net/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2011 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 "vis.h"
  29 #include "aggregation.h"
  30 #include "gateway_common.h"
  31 #include "originator.h"
  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, struct bat_priv *bat_priv)
  37 {
  38         int hop_penalty = atomic_read(&bat_priv->hop_penalty);
  39         return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
  40 }
  41
  42 /* when do we schedule our own packet to be sent */
  43 static unsigned long own_send_time(struct bat_priv *bat_priv)
  44 {
  45         return jiffies + msecs_to_jiffies(
  46                    atomic_read(&bat_priv->orig_interval) -
  47                    JITTER + (random32() % 2*JITTER));
  48 }
  49
  50 /* when do we schedule a forwarded packet to be sent */
  51 static unsigned long forward_send_time(void)
  52 {
  53         return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
  54 }
  55
  56 /* send out an already prepared packet to the given address via the
  57  * specified batman interface */
  58 int send_skb_packet(struct sk_buff *skb,
  59                                 struct batman_if *batman_if,
  60                                 uint8_t *dst_addr)
  61 {
  62         struct ethhdr *ethhdr;
  63
  64         if (batman_if->if_status != IF_ACTIVE)
  65                 goto send_skb_err;
  66
  67         if (unlikely(!batman_if->net_dev))
  68                 goto send_skb_err;
  69
  70         if (!(batman_if->net_dev->flags & IFF_UP)) {
  71                 pr_warning("Interface %s is not up - can't send packet via "
  72                            "that interface!\n", batman_if->net_dev->name);
  73                 goto send_skb_err;
  74         }
  75
  76         /* push to the ethernet header. */
  77         if (my_skb_head_push(skb, sizeof(struct ethhdr)) < 0)
  78                 goto send_skb_err;
  79
  80         skb_reset_mac_header(skb);
  81
  82         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  83         memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
  84         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  85         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  86
  87         skb_set_network_header(skb, ETH_HLEN);
  88         skb->priority = TC_PRIO_CONTROL;
  89         skb->protocol = __constant_htons(ETH_P_BATMAN);
  90
  91         skb->dev = batman_if->net_dev;
  92
  93         /* dev_queue_xmit() returns a negative result on error.  However on
  94          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  95          * (which is > 0). This will not be treated as an error. */
  96
  97         return dev_queue_xmit(skb);
  98 send_skb_err:
  99         kfree_skb(skb);
 100         return NET_XMIT_DROP;
 101 }
 102
 103 /* Send a packet to a given interface */
 104 static void send_packet_to_if(struct forw_packet *forw_packet,
 105                               struct batman_if *batman_if)
 106 {
 107         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 108         char *fwd_str;
 109         uint8_t packet_num;
 110         int16_t buff_pos;
 111         struct batman_packet *batman_packet;
 112         struct sk_buff *skb;
 113
 114         if (batman_if->if_status != IF_ACTIVE)
 115                 return;
 116
 117         packet_num = 0;
 118         buff_pos = 0;
 119         batman_packet = (struct batman_packet *)forw_packet->skb->data;
 120
 121         /* adjust all flags and log packets */
 122         while (aggregated_packet(buff_pos,
 123                                  forw_packet->packet_len,
 124                                  batman_packet->num_hna)) {
 125
 126                 /* we might have aggregated direct link packets with an
 127                  * ordinary base packet */
 128                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 129                     (forw_packet->if_incoming == batman_if))
 130                         batman_packet->flags |= DIRECTLINK;
 131                 else
 132                         batman_packet->flags &= ~DIRECTLINK;
 133
 134                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 135                                                             "Sending own" :
 136                                                             "Forwarding"));
 137                 bat_dbg(DBG_BATMAN, bat_priv,
 138                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 139                         " IDF %s) on interface %s [%pM]\n",
 140                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 141                         batman_packet->orig, ntohl(batman_packet->seqno),
 142                         batman_packet->tq, batman_packet->ttl,
 143                         (batman_packet->flags & DIRECTLINK ?
 144                          "on" : "off"),
 145                         batman_if->net_dev->name, batman_if->net_dev->dev_addr);
 146
 147                 buff_pos += sizeof(struct batman_packet) +
 148                         (batman_packet->num_hna * ETH_ALEN);
 149                 packet_num++;
 150                 batman_packet = (struct batman_packet *)
 151                         (forw_packet->skb->data + buff_pos);
 152         }
 153
 154         /* create clone because function is called more than once */
 155         skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
 156         if (skb)
 157                 send_skb_packet(skb, batman_if, broadcast_addr);
 158 }
 159
 160 /* send a batman packet */
 161 static void send_packet(struct forw_packet *forw_packet)
 162 {
 163         struct batman_if *batman_if;
 164         struct net_device *soft_iface;
 165         struct bat_priv *bat_priv;
 166         struct batman_packet *batman_packet =
 167                 (struct batman_packet *)(forw_packet->skb->data);
 168         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 169
 170         if (!forw_packet->if_incoming) {
 171                 pr_err("Error - can't forward packet: incoming iface not "
 172                        "specified\n");
 173                 return;
 174         }
 175
 176         soft_iface = forw_packet->if_incoming->soft_iface;
 177         bat_priv = netdev_priv(soft_iface);
 178
 179         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 180                 return;
 181
 182         /* multihomed peer assumed */
 183         /* non-primary OGMs are only broadcasted on their interface */
 184         if ((directlink && (batman_packet->ttl == 1)) ||
 185             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 186
 187                 /* FIXME: what about aggregated packets ? */
 188                 bat_dbg(DBG_BATMAN, bat_priv,
 189                         "%s packet (originator %pM, seqno %d, TTL %d) "
 190                         "on interface %s [%pM]\n",
 191                         (forw_packet->own ? "Sending own" : "Forwarding"),
 192                         batman_packet->orig, ntohl(batman_packet->seqno),
 193                         batman_packet->ttl,
 194                         forw_packet->if_incoming->net_dev->name,
 195                         forw_packet->if_incoming->net_dev->dev_addr);
 196
 197                 /* skb is only used once and than forw_packet is free'd */
 198                 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
 199                                 broadcast_addr);
 200                 forw_packet->skb = NULL;
 201
 202                 return;
 203         }
 204
 205         /* broadcast on every interface */
 206         rcu_read_lock();
 207         list_for_each_entry_rcu(batman_if, &if_list, list) {
 208                 if (batman_if->soft_iface != soft_iface)
 209                         continue;
 210
 211                 send_packet_to_if(forw_packet, batman_if);
 212         }
 213         rcu_read_unlock();
 214 }
 215
 216 static void rebuild_batman_packet(struct bat_priv *bat_priv,
 217                                   struct batman_if *batman_if)
 218 {
 219         int new_len;
 220         unsigned char *new_buff;
 221         struct batman_packet *batman_packet;
 222
 223         new_len = sizeof(struct batman_packet) +
 224                         (bat_priv->num_local_hna * ETH_ALEN);
 225         new_buff = kmalloc(new_len, GFP_ATOMIC);
 226
 227         /* keep old buffer if kmalloc should fail */
 228         if (new_buff) {
 229                 memcpy(new_buff, batman_if->packet_buff,
 230                        sizeof(struct batman_packet));
 231                 batman_packet = (struct batman_packet *)new_buff;
 232
 233                 batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
 234                                 new_buff + sizeof(struct batman_packet),
 235                                 new_len - sizeof(struct batman_packet));
 236
 237                 kfree(batman_if->packet_buff);
 238                 batman_if->packet_buff = new_buff;
 239                 batman_if->packet_len = new_len;
 240         }
 241 }
 242
 243 void schedule_own_packet(struct batman_if *batman_if)
 244 {
 245         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 246         unsigned long send_time;
 247         struct batman_packet *batman_packet;
 248         int vis_server;
 249
 250         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 251             (batman_if->if_status == IF_TO_BE_REMOVED))
 252                 return;
 253
 254         vis_server = atomic_read(&bat_priv->vis_mode);
 255
 256         /**
 257          * the interface gets activated here to avoid race conditions between
 258          * the moment of activating the interface in
 259          * hardif_activate_interface() where the originator mac is set and
 260          * outdated packets (especially uninitialized mac addresses) in the
 261          * packet queue
 262          */
 263         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 264                 batman_if->if_status = IF_ACTIVE;
 265
 266         /* if local hna has changed and interface is a primary interface */
 267         if ((atomic_read(&bat_priv->hna_local_changed)) &&
 268             (batman_if == bat_priv->primary_if))
 269                 rebuild_batman_packet(bat_priv, batman_if);
 270
 271         /**
 272          * NOTE: packet_buff might just have been re-allocated in
 273          * rebuild_batman_packet()
 274          */
 275         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 276
 277         /* change sequence number to network order */
 278         batman_packet->seqno =
 279                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 280
 281         if (vis_server == VIS_TYPE_SERVER_SYNC)
 282                 batman_packet->flags |= VIS_SERVER;
 283         else
 284                 batman_packet->flags &= ~VIS_SERVER;
 285
 286         if ((batman_if == bat_priv->primary_if) &&
 287             (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
 288                 batman_packet->gw_flags =
 289                                 (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
 290         else
 291                 batman_packet->gw_flags = 0;
 292
 293         atomic_inc(&batman_if->seqno);
 294
 295         slide_own_bcast_window(batman_if);
 296         send_time = own_send_time(bat_priv);
 297         add_bat_packet_to_list(bat_priv,
 298                                batman_if->packet_buff,
 299                                batman_if->packet_len,
 300                                batman_if, 1, send_time);
 301 }
 302
 303 void schedule_forward_packet(struct orig_node *orig_node,
 304                              struct ethhdr *ethhdr,
 305                              struct batman_packet *batman_packet,
 306                              uint8_t directlink, int hna_buff_len,
 307                              struct batman_if *if_incoming)
 308 {
 309         struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
 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, bat_priv);
 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();
 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);
 370 }
 371
 372 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 373                                       struct forw_packet *forw_packet,
 374                                       unsigned long send_time)
 375 {
 376         INIT_HLIST_NODE(&forw_packet->list);
 377
 378         /* add new packet to packet list */
 379         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 380         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 381         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 382
 383         /* start timer for this packet */
 384         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 385                           send_outstanding_bcast_packet);
 386         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 387                            send_time);
 388 }
 389
 390 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 391 /* add a broadcast packet to the queue and setup timers. broadcast packets
 392  * are sent multiple times to increase probability for beeing received.
 393  *
 394  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 395  * errors.
 396  *
 397  * The skb is not consumed, so the caller should make sure that the
 398  * skb is freed. */
 399 int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
 400 {
 401         struct forw_packet *forw_packet;
 402         struct bcast_packet *bcast_packet;
 403
 404         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 405                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 406                 goto out;
 407         }
 408
 409         if (!bat_priv->primary_if)
 410                 goto out;
 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->if_incoming = bat_priv->primary_if;
 429
 430         /* how often did we send the bcast packet ? */
 431         forw_packet->num_packets = 0;
 432
 433         _add_bcast_packet_to_list(bat_priv, forw_packet, 1);
 434         return NETDEV_TX_OK;
 435
 436 packet_free:
 437         kfree(forw_packet);
 438 out_and_inc:
 439         atomic_inc(&bat_priv->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         struct sk_buff *skb1;
 452         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 453         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 454
 455         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 456         hlist_del(&forw_packet->list);
 457         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 458
 459         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 460                 goto out;
 461
 462         /* rebroadcast packet */
 463         rcu_read_lock();
 464         list_for_each_entry_rcu(batman_if, &if_list, list) {
 465                 if (batman_if->soft_iface != soft_iface)
 466                         continue;
 467
 468                 /* send a copy of the saved skb */
 469                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 470                 if (skb1)
 471                         send_skb_packet(skb1, batman_if, broadcast_addr);
 472         }
 473         rcu_read_unlock();
 474
 475         forw_packet->num_packets++;
 476
 477         /* if we still have some more bcasts to send */
 478         if (forw_packet->num_packets < 3) {
 479                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 480                                           ((5 * HZ) / 1000));
 481                 return;
 482         }
 483
 484 out:
 485         forw_packet_free(forw_packet);
 486         atomic_inc(&bat_priv->bcast_queue_left);
 487 }
 488
 489 void send_outstanding_bat_packet(struct work_struct *work)
 490 {
 491         struct delayed_work *delayed_work =
 492                 container_of(work, struct delayed_work, work);
 493         struct forw_packet *forw_packet =
 494                 container_of(delayed_work, struct forw_packet, delayed_work);
 495         struct bat_priv *bat_priv;
 496
 497         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 498         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 499         hlist_del(&forw_packet->list);
 500         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 501
 502         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 503                 goto out;
 504
 505         send_packet(forw_packet);
 506
 507         /**
 508          * we have to have at least one packet in the queue
 509          * to determine the queues wake up time unless we are
 510          * shutting down
 511          */
 512         if (forw_packet->own)
 513                 schedule_own_packet(forw_packet->if_incoming);
 514
 515 out:
 516         /* don't count own packet */
 517         if (!forw_packet->own)
 518                 atomic_inc(&bat_priv->batman_queue_left);
 519
 520         forw_packet_free(forw_packet);
 521 }
 522
 523 void purge_outstanding_packets(struct bat_priv *bat_priv,
 524                                struct batman_if *batman_if)
 525 {
 526         struct forw_packet *forw_packet;
 527         struct hlist_node *tmp_node, *safe_tmp_node;
 528
 529         if (batman_if)
 530                 bat_dbg(DBG_BATMAN, bat_priv,
 531                         "purge_outstanding_packets(): %s\n",
 532                         batman_if->net_dev->name);
 533         else
 534                 bat_dbg(DBG_BATMAN, bat_priv,
 535                         "purge_outstanding_packets()\n");
 536
 537         /* free bcast list */
 538         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 539         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 540                                   &bat_priv->forw_bcast_list, list) {
 541
 542                 /**
 543                  * if purge_outstanding_packets() was called with an argmument
 544                  * we delete only packets belonging to the given interface
 545                  */
 546                 if ((batman_if) &&
 547                     (forw_packet->if_incoming != batman_if))
 548                         continue;
 549
 550                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 551
 552                 /**
 553                  * send_outstanding_bcast_packet() will lock the list to
 554                  * delete the item from the list
 555                  */
 556                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 557                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 558         }
 559         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 560
 561         /* free batman packet list */
 562         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 563         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 564                                   &bat_priv->forw_bat_list, list) {
 565
 566                 /**
 567                  * if purge_outstanding_packets() was called with an argmument
 568                  * we delete only packets belonging to the given interface
 569                  */
 570                 if ((batman_if) &&
 571                     (forw_packet->if_incoming != batman_if))
 572                         continue;
 573
 574                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 575
 576                 /**
 577                  * send_outstanding_bat_packet() will lock the list to
 578                  * delete the item from the list
 579                  */
 580                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 581                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 582         }
 583         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 584 }