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/netdevice.h>
  32 #include <linux/random.h>
  33 #include <linux/rculist.h>
  34 #include <linux/rcupdate.h>
  35 #include <linux/skbuff.h>
  36 #include <linux/slab.h>
  37 #include <linux/stddef.h>
  38 #include <linux/string.h>
  39 #include <linux/types.h>
  40 #include <linux/workqueue.h>
  41
  42 #include "bat_algo.h"
  43 #include "hard-interface.h"
  44 #include "hash.h"
  45 #include "log.h"
  46 #include "originator.h"
  47 #include "packet.h"
  48 #include "routing.h"
  49 #include "send.h"
  50 #include "translation-table.h"
  51 #include "tvlv.h"
  52
  53 /**
  54  * batadv_v_ogm_orig_get - retrieve and possibly create an originator node
  55  * @bat_priv: the bat priv with all the soft interface information
  56  * @addr: the address of the originator
  57  *
  58  * Return: the orig_node corresponding to the specified address. If such object
  59  * does not exist it is allocated here. In case of allocation failure returns
  60  * NULL.
  61  */
  62 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  63                                                const u8 *addr)
  64 {
  65         struct batadv_orig_node *orig_node;
  66         int hash_added;
  67
  68         orig_node = batadv_orig_hash_find(bat_priv, addr);
  69         if (orig_node)
  70                 return orig_node;
  71
  72         orig_node = batadv_orig_node_new(bat_priv, addr);
  73         if (!orig_node)
  74                 return NULL;
  75
  76         kref_get(&orig_node->refcount);
  77         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  78                                      batadv_choose_orig, orig_node,
  79                                      &orig_node->hash_entry);
  80         if (hash_added != 0) {
  81                 /* remove refcnt for newly created orig_node and hash entry */
  82                 batadv_orig_node_put(orig_node);
  83                 batadv_orig_node_put(orig_node);
  84                 orig_node = NULL;
  85         }
  86
  87         return orig_node;
  88 }
  89
  90 /**
  91  * batadv_v_ogm_start_timer - restart the OGM sending timer
  92  * @bat_priv: the bat priv with all the soft interface information
  93  */
  94 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
  95 {
  96         unsigned long msecs;
  97         /* this function may be invoked in different contexts (ogm rescheduling
  98          * or hard_iface activation), but the work timer should not be reset
  99          */
 100         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 101                 return;
 102
 103         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 104         msecs += prandom_u32() % (2 * BATADV_JITTER);
 105         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 106                            msecs_to_jiffies(msecs));
 107 }
 108
 109 /**
 110  * batadv_v_ogm_send_to_if - send a batman ogm using a given interface
 111  * @skb: the OGM to send
 112  * @hard_iface: the interface to use to send the OGM
 113  */
 114 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 115                                     struct batadv_hard_iface *hard_iface)
 116 {
 117         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 118
 119         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 120                 return;
 121
 122         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 123         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 124                            skb->len + ETH_HLEN);
 125
 126         batadv_send_broadcast_skb(skb, hard_iface);
 127 }
 128
 129 /**
 130  * batadv_v_ogm_send - periodic worker broadcasting the own OGM
 131  * @work: work queue item
 132  */
 133 static void batadv_v_ogm_send(struct work_struct *work)
 134 {
 135         struct batadv_hard_iface *hard_iface;
 136         struct batadv_priv_bat_v *bat_v;
 137         struct batadv_priv *bat_priv;
 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         int ret;
 144
 145         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 146         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 147
 148         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 149                 goto out;
 150
 151         ogm_buff = bat_priv->bat_v.ogm_buff;
 152         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 153         /* tt changes have to be committed before the tvlv data is
 154          * appended as it may alter the tt tvlv container
 155          */
 156         batadv_tt_local_commit_changes(bat_priv);
 157         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 158                                                     &ogm_buff_len,
 159                                                     BATADV_OGM2_HLEN);
 160
 161         bat_priv->bat_v.ogm_buff = ogm_buff;
 162         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 163
 164         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 165         if (!skb)
 166                 goto reschedule;
 167
 168         skb_reserve(skb, ETH_HLEN);
 169         pkt_buff = skb_put(skb, ogm_buff_len);
 170         memcpy(pkt_buff, ogm_buff, ogm_buff_len);
 171
 172         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 173         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 174         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 175         ogm_packet->tvlv_len = htons(tvlv_len);
 176
 177         /* broadcast on every interface */
 178         rcu_read_lock();
 179         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 180                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 181                         continue;
 182
 183                 if (!kref_get_unless_zero(&hard_iface->refcount))
 184                         continue;
 185
 186                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 187                 if (ret) {
 188                         char *type;
 189
 190                         switch (ret) {
 191                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 192                                 type = "no neighbor";
 193                                 break;
 194                         case BATADV_HARDIF_BCAST_DUPFWD:
 195                                 type = "single neighbor is source";
 196                                 break;
 197                         case BATADV_HARDIF_BCAST_DUPORIG:
 198                                 type = "single neighbor is originator";
 199                                 break;
 200                         default:
 201                                 type = "unknown";
 202                         }
 203
 204                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselve on %s surpressed: %s\n",
 205                                    hard_iface->net_dev->name, type);
 206
 207                         batadv_hardif_put(hard_iface);
 208                         continue;
 209                 }
 210
 211                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 212                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 213                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 214                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 215                            hard_iface->net_dev->name,
 216                            hard_iface->net_dev->dev_addr);
 217
 218                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 219                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 220                 if (!skb_tmp) {
 221                         batadv_hardif_put(hard_iface);
 222                         break;
 223                 }
 224
 225                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 226                 batadv_hardif_put(hard_iface);
 227         }
 228         rcu_read_unlock();
 229
 230         consume_skb(skb);
 231
 232 reschedule:
 233         batadv_v_ogm_start_timer(bat_priv);
 234 out:
 235         return;
 236 }
 237
 238 /**
 239  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
 240  * @hard_iface: the interface to prepare
 241  *
 242  * Takes care of scheduling own OGM sending routine for this interface.
 243  *
 244  * Return: 0 on success or a negative error code otherwise
 245  */
 246 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 247 {
 248         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 249
 250         batadv_v_ogm_start_timer(bat_priv);
 251
 252         return 0;
 253 }
 254
 255 /**
 256  * batadv_v_ogm_primary_iface_set - set a new primary interface
 257  * @primary_iface: the new primary interface
 258  */
 259 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 260 {
 261         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 262         struct batadv_ogm2_packet *ogm_packet;
 263
 264         if (!bat_priv->bat_v.ogm_buff)
 265                 return;
 266
 267         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 268         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 269 }
 270
 271 /**
 272  * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
 273  *  with B.A.T.M.A.N. V OGMs
 274  * @bat_priv: the bat priv with all the soft interface information
 275  * @if_incoming: the interface where the OGM has been received
 276  * @if_outgoing: the interface where the OGM has to be forwarded to
 277  * @throughput: the current throughput
 278  *
 279  * Apply a penalty on the current throughput metric value based on the
 280  * characteristic of the interface where the OGM has been received. The return
 281  * value is computed as follows:
 282  * - throughput * 50%          if the incoming and outgoing interface are the
 283  *                             same WiFi interface and the throughput is above
 284  *                             1MBit/s
 285  * - throughput                if the outgoing interface is the default
 286  *                             interface (i.e. this OGM is processed for the
 287  *                             internal table and not forwarded)
 288  * - throughput * hop penalty  otherwise
 289  *
 290  * Return: the penalised throughput metric.
 291  */
 292 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 293                                     struct batadv_hard_iface *if_incoming,
 294                                     struct batadv_hard_iface *if_outgoing,
 295                                     u32 throughput)
 296 {
 297         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 298         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 299
 300         /* Don't apply hop penalty in default originator table. */
 301         if (if_outgoing == BATADV_IF_DEFAULT)
 302                 return throughput;
 303
 304         /* Forwarding on the same WiFi interface cuts the throughput in half
 305          * due to the store & forward characteristics of WIFI.
 306          * Very low throughput values are the exception.
 307          */
 308         if ((throughput > 10) &&
 309             (if_incoming == if_outgoing) &&
 310             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 311                 return throughput / 2;
 312
 313         /* hop penalty of 255 equals 100% */
 314         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 315 }
 316
 317 /**
 318  * batadv_v_ogm_forward - check conditions and forward an OGM to the given
 319  *  outgoing interface
 320  * @bat_priv: the bat priv with all the soft interface information
 321  * @ogm_received: previously received OGM to be forwarded
 322  * @orig_node: the originator which has been updated
 323  * @neigh_node: the neigh_node through with the OGM has been received
 324  * @if_incoming: the interface on which this OGM was received on
 325  * @if_outgoing: the interface to which the OGM has to be forwarded to
 326  *
 327  * Forward an OGM to an interface after having altered the throughput metric and
 328  * the TTL value contained in it. The original OGM isn't modified.
 329  */
 330 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 331                                  const struct batadv_ogm2_packet *ogm_received,
 332                                  struct batadv_orig_node *orig_node,
 333                                  struct batadv_neigh_node *neigh_node,
 334                                  struct batadv_hard_iface *if_incoming,
 335                                  struct batadv_hard_iface *if_outgoing)
 336 {
 337         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 338         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 339         struct batadv_neigh_node *router = NULL;
 340         struct batadv_ogm2_packet *ogm_forward;
 341         unsigned char *skb_buff;
 342         struct sk_buff *skb;
 343         size_t packet_len;
 344         u16 tvlv_len;
 345
 346         /* only forward for specific interfaces, not for the default one. */
 347         if (if_outgoing == BATADV_IF_DEFAULT)
 348                 goto out;
 349
 350         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 351         if (!orig_ifinfo)
 352                 goto out;
 353
 354         /* acquire possibly updated router */
 355         router = batadv_orig_router_get(orig_node, if_outgoing);
 356
 357         /* strict rule: forward packets coming from the best next hop only */
 358         if (neigh_node != router)
 359                 goto out;
 360
 361         /* don't forward the same seqno twice on one interface */
 362         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 363                 goto out;
 364
 365         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 366
 367         if (ogm_received->ttl <= 1) {
 368                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 369                 goto out;
 370         }
 371
 372         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 373         if (!neigh_ifinfo)
 374                 goto out;
 375
 376         tvlv_len = ntohs(ogm_received->tvlv_len);
 377
 378         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 379         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 380                                         ETH_HLEN + packet_len);
 381         if (!skb)
 382                 goto out;
 383
 384         skb_reserve(skb, ETH_HLEN);
 385         skb_buff = skb_put(skb, packet_len);
 386         memcpy(skb_buff, ogm_received, packet_len);
 387
 388         /* apply forward penalty */
 389         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 390         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 391         ogm_forward->ttl--;
 392
 393         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 394                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 395                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 396                    ogm_forward->ttl, if_incoming->net_dev->name);
 397
 398         batadv_v_ogm_send_to_if(skb, if_outgoing);
 399
 400 out:
 401         if (orig_ifinfo)
 402                 batadv_orig_ifinfo_put(orig_ifinfo);
 403         if (router)
 404                 batadv_neigh_node_put(router);
 405         if (neigh_ifinfo)
 406                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 407 }
 408
 409 /**
 410  * batadv_v_ogm_metric_update - update route metric based on OGM
 411  * @bat_priv: the bat priv with all the soft interface information
 412  * @ogm2: OGM2 structure
 413  * @orig_node: Originator structure for which the OGM has been received
 414  * @neigh_node: the neigh_node through with the OGM has been received
 415  * @if_incoming: the interface where this packet was received
 416  * @if_outgoing: the interface for which the packet should be considered
 417  *
 418  * Return:
 419  *  1  if the OGM is new,
 420  *  0  if it is not new but valid,
 421  *  <0 on error (e.g. old OGM)
 422  */
 423 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 424                                       const struct batadv_ogm2_packet *ogm2,
 425                                       struct batadv_orig_node *orig_node,
 426                                       struct batadv_neigh_node *neigh_node,
 427                                       struct batadv_hard_iface *if_incoming,
 428                                       struct batadv_hard_iface *if_outgoing)
 429 {
 430         struct batadv_orig_ifinfo *orig_ifinfo;
 431         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 432         bool protection_started = false;
 433         int ret = -EINVAL;
 434         u32 path_throughput;
 435         s32 seq_diff;
 436
 437         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 438         if (!orig_ifinfo)
 439                 goto out;
 440
 441         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 442
 443         if (!hlist_empty(&orig_node->neigh_list) &&
 444             batadv_window_protected(bat_priv, seq_diff,
 445                                     BATADV_OGM_MAX_AGE,
 446                                     &orig_ifinfo->batman_seqno_reset,
 447                                     &protection_started)) {
 448                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 449                            "Drop packet: packet within window protection time from %pM\n",
 450                            ogm2->orig);
 451                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 452                            "Last reset: %ld, %ld\n",
 453                            orig_ifinfo->batman_seqno_reset, jiffies);
 454                 goto out;
 455         }
 456
 457         /* drop packets with old seqnos, however accept the first packet after
 458          * a host has been rebooted.
 459          */
 460         if ((seq_diff < 0) && !protection_started)
 461                 goto out;
 462
 463         neigh_node->last_seen = jiffies;
 464
 465         orig_node->last_seen = jiffies;
 466
 467         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 468         orig_ifinfo->last_ttl = ogm2->ttl;
 469
 470         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 471         if (!neigh_ifinfo)
 472                 goto out;
 473
 474         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 475                                                    if_outgoing,
 476                                                    ntohl(ogm2->throughput));
 477         neigh_ifinfo->bat_v.throughput = path_throughput;
 478         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 479         neigh_ifinfo->last_ttl = ogm2->ttl;
 480
 481         if (seq_diff > 0 || protection_started)
 482                 ret = 1;
 483         else
 484                 ret = 0;
 485 out:
 486         if (orig_ifinfo)
 487                 batadv_orig_ifinfo_put(orig_ifinfo);
 488         if (neigh_ifinfo)
 489                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 490
 491         return ret;
 492 }
 493
 494 /**
 495  * batadv_v_ogm_route_update - update routes based on OGM
 496  * @bat_priv: the bat priv with all the soft interface information
 497  * @ethhdr: the Ethernet header of the OGM2
 498  * @ogm2: OGM2 structure
 499  * @orig_node: Originator structure for which the OGM has been received
 500  * @neigh_node: the neigh_node through with the OGM has been received
 501  * @if_incoming: the interface where this packet was received
 502  * @if_outgoing: the interface for which the packet should be considered
 503  *
 504  * Return: true if the packet should be forwarded, false otherwise
 505  */
 506 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 507                                       const struct ethhdr *ethhdr,
 508                                       const struct batadv_ogm2_packet *ogm2,
 509                                       struct batadv_orig_node *orig_node,
 510                                       struct batadv_neigh_node *neigh_node,
 511                                       struct batadv_hard_iface *if_incoming,
 512                                       struct batadv_hard_iface *if_outgoing)
 513 {
 514         struct batadv_neigh_node *router = NULL;
 515         struct batadv_orig_node *orig_neigh_node;
 516         struct batadv_neigh_node *orig_neigh_router = NULL;
 517         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 518         u32 router_throughput, neigh_throughput;
 519         u32 router_last_seqno;
 520         u32 neigh_last_seqno;
 521         s32 neigh_seq_diff;
 522         bool forward = false;
 523
 524         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 525         if (!orig_neigh_node)
 526                 goto out;
 527
 528         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 529                                                    if_outgoing);
 530
 531         /* drop packet if sender is not a direct neighbor and if we
 532          * don't route towards it
 533          */
 534         router = batadv_orig_router_get(orig_node, if_outgoing);
 535         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 536                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 537                            "Drop packet: OGM via unknown neighbor!\n");
 538                 goto out;
 539         }
 540
 541         /* Mark the OGM to be considered for forwarding, and update routes
 542          * if needed.
 543          */
 544         forward = true;
 545
 546         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 547                    "Searching and updating originator entry of received packet\n");
 548
 549         /* if this neighbor already is our next hop there is nothing
 550          * to change
 551          */
 552         if (router == neigh_node)
 553                 goto out;
 554
 555         /* don't consider neighbours with worse throughput.
 556          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 557          * the last received seqno from our best next hop.
 558          */
 559         if (router) {
 560                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 561                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 562
 563                 /* if these are not allocated, something is wrong. */
 564                 if (!router_ifinfo || !neigh_ifinfo)
 565                         goto out;
 566
 567                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 568                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 569                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 570                 router_throughput = router_ifinfo->bat_v.throughput;
 571                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 572
 573                 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
 574                     (router_throughput >= neigh_throughput))
 575                         goto out;
 576         }
 577
 578         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 579 out:
 580         if (router)
 581                 batadv_neigh_node_put(router);
 582         if (orig_neigh_router)
 583                 batadv_neigh_node_put(orig_neigh_router);
 584         if (orig_neigh_node)
 585                 batadv_orig_node_put(orig_neigh_node);
 586         if (router_ifinfo)
 587                 batadv_neigh_ifinfo_put(router_ifinfo);
 588         if (neigh_ifinfo)
 589                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 590
 591         return forward;
 592 }
 593
 594 /**
 595  * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
 596  * @bat_priv: the bat priv with all the soft interface information
 597  * @ethhdr: the Ethernet header of the OGM2
 598  * @ogm2: OGM2 structure
 599  * @orig_node: Originator structure for which the OGM has been received
 600  * @neigh_node: the neigh_node through with the OGM has been received
 601  * @if_incoming: the interface where this packet was received
 602  * @if_outgoing: the interface for which the packet should be considered
 603  */
 604 static void
 605 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 606                                const struct ethhdr *ethhdr,
 607                                const struct batadv_ogm2_packet *ogm2,
 608                                struct batadv_orig_node *orig_node,
 609                                struct batadv_neigh_node *neigh_node,
 610                                struct batadv_hard_iface *if_incoming,
 611                                struct batadv_hard_iface *if_outgoing)
 612 {
 613         int seqno_age;
 614         bool forward;
 615
 616         /* first, update the metric with according sanity checks */
 617         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 618                                                neigh_node, if_incoming,
 619                                                if_outgoing);
 620
 621         /* outdated sequence numbers are to be discarded */
 622         if (seqno_age < 0)
 623                 return;
 624
 625         /* only unknown & newer OGMs contain TVLVs we are interested in */
 626         if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
 627                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 628                                                NULL, NULL,
 629                                                (unsigned char *)(ogm2 + 1),
 630                                                ntohs(ogm2->tvlv_len));
 631
 632         /* if the metric update went through, update routes if needed */
 633         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 634                                             neigh_node, if_incoming,
 635                                             if_outgoing);
 636
 637         /* if the routes have been processed correctly, check and forward */
 638         if (forward)
 639                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 640                                      if_incoming, if_outgoing);
 641 }
 642
 643 /**
 644  * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
 645  * @buff_pos: current position in the skb
 646  * @packet_len: total length of the skb
 647  * @tvlv_len: tvlv length of the previously considered OGM
 648  *
 649  * Return: true if there is enough space for another OGM, false otherwise.
 650  */
 651 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 652                                      __be16 tvlv_len)
 653 {
 654         int next_buff_pos = 0;
 655
 656         next_buff_pos += buff_pos + BATADV_OGM2_HLEN;
 657         next_buff_pos += ntohs(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         int ret;
 681
 682         ethhdr = eth_hdr(skb);
 683         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 684
 685         ogm_throughput = ntohl(ogm_packet->throughput);
 686
 687         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 688                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n",
 689                    ethhdr->h_source, if_incoming->net_dev->name,
 690                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 691                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 692                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 693
 694         /* If the troughput metric is 0, immediately drop the packet. No need to
 695          * create orig_node / neigh_node for an unusable route.
 696          */
 697         if (ogm_throughput == 0) {
 698                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 699                            "Drop packet: originator packet with troughput metric of 0\n");
 700                 return;
 701         }
 702
 703         /* require ELP packets be to received from this neighbor first */
 704         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 705         if (!hardif_neigh) {
 706                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 707                            "Drop packet: OGM via unknown neighbor!\n");
 708                 goto out;
 709         }
 710
 711         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 712         if (!orig_node)
 713                 return;
 714
 715         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 716                                                      ethhdr->h_source);
 717         if (!neigh_node)
 718                 goto out;
 719
 720         /* Update the received throughput metric to match the link
 721          * characteristic:
 722          *  - If this OGM traveled one hop so far (emitted by single hop
 723          *    neighbor) the path throughput metric equals the link throughput.
 724          *  - For OGMs traversing more than hop the path throughput metric is
 725          *    the smaller of the path throughput and the link throughput.
 726          */
 727         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 728         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 729         ogm_packet->throughput = htonl(path_throughput);
 730
 731         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 732                                        neigh_node, if_incoming,
 733                                        BATADV_IF_DEFAULT);
 734
 735         rcu_read_lock();
 736         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 737                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 738                         continue;
 739
 740                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 741                         continue;
 742
 743                 if (!kref_get_unless_zero(&hard_iface->refcount))
 744                         continue;
 745
 746                 ret = batadv_hardif_no_broadcast(hard_iface,
 747                                                  ogm_packet->orig,
 748                                                  hardif_neigh->orig);
 749
 750                 if (ret) {
 751                         char *type;
 752
 753                         switch (ret) {
 754                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 755                                 type = "no neighbor";
 756                                 break;
 757                         case BATADV_HARDIF_BCAST_DUPFWD:
 758                                 type = "single neighbor is source";
 759                                 break;
 760                         case BATADV_HARDIF_BCAST_DUPORIG:
 761                                 type = "single neighbor is originator";
 762                                 break;
 763                         default:
 764                                 type = "unknown";
 765                         }
 766
 767                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s surpressed: %s\n",
 768                                    ogm_packet->orig, hard_iface->net_dev->name,
 769                                    type);
 770
 771                         batadv_hardif_put(hard_iface);
 772                         continue;
 773                 }
 774
 775                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 776                                                orig_node, neigh_node,
 777                                                if_incoming, hard_iface);
 778
 779                 batadv_hardif_put(hard_iface);
 780         }
 781         rcu_read_unlock();
 782 out:
 783         if (orig_node)
 784                 batadv_orig_node_put(orig_node);
 785         if (neigh_node)
 786                 batadv_neigh_node_put(neigh_node);
 787         if (hardif_neigh)
 788                 batadv_hardif_neigh_put(hardif_neigh);
 789 }
 790
 791 /**
 792  * batadv_v_ogm_packet_recv - OGM2 receiving handler
 793  * @skb: the received OGM
 794  * @if_incoming: the interface where this OGM has been received
 795  *
 796  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 797  * (without freeing the skb) on failure
 798  */
 799 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 800                              struct batadv_hard_iface *if_incoming)
 801 {
 802         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 803         struct batadv_ogm2_packet *ogm_packet;
 804         struct ethhdr *ethhdr = eth_hdr(skb);
 805         int ogm_offset;
 806         u8 *packet_pos;
 807         int ret = NET_RX_DROP;
 808
 809         /* did we receive a OGM2 packet on an interface that does not have
 810          * B.A.T.M.A.N. V enabled ?
 811          */
 812         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 813                 goto free_skb;
 814
 815         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 816                 goto free_skb;
 817
 818         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 819                 goto free_skb;
 820
 821         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 822
 823         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
 824                 goto free_skb;
 825
 826         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 827         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 828                            skb->len + ETH_HLEN);
 829
 830         ogm_offset = 0;
 831         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 832
 833         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 834                                         ogm_packet->tvlv_len)) {
 835                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 836
 837                 ogm_offset += BATADV_OGM2_HLEN;
 838                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 839
 840                 packet_pos = skb->data + ogm_offset;
 841                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 842         }
 843
 844         ret = NET_RX_SUCCESS;
 845
 846 free_skb:
 847         if (ret == NET_RX_SUCCESS)
 848                 consume_skb(skb);
 849         else
 850                 kfree_skb(skb);
 851
 852         return ret;
 853 }
 854
 855 /**
 856  * batadv_v_ogm_init - initialise the OGM2 engine
 857  * @bat_priv: the bat priv with all the soft interface information
 858  *
 859  * Return: 0 on success or a negative error code in case of failure
 860  */
 861 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 862 {
 863         struct batadv_ogm2_packet *ogm_packet;
 864         unsigned char *ogm_buff;
 865         u32 random_seqno;
 866
 867         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 868         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 869         if (!ogm_buff)
 870                 return -ENOMEM;
 871
 872         bat_priv->bat_v.ogm_buff = ogm_buff;
 873         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 874         ogm_packet->packet_type = BATADV_OGM2;
 875         ogm_packet->version = BATADV_COMPAT_VERSION;
 876         ogm_packet->ttl = BATADV_TTL;
 877         ogm_packet->flags = BATADV_NO_FLAGS;
 878         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 879
 880         /* randomize initial seqno to avoid collision */
 881         get_random_bytes(&random_seqno, sizeof(random_seqno));
 882         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 883         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 884
 885         return 0;
 886 }
 887
 888 /**
 889  * batadv_v_ogm_free - free OGM private resources
 890  * @bat_priv: the bat priv with all the soft interface information
 891  */
 892 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 893 {
 894         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 895
 896         kfree(bat_priv->bat_v.ogm_buff);
 897         bat_priv->bat_v.ogm_buff = NULL;
 898         bat_priv->bat_v.ogm_buff_len = 0;
 899 }