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         drv->idx = wiphy_counter;
  57
  58         /* now increase counter for the next device unless
  59          * it has wrapped previously */
  60         if (wiphy_counter >= 0)
  61                 wiphy_counter++;
  62
  63         mutex_unlock(&cfg80211_drv_mutex);
  64
  65         if (unlikely(drv->idx < 0)) {
  66                 /* ugh, wrapped! */
  67                 kfree(drv);
  68                 return NULL;
  69         }
  70
  71         /* give it a proper name */
  72         snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE,
  73                  PHY_NAME "%d", drv->idx);
  74
  75         mutex_init(&drv->mtx);
  76         mutex_init(&drv->devlist_mtx);
  77         INIT_LIST_HEAD(&drv->netdev_list);
  78
  79         device_initialize(&drv->wiphy.dev);
  80         drv->wiphy.dev.class = &ieee80211_class;
  81         drv->wiphy.dev.platform_data = drv;
  82
  83         return &drv->wiphy;
  84 }
  85 EXPORT_SYMBOL(wiphy_new);
  86
  87 int wiphy_register(struct wiphy *wiphy)
  88 {
  89         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
  90         int res;
  91
  92         mutex_lock(&cfg80211_drv_mutex);
  93
  94
  95         res = device_add(&drv->wiphy.dev);
  96         if (res)
  97                 goto out_unlock;
  98
  99         list_add(&drv->list, &cfg80211_drv_list);
 100
 101         /* add to debugfs */
 102         drv->wiphy.debugfsdir =
 103                 debugfs_create_dir(wiphy_name(&drv->wiphy),
 104                                    ieee80211_debugfs_dir);
 105
 106         res = 0;
 107 out_unlock:
 108         mutex_unlock(&cfg80211_drv_mutex);
 109         return res;
 110 }
 111 EXPORT_SYMBOL(wiphy_register);
 112
 113 void wiphy_unregister(struct wiphy *wiphy)
 114 {
 115         struct cfg80211_registered_device *drv = wiphy_to_dev(wiphy);
 116
 117         mutex_lock(&cfg80211_drv_mutex);
 118
 119         /* hold registered driver mutex during list removal as well
 120          * to make sure no commands are in progress at the moment */
 121         mutex_lock(&drv->mtx);
 122         list_del(&drv->list);
 123         mutex_unlock(&drv->mtx);
 124
 125         device_del(&drv->wiphy.dev);
 126         debugfs_remove(drv->wiphy.debugfsdir);
 127
 128         mutex_unlock(&cfg80211_drv_mutex);
 129 }
 130 EXPORT_SYMBOL(wiphy_unregister);
 131
 132 void cfg80211_dev_free(struct cfg80211_registered_device *drv)
 133 {
 134         mutex_destroy(&drv->mtx);
 135         mutex_destroy(&drv->devlist_mtx);
 136         kfree(drv);
 137 }
 138
 139 void wiphy_free(struct wiphy *wiphy)
 140 {
 141         put_device(&wiphy->dev);
 142 }
 143 EXPORT_SYMBOL(wiphy_free);
 144
 145 static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 146                                          unsigned long state,
 147                                          void *ndev)
 148 {
 149         struct net_device *dev = ndev;
 150         struct cfg80211_registered_device *rdev;
 151
 152         if (!dev->ieee80211_ptr)
 153                 return 0;
 154
 155         rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy);
 156
 157         switch (state) {
 158         case NETDEV_REGISTER:
 159                 mutex_lock(&rdev->devlist_mtx);
 160                 list_add(&dev->ieee80211_ptr->list, &rdev->netdev_list);
 161                 if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj,
 162                                       "phy80211")) {
 163                         printk(KERN_ERR "wireless: failed to add phy80211 "
 164                                 "symlink to netdev!\n");
 165                 }
 166                 dev->ieee80211_ptr->netdev = dev;
 167                 mutex_unlock(&rdev->devlist_mtx);
 168                 break;
 169         case NETDEV_UNREGISTER:
 170                 mutex_lock(&rdev->devlist_mtx);
 171                 if (!list_empty(&dev->ieee80211_ptr->list)) {
 172                         sysfs_remove_link(&dev->dev.kobj, "phy80211");
 173                         list_del_init(&dev->ieee80211_ptr->list);
 174                 }
 175                 mutex_unlock(&rdev->devlist_mtx);
 176                 break;
 177         }
 178
 179         return 0;
 180 }
 181
 182 static struct notifier_block cfg80211_netdev_notifier = {
 183         .notifier_call = cfg80211_netdev_notifier_call,
 184 };
 185
 186 static int cfg80211_init(void)
 187 {
 188         int err = wiphy_sysfs_init();
 189         if (err)
 190                 goto out_fail_sysfs;
 191
 192         err = register_netdevice_notifier(&cfg80211_netdev_notifier);
 193         if (err)
 194                 goto out_fail_notifier;
 195
 196         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 197
 198         return 0;
 199
 200 out_fail_notifier:
 201         wiphy_sysfs_exit();
 202 out_fail_sysfs:
 203         return err;
 204 }
 205 module_init(cfg80211_init);
 206
 207 static void cfg80211_exit(void)
 208 {
 209         debugfs_remove(ieee80211_debugfs_dir);
 210         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 211         wiphy_sysfs_exit();
 212 }
 213 module_exit(cfg80211_exit);