net/wireless/core.c

   1 /*
   2  * This is the linux wireless configuration interface.
   3  *
   4  * Copyright 2006, 2007         Johannes Berg <johannes@sipsolutions.net>
   5  */
   6
   7 #include <linux/if.h>
   8 #include <linux/module.h>
   9 #include <linux/err.h>
  10 #include <linux/mutex.h>
  11 #include <linux/list.h>
  12 #include <linux/nl80211.h>
  13 #include <linux/debugfs.h>
  14 #include <linux/notifier.h>
  15 #include <linux/device.h>
  16 #include <net/genetlink.h>
  17 #include <net/cfg80211.h>
  18 #include <net/wireless.h>
  19 #include "core.h"
  20 #include "sysfs.h"
  21
  22 /* name for sysfs, %d is appended */
  23 #define PHY_NAME "phy"
  24
  25 MODULE_AUTHOR("Johannes Berg");
  26 MODULE_LICENSE("GPL");
  27 MODULE_DESCRIPTION("wireless configuration support");
  28
  29 /* RCU might be appropriate here since we usually
  30  * only read the list, and that can happen quite
  31  * often because we need to do it for each command */
  32 LIST_HEAD(cfg80211_drv_list);
  33 DEFINE_MUTEX(cfg80211_drv_mutex);
  34 static int wiphy_counter;
  35
  36 /* for debugfs */
  37 static struct dentry *ieee80211_debugfs_dir;
  38
  39 /* exported functions */
  40
  41 struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
  42 {
  43         struct cfg80211_registered_device *drv;
  44         int alloc_size;
  45
  46         alloc_size = sizeof(*drv) + sizeof_priv;
  47
  48         drv = kzalloc(alloc_size, GFP_KERNEL);
  49         if (!drv)
  50                 return NULL;
  51
  52         drv->ops = ops;
  53
  54         mutex_lock(&cfg80211_drv_mutex);
  55
  56         if (unlikely(wiphy_counter<0)) {
  57                 /* ugh, wrapped! */
  58                 kfree(drv);
  59                 return NULL;
  60         }
  61         drv->idx = wiphy_counter;
  62
  63         /* give it a proper name */
  64         snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE,
  65                  PHY_NAME "%d", drv->idx);
  66
  67         /* now increase counter for the next time */
  68         wiphy_counter++;
  69         mutex_unlock(&cfg80211_drv_mutex);
  70
  71         mutex_init(&drv->mtx);
  72         mutex_init(&drv->devlist_mtx);
  73         INIT_LIST_HEAD(&drv->netdev_list);
  74
  75         device_initialize(&drv->wiphy.dev);
  76         drv->wiphy.dev.class = &ieee80211_class;
  77         drv->wiphy.dev.platform_data = drv;
  78
  79         return &drv->wiphy;
  80 }
  81 EXPORT_SYMBOL(wiphy_new);
  82
  83 int wiphy_register(struct wiphy *wiphy)
  84 {
  85         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
  86         int res;
  87
  88         mutex_lock(&cfg80211_drv_mutex);
  89
  90
  91         res = device_add(&drv->wiphy.dev);
  92         if (res)
  93                 goto out_unlock;
  94
  95         list_add(&drv->list, &cfg80211_drv_list);
  96
  97         /* add to debugfs */
  98         drv->wiphy.debugfsdir =
  99                 debugfs_create_dir(wiphy_name(&drv->wiphy),
 100                                    ieee80211_debugfs_dir);
 101
 102         res = 0;
 103 out_unlock:
 104         mutex_unlock(&cfg80211_drv_mutex);
 105         return res;
 106 }
 107 EXPORT_SYMBOL(wiphy_register);
 108
 109 void wiphy_unregister(struct wiphy *wiphy)
 110 {
 111         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 112
 113         mutex_lock(&cfg80211_drv_mutex);
 114
 115         /* hold registered driver mutex during list removal as well
 116          * to make sure no commands are in progress at the moment */
 117         mutex_lock(&drv->mtx);
 118         list_del(&drv->list);
 119         mutex_unlock(&drv->mtx);
 120
 121         device_del(&drv->wiphy.dev);
 122         debugfs_remove(drv->wiphy.debugfsdir);
 123
 124         mutex_unlock(&cfg80211_drv_mutex);
 125 }
 126 EXPORT_SYMBOL(wiphy_unregister);
 127
 128 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 129 {
 130         mutex_destroy(&drv->mtx);
 131         mutex_destroy(&drv->devlist_mtx);
 132         kfree(drv);
 133 }
 134
 135 void wiphy_free(struct wiphy *wiphy)
 136 {
 137         put_device(&wiphy->dev);
 138 }
 139 EXPORT_SYMBOL(wiphy_free);
 140
 141 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 142                                          unsigned long state,
 143                                          void *ndev)
 144 {
 145         struct net_device *dev = ndev;
 146         struct cfg80211_registered_device *rdev;
 147
 148         if (!dev->ieee80211_ptr)
 149                 return 0;
 150
 151         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 152
 153         switch (state) {
 154         case NETDEV_REGISTER:
 155                 mutex_lock(&rdev->devlist_mtx);
 156                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 157                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 158                                       "phy80211")) {
 159                         printk(KERN_ERR "wireless: failed to add phy80211 "
 160                                 "symlink to netdev!\n");
 161                 }
 162                 dev->ieee80211_ptr->netdev = dev;
 163                 mutex_unlock(&rdev->devlist_mtx);
 164                 break;
 165         case NETDEV_UNREGISTER:
 166                 mutex_lock(&rdev->devlist_mtx);
 167                 if (!list_empty(&dev->ieee80211_ptr->list)) {
 168                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 169                         list_del_init(&dev->ieee80211_ptr->list);
 170                 }
 171                 mutex_unlock(&rdev->devlist_mtx);
 172                 break;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static struct notifier_block cfg80211_netdev_notifier = {
 179         .notifier_call = cfg80211_netdev_notifier_call,
 180 };
 181
 182 static int cfg80211_init(void)
 183 {
 184         int err = wiphy_sysfs_init();
 185         if (err)
 186                 goto out_fail_sysfs;
 187
 188         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 189         if (err)
 190                 goto out_fail_notifier;
 191
 192         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 193
 194         return 0;
 195
 196 out_fail_notifier:
 197         wiphy_sysfs_exit();
 198 out_fail_sysfs:
 199         return err;
 200 }
 201 module_init(cfg80211_init);
 202
 203 static void cfg80211_exit(void)
 204 {
 205         debugfs_remove(ieee80211_debugfs_dir);
 206         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 207         wiphy_sysfs_exit();
 208 }
 209 module_exit(cfg80211_exit);