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 net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 164         struct bat_priv *bat_priv = netdev_priv(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                 if (batman_if->soft_iface != soft_iface)
 204                         continue;
 205
 206                 send_packet_to_if(forw_packet, batman_if);
 207         }
 208         rcu_read_unlock();
 209 }
 210
 211 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 212                                   struct batman_if *batman_if)
 213 {
 214         int new_len;
 215         unsigned char *new_buff;
 216         struct batman_packet *batman_packet;
 217
 218         new_len = sizeof(struct batman_packet) +
 219                         (bat_priv->num_local_hna * ETH_ALEN);
 220         new_buff = kmalloc(new_len, GFP_ATOMIC);
 221
 222         /* keep old buffer if kmalloc should fail */
 223         if (new_buff) {
 224                 memcpy(new_buff, batman_if->packet_buff,
 225                        sizeof(struct batman_packet));
 226                 batman_packet = (struct batman_packet *)new_buff;
 227
 228                 batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
 229                                 new_buff + sizeof(struct batman_packet),
 230                                 new_len - sizeof(struct batman_packet));
 231
 232                 kfree(batman_if->packet_buff);
 233                 batman_if->packet_buff = new_buff;
 234                 batman_if->packet_len = new_len;
 235         }
 236 }
 237
 238 void schedule_own_packet(struct batman_if *batman_if)
 239 {
 240         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 241         unsigned long send_time;
 242         struct batman_packet *batman_packet;
 243         int vis_server;
 244
 245         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 246             (batman_if->if_status == IF_TO_BE_REMOVED))
 247                 return;
 248
 249         vis_server = atomic_read(&bat_priv->vis_mode);
 250
 251         /**
 252          * the interface gets activated here to avoid race conditions between
 253          * the moment of activating the interface in
 254          * hardif_activate_interface() where the originator mac is set and
 255          * outdated packets (especially uninitialized mac addresses) in the
 256          * packet queue
 257          */
 258         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 259                 batman_if->if_status = IF_ACTIVE;
 260
 261         /* if local hna has changed and interface is a primary interface */
 262         if ((atomic_read(&bat_priv->hna_local_changed)) &&
 263             (batman_if == bat_priv->primary_if))
 264                 rebuild_batman_packet(bat_priv, batman_if);
 265
 266         /**
 267          * NOTE: packet_buff might just have been re-allocated in
 268          * rebuild_batman_packet()
 269          */
 270         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 271
 272         /* change sequence number to network order */
 273         batman_packet->seqno =
 274                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 275
 276         if (vis_server == VIS_TYPE_SERVER_SYNC)
 277                 batman_packet->flags |= VIS_SERVER;
 278         else
 279                 batman_packet->flags &= ~VIS_SERVER;
 280
 281         atomic_inc(&batman_if->seqno);
 282
 283         slide_own_bcast_window(batman_if);
 284         send_time = own_send_time(bat_priv);
 285         add_bat_packet_to_list(bat_priv,
 286                                batman_if->packet_buff,
 287                                batman_if->packet_len,
 288                                batman_if, 1, send_time);
 289 }
 290
 291 void schedule_forward_packet(struct orig_node *orig_node,
 292                              struct ethhdr *ethhdr,
 293                              struct batman_packet *batman_packet,
 294                              uint8_t directlink, int hna_buff_len,
 295                              struct batman_if *if_incoming)
 296 {
 297         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 298         unsigned char in_tq, in_ttl, tq_avg = 0;
 299         unsigned long send_time;
 300
 301         if (batman_packet->ttl <= 1) {
 302                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 303                 return;
 304         }
 305
 306         in_tq = batman_packet->tq;
 307         in_ttl = batman_packet->ttl;
 308
 309         batman_packet->ttl--;
 310         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 311
 312         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 313          * of our best tq value */
 314         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 315
 316                 /* rebroadcast ogm of best ranking neighbor as is */
 317                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 318                         batman_packet->tq = orig_node->router->tq_avg;
 319
 320                         if (orig_node->router->last_ttl)
 321                                 batman_packet->ttl = orig_node->router->last_ttl
 322                                                         - 1;
 323                 }
 324
 325                 tq_avg = orig_node->router->tq_avg;
 326         }
 327
 328         /* apply hop penalty */
 329         batman_packet->tq = hop_penalty(batman_packet->tq);
 330
 331         bat_dbg(DBG_BATMAN, bat_priv,
 332                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 333                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 334                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 335                 batman_packet->ttl);
 336
 337         batman_packet->seqno = htonl(batman_packet->seqno);
 338
 339         /* switch of primaries first hop flag when forwarding */
 340         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 341         if (directlink)
 342                 batman_packet->flags |= DIRECTLINK;
 343         else
 344                 batman_packet->flags &= ~DIRECTLINK;
 345
 346         send_time = forward_send_time(bat_priv);
 347         add_bat_packet_to_list(bat_priv,
 348                                (unsigned char *)batman_packet,
 349                                sizeof(struct batman_packet) + hna_buff_len,
 350                                if_incoming, 0, send_time);
 351 }
 352
 353 static void forw_packet_free(struct forw_packet *forw_packet)
 354 {
 355         if (forw_packet->skb)
 356                 kfree_skb(forw_packet->skb);
 357         kfree(forw_packet);
 358 }
 359
 360 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 361                                       struct forw_packet *forw_packet,
 362                                       unsigned long send_time)
 363 {
 364         unsigned long flags;
 365         INIT_HLIST_NODE(&forw_packet->list);
 366
 367         /* add new packet to packet list */
 368         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 369         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 370         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 371
 372         /* start timer for this packet */
 373         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 374                           send_outstanding_bcast_packet);
 375         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 376                            send_time);
 377 }
 378
 379 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 380 /* add a broadcast packet to the queue and setup timers. broadcast packets
 381  * are sent multiple times to increase probability for beeing received.
 382  *
 383  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 384  * errors.
 385  *
 386  * The skb is not consumed, so the caller should make sure that the
 387  * skb is freed. */
 388 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 389 {
 390         struct forw_packet *forw_packet;
 391         struct bcast_packet *bcast_packet;
 392
 393         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 394                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 395                 goto out;
 396         }
 397
 398         if (!bat_priv->primary_if)
 399                 goto out;
 400
 401         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 402
 403         if (!forw_packet)
 404                 goto out_and_inc;
 405
 406         skb = skb_copy(skb, GFP_ATOMIC);
 407         if (!skb)
 408                 goto packet_free;
 409
 410         /* as we have a copy now, it is safe to decrease the TTL */
 411         bcast_packet = (struct bcast_packet *)skb->data;
 412         bcast_packet->ttl--;
 413
 414         skb_reset_mac_header(skb);
 415
 416         forw_packet->skb = skb;
 417         forw_packet->if_incoming = bat_priv->primary_if;
 418
 419         /* how often did we send the bcast packet ? */
 420         forw_packet->num_packets = 0;
 421
 422         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 423         return NETDEV_TX_OK;
 424
 425 packet_free:
 426         kfree(forw_packet);
 427 out_and_inc:
 428         atomic_inc(&bat_priv->bcast_queue_left);
 429 out:
 430         return NETDEV_TX_BUSY;
 431 }
 432
 433 static void send_outstanding_bcast_packet(struct work_struct *work)
 434 {
 435         struct batman_if *batman_if;
 436         struct delayed_work *delayed_work =
 437                 container_of(work, struct delayed_work, work);
 438         struct forw_packet *forw_packet =
 439                 container_of(delayed_work, struct forw_packet, delayed_work);
 440         unsigned long flags;
 441         struct sk_buff *skb1;
 442         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 443         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 444
 445         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 446         hlist_del(&forw_packet->list);
 447         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 448
 449         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 450                 goto out;
 451
 452         /* rebroadcast packet */
 453         rcu_read_lock();
 454         list_for_each_entry_rcu(batman_if, &if_list, list) {
 455                 if (batman_if->soft_iface != soft_iface)
 456                         continue;
 457
 458                 /* send a copy of the saved skb */
 459                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 460                 if (skb1)
 461                         send_skb_packet(skb1, batman_if, broadcast_addr);
 462         }
 463         rcu_read_unlock();
 464
 465         forw_packet->num_packets++;
 466
 467         /* if we still have some more bcasts to send */
 468         if (forw_packet->num_packets < 3) {
 469                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 470                                           ((5 * HZ) / 1000));
 471                 return;
 472         }
 473
 474 out:
 475         forw_packet_free(forw_packet);
 476         atomic_inc(&bat_priv->bcast_queue_left);
 477 }
 478
 479 void send_outstanding_bat_packet(struct work_struct *work)
 480 {
 481         struct delayed_work *delayed_work =
 482                 container_of(work, struct delayed_work, work);
 483         struct forw_packet *forw_packet =
 484                 container_of(delayed_work, struct forw_packet, delayed_work);
 485         unsigned long flags;
 486         struct bat_priv *bat_priv;
 487
 488         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 489         spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 490         hlist_del(&forw_packet->list);
 491         spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 492
 493         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 494                 goto out;
 495
 496         send_packet(forw_packet);
 497
 498         /**
 499          * we have to have at least one packet in the queue
 500          * to determine the queues wake up time unless we are
 501          * shutting down
 502          */
 503         if (forw_packet->own)
 504                 schedule_own_packet(forw_packet->if_incoming);
 505
 506 out:
 507         /* don't count own packet */
 508         if (!forw_packet->own)
 509                 atomic_inc(&bat_priv->batman_queue_left);
 510
 511         forw_packet_free(forw_packet);
 512 }
 513
 514 void purge_outstanding_packets(struct bat_priv *bat_priv,
 515                                struct batman_if *batman_if)
 516 {
 517         struct forw_packet *forw_packet;
 518         struct hlist_node *tmp_node, *safe_tmp_node;
 519         unsigned long flags;
 520
 521         if (batman_if)
 522                 bat_dbg(DBG_BATMAN, bat_priv,
 523                         "purge_outstanding_packets(): %s\n",
 524                         batman_if->dev);
 525         else
 526                 bat_dbg(DBG_BATMAN, bat_priv,
 527                         "purge_outstanding_packets()\n");
 528
 529         /* free bcast list */
 530         spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 531         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 532                                   &bat_priv->forw_bcast_list, list) {
 533
 534                 /**
 535                  * if purge_outstanding_packets() was called with an argmument
 536                  * we delete only packets belonging to the given interface
 537                  */
 538                 if ((batman_if) &&
 539                     (forw_packet->if_incoming != batman_if))
 540                         continue;
 541
 542                 spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 543
 544                 /**
 545                  * send_outstanding_bcast_packet() will lock the list to
 546                  * delete the item from the list
 547                  */
 548                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 549                 spin_lock_irqsave(&bat_priv->forw_bcast_list_lock, flags);
 550         }
 551         spin_unlock_irqrestore(&bat_priv->forw_bcast_list_lock, flags);
 552
 553         /* free batman packet list */
 554         spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 555         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 556                                   &bat_priv->forw_bat_list, list) {
 557
 558                 /**
 559                  * if purge_outstanding_packets() was called with an argmument
 560                  * we delete only packets belonging to the given interface
 561                  */
 562                 if ((batman_if) &&
 563                     (forw_packet->if_incoming != batman_if))
 564                         continue;
 565
 566                 spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 567
 568                 /**
 569                  * send_outstanding_bat_packet() will lock the list to
 570                  * delete the item from the list
 571                  */
 572                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 573                 spin_lock_irqsave(&bat_priv->forw_bat_list_lock, flags);
 574         }
 575         spin_unlock_irqrestore(&bat_priv->forw_bat_list_lock, flags);
 576 }