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