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