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
  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)
  37 {
  38         return (tq * (TQ_MAX_VALUE - TQ_HOP_PENALTY)) / (TQ_MAX_VALUE);
  39 }
  40
  41 /* when do we schedule our own packet to be sent */
  42 static unsigned long own_send_time(struct bat_priv *bat_priv)
  43 {
  44         return jiffies + msecs_to_jiffies(
  45                    atomic_read(&bat_priv->orig_interval) -
  46                    JITTER + (random32() % 2*JITTER));
  47 }
  48
  49 /* when do we schedule a forwarded packet to be sent */
  50 static unsigned long forward_send_time(struct bat_priv *bat_priv)
  51 {
  52         return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
  53 }
  54
  55 /* send out an already prepared packet to the given address via the
  56  * specified batman interface */
  57 int send_skb_packet(struct sk_buff *skb,
  58                                 struct batman_if *batman_if,
  59                                 uint8_t *dst_addr)
  60 {
  61         struct ethhdr *ethhdr;
  62
  63         if (batman_if->if_status != IF_ACTIVE)
  64                 goto send_skb_err;
  65
  66         if (unlikely(!batman_if->net_dev))
  67                 goto send_skb_err;
  68
  69         if (!(batman_if->net_dev->flags & IFF_UP)) {
  70                 pr_warning("Interface %s is not up - can't send packet via "
  71                            "that interface!\n", batman_if->net_dev->name);
  72                 goto send_skb_err;
  73         }
  74
  75         /* push to the ethernet header. */
  76         if (my_skb_head_push(skb, sizeof(struct 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, batman_if->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 = batman_if->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 batman_if *batman_if)
 105 {
 106         struct bat_priv *bat_priv = netdev_priv(batman_if->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 (batman_if->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_hna)) {
 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 == batman_if))
 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                         batman_if->net_dev->name, batman_if->net_dev->dev_addr);
 145
 146                 buff_pos += sizeof(struct batman_packet) +
 147                         (batman_packet->num_hna * ETH_ALEN);
 148                 packet_num++;
 149                 batman_packet = (struct batman_packet *)
 150                         (forw_packet->skb->data + buff_pos);
 151         }
 152
 153         /* create clone because function is called more than once */
 154         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 155         if (skb)
 156                 send_skb_packet(skb, batman_if, broadcast_addr);
 157 }
 158
 159 /* send a batman packet */
 160 static void send_packet(struct forw_packet *forw_packet)
 161 {
 162         struct batman_if *batman_if;
 163         struct net_device *soft_iface;
 164         struct bat_priv *bat_priv;
 165         struct batman_packet *batman_packet =
 166                 (struct batman_packet *)(forw_packet->skb->data);
 167         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 168
 169         if (!forw_packet->if_incoming) {
 170                 pr_err("Error - can't forward packet: incoming iface not "
 171                        "specified\n");
 172                 return;
 173         }
 174
 175         soft_iface = forw_packet->if_incoming->soft_iface;
 176         bat_priv = netdev_priv(soft_iface);
 177
 178         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 179                 return;
 180
 181         /* multihomed peer assumed */
 182         /* non-primary OGMs are only broadcasted on their interface */
 183         if ((directlink && (batman_packet->ttl == 1)) ||
 184             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 185
 186                 /* FIXME: what about aggregated packets ? */
 187                 bat_dbg(DBG_BATMAN, bat_priv,
 188                         "%s packet (originator %pM, seqno %d, TTL %d) "
 189                         "on interface %s [%pM]\n",
 190                         (forw_packet->own ? "Sending own" : "Forwarding"),
 191                         batman_packet->orig, ntohl(batman_packet->seqno),
 192                         batman_packet->ttl,
 193                         forw_packet->if_incoming->net_dev->name,
 194                         forw_packet->if_incoming->net_dev->dev_addr);
 195
 196                 /* skb is only used once and than forw_packet is free'd */
 197                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 198                                 broadcast_addr);
 199                 forw_packet->skb = NULL;
 200
 201                 return;
 202         }
 203
 204         /* broadcast on every interface */
 205         rcu_read_lock();
 206         list_for_each_entry_rcu(batman_if, &if_list, list) {
 207                 if (batman_if->soft_iface != soft_iface)
 208                         continue;
 209
 210                 send_packet_to_if(forw_packet, batman_if);
 211         }
 212         rcu_read_unlock();
 213 }
 214
 215 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 216                                   struct batman_if *batman_if)
 217 {
 218         int new_len;
 219         unsigned char *new_buff;
 220         struct batman_packet *batman_packet;
 221
 222         new_len = sizeof(struct batman_packet) +
 223                         (bat_priv->num_local_hna * 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, batman_if->packet_buff,
 229                        sizeof(struct batman_packet));
 230                 batman_packet = (struct batman_packet *)new_buff;
 231
 232                 batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
 233                                 new_buff + sizeof(struct batman_packet),
 234                                 new_len - sizeof(struct batman_packet));
 235
 236                 kfree(batman_if->packet_buff);
 237                 batman_if->packet_buff = new_buff;
 238                 batman_if->packet_len = new_len;
 239         }
 240 }
 241
 242 void schedule_own_packet(struct batman_if *batman_if)
 243 {
 244         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 245         unsigned long send_time;
 246         struct batman_packet *batman_packet;
 247         int vis_server;
 248
 249         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 250             (batman_if->if_status == IF_TO_BE_REMOVED))
 251                 return;
 252
 253         vis_server = atomic_read(&bat_priv->vis_mode);
 254
 255         /**
 256          * the interface gets activated here to avoid race conditions between
 257          * the moment of activating the interface in
 258          * hardif_activate_interface() where the originator mac is set and
 259          * outdated packets (especially uninitialized mac addresses) in the
 260          * packet queue
 261          */
 262         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 263                 batman_if->if_status = IF_ACTIVE;
 264
 265         /* if local hna has changed and interface is a primary interface */
 266         if ((atomic_read(&bat_priv->hna_local_changed)) &&
 267             (batman_if == bat_priv->primary_if))
 268                 rebuild_batman_packet(bat_priv, batman_if);
 269
 270         /**
 271          * NOTE: packet_buff might just have been re-allocated in
 272          * rebuild_batman_packet()
 273          */
 274         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 275
 276         /* change sequence number to network order */
 277         batman_packet->seqno =
 278                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 279
 280         if (vis_server == VIS_TYPE_SERVER_SYNC)
 281                 batman_packet->flags |= VIS_SERVER;
 282         else
 283                 batman_packet->flags &= ~VIS_SERVER;
 284
 285         atomic_inc(&batman_if->seqno);
 286
 287         slide_own_bcast_window(batman_if);
 288         send_time = own_send_time(bat_priv);
 289         add_bat_packet_to_list(bat_priv,
 290                                batman_if->packet_buff,
 291                                batman_if->packet_len,
 292                                batman_if, 1, send_time);
 293 }
 294
 295 void schedule_forward_packet(struct orig_node *orig_node,
 296                              struct ethhdr *ethhdr,
 297                              struct batman_packet *batman_packet,
 298                              uint8_t directlink, int hna_buff_len,
 299                              struct batman_if *if_incoming)
 300 {
 301         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 302         unsigned char in_tq, in_ttl, tq_avg = 0;
 303         unsigned long send_time;
 304
 305         if (batman_packet->ttl <= 1) {
 306                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 307                 return;
 308         }
 309
 310         in_tq = batman_packet->tq;
 311         in_ttl = batman_packet->ttl;
 312
 313         batman_packet->ttl--;
 314         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 315
 316         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 317          * of our best tq value */
 318         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 319
 320                 /* rebroadcast ogm of best ranking neighbor as is */
 321                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 322                         batman_packet->tq = orig_node->router->tq_avg;
 323
 324                         if (orig_node->router->last_ttl)
 325                                 batman_packet->ttl = orig_node->router->last_ttl
 326                                                         - 1;
 327                 }
 328
 329                 tq_avg = orig_node->router->tq_avg;
 330         }
 331
 332         /* apply hop penalty */
 333         batman_packet->tq = hop_penalty(batman_packet->tq);
 334
 335         bat_dbg(DBG_BATMAN, bat_priv,
 336                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 337                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 338                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 339                 batman_packet->ttl);
 340
 341         batman_packet->seqno = htonl(batman_packet->seqno);
 342
 343         /* switch of primaries first hop flag when forwarding */
 344         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 345         if (directlink)
 346                 batman_packet->flags |= DIRECTLINK;
 347         else
 348                 batman_packet->flags &= ~DIRECTLINK;
 349
 350         send_time = forward_send_time(bat_priv);
 351         add_bat_packet_to_list(bat_priv,
 352                                (unsigned char *)batman_packet,
 353                                sizeof(struct batman_packet) + hna_buff_len,
 354                                if_incoming, 0, send_time);
 355 }
 356
 357 static void forw_packet_free(struct forw_packet *forw_packet)
 358 {
 359         if (forw_packet->skb)
 360                 kfree_skb(forw_packet->skb);
 361         kfree(forw_packet);
 362 }
 363
 364 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 365                                       struct forw_packet *forw_packet,
 366                                       unsigned long send_time)
 367 {
 368         unsigned long flags;
 369         INIT_HLIST_NODE(&forw_packet->list);
 370
 371         /* add new packet to packet list */
 372         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 373         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 374         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 375
 376         /* start timer for this packet */
 377         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 378                           send_outstanding_bcast_packet);
 379         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 380                            send_time);
 381 }
 382
 383 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 384 /* add a broadcast packet to the queue and setup timers. broadcast packets
 385  * are sent multiple times to increase probability for beeing received.
 386  *
 387  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 388  * errors.
 389  *
 390  * The skb is not consumed, so the caller should make sure that the
 391  * skb is freed. */
 392 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 393 {
 394         struct forw_packet *forw_packet;
 395         struct bcast_packet *bcast_packet;
 396
 397         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 398                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 399                 goto out;
 400         }
 401
 402         if (!bat_priv->primary_if)
 403                 goto out;
 404
 405         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 406
 407         if (!forw_packet)
 408                 goto out_and_inc;
 409
 410         skb = skb_copy(skb, GFP_ATOMIC);
 411         if (!skb)
 412                 goto packet_free;
 413
 414         /* as we have a copy now, it is safe to decrease the TTL */
 415         bcast_packet = (struct bcast_packet *)skb->data;
 416         bcast_packet->ttl--;
 417
 418         skb_reset_mac_header(skb);
 419
 420         forw_packet->skb = skb;
 421         forw_packet->if_incoming = bat_priv->primary_if;
 422
 423         /* how often did we send the bcast packet ? */
 424         forw_packet->num_packets = 0;
 425
 426         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 427         return NETDEV_TX_OK;
 428
 429 packet_free:
 430         kfree(forw_packet);
 431 out_and_inc:
 432         atomic_inc(&bat_priv->bcast_queue_left);
 433 out:
 434         return NETDEV_TX_BUSY;
 435 }
 436
 437 static void send_outstanding_bcast_packet(struct work_struct *work)
 438 {
 439         struct batman_if *batman_if;
 440         struct delayed_work *delayed_work =
 441                 container_of(work, struct delayed_work, work);
 442         struct forw_packet *forw_packet =
 443                 container_of(delayed_work, struct forw_packet, delayed_work);
 444         unsigned long flags;
 445         struct sk_buff *skb1;
 446         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 447         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 448
 449         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 450         hlist_del(&forw_packet->list);
 451         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 452
 453         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 454                 goto out;
 455
 456         /* rebroadcast packet */
 457         rcu_read_lock();
 458         list_for_each_entry_rcu(batman_if, &if_list, list) {
 459                 if (batman_if->soft_iface != soft_iface)
 460                         continue;
 461
 462                 /* send a copy of the saved skb */
 463                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 464                 if (skb1)
 465                         send_skb_packet(skb1, batman_if, broadcast_addr);
 466         }
 467         rcu_read_unlock();
 468
 469         forw_packet->num_packets++;
 470
 471         /* if we still have some more bcasts to send */
 472         if (forw_packet->num_packets < 3) {
 473                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 474                                           ((5 * HZ) / 1000));
 475                 return;
 476         }
 477
 478 out:
 479         forw_packet_free(forw_packet);
 480         atomic_inc(&bat_priv->bcast_queue_left);
 481 }
 482
 483 void send_outstanding_bat_packet(struct work_struct *work)
 484 {
 485         struct delayed_work *delayed_work =
 486                 container_of(work, struct delayed_work, work);
 487         struct forw_packet *forw_packet =
 488                 container_of(delayed_work, struct forw_packet, delayed_work);
 489         unsigned long flags;
 490         struct bat_priv *bat_priv;
 491
 492         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 493         spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 494         hlist_del(&forw_packet->list);
 495         spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 496
 497         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 498                 goto out;
 499
 500         send_packet(forw_packet);
 501
 502         /**
 503          * we have to have at least one packet in the queue
 504          * to determine the queues wake up time unless we are
 505          * shutting down
 506          */
 507         if (forw_packet->own)
 508                 schedule_own_packet(forw_packet->if_incoming);
 509
 510 out:
 511         /* don't count own packet */
 512         if (!forw_packet->own)
 513                 atomic_inc(&bat_priv->batman_queue_left);
 514
 515         forw_packet_free(forw_packet);
 516 }
 517
 518 void purge_outstanding_packets(struct bat_priv *bat_priv,
 519                                struct batman_if *batman_if)
 520 {
 521         struct forw_packet *forw_packet;
 522         struct hlist_node *tmp_node, *safe_tmp_node;
 523         unsigned long flags;
 524
 525         if (batman_if)
 526                 bat_dbg(DBG_BATMAN, bat_priv,
 527                         "purge_outstanding_packets(): %s\n",
 528                         batman_if->net_dev->name);
 529         else
 530                 bat_dbg(DBG_BATMAN, bat_priv,
 531                         "purge_outstanding_packets()\n");
 532
 533         /* free bcast list */
 534         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 535         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 536                                   &bat_priv->forw_bcast_list, list) {
 537
 538                 /**
 539                  * if purge_outstanding_packets() was called with an argmument
 540                  * we delete only packets belonging to the given interface
 541                  */
 542                 if ((batman_if) &&
 543                     (forw_packet->if_incoming != batman_if))
 544                         continue;
 545
 546                 spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 547
 548                 /**
 549                  * send_outstanding_bcast_packet() will lock the list to
 550                  * delete the item from the list
 551                  */
 552                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 553                 spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 554         }
 555         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 556
 557         /* free batman packet list */
 558         spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 559         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 560                                   &bat_priv->forw_bat_list, list) {
 561
 562                 /**
 563                  * if purge_outstanding_packets() was called with an argmument
 564                  * we delete only packets belonging to the given interface
 565                  */
 566                 if ((batman_if) &&
 567                     (forw_packet->if_incoming != batman_if))
 568                         continue;
 569
 570                 spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 571
 572                 /**
 573                  * send_outstanding_bat_packet() will lock the list to
 574                  * delete the item from the list
 575                  */
 576                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 577                 spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 578         }
 579         spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 580 }