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/container_of.h>
  17 #include <linux/errno.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/gfp.h>
  20 #include <linux/if_ether.h>
  21 #include <linux/init.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/kref.h>
  24 #include <linux/list.h>
  25 #include <linux/lockdep.h>
  26 #include <linux/minmax.h>
  27 #include <linux/mutex.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/netlink.h>
  30 #include <linux/pkt_sched.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/string_choices.h>
  41 #include <linux/types.h>
  42 #include <linux/workqueue.h>
  43 #include <net/genetlink.h>
  44 #include <net/netlink.h>
  45 #include <uapi/linux/batadv_packet.h>
  46 #include <uapi/linux/batman_adv.h>
  47
  48 #include "bat_algo.h"
  49 #include "bitarray.h"
  50 #include "gateway_client.h"
  51 #include "hard-interface.h"
  52 #include "hash.h"
  53 #include "log.h"
  54 #include "netlink.h"
  55 #include "network-coding.h"
  56 #include "originator.h"
  57 #include "routing.h"
  58 #include "send.h"
  59 #include "translation-table.h"
  60 #include "tvlv.h"
  61
  62 static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work);
  63
  64 /**
  65  * enum batadv_dup_status - duplicate status
  66  */
  67 enum batadv_dup_status {
  68         /** @BATADV_NO_DUP: the packet is no duplicate */
  69         BATADV_NO_DUP = 0,
  70
  71         /**
  72          * @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for
  73          *  the neighbor)
  74          */
  75         BATADV_ORIG_DUP,
  76
  77         /** @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor */
  78         BATADV_NEIGH_DUP,
  79
  80         /**
  81          * @BATADV_PROTECTED: originator is currently protected (after reboot)
  82          */
  83         BATADV_PROTECTED,
  84 };
  85
  86 /**
  87  * batadv_ring_buffer_set() - update the ring buffer with the given value
  88  * @lq_recv: pointer to the ring buffer
  89  * @lq_index: index to store the value at
  90  * @value: value to store in the ring buffer
  91  */
  92 static void batadv_ring_buffer_set(u8 lq_recv[], u8 *lq_index, u8 value)
  93 {
  94         lq_recv[*lq_index] = value;
  95         *lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
  96 }
  97
  98 /**
  99  * batadv_ring_buffer_avg() - compute the average of all non-zero values stored
 100  * in the given ring buffer
 101  * @lq_recv: pointer to the ring buffer
 102  *
 103  * Return: computed average value.
 104  */
 105 static u8 batadv_ring_buffer_avg(const u8 lq_recv[])
 106 {
 107         const u8 *ptr;
 108         u16 count = 0;
 109         u16 i = 0;
 110         u16 sum = 0;
 111
 112         ptr = lq_recv;
 113
 114         while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
 115                 if (*ptr != 0) {
 116                         count++;
 117                         sum += *ptr;
 118                 }
 119
 120                 i++;
 121                 ptr++;
 122         }
 123
 124         if (count == 0)
 125                 return 0;
 126
 127         return (u8)(sum / count);
 128 }
 129
 130 /**
 131  * batadv_iv_ogm_orig_get() - retrieve or create (if does not exist) an
 132  *  originator
 133  * @bat_priv: the bat priv with all the mesh interface information
 134  * @addr: mac address of the originator
 135  *
 136  * Return: the originator object corresponding to the passed mac address or NULL
 137  * on failure.
 138  * If the object does not exist, it is created and initialised.
 139  */
 140 static struct batadv_orig_node *
 141 batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const u8 *addr)
 142 {
 143         struct batadv_orig_node *orig_node;
 144         int hash_added;
 145
 146         orig_node = batadv_orig_hash_find(bat_priv, addr);
 147         if (orig_node)
 148                 return orig_node;
 149
 150         orig_node = batadv_orig_node_new(bat_priv, addr);
 151         if (!orig_node)
 152                 return NULL;
 153
 154         spin_lock_init(&orig_node->bat_iv.ogm_cnt_lock);
 155
 156         kref_get(&orig_node->refcount);
 157         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
 158                                      batadv_choose_orig, orig_node,
 159                                      &orig_node->hash_entry);
 160         if (hash_added != 0)
 161                 goto free_orig_node_hash;
 162
 163         return orig_node;
 164
 165 free_orig_node_hash:
 166         /* reference for batadv_hash_add */
 167         batadv_orig_node_put(orig_node);
 168         /* reference from batadv_orig_node_new */
 169         batadv_orig_node_put(orig_node);
 170
 171         return NULL;
 172 }
 173
 174 static struct batadv_neigh_node *
 175 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
 176                         const u8 *neigh_addr,
 177                         struct batadv_orig_node *orig_node,
 178                         struct batadv_orig_node *orig_neigh)
 179 {
 180         struct batadv_neigh_node *neigh_node;
 181
 182         neigh_node = batadv_neigh_node_get_or_create(orig_node,
 183                                                      hard_iface, neigh_addr);
 184         if (!neigh_node)
 185                 goto out;
 186
 187         neigh_node->orig_node = orig_neigh;
 188
 189 out:
 190         return neigh_node;
 191 }
 192
 193 static int batadv_iv_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 194 {
 195         struct batadv_ogm_packet *batadv_ogm_packet;
 196         unsigned char *ogm_buff;
 197         u32 random_seqno;
 198
 199         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 200
 201         /* randomize initial seqno to avoid collision */
 202         get_random_bytes(&random_seqno, sizeof(random_seqno));
 203         atomic_set(&hard_iface->bat_iv.ogm_seqno, random_seqno);
 204
 205         hard_iface->bat_iv.ogm_buff_len = BATADV_OGM_HLEN;
 206         ogm_buff = kmalloc(hard_iface->bat_iv.ogm_buff_len, GFP_ATOMIC);
 207         if (!ogm_buff) {
 208                 mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 209                 return -ENOMEM;
 210         }
 211
 212         hard_iface->bat_iv.ogm_buff = ogm_buff;
 213
 214         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 215         batadv_ogm_packet->packet_type = BATADV_IV_OGM;
 216         batadv_ogm_packet->version = BATADV_COMPAT_VERSION;
 217         batadv_ogm_packet->ttl = 2;
 218         batadv_ogm_packet->flags = BATADV_NO_FLAGS;
 219         batadv_ogm_packet->reserved = 0;
 220         batadv_ogm_packet->tq = BATADV_TQ_MAX_VALUE;
 221
 222         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 223
 224         return 0;
 225 }
 226
 227 static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 228 {
 229         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 230
 231         kfree(hard_iface->bat_iv.ogm_buff);
 232         hard_iface->bat_iv.ogm_buff = NULL;
 233
 234         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 235 }
 236
 237 static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface)
 238 {
 239         struct batadv_ogm_packet *batadv_ogm_packet;
 240         void *ogm_buff;
 241
 242         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 243
 244         ogm_buff = hard_iface->bat_iv.ogm_buff;
 245         if (!ogm_buff)
 246                 goto unlock;
 247
 248         batadv_ogm_packet = ogm_buff;
 249         ether_addr_copy(batadv_ogm_packet->orig,
 250                         hard_iface->net_dev->dev_addr);
 251         ether_addr_copy(batadv_ogm_packet->prev_sender,
 252                         hard_iface->net_dev->dev_addr);
 253
 254 unlock:
 255         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 256 }
 257
 258 static void
 259 batadv_iv_ogm_primary_iface_set(struct batadv_hard_iface *hard_iface)
 260 {
 261         struct batadv_ogm_packet *batadv_ogm_packet;
 262         void *ogm_buff;
 263
 264         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 265
 266         ogm_buff = hard_iface->bat_iv.ogm_buff;
 267         if (!ogm_buff)
 268                 goto unlock;
 269
 270         batadv_ogm_packet = ogm_buff;
 271         batadv_ogm_packet->ttl = BATADV_TTL;
 272
 273 unlock:
 274         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 275 }
 276
 277 /* when do we schedule our own ogm to be sent */
 278 static unsigned long
 279 batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 280 {
 281         unsigned int msecs;
 282
 283         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 284         msecs += get_random_u32_below(2 * BATADV_JITTER);
 285
 286         return jiffies + msecs_to_jiffies(msecs);
 287 }
 288
 289 /* when do we schedule a ogm packet to be sent */
 290 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 291 {
 292         return jiffies + msecs_to_jiffies(get_random_u32_below(BATADV_JITTER / 2));
 293 }
 294
 295 /* apply hop penalty for a normal link */
 296 static u8 batadv_hop_penalty(u8 tq, const struct batadv_priv *bat_priv)
 297 {
 298         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 299         int new_tq;
 300
 301         new_tq = tq * (BATADV_TQ_MAX_VALUE - hop_penalty);
 302         new_tq /= BATADV_TQ_MAX_VALUE;
 303
 304         return new_tq;
 305 }
 306
 307 /**
 308  * batadv_iv_ogm_aggr_packet() - checks if there is another OGM attached
 309  * @buff_pos: current position in the skb
 310  * @packet_len: total length of the skb
 311  * @ogm_packet: potential OGM in buffer
 312  *
 313  * Return: true if there is enough space for another OGM, false otherwise.
 314  */
 315 static bool
 316 batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
 317                           const struct batadv_ogm_packet *ogm_packet)
 318 {
 319         int next_buff_pos = 0;
 320
 321         /* check if there is enough space for the header */
 322         next_buff_pos += buff_pos + sizeof(*ogm_packet);
 323         if (next_buff_pos > packet_len)
 324                 return false;
 325
 326         /* check if there is enough space for the optional TVLV */
 327         next_buff_pos += ntohs(ogm_packet->tvlv_len);
 328
 329         return next_buff_pos <= packet_len;
 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->mesh_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 (test_bit(packet_num, forw_packet->direct_link_flags) &&
 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                            str_on_off(batadv_ogm_packet->flags & BATADV_DIRECTLINK),
 376                            hard_iface->net_dev->name,
 377                            hard_iface->net_dev->dev_addr);
 378
 379                 buff_pos += BATADV_OGM_HLEN;
 380                 buff_pos += ntohs(batadv_ogm_packet->tvlv_len);
 381                 packet_num++;
 382                 packet_pos = forw_packet->skb->data + buff_pos;
 383                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 384         }
 385
 386         /* create clone because function is called more than once */
 387         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 388         if (skb) {
 389                 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 390                 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 391                                    skb->len + ETH_HLEN);
 392                 batadv_send_broadcast_skb(skb, hard_iface);
 393         }
 394 }
 395
 396 /* send a batman ogm packet */
 397 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 398 {
 399         struct net_device *mesh_iface;
 400
 401         if (!forw_packet->if_incoming) {
 402                 pr_err("Error - can't forward packet: incoming iface not specified\n");
 403                 return;
 404         }
 405
 406         mesh_iface = forw_packet->if_incoming->mesh_iface;
 407
 408         if (WARN_ON(!forw_packet->if_outgoing))
 409                 return;
 410
 411         if (forw_packet->if_outgoing->mesh_iface != mesh_iface) {
 412                 pr_warn("%s: mesh interface switch for queued OGM\n", __func__);
 413                 return;
 414         }
 415
 416         if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
 417                 return;
 418
 419         /* only for one specific outgoing interface */
 420         batadv_iv_ogm_send_to_if(forw_packet, forw_packet->if_outgoing);
 421 }
 422
 423 /**
 424  * batadv_iv_ogm_can_aggregate() - find out if an OGM can be aggregated on an
 425  *  existing forward packet
 426  * @new_bat_ogm_packet: OGM packet to be aggregated
 427  * @bat_priv: the bat priv with all the mesh interface information
 428  * @packet_len: (total) length of the OGM
 429  * @send_time: timestamp (jiffies) when the packet is to be sent
 430  * @directlink: true if this is a direct link packet
 431  * @if_incoming: interface where the packet was received
 432  * @if_outgoing: interface for which the retransmission should be considered
 433  * @forw_packet: the forwarded packet which should be checked
 434  *
 435  * Return: true if new_packet can be aggregated with forw_packet
 436  */
 437 static bool
 438 batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet,
 439                             struct batadv_priv *bat_priv,
 440                             int packet_len, unsigned long send_time,
 441                             bool directlink,
 442                             const struct batadv_hard_iface *if_incoming,
 443                             const struct batadv_hard_iface *if_outgoing,
 444                             const struct batadv_forw_packet *forw_packet)
 445 {
 446         struct batadv_ogm_packet *batadv_ogm_packet;
 447         unsigned int aggregated_bytes = forw_packet->packet_len + packet_len;
 448         struct batadv_hard_iface *primary_if = NULL;
 449         u8 packet_num = forw_packet->num_packets;
 450         bool res = false;
 451         unsigned long aggregation_end_time;
 452         unsigned int max_bytes;
 453
 454         batadv_ogm_packet = (struct batadv_ogm_packet *)forw_packet->skb->data;
 455         aggregation_end_time = send_time;
 456         aggregation_end_time += msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 457
 458         max_bytes = min_t(unsigned int, if_outgoing->net_dev->mtu,
 459                           BATADV_MAX_AGGREGATION_BYTES);
 460
 461         /* we can aggregate the current packet to this aggregated packet
 462          * if:
 463          *
 464          * - the send time is within our MAX_AGGREGATION_MS time
 465          * - the resulting packet won't be bigger than
 466          *   MAX_AGGREGATION_BYTES and MTU of the outgoing interface
 467          * - the number of packets is lower than MAX_AGGREGATION_PACKETS
 468          * otherwise aggregation is not possible
 469          */
 470         if (!time_before(send_time, forw_packet->send_time) ||
 471             !time_after_eq(aggregation_end_time, forw_packet->send_time))
 472                 return false;
 473
 474         if (aggregated_bytes > max_bytes)
 475                 return false;
 476
 477         if (packet_num >= BATADV_MAX_AGGREGATION_PACKETS)
 478                 return false;
 479
 480         /* packet is not leaving on the same interface. */
 481         if (forw_packet->if_outgoing != if_outgoing)
 482                 return false;
 483
 484         /* check aggregation compatibility
 485          * -> direct link packets are broadcasted on
 486          *    their interface only
 487          * -> aggregate packet if the current packet is
 488          *    a "global" packet as well as the base
 489          *    packet
 490          */
 491         primary_if = batadv_primary_if_get_selected(bat_priv);
 492         if (!primary_if)
 493                 return false;
 494
 495         /* packets without direct link flag and high TTL
 496          * are flooded through the net
 497          */
 498         if (!directlink &&
 499             !(batadv_ogm_packet->flags & BATADV_DIRECTLINK) &&
 500             batadv_ogm_packet->ttl != 1 &&
 501
 502             /* own packets originating non-primary
 503              * interfaces leave only that interface
 504              */
 505             (!forw_packet->own ||
 506              forw_packet->if_incoming == primary_if)) {
 507                 res = true;
 508                 goto out;
 509         }
 510
 511         /* if the incoming packet is sent via this one
 512          * interface only - we still can aggregate
 513          */
 514         if (directlink &&
 515             new_bat_ogm_packet->ttl == 1 &&
 516             forw_packet->if_incoming == if_incoming &&
 517
 518             /* packets from direct neighbors or
 519              * own secondary interface packets
 520              * (= secondary interface packets in general)
 521              */
 522             (batadv_ogm_packet->flags & BATADV_DIRECTLINK ||
 523              (forw_packet->own &&
 524               forw_packet->if_incoming != primary_if))) {
 525                 res = true;
 526                 goto out;
 527         }
 528
 529 out:
 530         batadv_hardif_put(primary_if);
 531         return res;
 532 }
 533
 534 /**
 535  * batadv_iv_ogm_aggregate_new() - create a new aggregated packet and add this
 536  *  packet to it.
 537  * @packet_buff: pointer to the OGM
 538  * @packet_len: (total) length of the OGM
 539  * @send_time: timestamp (jiffies) when the packet is to be sent
 540  * @direct_link: whether this OGM has direct link status
 541  * @if_incoming: interface where the packet was received
 542  * @if_outgoing: interface for which the retransmission should be considered
 543  * @own_packet: true if it is a self-generated ogm
 544  */
 545 static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 546                                         int packet_len, unsigned long send_time,
 547                                         bool direct_link,
 548                                         struct batadv_hard_iface *if_incoming,
 549                                         struct batadv_hard_iface *if_outgoing,
 550                                         int own_packet)
 551 {
 552         struct batadv_priv *bat_priv = netdev_priv(if_incoming->mesh_iface);
 553         struct batadv_forw_packet *forw_packet_aggr;
 554         struct sk_buff *skb;
 555         unsigned char *skb_buff;
 556         unsigned int skb_size;
 557         atomic_t *queue_left = own_packet ? NULL : &bat_priv->batman_queue_left;
 558
 559         if (atomic_read(&bat_priv->aggregated_ogms))
 560                 skb_size = max_t(unsigned int, BATADV_MAX_AGGREGATION_BYTES,
 561                                  packet_len);
 562         else
 563                 skb_size = packet_len;
 564
 565         skb_size += ETH_HLEN;
 566
 567         skb = netdev_alloc_skb_ip_align(NULL, skb_size);
 568         if (!skb)
 569                 return;
 570
 571         forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, if_outgoing,
 572                                                     queue_left, bat_priv, skb);
 573         if (!forw_packet_aggr) {
 574                 kfree_skb(skb);
 575                 return;
 576         }
 577
 578         forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
 579         skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 580
 581         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 582         forw_packet_aggr->packet_len = packet_len;
 583         memcpy(skb_buff, packet_buff, packet_len);
 584
 585         forw_packet_aggr->own = own_packet;
 586         bitmap_zero(forw_packet_aggr->direct_link_flags,
 587                     BATADV_MAX_AGGREGATION_PACKETS);
 588         forw_packet_aggr->send_time = send_time;
 589
 590         /* save packet direct link flag status */
 591         if (direct_link)
 592                 set_bit(0, forw_packet_aggr->direct_link_flags);
 593
 594         INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work,
 595                           batadv_iv_send_outstanding_bat_ogm_packet);
 596
 597         batadv_forw_packet_ogmv1_queue(bat_priv, forw_packet_aggr, send_time);
 598 }
 599
 600 /* aggregate a new packet into the existing ogm packet */
 601 static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr,
 602                                     const unsigned char *packet_buff,
 603                                     int packet_len, bool direct_link)
 604 {
 605         skb_put_data(forw_packet_aggr->skb, packet_buff, packet_len);
 606         forw_packet_aggr->packet_len += packet_len;
 607
 608         /* save packet direct link flag status */
 609         if (direct_link)
 610                 set_bit(forw_packet_aggr->num_packets,
 611                         forw_packet_aggr->direct_link_flags);
 612
 613         forw_packet_aggr->num_packets++;
 614 }
 615
 616 /**
 617  * batadv_iv_ogm_queue_add() - queue up an OGM for transmission
 618  * @bat_priv: the bat priv with all the mesh interface information
 619  * @packet_buff: pointer to the OGM
 620  * @packet_len: (total) length of the OGM
 621  * @if_incoming: interface where the packet was received
 622  * @if_outgoing: interface for which the retransmission should be considered
 623  * @own_packet: true if it is a self-generated ogm
 624  * @send_time: timestamp (jiffies) when the packet is to be sent
 625  */
 626 static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv,
 627                                     unsigned char *packet_buff,
 628                                     int packet_len,
 629                                     struct batadv_hard_iface *if_incoming,
 630                                     struct batadv_hard_iface *if_outgoing,
 631                                     int own_packet, unsigned long send_time)
 632 {
 633         /* _aggr -> pointer to the packet we want to aggregate with
 634          * _pos -> pointer to the position in the queue
 635          */
 636         struct batadv_forw_packet *forw_packet_aggr = NULL;
 637         struct batadv_forw_packet *forw_packet_pos = NULL;
 638         struct batadv_ogm_packet *batadv_ogm_packet;
 639         bool direct_link;
 640         unsigned long max_aggregation_jiffies;
 641
 642         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
 643         direct_link = !!(batadv_ogm_packet->flags & BATADV_DIRECTLINK);
 644         max_aggregation_jiffies = msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 645
 646         /* find position for the packet in the forward queue */
 647         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 648         /* own packets are not to be aggregated */
 649         if (atomic_read(&bat_priv->aggregated_ogms) && !own_packet) {
 650                 hlist_for_each_entry(forw_packet_pos,
 651                                      &bat_priv->forw_bat_list, list) {
 652                         if (batadv_iv_ogm_can_aggregate(batadv_ogm_packet,
 653                                                         bat_priv, packet_len,
 654                                                         send_time, direct_link,
 655                                                         if_incoming,
 656                                                         if_outgoing,
 657                                                         forw_packet_pos)) {
 658                                 forw_packet_aggr = forw_packet_pos;
 659                                 break;
 660                         }
 661                 }
 662         }
 663
 664         /* nothing to aggregate with - either aggregation disabled or no
 665          * suitable aggregation packet found
 666          */
 667         if (!forw_packet_aggr) {
 668                 /* the following section can run without the lock */
 669                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 670
 671                 /* if we could not aggregate this packet with one of the others
 672                  * we hold it back for a while, so that it might be aggregated
 673                  * later on
 674                  */
 675                 if (!own_packet && atomic_read(&bat_priv->aggregated_ogms))
 676                         send_time += max_aggregation_jiffies;
 677
 678                 batadv_iv_ogm_aggregate_new(packet_buff, packet_len,
 679                                             send_time, direct_link,
 680                                             if_incoming, if_outgoing,
 681                                             own_packet);
 682         } else {
 683                 batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff,
 684                                         packet_len, direct_link);
 685                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 686         }
 687 }
 688
 689 static void batadv_iv_ogm_forward(struct batadv_orig_node *orig_node,
 690                                   const struct ethhdr *ethhdr,
 691                                   struct batadv_ogm_packet *batadv_ogm_packet,
 692                                   bool is_single_hop_neigh,
 693                                   bool is_from_best_next_hop,
 694                                   struct batadv_hard_iface *if_incoming,
 695                                   struct batadv_hard_iface *if_outgoing)
 696 {
 697         struct batadv_priv *bat_priv = netdev_priv(if_incoming->mesh_iface);
 698         u16 tvlv_len;
 699
 700         if (batadv_ogm_packet->ttl <= 1) {
 701                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 702                 return;
 703         }
 704
 705         if (!is_from_best_next_hop) {
 706                 /* Mark the forwarded packet when it is not coming from our
 707                  * best next hop. We still need to forward the packet for our
 708                  * neighbor link quality detection to work in case the packet
 709                  * originated from a single hop neighbor. Otherwise we can
 710                  * simply drop the ogm.
 711                  */
 712                 if (is_single_hop_neigh)
 713                         batadv_ogm_packet->flags |= BATADV_NOT_BEST_NEXT_HOP;
 714                 else
 715                         return;
 716         }
 717
 718         tvlv_len = ntohs(batadv_ogm_packet->tvlv_len);
 719
 720         batadv_ogm_packet->ttl--;
 721         ether_addr_copy(batadv_ogm_packet->prev_sender, ethhdr->h_source);
 722
 723         /* apply hop penalty */
 724         batadv_ogm_packet->tq = batadv_hop_penalty(batadv_ogm_packet->tq,
 725                                                    bat_priv);
 726
 727         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 728                    "Forwarding packet: tq: %i, ttl: %i\n",
 729                    batadv_ogm_packet->tq, batadv_ogm_packet->ttl);
 730
 731         if (is_single_hop_neigh)
 732                 batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 733         else
 734                 batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 735
 736         batadv_iv_ogm_queue_add(bat_priv, (unsigned char *)batadv_ogm_packet,
 737                                 BATADV_OGM_HLEN + tvlv_len,
 738                                 if_incoming, if_outgoing, 0,
 739                                 batadv_iv_ogm_fwd_send_time());
 740 }
 741
 742 /**
 743  * batadv_iv_ogm_slide_own_bcast_window() - bitshift own OGM broadcast windows
 744  *  for the given interface
 745  * @hard_iface: the interface for which the windows have to be shifted
 746  */
 747 static void
 748 batadv_iv_ogm_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
 749 {
 750         struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface);
 751         struct batadv_hashtable *hash = bat_priv->orig_hash;
 752         struct hlist_head *head;
 753         struct batadv_orig_node *orig_node;
 754         struct batadv_orig_ifinfo *orig_ifinfo;
 755         unsigned long *word;
 756         u32 i;
 757         u8 *w;
 758
 759         for (i = 0; i < hash->size; i++) {
 760                 head = &hash->table[i];
 761
 762                 rcu_read_lock();
 763                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 764                         hlist_for_each_entry_rcu(orig_ifinfo,
 765                                                  &orig_node->ifinfo_list,
 766                                                  list) {
 767                                 if (orig_ifinfo->if_outgoing != hard_iface)
 768                                         continue;
 769
 770                                 spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 771                                 word = orig_ifinfo->bat_iv.bcast_own;
 772                                 batadv_bit_get_packet(bat_priv, word, 1, 0);
 773                                 w = &orig_ifinfo->bat_iv.bcast_own_sum;
 774                                 *w = bitmap_weight(word,
 775                                                    BATADV_TQ_LOCAL_WINDOW_SIZE);
 776                                 spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 777                         }
 778                 }
 779                 rcu_read_unlock();
 780         }
 781 }
 782
 783 /**
 784  * batadv_iv_ogm_schedule_buff() - schedule submission of hardif ogm buffer
 785  * @hard_iface: interface whose ogm buffer should be transmitted
 786  */
 787 static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface)
 788 {
 789         struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface);
 790         unsigned char **ogm_buff = &hard_iface->bat_iv.ogm_buff;
 791         struct batadv_ogm_packet *batadv_ogm_packet;
 792         struct batadv_hard_iface *primary_if, *tmp_hard_iface;
 793         int *ogm_buff_len = &hard_iface->bat_iv.ogm_buff_len;
 794         u32 seqno;
 795         u16 tvlv_len = 0;
 796         unsigned long send_time;
 797
 798         lockdep_assert_held(&hard_iface->bat_iv.ogm_buff_mutex);
 799
 800         /* interface already disabled by batadv_iv_ogm_iface_disable */
 801         if (!*ogm_buff)
 802                 return;
 803
 804         /* the interface gets activated here to avoid race conditions between
 805          * the moment of activating the interface in
 806          * hardif_activate_interface() where the originator mac is set and
 807          * outdated packets (especially uninitialized mac addresses) in the
 808          * packet queue
 809          */
 810         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 811                 hard_iface->if_status = BATADV_IF_ACTIVE;
 812
 813         primary_if = batadv_primary_if_get_selected(bat_priv);
 814
 815         if (hard_iface == primary_if) {
 816                 /* tt changes have to be committed before the tvlv data is
 817                  * appended as it may alter the tt tvlv container
 818                  */
 819                 batadv_tt_local_commit_changes(bat_priv);
 820                 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, ogm_buff,
 821                                                             ogm_buff_len,
 822                                                             BATADV_OGM_HLEN);
 823         }
 824
 825         batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff);
 826         batadv_ogm_packet->tvlv_len = htons(tvlv_len);
 827
 828         /* change sequence number to network order */
 829         seqno = (u32)atomic_read(&hard_iface->bat_iv.ogm_seqno);
 830         batadv_ogm_packet->seqno = htonl(seqno);
 831         atomic_inc(&hard_iface->bat_iv.ogm_seqno);
 832
 833         batadv_iv_ogm_slide_own_bcast_window(hard_iface);
 834
 835         send_time = batadv_iv_ogm_emit_send_time(bat_priv);
 836
 837         if (hard_iface != primary_if) {
 838                 /* OGMs from secondary interfaces are only scheduled on their
 839                  * respective interfaces.
 840                  */
 841                 batadv_iv_ogm_queue_add(bat_priv, *ogm_buff, *ogm_buff_len,
 842                                         hard_iface, hard_iface, 1, send_time);
 843                 goto out;
 844         }
 845
 846         /* OGMs from primary interfaces are scheduled on all
 847          * interfaces.
 848          */
 849         rcu_read_lock();
 850         list_for_each_entry_rcu(tmp_hard_iface, &batadv_hardif_list, list) {
 851                 if (tmp_hard_iface->mesh_iface != hard_iface->mesh_iface)
 852                         continue;
 853
 854                 if (!kref_get_unless_zero(&tmp_hard_iface->refcount))
 855                         continue;
 856
 857                 batadv_iv_ogm_queue_add(bat_priv, *ogm_buff,
 858                                         *ogm_buff_len, hard_iface,
 859                                         tmp_hard_iface, 1, send_time);
 860
 861                 batadv_hardif_put(tmp_hard_iface);
 862         }
 863         rcu_read_unlock();
 864
 865 out:
 866         batadv_hardif_put(primary_if);
 867 }
 868
 869 static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface)
 870 {
 871         if (hard_iface->if_status == BATADV_IF_NOT_IN_USE ||
 872             hard_iface->if_status == BATADV_IF_TO_BE_REMOVED)
 873                 return;
 874
 875         mutex_lock(&hard_iface->bat_iv.ogm_buff_mutex);
 876         batadv_iv_ogm_schedule_buff(hard_iface);
 877         mutex_unlock(&hard_iface->bat_iv.ogm_buff_mutex);
 878 }
 879
 880 /**
 881  * batadv_iv_orig_ifinfo_sum() - Get bcast_own sum for originator over interface
 882  * @orig_node: originator which reproadcasted the OGMs directly
 883  * @if_outgoing: interface which transmitted the original OGM and received the
 884  *  direct rebroadcast
 885  *
 886  * Return: Number of replied (rebroadcasted) OGMs which were transmitted by
 887  *  an originator and directly (without intermediate hop) received by a specific
 888  *  interface
 889  */
 890 static u8 batadv_iv_orig_ifinfo_sum(struct batadv_orig_node *orig_node,
 891                                     struct batadv_hard_iface *if_outgoing)
 892 {
 893         struct batadv_orig_ifinfo *orig_ifinfo;
 894         u8 sum;
 895
 896         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_outgoing);
 897         if (!orig_ifinfo)
 898                 return 0;
 899
 900         spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 901         sum = orig_ifinfo->bat_iv.bcast_own_sum;
 902         spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 903
 904         batadv_orig_ifinfo_put(orig_ifinfo);
 905
 906         return sum;
 907 }
 908
 909 /**
 910  * batadv_iv_ogm_orig_update() - use OGM to update corresponding data in an
 911  *  originator
 912  * @bat_priv: the bat priv with all the mesh interface information
 913  * @orig_node: the orig node who originally emitted the ogm packet
 914  * @orig_ifinfo: ifinfo for the outgoing interface of the orig_node
 915  * @ethhdr: Ethernet header of the OGM
 916  * @batadv_ogm_packet: the ogm packet
 917  * @if_incoming: interface where the packet was received
 918  * @if_outgoing: interface for which the retransmission should be considered
 919  * @dup_status: the duplicate status of this ogm packet.
 920  */
 921 static void
 922 batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
 923                           struct batadv_orig_node *orig_node,
 924                           struct batadv_orig_ifinfo *orig_ifinfo,
 925                           const struct ethhdr *ethhdr,
 926                           const struct batadv_ogm_packet *batadv_ogm_packet,
 927                           struct batadv_hard_iface *if_incoming,
 928                           struct batadv_hard_iface *if_outgoing,
 929                           enum batadv_dup_status dup_status)
 930 {
 931         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 932         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
 933         struct batadv_neigh_node *neigh_node = NULL;
 934         struct batadv_neigh_node *tmp_neigh_node = NULL;
 935         struct batadv_neigh_node *router = NULL;
 936         u8 sum_orig, sum_neigh;
 937         u8 *neigh_addr;
 938         u8 tq_avg;
 939
 940         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 941                    "%s(): Searching and updating originator entry of received packet\n",
 942                    __func__);
 943
 944         rcu_read_lock();
 945         hlist_for_each_entry_rcu(tmp_neigh_node,
 946                                  &orig_node->neigh_list, list) {
 947                 neigh_addr = tmp_neigh_node->addr;
 948                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
 949                     tmp_neigh_node->if_incoming == if_incoming &&
 950                     kref_get_unless_zero(&tmp_neigh_node->refcount)) {
 951                         if (WARN(neigh_node, "too many matching neigh_nodes"))
 952                                 batadv_neigh_node_put(neigh_node);
 953                         neigh_node = tmp_neigh_node;
 954                         continue;
 955                 }
 956
 957                 if (dup_status != BATADV_NO_DUP)
 958                         continue;
 959
 960                 /* only update the entry for this outgoing interface */
 961                 neigh_ifinfo = batadv_neigh_ifinfo_get(tmp_neigh_node,
 962                                                        if_outgoing);
 963                 if (!neigh_ifinfo)
 964                         continue;
 965
 966                 spin_lock_bh(&tmp_neigh_node->ifinfo_lock);
 967                 batadv_ring_buffer_set(neigh_ifinfo->bat_iv.tq_recv,
 968                                        &neigh_ifinfo->bat_iv.tq_index, 0);
 969                 tq_avg = batadv_ring_buffer_avg(neigh_ifinfo->bat_iv.tq_recv);
 970                 neigh_ifinfo->bat_iv.tq_avg = tq_avg;
 971                 spin_unlock_bh(&tmp_neigh_node->ifinfo_lock);
 972
 973                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 974                 neigh_ifinfo = NULL;
 975         }
 976
 977         if (!neigh_node) {
 978                 struct batadv_orig_node *orig_tmp;
 979
 980                 orig_tmp = batadv_iv_ogm_orig_get(bat_priv, ethhdr->h_source);
 981                 if (!orig_tmp)
 982                         goto unlock;
 983
 984                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 985                                                      ethhdr->h_source,
 986                                                      orig_node, orig_tmp);
 987
 988                 batadv_orig_node_put(orig_tmp);
 989                 if (!neigh_node)
 990                         goto unlock;
 991         } else {
 992                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 993                            "Updating existing last-hop neighbor of originator\n");
 994         }
 995
 996         rcu_read_unlock();
 997         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 998         if (!neigh_ifinfo)
 999                 goto out;
1000
1001         neigh_node->last_seen = jiffies;
1002
1003         spin_lock_bh(&neigh_node->ifinfo_lock);
1004         batadv_ring_buffer_set(neigh_ifinfo->bat_iv.tq_recv,
1005                                &neigh_ifinfo->bat_iv.tq_index,
1006                                batadv_ogm_packet->tq);
1007         tq_avg = batadv_ring_buffer_avg(neigh_ifinfo->bat_iv.tq_recv);
1008         neigh_ifinfo->bat_iv.tq_avg = tq_avg;
1009         spin_unlock_bh(&neigh_node->ifinfo_lock);
1010
1011         if (dup_status == BATADV_NO_DUP) {
1012                 orig_ifinfo->last_ttl = batadv_ogm_packet->ttl;
1013                 neigh_ifinfo->last_ttl = batadv_ogm_packet->ttl;
1014         }
1015
1016         /* if this neighbor already is our next hop there is nothing
1017          * to change
1018          */
1019         router = batadv_orig_router_get(orig_node, if_outgoing);
1020         if (router == neigh_node)
1021                 goto out;
1022
1023         if (router) {
1024                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
1025                 if (!router_ifinfo)
1026                         goto out;
1027
1028                 /* if this neighbor does not offer a better TQ we won't
1029                  * consider it
1030                  */
1031                 if (router_ifinfo->bat_iv.tq_avg > neigh_ifinfo->bat_iv.tq_avg)
1032                         goto out;
1033         }
1034
1035         /* if the TQ is the same and the link not more symmetric we
1036          * won't consider it either
1037          */
1038         if (router_ifinfo &&
1039             neigh_ifinfo->bat_iv.tq_avg == router_ifinfo->bat_iv.tq_avg) {
1040                 sum_orig = batadv_iv_orig_ifinfo_sum(router->orig_node,
1041                                                      router->if_incoming);
1042                 sum_neigh = batadv_iv_orig_ifinfo_sum(neigh_node->orig_node,
1043                                                       neigh_node->if_incoming);
1044                 if (sum_orig >= sum_neigh)
1045                         goto out;
1046         }
1047
1048         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
1049         goto out;
1050
1051 unlock:
1052         rcu_read_unlock();
1053 out:
1054         batadv_neigh_node_put(neigh_node);
1055         batadv_neigh_node_put(router);
1056         batadv_neigh_ifinfo_put(neigh_ifinfo);
1057         batadv_neigh_ifinfo_put(router_ifinfo);
1058 }
1059
1060 /**
1061  * batadv_iv_ogm_calc_tq() - calculate tq for current received ogm packet
1062  * @orig_node: the orig node who originally emitted the ogm packet
1063  * @orig_neigh_node: the orig node struct of the neighbor who sent the packet
1064  * @batadv_ogm_packet: the ogm packet
1065  * @if_incoming: interface where the packet was received
1066  * @if_outgoing: interface for which the retransmission should be considered
1067  *
1068  * Return: true if the link can be considered bidirectional, false otherwise
1069  */
1070 static bool batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
1071                                   struct batadv_orig_node *orig_neigh_node,
1072                                   struct batadv_ogm_packet *batadv_ogm_packet,
1073                                   struct batadv_hard_iface *if_incoming,
1074                                   struct batadv_hard_iface *if_outgoing)
1075 {
1076         struct batadv_priv *bat_priv = netdev_priv(if_incoming->mesh_iface);
1077         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node;
1078         struct batadv_neigh_ifinfo *neigh_ifinfo;
1079         u8 total_count;
1080         u8 orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
1081         unsigned int tq_iface_hop_penalty = BATADV_TQ_MAX_VALUE;
1082         unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
1083         unsigned int tq_asym_penalty, inv_asym_penalty;
1084         unsigned int combined_tq;
1085         bool ret = false;
1086
1087         /* find corresponding one hop neighbor */
1088         rcu_read_lock();
1089         hlist_for_each_entry_rcu(tmp_neigh_node,
1090                                  &orig_neigh_node->neigh_list, list) {
1091                 if (!batadv_compare_eth(tmp_neigh_node->addr,
1092                                         orig_neigh_node->orig))
1093                         continue;
1094
1095                 if (tmp_neigh_node->if_incoming != if_incoming)
1096                         continue;
1097
1098                 if (!kref_get_unless_zero(&tmp_neigh_node->refcount))
1099                         continue;
1100
1101                 neigh_node = tmp_neigh_node;
1102                 break;
1103         }
1104         rcu_read_unlock();
1105
1106         if (!neigh_node)
1107                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
1108                                                      orig_neigh_node->orig,
1109                                                      orig_neigh_node,
1110                                                      orig_neigh_node);
1111
1112         if (!neigh_node)
1113                 goto out;
1114
1115         /* if orig_node is direct neighbor update neigh_node last_seen */
1116         if (orig_node == orig_neigh_node)
1117                 neigh_node->last_seen = jiffies;
1118
1119         orig_node->last_seen = jiffies;
1120
1121         /* find packet count of corresponding one hop neighbor */
1122         orig_eq_count = batadv_iv_orig_ifinfo_sum(orig_neigh_node, if_incoming);
1123         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
1124         if (neigh_ifinfo) {
1125                 neigh_rq_count = neigh_ifinfo->bat_iv.real_packet_count;
1126                 batadv_neigh_ifinfo_put(neigh_ifinfo);
1127         } else {
1128                 neigh_rq_count = 0;
1129         }
1130
1131         /* pay attention to not get a value bigger than 100 % */
1132         if (orig_eq_count > neigh_rq_count)
1133                 total_count = neigh_rq_count;
1134         else
1135                 total_count = orig_eq_count;
1136
1137         /* if we have too few packets (too less data) we set tq_own to zero
1138          * if we receive too few packets it is not considered bidirectional
1139          */
1140         if (total_count < BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM ||
1141             neigh_rq_count < BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM)
1142                 tq_own = 0;
1143         else
1144                 /* neigh_node->real_packet_count is never zero as we
1145                  * only purge old information when getting new
1146                  * information
1147                  */
1148                 tq_own = (BATADV_TQ_MAX_VALUE * total_count) /  neigh_rq_count;
1149
1150         /* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
1151          * affect the nearly-symmetric links only a little, but
1152          * punishes asymmetric links more.  This will give a value
1153          * between 0 and TQ_MAX_VALUE
1154          */
1155         neigh_rq_inv = BATADV_TQ_LOCAL_WINDOW_SIZE - neigh_rq_count;
1156         neigh_rq_inv_cube = neigh_rq_inv * neigh_rq_inv * neigh_rq_inv;
1157         neigh_rq_max_cube = BATADV_TQ_LOCAL_WINDOW_SIZE *
1158                             BATADV_TQ_LOCAL_WINDOW_SIZE *
1159                             BATADV_TQ_LOCAL_WINDOW_SIZE;
1160         inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
1161         inv_asym_penalty /= neigh_rq_max_cube;
1162         tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
1163         tq_iface_hop_penalty -= atomic_read(&if_incoming->hop_penalty);
1164
1165         /* penalize if the OGM is forwarded on the same interface. WiFi
1166          * interfaces and other half duplex devices suffer from throughput
1167          * drops as they can't send and receive at the same time.
1168          */
1169         if (if_outgoing && if_incoming == if_outgoing &&
1170             batadv_is_wifi_hardif(if_outgoing))
1171                 tq_iface_hop_penalty = batadv_hop_penalty(tq_iface_hop_penalty,
1172                                                           bat_priv);
1173
1174         combined_tq = batadv_ogm_packet->tq *
1175                       tq_own *
1176                       tq_asym_penalty *
1177                       tq_iface_hop_penalty;
1178         combined_tq /= BATADV_TQ_MAX_VALUE *
1179                        BATADV_TQ_MAX_VALUE *
1180                        BATADV_TQ_MAX_VALUE;
1181         batadv_ogm_packet->tq = combined_tq;
1182
1183         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1184                    "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",
1185                    orig_node->orig, orig_neigh_node->orig, total_count,
1186                    neigh_rq_count, tq_own, tq_asym_penalty,
1187                    tq_iface_hop_penalty, batadv_ogm_packet->tq,
1188                    if_incoming->net_dev->name,
1189                    if_outgoing ? if_outgoing->net_dev->name : "DEFAULT");
1190
1191         /* if link has the minimum required transmission quality
1192          * consider it bidirectional
1193          */
1194         if (batadv_ogm_packet->tq >= BATADV_TQ_TOTAL_BIDRECT_LIMIT)
1195                 ret = true;
1196
1197 out:
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->mesh_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->mesh_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         batadv_neigh_ifinfo_put(router_ifinfo);
1500         batadv_neigh_node_put(router);
1501         batadv_neigh_node_put(router_router);
1502         batadv_neigh_node_put(orig_neigh_router);
1503         batadv_hardif_neigh_put(hardif_neigh);
1504
1505         consume_skb(skb_priv);
1506 }
1507
1508 /**
1509  * batadv_iv_ogm_process_reply() - Check OGM for direct reply and process it
1510  * @ogm_packet: rebroadcast OGM packet to process
1511  * @if_incoming: the interface where this packet was received
1512  * @orig_node: originator which reproadcasted the OGMs
1513  * @if_incoming_seqno: OGM sequence number when rebroadcast was received
1514  */
1515 static void batadv_iv_ogm_process_reply(struct batadv_ogm_packet *ogm_packet,
1516                                         struct batadv_hard_iface *if_incoming,
1517                                         struct batadv_orig_node *orig_node,
1518                                         u32 if_incoming_seqno)
1519 {
1520         struct batadv_orig_ifinfo *orig_ifinfo;
1521         s32 bit_pos;
1522         u8 *weight;
1523
1524         /* neighbor has to indicate direct link and it has to
1525          * come via the corresponding interface
1526          */
1527         if (!(ogm_packet->flags & BATADV_DIRECTLINK))
1528                 return;
1529
1530         if (!batadv_compare_eth(if_incoming->net_dev->dev_addr,
1531                                 ogm_packet->orig))
1532                 return;
1533
1534         orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_incoming);
1535         if (!orig_ifinfo)
1536                 return;
1537
1538         /* save packet seqno for bidirectional check */
1539         spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1540         bit_pos = if_incoming_seqno - 2;
1541         bit_pos -= ntohl(ogm_packet->seqno);
1542         batadv_set_bit(orig_ifinfo->bat_iv.bcast_own, bit_pos);
1543         weight = &orig_ifinfo->bat_iv.bcast_own_sum;
1544         *weight = bitmap_weight(orig_ifinfo->bat_iv.bcast_own,
1545                                 BATADV_TQ_LOCAL_WINDOW_SIZE);
1546         spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
1547
1548         batadv_orig_ifinfo_put(orig_ifinfo);
1549 }
1550
1551 /**
1552  * batadv_iv_ogm_process() - process an incoming batman iv OGM
1553  * @skb: the skb containing the OGM
1554  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
1555  * @if_incoming: the interface where this packet was received
1556  */
1557 static void batadv_iv_ogm_process(const struct sk_buff *skb, int ogm_offset,
1558                                   struct batadv_hard_iface *if_incoming)
1559 {
1560         struct batadv_priv *bat_priv = netdev_priv(if_incoming->mesh_iface);
1561         struct batadv_orig_node *orig_neigh_node, *orig_node;
1562         struct batadv_hard_iface *hard_iface;
1563         struct batadv_ogm_packet *ogm_packet;
1564         u32 if_incoming_seqno;
1565         bool has_directlink_flag;
1566         struct ethhdr *ethhdr;
1567         bool is_my_oldorig = false;
1568         bool is_my_addr = false;
1569         bool is_my_orig = false;
1570
1571         ogm_packet = (struct batadv_ogm_packet *)(skb->data + ogm_offset);
1572         ethhdr = eth_hdr(skb);
1573
1574         /* Silently drop when the batman packet is actually not a
1575          * correct packet.
1576          *
1577          * This might happen if a packet is padded (e.g. Ethernet has a
1578          * minimum frame length of 64 byte) and the aggregation interprets
1579          * it as an additional length.
1580          *
1581          * TODO: A more sane solution would be to have a bit in the
1582          * batadv_ogm_packet to detect whether the packet is the last
1583          * packet in an aggregation.  Here we expect that the padding
1584          * is always zero (or not 0x01)
1585          */
1586         if (ogm_packet->packet_type != BATADV_IV_OGM)
1587                 return;
1588
1589         /* could be changed by schedule_own_packet() */
1590         if_incoming_seqno = atomic_read(&if_incoming->bat_iv.ogm_seqno);
1591
1592         if (ogm_packet->flags & BATADV_DIRECTLINK)
1593                 has_directlink_flag = true;
1594         else
1595                 has_directlink_flag = false;
1596
1597         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1598                    "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",
1599                    ethhdr->h_source, if_incoming->net_dev->name,
1600                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
1601                    ogm_packet->prev_sender, ntohl(ogm_packet->seqno),
1602                    ogm_packet->tq, ogm_packet->ttl,
1603                    ogm_packet->version, has_directlink_flag);
1604
1605         rcu_read_lock();
1606         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1607                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1608                         continue;
1609
1610                 if (hard_iface->mesh_iface != if_incoming->mesh_iface)
1611                         continue;
1612
1613                 if (batadv_compare_eth(ethhdr->h_source,
1614                                        hard_iface->net_dev->dev_addr))
1615                         is_my_addr = true;
1616
1617                 if (batadv_compare_eth(ogm_packet->orig,
1618                                        hard_iface->net_dev->dev_addr))
1619                         is_my_orig = true;
1620
1621                 if (batadv_compare_eth(ogm_packet->prev_sender,
1622                                        hard_iface->net_dev->dev_addr))
1623                         is_my_oldorig = true;
1624         }
1625         rcu_read_unlock();
1626
1627         if (is_my_addr) {
1628                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1629                            "Drop packet: received my own broadcast (sender: %pM)\n",
1630                            ethhdr->h_source);
1631                 return;
1632         }
1633
1634         if (is_my_orig) {
1635                 orig_neigh_node = batadv_iv_ogm_orig_get(bat_priv,
1636                                                          ethhdr->h_source);
1637                 if (!orig_neigh_node)
1638                         return;
1639
1640                 batadv_iv_ogm_process_reply(ogm_packet, if_incoming,
1641                                             orig_neigh_node, if_incoming_seqno);
1642
1643                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1644                            "Drop packet: originator packet from myself (via neighbor)\n");
1645                 batadv_orig_node_put(orig_neigh_node);
1646                 return;
1647         }
1648
1649         if (is_my_oldorig) {
1650                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1651                            "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n",
1652                            ethhdr->h_source);
1653                 return;
1654         }
1655
1656         if (ogm_packet->flags & BATADV_NOT_BEST_NEXT_HOP) {
1657                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1658                            "Drop packet: ignoring all packets not forwarded from the best next hop (sender: %pM)\n",
1659                            ethhdr->h_source);
1660                 return;
1661         }
1662
1663         orig_node = batadv_iv_ogm_orig_get(bat_priv, ogm_packet->orig);
1664         if (!orig_node)
1665                 return;
1666
1667         batadv_iv_ogm_process_per_outif(skb, ogm_offset, orig_node,
1668                                         if_incoming, BATADV_IF_DEFAULT);
1669
1670         rcu_read_lock();
1671         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1672                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1673                         continue;
1674
1675                 if (hard_iface->mesh_iface != bat_priv->mesh_iface)
1676                         continue;
1677
1678                 if (!kref_get_unless_zero(&hard_iface->refcount))
1679                         continue;
1680
1681                 batadv_iv_ogm_process_per_outif(skb, ogm_offset, orig_node,
1682                                                 if_incoming, hard_iface);
1683
1684                 batadv_hardif_put(hard_iface);
1685         }
1686         rcu_read_unlock();
1687
1688         batadv_orig_node_put(orig_node);
1689 }
1690
1691 static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work)
1692 {
1693         struct delayed_work *delayed_work;
1694         struct batadv_forw_packet *forw_packet;
1695         struct batadv_priv *bat_priv;
1696         bool dropped = false;
1697
1698         delayed_work = to_delayed_work(work);
1699         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
1700                                    delayed_work);
1701         bat_priv = netdev_priv(forw_packet->if_incoming->mesh_iface);
1702
1703         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
1704                 dropped = true;
1705                 goto out;
1706         }
1707
1708         batadv_iv_ogm_emit(forw_packet);
1709
1710         /* we have to have at least one packet in the queue to determine the
1711          * queues wake up time unless we are shutting down.
1712          *
1713          * only re-schedule if this is the "original" copy, e.g. the OGM of the
1714          * primary interface should only be rescheduled once per period, but
1715          * this function will be called for the forw_packet instances of the
1716          * other secondary interfaces as well.
1717          */
1718         if (forw_packet->own &&
1719             forw_packet->if_incoming == forw_packet->if_outgoing)
1720                 batadv_iv_ogm_schedule(forw_packet->if_incoming);
1721
1722 out:
1723         /* do we get something for free()? */
1724         if (batadv_forw_packet_steal(forw_packet,
1725                                      &bat_priv->forw_bat_list_lock))
1726                 batadv_forw_packet_free(forw_packet, dropped);
1727 }
1728
1729 static int batadv_iv_ogm_receive(struct sk_buff *skb,
1730                                  struct batadv_hard_iface *if_incoming)
1731 {
1732         struct batadv_priv *bat_priv = netdev_priv(if_incoming->mesh_iface);
1733         struct batadv_ogm_packet *ogm_packet;
1734         u8 *packet_pos;
1735         int ogm_offset;
1736         bool res;
1737         int ret = NET_RX_DROP;
1738
1739         res = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN);
1740         if (!res)
1741                 goto free_skb;
1742
1743         /* did we receive a B.A.T.M.A.N. IV OGM packet on an interface
1744          * that does not have B.A.T.M.A.N. IV enabled ?
1745          */
1746         if (bat_priv->algo_ops->iface.enable != batadv_iv_ogm_iface_enable)
1747                 goto free_skb;
1748
1749         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1750         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1751                            skb->len + ETH_HLEN);
1752
1753         ogm_offset = 0;
1754         ogm_packet = (struct batadv_ogm_packet *)skb->data;
1755
1756         /* unpack the aggregated packets and process them one by one */
1757         while (batadv_iv_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1758                                          ogm_packet)) {
1759                 batadv_iv_ogm_process(skb, ogm_offset, if_incoming);
1760
1761                 ogm_offset += BATADV_OGM_HLEN;
1762                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1763
1764                 packet_pos = skb->data + ogm_offset;
1765                 ogm_packet = (struct batadv_ogm_packet *)packet_pos;
1766         }
1767
1768         ret = NET_RX_SUCCESS;
1769
1770 free_skb:
1771         if (ret == NET_RX_SUCCESS)
1772                 consume_skb(skb);
1773         else
1774                 kfree_skb(skb);
1775
1776         return ret;
1777 }
1778
1779 /**
1780  * batadv_iv_ogm_neigh_get_tq_avg() - Get the TQ average for a neighbour on a
1781  *  given outgoing interface.
1782  * @neigh_node: Neighbour of interest
1783  * @if_outgoing: Outgoing interface of interest
1784  * @tq_avg: Pointer of where to store the TQ average
1785  *
1786  * Return: False if no average TQ available, otherwise true.
1787  */
1788 static bool
1789 batadv_iv_ogm_neigh_get_tq_avg(struct batadv_neigh_node *neigh_node,
1790                                struct batadv_hard_iface *if_outgoing,
1791                                u8 *tq_avg)
1792 {
1793         struct batadv_neigh_ifinfo *n_ifinfo;
1794
1795         n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
1796         if (!n_ifinfo)
1797                 return false;
1798
1799         *tq_avg = n_ifinfo->bat_iv.tq_avg;
1800         batadv_neigh_ifinfo_put(n_ifinfo);
1801
1802         return true;
1803 }
1804
1805 /**
1806  * batadv_iv_ogm_orig_dump_subentry() - Dump an originator subentry into a
1807  *  message
1808  * @msg: Netlink message to dump into
1809  * @portid: Port making netlink request
1810  * @seq: Sequence number of netlink message
1811  * @bat_priv: The bat priv with all the mesh interface information
1812  * @if_outgoing: Limit dump to entries with this outgoing interface
1813  * @orig_node: Originator to dump
1814  * @neigh_node: Single hops neighbour
1815  * @best: Is the best originator
1816  *
1817  * Return: Error code, or 0 on success
1818  */
1819 static int
1820 batadv_iv_ogm_orig_dump_subentry(struct sk_buff *msg, u32 portid, u32 seq,
1821                                  struct batadv_priv *bat_priv,
1822                                  struct batadv_hard_iface *if_outgoing,
1823                                  struct batadv_orig_node *orig_node,
1824                                  struct batadv_neigh_node *neigh_node,
1825                                  bool best)
1826 {
1827         void *hdr;
1828         u8 tq_avg;
1829         unsigned int last_seen_msecs;
1830
1831         last_seen_msecs = jiffies_to_msecs(jiffies - orig_node->last_seen);
1832
1833         if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node, if_outgoing, &tq_avg))
1834                 return 0;
1835
1836         if (if_outgoing != BATADV_IF_DEFAULT &&
1837             if_outgoing != neigh_node->if_incoming)
1838                 return 0;
1839
1840         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
1841                           NLM_F_MULTI, BATADV_CMD_GET_ORIGINATORS);
1842         if (!hdr)
1843                 return -ENOBUFS;
1844
1845         if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
1846                     orig_node->orig) ||
1847             nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
1848                     neigh_node->addr) ||
1849             nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
1850                            neigh_node->if_incoming->net_dev->name) ||
1851             nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
1852                         neigh_node->if_incoming->net_dev->ifindex) ||
1853             nla_put_u8(msg, BATADV_ATTR_TQ, tq_avg) ||
1854             nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
1855                         last_seen_msecs))
1856                 goto nla_put_failure;
1857
1858         if (best && nla_put_flag(msg, BATADV_ATTR_FLAG_BEST))
1859                 goto nla_put_failure;
1860
1861         genlmsg_end(msg, hdr);
1862         return 0;
1863
1864  nla_put_failure:
1865         genlmsg_cancel(msg, hdr);
1866         return -EMSGSIZE;
1867 }
1868
1869 /**
1870  * batadv_iv_ogm_orig_dump_entry() - Dump an originator entry into a message
1871  * @msg: Netlink message to dump into
1872  * @portid: Port making netlink request
1873  * @seq: Sequence number of netlink message
1874  * @bat_priv: The bat priv with all the mesh interface information
1875  * @if_outgoing: Limit dump to entries with this outgoing interface
1876  * @orig_node: Originator to dump
1877  * @sub_s: Number of sub entries to skip
1878  *
1879  * This function assumes the caller holds rcu_read_lock().
1880  *
1881  * Return: Error code, or 0 on success
1882  */
1883 static int
1884 batadv_iv_ogm_orig_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
1885                               struct batadv_priv *bat_priv,
1886                               struct batadv_hard_iface *if_outgoing,
1887                               struct batadv_orig_node *orig_node, int *sub_s)
1888 {
1889         struct batadv_neigh_node *neigh_node_best;
1890         struct batadv_neigh_node *neigh_node;
1891         int sub = 0;
1892         bool best;
1893         u8 tq_avg_best;
1894
1895         neigh_node_best = batadv_orig_router_get(orig_node, if_outgoing);
1896         if (!neigh_node_best)
1897                 goto out;
1898
1899         if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node_best, if_outgoing,
1900                                             &tq_avg_best))
1901                 goto out;
1902
1903         if (tq_avg_best == 0)
1904                 goto out;
1905
1906         hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
1907                 if (sub++ < *sub_s)
1908                         continue;
1909
1910                 best = (neigh_node == neigh_node_best);
1911
1912                 if (batadv_iv_ogm_orig_dump_subentry(msg, portid, seq,
1913                                                      bat_priv, if_outgoing,
1914                                                      orig_node, neigh_node,
1915                                                      best)) {
1916                         batadv_neigh_node_put(neigh_node_best);
1917
1918                         *sub_s = sub - 1;
1919                         return -EMSGSIZE;
1920                 }
1921         }
1922
1923  out:
1924         batadv_neigh_node_put(neigh_node_best);
1925
1926         *sub_s = 0;
1927         return 0;
1928 }
1929
1930 /**
1931  * batadv_iv_ogm_orig_dump_bucket() - Dump an originator bucket into a
1932  *  message
1933  * @msg: Netlink message to dump into
1934  * @portid: Port making netlink request
1935  * @seq: Sequence number of netlink message
1936  * @bat_priv: The bat priv with all the mesh interface information
1937  * @if_outgoing: Limit dump to entries with this outgoing interface
1938  * @head: Bucket to be dumped
1939  * @idx_s: Number of entries to be skipped
1940  * @sub: Number of sub entries to be skipped
1941  *
1942  * Return: Error code, or 0 on success
1943  */
1944 static int
1945 batadv_iv_ogm_orig_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
1946                                struct batadv_priv *bat_priv,
1947                                struct batadv_hard_iface *if_outgoing,
1948                                struct hlist_head *head, int *idx_s, int *sub)
1949 {
1950         struct batadv_orig_node *orig_node;
1951         int idx = 0;
1952
1953         rcu_read_lock();
1954         hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
1955                 if (idx++ < *idx_s)
1956                         continue;
1957
1958                 if (batadv_iv_ogm_orig_dump_entry(msg, portid, seq, bat_priv,
1959                                                   if_outgoing, orig_node,
1960                                                   sub)) {
1961                         rcu_read_unlock();
1962                         *idx_s = idx - 1;
1963                         return -EMSGSIZE;
1964                 }
1965         }
1966         rcu_read_unlock();
1967
1968         *idx_s = 0;
1969         *sub = 0;
1970         return 0;
1971 }
1972
1973 /**
1974  * batadv_iv_ogm_orig_dump() - Dump the originators into a message
1975  * @msg: Netlink message to dump into
1976  * @cb: Control block containing additional options
1977  * @bat_priv: The bat priv with all the mesh interface information
1978  * @if_outgoing: Limit dump to entries with this outgoing interface
1979  */
1980 static void
1981 batadv_iv_ogm_orig_dump(struct sk_buff *msg, struct netlink_callback *cb,
1982                         struct batadv_priv *bat_priv,
1983                         struct batadv_hard_iface *if_outgoing)
1984 {
1985         struct batadv_hashtable *hash = bat_priv->orig_hash;
1986         struct hlist_head *head;
1987         int bucket = cb->args[0];
1988         int idx = cb->args[1];
1989         int sub = cb->args[2];
1990         int portid = NETLINK_CB(cb->skb).portid;
1991
1992         while (bucket < hash->size) {
1993                 head = &hash->table[bucket];
1994
1995                 if (batadv_iv_ogm_orig_dump_bucket(msg, portid,
1996                                                    cb->nlh->nlmsg_seq,
1997                                                    bat_priv, if_outgoing, head,
1998                                                    &idx, &sub))
1999                         break;
2000
2001                 bucket++;
2002         }
2003
2004         cb->args[0] = bucket;
2005         cb->args[1] = idx;
2006         cb->args[2] = sub;
2007 }
2008
2009 /**
2010  * batadv_iv_ogm_neigh_diff() - calculate tq difference of two neighbors
2011  * @neigh1: the first neighbor object of the comparison
2012  * @if_outgoing1: outgoing interface for the first neighbor
2013  * @neigh2: the second neighbor object of the comparison
2014  * @if_outgoing2: outgoing interface for the second neighbor
2015  * @diff: pointer to integer receiving the calculated difference
2016  *
2017  * The content of *@diff is only valid when this function returns true.
2018  * It is less, equal to or greater than 0 if the metric via neigh1 is lower,
2019  * the same as or higher than the metric via neigh2
2020  *
2021  * Return: true when the difference could be calculated, false otherwise
2022  */
2023 static bool batadv_iv_ogm_neigh_diff(struct batadv_neigh_node *neigh1,
2024                                      struct batadv_hard_iface *if_outgoing1,
2025                                      struct batadv_neigh_node *neigh2,
2026                                      struct batadv_hard_iface *if_outgoing2,
2027                                      int *diff)
2028 {
2029         struct batadv_neigh_ifinfo *neigh1_ifinfo, *neigh2_ifinfo;
2030         u8 tq1, tq2;
2031         bool ret = true;
2032
2033         neigh1_ifinfo = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
2034         neigh2_ifinfo = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
2035
2036         if (!neigh1_ifinfo || !neigh2_ifinfo) {
2037                 ret = false;
2038                 goto out;
2039         }
2040
2041         tq1 = neigh1_ifinfo->bat_iv.tq_avg;
2042         tq2 = neigh2_ifinfo->bat_iv.tq_avg;
2043         *diff = (int)tq1 - (int)tq2;
2044
2045 out:
2046         batadv_neigh_ifinfo_put(neigh1_ifinfo);
2047         batadv_neigh_ifinfo_put(neigh2_ifinfo);
2048
2049         return ret;
2050 }
2051
2052 /**
2053  * batadv_iv_ogm_neigh_dump_neigh() - Dump a neighbour into a netlink message
2054  * @msg: Netlink message to dump into
2055  * @portid: Port making netlink request
2056  * @seq: Sequence number of netlink message
2057  * @hardif_neigh: Neighbour to be dumped
2058  *
2059  * Return: Error code, or 0 on success
2060  */
2061 static int
2062 batadv_iv_ogm_neigh_dump_neigh(struct sk_buff *msg, u32 portid, u32 seq,
2063                                struct batadv_hardif_neigh_node *hardif_neigh)
2064 {
2065         void *hdr;
2066         unsigned int last_seen_msecs;
2067
2068         last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen);
2069
2070         hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
2071                           NLM_F_MULTI, BATADV_CMD_GET_NEIGHBORS);
2072         if (!hdr)
2073                 return -ENOBUFS;
2074
2075         if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
2076                     hardif_neigh->addr) ||
2077             nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
2078                            hardif_neigh->if_incoming->net_dev->name) ||
2079             nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
2080                         hardif_neigh->if_incoming->net_dev->ifindex) ||
2081             nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
2082                         last_seen_msecs))
2083                 goto nla_put_failure;
2084
2085         genlmsg_end(msg, hdr);
2086         return 0;
2087
2088  nla_put_failure:
2089         genlmsg_cancel(msg, hdr);
2090         return -EMSGSIZE;
2091 }
2092
2093 /**
2094  * batadv_iv_ogm_neigh_dump_hardif() - Dump the neighbours of a hard interface
2095  *  into a message
2096  * @msg: Netlink message to dump into
2097  * @portid: Port making netlink request
2098  * @seq: Sequence number of netlink message
2099  * @bat_priv: The bat priv with all the mesh interface information
2100  * @hard_iface: Hard interface to dump the neighbours for
2101  * @idx_s: Number of entries to skip
2102  *
2103  * This function assumes the caller holds rcu_read_lock().
2104  *
2105  * Return: Error code, or 0 on success
2106  */
2107 static int
2108 batadv_iv_ogm_neigh_dump_hardif(struct sk_buff *msg, u32 portid, u32 seq,
2109                                 struct batadv_priv *bat_priv,
2110                                 struct batadv_hard_iface *hard_iface,
2111                                 int *idx_s)
2112 {
2113         struct batadv_hardif_neigh_node *hardif_neigh;
2114         int idx = 0;
2115
2116         hlist_for_each_entry_rcu(hardif_neigh,
2117                                  &hard_iface->neigh_list, list) {
2118                 if (idx++ < *idx_s)
2119                         continue;
2120
2121                 if (batadv_iv_ogm_neigh_dump_neigh(msg, portid, seq,
2122                                                    hardif_neigh)) {
2123                         *idx_s = idx - 1;
2124                         return -EMSGSIZE;
2125                 }
2126         }
2127
2128         *idx_s = 0;
2129         return 0;
2130 }
2131
2132 /**
2133  * batadv_iv_ogm_neigh_dump() - Dump the neighbours into a message
2134  * @msg: Netlink message to dump into
2135  * @cb: Control block containing additional options
2136  * @bat_priv: The bat priv with all the mesh interface information
2137  * @single_hardif: Limit dump to this hard interface
2138  */
2139 static void
2140 batadv_iv_ogm_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb,
2141                          struct batadv_priv *bat_priv,
2142                          struct batadv_hard_iface *single_hardif)
2143 {
2144         struct batadv_hard_iface *hard_iface;
2145         int i_hardif = 0;
2146         int i_hardif_s = cb->args[0];
2147         int idx = cb->args[1];
2148         int portid = NETLINK_CB(cb->skb).portid;
2149
2150         rcu_read_lock();
2151         if (single_hardif) {
2152                 if (i_hardif_s == 0) {
2153                         if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
2154                                                             cb->nlh->nlmsg_seq,
2155                                                             bat_priv,
2156                                                             single_hardif,
2157                                                             &idx) == 0)
2158                                 i_hardif++;
2159                 }
2160         } else {
2161                 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list,
2162                                         list) {
2163                         if (hard_iface->mesh_iface != bat_priv->mesh_iface)
2164                                 continue;
2165
2166                         if (i_hardif++ < i_hardif_s)
2167                                 continue;
2168
2169                         if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
2170                                                             cb->nlh->nlmsg_seq,
2171                                                             bat_priv,
2172                                                             hard_iface, &idx)) {
2173                                 i_hardif--;
2174                                 break;
2175                         }
2176                 }
2177         }
2178         rcu_read_unlock();
2179
2180         cb->args[0] = i_hardif;
2181         cb->args[1] = idx;
2182 }
2183
2184 /**
2185  * batadv_iv_ogm_neigh_cmp() - compare the metrics of two neighbors
2186  * @neigh1: the first neighbor object of the comparison
2187  * @if_outgoing1: outgoing interface for the first neighbor
2188  * @neigh2: the second neighbor object of the comparison
2189  * @if_outgoing2: outgoing interface for the second neighbor
2190  *
2191  * Return: a value less, equal to or greater than 0 if the metric via neigh1 is
2192  * lower, the same as or higher than the metric via neigh2
2193  */
2194 static int batadv_iv_ogm_neigh_cmp(struct batadv_neigh_node *neigh1,
2195                                    struct batadv_hard_iface *if_outgoing1,
2196                                    struct batadv_neigh_node *neigh2,
2197                                    struct batadv_hard_iface *if_outgoing2)
2198 {
2199         bool ret;
2200         int diff;
2201
2202         ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
2203                                        if_outgoing2, &diff);
2204         if (!ret)
2205                 return 0;
2206
2207         return diff;
2208 }
2209
2210 /**
2211  * batadv_iv_ogm_neigh_is_sob() - check if neigh1 is similarly good or better
2212  *  than neigh2 from the metric prospective
2213  * @neigh1: the first neighbor object of the comparison
2214  * @if_outgoing1: outgoing interface for the first neighbor
2215  * @neigh2: the second neighbor object of the comparison
2216  * @if_outgoing2: outgoing interface for the second neighbor
2217  *
2218  * Return: true if the metric via neigh1 is equally good or better than
2219  * the metric via neigh2, false otherwise.
2220  */
2221 static bool
2222 batadv_iv_ogm_neigh_is_sob(struct batadv_neigh_node *neigh1,
2223                            struct batadv_hard_iface *if_outgoing1,
2224                            struct batadv_neigh_node *neigh2,
2225                            struct batadv_hard_iface *if_outgoing2)
2226 {
2227         bool ret;
2228         int diff;
2229
2230         ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
2231                                        if_outgoing2, &diff);
2232         if (!ret)
2233                 return false;
2234
2235         ret = diff > -BATADV_TQ_SIMILARITY_THRESHOLD;
2236         return ret;
2237 }
2238
2239 static void batadv_iv_iface_enabled(struct batadv_hard_iface *hard_iface)
2240 {
2241         /* begin scheduling originator messages on that interface */
2242         batadv_iv_ogm_schedule(hard_iface);
2243 }
2244
2245 /**
2246  * batadv_iv_init_sel_class() - initialize GW selection class
2247  * @bat_priv: the bat priv with all the mesh interface information
2248  */
2249 static void batadv_iv_init_sel_class(struct batadv_priv *bat_priv)
2250 {
2251         /* set default TQ difference threshold to 20 */
2252         atomic_set(&bat_priv->gw.sel_class, 20);
2253 }
2254
2255 static struct batadv_gw_node *
2256 batadv_iv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
2257 {
2258         struct batadv_neigh_node *router;
2259         struct batadv_neigh_ifinfo *router_ifinfo;
2260         struct batadv_gw_node *gw_node, *curr_gw = NULL;
2261         u64 max_gw_factor = 0;
2262         u64 tmp_gw_factor = 0;
2263         u8 max_tq = 0;
2264         u8 tq_avg;
2265         struct batadv_orig_node *orig_node;
2266
2267         rcu_read_lock();
2268         hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
2269                 orig_node = gw_node->orig_node;
2270                 router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
2271                 if (!router)
2272                         continue;
2273
2274                 router_ifinfo = batadv_neigh_ifinfo_get(router,
2275                                                         BATADV_IF_DEFAULT);
2276                 if (!router_ifinfo)
2277                         goto next;
2278
2279                 if (!kref_get_unless_zero(&gw_node->refcount))
2280                         goto next;
2281
2282                 tq_avg = router_ifinfo->bat_iv.tq_avg;
2283
2284                 switch (atomic_read(&bat_priv->gw.sel_class)) {
2285                 case 1: /* fast connection */
2286                         tmp_gw_factor = tq_avg * tq_avg;
2287                         tmp_gw_factor *= gw_node->bandwidth_down;
2288                         tmp_gw_factor *= 100 * 100;
2289                         tmp_gw_factor >>= 18;
2290
2291                         if (tmp_gw_factor > max_gw_factor ||
2292                             (tmp_gw_factor == max_gw_factor &&
2293                              tq_avg > max_tq)) {
2294                                 batadv_gw_node_put(curr_gw);
2295                                 curr_gw = gw_node;
2296                                 kref_get(&curr_gw->refcount);
2297                         }
2298                         break;
2299
2300                 default: /* 2:  stable connection (use best statistic)
2301                           * 3:  fast-switch (use best statistic but change as
2302                           *     soon as a better gateway appears)
2303                           * XX: late-switch (use best statistic but change as
2304                           *     soon as a better gateway appears which has
2305                           *     $routing_class more tq points)
2306                           */
2307                         if (tq_avg > max_tq) {
2308                                 batadv_gw_node_put(curr_gw);
2309                                 curr_gw = gw_node;
2310                                 kref_get(&curr_gw->refcount);
2311                         }
2312                         break;
2313                 }
2314
2315                 if (tq_avg > max_tq)
2316                         max_tq = tq_avg;
2317
2318                 if (tmp_gw_factor > max_gw_factor)
2319                         max_gw_factor = tmp_gw_factor;
2320
2321                 batadv_gw_node_put(gw_node);
2322
2323 next:
2324                 batadv_neigh_node_put(router);
2325                 batadv_neigh_ifinfo_put(router_ifinfo);
2326         }
2327         rcu_read_unlock();
2328
2329         return curr_gw;
2330 }
2331
2332 static bool batadv_iv_gw_is_eligible(struct batadv_priv *bat_priv,
2333                                      struct batadv_orig_node *curr_gw_orig,
2334                                      struct batadv_orig_node *orig_node)
2335 {
2336         struct batadv_neigh_ifinfo *router_orig_ifinfo = NULL;
2337         struct batadv_neigh_ifinfo *router_gw_ifinfo = NULL;
2338         struct batadv_neigh_node *router_gw = NULL;
2339         struct batadv_neigh_node *router_orig = NULL;
2340         u8 gw_tq_avg, orig_tq_avg;
2341         bool ret = false;
2342
2343         /* dynamic re-election is performed only on fast or late switch */
2344         if (atomic_read(&bat_priv->gw.sel_class) <= 2)
2345                 return false;
2346
2347         router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
2348         if (!router_gw) {
2349                 ret = true;
2350                 goto out;
2351         }
2352
2353         router_gw_ifinfo = batadv_neigh_ifinfo_get(router_gw,
2354                                                    BATADV_IF_DEFAULT);
2355         if (!router_gw_ifinfo) {
2356                 ret = true;
2357                 goto out;
2358         }
2359
2360         router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
2361         if (!router_orig)
2362                 goto out;
2363
2364         router_orig_ifinfo = batadv_neigh_ifinfo_get(router_orig,
2365                                                      BATADV_IF_DEFAULT);
2366         if (!router_orig_ifinfo)
2367                 goto out;
2368
2369         gw_tq_avg = router_gw_ifinfo->bat_iv.tq_avg;
2370         orig_tq_avg = router_orig_ifinfo->bat_iv.tq_avg;
2371
2372         /* the TQ value has to be better */
2373         if (orig_tq_avg < gw_tq_avg)
2374                 goto out;
2375
2376         /* if the routing class is greater than 3 the value tells us how much
2377          * greater the TQ value of the new gateway must be
2378          */
2379         if ((atomic_read(&bat_priv->gw.sel_class) > 3) &&
2380             (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw.sel_class)))
2381                 goto out;
2382
2383         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
2384                    "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
2385                    gw_tq_avg, orig_tq_avg);
2386
2387         ret = true;
2388 out:
2389         batadv_neigh_ifinfo_put(router_gw_ifinfo);
2390         batadv_neigh_ifinfo_put(router_orig_ifinfo);
2391         batadv_neigh_node_put(router_gw);
2392         batadv_neigh_node_put(router_orig);
2393
2394         return ret;
2395 }
2396
2397 /**
2398  * batadv_iv_gw_dump_entry() - Dump a gateway into a message
2399  * @msg: Netlink message to dump into
2400  * @portid: Port making netlink request
2401  * @cb: Control block containing additional options
2402  * @bat_priv: The bat priv with all the mesh interface information
2403  * @gw_node: Gateway to be dumped
2404  *
2405  * Return: Error code, or 0 on success
2406  */
2407 static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid,
2408                                    struct netlink_callback *cb,
2409                                    struct batadv_priv *bat_priv,
2410                                    struct batadv_gw_node *gw_node)
2411 {
2412         struct batadv_neigh_ifinfo *router_ifinfo = NULL;
2413         struct batadv_neigh_node *router;
2414         struct batadv_gw_node *curr_gw = NULL;
2415         int ret = 0;
2416         void *hdr;
2417
2418         router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
2419         if (!router)
2420                 goto out;
2421
2422         router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
2423         if (!router_ifinfo)
2424                 goto out;
2425
2426         curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
2427
2428         hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
2429                           &batadv_netlink_family, NLM_F_MULTI,
2430                           BATADV_CMD_GET_GATEWAYS);
2431         if (!hdr) {
2432                 ret = -ENOBUFS;
2433                 goto out;
2434         }
2435
2436         genl_dump_check_consistent(cb, hdr);
2437
2438         ret = -EMSGSIZE;
2439
2440         if (curr_gw == gw_node)
2441                 if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) {
2442                         genlmsg_cancel(msg, hdr);
2443                         goto out;
2444                 }
2445
2446         if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
2447                     gw_node->orig_node->orig) ||
2448             nla_put_u8(msg, BATADV_ATTR_TQ, router_ifinfo->bat_iv.tq_avg) ||
2449             nla_put(msg, BATADV_ATTR_ROUTER, ETH_ALEN,
2450                     router->addr) ||
2451             nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
2452                            router->if_incoming->net_dev->name) ||
2453             nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
2454                         router->if_incoming->net_dev->ifindex) ||
2455             nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
2456                         gw_node->bandwidth_down) ||
2457             nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP,
2458                         gw_node->bandwidth_up)) {
2459                 genlmsg_cancel(msg, hdr);
2460                 goto out;
2461         }
2462
2463         genlmsg_end(msg, hdr);
2464         ret = 0;
2465
2466 out:
2467         batadv_gw_node_put(curr_gw);
2468         batadv_neigh_ifinfo_put(router_ifinfo);
2469         batadv_neigh_node_put(router);
2470         return ret;
2471 }
2472
2473 /**
2474  * batadv_iv_gw_dump() - Dump gateways into a message
2475  * @msg: Netlink message to dump into
2476  * @cb: Control block containing additional options
2477  * @bat_priv: The bat priv with all the mesh interface information
2478  */
2479 static void batadv_iv_gw_dump(struct sk_buff *msg, struct netlink_callback *cb,
2480                               struct batadv_priv *bat_priv)
2481 {
2482         int portid = NETLINK_CB(cb->skb).portid;
2483         struct batadv_gw_node *gw_node;
2484         int idx_skip = cb->args[0];
2485         int idx = 0;
2486
2487         spin_lock_bh(&bat_priv->gw.list_lock);
2488         cb->seq = bat_priv->gw.generation << 1 | 1;
2489
2490         hlist_for_each_entry(gw_node, &bat_priv->gw.gateway_list, list) {
2491                 if (idx++ < idx_skip)
2492                         continue;
2493
2494                 if (batadv_iv_gw_dump_entry(msg, portid, cb, bat_priv,
2495                                             gw_node)) {
2496                         idx_skip = idx - 1;
2497                         goto unlock;
2498                 }
2499         }
2500
2501         idx_skip = idx;
2502 unlock:
2503         spin_unlock_bh(&bat_priv->gw.list_lock);
2504
2505         cb->args[0] = idx_skip;
2506 }
2507
2508 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
2509         .name = "BATMAN_IV",
2510         .iface = {
2511                 .enable = batadv_iv_ogm_iface_enable,
2512                 .enabled = batadv_iv_iface_enabled,
2513                 .disable = batadv_iv_ogm_iface_disable,
2514                 .update_mac = batadv_iv_ogm_iface_update_mac,
2515                 .primary_set = batadv_iv_ogm_primary_iface_set,
2516         },
2517         .neigh = {
2518                 .cmp = batadv_iv_ogm_neigh_cmp,
2519                 .is_similar_or_better = batadv_iv_ogm_neigh_is_sob,
2520                 .dump = batadv_iv_ogm_neigh_dump,
2521         },
2522         .orig = {
2523                 .dump = batadv_iv_ogm_orig_dump,
2524         },
2525         .gw = {
2526                 .init_sel_class = batadv_iv_init_sel_class,
2527                 .sel_class_max = BATADV_TQ_MAX_VALUE,
2528                 .get_best_gw_node = batadv_iv_gw_get_best_gw_node,
2529                 .is_eligible = batadv_iv_gw_is_eligible,
2530                 .dump = batadv_iv_gw_dump,
2531         },
2532 };
2533
2534 /**
2535  * batadv_iv_init() - B.A.T.M.A.N. IV initialization function
2536  *
2537  * Return: 0 on success or negative error number in case of failure
2538  */
2539 int __init batadv_iv_init(void)
2540 {
2541         int ret;
2542
2543         /* batman originator packet */
2544         ret = batadv_recv_handler_register(BATADV_IV_OGM,
2545                                            batadv_iv_ogm_receive);
2546         if (ret < 0)
2547                 goto out;
2548
2549         ret = batadv_algo_register(&batadv_batman_iv);
2550         if (ret < 0)
2551                 goto handler_unregister;
2552
2553         goto out;
2554
2555 handler_unregister:
2556         batadv_recv_handler_unregister(BATADV_IV_OGM);
2557 out:
2558         return ret;
2559 }