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 <asm/byteorder.h> 21 #include <linux/kthread.h> 22 #include <linux/usb.h> 23 #include <linux/usb/hcd.h> 24 25 #include "usbip_common.h" 26 #include "stub.h" 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 dev_err(&urb->dev->dev, 106 "usb_clear_halt error: devnum %d endp %d ret %d\n", 107 urb->dev->devnum, target_endp, ret); 108 else 109 dev_info(&urb->dev->dev, 110 "usb_clear_halt done: devnum %d endp %d\n", 111 urb->dev->devnum, target_endp); 112 113 return ret; 114 } 115 116 static int tweak_set_interface_cmd(struct urb *urb) 117 { 118 struct usb_ctrlrequest *req; 119 __u16 alternate; 120 __u16 interface; 121 int ret; 122 123 req = (struct usb_ctrlrequest *) urb->setup_packet; 124 alternate = le16_to_cpu(req->wValue); 125 interface = le16_to_cpu(req->wIndex); 126 127 usbip_dbg_stub_rx("set_interface: inf %u alt %u\n", 128 interface, alternate); 129 130 ret = usb_set_interface(urb->dev, interface, alternate); 131 if (ret < 0) 132 dev_err(&urb->dev->dev, 133 "usb_set_interface error: inf %u alt %u ret %d\n", 134 interface, alternate, ret); 135 else 136 dev_info(&urb->dev->dev, 137 "usb_set_interface done: inf %u alt %u\n", 138 interface, alternate); 139 140 return ret; 141 } 142 143 static int tweak_set_configuration_cmd(struct urb *urb) 144 { 145 struct stub_priv *priv = (struct stub_priv *) urb->context; 146 struct stub_device *sdev = priv->sdev; 147 struct usb_ctrlrequest *req; 148 __u16 config; 149 int err; 150 151 req = (struct usb_ctrlrequest *) urb->setup_packet; 152 config = le16_to_cpu(req->wValue); 153 154 err = usb_set_configuration(sdev->udev, config); 155 if (err && err != -ENODEV) 156 dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n", 157 config, err); 158 return 0; 159 } 160 161 static int tweak_reset_device_cmd(struct urb *urb) 162 { 163 struct stub_priv *priv = (struct stub_priv *) urb->context; 164 struct stub_device *sdev = priv->sdev; 165 166 dev_info(&urb->dev->dev, "usb_queue_reset_device\n"); 167 168 /* 169 * With the implementation of pre_reset and post_reset the driver no 170 * longer unbinds. This allows the use of synchronous reset. 171 */ 172 173 if (usb_lock_device_for_reset(sdev->udev, sdev->interface) < 0) { 174 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n"); 175 return 0; 176 } 177 usb_reset_device(sdev->udev); 178 usb_unlock_device(sdev->udev); 179 180 return 0; 181 } 182 183 /* 184 * clear_halt, set_interface, and set_configuration require special tricks. 185 */ 186 static void tweak_special_requests(struct urb *urb) 187 { 188 if (!urb || !urb->setup_packet) 189 return; 190 191 if (usb_pipetype(urb->pipe) != PIPE_CONTROL) 192 return; 193 194 if (is_clear_halt_cmd(urb)) 195 /* tweak clear_halt */ 196 tweak_clear_halt_cmd(urb); 197 198 else if (is_set_interface_cmd(urb)) 199 /* tweak set_interface */ 200 tweak_set_interface_cmd(urb); 201 202 else if (is_set_configuration_cmd(urb)) 203 /* tweak set_configuration */ 204 tweak_set_configuration_cmd(urb); 205 206 else if (is_reset_device_cmd(urb)) 207 tweak_reset_device_cmd(urb); 208 else 209 usbip_dbg_stub_rx("no need to tweak\n"); 210 } 211 212 /* 213 * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb(). 214 * By unlinking the urb asynchronously, stub_rx can continuously 215 * process coming urbs. Even if the urb is unlinked, its completion 216 * handler will be called and stub_tx will send a return pdu. 217 * 218 * See also comments about unlinking strategy in vhci_hcd.c. 219 */ 220 static int stub_recv_cmd_unlink(struct stub_device *sdev, 221 struct usbip_header *pdu) 222 { 223 int ret; 224 unsigned long flags; 225 struct stub_priv *priv; 226 227 spin_lock_irqsave(&sdev->priv_lock, flags); 228 229 list_for_each_entry(priv, &sdev->priv_init, list) { 230 if (priv->seqnum != pdu->u.cmd_unlink.seqnum) 231 continue; 232 233 dev_info(&priv->urb->dev->dev, "unlink urb %p\n", 234 priv->urb); 235 236 /* 237 * This matched urb is not completed yet (i.e., be in 238 * flight in usb hcd hardware/driver). Now we are 239 * cancelling it. The unlinking flag means that we are 240 * now not going to return the normal result pdu of a 241 * submission request, but going to return a result pdu 242 * of the unlink request. 243 */ 244 priv->unlinking = 1; 245 246 /* 247 * In the case that unlinking flag is on, prev->seqnum 248 * is changed from the seqnum of the cancelling urb to 249 * the seqnum of the unlink request. This will be used 250 * to make the result pdu of the unlink request. 251 */ 252 priv->seqnum = pdu->base.seqnum; 253 254 spin_unlock_irqrestore(&sdev->priv_lock, flags); 255 256 /* 257 * usb_unlink_urb() is now out of spinlocking to avoid 258 * spinlock recursion since stub_complete() is 259 * sometimes called in this context but not in the 260 * interrupt context. If stub_complete() is executed 261 * before we call usb_unlink_urb(), usb_unlink_urb() 262 * will return an error value. In this case, stub_tx 263 * will return the result pdu of this unlink request 264 * though submission is completed and actual unlinking 265 * is not executed. OK? 266 */ 267 /* In the above case, urb->status is not -ECONNRESET, 268 * so a driver in a client host will know the failure 269 * of the unlink request ? 270 */ 271 ret = usb_unlink_urb(priv->urb); 272 if (ret != -EINPROGRESS) 273 dev_err(&priv->urb->dev->dev, 274 "failed to unlink a urb %p, ret %d\n", 275 priv->urb, ret); 276 277 return 0; 278 } 279 280 usbip_dbg_stub_rx("seqnum %d is not pending\n", 281 pdu->u.cmd_unlink.seqnum); 282 283 /* 284 * The urb of the unlink target is not found in priv_init queue. It was 285 * already completed and its results is/was going to be sent by a 286 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only 287 * return the completeness of this unlink request to vhci_hcd. 288 */ 289 stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0); 290 291 spin_unlock_irqrestore(&sdev->priv_lock, flags); 292 293 return 0; 294 } 295 296 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu) 297 { 298 struct usbip_device *ud = &sdev->ud; 299 int valid = 0; 300 301 if (pdu->base.devid == sdev->devid) { 302 spin_lock_irq(&ud->lock); 303 if (ud->status == SDEV_ST_USED) { 304 /* A request is valid. */ 305 valid = 1; 306 } 307 spin_unlock_irq(&ud->lock); 308 } 309 310 return valid; 311 } 312 313 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev, 314 struct usbip_header *pdu) 315 { 316 struct stub_priv *priv; 317 struct usbip_device *ud = &sdev->ud; 318 unsigned long flags; 319 320 spin_lock_irqsave(&sdev->priv_lock, flags); 321 322 priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC); 323 if (!priv) { 324 dev_err(&sdev->interface->dev, "alloc stub_priv\n"); 325 spin_unlock_irqrestore(&sdev->priv_lock, flags); 326 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); 327 return NULL; 328 } 329 330 priv->seqnum = pdu->base.seqnum; 331 priv->sdev = sdev; 332 333 /* 334 * After a stub_priv is linked to a list_head, 335 * our error handler can free allocated data. 336 */ 337 list_add_tail(&priv->list, &sdev->priv_init); 338 339 spin_unlock_irqrestore(&sdev->priv_lock, flags); 340 341 return priv; 342 } 343 344 static int get_pipe(struct stub_device *sdev, int epnum, int dir) 345 { 346 struct usb_device *udev = sdev->udev; 347 struct usb_host_endpoint *ep; 348 struct usb_endpoint_descriptor *epd = NULL; 349 350 if (dir == USBIP_DIR_IN) 351 ep = udev->ep_in[epnum & 0x7f]; 352 else 353 ep = udev->ep_out[epnum & 0x7f]; 354 if (!ep) { 355 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n", 356 epnum); 357 BUG(); 358 } 359 360 epd = &ep->desc; 361 if (usb_endpoint_xfer_control(epd)) { 362 if (dir == USBIP_DIR_OUT) 363 return usb_sndctrlpipe(udev, epnum); 364 else 365 return usb_rcvctrlpipe(udev, epnum); 366 } 367 368 if (usb_endpoint_xfer_bulk(epd)) { 369 if (dir == USBIP_DIR_OUT) 370 return usb_sndbulkpipe(udev, epnum); 371 else 372 return usb_rcvbulkpipe(udev, epnum); 373 } 374 375 if (usb_endpoint_xfer_int(epd)) { 376 if (dir == USBIP_DIR_OUT) 377 return usb_sndintpipe(udev, epnum); 378 else 379 return usb_rcvintpipe(udev, epnum); 380 } 381 382 if (usb_endpoint_xfer_isoc(epd)) { 383 if (dir == USBIP_DIR_OUT) 384 return usb_sndisocpipe(udev, epnum); 385 else 386 return usb_rcvisocpipe(udev, epnum); 387 } 388 389 /* NOT REACHED */ 390 dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum); 391 return 0; 392 } 393 394 static void masking_bogus_flags(struct urb *urb) 395 { 396 int xfertype; 397 struct usb_device *dev; 398 struct usb_host_endpoint *ep; 399 int is_out; 400 unsigned int allowed; 401 402 if (!urb || urb->hcpriv || !urb->complete) 403 return; 404 dev = urb->dev; 405 if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) 406 return; 407 408 ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out) 409 [usb_pipeendpoint(urb->pipe)]; 410 if (!ep) 411 return; 412 413 xfertype = usb_endpoint_type(&ep->desc); 414 if (xfertype == USB_ENDPOINT_XFER_CONTROL) { 415 struct usb_ctrlrequest *setup = 416 (struct usb_ctrlrequest *) urb->setup_packet; 417 418 if (!setup) 419 return; 420 is_out = !(setup->bRequestType & USB_DIR_IN) || 421 !setup->wLength; 422 } else { 423 is_out = usb_endpoint_dir_out(&ep->desc); 424 } 425 426 /* enforce simple/standard policy */ 427 allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | 428 URB_DIR_MASK | URB_FREE_BUFFER); 429 switch (xfertype) { 430 case USB_ENDPOINT_XFER_BULK: 431 if (is_out) 432 allowed |= URB_ZERO_PACKET; 433 /* FALLTHROUGH */ 434 case USB_ENDPOINT_XFER_CONTROL: 435 allowed |= URB_NO_FSBR; /* only affects UHCI */ 436 /* FALLTHROUGH */ 437 default: /* all non-iso endpoints */ 438 if (!is_out) 439 allowed |= URB_SHORT_NOT_OK; 440 break; 441 case USB_ENDPOINT_XFER_ISOC: 442 allowed |= URB_ISO_ASAP; 443 break; 444 } 445 urb->transfer_flags &= allowed; 446 } 447 448 static void stub_recv_cmd_submit(struct stub_device *sdev, 449 struct usbip_header *pdu) 450 { 451 int ret; 452 struct stub_priv *priv; 453 struct usbip_device *ud = &sdev->ud; 454 struct usb_device *udev = sdev->udev; 455 int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction); 456 457 priv = stub_priv_alloc(sdev, pdu); 458 if (!priv) 459 return; 460 461 /* setup a urb */ 462 if (usb_pipeisoc(pipe)) 463 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets, 464 GFP_KERNEL); 465 else 466 priv->urb = usb_alloc_urb(0, GFP_KERNEL); 467 468 if (!priv->urb) { 469 dev_err(&sdev->interface->dev, "malloc urb\n"); 470 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); 471 return; 472 } 473 474 /* allocate urb transfer buffer, if needed */ 475 if (pdu->u.cmd_submit.transfer_buffer_length > 0) { 476 priv->urb->transfer_buffer = 477 kzalloc(pdu->u.cmd_submit.transfer_buffer_length, 478 GFP_KERNEL); 479 if (!priv->urb->transfer_buffer) { 480 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); 481 return; 482 } 483 } 484 485 /* copy urb setup packet */ 486 priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8, 487 GFP_KERNEL); 488 if (!priv->urb->setup_packet) { 489 dev_err(&sdev->interface->dev, "allocate setup_packet\n"); 490 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC); 491 return; 492 } 493 494 /* set other members from the base header of pdu */ 495 priv->urb->context = (void *) priv; 496 priv->urb->dev = udev; 497 priv->urb->pipe = pipe; 498 priv->urb->complete = stub_complete; 499 500 usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0); 501 502 503 if (usbip_recv_xbuff(ud, priv->urb) < 0) 504 return; 505 506 if (usbip_recv_iso(ud, priv->urb) < 0) 507 return; 508 509 /* no need to submit an intercepted request, but harmless? */ 510 tweak_special_requests(priv->urb); 511 512 masking_bogus_flags(priv->urb); 513 /* urb is now ready to submit */ 514 ret = usb_submit_urb(priv->urb, GFP_KERNEL); 515 516 if (ret == 0) 517 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n", 518 pdu->base.seqnum); 519 else { 520 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret); 521 usbip_dump_header(pdu); 522 usbip_dump_urb(priv->urb); 523 524 /* 525 * Pessimistic. 526 * This connection will be discarded. 527 */ 528 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT); 529 } 530 531 usbip_dbg_stub_rx("Leave\n"); 532 } 533 534 /* recv a pdu */ 535 static void stub_rx_pdu(struct usbip_device *ud) 536 { 537 int ret; 538 struct usbip_header pdu; 539 struct stub_device *sdev = container_of(ud, struct stub_device, ud); 540 struct device *dev = &sdev->udev->dev; 541 542 usbip_dbg_stub_rx("Enter\n"); 543 544 memset(&pdu, 0, sizeof(pdu)); 545 546 /* receive a pdu header */ 547 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu)); 548 if (ret != sizeof(pdu)) { 549 dev_err(dev, "recv a header, %d\n", ret); 550 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP); 551 return; 552 } 553 554 usbip_header_correct_endian(&pdu, 0); 555 556 if (usbip_dbg_flag_stub_rx) 557 usbip_dump_header(&pdu); 558 559 if (!valid_request(sdev, &pdu)) { 560 dev_err(dev, "recv invalid request\n"); 561 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP); 562 return; 563 } 564 565 switch (pdu.base.command) { 566 case USBIP_CMD_UNLINK: 567 stub_recv_cmd_unlink(sdev, &pdu); 568 break; 569 570 case USBIP_CMD_SUBMIT: 571 stub_recv_cmd_submit(sdev, &pdu); 572 break; 573 574 default: 575 /* NOTREACHED */ 576 dev_err(dev, "unknown pdu\n"); 577 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP); 578 break; 579 } 580 } 581 582 int stub_rx_loop(void *data) 583 { 584 struct usbip_device *ud = data; 585 586 while (!kthread_should_stop()) { 587 if (usbip_event_happened(ud)) 588 break; 589 590 stub_rx_pdu(ud); 591 } 592 593 return 0; 594 } 595