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 "
  69                        "is not up - can't send packet via that interface!\n",
  70                        batman_if->dev);
  71                 goto send_skb_err;
  72         }
  73
  74         /* push to the ethernet header. */
  75         if (my_skb_push(skb, sizeof(struct ethhdr)) < 0)
  76                 goto send_skb_err;
  77
  78         skb_reset_mac_header(skb);
  79
  80         ethhdr = (struct ethhdr *) skb_mac_header(skb);
  81         memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
  82         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  83         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  84
  85         skb_set_network_header(skb, ETH_HLEN);
  86         skb->priority = TC_PRIO_CONTROL;
  87         skb->protocol = __constant_htons(ETH_P_BATMAN);
  88
  89         skb->dev = batman_if->net_dev;
  90
  91         /* dev_queue_xmit() returns a negative result on error.  However on
  92          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  93          * (which is > 0). This will not be treated as an error. */
  94
  95         return dev_queue_xmit(skb);
  96 send_skb_err:
  97         kfree_skb(skb);
  98         return NET_XMIT_DROP;
  99 }
 100
 101 /* sends a raw packet. */
 102 void send_raw_packet(unsigned char *pack_buff, int pack_buff_len,
 103                      struct batman_if *batman_if, uint8_t *dst_addr)
 104 {
 105         struct sk_buff *skb;
 106         char *data;
 107
 108         skb = dev_alloc_skb(pack_buff_len + sizeof(struct ethhdr));
 109         if (!skb)
 110                 return;
 111         data = skb_put(skb, pack_buff_len + sizeof(struct ethhdr));
 112         memcpy(data + sizeof(struct ethhdr), pack_buff, pack_buff_len);
 113         /* pull back to the batman "network header" */
 114         skb_pull(skb, sizeof(struct ethhdr));
 115         send_skb_packet(skb, batman_if, dst_addr);
 116 }
 117
 118 /* Send a packet to a given interface */
 119 static void send_packet_to_if(struct forw_packet *forw_packet,
 120                               struct batman_if *batman_if)
 121 {
 122         char *fwd_str;
 123         uint8_t packet_num;
 124         int16_t buff_pos;
 125         struct batman_packet *batman_packet;
 126
 127         if (batman_if->if_status != IF_ACTIVE)
 128                 return;
 129
 130         packet_num = 0;
 131         buff_pos = 0;
 132         batman_packet = (struct batman_packet *)
 133                 (forw_packet->packet_buff);
 134
 135         /* adjust all flags and log packets */
 136         while (aggregated_packet(buff_pos,
 137                                  forw_packet->packet_len,
 138                                  batman_packet->num_hna)) {
 139
 140                 /* we might have aggregated direct link packets with an
 141                  * ordinary base packet */
 142                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 143                     (forw_packet->if_incoming == batman_if))
 144                         batman_packet->flags |= DIRECTLINK;
 145                 else
 146                         batman_packet->flags &= ~DIRECTLINK;
 147
 148                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 149                                                             "Sending own" :
 150                                                             "Forwarding"));
 151                 bat_dbg(DBG_BATMAN,
 152                         "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
 153                         " IDF %s) on interface %s [%s]\n",
 154                         fwd_str, (packet_num > 0 ? "aggregated " : ""),
 155                         batman_packet->orig, ntohs(batman_packet->seqno),
 156                         batman_packet->tq, batman_packet->ttl,
 157                         (batman_packet->flags & DIRECTLINK ?
 158                          "on" : "off"),
 159                         batman_if->dev, batman_if->addr_str);
 160
 161                 buff_pos += sizeof(struct batman_packet) +
 162                         (batman_packet->num_hna * ETH_ALEN);
 163                 packet_num++;
 164                 batman_packet = (struct batman_packet *)
 165                         (forw_packet->packet_buff + buff_pos);
 166         }
 167
 168         send_raw_packet(forw_packet->packet_buff,
 169                         forw_packet->packet_len,
 170                         batman_if, broadcastAddr);
 171 }
 172
 173 /* send a batman packet */
 174 static void send_packet(struct forw_packet *forw_packet)
 175 {
 176         struct batman_if *batman_if;
 177         struct batman_packet *batman_packet =
 178                 (struct batman_packet *)(forw_packet->packet_buff);
 179         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 180
 181         if (!forw_packet->if_incoming) {
 182                 printk(KERN_ERR "batman-adv: Error - can't forward packet: "
 183                        "incoming iface not specified\n");
 184                 return;
 185         }
 186
 187         if (forw_packet->if_incoming->if_status != IF_ACTIVE)
 188                 return;
 189
 190         /* multihomed peer assumed */
 191         /* non-primary OGMs are only broadcasted on their interface */
 192         if ((directlink && (batman_packet->ttl == 1)) ||
 193             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 194
 195                 /* FIXME: what about aggregated packets ? */
 196                 bat_dbg(DBG_BATMAN,
 197                         "%s packet (originator %pM, seqno %d, TTL %d) "
 198                         "on interface %s [%s]\n",
 199                         (forw_packet->own ? "Sending own" : "Forwarding"),
 200                         batman_packet->orig, ntohs(batman_packet->seqno),
 201                         batman_packet->ttl, forw_packet->if_incoming->dev,
 202                         forw_packet->if_incoming->addr_str);
 203
 204                 send_raw_packet(forw_packet->packet_buff,
 205                                 forw_packet->packet_len,
 206                                 forw_packet->if_incoming,
 207                                 broadcastAddr);
 208                 return;
 209         }
 210
 211         /* broadcast on every interface */
 212         rcu_read_lock();
 213         list_for_each_entry_rcu(batman_if, &if_list, list)
 214                 send_packet_to_if(forw_packet, batman_if);
 215         rcu_read_unlock();
 216 }
 217
 218 static void rebuild_batman_packet(struct batman_if *batman_if)
 219 {
 220         int new_len;
 221         unsigned char *new_buff;
 222         struct batman_packet *batman_packet;
 223
 224         new_len = sizeof(struct batman_packet) + (num_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(
 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         /* FIXME: each batman_if will be attached to a softif */
 246         struct bat_priv *bat_priv = netdev_priv(soft_device);
 247         unsigned long send_time;
 248         struct batman_packet *batman_packet;
 249         int vis_server;
 250
 251         if ((batman_if->if_status == IF_NOT_IN_USE) ||
 252             (batman_if->if_status == IF_TO_BE_REMOVED))
 253                 return;
 254
 255         vis_server = atomic_read(&bat_priv->vis_mode);
 256
 257         /**
 258          * the interface gets activated here to avoid race conditions between
 259          * the moment of activating the interface in
 260          * hardif_activate_interface() where the originator mac is set and
 261          * outdated packets (especially uninitialized mac addresses) in the
 262          * packet queue
 263          */
 264         if (batman_if->if_status == IF_TO_BE_ACTIVATED)
 265                 batman_if->if_status = IF_ACTIVE;
 266
 267         /* if local hna has changed and interface is a primary interface */
 268         if ((atomic_read(&hna_local_changed)) &&
 269             (batman_if == bat_priv->primary_if))
 270                 rebuild_batman_packet(batman_if);
 271
 272         /**
 273          * NOTE: packet_buff might just have been re-allocated in
 274          * rebuild_batman_packet()
 275          */
 276         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 277
 278         /* change sequence number to network order */
 279         batman_packet->seqno = htons((uint16_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         /* could be read by receive_bat_packet() */
 287         atomic_inc(&batman_if->seqno);
 288
 289         slide_own_bcast_window(batman_if);
 290         send_time = own_send_time(bat_priv);
 291         add_bat_packet_to_list(bat_priv,
 292                                batman_if->packet_buff,
 293                                batman_if->packet_len,
 294                                batman_if, 1, send_time);
 295 }
 296
 297 void schedule_forward_packet(struct orig_node *orig_node,
 298                              struct ethhdr *ethhdr,
 299                              struct batman_packet *batman_packet,
 300                              uint8_t directlink, int hna_buff_len,
 301                              struct batman_if *if_incoming)
 302 {
 303         /* FIXME: each batman_if will be attached to a softif */
 304         struct bat_priv *bat_priv = netdev_priv(soft_device);
 305         unsigned char in_tq, in_ttl, tq_avg = 0;
 306         unsigned long send_time;
 307
 308         if (batman_packet->ttl <= 1) {
 309                 bat_dbg(DBG_BATMAN, "ttl exceeded\n");
 310                 return;
 311         }
 312
 313         in_tq = batman_packet->tq;
 314         in_ttl = batman_packet->ttl;
 315
 316         batman_packet->ttl--;
 317         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 318
 319         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 320          * of our best tq value */
 321         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 322
 323                 /* rebroadcast ogm of best ranking neighbor as is */
 324                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 325                         batman_packet->tq = orig_node->router->tq_avg;
 326
 327                         if (orig_node->router->last_ttl)
 328                                 batman_packet->ttl = orig_node->router->last_ttl
 329                                                         - 1;
 330                 }
 331
 332                 tq_avg = orig_node->router->tq_avg;
 333         }
 334
 335         /* apply hop penalty */
 336         batman_packet->tq = hop_penalty(batman_packet->tq);
 337
 338         bat_dbg(DBG_BATMAN, "Forwarding packet: tq_orig: %i, tq_avg: %i, "
 339                 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
 340                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 341                 batman_packet->ttl);
 342
 343         batman_packet->seqno = htons(batman_packet->seqno);
 344
 345         if (directlink)
 346                 batman_packet->flags |= DIRECTLINK;
 347         else
 348                 batman_packet->flags &= ~DIRECTLINK;
 349
 350         send_time = forward_send_time(bat_priv);
 351         add_bat_packet_to_list(bat_priv,
 352                                (unsigned char *)batman_packet,
 353                                sizeof(struct batman_packet) + hna_buff_len,
 354                                if_incoming, 0, send_time);
 355 }
 356
 357 static void forw_packet_free(struct forw_packet *forw_packet)
 358 {
 359         if (forw_packet->skb)
 360                 kfree_skb(forw_packet->skb);
 361         kfree(forw_packet->packet_buff);
 362         kfree(forw_packet);
 363 }
 364
 365 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 366                                       unsigned long send_time)
 367 {
 368         unsigned long flags;
 369         INIT_HLIST_NODE(&forw_packet->list);
 370
 371         /* add new packet to packet list */
 372         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 373         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 374         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 375
 376         /* start timer for this packet */
 377         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 378                           send_outstanding_bcast_packet);
 379         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 380                            send_time);
 381 }
 382
 383 #define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
 384 /* add a broadcast packet to the queue and setup timers. broadcast packets
 385  * are sent multiple times to increase probability for beeing received.
 386  *
 387  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 388  * errors.
 389  *
 390  * The skb is not consumed, so the caller should make sure that the
 391  * skb is freed. */
 392 int add_bcast_packet_to_list(struct sk_buff *skb)
 393 {
 394         struct forw_packet *forw_packet;
 395
 396         if (!atomic_dec_not_zero(&bcast_queue_left)) {
 397                 bat_dbg(DBG_BATMAN, "bcast packet queue full\n");
 398                 goto out;
 399         }
 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         skb_reset_mac_header(skb);
 411
 412         forw_packet->skb = skb;
 413         forw_packet->packet_buff = NULL;
 414
 415         /* how often did we send the bcast packet ? */
 416         forw_packet->num_packets = 0;
 417
 418         _add_bcast_packet_to_list(forw_packet, 1);
 419         return NETDEV_TX_OK;
 420
 421 packet_free:
 422         kfree(forw_packet);
 423 out_and_inc:
 424         atomic_inc(&bcast_queue_left);
 425 out:
 426         return NETDEV_TX_BUSY;
 427 }
 428
 429 void send_outstanding_bcast_packet(struct work_struct *work)
 430 {
 431         struct batman_if *batman_if;
 432         struct delayed_work *delayed_work =
 433                 container_of(work, struct delayed_work, work);
 434         struct forw_packet *forw_packet =
 435                 container_of(delayed_work, struct forw_packet, delayed_work);
 436         unsigned long flags;
 437         struct sk_buff *skb1;
 438
 439         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 440         hlist_del(&forw_packet->list);
 441         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 442
 443         /* rebroadcast packet */
 444         rcu_read_lock();
 445         list_for_each_entry_rcu(batman_if, &if_list, list) {
 446                 /* send a copy of the saved skb */
 447                 skb1 = skb_copy(forw_packet->skb, GFP_ATOMIC);
 448                 if (skb1)
 449                         send_skb_packet(skb1,
 450                                 batman_if, broadcastAddr);
 451         }
 452         rcu_read_unlock();
 453
 454         forw_packet->num_packets++;
 455
 456         /* if we still have some more bcasts to send and we are not shutting
 457          * down */
 458         if ((forw_packet->num_packets < 3) &&
 459             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 460                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 461         else {
 462                 forw_packet_free(forw_packet);
 463                 atomic_inc(&bcast_queue_left);
 464         }
 465 }
 466
 467 void send_outstanding_bat_packet(struct work_struct *work)
 468 {
 469         struct delayed_work *delayed_work =
 470                 container_of(work, struct delayed_work, work);
 471         struct forw_packet *forw_packet =
 472                 container_of(delayed_work, struct forw_packet, delayed_work);
 473         unsigned long flags;
 474
 475         spin_lock_irqsave(&forw_bat_list_lock, flags);
 476         hlist_del(&forw_packet->list);
 477         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 478
 479         send_packet(forw_packet);
 480
 481         /**
 482          * we have to have at least one packet in the queue
 483          * to determine the queues wake up time unless we are
 484          * shutting down
 485          */
 486         if ((forw_packet->own) &&
 487             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 488                 schedule_own_packet(forw_packet->if_incoming);
 489
 490         /* don't count own packet */
 491         if (!forw_packet->own)
 492                 atomic_inc(&batman_queue_left);
 493
 494         forw_packet_free(forw_packet);
 495 }
 496
 497 void purge_outstanding_packets(struct batman_if *batman_if)
 498 {
 499         struct forw_packet *forw_packet;
 500         struct hlist_node *tmp_node, *safe_tmp_node;
 501         unsigned long flags;
 502
 503         if (batman_if)
 504                 bat_dbg(DBG_BATMAN, "purge_outstanding_packets(): %s\n",
 505                         batman_if->dev);
 506         else
 507                 bat_dbg(DBG_BATMAN, "purge_outstanding_packets()\n");
 508
 509         /* free bcast list */
 510         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 511         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 512                                   &forw_bcast_list, list) {
 513
 514                 /**
 515                  * if purge_outstanding_packets() was called with an argmument
 516                  * we delete only packets belonging to the given interface
 517                  */
 518                 if ((batman_if) &&
 519                     (forw_packet->if_incoming != batman_if))
 520                         continue;
 521
 522                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 523
 524                 /**
 525                  * send_outstanding_bcast_packet() will lock the list to
 526                  * delete the item from the list
 527                  */
 528                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 529                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 530         }
 531         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 532
 533         /* free batman packet list */
 534         spin_lock_irqsave(&forw_bat_list_lock, flags);
 535         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 536                                   &forw_bat_list, list) {
 537
 538                 /**
 539                  * if purge_outstanding_packets() was called with an argmument
 540                  * we delete only packets belonging to the given interface
 541                  */
 542                 if ((batman_if) &&
 543                     (forw_packet->if_incoming != batman_if))
 544                         continue;
 545
 546                 spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 547
 548                 /**
 549                  * send_outstanding_bat_packet() will lock the list to
 550                  * delete the item from the list
 551                  */
 552                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 553                 spin_lock_irqsave(&forw_bat_list_lock, flags);
 554         }
 555         spin_unlock_irqrestore(&forw_bat_list_lock, flags);
 556 }