batman-adv/bat_v_ogm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 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/container_of.h>
  13 #include <linux/errno.h>
  14 #include <linux/etherdevice.h>
  15 #include <linux/gfp.h>
  16 #include <linux/if_ether.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/kref.h>
  19 #include <linux/list.h>
  20 #include <linux/lockdep.h>
  21 #include <linux/minmax.h>
  22 #include <linux/mutex.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/prandom.h>
  25 #include <linux/random.h>
  26 #include <linux/rculist.h>
  27 #include <linux/rcupdate.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/slab.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/stddef.h>
  32 #include <linux/string.h>
  33 #include <linux/types.h>
  34 #include <linux/workqueue.h>
  35 #include <uapi/linux/batadv_packet.h>
  36
  37 #include "bat_algo.h"
  38 #include "hard-interface.h"
  39 #include "hash.h"
  40 #include "log.h"
  41 #include "originator.h"
  42 #include "routing.h"
  43 #include "send.h"
  44 #include "translation-table.h"
  45 #include "tvlv.h"
  46
  47 /**
  48  * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
  49  * @bat_priv: the bat priv with all the soft interface information
  50  * @addr: the address of the originator
  51  *
  52  * Return: the orig_node corresponding to the specified address. If such an
  53  * object does not exist, it is allocated here. In case of allocation failure
  54  * returns NULL.
  55  */
  56 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  57                                                const u8 *addr)
  58 {
  59         struct batadv_orig_node *orig_node;
  60         int hash_added;
  61
  62         orig_node = batadv_orig_hash_find(bat_priv, addr);
  63         if (orig_node)
  64                 return orig_node;
  65
  66         orig_node = batadv_orig_node_new(bat_priv, addr);
  67         if (!orig_node)
  68                 return NULL;
  69
  70         kref_get(&orig_node->refcount);
  71         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  72                                      batadv_choose_orig, orig_node,
  73                                      &orig_node->hash_entry);
  74         if (hash_added != 0) {
  75                 /* remove refcnt for newly created orig_node and hash entry */
  76                 batadv_orig_node_put(orig_node);
  77                 batadv_orig_node_put(orig_node);
  78                 orig_node = NULL;
  79         }
  80
  81         return orig_node;
  82 }
  83
  84 /**
  85  * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
  86  * @hard_iface: the interface to use to send the OGM
  87  */
  88 static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
  89 {
  90         unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
  91
  92         /* msecs * [0.9, 1.1] */
  93         msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
  94         queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
  95                            msecs_to_jiffies(msecs / 1000));
  96 }
  97
  98 /**
  99  * batadv_v_ogm_start_timer() - restart the OGM sending timer
 100  * @bat_priv: the bat priv with all the soft interface information
 101  */
 102 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
 103 {
 104         unsigned long msecs;
 105         /* this function may be invoked in different contexts (ogm rescheduling
 106          * or hard_iface activation), but the work timer should not be reset
 107          */
 108         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 109                 return;
 110
 111         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 112         msecs += prandom_u32_max(2 * BATADV_JITTER);
 113         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 114                            msecs_to_jiffies(msecs));
 115 }
 116
 117 /**
 118  * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 119  * @skb: the OGM to send
 120  * @hard_iface: the interface to use to send the OGM
 121  */
 122 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 123                                     struct batadv_hard_iface *hard_iface)
 124 {
 125         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 126
 127         if (hard_iface->if_status != BATADV_IF_ACTIVE) {
 128                 kfree_skb(skb);
 129                 return;
 130         }
 131
 132         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 133         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 134                            skb->len + ETH_HLEN);
 135
 136         batadv_send_broadcast_skb(skb, hard_iface);
 137 }
 138
 139 /**
 140  * batadv_v_ogm_len() - OGMv2 packet length
 141  * @skb: the OGM to check
 142  *
 143  * Return: Length of the given OGMv2 packet, including tvlv length, excluding
 144  * ethernet header length.
 145  */
 146 static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
 147 {
 148         struct batadv_ogm2_packet *ogm_packet;
 149
 150         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 151         return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
 152 }
 153
 154 /**
 155  * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
 156  * @skb: the OGM to check
 157  * @hard_iface: the interface to use to send the OGM
 158  *
 159  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 160  *
 161  * Return: True, if the given OGMv2 packet still fits, false otherwise.
 162  */
 163 static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
 164                                     struct batadv_hard_iface *hard_iface)
 165 {
 166         unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
 167                                  BATADV_MAX_AGGREGATION_BYTES);
 168         unsigned int ogm_len = batadv_v_ogm_len(skb);
 169
 170         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 171
 172         return hard_iface->bat_v.aggr_len + ogm_len <= max;
 173 }
 174
 175 /**
 176  * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
 177  * @hard_iface: the interface holding the aggregation queue
 178  *
 179  * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
 180  *
 181  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 182  */
 183 static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
 184 {
 185         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 186
 187         __skb_queue_purge(&hard_iface->bat_v.aggr_list);
 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 messages 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 its 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.
 463  *
 464  * Initially the per hardif hop penalty is applied to the throughput. After
 465  * that the return value is then computed as follows:
 466  * - throughput * 50%          if the incoming and outgoing interface are the
 467  *                             same WiFi interface and the throughput is above
 468  *                             1MBit/s
 469  * - throughput                if the outgoing interface is the default
 470  *                             interface (i.e. this OGM is processed for the
 471  *                             internal table and not forwarded)
 472  * - throughput * node hop penalty  otherwise
 473  *
 474  * Return: the penalised throughput metric.
 475  */
 476 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 477                                     struct batadv_hard_iface *if_incoming,
 478                                     struct batadv_hard_iface *if_outgoing,
 479                                     u32 throughput)
 480 {
 481         int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
 482         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 483         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 484
 485         /* Apply per hardif hop penalty */
 486         throughput = throughput * (hop_penalty_max - if_hop_penalty) /
 487                      hop_penalty_max;
 488
 489         /* Don't apply hop penalty in default originator table. */
 490         if (if_outgoing == BATADV_IF_DEFAULT)
 491                 return throughput;
 492
 493         /* Forwarding on the same WiFi interface cuts the throughput in half
 494          * due to the store & forward characteristics of WIFI.
 495          * Very low throughput values are the exception.
 496          */
 497         if (throughput > 10 &&
 498             if_incoming == if_outgoing &&
 499             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 500                 return throughput / 2;
 501
 502         /* hop penalty of 255 equals 100% */
 503         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 504 }
 505
 506 /**
 507  * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 508  *  outgoing interface
 509  * @bat_priv: the bat priv with all the soft interface information
 510  * @ogm_received: previously received OGM to be forwarded
 511  * @orig_node: the originator which has been updated
 512  * @neigh_node: the neigh_node through with the OGM has been received
 513  * @if_incoming: the interface on which this OGM was received on
 514  * @if_outgoing: the interface to which the OGM has to be forwarded to
 515  *
 516  * Forward an OGM to an interface after having altered the throughput metric and
 517  * the TTL value contained in it. The original OGM isn't modified.
 518  */
 519 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 520                                  const struct batadv_ogm2_packet *ogm_received,
 521                                  struct batadv_orig_node *orig_node,
 522                                  struct batadv_neigh_node *neigh_node,
 523                                  struct batadv_hard_iface *if_incoming,
 524                                  struct batadv_hard_iface *if_outgoing)
 525 {
 526         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 527         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 528         struct batadv_neigh_node *router = NULL;
 529         struct batadv_ogm2_packet *ogm_forward;
 530         unsigned char *skb_buff;
 531         struct sk_buff *skb;
 532         size_t packet_len;
 533         u16 tvlv_len;
 534
 535         /* only forward for specific interfaces, not for the default one. */
 536         if (if_outgoing == BATADV_IF_DEFAULT)
 537                 goto out;
 538
 539         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 540         if (!orig_ifinfo)
 541                 goto out;
 542
 543         /* acquire possibly updated router */
 544         router = batadv_orig_router_get(orig_node, if_outgoing);
 545
 546         /* strict rule: forward packets coming from the best next hop only */
 547         if (neigh_node != router)
 548                 goto out;
 549
 550         /* don't forward the same seqno twice on one interface */
 551         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 552                 goto out;
 553
 554         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 555
 556         if (ogm_received->ttl <= 1) {
 557                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 558                 goto out;
 559         }
 560
 561         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 562         if (!neigh_ifinfo)
 563                 goto out;
 564
 565         tvlv_len = ntohs(ogm_received->tvlv_len);
 566
 567         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 568         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 569                                         ETH_HLEN + packet_len);
 570         if (!skb)
 571                 goto out;
 572
 573         skb_reserve(skb, ETH_HLEN);
 574         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 575
 576         /* apply forward penalty */
 577         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 578         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 579         ogm_forward->ttl--;
 580
 581         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 582                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 583                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 584                    ogm_forward->ttl, if_incoming->net_dev->name);
 585
 586         batadv_v_ogm_queue_on_if(skb, if_outgoing);
 587
 588 out:
 589         batadv_orig_ifinfo_put(orig_ifinfo);
 590         batadv_neigh_node_put(router);
 591         batadv_neigh_ifinfo_put(neigh_ifinfo);
 592 }
 593
 594 /**
 595  * batadv_v_ogm_metric_update() - update route metric based on OGM
 596  * @bat_priv: the bat priv with all the soft interface information
 597  * @ogm2: OGM2 structure
 598  * @orig_node: Originator structure for which the OGM has been received
 599  * @neigh_node: the neigh_node through with the OGM has been received
 600  * @if_incoming: the interface where this packet was received
 601  * @if_outgoing: the interface for which the packet should be considered
 602  *
 603  * Return:
 604  *  1  if the OGM is new,
 605  *  0  if it is not new but valid,
 606  *  <0 on error (e.g. old OGM)
 607  */
 608 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
 609                                       const struct batadv_ogm2_packet *ogm2,
 610                                       struct batadv_orig_node *orig_node,
 611                                       struct batadv_neigh_node *neigh_node,
 612                                       struct batadv_hard_iface *if_incoming,
 613                                       struct batadv_hard_iface *if_outgoing)
 614 {
 615         struct batadv_orig_ifinfo *orig_ifinfo;
 616         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 617         bool protection_started = false;
 618         int ret = -EINVAL;
 619         u32 path_throughput;
 620         s32 seq_diff;
 621
 622         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 623         if (!orig_ifinfo)
 624                 goto out;
 625
 626         seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
 627
 628         if (!hlist_empty(&orig_node->neigh_list) &&
 629             batadv_window_protected(bat_priv, seq_diff,
 630                                     BATADV_OGM_MAX_AGE,
 631                                     &orig_ifinfo->batman_seqno_reset,
 632                                     &protection_started)) {
 633                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 634                            "Drop packet: packet within window protection time from %pM\n",
 635                            ogm2->orig);
 636                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 637                            "Last reset: %ld, %ld\n",
 638                            orig_ifinfo->batman_seqno_reset, jiffies);
 639                 goto out;
 640         }
 641
 642         /* drop packets with old seqnos, however accept the first packet after
 643          * a host has been rebooted.
 644          */
 645         if (seq_diff < 0 && !protection_started)
 646                 goto out;
 647
 648         neigh_node->last_seen = jiffies;
 649
 650         orig_node->last_seen = jiffies;
 651
 652         orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
 653         orig_ifinfo->last_ttl = ogm2->ttl;
 654
 655         neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
 656         if (!neigh_ifinfo)
 657                 goto out;
 658
 659         path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
 660                                                    if_outgoing,
 661                                                    ntohl(ogm2->throughput));
 662         neigh_ifinfo->bat_v.throughput = path_throughput;
 663         neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
 664         neigh_ifinfo->last_ttl = ogm2->ttl;
 665
 666         if (seq_diff > 0 || protection_started)
 667                 ret = 1;
 668         else
 669                 ret = 0;
 670 out:
 671         batadv_orig_ifinfo_put(orig_ifinfo);
 672         batadv_neigh_ifinfo_put(neigh_ifinfo);
 673
 674         return ret;
 675 }
 676
 677 /**
 678  * batadv_v_ogm_route_update() - update routes based on OGM
 679  * @bat_priv: the bat priv with all the soft interface information
 680  * @ethhdr: the Ethernet header of the OGM2
 681  * @ogm2: OGM2 structure
 682  * @orig_node: Originator structure for which the OGM has been received
 683  * @neigh_node: the neigh_node through with the OGM has been received
 684  * @if_incoming: the interface where this packet was received
 685  * @if_outgoing: the interface for which the packet should be considered
 686  *
 687  * Return: true if the packet should be forwarded, false otherwise
 688  */
 689 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 690                                       const struct ethhdr *ethhdr,
 691                                       const struct batadv_ogm2_packet *ogm2,
 692                                       struct batadv_orig_node *orig_node,
 693                                       struct batadv_neigh_node *neigh_node,
 694                                       struct batadv_hard_iface *if_incoming,
 695                                       struct batadv_hard_iface *if_outgoing)
 696 {
 697         struct batadv_neigh_node *router = NULL;
 698         struct batadv_orig_node *orig_neigh_node;
 699         struct batadv_neigh_node *orig_neigh_router = NULL;
 700         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 701         u32 router_throughput, neigh_throughput;
 702         u32 router_last_seqno;
 703         u32 neigh_last_seqno;
 704         s32 neigh_seq_diff;
 705         bool forward = false;
 706
 707         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 708         if (!orig_neigh_node)
 709                 goto out;
 710
 711         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 712                                                    if_outgoing);
 713
 714         /* drop packet if sender is not a direct neighbor and if we
 715          * don't route towards it
 716          */
 717         router = batadv_orig_router_get(orig_node, if_outgoing);
 718         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 719                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 720                            "Drop packet: OGM via unknown neighbor!\n");
 721                 goto out;
 722         }
 723
 724         /* Mark the OGM to be considered for forwarding, and update routes
 725          * if needed.
 726          */
 727         forward = true;
 728
 729         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 730                    "Searching and updating originator entry of received packet\n");
 731
 732         /* if this neighbor already is our next hop there is nothing
 733          * to change
 734          */
 735         if (router == neigh_node)
 736                 goto out;
 737
 738         /* don't consider neighbours with worse throughput.
 739          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 740          * the last received seqno from our best next hop.
 741          */
 742         if (router) {
 743                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 744                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 745
 746                 /* if these are not allocated, something is wrong. */
 747                 if (!router_ifinfo || !neigh_ifinfo)
 748                         goto out;
 749
 750                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 751                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 752                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 753                 router_throughput = router_ifinfo->bat_v.throughput;
 754                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 755
 756                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 757                     router_throughput >= neigh_throughput)
 758                         goto out;
 759         }
 760
 761         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 762 out:
 763         batadv_neigh_node_put(router);
 764         batadv_neigh_node_put(orig_neigh_router);
 765         batadv_orig_node_put(orig_neigh_node);
 766         batadv_neigh_ifinfo_put(router_ifinfo);
 767         batadv_neigh_ifinfo_put(neigh_ifinfo);
 768
 769         return forward;
 770 }
 771
 772 /**
 773  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 774  * @bat_priv: the bat priv with all the soft interface information
 775  * @ethhdr: the Ethernet header of the OGM2
 776  * @ogm2: OGM2 structure
 777  * @orig_node: Originator structure for which the OGM has been received
 778  * @neigh_node: the neigh_node through with the OGM has been received
 779  * @if_incoming: the interface where this packet was received
 780  * @if_outgoing: the interface for which the packet should be considered
 781  */
 782 static void
 783 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 784                                const struct ethhdr *ethhdr,
 785                                const struct batadv_ogm2_packet *ogm2,
 786                                struct batadv_orig_node *orig_node,
 787                                struct batadv_neigh_node *neigh_node,
 788                                struct batadv_hard_iface *if_incoming,
 789                                struct batadv_hard_iface *if_outgoing)
 790 {
 791         int seqno_age;
 792         bool forward;
 793
 794         /* first, update the metric with according sanity checks */
 795         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 796                                                neigh_node, if_incoming,
 797                                                if_outgoing);
 798
 799         /* outdated sequence numbers are to be discarded */
 800         if (seqno_age < 0)
 801                 return;
 802
 803         /* only unknown & newer OGMs contain TVLVs we are interested in */
 804         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 805                 batadv_tvlv_containers_process(bat_priv, true, orig_node,
 806                                                NULL, NULL,
 807                                                (unsigned char *)(ogm2 + 1),
 808                                                ntohs(ogm2->tvlv_len));
 809
 810         /* if the metric update went through, update routes if needed */
 811         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 812                                             neigh_node, if_incoming,
 813                                             if_outgoing);
 814
 815         /* if the routes have been processed correctly, check and forward */
 816         if (forward)
 817                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 818                                      if_incoming, if_outgoing);
 819 }
 820
 821 /**
 822  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 823  * @buff_pos: current position in the skb
 824  * @packet_len: total length of the skb
 825  * @ogm2_packet: potential OGM2 in buffer
 826  *
 827  * Return: true if there is enough space for another OGM, false otherwise.
 828  */
 829 static bool
 830 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 831                          const struct batadv_ogm2_packet *ogm2_packet)
 832 {
 833         int next_buff_pos = 0;
 834
 835         /* check if there is enough space for the header */
 836         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 837         if (next_buff_pos > packet_len)
 838                 return false;
 839
 840         /* check if there is enough space for the optional TVLV */
 841         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 842
 843         return (next_buff_pos <= packet_len) &&
 844                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 845 }
 846
 847 /**
 848  * batadv_v_ogm_process() - process an incoming batman v OGM
 849  * @skb: the skb containing the OGM
 850  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 851  * @if_incoming: the interface where this packet was received
 852  */
 853 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 854                                  struct batadv_hard_iface *if_incoming)
 855 {
 856         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 857         struct ethhdr *ethhdr;
 858         struct batadv_orig_node *orig_node = NULL;
 859         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 860         struct batadv_neigh_node *neigh_node = NULL;
 861         struct batadv_hard_iface *hard_iface;
 862         struct batadv_ogm2_packet *ogm_packet;
 863         u32 ogm_throughput, link_throughput, path_throughput;
 864         int ret;
 865
 866         ethhdr = eth_hdr(skb);
 867         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 868
 869         ogm_throughput = ntohl(ogm_packet->throughput);
 870
 871         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 872                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 873                    ethhdr->h_source, if_incoming->net_dev->name,
 874                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 875                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 876                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 877
 878         if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
 879                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 880                            "Drop packet: originator packet from ourself\n");
 881                 return;
 882         }
 883
 884         /* If the throughput metric is 0, immediately drop the packet. No need
 885          * to create orig_node / neigh_node for an unusable route.
 886          */
 887         if (ogm_throughput == 0) {
 888                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 889                            "Drop packet: originator packet with throughput metric of 0\n");
 890                 return;
 891         }
 892
 893         /* require ELP packets be to received from this neighbor first */
 894         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 895         if (!hardif_neigh) {
 896                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 897                            "Drop packet: OGM via unknown neighbor!\n");
 898                 goto out;
 899         }
 900
 901         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 902         if (!orig_node)
 903                 goto out;
 904
 905         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 906                                                      ethhdr->h_source);
 907         if (!neigh_node)
 908                 goto out;
 909
 910         /* Update the received throughput metric to match the link
 911          * characteristic:
 912          *  - If this OGM traveled one hop so far (emitted by single hop
 913          *    neighbor) the path throughput metric equals the link throughput.
 914          *  - For OGMs traversing more than hop the path throughput metric is
 915          *    the smaller of the path throughput and the link throughput.
 916          */
 917         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 918         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 919         ogm_packet->throughput = htonl(path_throughput);
 920
 921         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 922                                        neigh_node, if_incoming,
 923                                        BATADV_IF_DEFAULT);
 924
 925         rcu_read_lock();
 926         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 927                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 928                         continue;
 929
 930                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 931                         continue;
 932
 933                 if (!kref_get_unless_zero(&hard_iface->refcount))
 934                         continue;
 935
 936                 ret = batadv_hardif_no_broadcast(hard_iface,
 937                                                  ogm_packet->orig,
 938                                                  hardif_neigh->orig);
 939
 940                 if (ret) {
 941                         char *type;
 942
 943                         switch (ret) {
 944                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 945                                 type = "no neighbor";
 946                                 break;
 947                         case BATADV_HARDIF_BCAST_DUPFWD:
 948                                 type = "single neighbor is source";
 949                                 break;
 950                         case BATADV_HARDIF_BCAST_DUPORIG:
 951                                 type = "single neighbor is originator";
 952                                 break;
 953                         default:
 954                                 type = "unknown";
 955                         }
 956
 957                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 958                                    ogm_packet->orig, hard_iface->net_dev->name,
 959                                    type);
 960
 961                         batadv_hardif_put(hard_iface);
 962                         continue;
 963                 }
 964
 965                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 966                                                orig_node, neigh_node,
 967                                                if_incoming, hard_iface);
 968
 969                 batadv_hardif_put(hard_iface);
 970         }
 971         rcu_read_unlock();
 972 out:
 973         batadv_orig_node_put(orig_node);
 974         batadv_neigh_node_put(neigh_node);
 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;
 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         ethhdr = eth_hdr(skb);
1006         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1007                 goto free_skb;
1008
1009         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1010         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1011                            skb->len + ETH_HLEN);
1012
1013         ogm_offset = 0;
1014         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1015
1016         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1017                                         ogm_packet)) {
1018                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1019
1020                 ogm_offset += BATADV_OGM2_HLEN;
1021                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1022
1023                 packet_pos = skb->data + ogm_offset;
1024                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1025         }
1026
1027         ret = NET_RX_SUCCESS;
1028
1029 free_skb:
1030         if (ret == NET_RX_SUCCESS)
1031                 consume_skb(skb);
1032         else
1033                 kfree_skb(skb);
1034
1035         return ret;
1036 }
1037
1038 /**
1039  * batadv_v_ogm_init() - initialise the OGM2 engine
1040  * @bat_priv: the bat priv with all the soft interface information
1041  *
1042  * Return: 0 on success or a negative error code in case of failure
1043  */
1044 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1045 {
1046         struct batadv_ogm2_packet *ogm_packet;
1047         unsigned char *ogm_buff;
1048         u32 random_seqno;
1049
1050         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1051         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1052         if (!ogm_buff)
1053                 return -ENOMEM;
1054
1055         bat_priv->bat_v.ogm_buff = ogm_buff;
1056         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1057         ogm_packet->packet_type = BATADV_OGM2;
1058         ogm_packet->version = BATADV_COMPAT_VERSION;
1059         ogm_packet->ttl = BATADV_TTL;
1060         ogm_packet->flags = BATADV_NO_FLAGS;
1061         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1062
1063         /* randomize initial seqno to avoid collision */
1064         get_random_bytes(&random_seqno, sizeof(random_seqno));
1065         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
1066         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1067
1068         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1069
1070         return 0;
1071 }
1072
1073 /**
1074  * batadv_v_ogm_free() - free OGM private resources
1075  * @bat_priv: the bat priv with all the soft interface information
1076  */
1077 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1078 {
1079         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
1080
1081         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1082
1083         kfree(bat_priv->bat_v.ogm_buff);
1084         bat_priv->bat_v.ogm_buff = NULL;
1085         bat_priv->bat_v.ogm_buff_len = 0;
1086
1087         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
1088 }