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->dev);
  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 [%s]\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->dev, batman_if->addr_str);
 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 bat_priv *bat_priv =
 164                 netdev_priv(forw_packet->if_incoming->soft_iface);
 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         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 176                 return;
 177
 178         /* multihomed peer assumed */
 179         /* non-primary OGMs are only broadcasted on their interface */
 180         if ((directlink && (batman_packet->ttl == 1)) ||
 181             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 182
 183                 /* FIXME: what about aggregated packets ? */
 184                 bat_dbg(DBG_BATMAN, bat_priv,
 185                         "%s packet (originator %pM, seqno %d, TTL %d) "
 186                         "on interface %s [%s]\n",
 187                         (forw_packet->own ? "Sending own" : "Forwarding"),
 188                         batman_packet->orig, ntohl(batman_packet->seqno),
 189                         batman_packet->ttl, forw_packet->if_incoming->dev,
 190                         forw_packet->if_incoming->addr_str);
 191
 192                 /* skb is only used once and than forw_packet is free'd */
 193                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 194                                 broadcast_addr);
 195                 forw_packet->skb = NULL;
 196
 197                 return;
 198         }
 199
 200         /* broadcast on every interface */
 201         rcu_read_lock();
 202         list_for_each_entry_rcu(batman_if, &if_list, list)
 203                 send_packet_to_if(forw_packet, batman_if);
 204         rcu_read_unlock();
 205 }
 206
 207 static void rebuild_batman_packet(struct batman_if *batman_if)
 208 {
 209         int new_len;
 210         unsigned char *new_buff;
 211         struct batman_packet *batman_packet;
 212
 213         new_len = sizeof(struct batman_packet) + (num_hna * ETH_ALEN);
 214         new_buff = kmalloc(new_len, GFP_ATOMIC);
 215
 216         /* keep old buffer if kmalloc should fail */
 217         if (new_buff) {
 218                 memcpy(new_buff, batman_if->packet_buff,
 219                        sizeof(struct batman_packet));
 220                 batman_packet = (struct batman_packet *)new_buff;
 221
 222                 batman_packet->num_hna = hna_local_fill_buffer(
 223                         new_buff + sizeof(struct batman_packet),
 224                         new_len - sizeof(struct batman_packet));
 225
 226                 kfree(batman_if->packet_buff);
 227                 batman_if->packet_buff = new_buff;
 228                 batman_if->packet_len = new_len;
 229         }
 230 }
 231
 232 void schedule_own_packet(struct batman_if *batman_if)
 233 {
 234         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 235         unsigned long send_time;
 236         struct batman_packet *batman_packet;
 237         int vis_server;
 238
 239         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 240             (batman_if->if_status == IF_TO_BE_REMOVED))
 241                 return;
 242
 243         vis_server = atomic_read(&bat_priv->vis_mode);
 244
 245         /**
 246          * the interface gets activated here to avoid race conditions between
 247          * the moment of activating the interface in
 248          * hardif_activate_interface() where the originator mac is set and
 249          * outdated packets (especially uninitialized mac addresses) in the
 250          * packet queue
 251          */
 252         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 253                 batman_if->if_status = IF_ACTIVE;
 254
 255         /* if local hna has changed and interface is a primary interface */
 256         if ((atomic_read(&hna_local_changed)) &&
 257             (batman_if == bat_priv->primary_if))
 258                 rebuild_batman_packet(batman_if);
 259
 260         /**
 261          * NOTE: packet_buff might just have been re-allocated in
 262          * rebuild_batman_packet()
 263          */
 264         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 265
 266         /* change sequence number to network order */
 267         batman_packet->seqno =
 268                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 269
 270         if (vis_server == VIS_TYPE_SERVER_SYNC)
 271                 batman_packet->flags |= VIS_SERVER;
 272         else
 273                 batman_packet->flags &= ~VIS_SERVER;
 274
 275         atomic_inc(&batman_if->seqno);
 276
 277         slide_own_bcast_window(batman_if);
 278         send_time = own_send_time(bat_priv);
 279         add_bat_packet_to_list(bat_priv,
 280                                batman_if->packet_buff,
 281                                batman_if->packet_len,
 282                                batman_if, 1, send_time);
 283 }
 284
 285 void schedule_forward_packet(struct orig_node *orig_node,
 286                              struct ethhdr *ethhdr,
 287                              struct batman_packet *batman_packet,
 288                              uint8_t directlink, int hna_buff_len,
 289                              struct batman_if *if_incoming)
 290 {
 291         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 292         unsigned char in_tq, in_ttl, tq_avg = 0;
 293         unsigned long send_time;
 294
 295         if (batman_packet->ttl <= 1) {
 296                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 297                 return;
 298         }
 299
 300         in_tq = batman_packet->tq;
 301         in_ttl = batman_packet->ttl;
 302
 303         batman_packet->ttl--;
 304         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 305
 306         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 307          * of our best tq value */
 308         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 309
 310                 /* rebroadcast ogm of best ranking neighbor as is */
 311                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 312                         batman_packet->tq = orig_node->router->tq_avg;
 313
 314                         if (orig_node->router->last_ttl)
 315                                 batman_packet->ttl = orig_node->router->last_ttl
 316                                                         - 1;
 317                 }
 318
 319                 tq_avg = orig_node->router->tq_avg;
 320         }
 321
 322         /* apply hop penalty */
 323         batman_packet->tq = hop_penalty(batman_packet->tq);
 324
 325         bat_dbg(DBG_BATMAN, bat_priv,
 326                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 327                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 328                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 329                 batman_packet->ttl);
 330
 331         batman_packet->seqno = htonl(batman_packet->seqno);
 332
 333         /* switch of primaries first hop flag when forwarding */
 334         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 335         if (directlink)
 336                 batman_packet->flags |= DIRECTLINK;
 337         else
 338                 batman_packet->flags &= ~DIRECTLINK;
 339
 340         send_time = forward_send_time(bat_priv);
 341         add_bat_packet_to_list(bat_priv,
 342                                (unsigned char *)batman_packet,
 343                                sizeof(struct batman_packet) + hna_buff_len,
 344                                if_incoming, 0, send_time);
 345 }
 346
 347 static void forw_packet_free(struct forw_packet *forw_packet)
 348 {
 349         if (forw_packet->skb)
 350                 kfree_skb(forw_packet->skb);
 351         kfree(forw_packet);
 352 }
 353
 354 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 355                                       unsigned long send_time)
 356 {
 357         unsigned long flags;
 358         INIT_HLIST_NODE(&forw_packet->list);
 359
 360         /* add new packet to packet list */
 361         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 362         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 363         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 364
 365         /* start timer for this packet */
 366         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 367                           send_outstanding_bcast_packet);
 368         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 369                            send_time);
 370 }
 371
 372 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 373 /* add a broadcast packet to the queue and setup timers. broadcast packets
 374  * are sent multiple times to increase probability for beeing received.
 375  *
 376  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 377  * errors.
 378  *
 379  * The skb is not consumed, so the caller should make sure that the
 380  * skb is freed. */
 381 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 382 {
 383         struct forw_packet *forw_packet;
 384         struct bcast_packet *bcast_packet;
 385
 386         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 387                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 388                 goto out;
 389         }
 390
 391         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 392
 393         if (!forw_packet)
 394                 goto out_and_inc;
 395
 396         skb = skb_copy(skb, GFP_ATOMIC);
 397         if (!skb)
 398                 goto packet_free;
 399
 400         /* as we have a copy now, it is safe to decrease the TTL */
 401         bcast_packet = (struct bcast_packet *)skb->data;
 402         bcast_packet->ttl--;
 403
 404         skb_reset_mac_header(skb);
 405
 406         forw_packet->skb = skb;
 407         forw_packet->if_incoming = bat_priv->primary_if;
 408
 409         /* how often did we send the bcast packet ? */
 410         forw_packet->num_packets = 0;
 411
 412         _add_bcast_packet_to_list(forw_packet, 1);
 413         return NETDEV_TX_OK;
 414
 415 packet_free:
 416         kfree(forw_packet);
 417 out_and_inc:
 418         atomic_inc(&bat_priv->bcast_queue_left);
 419 out:
 420         return NETDEV_TX_BUSY;
 421 }
 422
 423 static void send_outstanding_bcast_packet(struct work_struct *work)
 424 {
 425         struct batman_if *batman_if;
 426         struct delayed_work *delayed_work =
 427                 container_of(work, struct delayed_work, work);
 428         struct forw_packet *forw_packet =
 429                 container_of(delayed_work, struct forw_packet, delayed_work);
 430         unsigned long flags;
 431         struct sk_buff *skb1;
 432         struct bat_priv *bat_priv;
 433
 434         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 435         hlist_del(&forw_packet->list);
 436         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 437
 438         if (atomic_read(&module_state) == MODULE_DEACTIVATING)
 439                 goto out;
 440
 441         /* rebroadcast packet */
 442         rcu_read_lock();
 443         list_for_each_entry_rcu(batman_if, &if_list, list) {
 444                 /* send a copy of the saved skb */
 445                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 446                 if (skb1)
 447                         send_skb_packet(skb1,
 448                                 batman_if, broadcast_addr);
 449         }
 450         rcu_read_unlock();
 451
 452         forw_packet->num_packets++;
 453
 454         /* if we still have some more bcasts to send */
 455         if (forw_packet->num_packets < 3) {
 456                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 457                 return;
 458         }
 459
 460 out:
 461         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 462         forw_packet_free(forw_packet);
 463         atomic_inc(&bat_priv->bcast_queue_left);
 464 }
 465
 466 void send_outstanding_bat_packet(struct work_struct *work)
 467 {
 468         struct delayed_work *delayed_work =
 469                 container_of(work, struct delayed_work, work);
 470         struct forw_packet *forw_packet =
 471                 container_of(delayed_work, struct forw_packet, delayed_work);
 472         unsigned long flags;
 473         struct bat_priv *bat_priv;
 474
 475         spin_lock_irqsave(&forw_bat_list_lock, flags);
 476         hlist_del(&forw_packet->list);
 477         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 478
 479         if (atomic_read(&module_state) == MODULE_DEACTIVATING)
 480                 goto out;
 481
 482         send_packet(forw_packet);
 483
 484         /**
 485          * we have to have at least one packet in the queue
 486          * to determine the queues wake up time unless we are
 487          * shutting down
 488          */
 489         if (forw_packet->own)
 490                 schedule_own_packet(forw_packet->if_incoming);
 491
 492 out:
 493         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 494
 495         /* don't count own packet */
 496         if (!forw_packet->own)
 497                 atomic_inc(&bat_priv->batman_queue_left);
 498
 499         forw_packet_free(forw_packet);
 500 }
 501
 502 void purge_outstanding_packets(struct batman_if *batman_if)
 503 {
 504         struct bat_priv *bat_priv;
 505         struct forw_packet *forw_packet;
 506         struct hlist_node *tmp_node, *safe_tmp_node;
 507         unsigned long flags;
 508
 509         if (batman_if->soft_iface) {
 510                 bat_priv = netdev_priv(batman_if->soft_iface);
 511
 512                 if (batman_if)
 513                         bat_dbg(DBG_BATMAN, bat_priv,
 514                                 "purge_outstanding_packets(): %s\n",
 515                                 batman_if->dev);
 516                 else
 517                         bat_dbg(DBG_BATMAN, bat_priv,
 518                                 "purge_outstanding_packets()\n");
 519         }
 520
 521         /* free bcast list */
 522         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 523         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 524                                   &forw_bcast_list, list) {
 525
 526                 /**
 527                  * if purge_outstanding_packets() was called with an argmument
 528                  * we delete only packets belonging to the given interface
 529                  */
 530                 if ((batman_if) &&
 531                     (forw_packet->if_incoming != batman_if))
 532                         continue;
 533
 534                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 535
 536                 /**
 537                  * send_outstanding_bcast_packet() will lock the list to
 538                  * delete the item from the list
 539                  */
 540                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 541                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 542         }
 543         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 544
 545         /* free batman packet list */
 546         spin_lock_irqsave(&forw_bat_list_lock, flags);
 547         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 548                                   &forw_bat_list, list) {
 549
 550                 /**
 551                  * if purge_outstanding_packets() was called with an argmument
 552                  * we delete only packets belonging to the given interface
 553                  */
 554                 if ((batman_if) &&
 555                     (forw_packet->if_incoming != batman_if))
 556                         continue;
 557
 558                 spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 559
 560                 /**
 561                  * send_outstanding_bat_packet() will lock the list to
 562                  * delete the item from the list
 563                  */
 564                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 565                 spin_lock_irqsave(&forw_bat_list_lock, flags);
 566         }
 567         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 568 }