net/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "send.h"
  24 #include "routing.h"
  25 #include "translation-table.h"
  26 #include "soft-interface.h"
  27 #include "hard-interface.h"
  28 #include "vis.h"
  29 #include "gateway_common.h"
  30 #include "originator.h"
  31
  32 static void send_outstanding_bcast_packet(struct work_struct *work);
  33
  34 /* send out an already prepared packet to the given address via the
  35  * specified batman interface */
  36 int batadv_send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
  37                            const uint8_t *dst_addr)
  38 {
  39         struct ethhdr *ethhdr;
  40
  41         if (hard_iface->if_status != 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(ETH_P_BATMAN);
  63
  64         skb_set_network_header(skb, ETH_HLEN);
  65         skb->priority = TC_PRIO_CONTROL;
  66         skb->protocol = __constant_htons(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 hard_iface *hard_iface)
  81 {
  82         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
  83
  84         if ((hard_iface->if_status == IF_NOT_IN_USE) ||
  85             (hard_iface->if_status == IF_TO_BE_REMOVED))
  86                 return;
  87
  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 == IF_TO_BE_ACTIVATED)
  96                 hard_iface->if_status = IF_ACTIVE;
  97
  98         bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
  99 }
 100
 101 static void forw_packet_free(struct forw_packet *forw_packet)
 102 {
 103         if (forw_packet->skb)
 104                 kfree_skb(forw_packet->skb);
 105         if (forw_packet->if_incoming)
 106                 hardif_free_ref(forw_packet->if_incoming);
 107         kfree(forw_packet);
 108 }
 109
 110 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 111                                       struct 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                           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 int batadv_add_bcast_packet_to_list(struct bat_priv *bat_priv,
 137                                     const struct sk_buff *skb,
 138                                     unsigned long delay)
 139 {
 140         struct hard_iface *primary_if = NULL;
 141         struct forw_packet *forw_packet;
 142         struct bcast_packet *bcast_packet;
 143         struct sk_buff *newskb;
 144
 145         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 146                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 147                 goto out;
 148         }
 149
 150         primary_if = 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         _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                 hardif_free_ref(primary_if);
 185         return NETDEV_TX_BUSY;
 186 }
 187
 188 static void 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) == 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                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 225                                           msecs_to_jiffies(5));
 226                 return;
 227         }
 228
 229 out:
 230         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) == MESH_DEACTIVATING)
 248                 goto out;
 249
 250         bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
 251
 252         /**
 253          * we have to have at least one packet in the queue
 254          * to determine the queues wake up time unless we are
 255          * shutting down
 256          */
 257         if (forw_packet->own)
 258                 batadv_schedule_bat_ogm(forw_packet->if_incoming);
 259
 260 out:
 261         /* don't count own packet */
 262         if (!forw_packet->own)
 263                 atomic_inc(&bat_priv->batman_queue_left);
 264
 265         forw_packet_free(forw_packet);
 266 }
 267
 268 void batadv_purge_outstanding_packets(struct bat_priv *bat_priv,
 269                                       const struct hard_iface *hard_iface)
 270 {
 271         struct forw_packet *forw_packet;
 272         struct hlist_node *tmp_node, *safe_tmp_node;
 273         bool pending;
 274
 275         if (hard_iface)
 276                 bat_dbg(DBG_BATMAN, bat_priv,
 277                         "purge_outstanding_packets(): %s\n",
 278                         hard_iface->net_dev->name);
 279         else
 280                 bat_dbg(DBG_BATMAN, bat_priv,
 281                         "purge_outstanding_packets()\n");
 282
 283         /* free bcast list */
 284         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 285         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 286                                   &bat_priv->forw_bcast_list, list) {
 287
 288                 /**
 289                  * if purge_outstanding_packets() was called with an argument
 290                  * we delete only packets belonging to the given interface
 291                  */
 292                 if ((hard_iface) &&
 293                     (forw_packet->if_incoming != hard_iface))
 294                         continue;
 295
 296                 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 297
 298                 /**
 299                  * send_outstanding_bcast_packet() will lock the list to
 300                  * delete the item from the list
 301                  */
 302                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 303                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 304
 305                 if (pending) {
 306                         hlist_del(&forw_packet->list);
 307                         forw_packet_free(forw_packet);
 308                 }
 309         }
 310         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 311
 312         /* free batman packet list */
 313         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 314         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 315                                   &bat_priv->forw_bat_list, list) {
 316
 317                 /**
 318                  * if purge_outstanding_packets() was called with an argument
 319                  * we delete only packets belonging to the given interface
 320                  */
 321                 if ((hard_iface) &&
 322                     (forw_packet->if_incoming != hard_iface))
 323                         continue;
 324
 325                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 326
 327                 /**
 328                  * send_outstanding_bat_packet() will lock the list to
 329                  * delete the item from the list
 330                  */
 331                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 332                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 333
 334                 if (pending) {
 335                         hlist_del(&forw_packet->list);
 336                         forw_packet_free(forw_packet);
 337                 }
 338         }
 339         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 340 }