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