drivers/staging/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2009 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 "hard-interface.h"
  27 #include "types.h"
  28 #include "vis.h"
  29 #include "aggregation.h"
  30
  31 #include "compat.h"
  32
  33 /* apply hop penalty for a normal link */
  34 static uint8_t hop_penalty(const uint8_t tq)
  35 {
  36         return (tq * (TQ_MAX_VALUE - TQ_HOP_PENALTY)) / (TQ_MAX_VALUE);
  37 }
  38
  39 /* when do we schedule our own packet to be sent */
  40 static unsigned long own_send_time(void)
  41 {
  42         return jiffies +
  43                 (((atomic_read(&originator_interval) - JITTER +
  44                    (random32() % 2*JITTER)) * HZ) / 1000);
  45 }
  46
  47 /* when do we schedule a forwarded packet to be sent */
  48 static unsigned long forward_send_time(void)
  49 {
  50         unsigned long send_time = jiffies; /* Starting now plus... */
  51
  52         if (atomic_read(&aggregation_enabled))
  53                 send_time += (((MAX_AGGREGATION_MS - (JITTER/2) +
  54                                 (random32() % JITTER)) * HZ) / 1000);
  55         else
  56                 send_time += (((random32() % (JITTER/2)) * HZ) / 1000);
  57
  58         return send_time;
  59 }
  60
  61 /* sends a raw packet. */
  62 void send_raw_packet(unsigned char *pack_buff, int pack_buff_len,
  63                      struct batman_if *batman_if, uint8_t *dst_addr)
  64 {
  65         struct ethhdr *ethhdr;
  66         struct sk_buff *skb;
  67         int retval;
  68         char *data;
  69
  70         if (batman_if->if_active != IF_ACTIVE)
  71                 return;
  72
  73         if (!(batman_if->net_dev->flags & IFF_UP)) {
  74                 printk(KERN_WARNING
  75                        "batman-adv:Interface %s is not up - can't send packet via that interface!\n",
  76                        batman_if->dev);
  77                 return;
  78         }
  79
  80         skb = dev_alloc_skb(pack_buff_len + sizeof(struct ethhdr));
  81         if (!skb)
  82                 return;
  83         data = skb_put(skb, pack_buff_len + sizeof(struct ethhdr));
  84
  85         memcpy(data + sizeof(struct ethhdr), pack_buff, pack_buff_len);
  86
  87         ethhdr = (struct ethhdr *) data;
  88         memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
  89         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  90         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  91
  92         skb_reset_mac_header(skb);
  93         skb_set_network_header(skb, ETH_HLEN);
  94         skb->priority = TC_PRIO_CONTROL;
  95         skb->protocol = __constant_htons(ETH_P_BATMAN);
  96         skb->dev = batman_if->net_dev;
  97
  98         /* dev_queue_xmit() returns a negative result on error.  However on
  99          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
 100          * (which is > 0). This will not be treated as an error. */
 101         retval = dev_queue_xmit(skb);
 102         if (retval < 0)
 103                 printk(KERN_WARNING
 104                        "batman-adv:Can't write to raw socket: %i\n",
 105                        retval);
 106 }
 107
 108 /* Send a packet to a given interface */
 109 static void send_packet_to_if(struct forw_packet *forw_packet,
 110                               struct batman_if *batman_if)
 111 {
 112         char *fwd_str;
 113         uint8_t packet_num;
 114         int16_t buff_pos;
 115         struct batman_packet *batman_packet;
 116         char orig_str[ETH_STR_LEN];
 117
 118         if (batman_if->if_active != IF_ACTIVE)
 119                 return;
 120
 121         packet_num = buff_pos = 0;
 122         batman_packet = (struct batman_packet *)
 123                 (forw_packet->packet_buff);
 124
 125         /* adjust all flags and log packets */
 126         while (aggregated_packet(buff_pos,
 127                                  forw_packet->packet_len,
 128                                  batman_packet->num_hna)) {
 129
 130                 /* we might have aggregated direct link packets with an
 131                  * ordinary base packet */
 132                 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
 133                     (forw_packet->if_incoming == batman_if))
 134                         batman_packet->flags |= DIRECTLINK;
 135                 else
 136                         batman_packet->flags &= ~DIRECTLINK;
 137
 138                 addr_to_string(orig_str, batman_packet->orig);
 139                 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
 140                                                             "Sending own" :
 141                                                             "Forwarding"));
 142                 bat_dbg(DBG_BATMAN,
 143                         "%s %spacket (originator %s, seqno %d, TQ %d, TTL %d, IDF %s) on interface %s [%s]\n",
 144                         fwd_str,
 145                         (packet_num > 0 ? "aggregated " : ""),
 146                         orig_str, ntohs(batman_packet->seqno),
 147                         batman_packet->tq, batman_packet->ttl,
 148                         (batman_packet->flags & DIRECTLINK ?
 149                          "on" : "off"),
 150                         batman_if->dev, batman_if->addr_str);
 151
 152                 buff_pos += sizeof(struct batman_packet) +
 153                         (batman_packet->num_hna * ETH_ALEN);
 154                 packet_num++;
 155                 batman_packet = (struct batman_packet *)
 156                         (forw_packet->packet_buff + buff_pos);
 157         }
 158
 159         send_raw_packet(forw_packet->packet_buff,
 160                         forw_packet->packet_len,
 161                         batman_if, broadcastAddr);
 162 }
 163
 164 /* send a batman packet */
 165 static void send_packet(struct forw_packet *forw_packet)
 166 {
 167         struct batman_if *batman_if;
 168         struct batman_packet *batman_packet =
 169                 (struct batman_packet *)(forw_packet->packet_buff);
 170         char orig_str[ETH_STR_LEN];
 171         unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
 172
 173         if (!forw_packet->if_incoming) {
 174                 printk(KERN_ERR "batman-adv: Error - can't forward packet: incoming iface not specified\n");
 175                 return;
 176         }
 177
 178         if (forw_packet->if_incoming->if_active != IF_ACTIVE)
 179                 return;
 180
 181         addr_to_string(orig_str, batman_packet->orig);
 182
 183         /* multihomed peer assumed */
 184         /* non-primary OGMs are only broadcasted on their interface */
 185         if ((directlink && (batman_packet->ttl == 1)) ||
 186             (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
 187
 188                 /* FIXME: what about aggregated packets ? */
 189                 bat_dbg(DBG_BATMAN,
 190                         "%s packet (originator %s, seqno %d, TTL %d) on interface %s [%s]\n",
 191                         (forw_packet->own ? "Sending own" : "Forwarding"),
 192                         orig_str, ntohs(batman_packet->seqno),
 193                         batman_packet->ttl, forw_packet->if_incoming->dev,
 194                         forw_packet->if_incoming->addr_str);
 195
 196                 send_raw_packet(forw_packet->packet_buff,
 197                                 forw_packet->packet_len,
 198                                 forw_packet->if_incoming,
 199                                 broadcastAddr);
 200                 return;
 201         }
 202
 203         /* broadcast on every interface */
 204         rcu_read_lock();
 205         list_for_each_entry_rcu(batman_if, &if_list, list)
 206                 send_packet_to_if(forw_packet, batman_if);
 207         rcu_read_unlock();
 208 }
 209
 210 static void rebuild_batman_packet(struct batman_if *batman_if)
 211 {
 212         int new_len;
 213         unsigned char *new_buff;
 214         struct batman_packet *batman_packet;
 215
 216         new_len = sizeof(struct batman_packet) + (num_hna * ETH_ALEN);
 217         new_buff = kmalloc(new_len, GFP_ATOMIC);
 218
 219         /* keep old buffer if kmalloc should fail */
 220         if (new_buff) {
 221                 memcpy(new_buff, batman_if->packet_buff,
 222                        sizeof(struct batman_packet));
 223                 batman_packet = (struct batman_packet *)new_buff;
 224
 225                 batman_packet->num_hna = hna_local_fill_buffer(
 226                         new_buff + sizeof(struct batman_packet),
 227                         new_len - sizeof(struct batman_packet));
 228
 229                 kfree(batman_if->packet_buff);
 230                 batman_if->packet_buff = new_buff;
 231                 batman_if->packet_len = new_len;
 232         }
 233 }
 234
 235 void schedule_own_packet(struct batman_if *batman_if)
 236 {
 237         unsigned long send_time;
 238         struct batman_packet *batman_packet;
 239
 240         /**
 241          * the interface gets activated here to avoid race conditions between
 242          * the moment of activating the interface in
 243          * hardif_activate_interface() where the originator mac is set and
 244          * outdated packets (especially uninitialized mac addresses) in the
 245          * packet queue
 246          */
 247         if (batman_if->if_active == IF_TO_BE_ACTIVATED)
 248                 batman_if->if_active = IF_ACTIVE;
 249
 250         /* if local hna has changed and interface is a primary interface */
 251         if ((atomic_read(&hna_local_changed)) && (batman_if->if_num == 0))
 252                 rebuild_batman_packet(batman_if);
 253
 254         /**
 255          * NOTE: packet_buff might just have been re-allocated in
 256          * rebuild_batman_packet()
 257          */
 258         batman_packet = (struct batman_packet *)batman_if->packet_buff;
 259
 260         /* change sequence number to network order */
 261         batman_packet->seqno = htons((uint16_t)atomic_read(&batman_if->seqno));
 262
 263         if (is_vis_server())
 264                 batman_packet->flags = VIS_SERVER;
 265         else
 266                 batman_packet->flags = 0;
 267
 268         /* could be read by receive_bat_packet() */
 269         atomic_inc(&batman_if->seqno);
 270
 271         slide_own_bcast_window(batman_if);
 272         send_time = own_send_time();
 273         add_bat_packet_to_list(batman_if->packet_buff,
 274                                batman_if->packet_len, batman_if, 1, send_time);
 275 }
 276
 277 void schedule_forward_packet(struct orig_node *orig_node,
 278                              struct ethhdr *ethhdr,
 279                              struct batman_packet *batman_packet,
 280                              uint8_t directlink, int hna_buff_len,
 281                              struct batman_if *if_incoming)
 282 {
 283         unsigned char in_tq, in_ttl, tq_avg = 0;
 284         unsigned long send_time;
 285
 286         if (batman_packet->ttl <= 1) {
 287                 bat_dbg(DBG_BATMAN, "ttl exceeded \n");
 288                 return;
 289         }
 290
 291         in_tq = batman_packet->tq;
 292         in_ttl = batman_packet->ttl;
 293
 294         batman_packet->ttl--;
 295         memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
 296
 297         /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
 298          * of our best tq value */
 299         if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
 300
 301                 /* rebroadcast ogm of best ranking neighbor as is */
 302                 if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
 303                         batman_packet->tq = orig_node->router->tq_avg;
 304
 305                         if (orig_node->router->last_ttl)
 306                                 batman_packet->ttl = orig_node->router->last_ttl - 1;
 307                 }
 308
 309                 tq_avg = orig_node->router->tq_avg;
 310         }
 311
 312         /* apply hop penalty */
 313         batman_packet->tq = hop_penalty(batman_packet->tq);
 314
 315         bat_dbg(DBG_BATMAN, "Forwarding packet: tq_orig: %i, tq_avg: %i, tq_forw: %i, ttl_orig: %i, ttl_forw: %i \n",
 316                 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
 317                 batman_packet->ttl);
 318
 319         batman_packet->seqno = htons(batman_packet->seqno);
 320
 321         if (directlink)
 322                 batman_packet->flags |= DIRECTLINK;
 323         else
 324                 batman_packet->flags &= ~DIRECTLINK;
 325
 326         send_time = forward_send_time();
 327         add_bat_packet_to_list((unsigned char *)batman_packet,
 328                                sizeof(struct batman_packet) + hna_buff_len,
 329                                if_incoming, 0, send_time);
 330 }
 331
 332 static void forw_packet_free(struct forw_packet *forw_packet)
 333 {
 334         kfree(forw_packet->packet_buff);
 335         kfree(forw_packet);
 336 }
 337
 338 static void _add_bcast_packet_to_list(struct forw_packet *forw_packet,
 339                                       unsigned long send_time)
 340 {
 341         unsigned long flags;
 342         INIT_HLIST_NODE(&forw_packet->list);
 343
 344         /* add new packet to packet list */
 345         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 346         hlist_add_head(&forw_packet->list, &forw_bcast_list);
 347         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 348
 349         /* start timer for this packet */
 350         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 351                           send_outstanding_bcast_packet);
 352         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 353                            send_time);
 354 }
 355
 356 void add_bcast_packet_to_list(unsigned char *packet_buff, int packet_len)
 357 {
 358         struct forw_packet *forw_packet;
 359
 360         forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
 361         if (!forw_packet)
 362                 return;
 363
 364         forw_packet->packet_buff = kmalloc(packet_len, GFP_ATOMIC);
 365         if (!forw_packet->packet_buff) {
 366                 kfree(forw_packet);
 367                 return;
 368         }
 369
 370         forw_packet->packet_len = packet_len;
 371         memcpy(forw_packet->packet_buff, packet_buff, forw_packet->packet_len);
 372
 373         /* how often did we send the bcast packet ? */
 374         forw_packet->num_packets = 0;
 375
 376         _add_bcast_packet_to_list(forw_packet, 1);
 377 }
 378
 379 void send_outstanding_bcast_packet(struct work_struct *work)
 380 {
 381         struct batman_if *batman_if;
 382         struct delayed_work *delayed_work =
 383                 container_of(work, struct delayed_work, work);
 384         struct forw_packet *forw_packet =
 385                 container_of(delayed_work, struct forw_packet, delayed_work);
 386         unsigned long flags;
 387
 388         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 389         hlist_del(&forw_packet->list);
 390         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 391
 392         /* rebroadcast packet */
 393         rcu_read_lock();
 394         list_for_each_entry_rcu(batman_if, &if_list, list) {
 395                 send_raw_packet(forw_packet->packet_buff,
 396                                 forw_packet->packet_len,
 397                                 batman_if, broadcastAddr);
 398         }
 399         rcu_read_unlock();
 400
 401         forw_packet->num_packets++;
 402
 403         /* if we still have some more bcasts to send and we are not shutting
 404          * down */
 405         if ((forw_packet->num_packets < 3) &&
 406             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 407                 _add_bcast_packet_to_list(forw_packet, ((5 * HZ) / 1000));
 408         else
 409                 forw_packet_free(forw_packet);
 410 }
 411
 412 void send_outstanding_bat_packet(struct work_struct *work)
 413 {
 414         struct delayed_work *delayed_work =
 415                 container_of(work, struct delayed_work, work);
 416         struct forw_packet *forw_packet =
 417                 container_of(delayed_work, struct forw_packet, delayed_work);
 418
 419         spin_lock(&forw_bat_list_lock);
 420         hlist_del(&forw_packet->list);
 421         spin_unlock(&forw_bat_list_lock);
 422
 423         send_packet(forw_packet);
 424
 425         /**
 426          * we have to have at least one packet in the queue
 427          * to determine the queues wake up time unless we are
 428          * shutting down
 429          */
 430         if ((forw_packet->own) &&
 431             (atomic_read(&module_state) != MODULE_DEACTIVATING))
 432                 schedule_own_packet(forw_packet->if_incoming);
 433
 434         forw_packet_free(forw_packet);
 435 }
 436
 437 void purge_outstanding_packets(void)
 438 {
 439         struct forw_packet *forw_packet;
 440         struct hlist_node *tmp_node, *safe_tmp_node;
 441         unsigned long flags;
 442
 443         bat_dbg(DBG_BATMAN, "purge_outstanding_packets()\n");
 444
 445         /* free bcast list */
 446         spin_lock_irqsave(&forw_bcast_list_lock, flags);
 447         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 448                                   &forw_bcast_list, list) {
 449
 450                 spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 451
 452                 /**
 453                  * send_outstanding_bcast_packet() will lock the list to
 454                  * delete the item from the list
 455                  */
 456                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 457                 spin_lock_irqsave(&forw_bcast_list_lock, flags);
 458         }
 459         spin_unlock_irqrestore(&forw_bcast_list_lock, flags);
 460
 461         /* free batman packet list */
 462         spin_lock(&forw_bat_list_lock);
 463         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 464                                   &forw_bat_list, list) {
 465
 466                 spin_unlock(&forw_bat_list_lock);
 467
 468                 /**
 469                  * send_outstanding_bat_packet() will lock the list to
 470                  * delete the item from the list
 471                  */
 472                 cancel_delayed_work_sync(&forw_packet->delayed_work);
 473                 spin_lock(&forw_bat_list_lock);
 474         }
 475         spin_unlock(&forw_bat_list_lock);
 476 }