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         INIT_LIST_HEAD(&rdev->wpan_dev_list);
 125         device_initialize(&rdev->wpan_phy.dev);
 126         dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
 127
 128         rdev->wpan_phy.dev.class = &wpan_phy_class;
 129         rdev->wpan_phy.dev.platform_data = rdev;
 130
 131         init_waitqueue_head(&rdev->dev_wait);
 132
 133         return &rdev->wpan_phy;
 134 }
 135 EXPORT_SYMBOL(wpan_phy_new);
 136
 137 int wpan_phy_register(struct wpan_phy *phy)
 138 {
 139         struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
 140         int ret;
 141
 142         rtnl_lock();
 143         ret = device_add(&phy->dev);
 144         if (ret) {
 145                 rtnl_unlock();
 146                 return ret;
 147         }
 148
 149         list_add_rcu(&rdev->list, &cfg802154_rdev_list);
 150         cfg802154_rdev_list_generation++;
 151
 152         /* TODO phy registered lock */
 153         rtnl_unlock();
 154
 155         /* TODO nl802154 phy notify */
 156
 157         return 0;
 158 }
 159 EXPORT_SYMBOL(wpan_phy_register);
 160
 161 void wpan_phy_unregister(struct wpan_phy *phy)
 162 {
 163         struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
 164
 165         wait_event(rdev->dev_wait, ({
 166                 int __count;
 167                 rtnl_lock();
 168                 __count = rdev->opencount;
 169                 rtnl_unlock();
 170                 __count == 0; }));
 171
 172         rtnl_lock();
 173         /* TODO nl802154 phy notify */
 174         /* TODO phy registered lock */
 175
 176         WARN_ON(!list_empty(&rdev->wpan_dev_list));
 177
 178         /* First remove the hardware from everywhere, this makes
 179          * it impossible to find from userspace.
 180          */
 181         list_del_rcu(&rdev->list);
 182         synchronize_rcu();
 183
 184         cfg802154_rdev_list_generation++;
 185
 186         device_del(&phy->dev);
 187
 188         rtnl_unlock();
 189 }
 190 EXPORT_SYMBOL(wpan_phy_unregister);
 191
 192 void wpan_phy_free(struct wpan_phy *phy)
 193 {
 194         put_device(&phy->dev);
 195 }
 196 EXPORT_SYMBOL(wpan_phy_free);
 197
 198 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
 199 {
 200         kfree(rdev);
 201 }
 202
 203 static void
 204 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
 205                            int iftype, int num)
 206 {
 207         ASSERT_RTNL();
 208
 209         rdev->num_running_ifaces += num;
 210 }
 211
 212 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
 213                                           unsigned long state, void *ptr)
 214 {
 215         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 216         struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
 217         struct cfg802154_registered_device *rdev;
 218
 219         if (!wpan_dev)
 220                 return NOTIFY_DONE;
 221
 222         rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
 223
 224         /* TODO WARN_ON unspec type */
 225
 226         switch (state) {
 227                 /* TODO NETDEV_DEVTYPE */
 228         case NETDEV_REGISTER:
 229                 dev->features |= NETIF_F_NETNS_LOCAL;
 230                 wpan_dev->identifier = ++rdev->wpan_dev_id;
 231                 list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
 232                 rdev->devlist_generation++;
 233
 234                 wpan_dev->netdev = dev;
 235                 break;
 236         case NETDEV_DOWN:
 237                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
 238
 239                 rdev->opencount--;
 240                 wake_up(&rdev->dev_wait);
 241                 break;
 242         case NETDEV_UP:
 243                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
 244
 245                 rdev->opencount++;
 246                 break;
 247         case NETDEV_UNREGISTER:
 248                 /* It is possible to get NETDEV_UNREGISTER
 249                  * multiple times. To detect that, check
 250                  * that the interface is still on the list
 251                  * of registered interfaces, and only then
 252                  * remove and clean it up.
 253                  */
 254                 if (!list_empty(&wpan_dev->list)) {
 255                         list_del_rcu(&wpan_dev->list);
 256                         rdev->devlist_generation++;
 257                 }
 258                 /* synchronize (so that we won't find this netdev
 259                  * from other code any more) and then clear the list
 260                  * head so that the above code can safely check for
 261                  * !list_empty() to avoid double-cleanup.
 262                  */
 263                 synchronize_rcu();
 264                 INIT_LIST_HEAD(&wpan_dev->list);
 265                 break;
 266         default:
 267                 return NOTIFY_DONE;
 268         }
 269
 270         return NOTIFY_OK;
 271 }
 272
 273 static struct notifier_block cfg802154_netdev_notifier = {
 274         .notifier_call = cfg802154_netdev_notifier_call,
 275 };
 276
 277 static int __init wpan_phy_class_init(void)
 278 {
 279         int rc;
 280
 281         rc = wpan_phy_sysfs_init();
 282         if (rc)
 283                 goto err;
 284
 285         rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
 286         if (rc)
 287                 goto err_nl;
 288
 289         rc = ieee802154_nl_init();
 290         if (rc)
 291                 goto err_notifier;
 292
 293         rc = nl802154_init();
 294         if (rc)
 295                 goto err_ieee802154_nl;
 296
 297         return 0;
 298
 299 err_ieee802154_nl:
 300         ieee802154_nl_exit();
 301
 302 err_notifier:
 303         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 304 err_nl:
 305         wpan_phy_sysfs_exit();
 306 err:
 307         return rc;
 308 }
 309 subsys_initcall(wpan_phy_class_init);
 310
 311 static void __exit wpan_phy_class_exit(void)
 312 {
 313         nl802154_exit();
 314         ieee802154_nl_exit();
 315         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 316         wpan_phy_sysfs_exit();
 317 }
 318 module_exit(wpan_phy_class_exit);
 319
 320 MODULE_LICENSE("GPL v2");
 321 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
 322 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
 323