net/batman-adv/bat_v_ogm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2013-2020  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 an
  51  * object does not exist, it is allocated here. In case of allocation failure
  52  * returns 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_max(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_max(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 contains.
 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         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 182
 183         __skb_queue_purge(&hard_iface->bat_v.aggr_list);
 184         hard_iface->bat_v.aggr_len = 0;
 185 }
 186
 187 /**
 188  * batadv_v_ogm_aggr_send() - flush & send aggregation queue
 189  * @hard_iface: the interface with the aggregation queue to flush
 190  *
 191  * Aggregates all OGMv2 packets currently in the aggregation queue into a
 192  * single OGMv2 packet and transmits this aggregate.
 193  *
 194  * The aggregation queue is empty after this call.
 195  *
 196  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 197  */
 198 static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
 199 {
 200         unsigned int aggr_len = hard_iface->bat_v.aggr_len;
 201         struct sk_buff *skb_aggr;
 202         unsigned int ogm_len;
 203         struct sk_buff *skb;
 204
 205         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 206
 207         if (!aggr_len)
 208                 return;
 209
 210         skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
 211         if (!skb_aggr) {
 212                 batadv_v_ogm_aggr_list_free(hard_iface);
 213                 return;
 214         }
 215
 216         skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
 217         skb_reset_network_header(skb_aggr);
 218
 219         while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
 220                 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
 221
 222                 ogm_len = batadv_v_ogm_len(skb);
 223                 skb_put_data(skb_aggr, skb->data, ogm_len);
 224
 225                 consume_skb(skb);
 226         }
 227
 228         batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
 229 }
 230
 231 /**
 232  * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
 233  * @skb: the OGM to queue
 234  * @hard_iface: the interface to queue the OGM on
 235  */
 236 static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
 237                                      struct batadv_hard_iface *hard_iface)
 238 {
 239         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 240
 241         if (!atomic_read(&bat_priv->aggregated_ogms)) {
 242                 batadv_v_ogm_send_to_if(skb, hard_iface);
 243                 return;
 244         }
 245
 246         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 247         if (!batadv_v_ogm_queue_left(skb, hard_iface))
 248                 batadv_v_ogm_aggr_send(hard_iface);
 249
 250         hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
 251         __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
 252         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 253 }
 254
 255 /**
 256  * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
 257  * @bat_priv: the bat priv with all the soft interface information
 258  */
 259 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
 260 {
 261         struct batadv_hard_iface *hard_iface;
 262         struct batadv_ogm2_packet *ogm_packet;
 263         struct sk_buff *skb, *skb_tmp;
 264         unsigned char *ogm_buff;
 265         int ogm_buff_len;
 266         u16 tvlv_len = 0;
 267         int ret;
 268
 269         lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 270
 271         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 272                 goto out;
 273
 274         ogm_buff = bat_priv->bat_v.ogm_buff;
 275         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 276         /* tt changes have to be committed before the tvlv data is
 277          * appended as it may alter the tt tvlv container
 278          */
 279         batadv_tt_local_commit_changes(bat_priv);
 280         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 281                                                     &ogm_buff_len,
 282                                                     BATADV_OGM2_HLEN);
 283
 284         bat_priv->bat_v.ogm_buff = ogm_buff;
 285         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 286
 287         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 288         if (!skb)
 289                 goto reschedule;
 290
 291         skb_reserve(skb, ETH_HLEN);
 292         skb_put_data(skb, ogm_buff, ogm_buff_len);
 293
 294         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 295         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 296         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 297         ogm_packet->tvlv_len = htons(tvlv_len);
 298
 299         /* broadcast on every interface */
 300         rcu_read_lock();
 301         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 302                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 303                         continue;
 304
 305                 if (!kref_get_unless_zero(&hard_iface->refcount))
 306                         continue;
 307
 308                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 309                 if (ret) {
 310                         char *type;
 311
 312                         switch (ret) {
 313                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 314                                 type = "no neighbor";
 315                                 break;
 316                         case BATADV_HARDIF_BCAST_DUPFWD:
 317                                 type = "single neighbor is source";
 318                                 break;
 319                         case BATADV_HARDIF_BCAST_DUPORIG:
 320                                 type = "single neighbor is originator";
 321                                 break;
 322                         default:
 323                                 type = "unknown";
 324                         }
 325
 326                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
 327                                    hard_iface->net_dev->name, type);
 328
 329                         batadv_hardif_put(hard_iface);
 330                         continue;
 331                 }
 332
 333                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 334                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 335                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 336                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 337                            hard_iface->net_dev->name,
 338                            hard_iface->net_dev->dev_addr);
 339
 340                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 341                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 342                 if (!skb_tmp) {
 343                         batadv_hardif_put(hard_iface);
 344                         break;
 345                 }
 346
 347                 batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
 348                 batadv_hardif_put(hard_iface);
 349         }
 350         rcu_read_unlock();
 351
 352         consume_skb(skb);
 353
 354 reschedule:
 355         batadv_v_ogm_start_timer(bat_priv);
 356 out:
 357         return;
 358 }
 359
 360 /**
 361  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 362  * @work: work queue item
 363  */
 364 static void batadv_v_ogm_send(struct work_struct *work)
 365 {
 366         struct batadv_priv_bat_v *bat_v;
 367         struct batadv_priv *bat_priv;
 368
 369         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 370         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 371
 372         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 373         batadv_v_ogm_send_softif(bat_priv);
 374         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 375 }
 376
 377 /**
 378  * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
 379  * @work: work queue item
 380  *
 381  * Emits aggregated OGM messages in regular intervals.
 382  */
 383 void batadv_v_ogm_aggr_work(struct work_struct *work)
 384 {
 385         struct batadv_hard_iface_bat_v *batv;
 386         struct batadv_hard_iface *hard_iface;
 387
 388         batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
 389         hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
 390
 391         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 392         batadv_v_ogm_aggr_send(hard_iface);
 393         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 394
 395         batadv_v_ogm_start_queue_timer(hard_iface);
 396 }
 397
 398 /**
 399  * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
 400  * @hard_iface: the interface to prepare
 401  *
 402  * Takes care of scheduling its own OGM sending routine for this interface.
 403  *
 404  * Return: 0 on success or a negative error code otherwise
 405  */
 406 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 407 {
 408         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 409
 410         batadv_v_ogm_start_queue_timer(hard_iface);
 411         batadv_v_ogm_start_timer(bat_priv);
 412
 413         return 0;
 414 }
 415
 416 /**
 417  * batadv_v_ogm_iface_disable() - release OGM interface private resources
 418  * @hard_iface: interface for which the resources have to be released
 419  */
 420 void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 421 {
 422         cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
 423
 424         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 425         batadv_v_ogm_aggr_list_free(hard_iface);
 426         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 427 }
 428
 429 /**
 430  * batadv_v_ogm_primary_iface_set() - set a new primary interface
 431  * @primary_iface: the new primary interface
 432  */
 433 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 434 {
 435         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 436         struct batadv_ogm2_packet *ogm_packet;
 437
 438         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 439         if (!bat_priv->bat_v.ogm_buff)
 440                 goto unlock;
 441
 442         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 443         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 444
 445 unlock:
 446         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 447 }
 448
 449 /**
 450  * batadv_v_forward_penalty() - apply a penalty to the throughput metric
 451  *  forwarded with B.A.T.M.A.N. V OGMs
 452  * @bat_priv: the bat priv with all the soft interface information
 453  * @if_incoming: the interface where the OGM has been received
 454  * @if_outgoing: the interface where the OGM has to be forwarded to
 455  * @throughput: the current throughput
 456  *
 457  * Apply a penalty on the current throughput metric value based on the
 458  * characteristic of the interface where the OGM has been received.
 459  *
 460  * Initially the per hardif hop penalty is applied to the throughput. After
 461  * that the return value is then computed as follows:
 462  * - throughput * 50%          if the incoming and outgoing interface are the
 463  *                             same WiFi interface and the throughput is above
 464  *                             1MBit/s
 465  * - throughput                if the outgoing interface is the default
 466  *                             interface (i.e. this OGM is processed for the
 467  *                             internal table and not forwarded)
 468  * - throughput * node hop penalty  otherwise
 469  *
 470  * Return: the penalised throughput metric.
 471  */
 472 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 473                                     struct batadv_hard_iface *if_incoming,
 474                                     struct batadv_hard_iface *if_outgoing,
 475                                     u32 throughput)
 476 {
 477         int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
 478         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 479         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 480
 481         /* Apply per hardif hop penalty */
 482         throughput = throughput * (hop_penalty_max - if_hop_penalty) /
 483                      hop_penalty_max;
 484
 485         /* Don't apply hop penalty in default originator table. */
 486         if (if_outgoing == BATADV_IF_DEFAULT)
 487                 return throughput;
 488
 489         /* Forwarding on the same WiFi interface cuts the throughput in half
 490          * due to the store & forward characteristics of WIFI.
 491          * Very low throughput values are the exception.
 492          */
 493         if (throughput > 10 &&
 494             if_incoming == if_outgoing &&
 495             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 496                 return throughput / 2;
 497
 498         /* hop penalty of 255 equals 100% */
 499         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 500 }
 501
 502 /**
 503  * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 504  *  outgoing interface
 505  * @bat_priv: the bat priv with all the soft interface information
 506  * @ogm_received: previously received OGM to be forwarded
 507  * @orig_node: the originator which has been updated
 508  * @neigh_node: the neigh_node through with the OGM has been received
 509  * @if_incoming: the interface on which this OGM was received on
 510  * @if_outgoing: the interface to which the OGM has to be forwarded to
 511  *
 512  * Forward an OGM to an interface after having altered the throughput metric and
 513  * the TTL value contained in it. The original OGM isn't modified.
 514  */
 515 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 516                                  const struct batadv_ogm2_packet *ogm_received,
 517                                  struct batadv_orig_node *orig_node,
 518                                  struct batadv_neigh_node *neigh_node,
 519                                  struct batadv_hard_iface *if_incoming,
 520                                  struct batadv_hard_iface *if_outgoing)
 521 {
 522         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 523         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 524         struct batadv_neigh_node *router = NULL;
 525         struct batadv_ogm2_packet *ogm_forward;
 526         unsigned char *skb_buff;
 527         struct sk_buff *skb;
 528         size_t packet_len;
 529         u16 tvlv_len;
 530
 531         /* only forward for specific interfaces, not for the default one. */
 532         if (if_outgoing == BATADV_IF_DEFAULT)
 533                 goto out;
 534
 535         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 536         if (!orig_ifinfo)
 537                 goto out;
 538
 539         /* acquire possibly updated router */
 540         router = batadv_orig_router_get(orig_node, if_outgoing);
 541
 542         /* strict rule: forward packets coming from the best next hop only */
 543         if (neigh_node != router)
 544                 goto out;
 545
 546         /* don't forward the same seqno twice on one interface */
 547         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 548                 goto out;
 549
 550         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 551
 552         if (ogm_received->ttl <= 1) {
 553                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 554                 goto out;
 555         }
 556
 557         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 558         if (!neigh_ifinfo)
 559                 goto out;
 560
 561         tvlv_len = ntohs(ogm_received->tvlv_len);
 562
 563         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 564         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 565                                         ETH_HLEN + packet_len);
 566         if (!skb)
 567                 goto out;
 568
 569         skb_reserve(skb, ETH_HLEN);
 570         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 571
 572         /* apply forward penalty */
 573         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 574         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 575         ogm_forward->ttl--;
 576
 577         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 578                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 579                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 580                    ogm_forward->ttl, if_incoming->net_dev->name);
 581
 582         batadv_v_ogm_queue_on_if(skb, if_outgoing);
 583
 584 out:
 585         if (orig_ifinfo)
 586                 batadv_orig_ifinfo_put(orig_ifinfo);
 587         if (router)
 588                 batadv_neigh_node_put(router);
 589         if (neigh_ifinfo)
 590                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 591 }
 592
 593 /**
 594  * batadv_v_ogm_metric_update() - update route metric based on OGM
 595  * @bat_priv: the bat priv with all the soft interface information
 596  * @ogm2: OGM2 structure
 597  * @orig_node: Originator structure for which the OGM has been received
 598  * @neigh_node: the neigh_node through with the OGM has been received
 599  * @if_incoming: the interface where this packet was received
 600  * @if_outgoing: the interface for which the packet should be considered
 601  *
 602  * Return:
 603  *  1  if the OGM is new,
 604  *  0  if it is not new but valid,
 605  *  <0 on error (e.g. old OGM)
 606  */
 607 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 608                                       const struct batadv_ogm2_packet *ogm2,
 609                                       struct batadv_orig_node *orig_node,
 610                                       struct batadv_neigh_node *neigh_node,
 611                                       struct batadv_hard_iface *if_incoming,
 612                                       struct batadv_hard_iface *if_outgoing)
 613 {
 614         struct batadv_orig_ifinfo *orig_ifinfo;
 615         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 616         bool protection_started = false;
 617         int ret = -EINVAL;
 618         u32 path_throughput;
 619         s32 seq_diff;
 620
 621         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 622         if (!orig_ifinfo)
 623                 goto out;
 624
 625         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 626
 627         if (!hlist_empty(&orig_node->neigh_list) &&
 628             batadv_window_protected(bat_priv, seq_diff,
 629                                     BATADV_OGM_MAX_AGE,
 630                                     &orig_ifinfo->batman_seqno_reset,
 631                                     &protection_started)) {
 632                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 633                            "Drop packet: packet within window protection time from %pM\n",
 634                            ogm2->orig);
 635                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 636                            "Last reset: %ld, %ld\n",
 637                            orig_ifinfo->batman_seqno_reset, jiffies);
 638                 goto out;
 639         }
 640
 641         /* drop packets with old seqnos, however accept the first packet after
 642          * a host has been rebooted.
 643          */
 644         if (seq_diff < 0 && !protection_started)
 645                 goto out;
 646
 647         neigh_node->last_seen = jiffies;
 648
 649         orig_node->last_seen = jiffies;
 650
 651         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 652         orig_ifinfo->last_ttl = ogm2->ttl;
 653
 654         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 655         if (!neigh_ifinfo)
 656                 goto out;
 657
 658         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 659                                                    if_outgoing,
 660                                                    ntohl(ogm2->throughput));
 661         neigh_ifinfo->bat_v.throughput = path_throughput;
 662         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 663         neigh_ifinfo->last_ttl = ogm2->ttl;
 664
 665         if (seq_diff > 0 || protection_started)
 666                 ret = 1;
 667         else
 668                 ret = 0;
 669 out:
 670         if (orig_ifinfo)
 671                 batadv_orig_ifinfo_put(orig_ifinfo);
 672         if (neigh_ifinfo)
 673                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 674
 675         return ret;
 676 }
 677
 678 /**
 679  * batadv_v_ogm_route_update() - update routes based on OGM
 680  * @bat_priv: the bat priv with all the soft interface information
 681  * @ethhdr: the Ethernet header of the OGM2
 682  * @ogm2: OGM2 structure
 683  * @orig_node: Originator structure for which the OGM has been received
 684  * @neigh_node: the neigh_node through with the OGM has been received
 685  * @if_incoming: the interface where this packet was received
 686  * @if_outgoing: the interface for which the packet should be considered
 687  *
 688  * Return: true if the packet should be forwarded, false otherwise
 689  */
 690 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 691                                       const struct ethhdr *ethhdr,
 692                                       const struct batadv_ogm2_packet *ogm2,
 693                                       struct batadv_orig_node *orig_node,
 694                                       struct batadv_neigh_node *neigh_node,
 695                                       struct batadv_hard_iface *if_incoming,
 696                                       struct batadv_hard_iface *if_outgoing)
 697 {
 698         struct batadv_neigh_node *router = NULL;
 699         struct batadv_orig_node *orig_neigh_node;
 700         struct batadv_neigh_node *orig_neigh_router = NULL;
 701         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 702         u32 router_throughput, neigh_throughput;
 703         u32 router_last_seqno;
 704         u32 neigh_last_seqno;
 705         s32 neigh_seq_diff;
 706         bool forward = false;
 707
 708         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 709         if (!orig_neigh_node)
 710                 goto out;
 711
 712         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 713                                                    if_outgoing);
 714
 715         /* drop packet if sender is not a direct neighbor and if we
 716          * don't route towards it
 717          */
 718         router = batadv_orig_router_get(orig_node, if_outgoing);
 719         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 720                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 721                            "Drop packet: OGM via unknown neighbor!\n");
 722                 goto out;
 723         }
 724
 725         /* Mark the OGM to be considered for forwarding, and update routes
 726          * if needed.
 727          */
 728         forward = true;
 729
 730         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 731                    "Searching and updating originator entry of received packet\n");
 732
 733         /* if this neighbor already is our next hop there is nothing
 734          * to change
 735          */
 736         if (router == neigh_node)
 737                 goto out;
 738
 739         /* don't consider neighbours with worse throughput.
 740          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 741          * the last received seqno from our best next hop.
 742          */
 743         if (router) {
 744                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 745                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 746
 747                 /* if these are not allocated, something is wrong. */
 748                 if (!router_ifinfo || !neigh_ifinfo)
 749                         goto out;
 750
 751                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 752                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 753                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 754                 router_throughput = router_ifinfo->bat_v.throughput;
 755                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 756
 757                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 758                     router_throughput >= neigh_throughput)
 759                         goto out;
 760         }
 761
 762         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 763 out:
 764         if (router)
 765                 batadv_neigh_node_put(router);
 766         if (orig_neigh_router)
 767                 batadv_neigh_node_put(orig_neigh_router);
 768         if (orig_neigh_node)
 769                 batadv_orig_node_put(orig_neigh_node);
 770         if (router_ifinfo)
 771                 batadv_neigh_ifinfo_put(router_ifinfo);
 772         if (neigh_ifinfo)
 773                 batadv_neigh_ifinfo_put(neigh_ifinfo);
 774
 775         return forward;
 776 }
 777
 778 /**
 779  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 780  * @bat_priv: the bat priv with all the soft interface information
 781  * @ethhdr: the Ethernet header of the OGM2
 782  * @ogm2: OGM2 structure
 783  * @orig_node: Originator structure for which the OGM has been received
 784  * @neigh_node: the neigh_node through with the OGM has been received
 785  * @if_incoming: the interface where this packet was received
 786  * @if_outgoing: the interface for which the packet should be considered
 787  */
 788 static void
 789 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 790                                const struct ethhdr *ethhdr,
 791                                const struct batadv_ogm2_packet *ogm2,
 792                                struct batadv_orig_node *orig_node,
 793                                struct batadv_neigh_node *neigh_node,
 794                                struct batadv_hard_iface *if_incoming,
 795                                struct batadv_hard_iface *if_outgoing)
 796 {
 797         int seqno_age;
 798         bool forward;
 799
 800         /* first, update the metric with according sanity checks */
 801         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 802                                                neigh_node, if_incoming,
 803                                                if_outgoing);
 804
 805         /* outdated sequence numbers are to be discarded */
 806         if (seqno_age < 0)
 807                 return;
 808
 809         /* only unknown & newer OGMs contain TVLVs we are interested in */
 810         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 811                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 812                                                NULL, NULL,
 813                                                (unsigned char *)(ogm2 + 1),
 814                                                ntohs(ogm2->tvlv_len));
 815
 816         /* if the metric update went through, update routes if needed */
 817         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 818                                             neigh_node, if_incoming,
 819                                             if_outgoing);
 820
 821         /* if the routes have been processed correctly, check and forward */
 822         if (forward)
 823                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 824                                      if_incoming, if_outgoing);
 825 }
 826
 827 /**
 828  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 829  * @buff_pos: current position in the skb
 830  * @packet_len: total length of the skb
 831  * @ogm2_packet: potential OGM2 in buffer
 832  *
 833  * Return: true if there is enough space for another OGM, false otherwise.
 834  */
 835 static bool
 836 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 837                          const struct batadv_ogm2_packet *ogm2_packet)
 838 {
 839         int next_buff_pos = 0;
 840
 841         /* check if there is enough space for the header */
 842         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 843         if (next_buff_pos > packet_len)
 844                 return false;
 845
 846         /* check if there is enough space for the optional TVLV */
 847         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 848
 849         return (next_buff_pos <= packet_len) &&
 850                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 851 }
 852
 853 /**
 854  * batadv_v_ogm_process() - process an incoming batman v OGM
 855  * @skb: the skb containing the OGM
 856  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 857  * @if_incoming: the interface where this packet was received
 858  */
 859 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 860                                  struct batadv_hard_iface *if_incoming)
 861 {
 862         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 863         struct ethhdr *ethhdr;
 864         struct batadv_orig_node *orig_node = NULL;
 865         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 866         struct batadv_neigh_node *neigh_node = NULL;
 867         struct batadv_hard_iface *hard_iface;
 868         struct batadv_ogm2_packet *ogm_packet;
 869         u32 ogm_throughput, link_throughput, path_throughput;
 870         int ret;
 871
 872         ethhdr = eth_hdr(skb);
 873         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 874
 875         ogm_throughput = ntohl(ogm_packet->throughput);
 876
 877         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 878                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 879                    ethhdr->h_source, if_incoming->net_dev->name,
 880                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 881                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 882                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 883
 884         if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
 885                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 886                            "Drop packet: originator packet from ourself\n");
 887                 return;
 888         }
 889
 890         /* If the throughput metric is 0, immediately drop the packet. No need
 891          * to create orig_node / neigh_node for an unusable route.
 892          */
 893         if (ogm_throughput == 0) {
 894                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 895                            "Drop packet: originator packet with throughput metric of 0\n");
 896                 return;
 897         }
 898
 899         /* require ELP packets be to received from this neighbor first */
 900         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 901         if (!hardif_neigh) {
 902                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 903                            "Drop packet: OGM via unknown neighbor!\n");
 904                 goto out;
 905         }
 906
 907         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 908         if (!orig_node)
 909                 goto out;
 910
 911         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 912                                                      ethhdr->h_source);
 913         if (!neigh_node)
 914                 goto out;
 915
 916         /* Update the received throughput metric to match the link
 917          * characteristic:
 918          *  - If this OGM traveled one hop so far (emitted by single hop
 919          *    neighbor) the path throughput metric equals the link throughput.
 920          *  - For OGMs traversing more than hop the path throughput metric is
 921          *    the smaller of the path throughput and the link throughput.
 922          */
 923         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 924         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 925         ogm_packet->throughput = htonl(path_throughput);
 926
 927         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 928                                        neigh_node, if_incoming,
 929                                        BATADV_IF_DEFAULT);
 930
 931         rcu_read_lock();
 932         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 933                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 934                         continue;
 935
 936                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 937                         continue;
 938
 939                 if (!kref_get_unless_zero(&hard_iface->refcount))
 940                         continue;
 941
 942                 ret = batadv_hardif_no_broadcast(hard_iface,
 943                                                  ogm_packet->orig,
 944                                                  hardif_neigh->orig);
 945
 946                 if (ret) {
 947                         char *type;
 948
 949                         switch (ret) {
 950                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 951                                 type = "no neighbor";
 952                                 break;
 953                         case BATADV_HARDIF_BCAST_DUPFWD:
 954                                 type = "single neighbor is source";
 955                                 break;
 956                         case BATADV_HARDIF_BCAST_DUPORIG:
 957                                 type = "single neighbor is originator";
 958                                 break;
 959                         default:
 960                                 type = "unknown";
 961                         }
 962
 963                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 964                                    ogm_packet->orig, hard_iface->net_dev->name,
 965                                    type);
 966
 967                         batadv_hardif_put(hard_iface);
 968                         continue;
 969                 }
 970
 971                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 972                                                orig_node, neigh_node,
 973                                                if_incoming, hard_iface);
 974
 975                 batadv_hardif_put(hard_iface);
 976         }
 977         rcu_read_unlock();
 978 out:
 979         if (orig_node)
 980                 batadv_orig_node_put(orig_node);
 981         if (neigh_node)
 982                 batadv_neigh_node_put(neigh_node);
 983         if (hardif_neigh)
 984                 batadv_hardif_neigh_put(hardif_neigh);
 985 }
 986
 987 /**
 988  * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 989  * @skb: the received OGM
 990  * @if_incoming: the interface where this OGM has been received
 991  *
 992  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 993  * (without freeing the skb) on failure
 994  */
 995 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 996                              struct batadv_hard_iface *if_incoming)
 997 {
 998         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 999         struct batadv_ogm2_packet *ogm_packet;
1000         struct ethhdr *ethhdr = eth_hdr(skb);
1001         int ogm_offset;
1002         u8 *packet_pos;
1003         int ret = NET_RX_DROP;
1004
1005         /* did we receive a OGM2 packet on an interface that does not have
1006          * B.A.T.M.A.N. V enabled ?
1007          */
1008         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
1009                 goto free_skb;
1010
1011         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
1012                 goto free_skb;
1013
1014         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1015                 goto free_skb;
1016
1017         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1018         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1019                            skb->len + ETH_HLEN);
1020
1021         ogm_offset = 0;
1022         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1023
1024         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1025                                         ogm_packet)) {
1026                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1027
1028                 ogm_offset += BATADV_OGM2_HLEN;
1029                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1030
1031                 packet_pos = skb->data + ogm_offset;
1032                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1033         }
1034
1035         ret = NET_RX_SUCCESS;
1036
1037 free_skb:
1038         if (ret == NET_RX_SUCCESS)
1039                 consume_skb(skb);
1040         else
1041                 kfree_skb(skb);
1042
1043         return ret;
1044 }
1045
1046 /**
1047  * batadv_v_ogm_init() - initialise the OGM2 engine
1048  * @bat_priv: the bat priv with all the soft interface information
1049  *
1050  * Return: 0 on success or a negative error code in case of failure
1051  */
1052 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1053 {
1054         struct batadv_ogm2_packet *ogm_packet;
1055         unsigned char *ogm_buff;
1056         u32 random_seqno;
1057
1058         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1059         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1060         if (!ogm_buff)
1061                 return -ENOMEM;
1062
1063         bat_priv->bat_v.ogm_buff = ogm_buff;
1064         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1065         ogm_packet->packet_type = BATADV_OGM2;
1066         ogm_packet->version = BATADV_COMPAT_VERSION;
1067         ogm_packet->ttl = BATADV_TTL;
1068         ogm_packet->flags = BATADV_NO_FLAGS;
1069         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1070
1071         /* randomize initial seqno to avoid collision */
1072         get_random_bytes(&random_seqno, sizeof(random_seqno));
1073         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
1074         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1075
1076         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1077
1078         return 0;
1079 }
1080
1081 /**
1082  * batadv_v_ogm_free() - free OGM private resources
1083  * @bat_priv: the bat priv with all the soft interface information
1084  */
1085 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1086 {
1087         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
1088
1089         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1090
1091         kfree(bat_priv->bat_v.ogm_buff);
1092         bat_priv->bat_v.ogm_buff = NULL;
1093         bat_priv->bat_v.ogm_buff_len = 0;
1094
1095         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
1096 }