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 /**
  33  * batadv_dup_status - duplicate status
  34  * @BATADV_NO_DUP: the packet is a duplicate
  35  * @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for the
  36  *  neighbor)
  37  * @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor
  38  * @BATADV_PROTECTED: originator is currently protected (after reboot)
  39  */
  40 enum batadv_dup_status {
  41         BATADV_NO_DUP = 0,
  42         BATADV_ORIG_DUP,
  43         BATADV_NEIGH_DUP,
  44         BATADV_PROTECTED,
  45 };
  46
  47 /**
  48  * batadv_ring_buffer_set - update the ring buffer with the given value
  49  * @lq_recv: pointer to the ring buffer
  50  * @lq_index: index to store the value at
  51  * @value: value to store in the ring buffer
  52  */
  53 static void batadv_ring_buffer_set(uint8_t lq_recv[], uint8_t *lq_index,
  54                                    uint8_t value)
  55 {
  56         lq_recv[*lq_index] = value;
  57         *lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
  58 }
  59
  60 /**
  61  * batadv_ring_buffer_set - compute the average of all non-zero values stored
  62  * in the given ring buffer
  63  * @lq_recv: pointer to the ring buffer
  64  *
  65  * Returns computed average value.
  66  */
  67 static uint8_t batadv_ring_buffer_avg(const uint8_t lq_recv[])
  68 {
  69         const uint8_t *ptr;
  70         uint16_t count = 0, i = 0, sum = 0;
  71
  72         ptr = lq_recv;
  73
  74         while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
  75                 if (*ptr != 0) {
  76                         count++;
  77                         sum += *ptr;
  78                 }
  79
  80                 i++;
  81                 ptr++;
  82         }
  83
  84         if (count == 0)
  85                 return 0;
  86
  87         return (uint8_t)(sum / count);
  88 }
  89
  90 static struct batadv_neigh_node *
  91 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
  92                         const uint8_t *neigh_addr,
  93                         struct batadv_orig_node *orig_node,
  94                         struct batadv_orig_node *orig_neigh)
  95 {
  96         struct batadv_neigh_node *neigh_node;
  97
  98         neigh_node = batadv_neigh_node_new(hard_iface, neigh_addr);
  99         if (!neigh_node)
 100                 goto out;
 101
 102         INIT_LIST_HEAD(&neigh_node->bonding_list);
 103
 104         neigh_node->orig_node = orig_neigh;
 105         neigh_node->if_incoming = hard_iface;
 106
 107         spin_lock_bh(&orig_node->neigh_list_lock);
 108         hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
 109         spin_unlock_bh(&orig_node->neigh_list_lock);
 110
 111 out:
 112         return neigh_node;
 113 }
 114
 115 static int batadv_iv_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 116 {
 117         struct batadv_ogm_packet *batadv_ogm_packet;
 118         unsigned char *ogm_buff;
 119         uint32_t random_seqno;
 120         int res = -ENOMEM;
 121
 122         /* randomize initial seqno to avoid collision */
 123         get_random_bytes(&random_seqno, sizeof(random_seqno));
 124         atomic_set(&hard_iface->bat_iv.ogm_seqno, random_seqno);
 125
 126         hard_iface->bat_iv.ogm_buff_len = BATADV_OGM_HLEN;
 127         ogm_buff = kmalloc(hard_iface->bat_iv.ogm_buff_len, GFP_ATOMIC);
 128         if (!ogm_buff)
 129                 goto out;
 130
 131         hard_iface->bat_iv.ogm_buff = ogm_buff;
 132
 133         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 134         batadv_ogm_packet->header.packet_type = BATADV_IV_OGM;
 135         batadv_ogm_packet->header.version = BATADV_COMPAT_VERSION;
 136         batadv_ogm_packet->header.ttl = 2;
 137         batadv_ogm_packet->flags = BATADV_NO_FLAGS;
 138         batadv_ogm_packet->tq = BATADV_TQ_MAX_VALUE;
 139         batadv_ogm_packet->tt_num_changes = 0;
 140         batadv_ogm_packet->ttvn = 0;
 141
 142         res = 0;
 143
 144 out:
 145         return res;
 146 }
 147
 148 static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 149 {
 150         kfree(hard_iface->bat_iv.ogm_buff);
 151         hard_iface->bat_iv.ogm_buff = NULL;
 152 }
 153
 154 static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface)
 155 {
 156         struct batadv_ogm_packet *batadv_ogm_packet;
 157         unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
 158
 159         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 160         memcpy(batadv_ogm_packet->orig,
 161                hard_iface->net_dev->dev_addr, ETH_ALEN);
 162         memcpy(batadv_ogm_packet->prev_sender,
 163                hard_iface->net_dev->dev_addr, ETH_ALEN);
 164 }
 165
 166 static void
 167 batadv_iv_ogm_primary_iface_set(struct batadv_hard_iface *hard_iface)
 168 {
 169         struct batadv_ogm_packet *batadv_ogm_packet;
 170         unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
 171
 172         batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
 173         batadv_ogm_packet->flags = BATADV_PRIMARIES_FIRST_HOP;
 174         batadv_ogm_packet->header.ttl = BATADV_TTL;
 175 }
 176
 177 /* when do we schedule our own ogm to be sent */
 178 static unsigned long
 179 batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
 180 {
 181         unsigned int msecs;
 182
 183         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 184         msecs += prandom_u32() % (2 * BATADV_JITTER);
 185
 186         return jiffies + msecs_to_jiffies(msecs);
 187 }
 188
 189 /* when do we schedule a ogm packet to be sent */
 190 static unsigned long batadv_iv_ogm_fwd_send_time(void)
 191 {
 192         return jiffies + msecs_to_jiffies(prandom_u32() % (BATADV_JITTER / 2));
 193 }
 194
 195 /* apply hop penalty for a normal link */
 196 static uint8_t batadv_hop_penalty(uint8_t tq,
 197                                   const struct batadv_priv *bat_priv)
 198 {
 199         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 200         int new_tq;
 201
 202         new_tq = tq * (BATADV_TQ_MAX_VALUE - hop_penalty);
 203         new_tq /= BATADV_TQ_MAX_VALUE;
 204
 205         return new_tq;
 206 }
 207
 208 /* is there another aggregated packet here? */
 209 static int batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
 210                                      int tt_num_changes)
 211 {
 212         int next_buff_pos = 0;
 213
 214         next_buff_pos += buff_pos + BATADV_OGM_HLEN;
 215         next_buff_pos += batadv_tt_len(tt_num_changes);
 216
 217         return (next_buff_pos <= packet_len) &&
 218                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 219 }
 220
 221 /* send a batman ogm to a given interface */
 222 static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
 223                                      struct batadv_hard_iface *hard_iface)
 224 {
 225         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 226         char *fwd_str;
 227         uint8_t packet_num;
 228         int16_t buff_pos;
 229         struct batadv_ogm_packet *batadv_ogm_packet;
 230         struct sk_buff *skb;
 231         uint8_t *packet_pos;
 232
 233         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 234                 return;
 235
 236         packet_num = 0;
 237         buff_pos = 0;
 238         packet_pos = forw_packet->skb->data;
 239         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 240
 241         /* adjust all flags and log packets */
 242         while (batadv_iv_ogm_aggr_packet(buff_pos, forw_packet->packet_len,
 243                                          batadv_ogm_packet->tt_num_changes)) {
 244                 /* we might have aggregated direct link packets with an
 245                  * ordinary base packet
 246                  */
 247                 if (forw_packet->direct_link_flags & BIT(packet_num) &&
 248                     forw_packet->if_incoming == hard_iface)
 249                         batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 250                 else
 251                         batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 252
 253                 if (packet_num > 0 || !forw_packet->own)
 254                         fwd_str = "Forwarding";
 255                 else
 256                         fwd_str = "Sending own";
 257
 258                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 259                            "%s %spacket (originator %pM, seqno %u, TQ %d, TTL %d, IDF %s, ttvn %d) on interface %s [%pM]\n",
 260                            fwd_str, (packet_num > 0 ? "aggregated " : ""),
 261                            batadv_ogm_packet->orig,
 262                            ntohl(batadv_ogm_packet->seqno),
 263                            batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl,
 264                            (batadv_ogm_packet->flags & BATADV_DIRECTLINK ?
 265                             "on" : "off"),
 266                            batadv_ogm_packet->ttvn, hard_iface->net_dev->name,
 267                            hard_iface->net_dev->dev_addr);
 268
 269                 buff_pos += BATADV_OGM_HLEN;
 270                 buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
 271                 packet_num++;
 272                 packet_pos = forw_packet->skb->data + buff_pos;
 273                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 274         }
 275
 276         /* create clone because function is called more than once */
 277         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 278         if (skb) {
 279                 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 280                 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 281                                    skb->len + ETH_HLEN);
 282                 batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
 283         }
 284 }
 285
 286 /* send a batman ogm packet */
 287 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 288 {
 289         struct batadv_hard_iface *hard_iface;
 290         struct net_device *soft_iface;
 291         struct batadv_priv *bat_priv;
 292         struct batadv_hard_iface *primary_if = NULL;
 293         struct batadv_ogm_packet *batadv_ogm_packet;
 294         unsigned char directlink;
 295         uint8_t *packet_pos;
 296
 297         packet_pos = forw_packet->skb->data;
 298         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
 299         directlink = (batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0);
 300
 301         if (!forw_packet->if_incoming) {
 302                 pr_err("Error - can't forward packet: incoming iface not specified\n");
 303                 goto out;
 304         }
 305
 306         soft_iface = forw_packet->if_incoming->soft_iface;
 307         bat_priv = netdev_priv(soft_iface);
 308
 309         if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
 310                 goto out;
 311
 312         primary_if = batadv_primary_if_get_selected(bat_priv);
 313         if (!primary_if)
 314                 goto out;
 315
 316         /* multihomed peer assumed
 317          * non-primary OGMs are only broadcasted on their interface
 318          */
 319         if ((directlink && (batadv_ogm_packet->header.ttl == 1)) ||
 320             (forw_packet->own && (forw_packet->if_incoming != primary_if))) {
 321                 /* FIXME: what about aggregated packets ? */
 322                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 323                            "%s packet (originator %pM, seqno %u, TTL %d) on interface %s [%pM]\n",
 324                            (forw_packet->own ? "Sending own" : "Forwarding"),
 325                            batadv_ogm_packet->orig,
 326                            ntohl(batadv_ogm_packet->seqno),
 327                            batadv_ogm_packet->header.ttl,
 328                            forw_packet->if_incoming->net_dev->name,
 329                            forw_packet->if_incoming->net_dev->dev_addr);
 330
 331                 /* skb is only used once and than forw_packet is free'd */
 332                 batadv_send_skb_packet(forw_packet->skb,
 333                                        forw_packet->if_incoming,
 334                                        batadv_broadcast_addr);
 335                 forw_packet->skb = NULL;
 336
 337                 goto out;
 338         }
 339
 340         /* broadcast on every interface */
 341         rcu_read_lock();
 342         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 343                 if (hard_iface->soft_iface != soft_iface)
 344                         continue;
 345
 346                 batadv_iv_ogm_send_to_if(forw_packet, hard_iface);
 347         }
 348         rcu_read_unlock();
 349
 350 out:
 351         if (primary_if)
 352                 batadv_hardif_free_ref(primary_if);
 353 }
 354
 355 /* return true if new_packet can be aggregated with forw_packet */
 356 static bool
 357 batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet,
 358                             struct batadv_priv *bat_priv,
 359                             int packet_len, unsigned long send_time,
 360                             bool directlink,
 361                             const struct batadv_hard_iface *if_incoming,
 362                             const struct batadv_forw_packet *forw_packet)
 363 {
 364         struct batadv_ogm_packet *batadv_ogm_packet;
 365         int aggregated_bytes = forw_packet->packet_len + packet_len;
 366         struct batadv_hard_iface *primary_if = NULL;
 367         bool res = false;
 368         unsigned long aggregation_end_time;
 369
 370         batadv_ogm_packet = (struct batadv_ogm_packet *)forw_packet->skb->data;
 371         aggregation_end_time = send_time;
 372         aggregation_end_time += msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 373
 374         /* we can aggregate the current packet to this aggregated packet
 375          * if:
 376          *
 377          * - the send time is within our MAX_AGGREGATION_MS time
 378          * - the resulting packet wont be bigger than
 379          *   MAX_AGGREGATION_BYTES
 380          */
 381         if (time_before(send_time, forw_packet->send_time) &&
 382             time_after_eq(aggregation_end_time, forw_packet->send_time) &&
 383             (aggregated_bytes <= BATADV_MAX_AGGREGATION_BYTES)) {
 384                 /* check aggregation compatibility
 385                  * -> direct link packets are broadcasted on
 386                  *    their interface only
 387                  * -> aggregate packet if the current packet is
 388                  *    a "global" packet as well as the base
 389                  *    packet
 390                  */
 391                 primary_if = batadv_primary_if_get_selected(bat_priv);
 392                 if (!primary_if)
 393                         goto out;
 394
 395                 /* packets without direct link flag and high TTL
 396                  * are flooded through the net
 397                  */
 398                 if ((!directlink) &&
 399                     (!(batadv_ogm_packet->flags & BATADV_DIRECTLINK)) &&
 400                     (batadv_ogm_packet->header.ttl != 1) &&
 401
 402                     /* own packets originating non-primary
 403                      * interfaces leave only that interface
 404                      */
 405                     ((!forw_packet->own) ||
 406                      (forw_packet->if_incoming == primary_if))) {
 407                         res = true;
 408                         goto out;
 409                 }
 410
 411                 /* if the incoming packet is sent via this one
 412                  * interface only - we still can aggregate
 413                  */
 414                 if ((directlink) &&
 415                     (new_bat_ogm_packet->header.ttl == 1) &&
 416                     (forw_packet->if_incoming == if_incoming) &&
 417
 418                     /* packets from direct neighbors or
 419                      * own secondary interface packets
 420                      * (= secondary interface packets in general)
 421                      */
 422                     (batadv_ogm_packet->flags & BATADV_DIRECTLINK ||
 423                      (forw_packet->own &&
 424                       forw_packet->if_incoming != primary_if))) {
 425                         res = true;
 426                         goto out;
 427                 }
 428         }
 429
 430 out:
 431         if (primary_if)
 432                 batadv_hardif_free_ref(primary_if);
 433         return res;
 434 }
 435
 436 /* create a new aggregated packet and add this packet to it */
 437 static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
 438                                         int packet_len, unsigned long send_time,
 439                                         bool direct_link,
 440                                         struct batadv_hard_iface *if_incoming,
 441                                         int own_packet)
 442 {
 443         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 444         struct batadv_forw_packet *forw_packet_aggr;
 445         unsigned char *skb_buff;
 446         unsigned int skb_size;
 447
 448         if (!atomic_inc_not_zero(&if_incoming->refcount))
 449                 return;
 450
 451         /* own packet should always be scheduled */
 452         if (!own_packet) {
 453                 if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
 454                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 455                                    "batman packet queue full\n");
 456                         goto out;
 457                 }
 458         }
 459
 460         forw_packet_aggr = kmalloc(sizeof(*forw_packet_aggr), GFP_ATOMIC);
 461         if (!forw_packet_aggr) {
 462                 if (!own_packet)
 463                         atomic_inc(&bat_priv->batman_queue_left);
 464                 goto out;
 465         }
 466
 467         if ((atomic_read(&bat_priv->aggregated_ogms)) &&
 468             (packet_len < BATADV_MAX_AGGREGATION_BYTES))
 469                 skb_size = BATADV_MAX_AGGREGATION_BYTES;
 470         else
 471                 skb_size = packet_len;
 472
 473         skb_size += ETH_HLEN;
 474
 475         forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size);
 476         if (!forw_packet_aggr->skb) {
 477                 if (!own_packet)
 478                         atomic_inc(&bat_priv->batman_queue_left);
 479                 kfree(forw_packet_aggr);
 480                 goto out;
 481         }
 482         forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
 483         skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 484
 485         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 486         forw_packet_aggr->packet_len = packet_len;
 487         memcpy(skb_buff, packet_buff, packet_len);
 488
 489         forw_packet_aggr->own = own_packet;
 490         forw_packet_aggr->if_incoming = if_incoming;
 491         forw_packet_aggr->num_packets = 0;
 492         forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;
 493         forw_packet_aggr->send_time = send_time;
 494
 495         /* save packet direct link flag status */
 496         if (direct_link)
 497                 forw_packet_aggr->direct_link_flags |= 1;
 498
 499         /* add new packet to packet list */
 500         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 501         hlist_add_head(&forw_packet_aggr->list, &bat_priv->forw_bat_list);
 502         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 503
 504         /* start timer for this packet */
 505         INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work,
 506                           batadv_send_outstanding_bat_ogm_packet);
 507         queue_delayed_work(batadv_event_workqueue,
 508                            &forw_packet_aggr->delayed_work,
 509                            send_time - jiffies);
 510
 511         return;
 512 out:
 513         batadv_hardif_free_ref(if_incoming);
 514 }
 515
 516 /* aggregate a new packet into the existing ogm packet */
 517 static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr,
 518                                     const unsigned char *packet_buff,
 519                                     int packet_len, bool direct_link)
 520 {
 521         unsigned char *skb_buff;
 522         unsigned long new_direct_link_flag;
 523
 524         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
 525         memcpy(skb_buff, packet_buff, packet_len);
 526         forw_packet_aggr->packet_len += packet_len;
 527         forw_packet_aggr->num_packets++;
 528
 529         /* save packet direct link flag status */
 530         if (direct_link) {
 531                 new_direct_link_flag = BIT(forw_packet_aggr->num_packets);
 532                 forw_packet_aggr->direct_link_flags |= new_direct_link_flag;
 533         }
 534 }
 535
 536 static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv,
 537                                     unsigned char *packet_buff,
 538                                     int packet_len,
 539                                     struct batadv_hard_iface *if_incoming,
 540                                     int own_packet, unsigned long send_time)
 541 {
 542         /* _aggr -> pointer to the packet we want to aggregate with
 543          * _pos -> pointer to the position in the queue
 544          */
 545         struct batadv_forw_packet *forw_packet_aggr = NULL;
 546         struct batadv_forw_packet *forw_packet_pos = NULL;
 547         struct batadv_ogm_packet *batadv_ogm_packet;
 548         bool direct_link;
 549         unsigned long max_aggregation_jiffies;
 550
 551         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
 552         direct_link = batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0;
 553         max_aggregation_jiffies = msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
 554
 555         /* find position for the packet in the forward queue */
 556         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 557         /* own packets are not to be aggregated */
 558         if ((atomic_read(&bat_priv->aggregated_ogms)) && (!own_packet)) {
 559                 hlist_for_each_entry(forw_packet_pos,
 560                                      &bat_priv->forw_bat_list, list) {
 561                         if (batadv_iv_ogm_can_aggregate(batadv_ogm_packet,
 562                                                         bat_priv, packet_len,
 563                                                         send_time, direct_link,
 564                                                         if_incoming,
 565                                                         forw_packet_pos)) {
 566                                 forw_packet_aggr = forw_packet_pos;
 567                                 break;
 568                         }
 569                 }
 570         }
 571
 572         /* nothing to aggregate with - either aggregation disabled or no
 573          * suitable aggregation packet found
 574          */
 575         if (!forw_packet_aggr) {
 576                 /* the following section can run without the lock */
 577                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 578
 579                 /* if we could not aggregate this packet with one of the others
 580                  * we hold it back for a while, so that it might be aggregated
 581                  * later on
 582                  */
 583                 if (!own_packet && atomic_read(&bat_priv->aggregated_ogms))
 584                         send_time += max_aggregation_jiffies;
 585
 586                 batadv_iv_ogm_aggregate_new(packet_buff, packet_len,
 587                                             send_time, direct_link,
 588                                             if_incoming, own_packet);
 589         } else {
 590                 batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff,
 591                                         packet_len, direct_link);
 592                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 593         }
 594 }
 595
 596 static void batadv_iv_ogm_forward(struct batadv_orig_node *orig_node,
 597                                   const struct ethhdr *ethhdr,
 598                                   struct batadv_ogm_packet *batadv_ogm_packet,
 599                                   bool is_single_hop_neigh,
 600                                   bool is_from_best_next_hop,
 601                                   struct batadv_hard_iface *if_incoming)
 602 {
 603         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 604         uint8_t tt_num_changes;
 605
 606         if (batadv_ogm_packet->header.ttl <= 1) {
 607                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 608                 return;
 609         }
 610
 611         if (!is_from_best_next_hop) {
 612                 /* Mark the forwarded packet when it is not coming from our
 613                  * best next hop. We still need to forward the packet for our
 614                  * neighbor link quality detection to work in case the packet
 615                  * originated from a single hop neighbor. Otherwise we can
 616                  * simply drop the ogm.
 617                  */
 618                 if (is_single_hop_neigh)
 619                         batadv_ogm_packet->flags |= BATADV_NOT_BEST_NEXT_HOP;
 620                 else
 621                         return;
 622         }
 623
 624         tt_num_changes = batadv_ogm_packet->tt_num_changes;
 625
 626         batadv_ogm_packet->header.ttl--;
 627         memcpy(batadv_ogm_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 628
 629         /* apply hop penalty */
 630         batadv_ogm_packet->tq = batadv_hop_penalty(batadv_ogm_packet->tq,
 631                                                    bat_priv);
 632
 633         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 634                    "Forwarding packet: tq: %i, ttl: %i\n",
 635                    batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl);
 636
 637         /* switch of primaries first hop flag when forwarding */
 638         batadv_ogm_packet->flags &= ~BATADV_PRIMARIES_FIRST_HOP;
 639         if (is_single_hop_neigh)
 640                 batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
 641         else
 642                 batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
 643
 644         batadv_iv_ogm_queue_add(bat_priv, (unsigned char *)batadv_ogm_packet,
 645                                 BATADV_OGM_HLEN + batadv_tt_len(tt_num_changes),
 646                                 if_incoming, 0, batadv_iv_ogm_fwd_send_time());
 647 }
 648
 649 /**
 650  * batadv_iv_ogm_slide_own_bcast_window - bitshift own OGM broadcast windows for
 651  * the given interface
 652  * @hard_iface: the interface for which the windows have to be shifted
 653  */
 654 static void
 655 batadv_iv_ogm_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
 656 {
 657         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 658         struct batadv_hashtable *hash = bat_priv->orig_hash;
 659         struct hlist_head *head;
 660         struct batadv_orig_node *orig_node;
 661         unsigned long *word;
 662         uint32_t i;
 663         size_t word_index;
 664         uint8_t *w;
 665
 666         for (i = 0; i < hash->size; i++) {
 667                 head = &hash->table[i];
 668
 669                 rcu_read_lock();
 670                 hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
 671                         spin_lock_bh(&orig_node->ogm_cnt_lock);
 672                         word_index = hard_iface->if_num * BATADV_NUM_WORDS;
 673                         word = &(orig_node->bcast_own[word_index]);
 674
 675                         batadv_bit_get_packet(bat_priv, word, 1, 0);
 676                         w = &orig_node->bcast_own_sum[hard_iface->if_num];
 677                         *w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
 678                         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 679                 }
 680                 rcu_read_unlock();
 681         }
 682 }
 683
 684 static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface)
 685 {
 686         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 687         unsigned char **ogm_buff = &hard_iface->bat_iv.ogm_buff;
 688         struct batadv_ogm_packet *batadv_ogm_packet;
 689         struct batadv_hard_iface *primary_if;
 690         int *ogm_buff_len = &hard_iface->bat_iv.ogm_buff_len;
 691         int vis_server, tt_num_changes = 0;
 692         uint32_t seqno;
 693         uint8_t bandwidth;
 694
 695         vis_server = atomic_read(&bat_priv->vis_mode);
 696         primary_if = batadv_primary_if_get_selected(bat_priv);
 697
 698         if (hard_iface == primary_if)
 699                 tt_num_changes = batadv_tt_append_diff(bat_priv, ogm_buff,
 700                                                        ogm_buff_len,
 701                                                        BATADV_OGM_HLEN);
 702
 703         batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff);
 704
 705         /* change sequence number to network order */
 706         seqno = (uint32_t)atomic_read(&hard_iface->bat_iv.ogm_seqno);
 707         batadv_ogm_packet->seqno = htonl(seqno);
 708         atomic_inc(&hard_iface->bat_iv.ogm_seqno);
 709
 710         batadv_ogm_packet->ttvn = atomic_read(&bat_priv->tt.vn);
 711         batadv_ogm_packet->tt_crc = htons(bat_priv->tt.local_crc);
 712         if (tt_num_changes >= 0)
 713                 batadv_ogm_packet->tt_num_changes = tt_num_changes;
 714
 715         if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC)
 716                 batadv_ogm_packet->flags |= BATADV_VIS_SERVER;
 717         else
 718                 batadv_ogm_packet->flags &= ~BATADV_VIS_SERVER;
 719
 720         if (hard_iface == primary_if &&
 721             atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_SERVER) {
 722                 bandwidth = (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
 723                 batadv_ogm_packet->gw_flags = bandwidth;
 724         } else {
 725                 batadv_ogm_packet->gw_flags = BATADV_NO_FLAGS;
 726         }
 727
 728         batadv_iv_ogm_slide_own_bcast_window(hard_iface);
 729         batadv_iv_ogm_queue_add(bat_priv, hard_iface->bat_iv.ogm_buff,
 730                                 hard_iface->bat_iv.ogm_buff_len, hard_iface, 1,
 731                                 batadv_iv_ogm_emit_send_time(bat_priv));
 732
 733         if (primary_if)
 734                 batadv_hardif_free_ref(primary_if);
 735 }
 736
 737 static void
 738 batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
 739                           struct batadv_orig_node *orig_node,
 740                           const struct ethhdr *ethhdr,
 741                           const struct batadv_ogm_packet *batadv_ogm_packet,
 742                           struct batadv_hard_iface *if_incoming,
 743                           const unsigned char *tt_buff,
 744                           enum batadv_dup_status dup_status)
 745 {
 746         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
 747         struct batadv_neigh_node *router = NULL;
 748         struct batadv_orig_node *orig_node_tmp;
 749         int if_num;
 750         uint8_t sum_orig, sum_neigh;
 751         uint8_t *neigh_addr;
 752         uint8_t tq_avg;
 753
 754         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 755                    "update_originator(): Searching and updating originator entry of received packet\n");
 756
 757         rcu_read_lock();
 758         hlist_for_each_entry_rcu(tmp_neigh_node,
 759                                  &orig_node->neigh_list, list) {
 760                 neigh_addr = tmp_neigh_node->addr;
 761                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
 762                     tmp_neigh_node->if_incoming == if_incoming &&
 763                     atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
 764                         if (WARN(neigh_node, "too many matching neigh_nodes"))
 765                                 batadv_neigh_node_free_ref(neigh_node);
 766                         neigh_node = tmp_neigh_node;
 767                         continue;
 768                 }
 769
 770                 if (dup_status != BATADV_NO_DUP)
 771                         continue;
 772
 773                 spin_lock_bh(&tmp_neigh_node->lq_update_lock);
 774                 batadv_ring_buffer_set(tmp_neigh_node->tq_recv,
 775                                        &tmp_neigh_node->tq_index, 0);
 776                 tq_avg = batadv_ring_buffer_avg(tmp_neigh_node->tq_recv);
 777                 tmp_neigh_node->tq_avg = tq_avg;
 778                 spin_unlock_bh(&tmp_neigh_node->lq_update_lock);
 779         }
 780
 781         if (!neigh_node) {
 782                 struct batadv_orig_node *orig_tmp;
 783
 784                 orig_tmp = batadv_get_orig_node(bat_priv, ethhdr->h_source);
 785                 if (!orig_tmp)
 786                         goto unlock;
 787
 788                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 789                                                      ethhdr->h_source,
 790                                                      orig_node, orig_tmp);
 791
 792                 batadv_orig_node_free_ref(orig_tmp);
 793                 if (!neigh_node)
 794                         goto unlock;
 795         } else
 796                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 797                            "Updating existing last-hop neighbor of originator\n");
 798
 799         rcu_read_unlock();
 800
 801         orig_node->flags = batadv_ogm_packet->flags;
 802         neigh_node->last_seen = jiffies;
 803
 804         spin_lock_bh(&neigh_node->lq_update_lock);
 805         batadv_ring_buffer_set(neigh_node->tq_recv,
 806                                &neigh_node->tq_index,
 807                                batadv_ogm_packet->tq);
 808         neigh_node->tq_avg = batadv_ring_buffer_avg(neigh_node->tq_recv);
 809         spin_unlock_bh(&neigh_node->lq_update_lock);
 810
 811         if (dup_status == BATADV_NO_DUP) {
 812                 orig_node->last_ttl = batadv_ogm_packet->header.ttl;
 813                 neigh_node->last_ttl = batadv_ogm_packet->header.ttl;
 814         }
 815
 816         batadv_bonding_candidate_add(orig_node, neigh_node);
 817
 818         /* if this neighbor already is our next hop there is nothing
 819          * to change
 820          */
 821         router = batadv_orig_node_get_router(orig_node);
 822         if (router == neigh_node)
 823                 goto update_tt;
 824
 825         /* if this neighbor does not offer a better TQ we won't consider it */
 826         if (router && (router->tq_avg > neigh_node->tq_avg))
 827                 goto update_tt;
 828
 829         /* if the TQ is the same and the link not more symmetric we
 830          * won't consider it either
 831          */
 832         if (router && (neigh_node->tq_avg == router->tq_avg)) {
 833                 orig_node_tmp = router->orig_node;
 834                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 835                 if_num = router->if_incoming->if_num;
 836                 sum_orig = orig_node_tmp->bcast_own_sum[if_num];
 837                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 838
 839                 orig_node_tmp = neigh_node->orig_node;
 840                 spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
 841                 if_num = neigh_node->if_incoming->if_num;
 842                 sum_neigh = orig_node_tmp->bcast_own_sum[if_num];
 843                 spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
 844
 845                 if (sum_orig >= sum_neigh)
 846                         goto update_tt;
 847         }
 848
 849         batadv_update_route(bat_priv, orig_node, neigh_node);
 850
 851 update_tt:
 852         /* I have to check for transtable changes only if the OGM has been
 853          * sent through a primary interface
 854          */
 855         if (((batadv_ogm_packet->orig != ethhdr->h_source) &&
 856              (batadv_ogm_packet->header.ttl > 2)) ||
 857             (batadv_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
 858                 batadv_tt_update_orig(bat_priv, orig_node, tt_buff,
 859                                       batadv_ogm_packet->tt_num_changes,
 860                                       batadv_ogm_packet->ttvn,
 861                                       ntohs(batadv_ogm_packet->tt_crc));
 862
 863         if (orig_node->gw_flags != batadv_ogm_packet->gw_flags)
 864                 batadv_gw_node_update(bat_priv, orig_node,
 865                                       batadv_ogm_packet->gw_flags);
 866
 867         orig_node->gw_flags = batadv_ogm_packet->gw_flags;
 868
 869         /* restart gateway selection if fast or late switching was enabled */
 870         if ((orig_node->gw_flags) &&
 871             (atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_CLIENT) &&
 872             (atomic_read(&bat_priv->gw_sel_class) > 2))
 873                 batadv_gw_check_election(bat_priv, orig_node);
 874
 875         goto out;
 876
 877 unlock:
 878         rcu_read_unlock();
 879 out:
 880         if (neigh_node)
 881                 batadv_neigh_node_free_ref(neigh_node);
 882         if (router)
 883                 batadv_neigh_node_free_ref(router);
 884 }
 885
 886 static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
 887                                  struct batadv_orig_node *orig_neigh_node,
 888                                  struct batadv_ogm_packet *batadv_ogm_packet,
 889                                  struct batadv_hard_iface *if_incoming)
 890 {
 891         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 892         struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node;
 893         uint8_t total_count;
 894         uint8_t orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
 895         unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
 896         int tq_asym_penalty, inv_asym_penalty, ret = 0;
 897         unsigned int combined_tq;
 898
 899         /* find corresponding one hop neighbor */
 900         rcu_read_lock();
 901         hlist_for_each_entry_rcu(tmp_neigh_node,
 902                                  &orig_neigh_node->neigh_list, list) {
 903                 if (!batadv_compare_eth(tmp_neigh_node->addr,
 904                                         orig_neigh_node->orig))
 905                         continue;
 906
 907                 if (tmp_neigh_node->if_incoming != if_incoming)
 908                         continue;
 909
 910                 if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
 911                         continue;
 912
 913                 neigh_node = tmp_neigh_node;
 914                 break;
 915         }
 916         rcu_read_unlock();
 917
 918         if (!neigh_node)
 919                 neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
 920                                                      orig_neigh_node->orig,
 921                                                      orig_neigh_node,
 922                                                      orig_neigh_node);
 923
 924         if (!neigh_node)
 925                 goto out;
 926
 927         /* if orig_node is direct neighbor update neigh_node last_seen */
 928         if (orig_node == orig_neigh_node)
 929                 neigh_node->last_seen = jiffies;
 930
 931         orig_node->last_seen = jiffies;
 932
 933         /* find packet count of corresponding one hop neighbor */
 934         spin_lock_bh(&orig_node->ogm_cnt_lock);
 935         orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
 936         neigh_rq_count = neigh_node->real_packet_count;
 937         spin_unlock_bh(&orig_node->ogm_cnt_lock);
 938
 939         /* pay attention to not get a value bigger than 100 % */
 940         if (orig_eq_count > neigh_rq_count)
 941                 total_count = neigh_rq_count;
 942         else
 943                 total_count = orig_eq_count;
 944
 945         /* if we have too few packets (too less data) we set tq_own to zero
 946          * if we receive too few packets it is not considered bidirectional
 947          */
 948         if (total_count < BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM ||
 949             neigh_rq_count < BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM)
 950                 tq_own = 0;
 951         else
 952                 /* neigh_node->real_packet_count is never zero as we
 953                  * only purge old information when getting new
 954                  * information
 955                  */
 956                 tq_own = (BATADV_TQ_MAX_VALUE * total_count) /  neigh_rq_count;
 957
 958         /* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
 959          * affect the nearly-symmetric links only a little, but
 960          * punishes asymmetric links more.  This will give a value
 961          * between 0 and TQ_MAX_VALUE
 962          */
 963         neigh_rq_inv = BATADV_TQ_LOCAL_WINDOW_SIZE - neigh_rq_count;
 964         neigh_rq_inv_cube = neigh_rq_inv * neigh_rq_inv * neigh_rq_inv;
 965         neigh_rq_max_cube = BATADV_TQ_LOCAL_WINDOW_SIZE *
 966                             BATADV_TQ_LOCAL_WINDOW_SIZE *
 967                             BATADV_TQ_LOCAL_WINDOW_SIZE;
 968         inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
 969         inv_asym_penalty /= neigh_rq_max_cube;
 970         tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
 971
 972         combined_tq = batadv_ogm_packet->tq * tq_own * tq_asym_penalty;
 973         combined_tq /= BATADV_TQ_MAX_VALUE * BATADV_TQ_MAX_VALUE;
 974         batadv_ogm_packet->tq = combined_tq;
 975
 976         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 977                    "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, total tq: %3i\n",
 978                    orig_node->orig, orig_neigh_node->orig, total_count,
 979                    neigh_rq_count, tq_own,
 980                    tq_asym_penalty, batadv_ogm_packet->tq);
 981
 982         /* if link has the minimum required transmission quality
 983          * consider it bidirectional
 984          */
 985         if (batadv_ogm_packet->tq >= BATADV_TQ_TOTAL_BIDRECT_LIMIT)
 986                 ret = 1;
 987
 988 out:
 989         if (neigh_node)
 990                 batadv_neigh_node_free_ref(neigh_node);
 991         return ret;
 992 }
 993
 994 /**
 995  * batadv_iv_ogm_update_seqnos -  process a batman packet for all interfaces,
 996  *  adjust the sequence number and find out whether it is a duplicate
 997  * @ethhdr: ethernet header of the packet
 998  * @batadv_ogm_packet: OGM packet to be considered
 999  * @if_incoming: interface on which the OGM packet was received
1000  *
1001  * Returns duplicate status as enum batadv_dup_status
1002  */
1003 static enum batadv_dup_status
1004 batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
1005                             const struct batadv_ogm_packet *batadv_ogm_packet,
1006                             const struct batadv_hard_iface *if_incoming)
1007 {
1008         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1009         struct batadv_orig_node *orig_node;
1010         struct batadv_neigh_node *tmp_neigh_node;
1011         int is_dup;
1012         int32_t seq_diff;
1013         int need_update = 0;
1014         int set_mark;
1015         enum batadv_dup_status ret = BATADV_NO_DUP;
1016         uint32_t seqno = ntohl(batadv_ogm_packet->seqno);
1017         uint8_t *neigh_addr;
1018         uint8_t packet_count;
1019
1020         orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1021         if (!orig_node)
1022                 return BATADV_NO_DUP;
1023
1024         spin_lock_bh(&orig_node->ogm_cnt_lock);
1025         seq_diff = seqno - orig_node->last_real_seqno;
1026
1027         /* signalize caller that the packet is to be dropped. */
1028         if (!hlist_empty(&orig_node->neigh_list) &&
1029             batadv_window_protected(bat_priv, seq_diff,
1030                                     &orig_node->batman_seqno_reset)) {
1031                 ret = BATADV_PROTECTED;
1032                 goto out;
1033         }
1034
1035         rcu_read_lock();
1036         hlist_for_each_entry_rcu(tmp_neigh_node,
1037                                  &orig_node->neigh_list, list) {
1038                 neigh_addr = tmp_neigh_node->addr;
1039                 is_dup = batadv_test_bit(tmp_neigh_node->real_bits,
1040                                          orig_node->last_real_seqno,
1041                                          seqno);
1042
1043                 if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
1044                     tmp_neigh_node->if_incoming == if_incoming) {
1045                         set_mark = 1;
1046                         if (is_dup)
1047                                 ret = BATADV_NEIGH_DUP;
1048                 } else {
1049                         set_mark = 0;
1050                         if (is_dup && (ret != BATADV_NEIGH_DUP))
1051                                 ret = BATADV_ORIG_DUP;
1052                 }
1053
1054                 /* if the window moved, set the update flag. */
1055                 need_update |= batadv_bit_get_packet(bat_priv,
1056                                                      tmp_neigh_node->real_bits,
1057                                                      seq_diff, set_mark);
1058
1059                 packet_count = bitmap_weight(tmp_neigh_node->real_bits,
1060                                              BATADV_TQ_LOCAL_WINDOW_SIZE);
1061                 tmp_neigh_node->real_packet_count = packet_count;
1062         }
1063         rcu_read_unlock();
1064
1065         if (need_update) {
1066                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1067                            "updating last_seqno: old %u, new %u\n",
1068                            orig_node->last_real_seqno, seqno);
1069                 orig_node->last_real_seqno = seqno;
1070         }
1071
1072 out:
1073         spin_unlock_bh(&orig_node->ogm_cnt_lock);
1074         batadv_orig_node_free_ref(orig_node);
1075         return ret;
1076 }
1077
1078 static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
1079                                   struct batadv_ogm_packet *batadv_ogm_packet,
1080                                   const unsigned char *tt_buff,
1081                                   struct batadv_hard_iface *if_incoming)
1082 {
1083         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1084         struct batadv_hard_iface *hard_iface;
1085         struct batadv_orig_node *orig_neigh_node, *orig_node;
1086         struct batadv_neigh_node *router = NULL, *router_router = NULL;
1087         struct batadv_neigh_node *orig_neigh_router = NULL;
1088         int has_directlink_flag;
1089         int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
1090         int is_bidirect;
1091         bool is_single_hop_neigh = false;
1092         bool is_from_best_next_hop = false;
1093         int sameseq, similar_ttl;
1094         enum batadv_dup_status dup_status;
1095         uint32_t if_incoming_seqno;
1096         uint8_t *prev_sender;
1097
1098         /* Silently drop when the batman packet is actually not a
1099          * correct packet.
1100          *
1101          * This might happen if a packet is padded (e.g. Ethernet has a
1102          * minimum frame length of 64 byte) and the aggregation interprets
1103          * it as an additional length.
1104          *
1105          * TODO: A more sane solution would be to have a bit in the
1106          * batadv_ogm_packet to detect whether the packet is the last
1107          * packet in an aggregation.  Here we expect that the padding
1108          * is always zero (or not 0x01)
1109          */
1110         if (batadv_ogm_packet->header.packet_type != BATADV_IV_OGM)
1111                 return;
1112
1113         /* could be changed by schedule_own_packet() */
1114         if_incoming_seqno = atomic_read(&if_incoming->bat_iv.ogm_seqno);
1115
1116         if (batadv_ogm_packet->flags & BATADV_DIRECTLINK)
1117                 has_directlink_flag = 1;
1118         else
1119                 has_directlink_flag = 0;
1120
1121         if (batadv_compare_eth(ethhdr->h_source, batadv_ogm_packet->orig))
1122                 is_single_hop_neigh = true;
1123
1124         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1125                    "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",
1126                    ethhdr->h_source, if_incoming->net_dev->name,
1127                    if_incoming->net_dev->dev_addr, batadv_ogm_packet->orig,
1128                    batadv_ogm_packet->prev_sender,
1129                    ntohl(batadv_ogm_packet->seqno), batadv_ogm_packet->ttvn,
1130                    ntohs(batadv_ogm_packet->tt_crc),
1131                    batadv_ogm_packet->tt_num_changes, batadv_ogm_packet->tq,
1132                    batadv_ogm_packet->header.ttl,
1133                    batadv_ogm_packet->header.version, has_directlink_flag);
1134
1135         rcu_read_lock();
1136         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1137                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
1138                         continue;
1139
1140                 if (hard_iface->soft_iface != if_incoming->soft_iface)
1141                         continue;
1142
1143                 if (batadv_compare_eth(ethhdr->h_source,
1144                                        hard_iface->net_dev->dev_addr))
1145                         is_my_addr = 1;
1146
1147                 if (batadv_compare_eth(batadv_ogm_packet->orig,
1148                                        hard_iface->net_dev->dev_addr))
1149                         is_my_orig = 1;
1150
1151                 if (batadv_compare_eth(batadv_ogm_packet->prev_sender,
1152                                        hard_iface->net_dev->dev_addr))
1153                         is_my_oldorig = 1;
1154         }
1155         rcu_read_unlock();
1156
1157         if (is_my_addr) {
1158                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1159                            "Drop packet: received my own broadcast (sender: %pM)\n",
1160                            ethhdr->h_source);
1161                 return;
1162         }
1163
1164         if (is_my_orig) {
1165                 unsigned long *word;
1166                 int offset;
1167                 int32_t bit_pos;
1168                 int16_t if_num;
1169                 uint8_t *weight;
1170
1171                 orig_neigh_node = batadv_get_orig_node(bat_priv,
1172                                                        ethhdr->h_source);
1173                 if (!orig_neigh_node)
1174                         return;
1175
1176                 /* neighbor has to indicate direct link and it has to
1177                  * come via the corresponding interface
1178                  * save packet seqno for bidirectional check
1179                  */
1180                 if (has_directlink_flag &&
1181                     batadv_compare_eth(if_incoming->net_dev->dev_addr,
1182                                        batadv_ogm_packet->orig)) {
1183                         if_num = if_incoming->if_num;
1184                         offset = if_num * BATADV_NUM_WORDS;
1185
1186                         spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
1187                         word = &(orig_neigh_node->bcast_own[offset]);
1188                         bit_pos = if_incoming_seqno - 2;
1189                         bit_pos -= ntohl(batadv_ogm_packet->seqno);
1190                         batadv_set_bit(word, bit_pos);
1191                         weight = &orig_neigh_node->bcast_own_sum[if_num];
1192                         *weight = bitmap_weight(word,
1193                                                 BATADV_TQ_LOCAL_WINDOW_SIZE);
1194                         spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
1195                 }
1196
1197                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1198                            "Drop packet: originator packet from myself (via neighbor)\n");
1199                 batadv_orig_node_free_ref(orig_neigh_node);
1200                 return;
1201         }
1202
1203         if (is_my_oldorig) {
1204                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1205                            "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n",
1206                            ethhdr->h_source);
1207                 return;
1208         }
1209
1210         if (batadv_ogm_packet->flags & BATADV_NOT_BEST_NEXT_HOP) {
1211                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1212                            "Drop packet: ignoring all packets not forwarded from the best next hop (sender: %pM)\n",
1213                            ethhdr->h_source);
1214                 return;
1215         }
1216
1217         orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1218         if (!orig_node)
1219                 return;
1220
1221         dup_status = batadv_iv_ogm_update_seqnos(ethhdr, batadv_ogm_packet,
1222                                                  if_incoming);
1223
1224         if (dup_status == BATADV_PROTECTED) {
1225                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1226                            "Drop packet: packet within seqno protection time (sender: %pM)\n",
1227                            ethhdr->h_source);
1228                 goto out;
1229         }
1230
1231         if (batadv_ogm_packet->tq == 0) {
1232                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1233                            "Drop packet: originator packet with tq equal 0\n");
1234                 goto out;
1235         }
1236
1237         router = batadv_orig_node_get_router(orig_node);
1238         if (router)
1239                 router_router = batadv_orig_node_get_router(router->orig_node);
1240
1241         if ((router && router->tq_avg != 0) &&
1242             (batadv_compare_eth(router->addr, ethhdr->h_source)))
1243                 is_from_best_next_hop = true;
1244
1245         prev_sender = batadv_ogm_packet->prev_sender;
1246         /* avoid temporary routing loops */
1247         if (router && router_router &&
1248             (batadv_compare_eth(router->addr, prev_sender)) &&
1249             !(batadv_compare_eth(batadv_ogm_packet->orig, prev_sender)) &&
1250             (batadv_compare_eth(router->addr, router_router->addr))) {
1251                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1252                            "Drop packet: ignoring all rebroadcast packets that may make me loop (sender: %pM)\n",
1253                            ethhdr->h_source);
1254                 goto out;
1255         }
1256
1257         /* if sender is a direct neighbor the sender mac equals
1258          * originator mac
1259          */
1260         if (is_single_hop_neigh)
1261                 orig_neigh_node = orig_node;
1262         else
1263                 orig_neigh_node = batadv_get_orig_node(bat_priv,
1264                                                        ethhdr->h_source);
1265
1266         if (!orig_neigh_node)
1267                 goto out;
1268
1269         /* Update nc_nodes of the originator */
1270         batadv_nc_update_nc_node(bat_priv, orig_node, orig_neigh_node,
1271                                  batadv_ogm_packet, is_single_hop_neigh);
1272
1273         orig_neigh_router = batadv_orig_node_get_router(orig_neigh_node);
1274
1275         /* drop packet if sender is not a direct neighbor and if we
1276          * don't route towards it
1277          */
1278         if (!is_single_hop_neigh && (!orig_neigh_router)) {
1279                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1280                            "Drop packet: OGM via unknown neighbor!\n");
1281                 goto out_neigh;
1282         }
1283
1284         is_bidirect = batadv_iv_ogm_calc_tq(orig_node, orig_neigh_node,
1285                                             batadv_ogm_packet, if_incoming);
1286
1287         batadv_bonding_save_primary(orig_node, orig_neigh_node,
1288                                     batadv_ogm_packet);
1289
1290         /* update ranking if it is not a duplicate or has the same
1291          * seqno and similar ttl as the non-duplicate
1292          */
1293         sameseq = orig_node->last_real_seqno == ntohl(batadv_ogm_packet->seqno);
1294         similar_ttl = orig_node->last_ttl - 3 <= batadv_ogm_packet->header.ttl;
1295         if (is_bidirect && ((dup_status == BATADV_NO_DUP) ||
1296                             (sameseq && similar_ttl)))
1297                 batadv_iv_ogm_orig_update(bat_priv, orig_node, ethhdr,
1298                                           batadv_ogm_packet, if_incoming,
1299                                           tt_buff, dup_status);
1300
1301         /* is single hop (direct) neighbor */
1302         if (is_single_hop_neigh) {
1303                 /* mark direct link on incoming interface */
1304                 batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1305                                       is_single_hop_neigh,
1306                                       is_from_best_next_hop, if_incoming);
1307
1308                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1309                            "Forwarding packet: rebroadcast neighbor packet with direct link flag\n");
1310                 goto out_neigh;
1311         }
1312
1313         /* multihop originator */
1314         if (!is_bidirect) {
1315                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1316                            "Drop packet: not received via bidirectional link\n");
1317                 goto out_neigh;
1318         }
1319
1320         if (dup_status == BATADV_NEIGH_DUP) {
1321                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1322                            "Drop packet: duplicate packet received\n");
1323                 goto out_neigh;
1324         }
1325
1326         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1327                    "Forwarding packet: rebroadcast originator packet\n");
1328         batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1329                               is_single_hop_neigh, is_from_best_next_hop,
1330                               if_incoming);
1331
1332 out_neigh:
1333         if ((orig_neigh_node) && (!is_single_hop_neigh))
1334                 batadv_orig_node_free_ref(orig_neigh_node);
1335 out:
1336         if (router)
1337                 batadv_neigh_node_free_ref(router);
1338         if (router_router)
1339                 batadv_neigh_node_free_ref(router_router);
1340         if (orig_neigh_router)
1341                 batadv_neigh_node_free_ref(orig_neigh_router);
1342
1343         batadv_orig_node_free_ref(orig_node);
1344 }
1345
1346 static int batadv_iv_ogm_receive(struct sk_buff *skb,
1347                                  struct batadv_hard_iface *if_incoming)
1348 {
1349         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1350         struct batadv_ogm_packet *batadv_ogm_packet;
1351         struct ethhdr *ethhdr;
1352         int buff_pos = 0, packet_len;
1353         unsigned char *tt_buff, *packet_buff;
1354         bool ret;
1355         uint8_t *packet_pos;
1356
1357         ret = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN);
1358         if (!ret)
1359                 return NET_RX_DROP;
1360
1361         /* did we receive a B.A.T.M.A.N. IV OGM packet on an interface
1362          * that does not have B.A.T.M.A.N. IV enabled ?
1363          */
1364         if (bat_priv->bat_algo_ops->bat_ogm_emit != batadv_iv_ogm_emit)
1365                 return NET_RX_DROP;
1366
1367         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1368         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1369                            skb->len + ETH_HLEN);
1370
1371         packet_len = skb_headlen(skb);
1372         ethhdr = eth_hdr(skb);
1373         packet_buff = skb->data;
1374         batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
1375
1376         /* unpack the aggregated packets and process them one by one */
1377         while (batadv_iv_ogm_aggr_packet(buff_pos, packet_len,
1378                                          batadv_ogm_packet->tt_num_changes)) {
1379                 tt_buff = packet_buff + buff_pos + BATADV_OGM_HLEN;
1380
1381                 batadv_iv_ogm_process(ethhdr, batadv_ogm_packet, tt_buff,
1382                                       if_incoming);
1383
1384                 buff_pos += BATADV_OGM_HLEN;
1385                 buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
1386
1387                 packet_pos = packet_buff + buff_pos;
1388                 batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
1389         }
1390
1391         kfree_skb(skb);
1392         return NET_RX_SUCCESS;
1393 }
1394
1395 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
1396         .name = "BATMAN_IV",
1397         .bat_iface_enable = batadv_iv_ogm_iface_enable,
1398         .bat_iface_disable = batadv_iv_ogm_iface_disable,
1399         .bat_iface_update_mac = batadv_iv_ogm_iface_update_mac,
1400         .bat_primary_iface_set = batadv_iv_ogm_primary_iface_set,
1401         .bat_ogm_schedule = batadv_iv_ogm_schedule,
1402         .bat_ogm_emit = batadv_iv_ogm_emit,
1403 };
1404
1405 int __init batadv_iv_init(void)
1406 {
1407         int ret;
1408
1409         /* batman originator packet */
1410         ret = batadv_recv_handler_register(BATADV_IV_OGM,
1411                                            batadv_iv_ogm_receive);
1412         if (ret < 0)
1413                 goto out;
1414
1415         ret = batadv_algo_register(&batadv_batman_iv);
1416         if (ret < 0)
1417                 goto handler_unregister;
1418
1419         goto out;
1420
1421 handler_unregister:
1422         batadv_recv_handler_unregister(BATADV_IV_OGM);
1423 out:
1424         return ret;
1425 }