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/string.h>
  21
  22 #include "usbip_common.h"
  23 #include "stub.h"
  24
  25 #define DRIVER_AUTHOR "Takahiro Hirofuchi"
  26 #define DRIVER_DESC "USB/IP Host Driver"
  27
  28 /* stub_priv is allocated from stub_priv_cache */
  29 struct kmem_cache *stub_priv_cache;
  30
  31 /*
  32  * busid_tables defines matching busids that usbip can grab. A user can change
  33  * dynamically what device is locally used and what device is exported to a
  34  * remote host.
  35  */
  36 #define MAX_BUSID 16
  37 static struct bus_id_priv busid_table[MAX_BUSID];
  38 static spinlock_t busid_table_lock;
  39
  40 int match_busid(const char *busid)
  41 {
  42         int i;
  43
  44         spin_lock(&busid_table_lock);
  45
  46         for (i = 0; i < MAX_BUSID; i++)
  47                 if (busid_table[i].name[0])
  48                         if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
  49                                 /* already registerd */
  50                                 spin_unlock(&busid_table_lock);
  51                                 return 0;
  52                         }
  53
  54         spin_unlock(&busid_table_lock);
  55
  56         return 1;
  57 }
  58
  59 struct bus_id_priv *get_busid_priv(const char *busid)
  60 {
  61         int i;
  62
  63         spin_lock(&busid_table_lock);
  64
  65         for (i = 0; i < MAX_BUSID; i++)
  66                 if (busid_table[i].name[0])
  67                         if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
  68                                 /* already registerd */
  69                                 spin_unlock(&busid_table_lock);
  70                                 return &(busid_table[i]);
  71                         }
  72
  73         spin_unlock(&busid_table_lock);
  74
  75         return NULL;
  76 }
  77
  78 static ssize_t show_match_busid(struct device_driver *drv, char *buf)
  79 {
  80         int i;
  81         char *out = buf;
  82
  83         spin_lock(&busid_table_lock);
  84
  85         for (i = 0; i < MAX_BUSID; i++)
  86                 if (busid_table[i].name[0])
  87                         out += sprintf(out, "%s ", busid_table[i].name);
  88
  89         spin_unlock(&busid_table_lock);
  90
  91         out += sprintf(out, "\n");
  92
  93         return out - buf;
  94 }
  95
  96 static int add_match_busid(char *busid)
  97 {
  98         int i;
  99
 100         if (!match_busid(busid))
 101                 return 0;
 102
 103         spin_lock(&busid_table_lock);
 104
 105         for (i = 0; i < MAX_BUSID; i++)
 106                 if (!busid_table[i].name[0]) {
 107                         strncpy(busid_table[i].name, busid, BUSID_SIZE);
 108                         if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
 109                             (busid_table[i].status != STUB_BUSID_REMOV))
 110                                 busid_table[i].status = STUB_BUSID_ADDED;
 111                         spin_unlock(&busid_table_lock);
 112                         return 0;
 113                 }
 114
 115         spin_unlock(&busid_table_lock);
 116
 117         return -1;
 118 }
 119
 120 int del_match_busid(char *busid)
 121 {
 122         int i;
 123
 124         spin_lock(&busid_table_lock);
 125
 126         for (i = 0; i < MAX_BUSID; i++)
 127                 if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
 128                         /* found */
 129                         if (busid_table[i].status == STUB_BUSID_OTHER)
 130                                 memset(busid_table[i].name, 0, BUSID_SIZE);
 131                         if ((busid_table[i].status != STUB_BUSID_OTHER) &&
 132                             (busid_table[i].status != STUB_BUSID_ADDED)) {
 133                                 busid_table[i].status = STUB_BUSID_REMOV;
 134                         }
 135                         spin_unlock(&busid_table_lock);
 136                         return 0;
 137                 }
 138
 139         spin_unlock(&busid_table_lock);
 140
 141         return -1;
 142 }
 143
 144 static void init_busid_table(void)
 145 {
 146         int i;
 147
 148         for (i = 0; i < MAX_BUSID; i++) {
 149                 memset(busid_table[i].name, 0, BUSID_SIZE);
 150                 busid_table[i].status = STUB_BUSID_OTHER;
 151                 busid_table[i].interf_count = 0;
 152                 busid_table[i].sdev = NULL;
 153                 busid_table[i].shutdown_busid = 0;
 154         }
 155
 156         spin_lock_init(&busid_table_lock);
 157 }
 158
 159 static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
 160                                  size_t count)
 161 {
 162         int len;
 163         char busid[BUSID_SIZE];
 164
 165         if (count < 5)
 166                 return -EINVAL;
 167
 168         /* strnlen() does not include \0 */
 169         len = strnlen(buf + 4, BUSID_SIZE);
 170
 171         /* busid needs to include \0 termination */
 172         if (!(len < BUSID_SIZE))
 173                 return -EINVAL;
 174
 175         strncpy(busid, buf + 4, BUSID_SIZE);
 176
 177         if (!strncmp(buf, "add ", 4)) {
 178                 if (add_match_busid(busid) < 0)
 179                         return -ENOMEM;
 180                 else {
 181                         pr_debug("add busid %s\n", busid);
 182                         return count;
 183                 }
 184         } else if (!strncmp(buf, "del ", 4)) {
 185                 if (del_match_busid(busid) < 0)
 186                         return -ENODEV;
 187                 else {
 188                         pr_debug("del busid %s\n", busid);
 189                         return count;
 190                 }
 191         } else
 192                 return -EINVAL;
 193 }
 194 static DRIVER_ATTR(match_busid, S_IRUSR|S_IWUSR, show_match_busid,
 195                    store_match_busid);
 196
 197 static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
 198 {
 199         struct stub_priv *priv, *tmp;
 200
 201         list_for_each_entry_safe(priv, tmp, listhead, list) {
 202                 list_del(&priv->list);
 203                 return priv;
 204         }
 205
 206         return NULL;
 207 }
 208
 209 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
 210 {
 211         unsigned long flags;
 212         struct stub_priv *priv;
 213
 214         spin_lock_irqsave(&sdev->priv_lock, flags);
 215
 216         priv = stub_priv_pop_from_listhead(&sdev->priv_init);
 217         if (priv) {
 218                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 219                 return priv;
 220         }
 221
 222         priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
 223         if (priv) {
 224                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 225                 return priv;
 226         }
 227
 228         priv = stub_priv_pop_from_listhead(&sdev->priv_free);
 229         if (priv) {
 230                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 231                 return priv;
 232         }
 233
 234         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 235         return NULL;
 236 }
 237
 238 void stub_device_cleanup_urbs(struct stub_device *sdev)
 239 {
 240         struct stub_priv *priv;
 241
 242         dev_dbg(&sdev->udev->dev, "free sdev %p\n", sdev);
 243
 244         while ((priv = stub_priv_pop(sdev))) {
 245                 struct urb *urb = priv->urb;
 246
 247                 dev_dbg(&sdev->udev->dev, "free urb %p\n", urb);
 248                 usb_kill_urb(urb);
 249
 250                 kmem_cache_free(stub_priv_cache, priv);
 251
 252                 kfree(urb->transfer_buffer);
 253                 kfree(urb->setup_packet);
 254
 255                 usb_free_urb(urb);
 256         }
 257 }
 258
 259 static int __init usb_stub_init(void)
 260 {
 261         int ret;
 262
 263         stub_priv_cache = kmem_cache_create("stub_priv",
 264                                             sizeof(struct stub_priv), 0,
 265                                             SLAB_HWCACHE_ALIGN, NULL);
 266
 267         if (!stub_priv_cache) {
 268                 pr_err("create stub_priv_cache error\n");
 269                 return -ENOMEM;
 270         }
 271
 272         ret = usb_register(&stub_driver);
 273         if (ret) {
 274                 pr_err("usb_register failed %d\n", ret);
 275                 goto error_usb_register;
 276         }
 277
 278         pr_info(DRIVER_DESC " " USBIP_VERSION "\n");
 279
 280         init_busid_table();
 281
 282         ret = driver_create_file(&stub_driver.drvwrap.driver,
 283                                  &driver_attr_match_busid);
 284
 285         if (ret) {
 286                 pr_err("create driver sysfs\n");
 287                 goto error_create_file;
 288         }
 289
 290         return ret;
 291 error_create_file:
 292         usb_deregister(&stub_driver);
 293 error_usb_register:
 294         kmem_cache_destroy(stub_priv_cache);
 295         return ret;
 296 }
 297
 298 static void __exit usb_stub_exit(void)
 299 {
 300         driver_remove_file(&stub_driver.drvwrap.driver,
 301                            &driver_attr_match_busid);
 302
 303         /*
 304          * deregister() calls stub_disconnect() for all devices. Device
 305          * specific data is cleared in stub_disconnect().
 306          */
 307         usb_deregister(&stub_driver);
 308
 309         kmem_cache_destroy(stub_priv_cache);
 310 }
 311
 312 module_init(usb_stub_init);
 313 module_exit(usb_stub_exit);
 314
 315 MODULE_AUTHOR(DRIVER_AUTHOR);
 316 MODULE_DESCRIPTION(DRIVER_DESC);
 317 MODULE_LICENSE("GPL");
 318 MODULE_VERSION(USBIP_VERSION);