net/batman-adv/bat_v_ogm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2013-2019  B.A.T.M.A.N. contributors:
   3  *
   4  * Antonio Quartulli
   5  */
   6
   7 #include "bat_v_ogm.h"
   8 #include "main.h"
   9
  10 #include <linux/atomic.h>
  11 #include <linux/byteorder/generic.h>
  12 #include <linux/errno.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/gfp.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/kernel.h>
  18 #include <linux/kref.h>
  19 #include <linux/list.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/random.h>
  22 #include <linux/rculist.h>
  23 #include <linux/rcupdate.h>
  24 #include <linux/skbuff.h>
  25 #include <linux/slab.h>
  26 #include <linux/stddef.h>
  27 #include <linux/string.h>
  28 #include <linux/types.h>
  29 #include <linux/workqueue.h>
  30 #include <uapi/linux/batadv_packet.h>
  31
  32 #include "bat_algo.h"
  33 #include "hard-interface.h"
  34 #include "hash.h"
  35 #include "log.h"
  36 #include "originator.h"
  37 #include "routing.h"
  38 #include "send.h"
  39 #include "translation-table.h"
  40 #include "tvlv.h"
  41
  42 /**
  43  * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
  44  * @bat_priv: the bat priv with all the soft interface information
  45  * @addr: the address of the originator
  46  *
  47  * Return: the orig_node corresponding to the specified address. If such object
  48  * does not exist it is allocated here. In case of allocation failure returns
  49  * NULL.
  50  */
  51 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  52                                                const u8 *addr)
  53 {
  54         struct batadv_orig_node *orig_node;
  55         int hash_added;
  56
  57         orig_node = batadv_orig_hash_find(bat_priv, addr);
  58         if (orig_node)
  59                 return orig_node;
  60
  61         orig_node = batadv_orig_node_new(bat_priv, addr);
  62         if (!orig_node)
  63                 return NULL;
  64
  65         kref_get(&orig_node->refcount);
  66         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  67                                      batadv_choose_orig, orig_node,
  68                                      &orig_node->hash_entry);
  69         if (hash_added != 0) {
  70                 /* remove refcnt for newly created orig_node and hash entry */
  71                 batadv_orig_node_put(orig_node);
  72                 batadv_orig_node_put(orig_node);
  73                 orig_node = NULL;
  74         }
  75
  76         return orig_node;
  77 }
  78
  79 /**
  80  * batadv_v_ogm_start_timer() - restart the OGM sending timer
  81  * @bat_priv: the bat priv with all the soft interface information
  82  */
  83 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
  84 {
  85         unsigned long msecs;
  86         /* this function may be invoked in different contexts (ogm rescheduling
  87          * or hard_iface activation), but the work timer should not be reset
  88          */
  89         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
  90                 return;
  91
  92         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
  93         msecs += prandom_u32() % (2 * BATADV_JITTER);
  94         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
  95                            msecs_to_jiffies(msecs));
  96 }
  97
  98 /**
  99  * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 100  * @skb: the OGM to send
 101  * @hard_iface: the interface to use to send the OGM
 102  */
 103 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 104                                     struct batadv_hard_iface *hard_iface)
 105 {
 106         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 107
 108         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 109                 return;
 110
 111         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 112         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 113                            skb->len + ETH_HLEN);
 114
 115         batadv_send_broadcast_skb(skb, hard_iface);
 116 }
 117
 118 /**
 119  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 120  * @work: work queue item
 121  */
 122 static void batadv_v_ogm_send(struct work_struct *work)
 123 {
 124         struct batadv_hard_iface *hard_iface;
 125         struct batadv_priv_bat_v *bat_v;
 126         struct batadv_priv *bat_priv;
 127         struct batadv_ogm2_packet *ogm_packet;
 128         struct sk_buff *skb, *skb_tmp;
 129         unsigned char *ogm_buff;
 130         int ogm_buff_len;
 131         u16 tvlv_len = 0;
 132         int ret;
 133
 134         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 135         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 136
 137         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 138                 goto out;
 139
 140         ogm_buff = bat_priv->bat_v.ogm_buff;
 141         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 142         /* tt changes have to be committed before the tvlv data is
 143          * appended as it may alter the tt tvlv container
 144          */
 145         batadv_tt_local_commit_changes(bat_priv);
 146         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 147                                                     &ogm_buff_len,
 148                                                     BATADV_OGM2_HLEN);
 149
 150         bat_priv->bat_v.ogm_buff = ogm_buff;
 151         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 152
 153         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 154         if (!skb)
 155                 goto reschedule;
 156
 157         skb_reserve(skb, ETH_HLEN);
 158         skb_put_data(skb, ogm_buff, ogm_buff_len);
 159
 160         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 161         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 162         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 163         ogm_packet->tvlv_len = htons(tvlv_len);
 164
 165         /* broadcast on every interface */
 166         rcu_read_lock();
 167         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 168                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 169                         continue;
 170
 171                 if (!kref_get_unless_zero(&hard_iface->refcount))
 172                         continue;
 173
 174                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 175                 if (ret) {
 176                         char *type;
 177
 178                         switch (ret) {
 179                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 180                                 type = "no neighbor";
 181                                 break;
 182                         case BATADV_HARDIF_BCAST_DUPFWD:
 183                                 type = "single neighbor is source";
 184                                 break;
 185                         case BATADV_HARDIF_BCAST_DUPORIG:
 186                                 type = "single neighbor is originator";
 187                                 break;
 188                         default:
 189                                 type = "unknown";
 190                         }
 191
 192                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
 193                                    hard_iface->net_dev->name, type);
 194
 195                         batadv_hardif_put(hard_iface);
 196                         continue;
 197                 }
 198
 199                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 200                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 201                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 202                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 203                            hard_iface->net_dev->name,
 204                            hard_iface->net_dev->dev_addr);
 205
 206                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 207                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 208                 if (!skb_tmp) {
 209                         batadv_hardif_put(hard_iface);
 210                         break;
 211                 }
 212
 213                 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
 214                 batadv_hardif_put(hard_iface);
 215         }
 216         rcu_read_unlock();
 217
 218         consume_skb(skb);
 219
 220 reschedule:
 221         batadv_v_ogm_start_timer(bat_priv);
 222 out:
 223         return;
 224 }
 225
 226 /**
 227  * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
 228  * @hard_iface: the interface to prepare
 229  *
 230  * Takes care of scheduling own OGM sending routine for this interface.
 231  *
 232  * Return: 0 on success or a negative error code otherwise
 233  */
 234 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 235 {
 236         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 237
 238         batadv_v_ogm_start_timer(bat_priv);
 239
 240         return 0;
 241 }
 242
 243 /**
 244  * batadv_v_ogm_primary_iface_set() - set a new primary interface
 245  * @primary_iface: the new primary interface
 246  */
 247 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 248 {
 249         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 250         struct batadv_ogm2_packet *ogm_packet;
 251
 252         if (!bat_priv->bat_v.ogm_buff)
 253                 return;
 254
 255         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 256         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 257 }
 258
 259 /**
 260  * batadv_v_forward_penalty() - apply a penalty to the throughput metric
 261  *  forwarded with B.A.T.M.A.N. V OGMs
 262  * @bat_priv: the bat priv with all the soft interface information
 263  * @if_incoming: the interface where the OGM has been received
 264  * @if_outgoing: the interface where the OGM has to be forwarded to
 265  * @throughput: the current throughput
 266  *
 267  * Apply a penalty on the current throughput metric value based on the
 268  * characteristic of the interface where the OGM has been received. The return
 269  * value is computed as follows:
 270  * - throughput * 50%          if the incoming and outgoing interface are the
 271  *                             same WiFi interface and the throughput is above
 272  *                             1MBit/s
 273  * - throughput                if the outgoing interface is the default
 274  *                             interface (i.e. this OGM is processed for the
 275  *                             internal table and not forwarded)
 276  * - throughput * hop penalty  otherwise
 277  *
 278  * Return: the penalised throughput metric.
 279  */
 280 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 281                                     struct batadv_hard_iface *if_incoming,
 282                                     struct batadv_hard_iface *if_outgoing,
 283                                     u32 throughput)
 284 {
 285         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 286         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 287
 288         /* Don't apply hop penalty in default originator table. */
 289         if (if_outgoing == BATADV_IF_DEFAULT)
 290                 return throughput;
 291
 292         /* Forwarding on the same WiFi interface cuts the throughput in half
 293          * due to the store & forward characteristics of WIFI.
 294          * Very low throughput values are the exception.
 295          */
 296         if (throughput > 10 &&
 297             if_incoming == if_outgoing &&
 298             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 299                 return throughput / 2;
 300
 301         /* hop penalty of 255 equals 100% */
 302         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 303 }
 304
 305 /**
 306  * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 307  *  outgoing interface
 308  * @bat_priv: the bat priv with all the soft interface information
 309  * @ogm_received: previously received OGM to be forwarded
 310  * @orig_node: the originator which has been updated
 311  * @neigh_node: the neigh_node through with the OGM has been received
 312  * @if_incoming: the interface on which this OGM was received on
 313  * @if_outgoing: the interface to which the OGM has to be forwarded to
 314  *
 315  * Forward an OGM to an interface after having altered the throughput metric and
 316  * the TTL value contained in it. The original OGM isn't modified.
 317  */
 318 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 319                                  const struct batadv_ogm2_packet *ogm_received,
 320                                  struct batadv_orig_node *orig_node,
 321                                  struct batadv_neigh_node *neigh_node,
 322                                  struct batadv_hard_iface *if_incoming,
 323                                  struct batadv_hard_iface *if_outgoing)
 324 {
 325         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 326         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 327         struct batadv_neigh_node *router = NULL;
 328         struct batadv_ogm2_packet *ogm_forward;
 329         unsigned char *skb_buff;
 330         struct sk_buff *skb;
 331         size_t packet_len;
 332         u16 tvlv_len;
 333
 334         /* only forward for specific interfaces, not for the default one. */
 335         if (if_outgoing == BATADV_IF_DEFAULT)
 336                 goto out;
 337
 338         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 339         if (!orig_ifinfo)
 340                 goto out;
 341
 342         /* acquire possibly updated router */
 343         router = batadv_orig_router_get(orig_node, if_outgoing);
 344
 345         /* strict rule: forward packets coming from the best next hop only */
 346         if (neigh_node != router)
 347                 goto out;
 348
 349         /* don't forward the same seqno twice on one interface */
 350         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 351                 goto out;
 352
 353         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 354
 355         if (ogm_received->ttl <= 1) {
 356                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 357                 goto out;
 358         }
 359
 360         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 361         if (!neigh_ifinfo)
 362                 goto out;
 363
 364         tvlv_len = ntohs(ogm_received->tvlv_len);
 365
 366         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 367         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 368                                         ETH_HLEN + packet_len);
 369         if (!skb)
 370                 goto out;
 371
 372         skb_reserve(skb, ETH_HLEN);
 373         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 374
 375         /* apply forward penalty */
 376         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 377         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 378         ogm_forward->ttl--;
 379
 380         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 381                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 382                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 383                    ogm_forward->ttl, if_incoming->net_dev->name);
 384
 385         batadv_v_ogm_send_to_if(skb, if_outgoing);
 386
 387 out:
 388         if (orig_ifinfo)
 389                 batadv_orig_ifinfo_put(orig_ifinfo);
 390         if (router)
 391                 batadv_neigh_node_put(router);
 392         if (neigh_ifinfo)
 393                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 394 }
 395
 396 /**
 397  * batadv_v_ogm_metric_update() - update route metric based on OGM
 398  * @bat_priv: the bat priv with all the soft interface information
 399  * @ogm2: OGM2 structure
 400  * @orig_node: Originator structure for which the OGM has been received
 401  * @neigh_node: the neigh_node through with the OGM has been received
 402  * @if_incoming: the interface where this packet was received
 403  * @if_outgoing: the interface for which the packet should be considered
 404  *
 405  * Return:
 406  *  1  if the OGM is new,
 407  *  0  if it is not new but valid,
 408  *  <0 on error (e.g. old OGM)
 409  */
 410 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 411                                       const struct batadv_ogm2_packet *ogm2,
 412                                       struct batadv_orig_node *orig_node,
 413                                       struct batadv_neigh_node *neigh_node,
 414                                       struct batadv_hard_iface *if_incoming,
 415                                       struct batadv_hard_iface *if_outgoing)
 416 {
 417         struct batadv_orig_ifinfo *orig_ifinfo;
 418         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 419         bool protection_started = false;
 420         int ret = -EINVAL;
 421         u32 path_throughput;
 422         s32 seq_diff;
 423
 424         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 425         if (!orig_ifinfo)
 426                 goto out;
 427
 428         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 429
 430         if (!hlist_empty(&orig_node->neigh_list) &&
 431             batadv_window_protected(bat_priv, seq_diff,
 432                                     BATADV_OGM_MAX_AGE,
 433                                     &orig_ifinfo->batman_seqno_reset,
 434                                     &protection_started)) {
 435                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 436                            "Drop packet: packet within window protection time from %pM\n",
 437                            ogm2->orig);
 438                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 439                            "Last reset: %ld, %ld\n",
 440                            orig_ifinfo->batman_seqno_reset, jiffies);
 441                 goto out;
 442         }
 443
 444         /* drop packets with old seqnos, however accept the first packet after
 445          * a host has been rebooted.
 446          */
 447         if (seq_diff < 0 && !protection_started)
 448                 goto out;
 449
 450         neigh_node->last_seen = jiffies;
 451
 452         orig_node->last_seen = jiffies;
 453
 454         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 455         orig_ifinfo->last_ttl = ogm2->ttl;
 456
 457         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 458         if (!neigh_ifinfo)
 459                 goto out;
 460
 461         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 462                                                    if_outgoing,
 463                                                    ntohl(ogm2->throughput));
 464         neigh_ifinfo->bat_v.throughput = path_throughput;
 465         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 466         neigh_ifinfo->last_ttl = ogm2->ttl;
 467
 468         if (seq_diff > 0 || protection_started)
 469                 ret = 1;
 470         else
 471                 ret = 0;
 472 out:
 473         if (orig_ifinfo)
 474                 batadv_orig_ifinfo_put(orig_ifinfo);
 475         if (neigh_ifinfo)
 476                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 477
 478         return ret;
 479 }
 480
 481 /**
 482  * batadv_v_ogm_route_update() - update routes based on OGM
 483  * @bat_priv: the bat priv with all the soft interface information
 484  * @ethhdr: the Ethernet header of the OGM2
 485  * @ogm2: OGM2 structure
 486  * @orig_node: Originator structure for which the OGM has been received
 487  * @neigh_node: the neigh_node through with the OGM has been received
 488  * @if_incoming: the interface where this packet was received
 489  * @if_outgoing: the interface for which the packet should be considered
 490  *
 491  * Return: true if the packet should be forwarded, false otherwise
 492  */
 493 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 494                                       const struct ethhdr *ethhdr,
 495                                       const struct batadv_ogm2_packet *ogm2,
 496                                       struct batadv_orig_node *orig_node,
 497                                       struct batadv_neigh_node *neigh_node,
 498                                       struct batadv_hard_iface *if_incoming,
 499                                       struct batadv_hard_iface *if_outgoing)
 500 {
 501         struct batadv_neigh_node *router = NULL;
 502         struct batadv_orig_node *orig_neigh_node;
 503         struct batadv_neigh_node *orig_neigh_router = NULL;
 504         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 505         u32 router_throughput, neigh_throughput;
 506         u32 router_last_seqno;
 507         u32 neigh_last_seqno;
 508         s32 neigh_seq_diff;
 509         bool forward = false;
 510
 511         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 512         if (!orig_neigh_node)
 513                 goto out;
 514
 515         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 516                                                    if_outgoing);
 517
 518         /* drop packet if sender is not a direct neighbor and if we
 519          * don't route towards it
 520          */
 521         router = batadv_orig_router_get(orig_node, if_outgoing);
 522         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 523                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 524                            "Drop packet: OGM via unknown neighbor!\n");
 525                 goto out;
 526         }
 527
 528         /* Mark the OGM to be considered for forwarding, and update routes
 529          * if needed.
 530          */
 531         forward = true;
 532
 533         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 534                    "Searching and updating originator entry of received packet\n");
 535
 536         /* if this neighbor already is our next hop there is nothing
 537          * to change
 538          */
 539         if (router == neigh_node)
 540                 goto out;
 541
 542         /* don't consider neighbours with worse throughput.
 543          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 544          * the last received seqno from our best next hop.
 545          */
 546         if (router) {
 547                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 548                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 549
 550                 /* if these are not allocated, something is wrong. */
 551                 if (!router_ifinfo || !neigh_ifinfo)
 552                         goto out;
 553
 554                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 555                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 556                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 557                 router_throughput = router_ifinfo->bat_v.throughput;
 558                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 559
 560                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 561                     router_throughput >= neigh_throughput)
 562                         goto out;
 563         }
 564
 565         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 566 out:
 567         if (router)
 568                 batadv_neigh_node_put(router);
 569         if (orig_neigh_router)
 570                 batadv_neigh_node_put(orig_neigh_router);
 571         if (orig_neigh_node)
 572                 batadv_orig_node_put(orig_neigh_node);
 573         if (router_ifinfo)
 574                 batadv_neigh_ifinfo_put(router_ifinfo);
 575         if (neigh_ifinfo)
 576                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 577
 578         return forward;
 579 }
 580
 581 /**
 582  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 583  * @bat_priv: the bat priv with all the soft interface information
 584  * @ethhdr: the Ethernet header of the OGM2
 585  * @ogm2: OGM2 structure
 586  * @orig_node: Originator structure for which the OGM has been received
 587  * @neigh_node: the neigh_node through with the OGM has been received
 588  * @if_incoming: the interface where this packet was received
 589  * @if_outgoing: the interface for which the packet should be considered
 590  */
 591 static void
 592 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 593                                const struct ethhdr *ethhdr,
 594                                const struct batadv_ogm2_packet *ogm2,
 595                                struct batadv_orig_node *orig_node,
 596                                struct batadv_neigh_node *neigh_node,
 597                                struct batadv_hard_iface *if_incoming,
 598                                struct batadv_hard_iface *if_outgoing)
 599 {
 600         int seqno_age;
 601         bool forward;
 602
 603         /* first, update the metric with according sanity checks */
 604         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 605                                                neigh_node, if_incoming,
 606                                                if_outgoing);
 607
 608         /* outdated sequence numbers are to be discarded */
 609         if (seqno_age < 0)
 610                 return;
 611
 612         /* only unknown & newer OGMs contain TVLVs we are interested in */
 613         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 614                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 615                                                NULL, NULL,
 616                                                (unsigned char *)(ogm2 + 1),
 617                                                ntohs(ogm2->tvlv_len));
 618
 619         /* if the metric update went through, update routes if needed */
 620         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 621                                             neigh_node, if_incoming,
 622                                             if_outgoing);
 623
 624         /* if the routes have been processed correctly, check and forward */
 625         if (forward)
 626                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 627                                      if_incoming, if_outgoing);
 628 }
 629
 630 /**
 631  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 632  * @buff_pos: current position in the skb
 633  * @packet_len: total length of the skb
 634  * @ogm2_packet: potential OGM2 in buffer
 635  *
 636  * Return: true if there is enough space for another OGM, false otherwise.
 637  */
 638 static bool
 639 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 640                          const struct batadv_ogm2_packet *ogm2_packet)
 641 {
 642         int next_buff_pos = 0;
 643
 644         /* check if there is enough space for the header */
 645         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 646         if (next_buff_pos > packet_len)
 647                 return false;
 648
 649         /* check if there is enough space for the optional TVLV */
 650         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 651
 652         return (next_buff_pos <= packet_len) &&
 653                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 654 }
 655
 656 /**
 657  * batadv_v_ogm_process() - process an incoming batman v OGM
 658  * @skb: the skb containing the OGM
 659  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 660  * @if_incoming: the interface where this packet was receved
 661  */
 662 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 663                                  struct batadv_hard_iface *if_incoming)
 664 {
 665         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 666         struct ethhdr *ethhdr;
 667         struct batadv_orig_node *orig_node = NULL;
 668         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 669         struct batadv_neigh_node *neigh_node = NULL;
 670         struct batadv_hard_iface *hard_iface;
 671         struct batadv_ogm2_packet *ogm_packet;
 672         u32 ogm_throughput, link_throughput, path_throughput;
 673         int ret;
 674
 675         ethhdr = eth_hdr(skb);
 676         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 677
 678         ogm_throughput = ntohl(ogm_packet->throughput);
 679
 680         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 681                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 682                    ethhdr->h_source, if_incoming->net_dev->name,
 683                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 684                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 685                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 686
 687         /* If the throughput metric is 0, immediately drop the packet. No need
 688          * to create orig_node / neigh_node for an unusable route.
 689          */
 690         if (ogm_throughput == 0) {
 691                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 692                            "Drop packet: originator packet with throughput metric of 0\n");
 693                 return;
 694         }
 695
 696         /* require ELP packets be to received from this neighbor first */
 697         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 698         if (!hardif_neigh) {
 699                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 700                            "Drop packet: OGM via unknown neighbor!\n");
 701                 goto out;
 702         }
 703
 704         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 705         if (!orig_node)
 706                 return;
 707
 708         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 709                                                      ethhdr->h_source);
 710         if (!neigh_node)
 711                 goto out;
 712
 713         /* Update the received throughput metric to match the link
 714          * characteristic:
 715          *  - If this OGM traveled one hop so far (emitted by single hop
 716          *    neighbor) the path throughput metric equals the link throughput.
 717          *  - For OGMs traversing more than hop the path throughput metric is
 718          *    the smaller of the path throughput and the link throughput.
 719          */
 720         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 721         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 722         ogm_packet->throughput = htonl(path_throughput);
 723
 724         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 725                                        neigh_node, if_incoming,
 726                                        BATADV_IF_DEFAULT);
 727
 728         rcu_read_lock();
 729         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 730                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 731                         continue;
 732
 733                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 734                         continue;
 735
 736                 if (!kref_get_unless_zero(&hard_iface->refcount))
 737                         continue;
 738
 739                 ret = batadv_hardif_no_broadcast(hard_iface,
 740                                                  ogm_packet->orig,
 741                                                  hardif_neigh->orig);
 742
 743                 if (ret) {
 744                         char *type;
 745
 746                         switch (ret) {
 747                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 748                                 type = "no neighbor";
 749                                 break;
 750                         case BATADV_HARDIF_BCAST_DUPFWD:
 751                                 type = "single neighbor is source";
 752                                 break;
 753                         case BATADV_HARDIF_BCAST_DUPORIG:
 754                                 type = "single neighbor is originator";
 755                                 break;
 756                         default:
 757                                 type = "unknown";
 758                         }
 759
 760                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 761                                    ogm_packet->orig, hard_iface->net_dev->name,
 762                                    type);
 763
 764                         batadv_hardif_put(hard_iface);
 765                         continue;
 766                 }
 767
 768                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 769                                                orig_node, neigh_node,
 770                                                if_incoming, hard_iface);
 771
 772                 batadv_hardif_put(hard_iface);
 773         }
 774         rcu_read_unlock();
 775 out:
 776         if (orig_node)
 777                 batadv_orig_node_put(orig_node);
 778         if (neigh_node)
 779                 batadv_neigh_node_put(neigh_node);
 780         if (hardif_neigh)
 781                 batadv_hardif_neigh_put(hardif_neigh);
 782 }
 783
 784 /**
 785  * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 786  * @skb: the received OGM
 787  * @if_incoming: the interface where this OGM has been received
 788  *
 789  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 790  * (without freeing the skb) on failure
 791  */
 792 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 793                              struct batadv_hard_iface *if_incoming)
 794 {
 795         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 796         struct batadv_ogm2_packet *ogm_packet;
 797         struct ethhdr *ethhdr = eth_hdr(skb);
 798         int ogm_offset;
 799         u8 *packet_pos;
 800         int ret = NET_RX_DROP;
 801
 802         /* did we receive a OGM2 packet on an interface that does not have
 803          * B.A.T.M.A.N. V enabled ?
 804          */
 805         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 806                 goto free_skb;
 807
 808         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
 809                 goto free_skb;
 810
 811         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
 812                 goto free_skb;
 813
 814         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 815
 816         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
 817                 goto free_skb;
 818
 819         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
 820         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
 821                            skb->len + ETH_HLEN);
 822
 823         ogm_offset = 0;
 824         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 825
 826         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
 827                                         ogm_packet)) {
 828                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
 829
 830                 ogm_offset += BATADV_OGM2_HLEN;
 831                 ogm_offset += ntohs(ogm_packet->tvlv_len);
 832
 833                 packet_pos = skb->data + ogm_offset;
 834                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
 835         }
 836
 837         ret = NET_RX_SUCCESS;
 838
 839 free_skb:
 840         if (ret == NET_RX_SUCCESS)
 841                 consume_skb(skb);
 842         else
 843                 kfree_skb(skb);
 844
 845         return ret;
 846 }
 847
 848 /**
 849  * batadv_v_ogm_init() - initialise the OGM2 engine
 850  * @bat_priv: the bat priv with all the soft interface information
 851  *
 852  * Return: 0 on success or a negative error code in case of failure
 853  */
 854 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
 855 {
 856         struct batadv_ogm2_packet *ogm_packet;
 857         unsigned char *ogm_buff;
 858         u32 random_seqno;
 859
 860         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
 861         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
 862         if (!ogm_buff)
 863                 return -ENOMEM;
 864
 865         bat_priv->bat_v.ogm_buff = ogm_buff;
 866         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
 867         ogm_packet->packet_type = BATADV_OGM2;
 868         ogm_packet->version = BATADV_COMPAT_VERSION;
 869         ogm_packet->ttl = BATADV_TTL;
 870         ogm_packet->flags = BATADV_NO_FLAGS;
 871         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
 872
 873         /* randomize initial seqno to avoid collision */
 874         get_random_bytes(&random_seqno, sizeof(random_seqno));
 875         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
 876         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
 877
 878         return 0;
 879 }
 880
 881 /**
 882  * batadv_v_ogm_free() - free OGM private resources
 883  * @bat_priv: the bat priv with all the soft interface information
 884  */
 885 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
 886 {
 887         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
 888
 889         kfree(bat_priv->bat_v.ogm_buff);
 890         bat_priv->bat_v.ogm_buff = NULL;
 891         bat_priv->bat_v.ogm_buff_len = 0;
 892 }