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/slab.h>
  21
  22 #include "usbip_common.h"
  23 #include "stub.h"
  24
  25 /* Version Information */
  26 #define DRIVER_VERSION "1.0"
  27 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  28 #define DRIVER_DESC "Stub Driver for USB/IP"
  29
  30 /* stub_priv is allocated from stub_priv_cache */
  31 struct kmem_cache *stub_priv_cache;
  32
  33 /*-------------------------------------------------------------------------*/
  34
  35 /* Define sysfs entries for the usbip driver */
  36
  37
  38 /*
  39  * busid_tables defines matching busids that usbip can grab. A user can change
  40  * dynamically what device is locally used and what device is exported to a
  41  * remote host.
  42  */
  43 #define MAX_BUSID 16
  44 static struct bus_id_priv busid_table[MAX_BUSID];
  45 static spinlock_t busid_table_lock;
  46
  47
  48 int match_busid(const char *busid)
  49 {
  50         int i;
  51
  52         spin_lock(&busid_table_lock);
  53
  54         for (i = 0; i < MAX_BUSID; i++)
  55                 if (busid_table[i].name[0])
  56                         if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
  57                                 /* already registerd */
  58                                 spin_unlock(&busid_table_lock);
  59                                 return 0;
  60                         }
  61
  62         spin_unlock(&busid_table_lock);
  63
  64         return 1;
  65 }
  66
  67 struct bus_id_priv *get_busid_priv(const char *busid)
  68 {
  69         int i;
  70
  71         spin_lock(&busid_table_lock);
  72
  73         for (i = 0; i < MAX_BUSID; i++)
  74                 if (busid_table[i].name[0])
  75                         if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
  76                                 /* already registerd */
  77                                 spin_unlock(&busid_table_lock);
  78                                 return &(busid_table[i]);
  79                         }
  80
  81         spin_unlock(&busid_table_lock);
  82
  83         return NULL;
  84 }
  85
  86 static ssize_t show_match_busid(struct device_driver *drv, char *buf)
  87 {
  88         int i;
  89         char *out = buf;
  90
  91         spin_lock(&busid_table_lock);
  92
  93         for (i = 0; i < MAX_BUSID; i++)
  94                 if (busid_table[i].name[0])
  95                         out += sprintf(out, "%s ", busid_table[i].name);
  96
  97         spin_unlock(&busid_table_lock);
  98
  99         out += sprintf(out, "\n");
 100
 101         return out - buf;
 102 }
 103
 104 static int add_match_busid(char *busid)
 105 {
 106         int i;
 107
 108         if (!match_busid(busid))
 109                 return 0;
 110
 111         spin_lock(&busid_table_lock);
 112
 113         for (i = 0; i < MAX_BUSID; i++)
 114                 if (!busid_table[i].name[0]) {
 115                         strncpy(busid_table[i].name, busid, BUSID_SIZE);
 116                         if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
 117                             (busid_table[i].status != STUB_BUSID_REMOV))
 118                                 busid_table[i].status = STUB_BUSID_ADDED;
 119                         spin_unlock(&busid_table_lock);
 120                         return 0;
 121                 }
 122
 123         spin_unlock(&busid_table_lock);
 124
 125         return -1;
 126 }
 127
 128 int del_match_busid(char *busid)
 129 {
 130         int i;
 131
 132         spin_lock(&busid_table_lock);
 133
 134         for (i = 0; i < MAX_BUSID; i++)
 135                 if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
 136                         /* found */
 137                         if (busid_table[i].status == STUB_BUSID_OTHER)
 138                                 memset(busid_table[i].name, 0, BUSID_SIZE);
 139                         if ((busid_table[i].status != STUB_BUSID_OTHER) &&
 140                             (busid_table[i].status != STUB_BUSID_ADDED)) {
 141                                 busid_table[i].status = STUB_BUSID_REMOV;
 142                         }
 143                         spin_unlock(&busid_table_lock);
 144                         return 0;
 145                 }
 146
 147         spin_unlock(&busid_table_lock);
 148
 149         return -1;
 150 }
 151 static void init_busid_table(void)
 152 {
 153         int i;
 154
 155
 156         for (i = 0; i < MAX_BUSID; i++) {
 157                 memset(busid_table[i].name, 0, BUSID_SIZE);
 158                 busid_table[i].status = STUB_BUSID_OTHER;
 159                 busid_table[i].interf_count = 0;
 160                 busid_table[i].sdev = NULL;
 161                 busid_table[i].shutdown_busid = 0;
 162         }
 163         spin_lock_init(&busid_table_lock);
 164 }
 165
 166 static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
 167                 size_t count)
 168 {
 169         int len;
 170         char busid[BUSID_SIZE];
 171
 172         if (count < 5)
 173                 return -EINVAL;
 174
 175         /* strnlen() does not include \0 */
 176         len = strnlen(buf + 4, BUSID_SIZE);
 177
 178         /* busid needs to include \0 termination */
 179         if (!(len < BUSID_SIZE))
 180                 return -EINVAL;
 181
 182         strncpy(busid, buf + 4, BUSID_SIZE);
 183
 184
 185         if (!strncmp(buf, "add ", 4)) {
 186                 if (add_match_busid(busid) < 0)
 187                         return -ENOMEM;
 188                 else {
 189                         usbip_udbg("add busid %s\n", busid);
 190                         return count;
 191                 }
 192         } else if (!strncmp(buf, "del ", 4)) {
 193                 if (del_match_busid(busid) < 0)
 194                         return -ENODEV;
 195                 else {
 196                         usbip_udbg("del busid %s\n", busid);
 197                         return count;
 198                 }
 199         } else
 200                 return -EINVAL;
 201 }
 202
 203 static DRIVER_ATTR(match_busid, S_IRUSR|S_IWUSR, show_match_busid,
 204                                                         store_match_busid);
 205
 206
 207
 208 /*-------------------------------------------------------------------------*/
 209
 210 /* Cleanup functions used to free private data */
 211
 212 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
 213 {
 214         struct stub_priv *priv, *tmp;
 215
 216         list_for_each_entry_safe(priv, tmp, listhead, list) {
 217                 list_del(&priv->list);
 218                 return priv;
 219         }
 220
 221         return NULL;
 222 }
 223
 224 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
 225 {
 226         unsigned long flags;
 227         struct stub_priv *priv;
 228
 229         spin_lock_irqsave(&sdev->priv_lock, flags);
 230
 231         priv = stub_priv_pop_from_listhead(&sdev->priv_init);
 232         if (priv) {
 233                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 234                 return priv;
 235         }
 236
 237         priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
 238         if (priv) {
 239                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 240                 return priv;
 241         }
 242
 243         priv = stub_priv_pop_from_listhead(&sdev->priv_free);
 244         if (priv) {
 245                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 246                 return priv;
 247         }
 248
 249         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 250         return NULL;
 251 }
 252
 253 void stub_device_cleanup_urbs(struct stub_device *sdev)
 254 {
 255         struct stub_priv *priv;
 256
 257         usbip_udbg("free sdev %p\n", sdev);
 258
 259         while ((priv = stub_priv_pop(sdev))) {
 260                 struct urb *urb = priv->urb;
 261
 262                 usbip_udbg("   free urb %p\n", urb);
 263                 usb_kill_urb(urb);
 264
 265                 kmem_cache_free(stub_priv_cache, priv);
 266
 267                 kfree(urb->transfer_buffer);
 268
 269                 kfree(urb->setup_packet);
 270
 271                 usb_free_urb(urb);
 272         }
 273 }
 274
 275
 276 /*-------------------------------------------------------------------------*/
 277
 278 static int __init usb_stub_init(void)
 279 {
 280         int ret;
 281
 282         stub_priv_cache = kmem_cache_create("stub_priv",
 283                                             sizeof(struct stub_priv), 0,
 284                                             SLAB_HWCACHE_ALIGN, NULL);
 285
 286         if (!stub_priv_cache) {
 287                 printk(KERN_ERR KBUILD_MODNAME
 288                        ": create stub_priv_cache error\n");
 289                 return -ENOMEM;
 290         }
 291
 292         ret = usb_register(&stub_driver);
 293         if (ret) {
 294                 printk(KERN_ERR KBUILD_MODNAME ": usb_register failed %d\n",
 295                        ret);
 296                 goto error_usb_register;
 297         }
 298
 299         printk(KERN_INFO KBUILD_MODNAME ":"
 300                DRIVER_DESC ":" DRIVER_VERSION "\n");
 301
 302         init_busid_table();
 303
 304         ret = driver_create_file(&stub_driver.drvwrap.driver,
 305                                  &driver_attr_match_busid);
 306
 307         if (ret) {
 308                 printk(KERN_ERR KBUILD_MODNAME ": create driver sysfs\n");
 309                 goto error_create_file;
 310         }
 311
 312         return ret;
 313 error_create_file:
 314         usb_deregister(&stub_driver);
 315 error_usb_register:
 316         kmem_cache_destroy(stub_priv_cache);
 317         return ret;
 318 }
 319
 320 static void __exit usb_stub_exit(void)
 321 {
 322         driver_remove_file(&stub_driver.drvwrap.driver,
 323                            &driver_attr_match_busid);
 324
 325         /*
 326          * deregister() calls stub_disconnect() for all devices. Device
 327          * specific data is cleared in stub_disconnect().
 328          */
 329         usb_deregister(&stub_driver);
 330
 331         kmem_cache_destroy(stub_priv_cache);
 332 }
 333
 334 module_init(usb_stub_init);
 335 module_exit(usb_stub_exit);
 336
 337 MODULE_AUTHOR(DRIVER_AUTHOR);
 338 MODULE_DESCRIPTION(DRIVER_DESC);
 339 MODULE_LICENSE("GPL");