net/batman-adv/send.c

   1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner, Simon Wunderlich
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "distributed-arp-table.h"
  22 #include "send.h"
  23 #include "routing.h"
  24 #include "translation-table.h"
  25 #include "soft-interface.h"
  26 #include "hard-interface.h"
  27 #include "vis.h"
  28 #include "gateway_common.h"
  29 #include "originator.h"
  30 #include "network-coding.h"
  31
  32 #include <linux/if_ether.h>
  33
  34 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  35
  36 /* send out an already prepared packet to the given address via the
  37  * specified batman interface
  38  */
  39 int batadv_send_skb_packet(struct sk_buff *skb,
  40                            struct batadv_hard_iface *hard_iface,
  41                            const uint8_t *dst_addr)
  42 {
  43         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  44         struct ethhdr *ethhdr;
  45
  46         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  47                 goto send_skb_err;
  48
  49         if (unlikely(!hard_iface->net_dev))
  50                 goto send_skb_err;
  51
  52         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  53                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  54                         hard_iface->net_dev->name);
  55                 goto send_skb_err;
  56         }
  57
  58         /* push to the ethernet header. */
  59         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  60                 goto send_skb_err;
  61
  62         skb_reset_mac_header(skb);
  63
  64         ethhdr = eth_hdr(skb);
  65         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  66         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  67         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  68
  69         skb_set_network_header(skb, ETH_HLEN);
  70         skb->priority = TC_PRIO_CONTROL;
  71         skb->protocol = __constant_htons(ETH_P_BATMAN);
  72
  73         skb->dev = hard_iface->net_dev;
  74
  75         /* Save a clone of the skb to use when decoding coded packets */
  76         batadv_nc_skb_store_for_decoding(bat_priv, skb);
  77
  78         /* dev_queue_xmit() returns a negative result on error.  However on
  79          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  80          * (which is > 0). This will not be treated as an error.
  81          */
  82         return dev_queue_xmit(skb);
  83 send_skb_err:
  84         kfree_skb(skb);
  85         return NET_XMIT_DROP;
  86 }
  87
  88 /**
  89  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  90  * @skb: Packet to be transmitted.
  91  * @orig_node: Final destination of the packet.
  92  * @recv_if: Interface used when receiving the packet (can be NULL).
  93  *
  94  * Looks up the best next-hop towards the passed originator and passes the
  95  * skb on for preparation of MAC header. If the packet originated from this
  96  * host, NULL can be passed as recv_if and no interface alternating is
  97  * attempted.
  98  *
  99  * Returns TRUE on success; FALSE otherwise.
 100  */
 101 bool batadv_send_skb_to_orig(struct sk_buff *skb,
 102                              struct batadv_orig_node *orig_node,
 103                              struct batadv_hard_iface *recv_if)
 104 {
 105         struct batadv_priv *bat_priv = orig_node->bat_priv;
 106         struct batadv_neigh_node *neigh_node;
 107
 108         /* batadv_find_router() increases neigh_nodes refcount if found. */
 109         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 110         if (!neigh_node)
 111                 return false;
 112
 113         /* route it */
 114         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 115
 116         batadv_neigh_node_free_ref(neigh_node);
 117
 118         return true;
 119 }
 120
 121 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 122 {
 123         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 124
 125         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 126             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 127                 return;
 128
 129         /* the interface gets activated here to avoid race conditions between
 130          * the moment of activating the interface in
 131          * hardif_activate_interface() where the originator mac is set and
 132          * outdated packets (especially uninitialized mac addresses) in the
 133          * packet queue
 134          */
 135         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 136                 hard_iface->if_status = BATADV_IF_ACTIVE;
 137
 138         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 139 }
 140
 141 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 142 {
 143         if (forw_packet->skb)
 144                 kfree_skb(forw_packet->skb);
 145         if (forw_packet->if_incoming)
 146                 batadv_hardif_free_ref(forw_packet->if_incoming);
 147         kfree(forw_packet);
 148 }
 149
 150 static void
 151 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 152                                  struct batadv_forw_packet *forw_packet,
 153                                  unsigned long send_time)
 154 {
 155         /* add new packet to packet list */
 156         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 157         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 158         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 159
 160         /* start timer for this packet */
 161         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 162                            send_time);
 163 }
 164
 165 /* add a broadcast packet to the queue and setup timers. broadcast packets
 166  * are sent multiple times to increase probability for being received.
 167  *
 168  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 169  * errors.
 170  *
 171  * The skb is not consumed, so the caller should make sure that the
 172  * skb is freed.
 173  */
 174 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 175                                     const struct sk_buff *skb,
 176                                     unsigned long delay)
 177 {
 178         struct batadv_hard_iface *primary_if = NULL;
 179         struct batadv_forw_packet *forw_packet;
 180         struct batadv_bcast_packet *bcast_packet;
 181         struct sk_buff *newskb;
 182
 183         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 184                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 185                            "bcast packet queue full\n");
 186                 goto out;
 187         }
 188
 189         primary_if = batadv_primary_if_get_selected(bat_priv);
 190         if (!primary_if)
 191                 goto out_and_inc;
 192
 193         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 194
 195         if (!forw_packet)
 196                 goto out_and_inc;
 197
 198         newskb = skb_copy(skb, GFP_ATOMIC);
 199         if (!newskb)
 200                 goto packet_free;
 201
 202         /* as we have a copy now, it is safe to decrease the TTL */
 203         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 204         bcast_packet->header.ttl--;
 205
 206         skb_reset_mac_header(newskb);
 207
 208         forw_packet->skb = newskb;
 209         forw_packet->if_incoming = primary_if;
 210
 211         /* how often did we send the bcast packet ? */
 212         forw_packet->num_packets = 0;
 213
 214         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 215                           batadv_send_outstanding_bcast_packet);
 216
 217         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 218         return NETDEV_TX_OK;
 219
 220 packet_free:
 221         kfree(forw_packet);
 222 out_and_inc:
 223         atomic_inc(&bat_priv->bcast_queue_left);
 224 out:
 225         if (primary_if)
 226                 batadv_hardif_free_ref(primary_if);
 227         return NETDEV_TX_BUSY;
 228 }
 229
 230 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 231 {
 232         struct batadv_hard_iface *hard_iface;
 233         struct delayed_work *delayed_work;
 234         struct batadv_forw_packet *forw_packet;
 235         struct sk_buff *skb1;
 236         struct net_device *soft_iface;
 237         struct batadv_priv *bat_priv;
 238
 239         delayed_work = container_of(work, struct delayed_work, work);
 240         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 241                                    delayed_work);
 242         soft_iface = forw_packet->if_incoming->soft_iface;
 243         bat_priv = netdev_priv(soft_iface);
 244
 245         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 246         hlist_del(&forw_packet->list);
 247         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 248
 249         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 250                 goto out;
 251
 252         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 253                 goto out;
 254
 255         /* rebroadcast packet */
 256         rcu_read_lock();
 257         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 258                 if (hard_iface->soft_iface != soft_iface)
 259                         continue;
 260
 261                 if (forw_packet->num_packets >= hard_iface->num_bcasts)
 262                         continue;
 263
 264                 /* send a copy of the saved skb */
 265                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 266                 if (skb1)
 267                         batadv_send_skb_packet(skb1, hard_iface,
 268                                                batadv_broadcast_addr);
 269         }
 270         rcu_read_unlock();
 271
 272         forw_packet->num_packets++;
 273
 274         /* if we still have some more bcasts to send */
 275         if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
 276                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 277                                                  msecs_to_jiffies(5));
 278                 return;
 279         }
 280
 281 out:
 282         batadv_forw_packet_free(forw_packet);
 283         atomic_inc(&bat_priv->bcast_queue_left);
 284 }
 285
 286 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 287 {
 288         struct delayed_work *delayed_work;
 289         struct batadv_forw_packet *forw_packet;
 290         struct batadv_priv *bat_priv;
 291
 292         delayed_work = container_of(work, struct delayed_work, work);
 293         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 294                                    delayed_work);
 295         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 296         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 297         hlist_del(&forw_packet->list);
 298         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 299
 300         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 301                 goto out;
 302
 303         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 304
 305         /* we have to have at least one packet in the queue
 306          * to determine the queues wake up time unless we are
 307          * shutting down
 308          */
 309         if (forw_packet->own)
 310                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 311
 312 out:
 313         /* don't count own packet */
 314         if (!forw_packet->own)
 315                 atomic_inc(&bat_priv->batman_queue_left);
 316
 317         batadv_forw_packet_free(forw_packet);
 318 }
 319
 320 void
 321 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 322                                  const struct batadv_hard_iface *hard_iface)
 323 {
 324         struct batadv_forw_packet *forw_packet;
 325         struct hlist_node *safe_tmp_node;
 326         bool pending;
 327
 328         if (hard_iface)
 329                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 330                            "purge_outstanding_packets(): %s\n",
 331                            hard_iface->net_dev->name);
 332         else
 333                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 334                            "purge_outstanding_packets()\n");
 335
 336         /* free bcast list */
 337         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 338         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 339                                   &bat_priv->forw_bcast_list, list) {
 340                 /* if purge_outstanding_packets() was called with an argument
 341                  * we delete only packets belonging to the given interface
 342                  */
 343                 if ((hard_iface) &&
 344                     (forw_packet->if_incoming != hard_iface))
 345                         continue;
 346
 347                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 348
 349                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 350                  * delete the item from the list
 351                  */
 352                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 353                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 354
 355                 if (pending) {
 356                         hlist_del(&forw_packet->list);
 357                         batadv_forw_packet_free(forw_packet);
 358                 }
 359         }
 360         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 361
 362         /* free batman packet list */
 363         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 364         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 365                                   &bat_priv->forw_bat_list, list) {
 366                 /* if purge_outstanding_packets() was called with an argument
 367                  * we delete only packets belonging to the given interface
 368                  */
 369                 if ((hard_iface) &&
 370                     (forw_packet->if_incoming != hard_iface))
 371                         continue;
 372
 373                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 374
 375                 /* send_outstanding_bat_packet() will lock the list to
 376                  * delete the item from the list
 377                  */
 378                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 379                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 380
 381                 if (pending) {
 382                         hlist_del(&forw_packet->list);
 383                         batadv_forw_packet_free(forw_packet);
 384                 }
 385         }
 386         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 387 }