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                 /*
 215                  * This matched urb is not completed yet (i.e., be in
 216                  * flight in usb hcd hardware/driver). Now we are
 217                  * cancelling it. The unlinking flag means that we are
 218                  * now not going to return the normal result pdu of a
 219                  * submission request, but going to return a result pdu
 220                  * of the unlink request.
 221                  */
 222                 priv->unlinking = 1;
 223
 224                 /*
 225                  * In the case that unlinking flag is on, prev->seqnum
 226                  * is changed from the seqnum of the cancelling urb to
 227                  * the seqnum of the unlink request. This will be used
 228                  * to make the result pdu of the unlink request.
 229                  */
 230                 priv->seqnum = pdu->base.seqnum;
 231
 232                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 233
 234                 /*
 235                  * usb_unlink_urb() is now out of spinlocking to avoid
 236                  * spinlock recursion since stub_complete() is
 237                  * sometimes called in this context but not in the
 238                  * interrupt context.  If stub_complete() is executed
 239                  * before we call usb_unlink_urb(), usb_unlink_urb()
 240                  * will return an error value. In this case, stub_tx
 241                  * will return the result pdu of this unlink request
 242                  * though submission is completed and actual unlinking
 243                  * is not executed. OK?
 244                  */
 245                 /* In the above case, urb->status is not -ECONNRESET,
 246                  * so a driver in a client host will know the failure
 247                  * of the unlink request ?
 248                  */
 249                 ret = usb_unlink_urb(priv->urb);
 250                 if (ret != -EINPROGRESS)
 251                         dev_err(&priv->urb->dev->dev,
 252                                 "failed to unlink a urb # %lu, ret %d\n",
 253                                 priv->seqnum, ret);
 254
 255                 return 0;
 256         }
 257
 258         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 259                           pdu->u.cmd_unlink.seqnum);
 260
 261         /*
 262          * The urb of the unlink target is not found in priv_init queue. It was
 263          * already completed and its results is/was going to be sent by a
 264          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 265          * return the completeness of this unlink request to vhci_hcd.
 266          */
 267         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 268
 269         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 270
 271         return 0;
 272 }
 273
 274 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 275 {
 276         struct usbip_device *ud = &sdev->ud;
 277         int valid = 0;
 278
 279         if (pdu->base.devid == sdev->devid) {
 280                 spin_lock_irq(&ud->lock);
 281                 if (ud->status == SDEV_ST_USED) {
 282                         /* A request is valid. */
 283                         valid = 1;
 284                 }
 285                 spin_unlock_irq(&ud->lock);
 286         }
 287
 288         return valid;
 289 }
 290
 291 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 292                                          struct usbip_header *pdu)
 293 {
 294         struct stub_priv *priv;
 295         struct usbip_device *ud = &sdev->ud;
 296         unsigned long flags;
 297
 298         spin_lock_irqsave(&sdev->priv_lock, flags);
 299
 300         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 301         if (!priv) {
 302                 dev_err(&sdev->udev->dev, "alloc stub_priv\n");
 303                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 304                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 305                 return NULL;
 306         }
 307
 308         priv->seqnum = pdu->base.seqnum;
 309         priv->sdev = sdev;
 310
 311         /*
 312          * After a stub_priv is linked to a list_head,
 313          * our error handler can free allocated data.
 314          */
 315         list_add_tail(&priv->list, &sdev->priv_init);
 316
 317         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 318
 319         return priv;
 320 }
 321
 322 static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
 323 {
 324         struct usb_device *udev = sdev->udev;
 325         struct usb_host_endpoint *ep;
 326         struct usb_endpoint_descriptor *epd = NULL;
 327         int epnum = pdu->base.ep;
 328         int dir = pdu->base.direction;
 329
 330         if (epnum < 0 || epnum > 15)
 331                 goto err_ret;
 332
 333         if (dir == USBIP_DIR_IN)
 334                 ep = udev->ep_in[epnum & 0x7f];
 335         else
 336                 ep = udev->ep_out[epnum & 0x7f];
 337         if (!ep)
 338                 goto err_ret;
 339
 340         epd = &ep->desc;
 341
 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                 /* validate packet size and number of packets */
 365                 unsigned int maxp, packets, bytes;
 366
 367                 maxp = usb_endpoint_maxp(epd);
 368                 maxp *= usb_endpoint_maxp_mult(epd);
 369                 bytes = pdu->u.cmd_submit.transfer_buffer_length;
 370                 packets = DIV_ROUND_UP(bytes, maxp);
 371
 372                 if (pdu->u.cmd_submit.number_of_packets < 0 ||
 373                     pdu->u.cmd_submit.number_of_packets > packets) {
 374                         dev_err(&sdev->udev->dev,
 375                                 "CMD_SUBMIT: isoc invalid num packets %d\n",
 376                                 pdu->u.cmd_submit.number_of_packets);
 377                         return -1;
 378                 }
 379                 if (dir == USBIP_DIR_OUT)
 380                         return usb_sndisocpipe(udev, epnum);
 381                 else
 382                         return usb_rcvisocpipe(udev, epnum);
 383         }
 384
 385 err_ret:
 386         /* NOT REACHED */
 387         dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
 388         return -1;
 389 }
 390
 391 static void masking_bogus_flags(struct urb *urb)
 392 {
 393         int                             xfertype;
 394         struct usb_device               *dev;
 395         struct usb_host_endpoint        *ep;
 396         int                             is_out;
 397         unsigned int    allowed;
 398
 399         if (!urb || urb->hcpriv || !urb->complete)
 400                 return;
 401         dev = urb->dev;
 402         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 403                 return;
 404
 405         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 406                 [usb_pipeendpoint(urb->pipe)];
 407         if (!ep)
 408                 return;
 409
 410         xfertype = usb_endpoint_type(&ep->desc);
 411         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 412                 struct usb_ctrlrequest *setup =
 413                         (struct usb_ctrlrequest *) urb->setup_packet;
 414
 415                 if (!setup)
 416                         return;
 417                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 418                         !setup->wLength;
 419         } else {
 420                 is_out = usb_endpoint_dir_out(&ep->desc);
 421         }
 422
 423         /* enforce simple/standard policy */
 424         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 425                    URB_DIR_MASK | URB_FREE_BUFFER);
 426         switch (xfertype) {
 427         case USB_ENDPOINT_XFER_BULK:
 428                 if (is_out)
 429                         allowed |= URB_ZERO_PACKET;
 430                 /* FALLTHROUGH */
 431         default:                        /* all non-iso endpoints */
 432                 if (!is_out)
 433                         allowed |= URB_SHORT_NOT_OK;
 434                 break;
 435         case USB_ENDPOINT_XFER_ISOC:
 436                 allowed |= URB_ISO_ASAP;
 437                 break;
 438         }
 439         urb->transfer_flags &= allowed;
 440 }
 441
 442 static void stub_recv_cmd_submit(struct stub_device *sdev,
 443                                  struct usbip_header *pdu)
 444 {
 445         int ret;
 446         struct stub_priv *priv;
 447         struct usbip_device *ud = &sdev->ud;
 448         struct usb_device *udev = sdev->udev;
 449         int pipe = get_pipe(sdev, pdu);
 450
 451         if (pipe == -1)
 452                 return;
 453
 454         priv = stub_priv_alloc(sdev, pdu);
 455         if (!priv)
 456                 return;
 457
 458         /* setup a urb */
 459         if (usb_pipeisoc(pipe))
 460                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 461                                           GFP_KERNEL);
 462         else
 463                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 464
 465         if (!priv->urb) {
 466                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 467                 return;
 468         }
 469
 470         /* allocate urb transfer buffer, if needed */
 471         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 472                 priv->urb->transfer_buffer =
 473                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 474                                 GFP_KERNEL);
 475                 if (!priv->urb->transfer_buffer) {
 476                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 477                         return;
 478                 }
 479         }
 480
 481         /* copy urb setup packet */
 482         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 483                                           GFP_KERNEL);
 484         if (!priv->urb->setup_packet) {
 485                 dev_err(&udev->dev, "allocate setup_packet\n");
 486                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 487                 return;
 488         }
 489
 490         /* set other members from the base header of pdu */
 491         priv->urb->context                = (void *) priv;
 492         priv->urb->dev                    = udev;
 493         priv->urb->pipe                   = pipe;
 494         priv->urb->complete               = stub_complete;
 495
 496         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 497
 498
 499         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 500                 return;
 501
 502         if (usbip_recv_iso(ud, priv->urb) < 0)
 503                 return;
 504
 505         /* no need to submit an intercepted request, but harmless? */
 506         tweak_special_requests(priv->urb);
 507
 508         masking_bogus_flags(priv->urb);
 509         /* urb is now ready to submit */
 510         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 511
 512         if (ret == 0)
 513                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 514                                   pdu->base.seqnum);
 515         else {
 516                 dev_err(&udev->dev, "submit_urb error, %d\n", ret);
 517                 usbip_dump_header(pdu);
 518                 usbip_dump_urb(priv->urb);
 519
 520                 /*
 521                  * Pessimistic.
 522                  * This connection will be discarded.
 523                  */
 524                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 525         }
 526
 527         usbip_dbg_stub_rx("Leave\n");
 528 }
 529
 530 /* recv a pdu */
 531 static void stub_rx_pdu(struct usbip_device *ud)
 532 {
 533         int ret;
 534         struct usbip_header pdu;
 535         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 536         struct device *dev = &sdev->udev->dev;
 537
 538         usbip_dbg_stub_rx("Enter\n");
 539
 540         memset(&pdu, 0, sizeof(pdu));
 541
 542         /* receive a pdu header */
 543         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 544         if (ret != sizeof(pdu)) {
 545                 dev_err(dev, "recv a header, %d\n", ret);
 546                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 547                 return;
 548         }
 549
 550         usbip_header_correct_endian(&pdu, 0);
 551
 552         if (usbip_dbg_flag_stub_rx)
 553                 usbip_dump_header(&pdu);
 554
 555         if (!valid_request(sdev, &pdu)) {
 556                 dev_err(dev, "recv invalid request\n");
 557                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 558                 return;
 559         }
 560
 561         switch (pdu.base.command) {
 562         case USBIP_CMD_UNLINK:
 563                 stub_recv_cmd_unlink(sdev, &pdu);
 564                 break;
 565
 566         case USBIP_CMD_SUBMIT:
 567                 stub_recv_cmd_submit(sdev, &pdu);
 568                 break;
 569
 570         default:
 571                 /* NOTREACHED */
 572                 dev_err(dev, "unknown pdu\n");
 573                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 574                 break;
 575         }
 576 }
 577
 578 int stub_rx_loop(void *data)
 579 {
 580         struct usbip_device *ud = data;
 581
 582         while (!kthread_should_stop()) {
 583                 if (usbip_event_happened(ud))
 584                         break;
 585
 586                 stub_rx_pdu(ud);
 587         }
 588
 589         return 0;
 590 }