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 /* apply hop penalty for a normal link */
  33 static uint8_t hop_penalty(const uint8_t tq)
  34 {
  35         return (tq * (TQ_MAX_VALUE - TQ_HOP_PENALTY)) / (TQ_MAX_VALUE);
  36 }
  37
  38 /* when do we schedule our own packet to be sent */
  39 static unsigned long own_send_time(struct bat_priv *bat_priv)
  40 {
  41         return jiffies +
  42                 (((atomic_read(&bat_priv->orig_interval) - JITTER +
  43                    (random32() % 2*JITTER)) * HZ) / 1000);
  44 }
  45
  46 /* when do we schedule a forwarded packet to be sent */
  47 static unsigned long forward_send_time(struct bat_priv *bat_priv)
  48 {
  49         return jiffies + (((random32() % (JITTER/2)) * HZ) / 1000);
  50 }
  51
  52 /* send out an already prepared packet to the given address via the
  53  * specified batman interface */
  54 int send_skb_packet(struct sk_buff *skb,
  55                                 struct batman_if *batman_if,
  56                                 uint8_t *dst_addr)
  57 {
  58         struct ethhdr *ethhdr;
  59
  60         if (batman_if->if_status != IF_ACTIVE)
  61                 goto send_skb_err;
  62
  63         if (unlikely(!batman_if->net_dev))
  64                 goto send_skb_err;
  65
  66         if (!(batman_if->net_dev->flags & IFF_UP)) {
  67                 printk(KERN_WARNING
  68                        "batman-adv:Interface %s is not up - can't send packet via that interface!\n",
  69                        batman_if->dev);
  70                 goto send_skb_err;
  71         }
  72
  73         /* push to the ethernet header. */
  74         if (my_skb_push(skb, sizeof(struct ethhdr)) < 0)
  75                 goto send_skb_err;
  76
  77         skb_reset_mac_header(skb);
  78
  79         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  80         memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
  81         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  82         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  83
  84         skb_set_network_header(skb, ETH_HLEN);
  85         skb->priority = TC_PRIO_CONTROL;
  86         skb->protocol = __constant_htons(ETH_P_BATMAN);
  87
  88         skb->dev = batman_if->net_dev;
  89
  90         /* dev_queue_xmit() returns a negative result on error.  However on
  91          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  92          * (which is > 0). This will not be treated as an error. */
  93
  94         return dev_queue_xmit(skb);
  95 send_skb_err:
  96         kfree_skb(skb);
  97         return NET_XMIT_DROP;
  98 }
  99
 100 /* sends a raw packet. */
 101 void send_raw_packet(unsigned char *pack_buff, int pack_buff_len,
 102                      struct batman_if *batman_if, uint8_t *dst_addr)
 103 {
 104         struct sk_buff *skb;
 105         char *data;
 106
 107         skb = dev_alloc_skb(pack_buff_len + sizeof(struct ethhdr));
 108         if (!skb)
 109                 return;
 110         data = skb_put(skb, pack_buff_len + sizeof(struct ethhdr));
 111         memcpy(data + sizeof(struct ethhdr), pack_buff, pack_buff_len);
 112         /* pull back to the batman "network header" */
 113         skb_pull(skb, sizeof(struct ethhdr));
 114         send_skb_packet(skb, batman_if, dst_addr);
 115 }
 116
 117 /* Send a packet to a given interface */
 118 static void send_packet_to_if(struct forw_packet *forw_packet,
 119                               struct batman_if *batman_if)
 120 {
 121         char *fwd_str;
 122         uint8_t packet_num;
 123         int16_t buff_pos;
 124         struct batman_packet *batman_packet;
 125
 126         if (batman_if->if_status != IF_ACTIVE)
 127                 return;
 128
 129         packet_num = 0;
 130         buff_pos = 0;
 131         batman_packet = (struct batman_packet *)
 132                 (forw_packet->packet_buff);
 133
 134         /* adjust all flags and log packets */
 135         while (aggregated_packet(buff_pos,
 136                                  forw_packet->packet_len,
 137                                  batman_packet->num_hna)) {
 138
 139                 /* we might have aggregated direct link packets with an
 140                  * ordinary base packet */
 141                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 142                     (forw_packet->if_incoming == batman_if))
 143                         batman_packet->flags |= DIRECTLINK;
 144                 else
 145                         batman_packet->flags &= ~DIRECTLINK;
 146
 147                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 148                                                             "Sending own" :
 149                                                             "Forwarding"));
 150                 bat_dbg(DBG_BATMAN,
 151                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d, IDF %s) on interface %s [%s]\n",
 152                         fwd_str,
 153                         (packet_num > 0 ? "aggregated " : ""),
 154                         batman_packet->orig, ntohs(batman_packet->seqno),
 155                         batman_packet->tq, batman_packet->ttl,
 156                         (batman_packet->flags & DIRECTLINK ?
 157                          "on" : "off"),
 158                         batman_if->dev, batman_if->addr_str);
 159
 160                 buff_pos += sizeof(struct batman_packet) +
 161                         (batman_packet->num_hna * ETH_ALEN);
 162                 packet_num++;
 163                 batman_packet = (struct batman_packet *)
 164                         (forw_packet->packet_buff + buff_pos);
 165         }
 166
 167         send_raw_packet(forw_packet->packet_buff,
 168                         forw_packet->packet_len,
 169                         batman_if, broadcastAddr);
 170 }
 171
 172 /* send a batman packet */
 173 static void send_packet(struct forw_packet *forw_packet)
 174 {
 175         struct batman_if *batman_if;
 176         struct batman_packet *batman_packet =
 177                 (struct batman_packet *)(forw_packet->packet_buff);
 178         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 179
 180         if (!forw_packet->if_incoming) {
 181                 printk(KERN_ERR "batman-adv: Error - can't forward packet: incoming iface not specified\n");
 182                 return;
 183         }
 184
 185         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 186                 return;
 187
 188         /* multihomed peer assumed */
 189         /* non-primary OGMs are only broadcasted on their interface */
 190         if ((directlink && (batman_packet->ttl == 1)) ||
 191             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 192
 193                 /* FIXME: what about aggregated packets ? */
 194                 bat_dbg(DBG_BATMAN,
 195                         "%s packet (originator %pM, seqno %d, TTL %d) on interface %s [%s]\n",
 196                         (forw_packet->own ? "Sending own" : "Forwarding"),
 197                         batman_packet->orig, ntohs(batman_packet->seqno),
 198                         batman_packet->ttl, forw_packet->if_incoming->dev,
 199                         forw_packet->if_incoming->addr_str);
 200
 201                 send_raw_packet(forw_packet->packet_buff,
 202                                 forw_packet->packet_len,
 203                                 forw_packet->if_incoming,
 204                                 broadcastAddr);
 205                 return;
 206         }
 207
 208         /* broadcast on every interface */
 209         rcu_read_lock();
 210         list_for_each_entry_rcu(batman_if, &if_list, list)
 211                 send_packet_to_if(forw_packet, batman_if);
 212         rcu_read_unlock();
 213 }
 214
 215 static void rebuild_batman_packet(struct batman_if *batman_if)
 216 {
 217         int new_len;
 218         unsigned char *new_buff;
 219         struct batman_packet *batman_packet;
 220
 221         new_len = sizeof(struct batman_packet) + (num_hna * ETH_ALEN);
 222         new_buff = kmalloc(new_len, GFP_ATOMIC);
 223
 224         /* keep old buffer if kmalloc should fail */
 225         if (new_buff) {
 226                 memcpy(new_buff, batman_if->packet_buff,
 227                        sizeof(struct batman_packet));
 228                 batman_packet = (struct batman_packet *)new_buff;
 229
 230                 batman_packet->num_hna = hna_local_fill_buffer(
 231                         new_buff + sizeof(struct batman_packet),
 232                         new_len - sizeof(struct batman_packet));
 233
 234                 kfree(batman_if->packet_buff);
 235                 batman_if->packet_buff = new_buff;
 236                 batman_if->packet_len = new_len;
 237         }
 238 }
 239
 240 void schedule_own_packet(struct batman_if *batman_if)
 241 {
 242         /* FIXME: each batman_if will be attached to a softif */
 243         struct bat_priv *bat_priv = netdev_priv(soft_device);
 244         unsigned long send_time;
 245         struct batman_packet *batman_packet;
 246         int vis_server;
 247
 248         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 249             (batman_if->if_status == IF_TO_BE_REMOVED))
 250                 return;
 251
 252         vis_server = atomic_read(&bat_priv->vis_mode);
 253
 254         /**
 255          * the interface gets activated here to avoid race conditions between
 256          * the moment of activating the interface in
 257          * hardif_activate_interface() where the originator mac is set and
 258          * outdated packets (especially uninitialized mac addresses) in the
 259          * packet queue
 260          */
 261         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 262                 batman_if->if_status = IF_ACTIVE;
 263
 264         /* if local hna has changed and interface is a primary interface */
 265         if ((atomic_read(&hna_local_changed)) &&
 266             (batman_if == bat_priv->primary_if))
 267                 rebuild_batman_packet(batman_if);
 268
 269         /**
 270          * NOTE: packet_buff might just have been re-allocated in
 271          * rebuild_batman_packet()
 272          */
 273         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 274
 275         /* change sequence number to network order */
 276         batman_packet->seqno = htons((uint16_t)atomic_read(&batman_if->seqno));
 277
 278         if (vis_server == VIS_TYPE_SERVER_SYNC)
 279                 batman_packet->flags = VIS_SERVER;
 280         else
 281                 batman_packet->flags &= ~VIS_SERVER;
 282
 283         /* could be read by receive_bat_packet() */
 284         atomic_inc(&batman_if->seqno);
 285
 286         slide_own_bcast_window(batman_if);
 287         send_time = own_send_time(bat_priv);
 288         add_bat_packet_to_list(bat_priv,
 289                                batman_if->packet_buff,
 290                                batman_if->packet_len,
 291                                batman_if, 1, send_time);
 292 }
 293
 294 void schedule_forward_packet(struct orig_node *orig_node,
 295                              struct ethhdr *ethhdr,
 296                              struct batman_packet *batman_packet,
 297                              uint8_t directlink, int hna_buff_len,
 298                              struct batman_if *if_incoming)
 299 {
 300         /* FIXME: each batman_if will be attached to a softif */
 301         struct bat_priv *bat_priv = netdev_priv(soft_device);
 302         unsigned char in_tq, in_ttl, tq_avg = 0;
 303         unsigned long send_time;
 304
 305         if (batman_packet->ttl <= 1) {
 306                 bat_dbg(DBG_BATMAN, "ttl exceeded\n");
 307                 return;
 308         }
 309
 310         in_tq = batman_packet->tq;
 311         in_ttl = batman_packet->ttl;
 312
 313         batman_packet->ttl--;
 314         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 315
 316         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 317          * of our best tq value */
 318         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 319
 320                 /* rebroadcast ogm of best ranking neighbor as is */
 321                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 322                         batman_packet->tq = orig_node->router->tq_avg;
 323
 324                         if (orig_node->router->last_ttl)
 325                                 batman_packet->ttl = orig_node->router->last_ttl - 1;
 326                 }
 327
 328                 tq_avg = orig_node->router->tq_avg;
 329         }
 330
 331         /* apply hop penalty */
 332         batman_packet->tq = hop_penalty(batman_packet->tq);
 333
 334         bat_dbg(DBG_BATMAN, "Forwarding packet: tq_orig: %i, tq_avg: %i, tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 335                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 336                 batman_packet->ttl);
 337
 338         batman_packet->seqno = htons(batman_packet->seqno);
 339
 340         if (directlink)
 341                 batman_packet->flags |= DIRECTLINK;
 342         else
 343                 batman_packet->flags &= ~DIRECTLINK;
 344
 345         send_time = forward_send_time(bat_priv);
 346         add_bat_packet_to_list(bat_priv,
 347                                (unsigned char *)batman_packet,
 348                                sizeof(struct batman_packet) + hna_buff_len,
 349                                if_incoming, 0, send_time);
 350 }
 351
 352 static void forw_packet_free(struct forw_packet *forw_packet)
 353 {
 354         if (forw_packet->skb)
 355                 kfree_skb(forw_packet->skb);
 356         kfree(forw_packet->packet_buff);
 357         kfree(forw_packet);
 358 }
 359
 360 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 361                                       unsigned long send_time)
 362 {
 363         unsigned long flags;
 364         INIT_HLIST_NODE(&forw_packet->list);
 365
 366         /* add new packet to packet list */
 367         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 368         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 369         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 370
 371         /* start timer for this packet */
 372         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 373                           send_outstanding_bcast_packet);
 374         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 375                            send_time);
 376 }
 377
 378 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 379 /* add a broadcast packet to the queue and setup timers. broadcast packets
 380  * are sent multiple times to increase probability for beeing received.
 381  *
 382  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 383  * errors.
 384  *
 385  * The skb is not consumed, so the caller should make sure that the
 386  * skb is freed. */
 387 int add_bcast_packet_to_list(struct sk_buff *skb)
 388 {
 389         struct forw_packet *forw_packet;
 390
 391         if (!atomic_dec_not_zero(&bcast_queue_left)) {
 392                 bat_dbg(DBG_BATMAN, "bcast packet queue full\n");
 393                 goto out;
 394         }
 395
 396         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 397
 398         if (!forw_packet)
 399                 goto out_and_inc;
 400
 401         skb = skb_copy(skb, GFP_ATOMIC);
 402         if (!skb)
 403                 goto packet_free;
 404
 405         skb_reset_mac_header(skb);
 406
 407         forw_packet->skb = skb;
 408         forw_packet->packet_buff = NULL;
 409
 410         /* how often did we send the bcast packet ? */
 411         forw_packet->num_packets = 0;
 412
 413         _add_bcast_packet_to_list(forw_packet, 1);
 414         return NETDEV_TX_OK;
 415
 416 packet_free:
 417         kfree(forw_packet);
 418 out_and_inc:
 419         atomic_inc(&bcast_queue_left);
 420 out:
 421         return NETDEV_TX_BUSY;
 422 }
 423
 424 void send_outstanding_bcast_packet(struct work_struct *work)
 425 {
 426         struct batman_if *batman_if;
 427         struct delayed_work *delayed_work =
 428                 container_of(work, struct delayed_work, work);
 429         struct forw_packet *forw_packet =
 430                 container_of(delayed_work, struct forw_packet, delayed_work);
 431         unsigned long flags;
 432         struct sk_buff *skb1;
 433
 434         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 435         hlist_del(&forw_packet->list);
 436         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 437
 438         /* rebroadcast packet */
 439         rcu_read_lock();
 440         list_for_each_entry_rcu(batman_if, &if_list, list) {
 441                 /* send a copy of the saved skb */
 442                 skb1 = skb_copy(forw_packet->skb, GFP_ATOMIC);
 443                 if (skb1)
 444                         send_skb_packet(skb1,
 445                                 batman_if, broadcastAddr);
 446         }
 447         rcu_read_unlock();
 448
 449         forw_packet->num_packets++;
 450
 451         /* if we still have some more bcasts to send and we are not shutting
 452          * down */
 453         if ((forw_packet->num_packets < 3) &&
 454             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 455                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 456         else {
 457                 forw_packet_free(forw_packet);
 458                 atomic_inc(&bcast_queue_left);
 459         }
 460 }
 461
 462 void send_outstanding_bat_packet(struct work_struct *work)
 463 {
 464         struct delayed_work *delayed_work =
 465                 container_of(work, struct delayed_work, work);
 466         struct forw_packet *forw_packet =
 467                 container_of(delayed_work, struct forw_packet, delayed_work);
 468         unsigned long flags;
 469
 470         spin_lock_irqsave(&forw_bat_list_lock, flags);
 471         hlist_del(&forw_packet->list);
 472         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 473
 474         send_packet(forw_packet);
 475
 476         /**
 477          * we have to have at least one packet in the queue
 478          * to determine the queues wake up time unless we are
 479          * shutting down
 480          */
 481         if ((forw_packet->own) &&
 482             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 483                 schedule_own_packet(forw_packet->if_incoming);
 484
 485         /* don't count own packet */
 486         if (!forw_packet->own)
 487                 atomic_inc(&batman_queue_left);
 488
 489         forw_packet_free(forw_packet);
 490 }
 491
 492 void purge_outstanding_packets(struct batman_if *batman_if)
 493 {
 494         struct forw_packet *forw_packet;
 495         struct hlist_node *tmp_node, *safe_tmp_node;
 496         unsigned long flags;
 497
 498         if (batman_if)
 499                 bat_dbg(DBG_BATMAN, "purge_outstanding_packets(): %s\n",
 500                         batman_if->dev);
 501         else
 502                 bat_dbg(DBG_BATMAN, "purge_outstanding_packets()\n");
 503
 504         /* free bcast list */
 505         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 506         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 507                                   &forw_bcast_list, list) {
 508
 509                 /**
 510                  * if purge_outstanding_packets() was called with an argmument
 511                  * we delete only packets belonging to the given interface
 512                  */
 513                 if ((batman_if) &&
 514                     (forw_packet->if_incoming != batman_if))
 515                         continue;
 516
 517                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 518
 519                 /**
 520                  * send_outstanding_bcast_packet() will lock the list to
 521                  * delete the item from the list
 522                  */
 523                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 524                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 525         }
 526         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 527
 528         /* free batman packet list */
 529         spin_lock_irqsave(&forw_bat_list_lock, flags);
 530         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 531                                   &forw_bat_list, list) {
 532
 533                 /**
 534                  * if purge_outstanding_packets() was called with an argmument
 535                  * we delete only packets belonging to the given interface
 536                  */
 537                 if ((batman_if) &&
 538                     (forw_packet->if_incoming != batman_if))
 539                         continue;
 540
 541                 spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 542
 543                 /**
 544                  * send_outstanding_bat_packet() will lock the list to
 545                  * delete the item from the list
 546                  */
 547                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 548                 spin_lock_irqsave(&forw_bat_list_lock, flags);
 549         }
 550         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 551 }