1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2003-2008 Takahiro Hirofuchi 4 */ 5 6 #include <linux/device.h> 7 #include <linux/file.h> 8 #include <linux/kthread.h> 9 #include <linux/module.h> 10 11 #include "usbip_common.h" 12 #include "stub.h" 13 14 /* 15 * usbip_status shows the status of usbip-host as long as this driver is bound 16 * to the target device. 17 */ 18 static ssize_t usbip_status_show(struct device *dev, 19 struct device_attribute *attr, char *buf) 20 { 21 struct stub_device *sdev = dev_get_drvdata(dev); 22 int status; 23 24 if (!sdev) { 25 dev_err(dev, "sdev is null\n"); 26 return -ENODEV; 27 } 28 29 spin_lock_irq(&sdev->ud.lock); 30 status = sdev->ud.status; 31 spin_unlock_irq(&sdev->ud.lock); 32 33 return snprintf(buf, PAGE_SIZE, "%d\n", status); 34 } 35 static DEVICE_ATTR_RO(usbip_status); 36 37 /* 38 * usbip_sockfd gets a socket descriptor of an established TCP connection that 39 * is used to transfer usbip requests by kernel threads. -1 is a magic number 40 * by which usbip connection is finished. 41 */ 42 static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr, 43 const char *buf, size_t count) 44 { 45 struct stub_device *sdev = dev_get_drvdata(dev); 46 int sockfd = 0; 47 struct socket *socket; 48 int rv; 49 50 if (!sdev) { 51 dev_err(dev, "sdev is null\n"); 52 return -ENODEV; 53 } 54 55 rv = sscanf(buf, "%d", &sockfd); 56 if (rv != 1) 57 return -EINVAL; 58 59 if (sockfd != -1) { 60 int err; 61 62 dev_info(dev, "stub up\n"); 63 64 spin_lock_irq(&sdev->ud.lock); 65 66 if (sdev->ud.status != SDEV_ST_AVAILABLE) { 67 dev_err(dev, "not ready\n"); 68 goto err; 69 } 70 71 socket = sockfd_lookup(sockfd, &err); 72 if (!socket) 73 goto err; 74 75 sdev->ud.tcp_socket = socket; 76 77 spin_unlock_irq(&sdev->ud.lock); 78 79 sdev->ud.tcp_rx = kthread_get_run(stub_rx_loop, &sdev->ud, 80 "stub_rx"); 81 sdev->ud.tcp_tx = kthread_get_run(stub_tx_loop, &sdev->ud, 82 "stub_tx"); 83 84 spin_lock_irq(&sdev->ud.lock); 85 sdev->ud.status = SDEV_ST_USED; 86 spin_unlock_irq(&sdev->ud.lock); 87 88 } else { 89 dev_info(dev, "stub down\n"); 90 91 spin_lock_irq(&sdev->ud.lock); 92 if (sdev->ud.status != SDEV_ST_USED) 93 goto err; 94 95 spin_unlock_irq(&sdev->ud.lock); 96 97 usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN); 98 } 99 100 return count; 101 102 err: 103 spin_unlock_irq(&sdev->ud.lock); 104 return -EINVAL; 105 } 106 static DEVICE_ATTR_WO(usbip_sockfd); 107 108 static int stub_add_files(struct device *dev) 109 { 110 int err = 0; 111 112 err = device_create_file(dev, &dev_attr_usbip_status); 113 if (err) 114 goto err_status; 115 116 err = device_create_file(dev, &dev_attr_usbip_sockfd); 117 if (err) 118 goto err_sockfd; 119 120 err = device_create_file(dev, &dev_attr_usbip_debug); 121 if (err) 122 goto err_debug; 123 124 return 0; 125 126 err_debug: 127 device_remove_file(dev, &dev_attr_usbip_sockfd); 128 err_sockfd: 129 device_remove_file(dev, &dev_attr_usbip_status); 130 err_status: 131 return err; 132 } 133 134 static void stub_remove_files(struct device *dev) 135 { 136 device_remove_file(dev, &dev_attr_usbip_status); 137 device_remove_file(dev, &dev_attr_usbip_sockfd); 138 device_remove_file(dev, &dev_attr_usbip_debug); 139 } 140 141 static void stub_shutdown_connection(struct usbip_device *ud) 142 { 143 struct stub_device *sdev = container_of(ud, struct stub_device, ud); 144 145 /* 146 * When removing an exported device, kernel panic sometimes occurred 147 * and then EIP was sk_wait_data of stub_rx thread. Is this because 148 * sk_wait_data returned though stub_rx thread was already finished by 149 * step 1? 150 */ 151 if (ud->tcp_socket) { 152 dev_dbg(&sdev->udev->dev, "shutdown sockfd %d\n", ud->sockfd); 153 kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR); 154 } 155 156 /* 1. stop threads */ 157 if (ud->tcp_rx) { 158 kthread_stop_put(ud->tcp_rx); 159 ud->tcp_rx = NULL; 160 } 161 if (ud->tcp_tx) { 162 kthread_stop_put(ud->tcp_tx); 163 ud->tcp_tx = NULL; 164 } 165 166 /* 167 * 2. close the socket 168 * 169 * tcp_socket is freed after threads are killed so that usbip_xmit does 170 * not touch NULL socket. 171 */ 172 if (ud->tcp_socket) { 173 sockfd_put(ud->tcp_socket); 174 ud->tcp_socket = NULL; 175 } 176 177 /* 3. free used data */ 178 stub_device_cleanup_urbs(sdev); 179 180 /* 4. free stub_unlink */ 181 { 182 unsigned long flags; 183 struct stub_unlink *unlink, *tmp; 184 185 spin_lock_irqsave(&sdev->priv_lock, flags); 186 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) { 187 list_del(&unlink->list); 188 kfree(unlink); 189 } 190 list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, 191 list) { 192 list_del(&unlink->list); 193 kfree(unlink); 194 } 195 spin_unlock_irqrestore(&sdev->priv_lock, flags); 196 } 197 } 198 199 static void stub_device_reset(struct usbip_device *ud) 200 { 201 struct stub_device *sdev = container_of(ud, struct stub_device, ud); 202 struct usb_device *udev = sdev->udev; 203 int ret; 204 205 dev_dbg(&udev->dev, "device reset"); 206 207 ret = usb_lock_device_for_reset(udev, NULL); 208 if (ret < 0) { 209 dev_err(&udev->dev, "lock for reset\n"); 210 spin_lock_irq(&ud->lock); 211 ud->status = SDEV_ST_ERROR; 212 spin_unlock_irq(&ud->lock); 213 return; 214 } 215 216 /* try to reset the device */ 217 ret = usb_reset_device(udev); 218 usb_unlock_device(udev); 219 220 spin_lock_irq(&ud->lock); 221 if (ret) { 222 dev_err(&udev->dev, "device reset\n"); 223 ud->status = SDEV_ST_ERROR; 224 } else { 225 dev_info(&udev->dev, "device reset\n"); 226 ud->status = SDEV_ST_AVAILABLE; 227 } 228 spin_unlock_irq(&ud->lock); 229 } 230 231 static void stub_device_unusable(struct usbip_device *ud) 232 { 233 spin_lock_irq(&ud->lock); 234 ud->status = SDEV_ST_ERROR; 235 spin_unlock_irq(&ud->lock); 236 } 237 238 /** 239 * stub_device_alloc - allocate a new stub_device struct 240 * @udev: usb_device of a new device 241 * 242 * Allocates and initializes a new stub_device struct. 243 */ 244 static struct stub_device *stub_device_alloc(struct usb_device *udev) 245 { 246 struct stub_device *sdev; 247 int busnum = udev->bus->busnum; 248 int devnum = udev->devnum; 249 250 dev_dbg(&udev->dev, "allocating stub device"); 251 252 /* yes, it's a new device */ 253 sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL); 254 if (!sdev) 255 return NULL; 256 257 sdev->udev = usb_get_dev(udev); 258 259 /* 260 * devid is defined with devnum when this driver is first allocated. 261 * devnum may change later if a device is reset. However, devid never 262 * changes during a usbip connection. 263 */ 264 sdev->devid = (busnum << 16) | devnum; 265 sdev->ud.side = USBIP_STUB; 266 sdev->ud.status = SDEV_ST_AVAILABLE; 267 spin_lock_init(&sdev->ud.lock); 268 sdev->ud.tcp_socket = NULL; 269 270 INIT_LIST_HEAD(&sdev->priv_init); 271 INIT_LIST_HEAD(&sdev->priv_tx); 272 INIT_LIST_HEAD(&sdev->priv_free); 273 INIT_LIST_HEAD(&sdev->unlink_free); 274 INIT_LIST_HEAD(&sdev->unlink_tx); 275 spin_lock_init(&sdev->priv_lock); 276 277 init_waitqueue_head(&sdev->tx_waitq); 278 279 sdev->ud.eh_ops.shutdown = stub_shutdown_connection; 280 sdev->ud.eh_ops.reset = stub_device_reset; 281 sdev->ud.eh_ops.unusable = stub_device_unusable; 282 283 usbip_start_eh(&sdev->ud); 284 285 dev_dbg(&udev->dev, "register new device\n"); 286 287 return sdev; 288 } 289 290 static void stub_device_free(struct stub_device *sdev) 291 { 292 kfree(sdev); 293 } 294 295 static int stub_probe(struct usb_device *udev) 296 { 297 struct stub_device *sdev = NULL; 298 const char *udev_busid = dev_name(&udev->dev); 299 struct bus_id_priv *busid_priv; 300 int rc; 301 302 dev_dbg(&udev->dev, "Enter\n"); 303 304 /* check we should claim or not by busid_table */ 305 busid_priv = get_busid_priv(udev_busid); 306 if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) || 307 (busid_priv->status == STUB_BUSID_OTHER)) { 308 dev_info(&udev->dev, 309 "%s is not in match_busid table... skip!\n", 310 udev_busid); 311 312 /* 313 * Return value should be ENODEV or ENOXIO to continue trying 314 * other matched drivers by the driver core. 315 * See driver_probe_device() in driver/base/dd.c 316 */ 317 return -ENODEV; 318 } 319 320 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) { 321 dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n", 322 udev_busid); 323 return -ENODEV; 324 } 325 326 if (!strcmp(udev->bus->bus_name, "vhci_hcd")) { 327 dev_dbg(&udev->dev, 328 "%s is attached on vhci_hcd... skip!\n", 329 udev_busid); 330 331 return -ENODEV; 332 } 333 334 /* ok, this is my device */ 335 sdev = stub_device_alloc(udev); 336 if (!sdev) 337 return -ENOMEM; 338 339 dev_info(&udev->dev, 340 "usbip-host: register new device (bus %u dev %u)\n", 341 udev->bus->busnum, udev->devnum); 342 343 busid_priv->shutdown_busid = 0; 344 345 /* set private data to usb_device */ 346 dev_set_drvdata(&udev->dev, sdev); 347 busid_priv->sdev = sdev; 348 busid_priv->udev = udev; 349 350 /* 351 * Claim this hub port. 352 * It doesn't matter what value we pass as owner 353 * (struct dev_state) as long as it is unique. 354 */ 355 rc = usb_hub_claim_port(udev->parent, udev->portnum, 356 (struct usb_dev_state *) udev); 357 if (rc) { 358 dev_dbg(&udev->dev, "unable to claim port\n"); 359 goto err_port; 360 } 361 362 rc = stub_add_files(&udev->dev); 363 if (rc) { 364 dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid); 365 goto err_files; 366 } 367 busid_priv->status = STUB_BUSID_ALLOC; 368 369 return 0; 370 err_files: 371 usb_hub_release_port(udev->parent, udev->portnum, 372 (struct usb_dev_state *) udev); 373 err_port: 374 dev_set_drvdata(&udev->dev, NULL); 375 usb_put_dev(udev); 376 377 busid_priv->sdev = NULL; 378 stub_device_free(sdev); 379 return rc; 380 } 381 382 static void shutdown_busid(struct bus_id_priv *busid_priv) 383 { 384 if (busid_priv->sdev && !busid_priv->shutdown_busid) { 385 busid_priv->shutdown_busid = 1; 386 usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED); 387 388 /* wait for the stop of the event handler */ 389 usbip_stop_eh(&busid_priv->sdev->ud); 390 } 391 } 392 393 /* 394 * called in usb_disconnect() or usb_deregister() 395 * but only if actconfig(active configuration) exists 396 */ 397 static void stub_disconnect(struct usb_device *udev) 398 { 399 struct stub_device *sdev; 400 const char *udev_busid = dev_name(&udev->dev); 401 struct bus_id_priv *busid_priv; 402 int rc; 403 404 dev_dbg(&udev->dev, "Enter\n"); 405 406 busid_priv = get_busid_priv(udev_busid); 407 if (!busid_priv) { 408 BUG(); 409 return; 410 } 411 412 sdev = dev_get_drvdata(&udev->dev); 413 414 /* get stub_device */ 415 if (!sdev) { 416 dev_err(&udev->dev, "could not get device"); 417 return; 418 } 419 420 dev_set_drvdata(&udev->dev, NULL); 421 422 /* 423 * NOTE: rx/tx threads are invoked for each usb_device. 424 */ 425 stub_remove_files(&udev->dev); 426 427 /* release port */ 428 rc = usb_hub_release_port(udev->parent, udev->portnum, 429 (struct usb_dev_state *) udev); 430 if (rc) { 431 dev_dbg(&udev->dev, "unable to release port\n"); 432 return; 433 } 434 435 /* If usb reset is called from event handler */ 436 if (usbip_in_eh(current)) 437 return; 438 439 /* shutdown the current connection */ 440 shutdown_busid(busid_priv); 441 442 usb_put_dev(sdev->udev); 443 444 /* free sdev */ 445 busid_priv->sdev = NULL; 446 stub_device_free(sdev); 447 448 if (busid_priv->status == STUB_BUSID_ALLOC) { 449 busid_priv->status = STUB_BUSID_ADDED; 450 } else { 451 busid_priv->status = STUB_BUSID_OTHER; 452 del_match_busid((char *)udev_busid); 453 } 454 } 455 456 #ifdef CONFIG_PM 457 458 /* These functions need usb_port_suspend and usb_port_resume, 459 * which reside in drivers/usb/core/usb.h. Skip for now. */ 460 461 static int stub_suspend(struct usb_device *udev, pm_message_t message) 462 { 463 dev_dbg(&udev->dev, "stub_suspend\n"); 464 465 return 0; 466 } 467 468 static int stub_resume(struct usb_device *udev, pm_message_t message) 469 { 470 dev_dbg(&udev->dev, "stub_resume\n"); 471 472 return 0; 473 } 474 475 #endif /* CONFIG_PM */ 476 477 struct usb_device_driver stub_driver = { 478 .name = "usbip-host", 479 .probe = stub_probe, 480 .disconnect = stub_disconnect, 481 #ifdef CONFIG_PM 482 .suspend = stub_suspend, 483 .resume = stub_resume, 484 #endif 485 .supports_autosuspend = 0, 486 }; 487