kernel/net/ieee802154/core.c

   1 /*
   2  * Copyright (C) 2007, 2008, 2009 Siemens AG
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <linux/slab.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/device.h>
  19
  20 #include <net/cfg802154.h>
  21 #include <net/rtnetlink.h>
  22
  23 #include "ieee802154.h"
  24 #include "nl802154.h"
  25 #include "sysfs.h"
  26 #include "core.h"
  27
  28 /* name for sysfs, %d is appended */
  29 #define PHY_NAME "phy"
  30
  31 /* RCU-protected (and RTNL for writers) */
  32 LIST_HEAD(cfg802154_rdev_list);
  33 int cfg802154_rdev_list_generation;
  34
  35 static int wpan_phy_match(struct device *dev, const void *data)
  36 {
  37         return !strcmp(dev_name(dev), (const char *)data);
  38 }
  39
  40 struct wpan_phy *wpan_phy_find(const char *str)
  41 {
  42         struct device *dev;
  43
  44         if (WARN_ON(!str))
  45                 return NULL;
  46
  47         dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
  48         if (!dev)
  49                 return NULL;
  50
  51         return container_of(dev, struct wpan_phy, dev);
  52 }
  53 EXPORT_SYMBOL(wpan_phy_find);
  54
  55 struct wpan_phy_iter_data {
  56         int (*fn)(struct wpan_phy *phy, void *data);
  57         void *data;
  58 };
  59
  60 static int wpan_phy_iter(struct device *dev, void *_data)
  61 {
  62         struct wpan_phy_iter_data *wpid = _data;
  63         struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
  64
  65         return wpid->fn(phy, wpid->data);
  66 }
  67
  68 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
  69                       void *data)
  70 {
  71         struct wpan_phy_iter_data wpid = {
  72                 .fn = fn,
  73                 .data = data,
  74         };
  75
  76         return class_for_each_device(&wpan_phy_class, NULL,
  77                         &wpid, wpan_phy_iter);
  78 }
  79 EXPORT_SYMBOL(wpan_phy_for_each);
  80
  81 struct cfg802154_registered_device *
  82 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
  83 {
  84         struct cfg802154_registered_device *result = NULL, *rdev;
  85
  86         ASSERT_RTNL();
  87
  88         list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
  89                 if (rdev->wpan_phy_idx == wpan_phy_idx) {
  90                         result = rdev;
  91                         break;
  92                 }
  93         }
  94
  95         return result;
  96 }
  97
  98 struct wpan_phy *
  99 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
 100 {
 101         static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
 102         struct cfg802154_registered_device *rdev;
 103         size_t alloc_size;
 104
 105         alloc_size = sizeof(*rdev) + priv_size;
 106         rdev = kzalloc(alloc_size, GFP_KERNEL);
 107         if (!rdev)
 108                 return NULL;
 109
 110         rdev->ops = ops;
 111
 112         rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
 113
 114         if (unlikely(rdev->wpan_phy_idx < 0)) {
 115                 /* ugh, wrapped! */
 116                 atomic_dec(&wpan_phy_counter);
 117                 kfree(rdev);
 118                 return NULL;
 119         }
 120
 121         /* atomic_inc_return makes it start at 1, make it start at 0 */
 122         rdev->wpan_phy_idx--;
 123
 124         mutex_init(&rdev->wpan_phy.pib_lock);
 125
 126         INIT_LIST_HEAD(&rdev->wpan_dev_list);
 127         device_initialize(&rdev->wpan_phy.dev);
 128         dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
 129
 130         rdev->wpan_phy.dev.class = &wpan_phy_class;
 131         rdev->wpan_phy.dev.platform_data = rdev;
 132
 133         init_waitqueue_head(&rdev->dev_wait);
 134
 135         return &rdev->wpan_phy;
 136 }
 137 EXPORT_SYMBOL(wpan_phy_new);
 138
 139 int wpan_phy_register(struct wpan_phy *phy)
 140 {
 141         struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
 142         int ret;
 143
 144         rtnl_lock();
 145         ret = device_add(&phy->dev);
 146         if (ret) {
 147                 rtnl_unlock();
 148                 return ret;
 149         }
 150
 151         list_add_rcu(&rdev->list, &cfg802154_rdev_list);
 152         cfg802154_rdev_list_generation++;
 153
 154         /* TODO phy registered lock */
 155         rtnl_unlock();
 156
 157         /* TODO nl802154 phy notify */
 158
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(wpan_phy_register);
 162
 163 void wpan_phy_unregister(struct wpan_phy *phy)
 164 {
 165         struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
 166
 167         wait_event(rdev->dev_wait, ({
 168                 int __count;
 169                 rtnl_lock();
 170                 __count = rdev->opencount;
 171                 rtnl_unlock();
 172                 __count == 0; }));
 173
 174         rtnl_lock();
 175         /* TODO nl802154 phy notify */
 176         /* TODO phy registered lock */
 177
 178         WARN_ON(!list_empty(&rdev->wpan_dev_list));
 179
 180         /* First remove the hardware from everywhere, this makes
 181          * it impossible to find from userspace.
 182          */
 183         list_del_rcu(&rdev->list);
 184         synchronize_rcu();
 185
 186         cfg802154_rdev_list_generation++;
 187
 188         device_del(&phy->dev);
 189
 190         rtnl_unlock();
 191 }
 192 EXPORT_SYMBOL(wpan_phy_unregister);
 193
 194 void wpan_phy_free(struct wpan_phy *phy)
 195 {
 196         put_device(&phy->dev);
 197 }
 198 EXPORT_SYMBOL(wpan_phy_free);
 199
 200 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
 201 {
 202         kfree(rdev);
 203 }
 204
 205 static void
 206 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
 207                            int iftype, int num)
 208 {
 209         ASSERT_RTNL();
 210
 211         rdev->num_running_ifaces += num;
 212 }
 213
 214 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
 215                                           unsigned long state, void *ptr)
 216 {
 217         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 218         struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
 219         struct cfg802154_registered_device *rdev;
 220
 221         if (!wpan_dev)
 222                 return NOTIFY_DONE;
 223
 224         rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
 225
 226         /* TODO WARN_ON unspec type */
 227
 228         switch (state) {
 229                 /* TODO NETDEV_DEVTYPE */
 230         case NETDEV_REGISTER:
 231                 dev->features |= NETIF_F_NETNS_LOCAL;
 232                 wpan_dev->identifier = ++rdev->wpan_dev_id;
 233                 list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
 234                 rdev->devlist_generation++;
 235
 236                 wpan_dev->netdev = dev;
 237                 break;
 238         case NETDEV_DOWN:
 239                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
 240
 241                 rdev->opencount--;
 242                 wake_up(&rdev->dev_wait);
 243                 break;
 244         case NETDEV_UP:
 245                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
 246
 247                 rdev->opencount++;
 248                 break;
 249         case NETDEV_UNREGISTER:
 250                 /* It is possible to get NETDEV_UNREGISTER
 251                  * multiple times. To detect that, check
 252                  * that the interface is still on the list
 253                  * of registered interfaces, and only then
 254                  * remove and clean it up.
 255                  */
 256                 if (!list_empty(&wpan_dev->list)) {
 257                         list_del_rcu(&wpan_dev->list);
 258                         rdev->devlist_generation++;
 259                 }
 260                 /* synchronize (so that we won't find this netdev
 261                  * from other code any more) and then clear the list
 262                  * head so that the above code can safely check for
 263                  * !list_empty() to avoid double-cleanup.
 264                  */
 265                 synchronize_rcu();
 266                 INIT_LIST_HEAD(&wpan_dev->list);
 267                 break;
 268         default:
 269                 return NOTIFY_DONE;
 270         }
 271
 272         return NOTIFY_OK;
 273 }
 274
 275 static struct notifier_block cfg802154_netdev_notifier = {
 276         .notifier_call = cfg802154_netdev_notifier_call,
 277 };
 278
 279 static int __init wpan_phy_class_init(void)
 280 {
 281         int rc;
 282
 283         rc = wpan_phy_sysfs_init();
 284         if (rc)
 285                 goto err;
 286
 287         rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
 288         if (rc)
 289                 goto err_nl;
 290
 291         rc = ieee802154_nl_init();
 292         if (rc)
 293                 goto err_notifier;
 294
 295         rc = nl802154_init();
 296         if (rc)
 297                 goto err_ieee802154_nl;
 298
 299         return 0;
 300
 301 err_ieee802154_nl:
 302         ieee802154_nl_exit();
 303
 304 err_notifier:
 305         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 306 err_nl:
 307         wpan_phy_sysfs_exit();
 308 err:
 309         return rc;
 310 }
 311 subsys_initcall(wpan_phy_class_init);
 312
 313 static void __exit wpan_phy_class_exit(void)
 314 {
 315         nl802154_exit();
 316         ieee802154_nl_exit();
 317         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 318         wpan_phy_sysfs_exit();
 319 }
 320 module_exit(wpan_phy_class_exit);
 321
 322 MODULE_LICENSE("GPL v2");
 323 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
 324 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
 325