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