net/batman-adv/bat_v_ogm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2013-2018  B.A.T.M.A.N. contributors:
   3  *
   4  * Antonio Quartulli
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "bat_v_ogm.h"
  20 #include "main.h"
  21
  22 #include <linux/atomic.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/etherdevice.h>
  26 #include <linux/gfp.h>
  27 #include <linux/if_ether.h>
  28 #include <linux/jiffies.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kref.h>
  31 #include <linux/list.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/random.h>
  34 #include <linux/rculist.h>
  35 #include <linux/rcupdate.h>
  36 #include <linux/skbuff.h>
  37 #include <linux/slab.h>
  38 #include <linux/stddef.h>
  39 #include <linux/string.h>
  40 #include <linux/types.h>
  41 #include <linux/workqueue.h>
  42 #include <uapi/linux/batadv_packet.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 "routing.h"
  50 #include "send.h"
  51 #include "translation-table.h"
  52 #include "tvlv.h"
  53
  54 /**
  55  * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
  56  * @bat_priv: the bat priv with all the soft interface information
  57  * @addr: the address of the originator
  58  *
  59  * Return: the orig_node corresponding to the specified address. If such object
  60  * does not exist it is allocated here. In case of allocation failure returns
  61  * NULL.
  62  */
  63 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  64                                                const u8 *addr)
  65 {
  66         struct batadv_orig_node *orig_node;
  67         int hash_added;
  68
  69         orig_node = batadv_orig_hash_find(bat_priv, addr);
  70         if (orig_node)
  71                 return orig_node;
  72
  73         orig_node = batadv_orig_node_new(bat_priv, addr);
  74         if (!orig_node)
  75                 return NULL;
  76
  77         kref_get(&orig_node->refcount);
  78         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  79                                      batadv_choose_orig, orig_node,
  80                                      &orig_node->hash_entry);
  81         if (hash_added != 0) {
  82                 /* remove refcnt for newly created orig_node and hash entry */
  83                 batadv_orig_node_put(orig_node);
  84                 batadv_orig_node_put(orig_node);
  85                 orig_node = NULL;
  86         }
  87
  88         return orig_node;
  89 }
  90
  91 /**
  92  * batadv_v_ogm_start_timer() - restart the OGM sending timer
  93  * @bat_priv: the bat priv with all the soft interface information
  94  */
  95 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
  96 {
  97         unsigned long msecs;
  98         /* this function may be invoked in different contexts (ogm rescheduling
  99          * or hard_iface activation), but the work timer should not be reset
 100          */
 101         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 102                 return;
 103
 104         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 105         msecs += prandom_u32() % (2 * BATADV_JITTER);
 106         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 107                            msecs_to_jiffies(msecs));
 108 }
 109
 110 /**
 111  * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 112  * @skb: the OGM to send
 113  * @hard_iface: the interface to use to send the OGM
 114  */
 115 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 116                                     struct batadv_hard_iface *hard_iface)
 117 {
 118         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 119
 120         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 121                 return;
 122
 123         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 124         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 125                            skb->len + ETH_HLEN);
 126
 127         batadv_send_broadcast_skb(skb, hard_iface);
 128 }
 129
 130 /**
 131  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 132  * @work: work queue item
 133  */
 134 static void batadv_v_ogm_send(struct work_struct *work)
 135 {
 136         struct batadv_hard_iface *hard_iface;
 137         struct batadv_priv_bat_v *bat_v;
 138         struct batadv_priv *bat_priv;
 139         struct batadv_ogm2_packet *ogm_packet;
 140         struct sk_buff *skb, *skb_tmp;
 141         unsigned char *ogm_buff;
 142         int ogm_buff_len;
 143         u16 tvlv_len = 0;
 144         int ret;
 145
 146         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 147         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 148
 149         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 150                 goto out;
 151
 152         ogm_buff = bat_priv->bat_v.ogm_buff;
 153         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 154         /* tt changes have to be committed before the tvlv data is
 155          * appended as it may alter the tt tvlv container
 156          */
 157         batadv_tt_local_commit_changes(bat_priv);
 158         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 159                                                     &ogm_buff_len,
 160                                                     BATADV_OGM2_HLEN);
 161
 162         bat_priv->bat_v.ogm_buff = ogm_buff;
 163         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 164
 165         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 166         if (!skb)
 167                 goto reschedule;
 168
 169         skb_reserve(skb, ETH_HLEN);
 170         skb_put_data(skb, 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 ourselves on %s suppressed: %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
 273  *  forwarded 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_data(skb, ogm_received, packet_len);
 386
 387         /* apply forward penalty */
 388         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 389         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 390         ogm_forward->ttl--;
 391
 392         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 393                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 394                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 395                    ogm_forward->ttl, if_incoming->net_dev->name);
 396
 397         batadv_v_ogm_send_to_if(skb, if_outgoing);
 398
 399 out:
 400         if (orig_ifinfo)
 401                 batadv_orig_ifinfo_put(orig_ifinfo);
 402         if (router)
 403                 batadv_neigh_node_put(router);
 404         if (neigh_ifinfo)
 405                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 406 }
 407
 408 /**
 409  * batadv_v_ogm_metric_update() - update route metric based on OGM
 410  * @bat_priv: the bat priv with all the soft interface information
 411  * @ogm2: OGM2 structure
 412  * @orig_node: Originator structure for which the OGM has been received
 413  * @neigh_node: the neigh_node through with the OGM has been received
 414  * @if_incoming: the interface where this packet was received
 415  * @if_outgoing: the interface for which the packet should be considered
 416  *
 417  * Return:
 418  *  1  if the OGM is new,
 419  *  0  if it is not new but valid,
 420  *  <0 on error (e.g. old OGM)
 421  */
 422 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 423                                       const struct batadv_ogm2_packet *ogm2,
 424                                       struct batadv_orig_node *orig_node,
 425                                       struct batadv_neigh_node *neigh_node,
 426                                       struct batadv_hard_iface *if_incoming,
 427                                       struct batadv_hard_iface *if_outgoing)
 428 {
 429         struct batadv_orig_ifinfo *orig_ifinfo;
 430         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 431         bool protection_started = false;
 432         int ret = -EINVAL;
 433         u32 path_throughput;
 434         s32 seq_diff;
 435
 436         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 437         if (!orig_ifinfo)
 438                 goto out;
 439
 440         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 441
 442         if (!hlist_empty(&orig_node->neigh_list) &&
 443             batadv_window_protected(bat_priv, seq_diff,
 444                                     BATADV_OGM_MAX_AGE,
 445                                     &orig_ifinfo->batman_seqno_reset,
 446                                     &protection_started)) {
 447                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 448                            "Drop packet: packet within window protection time from %pM\n",
 449                            ogm2->orig);
 450                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 451                            "Last reset: %ld, %ld\n",
 452                            orig_ifinfo->batman_seqno_reset, jiffies);
 453                 goto out;
 454         }
 455
 456         /* drop packets with old seqnos, however accept the first packet after
 457          * a host has been rebooted.
 458          */
 459         if (seq_diff < 0 && !protection_started)
 460                 goto out;
 461
 462         neigh_node->last_seen = jiffies;
 463
 464         orig_node->last_seen = jiffies;
 465
 466         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 467         orig_ifinfo->last_ttl = ogm2->ttl;
 468
 469         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 470         if (!neigh_ifinfo)
 471                 goto out;
 472
 473         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 474                                                    if_outgoing,
 475                                                    ntohl(ogm2->throughput));
 476         neigh_ifinfo->bat_v.throughput = path_throughput;
 477         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 478         neigh_ifinfo->last_ttl = ogm2->ttl;
 479
 480         if (seq_diff > 0 || protection_started)
 481                 ret = 1;
 482         else
 483                 ret = 0;
 484 out:
 485         if (orig_ifinfo)
 486                 batadv_orig_ifinfo_put(orig_ifinfo);
 487         if (neigh_ifinfo)
 488                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 489
 490         return ret;
 491 }
 492
 493 /**
 494  * batadv_v_ogm_route_update() - update routes based on OGM
 495  * @bat_priv: the bat priv with all the soft interface information
 496  * @ethhdr: the Ethernet header of the OGM2
 497  * @ogm2: OGM2 structure
 498  * @orig_node: Originator structure for which the OGM has been received
 499  * @neigh_node: the neigh_node through with the OGM has been received
 500  * @if_incoming: the interface where this packet was received
 501  * @if_outgoing: the interface for which the packet should be considered
 502  *
 503  * Return: true if the packet should be forwarded, false otherwise
 504  */
 505 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 506                                       const struct ethhdr *ethhdr,
 507                                       const struct batadv_ogm2_packet *ogm2,
 508                                       struct batadv_orig_node *orig_node,
 509                                       struct batadv_neigh_node *neigh_node,
 510                                       struct batadv_hard_iface *if_incoming,
 511                                       struct batadv_hard_iface *if_outgoing)
 512 {
 513         struct batadv_neigh_node *router = NULL;
 514         struct batadv_orig_node *orig_neigh_node;
 515         struct batadv_neigh_node *orig_neigh_router = NULL;
 516         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 517         u32 router_throughput, neigh_throughput;
 518         u32 router_last_seqno;
 519         u32 neigh_last_seqno;
 520         s32 neigh_seq_diff;
 521         bool forward = false;
 522
 523         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 524         if (!orig_neigh_node)
 525                 goto out;
 526
 527         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 528                                                    if_outgoing);
 529
 530         /* drop packet if sender is not a direct neighbor and if we
 531          * don't route towards it
 532          */
 533         router = batadv_orig_router_get(orig_node, if_outgoing);
 534         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 535                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 536                            "Drop packet: OGM via unknown neighbor!\n");
 537                 goto out;
 538         }
 539
 540         /* Mark the OGM to be considered for forwarding, and update routes
 541          * if needed.
 542          */
 543         forward = true;
 544
 545         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 546                    "Searching and updating originator entry of received packet\n");
 547
 548         /* if this neighbor already is our next hop there is nothing
 549          * to change
 550          */
 551         if (router == neigh_node)
 552                 goto out;
 553
 554         /* don't consider neighbours with worse throughput.
 555          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 556          * the last received seqno from our best next hop.
 557          */
 558         if (router) {
 559                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 560                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 561
 562                 /* if these are not allocated, something is wrong. */
 563                 if (!router_ifinfo || !neigh_ifinfo)
 564                         goto out;
 565
 566                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 567                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 568                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 569                 router_throughput = router_ifinfo->bat_v.throughput;
 570                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 571
 572                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 573                     router_throughput >= neigh_throughput)
 574                         goto out;
 575         }
 576
 577         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 578 out:
 579         if (router)
 580                 batadv_neigh_node_put(router);
 581         if (orig_neigh_router)
 582                 batadv_neigh_node_put(orig_neigh_router);
 583         if (orig_neigh_node)
 584                 batadv_orig_node_put(orig_neigh_node);
 585         if (router_ifinfo)
 586                 batadv_neigh_ifinfo_put(router_ifinfo);
 587         if (neigh_ifinfo)
 588                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 589
 590         return forward;
 591 }
 592
 593 /**
 594  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 595  * @bat_priv: the bat priv with all the soft interface information
 596  * @ethhdr: the Ethernet header of the OGM2
 597  * @ogm2: OGM2 structure
 598  * @orig_node: Originator structure for which the OGM has been received
 599  * @neigh_node: the neigh_node through with the OGM has been received
 600  * @if_incoming: the interface where this packet was received
 601  * @if_outgoing: the interface for which the packet should be considered
 602  */
 603 static void
 604 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 605                                const struct ethhdr *ethhdr,
 606                                const struct batadv_ogm2_packet *ogm2,
 607                                struct batadv_orig_node *orig_node,
 608                                struct batadv_neigh_node *neigh_node,
 609                                struct batadv_hard_iface *if_incoming,
 610                                struct batadv_hard_iface *if_outgoing)
 611 {
 612         int seqno_age;
 613         bool forward;
 614
 615         /* first, update the metric with according sanity checks */
 616         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 617                                                neigh_node, if_incoming,
 618                                                if_outgoing);
 619
 620         /* outdated sequence numbers are to be discarded */
 621         if (seqno_age < 0)
 622                 return;
 623
 624         /* only unknown & newer OGMs contain TVLVs we are interested in */
 625         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 626                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 627                                                NULL, NULL,
 628                                                (unsigned char *)(ogm2 + 1),
 629                                                ntohs(ogm2->tvlv_len));
 630
 631         /* if the metric update went through, update routes if needed */
 632         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 633                                             neigh_node, if_incoming,
 634                                             if_outgoing);
 635
 636         /* if the routes have been processed correctly, check and forward */
 637         if (forward)
 638                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 639                                      if_incoming, if_outgoing);
 640 }
 641
 642 /**
 643  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 644  * @buff_pos: current position in the skb
 645  * @packet_len: total length of the skb
 646  * @tvlv_len: tvlv length of the previously considered OGM
 647  *
 648  * Return: true if there is enough space for another OGM, false otherwise.
 649  */
 650 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 651                                      __be16 tvlv_len)
 652 {
 653         int next_buff_pos = 0;
 654
 655         next_buff_pos += buff_pos + BATADV_OGM2_HLEN;
 656         next_buff_pos += ntohs(tvlv_len);
 657
 658         return (next_buff_pos <= packet_len) &&
 659                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 660 }
 661
 662 /**
 663  * batadv_v_ogm_process() - process an incoming batman v OGM
 664  * @skb: the skb containing the OGM
 665  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 666  * @if_incoming: the interface where this packet was receved
 667  */
 668 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 669                                  struct batadv_hard_iface *if_incoming)
 670 {
 671         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 672         struct ethhdr *ethhdr;
 673         struct batadv_orig_node *orig_node = NULL;
 674         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 675         struct batadv_neigh_node *neigh_node = NULL;
 676         struct batadv_hard_iface *hard_iface;
 677         struct batadv_ogm2_packet *ogm_packet;
 678         u32 ogm_throughput, link_throughput, path_throughput;
 679         int ret;
 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, throughput %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 the throughput metric is 0, immediately drop the packet. No need
 694          * to create orig_node / neigh_node for an unusable route.
 695          */
 696         if (ogm_throughput == 0) {
 697                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 698                            "Drop packet: originator packet with throughput metric of 0\n");
 699                 return;
 700         }
 701
 702         /* require ELP packets be to received from this neighbor first */
 703         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 704         if (!hardif_neigh) {
 705                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 706                            "Drop packet: OGM via unknown neighbor!\n");
 707                 goto out;
 708         }
 709
 710         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 711         if (!orig_node)
 712                 return;
 713
 714         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 715                                                      ethhdr->h_source);
 716         if (!neigh_node)
 717                 goto out;
 718
 719         /* Update the received throughput metric to match the link
 720          * characteristic:
 721          *  - If this OGM traveled one hop so far (emitted by single hop
 722          *    neighbor) the path throughput metric equals the link throughput.
 723          *  - For OGMs traversing more than hop the path throughput metric is
 724          *    the smaller of the path throughput and the link throughput.
 725          */
 726         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 727         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 728         ogm_packet->throughput = htonl(path_throughput);
 729
 730         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 731                                        neigh_node, if_incoming,
 732                                        BATADV_IF_DEFAULT);
 733
 734         rcu_read_lock();
 735         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 736                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 737                         continue;
 738
 739                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 740                         continue;
 741
 742                 if (!kref_get_unless_zero(&hard_iface->refcount))
 743                         continue;
 744
 745                 ret = batadv_hardif_no_broadcast(hard_iface,
 746                                                  ogm_packet->orig,
 747                                                  hardif_neigh->orig);
 748
 749                 if (ret) {
 750                         char *type;
 751
 752                         switch (ret) {
 753                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 754                                 type = "no neighbor";
 755                                 break;
 756                         case BATADV_HARDIF_BCAST_DUPFWD:
 757                                 type = "single neighbor is source";
 758                                 break;
 759                         case BATADV_HARDIF_BCAST_DUPORIG:
 760                                 type = "single neighbor is originator";
 761                                 break;
 762                         default:
 763                                 type = "unknown";
 764                         }
 765
 766                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 767                                    ogm_packet->orig, hard_iface->net_dev->name,
 768                                    type);
 769
 770                         batadv_hardif_put(hard_iface);
 771                         continue;
 772                 }
 773
 774                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 775                                                orig_node, neigh_node,
 776                                                if_incoming, hard_iface);
 777
 778                 batadv_hardif_put(hard_iface);
 779         }
 780         rcu_read_unlock();
 781 out:
 782         if (orig_node)
 783                 batadv_orig_node_put(orig_node);
 784         if (neigh_node)
 785                 batadv_neigh_node_put(neigh_node);
 786         if (hardif_neigh)
 787                 batadv_hardif_neigh_put(hardif_neigh);
 788 }
 789
 790 /**
 791  * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 792  * @skb: the received OGM
 793  * @if_incoming: the interface where this OGM has been received
 794  *
 795  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 796  * (without freeing the skb) on failure
 797  */
 798 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 799                              struct batadv_hard_iface *if_incoming)
 800 {
 801         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 802         struct batadv_ogm2_packet *ogm_packet;
 803         struct ethhdr *ethhdr = eth_hdr(skb);
 804         int ogm_offset;
 805         u8 *packet_pos;
 806         int ret = NET_RX_DROP;
 807
 808         /* did we receive a OGM2 packet on an interface that does not have
 809          * B.A.T.M.A.N. V enabled ?
 810          */
 811         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 812                 goto free_skb;
 813
 814         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 815                 goto free_skb;
 816
 817         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 818                 goto free_skb;
 819
 820         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 821
 822         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
 823                 goto free_skb;
 824
 825         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 826         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 827                            skb->len + ETH_HLEN);
 828
 829         ogm_offset = 0;
 830         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 831
 832         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 833                                         ogm_packet->tvlv_len)) {
 834                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 835
 836                 ogm_offset += BATADV_OGM2_HLEN;
 837                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 838
 839                 packet_pos = skb->data + ogm_offset;
 840                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 841         }
 842
 843         ret = NET_RX_SUCCESS;
 844
 845 free_skb:
 846         if (ret == NET_RX_SUCCESS)
 847                 consume_skb(skb);
 848         else
 849                 kfree_skb(skb);
 850
 851         return ret;
 852 }
 853
 854 /**
 855  * batadv_v_ogm_init() - initialise the OGM2 engine
 856  * @bat_priv: the bat priv with all the soft interface information
 857  *
 858  * Return: 0 on success or a negative error code in case of failure
 859  */
 860 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 861 {
 862         struct batadv_ogm2_packet *ogm_packet;
 863         unsigned char *ogm_buff;
 864         u32 random_seqno;
 865
 866         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 867         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 868         if (!ogm_buff)
 869                 return -ENOMEM;
 870
 871         bat_priv->bat_v.ogm_buff = ogm_buff;
 872         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 873         ogm_packet->packet_type = BATADV_OGM2;
 874         ogm_packet->version = BATADV_COMPAT_VERSION;
 875         ogm_packet->ttl = BATADV_TTL;
 876         ogm_packet->flags = BATADV_NO_FLAGS;
 877         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 878
 879         /* randomize initial seqno to avoid collision */
 880         get_random_bytes(&random_seqno, sizeof(random_seqno));
 881         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 882         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 883
 884         return 0;
 885 }
 886
 887 /**
 888  * batadv_v_ogm_free() - free OGM private resources
 889  * @bat_priv: the bat priv with all the soft interface information
 890  */
 891 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 892 {
 893         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 894
 895         kfree(bat_priv->bat_v.ogm_buff);
 896         bat_priv->bat_v.ogm_buff = NULL;
 897         bat_priv->bat_v.ogm_buff_len = 0;
 898 }