Pileus Git - ~andy/linux/blob - 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 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
  82 {
  83         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  84
  85         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
  86             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
  87                 return;
  88
  89         /* the interface gets activated here to avoid race conditions between
  90          * the moment of activating the interface in
  91          * hardif_activate_interface() where the originator mac is set and
  92          * outdated packets (especially uninitialized mac addresses) in the
  93          * packet queue
  94          */
  95         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
  96                 hard_iface->if_status = BATADV_IF_ACTIVE;
  97
  98         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
  99 }
 100
 101 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 102 {
 103         if (forw_packet->skb)
 104                 kfree_skb(forw_packet->skb);
 105         if (forw_packet->if_incoming)
 106                 batadv_hardif_free_ref(forw_packet->if_incoming);
 107         kfree(forw_packet);
 108 }
 109
 110 static void
 111 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 112                                  struct batadv_forw_packet *forw_packet,
 113                                  unsigned long send_time)
 114 {
 115         INIT_HLIST_NODE(&forw_packet->list);
 116
 117         /* add new packet to packet list */
 118         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 119         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 120         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 121
 122         /* start timer for this packet */
 123         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 124                           batadv_send_outstanding_bcast_packet);
 125         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 126                            send_time);
 127 }
 128
 129 /* add a broadcast packet to the queue and setup timers. broadcast packets
 130  * are sent multiple times to increase probability for being received.
 131  *
 132  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 133  * errors.
 134  *
 135  * The skb is not consumed, so the caller should make sure that the
 136  * skb is freed.
 137  */
 138 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 139                                     const struct sk_buff *skb,
 140                                     unsigned long delay)
 141 {
 142         struct batadv_hard_iface *primary_if = NULL;
 143         struct batadv_forw_packet *forw_packet;
 144         struct batadv_bcast_packet *bcast_packet;
 145         struct sk_buff *newskb;
 146
 147         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 148                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 149                            "bcast packet queue full\n");
 150                 goto out;
 151         }
 152
 153         primary_if = batadv_primary_if_get_selected(bat_priv);
 154         if (!primary_if)
 155                 goto out_and_inc;
 156
 157         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 158
 159         if (!forw_packet)
 160                 goto out_and_inc;
 161
 162         newskb = skb_copy(skb, GFP_ATOMIC);
 163         if (!newskb)
 164                 goto packet_free;
 165
 166         /* as we have a copy now, it is safe to decrease the TTL */
 167         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 168         bcast_packet->header.ttl--;
 169
 170         skb_reset_mac_header(newskb);
 171
 172         forw_packet->skb = newskb;
 173         forw_packet->if_incoming = primary_if;
 174
 175         /* how often did we send the bcast packet ? */
 176         forw_packet->num_packets = 0;
 177
 178         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 179         return NETDEV_TX_OK;
 180
 181 packet_free:
 182         kfree(forw_packet);
 183 out_and_inc:
 184         atomic_inc(&bat_priv->bcast_queue_left);
 185 out:
 186         if (primary_if)
 187                 batadv_hardif_free_ref(primary_if);
 188         return NETDEV_TX_BUSY;
 189 }
 190
 191 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 192 {
 193         struct batadv_hard_iface *hard_iface;
 194         struct delayed_work *delayed_work;
 195         struct batadv_forw_packet *forw_packet;
 196         struct sk_buff *skb1;
 197         struct net_device *soft_iface;
 198         struct batadv_priv *bat_priv;
 199
 200         delayed_work = container_of(work, struct delayed_work, work);
 201         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 202                                    delayed_work);
 203         soft_iface = forw_packet->if_incoming->soft_iface;
 204         bat_priv = netdev_priv(soft_iface);
 205
 206         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 207         hlist_del(&forw_packet->list);
 208         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 209
 210         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 211                 goto out;
 212
 213         if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
 214                 goto out;
 215
 216         /* rebroadcast packet */
 217         rcu_read_lock();
 218         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 219                 if (hard_iface->soft_iface != soft_iface)
 220                         continue;
 221
 222                 /* send a copy of the saved skb */
 223                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 224                 if (skb1)
 225                         batadv_send_skb_packet(skb1, hard_iface,
 226                                                batadv_broadcast_addr);
 227         }
 228         rcu_read_unlock();
 229
 230         forw_packet->num_packets++;
 231
 232         /* if we still have some more bcasts to send */
 233         if (forw_packet->num_packets < 3) {
 234                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 235                                                  msecs_to_jiffies(5));
 236                 return;
 237         }
 238
 239 out:
 240         batadv_forw_packet_free(forw_packet);
 241         atomic_inc(&bat_priv->bcast_queue_left);
 242 }
 243
 244 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 245 {
 246         struct delayed_work *delayed_work;
 247         struct batadv_forw_packet *forw_packet;
 248         struct batadv_priv *bat_priv;
 249
 250         delayed_work = container_of(work, struct delayed_work, work);
 251         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 252                                    delayed_work);
 253         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 254         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 255         hlist_del(&forw_packet->list);
 256         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 257
 258         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 259                 goto out;
 260
 261         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 262
 263         /* we have to have at least one packet in the queue
 264          * to determine the queues wake up time unless we are
 265          * shutting down
 266          */
 267         if (forw_packet->own)
 268                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 269
 270 out:
 271         /* don't count own packet */
 272         if (!forw_packet->own)
 273                 atomic_inc(&bat_priv->batman_queue_left);
 274
 275         batadv_forw_packet_free(forw_packet);
 276 }
 277
 278 void
 279 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 280                                  const struct batadv_hard_iface *hard_iface)
 281 {
 282         struct batadv_forw_packet *forw_packet;
 283         struct hlist_node *tmp_node, *safe_tmp_node;
 284         bool pending;
 285
 286         if (hard_iface)
 287                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 288                            "purge_outstanding_packets(): %s\n",
 289                            hard_iface->net_dev->name);
 290         else
 291                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 292                            "purge_outstanding_packets()\n");
 293
 294         /* free bcast list */
 295         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 296         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 297                                   &bat_priv->forw_bcast_list, list) {
 298
 299                 /* if purge_outstanding_packets() was called with an argument
 300                  * we delete only packets belonging to the given interface
 301                  */
 302                 if ((hard_iface) &&
 303                     (forw_packet->if_incoming != hard_iface))
 304                         continue;
 305
 306                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 307
 308                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 309                  * delete the item from the list
 310                  */
 311                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 312                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 313
 314                 if (pending) {
 315                         hlist_del(&forw_packet->list);
 316                         batadv_forw_packet_free(forw_packet);
 317                 }
 318         }
 319         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 320
 321         /* free batman packet list */
 322         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 323         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 324                                   &bat_priv->forw_bat_list, list) {
 325
 326                 /* if purge_outstanding_packets() was called with an argument
 327                  * we delete only packets belonging to the given interface
 328                  */
 329                 if ((hard_iface) &&
 330                     (forw_packet->if_incoming != hard_iface))
 331                         continue;
 332
 333                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 334
 335                 /* send_outstanding_bat_packet() will lock the list to
 336                  * delete the item from the list
 337                  */
 338                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 339                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 340
 341                 if (pending) {
 342                         hlist_del(&forw_packet->list);
 343                         batadv_forw_packet_free(forw_packet);
 344                 }
 345         }
 346         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 347 }