net/ieee802154/core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2007, 2008, 2009 Siemens AG
   4  */
   5
   6 #include <linux/slab.h>
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/device.h>
  10
  11 #include <net/cfg802154.h>
  12 #include <net/rtnetlink.h>
  13
  14 #include "ieee802154.h"
  15 #include "nl802154.h"
  16 #include "sysfs.h"
  17 #include "core.h"
  18
  19 /* name for sysfs, %d is appended */
  20 #define PHY_NAME "phy"
  21
  22 /* RCU-protected (and RTNL for writers) */
  23 LIST_HEAD(cfg802154_rdev_list);
  24 int cfg802154_rdev_list_generation;
  25
  26 struct wpan_phy *wpan_phy_find(const char *str)
  27 {
  28         struct device *dev;
  29
  30         if (WARN_ON(!str))
  31                 return NULL;
  32
  33         dev = class_find_device_by_name(&wpan_phy_class, str);
  34         if (!dev)
  35                 return NULL;
  36
  37         return container_of(dev, struct wpan_phy, dev);
  38 }
  39 EXPORT_SYMBOL(wpan_phy_find);
  40
  41 struct wpan_phy_iter_data {
  42         int (*fn)(struct wpan_phy *phy, void *data);
  43         void *data;
  44 };
  45
  46 static int wpan_phy_iter(struct device *dev, void *_data)
  47 {
  48         struct wpan_phy_iter_data *wpid = _data;
  49         struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
  50
  51         return wpid->fn(phy, wpid->data);
  52 }
  53
  54 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
  55                       void *data)
  56 {
  57         struct wpan_phy_iter_data wpid = {
  58                 .fn = fn,
  59                 .data = data,
  60         };
  61
  62         return class_for_each_device(&wpan_phy_class, NULL,
  63                         &wpid, wpan_phy_iter);
  64 }
  65 EXPORT_SYMBOL(wpan_phy_for_each);
  66
  67 struct cfg802154_registered_device *
  68 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
  69 {
  70         struct cfg802154_registered_device *result = NULL, *rdev;
  71
  72         ASSERT_RTNL();
  73
  74         list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
  75                 if (rdev->wpan_phy_idx == wpan_phy_idx) {
  76                         result = rdev;
  77                         break;
  78                 }
  79         }
  80
  81         return result;
  82 }
  83
  84 struct wpan_phy *wpan_phy_idx_to_wpan_phy(int wpan_phy_idx)
  85 {
  86         struct cfg802154_registered_device *rdev;
  87
  88         ASSERT_RTNL();
  89
  90         rdev = cfg802154_rdev_by_wpan_phy_idx(wpan_phy_idx);
  91         if (!rdev)
  92                 return NULL;
  93         return &rdev->wpan_phy;
  94 }
  95
  96 struct wpan_phy *
  97 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
  98 {
  99         static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
 100         struct cfg802154_registered_device *rdev;
 101         size_t alloc_size;
 102
 103         alloc_size = sizeof(*rdev) + priv_size;
 104         rdev = kzalloc(alloc_size, GFP_KERNEL);
 105         if (!rdev)
 106                 return NULL;
 107
 108         rdev->ops = ops;
 109
 110         rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
 111
 112         if (unlikely(rdev->wpan_phy_idx < 0)) {
 113                 /* ugh, wrapped! */
 114                 atomic_dec(&wpan_phy_counter);
 115                 kfree(rdev);
 116                 return NULL;
 117         }
 118
 119         /* atomic_inc_return makes it start at 1, make it start at 0 */
 120         rdev->wpan_phy_idx--;
 121
 122         INIT_LIST_HEAD(&rdev->wpan_dev_list);
 123         device_initialize(&rdev->wpan_phy.dev);
 124         dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
 125
 126         rdev->wpan_phy.dev.class = &wpan_phy_class;
 127         rdev->wpan_phy.dev.platform_data = rdev;
 128
 129         wpan_phy_net_set(&rdev->wpan_phy, &init_net);
 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 int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
 199                            struct net *net)
 200 {
 201         struct wpan_dev *wpan_dev;
 202         int err = 0;
 203
 204         list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
 205                 if (!wpan_dev->netdev)
 206                         continue;
 207                 wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
 208                 err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
 209                 if (err)
 210                         break;
 211                 wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
 212         }
 213
 214         if (err) {
 215                 /* failed -- clean up to old netns */
 216                 net = wpan_phy_net(&rdev->wpan_phy);
 217
 218                 list_for_each_entry_continue_reverse(wpan_dev,
 219                                                      &rdev->wpan_dev_list,
 220                                                      list) {
 221                         if (!wpan_dev->netdev)
 222                                 continue;
 223                         wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
 224                         err = dev_change_net_namespace(wpan_dev->netdev, net,
 225                                                        "wpan%d");
 226                         WARN_ON(err);
 227                         wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
 228                 }
 229
 230                 return err;
 231         }
 232
 233         wpan_phy_net_set(&rdev->wpan_phy, net);
 234
 235         err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
 236         WARN_ON(err);
 237
 238         return 0;
 239 }
 240
 241 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
 242 {
 243         kfree(rdev);
 244 }
 245
 246 static void
 247 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
 248                            int iftype, int num)
 249 {
 250         ASSERT_RTNL();
 251
 252         rdev->num_running_ifaces += num;
 253 }
 254
 255 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
 256                                           unsigned long state, void *ptr)
 257 {
 258         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 259         struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
 260         struct cfg802154_registered_device *rdev;
 261
 262         if (!wpan_dev)
 263                 return NOTIFY_DONE;
 264
 265         rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
 266
 267         /* TODO WARN_ON unspec type */
 268
 269         switch (state) {
 270                 /* TODO NETDEV_DEVTYPE */
 271         case NETDEV_REGISTER:
 272                 dev->features |= NETIF_F_NETNS_LOCAL;
 273                 wpan_dev->identifier = ++rdev->wpan_dev_id;
 274                 list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
 275                 rdev->devlist_generation++;
 276
 277                 wpan_dev->netdev = dev;
 278                 break;
 279         case NETDEV_DOWN:
 280                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
 281
 282                 rdev->opencount--;
 283                 wake_up(&rdev->dev_wait);
 284                 break;
 285         case NETDEV_UP:
 286                 cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
 287
 288                 rdev->opencount++;
 289                 break;
 290         case NETDEV_UNREGISTER:
 291                 /* It is possible to get NETDEV_UNREGISTER
 292                  * multiple times. To detect that, check
 293                  * that the interface is still on the list
 294                  * of registered interfaces, and only then
 295                  * remove and clean it up.
 296                  */
 297                 if (!list_empty(&wpan_dev->list)) {
 298                         list_del_rcu(&wpan_dev->list);
 299                         rdev->devlist_generation++;
 300                 }
 301                 /* synchronize (so that we won't find this netdev
 302                  * from other code any more) and then clear the list
 303                  * head so that the above code can safely check for
 304                  * !list_empty() to avoid double-cleanup.
 305                  */
 306                 synchronize_rcu();
 307                 INIT_LIST_HEAD(&wpan_dev->list);
 308                 break;
 309         default:
 310                 return NOTIFY_DONE;
 311         }
 312
 313         return NOTIFY_OK;
 314 }
 315
 316 static struct notifier_block cfg802154_netdev_notifier = {
 317         .notifier_call = cfg802154_netdev_notifier_call,
 318 };
 319
 320 static void __net_exit cfg802154_pernet_exit(struct net *net)
 321 {
 322         struct cfg802154_registered_device *rdev;
 323
 324         rtnl_lock();
 325         list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
 326                 if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
 327                         WARN_ON(cfg802154_switch_netns(rdev, &init_net));
 328         }
 329         rtnl_unlock();
 330 }
 331
 332 static struct pernet_operations cfg802154_pernet_ops = {
 333         .exit = cfg802154_pernet_exit,
 334 };
 335
 336 static int __init wpan_phy_class_init(void)
 337 {
 338         int rc;
 339
 340         rc = register_pernet_device(&cfg802154_pernet_ops);
 341         if (rc)
 342                 goto err;
 343
 344         rc = wpan_phy_sysfs_init();
 345         if (rc)
 346                 goto err_sysfs;
 347
 348         rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
 349         if (rc)
 350                 goto err_nl;
 351
 352         rc = ieee802154_nl_init();
 353         if (rc)
 354                 goto err_notifier;
 355
 356         rc = nl802154_init();
 357         if (rc)
 358                 goto err_ieee802154_nl;
 359
 360         return 0;
 361
 362 err_ieee802154_nl:
 363         ieee802154_nl_exit();
 364
 365 err_notifier:
 366         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 367 err_nl:
 368         wpan_phy_sysfs_exit();
 369 err_sysfs:
 370         unregister_pernet_device(&cfg802154_pernet_ops);
 371 err:
 372         return rc;
 373 }
 374 subsys_initcall(wpan_phy_class_init);
 375
 376 static void __exit wpan_phy_class_exit(void)
 377 {
 378         nl802154_exit();
 379         ieee802154_nl_exit();
 380         unregister_netdevice_notifier(&cfg802154_netdev_notifier);
 381         wpan_phy_sysfs_exit();
 382         unregister_pernet_device(&cfg802154_pernet_ops);
 383 }
 384 module_exit(wpan_phy_class_exit);
 385
 386 MODULE_LICENSE("GPL v2");
 387 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
 388 MODULE_AUTHOR("Dmitry Eremin-Solenikov");