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 * busid_tables defines matching busids that usbip can grab. A user can change 19 * dynamically what device is locally used and what device is exported to a 20 * remote host. 21 */ 22 #define MAX_BUSID 16 23 static struct bus_id_priv busid_table[MAX_BUSID]; 24 static spinlock_t busid_table_lock; 25 26 static void init_busid_table(void) 27 { 28 /* 29 * This also sets the bus_table[i].status to 30 * STUB_BUSID_OTHER, which is 0. 31 */ 32 memset(busid_table, 0, sizeof(busid_table)); 33 34 spin_lock_init(&busid_table_lock); 35 } 36 37 /* 38 * Find the index of the busid by name. 39 * Must be called with busid_table_lock held. 40 */ 41 static int get_busid_idx(const char *busid) 42 { 43 int i; 44 int idx = -1; 45 46 for (i = 0; i < MAX_BUSID; i++) 47 if (busid_table[i].name[0]) 48 if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) { 49 idx = i; 50 break; 51 } 52 return idx; 53 } 54 55 struct bus_id_priv *get_busid_priv(const char *busid) 56 { 57 int idx; 58 struct bus_id_priv *bid = NULL; 59 60 spin_lock(&busid_table_lock); 61 idx = get_busid_idx(busid); 62 if (idx >= 0) 63 bid = &(busid_table[idx]); 64 spin_unlock(&busid_table_lock); 65 66 return bid; 67 } 68 69 static int add_match_busid(char *busid) 70 { 71 int i; 72 int ret = -1; 73 74 spin_lock(&busid_table_lock); 75 /* already registered? */ 76 if (get_busid_idx(busid) >= 0) { 77 ret = 0; 78 goto out; 79 } 80 81 for (i = 0; i < MAX_BUSID; i++) 82 if (!busid_table[i].name[0]) { 83 strlcpy(busid_table[i].name, busid, BUSID_SIZE); 84 if ((busid_table[i].status != STUB_BUSID_ALLOC) && 85 (busid_table[i].status != STUB_BUSID_REMOV)) 86 busid_table[i].status = STUB_BUSID_ADDED; 87 ret = 0; 88 break; 89 } 90 91 out: 92 spin_unlock(&busid_table_lock); 93 94 return ret; 95 } 96 97 int del_match_busid(char *busid) 98 { 99 int idx; 100 int ret = -1; 101 102 spin_lock(&busid_table_lock); 103 idx = get_busid_idx(busid); 104 if (idx < 0) 105 goto out; 106 107 /* found */ 108 ret = 0; 109 110 if (busid_table[idx].status == STUB_BUSID_OTHER) 111 memset(busid_table[idx].name, 0, BUSID_SIZE); 112 113 if ((busid_table[idx].status != STUB_BUSID_OTHER) && 114 (busid_table[idx].status != STUB_BUSID_ADDED)) 115 busid_table[idx].status = STUB_BUSID_REMOV; 116 117 out: 118 spin_unlock(&busid_table_lock); 119 120 return ret; 121 } 122 123 static ssize_t match_busid_show(struct device_driver *drv, char *buf) 124 { 125 int i; 126 char *out = buf; 127 128 spin_lock(&busid_table_lock); 129 for (i = 0; i < MAX_BUSID; i++) 130 if (busid_table[i].name[0]) 131 out += sprintf(out, "%s ", busid_table[i].name); 132 spin_unlock(&busid_table_lock); 133 out += sprintf(out, "\n"); 134 135 return out - buf; 136 } 137 138 static ssize_t match_busid_store(struct device_driver *dev, const char *buf, 139 size_t count) 140 { 141 int len; 142 char busid[BUSID_SIZE]; 143 144 if (count < 5) 145 return -EINVAL; 146 147 /* busid needs to include \0 termination */ 148 len = strlcpy(busid, buf + 4, BUSID_SIZE); 149 if (sizeof(busid) <= len) 150 return -EINVAL; 151 152 if (!strncmp(buf, "add ", 4)) { 153 if (add_match_busid(busid) < 0) 154 return -ENOMEM; 155 156 pr_debug("add busid %s\n", busid); 157 return count; 158 } 159 160 if (!strncmp(buf, "del ", 4)) { 161 if (del_match_busid(busid) < 0) 162 return -ENODEV; 163 164 pr_debug("del busid %s\n", busid); 165 return count; 166 } 167 168 return -EINVAL; 169 } 170 static DRIVER_ATTR_RW(match_busid); 171 172 static ssize_t rebind_store(struct device_driver *dev, const char *buf, 173 size_t count) 174 { 175 int ret; 176 int len; 177 struct bus_id_priv *bid; 178 179 /* buf length should be less that BUSID_SIZE */ 180 len = strnlen(buf, BUSID_SIZE); 181 182 if (!(len < BUSID_SIZE)) 183 return -EINVAL; 184 185 bid = get_busid_priv(buf); 186 if (!bid) 187 return -ENODEV; 188 189 ret = device_attach(&bid->udev->dev); 190 if (ret < 0) { 191 dev_err(&bid->udev->dev, "rebind failed\n"); 192 return ret; 193 } 194 195 return count; 196 } 197 198 static DRIVER_ATTR_WO(rebind); 199 200 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead) 201 { 202 struct stub_priv *priv, *tmp; 203 204 list_for_each_entry_safe(priv, tmp, listhead, list) { 205 list_del(&priv->list); 206 return priv; 207 } 208 209 return NULL; 210 } 211 212 static struct stub_priv *stub_priv_pop(struct stub_device *sdev) 213 { 214 unsigned long flags; 215 struct stub_priv *priv; 216 217 spin_lock_irqsave(&sdev->priv_lock, flags); 218 219 priv = stub_priv_pop_from_listhead(&sdev->priv_init); 220 if (priv) 221 goto done; 222 223 priv = stub_priv_pop_from_listhead(&sdev->priv_tx); 224 if (priv) 225 goto done; 226 227 priv = stub_priv_pop_from_listhead(&sdev->priv_free); 228 229 done: 230 spin_unlock_irqrestore(&sdev->priv_lock, flags); 231 232 return priv; 233 } 234 235 void stub_device_cleanup_urbs(struct stub_device *sdev) 236 { 237 struct stub_priv *priv; 238 struct urb *urb; 239 240 dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n"); 241 242 while ((priv = stub_priv_pop(sdev))) { 243 urb = priv->urb; 244 dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n", 245 priv->seqnum); 246 usb_kill_urb(urb); 247 248 kmem_cache_free(stub_priv_cache, priv); 249 250 kfree(urb->transfer_buffer); 251 urb->transfer_buffer = NULL; 252 253 kfree(urb->setup_packet); 254 urb->setup_packet = NULL; 255 256 usb_free_urb(urb); 257 } 258 } 259 260 static int __init usbip_host_init(void) 261 { 262 int ret; 263 264 init_busid_table(); 265 266 stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN); 267 if (!stub_priv_cache) { 268 pr_err("kmem_cache_create failed\n"); 269 return -ENOMEM; 270 } 271 272 ret = usb_register_device_driver(&stub_driver, THIS_MODULE); 273 if (ret) { 274 pr_err("usb_register failed %d\n", ret); 275 goto err_usb_register; 276 } 277 278 ret = driver_create_file(&stub_driver.drvwrap.driver, 279 &driver_attr_match_busid); 280 if (ret) { 281 pr_err("driver_create_file failed\n"); 282 goto err_create_file; 283 } 284 285 ret = driver_create_file(&stub_driver.drvwrap.driver, 286 &driver_attr_rebind); 287 if (ret) { 288 pr_err("driver_create_file failed\n"); 289 goto err_create_file; 290 } 291 292 return ret; 293 294 err_create_file: 295 usb_deregister_device_driver(&stub_driver); 296 err_usb_register: 297 kmem_cache_destroy(stub_priv_cache); 298 return ret; 299 } 300 301 static void __exit usbip_host_exit(void) 302 { 303 driver_remove_file(&stub_driver.drvwrap.driver, 304 &driver_attr_match_busid); 305 306 driver_remove_file(&stub_driver.drvwrap.driver, 307 &driver_attr_rebind); 308 309 /* 310 * deregister() calls stub_disconnect() for all devices. Device 311 * specific data is cleared in stub_disconnect(). 312 */ 313 usb_deregister_device_driver(&stub_driver); 314 315 kmem_cache_destroy(stub_priv_cache); 316 } 317 318 module_init(usbip_host_init); 319 module_exit(usbip_host_exit); 320 321 MODULE_AUTHOR(DRIVER_AUTHOR); 322 MODULE_DESCRIPTION(DRIVER_DESC); 323 MODULE_LICENSE("GPL"); 324