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