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_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 /* sends a raw packet. */
 103 void send_raw_packet(unsigned char *pack_buff, int pack_buff_len,
 104                      struct batman_if *batman_if, uint8_t *dst_addr)
 105 {
 106         struct sk_buff *skb;
 107         char *data;
 108
 109         skb = dev_alloc_skb(pack_buff_len + sizeof(struct ethhdr));
 110         if (!skb)
 111                 return;
 112         data = skb_put(skb, pack_buff_len + sizeof(struct ethhdr));
 113         memcpy(data + sizeof(struct ethhdr), pack_buff, pack_buff_len);
 114         /* pull back to the batman "network header" */
 115         skb_pull(skb, sizeof(struct ethhdr));
 116         send_skb_packet(skb, batman_if, dst_addr);
 117 }
 118
 119 /* Send a packet to a given interface */
 120 static void send_packet_to_if(struct forw_packet *forw_packet,
 121                               struct batman_if *batman_if)
 122 {
 123         /* FIXME: each batman_if will be attached to a softif */
 124         struct bat_priv *bat_priv = netdev_priv(soft_device);
 125         char *fwd_str;
 126         uint8_t packet_num;
 127         int16_t buff_pos;
 128         struct batman_packet *batman_packet;
 129
 130         if (batman_if->if_status != IF_ACTIVE)
 131                 return;
 132
 133         packet_num = 0;
 134         buff_pos = 0;
 135         batman_packet = (struct batman_packet *)
 136                 (forw_packet->packet_buff);
 137
 138         /* adjust all flags and log packets */
 139         while (aggregated_packet(buff_pos,
 140                                  forw_packet->packet_len,
 141                                  batman_packet->num_hna)) {
 142
 143                 /* we might have aggregated direct link packets with an
 144                  * ordinary base packet */
 145                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 146                     (forw_packet->if_incoming == batman_if))
 147                         batman_packet->flags |= DIRECTLINK;
 148                 else
 149                         batman_packet->flags &= ~DIRECTLINK;
 150
 151                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 152                                                             "Sending own" :
 153                                                             "Forwarding"));
 154                 bat_dbg(DBG_BATMAN, bat_priv,
 155                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 156                         " IDF %s) on interface %s [%s]\n",
 157                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 158                         batman_packet->orig, ntohl(batman_packet->seqno),
 159                         batman_packet->tq, batman_packet->ttl,
 160                         (batman_packet->flags & DIRECTLINK ?
 161                          "on" : "off"),
 162                         batman_if->dev, batman_if->addr_str);
 163
 164                 buff_pos += sizeof(struct batman_packet) +
 165                         (batman_packet->num_hna * ETH_ALEN);
 166                 packet_num++;
 167                 batman_packet = (struct batman_packet *)
 168                         (forw_packet->packet_buff + buff_pos);
 169         }
 170
 171         send_raw_packet(forw_packet->packet_buff,
 172                         forw_packet->packet_len,
 173                         batman_if, broadcast_addr);
 174 }
 175
 176 /* send a batman packet */
 177 static void send_packet(struct forw_packet *forw_packet)
 178 {
 179         /* FIXME: each batman_if will be attached to a softif */
 180         struct bat_priv *bat_priv = netdev_priv(soft_device);
 181         struct batman_if *batman_if;
 182         struct batman_packet *batman_packet =
 183                 (struct batman_packet *)(forw_packet->packet_buff);
 184         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 185
 186         if (!forw_packet->if_incoming) {
 187                 pr_err("Error - can't forward packet: incoming iface not "
 188                        "specified\n");
 189                 return;
 190         }
 191
 192         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 193                 return;
 194
 195         /* multihomed peer assumed */
 196         /* non-primary OGMs are only broadcasted on their interface */
 197         if ((directlink && (batman_packet->ttl == 1)) ||
 198             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 199
 200                 /* FIXME: what about aggregated packets ? */
 201                 bat_dbg(DBG_BATMAN, bat_priv,
 202                         "%s packet (originator %pM, seqno %d, TTL %d) "
 203                         "on interface %s [%s]\n",
 204                         (forw_packet->own ? "Sending own" : "Forwarding"),
 205                         batman_packet->orig, ntohl(batman_packet->seqno),
 206                         batman_packet->ttl, forw_packet->if_incoming->dev,
 207                         forw_packet->if_incoming->addr_str);
 208
 209                 send_raw_packet(forw_packet->packet_buff,
 210                                 forw_packet->packet_len,
 211                                 forw_packet->if_incoming,
 212                                 broadcast_addr);
 213                 return;
 214         }
 215
 216         /* broadcast on every interface */
 217         rcu_read_lock();
 218         list_for_each_entry_rcu(batman_if, &if_list, list)
 219                 send_packet_to_if(forw_packet, batman_if);
 220         rcu_read_unlock();
 221 }
 222
 223 static void rebuild_batman_packet(struct batman_if *batman_if)
 224 {
 225         int new_len;
 226         unsigned char *new_buff;
 227         struct batman_packet *batman_packet;
 228
 229         new_len = sizeof(struct batman_packet) + (num_hna * ETH_ALEN);
 230         new_buff = kmalloc(new_len, GFP_ATOMIC);
 231
 232         /* keep old buffer if kmalloc should fail */
 233         if (new_buff) {
 234                 memcpy(new_buff, batman_if->packet_buff,
 235                        sizeof(struct batman_packet));
 236                 batman_packet = (struct batman_packet *)new_buff;
 237
 238                 batman_packet->num_hna = hna_local_fill_buffer(
 239                         new_buff + sizeof(struct batman_packet),
 240                         new_len - sizeof(struct batman_packet));
 241
 242                 kfree(batman_if->packet_buff);
 243                 batman_if->packet_buff = new_buff;
 244                 batman_if->packet_len = new_len;
 245         }
 246 }
 247
 248 void schedule_own_packet(struct batman_if *batman_if)
 249 {
 250         /* FIXME: each batman_if will be attached to a softif */
 251         struct bat_priv *bat_priv = netdev_priv(soft_device);
 252         unsigned long send_time;
 253         struct batman_packet *batman_packet;
 254         int vis_server;
 255
 256         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 257             (batman_if->if_status == IF_TO_BE_REMOVED))
 258                 return;
 259
 260         vis_server = atomic_read(&bat_priv->vis_mode);
 261
 262         /**
 263          * the interface gets activated here to avoid race conditions between
 264          * the moment of activating the interface in
 265          * hardif_activate_interface() where the originator mac is set and
 266          * outdated packets (especially uninitialized mac addresses) in the
 267          * packet queue
 268          */
 269         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 270                 batman_if->if_status = IF_ACTIVE;
 271
 272         /* if local hna has changed and interface is a primary interface */
 273         if ((atomic_read(&hna_local_changed)) &&
 274             (batman_if == bat_priv->primary_if))
 275                 rebuild_batman_packet(batman_if);
 276
 277         /**
 278          * NOTE: packet_buff might just have been re-allocated in
 279          * rebuild_batman_packet()
 280          */
 281         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 282
 283         /* change sequence number to network order */
 284         batman_packet->seqno =
 285                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 286
 287         if (vis_server == VIS_TYPE_SERVER_SYNC)
 288                 batman_packet->flags |= VIS_SERVER;
 289         else
 290                 batman_packet->flags &= ~VIS_SERVER;
 291
 292         atomic_inc(&batman_if->seqno);
 293
 294         slide_own_bcast_window(batman_if);
 295         send_time = own_send_time(bat_priv);
 296         add_bat_packet_to_list(bat_priv,
 297                                batman_if->packet_buff,
 298                                batman_if->packet_len,
 299                                batman_if, 1, send_time);
 300 }
 301
 302 void schedule_forward_packet(struct orig_node *orig_node,
 303                              struct ethhdr *ethhdr,
 304                              struct batman_packet *batman_packet,
 305                              uint8_t directlink, int hna_buff_len,
 306                              struct batman_if *if_incoming)
 307 {
 308         /* FIXME: each batman_if will be attached to a softif */
 309         struct bat_priv *bat_priv = netdev_priv(soft_device);
 310         unsigned char in_tq, in_ttl, tq_avg = 0;
 311         unsigned long send_time;
 312
 313         if (batman_packet->ttl <= 1) {
 314                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 315                 return;
 316         }
 317
 318         in_tq = batman_packet->tq;
 319         in_ttl = batman_packet->ttl;
 320
 321         batman_packet->ttl--;
 322         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 323
 324         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 325          * of our best tq value */
 326         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 327
 328                 /* rebroadcast ogm of best ranking neighbor as is */
 329                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 330                         batman_packet->tq = orig_node->router->tq_avg;
 331
 332                         if (orig_node->router->last_ttl)
 333                                 batman_packet->ttl = orig_node->router->last_ttl
 334                                                         - 1;
 335                 }
 336
 337                 tq_avg = orig_node->router->tq_avg;
 338         }
 339
 340         /* apply hop penalty */
 341         batman_packet->tq = hop_penalty(batman_packet->tq);
 342
 343         bat_dbg(DBG_BATMAN, bat_priv,
 344                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 345                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 346                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 347                 batman_packet->ttl);
 348
 349         batman_packet->seqno = htonl(batman_packet->seqno);
 350
 351         /* switch of primaries first hop flag when forwarding */
 352         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 353         if (directlink)
 354                 batman_packet->flags |= DIRECTLINK;
 355         else
 356                 batman_packet->flags &= ~DIRECTLINK;
 357
 358         send_time = forward_send_time(bat_priv);
 359         add_bat_packet_to_list(bat_priv,
 360                                (unsigned char *)batman_packet,
 361                                sizeof(struct batman_packet) + hna_buff_len,
 362                                if_incoming, 0, send_time);
 363 }
 364
 365 static void forw_packet_free(struct forw_packet *forw_packet)
 366 {
 367         if (forw_packet->skb)
 368                 kfree_skb(forw_packet->skb);
 369         kfree(forw_packet->packet_buff);
 370         kfree(forw_packet);
 371 }
 372
 373 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 374                                       unsigned long send_time)
 375 {
 376         unsigned long flags;
 377         INIT_HLIST_NODE(&forw_packet->list);
 378
 379         /* add new packet to packet list */
 380         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 381         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 382         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 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 sk_buff *skb)
 401 {
 402         struct forw_packet *forw_packet;
 403         struct bcast_packet *bcast_packet;
 404         /* FIXME: each batman_if will be attached to a softif */
 405         struct bat_priv *bat_priv = netdev_priv(soft_device);
 406
 407         if (!atomic_dec_not_zero(&bcast_queue_left)) {
 408                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 409                 goto out;
 410         }
 411
 412         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 413
 414         if (!forw_packet)
 415                 goto out_and_inc;
 416
 417         skb = skb_copy(skb, GFP_ATOMIC);
 418         if (!skb)
 419                 goto packet_free;
 420
 421         /* as we have a copy now, it is safe to decrease the TTL */
 422         bcast_packet = (struct bcast_packet *)skb->data;
 423         bcast_packet->ttl--;
 424
 425         skb_reset_mac_header(skb);
 426
 427         forw_packet->skb = skb;
 428         forw_packet->packet_buff = NULL;
 429
 430         /* how often did we send the bcast packet ? */
 431         forw_packet->num_packets = 0;
 432
 433         _add_bcast_packet_to_list(forw_packet, 1);
 434         return NETDEV_TX_OK;
 435
 436 packet_free:
 437         kfree(forw_packet);
 438 out_and_inc:
 439         atomic_inc(&bcast_queue_left);
 440 out:
 441         return NETDEV_TX_BUSY;
 442 }
 443
 444 static void send_outstanding_bcast_packet(struct work_struct *work)
 445 {
 446         struct batman_if *batman_if;
 447         struct delayed_work *delayed_work =
 448                 container_of(work, struct delayed_work, work);
 449         struct forw_packet *forw_packet =
 450                 container_of(delayed_work, struct forw_packet, delayed_work);
 451         unsigned long flags;
 452         struct sk_buff *skb1;
 453
 454         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 455         hlist_del(&forw_packet->list);
 456         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 457
 458         if (atomic_read(&module_state) == MODULE_DEACTIVATING)
 459                 goto out;
 460
 461         /* rebroadcast packet */
 462         rcu_read_lock();
 463         list_for_each_entry_rcu(batman_if, &if_list, list) {
 464                 /* send a copy of the saved skb */
 465                 skb1 = skb_copy(forw_packet->skb, GFP_ATOMIC);
 466                 if (skb1)
 467                         send_skb_packet(skb1,
 468                                 batman_if, broadcast_addr);
 469         }
 470         rcu_read_unlock();
 471
 472         forw_packet->num_packets++;
 473
 474         /* if we still have some more bcasts to send */
 475         if (forw_packet->num_packets < 3) {
 476                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 477                 return;
 478         }
 479
 480 out:
 481         forw_packet_free(forw_packet);
 482         atomic_inc(&bcast_queue_left);
 483 }
 484
 485 void send_outstanding_bat_packet(struct work_struct *work)
 486 {
 487         struct delayed_work *delayed_work =
 488                 container_of(work, struct delayed_work, work);
 489         struct forw_packet *forw_packet =
 490                 container_of(delayed_work, struct forw_packet, delayed_work);
 491         unsigned long flags;
 492
 493         spin_lock_irqsave(&forw_bat_list_lock, flags);
 494         hlist_del(&forw_packet->list);
 495         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 496
 497         if (atomic_read(&module_state) == MODULE_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(&batman_queue_left);
 514
 515         forw_packet_free(forw_packet);
 516 }
 517
 518 void purge_outstanding_packets(struct batman_if *batman_if)
 519 {
 520         /* FIXME: each batman_if will be attached to a softif */
 521         struct bat_priv *bat_priv = netdev_priv(soft_device);
 522         struct forw_packet *forw_packet;
 523         struct hlist_node *tmp_node, *safe_tmp_node;
 524         unsigned long flags;
 525
 526         if (batman_if)
 527                 bat_dbg(DBG_BATMAN, bat_priv,
 528                         "purge_outstanding_packets(): %s\n",
 529                         batman_if->dev);
 530         else
 531                 bat_dbg(DBG_BATMAN, bat_priv,
 532                         "purge_outstanding_packets()\n");
 533
 534         /* free bcast list */
 535         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 536         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 537                                   &forw_bcast_list, list) {
 538
 539                 /**
 540                  * if purge_outstanding_packets() was called with an argmument
 541                  * we delete only packets belonging to the given interface
 542                  */
 543                 if ((batman_if) &&
 544                     (forw_packet->if_incoming != batman_if))
 545                         continue;
 546
 547                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 548
 549                 /**
 550                  * send_outstanding_bcast_packet() will lock the list to
 551                  * delete the item from the list
 552                  */
 553                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 554                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 555         }
 556         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 557
 558         /* free batman packet list */
 559         spin_lock_irqsave(&forw_bat_list_lock, flags);
 560         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 561                                   &forw_bat_list, list) {
 562
 563                 /**
 564                  * if purge_outstanding_packets() was called with an argmument
 565                  * we delete only packets belonging to the given interface
 566                  */
 567                 if ((batman_if) &&
 568                     (forw_packet->if_incoming != batman_if))
 569                         continue;
 570
 571                 spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 572
 573                 /**
 574                  * send_outstanding_bat_packet() will lock the list to
 575                  * delete the item from the list
 576                  */
 577                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 578                 spin_lock_irqsave(&forw_bat_list_lock, flags);
 579         }
 580         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 581 }