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 "send.h"
  22 #include "routing.h"
  23 #include "translation-table.h"
  24 #include "soft-interface.h"
  25 #include "hard-interface.h"
  26 #include "vis.h"
  27 #include "gateway_common.h"
  28 #include "originator.h"
  29
  30 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
  31
  32 /* send out an already prepared packet to the given address via the
  33  * specified batman interface
  34  */
  35 int batadv_send_skb_packet(struct sk_buff *skb,
  36                            struct batadv_hard_iface *hard_iface,
  37                            const uint8_t *dst_addr)
  38 {
  39         struct ethhdr *ethhdr;
  40
  41         if (hard_iface->if_status != BATADV_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_warn("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 (batadv_skb_head_push(skb, ETH_HLEN) < 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(BATADV_ETH_P_BATMAN);
  63
  64         skb_set_network_header(skb, ETH_HLEN);
  65         skb->priority = TC_PRIO_CONTROL;
  66         skb->protocol = __constant_htons(BATADV_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 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
  81 {
  82         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  83
  84         if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
  85             (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
  86                 return;
  87
  88         /* the interface gets activated here to avoid race conditions between
  89          * the moment of activating the interface in
  90          * hardif_activate_interface() where the originator mac is set and
  91          * outdated packets (especially uninitialized mac addresses) in the
  92          * packet queue
  93          */
  94         if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
  95                 hard_iface->if_status = BATADV_IF_ACTIVE;
  96
  97         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
  98 }
  99
 100 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
 101 {
 102         if (forw_packet->skb)
 103                 kfree_skb(forw_packet->skb);
 104         if (forw_packet->if_incoming)
 105                 batadv_hardif_free_ref(forw_packet->if_incoming);
 106         kfree(forw_packet);
 107 }
 108
 109 static void
 110 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 111                                  struct batadv_forw_packet *forw_packet,
 112                                  unsigned long send_time)
 113 {
 114         INIT_HLIST_NODE(&forw_packet->list);
 115
 116         /* add new packet to packet list */
 117         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 118         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 119         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 120
 121         /* start timer for this packet */
 122         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 123                           batadv_send_outstanding_bcast_packet);
 124         queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
 125                            send_time);
 126 }
 127
 128 /* add a broadcast packet to the queue and setup timers. broadcast packets
 129  * are sent multiple times to increase probability for being received.
 130  *
 131  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 132  * errors.
 133  *
 134  * The skb is not consumed, so the caller should make sure that the
 135  * skb is freed.
 136  */
 137 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
 138                                     const struct sk_buff *skb,
 139                                     unsigned long delay)
 140 {
 141         struct batadv_hard_iface *primary_if = NULL;
 142         struct batadv_forw_packet *forw_packet;
 143         struct batadv_bcast_packet *bcast_packet;
 144         struct sk_buff *newskb;
 145
 146         if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 147                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 148                            "bcast packet queue full\n");
 149                 goto out;
 150         }
 151
 152         primary_if = batadv_primary_if_get_selected(bat_priv);
 153         if (!primary_if)
 154                 goto out_and_inc;
 155
 156         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 157
 158         if (!forw_packet)
 159                 goto out_and_inc;
 160
 161         newskb = skb_copy(skb, GFP_ATOMIC);
 162         if (!newskb)
 163                 goto packet_free;
 164
 165         /* as we have a copy now, it is safe to decrease the TTL */
 166         bcast_packet = (struct batadv_bcast_packet *)newskb->data;
 167         bcast_packet->header.ttl--;
 168
 169         skb_reset_mac_header(newskb);
 170
 171         forw_packet->skb = newskb;
 172         forw_packet->if_incoming = primary_if;
 173
 174         /* how often did we send the bcast packet ? */
 175         forw_packet->num_packets = 0;
 176
 177         _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 178         return NETDEV_TX_OK;
 179
 180 packet_free:
 181         kfree(forw_packet);
 182 out_and_inc:
 183         atomic_inc(&bat_priv->bcast_queue_left);
 184 out:
 185         if (primary_if)
 186                 batadv_hardif_free_ref(primary_if);
 187         return NETDEV_TX_BUSY;
 188 }
 189
 190 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 191 {
 192         struct batadv_hard_iface *hard_iface;
 193         struct delayed_work *delayed_work;
 194         struct batadv_forw_packet *forw_packet;
 195         struct sk_buff *skb1;
 196         struct net_device *soft_iface;
 197         struct batadv_priv *bat_priv;
 198
 199         delayed_work = container_of(work, struct delayed_work, work);
 200         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 201                                    delayed_work);
 202         soft_iface = forw_packet->if_incoming->soft_iface;
 203         bat_priv = netdev_priv(soft_iface);
 204
 205         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 206         hlist_del(&forw_packet->list);
 207         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 208
 209         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 210                 goto out;
 211
 212         /* rebroadcast packet */
 213         rcu_read_lock();
 214         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 215                 if (hard_iface->soft_iface != soft_iface)
 216                         continue;
 217
 218                 /* send a copy of the saved skb */
 219                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 220                 if (skb1)
 221                         batadv_send_skb_packet(skb1, hard_iface,
 222                                                batadv_broadcast_addr);
 223         }
 224         rcu_read_unlock();
 225
 226         forw_packet->num_packets++;
 227
 228         /* if we still have some more bcasts to send */
 229         if (forw_packet->num_packets < 3) {
 230                 _batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
 231                                                  msecs_to_jiffies(5));
 232                 return;
 233         }
 234
 235 out:
 236         batadv_forw_packet_free(forw_packet);
 237         atomic_inc(&bat_priv->bcast_queue_left);
 238 }
 239
 240 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
 241 {
 242         struct delayed_work *delayed_work;
 243         struct batadv_forw_packet *forw_packet;
 244         struct batadv_priv *bat_priv;
 245
 246         delayed_work = container_of(work, struct delayed_work, work);
 247         forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 248                                    delayed_work);
 249         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 250         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 251         hlist_del(&forw_packet->list);
 252         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 253
 254         if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
 255                 goto out;
 256
 257         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 258
 259         /* we have to have at least one packet in the queue
 260          * to determine the queues wake up time unless we are
 261          * shutting down
 262          */
 263         if (forw_packet->own)
 264                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 265
 266 out:
 267         /* don't count own packet */
 268         if (!forw_packet->own)
 269                 atomic_inc(&bat_priv->batman_queue_left);
 270
 271         batadv_forw_packet_free(forw_packet);
 272 }
 273
 274 void
 275 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
 276                                  const struct batadv_hard_iface *hard_iface)
 277 {
 278         struct batadv_forw_packet *forw_packet;
 279         struct hlist_node *tmp_node, *safe_tmp_node;
 280         bool pending;
 281
 282         if (hard_iface)
 283                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 284                            "purge_outstanding_packets(): %s\n",
 285                            hard_iface->net_dev->name);
 286         else
 287                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 288                            "purge_outstanding_packets()\n");
 289
 290         /* free bcast list */
 291         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 292         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 293                                   &bat_priv->forw_bcast_list, list) {
 294
 295                 /* if purge_outstanding_packets() was called with an argument
 296                  * we delete only packets belonging to the given interface
 297                  */
 298                 if ((hard_iface) &&
 299                     (forw_packet->if_incoming != hard_iface))
 300                         continue;
 301
 302                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 303
 304                 /* batadv_send_outstanding_bcast_packet() will lock the list to
 305                  * delete the item from the list
 306                  */
 307                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 308                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 309
 310                 if (pending) {
 311                         hlist_del(&forw_packet->list);
 312                         batadv_forw_packet_free(forw_packet);
 313                 }
 314         }
 315         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 316
 317         /* free batman packet list */
 318         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 319         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 320                                   &bat_priv->forw_bat_list, list) {
 321
 322                 /* if purge_outstanding_packets() was called with an argument
 323                  * we delete only packets belonging to the given interface
 324                  */
 325                 if ((hard_iface) &&
 326                     (forw_packet->if_incoming != hard_iface))
 327                         continue;
 328
 329                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 330
 331                 /* send_outstanding_bat_packet() will lock the list to
 332                  * delete the item from the list
 333                  */
 334                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 335                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 336
 337                 if (pending) {
 338                         hlist_del(&forw_packet->list);
 339                         batadv_forw_packet_free(forw_packet);
 340                 }
 341         }
 342         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 343 }