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/lockdep.h>
  21 #include <linux/mutex.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/random.h>
  24 #include <linux/rculist.h>
  25 #include <linux/rcupdate.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/stddef.h>
  30 #include <linux/string.h>
  31 #include <linux/types.h>
  32 #include <linux/workqueue.h>
  33 #include <uapi/linux/batadv_packet.h>
  34
  35 #include "bat_algo.h"
  36 #include "hard-interface.h"
  37 #include "hash.h"
  38 #include "log.h"
  39 #include "originator.h"
  40 #include "routing.h"
  41 #include "send.h"
  42 #include "translation-table.h"
  43 #include "tvlv.h"
  44
  45 /**
  46  * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
  47  * @bat_priv: the bat priv with all the soft interface information
  48  * @addr: the address of the originator
  49  *
  50  * Return: the orig_node corresponding to the specified address. If such object
  51  * does not exist it is allocated here. In case of allocation failure returns
  52  * NULL.
  53  */
  54 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  55                                                const u8 *addr)
  56 {
  57         struct batadv_orig_node *orig_node;
  58         int hash_added;
  59
  60         orig_node = batadv_orig_hash_find(bat_priv, addr);
  61         if (orig_node)
  62                 return orig_node;
  63
  64         orig_node = batadv_orig_node_new(bat_priv, addr);
  65         if (!orig_node)
  66                 return NULL;
  67
  68         kref_get(&orig_node->refcount);
  69         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  70                                      batadv_choose_orig, orig_node,
  71                                      &orig_node->hash_entry);
  72         if (hash_added != 0) {
  73                 /* remove refcnt for newly created orig_node and hash entry */
  74                 batadv_orig_node_put(orig_node);
  75                 batadv_orig_node_put(orig_node);
  76                 orig_node = NULL;
  77         }
  78
  79         return orig_node;
  80 }
  81
  82 /**
  83  * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
  84  * @hard_iface: the interface to use to send the OGM
  85  */
  86 static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
  87 {
  88         unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
  89
  90         /* msecs * [0.9, 1.1] */
  91         msecs += prandom_u32() % (msecs / 5) - (msecs / 10);
  92         queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
  93                            msecs_to_jiffies(msecs / 1000));
  94 }
  95
  96 /**
  97  * batadv_v_ogm_start_timer() - restart the OGM sending timer
  98  * @bat_priv: the bat priv with all the soft interface information
  99  */
 100 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
 101 {
 102         unsigned long msecs;
 103         /* this function may be invoked in different contexts (ogm rescheduling
 104          * or hard_iface activation), but the work timer should not be reset
 105          */
 106         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 107                 return;
 108
 109         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 110         msecs += prandom_u32() % (2 * BATADV_JITTER);
 111         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 112                            msecs_to_jiffies(msecs));
 113 }
 114
 115 /**
 116  * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 117  * @skb: the OGM to send
 118  * @hard_iface: the interface to use to send the OGM
 119  */
 120 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 121                                     struct batadv_hard_iface *hard_iface)
 122 {
 123         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 124
 125         if (hard_iface->if_status != BATADV_IF_ACTIVE)
 126                 return;
 127
 128         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 129         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 130                            skb->len + ETH_HLEN);
 131
 132         batadv_send_broadcast_skb(skb, hard_iface);
 133 }
 134
 135 /**
 136  * batadv_v_ogm_len() - OGMv2 packet length
 137  * @skb: the OGM to check
 138  *
 139  * Return: Length of the given OGMv2 packet, including tvlv length, excluding
 140  * ethernet header length.
 141  */
 142 static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
 143 {
 144         struct batadv_ogm2_packet *ogm_packet;
 145
 146         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 147         return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
 148 }
 149
 150 /**
 151  * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
 152  * @skb: the OGM to check
 153  * @hard_iface: the interface to use to send the OGM
 154  *
 155  * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
 156  *
 157  * Return: True, if the given OGMv2 packet still fits, false otherwise.
 158  */
 159 static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
 160                                     struct batadv_hard_iface *hard_iface)
 161 {
 162         unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
 163                                  BATADV_MAX_AGGREGATION_BYTES);
 164         unsigned int ogm_len = batadv_v_ogm_len(skb);
 165
 166         lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
 167
 168         return hard_iface->bat_v.aggr_len + ogm_len <= max;
 169 }
 170
 171 /**
 172  * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
 173  * @hard_iface: the interface holding the aggregation queue
 174  *
 175  * Empties the OGMv2 aggregation queue and frees all the skbs it contained.
 176  *
 177  * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
 178  */
 179 static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
 180 {
 181         struct sk_buff *skb;
 182
 183         lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
 184
 185         while ((skb = skb_dequeue(&hard_iface->bat_v.aggr_list)))
 186                 kfree_skb(skb);
 187
 188         hard_iface->bat_v.aggr_len = 0;
 189 }
 190
 191 /**
 192  * batadv_v_ogm_aggr_send() - flush & send aggregation queue
 193  * @hard_iface: the interface with the aggregation queue to flush
 194  *
 195  * Aggregates all OGMv2 packets currently in the aggregation queue into a
 196  * single OGMv2 packet and transmits this aggregate.
 197  *
 198  * The aggregation queue is empty after this call.
 199  *
 200  * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
 201  */
 202 static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
 203 {
 204         unsigned int aggr_len = hard_iface->bat_v.aggr_len;
 205         struct sk_buff *skb_aggr;
 206         unsigned int ogm_len;
 207         struct sk_buff *skb;
 208
 209         lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
 210
 211         if (!aggr_len)
 212                 return;
 213
 214         skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
 215         if (!skb_aggr) {
 216                 batadv_v_ogm_aggr_list_free(hard_iface);
 217                 return;
 218         }
 219
 220         skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
 221         skb_reset_network_header(skb_aggr);
 222
 223         while ((skb = skb_dequeue(&hard_iface->bat_v.aggr_list))) {
 224                 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
 225
 226                 ogm_len = batadv_v_ogm_len(skb);
 227                 skb_put_data(skb_aggr, skb->data, ogm_len);
 228
 229                 consume_skb(skb);
 230         }
 231
 232         batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
 233 }
 234
 235 /**
 236  * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
 237  * @skb: the OGM to queue
 238  * @hard_iface: the interface to queue the OGM on
 239  */
 240 static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
 241                                      struct batadv_hard_iface *hard_iface)
 242 {
 243         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 244
 245         if (!atomic_read(&bat_priv->aggregated_ogms)) {
 246                 batadv_v_ogm_send_to_if(skb, hard_iface);
 247                 return;
 248         }
 249
 250         spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
 251         if (!batadv_v_ogm_queue_left(skb, hard_iface))
 252                 batadv_v_ogm_aggr_send(hard_iface);
 253
 254         hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
 255         skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
 256         spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
 257 }
 258
 259 /**
 260  * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
 261  * @bat_priv: the bat priv with all the soft interface information
 262  */
 263 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
 264 {
 265         struct batadv_hard_iface *hard_iface;
 266         struct batadv_ogm2_packet *ogm_packet;
 267         struct sk_buff *skb, *skb_tmp;
 268         unsigned char *ogm_buff;
 269         int ogm_buff_len;
 270         u16 tvlv_len = 0;
 271         int ret;
 272
 273         lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 274
 275         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 276                 goto out;
 277
 278         ogm_buff = bat_priv->bat_v.ogm_buff;
 279         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 280         /* tt changes have to be committed before the tvlv data is
 281          * appended as it may alter the tt tvlv container
 282          */
 283         batadv_tt_local_commit_changes(bat_priv);
 284         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 285                                                     &ogm_buff_len,
 286                                                     BATADV_OGM2_HLEN);
 287
 288         bat_priv->bat_v.ogm_buff = ogm_buff;
 289         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 290
 291         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 292         if (!skb)
 293                 goto reschedule;
 294
 295         skb_reserve(skb, ETH_HLEN);
 296         skb_put_data(skb, ogm_buff, ogm_buff_len);
 297
 298         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 299         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 300         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 301         ogm_packet->tvlv_len = htons(tvlv_len);
 302
 303         /* broadcast on every interface */
 304         rcu_read_lock();
 305         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 306                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 307                         continue;
 308
 309                 if (!kref_get_unless_zero(&hard_iface->refcount))
 310                         continue;
 311
 312                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 313                 if (ret) {
 314                         char *type;
 315
 316                         switch (ret) {
 317                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 318                                 type = "no neighbor";
 319                                 break;
 320                         case BATADV_HARDIF_BCAST_DUPFWD:
 321                                 type = "single neighbor is source";
 322                                 break;
 323                         case BATADV_HARDIF_BCAST_DUPORIG:
 324                                 type = "single neighbor is originator";
 325                                 break;
 326                         default:
 327                                 type = "unknown";
 328                         }
 329
 330                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
 331                                    hard_iface->net_dev->name, type);
 332
 333                         batadv_hardif_put(hard_iface);
 334                         continue;
 335                 }
 336
 337                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 338                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 339                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 340                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 341                            hard_iface->net_dev->name,
 342                            hard_iface->net_dev->dev_addr);
 343
 344                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 345                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 346                 if (!skb_tmp) {
 347                         batadv_hardif_put(hard_iface);
 348                         break;
 349                 }
 350
 351                 batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
 352                 batadv_hardif_put(hard_iface);
 353         }
 354         rcu_read_unlock();
 355
 356         consume_skb(skb);
 357
 358 reschedule:
 359         batadv_v_ogm_start_timer(bat_priv);
 360 out:
 361         return;
 362 }
 363
 364 /**
 365  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 366  * @work: work queue item
 367  */
 368 static void batadv_v_ogm_send(struct work_struct *work)
 369 {
 370         struct batadv_priv_bat_v *bat_v;
 371         struct batadv_priv *bat_priv;
 372
 373         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 374         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 375
 376         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 377         batadv_v_ogm_send_softif(bat_priv);
 378         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 379 }
 380
 381 /**
 382  * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
 383  * @work: work queue item
 384  *
 385  * Emits aggregated OGM message in regular intervals.
 386  */
 387 void batadv_v_ogm_aggr_work(struct work_struct *work)
 388 {
 389         struct batadv_hard_iface_bat_v *batv;
 390         struct batadv_hard_iface *hard_iface;
 391
 392         batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
 393         hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
 394
 395         spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
 396         batadv_v_ogm_aggr_send(hard_iface);
 397         spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
 398
 399         batadv_v_ogm_start_queue_timer(hard_iface);
 400 }
 401
 402 /**
 403  * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
 404  * @hard_iface: the interface to prepare
 405  *
 406  * Takes care of scheduling own OGM sending routine for this interface.
 407  *
 408  * Return: 0 on success or a negative error code otherwise
 409  */
 410 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 411 {
 412         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 413
 414         batadv_v_ogm_start_queue_timer(hard_iface);
 415         batadv_v_ogm_start_timer(bat_priv);
 416
 417         return 0;
 418 }
 419
 420 /**
 421  * batadv_v_ogm_iface_disable() - release OGM interface private resources
 422  * @hard_iface: interface for which the resources have to be released
 423  */
 424 void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 425 {
 426         cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
 427
 428         spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
 429         batadv_v_ogm_aggr_list_free(hard_iface);
 430         spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
 431 }
 432
 433 /**
 434  * batadv_v_ogm_primary_iface_set() - set a new primary interface
 435  * @primary_iface: the new primary interface
 436  */
 437 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 438 {
 439         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 440         struct batadv_ogm2_packet *ogm_packet;
 441
 442         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 443         if (!bat_priv->bat_v.ogm_buff)
 444                 goto unlock;
 445
 446         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 447         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 448
 449 unlock:
 450         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 451 }
 452
 453 /**
 454  * batadv_v_forward_penalty() - apply a penalty to the throughput metric
 455  *  forwarded with B.A.T.M.A.N. V OGMs
 456  * @bat_priv: the bat priv with all the soft interface information
 457  * @if_incoming: the interface where the OGM has been received
 458  * @if_outgoing: the interface where the OGM has to be forwarded to
 459  * @throughput: the current throughput
 460  *
 461  * Apply a penalty on the current throughput metric value based on the
 462  * characteristic of the interface where the OGM has been received. The return
 463  * value is computed as follows:
 464  * - throughput * 50%          if the incoming and outgoing interface are the
 465  *                             same WiFi interface and the throughput is above
 466  *                             1MBit/s
 467  * - throughput                if the outgoing interface is the default
 468  *                             interface (i.e. this OGM is processed for the
 469  *                             internal table and not forwarded)
 470  * - throughput * hop penalty  otherwise
 471  *
 472  * Return: the penalised throughput metric.
 473  */
 474 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 475                                     struct batadv_hard_iface *if_incoming,
 476                                     struct batadv_hard_iface *if_outgoing,
 477                                     u32 throughput)
 478 {
 479         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 480         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 481
 482         /* Don't apply hop penalty in default originator table. */
 483         if (if_outgoing == BATADV_IF_DEFAULT)
 484                 return throughput;
 485
 486         /* Forwarding on the same WiFi interface cuts the throughput in half
 487          * due to the store & forward characteristics of WIFI.
 488          * Very low throughput values are the exception.
 489          */
 490         if (throughput > 10 &&
 491             if_incoming == if_outgoing &&
 492             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 493                 return throughput / 2;
 494
 495         /* hop penalty of 255 equals 100% */
 496         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 497 }
 498
 499 /**
 500  * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 501  *  outgoing interface
 502  * @bat_priv: the bat priv with all the soft interface information
 503  * @ogm_received: previously received OGM to be forwarded
 504  * @orig_node: the originator which has been updated
 505  * @neigh_node: the neigh_node through with the OGM has been received
 506  * @if_incoming: the interface on which this OGM was received on
 507  * @if_outgoing: the interface to which the OGM has to be forwarded to
 508  *
 509  * Forward an OGM to an interface after having altered the throughput metric and
 510  * the TTL value contained in it. The original OGM isn't modified.
 511  */
 512 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 513                                  const struct batadv_ogm2_packet *ogm_received,
 514                                  struct batadv_orig_node *orig_node,
 515                                  struct batadv_neigh_node *neigh_node,
 516                                  struct batadv_hard_iface *if_incoming,
 517                                  struct batadv_hard_iface *if_outgoing)
 518 {
 519         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 520         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 521         struct batadv_neigh_node *router = NULL;
 522         struct batadv_ogm2_packet *ogm_forward;
 523         unsigned char *skb_buff;
 524         struct sk_buff *skb;
 525         size_t packet_len;
 526         u16 tvlv_len;
 527
 528         /* only forward for specific interfaces, not for the default one. */
 529         if (if_outgoing == BATADV_IF_DEFAULT)
 530                 goto out;
 531
 532         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 533         if (!orig_ifinfo)
 534                 goto out;
 535
 536         /* acquire possibly updated router */
 537         router = batadv_orig_router_get(orig_node, if_outgoing);
 538
 539         /* strict rule: forward packets coming from the best next hop only */
 540         if (neigh_node != router)
 541                 goto out;
 542
 543         /* don't forward the same seqno twice on one interface */
 544         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 545                 goto out;
 546
 547         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 548
 549         if (ogm_received->ttl <= 1) {
 550                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 551                 goto out;
 552         }
 553
 554         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 555         if (!neigh_ifinfo)
 556                 goto out;
 557
 558         tvlv_len = ntohs(ogm_received->tvlv_len);
 559
 560         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 561         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 562                                         ETH_HLEN + packet_len);
 563         if (!skb)
 564                 goto out;
 565
 566         skb_reserve(skb, ETH_HLEN);
 567         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 568
 569         /* apply forward penalty */
 570         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 571         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 572         ogm_forward->ttl--;
 573
 574         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 575                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 576                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 577                    ogm_forward->ttl, if_incoming->net_dev->name);
 578
 579         batadv_v_ogm_queue_on_if(skb, if_outgoing);
 580
 581 out:
 582         if (orig_ifinfo)
 583                 batadv_orig_ifinfo_put(orig_ifinfo);
 584         if (router)
 585                 batadv_neigh_node_put(router);
 586         if (neigh_ifinfo)
 587                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 588 }
 589
 590 /**
 591  * batadv_v_ogm_metric_update() - update route metric based on OGM
 592  * @bat_priv: the bat priv with all the soft interface information
 593  * @ogm2: OGM2 structure
 594  * @orig_node: Originator structure for which the OGM has been received
 595  * @neigh_node: the neigh_node through with the OGM has been received
 596  * @if_incoming: the interface where this packet was received
 597  * @if_outgoing: the interface for which the packet should be considered
 598  *
 599  * Return:
 600  *  1  if the OGM is new,
 601  *  0  if it is not new but valid,
 602  *  <0 on error (e.g. old OGM)
 603  */
 604 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 605                                       const struct batadv_ogm2_packet *ogm2,
 606                                       struct batadv_orig_node *orig_node,
 607                                       struct batadv_neigh_node *neigh_node,
 608                                       struct batadv_hard_iface *if_incoming,
 609                                       struct batadv_hard_iface *if_outgoing)
 610 {
 611         struct batadv_orig_ifinfo *orig_ifinfo;
 612         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 613         bool protection_started = false;
 614         int ret = -EINVAL;
 615         u32 path_throughput;
 616         s32 seq_diff;
 617
 618         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 619         if (!orig_ifinfo)
 620                 goto out;
 621
 622         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 623
 624         if (!hlist_empty(&orig_node->neigh_list) &&
 625             batadv_window_protected(bat_priv, seq_diff,
 626                                     BATADV_OGM_MAX_AGE,
 627                                     &orig_ifinfo->batman_seqno_reset,
 628                                     &protection_started)) {
 629                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 630                            "Drop packet: packet within window protection time from %pM\n",
 631                            ogm2->orig);
 632                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 633                            "Last reset: %ld, %ld\n",
 634                            orig_ifinfo->batman_seqno_reset, jiffies);
 635                 goto out;
 636         }
 637
 638         /* drop packets with old seqnos, however accept the first packet after
 639          * a host has been rebooted.
 640          */
 641         if (seq_diff < 0 && !protection_started)
 642                 goto out;
 643
 644         neigh_node->last_seen = jiffies;
 645
 646         orig_node->last_seen = jiffies;
 647
 648         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 649         orig_ifinfo->last_ttl = ogm2->ttl;
 650
 651         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 652         if (!neigh_ifinfo)
 653                 goto out;
 654
 655         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 656                                                    if_outgoing,
 657                                                    ntohl(ogm2->throughput));
 658         neigh_ifinfo->bat_v.throughput = path_throughput;
 659         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 660         neigh_ifinfo->last_ttl = ogm2->ttl;
 661
 662         if (seq_diff > 0 || protection_started)
 663                 ret = 1;
 664         else
 665                 ret = 0;
 666 out:
 667         if (orig_ifinfo)
 668                 batadv_orig_ifinfo_put(orig_ifinfo);
 669         if (neigh_ifinfo)
 670                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 671
 672         return ret;
 673 }
 674
 675 /**
 676  * batadv_v_ogm_route_update() - update routes based on OGM
 677  * @bat_priv: the bat priv with all the soft interface information
 678  * @ethhdr: the Ethernet header of the OGM2
 679  * @ogm2: OGM2 structure
 680  * @orig_node: Originator structure for which the OGM has been received
 681  * @neigh_node: the neigh_node through with the OGM has been received
 682  * @if_incoming: the interface where this packet was received
 683  * @if_outgoing: the interface for which the packet should be considered
 684  *
 685  * Return: true if the packet should be forwarded, false otherwise
 686  */
 687 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 688                                       const struct ethhdr *ethhdr,
 689                                       const struct batadv_ogm2_packet *ogm2,
 690                                       struct batadv_orig_node *orig_node,
 691                                       struct batadv_neigh_node *neigh_node,
 692                                       struct batadv_hard_iface *if_incoming,
 693                                       struct batadv_hard_iface *if_outgoing)
 694 {
 695         struct batadv_neigh_node *router = NULL;
 696         struct batadv_orig_node *orig_neigh_node;
 697         struct batadv_neigh_node *orig_neigh_router = NULL;
 698         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 699         u32 router_throughput, neigh_throughput;
 700         u32 router_last_seqno;
 701         u32 neigh_last_seqno;
 702         s32 neigh_seq_diff;
 703         bool forward = false;
 704
 705         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 706         if (!orig_neigh_node)
 707                 goto out;
 708
 709         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 710                                                    if_outgoing);
 711
 712         /* drop packet if sender is not a direct neighbor and if we
 713          * don't route towards it
 714          */
 715         router = batadv_orig_router_get(orig_node, if_outgoing);
 716         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 717                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 718                            "Drop packet: OGM via unknown neighbor!\n");
 719                 goto out;
 720         }
 721
 722         /* Mark the OGM to be considered for forwarding, and update routes
 723          * if needed.
 724          */
 725         forward = true;
 726
 727         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 728                    "Searching and updating originator entry of received packet\n");
 729
 730         /* if this neighbor already is our next hop there is nothing
 731          * to change
 732          */
 733         if (router == neigh_node)
 734                 goto out;
 735
 736         /* don't consider neighbours with worse throughput.
 737          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 738          * the last received seqno from our best next hop.
 739          */
 740         if (router) {
 741                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 742                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 743
 744                 /* if these are not allocated, something is wrong. */
 745                 if (!router_ifinfo || !neigh_ifinfo)
 746                         goto out;
 747
 748                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 749                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 750                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 751                 router_throughput = router_ifinfo->bat_v.throughput;
 752                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 753
 754                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 755                     router_throughput >= neigh_throughput)
 756                         goto out;
 757         }
 758
 759         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 760 out:
 761         if (router)
 762                 batadv_neigh_node_put(router);
 763         if (orig_neigh_router)
 764                 batadv_neigh_node_put(orig_neigh_router);
 765         if (orig_neigh_node)
 766                 batadv_orig_node_put(orig_neigh_node);
 767         if (router_ifinfo)
 768                 batadv_neigh_ifinfo_put(router_ifinfo);
 769         if (neigh_ifinfo)
 770                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 771
 772         return forward;
 773 }
 774
 775 /**
 776  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 777  * @bat_priv: the bat priv with all the soft interface information
 778  * @ethhdr: the Ethernet header of the OGM2
 779  * @ogm2: OGM2 structure
 780  * @orig_node: Originator structure for which the OGM has been received
 781  * @neigh_node: the neigh_node through with the OGM has been received
 782  * @if_incoming: the interface where this packet was received
 783  * @if_outgoing: the interface for which the packet should be considered
 784  */
 785 static void
 786 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 787                                const struct ethhdr *ethhdr,
 788                                const struct batadv_ogm2_packet *ogm2,
 789                                struct batadv_orig_node *orig_node,
 790                                struct batadv_neigh_node *neigh_node,
 791                                struct batadv_hard_iface *if_incoming,
 792                                struct batadv_hard_iface *if_outgoing)
 793 {
 794         int seqno_age;
 795         bool forward;
 796
 797         /* first, update the metric with according sanity checks */
 798         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 799                                                neigh_node, if_incoming,
 800                                                if_outgoing);
 801
 802         /* outdated sequence numbers are to be discarded */
 803         if (seqno_age < 0)
 804                 return;
 805
 806         /* only unknown & newer OGMs contain TVLVs we are interested in */
 807         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 808                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 809                                                NULL, NULL,
 810                                                (unsigned char *)(ogm2 + 1),
 811                                                ntohs(ogm2->tvlv_len));
 812
 813         /* if the metric update went through, update routes if needed */
 814         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 815                                             neigh_node, if_incoming,
 816                                             if_outgoing);
 817
 818         /* if the routes have been processed correctly, check and forward */
 819         if (forward)
 820                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 821                                      if_incoming, if_outgoing);
 822 }
 823
 824 /**
 825  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 826  * @buff_pos: current position in the skb
 827  * @packet_len: total length of the skb
 828  * @ogm2_packet: potential OGM2 in buffer
 829  *
 830  * Return: true if there is enough space for another OGM, false otherwise.
 831  */
 832 static bool
 833 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 834                          const struct batadv_ogm2_packet *ogm2_packet)
 835 {
 836         int next_buff_pos = 0;
 837
 838         /* check if there is enough space for the header */
 839         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 840         if (next_buff_pos > packet_len)
 841                 return false;
 842
 843         /* check if there is enough space for the optional TVLV */
 844         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 845
 846         return (next_buff_pos <= packet_len) &&
 847                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 848 }
 849
 850 /**
 851  * batadv_v_ogm_process() - process an incoming batman v OGM
 852  * @skb: the skb containing the OGM
 853  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 854  * @if_incoming: the interface where this packet was receved
 855  */
 856 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 857                                  struct batadv_hard_iface *if_incoming)
 858 {
 859         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 860         struct ethhdr *ethhdr;
 861         struct batadv_orig_node *orig_node = NULL;
 862         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 863         struct batadv_neigh_node *neigh_node = NULL;
 864         struct batadv_hard_iface *hard_iface;
 865         struct batadv_ogm2_packet *ogm_packet;
 866         u32 ogm_throughput, link_throughput, path_throughput;
 867         int ret;
 868
 869         ethhdr = eth_hdr(skb);
 870         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 871
 872         ogm_throughput = ntohl(ogm_packet->throughput);
 873
 874         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 875                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 876                    ethhdr->h_source, if_incoming->net_dev->name,
 877                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 878                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 879                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 880
 881         /* If the throughput metric is 0, immediately drop the packet. No need
 882          * to create orig_node / neigh_node for an unusable route.
 883          */
 884         if (ogm_throughput == 0) {
 885                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 886                            "Drop packet: originator packet with throughput metric of 0\n");
 887                 return;
 888         }
 889
 890         /* require ELP packets be to received from this neighbor first */
 891         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 892         if (!hardif_neigh) {
 893                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 894                            "Drop packet: OGM via unknown neighbor!\n");
 895                 goto out;
 896         }
 897
 898         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 899         if (!orig_node)
 900                 goto out;
 901
 902         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 903                                                      ethhdr->h_source);
 904         if (!neigh_node)
 905                 goto out;
 906
 907         /* Update the received throughput metric to match the link
 908          * characteristic:
 909          *  - If this OGM traveled one hop so far (emitted by single hop
 910          *    neighbor) the path throughput metric equals the link throughput.
 911          *  - For OGMs traversing more than hop the path throughput metric is
 912          *    the smaller of the path throughput and the link throughput.
 913          */
 914         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 915         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 916         ogm_packet->throughput = htonl(path_throughput);
 917
 918         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 919                                        neigh_node, if_incoming,
 920                                        BATADV_IF_DEFAULT);
 921
 922         rcu_read_lock();
 923         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 924                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 925                         continue;
 926
 927                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 928                         continue;
 929
 930                 if (!kref_get_unless_zero(&hard_iface->refcount))
 931                         continue;
 932
 933                 ret = batadv_hardif_no_broadcast(hard_iface,
 934                                                  ogm_packet->orig,
 935                                                  hardif_neigh->orig);
 936
 937                 if (ret) {
 938                         char *type;
 939
 940                         switch (ret) {
 941                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 942                                 type = "no neighbor";
 943                                 break;
 944                         case BATADV_HARDIF_BCAST_DUPFWD:
 945                                 type = "single neighbor is source";
 946                                 break;
 947                         case BATADV_HARDIF_BCAST_DUPORIG:
 948                                 type = "single neighbor is originator";
 949                                 break;
 950                         default:
 951                                 type = "unknown";
 952                         }
 953
 954                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 955                                    ogm_packet->orig, hard_iface->net_dev->name,
 956                                    type);
 957
 958                         batadv_hardif_put(hard_iface);
 959                         continue;
 960                 }
 961
 962                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 963                                                orig_node, neigh_node,
 964                                                if_incoming, hard_iface);
 965
 966                 batadv_hardif_put(hard_iface);
 967         }
 968         rcu_read_unlock();
 969 out:
 970         if (orig_node)
 971                 batadv_orig_node_put(orig_node);
 972         if (neigh_node)
 973                 batadv_neigh_node_put(neigh_node);
 974         if (hardif_neigh)
 975                 batadv_hardif_neigh_put(hardif_neigh);
 976 }
 977
 978 /**
 979  * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 980  * @skb: the received OGM
 981  * @if_incoming: the interface where this OGM has been received
 982  *
 983  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 984  * (without freeing the skb) on failure
 985  */
 986 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 987                              struct batadv_hard_iface *if_incoming)
 988 {
 989         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 990         struct batadv_ogm2_packet *ogm_packet;
 991         struct ethhdr *ethhdr = eth_hdr(skb);
 992         int ogm_offset;
 993         u8 *packet_pos;
 994         int ret = NET_RX_DROP;
 995
 996         /* did we receive a OGM2 packet on an interface that does not have
 997          * B.A.T.M.A.N. V enabled ?
 998          */
 999         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
1000                 goto free_skb;
1001
1002         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
1003                 goto free_skb;
1004
1005         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1006                 goto free_skb;
1007
1008         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1009
1010         if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
1011                 goto free_skb;
1012
1013         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1014         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1015                            skb->len + ETH_HLEN);
1016
1017         ogm_offset = 0;
1018         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1019
1020         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1021                                         ogm_packet)) {
1022                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1023
1024                 ogm_offset += BATADV_OGM2_HLEN;
1025                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1026
1027                 packet_pos = skb->data + ogm_offset;
1028                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1029         }
1030
1031         ret = NET_RX_SUCCESS;
1032
1033 free_skb:
1034         if (ret == NET_RX_SUCCESS)
1035                 consume_skb(skb);
1036         else
1037                 kfree_skb(skb);
1038
1039         return ret;
1040 }
1041
1042 /**
1043  * batadv_v_ogm_init() - initialise the OGM2 engine
1044  * @bat_priv: the bat priv with all the soft interface information
1045  *
1046  * Return: 0 on success or a negative error code in case of failure
1047  */
1048 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1049 {
1050         struct batadv_ogm2_packet *ogm_packet;
1051         unsigned char *ogm_buff;
1052         u32 random_seqno;
1053
1054         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1055         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1056         if (!ogm_buff)
1057                 return -ENOMEM;
1058
1059         bat_priv->bat_v.ogm_buff = ogm_buff;
1060         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1061         ogm_packet->packet_type = BATADV_OGM2;
1062         ogm_packet->version = BATADV_COMPAT_VERSION;
1063         ogm_packet->ttl = BATADV_TTL;
1064         ogm_packet->flags = BATADV_NO_FLAGS;
1065         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1066
1067         /* randomize initial seqno to avoid collision */
1068         get_random_bytes(&random_seqno, sizeof(random_seqno));
1069         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
1070         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1071
1072         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1073
1074         return 0;
1075 }
1076
1077 /**
1078  * batadv_v_ogm_free() - free OGM private resources
1079  * @bat_priv: the bat priv with all the soft interface information
1080  */
1081 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1082 {
1083         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
1084
1085         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1086
1087         kfree(bat_priv->bat_v.ogm_buff);
1088         bat_priv->bat_v.ogm_buff = NULL;
1089         bat_priv->bat_v.ogm_buff_len = 0;
1090
1091         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
1092 }