net/batman-adv/bat_v_ogm.c

   1 /* Copyright (C) 2013-2016 B.A.T.M.A.N. contributors:
   2  *
   3  * Antonio Quartulli
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "bat_v_ogm.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/errno.h>
  24 #include <linux/etherdevice.h>
  25 #include <linux/fs.h>
  26 #include <linux/if_ether.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/kernel.h>
  29 #include <linux/list.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/random.h>
  32 #include <linux/rculist.h>
  33 #include <linux/rcupdate.h>
  34 #include <linux/skbuff.h>
  35 #include <linux/slab.h>
  36 #include <linux/stddef.h>
  37 #include <linux/string.h>
  38 #include <linux/types.h>
  39 #include <linux/workqueue.h>
  40
  41 #include "hard-interface.h"
  42 #include "hash.h"
  43 #include "originator.h"
  44 #include "packet.h"
  45 #include "routing.h"
  46 #include "send.h"
  47 #include "translation-table.h"
  48
  49 /**
  50  * batadv_v_ogm_orig_get - retrieve and possibly create an originator node
  51  * @bat_priv: the bat priv with all the soft interface information
  52  * @addr: the address of the originator
  53  *
  54  * Return: the orig_node corresponding to the specified address. If such object
  55  * does not exist it is allocated here. In case of allocation failure returns
  56  * NULL.
  57  */
  58 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  59                                                const u8 *addr)
  60 {
  61         struct batadv_orig_node *orig_node;
  62         int hash_added;
  63
  64         orig_node = batadv_orig_hash_find(bat_priv, addr);
  65         if (orig_node)
  66                 return orig_node;
  67
  68         orig_node = batadv_orig_node_new(bat_priv, addr);
  69         if (!orig_node)
  70                 return NULL;
  71
  72         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  73                                      batadv_choose_orig, orig_node,
  74                                      &orig_node->hash_entry);
  75         if (hash_added != 0) {
  76                 /* orig_node->refcounter is initialised to 2 by
  77                  * batadv_orig_node_new()
  78                  */
  79                 batadv_orig_node_put(orig_node);
  80                 batadv_orig_node_put(orig_node);
  81                 orig_node = NULL;
  82         }
  83
  84         return orig_node;
  85 }
  86
  87 /**
  88  * batadv_v_ogm_start_timer - restart the OGM sending timer
  89  * @bat_priv: the bat priv with all the soft interface information
  90  */
  91 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
  92 {
  93         unsigned long msecs;
  94         /* this function may be invoked in different contexts (ogm rescheduling
  95          * or hard_iface activation), but the work timer should not be reset
  96          */
  97         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
  98                 return;
  99
 100         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 101         msecs += prandom_u32() % (2 * BATADV_JITTER);
 102         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 103                            msecs_to_jiffies(msecs));
 104 }
 105
 106 /**
 107  * batadv_v_ogm_send_to_if - send a batman ogm using a given interface
 108  * @skb: the OGM to send
 109  * @hard_iface: the interface to use to send the OGM
 110  */
 111 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 112                                     struct batadv_hard_iface *hard_iface)
 113 {
 114         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 115
 116         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 117                 return;
 118
 119         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 120         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 121                            skb->len + ETH_HLEN);
 122
 123         batadv_send_broadcast_skb(skb, hard_iface);
 124 }
 125
 126 /**
 127  * batadv_v_ogm_send - periodic worker broadcasting the own OGM
 128  * @work: work queue item
 129  */
 130 static void batadv_v_ogm_send(struct work_struct *work)
 131 {
 132         struct batadv_hard_iface *hard_iface;
 133         struct batadv_priv_bat_v *bat_v;
 134         struct batadv_priv *bat_priv;
 135         struct batadv_ogm2_packet *ogm_packet;
 136         struct sk_buff *skb, *skb_tmp;
 137         unsigned char *ogm_buff, *pkt_buff;
 138         int ogm_buff_len;
 139         u16 tvlv_len = 0;
 140
 141         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 142         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 143
 144         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 145                 goto out;
 146
 147         ogm_buff = bat_priv->bat_v.ogm_buff;
 148         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 149         /* tt changes have to be committed before the tvlv data is
 150          * appended as it may alter the tt tvlv container
 151          */
 152         batadv_tt_local_commit_changes(bat_priv);
 153         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 154                                                     &ogm_buff_len,
 155                                                     BATADV_OGM2_HLEN);
 156
 157         bat_priv->bat_v.ogm_buff = ogm_buff;
 158         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 159
 160         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 161         if (!skb)
 162                 goto reschedule;
 163
 164         skb_reserve(skb, ETH_HLEN);
 165         pkt_buff = skb_put(skb, ogm_buff_len);
 166         memcpy(pkt_buff, ogm_buff, ogm_buff_len);
 167
 168         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 169         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 170         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 171         ogm_packet->tvlv_len = htons(tvlv_len);
 172
 173         /* broadcast on every interface */
 174         rcu_read_lock();
 175         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 176                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 177                         continue;
 178
 179                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 180                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 181                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 182                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 183                            hard_iface->net_dev->name,
 184                            hard_iface->net_dev->dev_addr);
 185
 186                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 187                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 188                 if (!skb_tmp)
 189                         break;
 190
 191                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 192         }
 193         rcu_read_unlock();
 194
 195         consume_skb(skb);
 196
 197 reschedule:
 198         batadv_v_ogm_start_timer(bat_priv);
 199 out:
 200         return;
 201 }
 202
 203 /**
 204  * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
 205  * @hard_iface: the interface to prepare
 206  *
 207  * Takes care of scheduling own OGM sending routine for this interface.
 208  *
 209  * Return: 0 on success or a negative error code otherwise
 210  */
 211 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 212 {
 213         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 214
 215         batadv_v_ogm_start_timer(bat_priv);
 216
 217         return 0;
 218 }
 219
 220 /**
 221  * batadv_v_ogm_primary_iface_set - set a new primary interface
 222  * @primary_iface: the new primary interface
 223  */
 224 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 225 {
 226         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 227         struct batadv_ogm2_packet *ogm_packet;
 228
 229         if (!bat_priv->bat_v.ogm_buff)
 230                 return;
 231
 232         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 233         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 234 }
 235
 236 /**
 237  * batadv_v_ogm_orig_update - update the originator status based on the received
 238  *  OGM
 239  * @bat_priv: the bat priv with all the soft interface information
 240  * @orig_node: the originator to update
 241  * @neigh_node: the neighbour the OGM has been received from (to update)
 242  * @ogm2: the received OGM
 243  * @if_outgoing: the interface where this OGM is going to be forwarded through
 244  */
 245 static void
 246 batadv_v_ogm_orig_update(struct batadv_priv *bat_priv,
 247                          struct batadv_orig_node *orig_node,
 248                          struct batadv_neigh_node *neigh_node,
 249                          const struct batadv_ogm2_packet *ogm2,
 250                          struct batadv_hard_iface *if_outgoing)
 251 {
 252         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 253         struct batadv_neigh_node *router = NULL;
 254         s32 neigh_seq_diff;
 255         u32 neigh_last_seqno;
 256         u32 router_last_seqno;
 257         u32 router_throughput, neigh_throughput;
 258
 259         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 260                    "Searching and updating originator entry of received packet\n");
 261
 262         /* if this neighbor already is our next hop there is nothing
 263          * to change
 264          */
 265         router = batadv_orig_router_get(orig_node, if_outgoing);
 266         if (router == neigh_node)
 267                 goto out;
 268
 269         /* don't consider neighbours with worse throughput.
 270          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 271          * the last received seqno from our best next hop.
 272          */
 273         if (router) {
 274                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 275                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 276
 277                 /* if these are not allocated, something is wrong. */
 278                 if (!router_ifinfo || !neigh_ifinfo)
 279                         goto out;
 280
 281                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 282                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 283                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 284                 router_throughput = router_ifinfo->bat_v.throughput;
 285                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 286
 287                 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
 288                     (router_throughput >= neigh_throughput))
 289                         goto out;
 290         }
 291
 292         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 293
 294 out:
 295         if (router_ifinfo)
 296                 batadv_neigh_ifinfo_put(router_ifinfo);
 297         if (neigh_ifinfo)
 298                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 299         if (router)
 300                 batadv_neigh_node_put(router);
 301 }
 302
 303 /**
 304  * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
 305  *  with B.A.T.M.A.N. V OGMs
 306  * @bat_priv: the bat priv with all the soft interface information
 307  * @if_incoming: the interface where the OGM has been received
 308  * @if_outgoing: the interface where the OGM has to be forwarded to
 309  * @throughput: the current throughput
 310  *
 311  * Apply a penalty on the current throughput metric value based on the
 312  * characteristic of the interface where the OGM has been received. The return
 313  * value is computed as follows:
 314  * - throughput * 50%          if the incoming and outgoing interface are the
 315  *                             same WiFi interface and the throughput is above
 316  *                             1MBit/s
 317  * - throughput                if the outgoing interface is the default
 318  *                             interface (i.e. this OGM is processed for the
 319  *                             internal table and not forwarded)
 320  * - throughput * hop penalty  otherwise
 321  *
 322  * Return: the penalised throughput metric.
 323  */
 324 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 325                                     struct batadv_hard_iface *if_incoming,
 326                                     struct batadv_hard_iface *if_outgoing,
 327                                     u32 throughput)
 328 {
 329         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 330         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 331
 332         /* Don't apply hop penalty in default originator table. */
 333         if (if_outgoing == BATADV_IF_DEFAULT)
 334                 return throughput;
 335
 336         /* Forwarding on the same WiFi interface cuts the throughput in half
 337          * due to the store & forward characteristics of WIFI.
 338          * Very low throughput values are the exception.
 339          */
 340         if ((throughput > 10) &&
 341             (if_incoming == if_outgoing) &&
 342             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 343                 return throughput / 2;
 344
 345         /* hop penalty of 255 equals 100% */
 346         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 347 }
 348
 349 /**
 350  * batadv_v_ogm_forward - forward an OGM to the given outgoing interface
 351  * @bat_priv: the bat priv with all the soft interface information
 352  * @ogm_received: previously received OGM to be forwarded
 353  * @throughput: throughput to announce, may vary per outgoing interface
 354  * @if_incoming: the interface on which this OGM was received on
 355  * @if_outgoing: the interface to which the OGM has to be forwarded to
 356  *
 357  * Forward an OGM to an interface after having altered the throughput metric and
 358  * the TTL value contained in it. The original OGM isn't modified.
 359  */
 360 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 361                                  const struct batadv_ogm2_packet *ogm_received,
 362                                  u32 throughput,
 363                                  struct batadv_hard_iface *if_incoming,
 364                                  struct batadv_hard_iface *if_outgoing)
 365 {
 366         struct batadv_ogm2_packet *ogm_forward;
 367         unsigned char *skb_buff;
 368         struct sk_buff *skb;
 369         size_t packet_len;
 370         u16 tvlv_len;
 371
 372         if (ogm_received->ttl <= 1) {
 373                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 374                 return;
 375         }
 376
 377         tvlv_len = ntohs(ogm_received->tvlv_len);
 378
 379         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 380         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 381                                         ETH_HLEN + packet_len);
 382         if (!skb)
 383                 return;
 384
 385         skb_reserve(skb, ETH_HLEN);
 386         skb_buff = skb_put(skb, packet_len);
 387         memcpy(skb_buff, ogm_received, packet_len);
 388
 389         /* apply forward penalty */
 390         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 391         ogm_forward->throughput = htonl(throughput);
 392         ogm_forward->ttl--;
 393
 394         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 395                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 396                    if_outgoing->net_dev->name, throughput, ogm_forward->ttl,
 397                    if_incoming->net_dev->name);
 398
 399         batadv_v_ogm_send_to_if(skb, if_outgoing);
 400 }
 401
 402 /**
 403  * batadv_v_ogm_metric_update - update route metric based on OGM
 404  * @bat_priv: the bat priv with all the soft interface information
 405  * @ogm2: OGM2 structure
 406  * @orig_node: Originator structure for which the OGM has been received
 407  * @neigh_node: the neigh_node through with the OGM has been received
 408  * @if_incoming: the interface where this packet was received
 409  * @if_outgoing: the interface for which the packet should be considered
 410  *
 411  * Return:
 412  *  1  if the OGM is new,
 413  *  0  if it is not new but valid,
 414  *  <0 on error (e.g. old OGM)
 415  */
 416 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 417                                       const struct batadv_ogm2_packet *ogm2,
 418                                       struct batadv_orig_node *orig_node,
 419                                       struct batadv_neigh_node *neigh_node,
 420                                       struct batadv_hard_iface *if_incoming,
 421                                       struct batadv_hard_iface *if_outgoing)
 422 {
 423         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 424         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 425         bool protection_started = false;
 426         int ret = -EINVAL;
 427         u32 path_throughput;
 428         s32 seq_diff;
 429
 430         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 431         if (!orig_ifinfo)
 432                 goto out;
 433
 434         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 435
 436         if (!hlist_empty(&orig_node->neigh_list) &&
 437             batadv_window_protected(bat_priv, seq_diff,
 438                                     BATADV_OGM_MAX_AGE,
 439                                     &orig_ifinfo->batman_seqno_reset,
 440                                     &protection_started)) {
 441                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 442                            "Drop packet: packet within window protection time from %pM\n",
 443                            ogm2->orig);
 444                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 445                            "Last reset: %ld, %ld\n",
 446                            orig_ifinfo->batman_seqno_reset, jiffies);
 447                 goto out;
 448         }
 449
 450         /* drop packets with old seqnos, however accept the first packet after
 451          * a host has been rebooted.
 452          */
 453         if ((seq_diff < 0) && !protection_started)
 454                 goto out;
 455
 456         neigh_node->last_seen = jiffies;
 457
 458         orig_node->last_seen = jiffies;
 459
 460         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 461         orig_ifinfo->last_ttl = ogm2->ttl;
 462
 463         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 464         if (!neigh_ifinfo)
 465                 goto out;
 466
 467         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 468                                                    if_outgoing,
 469                                                    ntohl(ogm2->throughput));
 470         neigh_ifinfo->bat_v.throughput = path_throughput;
 471         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 472         neigh_ifinfo->last_ttl = ogm2->ttl;
 473
 474         if (seq_diff > 0 || protection_started)
 475                 ret = 1;
 476         else
 477                 ret = 0;
 478 out:
 479         if (orig_ifinfo)
 480                 batadv_orig_ifinfo_put(orig_ifinfo);
 481         if (neigh_ifinfo)
 482                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 483
 484         return ret;
 485 }
 486
 487 /**
 488  * batadv_v_ogm_route_update - update routes based on OGM
 489  * @bat_priv: the bat priv with all the soft interface information
 490  * @ethhdr: the Ethernet header of the OGM2
 491  * @ogm2: OGM2 structure
 492  * @orig_node: Originator structure for which the OGM has been received
 493  * @neigh_node: the neigh_node through with the OGM has been received
 494  * @if_incoming: the interface where this packet was received
 495  * @if_outgoing: the interface for which the packet should be considered
 496  */
 497 static void batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 498                                       const struct ethhdr *ethhdr,
 499                                       const struct batadv_ogm2_packet *ogm2,
 500                                       struct batadv_orig_node *orig_node,
 501                                       struct batadv_neigh_node *neigh_node,
 502                                       struct batadv_hard_iface *if_incoming,
 503                                       struct batadv_hard_iface *if_outgoing)
 504 {
 505         struct batadv_neigh_node *router = NULL;
 506         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 507         struct batadv_orig_node *orig_neigh_node = NULL;
 508         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 509         struct batadv_neigh_node *orig_neigh_router = NULL;
 510
 511         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 512         if (!neigh_ifinfo)
 513                 goto out;
 514
 515         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 516         if (!orig_neigh_node)
 517                 goto out;
 518
 519         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 520                                                    if_outgoing);
 521
 522         /* drop packet if sender is not a direct neighbor and if we
 523          * don't route towards it
 524          */
 525         router = batadv_orig_router_get(orig_node, if_outgoing);
 526         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 527                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 528                            "Drop packet: OGM via unknown neighbor!\n");
 529                 goto out;
 530         }
 531
 532         if (router)
 533                 batadv_neigh_node_put(router);
 534
 535         /* Update routes, and check if the OGM is from the best next hop */
 536         batadv_v_ogm_orig_update(bat_priv, orig_node, neigh_node, ogm2,
 537                                  if_outgoing);
 538
 539         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 540         if (!orig_ifinfo)
 541                 goto out;
 542
 543         /* don't forward the same seqno twice on one interface */
 544         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm2->seqno))
 545                 goto out;
 546
 547         /* acquire possibly updated router */
 548         router = batadv_orig_router_get(orig_node, if_outgoing);
 549
 550         /* strict rule: forward packets coming from the best next hop only */
 551         if (neigh_node != router)
 552                 goto out;
 553
 554         /* only forward for specific interface, not for the default one. */
 555         if (if_outgoing != BATADV_IF_DEFAULT) {
 556                 orig_ifinfo->last_seqno_forwarded = ntohl(ogm2->seqno);
 557                 batadv_v_ogm_forward(bat_priv, ogm2,
 558                                      neigh_ifinfo->bat_v.throughput,
 559                                      if_incoming, if_outgoing);
 560         }
 561
 562 out:
 563         if (orig_ifinfo)
 564                 batadv_orig_ifinfo_put(orig_ifinfo);
 565         if (router)
 566                 batadv_neigh_node_put(router);
 567         if (orig_neigh_router)
 568                 batadv_neigh_node_put(orig_neigh_router);
 569         if (orig_neigh_node)
 570                 batadv_orig_node_put(orig_neigh_node);
 571         if (neigh_ifinfo)
 572                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 573 }
 574
 575 /**
 576  * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
 577  * @bat_priv: the bat priv with all the soft interface information
 578  * @ethhdr: the Ethernet header of the OGM2
 579  * @ogm2: OGM2 structure
 580  * @orig_node: Originator structure for which the OGM has been received
 581  * @neigh_node: the neigh_node through with the OGM has been received
 582  * @if_incoming: the interface where this packet was received
 583  * @if_outgoing: the interface for which the packet should be considered
 584  */
 585 static void
 586 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 587                                const struct ethhdr *ethhdr,
 588                                const struct batadv_ogm2_packet *ogm2,
 589                                struct batadv_orig_node *orig_node,
 590                                struct batadv_neigh_node *neigh_node,
 591                                struct batadv_hard_iface *if_incoming,
 592                                struct batadv_hard_iface *if_outgoing)
 593 {
 594         int seqno_age;
 595
 596         /* first, update the metric with according sanity checks */
 597         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 598                                                neigh_node, if_incoming,
 599                                                if_outgoing);
 600
 601         /* outdated sequence numbers are to be discarded */
 602         if (seqno_age < 0)
 603                 return;
 604
 605         /* only unknown & newer OGMs contain TVLVs we are interested in */
 606         if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
 607                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 608                                                NULL, NULL,
 609                                                (unsigned char *)(ogm2 + 1),
 610                                                ntohs(ogm2->tvlv_len));
 611
 612         /* if the metric update went through, update routes if needed */
 613         batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 614                                   neigh_node, if_incoming, if_outgoing);
 615 }
 616
 617 /**
 618  * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
 619  * @buff_pos: current position in the skb
 620  * @packet_len: total length of the skb
 621  * @tvlv_len: tvlv length of the previously considered OGM
 622  *
 623  * Return: true if there is enough space for another OGM, false otherwise.
 624  */
 625 static bool batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 626                                      __be16 tvlv_len)
 627 {
 628         int next_buff_pos = 0;
 629
 630         next_buff_pos += buff_pos + BATADV_OGM2_HLEN;
 631         next_buff_pos += ntohs(tvlv_len);
 632
 633         return (next_buff_pos <= packet_len) &&
 634                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 635 }
 636
 637 /**
 638  * batadv_v_ogm_process - process an incoming batman v OGM
 639  * @skb: the skb containing the OGM
 640  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 641  * @if_incoming: the interface where this packet was receved
 642  */
 643 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 644                                  struct batadv_hard_iface *if_incoming)
 645 {
 646         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 647         struct ethhdr *ethhdr;
 648         struct batadv_orig_node *orig_node = NULL;
 649         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 650         struct batadv_neigh_node *neigh_node = NULL;
 651         struct batadv_hard_iface *hard_iface;
 652         struct batadv_ogm2_packet *ogm_packet;
 653         u32 ogm_throughput, link_throughput, path_throughput;
 654
 655         ethhdr = eth_hdr(skb);
 656         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 657
 658         ogm_throughput = ntohl(ogm_packet->throughput);
 659
 660         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 661                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, troughput %u, TTL %u, V %u, tvlv_len %u)\n",
 662                    ethhdr->h_source, if_incoming->net_dev->name,
 663                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 664                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 665                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 666
 667         /* If the troughput metric is 0, immediately drop the packet. No need to
 668          * create orig_node / neigh_node for an unusable route.
 669          */
 670         if (ogm_throughput == 0) {
 671                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 672                            "Drop packet: originator packet with troughput metric of 0\n");
 673                 return;
 674         }
 675
 676         /* require ELP packets be to received from this neighbor first */
 677         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 678         if (!hardif_neigh) {
 679                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 680                            "Drop packet: OGM via unknown neighbor!\n");
 681                 goto out;
 682         }
 683
 684         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 685         if (!orig_node)
 686                 return;
 687
 688         neigh_node = batadv_neigh_node_new(orig_node, if_incoming,
 689                                            ethhdr->h_source);
 690         if (!neigh_node)
 691                 goto out;
 692
 693         /* Update the received throughput metric to match the link
 694          * characteristic:
 695          *  - If this OGM traveled one hop so far (emitted by single hop
 696          *    neighbor) the path throughput metric equals the link throughput.
 697          *  - For OGMs traversing more than hop the path throughput metric is
 698          *    the smaller of the path throughput and the link throughput.
 699          */
 700         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 701         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 702         ogm_packet->throughput = htonl(path_throughput);
 703
 704         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 705                                        neigh_node, if_incoming,
 706                                        BATADV_IF_DEFAULT);
 707
 708         rcu_read_lock();
 709         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 710                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 711                         continue;
 712
 713                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 714                         continue;
 715
 716                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 717                                                orig_node, neigh_node,
 718                                                if_incoming, hard_iface);
 719         }
 720         rcu_read_unlock();
 721 out:
 722         if (orig_node)
 723                 batadv_orig_node_put(orig_node);
 724         if (neigh_node)
 725                 batadv_neigh_node_put(neigh_node);
 726         if (hardif_neigh)
 727                 batadv_hardif_neigh_put(hardif_neigh);
 728 }
 729
 730 /**
 731  * batadv_v_ogm_packet_recv - OGM2 receiving handler
 732  * @skb: the received OGM
 733  * @if_incoming: the interface where this OGM has been received
 734  *
 735  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 736  * (without freeing the skb) on failure
 737  */
 738 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 739                              struct batadv_hard_iface *if_incoming)
 740 {
 741         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 742         struct batadv_ogm2_packet *ogm_packet;
 743         struct ethhdr *ethhdr = eth_hdr(skb);
 744         int ogm_offset;
 745         u8 *packet_pos;
 746         int ret = NET_RX_DROP;
 747
 748         /* did we receive a OGM2 packet on an interface that does not have
 749          * B.A.T.M.A.N. V enabled ?
 750          */
 751         if (strcmp(bat_priv->bat_algo_ops->name, "BATMAN_V") != 0)
 752                 return NET_RX_DROP;
 753
 754         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 755                 return NET_RX_DROP;
 756
 757         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 758                 return NET_RX_DROP;
 759
 760         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 761
 762         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
 763                 return NET_RX_DROP;
 764
 765         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 766         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 767                            skb->len + ETH_HLEN);
 768
 769         ogm_offset = 0;
 770         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 771
 772         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 773                                         ogm_packet->tvlv_len)) {
 774                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 775
 776                 ogm_offset += BATADV_OGM2_HLEN;
 777                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 778
 779                 packet_pos = skb->data + ogm_offset;
 780                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 781         }
 782
 783         ret = NET_RX_SUCCESS;
 784         consume_skb(skb);
 785
 786         return ret;
 787 }
 788
 789 /**
 790  * batadv_v_ogm_init - initialise the OGM2 engine
 791  * @bat_priv: the bat priv with all the soft interface information
 792  *
 793  * Return: 0 on success or a negative error code in case of failure
 794  */
 795 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 796 {
 797         struct batadv_ogm2_packet *ogm_packet;
 798         unsigned char *ogm_buff;
 799         u32 random_seqno;
 800
 801         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 802         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 803         if (!ogm_buff)
 804                 return -ENOMEM;
 805
 806         bat_priv->bat_v.ogm_buff = ogm_buff;
 807         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 808         ogm_packet->packet_type = BATADV_OGM2;
 809         ogm_packet->version = BATADV_COMPAT_VERSION;
 810         ogm_packet->ttl = BATADV_TTL;
 811         ogm_packet->flags = BATADV_NO_FLAGS;
 812         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 813
 814         /* randomize initial seqno to avoid collision */
 815         get_random_bytes(&random_seqno, sizeof(random_seqno));
 816         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 817         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 818
 819         return 0;
 820 }
 821
 822 /**
 823  * batadv_v_ogm_free - free OGM private resources
 824  * @bat_priv: the bat priv with all the soft interface information
 825  */
 826 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 827 {
 828         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 829
 830         kfree(bat_priv->bat_v.ogm_buff);
 831         bat_priv->bat_v.ogm_buff = NULL;
 832         bat_priv->bat_v.ogm_buff_len = 0;
 833 }