1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2003-2008 Takahiro Hirofuchi 4 */ 5 6 #include <linux/string.h> 7 #include <linux/module.h> 8 #include <linux/device.h> 9 10 #include "usbip_common.h" 11 #include "stub.h" 12 13 #define DRIVER_AUTHOR "Takahiro Hirofuchi" 14 #define DRIVER_DESC "USB/IP Host Driver" 15 16 struct kmem_cache *stub_priv_cache; 17 18 /* 19 * busid_tables defines matching busids that usbip can grab. A user can change 20 * dynamically what device is locally used and what device is exported to a 21 * remote host. 22 */ 23 #define MAX_BUSID 16 24 static struct bus_id_priv busid_table[MAX_BUSID]; 25 static spinlock_t busid_table_lock; 26 27 static void init_busid_table(void) 28 { 29 int i; 30 31 /* 32 * This also sets the bus_table[i].status to 33 * STUB_BUSID_OTHER, which is 0. 34 */ 35 memset(busid_table, 0, sizeof(busid_table)); 36 37 spin_lock_init(&busid_table_lock); 38 39 for (i = 0; i < MAX_BUSID; i++) 40 spin_lock_init(&busid_table[i].busid_lock); 41 } 42 43 /* 44 * Find the index of the busid by name. 45 * Must be called with busid_table_lock held. 46 */ 47 static int get_busid_idx(const char *busid) 48 { 49 int i; 50 int idx = -1; 51 52 for (i = 0; i < MAX_BUSID; i++) { 53 spin_lock(&busid_table[i].busid_lock); 54 if (busid_table[i].name[0]) 55 if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) { 56 idx = i; 57 spin_unlock(&busid_table[i].busid_lock); 58 break; 59 } 60 spin_unlock(&busid_table[i].busid_lock); 61 } 62 return idx; 63 } 64 65 /* Returns holding busid_lock. Should call put_busid_priv() to unlock */ 66 struct bus_id_priv *get_busid_priv(const char *busid) 67 { 68 int idx; 69 struct bus_id_priv *bid = NULL; 70 71 spin_lock(&busid_table_lock); 72 idx = get_busid_idx(busid); 73 if (idx >= 0) { 74 bid = &(busid_table[idx]); 75 /* get busid_lock before returning */ 76 spin_lock(&bid->busid_lock); 77 } 78 spin_unlock(&busid_table_lock); 79 80 return bid; 81 } 82 83 void put_busid_priv(struct bus_id_priv *bid) 84 { 85 if (bid) 86 spin_unlock(&bid->busid_lock); 87 } 88 89 static int add_match_busid(char *busid) 90 { 91 int i; 92 int ret = -1; 93 94 spin_lock(&busid_table_lock); 95 /* already registered? */ 96 if (get_busid_idx(busid) >= 0) { 97 ret = 0; 98 goto out; 99 } 100 101 for (i = 0; i < MAX_BUSID; i++) { 102 spin_lock(&busid_table[i].busid_lock); 103 if (!busid_table[i].name[0]) { 104 strlcpy(busid_table[i].name, busid, BUSID_SIZE); 105 if ((busid_table[i].status != STUB_BUSID_ALLOC) && 106 (busid_table[i].status != STUB_BUSID_REMOV)) 107 busid_table[i].status = STUB_BUSID_ADDED; 108 ret = 0; 109 spin_unlock(&busid_table[i].busid_lock); 110 break; 111 } 112 spin_unlock(&busid_table[i].busid_lock); 113 } 114 115 out: 116 spin_unlock(&busid_table_lock); 117 118 return ret; 119 } 120 121 int del_match_busid(char *busid) 122 { 123 int idx; 124 int ret = -1; 125 126 spin_lock(&busid_table_lock); 127 idx = get_busid_idx(busid); 128 if (idx < 0) 129 goto out; 130 131 /* found */ 132 ret = 0; 133 134 spin_lock(&busid_table[idx].busid_lock); 135 136 if (busid_table[idx].status == STUB_BUSID_OTHER) 137 memset(busid_table[idx].name, 0, BUSID_SIZE); 138 139 if ((busid_table[idx].status != STUB_BUSID_OTHER) && 140 (busid_table[idx].status != STUB_BUSID_ADDED)) 141 busid_table[idx].status = STUB_BUSID_REMOV; 142 143 spin_unlock(&busid_table[idx].busid_lock); 144 out: 145 spin_unlock(&busid_table_lock); 146 147 return ret; 148 } 149 150 static ssize_t match_busid_show(struct device_driver *drv, char *buf) 151 { 152 int i; 153 char *out = buf; 154 155 spin_lock(&busid_table_lock); 156 for (i = 0; i < MAX_BUSID; i++) { 157 spin_lock(&busid_table[i].busid_lock); 158 if (busid_table[i].name[0]) 159 out += sprintf(out, "%s ", busid_table[i].name); 160 spin_unlock(&busid_table[i].busid_lock); 161 } 162 spin_unlock(&busid_table_lock); 163 out += sprintf(out, "\n"); 164 165 return out - buf; 166 } 167 168 static ssize_t match_busid_store(struct device_driver *dev, const char *buf, 169 size_t count) 170 { 171 int len; 172 char busid[BUSID_SIZE]; 173 174 if (count < 5) 175 return -EINVAL; 176 177 /* busid needs to include \0 termination */ 178 len = strlcpy(busid, buf + 4, BUSID_SIZE); 179 if (sizeof(busid) <= len) 180 return -EINVAL; 181 182 if (!strncmp(buf, "add ", 4)) { 183 if (add_match_busid(busid) < 0) 184 return -ENOMEM; 185 186 pr_debug("add busid %s\n", busid); 187 return count; 188 } 189 190 if (!strncmp(buf, "del ", 4)) { 191 if (del_match_busid(busid) < 0) 192 return -ENODEV; 193 194 pr_debug("del busid %s\n", busid); 195 return count; 196 } 197 198 return -EINVAL; 199 } 200 static DRIVER_ATTR_RW(match_busid); 201 202 static int do_rebind(char *busid, struct bus_id_priv *busid_priv) 203 { 204 int ret; 205 206 /* device_attach() callers should hold parent lock for USB */ 207 if (busid_priv->udev->dev.parent) 208 device_lock(busid_priv->udev->dev.parent); 209 ret = device_attach(&busid_priv->udev->dev); 210 if (busid_priv->udev->dev.parent) 211 device_unlock(busid_priv->udev->dev.parent); 212 if (ret < 0) { 213 dev_err(&busid_priv->udev->dev, "rebind failed\n"); 214 return ret; 215 } 216 return 0; 217 } 218 219 static void stub_device_rebind(void) 220 { 221 #if IS_MODULE(CONFIG_USBIP_HOST) 222 struct bus_id_priv *busid_priv; 223 int i; 224 225 /* update status to STUB_BUSID_OTHER so probe ignores the device */ 226 spin_lock(&busid_table_lock); 227 for (i = 0; i < MAX_BUSID; i++) { 228 if (busid_table[i].name[0] && 229 busid_table[i].shutdown_busid) { 230 busid_priv = &(busid_table[i]); 231 busid_priv->status = STUB_BUSID_OTHER; 232 } 233 } 234 spin_unlock(&busid_table_lock); 235 236 /* now run rebind - no need to hold locks. driver files are removed */ 237 for (i = 0; i < MAX_BUSID; i++) { 238 if (busid_table[i].name[0] && 239 busid_table[i].shutdown_busid) { 240 busid_priv = &(busid_table[i]); 241 do_rebind(busid_table[i].name, busid_priv); 242 } 243 } 244 #endif 245 } 246 247 static ssize_t rebind_store(struct device_driver *dev, const char *buf, 248 size_t count) 249 { 250 int ret; 251 int len; 252 struct bus_id_priv *bid; 253 254 /* buf length should be less that BUSID_SIZE */ 255 len = strnlen(buf, BUSID_SIZE); 256 257 if (!(len < BUSID_SIZE)) 258 return -EINVAL; 259 260 bid = get_busid_priv(buf); 261 if (!bid) 262 return -ENODEV; 263 264 /* mark the device for deletion so probe ignores it during rescan */ 265 bid->status = STUB_BUSID_OTHER; 266 /* release the busid lock */ 267 put_busid_priv(bid); 268 269 ret = do_rebind((char *) buf, bid); 270 if (ret < 0) 271 return ret; 272 273 /* delete device from busid_table */ 274 del_match_busid((char *) buf); 275 276 return count; 277 } 278 279 static DRIVER_ATTR_WO(rebind); 280 281 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead) 282 { 283 struct stub_priv *priv, *tmp; 284 285 list_for_each_entry_safe(priv, tmp, listhead, list) { 286 list_del(&priv->list); 287 return priv; 288 } 289 290 return NULL; 291 } 292 293 static struct stub_priv *stub_priv_pop(struct stub_device *sdev) 294 { 295 unsigned long flags; 296 struct stub_priv *priv; 297 298 spin_lock_irqsave(&sdev->priv_lock, flags); 299 300 priv = stub_priv_pop_from_listhead(&sdev->priv_init); 301 if (priv) 302 goto done; 303 304 priv = stub_priv_pop_from_listhead(&sdev->priv_tx); 305 if (priv) 306 goto done; 307 308 priv = stub_priv_pop_from_listhead(&sdev->priv_free); 309 310 done: 311 spin_unlock_irqrestore(&sdev->priv_lock, flags); 312 313 return priv; 314 } 315 316 void stub_device_cleanup_urbs(struct stub_device *sdev) 317 { 318 struct stub_priv *priv; 319 struct urb *urb; 320 321 dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n"); 322 323 while ((priv = stub_priv_pop(sdev))) { 324 urb = priv->urb; 325 dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n", 326 priv->seqnum); 327 usb_kill_urb(urb); 328 329 kmem_cache_free(stub_priv_cache, priv); 330 331 kfree(urb->transfer_buffer); 332 urb->transfer_buffer = NULL; 333 334 kfree(urb->setup_packet); 335 urb->setup_packet = NULL; 336 337 usb_free_urb(urb); 338 } 339 } 340 341 static int __init usbip_host_init(void) 342 { 343 int ret; 344 345 init_busid_table(); 346 347 stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN); 348 if (!stub_priv_cache) { 349 pr_err("kmem_cache_create failed\n"); 350 return -ENOMEM; 351 } 352 353 ret = usb_register_device_driver(&stub_driver, THIS_MODULE); 354 if (ret) { 355 pr_err("usb_register failed %d\n", ret); 356 goto err_usb_register; 357 } 358 359 ret = driver_create_file(&stub_driver.drvwrap.driver, 360 &driver_attr_match_busid); 361 if (ret) { 362 pr_err("driver_create_file failed\n"); 363 goto err_create_file; 364 } 365 366 ret = driver_create_file(&stub_driver.drvwrap.driver, 367 &driver_attr_rebind); 368 if (ret) { 369 pr_err("driver_create_file failed\n"); 370 goto err_create_file; 371 } 372 373 return ret; 374 375 err_create_file: 376 usb_deregister_device_driver(&stub_driver); 377 err_usb_register: 378 kmem_cache_destroy(stub_priv_cache); 379 return ret; 380 } 381 382 static void __exit usbip_host_exit(void) 383 { 384 driver_remove_file(&stub_driver.drvwrap.driver, 385 &driver_attr_match_busid); 386 387 driver_remove_file(&stub_driver.drvwrap.driver, 388 &driver_attr_rebind); 389 390 /* 391 * deregister() calls stub_disconnect() for all devices. Device 392 * specific data is cleared in stub_disconnect(). 393 */ 394 usb_deregister_device_driver(&stub_driver); 395 396 /* initiate scan to attach devices */ 397 stub_device_rebind(); 398 399 kmem_cache_destroy(stub_priv_cache); 400 } 401 402 module_init(usbip_host_init); 403 module_exit(usbip_host_exit); 404 405 MODULE_AUTHOR(DRIVER_AUTHOR); 406 MODULE_DESCRIPTION(DRIVER_DESC); 407 MODULE_LICENSE("GPL"); 408