drivers/staging/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2010 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 "types.h"
  29 #include "vis.h"
  30 #include "aggregation.h"
  31 #include "gateway_common.h"
  32 #include "originator.h"
  33
  34
  35 static void send_outstanding_bcast_packet(struct work_struct *work);
  36
  37 /* apply hop penalty for a normal link */
  38 static uint8_t hop_penalty(const uint8_t tq, struct bat_priv *bat_priv)
  39 {
  40         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
  41         return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
  42 }
  43
  44 /* when do we schedule our own packet to be sent */
  45 static unsigned long own_send_time(struct bat_priv *bat_priv)
  46 {
  47         return jiffies + msecs_to_jiffies(
  48                    atomic_read(&bat_priv->orig_interval) -
  49                    JITTER + (random32() % 2*JITTER));
  50 }
  51
  52 /* when do we schedule a forwarded packet to be sent */
  53 static unsigned long forward_send_time(struct bat_priv *bat_priv)
  54 {
  55         return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
  56 }
  57
  58 /* send out an already prepared packet to the given address via the
  59  * specified batman interface */
  60 int send_skb_packet(struct sk_buff *skb,
  61                                 struct batman_if *batman_if,
  62                                 uint8_t *dst_addr)
  63 {
  64         struct ethhdr *ethhdr;
  65
  66         if (batman_if->if_status != IF_ACTIVE)
  67                 goto send_skb_err;
  68
  69         if (unlikely(!batman_if->net_dev))
  70                 goto send_skb_err;
  71
  72         if (!(batman_if->net_dev->flags & IFF_UP)) {
  73                 pr_warning("Interface %s is not up - can't send packet via "
  74                            "that interface!\n", batman_if->net_dev->name);
  75                 goto send_skb_err;
  76         }
  77
  78         /* push to the ethernet header. */
  79         if (my_skb_head_push(skb, sizeof(struct ethhdr)) < 0)
  80                 goto send_skb_err;
  81
  82         skb_reset_mac_header(skb);
  83
  84         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  85         memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
  86         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  87         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  88
  89         skb_set_network_header(skb, ETH_HLEN);
  90         skb->priority = TC_PRIO_CONTROL;
  91         skb->protocol = __constant_htons(ETH_P_BATMAN);
  92
  93         skb->dev = batman_if->net_dev;
  94
  95         /* dev_queue_xmit() returns a negative result on error.  However on
  96          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  97          * (which is > 0). This will not be treated as an error. */
  98
  99         return dev_queue_xmit(skb);
 100 send_skb_err:
 101         kfree_skb(skb);
 102         return NET_XMIT_DROP;
 103 }
 104
 105 /* Send a packet to a given interface */
 106 static void send_packet_to_if(struct forw_packet *forw_packet,
 107                               struct batman_if *batman_if)
 108 {
 109         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 110         char *fwd_str;
 111         uint8_t packet_num;
 112         int16_t buff_pos;
 113         struct batman_packet *batman_packet;
 114         struct sk_buff *skb;
 115
 116         if (batman_if->if_status != IF_ACTIVE)
 117                 return;
 118
 119         packet_num = 0;
 120         buff_pos = 0;
 121         batman_packet = (struct batman_packet *)forw_packet->skb->data;
 122
 123         /* adjust all flags and log packets */
 124         while (aggregated_packet(buff_pos,
 125                                  forw_packet->packet_len,
 126                                  batman_packet->num_hna)) {
 127
 128                 /* we might have aggregated direct link packets with an
 129                  * ordinary base packet */
 130                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 131                     (forw_packet->if_incoming == batman_if))
 132                         batman_packet->flags |= DIRECTLINK;
 133                 else
 134                         batman_packet->flags &= ~DIRECTLINK;
 135
 136                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 137                                                             "Sending own" :
 138                                                             "Forwarding"));
 139                 bat_dbg(DBG_BATMAN, bat_priv,
 140                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 141                         " IDF %s) on interface %s [%pM]\n",
 142                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 143                         batman_packet->orig, ntohl(batman_packet->seqno),
 144                         batman_packet->tq, batman_packet->ttl,
 145                         (batman_packet->flags & DIRECTLINK ?
 146                          "on" : "off"),
 147                         batman_if->net_dev->name, batman_if->net_dev->dev_addr);
 148
 149                 buff_pos += sizeof(struct batman_packet) +
 150                         (batman_packet->num_hna * ETH_ALEN);
 151                 packet_num++;
 152                 batman_packet = (struct batman_packet *)
 153                         (forw_packet->skb->data + buff_pos);
 154         }
 155
 156         /* create clone because function is called more than once */
 157         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 158         if (skb)
 159                 send_skb_packet(skb, batman_if, broadcast_addr);
 160 }
 161
 162 /* send a batman packet */
 163 static void send_packet(struct forw_packet *forw_packet)
 164 {
 165         struct batman_if *batman_if;
 166         struct net_device *soft_iface;
 167         struct bat_priv *bat_priv;
 168         struct batman_packet *batman_packet =
 169                 (struct batman_packet *)(forw_packet->skb->data);
 170         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 171
 172         if (!forw_packet->if_incoming) {
 173                 pr_err("Error - can't forward packet: incoming iface not "
 174                        "specified\n");
 175                 return;
 176         }
 177
 178         soft_iface = forw_packet->if_incoming->soft_iface;
 179         bat_priv = netdev_priv(soft_iface);
 180
 181         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 182                 return;
 183
 184         /* multihomed peer assumed */
 185         /* non-primary OGMs are only broadcasted on their interface */
 186         if ((directlink && (batman_packet->ttl == 1)) ||
 187             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 188
 189                 /* FIXME: what about aggregated packets ? */
 190                 bat_dbg(DBG_BATMAN, bat_priv,
 191                         "%s packet (originator %pM, seqno %d, TTL %d) "
 192                         "on interface %s [%pM]\n",
 193                         (forw_packet->own ? "Sending own" : "Forwarding"),
 194                         batman_packet->orig, ntohl(batman_packet->seqno),
 195                         batman_packet->ttl,
 196                         forw_packet->if_incoming->net_dev->name,
 197                         forw_packet->if_incoming->net_dev->dev_addr);
 198
 199                 /* skb is only used once and than forw_packet is free'd */
 200                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 201                                 broadcast_addr);
 202                 forw_packet->skb = NULL;
 203
 204                 return;
 205         }
 206
 207         /* broadcast on every interface */
 208         rcu_read_lock();
 209         list_for_each_entry_rcu(batman_if, &if_list, list) {
 210                 if (batman_if->soft_iface != soft_iface)
 211                         continue;
 212
 213                 send_packet_to_if(forw_packet, batman_if);
 214         }
 215         rcu_read_unlock();
 216 }
 217
 218 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 219                                   struct batman_if *batman_if)
 220 {
 221         int new_len;
 222         unsigned char *new_buff;
 223         struct batman_packet *batman_packet;
 224
 225         new_len = sizeof(struct batman_packet) +
 226                         (bat_priv->num_local_hna * ETH_ALEN);
 227         new_buff = kmalloc(new_len, GFP_ATOMIC);
 228
 229         /* keep old buffer if kmalloc should fail */
 230         if (new_buff) {
 231                 memcpy(new_buff, batman_if->packet_buff,
 232                        sizeof(struct batman_packet));
 233                 batman_packet = (struct batman_packet *)new_buff;
 234
 235                 batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
 236                                 new_buff + sizeof(struct batman_packet),
 237                                 new_len - sizeof(struct batman_packet));
 238
 239                 kfree(batman_if->packet_buff);
 240                 batman_if->packet_buff = new_buff;
 241                 batman_if->packet_len = new_len;
 242         }
 243 }
 244
 245 void schedule_own_packet(struct batman_if *batman_if)
 246 {
 247         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 248         unsigned long send_time;
 249         struct batman_packet *batman_packet;
 250         int vis_server;
 251
 252         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 253             (batman_if->if_status == IF_TO_BE_REMOVED))
 254                 return;
 255
 256         vis_server = atomic_read(&bat_priv->vis_mode);
 257
 258         /**
 259          * the interface gets activated here to avoid race conditions between
 260          * the moment of activating the interface in
 261          * hardif_activate_interface() where the originator mac is set and
 262          * outdated packets (especially uninitialized mac addresses) in the
 263          * packet queue
 264          */
 265         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 266                 batman_if->if_status = IF_ACTIVE;
 267
 268         /* if local hna has changed and interface is a primary interface */
 269         if ((atomic_read(&bat_priv->hna_local_changed)) &&
 270             (batman_if == bat_priv->primary_if))
 271                 rebuild_batman_packet(bat_priv, batman_if);
 272
 273         /**
 274          * NOTE: packet_buff might just have been re-allocated in
 275          * rebuild_batman_packet()
 276          */
 277         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 278
 279         /* change sequence number to network order */
 280         batman_packet->seqno =
 281                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 282
 283         if (vis_server == VIS_TYPE_SERVER_SYNC)
 284                 batman_packet->flags |= VIS_SERVER;
 285         else
 286                 batman_packet->flags &= ~VIS_SERVER;
 287
 288         if ((batman_if == bat_priv->primary_if) &&
 289             (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
 290                 batman_packet->gw_flags =
 291                                 (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
 292         else
 293                 batman_packet->gw_flags = 0;
 294
 295         atomic_inc(&batman_if->seqno);
 296
 297         slide_own_bcast_window(batman_if);
 298         send_time = own_send_time(bat_priv);
 299         add_bat_packet_to_list(bat_priv,
 300                                batman_if->packet_buff,
 301                                batman_if->packet_len,
 302                                batman_if, 1, send_time);
 303 }
 304
 305 void schedule_forward_packet(struct orig_node *orig_node,
 306                              struct ethhdr *ethhdr,
 307                              struct batman_packet *batman_packet,
 308                              uint8_t directlink, int hna_buff_len,
 309                              struct batman_if *if_incoming)
 310 {
 311         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 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         in_tq = batman_packet->tq;
 321         in_ttl = batman_packet->ttl;
 322
 323         batman_packet->ttl--;
 324         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 325
 326         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 327          * of our best tq value */
 328         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 329
 330                 /* rebroadcast ogm of best ranking neighbor as is */
 331                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 332                         batman_packet->tq = orig_node->router->tq_avg;
 333
 334                         if (orig_node->router->last_ttl)
 335                                 batman_packet->ttl = orig_node->router->last_ttl
 336                                                         - 1;
 337                 }
 338
 339                 tq_avg = orig_node->router->tq_avg;
 340         }
 341
 342         /* apply hop penalty */
 343         batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
 344
 345         bat_dbg(DBG_BATMAN, bat_priv,
 346                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 347                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 348                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 349                 batman_packet->ttl);
 350
 351         batman_packet->seqno = htonl(batman_packet->seqno);
 352
 353         /* switch of primaries first hop flag when forwarding */
 354         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 355         if (directlink)
 356                 batman_packet->flags |= DIRECTLINK;
 357         else
 358                 batman_packet->flags &= ~DIRECTLINK;
 359
 360         send_time = forward_send_time(bat_priv);
 361         add_bat_packet_to_list(bat_priv,
 362                                (unsigned char *)batman_packet,
 363                                sizeof(struct batman_packet) + hna_buff_len,
 364                                if_incoming, 0, send_time);
 365 }
 366
 367 static void forw_packet_free(struct forw_packet *forw_packet)
 368 {
 369         if (forw_packet->skb)
 370                 kfree_skb(forw_packet->skb);
 371         kfree(forw_packet);
 372 }
 373
 374 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 375                                       struct forw_packet *forw_packet,
 376                                       unsigned long send_time)
 377 {
 378         INIT_HLIST_NODE(&forw_packet->list);
 379
 380         /* add new packet to packet list */
 381         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 382         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 383         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 384
 385         /* start timer for this packet */
 386         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 387                           send_outstanding_bcast_packet);
 388         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 389                            send_time);
 390 }
 391
 392 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 393 /* add a broadcast packet to the queue and setup timers. broadcast packets
 394  * are sent multiple times to increase probability for beeing received.
 395  *
 396  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 397  * errors.
 398  *
 399  * The skb is not consumed, so the caller should make sure that the
 400  * skb is freed. */
 401 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 402 {
 403         struct forw_packet *forw_packet;
 404         struct bcast_packet *bcast_packet;
 405
 406         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 407                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 408                 goto out;
 409         }
 410
 411         if (!bat_priv->primary_if)
 412                 goto out;
 413
 414         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 415
 416         if (!forw_packet)
 417                 goto out_and_inc;
 418
 419         skb = skb_copy(skb, GFP_ATOMIC);
 420         if (!skb)
 421                 goto packet_free;
 422
 423         /* as we have a copy now, it is safe to decrease the TTL */
 424         bcast_packet = (struct bcast_packet *)skb->data;
 425         bcast_packet->ttl--;
 426
 427         skb_reset_mac_header(skb);
 428
 429         forw_packet->skb = skb;
 430         forw_packet->if_incoming = bat_priv->primary_if;
 431
 432         /* how often did we send the bcast packet ? */
 433         forw_packet->num_packets = 0;
 434
 435         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 436         return NETDEV_TX_OK;
 437
 438 packet_free:
 439         kfree(forw_packet);
 440 out_and_inc:
 441         atomic_inc(&bat_priv->bcast_queue_left);
 442 out:
 443         return NETDEV_TX_BUSY;
 444 }
 445
 446 static void send_outstanding_bcast_packet(struct work_struct *work)
 447 {
 448         struct batman_if *batman_if;
 449         struct delayed_work *delayed_work =
 450                 container_of(work, struct delayed_work, work);
 451         struct forw_packet *forw_packet =
 452                 container_of(delayed_work, struct forw_packet, delayed_work);
 453         struct sk_buff *skb1;
 454         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 455         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 456
 457         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 458         hlist_del(&forw_packet->list);
 459         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 460
 461         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 462                 goto out;
 463
 464         /* rebroadcast packet */
 465         rcu_read_lock();
 466         list_for_each_entry_rcu(batman_if, &if_list, list) {
 467                 if (batman_if->soft_iface != soft_iface)
 468                         continue;
 469
 470                 /* send a copy of the saved skb */
 471                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 472                 if (skb1)
 473                         send_skb_packet(skb1, batman_if, broadcast_addr);
 474         }
 475         rcu_read_unlock();
 476
 477         forw_packet->num_packets++;
 478
 479         /* if we still have some more bcasts to send */
 480         if (forw_packet->num_packets < 3) {
 481                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 482                                           ((5 * HZ) / 1000));
 483                 return;
 484         }
 485
 486 out:
 487         forw_packet_free(forw_packet);
 488         atomic_inc(&bat_priv->bcast_queue_left);
 489 }
 490
 491 void send_outstanding_bat_packet(struct work_struct *work)
 492 {
 493         struct delayed_work *delayed_work =
 494                 container_of(work, struct delayed_work, work);
 495         struct forw_packet *forw_packet =
 496                 container_of(delayed_work, struct forw_packet, delayed_work);
 497         struct bat_priv *bat_priv;
 498
 499         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 500         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 501         hlist_del(&forw_packet->list);
 502         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 503
 504         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 505                 goto out;
 506
 507         send_packet(forw_packet);
 508
 509         /**
 510          * we have to have at least one packet in the queue
 511          * to determine the queues wake up time unless we are
 512          * shutting down
 513          */
 514         if (forw_packet->own)
 515                 schedule_own_packet(forw_packet->if_incoming);
 516
 517 out:
 518         /* don't count own packet */
 519         if (!forw_packet->own)
 520                 atomic_inc(&bat_priv->batman_queue_left);
 521
 522         forw_packet_free(forw_packet);
 523 }
 524
 525 void purge_outstanding_packets(struct bat_priv *bat_priv,
 526                                struct batman_if *batman_if)
 527 {
 528         struct forw_packet *forw_packet;
 529         struct hlist_node *tmp_node, *safe_tmp_node;
 530
 531         if (batman_if)
 532                 bat_dbg(DBG_BATMAN, bat_priv,
 533                         "purge_outstanding_packets(): %s\n",
 534                         batman_if->net_dev->name);
 535         else
 536                 bat_dbg(DBG_BATMAN, bat_priv,
 537                         "purge_outstanding_packets()\n");
 538
 539         /* free bcast list */
 540         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 541         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 542                                   &bat_priv->forw_bcast_list, list) {
 543
 544                 /**
 545                  * if purge_outstanding_packets() was called with an argmument
 546                  * we delete only packets belonging to the given interface
 547                  */
 548                 if ((batman_if) &&
 549                     (forw_packet->if_incoming != batman_if))
 550                         continue;
 551
 552                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 553
 554                 /**
 555                  * send_outstanding_bcast_packet() will lock the list to
 556                  * delete the item from the list
 557                  */
 558                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 559                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 560         }
 561         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 562
 563         /* free batman packet list */
 564         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 565         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 566                                   &bat_priv->forw_bat_list, list) {
 567
 568                 /**
 569                  * if purge_outstanding_packets() was called with an argmument
 570                  * we delete only packets belonging to the given interface
 571                  */
 572                 if ((batman_if) &&
 573                     (forw_packet->if_incoming != batman_if))
 574                         continue;
 575
 576                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 577
 578                 /**
 579                  * send_outstanding_bat_packet() will lock the list to
 580                  * delete the item from the list
 581                  */
 582                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 583                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 584         }
 585         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 586 }