net/batman-adv/bat_v_ogm.c

   1 /* Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
   2  *
   3  * Antonio Quartulli
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "bat_v_ogm.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/errno.h>
  24 #include <linux/etherdevice.h>
  25 #include <linux/fs.h>
  26 #include <linux/if_ether.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/kernel.h>
  29 #include <linux/kref.h>
  30 #include <linux/list.h>
  31 #include <linux/lockdep.h>
  32 #include <linux/mutex.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/random.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rcupdate.h>
  37 #include <linux/skbuff.h>
  38 #include <linux/slab.h>
  39 #include <linux/stddef.h>
  40 #include <linux/string.h>
  41 #include <linux/types.h>
  42 #include <linux/workqueue.h>
  43
  44 #include "bat_algo.h"
  45 #include "hard-interface.h"
  46 #include "hash.h"
  47 #include "log.h"
  48 #include "originator.h"
  49 #include "packet.h"
  50 #include "routing.h"
  51 #include "send.h"
  52 #include "translation-table.h"
  53 #include "tvlv.h"
  54
  55 /**
  56  * batadv_v_ogm_orig_get - retrieve and possibly create an originator node
  57  * @bat_priv: the bat priv with all the soft interface information
  58  * @addr: the address of the originator
  59  *
  60  * Return: the orig_node corresponding to the specified address. If such object
  61  * does not exist it is allocated here. In case of allocation failure returns
  62  * NULL.
  63  */
  64 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  65                                                const u8 *addr)
  66 {
  67         struct batadv_orig_node *orig_node;
  68         int hash_added;
  69
  70         orig_node = batadv_orig_hash_find(bat_priv, addr);
  71         if (orig_node)
  72                 return orig_node;
  73
  74         orig_node = batadv_orig_node_new(bat_priv, addr);
  75         if (!orig_node)
  76                 return NULL;
  77
  78         kref_get(&orig_node->refcount);
  79         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  80                                      batadv_choose_orig, orig_node,
  81                                      &orig_node->hash_entry);
  82         if (hash_added != 0) {
  83                 /* remove refcnt for newly created orig_node and hash entry */
  84                 batadv_orig_node_put(orig_node);
  85                 batadv_orig_node_put(orig_node);
  86                 orig_node = NULL;
  87         }
  88
  89         return orig_node;
  90 }
  91
  92 /**
  93  * batadv_v_ogm_start_timer - restart the OGM sending timer
  94  * @bat_priv: the bat priv with all the soft interface information
  95  */
  96 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
  97 {
  98         unsigned long msecs;
  99         /* this function may be invoked in different contexts (ogm rescheduling
 100          * or hard_iface activation), but the work timer should not be reset
 101          */
 102         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 103                 return;
 104
 105         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 106         msecs += prandom_u32() % (2 * BATADV_JITTER);
 107         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 108                            msecs_to_jiffies(msecs));
 109 }
 110
 111 /**
 112  * batadv_v_ogm_send_to_if - send a batman ogm using a given interface
 113  * @skb: the OGM to send
 114  * @hard_iface: the interface to use to send the OGM
 115  */
 116 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 117                                     struct batadv_hard_iface *hard_iface)
 118 {
 119         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 120
 121         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 122                 return;
 123
 124         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 125         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 126                            skb->len + ETH_HLEN);
 127
 128         batadv_send_broadcast_skb(skb, hard_iface);
 129 }
 130
 131 /**
 132  * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
 133  *  @bat_priv: the bat priv with all the soft interface information
 134  */
 135 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
 136 {
 137         struct batadv_hard_iface *hard_iface;
 138         struct batadv_ogm2_packet *ogm_packet;
 139         struct sk_buff *skb, *skb_tmp;
 140         unsigned char *ogm_buff;
 141         int ogm_buff_len;
 142         u16 tvlv_len = 0;
 143         int ret;
 144
 145         lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 146
 147         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 148                 goto out;
 149
 150         ogm_buff = bat_priv->bat_v.ogm_buff;
 151         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 152         /* tt changes have to be committed before the tvlv data is
 153          * appended as it may alter the tt tvlv container
 154          */
 155         batadv_tt_local_commit_changes(bat_priv);
 156         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 157                                                     &ogm_buff_len,
 158                                                     BATADV_OGM2_HLEN);
 159
 160         bat_priv->bat_v.ogm_buff = ogm_buff;
 161         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 162
 163         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 164         if (!skb)
 165                 goto reschedule;
 166
 167         skb_reserve(skb, ETH_HLEN);
 168         skb_put_data(skb, ogm_buff, ogm_buff_len);
 169
 170         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 171         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 172         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 173         ogm_packet->tvlv_len = htons(tvlv_len);
 174
 175         /* broadcast on every interface */
 176         rcu_read_lock();
 177         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 178                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 179                         continue;
 180
 181                 if (!kref_get_unless_zero(&hard_iface->refcount))
 182                         continue;
 183
 184                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 185                 if (ret) {
 186                         char *type;
 187
 188                         switch (ret) {
 189                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 190                                 type = "no neighbor";
 191                                 break;
 192                         case BATADV_HARDIF_BCAST_DUPFWD:
 193                                 type = "single neighbor is source";
 194                                 break;
 195                         case BATADV_HARDIF_BCAST_DUPORIG:
 196                                 type = "single neighbor is originator";
 197                                 break;
 198                         default:
 199                                 type = "unknown";
 200                         }
 201
 202                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
 203                                    hard_iface->net_dev->name, type);
 204
 205                         batadv_hardif_put(hard_iface);
 206                         continue;
 207                 }
 208
 209                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 210                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 211                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 212                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 213                            hard_iface->net_dev->name,
 214                            hard_iface->net_dev->dev_addr);
 215
 216                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 217                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 218                 if (!skb_tmp) {
 219                         batadv_hardif_put(hard_iface);
 220                         break;
 221                 }
 222
 223                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 224                 batadv_hardif_put(hard_iface);
 225         }
 226         rcu_read_unlock();
 227
 228         consume_skb(skb);
 229
 230 reschedule:
 231         batadv_v_ogm_start_timer(bat_priv);
 232 out:
 233         return;
 234 }
 235
 236 /**
 237  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 238  * @work: work queue item
 239  */
 240 static void batadv_v_ogm_send(struct work_struct *work)
 241 {
 242         struct batadv_priv_bat_v *bat_v;
 243         struct batadv_priv *bat_priv;
 244
 245         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 246         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 247
 248         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 249         batadv_v_ogm_send_softif(bat_priv);
 250         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 251 }
 252
 253 /**
 254  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
 255  * @hard_iface: the interface to prepare
 256  *
 257  * Takes care of scheduling own OGM sending routine for this interface.
 258  *
 259  * Return: 0 on success or a negative error code otherwise
 260  */
 261 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 262 {
 263         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 264
 265         batadv_v_ogm_start_timer(bat_priv);
 266
 267         return 0;
 268 }
 269
 270 /**
 271  * batadv_v_ogm_primary_iface_set - set a new primary interface
 272  * @primary_iface: the new primary interface
 273  */
 274 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 275 {
 276         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 277         struct batadv_ogm2_packet *ogm_packet;
 278
 279         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 280         if (!bat_priv->bat_v.ogm_buff)
 281                 goto unlock;
 282
 283         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 284         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 285
 286 unlock:
 287         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 288 }
 289
 290 /**
 291  * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
 292  *  with B.A.T.M.A.N. V OGMs
 293  * @bat_priv: the bat priv with all the soft interface information
 294  * @if_incoming: the interface where the OGM has been received
 295  * @if_outgoing: the interface where the OGM has to be forwarded to
 296  * @throughput: the current throughput
 297  *
 298  * Apply a penalty on the current throughput metric value based on the
 299  * characteristic of the interface where the OGM has been received. The return
 300  * value is computed as follows:
 301  * - throughput * 50%          if the incoming and outgoing interface are the
 302  *                             same WiFi interface and the throughput is above
 303  *                             1MBit/s
 304  * - throughput                if the outgoing interface is the default
 305  *                             interface (i.e. this OGM is processed for the
 306  *                             internal table and not forwarded)
 307  * - throughput * hop penalty  otherwise
 308  *
 309  * Return: the penalised throughput metric.
 310  */
 311 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 312                                     struct batadv_hard_iface *if_incoming,
 313                                     struct batadv_hard_iface *if_outgoing,
 314                                     u32 throughput)
 315 {
 316         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 317         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 318
 319         /* Don't apply hop penalty in default originator table. */
 320         if (if_outgoing == BATADV_IF_DEFAULT)
 321                 return throughput;
 322
 323         /* Forwarding on the same WiFi interface cuts the throughput in half
 324          * due to the store & forward characteristics of WIFI.
 325          * Very low throughput values are the exception.
 326          */
 327         if ((throughput > 10) &&
 328             (if_incoming == if_outgoing) &&
 329             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 330                 return throughput / 2;
 331
 332         /* hop penalty of 255 equals 100% */
 333         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 334 }
 335
 336 /**
 337  * batadv_v_ogm_forward - check conditions and forward an OGM to the given
 338  *  outgoing interface
 339  * @bat_priv: the bat priv with all the soft interface information
 340  * @ogm_received: previously received OGM to be forwarded
 341  * @orig_node: the originator which has been updated
 342  * @neigh_node: the neigh_node through with the OGM has been received
 343  * @if_incoming: the interface on which this OGM was received on
 344  * @if_outgoing: the interface to which the OGM has to be forwarded to
 345  *
 346  * Forward an OGM to an interface after having altered the throughput metric and
 347  * the TTL value contained in it. The original OGM isn't modified.
 348  */
 349 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 350                                  const struct batadv_ogm2_packet *ogm_received,
 351                                  struct batadv_orig_node *orig_node,
 352                                  struct batadv_neigh_node *neigh_node,
 353                                  struct batadv_hard_iface *if_incoming,
 354                                  struct batadv_hard_iface *if_outgoing)
 355 {
 356         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 357         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 358         struct batadv_neigh_node *router = NULL;
 359         struct batadv_ogm2_packet *ogm_forward;
 360         unsigned char *skb_buff;
 361         struct sk_buff *skb;
 362         size_t packet_len;
 363         u16 tvlv_len;
 364
 365         /* only forward for specific interfaces, not for the default one. */
 366         if (if_outgoing == BATADV_IF_DEFAULT)
 367                 goto out;
 368
 369         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 370         if (!orig_ifinfo)
 371                 goto out;
 372
 373         /* acquire possibly updated router */
 374         router = batadv_orig_router_get(orig_node, if_outgoing);
 375
 376         /* strict rule: forward packets coming from the best next hop only */
 377         if (neigh_node != router)
 378                 goto out;
 379
 380         /* don't forward the same seqno twice on one interface */
 381         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 382                 goto out;
 383
 384         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 385
 386         if (ogm_received->ttl <= 1) {
 387                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 388                 goto out;
 389         }
 390
 391         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 392         if (!neigh_ifinfo)
 393                 goto out;
 394
 395         tvlv_len = ntohs(ogm_received->tvlv_len);
 396
 397         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 398         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 399                                         ETH_HLEN + packet_len);
 400         if (!skb)
 401                 goto out;
 402
 403         skb_reserve(skb, ETH_HLEN);
 404         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 405
 406         /* apply forward penalty */
 407         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 408         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 409         ogm_forward->ttl--;
 410
 411         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 412                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 413                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 414                    ogm_forward->ttl, if_incoming->net_dev->name);
 415
 416         batadv_v_ogm_send_to_if(skb, if_outgoing);
 417
 418 out:
 419         if (orig_ifinfo)
 420                 batadv_orig_ifinfo_put(orig_ifinfo);
 421         if (router)
 422                 batadv_neigh_node_put(router);
 423         if (neigh_ifinfo)
 424                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 425 }
 426
 427 /**
 428  * batadv_v_ogm_metric_update - update route metric based on OGM
 429  * @bat_priv: the bat priv with all the soft interface information
 430  * @ogm2: OGM2 structure
 431  * @orig_node: Originator structure for which the OGM has been received
 432  * @neigh_node: the neigh_node through with the OGM has been received
 433  * @if_incoming: the interface where this packet was received
 434  * @if_outgoing: the interface for which the packet should be considered
 435  *
 436  * Return:
 437  *  1  if the OGM is new,
 438  *  0  if it is not new but valid,
 439  *  <0 on error (e.g. old OGM)
 440  */
 441 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 442                                       const struct batadv_ogm2_packet *ogm2,
 443                                       struct batadv_orig_node *orig_node,
 444                                       struct batadv_neigh_node *neigh_node,
 445                                       struct batadv_hard_iface *if_incoming,
 446                                       struct batadv_hard_iface *if_outgoing)
 447 {
 448         struct batadv_orig_ifinfo *orig_ifinfo;
 449         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 450         bool protection_started = false;
 451         int ret = -EINVAL;
 452         u32 path_throughput;
 453         s32 seq_diff;
 454
 455         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 456         if (!orig_ifinfo)
 457                 goto out;
 458
 459         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 460
 461         if (!hlist_empty(&orig_node->neigh_list) &&
 462             batadv_window_protected(bat_priv, seq_diff,
 463                                     BATADV_OGM_MAX_AGE,
 464                                     &orig_ifinfo->batman_seqno_reset,
 465                                     &protection_started)) {
 466                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 467                            "Drop packet: packet within window protection time from %pM\n",
 468                            ogm2->orig);
 469                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 470                            "Last reset: %ld, %ld\n",
 471                            orig_ifinfo->batman_seqno_reset, jiffies);
 472                 goto out;
 473         }
 474
 475         /* drop packets with old seqnos, however accept the first packet after
 476          * a host has been rebooted.
 477          */
 478         if ((seq_diff < 0) && !protection_started)
 479                 goto out;
 480
 481         neigh_node->last_seen = jiffies;
 482
 483         orig_node->last_seen = jiffies;
 484
 485         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 486         orig_ifinfo->last_ttl = ogm2->ttl;
 487
 488         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 489         if (!neigh_ifinfo)
 490                 goto out;
 491
 492         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 493                                                    if_outgoing,
 494                                                    ntohl(ogm2->throughput));
 495         neigh_ifinfo->bat_v.throughput = path_throughput;
 496         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 497         neigh_ifinfo->last_ttl = ogm2->ttl;
 498
 499         if (seq_diff > 0 || protection_started)
 500                 ret = 1;
 501         else
 502                 ret = 0;
 503 out:
 504         if (orig_ifinfo)
 505                 batadv_orig_ifinfo_put(orig_ifinfo);
 506         if (neigh_ifinfo)
 507                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 508
 509         return ret;
 510 }
 511
 512 /**
 513  * batadv_v_ogm_route_update - update routes based on OGM
 514  * @bat_priv: the bat priv with all the soft interface information
 515  * @ethhdr: the Ethernet header of the OGM2
 516  * @ogm2: OGM2 structure
 517  * @orig_node: Originator structure for which the OGM has been received
 518  * @neigh_node: the neigh_node through with the OGM has been received
 519  * @if_incoming: the interface where this packet was received
 520  * @if_outgoing: the interface for which the packet should be considered
 521  *
 522  * Return: true if the packet should be forwarded, false otherwise
 523  */
 524 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 525                                       const struct ethhdr *ethhdr,
 526                                       const struct batadv_ogm2_packet *ogm2,
 527                                       struct batadv_orig_node *orig_node,
 528                                       struct batadv_neigh_node *neigh_node,
 529                                       struct batadv_hard_iface *if_incoming,
 530                                       struct batadv_hard_iface *if_outgoing)
 531 {
 532         struct batadv_neigh_node *router = NULL;
 533         struct batadv_orig_node *orig_neigh_node;
 534         struct batadv_neigh_node *orig_neigh_router = NULL;
 535         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 536         u32 router_throughput, neigh_throughput;
 537         u32 router_last_seqno;
 538         u32 neigh_last_seqno;
 539         s32 neigh_seq_diff;
 540         bool forward = false;
 541
 542         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 543         if (!orig_neigh_node)
 544                 goto out;
 545
 546         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 547                                                    if_outgoing);
 548
 549         /* drop packet if sender is not a direct neighbor and if we
 550          * don't route towards it
 551          */
 552         router = batadv_orig_router_get(orig_node, if_outgoing);
 553         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 554                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 555                            "Drop packet: OGM via unknown neighbor!\n");
 556                 goto out;
 557         }
 558
 559         /* Mark the OGM to be considered for forwarding, and update routes
 560          * if needed.
 561          */
 562         forward = true;
 563
 564         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 565                    "Searching and updating originator entry of received packet\n");
 566
 567         /* if this neighbor already is our next hop there is nothing
 568          * to change
 569          */
 570         if (router == neigh_node)
 571                 goto out;
 572
 573         /* don't consider neighbours with worse throughput.
 574          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 575          * the last received seqno from our best next hop.
 576          */
 577         if (router) {
 578                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 579                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 580
 581                 /* if these are not allocated, something is wrong. */
 582                 if (!router_ifinfo || !neigh_ifinfo)
 583                         goto out;
 584
 585                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 586                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 587                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 588                 router_throughput = router_ifinfo->bat_v.throughput;
 589                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 590
 591                 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
 592                     (router_throughput >= neigh_throughput))
 593                         goto out;
 594         }
 595
 596         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 597 out:
 598         if (router)
 599                 batadv_neigh_node_put(router);
 600         if (orig_neigh_router)
 601                 batadv_neigh_node_put(orig_neigh_router);
 602         if (orig_neigh_node)
 603                 batadv_orig_node_put(orig_neigh_node);
 604         if (router_ifinfo)
 605                 batadv_neigh_ifinfo_put(router_ifinfo);
 606         if (neigh_ifinfo)
 607                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 608
 609         return forward;
 610 }
 611
 612 /**
 613  * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
 614  * @bat_priv: the bat priv with all the soft interface information
 615  * @ethhdr: the Ethernet header of the OGM2
 616  * @ogm2: OGM2 structure
 617  * @orig_node: Originator structure for which the OGM has been received
 618  * @neigh_node: the neigh_node through with the OGM has been received
 619  * @if_incoming: the interface where this packet was received
 620  * @if_outgoing: the interface for which the packet should be considered
 621  */
 622 static void
 623 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 624                                const struct ethhdr *ethhdr,
 625                                const struct batadv_ogm2_packet *ogm2,
 626                                struct batadv_orig_node *orig_node,
 627                                struct batadv_neigh_node *neigh_node,
 628                                struct batadv_hard_iface *if_incoming,
 629                                struct batadv_hard_iface *if_outgoing)
 630 {
 631         int seqno_age;
 632         bool forward;
 633
 634         /* first, update the metric with according sanity checks */
 635         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 636                                                neigh_node, if_incoming,
 637                                                if_outgoing);
 638
 639         /* outdated sequence numbers are to be discarded */
 640         if (seqno_age < 0)
 641                 return;
 642
 643         /* only unknown & newer OGMs contain TVLVs we are interested in */
 644         if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
 645                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 646                                                NULL, NULL,
 647                                                (unsigned char *)(ogm2 + 1),
 648                                                ntohs(ogm2->tvlv_len));
 649
 650         /* if the metric update went through, update routes if needed */
 651         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 652                                             neigh_node, if_incoming,
 653                                             if_outgoing);
 654
 655         /* if the routes have been processed correctly, check and forward */
 656         if (forward)
 657                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 658                                      if_incoming, if_outgoing);
 659 }
 660
 661 /**
 662  * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
 663  * @buff_pos: current position in the skb
 664  * @packet_len: total length of the skb
 665  * @ogm2_packet: potential OGM2 in buffer
 666  *
 667  * Return: true if there is enough space for another OGM, false otherwise.
 668  */
 669 static bool
 670 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 671                          const struct batadv_ogm2_packet *ogm2_packet)
 672 {
 673         int next_buff_pos = 0;
 674
 675         /* check if there is enough space for the header */
 676         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 677         if (next_buff_pos > packet_len)
 678                 return false;
 679
 680         /* check if there is enough space for the optional TVLV */
 681         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 682
 683         return (next_buff_pos <= packet_len) &&
 684                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 685 }
 686
 687 /**
 688  * batadv_v_ogm_process - process an incoming batman v OGM
 689  * @skb: the skb containing the OGM
 690  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 691  * @if_incoming: the interface where this packet was receved
 692  */
 693 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 694                                  struct batadv_hard_iface *if_incoming)
 695 {
 696         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 697         struct ethhdr *ethhdr;
 698         struct batadv_orig_node *orig_node = NULL;
 699         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 700         struct batadv_neigh_node *neigh_node = NULL;
 701         struct batadv_hard_iface *hard_iface;
 702         struct batadv_ogm2_packet *ogm_packet;
 703         u32 ogm_throughput, link_throughput, path_throughput;
 704         int ret;
 705
 706         ethhdr = eth_hdr(skb);
 707         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 708
 709         ogm_throughput = ntohl(ogm_packet->throughput);
 710
 711         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 712                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 713                    ethhdr->h_source, if_incoming->net_dev->name,
 714                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 715                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 716                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 717
 718         if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
 719                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 720                            "Drop packet: originator packet from ourself\n");
 721                 return;
 722         }
 723
 724         /* If the throughput metric is 0, immediately drop the packet. No need
 725          * to create orig_node / neigh_node for an unusable route.
 726          */
 727         if (ogm_throughput == 0) {
 728                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 729                            "Drop packet: originator packet with throughput metric of 0\n");
 730                 return;
 731         }
 732
 733         /* require ELP packets be to received from this neighbor first */
 734         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 735         if (!hardif_neigh) {
 736                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 737                            "Drop packet: OGM via unknown neighbor!\n");
 738                 goto out;
 739         }
 740
 741         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 742         if (!orig_node)
 743                 goto out;
 744
 745         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 746                                                      ethhdr->h_source);
 747         if (!neigh_node)
 748                 goto out;
 749
 750         /* Update the received throughput metric to match the link
 751          * characteristic:
 752          *  - If this OGM traveled one hop so far (emitted by single hop
 753          *    neighbor) the path throughput metric equals the link throughput.
 754          *  - For OGMs traversing more than hop the path throughput metric is
 755          *    the smaller of the path throughput and the link throughput.
 756          */
 757         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 758         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 759         ogm_packet->throughput = htonl(path_throughput);
 760
 761         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 762                                        neigh_node, if_incoming,
 763                                        BATADV_IF_DEFAULT);
 764
 765         rcu_read_lock();
 766         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 767                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 768                         continue;
 769
 770                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 771                         continue;
 772
 773                 if (!kref_get_unless_zero(&hard_iface->refcount))
 774                         continue;
 775
 776                 ret = batadv_hardif_no_broadcast(hard_iface,
 777                                                  ogm_packet->orig,
 778                                                  hardif_neigh->orig);
 779
 780                 if (ret) {
 781                         char *type;
 782
 783                         switch (ret) {
 784                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 785                                 type = "no neighbor";
 786                                 break;
 787                         case BATADV_HARDIF_BCAST_DUPFWD:
 788                                 type = "single neighbor is source";
 789                                 break;
 790                         case BATADV_HARDIF_BCAST_DUPORIG:
 791                                 type = "single neighbor is originator";
 792                                 break;
 793                         default:
 794                                 type = "unknown";
 795                         }
 796
 797                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 798                                    ogm_packet->orig, hard_iface->net_dev->name,
 799                                    type);
 800
 801                         batadv_hardif_put(hard_iface);
 802                         continue;
 803                 }
 804
 805                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 806                                                orig_node, neigh_node,
 807                                                if_incoming, hard_iface);
 808
 809                 batadv_hardif_put(hard_iface);
 810         }
 811         rcu_read_unlock();
 812 out:
 813         if (orig_node)
 814                 batadv_orig_node_put(orig_node);
 815         if (neigh_node)
 816                 batadv_neigh_node_put(neigh_node);
 817         if (hardif_neigh)
 818                 batadv_hardif_neigh_put(hardif_neigh);
 819 }
 820
 821 /**
 822  * batadv_v_ogm_packet_recv - OGM2 receiving handler
 823  * @skb: the received OGM
 824  * @if_incoming: the interface where this OGM has been received
 825  *
 826  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 827  * (without freeing the skb) on failure
 828  */
 829 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 830                              struct batadv_hard_iface *if_incoming)
 831 {
 832         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 833         struct batadv_ogm2_packet *ogm_packet;
 834         struct ethhdr *ethhdr = eth_hdr(skb);
 835         int ogm_offset;
 836         u8 *packet_pos;
 837         int ret = NET_RX_DROP;
 838
 839         /* did we receive a OGM2 packet on an interface that does not have
 840          * B.A.T.M.A.N. V enabled ?
 841          */
 842         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 843                 goto free_skb;
 844
 845         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 846                 goto free_skb;
 847
 848         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 849                 goto free_skb;
 850
 851         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 852         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 853                            skb->len + ETH_HLEN);
 854
 855         ogm_offset = 0;
 856         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 857
 858         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 859                                         ogm_packet)) {
 860                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 861
 862                 ogm_offset += BATADV_OGM2_HLEN;
 863                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 864
 865                 packet_pos = skb->data + ogm_offset;
 866                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 867         }
 868
 869         ret = NET_RX_SUCCESS;
 870
 871 free_skb:
 872         if (ret == NET_RX_SUCCESS)
 873                 consume_skb(skb);
 874         else
 875                 kfree_skb(skb);
 876
 877         return ret;
 878 }
 879
 880 /**
 881  * batadv_v_ogm_init - initialise the OGM2 engine
 882  * @bat_priv: the bat priv with all the soft interface information
 883  *
 884  * Return: 0 on success or a negative error code in case of failure
 885  */
 886 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 887 {
 888         struct batadv_ogm2_packet *ogm_packet;
 889         unsigned char *ogm_buff;
 890         u32 random_seqno;
 891
 892         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 893         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 894         if (!ogm_buff)
 895                 return -ENOMEM;
 896
 897         bat_priv->bat_v.ogm_buff = ogm_buff;
 898         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 899         ogm_packet->packet_type = BATADV_OGM2;
 900         ogm_packet->version = BATADV_COMPAT_VERSION;
 901         ogm_packet->ttl = BATADV_TTL;
 902         ogm_packet->flags = BATADV_NO_FLAGS;
 903         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 904
 905         /* randomize initial seqno to avoid collision */
 906         get_random_bytes(&random_seqno, sizeof(random_seqno));
 907         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 908         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 909
 910         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
 911
 912         return 0;
 913 }
 914
 915 /**
 916  * batadv_v_ogm_free - free OGM private resources
 917  * @bat_priv: the bat priv with all the soft interface information
 918  */
 919 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 920 {
 921         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 922
 923         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 924
 925         kfree(bat_priv->bat_v.ogm_buff);
 926         bat_priv->bat_v.ogm_buff = NULL;
 927         bat_priv->bat_v.ogm_buff_len = 0;
 928
 929         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 930 }