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 #include <linux/netfilter_bridge.h>
  33
  34 static void send_outstanding_bcast_packet(struct work_struct *work);
  35
  36 /* apply hop penalty for a normal link */
  37 static uint8_t hop_penalty(const uint8_t tq)
  38 {
  39         return (tq * (TQ_MAX_VALUE - TQ_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(struct bat_priv *bat_priv)
  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->dev);
  73                 goto send_skb_err;
  74         }
  75
  76         /* push to the ethernet header. */
  77         if (my_skb_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          * Also, if netfilter/ebtables wants to block outgoing batman
  97          * packets then giving them a chance to do so here */
  98
  99         return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 100                        dev_queue_xmit);
 101 send_skb_err:
 102         kfree_skb(skb);
 103         return NET_XMIT_DROP;
 104 }
 105
 106 /* sends a raw packet. */
 107 void send_raw_packet(unsigned char *pack_buff, int pack_buff_len,
 108                      struct batman_if *batman_if, uint8_t *dst_addr)
 109 {
 110         struct sk_buff *skb;
 111         char *data;
 112
 113         skb = dev_alloc_skb(pack_buff_len + sizeof(struct ethhdr));
 114         if (!skb)
 115                 return;
 116         data = skb_put(skb, pack_buff_len + sizeof(struct ethhdr));
 117         memcpy(data + sizeof(struct ethhdr), pack_buff, pack_buff_len);
 118         /* pull back to the batman "network header" */
 119         skb_pull(skb, sizeof(struct ethhdr));
 120         send_skb_packet(skb, batman_if, dst_addr);
 121 }
 122
 123 /* Send a packet to a given interface */
 124 static void send_packet_to_if(struct forw_packet *forw_packet,
 125                               struct batman_if *batman_if)
 126 {
 127         /* FIXME: each batman_if will be attached to a softif */
 128         struct bat_priv *bat_priv = netdev_priv(soft_device);
 129         char *fwd_str;
 130         uint8_t packet_num;
 131         int16_t buff_pos;
 132         struct batman_packet *batman_packet;
 133
 134         if (batman_if->if_status != IF_ACTIVE)
 135                 return;
 136
 137         packet_num = 0;
 138         buff_pos = 0;
 139         batman_packet = (struct batman_packet *)
 140                 (forw_packet->packet_buff);
 141
 142         /* adjust all flags and log packets */
 143         while (aggregated_packet(buff_pos,
 144                                  forw_packet->packet_len,
 145                                  batman_packet->num_hna)) {
 146
 147                 /* we might have aggregated direct link packets with an
 148                  * ordinary base packet */
 149                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 150                     (forw_packet->if_incoming == batman_if))
 151                         batman_packet->flags |= DIRECTLINK;
 152                 else
 153                         batman_packet->flags &= ~DIRECTLINK;
 154
 155                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 156                                                             "Sending own" :
 157                                                             "Forwarding"));
 158                 bat_dbg(DBG_BATMAN, bat_priv,
 159                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 160                         " IDF %s) on interface %s [%s]\n",
 161                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 162                         batman_packet->orig, ntohl(batman_packet->seqno),
 163                         batman_packet->tq, batman_packet->ttl,
 164                         (batman_packet->flags & DIRECTLINK ?
 165                          "on" : "off"),
 166                         batman_if->dev, batman_if->addr_str);
 167
 168                 buff_pos += sizeof(struct batman_packet) +
 169                         (batman_packet->num_hna * ETH_ALEN);
 170                 packet_num++;
 171                 batman_packet = (struct batman_packet *)
 172                         (forw_packet->packet_buff + buff_pos);
 173         }
 174
 175         send_raw_packet(forw_packet->packet_buff,
 176                         forw_packet->packet_len,
 177                         batman_if, broadcast_addr);
 178 }
 179
 180 /* send a batman packet */
 181 static void send_packet(struct forw_packet *forw_packet)
 182 {
 183         /* FIXME: each batman_if will be attached to a softif */
 184         struct bat_priv *bat_priv = netdev_priv(soft_device);
 185         struct batman_if *batman_if;
 186         struct batman_packet *batman_packet =
 187                 (struct batman_packet *)(forw_packet->packet_buff);
 188         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 189
 190         if (!forw_packet->if_incoming) {
 191                 pr_err("Error - can't forward packet: incoming iface not "
 192                        "specified\n");
 193                 return;
 194         }
 195
 196         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 197                 return;
 198
 199         /* multihomed peer assumed */
 200         /* non-primary OGMs are only broadcasted on their interface */
 201         if ((directlink && (batman_packet->ttl == 1)) ||
 202             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 203
 204                 /* FIXME: what about aggregated packets ? */
 205                 bat_dbg(DBG_BATMAN, bat_priv,
 206                         "%s packet (originator %pM, seqno %d, TTL %d) "
 207                         "on interface %s [%s]\n",
 208                         (forw_packet->own ? "Sending own" : "Forwarding"),
 209                         batman_packet->orig, ntohl(batman_packet->seqno),
 210                         batman_packet->ttl, forw_packet->if_incoming->dev,
 211                         forw_packet->if_incoming->addr_str);
 212
 213                 send_raw_packet(forw_packet->packet_buff,
 214                                 forw_packet->packet_len,
 215                                 forw_packet->if_incoming,
 216                                 broadcast_addr);
 217                 return;
 218         }
 219
 220         /* broadcast on every interface */
 221         rcu_read_lock();
 222         list_for_each_entry_rcu(batman_if, &if_list, list)
 223                 send_packet_to_if(forw_packet, batman_if);
 224         rcu_read_unlock();
 225 }
 226
 227 static void rebuild_batman_packet(struct batman_if *batman_if)
 228 {
 229         int new_len;
 230         unsigned char *new_buff;
 231         struct batman_packet *batman_packet;
 232
 233         new_len = sizeof(struct batman_packet) + (num_hna * ETH_ALEN);
 234         new_buff = kmalloc(new_len, GFP_ATOMIC);
 235
 236         /* keep old buffer if kmalloc should fail */
 237         if (new_buff) {
 238                 memcpy(new_buff, batman_if->packet_buff,
 239                        sizeof(struct batman_packet));
 240                 batman_packet = (struct batman_packet *)new_buff;
 241
 242                 batman_packet->num_hna = hna_local_fill_buffer(
 243                         new_buff + sizeof(struct batman_packet),
 244                         new_len - sizeof(struct batman_packet));
 245
 246                 kfree(batman_if->packet_buff);
 247                 batman_if->packet_buff = new_buff;
 248                 batman_if->packet_len = new_len;
 249         }
 250 }
 251
 252 void schedule_own_packet(struct batman_if *batman_if)
 253 {
 254         /* FIXME: each batman_if will be attached to a softif */
 255         struct bat_priv *bat_priv = netdev_priv(soft_device);
 256         unsigned long send_time;
 257         struct batman_packet *batman_packet;
 258         int vis_server;
 259
 260         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 261             (batman_if->if_status == IF_TO_BE_REMOVED))
 262                 return;
 263
 264         vis_server = atomic_read(&bat_priv->vis_mode);
 265
 266         /**
 267          * the interface gets activated here to avoid race conditions between
 268          * the moment of activating the interface in
 269          * hardif_activate_interface() where the originator mac is set and
 270          * outdated packets (especially uninitialized mac addresses) in the
 271          * packet queue
 272          */
 273         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 274                 batman_if->if_status = IF_ACTIVE;
 275
 276         /* if local hna has changed and interface is a primary interface */
 277         if ((atomic_read(&hna_local_changed)) &&
 278             (batman_if == bat_priv->primary_if))
 279                 rebuild_batman_packet(batman_if);
 280
 281         /**
 282          * NOTE: packet_buff might just have been re-allocated in
 283          * rebuild_batman_packet()
 284          */
 285         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 286
 287         /* change sequence number to network order */
 288         batman_packet->seqno =
 289                 htonl((uint32_t)atomic_read(&batman_if->seqno));
 290
 291         if (vis_server == VIS_TYPE_SERVER_SYNC)
 292                 batman_packet->flags |= VIS_SERVER;
 293         else
 294                 batman_packet->flags &= ~VIS_SERVER;
 295
 296         atomic_inc(&batman_if->seqno);
 297
 298         slide_own_bcast_window(batman_if);
 299         send_time = own_send_time(bat_priv);
 300         add_bat_packet_to_list(bat_priv,
 301                                batman_if->packet_buff,
 302                                batman_if->packet_len,
 303                                batman_if, 1, send_time);
 304 }
 305
 306 void schedule_forward_packet(struct orig_node *orig_node,
 307                              struct ethhdr *ethhdr,
 308                              struct batman_packet *batman_packet,
 309                              uint8_t directlink, int hna_buff_len,
 310                              struct batman_if *if_incoming)
 311 {
 312         /* FIXME: each batman_if will be attached to a softif */
 313         struct bat_priv *bat_priv = netdev_priv(soft_device);
 314         unsigned char in_tq, in_ttl, tq_avg = 0;
 315         unsigned long send_time;
 316
 317         if (batman_packet->ttl <= 1) {
 318                 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
 319                 return;
 320         }
 321
 322         in_tq = batman_packet->tq;
 323         in_ttl = batman_packet->ttl;
 324
 325         batman_packet->ttl--;
 326         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 327
 328         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 329          * of our best tq value */
 330         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 331
 332                 /* rebroadcast ogm of best ranking neighbor as is */
 333                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 334                         batman_packet->tq = orig_node->router->tq_avg;
 335
 336                         if (orig_node->router->last_ttl)
 337                                 batman_packet->ttl = orig_node->router->last_ttl
 338                                                         - 1;
 339                 }
 340
 341                 tq_avg = orig_node->router->tq_avg;
 342         }
 343
 344         /* apply hop penalty */
 345         batman_packet->tq = hop_penalty(batman_packet->tq);
 346
 347         bat_dbg(DBG_BATMAN, bat_priv,
 348                 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 349                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 350                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 351                 batman_packet->ttl);
 352
 353         batman_packet->seqno = htonl(batman_packet->seqno);
 354
 355         /* switch of primaries first hop flag when forwarding */
 356         batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
 357         if (directlink)
 358                 batman_packet->flags |= DIRECTLINK;
 359         else
 360                 batman_packet->flags &= ~DIRECTLINK;
 361
 362         send_time = forward_send_time(bat_priv);
 363         add_bat_packet_to_list(bat_priv,
 364                                (unsigned char *)batman_packet,
 365                                sizeof(struct batman_packet) + hna_buff_len,
 366                                if_incoming, 0, send_time);
 367 }
 368
 369 static void forw_packet_free(struct forw_packet *forw_packet)
 370 {
 371         if (forw_packet->skb)
 372                 kfree_skb(forw_packet->skb);
 373         kfree(forw_packet->packet_buff);
 374         kfree(forw_packet);
 375 }
 376
 377 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 378                                       unsigned long send_time)
 379 {
 380         unsigned long flags;
 381         INIT_HLIST_NODE(&forw_packet->list);
 382
 383         /* add new packet to packet list */
 384         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 385         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 386         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 387
 388         /* start timer for this packet */
 389         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 390                           send_outstanding_bcast_packet);
 391         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 392                            send_time);
 393 }
 394
 395 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 396 /* add a broadcast packet to the queue and setup timers. broadcast packets
 397  * are sent multiple times to increase probability for beeing received.
 398  *
 399  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 400  * errors.
 401  *
 402  * The skb is not consumed, so the caller should make sure that the
 403  * skb is freed. */
 404 int add_bcast_packet_to_list(struct sk_buff *skb)
 405 {
 406         struct forw_packet *forw_packet;
 407         struct bcast_packet *bcast_packet;
 408         /* FIXME: each batman_if will be attached to a softif */
 409         struct bat_priv *bat_priv = netdev_priv(soft_device);
 410
 411         if (!atomic_dec_not_zero(&bcast_queue_left)) {
 412                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 413                 goto out;
 414         }
 415
 416         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 417
 418         if (!forw_packet)
 419                 goto out_and_inc;
 420
 421         skb = skb_copy(skb, GFP_ATOMIC);
 422         if (!skb)
 423                 goto packet_free;
 424
 425         /* as we have a copy now, it is safe to decrease the TTL */
 426         bcast_packet = (struct bcast_packet *)skb->data;
 427         bcast_packet->ttl--;
 428
 429         skb_reset_mac_header(skb);
 430
 431         forw_packet->skb = skb;
 432         forw_packet->packet_buff = NULL;
 433
 434         /* how often did we send the bcast packet ? */
 435         forw_packet->num_packets = 0;
 436
 437         _add_bcast_packet_to_list(forw_packet, 1);
 438         return NETDEV_TX_OK;
 439
 440 packet_free:
 441         kfree(forw_packet);
 442 out_and_inc:
 443         atomic_inc(&bcast_queue_left);
 444 out:
 445         return NETDEV_TX_BUSY;
 446 }
 447
 448 static void send_outstanding_bcast_packet(struct work_struct *work)
 449 {
 450         struct batman_if *batman_if;
 451         struct delayed_work *delayed_work =
 452                 container_of(work, struct delayed_work, work);
 453         struct forw_packet *forw_packet =
 454                 container_of(delayed_work, struct forw_packet, delayed_work);
 455         unsigned long flags;
 456         struct sk_buff *skb1;
 457
 458         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 459         hlist_del(&forw_packet->list);
 460         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 461
 462         if (atomic_read(&module_state) == MODULE_DEACTIVATING)
 463                 goto out;
 464
 465         /* rebroadcast packet */
 466         rcu_read_lock();
 467         list_for_each_entry_rcu(batman_if, &if_list, list) {
 468                 /* send a copy of the saved skb */
 469                 skb1 = skb_copy(forw_packet->skb, GFP_ATOMIC);
 470                 if (skb1)
 471                         send_skb_packet(skb1,
 472                                 batman_if, broadcast_addr);
 473         }
 474         rcu_read_unlock();
 475
 476         forw_packet->num_packets++;
 477
 478         /* if we still have some more bcasts to send */
 479         if (forw_packet->num_packets < 3) {
 480                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 481                 return;
 482         }
 483
 484 out:
 485         forw_packet_free(forw_packet);
 486         atomic_inc(&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         unsigned long flags;
 496
 497         spin_lock_irqsave(&forw_bat_list_lock, flags);
 498         hlist_del(&forw_packet->list);
 499         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 500
 501         if (atomic_read(&module_state) == MODULE_DEACTIVATING)
 502                 goto out;
 503
 504         send_packet(forw_packet);
 505
 506         /**
 507          * we have to have at least one packet in the queue
 508          * to determine the queues wake up time unless we are
 509          * shutting down
 510          */
 511         if (forw_packet->own)
 512                 schedule_own_packet(forw_packet->if_incoming);
 513
 514 out:
 515         /* don't count own packet */
 516         if (!forw_packet->own)
 517                 atomic_inc(&batman_queue_left);
 518
 519         forw_packet_free(forw_packet);
 520 }
 521
 522 void purge_outstanding_packets(struct batman_if *batman_if)
 523 {
 524         /* FIXME: each batman_if will be attached to a softif */
 525         struct bat_priv *bat_priv = netdev_priv(soft_device);
 526         struct forw_packet *forw_packet;
 527         struct hlist_node *tmp_node, *safe_tmp_node;
 528         unsigned long flags;
 529
 530         if (batman_if)
 531                 bat_dbg(DBG_BATMAN, bat_priv,
 532                         "purge_outstanding_packets(): %s\n",
 533                         batman_if->dev);
 534         else
 535                 bat_dbg(DBG_BATMAN, bat_priv,
 536                         "purge_outstanding_packets()\n");
 537
 538         /* free bcast list */
 539         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 540         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 541                                   &forw_bcast_list, list) {
 542
 543                 /**
 544                  * if purge_outstanding_packets() was called with an argmument
 545                  * we delete only packets belonging to the given interface
 546                  */
 547                 if ((batman_if) &&
 548                     (forw_packet->if_incoming != batman_if))
 549                         continue;
 550
 551                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 552
 553                 /**
 554                  * send_outstanding_bcast_packet() will lock the list to
 555                  * delete the item from the list
 556                  */
 557                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 558                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 559         }
 560         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 561
 562         /* free batman packet list */
 563         spin_lock_irqsave(&forw_bat_list_lock, flags);
 564         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 565                                   &forw_bat_list, list) {
 566
 567                 /**
 568                  * if purge_outstanding_packets() was called with an argmument
 569                  * we delete only packets belonging to the given interface
 570                  */
 571                 if ((batman_if) &&
 572                     (forw_packet->if_incoming != batman_if))
 573                         continue;
 574
 575                 spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 576
 577                 /**
 578                  * send_outstanding_bat_packet() will lock the list to
 579                  * delete the item from the list
 580                  */
 581                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 582                 spin_lock_irqsave(&forw_bat_list_lock, flags);
 583         }
 584         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 585 }