net/batman-adv/bat_iv_ogm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  */
   6
   7 #include "bat_iv_ogm.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/bitmap.h>
  12 #include <linux/bitops.h>
  13 #include <linux/bug.h>
  14 #include <linux/byteorder/generic.h>
  15 #include <linux/cache.h>
  16 #include <linux/errno.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/gfp.h>
  19 #include <linux/if_ether.h>
  20 #include <linux/init.h>
  21 #include <linux/jiffies.h>
  22 #include <linux/kernel.h>
  23 #include <linux/kref.h>
  24 #include <linux/list.h>
  25 #include <linux/lockdep.h>
  26 #include <linux/mutex.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/netlink.h>
  29 #include <linux/pkt_sched.h>
  30 #include <linux/prandom.h>
  31 #include <linux/printk.h>
  32 #include <linux/random.h>
  33 #include <linux/rculist.h>
  34 #include <linux/rcupdate.h>
  35 #include <linux/skbuff.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/stddef.h>
  39 #include <linux/string.h>
  40 #include <linux/types.h>
  41 #include <linux/workqueue.h>
  42 #include <net/genetlink.h>
  43 #include <net/netlink.h>
  44 #include <uapi/linux/batadv_packet.h>
  45 #include <uapi/linux/batman_adv.h>
  46
  47 #include "bat_algo.h"
  48 #include "bitarray.h"
  49 #include "gateway_client.h"
  50 #include "hard-interface.h"
  51 #include "hash.h"
  52 #include "log.h"
  53 #include "netlink.h"
  54 #include "network-coding.h"
  55 #include "originator.h"
  56 #include "routing.h"
  57 #include "send.h"
  58 #include "translation-table.h"
  59 #include "tvlv.h"
  60
  61 static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work);
  62
  63 /**
  64  * enum batadv_dup_status - duplicate status
  65  */
  66 enum batadv_dup_status {
  67         /** @BATADV_NO_DUP: the packet is no duplicate */
  68         BATADV_NO_DUP = 0,
  69
  70         /**
  71          * @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for
  72          *  the neighbor)
  73          */
  74         BATADV_ORIG_DUP,
  75
  76         /** @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor */
  77         BATADV_NEIGH_DUP,
  78
  79         /**
  80          * @BATADV_PROTECTED: originator is currently protected (after reboot)
  81          */
  82         BATADV_PROTECTED,
  83 };
  84
  85 /**
  86  * batadv_ring_buffer_set() - update the ring buffer with the given value
  87  * @lq_recv: pointer to the ring buffer
  88  * @lq_index: index to store the value at
  89  * @value: value to store in the ring buffer
  90  */
  91 static void batadv_ring_buffer_set(u8 lq_recv[], u8 *lq_index, u8 value)
  92 {
  93         lq_recv[*lq_index] = value;
  94         *lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
  95 }
  96
  97 /**
  98  * batadv_ring_buffer_avg() - compute the average of all non-zero values stored
  99  * in the given ring buffer
 100  * @lq_recv: pointer to the ring buffer
 101  *
 102  * Return: computed average value.
 103  */
 104 static u8 batadv_ring_buffer_avg(const u8 lq_recv[])
 105 {
 106         const u8 *ptr;
 107         u16 count = 0;
 108         u16 i = 0;
 109         u16 sum = 0;
 110
 111         ptr = lq_recv;
 112
 113         while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
 114                 if (*ptr != 0) {
 115                         count++;
 116                         sum += *ptr;
 117                 }
 118
 119                 i++;
 120                 ptr++;
 121         }
 122
 123         if (count == 0)
 124                 return 0;
 125
 126         return (u8)(sum / count);
 127 }
 128
 129 /**
 130  * batadv_iv_ogm_orig_get() - retrieve or create (if does not exist) an
 131  *  originator
 132  * @bat_priv: the bat priv with all the soft interface information
 133  * @addr: mac address of the originator
 134  *
 135  * Return: the originator object corresponding to the passed mac address or NULL
 136  * on failure.
 137  * If the object does not exist, it is created and initialised.
 138  */
 139 static struct batadv_orig_node *
 140 batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const u8 *addr)
 141 {
 142         struct batadv_orig_node *orig_node;
 143         int hash_added;
 144
 145         orig_node = batadv_orig_hash_find(bat_priv, addr);
 146         if (orig_node)
 147                 return orig_node;
 148
 149         orig_node = batadv_orig_node_new(bat_priv, addr);
 150         if (!orig_node)
 151                 return NULL;
 152
 153         spin_lock_init(&orig_node->bat_iv.ogm_cnt_lock);
 154
 155         kref_get(&orig_node->refcount);
 156         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
 157                                      batadv_choose_orig, orig_node,
 158                                      &orig_node->hash_entry);
 159         if (hash_added != 0)
 160                 goto free_orig_node_hash;
 161
 162         return orig_node;
 163
 164 free_orig_node_hash:
 165         /* reference for batadv_hash_add */
 166         batadv_orig_node_put(orig_node);
 167         /* reference from batadv_orig_node_new */
 168         batadv_orig_node_put(orig_node);
 169
 170         return NULL;
 171 }
 172
 173 static struct batadv_neigh_node *
 174 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
 175                         const u8 *neigh_addr,
 176                         struct batadv_orig_node *orig_node,
 177                         struct batadv_orig_node *orig_neigh)
 178 {
 179         struct batadv_neigh_node *neigh_node;
 180
 181         neigh_node = batadv_neigh_node_get_or_create(orig_node,
 182                                                      hard_iface, neigh_addr);
 183         if (!neigh_node)
 184                 goto out;
 185
 186         neigh_node->orig_node = orig_neigh;
 187
 188 out:
 189         return neigh_node;
 190 }
 191
 192 static int batadv_iv_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 193 {
 194         struct batadv_ogm_packet *batadv_ogm_packet;
 195         unsigned char *ogm_buff;
 196         u32 random_seqno;
 197
 198         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 199
 200         /* randomize initial seqno to avoid collision */
 201         get_random_bytes(&random_seqno, sizeof(random_seqno));
 202         atomic_set(&hard_iface->bat_iv.ogm_seqno, random_seqno);
 203
 204         hard_iface->bat_iv.ogm_buff_len = BATADV_OGM_HLEN;
 205         ogm_buff = kmalloc(hard_iface->bat_iv.ogm_buff_len, GFP_ATOMIC);
 206         if (!ogm_buff) {
 207                 mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 208                 return -ENOMEM;
 209         }
 210
 211         hard_iface->bat_iv.ogm_buff = ogm_buff;
 212
 213         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 214         batadv_ogm_packet->packet_type = BATADV_IV_OGM;
 215         batadv_ogm_packet->version = BATADV_COMPAT_VERSION;
 216         batadv_ogm_packet->ttl = 2;
 217         batadv_ogm_packet->flags = BATADV_NO_FLAGS;
 218         batadv_ogm_packet->reserved = 0;
 219         batadv_ogm_packet->tq = BATADV_TQ_MAX_VALUE;
 220
 221         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 222
 223         return 0;
 224 }
 225
 226 static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 227 {
 228         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 229
 230         kfree(hard_iface->bat_iv.ogm_buff);
 231         hard_iface->bat_iv.ogm_buff = NULL;
 232
 233         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 234 }
 235
 236 static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface)
 237 {
 238         struct batadv_ogm_packet *batadv_ogm_packet;
 239         void *ogm_buff;
 240
 241         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 242
 243         ogm_buff = hard_iface->bat_iv.ogm_buff;
 244         if (!ogm_buff)
 245                 goto unlock;
 246
 247         batadv_ogm_packet = ogm_buff;
 248         ether_addr_copy(batadv_ogm_packet->orig,
 249                         hard_iface->net_dev->dev_addr);
 250         ether_addr_copy(batadv_ogm_packet->prev_sender,
 251                         hard_iface->net_dev->dev_addr);
 252
 253 unlock:
 254         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 255 }
 256
 257 static void
 258 batadv_iv_ogm_primary_iface_set(struct batadv_hard_iface *hard_iface)
 259 {
 260         struct batadv_ogm_packet *batadv_ogm_packet;
 261         void *ogm_buff;
 262
 263         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 264
 265         ogm_buff = hard_iface->bat_iv.ogm_buff;
 266         if (!ogm_buff)
 267                 goto unlock;
 268
 269         batadv_ogm_packet = ogm_buff;
 270         batadv_ogm_packet->ttl = BATADV_TTL;
 271
 272 unlock:
 273         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 274 }
 275
 276 /* when do we schedule our own ogm to be sent */
 277 static unsigned long
 278 batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 279 {
 280         unsigned int msecs;
 281
 282         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 283         msecs += prandom_u32_max(2 * BATADV_JITTER);
 284
 285         return jiffies + msecs_to_jiffies(msecs);
 286 }
 287
 288 /* when do we schedule a ogm packet to be sent */
 289 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 290 {
 291         return jiffies + msecs_to_jiffies(prandom_u32_max(BATADV_JITTER / 2));
 292 }
 293
 294 /* apply hop penalty for a normal link */
 295 static u8 batadv_hop_penalty(u8 tq, const struct batadv_priv *bat_priv)
 296 {
 297         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 298         int new_tq;
 299
 300         new_tq = tq * (BATADV_TQ_MAX_VALUE - hop_penalty);
 301         new_tq /= BATADV_TQ_MAX_VALUE;
 302
 303         return new_tq;
 304 }
 305
 306 /**
 307  * batadv_iv_ogm_aggr_packet() - checks if there is another OGM attached
 308  * @buff_pos: current position in the skb
 309  * @packet_len: total length of the skb
 310  * @ogm_packet: potential OGM in buffer
 311  *
 312  * Return: true if there is enough space for another OGM, false otherwise.
 313  */
 314 static bool
 315 batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
 316                           const struct batadv_ogm_packet *ogm_packet)
 317 {
 318         int next_buff_pos = 0;
 319
 320         /* check if there is enough space for the header */
 321         next_buff_pos += buff_pos + sizeof(*ogm_packet);
 322         if (next_buff_pos > packet_len)
 323                 return false;
 324
 325         /* check if there is enough space for the optional TVLV */
 326         next_buff_pos += ntohs(ogm_packet->tvlv_len);
 327
 328         return (next_buff_pos <= packet_len) &&
 329                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 330 }
 331
 332 /* send a batman ogm to a given interface */
 333 static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
 334                                      struct batadv_hard_iface *hard_iface)
 335 {
 336         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 337         const char *fwd_str;
 338         u8 packet_num;
 339         s16 buff_pos;
 340         struct batadv_ogm_packet *batadv_ogm_packet;
 341         struct sk_buff *skb;
 342         u8 *packet_pos;
 343
 344         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 345                 return;
 346
 347         packet_num = 0;
 348         buff_pos = 0;
 349         packet_pos = forw_packet->skb->data;
 350         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 351
 352         /* adjust all flags and log packets */
 353         while (batadv_iv_ogm_aggr_packet(buff_pos, forw_packet->packet_len,
 354                                          batadv_ogm_packet)) {
 355                 /* we might have aggregated direct link packets with an
 356                  * ordinary base packet
 357                  */
 358                 if (forw_packet->direct_link_flags & BIT(packet_num) &&
 359                     forw_packet->if_incoming == hard_iface)
 360                         batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 361                 else
 362                         batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 363
 364                 if (packet_num > 0 || !forw_packet->own)
 365                         fwd_str = "Forwarding";
 366                 else
 367                         fwd_str = "Sending own";
 368
 369                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 370                            "%s %spacket (originator %pM, seqno %u, TQ %d, TTL %d, IDF %s) on interface %s [%pM]\n",
 371                            fwd_str, (packet_num > 0 ? "aggregated " : ""),
 372                            batadv_ogm_packet->orig,
 373                            ntohl(batadv_ogm_packet->seqno),
 374                            batadv_ogm_packet->tq, batadv_ogm_packet->ttl,
 375                            ((batadv_ogm_packet->flags & BATADV_DIRECTLINK) ?
 376                             "on" : "off"),
 377                            hard_iface->net_dev->name,
 378                            hard_iface->net_dev->dev_addr);
 379
 380                 buff_pos += BATADV_OGM_HLEN;
 381                 buff_pos += ntohs(batadv_ogm_packet->tvlv_len);
 382                 packet_num++;
 383                 packet_pos = forw_packet->skb->data + buff_pos;
 384                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 385         }
 386
 387         /* create clone because function is called more than once */
 388         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 389         if (skb) {
 390                 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 391                 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 392                                    skb->len + ETH_HLEN);
 393                 batadv_send_broadcast_skb(skb, hard_iface);
 394         }
 395 }
 396
 397 /* send a batman ogm packet */
 398 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 399 {
 400         struct net_device *soft_iface;
 401
 402         if (!forw_packet->if_incoming) {
 403                 pr_err("Error - can't forward packet: incoming iface not specified\n");
 404                 return;
 405         }
 406
 407         soft_iface = forw_packet->if_incoming->soft_iface;
 408
 409         if (WARN_ON(!forw_packet->if_outgoing))
 410                 return;
 411
 412         if (forw_packet->if_outgoing->soft_iface != soft_iface) {
 413                 pr_warn("%s: soft interface switch for queued OGM\n", __func__);
 414                 return;
 415         }
 416
 417         if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
 418                 return;
 419
 420         /* only for one specific outgoing interface */
 421         batadv_iv_ogm_send_to_if(forw_packet, forw_packet->if_outgoing);
 422 }
 423
 424 /**
 425  * batadv_iv_ogm_can_aggregate() - find out if an OGM can be aggregated on an
 426  *  existing forward packet
 427  * @new_bat_ogm_packet: OGM packet to be aggregated
 428  * @bat_priv: the bat priv with all the soft interface information
 429  * @packet_len: (total) length of the OGM
 430  * @send_time: timestamp (jiffies) when the packet is to be sent
 431  * @directlink: true if this is a direct link packet
 432  * @if_incoming: interface where the packet was received
 433  * @if_outgoing: interface for which the retransmission should be considered
 434  * @forw_packet: the forwarded packet which should be checked
 435  *
 436  * Return: true if new_packet can be aggregated with forw_packet
 437  */
 438 static bool
 439 batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet,
 440                             struct batadv_priv *bat_priv,
 441                             int packet_len, unsigned long send_time,
 442                             bool directlink,
 443                             const struct batadv_hard_iface *if_incoming,
 444                             const struct batadv_hard_iface *if_outgoing,
 445                             const struct batadv_forw_packet *forw_packet)
 446 {
 447         struct batadv_ogm_packet *batadv_ogm_packet;
 448         int aggregated_bytes = forw_packet->packet_len + packet_len;
 449         struct batadv_hard_iface *primary_if = NULL;
 450         bool res = false;
 451         unsigned long aggregation_end_time;
 452
 453         batadv_ogm_packet = (struct batadv_ogm_packet *)forw_packet->skb->data;
 454         aggregation_end_time = send_time;
 455         aggregation_end_time += msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 456
 457         /* we can aggregate the current packet to this aggregated packet
 458          * if:
 459          *
 460          * - the send time is within our MAX_AGGREGATION_MS time
 461          * - the resulting packet won't be bigger than
 462          *   MAX_AGGREGATION_BYTES
 463          * otherwise aggregation is not possible
 464          */
 465         if (!time_before(send_time, forw_packet->send_time) ||
 466             !time_after_eq(aggregation_end_time, forw_packet->send_time))
 467                 return false;
 468
 469         if (aggregated_bytes > BATADV_MAX_AGGREGATION_BYTES)
 470                 return false;
 471
 472         /* packet is not leaving on the same interface. */
 473         if (forw_packet->if_outgoing != if_outgoing)
 474                 return false;
 475
 476         /* check aggregation compatibility
 477          * -> direct link packets are broadcasted on
 478          *    their interface only
 479          * -> aggregate packet if the current packet is
 480          *    a "global" packet as well as the base
 481          *    packet
 482          */
 483         primary_if = batadv_primary_if_get_selected(bat_priv);
 484         if (!primary_if)
 485                 return false;
 486
 487         /* packets without direct link flag and high TTL
 488          * are flooded through the net
 489          */
 490         if (!directlink &&
 491             !(batadv_ogm_packet->flags & BATADV_DIRECTLINK) &&
 492             batadv_ogm_packet->ttl != 1 &&
 493
 494             /* own packets originating non-primary
 495              * interfaces leave only that interface
 496              */
 497             (!forw_packet->own ||
 498              forw_packet->if_incoming == primary_if)) {
 499                 res = true;
 500                 goto out;
 501         }
 502
 503         /* if the incoming packet is sent via this one
 504          * interface only - we still can aggregate
 505          */
 506         if (directlink &&
 507             new_bat_ogm_packet->ttl == 1 &&
 508             forw_packet->if_incoming == if_incoming &&
 509
 510             /* packets from direct neighbors or
 511              * own secondary interface packets
 512              * (= secondary interface packets in general)
 513              */
 514             (batadv_ogm_packet->flags & BATADV_DIRECTLINK ||
 515              (forw_packet->own &&
 516               forw_packet->if_incoming != primary_if))) {
 517                 res = true;
 518                 goto out;
 519         }
 520
 521 out:
 522         if (primary_if)
 523                 batadv_hardif_put(primary_if);
 524         return res;
 525 }
 526
 527 /**
 528  * batadv_iv_ogm_aggregate_new() - create a new aggregated packet and add this
 529  *  packet to it.
 530  * @packet_buff: pointer to the OGM
 531  * @packet_len: (total) length of the OGM
 532  * @send_time: timestamp (jiffies) when the packet is to be sent
 533  * @direct_link: whether this OGM has direct link status
 534  * @if_incoming: interface where the packet was received
 535  * @if_outgoing: interface for which the retransmission should be considered
 536  * @own_packet: true if it is a self-generated ogm
 537  */
 538 static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 539                                         int packet_len, unsigned long send_time,
 540                                         bool direct_link,
 541                                         struct batadv_hard_iface *if_incoming,
 542                                         struct batadv_hard_iface *if_outgoing,
 543                                         int own_packet)
 544 {
 545         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 546         struct batadv_forw_packet *forw_packet_aggr;
 547         struct sk_buff *skb;
 548         unsigned char *skb_buff;
 549         unsigned int skb_size;
 550         atomic_t *queue_left = own_packet ? NULL : &bat_priv->batman_queue_left;
 551
 552         if (atomic_read(&bat_priv->aggregated_ogms) &&
 553             packet_len < BATADV_MAX_AGGREGATION_BYTES)
 554                 skb_size = BATADV_MAX_AGGREGATION_BYTES;
 555         else
 556                 skb_size = packet_len;
 557
 558         skb_size += ETH_HLEN;
 559
 560         skb = netdev_alloc_skb_ip_align(NULL, skb_size);
 561         if (!skb)
 562                 return;
 563
 564         forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, if_outgoing,
 565                                                     queue_left, bat_priv, skb);
 566         if (!forw_packet_aggr) {
 567                 kfree_skb(skb);
 568                 return;
 569         }
 570
 571         forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
 572         skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 573
 574         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 575         forw_packet_aggr->packet_len = packet_len;
 576         memcpy(skb_buff, packet_buff, packet_len);
 577
 578         forw_packet_aggr->own = own_packet;
 579         forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;
 580         forw_packet_aggr->send_time = send_time;
 581
 582         /* save packet direct link flag status */
 583         if (direct_link)
 584                 forw_packet_aggr->direct_link_flags |= 1;
 585
 586         INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work,
 587                           batadv_iv_send_outstanding_bat_ogm_packet);
 588
 589         batadv_forw_packet_ogmv1_queue(bat_priv, forw_packet_aggr, send_time);
 590 }
 591
 592 /* aggregate a new packet into the existing ogm packet */
 593 static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr,
 594                                     const unsigned char *packet_buff,
 595                                     int packet_len, bool direct_link)
 596 {
 597         unsigned long new_direct_link_flag;
 598
 599         skb_put_data(forw_packet_aggr->skb, packet_buff, packet_len);
 600         forw_packet_aggr->packet_len += packet_len;
 601         forw_packet_aggr->num_packets++;
 602
 603         /* save packet direct link flag status */
 604         if (direct_link) {
 605                 new_direct_link_flag = BIT(forw_packet_aggr->num_packets);
 606                 forw_packet_aggr->direct_link_flags |= new_direct_link_flag;
 607         }
 608 }
 609
 610 /**
 611  * batadv_iv_ogm_queue_add() - queue up an OGM for transmission
 612  * @bat_priv: the bat priv with all the soft interface information
 613  * @packet_buff: pointer to the OGM
 614  * @packet_len: (total) length of the OGM
 615  * @if_incoming: interface where the packet was received
 616  * @if_outgoing: interface for which the retransmission should be considered
 617  * @own_packet: true if it is a self-generated ogm
 618  * @send_time: timestamp (jiffies) when the packet is to be sent
 619  */
 620 static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv,
 621                                     unsigned char *packet_buff,
 622                                     int packet_len,
 623                                     struct batadv_hard_iface *if_incoming,
 624                                     struct batadv_hard_iface *if_outgoing,
 625                                     int own_packet, unsigned long send_time)
 626 {
 627         /* _aggr -> pointer to the packet we want to aggregate with
 628          * _pos -> pointer to the position in the queue
 629          */
 630         struct batadv_forw_packet *forw_packet_aggr = NULL;
 631         struct batadv_forw_packet *forw_packet_pos = NULL;
 632         struct batadv_ogm_packet *batadv_ogm_packet;
 633         bool direct_link;
 634         unsigned long max_aggregation_jiffies;
 635
 636         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
 637         direct_link = !!(batadv_ogm_packet->flags & BATADV_DIRECTLINK);
 638         max_aggregation_jiffies = msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 639
 640         /* find position for the packet in the forward queue */
 641         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 642         /* own packets are not to be aggregated */
 643         if (atomic_read(&bat_priv->aggregated_ogms) && !own_packet) {
 644                 hlist_for_each_entry(forw_packet_pos,
 645                                      &bat_priv->forw_bat_list, list) {
 646                         if (batadv_iv_ogm_can_aggregate(batadv_ogm_packet,
 647                                                         bat_priv, packet_len,
 648                                                         send_time, direct_link,
 649                                                         if_incoming,
 650                                                         if_outgoing,
 651                                                         forw_packet_pos)) {
 652                                 forw_packet_aggr = forw_packet_pos;
 653                                 break;
 654                         }
 655                 }
 656         }
 657
 658         /* nothing to aggregate with - either aggregation disabled or no
 659          * suitable aggregation packet found
 660          */
 661         if (!forw_packet_aggr) {
 662                 /* the following section can run without the lock */
 663                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 664
 665                 /* if we could not aggregate this packet with one of the others
 666                  * we hold it back for a while, so that it might be aggregated
 667                  * later on
 668                  */
 669                 if (!own_packet && atomic_read(&bat_priv->aggregated_ogms))
 670                         send_time += max_aggregation_jiffies;
 671
 672                 batadv_iv_ogm_aggregate_new(packet_buff, packet_len,
 673                                             send_time, direct_link,
 674                                             if_incoming, if_outgoing,
 675                                             own_packet);
 676         } else {
 677                 batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff,
 678                                         packet_len, direct_link);
 679                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 680         }
 681 }
 682
 683 static void batadv_iv_ogm_forward(struct batadv_orig_node *orig_node,
 684                                   const struct ethhdr *ethhdr,
 685                                   struct batadv_ogm_packet *batadv_ogm_packet,
 686                                   bool is_single_hop_neigh,
 687                                   bool is_from_best_next_hop,
 688                                   struct batadv_hard_iface *if_incoming,
 689                                   struct batadv_hard_iface *if_outgoing)
 690 {
 691         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 692         u16 tvlv_len;
 693
 694         if (batadv_ogm_packet->ttl <= 1) {
 695                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 696                 return;
 697         }
 698
 699         if (!is_from_best_next_hop) {
 700                 /* Mark the forwarded packet when it is not coming from our
 701                  * best next hop. We still need to forward the packet for our
 702                  * neighbor link quality detection to work in case the packet
 703                  * originated from a single hop neighbor. Otherwise we can
 704                  * simply drop the ogm.
 705                  */
 706                 if (is_single_hop_neigh)
 707                         batadv_ogm_packet->flags |= BATADV_NOT_BEST_NEXT_HOP;
 708                 else
 709                         return;
 710         }
 711
 712         tvlv_len = ntohs(batadv_ogm_packet->tvlv_len);
 713
 714         batadv_ogm_packet->ttl--;
 715         ether_addr_copy(batadv_ogm_packet->prev_sender, ethhdr->h_source);
 716
 717         /* apply hop penalty */
 718         batadv_ogm_packet->tq = batadv_hop_penalty(batadv_ogm_packet->tq,
 719                                                    bat_priv);
 720
 721         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 722                    "Forwarding packet: tq: %i, ttl: %i\n",
 723                    batadv_ogm_packet->tq, batadv_ogm_packet->ttl);
 724
 725         if (is_single_hop_neigh)
 726                 batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 727         else
 728                 batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 729
 730         batadv_iv_ogm_queue_add(bat_priv, (unsigned char *)batadv_ogm_packet,
 731                                 BATADV_OGM_HLEN + tvlv_len,
 732                                 if_incoming, if_outgoing, 0,
 733                                 batadv_iv_ogm_fwd_send_time());
 734 }
 735
 736 /**
 737  * batadv_iv_ogm_slide_own_bcast_window() - bitshift own OGM broadcast windows
 738  *  for the given interface
 739  * @hard_iface: the interface for which the windows have to be shifted
 740  */
 741 static void
 742 batadv_iv_ogm_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
 743 {
 744         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 745         struct batadv_hashtable *hash = bat_priv->orig_hash;
 746         struct hlist_head *head;
 747         struct batadv_orig_node *orig_node;
 748         struct batadv_orig_ifinfo *orig_ifinfo;
 749         unsigned long *word;
 750         u32 i;
 751         u8 *w;
 752
 753         for (i = 0; i < hash->size; i++) {
 754                 head = &hash->table[i];
 755
 756                 rcu_read_lock();
 757                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 758                         hlist_for_each_entry_rcu(orig_ifinfo,
 759                                                  &orig_node->ifinfo_list,
 760                                                  list) {
 761                                 if (orig_ifinfo->if_outgoing != hard_iface)
 762                                         continue;
 763
 764                                 spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 765                                 word = orig_ifinfo->bat_iv.bcast_own;
 766                                 batadv_bit_get_packet(bat_priv, word, 1, 0);
 767                                 w = &orig_ifinfo->bat_iv.bcast_own_sum;
 768                                 *w = bitmap_weight(word,
 769                                                    BATADV_TQ_LOCAL_WINDOW_SIZE);
 770                                 spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 771                         }
 772                 }
 773                 rcu_read_unlock();
 774         }
 775 }
 776
 777 /**
 778  * batadv_iv_ogm_schedule_buff() - schedule submission of hardif ogm buffer
 779  * @hard_iface: interface whose ogm buffer should be transmitted
 780  */
 781 static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface)
 782 {
 783         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 784         unsigned char **ogm_buff = &hard_iface->bat_iv.ogm_buff;
 785         struct batadv_ogm_packet *batadv_ogm_packet;
 786         struct batadv_hard_iface *primary_if, *tmp_hard_iface;
 787         int *ogm_buff_len = &hard_iface->bat_iv.ogm_buff_len;
 788         u32 seqno;
 789         u16 tvlv_len = 0;
 790         unsigned long send_time;
 791
 792         lockdep_assert_held(&hard_iface->bat_iv.ogm_buff_mutex);
 793
 794         /* interface already disabled by batadv_iv_ogm_iface_disable */
 795         if (!*ogm_buff)
 796                 return;
 797
 798         /* the interface gets activated here to avoid race conditions between
 799          * the moment of activating the interface in
 800          * hardif_activate_interface() where the originator mac is set and
 801          * outdated packets (especially uninitialized mac addresses) in the
 802          * packet queue
 803          */
 804         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 805                 hard_iface->if_status = BATADV_IF_ACTIVE;
 806
 807         primary_if = batadv_primary_if_get_selected(bat_priv);
 808
 809         if (hard_iface == primary_if) {
 810                 /* tt changes have to be committed before the tvlv data is
 811                  * appended as it may alter the tt tvlv container
 812                  */
 813                 batadv_tt_local_commit_changes(bat_priv);
 814                 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, ogm_buff,
 815                                                             ogm_buff_len,
 816                                                             BATADV_OGM_HLEN);
 817         }
 818
 819         batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff);
 820         batadv_ogm_packet->tvlv_len = htons(tvlv_len);
 821
 822         /* change sequence number to network order */
 823         seqno = (u32)atomic_read(&hard_iface->bat_iv.ogm_seqno);
 824         batadv_ogm_packet->seqno = htonl(seqno);
 825         atomic_inc(&hard_iface->bat_iv.ogm_seqno);
 826
 827         batadv_iv_ogm_slide_own_bcast_window(hard_iface);
 828
 829         send_time = batadv_iv_ogm_emit_send_time(bat_priv);
 830
 831         if (hard_iface != primary_if) {
 832                 /* OGMs from secondary interfaces are only scheduled on their
 833                  * respective interfaces.
 834                  */
 835                 batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, *ogm_buff_len,
 836                                         hard_iface, hard_iface, 1, send_time);
 837                 goto out;
 838         }
 839
 840         /* OGMs from primary interfaces are scheduled on all
 841          * interfaces.
 842          */
 843         rcu_read_lock();
 844         list_for_each_entry_rcu(tmp_hard_iface, &batadv_hardif_list, list) {
 845                 if (tmp_hard_iface->soft_iface != hard_iface->soft_iface)
 846                         continue;
 847
 848                 if (!kref_get_unless_zero(&tmp_hard_iface->refcount))
 849                         continue;
 850
 851                 batadv_iv_ogm_queue_add(bat_priv, *ogm_buff,
 852                                         *ogm_buff_len, hard_iface,
 853                                         tmp_hard_iface, 1, send_time);
 854
 855                 batadv_hardif_put(tmp_hard_iface);
 856         }
 857         rcu_read_unlock();
 858
 859 out:
 860         if (primary_if)
 861                 batadv_hardif_put(primary_if);
 862 }
 863
 864 static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface)
 865 {
 866         if (hard_iface->if_status == BATADV_IF_NOT_IN_USE ||
 867             hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
 868                 return;
 869
 870         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 871         batadv_iv_ogm_schedule_buff(hard_iface);
 872         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 873 }
 874
 875 /**
 876  * batadv_iv_orig_ifinfo_sum() - Get bcast_own sum for originator over interface
 877  * @orig_node: originator which reproadcasted the OGMs directly
 878  * @if_outgoing: interface which transmitted the original OGM and received the
 879  *  direct rebroadcast
 880  *
 881  * Return: Number of replied (rebroadcasted) OGMs which were transmitted by
 882  *  an originator and directly (without intermediate hop) received by a specific
 883  *  interface
 884  */
 885 static u8 batadv_iv_orig_ifinfo_sum(struct batadv_orig_node *orig_node,
 886                                     struct batadv_hard_iface *if_outgoing)
 887 {
 888         struct batadv_orig_ifinfo *orig_ifinfo;
 889         u8 sum;
 890
 891         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_outgoing);
 892         if (!orig_ifinfo)
 893                 return 0;
 894
 895         spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 896         sum = orig_ifinfo->bat_iv.bcast_own_sum;
 897         spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 898
 899         batadv_orig_ifinfo_put(orig_ifinfo);
 900
 901         return sum;
 902 }
 903
 904 /**
 905  * batadv_iv_ogm_orig_update() - use OGM to update corresponding data in an
 906  *  originator
 907  * @bat_priv: the bat priv with all the soft interface information
 908  * @orig_node: the orig node who originally emitted the ogm packet
 909  * @orig_ifinfo: ifinfo for the outgoing interface of the orig_node
 910  * @ethhdr: Ethernet header of the OGM
 911  * @batadv_ogm_packet: the ogm packet
 912  * @if_incoming: interface where the packet was received
 913  * @if_outgoing: interface for which the retransmission should be considered
 914  * @dup_status: the duplicate status of this ogm packet.
 915  */
 916 static void
 917 batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
 918                           struct batadv_orig_node *orig_node,
 919                           struct batadv_orig_ifinfo *orig_ifinfo,
 920                           const struct ethhdr *ethhdr,
 921                           const struct batadv_ogm_packet *batadv_ogm_packet,
 922                           struct batadv_hard_iface *if_incoming,
 923                           struct batadv_hard_iface *if_outgoing,
 924                           enum batadv_dup_status dup_status)
 925 {
 926         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 927         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 928         struct batadv_neigh_node *neigh_node = NULL;
 929         struct batadv_neigh_node *tmp_neigh_node = NULL;
 930         struct batadv_neigh_node *router = NULL;
 931         u8 sum_orig, sum_neigh;
 932         u8 *neigh_addr;
 933         u8 tq_avg;
 934
 935         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 936                    "%s(): Searching and updating originator entry of received packet\n",
 937                    __func__);
 938
 939         rcu_read_lock();
 940         hlist_for_each_entry_rcu(tmp_neigh_node,
 941                                  &orig_node->neigh_list, list) {
 942                 neigh_addr = tmp_neigh_node->addr;
 943                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
 944                     tmp_neigh_node->if_incoming == if_incoming &&
 945                     kref_get_unless_zero(&tmp_neigh_node->refcount)) {
 946                         if (WARN(neigh_node, "too many matching neigh_nodes"))
 947                                 batadv_neigh_node_put(neigh_node);
 948                         neigh_node = tmp_neigh_node;
 949                         continue;
 950                 }
 951
 952                 if (dup_status != BATADV_NO_DUP)
 953                         continue;
 954
 955                 /* only update the entry for this outgoing interface */
 956                 neigh_ifinfo = batadv_neigh_ifinfo_get(tmp_neigh_node,
 957                                                        if_outgoing);
 958                 if (!neigh_ifinfo)
 959                         continue;
 960
 961                 spin_lock_bh(&tmp_neigh_node->ifinfo_lock);
 962                 batadv_ring_buffer_set(neigh_ifinfo->bat_iv.tq_recv,
 963                                        &neigh_ifinfo->bat_iv.tq_index, 0);
 964                 tq_avg = batadv_ring_buffer_avg(neigh_ifinfo->bat_iv.tq_recv);
 965                 neigh_ifinfo->bat_iv.tq_avg = tq_avg;
 966                 spin_unlock_bh(&tmp_neigh_node->ifinfo_lock);
 967
 968                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 969                 neigh_ifinfo = NULL;
 970         }
 971
 972         if (!neigh_node) {
 973                 struct batadv_orig_node *orig_tmp;
 974
 975                 orig_tmp = batadv_iv_ogm_orig_get(bat_priv, ethhdr->h_source);
 976                 if (!orig_tmp)
 977                         goto unlock;
 978
 979                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 980                                                      ethhdr->h_source,
 981                                                      orig_node, orig_tmp);
 982
 983                 batadv_orig_node_put(orig_tmp);
 984                 if (!neigh_node)
 985                         goto unlock;
 986         } else {
 987                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 988                            "Updating existing last-hop neighbor of originator\n");
 989         }
 990
 991         rcu_read_unlock();
 992         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 993         if (!neigh_ifinfo)
 994                 goto out;
 995
 996         neigh_node->last_seen = jiffies;
 997
 998         spin_lock_bh(&neigh_node->ifinfo_lock);
 999         batadv_ring_buffer_set(neigh_ifinfo->bat_iv.tq_recv,
1000                                &neigh_ifinfo->bat_iv.tq_index,
1001                                batadv_ogm_packet->tq);
1002         tq_avg = batadv_ring_buffer_avg(neigh_ifinfo->bat_iv.tq_recv);
1003         neigh_ifinfo->bat_iv.tq_avg = tq_avg;
1004         spin_unlock_bh(&neigh_node->ifinfo_lock);
1005
1006         if (dup_status == BATADV_NO_DUP) {
1007                 orig_ifinfo->last_ttl = batadv_ogm_packet->ttl;
1008                 neigh_ifinfo->last_ttl = batadv_ogm_packet->ttl;
1009         }
1010
1011         /* if this neighbor already is our next hop there is nothing
1012          * to change
1013          */
1014         router = batadv_orig_router_get(orig_node, if_outgoing);
1015         if (router == neigh_node)
1016                 goto out;
1017
1018         if (router) {
1019                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
1020                 if (!router_ifinfo)
1021                         goto out;
1022
1023                 /* if this neighbor does not offer a better TQ we won't
1024                  * consider it
1025                  */
1026                 if (router_ifinfo->bat_iv.tq_avg > neigh_ifinfo->bat_iv.tq_avg)
1027                         goto out;
1028         }
1029
1030         /* if the TQ is the same and the link not more symmetric we
1031          * won't consider it either
1032          */
1033         if (router_ifinfo &&
1034             neigh_ifinfo->bat_iv.tq_avg == router_ifinfo->bat_iv.tq_avg) {
1035                 sum_orig = batadv_iv_orig_ifinfo_sum(router->orig_node,
1036                                                      router->if_incoming);
1037                 sum_neigh = batadv_iv_orig_ifinfo_sum(neigh_node->orig_node,
1038                                                       neigh_node->if_incoming);
1039                 if (sum_orig >= sum_neigh)
1040                         goto out;
1041         }
1042
1043         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
1044         goto out;
1045
1046 unlock:
1047         rcu_read_unlock();
1048 out:
1049         if (neigh_node)
1050                 batadv_neigh_node_put(neigh_node);
1051         if (router)
1052                 batadv_neigh_node_put(router);
1053         if (neigh_ifinfo)
1054                 batadv_neigh_ifinfo_put(neigh_ifinfo);
1055         if (router_ifinfo)
1056                 batadv_neigh_ifinfo_put(router_ifinfo);
1057 }
1058
1059 /**
1060  * batadv_iv_ogm_calc_tq() - calculate tq for current received ogm packet
1061  * @orig_node: the orig node who originally emitted the ogm packet
1062  * @orig_neigh_node: the orig node struct of the neighbor who sent the packet
1063  * @batadv_ogm_packet: the ogm packet
1064  * @if_incoming: interface where the packet was received
1065  * @if_outgoing: interface for which the retransmission should be considered
1066  *
1067  * Return: true if the link can be considered bidirectional, false otherwise
1068  */
1069 static bool batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
1070                                   struct batadv_orig_node *orig_neigh_node,
1071                                   struct batadv_ogm_packet *batadv_ogm_packet,
1072                                   struct batadv_hard_iface *if_incoming,
1073                                   struct batadv_hard_iface *if_outgoing)
1074 {
1075         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1076         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node;
1077         struct batadv_neigh_ifinfo *neigh_ifinfo;
1078         u8 total_count;
1079         u8 orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
1080         unsigned int tq_iface_hop_penalty = BATADV_TQ_MAX_VALUE;
1081         unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
1082         unsigned int tq_asym_penalty, inv_asym_penalty;
1083         unsigned int combined_tq;
1084         bool ret = false;
1085
1086         /* find corresponding one hop neighbor */
1087         rcu_read_lock();
1088         hlist_for_each_entry_rcu(tmp_neigh_node,
1089                                  &orig_neigh_node->neigh_list, list) {
1090                 if (!batadv_compare_eth(tmp_neigh_node->addr,
1091                                         orig_neigh_node->orig))
1092                         continue;
1093
1094                 if (tmp_neigh_node->if_incoming != if_incoming)
1095                         continue;
1096
1097                 if (!kref_get_unless_zero(&tmp_neigh_node->refcount))
1098                         continue;
1099
1100                 neigh_node = tmp_neigh_node;
1101                 break;
1102         }
1103         rcu_read_unlock();
1104
1105         if (!neigh_node)
1106                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
1107                                                      orig_neigh_node->orig,
1108                                                      orig_neigh_node,
1109                                                      orig_neigh_node);
1110
1111         if (!neigh_node)
1112                 goto out;
1113
1114         /* if orig_node is direct neighbor update neigh_node last_seen */
1115         if (orig_node == orig_neigh_node)
1116                 neigh_node->last_seen = jiffies;
1117
1118         orig_node->last_seen = jiffies;
1119
1120         /* find packet count of corresponding one hop neighbor */
1121         orig_eq_count = batadv_iv_orig_ifinfo_sum(orig_neigh_node, if_incoming);
1122         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
1123         if (neigh_ifinfo) {
1124                 neigh_rq_count = neigh_ifinfo->bat_iv.real_packet_count;
1125                 batadv_neigh_ifinfo_put(neigh_ifinfo);
1126         } else {
1127                 neigh_rq_count = 0;
1128         }
1129
1130         /* pay attention to not get a value bigger than 100 % */
1131         if (orig_eq_count > neigh_rq_count)
1132                 total_count = neigh_rq_count;
1133         else
1134                 total_count = orig_eq_count;
1135
1136         /* if we have too few packets (too less data) we set tq_own to zero
1137          * if we receive too few packets it is not considered bidirectional
1138          */
1139         if (total_count < BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM ||
1140             neigh_rq_count < BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM)
1141                 tq_own = 0;
1142         else
1143                 /* neigh_node->real_packet_count is never zero as we
1144                  * only purge old information when getting new
1145                  * information
1146                  */
1147                 tq_own = (BATADV_TQ_MAX_VALUE * total_count) /  neigh_rq_count;
1148
1149         /* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
1150          * affect the nearly-symmetric links only a little, but
1151          * punishes asymmetric links more.  This will give a value
1152          * between 0 and TQ_MAX_VALUE
1153          */
1154         neigh_rq_inv = BATADV_TQ_LOCAL_WINDOW_SIZE - neigh_rq_count;
1155         neigh_rq_inv_cube = neigh_rq_inv * neigh_rq_inv * neigh_rq_inv;
1156         neigh_rq_max_cube = BATADV_TQ_LOCAL_WINDOW_SIZE *
1157                             BATADV_TQ_LOCAL_WINDOW_SIZE *
1158                             BATADV_TQ_LOCAL_WINDOW_SIZE;
1159         inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
1160         inv_asym_penalty /= neigh_rq_max_cube;
1161         tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
1162         tq_iface_hop_penalty -= atomic_read(&if_incoming->hop_penalty);
1163
1164         /* penalize if the OGM is forwarded on the same interface. WiFi
1165          * interfaces and other half duplex devices suffer from throughput
1166          * drops as they can't send and receive at the same time.
1167          */
1168         if (if_outgoing && if_incoming == if_outgoing &&
1169             batadv_is_wifi_hardif(if_outgoing))
1170                 tq_iface_hop_penalty = batadv_hop_penalty(tq_iface_hop_penalty,
1171                                                           bat_priv);
1172
1173         combined_tq = batadv_ogm_packet->tq *
1174                       tq_own *
1175                       tq_asym_penalty *
1176                       tq_iface_hop_penalty;
1177         combined_tq /= BATADV_TQ_MAX_VALUE *
1178                        BATADV_TQ_MAX_VALUE *
1179                        BATADV_TQ_MAX_VALUE;
1180         batadv_ogm_packet->tq = combined_tq;
1181
1182         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1183                    "bidirectional: orig = %pM neigh = %pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, iface_hop_penalty: %3i, total tq: %3i, if_incoming = %s, if_outgoing = %s\n",
1184                    orig_node->orig, orig_neigh_node->orig, total_count,
1185                    neigh_rq_count, tq_own, tq_asym_penalty,
1186                    tq_iface_hop_penalty, batadv_ogm_packet->tq,
1187                    if_incoming->net_dev->name,
1188                    if_outgoing ? if_outgoing->net_dev->name : "DEFAULT");
1189
1190         /* if link has the minimum required transmission quality
1191          * consider it bidirectional
1192          */
1193         if (batadv_ogm_packet->tq >= BATADV_TQ_TOTAL_BIDRECT_LIMIT)
1194                 ret = true;
1195
1196 out:
1197         if (neigh_node)
1198                 batadv_neigh_node_put(neigh_node);
1199         return ret;
1200 }
1201
1202 /**
1203  * batadv_iv_ogm_update_seqnos() -  process a batman packet for all interfaces,
1204  *  adjust the sequence number and find out whether it is a duplicate
1205  * @ethhdr: ethernet header of the packet
1206  * @batadv_ogm_packet: OGM packet to be considered
1207  * @if_incoming: interface on which the OGM packet was received
1208  * @if_outgoing: interface for which the retransmission should be considered
1209  *
1210  * Return: duplicate status as enum batadv_dup_status
1211  */
1212 static enum batadv_dup_status
1213 batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
1214                             const struct batadv_ogm_packet *batadv_ogm_packet,
1215                             const struct batadv_hard_iface *if_incoming,
1216                             struct batadv_hard_iface *if_outgoing)
1217 {
1218         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1219         struct batadv_orig_node *orig_node;
1220         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
1221         struct batadv_neigh_node *neigh_node;
1222         struct batadv_neigh_ifinfo *neigh_ifinfo;
1223         bool is_dup;
1224         s32 seq_diff;
1225         bool need_update = false;
1226         int set_mark;
1227         enum batadv_dup_status ret = BATADV_NO_DUP;
1228         u32 seqno = ntohl(batadv_ogm_packet->seqno);
1229         u8 *neigh_addr;
1230         u8 packet_count;
1231         unsigned long *bitmap;
1232
1233         orig_node = batadv_iv_ogm_orig_get(bat_priv, batadv_ogm_packet->orig);
1234         if (!orig_node)
1235                 return BATADV_NO_DUP;
1236
1237         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
1238         if (WARN_ON(!orig_ifinfo)) {
1239                 batadv_orig_node_put(orig_node);
1240                 return 0;
1241         }
1242
1243         spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1244         seq_diff = seqno - orig_ifinfo->last_real_seqno;
1245
1246         /* signalize caller that the packet is to be dropped. */
1247         if (!hlist_empty(&orig_node->neigh_list) &&
1248             batadv_window_protected(bat_priv, seq_diff,
1249                                     BATADV_TQ_LOCAL_WINDOW_SIZE,
1250                                     &orig_ifinfo->batman_seqno_reset, NULL)) {
1251                 ret = BATADV_PROTECTED;
1252                 goto out;
1253         }
1254
1255         rcu_read_lock();
1256         hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
1257                 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node,
1258                                                        if_outgoing);
1259                 if (!neigh_ifinfo)
1260                         continue;
1261
1262                 neigh_addr = neigh_node->addr;
1263                 is_dup = batadv_test_bit(neigh_ifinfo->bat_iv.real_bits,
1264                                          orig_ifinfo->last_real_seqno,
1265                                          seqno);
1266
1267                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
1268                     neigh_node->if_incoming == if_incoming) {
1269                         set_mark = 1;
1270                         if (is_dup)
1271                                 ret = BATADV_NEIGH_DUP;
1272                 } else {
1273                         set_mark = 0;
1274                         if (is_dup && ret != BATADV_NEIGH_DUP)
1275                                 ret = BATADV_ORIG_DUP;
1276                 }
1277
1278                 /* if the window moved, set the update flag. */
1279                 bitmap = neigh_ifinfo->bat_iv.real_bits;
1280                 need_update |= batadv_bit_get_packet(bat_priv, bitmap,
1281                                                      seq_diff, set_mark);
1282
1283                 packet_count = bitmap_weight(bitmap,
1284                                              BATADV_TQ_LOCAL_WINDOW_SIZE);
1285                 neigh_ifinfo->bat_iv.real_packet_count = packet_count;
1286                 batadv_neigh_ifinfo_put(neigh_ifinfo);
1287         }
1288         rcu_read_unlock();
1289
1290         if (need_update) {
1291                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1292                            "%s updating last_seqno: old %u, new %u\n",
1293                            if_outgoing ? if_outgoing->net_dev->name : "DEFAULT",
1294                            orig_ifinfo->last_real_seqno, seqno);
1295                 orig_ifinfo->last_real_seqno = seqno;
1296         }
1297
1298 out:
1299         spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1300         batadv_orig_node_put(orig_node);
1301         batadv_orig_ifinfo_put(orig_ifinfo);
1302         return ret;
1303 }
1304
1305 /**
1306  * batadv_iv_ogm_process_per_outif() - process a batman iv OGM for an outgoing
1307  *  interface
1308  * @skb: the skb containing the OGM
1309  * @ogm_offset: offset from skb->data to start of ogm header
1310  * @orig_node: the (cached) orig node for the originator of this OGM
1311  * @if_incoming: the interface where this packet was received
1312  * @if_outgoing: the interface for which the packet should be considered
1313  */
1314 static void
1315 batadv_iv_ogm_process_per_outif(const struct sk_buff *skb, int ogm_offset,
1316                                 struct batadv_orig_node *orig_node,
1317                                 struct batadv_hard_iface *if_incoming,
1318                                 struct batadv_hard_iface *if_outgoing)
1319 {
1320         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1321         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
1322         struct batadv_neigh_node *router = NULL;
1323         struct batadv_neigh_node *router_router = NULL;
1324         struct batadv_orig_node *orig_neigh_node;
1325         struct batadv_orig_ifinfo *orig_ifinfo;
1326         struct batadv_neigh_node *orig_neigh_router = NULL;
1327         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
1328         struct batadv_ogm_packet *ogm_packet;
1329         enum batadv_dup_status dup_status;
1330         bool is_from_best_next_hop = false;
1331         bool is_single_hop_neigh = false;
1332         bool sameseq, similar_ttl;
1333         struct sk_buff *skb_priv;
1334         struct ethhdr *ethhdr;
1335         u8 *prev_sender;
1336         bool is_bidirect;
1337
1338         /* create a private copy of the skb, as some functions change tq value
1339          * and/or flags.
1340          */
1341         skb_priv = skb_copy(skb, GFP_ATOMIC);
1342         if (!skb_priv)
1343                 return;
1344
1345         ethhdr = eth_hdr(skb_priv);
1346         ogm_packet = (struct batadv_ogm_packet *)(skb_priv->data + ogm_offset);
1347
1348         dup_status = batadv_iv_ogm_update_seqnos(ethhdr, ogm_packet,
1349                                                  if_incoming, if_outgoing);
1350         if (batadv_compare_eth(ethhdr->h_source, ogm_packet->orig))
1351                 is_single_hop_neigh = true;
1352
1353         if (dup_status == BATADV_PROTECTED) {
1354                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1355                            "Drop packet: packet within seqno protection time (sender: %pM)\n",
1356                            ethhdr->h_source);
1357                 goto out;
1358         }
1359
1360         if (ogm_packet->tq == 0) {
1361                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1362                            "Drop packet: originator packet with tq equal 0\n");
1363                 goto out;
1364         }
1365
1366         if (is_single_hop_neigh) {
1367                 hardif_neigh = batadv_hardif_neigh_get(if_incoming,
1368                                                        ethhdr->h_source);
1369                 if (hardif_neigh)
1370                         hardif_neigh->last_seen = jiffies;
1371         }
1372
1373         router = batadv_orig_router_get(orig_node, if_outgoing);
1374         if (router) {
1375                 router_router = batadv_orig_router_get(router->orig_node,
1376                                                        if_outgoing);
1377                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
1378         }
1379
1380         if ((router_ifinfo && router_ifinfo->bat_iv.tq_avg != 0) &&
1381             (batadv_compare_eth(router->addr, ethhdr->h_source)))
1382                 is_from_best_next_hop = true;
1383
1384         prev_sender = ogm_packet->prev_sender;
1385         /* avoid temporary routing loops */
1386         if (router && router_router &&
1387             (batadv_compare_eth(router->addr, prev_sender)) &&
1388             !(batadv_compare_eth(ogm_packet->orig, prev_sender)) &&
1389             (batadv_compare_eth(router->addr, router_router->addr))) {
1390                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1391                            "Drop packet: ignoring all rebroadcast packets that may make me loop (sender: %pM)\n",
1392                            ethhdr->h_source);
1393                 goto out;
1394         }
1395
1396         if (if_outgoing == BATADV_IF_DEFAULT)
1397                 batadv_tvlv_ogm_receive(bat_priv, ogm_packet, orig_node);
1398
1399         /* if sender is a direct neighbor the sender mac equals
1400          * originator mac
1401          */
1402         if (is_single_hop_neigh)
1403                 orig_neigh_node = orig_node;
1404         else
1405                 orig_neigh_node = batadv_iv_ogm_orig_get(bat_priv,
1406                                                          ethhdr->h_source);
1407
1408         if (!orig_neigh_node)
1409                 goto out;
1410
1411         /* Update nc_nodes of the originator */
1412         batadv_nc_update_nc_node(bat_priv, orig_node, orig_neigh_node,
1413                                  ogm_packet, is_single_hop_neigh);
1414
1415         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
1416                                                    if_outgoing);
1417
1418         /* drop packet if sender is not a direct neighbor and if we
1419          * don't route towards it
1420          */
1421         if (!is_single_hop_neigh && !orig_neigh_router) {
1422                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1423                            "Drop packet: OGM via unknown neighbor!\n");
1424                 goto out_neigh;
1425         }
1426
1427         is_bidirect = batadv_iv_ogm_calc_tq(orig_node, orig_neigh_node,
1428                                             ogm_packet, if_incoming,
1429                                             if_outgoing);
1430
1431         /* update ranking if it is not a duplicate or has the same
1432          * seqno and similar ttl as the non-duplicate
1433          */
1434         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
1435         if (!orig_ifinfo)
1436                 goto out_neigh;
1437
1438         sameseq = orig_ifinfo->last_real_seqno == ntohl(ogm_packet->seqno);
1439         similar_ttl = (orig_ifinfo->last_ttl - 3) <= ogm_packet->ttl;
1440
1441         if (is_bidirect && (dup_status == BATADV_NO_DUP ||
1442                             (sameseq && similar_ttl))) {
1443                 batadv_iv_ogm_orig_update(bat_priv, orig_node,
1444                                           orig_ifinfo, ethhdr,
1445                                           ogm_packet, if_incoming,
1446                                           if_outgoing, dup_status);
1447         }
1448         batadv_orig_ifinfo_put(orig_ifinfo);
1449
1450         /* only forward for specific interface, not for the default one. */
1451         if (if_outgoing == BATADV_IF_DEFAULT)
1452                 goto out_neigh;
1453
1454         /* is single hop (direct) neighbor */
1455         if (is_single_hop_neigh) {
1456                 /* OGMs from secondary interfaces should only scheduled once
1457                  * per interface where it has been received, not multiple times
1458                  */
1459                 if (ogm_packet->ttl <= 2 &&
1460                     if_incoming != if_outgoing) {
1461                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1462                                    "Drop packet: OGM from secondary interface and wrong outgoing interface\n");
1463                         goto out_neigh;
1464                 }
1465                 /* mark direct link on incoming interface */
1466                 batadv_iv_ogm_forward(orig_node, ethhdr, ogm_packet,
1467                                       is_single_hop_neigh,
1468                                       is_from_best_next_hop, if_incoming,
1469                                       if_outgoing);
1470
1471                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1472                            "Forwarding packet: rebroadcast neighbor packet with direct link flag\n");
1473                 goto out_neigh;
1474         }
1475
1476         /* multihop originator */
1477         if (!is_bidirect) {
1478                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1479                            "Drop packet: not received via bidirectional link\n");
1480                 goto out_neigh;
1481         }
1482
1483         if (dup_status == BATADV_NEIGH_DUP) {
1484                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1485                            "Drop packet: duplicate packet received\n");
1486                 goto out_neigh;
1487         }
1488
1489         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1490                    "Forwarding packet: rebroadcast originator packet\n");
1491         batadv_iv_ogm_forward(orig_node, ethhdr, ogm_packet,
1492                               is_single_hop_neigh, is_from_best_next_hop,
1493                               if_incoming, if_outgoing);
1494
1495 out_neigh:
1496         if (orig_neigh_node && !is_single_hop_neigh)
1497                 batadv_orig_node_put(orig_neigh_node);
1498 out:
1499         if (router_ifinfo)
1500                 batadv_neigh_ifinfo_put(router_ifinfo);
1501         if (router)
1502                 batadv_neigh_node_put(router);
1503         if (router_router)
1504                 batadv_neigh_node_put(router_router);
1505         if (orig_neigh_router)
1506                 batadv_neigh_node_put(orig_neigh_router);
1507         if (hardif_neigh)
1508                 batadv_hardif_neigh_put(hardif_neigh);
1509
1510         consume_skb(skb_priv);
1511 }
1512
1513 /**
1514  * batadv_iv_ogm_process_reply() - Check OGM for direct reply and process it
1515  * @ogm_packet: rebroadcast OGM packet to process
1516  * @if_incoming: the interface where this packet was received
1517  * @orig_node: originator which reproadcasted the OGMs
1518  * @if_incoming_seqno: OGM sequence number when rebroadcast was received
1519  */
1520 static void batadv_iv_ogm_process_reply(struct batadv_ogm_packet *ogm_packet,
1521                                         struct batadv_hard_iface *if_incoming,
1522                                         struct batadv_orig_node *orig_node,
1523                                         u32 if_incoming_seqno)
1524 {
1525         struct batadv_orig_ifinfo *orig_ifinfo;
1526         s32 bit_pos;
1527         u8 *weight;
1528
1529         /* neighbor has to indicate direct link and it has to
1530          * come via the corresponding interface
1531          */
1532         if (!(ogm_packet->flags & BATADV_DIRECTLINK))
1533                 return;
1534
1535         if (!batadv_compare_eth(if_incoming->net_dev->dev_addr,
1536                                 ogm_packet->orig))
1537                 return;
1538
1539         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_incoming);
1540         if (!orig_ifinfo)
1541                 return;
1542
1543         /* save packet seqno for bidirectional check */
1544         spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1545         bit_pos = if_incoming_seqno - 2;
1546         bit_pos -= ntohl(ogm_packet->seqno);
1547         batadv_set_bit(orig_ifinfo->bat_iv.bcast_own, bit_pos);
1548         weight = &orig_ifinfo->bat_iv.bcast_own_sum;
1549         *weight = bitmap_weight(orig_ifinfo->bat_iv.bcast_own,
1550                                 BATADV_TQ_LOCAL_WINDOW_SIZE);
1551         spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1552
1553         batadv_orig_ifinfo_put(orig_ifinfo);
1554 }
1555
1556 /**
1557  * batadv_iv_ogm_process() - process an incoming batman iv OGM
1558  * @skb: the skb containing the OGM
1559  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
1560  * @if_incoming: the interface where this packet was received
1561  */
1562 static void batadv_iv_ogm_process(const struct sk_buff *skb, int ogm_offset,
1563                                   struct batadv_hard_iface *if_incoming)
1564 {
1565         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1566         struct batadv_orig_node *orig_neigh_node, *orig_node;
1567         struct batadv_hard_iface *hard_iface;
1568         struct batadv_ogm_packet *ogm_packet;
1569         u32 if_incoming_seqno;
1570         bool has_directlink_flag;
1571         struct ethhdr *ethhdr;
1572         bool is_my_oldorig = false;
1573         bool is_my_addr = false;
1574         bool is_my_orig = false;
1575
1576         ogm_packet = (struct batadv_ogm_packet *)(skb->data + ogm_offset);
1577         ethhdr = eth_hdr(skb);
1578
1579         /* Silently drop when the batman packet is actually not a
1580          * correct packet.
1581          *
1582          * This might happen if a packet is padded (e.g. Ethernet has a
1583          * minimum frame length of 64 byte) and the aggregation interprets
1584          * it as an additional length.
1585          *
1586          * TODO: A more sane solution would be to have a bit in the
1587          * batadv_ogm_packet to detect whether the packet is the last
1588          * packet in an aggregation.  Here we expect that the padding
1589          * is always zero (or not 0x01)
1590          */
1591         if (ogm_packet->packet_type != BATADV_IV_OGM)
1592                 return;
1593
1594         /* could be changed by schedule_own_packet() */
1595         if_incoming_seqno = atomic_read(&if_incoming->bat_iv.ogm_seqno);
1596
1597         if (ogm_packet->flags & BATADV_DIRECTLINK)
1598                 has_directlink_flag = true;
1599         else
1600                 has_directlink_flag = false;
1601
1602         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1603                    "Received BATMAN packet via NB: %pM, IF: %s [%pM] (from OG: %pM, via prev OG: %pM, seqno %u, tq %d, TTL %d, V %d, IDF %d)\n",
1604                    ethhdr->h_source, if_incoming->net_dev->name,
1605                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
1606                    ogm_packet->prev_sender, ntohl(ogm_packet->seqno),
1607                    ogm_packet->tq, ogm_packet->ttl,
1608                    ogm_packet->version, has_directlink_flag);
1609
1610         rcu_read_lock();
1611         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1612                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1613                         continue;
1614
1615                 if (hard_iface->soft_iface != if_incoming->soft_iface)
1616                         continue;
1617
1618                 if (batadv_compare_eth(ethhdr->h_source,
1619                                        hard_iface->net_dev->dev_addr))
1620                         is_my_addr = true;
1621
1622                 if (batadv_compare_eth(ogm_packet->orig,
1623                                        hard_iface->net_dev->dev_addr))
1624                         is_my_orig = true;
1625
1626                 if (batadv_compare_eth(ogm_packet->prev_sender,
1627                                        hard_iface->net_dev->dev_addr))
1628                         is_my_oldorig = true;
1629         }
1630         rcu_read_unlock();
1631
1632         if (is_my_addr) {
1633                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1634                            "Drop packet: received my own broadcast (sender: %pM)\n",
1635                            ethhdr->h_source);
1636                 return;
1637         }
1638
1639         if (is_my_orig) {
1640                 orig_neigh_node = batadv_iv_ogm_orig_get(bat_priv,
1641                                                          ethhdr->h_source);
1642                 if (!orig_neigh_node)
1643                         return;
1644
1645                 batadv_iv_ogm_process_reply(ogm_packet, if_incoming,
1646                                             orig_neigh_node, if_incoming_seqno);
1647
1648                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1649                            "Drop packet: originator packet from myself (via neighbor)\n");
1650                 batadv_orig_node_put(orig_neigh_node);
1651                 return;
1652         }
1653
1654         if (is_my_oldorig) {
1655                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1656                            "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n",
1657                            ethhdr->h_source);
1658                 return;
1659         }
1660
1661         if (ogm_packet->flags & BATADV_NOT_BEST_NEXT_HOP) {
1662                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1663                            "Drop packet: ignoring all packets not forwarded from the best next hop (sender: %pM)\n",
1664                            ethhdr->h_source);
1665                 return;
1666         }
1667
1668         orig_node = batadv_iv_ogm_orig_get(bat_priv, ogm_packet->orig);
1669         if (!orig_node)
1670                 return;
1671
1672         batadv_iv_ogm_process_per_outif(skb, ogm_offset, orig_node,
1673                                         if_incoming, BATADV_IF_DEFAULT);
1674
1675         rcu_read_lock();
1676         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1677                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1678                         continue;
1679
1680                 if (hard_iface->soft_iface != bat_priv->soft_iface)
1681                         continue;
1682
1683                 if (!kref_get_unless_zero(&hard_iface->refcount))
1684                         continue;
1685
1686                 batadv_iv_ogm_process_per_outif(skb, ogm_offset, orig_node,
1687                                                 if_incoming, hard_iface);
1688
1689                 batadv_hardif_put(hard_iface);
1690         }
1691         rcu_read_unlock();
1692
1693         batadv_orig_node_put(orig_node);
1694 }
1695
1696 static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work)
1697 {
1698         struct delayed_work *delayed_work;
1699         struct batadv_forw_packet *forw_packet;
1700         struct batadv_priv *bat_priv;
1701         bool dropped = false;
1702
1703         delayed_work = to_delayed_work(work);
1704         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
1705                                    delayed_work);
1706         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
1707
1708         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
1709                 dropped = true;
1710                 goto out;
1711         }
1712
1713         batadv_iv_ogm_emit(forw_packet);
1714
1715         /* we have to have at least one packet in the queue to determine the
1716          * queues wake up time unless we are shutting down.
1717          *
1718          * only re-schedule if this is the "original" copy, e.g. the OGM of the
1719          * primary interface should only be rescheduled once per period, but
1720          * this function will be called for the forw_packet instances of the
1721          * other secondary interfaces as well.
1722          */
1723         if (forw_packet->own &&
1724             forw_packet->if_incoming == forw_packet->if_outgoing)
1725                 batadv_iv_ogm_schedule(forw_packet->if_incoming);
1726
1727 out:
1728         /* do we get something for free()? */
1729         if (batadv_forw_packet_steal(forw_packet,
1730                                      &bat_priv->forw_bat_list_lock))
1731                 batadv_forw_packet_free(forw_packet, dropped);
1732 }
1733
1734 static int batadv_iv_ogm_receive(struct sk_buff *skb,
1735                                  struct batadv_hard_iface *if_incoming)
1736 {
1737         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1738         struct batadv_ogm_packet *ogm_packet;
1739         u8 *packet_pos;
1740         int ogm_offset;
1741         bool res;
1742         int ret = NET_RX_DROP;
1743
1744         res = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN);
1745         if (!res)
1746                 goto free_skb;
1747
1748         /* did we receive a B.A.T.M.A.N. IV OGM packet on an interface
1749          * that does not have B.A.T.M.A.N. IV enabled ?
1750          */
1751         if (bat_priv->algo_ops->iface.enable != batadv_iv_ogm_iface_enable)
1752                 goto free_skb;
1753
1754         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1755         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1756                            skb->len + ETH_HLEN);
1757
1758         ogm_offset = 0;
1759         ogm_packet = (struct batadv_ogm_packet *)skb->data;
1760
1761         /* unpack the aggregated packets and process them one by one */
1762         while (batadv_iv_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1763                                          ogm_packet)) {
1764                 batadv_iv_ogm_process(skb, ogm_offset, if_incoming);
1765
1766                 ogm_offset += BATADV_OGM_HLEN;
1767                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1768
1769                 packet_pos = skb->data + ogm_offset;
1770                 ogm_packet = (struct batadv_ogm_packet *)packet_pos;
1771         }
1772
1773         ret = NET_RX_SUCCESS;
1774
1775 free_skb:
1776         if (ret == NET_RX_SUCCESS)
1777                 consume_skb(skb);
1778         else
1779                 kfree_skb(skb);
1780
1781         return ret;
1782 }
1783
1784 /**
1785  * batadv_iv_ogm_neigh_get_tq_avg() - Get the TQ average for a neighbour on a
1786  *  given outgoing interface.
1787  * @neigh_node: Neighbour of interest
1788  * @if_outgoing: Outgoing interface of interest
1789  * @tq_avg: Pointer of where to store the TQ average
1790  *
1791  * Return: False if no average TQ available, otherwise true.
1792  */
1793 static bool
1794 batadv_iv_ogm_neigh_get_tq_avg(struct batadv_neigh_node *neigh_node,
1795                                struct batadv_hard_iface *if_outgoing,
1796                                u8 *tq_avg)
1797 {
1798         struct batadv_neigh_ifinfo *n_ifinfo;
1799
1800         n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
1801         if (!n_ifinfo)
1802                 return false;
1803
1804         *tq_avg = n_ifinfo->bat_iv.tq_avg;
1805         batadv_neigh_ifinfo_put(n_ifinfo);
1806
1807         return true;
1808 }
1809
1810 /**
1811  * batadv_iv_ogm_orig_dump_subentry() - Dump an originator subentry into a
1812  *  message
1813  * @msg: Netlink message to dump into
1814  * @portid: Port making netlink request
1815  * @seq: Sequence number of netlink message
1816  * @bat_priv: The bat priv with all the soft interface information
1817  * @if_outgoing: Limit dump to entries with this outgoing interface
1818  * @orig_node: Originator to dump
1819  * @neigh_node: Single hops neighbour
1820  * @best: Is the best originator
1821  *
1822  * Return: Error code, or 0 on success
1823  */
1824 static int
1825 batadv_iv_ogm_orig_dump_subentry(struct sk_buff *msg, u32 portid, u32 seq,
1826                                  struct batadv_priv *bat_priv,
1827                                  struct batadv_hard_iface *if_outgoing,
1828                                  struct batadv_orig_node *orig_node,
1829                                  struct batadv_neigh_node *neigh_node,
1830                                  bool best)
1831 {
1832         void *hdr;
1833         u8 tq_avg;
1834         unsigned int last_seen_msecs;
1835
1836         last_seen_msecs = jiffies_to_msecs(jiffies - orig_node->last_seen);
1837
1838         if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node, if_outgoing, &tq_avg))
1839                 return 0;
1840
1841         if (if_outgoing != BATADV_IF_DEFAULT &&
1842             if_outgoing != neigh_node->if_incoming)
1843                 return 0;
1844
1845         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
1846                           NLM_F_MULTI, BATADV_CMD_GET_ORIGINATORS);
1847         if (!hdr)
1848                 return -ENOBUFS;
1849
1850         if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
1851                     orig_node->orig) ||
1852             nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
1853                     neigh_node->addr) ||
1854             nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
1855                         neigh_node->if_incoming->net_dev->ifindex) ||
1856             nla_put_u8(msg, BATADV_ATTR_TQ, tq_avg) ||
1857             nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
1858                         last_seen_msecs))
1859                 goto nla_put_failure;
1860
1861         if (best && nla_put_flag(msg, BATADV_ATTR_FLAG_BEST))
1862                 goto nla_put_failure;
1863
1864         genlmsg_end(msg, hdr);
1865         return 0;
1866
1867  nla_put_failure:
1868         genlmsg_cancel(msg, hdr);
1869         return -EMSGSIZE;
1870 }
1871
1872 /**
1873  * batadv_iv_ogm_orig_dump_entry() - Dump an originator entry into a message
1874  * @msg: Netlink message to dump into
1875  * @portid: Port making netlink request
1876  * @seq: Sequence number of netlink message
1877  * @bat_priv: The bat priv with all the soft interface information
1878  * @if_outgoing: Limit dump to entries with this outgoing interface
1879  * @orig_node: Originator to dump
1880  * @sub_s: Number of sub entries to skip
1881  *
1882  * This function assumes the caller holds rcu_read_lock().
1883  *
1884  * Return: Error code, or 0 on success
1885  */
1886 static int
1887 batadv_iv_ogm_orig_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
1888                               struct batadv_priv *bat_priv,
1889                               struct batadv_hard_iface *if_outgoing,
1890                               struct batadv_orig_node *orig_node, int *sub_s)
1891 {
1892         struct batadv_neigh_node *neigh_node_best;
1893         struct batadv_neigh_node *neigh_node;
1894         int sub = 0;
1895         bool best;
1896         u8 tq_avg_best;
1897
1898         neigh_node_best = batadv_orig_router_get(orig_node, if_outgoing);
1899         if (!neigh_node_best)
1900                 goto out;
1901
1902         if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node_best, if_outgoing,
1903                                             &tq_avg_best))
1904                 goto out;
1905
1906         if (tq_avg_best == 0)
1907                 goto out;
1908
1909         hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
1910                 if (sub++ < *sub_s)
1911                         continue;
1912
1913                 best = (neigh_node == neigh_node_best);
1914
1915                 if (batadv_iv_ogm_orig_dump_subentry(msg, portid, seq,
1916                                                      bat_priv, if_outgoing,
1917                                                      orig_node, neigh_node,
1918                                                      best)) {
1919                         batadv_neigh_node_put(neigh_node_best);
1920
1921                         *sub_s = sub - 1;
1922                         return -EMSGSIZE;
1923                 }
1924         }
1925
1926  out:
1927         if (neigh_node_best)
1928                 batadv_neigh_node_put(neigh_node_best);
1929
1930         *sub_s = 0;
1931         return 0;
1932 }
1933
1934 /**
1935  * batadv_iv_ogm_orig_dump_bucket() - Dump an originator bucket into a
1936  *  message
1937  * @msg: Netlink message to dump into
1938  * @portid: Port making netlink request
1939  * @seq: Sequence number of netlink message
1940  * @bat_priv: The bat priv with all the soft interface information
1941  * @if_outgoing: Limit dump to entries with this outgoing interface
1942  * @head: Bucket to be dumped
1943  * @idx_s: Number of entries to be skipped
1944  * @sub: Number of sub entries to be skipped
1945  *
1946  * Return: Error code, or 0 on success
1947  */
1948 static int
1949 batadv_iv_ogm_orig_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
1950                                struct batadv_priv *bat_priv,
1951                                struct batadv_hard_iface *if_outgoing,
1952                                struct hlist_head *head, int *idx_s, int *sub)
1953 {
1954         struct batadv_orig_node *orig_node;
1955         int idx = 0;
1956
1957         rcu_read_lock();
1958         hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1959                 if (idx++ < *idx_s)
1960                         continue;
1961
1962                 if (batadv_iv_ogm_orig_dump_entry(msg, portid, seq, bat_priv,
1963                                                   if_outgoing, orig_node,
1964                                                   sub)) {
1965                         rcu_read_unlock();
1966                         *idx_s = idx - 1;
1967                         return -EMSGSIZE;
1968                 }
1969         }
1970         rcu_read_unlock();
1971
1972         *idx_s = 0;
1973         *sub = 0;
1974         return 0;
1975 }
1976
1977 /**
1978  * batadv_iv_ogm_orig_dump() - Dump the originators into a message
1979  * @msg: Netlink message to dump into
1980  * @cb: Control block containing additional options
1981  * @bat_priv: The bat priv with all the soft interface information
1982  * @if_outgoing: Limit dump to entries with this outgoing interface
1983  */
1984 static void
1985 batadv_iv_ogm_orig_dump(struct sk_buff *msg, struct netlink_callback *cb,
1986                         struct batadv_priv *bat_priv,
1987                         struct batadv_hard_iface *if_outgoing)
1988 {
1989         struct batadv_hashtable *hash = bat_priv->orig_hash;
1990         struct hlist_head *head;
1991         int bucket = cb->args[0];
1992         int idx = cb->args[1];
1993         int sub = cb->args[2];
1994         int portid = NETLINK_CB(cb->skb).portid;
1995
1996         while (bucket < hash->size) {
1997                 head = &hash->table[bucket];
1998
1999                 if (batadv_iv_ogm_orig_dump_bucket(msg, portid,
2000                                                    cb->nlh->nlmsg_seq,
2001                                                    bat_priv, if_outgoing, head,
2002                                                    &idx, &sub))
2003                         break;
2004
2005                 bucket++;
2006         }
2007
2008         cb->args[0] = bucket;
2009         cb->args[1] = idx;
2010         cb->args[2] = sub;
2011 }
2012
2013 /**
2014  * batadv_iv_ogm_neigh_diff() - calculate tq difference of two neighbors
2015  * @neigh1: the first neighbor object of the comparison
2016  * @if_outgoing1: outgoing interface for the first neighbor
2017  * @neigh2: the second neighbor object of the comparison
2018  * @if_outgoing2: outgoing interface for the second neighbor
2019  * @diff: pointer to integer receiving the calculated difference
2020  *
2021  * The content of *@diff is only valid when this function returns true.
2022  * It is less, equal to or greater than 0 if the metric via neigh1 is lower,
2023  * the same as or higher than the metric via neigh2
2024  *
2025  * Return: true when the difference could be calculated, false otherwise
2026  */
2027 static bool batadv_iv_ogm_neigh_diff(struct batadv_neigh_node *neigh1,
2028                                      struct batadv_hard_iface *if_outgoing1,
2029                                      struct batadv_neigh_node *neigh2,
2030                                      struct batadv_hard_iface *if_outgoing2,
2031                                      int *diff)
2032 {
2033         struct batadv_neigh_ifinfo *neigh1_ifinfo, *neigh2_ifinfo;
2034         u8 tq1, tq2;
2035         bool ret = true;
2036
2037         neigh1_ifinfo = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
2038         neigh2_ifinfo = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
2039
2040         if (!neigh1_ifinfo || !neigh2_ifinfo) {
2041                 ret = false;
2042                 goto out;
2043         }
2044
2045         tq1 = neigh1_ifinfo->bat_iv.tq_avg;
2046         tq2 = neigh2_ifinfo->bat_iv.tq_avg;
2047         *diff = (int)tq1 - (int)tq2;
2048
2049 out:
2050         if (neigh1_ifinfo)
2051                 batadv_neigh_ifinfo_put(neigh1_ifinfo);
2052         if (neigh2_ifinfo)
2053                 batadv_neigh_ifinfo_put(neigh2_ifinfo);
2054
2055         return ret;
2056 }
2057
2058 /**
2059  * batadv_iv_ogm_neigh_dump_neigh() - Dump a neighbour into a netlink message
2060  * @msg: Netlink message to dump into
2061  * @portid: Port making netlink request
2062  * @seq: Sequence number of netlink message
2063  * @hardif_neigh: Neighbour to be dumped
2064  *
2065  * Return: Error code, or 0 on success
2066  */
2067 static int
2068 batadv_iv_ogm_neigh_dump_neigh(struct sk_buff *msg, u32 portid, u32 seq,
2069                                struct batadv_hardif_neigh_node *hardif_neigh)
2070 {
2071         void *hdr;
2072         unsigned int last_seen_msecs;
2073
2074         last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen);
2075
2076         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
2077                           NLM_F_MULTI, BATADV_CMD_GET_NEIGHBORS);
2078         if (!hdr)
2079                 return -ENOBUFS;
2080
2081         if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
2082                     hardif_neigh->addr) ||
2083             nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
2084                         hardif_neigh->if_incoming->net_dev->ifindex) ||
2085             nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
2086                         last_seen_msecs))
2087                 goto nla_put_failure;
2088
2089         genlmsg_end(msg, hdr);
2090         return 0;
2091
2092  nla_put_failure:
2093         genlmsg_cancel(msg, hdr);
2094         return -EMSGSIZE;
2095 }
2096
2097 /**
2098  * batadv_iv_ogm_neigh_dump_hardif() - Dump the neighbours of a hard interface
2099  *  into a message
2100  * @msg: Netlink message to dump into
2101  * @portid: Port making netlink request
2102  * @seq: Sequence number of netlink message
2103  * @bat_priv: The bat priv with all the soft interface information
2104  * @hard_iface: Hard interface to dump the neighbours for
2105  * @idx_s: Number of entries to skip
2106  *
2107  * This function assumes the caller holds rcu_read_lock().
2108  *
2109  * Return: Error code, or 0 on success
2110  */
2111 static int
2112 batadv_iv_ogm_neigh_dump_hardif(struct sk_buff *msg, u32 portid, u32 seq,
2113                                 struct batadv_priv *bat_priv,
2114                                 struct batadv_hard_iface *hard_iface,
2115                                 int *idx_s)
2116 {
2117         struct batadv_hardif_neigh_node *hardif_neigh;
2118         int idx = 0;
2119
2120         hlist_for_each_entry_rcu(hardif_neigh,
2121                                  &hard_iface->neigh_list, list) {
2122                 if (idx++ < *idx_s)
2123                         continue;
2124
2125                 if (batadv_iv_ogm_neigh_dump_neigh(msg, portid, seq,
2126                                                    hardif_neigh)) {
2127                         *idx_s = idx - 1;
2128                         return -EMSGSIZE;
2129                 }
2130         }
2131
2132         *idx_s = 0;
2133         return 0;
2134 }
2135
2136 /**
2137  * batadv_iv_ogm_neigh_dump() - Dump the neighbours into a message
2138  * @msg: Netlink message to dump into
2139  * @cb: Control block containing additional options
2140  * @bat_priv: The bat priv with all the soft interface information
2141  * @single_hardif: Limit dump to this hard interface
2142  */
2143 static void
2144 batadv_iv_ogm_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb,
2145                          struct batadv_priv *bat_priv,
2146                          struct batadv_hard_iface *single_hardif)
2147 {
2148         struct batadv_hard_iface *hard_iface;
2149         int i_hardif = 0;
2150         int i_hardif_s = cb->args[0];
2151         int idx = cb->args[1];
2152         int portid = NETLINK_CB(cb->skb).portid;
2153
2154         rcu_read_lock();
2155         if (single_hardif) {
2156                 if (i_hardif_s == 0) {
2157                         if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
2158                                                             cb->nlh->nlmsg_seq,
2159                                                             bat_priv,
2160                                                             single_hardif,
2161                                                             &idx) == 0)
2162                                 i_hardif++;
2163                 }
2164         } else {
2165                 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list,
2166                                         list) {
2167                         if (hard_iface->soft_iface != bat_priv->soft_iface)
2168                                 continue;
2169
2170                         if (i_hardif++ < i_hardif_s)
2171                                 continue;
2172
2173                         if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
2174                                                             cb->nlh->nlmsg_seq,
2175                                                             bat_priv,
2176                                                             hard_iface, &idx)) {
2177                                 i_hardif--;
2178                                 break;
2179                         }
2180                 }
2181         }
2182         rcu_read_unlock();
2183
2184         cb->args[0] = i_hardif;
2185         cb->args[1] = idx;
2186 }
2187
2188 /**
2189  * batadv_iv_ogm_neigh_cmp() - compare the metrics of two neighbors
2190  * @neigh1: the first neighbor object of the comparison
2191  * @if_outgoing1: outgoing interface for the first neighbor
2192  * @neigh2: the second neighbor object of the comparison
2193  * @if_outgoing2: outgoing interface for the second neighbor
2194  *
2195  * Return: a value less, equal to or greater than 0 if the metric via neigh1 is
2196  * lower, the same as or higher than the metric via neigh2
2197  */
2198 static int batadv_iv_ogm_neigh_cmp(struct batadv_neigh_node *neigh1,
2199                                    struct batadv_hard_iface *if_outgoing1,
2200                                    struct batadv_neigh_node *neigh2,
2201                                    struct batadv_hard_iface *if_outgoing2)
2202 {
2203         bool ret;
2204         int diff;
2205
2206         ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
2207                                        if_outgoing2, &diff);
2208         if (!ret)
2209                 return 0;
2210
2211         return diff;
2212 }
2213
2214 /**
2215  * batadv_iv_ogm_neigh_is_sob() - check if neigh1 is similarly good or better
2216  *  than neigh2 from the metric prospective
2217  * @neigh1: the first neighbor object of the comparison
2218  * @if_outgoing1: outgoing interface for the first neighbor
2219  * @neigh2: the second neighbor object of the comparison
2220  * @if_outgoing2: outgoing interface for the second neighbor
2221  *
2222  * Return: true if the metric via neigh1 is equally good or better than
2223  * the metric via neigh2, false otherwise.
2224  */
2225 static bool
2226 batadv_iv_ogm_neigh_is_sob(struct batadv_neigh_node *neigh1,
2227                            struct batadv_hard_iface *if_outgoing1,
2228                            struct batadv_neigh_node *neigh2,
2229                            struct batadv_hard_iface *if_outgoing2)
2230 {
2231         bool ret;
2232         int diff;
2233
2234         ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
2235                                        if_outgoing2, &diff);
2236         if (!ret)
2237                 return false;
2238
2239         ret = diff > -BATADV_TQ_SIMILARITY_THRESHOLD;
2240         return ret;
2241 }
2242
2243 static void batadv_iv_iface_enabled(struct batadv_hard_iface *hard_iface)
2244 {
2245         /* begin scheduling originator messages on that interface */
2246         batadv_iv_ogm_schedule(hard_iface);
2247 }
2248
2249 /**
2250  * batadv_iv_init_sel_class() - initialize GW selection class
2251  * @bat_priv: the bat priv with all the soft interface information
2252  */
2253 static void batadv_iv_init_sel_class(struct batadv_priv *bat_priv)
2254 {
2255         /* set default TQ difference threshold to 20 */
2256         atomic_set(&bat_priv->gw.sel_class, 20);
2257 }
2258
2259 static struct batadv_gw_node *
2260 batadv_iv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
2261 {
2262         struct batadv_neigh_node *router;
2263         struct batadv_neigh_ifinfo *router_ifinfo;
2264         struct batadv_gw_node *gw_node, *curr_gw = NULL;
2265         u64 max_gw_factor = 0;
2266         u64 tmp_gw_factor = 0;
2267         u8 max_tq = 0;
2268         u8 tq_avg;
2269         struct batadv_orig_node *orig_node;
2270
2271         rcu_read_lock();
2272         hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
2273                 orig_node = gw_node->orig_node;
2274                 router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
2275                 if (!router)
2276                         continue;
2277
2278                 router_ifinfo = batadv_neigh_ifinfo_get(router,
2279                                                         BATADV_IF_DEFAULT);
2280                 if (!router_ifinfo)
2281                         goto next;
2282
2283                 if (!kref_get_unless_zero(&gw_node->refcount))
2284                         goto next;
2285
2286                 tq_avg = router_ifinfo->bat_iv.tq_avg;
2287
2288                 switch (atomic_read(&bat_priv->gw.sel_class)) {
2289                 case 1: /* fast connection */
2290                         tmp_gw_factor = tq_avg * tq_avg;
2291                         tmp_gw_factor *= gw_node->bandwidth_down;
2292                         tmp_gw_factor *= 100 * 100;
2293                         tmp_gw_factor >>= 18;
2294
2295                         if (tmp_gw_factor > max_gw_factor ||
2296                             (tmp_gw_factor == max_gw_factor &&
2297                              tq_avg > max_tq)) {
2298                                 if (curr_gw)
2299                                         batadv_gw_node_put(curr_gw);
2300                                 curr_gw = gw_node;
2301                                 kref_get(&curr_gw->refcount);
2302                         }
2303                         break;
2304
2305                 default: /* 2:  stable connection (use best statistic)
2306                           * 3:  fast-switch (use best statistic but change as
2307                           *     soon as a better gateway appears)
2308                           * XX: late-switch (use best statistic but change as
2309                           *     soon as a better gateway appears which has
2310                           *     $routing_class more tq points)
2311                           */
2312                         if (tq_avg > max_tq) {
2313                                 if (curr_gw)
2314                                         batadv_gw_node_put(curr_gw);
2315                                 curr_gw = gw_node;
2316                                 kref_get(&curr_gw->refcount);
2317                         }
2318                         break;
2319                 }
2320
2321                 if (tq_avg > max_tq)
2322                         max_tq = tq_avg;
2323
2324                 if (tmp_gw_factor > max_gw_factor)
2325                         max_gw_factor = tmp_gw_factor;
2326
2327                 batadv_gw_node_put(gw_node);
2328
2329 next:
2330                 batadv_neigh_node_put(router);
2331                 if (router_ifinfo)
2332                         batadv_neigh_ifinfo_put(router_ifinfo);
2333         }
2334         rcu_read_unlock();
2335
2336         return curr_gw;
2337 }
2338
2339 static bool batadv_iv_gw_is_eligible(struct batadv_priv *bat_priv,
2340                                      struct batadv_orig_node *curr_gw_orig,
2341                                      struct batadv_orig_node *orig_node)
2342 {
2343         struct batadv_neigh_ifinfo *router_orig_ifinfo = NULL;
2344         struct batadv_neigh_ifinfo *router_gw_ifinfo = NULL;
2345         struct batadv_neigh_node *router_gw = NULL;
2346         struct batadv_neigh_node *router_orig = NULL;
2347         u8 gw_tq_avg, orig_tq_avg;
2348         bool ret = false;
2349
2350         /* dynamic re-election is performed only on fast or late switch */
2351         if (atomic_read(&bat_priv->gw.sel_class) <= 2)
2352                 return false;
2353
2354         router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
2355         if (!router_gw) {
2356                 ret = true;
2357                 goto out;
2358         }
2359
2360         router_gw_ifinfo = batadv_neigh_ifinfo_get(router_gw,
2361                                                    BATADV_IF_DEFAULT);
2362         if (!router_gw_ifinfo) {
2363                 ret = true;
2364                 goto out;
2365         }
2366
2367         router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
2368         if (!router_orig)
2369                 goto out;
2370
2371         router_orig_ifinfo = batadv_neigh_ifinfo_get(router_orig,
2372                                                      BATADV_IF_DEFAULT);
2373         if (!router_orig_ifinfo)
2374                 goto out;
2375
2376         gw_tq_avg = router_gw_ifinfo->bat_iv.tq_avg;
2377         orig_tq_avg = router_orig_ifinfo->bat_iv.tq_avg;
2378
2379         /* the TQ value has to be better */
2380         if (orig_tq_avg < gw_tq_avg)
2381                 goto out;
2382
2383         /* if the routing class is greater than 3 the value tells us how much
2384          * greater the TQ value of the new gateway must be
2385          */
2386         if ((atomic_read(&bat_priv->gw.sel_class) > 3) &&
2387             (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw.sel_class)))
2388                 goto out;
2389
2390         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
2391                    "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
2392                    gw_tq_avg, orig_tq_avg);
2393
2394         ret = true;
2395 out:
2396         if (router_gw_ifinfo)
2397                 batadv_neigh_ifinfo_put(router_gw_ifinfo);
2398         if (router_orig_ifinfo)
2399                 batadv_neigh_ifinfo_put(router_orig_ifinfo);
2400         if (router_gw)
2401                 batadv_neigh_node_put(router_gw);
2402         if (router_orig)
2403                 batadv_neigh_node_put(router_orig);
2404
2405         return ret;
2406 }
2407
2408 /**
2409  * batadv_iv_gw_dump_entry() - Dump a gateway into a message
2410  * @msg: Netlink message to dump into
2411  * @portid: Port making netlink request
2412  * @cb: Control block containing additional options
2413  * @bat_priv: The bat priv with all the soft interface information
2414  * @gw_node: Gateway to be dumped
2415  *
2416  * Return: Error code, or 0 on success
2417  */
2418 static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid,
2419                                    struct netlink_callback *cb,
2420                                    struct batadv_priv *bat_priv,
2421                                    struct batadv_gw_node *gw_node)
2422 {
2423         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
2424         struct batadv_neigh_node *router;
2425         struct batadv_gw_node *curr_gw = NULL;
2426         int ret = 0;
2427         void *hdr;
2428
2429         router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
2430         if (!router)
2431                 goto out;
2432
2433         router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
2434         if (!router_ifinfo)
2435                 goto out;
2436
2437         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
2438
2439         hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
2440                           &batadv_netlink_family, NLM_F_MULTI,
2441                           BATADV_CMD_GET_GATEWAYS);
2442         if (!hdr) {
2443                 ret = -ENOBUFS;
2444                 goto out;
2445         }
2446
2447         genl_dump_check_consistent(cb, hdr);
2448
2449         ret = -EMSGSIZE;
2450
2451         if (curr_gw == gw_node)
2452                 if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) {
2453                         genlmsg_cancel(msg, hdr);
2454                         goto out;
2455                 }
2456
2457         if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
2458                     gw_node->orig_node->orig) ||
2459             nla_put_u8(msg, BATADV_ATTR_TQ, router_ifinfo->bat_iv.tq_avg) ||
2460             nla_put(msg, BATADV_ATTR_ROUTER, ETH_ALEN,
2461                     router->addr) ||
2462             nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
2463                            router->if_incoming->net_dev->name) ||
2464             nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
2465                         gw_node->bandwidth_down) ||
2466             nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP,
2467                         gw_node->bandwidth_up)) {
2468                 genlmsg_cancel(msg, hdr);
2469                 goto out;
2470         }
2471
2472         genlmsg_end(msg, hdr);
2473         ret = 0;
2474
2475 out:
2476         if (curr_gw)
2477                 batadv_gw_node_put(curr_gw);
2478         if (router_ifinfo)
2479                 batadv_neigh_ifinfo_put(router_ifinfo);
2480         if (router)
2481                 batadv_neigh_node_put(router);
2482         return ret;
2483 }
2484
2485 /**
2486  * batadv_iv_gw_dump() - Dump gateways into a message
2487  * @msg: Netlink message to dump into
2488  * @cb: Control block containing additional options
2489  * @bat_priv: The bat priv with all the soft interface information
2490  */
2491 static void batadv_iv_gw_dump(struct sk_buff *msg, struct netlink_callback *cb,
2492                               struct batadv_priv *bat_priv)
2493 {
2494         int portid = NETLINK_CB(cb->skb).portid;
2495         struct batadv_gw_node *gw_node;
2496         int idx_skip = cb->args[0];
2497         int idx = 0;
2498
2499         spin_lock_bh(&bat_priv->gw.list_lock);
2500         cb->seq = bat_priv->gw.generation << 1 | 1;
2501
2502         hlist_for_each_entry(gw_node, &bat_priv->gw.gateway_list, list) {
2503                 if (idx++ < idx_skip)
2504                         continue;
2505
2506                 if (batadv_iv_gw_dump_entry(msg, portid, cb, bat_priv,
2507                                             gw_node)) {
2508                         idx_skip = idx - 1;
2509                         goto unlock;
2510                 }
2511         }
2512
2513         idx_skip = idx;
2514 unlock:
2515         spin_unlock_bh(&bat_priv->gw.list_lock);
2516
2517         cb->args[0] = idx_skip;
2518 }
2519
2520 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
2521         .name = "BATMAN_IV",
2522         .iface = {
2523                 .enable = batadv_iv_ogm_iface_enable,
2524                 .enabled = batadv_iv_iface_enabled,
2525                 .disable = batadv_iv_ogm_iface_disable,
2526                 .update_mac = batadv_iv_ogm_iface_update_mac,
2527                 .primary_set = batadv_iv_ogm_primary_iface_set,
2528         },
2529         .neigh = {
2530                 .cmp = batadv_iv_ogm_neigh_cmp,
2531                 .is_similar_or_better = batadv_iv_ogm_neigh_is_sob,
2532                 .dump = batadv_iv_ogm_neigh_dump,
2533         },
2534         .orig = {
2535                 .dump = batadv_iv_ogm_orig_dump,
2536         },
2537         .gw = {
2538                 .init_sel_class = batadv_iv_init_sel_class,
2539                 .get_best_gw_node = batadv_iv_gw_get_best_gw_node,
2540                 .is_eligible = batadv_iv_gw_is_eligible,
2541                 .dump = batadv_iv_gw_dump,
2542         },
2543 };
2544
2545 /**
2546  * batadv_iv_init() - B.A.T.M.A.N. IV initialization function
2547  *
2548  * Return: 0 on success or negative error number in case of failure
2549  */
2550 int __init batadv_iv_init(void)
2551 {
2552         int ret;
2553
2554         /* batman originator packet */
2555         ret = batadv_recv_handler_register(BATADV_IV_OGM,
2556                                            batadv_iv_ogm_receive);
2557         if (ret < 0)
2558                 goto out;
2559
2560         ret = batadv_algo_register(&batadv_batman_iv);
2561         if (ret < 0)
2562                 goto handler_unregister;
2563
2564         goto out;
2565
2566 handler_unregister:
2567         batadv_recv_handler_unregister(BATADV_IV_OGM);
2568 out:
2569         return ret;
2570 }