net/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2012 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 "gateway_common.h"
  30 #include "originator.h"
  31
  32 static void send_outstanding_bcast_packet(struct work_struct *work);
  33
  34 /* send out an already prepared packet to the given address via the
  35  * specified batman interface */
  36 int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
  37                     const uint8_t *dst_addr)
  38 {
  39         struct ethhdr *ethhdr;
  40
  41         if (hard_iface->if_status != IF_ACTIVE)
  42                 goto send_skb_err;
  43
  44         if (unlikely(!hard_iface->net_dev))
  45                 goto send_skb_err;
  46
  47         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  48                 pr_warning("Interface %s is not up - can't send packet via that interface!\n",
  49                            hard_iface->net_dev->name);
  50                 goto send_skb_err;
  51         }
  52
  53         /* push to the ethernet header. */
  54         if (my_skb_head_push(skb, sizeof(*ethhdr)) < 0)
  55                 goto send_skb_err;
  56
  57         skb_reset_mac_header(skb);
  58
  59         ethhdr = (struct ethhdr *)skb_mac_header(skb);
  60         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  61         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  62         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  63
  64         skb_set_network_header(skb, ETH_HLEN);
  65         skb->priority = TC_PRIO_CONTROL;
  66         skb->protocol = __constant_htons(ETH_P_BATMAN);
  67
  68         skb->dev = hard_iface->net_dev;
  69
  70         /* dev_queue_xmit() returns a negative result on error.  However on
  71          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  72          * (which is > 0). This will not be treated as an error. */
  73
  74         return dev_queue_xmit(skb);
  75 send_skb_err:
  76         kfree_skb(skb);
  77         return NET_XMIT_DROP;
  78 }
  79
  80 static void realloc_packet_buffer(struct hard_iface *hard_iface,
  81                                   int new_len)
  82 {
  83         unsigned char *new_buff;
  84
  85         new_buff = kmalloc(new_len, GFP_ATOMIC);
  86
  87         /* keep old buffer if kmalloc should fail */
  88         if (new_buff) {
  89                 memcpy(new_buff, hard_iface->packet_buff,
  90                        BATMAN_OGM_LEN);
  91
  92                 kfree(hard_iface->packet_buff);
  93                 hard_iface->packet_buff = new_buff;
  94                 hard_iface->packet_len = new_len;
  95         }
  96 }
  97
  98 /* when calling this function (hard_iface == primary_if) has to be true */
  99 static int prepare_packet_buffer(struct bat_priv *bat_priv,
 100                                   struct hard_iface *hard_iface)
 101 {
 102         int new_len;
 103
 104         new_len = BATMAN_OGM_LEN +
 105                   tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));
 106
 107         /* if we have too many changes for one packet don't send any
 108          * and wait for the tt table request which will be fragmented */
 109         if (new_len > hard_iface->soft_iface->mtu)
 110                 new_len = BATMAN_OGM_LEN;
 111
 112         realloc_packet_buffer(hard_iface, new_len);
 113
 114         atomic_set(&bat_priv->tt_crc, tt_local_crc(bat_priv));
 115
 116         /* reset the sending counter */
 117         atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);
 118
 119         return tt_changes_fill_buffer(bat_priv,
 120                                       hard_iface->packet_buff + BATMAN_OGM_LEN,
 121                                       hard_iface->packet_len - BATMAN_OGM_LEN);
 122 }
 123
 124 static int reset_packet_buffer(struct bat_priv *bat_priv,
 125                                 struct hard_iface *hard_iface)
 126 {
 127         realloc_packet_buffer(hard_iface, BATMAN_OGM_LEN);
 128         return 0;
 129 }
 130
 131 void schedule_bat_ogm(struct hard_iface *hard_iface)
 132 {
 133         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 134         struct hard_iface *primary_if;
 135         int tt_num_changes = -1;
 136
 137         if ((hard_iface->if_status == IF_NOT_IN_USE) ||
 138             (hard_iface->if_status == IF_TO_BE_REMOVED))
 139                 return;
 140
 141         /**
 142          * the interface gets activated here to avoid race conditions between
 143          * the moment of activating the interface in
 144          * hardif_activate_interface() where the originator mac is set and
 145          * outdated packets (especially uninitialized mac addresses) in the
 146          * packet queue
 147          */
 148         if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
 149                 hard_iface->if_status = IF_ACTIVE;
 150
 151         primary_if = primary_if_get_selected(bat_priv);
 152
 153         if (hard_iface == primary_if) {
 154                 /* if at least one change happened */
 155                 if (atomic_read(&bat_priv->tt_local_changes) > 0) {
 156                         tt_commit_changes(bat_priv);
 157                         tt_num_changes = prepare_packet_buffer(bat_priv,
 158                                                                hard_iface);
 159                 }
 160
 161                 /* if the changes have been sent often enough */
 162                 if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
 163                         tt_num_changes = reset_packet_buffer(bat_priv,
 164                                                              hard_iface);
 165         }
 166
 167         if (primary_if)
 168                 hardif_free_ref(primary_if);
 169
 170         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface, tt_num_changes);
 171 }
 172
 173 static void forw_packet_free(struct forw_packet *forw_packet)
 174 {
 175         if (forw_packet->skb)
 176                 kfree_skb(forw_packet->skb);
 177         if (forw_packet->if_incoming)
 178                 hardif_free_ref(forw_packet->if_incoming);
 179         kfree(forw_packet);
 180 }
 181
 182 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 183                                       struct forw_packet *forw_packet,
 184                                       unsigned long send_time)
 185 {
 186         INIT_HLIST_NODE(&forw_packet->list);
 187
 188         /* add new packet to packet list */
 189         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 190         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 191         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 192
 193         /* start timer for this packet */
 194         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 195                           send_outstanding_bcast_packet);
 196         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 197                            send_time);
 198 }
 199
 200 /* add a broadcast packet to the queue and setup timers. broadcast packets
 201  * are sent multiple times to increase probability for being received.
 202  *
 203  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 204  * errors.
 205  *
 206  * The skb is not consumed, so the caller should make sure that the
 207  * skb is freed. */
 208 int add_bcast_packet_to_list(struct bat_priv *bat_priv,
 209                              const struct sk_buff *skb, unsigned long delay)
 210 {
 211         struct hard_iface *primary_if = NULL;
 212         struct forw_packet *forw_packet;
 213         struct bcast_packet *bcast_packet;
 214         struct sk_buff *newskb;
 215
 216         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 217                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 218                 goto out;
 219         }
 220
 221         primary_if = primary_if_get_selected(bat_priv);
 222         if (!primary_if)
 223                 goto out_and_inc;
 224
 225         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 226
 227         if (!forw_packet)
 228                 goto out_and_inc;
 229
 230         newskb = skb_copy(skb, GFP_ATOMIC);
 231         if (!newskb)
 232                 goto packet_free;
 233
 234         /* as we have a copy now, it is safe to decrease the TTL */
 235         bcast_packet = (struct bcast_packet *)newskb->data;
 236         bcast_packet->header.ttl--;
 237
 238         skb_reset_mac_header(newskb);
 239
 240         forw_packet->skb = newskb;
 241         forw_packet->if_incoming = primary_if;
 242
 243         /* how often did we send the bcast packet ? */
 244         forw_packet->num_packets = 0;
 245
 246         _add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 247         return NETDEV_TX_OK;
 248
 249 packet_free:
 250         kfree(forw_packet);
 251 out_and_inc:
 252         atomic_inc(&bat_priv->bcast_queue_left);
 253 out:
 254         if (primary_if)
 255                 hardif_free_ref(primary_if);
 256         return NETDEV_TX_BUSY;
 257 }
 258
 259 static void send_outstanding_bcast_packet(struct work_struct *work)
 260 {
 261         struct hard_iface *hard_iface;
 262         struct delayed_work *delayed_work =
 263                 container_of(work, struct delayed_work, work);
 264         struct forw_packet *forw_packet =
 265                 container_of(delayed_work, struct forw_packet, delayed_work);
 266         struct sk_buff *skb1;
 267         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 268         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 269
 270         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 271         hlist_del(&forw_packet->list);
 272         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 273
 274         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 275                 goto out;
 276
 277         /* rebroadcast packet */
 278         rcu_read_lock();
 279         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 280                 if (hard_iface->soft_iface != soft_iface)
 281                         continue;
 282
 283                 /* send a copy of the saved skb */
 284                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 285                 if (skb1)
 286                         send_skb_packet(skb1, hard_iface, broadcast_addr);
 287         }
 288         rcu_read_unlock();
 289
 290         forw_packet->num_packets++;
 291
 292         /* if we still have some more bcasts to send */
 293         if (forw_packet->num_packets < 3) {
 294                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 295                                           ((5 * HZ) / 1000));
 296                 return;
 297         }
 298
 299 out:
 300         forw_packet_free(forw_packet);
 301         atomic_inc(&bat_priv->bcast_queue_left);
 302 }
 303
 304 void send_outstanding_bat_ogm_packet(struct work_struct *work)
 305 {
 306         struct delayed_work *delayed_work =
 307                 container_of(work, struct delayed_work, work);
 308         struct forw_packet *forw_packet =
 309                 container_of(delayed_work, struct forw_packet, delayed_work);
 310         struct bat_priv *bat_priv;
 311
 312         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 313         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 314         hlist_del(&forw_packet->list);
 315         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 316
 317         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 318                 goto out;
 319
 320         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 321
 322         /**
 323          * we have to have at least one packet in the queue
 324          * to determine the queues wake up time unless we are
 325          * shutting down
 326          */
 327         if (forw_packet->own)
 328                 schedule_bat_ogm(forw_packet->if_incoming);
 329
 330 out:
 331         /* don't count own packet */
 332         if (!forw_packet->own)
 333                 atomic_inc(&bat_priv->batman_queue_left);
 334
 335         forw_packet_free(forw_packet);
 336 }
 337
 338 void purge_outstanding_packets(struct bat_priv *bat_priv,
 339                                const struct hard_iface *hard_iface)
 340 {
 341         struct forw_packet *forw_packet;
 342         struct hlist_node *tmp_node, *safe_tmp_node;
 343         bool pending;
 344
 345         if (hard_iface)
 346                 bat_dbg(DBG_BATMAN, bat_priv,
 347                         "purge_outstanding_packets(): %s\n",
 348                         hard_iface->net_dev->name);
 349         else
 350                 bat_dbg(DBG_BATMAN, bat_priv,
 351                         "purge_outstanding_packets()\n");
 352
 353         /* free bcast list */
 354         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 355         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 356                                   &bat_priv->forw_bcast_list, list) {
 357
 358                 /**
 359                  * if purge_outstanding_packets() was called with an argument
 360                  * we delete only packets belonging to the given interface
 361                  */
 362                 if ((hard_iface) &&
 363                     (forw_packet->if_incoming != hard_iface))
 364                         continue;
 365
 366                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 367
 368                 /**
 369                  * send_outstanding_bcast_packet() will lock the list to
 370                  * delete the item from the list
 371                  */
 372                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 373                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 374
 375                 if (pending) {
 376                         hlist_del(&forw_packet->list);
 377                         forw_packet_free(forw_packet);
 378                 }
 379         }
 380         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 381
 382         /* free batman packet list */
 383         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 384         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 385                                   &bat_priv->forw_bat_list, list) {
 386
 387                 /**
 388                  * if purge_outstanding_packets() was called with an argument
 389                  * we delete only packets belonging to the given interface
 390                  */
 391                 if ((hard_iface) &&
 392                     (forw_packet->if_incoming != hard_iface))
 393                         continue;
 394
 395                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 396
 397                 /**
 398                  * send_outstanding_bat_packet() will lock the list to
 399                  * delete the item from the list
 400                  */
 401                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 402                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 403
 404                 if (pending) {
 405                         hlist_del(&forw_packet->list);
 406                         forw_packet_free(forw_packet);
 407                 }
 408         }
 409         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 410 }