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 = 0; 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 } 216 217 static void stub_device_rebind(void) 218 { 219 #if IS_MODULE(CONFIG_USBIP_HOST) 220 struct bus_id_priv *busid_priv; 221 int i; 222 223 /* update status to STUB_BUSID_OTHER so probe ignores the device */ 224 spin_lock(&busid_table_lock); 225 for (i = 0; i < MAX_BUSID; i++) { 226 if (busid_table[i].name[0] && 227 busid_table[i].shutdown_busid) { 228 busid_priv = &(busid_table[i]); 229 busid_priv->status = STUB_BUSID_OTHER; 230 } 231 } 232 spin_unlock(&busid_table_lock); 233 234 /* now run rebind - no need to hold locks. driver files are removed */ 235 for (i = 0; i < MAX_BUSID; i++) { 236 if (busid_table[i].name[0] && 237 busid_table[i].shutdown_busid) { 238 busid_priv = &(busid_table[i]); 239 do_rebind(busid_table[i].name, busid_priv); 240 } 241 } 242 #endif 243 } 244 245 static ssize_t rebind_store(struct device_driver *dev, const char *buf, 246 size_t count) 247 { 248 int ret; 249 int len; 250 struct bus_id_priv *bid; 251 252 /* buf length should be less that BUSID_SIZE */ 253 len = strnlen(buf, BUSID_SIZE); 254 255 if (!(len < BUSID_SIZE)) 256 return -EINVAL; 257 258 bid = get_busid_priv(buf); 259 if (!bid) 260 return -ENODEV; 261 262 /* mark the device for deletion so probe ignores it during rescan */ 263 bid->status = STUB_BUSID_OTHER; 264 /* release the busid lock */ 265 put_busid_priv(bid); 266 267 ret = do_rebind((char *) buf, bid); 268 if (ret < 0) 269 return ret; 270 271 /* delete device from busid_table */ 272 del_match_busid((char *) buf); 273 274 return count; 275 } 276 277 static DRIVER_ATTR_WO(rebind); 278 279 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead) 280 { 281 struct stub_priv *priv, *tmp; 282 283 list_for_each_entry_safe(priv, tmp, listhead, list) { 284 list_del(&priv->list); 285 return priv; 286 } 287 288 return NULL; 289 } 290 291 static struct stub_priv *stub_priv_pop(struct stub_device *sdev) 292 { 293 unsigned long flags; 294 struct stub_priv *priv; 295 296 spin_lock_irqsave(&sdev->priv_lock, flags); 297 298 priv = stub_priv_pop_from_listhead(&sdev->priv_init); 299 if (priv) 300 goto done; 301 302 priv = stub_priv_pop_from_listhead(&sdev->priv_tx); 303 if (priv) 304 goto done; 305 306 priv = stub_priv_pop_from_listhead(&sdev->priv_free); 307 308 done: 309 spin_unlock_irqrestore(&sdev->priv_lock, flags); 310 311 return priv; 312 } 313 314 void stub_device_cleanup_urbs(struct stub_device *sdev) 315 { 316 struct stub_priv *priv; 317 struct urb *urb; 318 319 dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n"); 320 321 while ((priv = stub_priv_pop(sdev))) { 322 urb = priv->urb; 323 dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n", 324 priv->seqnum); 325 usb_kill_urb(urb); 326 327 kmem_cache_free(stub_priv_cache, priv); 328 329 kfree(urb->transfer_buffer); 330 urb->transfer_buffer = NULL; 331 332 kfree(urb->setup_packet); 333 urb->setup_packet = NULL; 334 335 usb_free_urb(urb); 336 } 337 } 338 339 static int __init usbip_host_init(void) 340 { 341 int ret; 342 343 init_busid_table(); 344 345 stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN); 346 if (!stub_priv_cache) { 347 pr_err("kmem_cache_create failed\n"); 348 return -ENOMEM; 349 } 350 351 ret = usb_register_device_driver(&stub_driver, THIS_MODULE); 352 if (ret) { 353 pr_err("usb_register failed %d\n", ret); 354 goto err_usb_register; 355 } 356 357 ret = driver_create_file(&stub_driver.drvwrap.driver, 358 &driver_attr_match_busid); 359 if (ret) { 360 pr_err("driver_create_file failed\n"); 361 goto err_create_file; 362 } 363 364 ret = driver_create_file(&stub_driver.drvwrap.driver, 365 &driver_attr_rebind); 366 if (ret) { 367 pr_err("driver_create_file failed\n"); 368 goto err_create_file; 369 } 370 371 return ret; 372 373 err_create_file: 374 usb_deregister_device_driver(&stub_driver); 375 err_usb_register: 376 kmem_cache_destroy(stub_priv_cache); 377 return ret; 378 } 379 380 static void __exit usbip_host_exit(void) 381 { 382 driver_remove_file(&stub_driver.drvwrap.driver, 383 &driver_attr_match_busid); 384 385 driver_remove_file(&stub_driver.drvwrap.driver, 386 &driver_attr_rebind); 387 388 /* 389 * deregister() calls stub_disconnect() for all devices. Device 390 * specific data is cleared in stub_disconnect(). 391 */ 392 usb_deregister_device_driver(&stub_driver); 393 394 /* initiate scan to attach devices */ 395 stub_device_rebind(); 396 397 kmem_cache_destroy(stub_priv_cache); 398 } 399 400 module_init(usbip_host_init); 401 module_exit(usbip_host_exit); 402 403 MODULE_AUTHOR(DRIVER_AUTHOR); 404 MODULE_DESCRIPTION(DRIVER_DESC); 405 MODULE_LICENSE("GPL"); 406