net/batman-adv/bat_iv_ogm.c

   1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "translation-table.h"
  22 #include "originator.h"
  23 #include "routing.h"
  24 #include "gateway_common.h"
  25 #include "gateway_client.h"
  26 #include "hard-interface.h"
  27 #include "send.h"
  28 #include "bat_algo.h"
  29 #include "network-coding.h"
  30
  31 /**
  32  * batadv_ring_buffer_set - update the ring buffer with the given value
  33  * @lq_recv: pointer to the ring buffer
  34  * @lq_index: index to store the value at
  35  * @value: value to store in the ring buffer
  36  */
  37 static void batadv_ring_buffer_set(uint8_t lq_recv[], uint8_t *lq_index,
  38                                    uint8_t value)
  39 {
  40         lq_recv[*lq_index] = value;
  41         *lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
  42 }
  43
  44 /**
  45  * batadv_ring_buffer_set - compute the average of all non-zero values stored
  46  * in the given ring buffer
  47  * @lq_recv: pointer to the ring buffer
  48  *
  49  * Returns computed average value.
  50  */
  51 static uint8_t batadv_ring_buffer_avg(const uint8_t lq_recv[])
  52 {
  53         const uint8_t *ptr;
  54         uint16_t count = 0, i = 0, sum = 0;
  55
  56         ptr = lq_recv;
  57
  58         while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
  59                 if (*ptr != 0) {
  60                         count++;
  61                         sum += *ptr;
  62                 }
  63
  64                 i++;
  65                 ptr++;
  66         }
  67
  68         if (count == 0)
  69                 return 0;
  70
  71         return (uint8_t)(sum / count);
  72 }
  73
  74 /*
  75  * batadv_dup_status - duplicate status
  76  * @BATADV_NO_DUP: the packet is a duplicate
  77  * @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for the
  78  *  neighbor)
  79  * @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor
  80  * @BATADV_PROTECTED: originator is currently protected (after reboot)
  81  */
  82 enum batadv_dup_status {
  83         BATADV_NO_DUP = 0,
  84         BATADV_ORIG_DUP,
  85         BATADV_NEIGH_DUP,
  86         BATADV_PROTECTED,
  87 };
  88
  89 static struct batadv_neigh_node *
  90 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
  91                         const uint8_t *neigh_addr,
  92                         struct batadv_orig_node *orig_node,
  93                         struct batadv_orig_node *orig_neigh)
  94 {
  95         struct batadv_neigh_node *neigh_node;
  96
  97         neigh_node = batadv_neigh_node_new(hard_iface, neigh_addr);
  98         if (!neigh_node)
  99                 goto out;
 100
 101         INIT_LIST_HEAD(&neigh_node->bonding_list);
 102
 103         neigh_node->orig_node = orig_neigh;
 104         neigh_node->if_incoming = hard_iface;
 105
 106         spin_lock_bh(&orig_node->neigh_list_lock);
 107         hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
 108         spin_unlock_bh(&orig_node->neigh_list_lock);
 109
 110 out:
 111         return neigh_node;
 112 }
 113
 114 static int batadv_iv_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 115 {
 116         struct batadv_ogm_packet *batadv_ogm_packet;
 117         unsigned char *ogm_buff;
 118         uint32_t random_seqno;
 119         int res = -ENOMEM;
 120
 121         /* randomize initial seqno to avoid collision */
 122         get_random_bytes(&random_seqno, sizeof(random_seqno));
 123         atomic_set(&hard_iface->bat_iv.ogm_seqno, random_seqno);
 124
 125         hard_iface->bat_iv.ogm_buff_len = BATADV_OGM_HLEN;
 126         ogm_buff = kmalloc(hard_iface->bat_iv.ogm_buff_len, GFP_ATOMIC);
 127         if (!ogm_buff)
 128                 goto out;
 129
 130         hard_iface->bat_iv.ogm_buff = ogm_buff;
 131
 132         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 133         batadv_ogm_packet->header.packet_type = BATADV_IV_OGM;
 134         batadv_ogm_packet->header.version = BATADV_COMPAT_VERSION;
 135         batadv_ogm_packet->header.ttl = 2;
 136         batadv_ogm_packet->flags = BATADV_NO_FLAGS;
 137         batadv_ogm_packet->tq = BATADV_TQ_MAX_VALUE;
 138         batadv_ogm_packet->tt_num_changes = 0;
 139         batadv_ogm_packet->ttvn = 0;
 140
 141         res = 0;
 142
 143 out:
 144         return res;
 145 }
 146
 147 static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 148 {
 149         kfree(hard_iface->bat_iv.ogm_buff);
 150         hard_iface->bat_iv.ogm_buff = NULL;
 151 }
 152
 153 static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface)
 154 {
 155         struct batadv_ogm_packet *batadv_ogm_packet;
 156         unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
 157
 158         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 159         memcpy(batadv_ogm_packet->orig,
 160                hard_iface->net_dev->dev_addr, ETH_ALEN);
 161         memcpy(batadv_ogm_packet->prev_sender,
 162                hard_iface->net_dev->dev_addr, ETH_ALEN);
 163 }
 164
 165 static void
 166 batadv_iv_ogm_primary_iface_set(struct batadv_hard_iface *hard_iface)
 167 {
 168         struct batadv_ogm_packet *batadv_ogm_packet;
 169         unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
 170
 171         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 172         batadv_ogm_packet->flags = BATADV_PRIMARIES_FIRST_HOP;
 173         batadv_ogm_packet->header.ttl = BATADV_TTL;
 174 }
 175
 176 /* when do we schedule our own ogm to be sent */
 177 static unsigned long
 178 batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 179 {
 180         unsigned int msecs;
 181
 182         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 183         msecs += prandom_u32() % (2 * BATADV_JITTER);
 184
 185         return jiffies + msecs_to_jiffies(msecs);
 186 }
 187
 188 /* when do we schedule a ogm packet to be sent */
 189 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 190 {
 191         return jiffies + msecs_to_jiffies(prandom_u32() % (BATADV_JITTER / 2));
 192 }
 193
 194 /* apply hop penalty for a normal link */
 195 static uint8_t batadv_hop_penalty(uint8_t tq,
 196                                   const struct batadv_priv *bat_priv)
 197 {
 198         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 199         int new_tq;
 200
 201         new_tq = tq * (BATADV_TQ_MAX_VALUE - hop_penalty);
 202         new_tq /= BATADV_TQ_MAX_VALUE;
 203
 204         return new_tq;
 205 }
 206
 207 /* is there another aggregated packet here? */
 208 static int batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
 209                                      int tt_num_changes)
 210 {
 211         int next_buff_pos = 0;
 212
 213         next_buff_pos += buff_pos + BATADV_OGM_HLEN;
 214         next_buff_pos += batadv_tt_len(tt_num_changes);
 215
 216         return (next_buff_pos <= packet_len) &&
 217                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 218 }
 219
 220 /* send a batman ogm to a given interface */
 221 static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
 222                                      struct batadv_hard_iface *hard_iface)
 223 {
 224         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 225         char *fwd_str;
 226         uint8_t packet_num;
 227         int16_t buff_pos;
 228         struct batadv_ogm_packet *batadv_ogm_packet;
 229         struct sk_buff *skb;
 230         uint8_t *packet_pos;
 231
 232         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 233                 return;
 234
 235         packet_num = 0;
 236         buff_pos = 0;
 237         packet_pos = forw_packet->skb->data;
 238         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 239
 240         /* adjust all flags and log packets */
 241         while (batadv_iv_ogm_aggr_packet(buff_pos, forw_packet->packet_len,
 242                                          batadv_ogm_packet->tt_num_changes)) {
 243                 /* we might have aggregated direct link packets with an
 244                  * ordinary base packet
 245                  */
 246                 if (forw_packet->direct_link_flags & BIT(packet_num) &&
 247                     forw_packet->if_incoming == hard_iface)
 248                         batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 249                 else
 250                         batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 251
 252                 if (packet_num > 0 || !forw_packet->own)
 253                         fwd_str = "Forwarding";
 254                 else
 255                         fwd_str = "Sending own";
 256
 257                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 258                            "%s %spacket (originator %pM, seqno %u, TQ %d, TTL %d, IDF %s, ttvn %d) on interface %s [%pM]\n",
 259                            fwd_str, (packet_num > 0 ? "aggregated " : ""),
 260                            batadv_ogm_packet->orig,
 261                            ntohl(batadv_ogm_packet->seqno),
 262                            batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl,
 263                            (batadv_ogm_packet->flags & BATADV_DIRECTLINK ?
 264                             "on" : "off"),
 265                            batadv_ogm_packet->ttvn, hard_iface->net_dev->name,
 266                            hard_iface->net_dev->dev_addr);
 267
 268                 buff_pos += BATADV_OGM_HLEN;
 269                 buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
 270                 packet_num++;
 271                 packet_pos = forw_packet->skb->data + buff_pos;
 272                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 273         }
 274
 275         /* create clone because function is called more than once */
 276         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 277         if (skb) {
 278                 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 279                 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 280                                    skb->len + ETH_HLEN);
 281                 batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
 282         }
 283 }
 284
 285 /* send a batman ogm packet */
 286 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 287 {
 288         struct batadv_hard_iface *hard_iface;
 289         struct net_device *soft_iface;
 290         struct batadv_priv *bat_priv;
 291         struct batadv_hard_iface *primary_if = NULL;
 292         struct batadv_ogm_packet *batadv_ogm_packet;
 293         unsigned char directlink;
 294         uint8_t *packet_pos;
 295
 296         packet_pos = forw_packet->skb->data;
 297         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 298         directlink = (batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0);
 299
 300         if (!forw_packet->if_incoming) {
 301                 pr_err("Error - can't forward packet: incoming iface not specified\n");
 302                 goto out;
 303         }
 304
 305         soft_iface = forw_packet->if_incoming->soft_iface;
 306         bat_priv = netdev_priv(soft_iface);
 307
 308         if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
 309                 goto out;
 310
 311         primary_if = batadv_primary_if_get_selected(bat_priv);
 312         if (!primary_if)
 313                 goto out;
 314
 315         /* multihomed peer assumed
 316          * non-primary OGMs are only broadcasted on their interface
 317          */
 318         if ((directlink && (batadv_ogm_packet->header.ttl == 1)) ||
 319             (forw_packet->own && (forw_packet->if_incoming != primary_if))) {
 320                 /* FIXME: what about aggregated packets ? */
 321                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 322                            "%s packet (originator %pM, seqno %u, TTL %d) on interface %s [%pM]\n",
 323                            (forw_packet->own ? "Sending own" : "Forwarding"),
 324                            batadv_ogm_packet->orig,
 325                            ntohl(batadv_ogm_packet->seqno),
 326                            batadv_ogm_packet->header.ttl,
 327                            forw_packet->if_incoming->net_dev->name,
 328                            forw_packet->if_incoming->net_dev->dev_addr);
 329
 330                 /* skb is only used once and than forw_packet is free'd */
 331                 batadv_send_skb_packet(forw_packet->skb,
 332                                        forw_packet->if_incoming,
 333                                        batadv_broadcast_addr);
 334                 forw_packet->skb = NULL;
 335
 336                 goto out;
 337         }
 338
 339         /* broadcast on every interface */
 340         rcu_read_lock();
 341         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 342                 if (hard_iface->soft_iface != soft_iface)
 343                         continue;
 344
 345                 batadv_iv_ogm_send_to_if(forw_packet, hard_iface);
 346         }
 347         rcu_read_unlock();
 348
 349 out:
 350         if (primary_if)
 351                 batadv_hardif_free_ref(primary_if);
 352 }
 353
 354 /* return true if new_packet can be aggregated with forw_packet */
 355 static bool
 356 batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet,
 357                             struct batadv_priv *bat_priv,
 358                             int packet_len, unsigned long send_time,
 359                             bool directlink,
 360                             const struct batadv_hard_iface *if_incoming,
 361                             const struct batadv_forw_packet *forw_packet)
 362 {
 363         struct batadv_ogm_packet *batadv_ogm_packet;
 364         int aggregated_bytes = forw_packet->packet_len + packet_len;
 365         struct batadv_hard_iface *primary_if = NULL;
 366         bool res = false;
 367         unsigned long aggregation_end_time;
 368
 369         batadv_ogm_packet = (struct batadv_ogm_packet *)forw_packet->skb->data;
 370         aggregation_end_time = send_time;
 371         aggregation_end_time += msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 372
 373         /* we can aggregate the current packet to this aggregated packet
 374          * if:
 375          *
 376          * - the send time is within our MAX_AGGREGATION_MS time
 377          * - the resulting packet wont be bigger than
 378          *   MAX_AGGREGATION_BYTES
 379          */
 380         if (time_before(send_time, forw_packet->send_time) &&
 381             time_after_eq(aggregation_end_time, forw_packet->send_time) &&
 382             (aggregated_bytes <= BATADV_MAX_AGGREGATION_BYTES)) {
 383                 /* check aggregation compatibility
 384                  * -> direct link packets are broadcasted on
 385                  *    their interface only
 386                  * -> aggregate packet if the current packet is
 387                  *    a "global" packet as well as the base
 388                  *    packet
 389                  */
 390                 primary_if = batadv_primary_if_get_selected(bat_priv);
 391                 if (!primary_if)
 392                         goto out;
 393
 394                 /* packets without direct link flag and high TTL
 395                  * are flooded through the net
 396                  */
 397                 if ((!directlink) &&
 398                     (!(batadv_ogm_packet->flags & BATADV_DIRECTLINK)) &&
 399                     (batadv_ogm_packet->header.ttl != 1) &&
 400
 401                     /* own packets originating non-primary
 402                      * interfaces leave only that interface
 403                      */
 404                     ((!forw_packet->own) ||
 405                      (forw_packet->if_incoming == primary_if))) {
 406                         res = true;
 407                         goto out;
 408                 }
 409
 410                 /* if the incoming packet is sent via this one
 411                  * interface only - we still can aggregate
 412                  */
 413                 if ((directlink) &&
 414                     (new_bat_ogm_packet->header.ttl == 1) &&
 415                     (forw_packet->if_incoming == if_incoming) &&
 416
 417                     /* packets from direct neighbors or
 418                      * own secondary interface packets
 419                      * (= secondary interface packets in general)
 420                      */
 421                     (batadv_ogm_packet->flags & BATADV_DIRECTLINK ||
 422                      (forw_packet->own &&
 423                       forw_packet->if_incoming != primary_if))) {
 424                         res = true;
 425                         goto out;
 426                 }
 427         }
 428
 429 out:
 430         if (primary_if)
 431                 batadv_hardif_free_ref(primary_if);
 432         return res;
 433 }
 434
 435 /* create a new aggregated packet and add this packet to it */
 436 static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 437                                         int packet_len, unsigned long send_time,
 438                                         bool direct_link,
 439                                         struct batadv_hard_iface *if_incoming,
 440                                         int own_packet)
 441 {
 442         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 443         struct batadv_forw_packet *forw_packet_aggr;
 444         unsigned char *skb_buff;
 445         unsigned int skb_size;
 446
 447         if (!atomic_inc_not_zero(&if_incoming->refcount))
 448                 return;
 449
 450         /* own packet should always be scheduled */
 451         if (!own_packet) {
 452                 if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
 453                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 454                                    "batman packet queue full\n");
 455                         goto out;
 456                 }
 457         }
 458
 459         forw_packet_aggr = kmalloc(sizeof(*forw_packet_aggr), GFP_ATOMIC);
 460         if (!forw_packet_aggr) {
 461                 if (!own_packet)
 462                         atomic_inc(&bat_priv->batman_queue_left);
 463                 goto out;
 464         }
 465
 466         if ((atomic_read(&bat_priv->aggregated_ogms)) &&
 467             (packet_len < BATADV_MAX_AGGREGATION_BYTES))
 468                 skb_size = BATADV_MAX_AGGREGATION_BYTES;
 469         else
 470                 skb_size = packet_len;
 471
 472         skb_size += ETH_HLEN;
 473
 474         forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size);
 475         if (!forw_packet_aggr->skb) {
 476                 if (!own_packet)
 477                         atomic_inc(&bat_priv->batman_queue_left);
 478                 kfree(forw_packet_aggr);
 479                 goto out;
 480         }
 481         skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 482
 483         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 484         forw_packet_aggr->packet_len = packet_len;
 485         memcpy(skb_buff, packet_buff, packet_len);
 486
 487         forw_packet_aggr->own = own_packet;
 488         forw_packet_aggr->if_incoming = if_incoming;
 489         forw_packet_aggr->num_packets = 0;
 490         forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;
 491         forw_packet_aggr->send_time = send_time;
 492
 493         /* save packet direct link flag status */
 494         if (direct_link)
 495                 forw_packet_aggr->direct_link_flags |= 1;
 496
 497         /* add new packet to packet list */
 498         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 499         hlist_add_head(&forw_packet_aggr->list, &bat_priv->forw_bat_list);
 500         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 501
 502         /* start timer for this packet */
 503         INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work,
 504                           batadv_send_outstanding_bat_ogm_packet);
 505         queue_delayed_work(batadv_event_workqueue,
 506                            &forw_packet_aggr->delayed_work,
 507                            send_time - jiffies);
 508
 509         return;
 510 out:
 511         batadv_hardif_free_ref(if_incoming);
 512 }
 513
 514 /* aggregate a new packet into the existing ogm packet */
 515 static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr,
 516                                     const unsigned char *packet_buff,
 517                                     int packet_len, bool direct_link)
 518 {
 519         unsigned char *skb_buff;
 520         unsigned long new_direct_link_flag;
 521
 522         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 523         memcpy(skb_buff, packet_buff, packet_len);
 524         forw_packet_aggr->packet_len += packet_len;
 525         forw_packet_aggr->num_packets++;
 526
 527         /* save packet direct link flag status */
 528         if (direct_link) {
 529                 new_direct_link_flag = BIT(forw_packet_aggr->num_packets);
 530                 forw_packet_aggr->direct_link_flags |= new_direct_link_flag;
 531         }
 532 }
 533
 534 static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv,
 535                                     unsigned char *packet_buff,
 536                                     int packet_len,
 537                                     struct batadv_hard_iface *if_incoming,
 538                                     int own_packet, unsigned long send_time)
 539 {
 540         /* _aggr -> pointer to the packet we want to aggregate with
 541          * _pos -> pointer to the position in the queue
 542          */
 543         struct batadv_forw_packet *forw_packet_aggr = NULL;
 544         struct batadv_forw_packet *forw_packet_pos = NULL;
 545         struct batadv_ogm_packet *batadv_ogm_packet;
 546         bool direct_link;
 547         unsigned long max_aggregation_jiffies;
 548
 549         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
 550         direct_link = batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0;
 551         max_aggregation_jiffies = msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 552
 553         /* find position for the packet in the forward queue */
 554         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 555         /* own packets are not to be aggregated */
 556         if ((atomic_read(&bat_priv->aggregated_ogms)) && (!own_packet)) {
 557                 hlist_for_each_entry(forw_packet_pos,
 558                                      &bat_priv->forw_bat_list, list) {
 559                         if (batadv_iv_ogm_can_aggregate(batadv_ogm_packet,
 560                                                         bat_priv, packet_len,
 561                                                         send_time, direct_link,
 562                                                         if_incoming,
 563                                                         forw_packet_pos)) {
 564                                 forw_packet_aggr = forw_packet_pos;
 565                                 break;
 566                         }
 567                 }
 568         }
 569
 570         /* nothing to aggregate with - either aggregation disabled or no
 571          * suitable aggregation packet found
 572          */
 573         if (!forw_packet_aggr) {
 574                 /* the following section can run without the lock */
 575                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 576
 577                 /* if we could not aggregate this packet with one of the others
 578                  * we hold it back for a while, so that it might be aggregated
 579                  * later on
 580                  */
 581                 if (!own_packet && atomic_read(&bat_priv->aggregated_ogms))
 582                         send_time += max_aggregation_jiffies;
 583
 584                 batadv_iv_ogm_aggregate_new(packet_buff, packet_len,
 585                                             send_time, direct_link,
 586                                             if_incoming, own_packet);
 587         } else {
 588                 batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff,
 589                                         packet_len, direct_link);
 590                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 591         }
 592 }
 593
 594 static void batadv_iv_ogm_forward(struct batadv_orig_node *orig_node,
 595                                   const struct ethhdr *ethhdr,
 596                                   struct batadv_ogm_packet *batadv_ogm_packet,
 597                                   bool is_single_hop_neigh,
 598                                   bool is_from_best_next_hop,
 599                                   struct batadv_hard_iface *if_incoming)
 600 {
 601         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 602         uint8_t tt_num_changes;
 603
 604         if (batadv_ogm_packet->header.ttl <= 1) {
 605                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 606                 return;
 607         }
 608
 609         if (!is_from_best_next_hop) {
 610                 /* Mark the forwarded packet when it is not coming from our
 611                  * best next hop. We still need to forward the packet for our
 612                  * neighbor link quality detection to work in case the packet
 613                  * originated from a single hop neighbor. Otherwise we can
 614                  * simply drop the ogm.
 615                  */
 616                 if (is_single_hop_neigh)
 617                         batadv_ogm_packet->flags |= BATADV_NOT_BEST_NEXT_HOP;
 618                 else
 619                         return;
 620         }
 621
 622         tt_num_changes = batadv_ogm_packet->tt_num_changes;
 623
 624         batadv_ogm_packet->header.ttl--;
 625         memcpy(batadv_ogm_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 626
 627         /* apply hop penalty */
 628         batadv_ogm_packet->tq = batadv_hop_penalty(batadv_ogm_packet->tq,
 629                                                    bat_priv);
 630
 631         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 632                    "Forwarding packet: tq: %i, ttl: %i\n",
 633                    batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl);
 634
 635         /* switch of primaries first hop flag when forwarding */
 636         batadv_ogm_packet->flags &= ~BATADV_PRIMARIES_FIRST_HOP;
 637         if (is_single_hop_neigh)
 638                 batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 639         else
 640                 batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 641
 642         batadv_iv_ogm_queue_add(bat_priv, (unsigned char *)batadv_ogm_packet,
 643                                 BATADV_OGM_HLEN + batadv_tt_len(tt_num_changes),
 644                                 if_incoming, 0, batadv_iv_ogm_fwd_send_time());
 645 }
 646
 647 /**
 648  * batadv_iv_ogm_slide_own_bcast_window - bitshift own OGM broadcast windows for
 649  * the given interface
 650  * @hard_iface: the interface for which the windows have to be shifted
 651  */
 652 static void
 653 batadv_iv_ogm_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
 654 {
 655         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 656         struct batadv_hashtable *hash = bat_priv->orig_hash;
 657         struct hlist_head *head;
 658         struct batadv_orig_node *orig_node;
 659         unsigned long *word;
 660         uint32_t i;
 661         size_t word_index;
 662         uint8_t *w;
 663
 664         for (i = 0; i < hash->size; i++) {
 665                 head = &hash->table[i];
 666
 667                 rcu_read_lock();
 668                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 669                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 670                         word_index = hard_iface->if_num * BATADV_NUM_WORDS;
 671                         word = &(orig_node->bcast_own[word_index]);
 672
 673                         batadv_bit_get_packet(bat_priv, word, 1, 0);
 674                         w = &orig_node->bcast_own_sum[hard_iface->if_num];
 675                         *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
 676                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 677                 }
 678                 rcu_read_unlock();
 679         }
 680 }
 681
 682 static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface)
 683 {
 684         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 685         unsigned char **ogm_buff = &hard_iface->bat_iv.ogm_buff;
 686         struct batadv_ogm_packet *batadv_ogm_packet;
 687         struct batadv_hard_iface *primary_if;
 688         int *ogm_buff_len = &hard_iface->bat_iv.ogm_buff_len;
 689         int vis_server, tt_num_changes = 0;
 690         uint32_t seqno;
 691         uint8_t bandwidth;
 692
 693         vis_server = atomic_read(&bat_priv->vis_mode);
 694         primary_if = batadv_primary_if_get_selected(bat_priv);
 695
 696         if (hard_iface == primary_if)
 697                 tt_num_changes = batadv_tt_append_diff(bat_priv, ogm_buff,
 698                                                        ogm_buff_len,
 699                                                        BATADV_OGM_HLEN);
 700
 701         batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff);
 702
 703         /* change sequence number to network order */
 704         seqno = (uint32_t)atomic_read(&hard_iface->bat_iv.ogm_seqno);
 705         batadv_ogm_packet->seqno = htonl(seqno);
 706         atomic_inc(&hard_iface->bat_iv.ogm_seqno);
 707
 708         batadv_ogm_packet->ttvn = atomic_read(&bat_priv->tt.vn);
 709         batadv_ogm_packet->tt_crc = htons(bat_priv->tt.local_crc);
 710         if (tt_num_changes >= 0)
 711                 batadv_ogm_packet->tt_num_changes = tt_num_changes;
 712
 713         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC)
 714                 batadv_ogm_packet->flags |= BATADV_VIS_SERVER;
 715         else
 716                 batadv_ogm_packet->flags &= ~BATADV_VIS_SERVER;
 717
 718         if (hard_iface == primary_if &&
 719             atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_SERVER) {
 720                 bandwidth = (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
 721                 batadv_ogm_packet->gw_flags = bandwidth;
 722         } else {
 723                 batadv_ogm_packet->gw_flags = BATADV_NO_FLAGS;
 724         }
 725
 726         batadv_iv_ogm_slide_own_bcast_window(hard_iface);
 727         batadv_iv_ogm_queue_add(bat_priv, hard_iface->bat_iv.ogm_buff,
 728                                 hard_iface->bat_iv.ogm_buff_len, hard_iface, 1,
 729                                 batadv_iv_ogm_emit_send_time(bat_priv));
 730
 731         if (primary_if)
 732                 batadv_hardif_free_ref(primary_if);
 733 }
 734
 735 static void
 736 batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
 737                           struct batadv_orig_node *orig_node,
 738                           const struct ethhdr *ethhdr,
 739                           const struct batadv_ogm_packet *batadv_ogm_packet,
 740                           struct batadv_hard_iface *if_incoming,
 741                           const unsigned char *tt_buff,
 742                           enum batadv_dup_status dup_status)
 743 {
 744         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
 745         struct batadv_neigh_node *router = NULL;
 746         struct batadv_orig_node *orig_node_tmp;
 747         int if_num;
 748         uint8_t sum_orig, sum_neigh;
 749         uint8_t *neigh_addr;
 750         uint8_t tq_avg;
 751
 752         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 753                    "update_originator(): Searching and updating originator entry of received packet\n");
 754
 755         rcu_read_lock();
 756         hlist_for_each_entry_rcu(tmp_neigh_node,
 757                                  &orig_node->neigh_list, list) {
 758                 neigh_addr = tmp_neigh_node->addr;
 759                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
 760                     tmp_neigh_node->if_incoming == if_incoming &&
 761                     atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
 762                         if (WARN(neigh_node, "too many matching neigh_nodes"))
 763                                 batadv_neigh_node_free_ref(neigh_node);
 764                         neigh_node = tmp_neigh_node;
 765                         continue;
 766                 }
 767
 768                 if (dup_status != BATADV_NO_DUP)
 769                         continue;
 770
 771                 spin_lock_bh(&tmp_neigh_node->lq_update_lock);
 772                 batadv_ring_buffer_set(tmp_neigh_node->tq_recv,
 773                                        &tmp_neigh_node->tq_index, 0);
 774                 tq_avg = batadv_ring_buffer_avg(tmp_neigh_node->tq_recv);
 775                 tmp_neigh_node->tq_avg = tq_avg;
 776                 spin_unlock_bh(&tmp_neigh_node->lq_update_lock);
 777         }
 778
 779         if (!neigh_node) {
 780                 struct batadv_orig_node *orig_tmp;
 781
 782                 orig_tmp = batadv_get_orig_node(bat_priv, ethhdr->h_source);
 783                 if (!orig_tmp)
 784                         goto unlock;
 785
 786                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 787                                                      ethhdr->h_source,
 788                                                      orig_node, orig_tmp);
 789
 790                 batadv_orig_node_free_ref(orig_tmp);
 791                 if (!neigh_node)
 792                         goto unlock;
 793         } else
 794                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 795                            "Updating existing last-hop neighbor of originator\n");
 796
 797         rcu_read_unlock();
 798
 799         orig_node->flags = batadv_ogm_packet->flags;
 800         neigh_node->last_seen = jiffies;
 801
 802         spin_lock_bh(&neigh_node->lq_update_lock);
 803         batadv_ring_buffer_set(neigh_node->tq_recv,
 804                                &neigh_node->tq_index,
 805                                batadv_ogm_packet->tq);
 806         neigh_node->tq_avg = batadv_ring_buffer_avg(neigh_node->tq_recv);
 807         spin_unlock_bh(&neigh_node->lq_update_lock);
 808
 809         if (dup_status == BATADV_NO_DUP) {
 810                 orig_node->last_ttl = batadv_ogm_packet->header.ttl;
 811                 neigh_node->last_ttl = batadv_ogm_packet->header.ttl;
 812         }
 813
 814         batadv_bonding_candidate_add(orig_node, neigh_node);
 815
 816         /* if this neighbor already is our next hop there is nothing
 817          * to change
 818          */
 819         router = batadv_orig_node_get_router(orig_node);
 820         if (router == neigh_node)
 821                 goto update_tt;
 822
 823         /* if this neighbor does not offer a better TQ we won't consider it */
 824         if (router && (router->tq_avg > neigh_node->tq_avg))
 825                 goto update_tt;
 826
 827         /* if the TQ is the same and the link not more symmetric we
 828          * won't consider it either
 829          */
 830         if (router && (neigh_node->tq_avg == router->tq_avg)) {
 831                 orig_node_tmp = router->orig_node;
 832                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 833                 if_num = router->if_incoming->if_num;
 834                 sum_orig = orig_node_tmp->bcast_own_sum[if_num];
 835                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 836
 837                 orig_node_tmp = neigh_node->orig_node;
 838                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 839                 if_num = neigh_node->if_incoming->if_num;
 840                 sum_neigh = orig_node_tmp->bcast_own_sum[if_num];
 841                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 842
 843                 if (sum_orig >= sum_neigh)
 844                         goto update_tt;
 845         }
 846
 847         batadv_update_route(bat_priv, orig_node, neigh_node);
 848
 849 update_tt:
 850         /* I have to check for transtable changes only if the OGM has been
 851          * sent through a primary interface
 852          */
 853         if (((batadv_ogm_packet->orig != ethhdr->h_source) &&
 854              (batadv_ogm_packet->header.ttl > 2)) ||
 855             (batadv_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
 856                 batadv_tt_update_orig(bat_priv, orig_node, tt_buff,
 857                                       batadv_ogm_packet->tt_num_changes,
 858                                       batadv_ogm_packet->ttvn,
 859                                       ntohs(batadv_ogm_packet->tt_crc));
 860
 861         if (orig_node->gw_flags != batadv_ogm_packet->gw_flags)
 862                 batadv_gw_node_update(bat_priv, orig_node,
 863                                       batadv_ogm_packet->gw_flags);
 864
 865         orig_node->gw_flags = batadv_ogm_packet->gw_flags;
 866
 867         /* restart gateway selection if fast or late switching was enabled */
 868         if ((orig_node->gw_flags) &&
 869             (atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_CLIENT) &&
 870             (atomic_read(&bat_priv->gw_sel_class) > 2))
 871                 batadv_gw_check_election(bat_priv, orig_node);
 872
 873         goto out;
 874
 875 unlock:
 876         rcu_read_unlock();
 877 out:
 878         if (neigh_node)
 879                 batadv_neigh_node_free_ref(neigh_node);
 880         if (router)
 881                 batadv_neigh_node_free_ref(router);
 882 }
 883
 884 static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
 885                                  struct batadv_orig_node *orig_neigh_node,
 886                                  struct batadv_ogm_packet *batadv_ogm_packet,
 887                                  struct batadv_hard_iface *if_incoming)
 888 {
 889         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 890         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node;
 891         uint8_t total_count;
 892         uint8_t orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
 893         unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
 894         int tq_asym_penalty, inv_asym_penalty, ret = 0;
 895         unsigned int combined_tq;
 896
 897         /* find corresponding one hop neighbor */
 898         rcu_read_lock();
 899         hlist_for_each_entry_rcu(tmp_neigh_node,
 900                                  &orig_neigh_node->neigh_list, list) {
 901                 if (!batadv_compare_eth(tmp_neigh_node->addr,
 902                                         orig_neigh_node->orig))
 903                         continue;
 904
 905                 if (tmp_neigh_node->if_incoming != if_incoming)
 906                         continue;
 907
 908                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 909                         continue;
 910
 911                 neigh_node = tmp_neigh_node;
 912                 break;
 913         }
 914         rcu_read_unlock();
 915
 916         if (!neigh_node)
 917                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 918                                                      orig_neigh_node->orig,
 919                                                      orig_neigh_node,
 920                                                      orig_neigh_node);
 921
 922         if (!neigh_node)
 923                 goto out;
 924
 925         /* if orig_node is direct neighbor update neigh_node last_seen */
 926         if (orig_node == orig_neigh_node)
 927                 neigh_node->last_seen = jiffies;
 928
 929         orig_node->last_seen = jiffies;
 930
 931         /* find packet count of corresponding one hop neighbor */
 932         spin_lock_bh(&orig_node->ogm_cnt_lock);
 933         orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
 934         neigh_rq_count = neigh_node->real_packet_count;
 935         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 936
 937         /* pay attention to not get a value bigger than 100 % */
 938         if (orig_eq_count > neigh_rq_count)
 939                 total_count = neigh_rq_count;
 940         else
 941                 total_count = orig_eq_count;
 942
 943         /* if we have too few packets (too less data) we set tq_own to zero
 944          * if we receive too few packets it is not considered bidirectional
 945          */
 946         if (total_count < BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM ||
 947             neigh_rq_count < BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM)
 948                 tq_own = 0;
 949         else
 950                 /* neigh_node->real_packet_count is never zero as we
 951                  * only purge old information when getting new
 952                  * information
 953                  */
 954                 tq_own = (BATADV_TQ_MAX_VALUE * total_count) /  neigh_rq_count;
 955
 956         /* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
 957          * affect the nearly-symmetric links only a little, but
 958          * punishes asymmetric links more.  This will give a value
 959          * between 0 and TQ_MAX_VALUE
 960          */
 961         neigh_rq_inv = BATADV_TQ_LOCAL_WINDOW_SIZE - neigh_rq_count;
 962         neigh_rq_inv_cube = neigh_rq_inv * neigh_rq_inv * neigh_rq_inv;
 963         neigh_rq_max_cube = BATADV_TQ_LOCAL_WINDOW_SIZE *
 964                             BATADV_TQ_LOCAL_WINDOW_SIZE *
 965                             BATADV_TQ_LOCAL_WINDOW_SIZE;
 966         inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
 967         inv_asym_penalty /= neigh_rq_max_cube;
 968         tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
 969
 970         combined_tq = batadv_ogm_packet->tq * tq_own * tq_asym_penalty;
 971         combined_tq /= BATADV_TQ_MAX_VALUE * BATADV_TQ_MAX_VALUE;
 972         batadv_ogm_packet->tq = combined_tq;
 973
 974         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 975                    "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, total tq: %3i\n",
 976                    orig_node->orig, orig_neigh_node->orig, total_count,
 977                    neigh_rq_count, tq_own,
 978                    tq_asym_penalty, batadv_ogm_packet->tq);
 979
 980         /* if link has the minimum required transmission quality
 981          * consider it bidirectional
 982          */
 983         if (batadv_ogm_packet->tq >= BATADV_TQ_TOTAL_BIDRECT_LIMIT)
 984                 ret = 1;
 985
 986 out:
 987         if (neigh_node)
 988                 batadv_neigh_node_free_ref(neigh_node);
 989         return ret;
 990 }
 991
 992 /**
 993  * batadv_iv_ogm_update_seqnos -  process a batman packet for all interfaces,
 994  *  adjust the sequence number and find out whether it is a duplicate
 995  * @ethhdr: ethernet header of the packet
 996  * @batadv_ogm_packet: OGM packet to be considered
 997  * @if_incoming: interface on which the OGM packet was received
 998  *
 999  * Returns duplicate status as enum batadv_dup_status
1000  */
1001 static enum batadv_dup_status
1002 batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
1003                             const struct batadv_ogm_packet *batadv_ogm_packet,
1004                             const struct batadv_hard_iface *if_incoming)
1005 {
1006         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1007         struct batadv_orig_node *orig_node;
1008         struct batadv_neigh_node *tmp_neigh_node;
1009         int is_dup;
1010         int32_t seq_diff;
1011         int need_update = 0;
1012         int set_mark;
1013         enum batadv_dup_status ret = BATADV_NO_DUP;
1014         uint32_t seqno = ntohl(batadv_ogm_packet->seqno);
1015         uint8_t *neigh_addr;
1016         uint8_t packet_count;
1017
1018         orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1019         if (!orig_node)
1020                 return BATADV_NO_DUP;
1021
1022         spin_lock_bh(&orig_node->ogm_cnt_lock);
1023         seq_diff = seqno - orig_node->last_real_seqno;
1024
1025         /* signalize caller that the packet is to be dropped. */
1026         if (!hlist_empty(&orig_node->neigh_list) &&
1027             batadv_window_protected(bat_priv, seq_diff,
1028                                     &orig_node->batman_seqno_reset)) {
1029                 ret = BATADV_PROTECTED;
1030                 goto out;
1031         }
1032
1033         rcu_read_lock();
1034         hlist_for_each_entry_rcu(tmp_neigh_node,
1035                                  &orig_node->neigh_list, list) {
1036                 neigh_addr = tmp_neigh_node->addr;
1037                 is_dup = batadv_test_bit(tmp_neigh_node->real_bits,
1038                                          orig_node->last_real_seqno,
1039                                          seqno);
1040
1041                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
1042                     tmp_neigh_node->if_incoming == if_incoming) {
1043                         set_mark = 1;
1044                         if (is_dup)
1045                                 ret = BATADV_NEIGH_DUP;
1046                 } else {
1047                         set_mark = 0;
1048                         if (is_dup && (ret != BATADV_NEIGH_DUP))
1049                                 ret = BATADV_ORIG_DUP;
1050                 }
1051
1052                 /* if the window moved, set the update flag. */
1053                 need_update |= batadv_bit_get_packet(bat_priv,
1054                                                      tmp_neigh_node->real_bits,
1055                                                      seq_diff, set_mark);
1056
1057                 packet_count = bitmap_weight(tmp_neigh_node->real_bits,
1058                                              BATADV_TQ_LOCAL_WINDOW_SIZE);
1059                 tmp_neigh_node->real_packet_count = packet_count;
1060         }
1061         rcu_read_unlock();
1062
1063         if (need_update) {
1064                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1065                            "updating last_seqno: old %u, new %u\n",
1066                            orig_node->last_real_seqno, seqno);
1067                 orig_node->last_real_seqno = seqno;
1068         }
1069
1070 out:
1071         spin_unlock_bh(&orig_node->ogm_cnt_lock);
1072         batadv_orig_node_free_ref(orig_node);
1073         return ret;
1074 }
1075
1076 static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
1077                                   struct batadv_ogm_packet *batadv_ogm_packet,
1078                                   const unsigned char *tt_buff,
1079                                   struct batadv_hard_iface *if_incoming)
1080 {
1081         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1082         struct batadv_hard_iface *hard_iface;
1083         struct batadv_orig_node *orig_neigh_node, *orig_node;
1084         struct batadv_neigh_node *router = NULL, *router_router = NULL;
1085         struct batadv_neigh_node *orig_neigh_router = NULL;
1086         int has_directlink_flag;
1087         int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
1088         int is_bidirect;
1089         bool is_single_hop_neigh = false;
1090         bool is_from_best_next_hop = false;
1091         int sameseq, similar_ttl;
1092         enum batadv_dup_status dup_status;
1093         uint32_t if_incoming_seqno;
1094         uint8_t *prev_sender;
1095
1096         /* Silently drop when the batman packet is actually not a
1097          * correct packet.
1098          *
1099          * This might happen if a packet is padded (e.g. Ethernet has a
1100          * minimum frame length of 64 byte) and the aggregation interprets
1101          * it as an additional length.
1102          *
1103          * TODO: A more sane solution would be to have a bit in the
1104          * batadv_ogm_packet to detect whether the packet is the last
1105          * packet in an aggregation.  Here we expect that the padding
1106          * is always zero (or not 0x01)
1107          */
1108         if (batadv_ogm_packet->header.packet_type != BATADV_IV_OGM)
1109                 return;
1110
1111         /* could be changed by schedule_own_packet() */
1112         if_incoming_seqno = atomic_read(&if_incoming->bat_iv.ogm_seqno);
1113
1114         if (batadv_ogm_packet->flags & BATADV_DIRECTLINK)
1115                 has_directlink_flag = 1;
1116         else
1117                 has_directlink_flag = 0;
1118
1119         if (batadv_compare_eth(ethhdr->h_source, batadv_ogm_packet->orig))
1120                 is_single_hop_neigh = true;
1121
1122         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1123                    "Received BATMAN packet via NB: %pM, IF: %s [%pM] (from OG: %pM, via prev OG: %pM, seqno %u, ttvn %u, crc %#.4x, changes %u, tq %d, TTL %d, V %d, IDF %d)\n",
1124                    ethhdr->h_source, if_incoming->net_dev->name,
1125                    if_incoming->net_dev->dev_addr, batadv_ogm_packet->orig,
1126                    batadv_ogm_packet->prev_sender,
1127                    ntohl(batadv_ogm_packet->seqno), batadv_ogm_packet->ttvn,
1128                    ntohs(batadv_ogm_packet->tt_crc),
1129                    batadv_ogm_packet->tt_num_changes, batadv_ogm_packet->tq,
1130                    batadv_ogm_packet->header.ttl,
1131                    batadv_ogm_packet->header.version, has_directlink_flag);
1132
1133         rcu_read_lock();
1134         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1135                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1136                         continue;
1137
1138                 if (hard_iface->soft_iface != if_incoming->soft_iface)
1139                         continue;
1140
1141                 if (batadv_compare_eth(ethhdr->h_source,
1142                                        hard_iface->net_dev->dev_addr))
1143                         is_my_addr = 1;
1144
1145                 if (batadv_compare_eth(batadv_ogm_packet->orig,
1146                                        hard_iface->net_dev->dev_addr))
1147                         is_my_orig = 1;
1148
1149                 if (batadv_compare_eth(batadv_ogm_packet->prev_sender,
1150                                        hard_iface->net_dev->dev_addr))
1151                         is_my_oldorig = 1;
1152         }
1153         rcu_read_unlock();
1154
1155         if (is_my_addr) {
1156                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1157                            "Drop packet: received my own broadcast (sender: %pM)\n",
1158                            ethhdr->h_source);
1159                 return;
1160         }
1161
1162         if (is_my_orig) {
1163                 unsigned long *word;
1164                 int offset;
1165                 int32_t bit_pos;
1166                 int16_t if_num;
1167                 uint8_t *weight;
1168
1169                 orig_neigh_node = batadv_get_orig_node(bat_priv,
1170                                                        ethhdr->h_source);
1171                 if (!orig_neigh_node)
1172                         return;
1173
1174                 /* neighbor has to indicate direct link and it has to
1175                  * come via the corresponding interface
1176                  * save packet seqno for bidirectional check
1177                  */
1178                 if (has_directlink_flag &&
1179                     batadv_compare_eth(if_incoming->net_dev->dev_addr,
1180                                        batadv_ogm_packet->orig)) {
1181                         if_num = if_incoming->if_num;
1182                         offset = if_num * BATADV_NUM_WORDS;
1183
1184                         spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
1185                         word = &(orig_neigh_node->bcast_own[offset]);
1186                         bit_pos = if_incoming_seqno - 2;
1187                         bit_pos -= ntohl(batadv_ogm_packet->seqno);
1188                         batadv_set_bit(word, bit_pos);
1189                         weight = &orig_neigh_node->bcast_own_sum[if_num];
1190                         *weight = bitmap_weight(word,
1191                                                 BATADV_TQ_LOCAL_WINDOW_SIZE);
1192                         spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
1193                 }
1194
1195                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1196                            "Drop packet: originator packet from myself (via neighbor)\n");
1197                 batadv_orig_node_free_ref(orig_neigh_node);
1198                 return;
1199         }
1200
1201         if (is_my_oldorig) {
1202                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1203                            "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n",
1204                            ethhdr->h_source);
1205                 return;
1206         }
1207
1208         if (batadv_ogm_packet->flags & BATADV_NOT_BEST_NEXT_HOP) {
1209                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1210                            "Drop packet: ignoring all packets not forwarded from the best next hop (sender: %pM)\n",
1211                            ethhdr->h_source);
1212                 return;
1213         }
1214
1215         orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1216         if (!orig_node)
1217                 return;
1218
1219         dup_status = batadv_iv_ogm_update_seqnos(ethhdr, batadv_ogm_packet,
1220                                                  if_incoming);
1221
1222         if (dup_status == BATADV_PROTECTED) {
1223                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1224                            "Drop packet: packet within seqno protection time (sender: %pM)\n",
1225                            ethhdr->h_source);
1226                 goto out;
1227         }
1228
1229         if (batadv_ogm_packet->tq == 0) {
1230                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1231                            "Drop packet: originator packet with tq equal 0\n");
1232                 goto out;
1233         }
1234
1235         router = batadv_orig_node_get_router(orig_node);
1236         if (router)
1237                 router_router = batadv_orig_node_get_router(router->orig_node);
1238
1239         if ((router && router->tq_avg != 0) &&
1240             (batadv_compare_eth(router->addr, ethhdr->h_source)))
1241                 is_from_best_next_hop = true;
1242
1243         prev_sender = batadv_ogm_packet->prev_sender;
1244         /* avoid temporary routing loops */
1245         if (router && router_router &&
1246             (batadv_compare_eth(router->addr, prev_sender)) &&
1247             !(batadv_compare_eth(batadv_ogm_packet->orig, prev_sender)) &&
1248             (batadv_compare_eth(router->addr, router_router->addr))) {
1249                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1250                            "Drop packet: ignoring all rebroadcast packets that may make me loop (sender: %pM)\n",
1251                            ethhdr->h_source);
1252                 goto out;
1253         }
1254
1255         /* if sender is a direct neighbor the sender mac equals
1256          * originator mac
1257          */
1258         if (is_single_hop_neigh)
1259                 orig_neigh_node = orig_node;
1260         else
1261                 orig_neigh_node = batadv_get_orig_node(bat_priv,
1262                                                        ethhdr->h_source);
1263
1264         if (!orig_neigh_node)
1265                 goto out;
1266
1267         /* Update nc_nodes of the originator */
1268         batadv_nc_update_nc_node(bat_priv, orig_node, orig_neigh_node,
1269                                  batadv_ogm_packet, is_single_hop_neigh);
1270
1271         orig_neigh_router = batadv_orig_node_get_router(orig_neigh_node);
1272
1273         /* drop packet if sender is not a direct neighbor and if we
1274          * don't route towards it
1275          */
1276         if (!is_single_hop_neigh && (!orig_neigh_router)) {
1277                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1278                            "Drop packet: OGM via unknown neighbor!\n");
1279                 goto out_neigh;
1280         }
1281
1282         is_bidirect = batadv_iv_ogm_calc_tq(orig_node, orig_neigh_node,
1283                                             batadv_ogm_packet, if_incoming);
1284
1285         batadv_bonding_save_primary(orig_node, orig_neigh_node,
1286                                     batadv_ogm_packet);
1287
1288         /* update ranking if it is not a duplicate or has the same
1289          * seqno and similar ttl as the non-duplicate
1290          */
1291         sameseq = orig_node->last_real_seqno == ntohl(batadv_ogm_packet->seqno);
1292         similar_ttl = orig_node->last_ttl - 3 <= batadv_ogm_packet->header.ttl;
1293         if (is_bidirect && ((dup_status == BATADV_NO_DUP) ||
1294                             (sameseq && similar_ttl)))
1295                 batadv_iv_ogm_orig_update(bat_priv, orig_node, ethhdr,
1296                                           batadv_ogm_packet, if_incoming,
1297                                           tt_buff, dup_status);
1298
1299         /* is single hop (direct) neighbor */
1300         if (is_single_hop_neigh) {
1301                 /* mark direct link on incoming interface */
1302                 batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1303                                       is_single_hop_neigh,
1304                                       is_from_best_next_hop, if_incoming);
1305
1306                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1307                            "Forwarding packet: rebroadcast neighbor packet with direct link flag\n");
1308                 goto out_neigh;
1309         }
1310
1311         /* multihop originator */
1312         if (!is_bidirect) {
1313                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1314                            "Drop packet: not received via bidirectional link\n");
1315                 goto out_neigh;
1316         }
1317
1318         if (dup_status == BATADV_NEIGH_DUP) {
1319                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1320                            "Drop packet: duplicate packet received\n");
1321                 goto out_neigh;
1322         }
1323
1324         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1325                    "Forwarding packet: rebroadcast originator packet\n");
1326         batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1327                               is_single_hop_neigh, is_from_best_next_hop,
1328                               if_incoming);
1329
1330 out_neigh:
1331         if ((orig_neigh_node) && (!is_single_hop_neigh))
1332                 batadv_orig_node_free_ref(orig_neigh_node);
1333 out:
1334         if (router)
1335                 batadv_neigh_node_free_ref(router);
1336         if (router_router)
1337                 batadv_neigh_node_free_ref(router_router);
1338         if (orig_neigh_router)
1339                 batadv_neigh_node_free_ref(orig_neigh_router);
1340
1341         batadv_orig_node_free_ref(orig_node);
1342 }
1343
1344 static int batadv_iv_ogm_receive(struct sk_buff *skb,
1345                                  struct batadv_hard_iface *if_incoming)
1346 {
1347         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1348         struct batadv_ogm_packet *batadv_ogm_packet;
1349         struct ethhdr *ethhdr;
1350         int buff_pos = 0, packet_len;
1351         unsigned char *tt_buff, *packet_buff;
1352         bool ret;
1353         uint8_t *packet_pos;
1354
1355         ret = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN);
1356         if (!ret)
1357                 return NET_RX_DROP;
1358
1359         /* did we receive a B.A.T.M.A.N. IV OGM packet on an interface
1360          * that does not have B.A.T.M.A.N. IV enabled ?
1361          */
1362         if (bat_priv->bat_algo_ops->bat_ogm_emit != batadv_iv_ogm_emit)
1363                 return NET_RX_DROP;
1364
1365         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1366         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1367                            skb->len + ETH_HLEN);
1368
1369         packet_len = skb_headlen(skb);
1370         ethhdr = eth_hdr(skb);
1371         packet_buff = skb->data;
1372         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
1373
1374         /* unpack the aggregated packets and process them one by one */
1375         while (batadv_iv_ogm_aggr_packet(buff_pos, packet_len,
1376                                          batadv_ogm_packet->tt_num_changes)) {
1377                 tt_buff = packet_buff + buff_pos + BATADV_OGM_HLEN;
1378
1379                 batadv_iv_ogm_process(ethhdr, batadv_ogm_packet, tt_buff,
1380                                       if_incoming);
1381
1382                 buff_pos += BATADV_OGM_HLEN;
1383                 buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
1384
1385                 packet_pos = packet_buff + buff_pos;
1386                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
1387         }
1388
1389         kfree_skb(skb);
1390         return NET_RX_SUCCESS;
1391 }
1392
1393 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
1394         .name = "BATMAN_IV",
1395         .bat_iface_enable = batadv_iv_ogm_iface_enable,
1396         .bat_iface_disable = batadv_iv_ogm_iface_disable,
1397         .bat_iface_update_mac = batadv_iv_ogm_iface_update_mac,
1398         .bat_primary_iface_set = batadv_iv_ogm_primary_iface_set,
1399         .bat_ogm_schedule = batadv_iv_ogm_schedule,
1400         .bat_ogm_emit = batadv_iv_ogm_emit,
1401 };
1402
1403 int __init batadv_iv_init(void)
1404 {
1405         int ret;
1406
1407         /* batman originator packet */
1408         ret = batadv_recv_handler_register(BATADV_IV_OGM,
1409                                            batadv_iv_ogm_receive);
1410         if (ret < 0)
1411                 goto out;
1412
1413         ret = batadv_algo_register(&batadv_batman_iv);
1414         if (ret < 0)
1415                 goto handler_unregister;
1416
1417         goto out;
1418
1419 handler_unregister:
1420         batadv_recv_handler_unregister(BATADV_IV_OGM);
1421 out:
1422         return ret;
1423 }