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_data(skb, ogm_buff, ogm_buff_len);
 170
 171         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 172         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 173         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 174         ogm_packet->tvlv_len = htons(tvlv_len);
 175
 176         /* broadcast on every interface */
 177         rcu_read_lock();
 178         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 179                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 180                         continue;
 181
 182                 if (!kref_get_unless_zero(&hard_iface->refcount))
 183                         continue;
 184
 185                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 186                 if (ret) {
 187                         char *type;
 188
 189                         switch (ret) {
 190                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 191                                 type = "no neighbor";
 192                                 break;
 193                         case BATADV_HARDIF_BCAST_DUPFWD:
 194                                 type = "single neighbor is source";
 195                                 break;
 196                         case BATADV_HARDIF_BCAST_DUPORIG:
 197                                 type = "single neighbor is originator";
 198                                 break;
 199                         default:
 200                                 type = "unknown";
 201                         }
 202
 203                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselve on %s surpressed: %s\n",
 204                                    hard_iface->net_dev->name, type);
 205
 206                         batadv_hardif_put(hard_iface);
 207                         continue;
 208                 }
 209
 210                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 211                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 212                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 213                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 214                            hard_iface->net_dev->name,
 215                            hard_iface->net_dev->dev_addr);
 216
 217                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 218                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 219                 if (!skb_tmp) {
 220                         batadv_hardif_put(hard_iface);
 221                         break;
 222                 }
 223
 224                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 225                 batadv_hardif_put(hard_iface);
 226         }
 227         rcu_read_unlock();
 228
 229         consume_skb(skb);
 230
 231 reschedule:
 232         batadv_v_ogm_start_timer(bat_priv);
 233 out:
 234         return;
 235 }
 236
 237 /**
 238  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
 239  * @hard_iface: the interface to prepare
 240  *
 241  * Takes care of scheduling own OGM sending routine for this interface.
 242  *
 243  * Return: 0 on success or a negative error code otherwise
 244  */
 245 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 246 {
 247         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 248
 249         batadv_v_ogm_start_timer(bat_priv);
 250
 251         return 0;
 252 }
 253
 254 /**
 255  * batadv_v_ogm_primary_iface_set - set a new primary interface
 256  * @primary_iface: the new primary interface
 257  */
 258 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 259 {
 260         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 261         struct batadv_ogm2_packet *ogm_packet;
 262
 263         if (!bat_priv->bat_v.ogm_buff)
 264                 return;
 265
 266         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 267         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 268 }
 269
 270 /**
 271  * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
 272  *  with B.A.T.M.A.N. V OGMs
 273  * @bat_priv: the bat priv with all the soft interface information
 274  * @if_incoming: the interface where the OGM has been received
 275  * @if_outgoing: the interface where the OGM has to be forwarded to
 276  * @throughput: the current throughput
 277  *
 278  * Apply a penalty on the current throughput metric value based on the
 279  * characteristic of the interface where the OGM has been received. The return
 280  * value is computed as follows:
 281  * - throughput * 50%          if the incoming and outgoing interface are the
 282  *                             same WiFi interface and the throughput is above
 283  *                             1MBit/s
 284  * - throughput                if the outgoing interface is the default
 285  *                             interface (i.e. this OGM is processed for the
 286  *                             internal table and not forwarded)
 287  * - throughput * hop penalty  otherwise
 288  *
 289  * Return: the penalised throughput metric.
 290  */
 291 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 292                                     struct batadv_hard_iface *if_incoming,
 293                                     struct batadv_hard_iface *if_outgoing,
 294                                     u32 throughput)
 295 {
 296         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 297         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 298
 299         /* Don't apply hop penalty in default originator table. */
 300         if (if_outgoing == BATADV_IF_DEFAULT)
 301                 return throughput;
 302
 303         /* Forwarding on the same WiFi interface cuts the throughput in half
 304          * due to the store & forward characteristics of WIFI.
 305          * Very low throughput values are the exception.
 306          */
 307         if ((throughput > 10) &&
 308             (if_incoming == if_outgoing) &&
 309             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 310                 return throughput / 2;
 311
 312         /* hop penalty of 255 equals 100% */
 313         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 314 }
 315
 316 /**
 317  * batadv_v_ogm_forward - check conditions and forward an OGM to the given
 318  *  outgoing interface
 319  * @bat_priv: the bat priv with all the soft interface information
 320  * @ogm_received: previously received OGM to be forwarded
 321  * @orig_node: the originator which has been updated
 322  * @neigh_node: the neigh_node through with the OGM has been received
 323  * @if_incoming: the interface on which this OGM was received on
 324  * @if_outgoing: the interface to which the OGM has to be forwarded to
 325  *
 326  * Forward an OGM to an interface after having altered the throughput metric and
 327  * the TTL value contained in it. The original OGM isn't modified.
 328  */
 329 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 330                                  const struct batadv_ogm2_packet *ogm_received,
 331                                  struct batadv_orig_node *orig_node,
 332                                  struct batadv_neigh_node *neigh_node,
 333                                  struct batadv_hard_iface *if_incoming,
 334                                  struct batadv_hard_iface *if_outgoing)
 335 {
 336         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 337         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 338         struct batadv_neigh_node *router = NULL;
 339         struct batadv_ogm2_packet *ogm_forward;
 340         unsigned char *skb_buff;
 341         struct sk_buff *skb;
 342         size_t packet_len;
 343         u16 tvlv_len;
 344
 345         /* only forward for specific interfaces, not for the default one. */
 346         if (if_outgoing == BATADV_IF_DEFAULT)
 347                 goto out;
 348
 349         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 350         if (!orig_ifinfo)
 351                 goto out;
 352
 353         /* acquire possibly updated router */
 354         router = batadv_orig_router_get(orig_node, if_outgoing);
 355
 356         /* strict rule: forward packets coming from the best next hop only */
 357         if (neigh_node != router)
 358                 goto out;
 359
 360         /* don't forward the same seqno twice on one interface */
 361         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 362                 goto out;
 363
 364         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 365
 366         if (ogm_received->ttl <= 1) {
 367                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 368                 goto out;
 369         }
 370
 371         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 372         if (!neigh_ifinfo)
 373                 goto out;
 374
 375         tvlv_len = ntohs(ogm_received->tvlv_len);
 376
 377         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 378         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 379                                         ETH_HLEN + packet_len);
 380         if (!skb)
 381                 goto out;
 382
 383         skb_reserve(skb, ETH_HLEN);
 384         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 385
 386         /* apply forward penalty */
 387         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 388         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 389         ogm_forward->ttl--;
 390
 391         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 392                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 393                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 394                    ogm_forward->ttl, if_incoming->net_dev->name);
 395
 396         batadv_v_ogm_send_to_if(skb, if_outgoing);
 397
 398 out:
 399         if (orig_ifinfo)
 400                 batadv_orig_ifinfo_put(orig_ifinfo);
 401         if (router)
 402                 batadv_neigh_node_put(router);
 403         if (neigh_ifinfo)
 404                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 405 }
 406
 407 /**
 408  * batadv_v_ogm_metric_update - update route metric based on OGM
 409  * @bat_priv: the bat priv with all the soft interface information
 410  * @ogm2: OGM2 structure
 411  * @orig_node: Originator structure for which the OGM has been received
 412  * @neigh_node: the neigh_node through with the OGM has been received
 413  * @if_incoming: the interface where this packet was received
 414  * @if_outgoing: the interface for which the packet should be considered
 415  *
 416  * Return:
 417  *  1  if the OGM is new,
 418  *  0  if it is not new but valid,
 419  *  <0 on error (e.g. old OGM)
 420  */
 421 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 422                                       const struct batadv_ogm2_packet *ogm2,
 423                                       struct batadv_orig_node *orig_node,
 424                                       struct batadv_neigh_node *neigh_node,
 425                                       struct batadv_hard_iface *if_incoming,
 426                                       struct batadv_hard_iface *if_outgoing)
 427 {
 428         struct batadv_orig_ifinfo *orig_ifinfo;
 429         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 430         bool protection_started = false;
 431         int ret = -EINVAL;
 432         u32 path_throughput;
 433         s32 seq_diff;
 434
 435         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 436         if (!orig_ifinfo)
 437                 goto out;
 438
 439         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 440
 441         if (!hlist_empty(&orig_node->neigh_list) &&
 442             batadv_window_protected(bat_priv, seq_diff,
 443                                     BATADV_OGM_MAX_AGE,
 444                                     &orig_ifinfo->batman_seqno_reset,
 445                                     &protection_started)) {
 446                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 447                            "Drop packet: packet within window protection time from %pM\n",
 448                            ogm2->orig);
 449                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 450                            "Last reset: %ld, %ld\n",
 451                            orig_ifinfo->batman_seqno_reset, jiffies);
 452                 goto out;
 453         }
 454
 455         /* drop packets with old seqnos, however accept the first packet after
 456          * a host has been rebooted.
 457          */
 458         if ((seq_diff < 0) && !protection_started)
 459                 goto out;
 460
 461         neigh_node->last_seen = jiffies;
 462
 463         orig_node->last_seen = jiffies;
 464
 465         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 466         orig_ifinfo->last_ttl = ogm2->ttl;
 467
 468         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 469         if (!neigh_ifinfo)
 470                 goto out;
 471
 472         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 473                                                    if_outgoing,
 474                                                    ntohl(ogm2->throughput));
 475         neigh_ifinfo->bat_v.throughput = path_throughput;
 476         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 477         neigh_ifinfo->last_ttl = ogm2->ttl;
 478
 479         if (seq_diff > 0 || protection_started)
 480                 ret = 1;
 481         else
 482                 ret = 0;
 483 out:
 484         if (orig_ifinfo)
 485                 batadv_orig_ifinfo_put(orig_ifinfo);
 486         if (neigh_ifinfo)
 487                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 488
 489         return ret;
 490 }
 491
 492 /**
 493  * batadv_v_ogm_route_update - update routes based on OGM
 494  * @bat_priv: the bat priv with all the soft interface information
 495  * @ethhdr: the Ethernet header of the OGM2
 496  * @ogm2: OGM2 structure
 497  * @orig_node: Originator structure for which the OGM has been received
 498  * @neigh_node: the neigh_node through with the OGM has been received
 499  * @if_incoming: the interface where this packet was received
 500  * @if_outgoing: the interface for which the packet should be considered
 501  *
 502  * Return: true if the packet should be forwarded, false otherwise
 503  */
 504 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 505                                       const struct ethhdr *ethhdr,
 506                                       const struct batadv_ogm2_packet *ogm2,
 507                                       struct batadv_orig_node *orig_node,
 508                                       struct batadv_neigh_node *neigh_node,
 509                                       struct batadv_hard_iface *if_incoming,
 510                                       struct batadv_hard_iface *if_outgoing)
 511 {
 512         struct batadv_neigh_node *router = NULL;
 513         struct batadv_orig_node *orig_neigh_node;
 514         struct batadv_neigh_node *orig_neigh_router = NULL;
 515         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 516         u32 router_throughput, neigh_throughput;
 517         u32 router_last_seqno;
 518         u32 neigh_last_seqno;
 519         s32 neigh_seq_diff;
 520         bool forward = false;
 521
 522         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 523         if (!orig_neigh_node)
 524                 goto out;
 525
 526         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 527                                                    if_outgoing);
 528
 529         /* drop packet if sender is not a direct neighbor and if we
 530          * don't route towards it
 531          */
 532         router = batadv_orig_router_get(orig_node, if_outgoing);
 533         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 534                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 535                            "Drop packet: OGM via unknown neighbor!\n");
 536                 goto out;
 537         }
 538
 539         /* Mark the OGM to be considered for forwarding, and update routes
 540          * if needed.
 541          */
 542         forward = true;
 543
 544         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 545                    "Searching and updating originator entry of received packet\n");
 546
 547         /* if this neighbor already is our next hop there is nothing
 548          * to change
 549          */
 550         if (router == neigh_node)
 551                 goto out;
 552
 553         /* don't consider neighbours with worse throughput.
 554          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 555          * the last received seqno from our best next hop.
 556          */
 557         if (router) {
 558                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 559                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 560
 561                 /* if these are not allocated, something is wrong. */
 562                 if (!router_ifinfo || !neigh_ifinfo)
 563                         goto out;
 564
 565                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 566                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 567                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 568                 router_throughput = router_ifinfo->bat_v.throughput;
 569                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 570
 571                 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
 572                     (router_throughput >= neigh_throughput))
 573                         goto out;
 574         }
 575
 576         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 577 out:
 578         if (router)
 579                 batadv_neigh_node_put(router);
 580         if (orig_neigh_router)
 581                 batadv_neigh_node_put(orig_neigh_router);
 582         if (orig_neigh_node)
 583                 batadv_orig_node_put(orig_neigh_node);
 584         if (router_ifinfo)
 585                 batadv_neigh_ifinfo_put(router_ifinfo);
 586         if (neigh_ifinfo)
 587                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 588
 589         return forward;
 590 }
 591
 592 /**
 593  * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
 594  * @bat_priv: the bat priv with all the soft interface information
 595  * @ethhdr: the Ethernet header of the OGM2
 596  * @ogm2: OGM2 structure
 597  * @orig_node: Originator structure for which the OGM has been received
 598  * @neigh_node: the neigh_node through with the OGM has been received
 599  * @if_incoming: the interface where this packet was received
 600  * @if_outgoing: the interface for which the packet should be considered
 601  */
 602 static void
 603 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 604                                const struct ethhdr *ethhdr,
 605                                const struct batadv_ogm2_packet *ogm2,
 606                                struct batadv_orig_node *orig_node,
 607                                struct batadv_neigh_node *neigh_node,
 608                                struct batadv_hard_iface *if_incoming,
 609                                struct batadv_hard_iface *if_outgoing)
 610 {
 611         int seqno_age;
 612         bool forward;
 613
 614         /* first, update the metric with according sanity checks */
 615         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 616                                                neigh_node, if_incoming,
 617                                                if_outgoing);
 618
 619         /* outdated sequence numbers are to be discarded */
 620         if (seqno_age < 0)
 621                 return;
 622
 623         /* only unknown & newer OGMs contain TVLVs we are interested in */
 624         if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
 625                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 626                                                NULL, NULL,
 627                                                (unsigned char *)(ogm2 + 1),
 628                                                ntohs(ogm2->tvlv_len));
 629
 630         /* if the metric update went through, update routes if needed */
 631         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 632                                             neigh_node, if_incoming,
 633                                             if_outgoing);
 634
 635         /* if the routes have been processed correctly, check and forward */
 636         if (forward)
 637                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 638                                      if_incoming, if_outgoing);
 639 }
 640
 641 /**
 642  * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
 643  * @buff_pos: current position in the skb
 644  * @packet_len: total length of the skb
 645  * @tvlv_len: tvlv length of the previously considered OGM
 646  *
 647  * Return: true if there is enough space for another OGM, false otherwise.
 648  */
 649 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 650                                      __be16 tvlv_len)
 651 {
 652         int next_buff_pos = 0;
 653
 654         next_buff_pos += buff_pos + BATADV_OGM2_HLEN;
 655         next_buff_pos += ntohs(tvlv_len);
 656
 657         return (next_buff_pos <= packet_len) &&
 658                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 659 }
 660
 661 /**
 662  * batadv_v_ogm_process - process an incoming batman v OGM
 663  * @skb: the skb containing the OGM
 664  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 665  * @if_incoming: the interface where this packet was receved
 666  */
 667 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 668                                  struct batadv_hard_iface *if_incoming)
 669 {
 670         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 671         struct ethhdr *ethhdr;
 672         struct batadv_orig_node *orig_node = NULL;
 673         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 674         struct batadv_neigh_node *neigh_node = NULL;
 675         struct batadv_hard_iface *hard_iface;
 676         struct batadv_ogm2_packet *ogm_packet;
 677         u32 ogm_throughput, link_throughput, path_throughput;
 678         int ret;
 679
 680         ethhdr = eth_hdr(skb);
 681         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 682
 683         ogm_throughput = ntohl(ogm_packet->throughput);
 684
 685         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 686                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n",
 687                    ethhdr->h_source, if_incoming->net_dev->name,
 688                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 689                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 690                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 691
 692         /* If the troughput metric is 0, immediately drop the packet. No need to
 693          * create orig_node / neigh_node for an unusable route.
 694          */
 695         if (ogm_throughput == 0) {
 696                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 697                            "Drop packet: originator packet with troughput metric of 0\n");
 698                 return;
 699         }
 700
 701         /* require ELP packets be to received from this neighbor first */
 702         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 703         if (!hardif_neigh) {
 704                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 705                            "Drop packet: OGM via unknown neighbor!\n");
 706                 goto out;
 707         }
 708
 709         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 710         if (!orig_node)
 711                 return;
 712
 713         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 714                                                      ethhdr->h_source);
 715         if (!neigh_node)
 716                 goto out;
 717
 718         /* Update the received throughput metric to match the link
 719          * characteristic:
 720          *  - If this OGM traveled one hop so far (emitted by single hop
 721          *    neighbor) the path throughput metric equals the link throughput.
 722          *  - For OGMs traversing more than hop the path throughput metric is
 723          *    the smaller of the path throughput and the link throughput.
 724          */
 725         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 726         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 727         ogm_packet->throughput = htonl(path_throughput);
 728
 729         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 730                                        neigh_node, if_incoming,
 731                                        BATADV_IF_DEFAULT);
 732
 733         rcu_read_lock();
 734         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 735                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 736                         continue;
 737
 738                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 739                         continue;
 740
 741                 if (!kref_get_unless_zero(&hard_iface->refcount))
 742                         continue;
 743
 744                 ret = batadv_hardif_no_broadcast(hard_iface,
 745                                                  ogm_packet->orig,
 746                                                  hardif_neigh->orig);
 747
 748                 if (ret) {
 749                         char *type;
 750
 751                         switch (ret) {
 752                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 753                                 type = "no neighbor";
 754                                 break;
 755                         case BATADV_HARDIF_BCAST_DUPFWD:
 756                                 type = "single neighbor is source";
 757                                 break;
 758                         case BATADV_HARDIF_BCAST_DUPORIG:
 759                                 type = "single neighbor is originator";
 760                                 break;
 761                         default:
 762                                 type = "unknown";
 763                         }
 764
 765                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s surpressed: %s\n",
 766                                    ogm_packet->orig, hard_iface->net_dev->name,
 767                                    type);
 768
 769                         batadv_hardif_put(hard_iface);
 770                         continue;
 771                 }
 772
 773                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 774                                                orig_node, neigh_node,
 775                                                if_incoming, hard_iface);
 776
 777                 batadv_hardif_put(hard_iface);
 778         }
 779         rcu_read_unlock();
 780 out:
 781         if (orig_node)
 782                 batadv_orig_node_put(orig_node);
 783         if (neigh_node)
 784                 batadv_neigh_node_put(neigh_node);
 785         if (hardif_neigh)
 786                 batadv_hardif_neigh_put(hardif_neigh);
 787 }
 788
 789 /**
 790  * batadv_v_ogm_packet_recv - OGM2 receiving handler
 791  * @skb: the received OGM
 792  * @if_incoming: the interface where this OGM has been received
 793  *
 794  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 795  * (without freeing the skb) on failure
 796  */
 797 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 798                              struct batadv_hard_iface *if_incoming)
 799 {
 800         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 801         struct batadv_ogm2_packet *ogm_packet;
 802         struct ethhdr *ethhdr = eth_hdr(skb);
 803         int ogm_offset;
 804         u8 *packet_pos;
 805         int ret = NET_RX_DROP;
 806
 807         /* did we receive a OGM2 packet on an interface that does not have
 808          * B.A.T.M.A.N. V enabled ?
 809          */
 810         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 811                 goto free_skb;
 812
 813         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 814                 goto free_skb;
 815
 816         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 817                 goto free_skb;
 818
 819         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 820
 821         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
 822                 goto free_skb;
 823
 824         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 825         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 826                            skb->len + ETH_HLEN);
 827
 828         ogm_offset = 0;
 829         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 830
 831         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 832                                         ogm_packet->tvlv_len)) {
 833                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 834
 835                 ogm_offset += BATADV_OGM2_HLEN;
 836                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 837
 838                 packet_pos = skb->data + ogm_offset;
 839                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 840         }
 841
 842         ret = NET_RX_SUCCESS;
 843
 844 free_skb:
 845         if (ret == NET_RX_SUCCESS)
 846                 consume_skb(skb);
 847         else
 848                 kfree_skb(skb);
 849
 850         return ret;
 851 }
 852
 853 /**
 854  * batadv_v_ogm_init - initialise the OGM2 engine
 855  * @bat_priv: the bat priv with all the soft interface information
 856  *
 857  * Return: 0 on success or a negative error code in case of failure
 858  */
 859 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 860 {
 861         struct batadv_ogm2_packet *ogm_packet;
 862         unsigned char *ogm_buff;
 863         u32 random_seqno;
 864
 865         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 866         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 867         if (!ogm_buff)
 868                 return -ENOMEM;
 869
 870         bat_priv->bat_v.ogm_buff = ogm_buff;
 871         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 872         ogm_packet->packet_type = BATADV_OGM2;
 873         ogm_packet->version = BATADV_COMPAT_VERSION;
 874         ogm_packet->ttl = BATADV_TTL;
 875         ogm_packet->flags = BATADV_NO_FLAGS;
 876         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 877
 878         /* randomize initial seqno to avoid collision */
 879         get_random_bytes(&random_seqno, sizeof(random_seqno));
 880         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 881         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 882
 883         return 0;
 884 }
 885
 886 /**
 887  * batadv_v_ogm_free - free OGM private resources
 888  * @bat_priv: the bat priv with all the soft interface information
 889  */
 890 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 891 {
 892         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 893
 894         kfree(bat_priv->bat_v.ogm_buff);
 895         bat_priv->bat_v.ogm_buff = NULL;
 896         bat_priv->bat_v.ogm_buff_len = 0;
 897 }