drivers/staging/usbip/stub_main.c

   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 <linux/string.h>
  21 #include <linux/module.h>
  22 #include <linux/device.h>
  23
  24 #include "usbip_common.h"
  25 #include "stub.h"
  26
  27 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  28 #define DRIVER_DESC "USB/IP Host Driver"
  29
  30 struct kmem_cache *stub_priv_cache;
  31 /*
  32  * busid_tables defines matching busids that usbip can grab. A user can change
  33  * dynamically what device is locally used and what device is exported to a
  34  * remote host.
  35  */
  36 #define MAX_BUSID 16
  37 static struct bus_id_priv busid_table[MAX_BUSID];
  38 static spinlock_t busid_table_lock;
  39
  40 static void init_busid_table(void)
  41 {
  42         /*
  43          * This also sets the bus_table[i].status to
  44          * STUB_BUSID_OTHER, which is 0.
  45          */
  46         memset(busid_table, 0, sizeof(busid_table));
  47
  48         spin_lock_init(&busid_table_lock);
  49 }
  50
  51 /*
  52  * Find the index of the busid by name.
  53  * Must be called with busid_table_lock held.
  54  */
  55 static int get_busid_idx(const char *busid)
  56 {
  57         int i;
  58         int idx = -1;
  59
  60         for (i = 0; i < MAX_BUSID; i++)
  61                 if (busid_table[i].name[0])
  62                         if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
  63                                 idx = i;
  64                                 break;
  65                         }
  66         return idx;
  67 }
  68
  69 struct bus_id_priv *get_busid_priv(const char *busid)
  70 {
  71         int idx;
  72         struct bus_id_priv *bid = NULL;
  73
  74         spin_lock(&busid_table_lock);
  75         idx = get_busid_idx(busid);
  76         if (idx >= 0)
  77                 bid = &(busid_table[idx]);
  78         spin_unlock(&busid_table_lock);
  79
  80         return bid;
  81 }
  82
  83 static int add_match_busid(char *busid)
  84 {
  85         int i;
  86         int ret = -1;
  87
  88         spin_lock(&busid_table_lock);
  89         /* already registered? */
  90         if (get_busid_idx(busid) >= 0) {
  91                 ret = 0;
  92                 goto out;
  93         }
  94
  95         for (i = 0; i < MAX_BUSID; i++)
  96                 if (!busid_table[i].name[0]) {
  97                         strncpy(busid_table[i].name, busid, BUSID_SIZE);
  98                         if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
  99                             (busid_table[i].status != STUB_BUSID_REMOV))
 100                                 busid_table[i].status = STUB_BUSID_ADDED;
 101                         ret = 0;
 102                         break;
 103                 }
 104
 105 out:
 106         spin_unlock(&busid_table_lock);
 107
 108         return ret;
 109 }
 110
 111 int del_match_busid(char *busid)
 112 {
 113         int idx;
 114         int ret = -1;
 115
 116         spin_lock(&busid_table_lock);
 117         idx = get_busid_idx(busid);
 118         if (idx < 0)
 119                 goto out;
 120
 121         /* found */
 122         ret = 0;
 123
 124         if (busid_table[idx].status == STUB_BUSID_OTHER)
 125                 memset(busid_table[idx].name, 0, BUSID_SIZE);
 126
 127         if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
 128             (busid_table[idx].status != STUB_BUSID_ADDED))
 129                 busid_table[idx].status = STUB_BUSID_REMOV;
 130
 131 out:
 132         spin_unlock(&busid_table_lock);
 133
 134         return ret;
 135 }
 136
 137 static ssize_t show_match_busid(struct device_driver *drv, char *buf)
 138 {
 139         int i;
 140         char *out = buf;
 141
 142         spin_lock(&busid_table_lock);
 143         for (i = 0; i < MAX_BUSID; i++)
 144                 if (busid_table[i].name[0])
 145                         out += sprintf(out, "%s ", busid_table[i].name);
 146         spin_unlock(&busid_table_lock);
 147         out += sprintf(out, "\n");
 148
 149         return out - buf;
 150 }
 151
 152 static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
 153                                  size_t count)
 154 {
 155         int len;
 156         char busid[BUSID_SIZE];
 157
 158         if (count < 5)
 159                 return -EINVAL;
 160
 161         /* strnlen() does not include \0 */
 162         len = strnlen(buf + 4, BUSID_SIZE);
 163
 164         /* busid needs to include \0 termination */
 165         if (!(len < BUSID_SIZE))
 166                 return -EINVAL;
 167
 168         strncpy(busid, buf + 4, BUSID_SIZE);
 169
 170         if (!strncmp(buf, "add ", 4)) {
 171                 if (add_match_busid(busid) < 0)
 172                         return -ENOMEM;
 173
 174                 pr_debug("add busid %s\n", busid);
 175                 return count;
 176         }
 177
 178         if (!strncmp(buf, "del ", 4)) {
 179                 if (del_match_busid(busid) < 0)
 180                         return -ENODEV;
 181
 182                 pr_debug("del busid %s\n", busid);
 183                 return count;
 184         }
 185
 186         return -EINVAL;
 187 }
 188 static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid,
 189                    store_match_busid);
 190
 191 static ssize_t rebind_store(struct device_driver *dev, const char *buf,
 192                                  size_t count)
 193 {
 194         int ret;
 195         int len;
 196         struct bus_id_priv *bid;
 197
 198         /* buf length should be less that BUSID_SIZE */
 199         len = strnlen(buf, BUSID_SIZE);
 200
 201         if (!(len < BUSID_SIZE))
 202                 return -EINVAL;
 203
 204         bid = get_busid_priv(buf);
 205         if (!bid)
 206                 return -ENODEV;
 207
 208         ret = device_attach(&bid->udev->dev);
 209         if (ret < 0) {
 210                 dev_err(&bid->udev->dev, "rebind failed\n");
 211                 return ret;
 212         }
 213
 214         return count;
 215 }
 216
 217 static DRIVER_ATTR_WO(rebind);
 218
 219 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
 220 {
 221         struct stub_priv *priv, *tmp;
 222
 223         list_for_each_entry_safe(priv, tmp, listhead, list) {
 224                 list_del(&priv->list);
 225                 return priv;
 226         }
 227
 228         return NULL;
 229 }
 230
 231 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
 232 {
 233         unsigned long flags;
 234         struct stub_priv *priv;
 235
 236         spin_lock_irqsave(&sdev->priv_lock, flags);
 237
 238         priv = stub_priv_pop_from_listhead(&sdev->priv_init);
 239         if (priv)
 240                 goto done;
 241
 242         priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
 243         if (priv)
 244                 goto done;
 245
 246         priv = stub_priv_pop_from_listhead(&sdev->priv_free);
 247
 248 done:
 249         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 250
 251         return priv;
 252 }
 253
 254 void stub_device_cleanup_urbs(struct stub_device *sdev)
 255 {
 256         struct stub_priv *priv;
 257         struct urb *urb;
 258
 259         dev_dbg(&sdev->udev->dev, "free sdev %p\n", sdev);
 260
 261         while ((priv = stub_priv_pop(sdev))) {
 262                 urb = priv->urb;
 263                 dev_dbg(&sdev->udev->dev, "free urb %p\n", urb);
 264                 usb_kill_urb(urb);
 265
 266                 kmem_cache_free(stub_priv_cache, priv);
 267
 268                 kfree(urb->transfer_buffer);
 269                 kfree(urb->setup_packet);
 270                 usb_free_urb(urb);
 271         }
 272 }
 273
 274 static int __init usbip_host_init(void)
 275 {
 276         int ret;
 277
 278         init_busid_table();
 279
 280         stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
 281         if (!stub_priv_cache) {
 282                 pr_err("kmem_cache_create failed\n");
 283                 return -ENOMEM;
 284         }
 285
 286         ret = usb_register_device_driver(&stub_driver, THIS_MODULE);
 287         if (ret) {
 288                 pr_err("usb_register failed %d\n", ret);
 289                 goto err_usb_register;
 290         }
 291
 292         ret = driver_create_file(&stub_driver.drvwrap.driver,
 293                                  &driver_attr_match_busid);
 294         if (ret) {
 295                 pr_err("driver_create_file failed\n");
 296                 goto err_create_file;
 297         }
 298
 299         ret = driver_create_file(&stub_driver.drvwrap.driver,
 300                                  &driver_attr_rebind);
 301         if (ret) {
 302                 pr_err("driver_create_file failed\n");
 303                 goto err_create_file;
 304         }
 305
 306         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
 307         return ret;
 308
 309 err_create_file:
 310         usb_deregister_device_driver(&stub_driver);
 311 err_usb_register:
 312         kmem_cache_destroy(stub_priv_cache);
 313         return ret;
 314 }
 315
 316 static void __exit usbip_host_exit(void)
 317 {
 318         driver_remove_file(&stub_driver.drvwrap.driver,
 319                            &driver_attr_match_busid);
 320
 321         driver_remove_file(&stub_driver.drvwrap.driver,
 322                            &driver_attr_rebind);
 323
 324         /*
 325          * deregister() calls stub_disconnect() for all devices. Device
 326          * specific data is cleared in stub_disconnect().
 327          */
 328         usb_deregister_device_driver(&stub_driver);
 329
 330         kmem_cache_destroy(stub_priv_cache);
 331 }
 332
 333 module_init(usbip_host_init);
 334 module_exit(usbip_host_exit);
 335
 336 MODULE_AUTHOR(DRIVER_AUTHOR);
 337 MODULE_DESCRIPTION(DRIVER_DESC);
 338 MODULE_LICENSE("GPL");
 339 MODULE_VERSION(USBIP_VERSION);