net/wimax/stack.c

   1 /*
   2  * Linux WiMAX
   3  * Initialization, addition and removal of wimax devices
   4  *
   5  *
   6  * Copyright (C) 2005-2006 Intel Corporation <linux-wimax@intel.com>
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License version
  11  * 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301, USA.
  22  *
  23  *
  24  * This implements:
  25  *
  26  *   - basic life cycle of 'struct wimax_dev' [wimax_dev_*()]; on
  27  *     addition/registration initialize all subfields and allocate
  28  *     generic netlink resources for user space communication. On
  29  *     removal/unregistration, undo all that.
  30  *
  31  *   - device state machine [wimax_state_change()] and support to send
  32  *     reports to user space when the state changes
  33  *     [wimax_gnl_re_state_change*()].
  34  *
  35  * See include/net/wimax.h for rationales and design.
  36  *
  37  * ROADMAP
  38  *
  39  * [__]wimax_state_change()     Called by drivers to update device's state
  40  *   wimax_gnl_re_state_change_alloc()
  41  *   wimax_gnl_re_state_change_send()
  42  *
  43  * wimax_dev_init()             Init a device
  44  * wimax_dev_add()              Register
  45  *   wimax_rfkill_add()
  46  *   wimax_gnl_add()            Register all the generic netlink resources.
  47  *   wimax_id_table_add()
  48  * wimax_dev_rm()               Unregister
  49  *   wimax_id_table_rm()
  50  *   wimax_gnl_rm()
  51  *   wimax_rfkill_rm()
  52  */
  53 #include <linux/device.h>
  54 #include <net/genetlink.h>
  55 #include <linux/netdevice.h>
  56 #include <linux/wimax.h>
  57 #include "wimax-internal.h"
  58
  59
  60 #define D_SUBMODULE stack
  61 #include "debug-levels.h"
  62
  63 static char wimax_debug_params[128];
  64 module_param_string(debug, wimax_debug_params, sizeof(wimax_debug_params),
  65                     0644);
  66 MODULE_PARM_DESC(debug,
  67                  "String of space-separated NAME:VALUE pairs, where NAMEs "
  68                  "are the different debug submodules and VALUE are the "
  69                  "initial debug value to set.");
  70
  71 /*
  72  * Authoritative source for the RE_STATE_CHANGE attribute policy
  73  *
  74  * We don't really use it here, but /me likes to keep the definition
  75  * close to where the data is generated.
  76  */
  77 /*
  78 static const
  79 struct nla_policy wimax_gnl_re_status_change[WIMAX_GNL_ATTR_MAX + 1] = {
  80         [WIMAX_GNL_STCH_STATE_OLD] = { .type = NLA_U8 },
  81         [WIMAX_GNL_STCH_STATE_NEW] = { .type = NLA_U8 },
  82 };
  83 */
  84
  85
  86 /*
  87  * Allocate a Report State Change message
  88  *
  89  * @header: save it, you need it for _send()
  90  *
  91  * Creates and fills a basic state change message; different code
  92  * paths can then add more attributes to the message as needed.
  93  *
  94  * Use wimax_gnl_re_state_change_send() to send the returned skb.
  95  *
  96  * Returns: skb with the genl message if ok, IS_ERR() ptr on error
  97  *     with an errno code.
  98  */
  99 static
 100 struct sk_buff *wimax_gnl_re_state_change_alloc(
 101         struct wimax_dev *wimax_dev,
 102         enum wimax_st new_state, enum wimax_st old_state,
 103         void **header)
 104 {
 105         int result;
 106         struct device *dev = wimax_dev_to_dev(wimax_dev);
 107         void *data;
 108         struct sk_buff *report_skb;
 109
 110         d_fnstart(3, dev, "(wimax_dev %p new_state %u old_state %u)\n",
 111                   wimax_dev, new_state, old_state);
 112         result = -ENOMEM;
 113         report_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 114         if (report_skb == NULL) {
 115                 dev_err(dev, "RE_STCH: can't create message\n");
 116                 goto error_new;
 117         }
 118         data = genlmsg_put(report_skb, 0, wimax_gnl_mcg.id, &wimax_gnl_family,
 119                            0, WIMAX_GNL_RE_STATE_CHANGE);
 120         if (data == NULL) {
 121                 dev_err(dev, "RE_STCH: can't put data into message\n");
 122                 goto error_put;
 123         }
 124         *header = data;
 125
 126         result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_OLD, old_state);
 127         if (result < 0) {
 128                 dev_err(dev, "RE_STCH: Error adding OLD attr: %d\n", result);
 129                 goto error_put;
 130         }
 131         result = nla_put_u8(report_skb, WIMAX_GNL_STCH_STATE_NEW, new_state);
 132         if (result < 0) {
 133                 dev_err(dev, "RE_STCH: Error adding NEW attr: %d\n", result);
 134                 goto error_put;
 135         }
 136         result = nla_put_u32(report_skb, WIMAX_GNL_STCH_IFIDX,
 137                              wimax_dev->net_dev->ifindex);
 138         if (result < 0) {
 139                 dev_err(dev, "RE_STCH: Error adding IFINDEX attribute\n");
 140                 goto error_put;
 141         }
 142         d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %p\n",
 143                 wimax_dev, new_state, old_state, report_skb);
 144         return report_skb;
 145
 146 error_put:
 147         nlmsg_free(report_skb);
 148 error_new:
 149         d_fnend(3, dev, "(wimax_dev %p new_state %u old_state %u) = %d\n",
 150                 wimax_dev, new_state, old_state, result);
 151         return ERR_PTR(result);
 152 }
 153
 154
 155 /*
 156  * Send a Report State Change message (as created with _alloc).
 157  *
 158  * @report_skb: as returned by wimax_gnl_re_state_change_alloc()
 159  * @header: as returned by wimax_gnl_re_state_change_alloc()
 160  *
 161  * Returns: 0 if ok, < 0 errno code on error.
 162  *
 163  * If the message is  NULL, pretend it didn't happen.
 164  */
 165 static
 166 int wimax_gnl_re_state_change_send(
 167         struct wimax_dev *wimax_dev, struct sk_buff *report_skb,
 168         void *header)
 169 {
 170         int result = 0;
 171         struct device *dev = wimax_dev_to_dev(wimax_dev);
 172         d_fnstart(3, dev, "(wimax_dev %p report_skb %p)\n",
 173                   wimax_dev, report_skb);
 174         if (report_skb == NULL) {
 175                 result = -ENOMEM;
 176                 goto out;
 177         }
 178         genlmsg_end(report_skb, header);
 179         genlmsg_multicast(report_skb, 0, wimax_gnl_mcg.id, GFP_KERNEL);
 180 out:
 181         d_fnend(3, dev, "(wimax_dev %p report_skb %p) = %d\n",
 182                 wimax_dev, report_skb, result);
 183         return result;
 184 }
 185
 186
 187 static
 188 void __check_new_state(enum wimax_st old_state, enum wimax_st new_state,
 189                        unsigned allowed_states_bm)
 190 {
 191         if (WARN_ON(((1 << new_state) & allowed_states_bm) == 0)) {
 192                 printk(KERN_ERR "SW BUG! Forbidden state change %u -> %u\n",
 193                         old_state, new_state);
 194         }
 195 }
 196
 197
 198 /*
 199  * Set the current state of a WiMAX device [unlocking version of
 200  * wimax_state_change().
 201  */
 202 void __wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
 203 {
 204         struct device *dev = wimax_dev_to_dev(wimax_dev);
 205         enum wimax_st old_state = wimax_dev->state;
 206         struct sk_buff *stch_skb;
 207         void *header;
 208
 209         d_fnstart(3, dev, "(wimax_dev %p new_state %u [old %u])\n",
 210                   wimax_dev, new_state, old_state);
 211
 212         if (WARN_ON(new_state >= __WIMAX_ST_INVALID)) {
 213                 dev_err(dev, "SW BUG: requesting invalid state %u\n",
 214                         new_state);
 215                 goto out;
 216         }
 217         if (old_state == new_state)
 218                 goto out;
 219         header = NULL;  /* gcc complains? can't grok why */
 220         stch_skb = wimax_gnl_re_state_change_alloc(
 221                 wimax_dev, new_state, old_state, &header);
 222
 223         /* Verify the state transition and do exit-from-state actions */
 224         switch (old_state) {
 225         case __WIMAX_ST_NULL:
 226                 __check_new_state(old_state, new_state,
 227                                   1 << WIMAX_ST_DOWN);
 228                 break;
 229         case WIMAX_ST_DOWN:
 230                 __check_new_state(old_state, new_state,
 231                                   1 << __WIMAX_ST_QUIESCING
 232                                   | 1 << WIMAX_ST_UNINITIALIZED
 233                                   | 1 << WIMAX_ST_RADIO_OFF);
 234                 break;
 235         case __WIMAX_ST_QUIESCING:
 236                 __check_new_state(old_state, new_state, 1 << WIMAX_ST_DOWN);
 237                 break;
 238         case WIMAX_ST_UNINITIALIZED:
 239                 __check_new_state(old_state, new_state,
 240                                   1 << __WIMAX_ST_QUIESCING
 241                                   | 1 << WIMAX_ST_RADIO_OFF);
 242                 break;
 243         case WIMAX_ST_RADIO_OFF:
 244                 __check_new_state(old_state, new_state,
 245                                   1 << __WIMAX_ST_QUIESCING
 246                                   | 1 << WIMAX_ST_READY);
 247                 break;
 248         case WIMAX_ST_READY:
 249                 __check_new_state(old_state, new_state,
 250                                   1 << __WIMAX_ST_QUIESCING
 251                                   | 1 << WIMAX_ST_RADIO_OFF
 252                                   | 1 << WIMAX_ST_SCANNING
 253                                   | 1 << WIMAX_ST_CONNECTING
 254                                   | 1 << WIMAX_ST_CONNECTED);
 255                 break;
 256         case WIMAX_ST_SCANNING:
 257                 __check_new_state(old_state, new_state,
 258                                   1 << __WIMAX_ST_QUIESCING
 259                                   | 1 << WIMAX_ST_RADIO_OFF
 260                                   | 1 << WIMAX_ST_READY
 261                                   | 1 << WIMAX_ST_CONNECTING
 262                                   | 1 << WIMAX_ST_CONNECTED);
 263                 break;
 264         case WIMAX_ST_CONNECTING:
 265                 __check_new_state(old_state, new_state,
 266                                   1 << __WIMAX_ST_QUIESCING
 267                                   | 1 << WIMAX_ST_RADIO_OFF
 268                                   | 1 << WIMAX_ST_READY
 269                                   | 1 << WIMAX_ST_SCANNING
 270                                   | 1 << WIMAX_ST_CONNECTED);
 271                 break;
 272         case WIMAX_ST_CONNECTED:
 273                 __check_new_state(old_state, new_state,
 274                                   1 << __WIMAX_ST_QUIESCING
 275                                   | 1 << WIMAX_ST_RADIO_OFF
 276                                   | 1 << WIMAX_ST_READY);
 277                 netif_tx_disable(wimax_dev->net_dev);
 278                 netif_carrier_off(wimax_dev->net_dev);
 279                 break;
 280         case __WIMAX_ST_INVALID:
 281         default:
 282                 dev_err(dev, "SW BUG: wimax_dev %p is in unknown state %u\n",
 283                         wimax_dev, wimax_dev->state);
 284                 WARN_ON(1);
 285                 goto out;
 286         }
 287
 288         /* Execute the actions of entry to the new state */
 289         switch (new_state) {
 290         case __WIMAX_ST_NULL:
 291                 dev_err(dev, "SW BUG: wimax_dev %p entering NULL state "
 292                         "from %u\n", wimax_dev, wimax_dev->state);
 293                 WARN_ON(1);             /* Nobody can enter this state */
 294                 break;
 295         case WIMAX_ST_DOWN:
 296                 break;
 297         case __WIMAX_ST_QUIESCING:
 298                 break;
 299         case WIMAX_ST_UNINITIALIZED:
 300                 break;
 301         case WIMAX_ST_RADIO_OFF:
 302                 break;
 303         case WIMAX_ST_READY:
 304                 break;
 305         case WIMAX_ST_SCANNING:
 306                 break;
 307         case WIMAX_ST_CONNECTING:
 308                 break;
 309         case WIMAX_ST_CONNECTED:
 310                 netif_carrier_on(wimax_dev->net_dev);
 311                 netif_wake_queue(wimax_dev->net_dev);
 312                 break;
 313         case __WIMAX_ST_INVALID:
 314         default:
 315                 BUG();
 316         }
 317         __wimax_state_set(wimax_dev, new_state);
 318         if (stch_skb)
 319                 wimax_gnl_re_state_change_send(wimax_dev, stch_skb, header);
 320 out:
 321         d_fnend(3, dev, "(wimax_dev %p new_state %u [old %u]) = void\n",
 322                 wimax_dev, new_state, old_state);
 323         return;
 324 }
 325
 326
 327 /**
 328  * wimax_state_change - Set the current state of a WiMAX device
 329  *
 330  * @wimax_dev: WiMAX device descriptor (properly referenced)
 331  * @new_state: New state to switch to
 332  *
 333  * This implements the state changes for the wimax devices. It will
 334  *
 335  * - verify that the state transition is legal (for now it'll just
 336  *   print a warning if not) according to the table in
 337  *   linux/wimax.h's documentation for 'enum wimax_st'.
 338  *
 339  * - perform the actions needed for leaving the current state and
 340  *   whichever are needed for entering the new state.
 341  *
 342  * - issue a report to user space indicating the new state (and an
 343  *   optional payload with information about the new state).
 344  *
 345  * NOTE: @wimax_dev must be locked
 346  */
 347 void wimax_state_change(struct wimax_dev *wimax_dev, enum wimax_st new_state)
 348 {
 349         /*
 350          * A driver cannot take the wimax_dev out of the
 351          * __WIMAX_ST_NULL state unless by calling wimax_dev_add(). If
 352          * the wimax_dev's state is still NULL, we ignore any request
 353          * to change its state because it means it hasn't been yet
 354          * registered.
 355          *
 356          * There is no need to complain about it, as routines that
 357          * call this might be shared from different code paths that
 358          * are called before or after wimax_dev_add() has done its
 359          * job.
 360          */
 361         mutex_lock(&wimax_dev->mutex);
 362         if (wimax_dev->state > __WIMAX_ST_NULL)
 363                 __wimax_state_change(wimax_dev, new_state);
 364         mutex_unlock(&wimax_dev->mutex);
 365         return;
 366 }
 367 EXPORT_SYMBOL_GPL(wimax_state_change);
 368
 369
 370 /**
 371  * wimax_state_get() - Return the current state of a WiMAX device
 372  *
 373  * @wimax_dev: WiMAX device descriptor
 374  *
 375  * Returns: Current state of the device according to its driver.
 376  */
 377 enum wimax_st wimax_state_get(struct wimax_dev *wimax_dev)
 378 {
 379         enum wimax_st state;
 380         mutex_lock(&wimax_dev->mutex);
 381         state = wimax_dev->state;
 382         mutex_unlock(&wimax_dev->mutex);
 383         return state;
 384 }
 385 EXPORT_SYMBOL_GPL(wimax_state_get);
 386
 387
 388 /**
 389  * wimax_dev_init - initialize a newly allocated instance
 390  *
 391  * @wimax_dev: WiMAX device descriptor to initialize.
 392  *
 393  * Initializes fields of a freshly allocated @wimax_dev instance. This
 394  * function assumes that after allocation, the memory occupied by
 395  * @wimax_dev was zeroed.
 396  */
 397 void wimax_dev_init(struct wimax_dev *wimax_dev)
 398 {
 399         INIT_LIST_HEAD(&wimax_dev->id_table_node);
 400         __wimax_state_set(wimax_dev, __WIMAX_ST_NULL);
 401         mutex_init(&wimax_dev->mutex);
 402         mutex_init(&wimax_dev->mutex_reset);
 403 }
 404 EXPORT_SYMBOL_GPL(wimax_dev_init);
 405
 406 /*
 407  * This extern is declared here because it's easier to keep track --
 408  * both declarations are a list of the same
 409  */
 410 extern struct genl_ops
 411         wimax_gnl_msg_from_user,
 412         wimax_gnl_reset,
 413         wimax_gnl_rfkill,
 414         wimax_gnl_state_get;
 415
 416 static
 417 struct genl_ops *wimax_gnl_ops[] = {
 418         &wimax_gnl_msg_from_user,
 419         &wimax_gnl_reset,
 420         &wimax_gnl_rfkill,
 421         &wimax_gnl_state_get,
 422 };
 423
 424
 425 static
 426 size_t wimax_addr_scnprint(char *addr_str, size_t addr_str_size,
 427                            unsigned char *addr, size_t addr_len)
 428 {
 429         unsigned cnt, total;
 430         for (total = cnt = 0; cnt < addr_len; cnt++)
 431                 total += scnprintf(addr_str + total, addr_str_size - total,
 432                                    "%02x%c", addr[cnt],
 433                                    cnt == addr_len - 1 ? '\0' : ':');
 434         return total;
 435 }
 436
 437
 438 /**
 439  * wimax_dev_add - Register a new WiMAX device
 440  *
 441  * @wimax_dev: WiMAX device descriptor (as embedded in your @net_dev's
 442  *     priv data). You must have called wimax_dev_init() on it before.
 443  *
 444  * @net_dev: net device the @wimax_dev is associated with. The
 445  *     function expects SET_NETDEV_DEV() and register_netdev() were
 446  *     already called on it.
 447  *
 448  * Registers the new WiMAX device, sets up the user-kernel control
 449  * interface (generic netlink) and common WiMAX infrastructure.
 450  *
 451  * Note that the parts that will allow interaction with user space are
 452  * setup at the very end, when the rest is in place, as once that
 453  * happens, the driver might get user space control requests via
 454  * netlink or from debugfs that might translate into calls into
 455  * wimax_dev->op_*().
 456  */
 457 int wimax_dev_add(struct wimax_dev *wimax_dev, struct net_device *net_dev)
 458 {
 459         int result;
 460         struct device *dev = net_dev->dev.parent;
 461         char addr_str[32];
 462
 463         d_fnstart(3, dev, "(wimax_dev %p net_dev %p)\n", wimax_dev, net_dev);
 464
 465         /* Do the RFKILL setup before locking, as RFKILL will call
 466          * into our functions. */
 467         wimax_dev->net_dev = net_dev;
 468         result = wimax_rfkill_add(wimax_dev);
 469         if (result < 0)
 470                 goto error_rfkill_add;
 471
 472         /* Set up user-space interaction */
 473         mutex_lock(&wimax_dev->mutex);
 474         wimax_id_table_add(wimax_dev);
 475         result = wimax_debugfs_add(wimax_dev);
 476         if (result < 0) {
 477                 dev_err(dev, "cannot initialize debugfs: %d\n",
 478                         result);
 479                 goto error_debugfs_add;
 480         }
 481
 482         __wimax_state_set(wimax_dev, WIMAX_ST_DOWN);
 483         mutex_unlock(&wimax_dev->mutex);
 484
 485         wimax_addr_scnprint(addr_str, sizeof(addr_str),
 486                             net_dev->dev_addr, net_dev->addr_len);
 487         dev_err(dev, "WiMAX interface %s (%s) ready\n",
 488                 net_dev->name, addr_str);
 489         d_fnend(3, dev, "(wimax_dev %p net_dev %p) = 0\n", wimax_dev, net_dev);
 490         return 0;
 491
 492 error_debugfs_add:
 493         wimax_id_table_rm(wimax_dev);
 494         mutex_unlock(&wimax_dev->mutex);
 495         wimax_rfkill_rm(wimax_dev);
 496 error_rfkill_add:
 497         d_fnend(3, dev, "(wimax_dev %p net_dev %p) = %d\n",
 498                 wimax_dev, net_dev, result);
 499         return result;
 500 }
 501 EXPORT_SYMBOL_GPL(wimax_dev_add);
 502
 503
 504 /**
 505  * wimax_dev_rm - Unregister an existing WiMAX device
 506  *
 507  * @wimax_dev: WiMAX device descriptor
 508  *
 509  * Unregisters a WiMAX device previously registered for use with
 510  * wimax_add_rm().
 511  *
 512  * IMPORTANT! Must call before calling unregister_netdev().
 513  *
 514  * After this function returns, you will not get any more user space
 515  * control requests (via netlink or debugfs) and thus to wimax_dev->ops.
 516  *
 517  * Reentrancy control is ensured by setting the state to
 518  * %__WIMAX_ST_QUIESCING. rfkill operations coming through
 519  * wimax_*rfkill*() will be stopped by the quiescing state; ops coming
 520  * from the rfkill subsystem will be stopped by the support being
 521  * removed by wimax_rfkill_rm().
 522  */
 523 void wimax_dev_rm(struct wimax_dev *wimax_dev)
 524 {
 525         d_fnstart(3, NULL, "(wimax_dev %p)\n", wimax_dev);
 526
 527         mutex_lock(&wimax_dev->mutex);
 528         __wimax_state_change(wimax_dev, __WIMAX_ST_QUIESCING);
 529         wimax_debugfs_rm(wimax_dev);
 530         wimax_id_table_rm(wimax_dev);
 531         __wimax_state_change(wimax_dev, WIMAX_ST_DOWN);
 532         mutex_unlock(&wimax_dev->mutex);
 533         wimax_rfkill_rm(wimax_dev);
 534         d_fnend(3, NULL, "(wimax_dev %p) = void\n", wimax_dev);
 535 }
 536 EXPORT_SYMBOL_GPL(wimax_dev_rm);
 537
 538
 539 /* Debug framework control of debug levels */
 540 struct d_level D_LEVEL[] = {
 541         D_SUBMODULE_DEFINE(debugfs),
 542         D_SUBMODULE_DEFINE(id_table),
 543         D_SUBMODULE_DEFINE(op_msg),
 544         D_SUBMODULE_DEFINE(op_reset),
 545         D_SUBMODULE_DEFINE(op_rfkill),
 546         D_SUBMODULE_DEFINE(op_state_get),
 547         D_SUBMODULE_DEFINE(stack),
 548 };
 549 size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
 550
 551
 552 struct genl_family wimax_gnl_family = {
 553         .id = GENL_ID_GENERATE,
 554         .name = "WiMAX",
 555         .version = WIMAX_GNL_VERSION,
 556         .hdrsize = 0,
 557         .maxattr = WIMAX_GNL_ATTR_MAX,
 558 };
 559
 560 struct genl_multicast_group wimax_gnl_mcg = {
 561         .name = "msg",
 562 };
 563
 564
 565
 566 /* Shutdown the wimax stack */
 567 static
 568 int __init wimax_subsys_init(void)
 569 {
 570         int result, cnt;
 571
 572         d_fnstart(4, NULL, "()\n");
 573         d_parse_params(D_LEVEL, D_LEVEL_SIZE, wimax_debug_params,
 574                        "wimax.debug");
 575
 576         snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
 577                  "WiMAX");
 578         result = genl_register_family(&wimax_gnl_family);
 579         if (unlikely(result < 0)) {
 580                 printk(KERN_ERR "cannot register generic netlink family: %d\n",
 581                        result);
 582                 goto error_register_family;
 583         }
 584
 585         for (cnt = 0; cnt < ARRAY_SIZE(wimax_gnl_ops); cnt++) {
 586                 result = genl_register_ops(&wimax_gnl_family,
 587                                            wimax_gnl_ops[cnt]);
 588                 d_printf(4, NULL, "registering generic netlink op code "
 589                          "%u: %d\n", wimax_gnl_ops[cnt]->cmd, result);
 590                 if (unlikely(result < 0)) {
 591                         printk(KERN_ERR "cannot register generic netlink op "
 592                                "code %u: %d\n",
 593                                wimax_gnl_ops[cnt]->cmd, result);
 594                         goto error_register_ops;
 595                 }
 596         }
 597
 598         result = genl_register_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
 599         if (result < 0)
 600                 goto error_mc_group;
 601         d_fnend(4, NULL, "() = 0\n");
 602         return 0;
 603
 604 error_mc_group:
 605 error_register_ops:
 606         for (cnt--; cnt >= 0; cnt--)
 607                 genl_unregister_ops(&wimax_gnl_family,
 608                                     wimax_gnl_ops[cnt]);
 609         genl_unregister_family(&wimax_gnl_family);
 610 error_register_family:
 611         d_fnend(4, NULL, "() = %d\n", result);
 612         return result;
 613
 614 }
 615 module_init(wimax_subsys_init);
 616
 617
 618 /* Shutdown the wimax stack */
 619 static
 620 void __exit wimax_subsys_exit(void)
 621 {
 622         int cnt;
 623         wimax_id_table_release();
 624         genl_unregister_mc_group(&wimax_gnl_family, &wimax_gnl_mcg);
 625         for (cnt = ARRAY_SIZE(wimax_gnl_ops) - 1; cnt >= 0; cnt--)
 626                 genl_unregister_ops(&wimax_gnl_family,
 627                                     wimax_gnl_ops[cnt]);
 628         genl_unregister_family(&wimax_gnl_family);
 629 }
 630 module_exit(wimax_subsys_exit);
 631
 632 MODULE_AUTHOR("Intel Corporation <linux-wimax@intel.com>");
 633 MODULE_DESCRIPTION("Linux WiMAX stack");
 634 MODULE_LICENSE("GPL");
 635