net/batman-adv/send.c

   1 /* Copyright (C) 2007-2012 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
  31 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  32
  33 /* send out an already prepared packet to the given address via the
  34  * specified batman interface
  35  */
  36 int batadv_send_skb_packet(struct sk_buff *skb,
  37                            struct batadv_hard_iface *hard_iface,
  38                            const uint8_t *dst_addr)
  39 {
  40         struct ethhdr *ethhdr;
  41
  42         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  43                 goto send_skb_err;
  44
  45         if (unlikely(!hard_iface->net_dev))
  46                 goto send_skb_err;
  47
  48         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  49                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  50                         hard_iface->net_dev->name);
  51                 goto send_skb_err;
  52         }
  53
  54         /* push to the ethernet header. */
  55         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  56                 goto send_skb_err;
  57
  58         skb_reset_mac_header(skb);
  59
  60         ethhdr = (struct ethhdr *)skb_mac_header(skb);
  61         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  62         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  63         ethhdr->h_proto = __constant_htons(BATADV_ETH_P_BATMAN);
  64
  65         skb_set_network_header(skb, ETH_HLEN);
  66         skb->priority = TC_PRIO_CONTROL;
  67         skb->protocol = __constant_htons(BATADV_ETH_P_BATMAN);
  68
  69         skb->dev = hard_iface->net_dev;
  70
  71         /* dev_queue_xmit() returns a negative result on error.  However on
  72          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  73          * (which is > 0). This will not be treated as an error.
  74          */
  75         return dev_queue_xmit(skb);
  76 send_skb_err:
  77         kfree_skb(skb);
  78         return NET_XMIT_DROP;
  79 }
  80
  81 /**
  82  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  83  * @skb: Packet to be transmitted.
  84  * @orig_node: Final destination of the packet.
  85  * @recv_if: Interface used when receiving the packet (can be NULL).
  86  *
  87  * Looks up the best next-hop towards the passed originator and passes the
  88  * skb on for preparation of MAC header. If the packet originated from this
  89  * host, NULL can be passed as recv_if and no interface alternating is
  90  * attempted.
  91  *
  92  * Returns TRUE on success; FALSE otherwise.
  93  */
  94 bool batadv_send_skb_to_orig(struct sk_buff *skb,
  95                              struct batadv_orig_node *orig_node,
  96                              struct batadv_hard_iface *recv_if)
  97 {
  98         struct batadv_priv *bat_priv = orig_node->bat_priv;
  99         struct batadv_neigh_node *neigh_node;
 100
 101         /* batadv_find_router() increases neigh_nodes refcount if found. */
 102         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 103         if (!neigh_node)
 104                 return false;
 105
 106         /* route it */
 107         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 108
 109         batadv_neigh_node_free_ref(neigh_node);
 110
 111         return true;
 112 }
 113
 114 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 115 {
 116         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 117
 118         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 119             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 120                 return;
 121
 122         /* the interface gets activated here to avoid race conditions between
 123          * the moment of activating the interface in
 124          * hardif_activate_interface() where the originator mac is set and
 125          * outdated packets (especially uninitialized mac addresses) in the
 126          * packet queue
 127          */
 128         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 129                 hard_iface->if_status = BATADV_IF_ACTIVE;
 130
 131         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 132 }
 133
 134 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 135 {
 136         if (forw_packet->skb)
 137                 kfree_skb(forw_packet->skb);
 138         if (forw_packet->if_incoming)
 139                 batadv_hardif_free_ref(forw_packet->if_incoming);
 140         kfree(forw_packet);
 141 }
 142
 143 static void
 144 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 145                                  struct batadv_forw_packet *forw_packet,
 146                                  unsigned long send_time)
 147 {
 148         INIT_HLIST_NODE(&forw_packet->list);
 149
 150         /* add new packet to packet list */
 151         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 152         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 153         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 154
 155         /* start timer for this packet */
 156         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 157                           batadv_send_outstanding_bcast_packet);
 158         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 159                            send_time);
 160 }
 161
 162 /* add a broadcast packet to the queue and setup timers. broadcast packets
 163  * are sent multiple times to increase probability for being received.
 164  *
 165  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 166  * errors.
 167  *
 168  * The skb is not consumed, so the caller should make sure that the
 169  * skb is freed.
 170  */
 171 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 172                                     const struct sk_buff *skb,
 173                                     unsigned long delay)
 174 {
 175         struct batadv_hard_iface *primary_if = NULL;
 176         struct batadv_forw_packet *forw_packet;
 177         struct batadv_bcast_packet *bcast_packet;
 178         struct sk_buff *newskb;
 179
 180         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 181                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 182                            "bcast packet queue full\n");
 183                 goto out;
 184         }
 185
 186         primary_if = batadv_primary_if_get_selected(bat_priv);
 187         if (!primary_if)
 188                 goto out_and_inc;
 189
 190         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 191
 192         if (!forw_packet)
 193                 goto out_and_inc;
 194
 195         newskb = skb_copy(skb, GFP_ATOMIC);
 196         if (!newskb)
 197                 goto packet_free;
 198
 199         /* as we have a copy now, it is safe to decrease the TTL */
 200         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 201         bcast_packet->header.ttl--;
 202
 203         skb_reset_mac_header(newskb);
 204
 205         forw_packet->skb = newskb;
 206         forw_packet->if_incoming = primary_if;
 207
 208         /* how often did we send the bcast packet ? */
 209         forw_packet->num_packets = 0;
 210
 211         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 212         return NETDEV_TX_OK;
 213
 214 packet_free:
 215         kfree(forw_packet);
 216 out_and_inc:
 217         atomic_inc(&bat_priv->bcast_queue_left);
 218 out:
 219         if (primary_if)
 220                 batadv_hardif_free_ref(primary_if);
 221         return NETDEV_TX_BUSY;
 222 }
 223
 224 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 225 {
 226         struct batadv_hard_iface *hard_iface;
 227         struct delayed_work *delayed_work;
 228         struct batadv_forw_packet *forw_packet;
 229         struct sk_buff *skb1;
 230         struct net_device *soft_iface;
 231         struct batadv_priv *bat_priv;
 232
 233         delayed_work = container_of(work, struct delayed_work, work);
 234         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 235                                    delayed_work);
 236         soft_iface = forw_packet->if_incoming->soft_iface;
 237         bat_priv = netdev_priv(soft_iface);
 238
 239         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 240         hlist_del(&forw_packet->list);
 241         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 242
 243         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 244                 goto out;
 245
 246         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 247                 goto out;
 248
 249         /* rebroadcast packet */
 250         rcu_read_lock();
 251         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 252                 if (hard_iface->soft_iface != soft_iface)
 253                         continue;
 254
 255                 /* send a copy of the saved skb */
 256                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 257                 if (skb1)
 258                         batadv_send_skb_packet(skb1, hard_iface,
 259                                                batadv_broadcast_addr);
 260         }
 261         rcu_read_unlock();
 262
 263         forw_packet->num_packets++;
 264
 265         /* if we still have some more bcasts to send */
 266         if (forw_packet->num_packets < 3) {
 267                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 268                                                  msecs_to_jiffies(5));
 269                 return;
 270         }
 271
 272 out:
 273         batadv_forw_packet_free(forw_packet);
 274         atomic_inc(&bat_priv->bcast_queue_left);
 275 }
 276
 277 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 278 {
 279         struct delayed_work *delayed_work;
 280         struct batadv_forw_packet *forw_packet;
 281         struct batadv_priv *bat_priv;
 282
 283         delayed_work = container_of(work, struct delayed_work, work);
 284         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 285                                    delayed_work);
 286         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 287         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 288         hlist_del(&forw_packet->list);
 289         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 290
 291         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 292                 goto out;
 293
 294         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 295
 296         /* we have to have at least one packet in the queue
 297          * to determine the queues wake up time unless we are
 298          * shutting down
 299          */
 300         if (forw_packet->own)
 301                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 302
 303 out:
 304         /* don't count own packet */
 305         if (!forw_packet->own)
 306                 atomic_inc(&bat_priv->batman_queue_left);
 307
 308         batadv_forw_packet_free(forw_packet);
 309 }
 310
 311 void
 312 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 313                                  const struct batadv_hard_iface *hard_iface)
 314 {
 315         struct batadv_forw_packet *forw_packet;
 316         struct hlist_node *tmp_node, *safe_tmp_node;
 317         bool pending;
 318
 319         if (hard_iface)
 320                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 321                            "purge_outstanding_packets(): %s\n",
 322                            hard_iface->net_dev->name);
 323         else
 324                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 325                            "purge_outstanding_packets()\n");
 326
 327         /* free bcast list */
 328         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 329         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 330                                   &bat_priv->forw_bcast_list, list) {
 331
 332                 /* if purge_outstanding_packets() was called with an argument
 333                  * we delete only packets belonging to the given interface
 334                  */
 335                 if ((hard_iface) &&
 336                     (forw_packet->if_incoming != hard_iface))
 337                         continue;
 338
 339                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 340
 341                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 342                  * delete the item from the list
 343                  */
 344                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 345                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 346
 347                 if (pending) {
 348                         hlist_del(&forw_packet->list);
 349                         batadv_forw_packet_free(forw_packet);
 350                 }
 351         }
 352         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 353
 354         /* free batman packet list */
 355         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 356         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 357                                   &bat_priv->forw_bat_list, list) {
 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_bat_list_lock);
 367
 368                 /* send_outstanding_bat_packet() will lock the list to
 369                  * delete the item from the list
 370                  */
 371                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 372                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 373
 374                 if (pending) {
 375                         hlist_del(&forw_packet->list);
 376                         batadv_forw_packet_free(forw_packet);
 377                 }
 378         }
 379         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 380 }