net/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "routing.h"
  25 #include "translation-table.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "vis.h"
  29 #include "aggregation.h"
  30 #include "gateway_common.h"
  31 #include "originator.h"
  32
  33 static void send_outstanding_bcast_packet(struct work_struct *work);
  34
  35 /* apply hop penalty for a normal link */
  36 static uint8_t hop_penalty(const uint8_t tq, struct bat_priv *bat_priv)
  37 {
  38         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
  39         return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
  40 }
  41
  42 /* when do we schedule our own packet to be sent */
  43 static unsigned long own_send_time(struct bat_priv *bat_priv)
  44 {
  45         return jiffies + msecs_to_jiffies(
  46                    atomic_read(&bat_priv->orig_interval) -
  47                    JITTER + (random32() % 2*JITTER));
  48 }
  49
  50 /* when do we schedule a forwarded packet to be sent */
  51 static unsigned long forward_send_time(void)
  52 {
  53         return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
  54 }
  55
  56 /* send out an already prepared packet to the given address via the
  57  * specified batman interface */
  58 int send_skb_packet(struct sk_buff *skb,
  59                                 struct hard_iface *hard_iface,
  60                                 uint8_t *dst_addr)
  61 {
  62         struct ethhdr *ethhdr;
  63
  64         if (hard_iface->if_status != IF_ACTIVE)
  65                 goto send_skb_err;
  66
  67         if (unlikely(!hard_iface->net_dev))
  68                 goto send_skb_err;
  69
  70         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  71                 pr_warning("Interface %s is not up - can't send packet via "
  72                            "that interface!\n", hard_iface->net_dev->name);
  73                 goto send_skb_err;
  74         }
  75
  76         /* push to the ethernet header. */
  77         if (my_skb_head_push(skb, sizeof(struct ethhdr)) < 0)
  78                 goto send_skb_err;
  79
  80         skb_reset_mac_header(skb);
  81
  82         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  83         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  84         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  85         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  86
  87         skb_set_network_header(skb, ETH_HLEN);
  88         skb->priority = TC_PRIO_CONTROL;
  89         skb->protocol = __constant_htons(ETH_P_BATMAN);
  90
  91         skb->dev = hard_iface->net_dev;
  92
  93         /* dev_queue_xmit() returns a negative result on error.  However on
  94          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  95          * (which is > 0). This will not be treated as an error. */
  96
  97         return dev_queue_xmit(skb);
  98 send_skb_err:
  99         kfree_skb(skb);
 100         return NET_XMIT_DROP;
 101 }
 102
 103 /* Send a packet to a given interface */
 104 static void send_packet_to_if(struct forw_packet *forw_packet,
 105                               struct hard_iface *hard_iface)
 106 {
 107         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 108         char *fwd_str;
 109         uint8_t packet_num;
 110         int16_t buff_pos;
 111         struct batman_packet *batman_packet;
 112         struct sk_buff *skb;
 113
 114         if (hard_iface->if_status != IF_ACTIVE)
 115                 return;
 116
 117         packet_num = 0;
 118         buff_pos = 0;
 119         batman_packet = (struct batman_packet *)forw_packet->skb->data;
 120
 121         /* adjust all flags and log packets */
 122         while (aggregated_packet(buff_pos,
 123                                  forw_packet->packet_len,
 124                                  batman_packet->num_hna)) {
 125
 126                 /* we might have aggregated direct link packets with an
 127                  * ordinary base packet */
 128                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 129                     (forw_packet->if_incoming == hard_iface))
 130                         batman_packet->flags |= DIRECTLINK;
 131                 else
 132                         batman_packet->flags &= ~DIRECTLINK;
 133
 134                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 135                                                             "Sending own" :
 136                                                             "Forwarding"));
 137                 bat_dbg(DBG_BATMAN, bat_priv,
 138                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 139                         " IDF %s) on interface %s [%pM]\n",
 140                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 141                         batman_packet->orig, ntohl(batman_packet->seqno),
 142                         batman_packet->tq, batman_packet->ttl,
 143                         (batman_packet->flags & DIRECTLINK ?
 144                          "on" : "off"),
 145                         hard_iface->net_dev->name,
 146                         hard_iface->net_dev->dev_addr);
 147
 148                 buff_pos += sizeof(struct batman_packet) +
 149                         (batman_packet->num_hna * ETH_ALEN);
 150                 packet_num++;
 151                 batman_packet = (struct batman_packet *)
 152                         (forw_packet->skb->data + buff_pos);
 153         }
 154
 155         /* create clone because function is called more than once */
 156         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 157         if (skb)
 158                 send_skb_packet(skb, hard_iface, broadcast_addr);
 159 }
 160
 161 /* send a batman packet */
 162 static void send_packet(struct forw_packet *forw_packet)
 163 {
 164         struct hard_iface *hard_iface;
 165         struct net_device *soft_iface;
 166         struct bat_priv *bat_priv;
 167         struct batman_packet *batman_packet =
 168                 (struct batman_packet *)(forw_packet->skb->data);
 169         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 170
 171         if (!forw_packet->if_incoming) {
 172                 pr_err("Error - can't forward packet: incoming iface not "
 173                        "specified\n");
 174                 return;
 175         }
 176
 177         soft_iface = forw_packet->if_incoming->soft_iface;
 178         bat_priv = netdev_priv(soft_iface);
 179
 180         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 181                 return;
 182
 183         /* multihomed peer assumed */
 184         /* non-primary OGMs are only broadcasted on their interface */
 185         if ((directlink && (batman_packet->ttl == 1)) ||
 186             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 187
 188                 /* FIXME: what about aggregated packets ? */
 189                 bat_dbg(DBG_BATMAN, bat_priv,
 190                         "%s packet (originator %pM, seqno %d, TTL %d) "
 191                         "on interface %s [%pM]\n",
 192                         (forw_packet->own ? "Sending own" : "Forwarding"),
 193                         batman_packet->orig, ntohl(batman_packet->seqno),
 194                         batman_packet->ttl,
 195                         forw_packet->if_incoming->net_dev->name,
 196                         forw_packet->if_incoming->net_dev->dev_addr);
 197
 198                 /* skb is only used once and than forw_packet is free'd */
 199                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 200                                 broadcast_addr);
 201                 forw_packet->skb = NULL;
 202
 203                 return;
 204         }
 205
 206         /* broadcast on every interface */
 207         rcu_read_lock();
 208         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 209                 if (hard_iface->soft_iface != soft_iface)
 210                         continue;
 211
 212                 send_packet_to_if(forw_packet, hard_iface);
 213         }
 214         rcu_read_unlock();
 215 }
 216
 217 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 218                                   struct hard_iface *hard_iface)
 219 {
 220         int new_len;
 221         unsigned char *new_buff;
 222         struct batman_packet *batman_packet;
 223
 224         new_len = sizeof(struct batman_packet) +
 225                         (bat_priv->num_local_hna * ETH_ALEN);
 226         new_buff = kmalloc(new_len, GFP_ATOMIC);
 227
 228         /* keep old buffer if kmalloc should fail */
 229         if (new_buff) {
 230                 memcpy(new_buff, hard_iface->packet_buff,
 231                        sizeof(struct batman_packet));
 232                 batman_packet = (struct batman_packet *)new_buff;
 233
 234                 batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
 235                                 new_buff + sizeof(struct batman_packet),
 236                                 new_len - sizeof(struct batman_packet));
 237
 238                 kfree(hard_iface->packet_buff);
 239                 hard_iface->packet_buff = new_buff;
 240                 hard_iface->packet_len = new_len;
 241         }
 242 }
 243
 244 void schedule_own_packet(struct hard_iface *hard_iface)
 245 {
 246         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 247         unsigned long send_time;
 248         struct batman_packet *batman_packet;
 249         int vis_server;
 250
 251         if ((hard_iface->if_status == IF_NOT_IN_USE) ||
 252             (hard_iface->if_status == IF_TO_BE_REMOVED))
 253                 return;
 254
 255         vis_server = atomic_read(&bat_priv->vis_mode);
 256
 257         /**
 258          * the interface gets activated here to avoid race conditions between
 259          * the moment of activating the interface in
 260          * hardif_activate_interface() where the originator mac is set and
 261          * outdated packets (especially uninitialized mac addresses) in the
 262          * packet queue
 263          */
 264         if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
 265                 hard_iface->if_status = IF_ACTIVE;
 266
 267         /* if local hna has changed and interface is a primary interface */
 268         if ((atomic_read(&bat_priv->hna_local_changed)) &&
 269             (hard_iface == bat_priv->primary_if))
 270                 rebuild_batman_packet(bat_priv, hard_iface);
 271
 272         /**
 273          * NOTE: packet_buff might just have been re-allocated in
 274          * rebuild_batman_packet()
 275          */
 276         batman_packet = (struct batman_packet *)hard_iface->packet_buff;
 277
 278         /* change sequence number to network order */
 279         batman_packet->seqno =
 280                 htonl((uint32_t)atomic_read(&hard_iface->seqno));
 281
 282         if (vis_server == VIS_TYPE_SERVER_SYNC)
 283                 batman_packet->flags |= VIS_SERVER;
 284         else
 285                 batman_packet->flags &= ~VIS_SERVER;
 286
 287         if ((hard_iface == bat_priv->primary_if) &&
 288             (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
 289                 batman_packet->gw_flags =
 290                                 (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
 291         else
 292                 batman_packet->gw_flags = 0;
 293
 294         atomic_inc(&hard_iface->seqno);
 295
 296         slide_own_bcast_window(hard_iface);
 297         send_time = own_send_time(bat_priv);
 298         add_bat_packet_to_list(bat_priv,
 299                                hard_iface->packet_buff,
 300                                hard_iface->packet_len,
 301                                hard_iface, 1, send_time);
 302 }
 303
 304 void schedule_forward_packet(struct orig_node *orig_node,
 305                              struct ethhdr *ethhdr,
 306                              struct batman_packet *batman_packet,
 307                              uint8_t directlink, int hna_buff_len,
 308                              struct hard_iface *if_incoming)
 309 {
 310         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 311         struct neigh_node *router;
 312         unsigned char in_tq, in_ttl, tq_avg = 0;
 313         unsigned long send_time;
 314
 315         if (batman_packet->ttl <= 1) {
 316                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 317                 return;
 318         }
 319
 320         router = orig_node_get_router(orig_node);
 321
 322         in_tq = batman_packet->tq;
 323         in_ttl = batman_packet->ttl;
 324
 325         batman_packet->ttl--;
 326         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 327
 328         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 329          * of our best tq value */
 330         if (router && router->tq_avg != 0) {
 331
 332                 /* rebroadcast ogm of best ranking neighbor as is */
 333                 if (!compare_eth(router->addr, ethhdr->h_source)) {
 334                         batman_packet->tq = router->tq_avg;
 335
 336                         if (router->last_ttl)
 337                                 batman_packet->ttl = router->last_ttl - 1;
 338                 }
 339
 340                 tq_avg = router->tq_avg;
 341         }
 342
 343         if (router)
 344                 neigh_node_free_ref(router);
 345
 346         /* apply hop penalty */
 347         batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
 348
 349         bat_dbg(DBG_BATMAN, bat_priv,
 350                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 351                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 352                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 353                 batman_packet->ttl);
 354
 355         batman_packet->seqno = htonl(batman_packet->seqno);
 356
 357         /* switch of primaries first hop flag when forwarding */
 358         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 359         if (directlink)
 360                 batman_packet->flags |= DIRECTLINK;
 361         else
 362                 batman_packet->flags &= ~DIRECTLINK;
 363
 364         send_time = forward_send_time();
 365         add_bat_packet_to_list(bat_priv,
 366                                (unsigned char *)batman_packet,
 367                                sizeof(struct batman_packet) + hna_buff_len,
 368                                if_incoming, 0, send_time);
 369 }
 370
 371 static void forw_packet_free(struct forw_packet *forw_packet)
 372 {
 373         if (forw_packet->skb)
 374                 kfree_skb(forw_packet->skb);
 375         kfree(forw_packet);
 376 }
 377
 378 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 379                                       struct forw_packet *forw_packet,
 380                                       unsigned long send_time)
 381 {
 382         INIT_HLIST_NODE(&forw_packet->list);
 383
 384         /* add new packet to packet list */
 385         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 386         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 387         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 388
 389         /* start timer for this packet */
 390         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 391                           send_outstanding_bcast_packet);
 392         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 393                            send_time);
 394 }
 395
 396 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 397 /* add a broadcast packet to the queue and setup timers. broadcast packets
 398  * are sent multiple times to increase probability for beeing received.
 399  *
 400  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 401  * errors.
 402  *
 403  * The skb is not consumed, so the caller should make sure that the
 404  * skb is freed. */
 405 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 406 {
 407         struct forw_packet *forw_packet;
 408         struct bcast_packet *bcast_packet;
 409
 410         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 411                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 412                 goto out;
 413         }
 414
 415         if (!bat_priv->primary_if)
 416                 goto out;
 417
 418         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 419
 420         if (!forw_packet)
 421                 goto out_and_inc;
 422
 423         skb = skb_copy(skb, GFP_ATOMIC);
 424         if (!skb)
 425                 goto packet_free;
 426
 427         /* as we have a copy now, it is safe to decrease the TTL */
 428         bcast_packet = (struct bcast_packet *)skb->data;
 429         bcast_packet->ttl--;
 430
 431         skb_reset_mac_header(skb);
 432
 433         forw_packet->skb = skb;
 434         forw_packet->if_incoming = bat_priv->primary_if;
 435
 436         /* how often did we send the bcast packet ? */
 437         forw_packet->num_packets = 0;
 438
 439         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 440         return NETDEV_TX_OK;
 441
 442 packet_free:
 443         kfree(forw_packet);
 444 out_and_inc:
 445         atomic_inc(&bat_priv->bcast_queue_left);
 446 out:
 447         return NETDEV_TX_BUSY;
 448 }
 449
 450 static void send_outstanding_bcast_packet(struct work_struct *work)
 451 {
 452         struct hard_iface *hard_iface;
 453         struct delayed_work *delayed_work =
 454                 container_of(work, struct delayed_work, work);
 455         struct forw_packet *forw_packet =
 456                 container_of(delayed_work, struct forw_packet, delayed_work);
 457         struct sk_buff *skb1;
 458         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 459         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 460
 461         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 462         hlist_del(&forw_packet->list);
 463         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 464
 465         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 466                 goto out;
 467
 468         /* rebroadcast packet */
 469         rcu_read_lock();
 470         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 471                 if (hard_iface->soft_iface != soft_iface)
 472                         continue;
 473
 474                 /* send a copy of the saved skb */
 475                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 476                 if (skb1)
 477                         send_skb_packet(skb1, hard_iface, broadcast_addr);
 478         }
 479         rcu_read_unlock();
 480
 481         forw_packet->num_packets++;
 482
 483         /* if we still have some more bcasts to send */
 484         if (forw_packet->num_packets < 3) {
 485                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 486                                           ((5 * HZ) / 1000));
 487                 return;
 488         }
 489
 490 out:
 491         forw_packet_free(forw_packet);
 492         atomic_inc(&bat_priv->bcast_queue_left);
 493 }
 494
 495 void send_outstanding_bat_packet(struct work_struct *work)
 496 {
 497         struct delayed_work *delayed_work =
 498                 container_of(work, struct delayed_work, work);
 499         struct forw_packet *forw_packet =
 500                 container_of(delayed_work, struct forw_packet, delayed_work);
 501         struct bat_priv *bat_priv;
 502
 503         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 504         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 505         hlist_del(&forw_packet->list);
 506         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 507
 508         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 509                 goto out;
 510
 511         send_packet(forw_packet);
 512
 513         /**
 514          * we have to have at least one packet in the queue
 515          * to determine the queues wake up time unless we are
 516          * shutting down
 517          */
 518         if (forw_packet->own)
 519                 schedule_own_packet(forw_packet->if_incoming);
 520
 521 out:
 522         /* don't count own packet */
 523         if (!forw_packet->own)
 524                 atomic_inc(&bat_priv->batman_queue_left);
 525
 526         forw_packet_free(forw_packet);
 527 }
 528
 529 void purge_outstanding_packets(struct bat_priv *bat_priv,
 530                                struct hard_iface *hard_iface)
 531 {
 532         struct forw_packet *forw_packet;
 533         struct hlist_node *tmp_node, *safe_tmp_node;
 534
 535         if (hard_iface)
 536                 bat_dbg(DBG_BATMAN, bat_priv,
 537                         "purge_outstanding_packets(): %s\n",
 538                         hard_iface->net_dev->name);
 539         else
 540                 bat_dbg(DBG_BATMAN, bat_priv,
 541                         "purge_outstanding_packets()\n");
 542
 543         /* free bcast list */
 544         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 545         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 546                                   &bat_priv->forw_bcast_list, list) {
 547
 548                 /**
 549                  * if purge_outstanding_packets() was called with an argmument
 550                  * we delete only packets belonging to the given interface
 551                  */
 552                 if ((hard_iface) &&
 553                     (forw_packet->if_incoming != hard_iface))
 554                         continue;
 555
 556                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 557
 558                 /**
 559                  * send_outstanding_bcast_packet() will lock the list to
 560                  * delete the item from the list
 561                  */
 562                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 563                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 564         }
 565         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 566
 567         /* free batman packet list */
 568         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 569         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 570                                   &bat_priv->forw_bat_list, list) {
 571
 572                 /**
 573                  * if purge_outstanding_packets() was called with an argmument
 574                  * we delete only packets belonging to the given interface
 575                  */
 576                 if ((hard_iface) &&
 577                     (forw_packet->if_incoming != hard_iface))
 578                         continue;
 579
 580                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 581
 582                 /**
 583                  * send_outstanding_bat_packet() will lock the list to
 584                  * delete the item from the list
 585                  */
 586                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 587                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 588         }
 589         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 590 }