net/batman-adv/send.c

   1 /*
   2  * Copyright (C) 2007-2011 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 #include "bat_ogm.h"
  32
  33 static void 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 int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
  38                     const uint8_t *dst_addr)
  39 {
  40         struct ethhdr *ethhdr;
  41
  42         if (hard_iface->if_status != 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_warning("Interface %s is not up - can't send packet via "
  50                            "that interface!\n", hard_iface->net_dev->name);
  51                 goto send_skb_err;
  52         }
  53
  54         /* push to the ethernet header. */
  55         if (my_skb_head_push(skb, sizeof(*ethhdr)) < 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(ETH_P_BATMAN);
  64
  65         skb_set_network_header(skb, ETH_HLEN);
  66         skb->priority = TC_PRIO_CONTROL;
  67         skb->protocol = __constant_htons(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 static void realloc_packet_buffer(struct hard_iface *hard_iface,
  82                                   int new_len)
  83 {
  84         unsigned char *new_buff;
  85
  86         new_buff = kmalloc(new_len, GFP_ATOMIC);
  87
  88         /* keep old buffer if kmalloc should fail */
  89         if (new_buff) {
  90                 memcpy(new_buff, hard_iface->packet_buff,
  91                        BATMAN_OGM_LEN);
  92
  93                 kfree(hard_iface->packet_buff);
  94                 hard_iface->packet_buff = new_buff;
  95                 hard_iface->packet_len = new_len;
  96         }
  97 }
  98
  99 /* when calling this function (hard_iface == primary_if) has to be true */
 100 static int prepare_packet_buffer(struct bat_priv *bat_priv,
 101                                   struct hard_iface *hard_iface)
 102 {
 103         int new_len;
 104
 105         new_len = BATMAN_OGM_LEN +
 106                   tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));
 107
 108         /* if we have too many changes for one packet don't send any
 109          * and wait for the tt table request which will be fragmented */
 110         if (new_len > hard_iface->soft_iface->mtu)
 111                 new_len = BATMAN_OGM_LEN;
 112
 113         realloc_packet_buffer(hard_iface, new_len);
 114
 115         atomic_set(&bat_priv->tt_crc, tt_local_crc(bat_priv));
 116
 117         /* reset the sending counter */
 118         atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);
 119
 120         return tt_changes_fill_buffer(bat_priv,
 121                                       hard_iface->packet_buff + BATMAN_OGM_LEN,
 122                                       hard_iface->packet_len - BATMAN_OGM_LEN);
 123 }
 124
 125 static int reset_packet_buffer(struct bat_priv *bat_priv,
 126                                 struct hard_iface *hard_iface)
 127 {
 128         realloc_packet_buffer(hard_iface, BATMAN_OGM_LEN);
 129         return 0;
 130 }
 131
 132 void schedule_bat_ogm(struct hard_iface *hard_iface)
 133 {
 134         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 135         struct hard_iface *primary_if;
 136         int tt_num_changes = -1;
 137
 138         if ((hard_iface->if_status == IF_NOT_IN_USE) ||
 139             (hard_iface->if_status == IF_TO_BE_REMOVED))
 140                 return;
 141
 142         /**
 143          * the interface gets activated here to avoid race conditions between
 144          * the moment of activating the interface in
 145          * hardif_activate_interface() where the originator mac is set and
 146          * outdated packets (especially uninitialized mac addresses) in the
 147          * packet queue
 148          */
 149         if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
 150                 hard_iface->if_status = IF_ACTIVE;
 151
 152         primary_if = primary_if_get_selected(bat_priv);
 153
 154         if (hard_iface == primary_if) {
 155                 /* if at least one change happened */
 156                 if (atomic_read(&bat_priv->tt_local_changes) > 0) {
 157                         tt_commit_changes(bat_priv);
 158                         tt_num_changes = prepare_packet_buffer(bat_priv,
 159                                                                hard_iface);
 160                 }
 161
 162                 /* if the changes have been sent often enough */
 163                 if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
 164                         tt_num_changes = reset_packet_buffer(bat_priv,
 165                                                              hard_iface);
 166         }
 167
 168         if (primary_if)
 169                 hardif_free_ref(primary_if);
 170
 171         bat_ogm_schedule(hard_iface, tt_num_changes);
 172 }
 173
 174 static void forw_packet_free(struct forw_packet *forw_packet)
 175 {
 176         if (forw_packet->skb)
 177                 kfree_skb(forw_packet->skb);
 178         if (forw_packet->if_incoming)
 179                 hardif_free_ref(forw_packet->if_incoming);
 180         kfree(forw_packet);
 181 }
 182
 183 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
 184                                       struct forw_packet *forw_packet,
 185                                       unsigned long send_time)
 186 {
 187         INIT_HLIST_NODE(&forw_packet->list);
 188
 189         /* add new packet to packet list */
 190         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 191         hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
 192         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 193
 194         /* start timer for this packet */
 195         INIT_DELAYED_WORK(&forw_packet->delayed_work,
 196                           send_outstanding_bcast_packet);
 197         queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
 198                            send_time);
 199 }
 200
 201 /* add a broadcast packet to the queue and setup timers. broadcast packets
 202  * are sent multiple times to increase probability for being received.
 203  *
 204  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 205  * errors.
 206  *
 207  * The skb is not consumed, so the caller should make sure that the
 208  * skb is freed. */
 209 int add_bcast_packet_to_list(struct bat_priv *bat_priv,
 210                              const struct sk_buff *skb, unsigned long delay)
 211 {
 212         struct hard_iface *primary_if = NULL;
 213         struct forw_packet *forw_packet;
 214         struct bcast_packet *bcast_packet;
 215         struct sk_buff *newskb;
 216
 217         if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
 218                 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
 219                 goto out;
 220         }
 221
 222         primary_if = primary_if_get_selected(bat_priv);
 223         if (!primary_if)
 224                 goto out_and_inc;
 225
 226         forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
 227
 228         if (!forw_packet)
 229                 goto out_and_inc;
 230
 231         newskb = skb_copy(skb, GFP_ATOMIC);
 232         if (!newskb)
 233                 goto packet_free;
 234
 235         /* as we have a copy now, it is safe to decrease the TTL */
 236         bcast_packet = (struct bcast_packet *)newskb->data;
 237         bcast_packet->ttl--;
 238
 239         skb_reset_mac_header(newskb);
 240
 241         forw_packet->skb = newskb;
 242         forw_packet->if_incoming = primary_if;
 243
 244         /* how often did we send the bcast packet ? */
 245         forw_packet->num_packets = 0;
 246
 247         _add_bcast_packet_to_list(bat_priv, forw_packet, delay);
 248         return NETDEV_TX_OK;
 249
 250 packet_free:
 251         kfree(forw_packet);
 252 out_and_inc:
 253         atomic_inc(&bat_priv->bcast_queue_left);
 254 out:
 255         if (primary_if)
 256                 hardif_free_ref(primary_if);
 257         return NETDEV_TX_BUSY;
 258 }
 259
 260 static void send_outstanding_bcast_packet(struct work_struct *work)
 261 {
 262         struct hard_iface *hard_iface;
 263         struct delayed_work *delayed_work =
 264                 container_of(work, struct delayed_work, work);
 265         struct forw_packet *forw_packet =
 266                 container_of(delayed_work, struct forw_packet, delayed_work);
 267         struct sk_buff *skb1;
 268         struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
 269         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 270
 271         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 272         hlist_del(&forw_packet->list);
 273         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 274
 275         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 276                 goto out;
 277
 278         /* rebroadcast packet */
 279         rcu_read_lock();
 280         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 281                 if (hard_iface->soft_iface != soft_iface)
 282                         continue;
 283
 284                 /* send a copy of the saved skb */
 285                 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
 286                 if (skb1)
 287                         send_skb_packet(skb1, hard_iface, broadcast_addr);
 288         }
 289         rcu_read_unlock();
 290
 291         forw_packet->num_packets++;
 292
 293         /* if we still have some more bcasts to send */
 294         if (forw_packet->num_packets < 3) {
 295                 _add_bcast_packet_to_list(bat_priv, forw_packet,
 296                                           ((5 * HZ) / 1000));
 297                 return;
 298         }
 299
 300 out:
 301         forw_packet_free(forw_packet);
 302         atomic_inc(&bat_priv->bcast_queue_left);
 303 }
 304
 305 void send_outstanding_bat_ogm_packet(struct work_struct *work)
 306 {
 307         struct delayed_work *delayed_work =
 308                 container_of(work, struct delayed_work, work);
 309         struct forw_packet *forw_packet =
 310                 container_of(delayed_work, struct forw_packet, delayed_work);
 311         struct bat_priv *bat_priv;
 312
 313         bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 314         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 315         hlist_del(&forw_packet->list);
 316         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 317
 318         if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
 319                 goto out;
 320
 321         bat_ogm_emit(forw_packet);
 322
 323         /**
 324          * we have to have at least one packet in the queue
 325          * to determine the queues wake up time unless we are
 326          * shutting down
 327          */
 328         if (forw_packet->own)
 329                 schedule_bat_ogm(forw_packet->if_incoming);
 330
 331 out:
 332         /* don't count own packet */
 333         if (!forw_packet->own)
 334                 atomic_inc(&bat_priv->batman_queue_left);
 335
 336         forw_packet_free(forw_packet);
 337 }
 338
 339 void purge_outstanding_packets(struct bat_priv *bat_priv,
 340                                const struct hard_iface *hard_iface)
 341 {
 342         struct forw_packet *forw_packet;
 343         struct hlist_node *tmp_node, *safe_tmp_node;
 344         bool pending;
 345
 346         if (hard_iface)
 347                 bat_dbg(DBG_BATMAN, bat_priv,
 348                         "purge_outstanding_packets(): %s\n",
 349                         hard_iface->net_dev->name);
 350         else
 351                 bat_dbg(DBG_BATMAN, bat_priv,
 352                         "purge_outstanding_packets()\n");
 353
 354         /* free bcast list */
 355         spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 356         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 357                                   &bat_priv->forw_bcast_list, list) {
 358
 359                 /**
 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_bcast_list_lock);
 368
 369                 /**
 370                  * send_outstanding_bcast_packet() will lock the list to
 371                  * delete the item from the list
 372                  */
 373                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 374                 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
 375
 376                 if (pending) {
 377                         hlist_del(&forw_packet->list);
 378                         if (!forw_packet->own)
 379                                 atomic_inc(&bat_priv->bcast_queue_left);
 380
 381                         forw_packet_free(forw_packet);
 382                 }
 383         }
 384         spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 385
 386         /* free batman packet list */
 387         spin_lock_bh(&bat_priv->forw_bat_list_lock);
 388         hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
 389                                   &bat_priv->forw_bat_list, list) {
 390
 391                 /**
 392                  * if purge_outstanding_packets() was called with an argument
 393                  * we delete only packets belonging to the given interface
 394                  */
 395                 if ((hard_iface) &&
 396                     (forw_packet->if_incoming != hard_iface))
 397                         continue;
 398
 399                 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 400
 401                 /**
 402                  * send_outstanding_bat_packet() will lock the list to
 403                  * delete the item from the list
 404                  */
 405                 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
 406                 spin_lock_bh(&bat_priv->forw_bat_list_lock);
 407
 408                 if (pending) {
 409                         hlist_del(&forw_packet->list);
 410                         if (!forw_packet->own)
 411                                 atomic_inc(&bat_priv->batman_queue_left);
 412
 413                         forw_packet_free(forw_packet);
 414                 }
 415         }
 416         spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 417 }