net/batman-adv/originator.c

   1 /* Copyright (C) 2009-2015 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "originator.h"
  19 #include "main.h"
  20
  21 #include <linux/errno.h>
  22 #include <linux/etherdevice.h>
  23 #include <linux/fs.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/kernel.h>
  26 #include <linux/list.h>
  27 #include <linux/lockdep.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/rculist.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/slab.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/workqueue.h>
  34
  35 #include "distributed-arp-table.h"
  36 #include "fragmentation.h"
  37 #include "gateway_client.h"
  38 #include "hard-interface.h"
  39 #include "hash.h"
  40 #include "multicast.h"
  41 #include "network-coding.h"
  42 #include "routing.h"
  43 #include "translation-table.h"
  44
  45 /* hash class keys */
  46 static struct lock_class_key batadv_orig_hash_lock_class_key;
  47
  48 static void batadv_purge_orig(struct work_struct *work);
  49
  50 /* returns 1 if they are the same originator */
  51 int batadv_compare_orig(const struct hlist_node *node, const void *data2)
  52 {
  53         const void *data1 = container_of(node, struct batadv_orig_node,
  54                                          hash_entry);
  55
  56         return batadv_compare_eth(data1, data2);
  57 }
  58
  59 /**
  60  * batadv_orig_node_vlan_get - get an orig_node_vlan object
  61  * @orig_node: the originator serving the VLAN
  62  * @vid: the VLAN identifier
  63  *
  64  * Returns the vlan object identified by vid and belonging to orig_node or NULL
  65  * if it does not exist.
  66  */
  67 struct batadv_orig_node_vlan *
  68 batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
  69                           unsigned short vid)
  70 {
  71         struct batadv_orig_node_vlan *vlan = NULL, *tmp;
  72
  73         rcu_read_lock();
  74         hlist_for_each_entry_rcu(tmp, &orig_node->vlan_list, list) {
  75                 if (tmp->vid != vid)
  76                         continue;
  77
  78                 if (!atomic_inc_not_zero(&tmp->refcount))
  79                         continue;
  80
  81                 vlan = tmp;
  82
  83                 break;
  84         }
  85         rcu_read_unlock();
  86
  87         return vlan;
  88 }
  89
  90 /**
  91  * batadv_orig_node_vlan_new - search and possibly create an orig_node_vlan
  92  *  object
  93  * @orig_node: the originator serving the VLAN
  94  * @vid: the VLAN identifier
  95  *
  96  * Returns NULL in case of failure or the vlan object identified by vid and
  97  * belonging to orig_node otherwise. The object is created and added to the list
  98  * if it does not exist.
  99  *
 100  * The object is returned with refcounter increased by 1.
 101  */
 102 struct batadv_orig_node_vlan *
 103 batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
 104                           unsigned short vid)
 105 {
 106         struct batadv_orig_node_vlan *vlan;
 107
 108         spin_lock_bh(&orig_node->vlan_list_lock);
 109
 110         /* first look if an object for this vid already exists */
 111         vlan = batadv_orig_node_vlan_get(orig_node, vid);
 112         if (vlan)
 113                 goto out;
 114
 115         vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
 116         if (!vlan)
 117                 goto out;
 118
 119         atomic_set(&vlan->refcount, 2);
 120         vlan->vid = vid;
 121
 122         hlist_add_head_rcu(&vlan->list, &orig_node->vlan_list);
 123
 124 out:
 125         spin_unlock_bh(&orig_node->vlan_list_lock);
 126
 127         return vlan;
 128 }
 129
 130 /**
 131  * batadv_orig_node_vlan_free_ref - decrement the refcounter and possibly free
 132  *  the originator-vlan object
 133  * @orig_vlan: the originator-vlan object to release
 134  */
 135 void batadv_orig_node_vlan_free_ref(struct batadv_orig_node_vlan *orig_vlan)
 136 {
 137         if (atomic_dec_and_test(&orig_vlan->refcount))
 138                 kfree_rcu(orig_vlan, rcu);
 139 }
 140
 141 int batadv_originator_init(struct batadv_priv *bat_priv)
 142 {
 143         if (bat_priv->orig_hash)
 144                 return 0;
 145
 146         bat_priv->orig_hash = batadv_hash_new(1024);
 147
 148         if (!bat_priv->orig_hash)
 149                 goto err;
 150
 151         batadv_hash_set_lock_class(bat_priv->orig_hash,
 152                                    &batadv_orig_hash_lock_class_key);
 153
 154         INIT_DELAYED_WORK(&bat_priv->orig_work, batadv_purge_orig);
 155         queue_delayed_work(batadv_event_workqueue,
 156                            &bat_priv->orig_work,
 157                            msecs_to_jiffies(BATADV_ORIG_WORK_PERIOD));
 158
 159         return 0;
 160
 161 err:
 162         return -ENOMEM;
 163 }
 164
 165 /**
 166  * batadv_neigh_ifinfo_free_rcu - free the neigh_ifinfo object
 167  * @rcu: rcu pointer of the neigh_ifinfo object
 168  */
 169 static void batadv_neigh_ifinfo_free_rcu(struct rcu_head *rcu)
 170 {
 171         struct batadv_neigh_ifinfo *neigh_ifinfo;
 172
 173         neigh_ifinfo = container_of(rcu, struct batadv_neigh_ifinfo, rcu);
 174
 175         if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
 176                 batadv_hardif_free_ref_now(neigh_ifinfo->if_outgoing);
 177
 178         kfree(neigh_ifinfo);
 179 }
 180
 181 /**
 182  * batadv_neigh_ifinfo_free_now - decrement the refcounter and possibly free
 183  *  the neigh_ifinfo (without rcu callback)
 184  * @neigh_ifinfo: the neigh_ifinfo object to release
 185  */
 186 static void
 187 batadv_neigh_ifinfo_free_ref_now(struct batadv_neigh_ifinfo *neigh_ifinfo)
 188 {
 189         if (atomic_dec_and_test(&neigh_ifinfo->refcount))
 190                 batadv_neigh_ifinfo_free_rcu(&neigh_ifinfo->rcu);
 191 }
 192
 193 /**
 194  * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly free
 195  *  the neigh_ifinfo
 196  * @neigh_ifinfo: the neigh_ifinfo object to release
 197  */
 198 void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo)
 199 {
 200         if (atomic_dec_and_test(&neigh_ifinfo->refcount))
 201                 call_rcu(&neigh_ifinfo->rcu, batadv_neigh_ifinfo_free_rcu);
 202 }
 203
 204 /**
 205  * batadv_neigh_node_free_rcu - free the neigh_node
 206  * @rcu: rcu pointer of the neigh_node
 207  */
 208 static void batadv_neigh_node_free_rcu(struct rcu_head *rcu)
 209 {
 210         struct hlist_node *node_tmp;
 211         struct batadv_neigh_node *neigh_node;
 212         struct batadv_neigh_ifinfo *neigh_ifinfo;
 213         struct batadv_algo_ops *bao;
 214
 215         neigh_node = container_of(rcu, struct batadv_neigh_node, rcu);
 216         bao = neigh_node->orig_node->bat_priv->bat_algo_ops;
 217
 218         hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
 219                                   &neigh_node->ifinfo_list, list) {
 220                 batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo);
 221         }
 222
 223         if (bao->bat_neigh_free)
 224                 bao->bat_neigh_free(neigh_node);
 225
 226         batadv_hardif_free_ref_now(neigh_node->if_incoming);
 227
 228         kfree(neigh_node);
 229 }
 230
 231 /**
 232  * batadv_neigh_node_free_ref_now - decrement the neighbors refcounter
 233  *  and possibly free it (without rcu callback)
 234  * @neigh_node: neigh neighbor to free
 235  */
 236 static void
 237 batadv_neigh_node_free_ref_now(struct batadv_neigh_node *neigh_node)
 238 {
 239         if (atomic_dec_and_test(&neigh_node->refcount))
 240                 batadv_neigh_node_free_rcu(&neigh_node->rcu);
 241 }
 242
 243 /**
 244  * batadv_neigh_node_free_ref - decrement the neighbors refcounter
 245  *  and possibly free it
 246  * @neigh_node: neigh neighbor to free
 247  */
 248 void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node)
 249 {
 250         if (atomic_dec_and_test(&neigh_node->refcount))
 251                 call_rcu(&neigh_node->rcu, batadv_neigh_node_free_rcu);
 252 }
 253
 254 /**
 255  * batadv_orig_node_get_router - router to the originator depending on iface
 256  * @orig_node: the orig node for the router
 257  * @if_outgoing: the interface where the payload packet has been received or
 258  *  the OGM should be sent to
 259  *
 260  * Returns the neighbor which should be router for this orig_node/iface.
 261  *
 262  * The object is returned with refcounter increased by 1.
 263  */
 264 struct batadv_neigh_node *
 265 batadv_orig_router_get(struct batadv_orig_node *orig_node,
 266                        const struct batadv_hard_iface *if_outgoing)
 267 {
 268         struct batadv_orig_ifinfo *orig_ifinfo;
 269         struct batadv_neigh_node *router = NULL;
 270
 271         rcu_read_lock();
 272         hlist_for_each_entry_rcu(orig_ifinfo, &orig_node->ifinfo_list, list) {
 273                 if (orig_ifinfo->if_outgoing != if_outgoing)
 274                         continue;
 275
 276                 router = rcu_dereference(orig_ifinfo->router);
 277                 break;
 278         }
 279
 280         if (router && !atomic_inc_not_zero(&router->refcount))
 281                 router = NULL;
 282
 283         rcu_read_unlock();
 284         return router;
 285 }
 286
 287 /**
 288  * batadv_orig_ifinfo_get - find the ifinfo from an orig_node
 289  * @orig_node: the orig node to be queried
 290  * @if_outgoing: the interface for which the ifinfo should be acquired
 291  *
 292  * Returns the requested orig_ifinfo or NULL if not found.
 293  *
 294  * The object is returned with refcounter increased by 1.
 295  */
 296 struct batadv_orig_ifinfo *
 297 batadv_orig_ifinfo_get(struct batadv_orig_node *orig_node,
 298                        struct batadv_hard_iface *if_outgoing)
 299 {
 300         struct batadv_orig_ifinfo *tmp, *orig_ifinfo = NULL;
 301
 302         rcu_read_lock();
 303         hlist_for_each_entry_rcu(tmp, &orig_node->ifinfo_list,
 304                                  list) {
 305                 if (tmp->if_outgoing != if_outgoing)
 306                         continue;
 307
 308                 if (!atomic_inc_not_zero(&tmp->refcount))
 309                         continue;
 310
 311                 orig_ifinfo = tmp;
 312                 break;
 313         }
 314         rcu_read_unlock();
 315
 316         return orig_ifinfo;
 317 }
 318
 319 /**
 320  * batadv_orig_ifinfo_new - search and possibly create an orig_ifinfo object
 321  * @orig_node: the orig node to be queried
 322  * @if_outgoing: the interface for which the ifinfo should be acquired
 323  *
 324  * Returns NULL in case of failure or the orig_ifinfo object for the if_outgoing
 325  * interface otherwise. The object is created and added to the list
 326  * if it does not exist.
 327  *
 328  * The object is returned with refcounter increased by 1.
 329  */
 330 struct batadv_orig_ifinfo *
 331 batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node,
 332                        struct batadv_hard_iface *if_outgoing)
 333 {
 334         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 335         unsigned long reset_time;
 336
 337         spin_lock_bh(&orig_node->neigh_list_lock);
 338
 339         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_outgoing);
 340         if (orig_ifinfo)
 341                 goto out;
 342
 343         orig_ifinfo = kzalloc(sizeof(*orig_ifinfo), GFP_ATOMIC);
 344         if (!orig_ifinfo)
 345                 goto out;
 346
 347         if (if_outgoing != BATADV_IF_DEFAULT &&
 348             !atomic_inc_not_zero(&if_outgoing->refcount)) {
 349                 kfree(orig_ifinfo);
 350                 orig_ifinfo = NULL;
 351                 goto out;
 352         }
 353
 354         reset_time = jiffies - 1;
 355         reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
 356         orig_ifinfo->batman_seqno_reset = reset_time;
 357         orig_ifinfo->if_outgoing = if_outgoing;
 358         INIT_HLIST_NODE(&orig_ifinfo->list);
 359         atomic_set(&orig_ifinfo->refcount, 2);
 360         hlist_add_head_rcu(&orig_ifinfo->list,
 361                            &orig_node->ifinfo_list);
 362 out:
 363         spin_unlock_bh(&orig_node->neigh_list_lock);
 364         return orig_ifinfo;
 365 }
 366
 367 /**
 368  * batadv_neigh_ifinfo_get - find the ifinfo from an neigh_node
 369  * @neigh_node: the neigh node to be queried
 370  * @if_outgoing: the interface for which the ifinfo should be acquired
 371  *
 372  * The object is returned with refcounter increased by 1.
 373  *
 374  * Returns the requested neigh_ifinfo or NULL if not found
 375  */
 376 struct batadv_neigh_ifinfo *
 377 batadv_neigh_ifinfo_get(struct batadv_neigh_node *neigh,
 378                         struct batadv_hard_iface *if_outgoing)
 379 {
 380         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL,
 381                                    *tmp_neigh_ifinfo;
 382
 383         rcu_read_lock();
 384         hlist_for_each_entry_rcu(tmp_neigh_ifinfo, &neigh->ifinfo_list,
 385                                  list) {
 386                 if (tmp_neigh_ifinfo->if_outgoing != if_outgoing)
 387                         continue;
 388
 389                 if (!atomic_inc_not_zero(&tmp_neigh_ifinfo->refcount))
 390                         continue;
 391
 392                 neigh_ifinfo = tmp_neigh_ifinfo;
 393                 break;
 394         }
 395         rcu_read_unlock();
 396
 397         return neigh_ifinfo;
 398 }
 399
 400 /**
 401  * batadv_neigh_ifinfo_new - search and possibly create an neigh_ifinfo object
 402  * @neigh_node: the neigh node to be queried
 403  * @if_outgoing: the interface for which the ifinfo should be acquired
 404  *
 405  * Returns NULL in case of failure or the neigh_ifinfo object for the
 406  * if_outgoing interface otherwise. The object is created and added to the list
 407  * if it does not exist.
 408  *
 409  * The object is returned with refcounter increased by 1.
 410  */
 411 struct batadv_neigh_ifinfo *
 412 batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh,
 413                         struct batadv_hard_iface *if_outgoing)
 414 {
 415         struct batadv_neigh_ifinfo *neigh_ifinfo;
 416
 417         spin_lock_bh(&neigh->ifinfo_lock);
 418
 419         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh, if_outgoing);
 420         if (neigh_ifinfo)
 421                 goto out;
 422
 423         neigh_ifinfo = kzalloc(sizeof(*neigh_ifinfo), GFP_ATOMIC);
 424         if (!neigh_ifinfo)
 425                 goto out;
 426
 427         if (if_outgoing && !atomic_inc_not_zero(&if_outgoing->refcount)) {
 428                 kfree(neigh_ifinfo);
 429                 neigh_ifinfo = NULL;
 430                 goto out;
 431         }
 432
 433         INIT_HLIST_NODE(&neigh_ifinfo->list);
 434         atomic_set(&neigh_ifinfo->refcount, 2);
 435         neigh_ifinfo->if_outgoing = if_outgoing;
 436
 437         hlist_add_head_rcu(&neigh_ifinfo->list, &neigh->ifinfo_list);
 438
 439 out:
 440         spin_unlock_bh(&neigh->ifinfo_lock);
 441
 442         return neigh_ifinfo;
 443 }
 444
 445 /**
 446  * batadv_neigh_node_get - retrieve a neighbour from the list
 447  * @orig_node: originator which the neighbour belongs to
 448  * @hard_iface: the interface where this neighbour is connected to
 449  * @addr: the address of the neighbour
 450  *
 451  * Looks for and possibly returns a neighbour belonging to this originator list
 452  * which is connected through the provided hard interface.
 453  * Returns NULL if the neighbour is not found.
 454  */
 455 static struct batadv_neigh_node *
 456 batadv_neigh_node_get(const struct batadv_orig_node *orig_node,
 457                       const struct batadv_hard_iface *hard_iface,
 458                       const u8 *addr)
 459 {
 460         struct batadv_neigh_node *tmp_neigh_node, *res = NULL;
 461
 462         rcu_read_lock();
 463         hlist_for_each_entry_rcu(tmp_neigh_node, &orig_node->neigh_list, list) {
 464                 if (!batadv_compare_eth(tmp_neigh_node->addr, addr))
 465                         continue;
 466
 467                 if (tmp_neigh_node->if_incoming != hard_iface)
 468                         continue;
 469
 470                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 471                         continue;
 472
 473                 res = tmp_neigh_node;
 474                 break;
 475         }
 476         rcu_read_unlock();
 477
 478         return res;
 479 }
 480
 481 /**
 482  * batadv_neigh_node_new - create and init a new neigh_node object
 483  * @orig_node: originator object representing the neighbour
 484  * @hard_iface: the interface where the neighbour is connected to
 485  * @neigh_addr: the mac address of the neighbour interface
 486  *
 487  * Allocates a new neigh_node object and initialises all the generic fields.
 488  * Returns the new object or NULL on failure.
 489  */
 490 struct batadv_neigh_node *
 491 batadv_neigh_node_new(struct batadv_orig_node *orig_node,
 492                       struct batadv_hard_iface *hard_iface,
 493                       const u8 *neigh_addr)
 494 {
 495         struct batadv_neigh_node *neigh_node;
 496
 497         neigh_node = batadv_neigh_node_get(orig_node, hard_iface, neigh_addr);
 498         if (neigh_node)
 499                 goto out;
 500
 501         neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC);
 502         if (!neigh_node)
 503                 goto out;
 504
 505         if (!atomic_inc_not_zero(&hard_iface->refcount)) {
 506                 kfree(neigh_node);
 507                 neigh_node = NULL;
 508                 goto out;
 509         }
 510
 511         INIT_HLIST_NODE(&neigh_node->list);
 512         INIT_HLIST_HEAD(&neigh_node->ifinfo_list);
 513         spin_lock_init(&neigh_node->ifinfo_lock);
 514
 515         ether_addr_copy(neigh_node->addr, neigh_addr);
 516         neigh_node->if_incoming = hard_iface;
 517         neigh_node->orig_node = orig_node;
 518
 519         /* extra reference for return */
 520         atomic_set(&neigh_node->refcount, 2);
 521
 522         spin_lock_bh(&orig_node->neigh_list_lock);
 523         hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
 524         spin_unlock_bh(&orig_node->neigh_list_lock);
 525
 526         batadv_dbg(BATADV_DBG_BATMAN, orig_node->bat_priv,
 527                    "Creating new neighbor %pM for orig_node %pM on interface %s\n",
 528                    neigh_addr, orig_node->orig, hard_iface->net_dev->name);
 529
 530 out:
 531         return neigh_node;
 532 }
 533
 534 /**
 535  * batadv_orig_ifinfo_free_rcu - free the orig_ifinfo object
 536  * @rcu: rcu pointer of the orig_ifinfo object
 537  */
 538 static void batadv_orig_ifinfo_free_rcu(struct rcu_head *rcu)
 539 {
 540         struct batadv_orig_ifinfo *orig_ifinfo;
 541         struct batadv_neigh_node *router;
 542
 543         orig_ifinfo = container_of(rcu, struct batadv_orig_ifinfo, rcu);
 544
 545         if (orig_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
 546                 batadv_hardif_free_ref_now(orig_ifinfo->if_outgoing);
 547
 548         /* this is the last reference to this object */
 549         router = rcu_dereference_protected(orig_ifinfo->router, true);
 550         if (router)
 551                 batadv_neigh_node_free_ref_now(router);
 552         kfree(orig_ifinfo);
 553 }
 554
 555 /**
 556  * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free
 557  *  the orig_ifinfo (without rcu callback)
 558  * @orig_ifinfo: the orig_ifinfo object to release
 559  */
 560 static void
 561 batadv_orig_ifinfo_free_ref_now(struct batadv_orig_ifinfo *orig_ifinfo)
 562 {
 563         if (atomic_dec_and_test(&orig_ifinfo->refcount))
 564                 batadv_orig_ifinfo_free_rcu(&orig_ifinfo->rcu);
 565 }
 566
 567 /**
 568  * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free
 569  *  the orig_ifinfo
 570  * @orig_ifinfo: the orig_ifinfo object to release
 571  */
 572 void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo)
 573 {
 574         if (atomic_dec_and_test(&orig_ifinfo->refcount))
 575                 call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu);
 576 }
 577
 578 static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
 579 {
 580         struct hlist_node *node_tmp;
 581         struct batadv_neigh_node *neigh_node;
 582         struct batadv_orig_node *orig_node;
 583         struct batadv_orig_ifinfo *orig_ifinfo;
 584
 585         orig_node = container_of(rcu, struct batadv_orig_node, rcu);
 586
 587         spin_lock_bh(&orig_node->neigh_list_lock);
 588
 589         /* for all neighbors towards this originator ... */
 590         hlist_for_each_entry_safe(neigh_node, node_tmp,
 591                                   &orig_node->neigh_list, list) {
 592                 hlist_del_rcu(&neigh_node->list);
 593                 batadv_neigh_node_free_ref_now(neigh_node);
 594         }
 595
 596         hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
 597                                   &orig_node->ifinfo_list, list) {
 598                 hlist_del_rcu(&orig_ifinfo->list);
 599                 batadv_orig_ifinfo_free_ref_now(orig_ifinfo);
 600         }
 601         spin_unlock_bh(&orig_node->neigh_list_lock);
 602
 603         batadv_mcast_purge_orig(orig_node);
 604
 605         /* Free nc_nodes */
 606         batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
 607
 608         batadv_frag_purge_orig(orig_node, NULL);
 609
 610         if (orig_node->bat_priv->bat_algo_ops->bat_orig_free)
 611                 orig_node->bat_priv->bat_algo_ops->bat_orig_free(orig_node);
 612
 613         kfree(orig_node->tt_buff);
 614         kfree(orig_node);
 615 }
 616
 617 /**
 618  * batadv_orig_node_free_ref - decrement the orig node refcounter and possibly
 619  * schedule an rcu callback for freeing it
 620  * @orig_node: the orig node to free
 621  */
 622 void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node)
 623 {
 624         if (atomic_dec_and_test(&orig_node->refcount))
 625                 call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
 626 }
 627
 628 /**
 629  * batadv_orig_node_free_ref_now - decrement the orig node refcounter and
 630  * possibly free it (without rcu callback)
 631  * @orig_node: the orig node to free
 632  */
 633 void batadv_orig_node_free_ref_now(struct batadv_orig_node *orig_node)
 634 {
 635         if (atomic_dec_and_test(&orig_node->refcount))
 636                 batadv_orig_node_free_rcu(&orig_node->rcu);
 637 }
 638
 639 void batadv_originator_free(struct batadv_priv *bat_priv)
 640 {
 641         struct batadv_hashtable *hash = bat_priv->orig_hash;
 642         struct hlist_node *node_tmp;
 643         struct hlist_head *head;
 644         spinlock_t *list_lock; /* spinlock to protect write access */
 645         struct batadv_orig_node *orig_node;
 646         u32 i;
 647
 648         if (!hash)
 649                 return;
 650
 651         cancel_delayed_work_sync(&bat_priv->orig_work);
 652
 653         bat_priv->orig_hash = NULL;
 654
 655         for (i = 0; i < hash->size; i++) {
 656                 head = &hash->table[i];
 657                 list_lock = &hash->list_locks[i];
 658
 659                 spin_lock_bh(list_lock);
 660                 hlist_for_each_entry_safe(orig_node, node_tmp,
 661                                           head, hash_entry) {
 662                         hlist_del_rcu(&orig_node->hash_entry);
 663                         batadv_orig_node_free_ref(orig_node);
 664                 }
 665                 spin_unlock_bh(list_lock);
 666         }
 667
 668         batadv_hash_destroy(hash);
 669 }
 670
 671 /**
 672  * batadv_orig_node_new - creates a new orig_node
 673  * @bat_priv: the bat priv with all the soft interface information
 674  * @addr: the mac address of the originator
 675  *
 676  * Creates a new originator object and initialise all the generic fields.
 677  * The new object is not added to the originator list.
 678  * Returns the newly created object or NULL on failure.
 679  */
 680 struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
 681                                               const u8 *addr)
 682 {
 683         struct batadv_orig_node *orig_node;
 684         struct batadv_orig_node_vlan *vlan;
 685         unsigned long reset_time;
 686         int i;
 687
 688         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 689                    "Creating new originator: %pM\n", addr);
 690
 691         orig_node = kzalloc(sizeof(*orig_node), GFP_ATOMIC);
 692         if (!orig_node)
 693                 return NULL;
 694
 695         INIT_HLIST_HEAD(&orig_node->neigh_list);
 696         INIT_HLIST_HEAD(&orig_node->vlan_list);
 697         INIT_HLIST_HEAD(&orig_node->ifinfo_list);
 698         spin_lock_init(&orig_node->bcast_seqno_lock);
 699         spin_lock_init(&orig_node->neigh_list_lock);
 700         spin_lock_init(&orig_node->tt_buff_lock);
 701         spin_lock_init(&orig_node->tt_lock);
 702         spin_lock_init(&orig_node->vlan_list_lock);
 703
 704         batadv_nc_init_orig(orig_node);
 705
 706         /* extra reference for return */
 707         atomic_set(&orig_node->refcount, 2);
 708
 709         orig_node->bat_priv = bat_priv;
 710         ether_addr_copy(orig_node->orig, addr);
 711         batadv_dat_init_orig_node_addr(orig_node);
 712         atomic_set(&orig_node->last_ttvn, 0);
 713         orig_node->tt_buff = NULL;
 714         orig_node->tt_buff_len = 0;
 715         orig_node->last_seen = jiffies;
 716         reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
 717         orig_node->bcast_seqno_reset = reset_time;
 718
 719 #ifdef CONFIG_BATMAN_ADV_MCAST
 720         orig_node->mcast_flags = BATADV_NO_FLAGS;
 721         INIT_HLIST_NODE(&orig_node->mcast_want_all_unsnoopables_node);
 722         INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv4_node);
 723         INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv6_node);
 724         spin_lock_init(&orig_node->mcast_handler_lock);
 725 #endif
 726
 727         /* create a vlan object for the "untagged" LAN */
 728         vlan = batadv_orig_node_vlan_new(orig_node, BATADV_NO_FLAGS);
 729         if (!vlan)
 730                 goto free_orig_node;
 731         /* batadv_orig_node_vlan_new() increases the refcounter.
 732          * Immediately release vlan since it is not needed anymore in this
 733          * context
 734          */
 735         batadv_orig_node_vlan_free_ref(vlan);
 736
 737         for (i = 0; i < BATADV_FRAG_BUFFER_COUNT; i++) {
 738                 INIT_HLIST_HEAD(&orig_node->fragments[i].head);
 739                 spin_lock_init(&orig_node->fragments[i].lock);
 740                 orig_node->fragments[i].size = 0;
 741         }
 742
 743         return orig_node;
 744 free_orig_node:
 745         kfree(orig_node);
 746         return NULL;
 747 }
 748
 749 /**
 750  * batadv_purge_neigh_ifinfo - purge obsolete ifinfo entries from neighbor
 751  * @bat_priv: the bat priv with all the soft interface information
 752  * @neigh: orig node which is to be checked
 753  */
 754 static void
 755 batadv_purge_neigh_ifinfo(struct batadv_priv *bat_priv,
 756                           struct batadv_neigh_node *neigh)
 757 {
 758         struct batadv_neigh_ifinfo *neigh_ifinfo;
 759         struct batadv_hard_iface *if_outgoing;
 760         struct hlist_node *node_tmp;
 761
 762         spin_lock_bh(&neigh->ifinfo_lock);
 763
 764         /* for all ifinfo objects for this neighinator */
 765         hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
 766                                   &neigh->ifinfo_list, list) {
 767                 if_outgoing = neigh_ifinfo->if_outgoing;
 768
 769                 /* always keep the default interface */
 770                 if (if_outgoing == BATADV_IF_DEFAULT)
 771                         continue;
 772
 773                 /* don't purge if the interface is not (going) down */
 774                 if ((if_outgoing->if_status != BATADV_IF_INACTIVE) &&
 775                     (if_outgoing->if_status != BATADV_IF_NOT_IN_USE) &&
 776                     (if_outgoing->if_status != BATADV_IF_TO_BE_REMOVED))
 777                         continue;
 778
 779                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 780                            "neighbor/ifinfo purge: neighbor %pM, iface: %s\n",
 781                            neigh->addr, if_outgoing->net_dev->name);
 782
 783                 hlist_del_rcu(&neigh_ifinfo->list);
 784                 batadv_neigh_ifinfo_free_ref(neigh_ifinfo);
 785         }
 786
 787         spin_unlock_bh(&neigh->ifinfo_lock);
 788 }
 789
 790 /**
 791  * batadv_purge_orig_ifinfo - purge obsolete ifinfo entries from originator
 792  * @bat_priv: the bat priv with all the soft interface information
 793  * @orig_node: orig node which is to be checked
 794  *
 795  * Returns true if any ifinfo entry was purged, false otherwise.
 796  */
 797 static bool
 798 batadv_purge_orig_ifinfo(struct batadv_priv *bat_priv,
 799                          struct batadv_orig_node *orig_node)
 800 {
 801         struct batadv_orig_ifinfo *orig_ifinfo;
 802         struct batadv_hard_iface *if_outgoing;
 803         struct hlist_node *node_tmp;
 804         bool ifinfo_purged = false;
 805
 806         spin_lock_bh(&orig_node->neigh_list_lock);
 807
 808         /* for all ifinfo objects for this originator */
 809         hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
 810                                   &orig_node->ifinfo_list, list) {
 811                 if_outgoing = orig_ifinfo->if_outgoing;
 812
 813                 /* always keep the default interface */
 814                 if (if_outgoing == BATADV_IF_DEFAULT)
 815                         continue;
 816
 817                 /* don't purge if the interface is not (going) down */
 818                 if ((if_outgoing->if_status != BATADV_IF_INACTIVE) &&
 819                     (if_outgoing->if_status != BATADV_IF_NOT_IN_USE) &&
 820                     (if_outgoing->if_status != BATADV_IF_TO_BE_REMOVED))
 821                         continue;
 822
 823                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 824                            "router/ifinfo purge: originator %pM, iface: %s\n",
 825                            orig_node->orig, if_outgoing->net_dev->name);
 826
 827                 ifinfo_purged = true;
 828
 829                 hlist_del_rcu(&orig_ifinfo->list);
 830                 batadv_orig_ifinfo_free_ref(orig_ifinfo);
 831                 if (orig_node->last_bonding_candidate == orig_ifinfo) {
 832                         orig_node->last_bonding_candidate = NULL;
 833                         batadv_orig_ifinfo_free_ref(orig_ifinfo);
 834                 }
 835         }
 836
 837         spin_unlock_bh(&orig_node->neigh_list_lock);
 838
 839         return ifinfo_purged;
 840 }
 841
 842 /**
 843  * batadv_purge_orig_neighbors - purges neighbors from originator
 844  * @bat_priv: the bat priv with all the soft interface information
 845  * @orig_node: orig node which is to be checked
 846  *
 847  * Returns true if any neighbor was purged, false otherwise
 848  */
 849 static bool
 850 batadv_purge_orig_neighbors(struct batadv_priv *bat_priv,
 851                             struct batadv_orig_node *orig_node)
 852 {
 853         struct hlist_node *node_tmp;
 854         struct batadv_neigh_node *neigh_node;
 855         bool neigh_purged = false;
 856         unsigned long last_seen;
 857         struct batadv_hard_iface *if_incoming;
 858
 859         spin_lock_bh(&orig_node->neigh_list_lock);
 860
 861         /* for all neighbors towards this originator ... */
 862         hlist_for_each_entry_safe(neigh_node, node_tmp,
 863                                   &orig_node->neigh_list, list) {
 864                 last_seen = neigh_node->last_seen;
 865                 if_incoming = neigh_node->if_incoming;
 866
 867                 if ((batadv_has_timed_out(last_seen, BATADV_PURGE_TIMEOUT)) ||
 868                     (if_incoming->if_status == BATADV_IF_INACTIVE) ||
 869                     (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 870                     (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED)) {
 871                         if ((if_incoming->if_status == BATADV_IF_INACTIVE) ||
 872                             (if_incoming->if_status == BATADV_IF_NOT_IN_USE) ||
 873                             (if_incoming->if_status == BATADV_IF_TO_BE_REMOVED))
 874                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 875                                            "neighbor purge: originator %pM, neighbor: %pM, iface: %s\n",
 876                                            orig_node->orig, neigh_node->addr,
 877                                            if_incoming->net_dev->name);
 878                         else
 879                                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 880                                            "neighbor timeout: originator %pM, neighbor: %pM, last_seen: %u\n",
 881                                            orig_node->orig, neigh_node->addr,
 882                                            jiffies_to_msecs(last_seen));
 883
 884                         neigh_purged = true;
 885
 886                         hlist_del_rcu(&neigh_node->list);
 887                         batadv_neigh_node_free_ref(neigh_node);
 888                 } else {
 889                         /* only necessary if not the whole neighbor is to be
 890                          * deleted, but some interface has been removed.
 891                          */
 892                         batadv_purge_neigh_ifinfo(bat_priv, neigh_node);
 893                 }
 894         }
 895
 896         spin_unlock_bh(&orig_node->neigh_list_lock);
 897         return neigh_purged;
 898 }
 899
 900 /**
 901  * batadv_find_best_neighbor - finds the best neighbor after purging
 902  * @bat_priv: the bat priv with all the soft interface information
 903  * @orig_node: orig node which is to be checked
 904  * @if_outgoing: the interface for which the metric should be compared
 905  *
 906  * Returns the current best neighbor, with refcount increased.
 907  */
 908 static struct batadv_neigh_node *
 909 batadv_find_best_neighbor(struct batadv_priv *bat_priv,
 910                           struct batadv_orig_node *orig_node,
 911                           struct batadv_hard_iface *if_outgoing)
 912 {
 913         struct batadv_neigh_node *best = NULL, *neigh;
 914         struct batadv_algo_ops *bao = bat_priv->bat_algo_ops;
 915
 916         rcu_read_lock();
 917         hlist_for_each_entry_rcu(neigh, &orig_node->neigh_list, list) {
 918                 if (best && (bao->bat_neigh_cmp(neigh, if_outgoing,
 919                                                 best, if_outgoing) <= 0))
 920                         continue;
 921
 922                 if (!atomic_inc_not_zero(&neigh->refcount))
 923                         continue;
 924
 925                 if (best)
 926                         batadv_neigh_node_free_ref(best);
 927
 928                 best = neigh;
 929         }
 930         rcu_read_unlock();
 931
 932         return best;
 933 }
 934
 935 /**
 936  * batadv_purge_orig_node - purges obsolete information from an orig_node
 937  * @bat_priv: the bat priv with all the soft interface information
 938  * @orig_node: orig node which is to be checked
 939  *
 940  * This function checks if the orig_node or substructures of it have become
 941  * obsolete, and purges this information if that's the case.
 942  *
 943  * Returns true if the orig_node is to be removed, false otherwise.
 944  */
 945 static bool batadv_purge_orig_node(struct batadv_priv *bat_priv,
 946                                    struct batadv_orig_node *orig_node)
 947 {
 948         struct batadv_neigh_node *best_neigh_node;
 949         struct batadv_hard_iface *hard_iface;
 950         bool changed_ifinfo, changed_neigh;
 951
 952         if (batadv_has_timed_out(orig_node->last_seen,
 953                                  2 * BATADV_PURGE_TIMEOUT)) {
 954                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 955                            "Originator timeout: originator %pM, last_seen %u\n",
 956                            orig_node->orig,
 957                            jiffies_to_msecs(orig_node->last_seen));
 958                 return true;
 959         }
 960         changed_ifinfo = batadv_purge_orig_ifinfo(bat_priv, orig_node);
 961         changed_neigh = batadv_purge_orig_neighbors(bat_priv, orig_node);
 962
 963         if (!changed_ifinfo && !changed_neigh)
 964                 return false;
 965
 966         /* first for NULL ... */
 967         best_neigh_node = batadv_find_best_neighbor(bat_priv, orig_node,
 968                                                     BATADV_IF_DEFAULT);
 969         batadv_update_route(bat_priv, orig_node, BATADV_IF_DEFAULT,
 970                             best_neigh_node);
 971         if (best_neigh_node)
 972                 batadv_neigh_node_free_ref(best_neigh_node);
 973
 974         /* ... then for all other interfaces. */
 975         rcu_read_lock();
 976         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 977                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 978                         continue;
 979
 980                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 981                         continue;
 982
 983                 best_neigh_node = batadv_find_best_neighbor(bat_priv,
 984                                                             orig_node,
 985                                                             hard_iface);
 986                 batadv_update_route(bat_priv, orig_node, hard_iface,
 987                                     best_neigh_node);
 988                 if (best_neigh_node)
 989                         batadv_neigh_node_free_ref(best_neigh_node);
 990         }
 991         rcu_read_unlock();
 992
 993         return false;
 994 }
 995
 996 static void _batadv_purge_orig(struct batadv_priv *bat_priv)
 997 {
 998         struct batadv_hashtable *hash = bat_priv->orig_hash;
 999         struct hlist_node *node_tmp;
1000         struct hlist_head *head;
1001         spinlock_t *list_lock; /* spinlock to protect write access */
1002         struct batadv_orig_node *orig_node;
1003         u32 i;
1004
1005         if (!hash)
1006                 return;
1007
1008         /* for all origins... */
1009         for (i = 0; i < hash->size; i++) {
1010                 head = &hash->table[i];
1011                 list_lock = &hash->list_locks[i];
1012
1013                 spin_lock_bh(list_lock);
1014                 hlist_for_each_entry_safe(orig_node, node_tmp,
1015                                           head, hash_entry) {
1016                         if (batadv_purge_orig_node(bat_priv, orig_node)) {
1017                                 batadv_gw_node_delete(bat_priv, orig_node);
1018                                 hlist_del_rcu(&orig_node->hash_entry);
1019                                 batadv_tt_global_del_orig(orig_node->bat_priv,
1020                                                           orig_node, -1,
1021                                                           "originator timed out");
1022                                 batadv_orig_node_free_ref(orig_node);
1023                                 continue;
1024                         }
1025
1026                         batadv_frag_purge_orig(orig_node,
1027                                                batadv_frag_check_entry);
1028                 }
1029                 spin_unlock_bh(list_lock);
1030         }
1031
1032         batadv_gw_election(bat_priv);
1033 }
1034
1035 static void batadv_purge_orig(struct work_struct *work)
1036 {
1037         struct delayed_work *delayed_work;
1038         struct batadv_priv *bat_priv;
1039
1040         delayed_work = container_of(work, struct delayed_work, work);
1041         bat_priv = container_of(delayed_work, struct batadv_priv, orig_work);
1042         _batadv_purge_orig(bat_priv);
1043         queue_delayed_work(batadv_event_workqueue,
1044                            &bat_priv->orig_work,
1045                            msecs_to_jiffies(BATADV_ORIG_WORK_PERIOD));
1046 }
1047
1048 void batadv_purge_orig_ref(struct batadv_priv *bat_priv)
1049 {
1050         _batadv_purge_orig(bat_priv);
1051 }
1052
1053 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset)
1054 {
1055         struct net_device *net_dev = (struct net_device *)seq->private;
1056         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1057         struct batadv_hard_iface *primary_if;
1058
1059         primary_if = batadv_seq_print_text_primary_if_get(seq);
1060         if (!primary_if)
1061                 return 0;
1062
1063         seq_printf(seq, "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s %s)]\n",
1064                    BATADV_SOURCE_VERSION, primary_if->net_dev->name,
1065                    primary_if->net_dev->dev_addr, net_dev->name,
1066                    bat_priv->bat_algo_ops->name);
1067
1068         batadv_hardif_free_ref(primary_if);
1069
1070         if (!bat_priv->bat_algo_ops->bat_orig_print) {
1071                 seq_puts(seq,
1072                          "No printing function for this routing protocol\n");
1073                 return 0;
1074         }
1075
1076         bat_priv->bat_algo_ops->bat_orig_print(bat_priv, seq,
1077                                                BATADV_IF_DEFAULT);
1078
1079         return 0;
1080 }
1081
1082 /**
1083  * batadv_orig_hardif_seq_print_text - writes originator infos for a specific
1084  *  outgoing interface
1085  * @seq: debugfs table seq_file struct
1086  * @offset: not used
1087  *
1088  * Returns 0
1089  */
1090 int batadv_orig_hardif_seq_print_text(struct seq_file *seq, void *offset)
1091 {
1092         struct net_device *net_dev = (struct net_device *)seq->private;
1093         struct batadv_hard_iface *hard_iface;
1094         struct batadv_priv *bat_priv;
1095
1096         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1097
1098         if (!hard_iface || !hard_iface->soft_iface) {
1099                 seq_puts(seq, "Interface not known to B.A.T.M.A.N.\n");
1100                 goto out;
1101         }
1102
1103         bat_priv = netdev_priv(hard_iface->soft_iface);
1104         if (!bat_priv->bat_algo_ops->bat_orig_print) {
1105                 seq_puts(seq,
1106                          "No printing function for this routing protocol\n");
1107                 goto out;
1108         }
1109
1110         if (hard_iface->if_status != BATADV_IF_ACTIVE) {
1111                 seq_puts(seq, "Interface not active\n");
1112                 goto out;
1113         }
1114
1115         seq_printf(seq, "[B.A.T.M.A.N. adv %s, IF/MAC: %s/%pM (%s %s)]\n",
1116                    BATADV_SOURCE_VERSION, hard_iface->net_dev->name,
1117                    hard_iface->net_dev->dev_addr,
1118                    hard_iface->soft_iface->name, bat_priv->bat_algo_ops->name);
1119
1120         bat_priv->bat_algo_ops->bat_orig_print(bat_priv, seq, hard_iface);
1121
1122 out:
1123         if (hard_iface)
1124                 batadv_hardif_free_ref(hard_iface);
1125         return 0;
1126 }
1127
1128 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
1129                             int max_if_num)
1130 {
1131         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
1132         struct batadv_algo_ops *bao = bat_priv->bat_algo_ops;
1133         struct batadv_hashtable *hash = bat_priv->orig_hash;
1134         struct hlist_head *head;
1135         struct batadv_orig_node *orig_node;
1136         u32 i;
1137         int ret;
1138
1139         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
1140          * if_num
1141          */
1142         for (i = 0; i < hash->size; i++) {
1143                 head = &hash->table[i];
1144
1145                 rcu_read_lock();
1146                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1147                         ret = 0;
1148                         if (bao->bat_orig_add_if)
1149                                 ret = bao->bat_orig_add_if(orig_node,
1150                                                            max_if_num);
1151                         if (ret == -ENOMEM)
1152                                 goto err;
1153                 }
1154                 rcu_read_unlock();
1155         }
1156
1157         return 0;
1158
1159 err:
1160         rcu_read_unlock();
1161         return -ENOMEM;
1162 }
1163
1164 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
1165                             int max_if_num)
1166 {
1167         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
1168         struct batadv_hashtable *hash = bat_priv->orig_hash;
1169         struct hlist_head *head;
1170         struct batadv_hard_iface *hard_iface_tmp;
1171         struct batadv_orig_node *orig_node;
1172         struct batadv_algo_ops *bao = bat_priv->bat_algo_ops;
1173         u32 i;
1174         int ret;
1175
1176         /* resize all orig nodes because orig_node->bcast_own(_sum) depend on
1177          * if_num
1178          */
1179         for (i = 0; i < hash->size; i++) {
1180                 head = &hash->table[i];
1181
1182                 rcu_read_lock();
1183                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1184                         ret = 0;
1185                         if (bao->bat_orig_del_if)
1186                                 ret = bao->bat_orig_del_if(orig_node,
1187                                                            max_if_num,
1188                                                            hard_iface->if_num);
1189                         if (ret == -ENOMEM)
1190                                 goto err;
1191                 }
1192                 rcu_read_unlock();
1193         }
1194
1195         /* renumber remaining batman interfaces _inside_ of orig_hash_lock */
1196         rcu_read_lock();
1197         list_for_each_entry_rcu(hard_iface_tmp, &batadv_hardif_list, list) {
1198                 if (hard_iface_tmp->if_status == BATADV_IF_NOT_IN_USE)
1199                         continue;
1200
1201                 if (hard_iface == hard_iface_tmp)
1202                         continue;
1203
1204                 if (hard_iface->soft_iface != hard_iface_tmp->soft_iface)
1205                         continue;
1206
1207                 if (hard_iface_tmp->if_num > hard_iface->if_num)
1208                         hard_iface_tmp->if_num--;
1209         }
1210         rcu_read_unlock();
1211
1212         hard_iface->if_num = -1;
1213         return 0;
1214
1215 err:
1216         rcu_read_unlock();
1217         return -ENOMEM;
1218 }