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(uint8_t tq, const 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(const 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, struct hard_iface *hard_iface,
  59                     const uint8_t *dst_addr)
  60 {
  61         struct ethhdr *ethhdr;
  62
  63         if (hard_iface->if_status != IF_ACTIVE)
  64                 goto send_skb_err;
  65
  66         if (unlikely(!hard_iface->net_dev))
  67                 goto send_skb_err;
  68
  69         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  70                 pr_warning("Interface %s is not up - can't send packet via "
  71                            "that interface!\n", hard_iface->net_dev->name);
  72                 goto send_skb_err;
  73         }
  74
  75         /* push to the ethernet header. */
  76         if (my_skb_head_push(skb, sizeof(*ethhdr)) < 0)
  77                 goto send_skb_err;
  78
  79         skb_reset_mac_header(skb);
  80
  81         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  82         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  83         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  84         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  85
  86         skb_set_network_header(skb, ETH_HLEN);
  87         skb->priority = TC_PRIO_CONTROL;
  88         skb->protocol = __constant_htons(ETH_P_BATMAN);
  89
  90         skb->dev = hard_iface->net_dev;
  91
  92         /* dev_queue_xmit() returns a negative result on error.  However on
  93          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  94          * (which is > 0). This will not be treated as an error. */
  95
  96         return dev_queue_xmit(skb);
  97 send_skb_err:
  98         kfree_skb(skb);
  99         return NET_XMIT_DROP;
 100 }
 101
 102 /* Send a packet to a given interface */
 103 static void send_packet_to_if(struct forw_packet *forw_packet,
 104                               struct hard_iface *hard_iface)
 105 {
 106         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 107         char *fwd_str;
 108         uint8_t packet_num;
 109         int16_t buff_pos;
 110         struct batman_packet *batman_packet;
 111         struct sk_buff *skb;
 112
 113         if (hard_iface->if_status != IF_ACTIVE)
 114                 return;
 115
 116         packet_num = 0;
 117         buff_pos = 0;
 118         batman_packet = (struct batman_packet *)forw_packet->skb->data;
 119
 120         /* adjust all flags and log packets */
 121         while (aggregated_packet(buff_pos,
 122                                  forw_packet->packet_len,
 123                                  batman_packet->num_tt)) {
 124
 125                 /* we might have aggregated direct link packets with an
 126                  * ordinary base packet */
 127                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 128                     (forw_packet->if_incoming == hard_iface))
 129                         batman_packet->flags |= DIRECTLINK;
 130                 else
 131                         batman_packet->flags &= ~DIRECTLINK;
 132
 133                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 134                                                             "Sending own" :
 135                                                             "Forwarding"));
 136                 bat_dbg(DBG_BATMAN, bat_priv,
 137                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 138                         " IDF %s) on interface %s [%pM]\n",
 139                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 140                         batman_packet->orig, ntohl(batman_packet->seqno),
 141                         batman_packet->tq, batman_packet->ttl,
 142                         (batman_packet->flags & DIRECTLINK ?
 143                          "on" : "off"),
 144                         hard_iface->net_dev->name,
 145                         hard_iface->net_dev->dev_addr);
 146
 147                 buff_pos += sizeof(*batman_packet) +
 148                         (batman_packet->num_tt * ETH_ALEN);
 149                 packet_num++;
 150                 batman_packet = (struct batman_packet *)
 151                         (forw_packet->skb->data + buff_pos);
 152         }
 153
 154         /* create clone because function is called more than once */
 155         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 156         if (skb)
 157                 send_skb_packet(skb, hard_iface, broadcast_addr);
 158 }
 159
 160 /* send a batman packet */
 161 static void send_packet(struct forw_packet *forw_packet)
 162 {
 163         struct hard_iface *hard_iface;
 164         struct net_device *soft_iface;
 165         struct bat_priv *bat_priv;
 166         struct batman_packet *batman_packet =
 167                 (struct batman_packet *)(forw_packet->skb->data);
 168         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 169
 170         if (!forw_packet->if_incoming) {
 171                 pr_err("Error - can't forward packet: incoming iface not "
 172                        "specified\n");
 173                 return;
 174         }
 175
 176         soft_iface = forw_packet->if_incoming->soft_iface;
 177         bat_priv = netdev_priv(soft_iface);
 178
 179         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 180                 return;
 181
 182         /* multihomed peer assumed */
 183         /* non-primary OGMs are only broadcasted on their interface */
 184         if ((directlink && (batman_packet->ttl == 1)) ||
 185             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 186
 187                 /* FIXME: what about aggregated packets ? */
 188                 bat_dbg(DBG_BATMAN, bat_priv,
 189                         "%s packet (originator %pM, seqno %d, TTL %d) "
 190                         "on interface %s [%pM]\n",
 191                         (forw_packet->own ? "Sending own" : "Forwarding"),
 192                         batman_packet->orig, ntohl(batman_packet->seqno),
 193                         batman_packet->ttl,
 194                         forw_packet->if_incoming->net_dev->name,
 195                         forw_packet->if_incoming->net_dev->dev_addr);
 196
 197                 /* skb is only used once and than forw_packet is free'd */
 198                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 199                                 broadcast_addr);
 200                 forw_packet->skb = NULL;
 201
 202                 return;
 203         }
 204
 205         /* broadcast on every interface */
 206         rcu_read_lock();
 207         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 208                 if (hard_iface->soft_iface != soft_iface)
 209                         continue;
 210
 211                 send_packet_to_if(forw_packet, hard_iface);
 212         }
 213         rcu_read_unlock();
 214 }
 215
 216 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 217                                   struct hard_iface *hard_iface)
 218 {
 219         int new_len;
 220         unsigned char *new_buff;
 221         struct batman_packet *batman_packet;
 222
 223         new_len = sizeof(*batman_packet) + (bat_priv->num_local_tt * ETH_ALEN);
 224         new_buff = kmalloc(new_len, GFP_ATOMIC);
 225
 226         /* keep old buffer if kmalloc should fail */
 227         if (new_buff) {
 228                 memcpy(new_buff, hard_iface->packet_buff,
 229                        sizeof(*batman_packet));
 230                 batman_packet = (struct batman_packet *)new_buff;
 231
 232                 batman_packet->num_tt = tt_local_fill_buffer(bat_priv,
 233                                         new_buff + sizeof(*batman_packet),
 234                                         new_len - sizeof(*batman_packet));
 235
 236                 kfree(hard_iface->packet_buff);
 237                 hard_iface->packet_buff = new_buff;
 238                 hard_iface->packet_len = new_len;
 239         }
 240 }
 241
 242 void schedule_own_packet(struct hard_iface *hard_iface)
 243 {
 244         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 245         struct hard_iface *primary_if;
 246         unsigned long send_time;
 247         struct batman_packet *batman_packet;
 248         int vis_server;
 249
 250         if ((hard_iface->if_status == IF_NOT_IN_USE) ||
 251             (hard_iface->if_status == IF_TO_BE_REMOVED))
 252                 return;
 253
 254         vis_server = atomic_read(&bat_priv->vis_mode);
 255         primary_if = primary_if_get_selected(bat_priv);
 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 tt has changed and interface is a primary interface */
 268         if ((atomic_read(&bat_priv->tt_local_changed)) &&
 269             (hard_iface == 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 == 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 = NO_FLAGS;
 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         if (primary_if)
 304                 hardif_free_ref(primary_if);
 305 }
 306
 307 void schedule_forward_packet(struct orig_node *orig_node,
 308                              const struct ethhdr *ethhdr,
 309                              struct batman_packet *batman_packet,
 310                              uint8_t directlink, int tt_buff_len,
 311                              struct hard_iface *if_incoming)
 312 {
 313         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 314         struct neigh_node *router;
 315         unsigned char in_tq, in_ttl, tq_avg = 0;
 316         unsigned long send_time;
 317
 318         if (batman_packet->ttl <= 1) {
 319                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 320                 return;
 321         }
 322
 323         router = orig_node_get_router(orig_node);
 324
 325         in_tq = batman_packet->tq;
 326         in_ttl = batman_packet->ttl;
 327
 328         batman_packet->ttl--;
 329         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 330
 331         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 332          * of our best tq value */
 333         if (router && router->tq_avg != 0) {
 334
 335                 /* rebroadcast ogm of best ranking neighbor as is */
 336                 if (!compare_eth(router->addr, ethhdr->h_source)) {
 337                         batman_packet->tq = router->tq_avg;
 338
 339                         if (router->last_ttl)
 340                                 batman_packet->ttl = router->last_ttl - 1;
 341                 }
 342
 343                 tq_avg = router->tq_avg;
 344         }
 345
 346         if (router)
 347                 neigh_node_free_ref(router);
 348
 349         /* apply hop penalty */
 350         batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
 351
 352         bat_dbg(DBG_BATMAN, bat_priv,
 353                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 354                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 355                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 356                 batman_packet->ttl);
 357
 358         batman_packet->seqno = htonl(batman_packet->seqno);
 359
 360         /* switch of primaries first hop flag when forwarding */
 361         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 362         if (directlink)
 363                 batman_packet->flags |= DIRECTLINK;
 364         else
 365                 batman_packet->flags &= ~DIRECTLINK;
 366
 367         send_time = forward_send_time();
 368         add_bat_packet_to_list(bat_priv,
 369                                (unsigned char *)batman_packet,
 370                                sizeof(*batman_packet) + tt_buff_len,
 371                                if_incoming, 0, send_time);
 372 }
 373
 374 static void forw_packet_free(struct forw_packet *forw_packet)
 375 {
 376         if (forw_packet->skb)
 377                 kfree_skb(forw_packet->skb);
 378         if (forw_packet->if_incoming)
 379                 hardif_free_ref(forw_packet->if_incoming);
 380         kfree(forw_packet);
 381 }
 382
 383 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 384                                       struct forw_packet *forw_packet,
 385                                       unsigned long send_time)
 386 {
 387         INIT_HLIST_NODE(&forw_packet->list);
 388
 389         /* add new packet to packet list */
 390         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 391         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 392         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 393
 394         /* start timer for this packet */
 395         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 396                           send_outstanding_bcast_packet);
 397         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 398                            send_time);
 399 }
 400
 401 /* add a broadcast packet to the queue and setup timers. broadcast packets
 402  * are sent multiple times to increase probability for beeing received.
 403  *
 404  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 405  * errors.
 406  *
 407  * The skb is not consumed, so the caller should make sure that the
 408  * skb is freed. */
 409 int add_bcast_packet_to_list(struct bat_priv *bat_priv,
 410                              const struct sk_buff *skb)
 411 {
 412         struct hard_iface *primary_if = NULL;
 413         struct forw_packet *forw_packet;
 414         struct bcast_packet *bcast_packet;
 415         struct sk_buff *newskb;
 416
 417         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 418                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 419                 goto out;
 420         }
 421
 422         primary_if = primary_if_get_selected(bat_priv);
 423         if (!primary_if)
 424                 goto out_and_inc;
 425
 426         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 427
 428         if (!forw_packet)
 429                 goto out_and_inc;
 430
 431         newskb = skb_copy(skb, GFP_ATOMIC);
 432         if (!newskb)
 433                 goto packet_free;
 434
 435         /* as we have a copy now, it is safe to decrease the TTL */
 436         bcast_packet = (struct bcast_packet *)newskb->data;
 437         bcast_packet->ttl--;
 438
 439         skb_reset_mac_header(newskb);
 440
 441         forw_packet->skb = newskb;
 442         forw_packet->if_incoming = primary_if;
 443
 444         /* how often did we send the bcast packet ? */
 445         forw_packet->num_packets = 0;
 446
 447         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 448         return NETDEV_TX_OK;
 449
 450 packet_free:
 451         kfree(forw_packet);
 452 out_and_inc:
 453         atomic_inc(&bat_priv->bcast_queue_left);
 454 out:
 455         if (primary_if)
 456                 hardif_free_ref(primary_if);
 457         return NETDEV_TX_BUSY;
 458 }
 459
 460 static void send_outstanding_bcast_packet(struct work_struct *work)
 461 {
 462         struct hard_iface *hard_iface;
 463         struct delayed_work *delayed_work =
 464                 container_of(work, struct delayed_work, work);
 465         struct forw_packet *forw_packet =
 466                 container_of(delayed_work, struct forw_packet, delayed_work);
 467         struct sk_buff *skb1;
 468         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 469         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 470
 471         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 472         hlist_del(&forw_packet->list);
 473         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 474
 475         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 476                 goto out;
 477
 478         /* rebroadcast packet */
 479         rcu_read_lock();
 480         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 481                 if (hard_iface->soft_iface != soft_iface)
 482                         continue;
 483
 484                 /* send a copy of the saved skb */
 485                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 486                 if (skb1)
 487                         send_skb_packet(skb1, hard_iface, broadcast_addr);
 488         }
 489         rcu_read_unlock();
 490
 491         forw_packet->num_packets++;
 492
 493         /* if we still have some more bcasts to send */
 494         if (forw_packet->num_packets < 3) {
 495                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 496                                           ((5 * HZ) / 1000));
 497                 return;
 498         }
 499
 500 out:
 501         forw_packet_free(forw_packet);
 502         atomic_inc(&bat_priv->bcast_queue_left);
 503 }
 504
 505 void send_outstanding_bat_packet(struct work_struct *work)
 506 {
 507         struct delayed_work *delayed_work =
 508                 container_of(work, struct delayed_work, work);
 509         struct forw_packet *forw_packet =
 510                 container_of(delayed_work, struct forw_packet, delayed_work);
 511         struct bat_priv *bat_priv;
 512
 513         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 514         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 515         hlist_del(&forw_packet->list);
 516         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 517
 518         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 519                 goto out;
 520
 521         send_packet(forw_packet);
 522
 523         /**
 524          * we have to have at least one packet in the queue
 525          * to determine the queues wake up time unless we are
 526          * shutting down
 527          */
 528         if (forw_packet->own)
 529                 schedule_own_packet(forw_packet->if_incoming);
 530
 531 out:
 532         /* don't count own packet */
 533         if (!forw_packet->own)
 534                 atomic_inc(&bat_priv->batman_queue_left);
 535
 536         forw_packet_free(forw_packet);
 537 }
 538
 539 void purge_outstanding_packets(struct bat_priv *bat_priv,
 540                                const struct hard_iface *hard_iface)
 541 {
 542         struct forw_packet *forw_packet;
 543         struct hlist_node *tmp_node, *safe_tmp_node;
 544         bool pending;
 545
 546         if (hard_iface)
 547                 bat_dbg(DBG_BATMAN, bat_priv,
 548                         "purge_outstanding_packets(): %s\n",
 549                         hard_iface->net_dev->name);
 550         else
 551                 bat_dbg(DBG_BATMAN, bat_priv,
 552                         "purge_outstanding_packets()\n");
 553
 554         /* free bcast list */
 555         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 556         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 557                                   &bat_priv->forw_bcast_list, list) {
 558
 559                 /**
 560                  * if purge_outstanding_packets() was called with an argmument
 561                  * we delete only packets belonging to the given interface
 562                  */
 563                 if ((hard_iface) &&
 564                     (forw_packet->if_incoming != hard_iface))
 565                         continue;
 566
 567                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 568
 569                 /**
 570                  * send_outstanding_bcast_packet() will lock the list to
 571                  * delete the item from the list
 572                  */
 573                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 574                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 575
 576                 if (pending) {
 577                         hlist_del(&forw_packet->list);
 578                         forw_packet_free(forw_packet);
 579                 }
 580         }
 581         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 582
 583         /* free batman packet list */
 584         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 585         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 586                                   &bat_priv->forw_bat_list, list) {
 587
 588                 /**
 589                  * if purge_outstanding_packets() was called with an argmument
 590                  * we delete only packets belonging to the given interface
 591                  */
 592                 if ((hard_iface) &&
 593                     (forw_packet->if_incoming != hard_iface))
 594                         continue;
 595
 596                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 597
 598                 /**
 599                  * send_outstanding_bat_packet() will lock the list to
 600                  * delete the item from the list
 601                  */
 602                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 603                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 604
 605                 if (pending) {
 606                         hlist_del(&forw_packet->list);
 607                         forw_packet_free(forw_packet);
 608                 }
 609         }
 610         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 611 }