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         unsigned char in_tq, in_ttl, tq_avg = 0;
 312         unsigned long send_time;
 313
 314         if (batman_packet->ttl <= 1) {
 315                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 316                 return;
 317         }
 318
 319         in_tq = batman_packet->tq;
 320         in_ttl = batman_packet->ttl;
 321
 322         batman_packet->ttl--;
 323         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 324
 325         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 326          * of our best tq value */
 327         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 328
 329                 /* rebroadcast ogm of best ranking neighbor as is */
 330                 if (!compare_eth(orig_node->router->addr, ethhdr->h_source)) {
 331                         batman_packet->tq = orig_node->router->tq_avg;
 332
 333                         if (orig_node->router->last_ttl)
 334                                 batman_packet->ttl = orig_node->router->last_ttl
 335                                                         - 1;
 336                 }
 337
 338                 tq_avg = orig_node->router->tq_avg;
 339         }
 340
 341         /* apply hop penalty */
 342         batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
 343
 344         bat_dbg(DBG_BATMAN, bat_priv,
 345                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 346                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 347                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 348                 batman_packet->ttl);
 349
 350         batman_packet->seqno = htonl(batman_packet->seqno);
 351
 352         /* switch of primaries first hop flag when forwarding */
 353         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 354         if (directlink)
 355                 batman_packet->flags |= DIRECTLINK;
 356         else
 357                 batman_packet->flags &= ~DIRECTLINK;
 358
 359         send_time = forward_send_time();
 360         add_bat_packet_to_list(bat_priv,
 361                                (unsigned char *)batman_packet,
 362                                sizeof(struct batman_packet) + hna_buff_len,
 363                                if_incoming, 0, send_time);
 364 }
 365
 366 static void forw_packet_free(struct forw_packet *forw_packet)
 367 {
 368         if (forw_packet->skb)
 369                 kfree_skb(forw_packet->skb);
 370         kfree(forw_packet);
 371 }
 372
 373 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 374                                       struct forw_packet *forw_packet,
 375                                       unsigned long send_time)
 376 {
 377         INIT_HLIST_NODE(&forw_packet->list);
 378
 379         /* add new packet to packet list */
 380         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 381         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 382         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 383
 384         /* start timer for this packet */
 385         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 386                           send_outstanding_bcast_packet);
 387         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 388                            send_time);
 389 }
 390
 391 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 392 /* add a broadcast packet to the queue and setup timers. broadcast packets
 393  * are sent multiple times to increase probability for beeing received.
 394  *
 395  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 396  * errors.
 397  *
 398  * The skb is not consumed, so the caller should make sure that the
 399  * skb is freed. */
 400 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 401 {
 402         struct forw_packet *forw_packet;
 403         struct bcast_packet *bcast_packet;
 404
 405         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 406                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 407                 goto out;
 408         }
 409
 410         if (!bat_priv->primary_if)
 411                 goto out;
 412
 413         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 414
 415         if (!forw_packet)
 416                 goto out_and_inc;
 417
 418         skb = skb_copy(skb, GFP_ATOMIC);
 419         if (!skb)
 420                 goto packet_free;
 421
 422         /* as we have a copy now, it is safe to decrease the TTL */
 423         bcast_packet = (struct bcast_packet *)skb->data;
 424         bcast_packet->ttl--;
 425
 426         skb_reset_mac_header(skb);
 427
 428         forw_packet->skb = skb;
 429         forw_packet->if_incoming = bat_priv->primary_if;
 430
 431         /* how often did we send the bcast packet ? */
 432         forw_packet->num_packets = 0;
 433
 434         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 435         return NETDEV_TX_OK;
 436
 437 packet_free:
 438         kfree(forw_packet);
 439 out_and_inc:
 440         atomic_inc(&bat_priv->bcast_queue_left);
 441 out:
 442         return NETDEV_TX_BUSY;
 443 }
 444
 445 static void send_outstanding_bcast_packet(struct work_struct *work)
 446 {
 447         struct hard_iface *hard_iface;
 448         struct delayed_work *delayed_work =
 449                 container_of(work, struct delayed_work, work);
 450         struct forw_packet *forw_packet =
 451                 container_of(delayed_work, struct forw_packet, delayed_work);
 452         struct sk_buff *skb1;
 453         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 454         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 455
 456         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 457         hlist_del(&forw_packet->list);
 458         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 459
 460         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 461                 goto out;
 462
 463         /* rebroadcast packet */
 464         rcu_read_lock();
 465         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 466                 if (hard_iface->soft_iface != soft_iface)
 467                         continue;
 468
 469                 /* send a copy of the saved skb */
 470                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 471                 if (skb1)
 472                         send_skb_packet(skb1, hard_iface, broadcast_addr);
 473         }
 474         rcu_read_unlock();
 475
 476         forw_packet->num_packets++;
 477
 478         /* if we still have some more bcasts to send */
 479         if (forw_packet->num_packets < 3) {
 480                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 481                                           ((5 * HZ) / 1000));
 482                 return;
 483         }
 484
 485 out:
 486         forw_packet_free(forw_packet);
 487         atomic_inc(&bat_priv->bcast_queue_left);
 488 }
 489
 490 void send_outstanding_bat_packet(struct work_struct *work)
 491 {
 492         struct delayed_work *delayed_work =
 493                 container_of(work, struct delayed_work, work);
 494         struct forw_packet *forw_packet =
 495                 container_of(delayed_work, struct forw_packet, delayed_work);
 496         struct bat_priv *bat_priv;
 497
 498         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 499         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 500         hlist_del(&forw_packet->list);
 501         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 502
 503         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 504                 goto out;
 505
 506         send_packet(forw_packet);
 507
 508         /**
 509          * we have to have at least one packet in the queue
 510          * to determine the queues wake up time unless we are
 511          * shutting down
 512          */
 513         if (forw_packet->own)
 514                 schedule_own_packet(forw_packet->if_incoming);
 515
 516 out:
 517         /* don't count own packet */
 518         if (!forw_packet->own)
 519                 atomic_inc(&bat_priv->batman_queue_left);
 520
 521         forw_packet_free(forw_packet);
 522 }
 523
 524 void purge_outstanding_packets(struct bat_priv *bat_priv,
 525                                struct hard_iface *hard_iface)
 526 {
 527         struct forw_packet *forw_packet;
 528         struct hlist_node *tmp_node, *safe_tmp_node;
 529
 530         if (hard_iface)
 531                 bat_dbg(DBG_BATMAN, bat_priv,
 532                         "purge_outstanding_packets(): %s\n",
 533                         hard_iface->net_dev->name);
 534         else
 535                 bat_dbg(DBG_BATMAN, bat_priv,
 536                         "purge_outstanding_packets()\n");
 537
 538         /* free bcast list */
 539         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 540         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 541                                   &bat_priv->forw_bcast_list, list) {
 542
 543                 /**
 544                  * if purge_outstanding_packets() was called with an argmument
 545                  * we delete only packets belonging to the given interface
 546                  */
 547                 if ((hard_iface) &&
 548                     (forw_packet->if_incoming != hard_iface))
 549                         continue;
 550
 551                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 552
 553                 /**
 554                  * send_outstanding_bcast_packet() will lock the list to
 555                  * delete the item from the list
 556                  */
 557                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 558                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 559         }
 560         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 561
 562         /* free batman packet list */
 563         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 564         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 565                                   &bat_priv->forw_bat_list, list) {
 566
 567                 /**
 568                  * if purge_outstanding_packets() was called with an argmument
 569                  * we delete only packets belonging to the given interface
 570                  */
 571                 if ((hard_iface) &&
 572                     (forw_packet->if_incoming != hard_iface))
 573                         continue;
 574
 575                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 576
 577                 /**
 578                  * send_outstanding_bat_packet() will lock the list to
 579                  * delete the item from the list
 580                  */
 581                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 582                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 583         }
 584         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 585 }