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
  31 #include <linux/if_ether.h>
  32
  33 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  34
  35 /* send out an already prepared packet to the given address via the
  36  * specified batman interface
  37  */
  38 int batadv_send_skb_packet(struct sk_buff *skb,
  39                            struct batadv_hard_iface *hard_iface,
  40                            const uint8_t *dst_addr)
  41 {
  42         struct ethhdr *ethhdr;
  43
  44         if (hard_iface->if_status != BATADV_IF_ACTIVE)
  45                 goto send_skb_err;
  46
  47         if (unlikely(!hard_iface->net_dev))
  48                 goto send_skb_err;
  49
  50         if (!(hard_iface->net_dev->flags & IFF_UP)) {
  51                 pr_warn("Interface %s is not up - can't send packet via that interface!\n",
  52                         hard_iface->net_dev->name);
  53                 goto send_skb_err;
  54         }
  55
  56         /* push to the ethernet header. */
  57         if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
  58                 goto send_skb_err;
  59
  60         skb_reset_mac_header(skb);
  61
  62         ethhdr = (struct ethhdr *)skb_mac_header(skb);
  63         memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
  64         memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
  65         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
  66
  67         skb_set_network_header(skb, ETH_HLEN);
  68         skb->priority = TC_PRIO_CONTROL;
  69         skb->protocol = __constant_htons(ETH_P_BATMAN);
  70
  71         skb->dev = hard_iface->net_dev;
  72
  73         /* dev_queue_xmit() returns a negative result on error.  However on
  74          * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
  75          * (which is > 0). This will not be treated as an error.
  76          */
  77         return dev_queue_xmit(skb);
  78 send_skb_err:
  79         kfree_skb(skb);
  80         return NET_XMIT_DROP;
  81 }
  82
  83 /**
  84  * batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
  85  * @skb: Packet to be transmitted.
  86  * @orig_node: Final destination of the packet.
  87  * @recv_if: Interface used when receiving the packet (can be NULL).
  88  *
  89  * Looks up the best next-hop towards the passed originator and passes the
  90  * skb on for preparation of MAC header. If the packet originated from this
  91  * host, NULL can be passed as recv_if and no interface alternating is
  92  * attempted.
  93  *
  94  * Returns TRUE on success; FALSE otherwise.
  95  */
  96 bool batadv_send_skb_to_orig(struct sk_buff *skb,
  97                              struct batadv_orig_node *orig_node,
  98                              struct batadv_hard_iface *recv_if)
  99 {
 100         struct batadv_priv *bat_priv = orig_node->bat_priv;
 101         struct batadv_neigh_node *neigh_node;
 102
 103         /* batadv_find_router() increases neigh_nodes refcount if found. */
 104         neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
 105         if (!neigh_node)
 106                 return false;
 107
 108         /* route it */
 109         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 110
 111         batadv_neigh_node_free_ref(neigh_node);
 112
 113         return true;
 114 }
 115
 116 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
 117 {
 118         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 119
 120         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
 121             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
 122                 return;
 123
 124         /* the interface gets activated here to avoid race conditions between
 125          * the moment of activating the interface in
 126          * hardif_activate_interface() where the originator mac is set and
 127          * outdated packets (especially uninitialized mac addresses) in the
 128          * packet queue
 129          */
 130         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
 131                 hard_iface->if_status = BATADV_IF_ACTIVE;
 132
 133         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
 134 }
 135
 136 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 137 {
 138         if (forw_packet->skb)
 139                 kfree_skb(forw_packet->skb);
 140         if (forw_packet->if_incoming)
 141                 batadv_hardif_free_ref(forw_packet->if_incoming);
 142         kfree(forw_packet);
 143 }
 144
 145 static void
 146 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 147                                  struct batadv_forw_packet *forw_packet,
 148                                  unsigned long send_time)
 149 {
 150         INIT_HLIST_NODE(&forw_packet->list);
 151
 152         /* add new packet to packet list */
 153         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 154         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 155         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 156
 157         /* start timer for this 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         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 212                           batadv_send_outstanding_bcast_packet);
 213
 214         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 215         return NETDEV_TX_OK;
 216
 217 packet_free:
 218         kfree(forw_packet);
 219 out_and_inc:
 220         atomic_inc(&bat_priv->bcast_queue_left);
 221 out:
 222         if (primary_if)
 223                 batadv_hardif_free_ref(primary_if);
 224         return NETDEV_TX_BUSY;
 225 }
 226
 227 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 228 {
 229         struct batadv_hard_iface *hard_iface;
 230         struct delayed_work *delayed_work;
 231         struct batadv_forw_packet *forw_packet;
 232         struct sk_buff *skb1;
 233         struct net_device *soft_iface;
 234         struct batadv_priv *bat_priv;
 235
 236         delayed_work = container_of(work, struct delayed_work, work);
 237         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 238                                    delayed_work);
 239         soft_iface = forw_packet->if_incoming->soft_iface;
 240         bat_priv = netdev_priv(soft_iface);
 241
 242         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 243         hlist_del(&forw_packet->list);
 244         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 245
 246         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 247                 goto out;
 248
 249         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 250                 goto out;
 251
 252         /* rebroadcast packet */
 253         rcu_read_lock();
 254         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 255                 if (hard_iface->soft_iface != soft_iface)
 256                         continue;
 257
 258                 /* send a copy of the saved skb */
 259                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 260                 if (skb1)
 261                         batadv_send_skb_packet(skb1, hard_iface,
 262                                                batadv_broadcast_addr);
 263         }
 264         rcu_read_unlock();
 265
 266         forw_packet->num_packets++;
 267
 268         /* if we still have some more bcasts to send */
 269         if (forw_packet->num_packets < 3) {
 270                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 271                                                  msecs_to_jiffies(5));
 272                 return;
 273         }
 274
 275 out:
 276         batadv_forw_packet_free(forw_packet);
 277         atomic_inc(&bat_priv->bcast_queue_left);
 278 }
 279
 280 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 281 {
 282         struct delayed_work *delayed_work;
 283         struct batadv_forw_packet *forw_packet;
 284         struct batadv_priv *bat_priv;
 285
 286         delayed_work = container_of(work, struct delayed_work, work);
 287         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 288                                    delayed_work);
 289         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 290         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 291         hlist_del(&forw_packet->list);
 292         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 293
 294         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 295                 goto out;
 296
 297         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 298
 299         /* we have to have at least one packet in the queue
 300          * to determine the queues wake up time unless we are
 301          * shutting down
 302          */
 303         if (forw_packet->own)
 304                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 305
 306 out:
 307         /* don't count own packet */
 308         if (!forw_packet->own)
 309                 atomic_inc(&bat_priv->batman_queue_left);
 310
 311         batadv_forw_packet_free(forw_packet);
 312 }
 313
 314 void
 315 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 316                                  const struct batadv_hard_iface *hard_iface)
 317 {
 318         struct batadv_forw_packet *forw_packet;
 319         struct hlist_node *safe_tmp_node;
 320         bool pending;
 321
 322         if (hard_iface)
 323                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 324                            "purge_outstanding_packets(): %s\n",
 325                            hard_iface->net_dev->name);
 326         else
 327                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 328                            "purge_outstanding_packets()\n");
 329
 330         /* free bcast list */
 331         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 332         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 333                                   &bat_priv->forw_bcast_list, list) {
 334                 /* if purge_outstanding_packets() was called with an argument
 335                  * we delete only packets belonging to the given interface
 336                  */
 337                 if ((hard_iface) &&
 338                     (forw_packet->if_incoming != hard_iface))
 339                         continue;
 340
 341                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 342
 343                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 344                  * delete the item from the list
 345                  */
 346                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 347                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 348
 349                 if (pending) {
 350                         hlist_del(&forw_packet->list);
 351                         batadv_forw_packet_free(forw_packet);
 352                 }
 353         }
 354         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 355
 356         /* free batman packet list */
 357         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 358         hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
 359                                   &bat_priv->forw_bat_list, list) {
 360                 /* if purge_outstanding_packets() was called with an argument
 361                  * we delete only packets belonging to the given interface
 362                  */
 363                 if ((hard_iface) &&
 364                     (forw_packet->if_incoming != hard_iface))
 365                         continue;
 366
 367                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 368
 369                 /* send_outstanding_bat_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_bat_list_lock);
 374
 375                 if (pending) {
 376                         hlist_del(&forw_packet->list);
 377                         batadv_forw_packet_free(forw_packet);
 378                 }
 379         }
 380         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 381 }