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/random.h>
  25 #include <linux/rculist.h>
  26 #include <linux/rcupdate.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/slab.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/stddef.h>
  31 #include <linux/string.h>
  32 #include <linux/types.h>
  33 #include <linux/workqueue.h>
  34 #include <uapi/linux/batadv_packet.h>
  35
  36 #include "bat_algo.h"
  37 #include "hard-interface.h"
  38 #include "hash.h"
  39 #include "log.h"
  40 #include "originator.h"
  41 #include "routing.h"
  42 #include "send.h"
  43 #include "translation-table.h"
  44 #include "tvlv.h"
  45
  46 /**
  47  * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
  48  * @bat_priv: the bat priv with all the soft interface information
  49  * @addr: the address of the originator
  50  *
  51  * Return: the orig_node corresponding to the specified address. If such an
  52  * object does not exist, it is allocated here. In case of allocation failure
  53  * returns NULL.
  54  */
  55 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
  56                                                const u8 *addr)
  57 {
  58         struct batadv_orig_node *orig_node;
  59         int hash_added;
  60
  61         orig_node = batadv_orig_hash_find(bat_priv, addr);
  62         if (orig_node)
  63                 return orig_node;
  64
  65         orig_node = batadv_orig_node_new(bat_priv, addr);
  66         if (!orig_node)
  67                 return NULL;
  68
  69         kref_get(&orig_node->refcount);
  70         hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
  71                                      batadv_choose_orig, orig_node,
  72                                      &orig_node->hash_entry);
  73         if (hash_added != 0) {
  74                 /* remove refcnt for newly created orig_node and hash entry */
  75                 batadv_orig_node_put(orig_node);
  76                 batadv_orig_node_put(orig_node);
  77                 orig_node = NULL;
  78         }
  79
  80         return orig_node;
  81 }
  82
  83 /**
  84  * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
  85  * @hard_iface: the interface to use to send the OGM
  86  */
  87 static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
  88 {
  89         unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
  90
  91         /* msecs * [0.9, 1.1] */
  92         msecs += get_random_u32_below(msecs / 5) - (msecs / 10);
  93         queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
  94                            msecs_to_jiffies(msecs / 1000));
  95 }
  96
  97 /**
  98  * batadv_v_ogm_start_timer() - restart the OGM sending timer
  99  * @bat_priv: the bat priv with all the soft interface information
 100  */
 101 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
 102 {
 103         unsigned long msecs;
 104         /* this function may be invoked in different contexts (ogm rescheduling
 105          * or hard_iface activation), but the work timer should not be reset
 106          */
 107         if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
 108                 return;
 109
 110         msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
 111         msecs += get_random_u32_below(2 * BATADV_JITTER);
 112         queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
 113                            msecs_to_jiffies(msecs));
 114 }
 115
 116 /**
 117  * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 118  * @skb: the OGM to send
 119  * @hard_iface: the interface to use to send the OGM
 120  */
 121 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
 122                                     struct batadv_hard_iface *hard_iface)
 123 {
 124         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 125
 126         if (hard_iface->if_status != BATADV_IF_ACTIVE) {
 127                 kfree_skb(skb);
 128                 return;
 129         }
 130
 131         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
 132         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
 133                            skb->len + ETH_HLEN);
 134
 135         batadv_send_broadcast_skb(skb, hard_iface);
 136 }
 137
 138 /**
 139  * batadv_v_ogm_len() - OGMv2 packet length
 140  * @skb: the OGM to check
 141  *
 142  * Return: Length of the given OGMv2 packet, including tvlv length, excluding
 143  * ethernet header length.
 144  */
 145 static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
 146 {
 147         struct batadv_ogm2_packet *ogm_packet;
 148
 149         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 150         return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
 151 }
 152
 153 /**
 154  * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
 155  * @skb: the OGM to check
 156  * @hard_iface: the interface to use to send the OGM
 157  *
 158  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 159  *
 160  * Return: True, if the given OGMv2 packet still fits, false otherwise.
 161  */
 162 static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
 163                                     struct batadv_hard_iface *hard_iface)
 164 {
 165         unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
 166                                  BATADV_MAX_AGGREGATION_BYTES);
 167         unsigned int ogm_len = batadv_v_ogm_len(skb);
 168
 169         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 170
 171         return hard_iface->bat_v.aggr_len + ogm_len <= max;
 172 }
 173
 174 /**
 175  * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
 176  * @hard_iface: the interface holding the aggregation queue
 177  *
 178  * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
 179  *
 180  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 181  */
 182 static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
 183 {
 184         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 185
 186         __skb_queue_purge(&hard_iface->bat_v.aggr_list);
 187         hard_iface->bat_v.aggr_len = 0;
 188 }
 189
 190 /**
 191  * batadv_v_ogm_aggr_send() - flush & send aggregation queue
 192  * @hard_iface: the interface with the aggregation queue to flush
 193  *
 194  * Aggregates all OGMv2 packets currently in the aggregation queue into a
 195  * single OGMv2 packet and transmits this aggregate.
 196  *
 197  * The aggregation queue is empty after this call.
 198  *
 199  * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 200  */
 201 static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
 202 {
 203         unsigned int aggr_len = hard_iface->bat_v.aggr_len;
 204         struct sk_buff *skb_aggr;
 205         unsigned int ogm_len;
 206         struct sk_buff *skb;
 207
 208         lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
 209
 210         if (!aggr_len)
 211                 return;
 212
 213         skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
 214         if (!skb_aggr) {
 215                 batadv_v_ogm_aggr_list_free(hard_iface);
 216                 return;
 217         }
 218
 219         skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
 220         skb_reset_network_header(skb_aggr);
 221
 222         while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
 223                 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
 224
 225                 ogm_len = batadv_v_ogm_len(skb);
 226                 skb_put_data(skb_aggr, skb->data, ogm_len);
 227
 228                 consume_skb(skb);
 229         }
 230
 231         batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
 232 }
 233
 234 /**
 235  * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
 236  * @skb: the OGM to queue
 237  * @hard_iface: the interface to queue the OGM on
 238  */
 239 static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
 240                                      struct batadv_hard_iface *hard_iface)
 241 {
 242         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 243
 244         if (!atomic_read(&bat_priv->aggregated_ogms)) {
 245                 batadv_v_ogm_send_to_if(skb, hard_iface);
 246                 return;
 247         }
 248
 249         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 250         if (!batadv_v_ogm_queue_left(skb, hard_iface))
 251                 batadv_v_ogm_aggr_send(hard_iface);
 252
 253         hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
 254         __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
 255         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 256 }
 257
 258 /**
 259  * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
 260  * @bat_priv: the bat priv with all the soft interface information
 261  */
 262 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
 263 {
 264         struct batadv_hard_iface *hard_iface;
 265         struct batadv_ogm2_packet *ogm_packet;
 266         struct sk_buff *skb, *skb_tmp;
 267         unsigned char *ogm_buff;
 268         int ogm_buff_len;
 269         u16 tvlv_len = 0;
 270         int ret;
 271
 272         lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
 273
 274         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 275                 goto out;
 276
 277         ogm_buff = bat_priv->bat_v.ogm_buff;
 278         ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
 279         /* tt changes have to be committed before the tvlv data is
 280          * appended as it may alter the tt tvlv container
 281          */
 282         batadv_tt_local_commit_changes(bat_priv);
 283         tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
 284                                                     &ogm_buff_len,
 285                                                     BATADV_OGM2_HLEN);
 286
 287         bat_priv->bat_v.ogm_buff = ogm_buff;
 288         bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
 289
 290         skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
 291         if (!skb)
 292                 goto reschedule;
 293
 294         skb_reserve(skb, ETH_HLEN);
 295         skb_put_data(skb, ogm_buff, ogm_buff_len);
 296
 297         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
 298         ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
 299         atomic_inc(&bat_priv->bat_v.ogm_seqno);
 300         ogm_packet->tvlv_len = htons(tvlv_len);
 301
 302         /* broadcast on every interface */
 303         rcu_read_lock();
 304         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 305                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 306                         continue;
 307
 308                 if (!kref_get_unless_zero(&hard_iface->refcount))
 309                         continue;
 310
 311                 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
 312                 if (ret) {
 313                         char *type;
 314
 315                         switch (ret) {
 316                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 317                                 type = "no neighbor";
 318                                 break;
 319                         case BATADV_HARDIF_BCAST_DUPFWD:
 320                                 type = "single neighbor is source";
 321                                 break;
 322                         case BATADV_HARDIF_BCAST_DUPORIG:
 323                                 type = "single neighbor is originator";
 324                                 break;
 325                         default:
 326                                 type = "unknown";
 327                         }
 328
 329                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
 330                                    hard_iface->net_dev->name, type);
 331
 332                         batadv_hardif_put(hard_iface);
 333                         continue;
 334                 }
 335
 336                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 337                            "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
 338                            ogm_packet->orig, ntohl(ogm_packet->seqno),
 339                            ntohl(ogm_packet->throughput), ogm_packet->ttl,
 340                            hard_iface->net_dev->name,
 341                            hard_iface->net_dev->dev_addr);
 342
 343                 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
 344                 skb_tmp = skb_clone(skb, GFP_ATOMIC);
 345                 if (!skb_tmp) {
 346                         batadv_hardif_put(hard_iface);
 347                         break;
 348                 }
 349
 350                 batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
 351                 batadv_hardif_put(hard_iface);
 352         }
 353         rcu_read_unlock();
 354
 355         consume_skb(skb);
 356
 357 reschedule:
 358         batadv_v_ogm_start_timer(bat_priv);
 359 out:
 360         return;
 361 }
 362
 363 /**
 364  * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 365  * @work: work queue item
 366  */
 367 static void batadv_v_ogm_send(struct work_struct *work)
 368 {
 369         struct batadv_priv_bat_v *bat_v;
 370         struct batadv_priv *bat_priv;
 371
 372         bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
 373         bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
 374
 375         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 376         batadv_v_ogm_send_softif(bat_priv);
 377         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 378 }
 379
 380 /**
 381  * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
 382  * @work: work queue item
 383  *
 384  * Emits aggregated OGM messages in regular intervals.
 385  */
 386 void batadv_v_ogm_aggr_work(struct work_struct *work)
 387 {
 388         struct batadv_hard_iface_bat_v *batv;
 389         struct batadv_hard_iface *hard_iface;
 390
 391         batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
 392         hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
 393
 394         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 395         batadv_v_ogm_aggr_send(hard_iface);
 396         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 397
 398         batadv_v_ogm_start_queue_timer(hard_iface);
 399 }
 400
 401 /**
 402  * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
 403  * @hard_iface: the interface to prepare
 404  *
 405  * Takes care of scheduling its own OGM sending routine for this interface.
 406  *
 407  * Return: 0 on success or a negative error code otherwise
 408  */
 409 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
 410 {
 411         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 412
 413         batadv_v_ogm_start_queue_timer(hard_iface);
 414         batadv_v_ogm_start_timer(bat_priv);
 415
 416         return 0;
 417 }
 418
 419 /**
 420  * batadv_v_ogm_iface_disable() - release OGM interface private resources
 421  * @hard_iface: interface for which the resources have to be released
 422  */
 423 void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
 424 {
 425         cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
 426
 427         spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
 428         batadv_v_ogm_aggr_list_free(hard_iface);
 429         spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
 430 }
 431
 432 /**
 433  * batadv_v_ogm_primary_iface_set() - set a new primary interface
 434  * @primary_iface: the new primary interface
 435  */
 436 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
 437 {
 438         struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
 439         struct batadv_ogm2_packet *ogm_packet;
 440
 441         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
 442         if (!bat_priv->bat_v.ogm_buff)
 443                 goto unlock;
 444
 445         ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
 446         ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
 447
 448 unlock:
 449         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
 450 }
 451
 452 /**
 453  * batadv_v_forward_penalty() - apply a penalty to the throughput metric
 454  *  forwarded with B.A.T.M.A.N. V OGMs
 455  * @bat_priv: the bat priv with all the soft interface information
 456  * @if_incoming: the interface where the OGM has been received
 457  * @if_outgoing: the interface where the OGM has to be forwarded to
 458  * @throughput: the current throughput
 459  *
 460  * Apply a penalty on the current throughput metric value based on the
 461  * characteristic of the interface where the OGM has been received.
 462  *
 463  * Initially the per hardif hop penalty is applied to the throughput. After
 464  * that the return value is then computed as follows:
 465  * - throughput * 50%          if the incoming and outgoing interface are the
 466  *                             same WiFi interface and the throughput is above
 467  *                             1MBit/s
 468  * - throughput                if the outgoing interface is the default
 469  *                             interface (i.e. this OGM is processed for the
 470  *                             internal table and not forwarded)
 471  * - throughput * node hop penalty  otherwise
 472  *
 473  * Return: the penalised throughput metric.
 474  */
 475 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
 476                                     struct batadv_hard_iface *if_incoming,
 477                                     struct batadv_hard_iface *if_outgoing,
 478                                     u32 throughput)
 479 {
 480         int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
 481         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
 482         int hop_penalty_max = BATADV_TQ_MAX_VALUE;
 483
 484         /* Apply per hardif hop penalty */
 485         throughput = throughput * (hop_penalty_max - if_hop_penalty) /
 486                      hop_penalty_max;
 487
 488         /* Don't apply hop penalty in default originator table. */
 489         if (if_outgoing == BATADV_IF_DEFAULT)
 490                 return throughput;
 491
 492         /* Forwarding on the same WiFi interface cuts the throughput in half
 493          * due to the store & forward characteristics of WIFI.
 494          * Very low throughput values are the exception.
 495          */
 496         if (throughput > 10 &&
 497             if_incoming == if_outgoing &&
 498             !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
 499                 return throughput / 2;
 500
 501         /* hop penalty of 255 equals 100% */
 502         return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
 503 }
 504
 505 /**
 506  * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 507  *  outgoing interface
 508  * @bat_priv: the bat priv with all the soft interface information
 509  * @ogm_received: previously received OGM to be forwarded
 510  * @orig_node: the originator which has been updated
 511  * @neigh_node: the neigh_node through with the OGM has been received
 512  * @if_incoming: the interface on which this OGM was received on
 513  * @if_outgoing: the interface to which the OGM has to be forwarded to
 514  *
 515  * Forward an OGM to an interface after having altered the throughput metric and
 516  * the TTL value contained in it. The original OGM isn't modified.
 517  */
 518 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
 519                                  const struct batadv_ogm2_packet *ogm_received,
 520                                  struct batadv_orig_node *orig_node,
 521                                  struct batadv_neigh_node *neigh_node,
 522                                  struct batadv_hard_iface *if_incoming,
 523                                  struct batadv_hard_iface *if_outgoing)
 524 {
 525         struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
 526         struct batadv_orig_ifinfo *orig_ifinfo = NULL;
 527         struct batadv_neigh_node *router = NULL;
 528         struct batadv_ogm2_packet *ogm_forward;
 529         unsigned char *skb_buff;
 530         struct sk_buff *skb;
 531         size_t packet_len;
 532         u16 tvlv_len;
 533
 534         /* only forward for specific interfaces, not for the default one. */
 535         if (if_outgoing == BATADV_IF_DEFAULT)
 536                 goto out;
 537
 538         orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
 539         if (!orig_ifinfo)
 540                 goto out;
 541
 542         /* acquire possibly updated router */
 543         router = batadv_orig_router_get(orig_node, if_outgoing);
 544
 545         /* strict rule: forward packets coming from the best next hop only */
 546         if (neigh_node != router)
 547                 goto out;
 548
 549         /* don't forward the same seqno twice on one interface */
 550         if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
 551                 goto out;
 552
 553         orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
 554
 555         if (ogm_received->ttl <= 1) {
 556                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
 557                 goto out;
 558         }
 559
 560         neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 561         if (!neigh_ifinfo)
 562                 goto out;
 563
 564         tvlv_len = ntohs(ogm_received->tvlv_len);
 565
 566         packet_len = BATADV_OGM2_HLEN + tvlv_len;
 567         skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
 568                                         ETH_HLEN + packet_len);
 569         if (!skb)
 570                 goto out;
 571
 572         skb_reserve(skb, ETH_HLEN);
 573         skb_buff = skb_put_data(skb, ogm_received, packet_len);
 574
 575         /* apply forward penalty */
 576         ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
 577         ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
 578         ogm_forward->ttl--;
 579
 580         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 581                    "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
 582                    if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
 583                    ogm_forward->ttl, if_incoming->net_dev->name);
 584
 585         batadv_v_ogm_queue_on_if(skb, if_outgoing);
 586
 587 out:
 588         batadv_orig_ifinfo_put(orig_ifinfo);
 589         batadv_neigh_node_put(router);
 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         batadv_orig_ifinfo_put(orig_ifinfo);
 671         batadv_neigh_ifinfo_put(neigh_ifinfo);
 672
 673         return ret;
 674 }
 675
 676 /**
 677  * batadv_v_ogm_route_update() - update routes based on OGM
 678  * @bat_priv: the bat priv with all the soft interface information
 679  * @ethhdr: the Ethernet header of the OGM2
 680  * @ogm2: OGM2 structure
 681  * @orig_node: Originator structure for which the OGM has been received
 682  * @neigh_node: the neigh_node through with the OGM has been received
 683  * @if_incoming: the interface where this packet was received
 684  * @if_outgoing: the interface for which the packet should be considered
 685  *
 686  * Return: true if the packet should be forwarded, false otherwise
 687  */
 688 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
 689                                       const struct ethhdr *ethhdr,
 690                                       const struct batadv_ogm2_packet *ogm2,
 691                                       struct batadv_orig_node *orig_node,
 692                                       struct batadv_neigh_node *neigh_node,
 693                                       struct batadv_hard_iface *if_incoming,
 694                                       struct batadv_hard_iface *if_outgoing)
 695 {
 696         struct batadv_neigh_node *router = NULL;
 697         struct batadv_orig_node *orig_neigh_node;
 698         struct batadv_neigh_node *orig_neigh_router = NULL;
 699         struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
 700         u32 router_throughput, neigh_throughput;
 701         u32 router_last_seqno;
 702         u32 neigh_last_seqno;
 703         s32 neigh_seq_diff;
 704         bool forward = false;
 705
 706         orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
 707         if (!orig_neigh_node)
 708                 goto out;
 709
 710         orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
 711                                                    if_outgoing);
 712
 713         /* drop packet if sender is not a direct neighbor and if we
 714          * don't route towards it
 715          */
 716         router = batadv_orig_router_get(orig_node, if_outgoing);
 717         if (router && router->orig_node != orig_node && !orig_neigh_router) {
 718                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 719                            "Drop packet: OGM via unknown neighbor!\n");
 720                 goto out;
 721         }
 722
 723         /* Mark the OGM to be considered for forwarding, and update routes
 724          * if needed.
 725          */
 726         forward = true;
 727
 728         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 729                    "Searching and updating originator entry of received packet\n");
 730
 731         /* if this neighbor already is our next hop there is nothing
 732          * to change
 733          */
 734         if (router == neigh_node)
 735                 goto out;
 736
 737         /* don't consider neighbours with worse throughput.
 738          * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
 739          * the last received seqno from our best next hop.
 740          */
 741         if (router) {
 742                 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
 743                 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
 744
 745                 /* if these are not allocated, something is wrong. */
 746                 if (!router_ifinfo || !neigh_ifinfo)
 747                         goto out;
 748
 749                 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
 750                 router_last_seqno = router_ifinfo->bat_v.last_seqno;
 751                 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
 752                 router_throughput = router_ifinfo->bat_v.throughput;
 753                 neigh_throughput = neigh_ifinfo->bat_v.throughput;
 754
 755                 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
 756                     router_throughput >= neigh_throughput)
 757                         goto out;
 758         }
 759
 760         batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
 761 out:
 762         batadv_neigh_node_put(router);
 763         batadv_neigh_node_put(orig_neigh_router);
 764         batadv_orig_node_put(orig_neigh_node);
 765         batadv_neigh_ifinfo_put(router_ifinfo);
 766         batadv_neigh_ifinfo_put(neigh_ifinfo);
 767
 768         return forward;
 769 }
 770
 771 /**
 772  * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 773  * @bat_priv: the bat priv with all the soft interface information
 774  * @ethhdr: the Ethernet header of the OGM2
 775  * @ogm2: OGM2 structure
 776  * @orig_node: Originator structure for which the OGM has been received
 777  * @neigh_node: the neigh_node through with the OGM has been received
 778  * @if_incoming: the interface where this packet was received
 779  * @if_outgoing: the interface for which the packet should be considered
 780  */
 781 static void
 782 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
 783                                const struct ethhdr *ethhdr,
 784                                const struct batadv_ogm2_packet *ogm2,
 785                                struct batadv_orig_node *orig_node,
 786                                struct batadv_neigh_node *neigh_node,
 787                                struct batadv_hard_iface *if_incoming,
 788                                struct batadv_hard_iface *if_outgoing)
 789 {
 790         int seqno_age;
 791         bool forward;
 792
 793         /* first, update the metric with according sanity checks */
 794         seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
 795                                                neigh_node, if_incoming,
 796                                                if_outgoing);
 797
 798         /* outdated sequence numbers are to be discarded */
 799         if (seqno_age < 0)
 800                 return;
 801
 802         /* only unknown & newer OGMs contain TVLVs we are interested in */
 803         if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
 804                 batadv_tvlv_containers_process(bat_priv, BATADV_OGM2, orig_node,
 805                                                NULL,
 806                                                (unsigned char *)(ogm2 + 1),
 807                                                ntohs(ogm2->tvlv_len));
 808
 809         /* if the metric update went through, update routes if needed */
 810         forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
 811                                             neigh_node, if_incoming,
 812                                             if_outgoing);
 813
 814         /* if the routes have been processed correctly, check and forward */
 815         if (forward)
 816                 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
 817                                      if_incoming, if_outgoing);
 818 }
 819
 820 /**
 821  * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 822  * @buff_pos: current position in the skb
 823  * @packet_len: total length of the skb
 824  * @ogm2_packet: potential OGM2 in buffer
 825  *
 826  * Return: true if there is enough space for another OGM, false otherwise.
 827  */
 828 static bool
 829 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
 830                          const struct batadv_ogm2_packet *ogm2_packet)
 831 {
 832         int next_buff_pos = 0;
 833
 834         /* check if there is enough space for the header */
 835         next_buff_pos += buff_pos + sizeof(*ogm2_packet);
 836         if (next_buff_pos > packet_len)
 837                 return false;
 838
 839         /* check if there is enough space for the optional TVLV */
 840         next_buff_pos += ntohs(ogm2_packet->tvlv_len);
 841
 842         return (next_buff_pos <= packet_len) &&
 843                (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
 844 }
 845
 846 /**
 847  * batadv_v_ogm_process() - process an incoming batman v OGM
 848  * @skb: the skb containing the OGM
 849  * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 850  * @if_incoming: the interface where this packet was received
 851  */
 852 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
 853                                  struct batadv_hard_iface *if_incoming)
 854 {
 855         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 856         struct ethhdr *ethhdr;
 857         struct batadv_orig_node *orig_node = NULL;
 858         struct batadv_hardif_neigh_node *hardif_neigh = NULL;
 859         struct batadv_neigh_node *neigh_node = NULL;
 860         struct batadv_hard_iface *hard_iface;
 861         struct batadv_ogm2_packet *ogm_packet;
 862         u32 ogm_throughput, link_throughput, path_throughput;
 863         int ret;
 864
 865         ethhdr = eth_hdr(skb);
 866         ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
 867
 868         ogm_throughput = ntohl(ogm_packet->throughput);
 869
 870         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 871                    "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
 872                    ethhdr->h_source, if_incoming->net_dev->name,
 873                    if_incoming->net_dev->dev_addr, ogm_packet->orig,
 874                    ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
 875                    ogm_packet->version, ntohs(ogm_packet->tvlv_len));
 876
 877         if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
 878                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 879                            "Drop packet: originator packet from ourself\n");
 880                 return;
 881         }
 882
 883         /* If the throughput metric is 0, immediately drop the packet. No need
 884          * to create orig_node / neigh_node for an unusable route.
 885          */
 886         if (ogm_throughput == 0) {
 887                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 888                            "Drop packet: originator packet with throughput metric of 0\n");
 889                 return;
 890         }
 891
 892         /* require ELP packets be to received from this neighbor first */
 893         hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
 894         if (!hardif_neigh) {
 895                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 896                            "Drop packet: OGM via unknown neighbor!\n");
 897                 goto out;
 898         }
 899
 900         orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
 901         if (!orig_node)
 902                 goto out;
 903
 904         neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
 905                                                      ethhdr->h_source);
 906         if (!neigh_node)
 907                 goto out;
 908
 909         /* Update the received throughput metric to match the link
 910          * characteristic:
 911          *  - If this OGM traveled one hop so far (emitted by single hop
 912          *    neighbor) the path throughput metric equals the link throughput.
 913          *  - For OGMs traversing more than hop the path throughput metric is
 914          *    the smaller of the path throughput and the link throughput.
 915          */
 916         link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
 917         path_throughput = min_t(u32, link_throughput, ogm_throughput);
 918         ogm_packet->throughput = htonl(path_throughput);
 919
 920         batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
 921                                        neigh_node, if_incoming,
 922                                        BATADV_IF_DEFAULT);
 923
 924         rcu_read_lock();
 925         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 926                 if (hard_iface->if_status != BATADV_IF_ACTIVE)
 927                         continue;
 928
 929                 if (hard_iface->soft_iface != bat_priv->soft_iface)
 930                         continue;
 931
 932                 if (!kref_get_unless_zero(&hard_iface->refcount))
 933                         continue;
 934
 935                 ret = batadv_hardif_no_broadcast(hard_iface,
 936                                                  ogm_packet->orig,
 937                                                  hardif_neigh->orig);
 938
 939                 if (ret) {
 940                         char *type;
 941
 942                         switch (ret) {
 943                         case BATADV_HARDIF_BCAST_NORECIPIENT:
 944                                 type = "no neighbor";
 945                                 break;
 946                         case BATADV_HARDIF_BCAST_DUPFWD:
 947                                 type = "single neighbor is source";
 948                                 break;
 949                         case BATADV_HARDIF_BCAST_DUPORIG:
 950                                 type = "single neighbor is originator";
 951                                 break;
 952                         default:
 953                                 type = "unknown";
 954                         }
 955
 956                         batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
 957                                    ogm_packet->orig, hard_iface->net_dev->name,
 958                                    type);
 959
 960                         batadv_hardif_put(hard_iface);
 961                         continue;
 962                 }
 963
 964                 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
 965                                                orig_node, neigh_node,
 966                                                if_incoming, hard_iface);
 967
 968                 batadv_hardif_put(hard_iface);
 969         }
 970         rcu_read_unlock();
 971 out:
 972         batadv_orig_node_put(orig_node);
 973         batadv_neigh_node_put(neigh_node);
 974         batadv_hardif_neigh_put(hardif_neigh);
 975 }
 976
 977 /**
 978  * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 979  * @skb: the received OGM
 980  * @if_incoming: the interface where this OGM has been received
 981  *
 982  * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 983  * (without freeing the skb) on failure
 984  */
 985 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
 986                              struct batadv_hard_iface *if_incoming)
 987 {
 988         struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 989         struct batadv_ogm2_packet *ogm_packet;
 990         struct ethhdr *ethhdr;
 991         int ogm_offset;
 992         u8 *packet_pos;
 993         int ret = NET_RX_DROP;
 994
 995         /* did we receive a OGM2 packet on an interface that does not have
 996          * B.A.T.M.A.N. V enabled ?
 997          */
 998         if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
 999                 goto free_skb;
1000
1001         if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
1002                 goto free_skb;
1003
1004         ethhdr = eth_hdr(skb);
1005         if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1006                 goto free_skb;
1007
1008         batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1009         batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1010                            skb->len + ETH_HLEN);
1011
1012         ogm_offset = 0;
1013         ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1014
1015         while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1016                                         ogm_packet)) {
1017                 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1018
1019                 ogm_offset += BATADV_OGM2_HLEN;
1020                 ogm_offset += ntohs(ogm_packet->tvlv_len);
1021
1022                 packet_pos = skb->data + ogm_offset;
1023                 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1024         }
1025
1026         ret = NET_RX_SUCCESS;
1027
1028 free_skb:
1029         if (ret == NET_RX_SUCCESS)
1030                 consume_skb(skb);
1031         else
1032                 kfree_skb(skb);
1033
1034         return ret;
1035 }
1036
1037 /**
1038  * batadv_v_ogm_init() - initialise the OGM2 engine
1039  * @bat_priv: the bat priv with all the soft interface information
1040  *
1041  * Return: 0 on success or a negative error code in case of failure
1042  */
1043 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1044 {
1045         struct batadv_ogm2_packet *ogm_packet;
1046         unsigned char *ogm_buff;
1047         u32 random_seqno;
1048
1049         bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1050         ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1051         if (!ogm_buff)
1052                 return -ENOMEM;
1053
1054         bat_priv->bat_v.ogm_buff = ogm_buff;
1055         ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1056         ogm_packet->packet_type = BATADV_OGM2;
1057         ogm_packet->version = BATADV_COMPAT_VERSION;
1058         ogm_packet->ttl = BATADV_TTL;
1059         ogm_packet->flags = BATADV_NO_FLAGS;
1060         ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1061
1062         /* randomize initial seqno to avoid collision */
1063         get_random_bytes(&random_seqno, sizeof(random_seqno));
1064         atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
1065         INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1066
1067         mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1068
1069         return 0;
1070 }
1071
1072 /**
1073  * batadv_v_ogm_free() - free OGM private resources
1074  * @bat_priv: the bat priv with all the soft interface information
1075  */
1076 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1077 {
1078         cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
1079
1080         mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1081
1082         kfree(bat_priv->bat_v.ogm_buff);
1083         bat_priv->bat_v.ogm_buff = NULL;
1084         bat_priv->bat_v.ogm_buff_len = 0;
1085
1086         mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
1087 }