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 #define BUSID_SIZE 20
  45 static char busid_table[MAX_BUSID][BUSID_SIZE];
  46 static spinlock_t busid_table_lock;
  47
  48
  49 int match_busid(const char *busid)
  50 {
  51         int i;
  52
  53         spin_lock(&busid_table_lock);
  54
  55         for (i = 0; i < MAX_BUSID; i++)
  56                 if (busid_table[i][0])
  57                         if (!strncmp(busid_table[i], busid, BUSID_SIZE)) {
  58                                 /* already registerd */
  59                                 spin_unlock(&busid_table_lock);
  60                                 return 0;
  61                         }
  62
  63         spin_unlock(&busid_table_lock);
  64
  65         return 1;
  66 }
  67
  68 static ssize_t show_match_busid(struct device_driver *drv, char *buf)
  69 {
  70         int i;
  71         char *out = buf;
  72
  73         spin_lock(&busid_table_lock);
  74
  75         for (i = 0; i < MAX_BUSID; i++)
  76                 if (busid_table[i][0])
  77                         out += sprintf(out, "%s ", busid_table[i]);
  78
  79         spin_unlock(&busid_table_lock);
  80
  81         out += sprintf(out, "\n");
  82
  83         return out - buf;
  84 }
  85
  86 static int add_match_busid(char *busid)
  87 {
  88         int i;
  89
  90         if (!match_busid(busid))
  91                 return 0;
  92
  93         spin_lock(&busid_table_lock);
  94
  95         for (i = 0; i < MAX_BUSID; i++)
  96                 if (!busid_table[i][0]) {
  97                         strncpy(busid_table[i], busid, BUSID_SIZE);
  98                         spin_unlock(&busid_table_lock);
  99                         return 0;
 100                 }
 101
 102         spin_unlock(&busid_table_lock);
 103
 104         return -1;
 105 }
 106
 107 static int del_match_busid(char *busid)
 108 {
 109         int i;
 110
 111         spin_lock(&busid_table_lock);
 112
 113         for (i = 0; i < MAX_BUSID; i++)
 114                 if (!strncmp(busid_table[i], busid, BUSID_SIZE)) {
 115                         /* found */
 116                         memset(busid_table[i], 0, BUSID_SIZE);
 117                         spin_unlock(&busid_table_lock);
 118                         return 0;
 119                 }
 120
 121         spin_unlock(&busid_table_lock);
 122
 123         return -1;
 124 }
 125
 126 static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
 127                 size_t count)
 128 {
 129         int len;
 130         char busid[BUSID_SIZE];
 131
 132         if (count < 5)
 133                 return -EINVAL;
 134
 135         /* strnlen() does not include \0 */
 136         len = strnlen(buf + 4, BUSID_SIZE);
 137
 138         /* busid needs to include \0 termination */
 139         if (!(len < BUSID_SIZE))
 140                 return -EINVAL;
 141
 142         strncpy(busid, buf + 4, BUSID_SIZE);
 143
 144
 145         if (!strncmp(buf, "add ", 4)) {
 146                 if (add_match_busid(busid) < 0)
 147                         return -ENOMEM;
 148                 else {
 149                         usbip_udbg("add busid %s\n", busid);
 150                         return count;
 151                 }
 152         } else if (!strncmp(buf, "del ", 4)) {
 153                 if (del_match_busid(busid) < 0)
 154                         return -ENODEV;
 155                 else {
 156                         usbip_udbg("del busid %s\n", busid);
 157                         return count;
 158                 }
 159         } else
 160                 return -EINVAL;
 161 }
 162
 163 static DRIVER_ATTR(match_busid, S_IRUSR|S_IWUSR, show_match_busid,
 164                                                         store_match_busid);
 165
 166
 167
 168 /*-------------------------------------------------------------------------*/
 169
 170 /* Cleanup functions used to free private data */
 171
 172 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
 173 {
 174         struct stub_priv *priv, *tmp;
 175
 176         list_for_each_entry_safe(priv, tmp, listhead, list) {
 177                 list_del(&priv->list);
 178                 return priv;
 179         }
 180
 181         return NULL;
 182 }
 183
 184 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
 185 {
 186         unsigned long flags;
 187         struct stub_priv *priv;
 188
 189         spin_lock_irqsave(&sdev->priv_lock, flags);
 190
 191         priv = stub_priv_pop_from_listhead(&sdev->priv_init);
 192         if (priv) {
 193                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 194                 return priv;
 195         }
 196
 197         priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
 198         if (priv) {
 199                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 200                 return priv;
 201         }
 202
 203         priv = stub_priv_pop_from_listhead(&sdev->priv_free);
 204         if (priv) {
 205                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 206                 return priv;
 207         }
 208
 209         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 210         return NULL;
 211 }
 212
 213 void stub_device_cleanup_urbs(struct stub_device *sdev)
 214 {
 215         struct stub_priv *priv;
 216
 217         usbip_udbg("free sdev %p\n", sdev);
 218
 219         while ((priv = stub_priv_pop(sdev))) {
 220                 struct urb *urb = priv->urb;
 221
 222                 usbip_udbg("   free urb %p\n", urb);
 223                 usb_kill_urb(urb);
 224
 225                 kmem_cache_free(stub_priv_cache, priv);
 226
 227                 if (urb->transfer_buffer != NULL)
 228                         kfree(urb->transfer_buffer);
 229
 230                 if (urb->setup_packet != NULL)
 231                         kfree(urb->setup_packet);
 232
 233                 usb_free_urb(urb);
 234         }
 235 }
 236
 237
 238 /*-------------------------------------------------------------------------*/
 239
 240 static int __init usb_stub_init(void)
 241 {
 242         int ret;
 243
 244         stub_priv_cache = kmem_cache_create("stub_priv",
 245                                             sizeof(struct stub_priv), 0,
 246                                             SLAB_HWCACHE_ALIGN, NULL);
 247
 248         if (!stub_priv_cache) {
 249                 printk(KERN_ERR KBUILD_MODNAME
 250                        ": create stub_priv_cache error\n");
 251                 return -ENOMEM;
 252         }
 253
 254         ret = usb_register(&stub_driver);
 255         if (ret) {
 256                 printk(KERN_ERR KBUILD_MODNAME ": usb_register failed %d\n",
 257                        ret);
 258                 goto error_usb_register;
 259         }
 260
 261         printk(KERN_INFO KBUILD_MODNAME ":"
 262                DRIVER_DESC ":" DRIVER_VERSION "\n");
 263
 264         memset(busid_table, 0, sizeof(busid_table));
 265         spin_lock_init(&busid_table_lock);
 266
 267         ret = driver_create_file(&stub_driver.drvwrap.driver,
 268                                  &driver_attr_match_busid);
 269
 270         if (ret) {
 271                 printk(KERN_ERR KBUILD_MODNAME ": create driver sysfs\n");
 272                 goto error_create_file;
 273         }
 274
 275         return ret;
 276 error_create_file:
 277         usb_deregister(&stub_driver);
 278 error_usb_register:
 279         kmem_cache_destroy(stub_priv_cache);
 280         return ret;
 281 }
 282
 283 static void __exit usb_stub_exit(void)
 284 {
 285         driver_remove_file(&stub_driver.drvwrap.driver,
 286                            &driver_attr_match_busid);
 287
 288         /*
 289          * deregister() calls stub_disconnect() for all devices. Device
 290          * specific data is cleared in stub_disconnect().
 291          */
 292         usb_deregister(&stub_driver);
 293
 294         kmem_cache_destroy(stub_priv_cache);
 295 }
 296
 297 module_init(usb_stub_init);
 298 module_exit(usb_stub_exit);
 299
 300 MODULE_AUTHOR(DRIVER_AUTHOR);
 301 MODULE_DESCRIPTION(DRIVER_DESC);
 302 MODULE_LICENSE("GPL");