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  90          * outdated packets (especially uninitialized mac addresses) in the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