net/batman-adv/bat_v_ogm.c

   1 /* Copyright (C) 2013-2016 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, *pkt_buff;
 141         int ogm_buff_len;
 142         u16 tvlv_len = 0;
 143
 144         lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 145
 146         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 147                 goto out;
 148
 149         ogm_buff = bat_priv->bat_v.ogm_buff;
 150         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 151         /* tt changes have to be committed before the tvlv data is
 152          * appended as it may alter the tt tvlv container
 153          */
 154         batadv_tt_local_commit_changes(bat_priv);
 155         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 156                                                     &ogm_buff_len,
 157                                                     BATADV_OGM2_HLEN);
 158
 159         bat_priv->bat_v.ogm_buff = ogm_buff;
 160         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 161
 162         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 163         if (!skb)
 164                 goto reschedule;
 165
 166         skb_reserve(skb, ETH_HLEN);
 167         pkt_buff = skb_put(skb, ogm_buff_len);
 168         memcpy(pkt_buff, 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                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 185                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 186                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 187                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 188                            hard_iface->net_dev->name,
 189                            hard_iface->net_dev->dev_addr);
 190
 191                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 192                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 193                 if (!skb_tmp) {
 194                         batadv_hardif_put(hard_iface);
 195                         break;
 196                 }
 197
 198                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 199                 batadv_hardif_put(hard_iface);
 200         }
 201         rcu_read_unlock();
 202
 203         consume_skb(skb);
 204
 205 reschedule:
 206         batadv_v_ogm_start_timer(bat_priv);
 207 out:
 208         return;
 209 }
 210
 211 /**
 212  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 213  * @work: work queue item
 214  */
 215 static void batadv_v_ogm_send(struct work_struct *work)
 216 {
 217         struct batadv_priv_bat_v *bat_v;
 218         struct batadv_priv *bat_priv;
 219
 220         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 221         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 222
 223         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 224         batadv_v_ogm_send_softif(bat_priv);
 225         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 226 }
 227
 228 /**
 229  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
 230  * @hard_iface: the interface to prepare
 231  *
 232  * Takes care of scheduling own OGM sending routine for this interface.
 233  *
 234  * Return: 0 on success or a negative error code otherwise
 235  */
 236 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 237 {
 238         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 239
 240         batadv_v_ogm_start_timer(bat_priv);
 241
 242         return 0;
 243 }
 244
 245 /**
 246  * batadv_v_ogm_primary_iface_set - set a new primary interface
 247  * @primary_iface: the new primary interface
 248  */
 249 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 250 {
 251         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 252         struct batadv_ogm2_packet *ogm_packet;
 253
 254         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 255         if (!bat_priv->bat_v.ogm_buff)
 256                 goto unlock;
 257
 258         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 259         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 260
 261 unlock:
 262         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 263 }
 264
 265 /**
 266  * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
 267  *  with B.A.T.M.A.N. V OGMs
 268  * @bat_priv: the bat priv with all the soft interface information
 269  * @if_incoming: the interface where the OGM has been received
 270  * @if_outgoing: the interface where the OGM has to be forwarded to
 271  * @throughput: the current throughput
 272  *
 273  * Apply a penalty on the current throughput metric value based on the
 274  * characteristic of the interface where the OGM has been received. The return
 275  * value is computed as follows:
 276  * - throughput * 50%          if the incoming and outgoing interface are the
 277  *                             same WiFi interface and the throughput is above
 278  *                             1MBit/s
 279  * - throughput                if the outgoing interface is the default
 280  *                             interface (i.e. this OGM is processed for the
 281  *                             internal table and not forwarded)
 282  * - throughput * hop penalty  otherwise
 283  *
 284  * Return: the penalised throughput metric.
 285  */
 286 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 287                                     struct batadv_hard_iface *if_incoming,
 288                                     struct batadv_hard_iface *if_outgoing,
 289                                     u32 throughput)
 290 {
 291         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 292         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 293
 294         /* Don't apply hop penalty in default originator table. */
 295         if (if_outgoing == BATADV_IF_DEFAULT)
 296                 return throughput;
 297
 298         /* Forwarding on the same WiFi interface cuts the throughput in half
 299          * due to the store & forward characteristics of WIFI.
 300          * Very low throughput values are the exception.
 301          */
 302         if ((throughput > 10) &&
 303             (if_incoming == if_outgoing) &&
 304             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 305                 return throughput / 2;
 306
 307         /* hop penalty of 255 equals 100% */
 308         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 309 }
 310
 311 /**
 312  * batadv_v_ogm_forward - check conditions and forward an OGM to the given
 313  *  outgoing interface
 314  * @bat_priv: the bat priv with all the soft interface information
 315  * @ogm_received: previously received OGM to be forwarded
 316  * @orig_node: the originator which has been updated
 317  * @neigh_node: the neigh_node through with the OGM has been received
 318  * @if_incoming: the interface on which this OGM was received on
 319  * @if_outgoing: the interface to which the OGM has to be forwarded to
 320  *
 321  * Forward an OGM to an interface after having altered the throughput metric and
 322  * the TTL value contained in it. The original OGM isn't modified.
 323  */
 324 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 325                                  const struct batadv_ogm2_packet *ogm_received,
 326                                  struct batadv_orig_node *orig_node,
 327                                  struct batadv_neigh_node *neigh_node,
 328                                  struct batadv_hard_iface *if_incoming,
 329                                  struct batadv_hard_iface *if_outgoing)
 330 {
 331         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 332         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 333         struct batadv_neigh_node *router = NULL;
 334         struct batadv_ogm2_packet *ogm_forward;
 335         unsigned char *skb_buff;
 336         struct sk_buff *skb;
 337         size_t packet_len;
 338         u16 tvlv_len;
 339
 340         /* only forward for specific interfaces, not for the default one. */
 341         if (if_outgoing == BATADV_IF_DEFAULT)
 342                 goto out;
 343
 344         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 345         if (!orig_ifinfo)
 346                 goto out;
 347
 348         /* acquire possibly updated router */
 349         router = batadv_orig_router_get(orig_node, if_outgoing);
 350
 351         /* strict rule: forward packets coming from the best next hop only */
 352         if (neigh_node != router)
 353                 goto out;
 354
 355         /* don't forward the same seqno twice on one interface */
 356         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 357                 goto out;
 358
 359         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 360
 361         if (ogm_received->ttl <= 1) {
 362                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 363                 goto out;
 364         }
 365
 366         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 367         if (!neigh_ifinfo)
 368                 goto out;
 369
 370         tvlv_len = ntohs(ogm_received->tvlv_len);
 371
 372         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 373         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 374                                         ETH_HLEN + packet_len);
 375         if (!skb)
 376                 goto out;
 377
 378         skb_reserve(skb, ETH_HLEN);
 379         skb_buff = skb_put(skb, packet_len);
 380         memcpy(skb_buff, ogm_received, packet_len);
 381
 382         /* apply forward penalty */
 383         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 384         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 385         ogm_forward->ttl--;
 386
 387         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 388                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 389                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 390                    ogm_forward->ttl, if_incoming->net_dev->name);
 391
 392         batadv_v_ogm_send_to_if(skb, if_outgoing);
 393
 394 out:
 395         if (orig_ifinfo)
 396                 batadv_orig_ifinfo_put(orig_ifinfo);
 397         if (router)
 398                 batadv_neigh_node_put(router);
 399         if (neigh_ifinfo)
 400                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 401 }
 402
 403 /**
 404  * batadv_v_ogm_metric_update - update route metric based on OGM
 405  * @bat_priv: the bat priv with all the soft interface information
 406  * @ogm2: OGM2 structure
 407  * @orig_node: Originator structure for which the OGM has been received
 408  * @neigh_node: the neigh_node through with the OGM has been received
 409  * @if_incoming: the interface where this packet was received
 410  * @if_outgoing: the interface for which the packet should be considered
 411  *
 412  * Return:
 413  *  1  if the OGM is new,
 414  *  0  if it is not new but valid,
 415  *  <0 on error (e.g. old OGM)
 416  */
 417 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 418                                       const struct batadv_ogm2_packet *ogm2,
 419                                       struct batadv_orig_node *orig_node,
 420                                       struct batadv_neigh_node *neigh_node,
 421                                       struct batadv_hard_iface *if_incoming,
 422                                       struct batadv_hard_iface *if_outgoing)
 423 {
 424         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 425         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 426         bool protection_started = false;
 427         int ret = -EINVAL;
 428         u32 path_throughput;
 429         s32 seq_diff;
 430
 431         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 432         if (!orig_ifinfo)
 433                 goto out;
 434
 435         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 436
 437         if (!hlist_empty(&orig_node->neigh_list) &&
 438             batadv_window_protected(bat_priv, seq_diff,
 439                                     BATADV_OGM_MAX_AGE,
 440                                     &orig_ifinfo->batman_seqno_reset,
 441                                     &protection_started)) {
 442                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 443                            "Drop packet: packet within window protection time from %pM\n",
 444                            ogm2->orig);
 445                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 446                            "Last reset: %ld, %ld\n",
 447                            orig_ifinfo->batman_seqno_reset, jiffies);
 448                 goto out;
 449         }
 450
 451         /* drop packets with old seqnos, however accept the first packet after
 452          * a host has been rebooted.
 453          */
 454         if ((seq_diff < 0) && !protection_started)
 455                 goto out;
 456
 457         neigh_node->last_seen = jiffies;
 458
 459         orig_node->last_seen = jiffies;
 460
 461         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 462         orig_ifinfo->last_ttl = ogm2->ttl;
 463
 464         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 465         if (!neigh_ifinfo)
 466                 goto out;
 467
 468         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 469                                                    if_outgoing,
 470                                                    ntohl(ogm2->throughput));
 471         neigh_ifinfo->bat_v.throughput = path_throughput;
 472         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 473         neigh_ifinfo->last_ttl = ogm2->ttl;
 474
 475         if (seq_diff > 0 || protection_started)
 476                 ret = 1;
 477         else
 478                 ret = 0;
 479 out:
 480         if (orig_ifinfo)
 481                 batadv_orig_ifinfo_put(orig_ifinfo);
 482         if (neigh_ifinfo)
 483                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 484
 485         return ret;
 486 }
 487
 488 /**
 489  * batadv_v_ogm_route_update - update routes based on OGM
 490  * @bat_priv: the bat priv with all the soft interface information
 491  * @ethhdr: the Ethernet header of the OGM2
 492  * @ogm2: OGM2 structure
 493  * @orig_node: Originator structure for which the OGM has been received
 494  * @neigh_node: the neigh_node through with the OGM has been received
 495  * @if_incoming: the interface where this packet was received
 496  * @if_outgoing: the interface for which the packet should be considered
 497  *
 498  * Return: true if the packet should be forwarded, false otherwise
 499  */
 500 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 501                                       const struct ethhdr *ethhdr,
 502                                       const struct batadv_ogm2_packet *ogm2,
 503                                       struct batadv_orig_node *orig_node,
 504                                       struct batadv_neigh_node *neigh_node,
 505                                       struct batadv_hard_iface *if_incoming,
 506                                       struct batadv_hard_iface *if_outgoing)
 507 {
 508         struct batadv_neigh_node *router = NULL;
 509         struct batadv_orig_node *orig_neigh_node = NULL;
 510         struct batadv_neigh_node *orig_neigh_router = NULL;
 511         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 512         u32 router_throughput, neigh_throughput;
 513         u32 router_last_seqno;
 514         u32 neigh_last_seqno;
 515         s32 neigh_seq_diff;
 516         bool forward = false;
 517
 518         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 519         if (!orig_neigh_node)
 520                 goto out;
 521
 522         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 523                                                    if_outgoing);
 524
 525         /* drop packet if sender is not a direct neighbor and if we
 526          * don't route towards it
 527          */
 528         router = batadv_orig_router_get(orig_node, if_outgoing);
 529         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 530                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 531                            "Drop packet: OGM via unknown neighbor!\n");
 532                 goto out;
 533         }
 534
 535         /* Mark the OGM to be considered for forwarding, and update routes
 536          * if needed.
 537          */
 538         forward = true;
 539
 540         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 541                    "Searching and updating originator entry of received packet\n");
 542
 543         /* if this neighbor already is our next hop there is nothing
 544          * to change
 545          */
 546         if (router == neigh_node)
 547                 goto out;
 548
 549         /* don't consider neighbours with worse throughput.
 550          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 551          * the last received seqno from our best next hop.
 552          */
 553         if (router) {
 554                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 555                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 556
 557                 /* if these are not allocated, something is wrong. */
 558                 if (!router_ifinfo || !neigh_ifinfo)
 559                         goto out;
 560
 561                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 562                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 563                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 564                 router_throughput = router_ifinfo->bat_v.throughput;
 565                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 566
 567                 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
 568                     (router_throughput >= neigh_throughput))
 569                         goto out;
 570         }
 571
 572         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 573 out:
 574         if (router)
 575                 batadv_neigh_node_put(router);
 576         if (orig_neigh_router)
 577                 batadv_neigh_node_put(orig_neigh_router);
 578         if (orig_neigh_node)
 579                 batadv_orig_node_put(orig_neigh_node);
 580         if (router_ifinfo)
 581                 batadv_neigh_ifinfo_put(router_ifinfo);
 582         if (neigh_ifinfo)
 583                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 584
 585         return forward;
 586 }
 587
 588 /**
 589  * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
 590  * @bat_priv: the bat priv with all the soft interface information
 591  * @ethhdr: the Ethernet header of the OGM2
 592  * @ogm2: OGM2 structure
 593  * @orig_node: Originator structure for which the OGM has been received
 594  * @neigh_node: the neigh_node through with the OGM has been received
 595  * @if_incoming: the interface where this packet was received
 596  * @if_outgoing: the interface for which the packet should be considered
 597  */
 598 static void
 599 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 600                                const struct ethhdr *ethhdr,
 601                                const struct batadv_ogm2_packet *ogm2,
 602                                struct batadv_orig_node *orig_node,
 603                                struct batadv_neigh_node *neigh_node,
 604                                struct batadv_hard_iface *if_incoming,
 605                                struct batadv_hard_iface *if_outgoing)
 606 {
 607         int seqno_age;
 608         bool forward;
 609
 610         /* first, update the metric with according sanity checks */
 611         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 612                                                neigh_node, if_incoming,
 613                                                if_outgoing);
 614
 615         /* outdated sequence numbers are to be discarded */
 616         if (seqno_age < 0)
 617                 return;
 618
 619         /* only unknown & newer OGMs contain TVLVs we are interested in */
 620         if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
 621                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 622                                                NULL, NULL,
 623                                                (unsigned char *)(ogm2 + 1),
 624                                                ntohs(ogm2->tvlv_len));
 625
 626         /* if the metric update went through, update routes if needed */
 627         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 628                                             neigh_node, if_incoming,
 629                                             if_outgoing);
 630
 631         /* if the routes have been processed correctly, check and forward */
 632         if (forward)
 633                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 634                                      if_incoming, if_outgoing);
 635 }
 636
 637 /**
 638  * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
 639  * @buff_pos: current position in the skb
 640  * @packet_len: total length of the skb
 641  * @ogm2_packet: potential OGM2 in buffer
 642  *
 643  * Return: true if there is enough space for another OGM, false otherwise.
 644  */
 645 static bool
 646 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 647                          const struct batadv_ogm2_packet *ogm2_packet)
 648 {
 649         int next_buff_pos = 0;
 650
 651         /* check if there is enough space for the header */
 652         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 653         if (next_buff_pos > packet_len)
 654                 return false;
 655
 656         /* check if there is enough space for the optional TVLV */
 657         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 658
 659         return (next_buff_pos <= packet_len) &&
 660                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 661 }
 662
 663 /**
 664  * batadv_v_ogm_process - process an incoming batman v OGM
 665  * @skb: the skb containing the OGM
 666  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 667  * @if_incoming: the interface where this packet was receved
 668  */
 669 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 670                                  struct batadv_hard_iface *if_incoming)
 671 {
 672         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 673         struct ethhdr *ethhdr;
 674         struct batadv_orig_node *orig_node = NULL;
 675         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 676         struct batadv_neigh_node *neigh_node = NULL;
 677         struct batadv_hard_iface *hard_iface;
 678         struct batadv_ogm2_packet *ogm_packet;
 679         u32 ogm_throughput, link_throughput, path_throughput;
 680
 681         ethhdr = eth_hdr(skb);
 682         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 683
 684         ogm_throughput = ntohl(ogm_packet->throughput);
 685
 686         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 687                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n",
 688                    ethhdr->h_source, if_incoming->net_dev->name,
 689                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 690                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 691                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 692
 693         if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
 694                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 695                            "Drop packet: originator packet from ourself\n");
 696                 return;
 697         }
 698
 699         /* If the troughput metric is 0, immediately drop the packet. No need to
 700          * create orig_node / neigh_node for an unusable route.
 701          */
 702         if (ogm_throughput == 0) {
 703                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 704                            "Drop packet: originator packet with troughput metric of 0\n");
 705                 return;
 706         }
 707
 708         /* require ELP packets be to received from this neighbor first */
 709         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 710         if (!hardif_neigh) {
 711                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 712                            "Drop packet: OGM via unknown neighbor!\n");
 713                 goto out;
 714         }
 715
 716         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 717         if (!orig_node)
 718                 goto out;
 719
 720         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 721                                                      ethhdr->h_source);
 722         if (!neigh_node)
 723                 goto out;
 724
 725         /* Update the received throughput metric to match the link
 726          * characteristic:
 727          *  - If this OGM traveled one hop so far (emitted by single hop
 728          *    neighbor) the path throughput metric equals the link throughput.
 729          *  - For OGMs traversing more than hop the path throughput metric is
 730          *    the smaller of the path throughput and the link throughput.
 731          */
 732         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 733         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 734         ogm_packet->throughput = htonl(path_throughput);
 735
 736         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 737                                        neigh_node, if_incoming,
 738                                        BATADV_IF_DEFAULT);
 739
 740         rcu_read_lock();
 741         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 742                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 743                         continue;
 744
 745                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 746                         continue;
 747
 748                 if (!kref_get_unless_zero(&hard_iface->refcount))
 749                         continue;
 750
 751                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 752                                                orig_node, neigh_node,
 753                                                if_incoming, hard_iface);
 754
 755                 batadv_hardif_put(hard_iface);
 756         }
 757         rcu_read_unlock();
 758 out:
 759         if (orig_node)
 760                 batadv_orig_node_put(orig_node);
 761         if (neigh_node)
 762                 batadv_neigh_node_put(neigh_node);
 763         if (hardif_neigh)
 764                 batadv_hardif_neigh_put(hardif_neigh);
 765 }
 766
 767 /**
 768  * batadv_v_ogm_packet_recv - OGM2 receiving handler
 769  * @skb: the received OGM
 770  * @if_incoming: the interface where this OGM has been received
 771  *
 772  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 773  * (without freeing the skb) on failure
 774  */
 775 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 776                              struct batadv_hard_iface *if_incoming)
 777 {
 778         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 779         struct batadv_ogm2_packet *ogm_packet;
 780         struct ethhdr *ethhdr = eth_hdr(skb);
 781         int ogm_offset;
 782         u8 *packet_pos;
 783         int ret = NET_RX_DROP;
 784
 785         /* did we receive a OGM2 packet on an interface that does not have
 786          * B.A.T.M.A.N. V enabled ?
 787          */
 788         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 789                 return NET_RX_DROP;
 790
 791         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 792                 return NET_RX_DROP;
 793
 794         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 795                 return NET_RX_DROP;
 796
 797         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 798         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 799                            skb->len + ETH_HLEN);
 800
 801         ogm_offset = 0;
 802         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 803
 804         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 805                                         ogm_packet)) {
 806                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 807
 808                 ogm_offset += BATADV_OGM2_HLEN;
 809                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 810
 811                 packet_pos = skb->data + ogm_offset;
 812                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 813         }
 814
 815         ret = NET_RX_SUCCESS;
 816         consume_skb(skb);
 817
 818         return ret;
 819 }
 820
 821 /**
 822  * batadv_v_ogm_init - initialise the OGM2 engine
 823  * @bat_priv: the bat priv with all the soft interface information
 824  *
 825  * Return: 0 on success or a negative error code in case of failure
 826  */
 827 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 828 {
 829         struct batadv_ogm2_packet *ogm_packet;
 830         unsigned char *ogm_buff;
 831         u32 random_seqno;
 832
 833         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 834         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 835         if (!ogm_buff)
 836                 return -ENOMEM;
 837
 838         bat_priv->bat_v.ogm_buff = ogm_buff;
 839         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 840         ogm_packet->packet_type = BATADV_OGM2;
 841         ogm_packet->version = BATADV_COMPAT_VERSION;
 842         ogm_packet->ttl = BATADV_TTL;
 843         ogm_packet->flags = BATADV_NO_FLAGS;
 844         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 845
 846         /* randomize initial seqno to avoid collision */
 847         get_random_bytes(&random_seqno, sizeof(random_seqno));
 848         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 849         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 850
 851         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
 852
 853         return 0;
 854 }
 855
 856 /**
 857  * batadv_v_ogm_free - free OGM private resources
 858  * @bat_priv: the bat priv with all the soft interface information
 859  */
 860 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 861 {
 862         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 863
 864         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 865
 866         kfree(bat_priv->bat_v.ogm_buff);
 867         bat_priv->bat_v.ogm_buff = NULL;
 868         bat_priv->bat_v.ogm_buff_len = 0;
 869
 870         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 871 }