352                 else
 353                         return usb_rcvbulkpipe(udev, epnum);
 354         }
 355
 356         if (usb_endpoint_xfer_int(epd)) {
 357                 if (dir == USBIP_DIR_OUT)
 358                         return usb_sndintpipe(udev, epnum);
 359                 else
 360                         return usb_rcvintpipe(udev, epnum);
 361         }
 362
 363         if (usb_endpoint_xfer_isoc(epd)) {
 364                 if (dir == USBIP_DIR_OUT)
 365                         return usb_sndisocpipe(udev, epnum);
 366                 else
 367                         return usb_rcvisocpipe(udev, epnum);
 368         }
 369
 370         /* NOT REACHED */
 371         dev_err(&sdev->udev->dev, "get pipe, epnum %d\n", epnum);
 372         return 0;
 373 }
 374
 375 static void masking_bogus_flags(struct urb *urb)
 376 {
 377         int                             xfertype;
 378         struct usb_device               *dev;
 379         struct usb_host_endpoint        *ep;
 380         int                             is_out;
 381         unsigned int    allowed;
 382
 383         if (!urb || urb->hcpriv || !urb->complete)
 384                 return;
 385         dev = urb->dev;
 386         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 387                 return;
 388
 389         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 390                 [usb_pipeendpoint(urb->pipe)];
 391         if (!ep)
 392                 return;
 393
 394         xfertype = usb_endpoint_type(&ep->desc);
 395         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 396                 struct usb_ctrlrequest *setup =
 397                         (struct usb_ctrlrequest *) urb->setup_packet;
 398
 399                 if (!setup)
 400                         return;
 401                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 402                         !setup->wLength;
 403         } else {
 404                 is_out = usb_endpoint_dir_out(&ep->desc);
 405         }
 406
 407         /* enforce simple/standard policy */
 408         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 409                    URB_DIR_MASK | URB_FREE_BUFFER);
 410         switch (xfertype) {
 411         case USB_ENDPOINT_XFER_BULK:
 412                 if (is_out)
 413                         allowed |= URB_ZERO_PACKET;
 414                 /* FALLTHROUGH */
 415         case USB_ENDPOINT_XFER_CONTROL:
 416                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 417                 /* FALLTHROUGH */
 418         default:                        /* all non-iso endpoints */
 419                 if (!is_out)
 420                         allowed |= URB_SHORT_NOT_OK;
 421                 break;
 422         case USB_ENDPOINT_XFER_ISOC:
 423                 allowed |= URB_ISO_ASAP;
 424                 break;
 425         }
 426         urb->transfer_flags &= allowed;
 427 }
 428
 429 static void stub_recv_cmd_submit(struct stub_device *sdev,
 430                                  struct usbip_header *pdu)
 431 {
 432         int ret;
 433         struct stub_priv *priv;
 434         struct usbip_device *ud = &sdev->ud;
 435         struct usb_device *udev = sdev->udev;
 436         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 437
 438         priv = stub_priv_alloc(sdev, pdu);
 439         if (!priv)
 440                 return;
 441
 442         /* setup a urb */
 443         if (usb_pipeisoc(pipe))
 444                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 445                                           GFP_KERNEL);
 446         else
 447                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 448
 449         if (!priv->urb) {
 450                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 451                 return;
 452         }
 453
 454         /* allocate urb transfer buffer, if needed */
 455         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 456                 priv->urb->transfer_buffer =
 457                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 458                                 GFP_KERNEL);
 459                 if (!priv->urb->transfer_buffer) {
 460                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 461                         return;
 462                 }
 463         }
 464
 465         /* copy urb setup packet */
 466         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 467                                           GFP_KERNEL);
 468         if (!priv->urb->setup_packet) {
 469                 dev_err(&udev->dev, "allocate setup_packet\n");
 470                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 471                 return;
 472         }
 473
 474         /* set other members from the base header of pdu */
 475         priv->urb->context                = (void *) priv;
 476         priv->urb->dev                    = udev;
 477         priv->urb->pipe                   = pipe;
 478         priv->urb->complete               = stub_complete;
 479
 480         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 481
 482
 483         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 484                 return;
 485
 486         if (usbip_recv_iso(ud, priv->urb) < 0)
 487                 return;
 488
 489         /* no need to submit an intercepted request, but harmless? */
 490         tweak_special_requests(priv->urb);
 491
 492         masking_bogus_flags(priv->urb);
 493         /* urb is now ready to submit */
 494         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 495
 496         if (ret == 0)
 497                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 498                                   pdu->base.seqnum);
 499         else {
 500                 dev_err(&udev->dev, "submit_urb error, %d\n", ret);
 501                 usbip_dump_header(pdu);
 502                 usbip_dump_urb(priv->urb);
 503
 504                 /*
 505                  * Pessimistic.
 506                  * This connection will be discarded.
 507                  */
 508                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 509         }
 510
 511         usbip_dbg_stub_rx("Leave\n");
 512 }
 513
 514 /* recv a pdu */
 515 static void stub_rx_pdu(struct usbip_device *ud)
 516 {
 517         int ret;
 518         struct usbip_header pdu;
 519         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 520         struct device *dev = &sdev->udev->dev;
 521
 522         usbip_dbg_stub_rx("Enter\n");
 523
 524         memset(&pdu, 0, sizeof(pdu));
 525
 526         /* receive a pdu header */
 527         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 528         if (ret != sizeof(pdu)) {
 529                 dev_err(dev, "recv a header, %d\n", ret);
 530                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 531                 return;
 532         }
 533
 534         usbip_header_correct_endian(&pdu, 0);
 535
 536         if (usbip_dbg_flag_stub_rx)
 537                 usbip_dump_header(&pdu);
 538
 539         if (!valid_request(sdev, &pdu)) {
 540                 dev_err(dev, "recv invalid request\n");
 541                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 542                 return;
 543         }
 544
 545         switch (pdu.base.command) {
 546         case USBIP_CMD_UNLINK:
 547                 stub_recv_cmd_unlink(sdev, &pdu);
 548                 break;
 549
 550         case USBIP_CMD_SUBMIT:
 551                 stub_recv_cmd_submit(sdev, &pdu);
 552                 break;
 553
 554         default:
 555                 /* NOTREACHED */
 556                 dev_err(dev, "unknown pdu\n");
 557                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 558                 break;
 559         }
 560 }
 561
 562 int stub_rx_loop(void *data)
 563 {
 564         struct usbip_device *ud = data;
 565
 566         while (!kthread_should_stop()) {
 567                 if (usbip_event_happened(ud))
 568                         break;
 569
 570                 stub_rx_pdu(ud);
 571         }
 572
 573         return 0;
 574 }