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