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Sourcecode: batman-adv version File versions

vis.c

/*
 * Copyright (C) 2008 B.A.T.M.A.N. contributors:
 * Simon Wunderlich
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 *
 */





#include "main.h"
#include "send.h"
#include "translation-table.h"
#include "vis.h"
#include "log.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "hash.h"


static DECLARE_DELAYED_WORK(vis_timer_wq, send_vis_packets);

struct hashtable_t *vis_hash;
DEFINE_SPINLOCK(vis_hash_lock);
static struct vis_info *my_vis_info = NULL;
static struct list_head send_list;  /* always locked with vis_hash_lock ... */

void free_info(void *data);
void send_vis_packet(struct vis_info *info);
void start_vis_timer(void);


int vis_info_cmp(void *data1, void *data2) {
      struct vis_info *d1, *d2;
      d1 = data1;
      d2 = data2;
      return(memcmp(d1->packet.vis_orig, d2->packet.vis_orig, ETH_ALEN) == 0);
}

/* hashfunction to choose an entry in a hash table of given size */
/* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
int vis_info_choose(void *data, int size) {
      struct vis_info *vis_info = data;
      unsigned char *key;
      uint32_t hash = 0;
      size_t i;

      key = vis_info->packet.vis_orig;
      for (i = 0; i < ETH_ALEN; i++) {
            hash += key[i];
            hash += (hash << 10);
            hash ^= (hash >> 6);
      }

      hash += (hash << 3);
      hash ^= (hash >> 11);
      hash += (hash << 15);

      return (hash%size);
}

/* tries to add one entry to the receive list. */
void recv_list_add(struct list_head *recv_list, char *mac)
{
      struct recvlist_node *entry;
      entry = kmalloc(sizeof(struct recvlist_node), GFP_KERNEL);
      if (!entry)
            return;

      memcpy(entry->mac, mac, ETH_ALEN);
      list_add_tail(&entry->list, recv_list);
}

/* returns 1 if this mac is in the recv_list */
int recv_list_is_in(struct list_head *recv_list, char *mac)
{
      struct recvlist_node *entry;

      list_for_each_entry(entry, recv_list, list) {

            if (memcmp(entry->mac, mac, ETH_ALEN) == 0)
                  return 1;
      }

      return 0;
}

/* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old, broken.. ).
 * vis hash must be locked outside.
 * is_new is set when the packet is newer than old entries in the hash. */

struct vis_info *add_packet(struct vis_packet *vis_packet, int vis_info_len, int *is_new)
{
      struct vis_info *info, *old_info;
      struct vis_info search_elem;

      *is_new = 0;
      /* sanity check */
      if (vis_hash == NULL)
            return NULL;

      /* see if the packet is already in vis_hash */
      memcpy(search_elem.packet.vis_orig, vis_packet->vis_orig, ETH_ALEN);
      old_info = hash_find(vis_hash, &search_elem);

      if (old_info != NULL) {
            if (vis_packet->seqno - old_info->packet.seqno <= 0) {
                  if (old_info->packet.seqno == vis_packet->seqno) {

                        recv_list_add(&old_info->recv_list, vis_packet->sender_orig);
                        return(old_info);
                  } else {
                        /* newer packet is already in hash. */
                        return(NULL);
                  }
            }
            /* remove old entry */
            hash_remove(vis_hash, old_info);
            free_info(old_info);
      }

      info = kmalloc(sizeof(struct vis_info) + vis_info_len,GFP_KERNEL);
      if (info == NULL)
            return NULL;

      INIT_LIST_HEAD(&info->send_list);
      INIT_LIST_HEAD(&info->recv_list);
      info->first_seen = jiffies;
      memcpy(&info->packet, vis_packet, sizeof(struct vis_packet) + vis_info_len);

      /* initialize and add new packet. */
      *is_new = 1;

      /* repair if entries is longer than packet. */
      if (info->packet.entries * sizeof(struct vis_info_entry) > vis_info_len)
            info->packet.entries = vis_info_len / sizeof(struct vis_info);

      recv_list_add(&info->recv_list, info->packet.sender_orig);

      /* try to add it */
      if (hash_add(vis_hash, info)< 0) {
            /* did not work (for some reason) */
            free_info(info);
            info = NULL;
      }
      return info;
}

/* handle the server sync packet, forward if needed. */
void receive_server_sync_packet(struct vis_packet *vis_packet, int vis_info_len)
{
      struct vis_info *info;
      int is_new;

      spin_lock(&vis_hash_lock);
      info = add_packet(vis_packet, vis_info_len, &is_new);
      if (info == NULL)
            goto end;

      /* only if we are server ourselves and packet is newer than the one in hash.*/
      if (is_vis_server_locked() && is_new) {
            memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);
            if (list_empty(&info->send_list)) 
                  list_add_tail(&info->send_list, &send_list);
      }

end:
      spin_unlock(&vis_hash_lock);

}

/* handle an incoming client update packet and schedule forward if needed. */
void receive_client_update_packet(struct vis_packet *vis_packet, int vis_info_len)
{
      struct vis_info *info;
      int is_new;
      /* clients shall not broadcast. */
      if (is_bcast(vis_packet->target_orig))
            return;

      spin_lock(&vis_hash_lock);
      info = add_packet(vis_packet, vis_info_len, &is_new);
      if (info == NULL)
            goto end;
      /* note that outdated packets will be dropped at this point. */


      /* send only if we're the target server or ... */
      if (is_vis_server_locked()
            && is_my_mac(info->packet.target_orig)
            && is_new) {

            info->packet.vis_type = VIS_TYPE_SERVER_SYNC;   /* upgrade! */
            memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);
            if (list_empty(&info->send_list))
                  list_add_tail(&info->send_list, &send_list);

       /* ... we're not the recipient (and thus need to forward). */
      } else if (!is_my_mac(info->packet.target_orig)) {

            if (list_empty(&info->send_list))
                  list_add_tail(&info->send_list, &send_list);
      }

end:
      spin_unlock(&vis_hash_lock);
}

/* set the mode of the visualization to client or server */
void vis_set_mode(int mode) 
{
      spin_lock(&vis_hash_lock);

      if (my_vis_info != NULL) 
            my_vis_info->packet.vis_type = mode;

      spin_unlock(&vis_hash_lock);

}

/* is_vis_server(), locked outside */
int is_vis_server_locked(void) 
{
      if (my_vis_info != NULL) 
            if (my_vis_info->packet.vis_type == VIS_TYPE_SERVER_SYNC)
                  return 1;

      return 0;
}
/* get the current set mode */
int is_vis_server(void) 
{
      int ret = 0;

      spin_lock(&vis_hash_lock);
      ret = is_vis_server_locked();
      spin_unlock(&vis_hash_lock);

      return ret;
}

/* generates a packet of own vis data,
 * returns 0 on success, -1 if no packet could be generated */

static int generate_vis_packet(void)
{
      struct hash_it_t *hashit = NULL;
      struct orig_node *orig_node;
      struct vis_info *info = (struct vis_info *)my_vis_info;
      struct vis_info_entry *entry, *entry_array;
      struct hna_local_entry *hna_local_entry;
      int best_tq = -1;
      unsigned long flags;

      info->first_seen = jiffies;

      spin_lock(&orig_hash_lock);
      memcpy(info->packet.target_orig, broadcastAddr, 6);
      info->packet.ttl = TTL;
      info->packet.seqno++;
      info->packet.entries = 0;

      if (!is_vis_server_locked()) {
            /* find vis-server to receive. */
            while (NULL != (hashit = hash_iterate(orig_hash, hashit))) {
                  orig_node = hashit->bucket->data;
                  if ((orig_node != NULL) && (orig_node->router != NULL)) {
                        if ((orig_node->flags & VIS_SERVER) && orig_node->router->tq_avg > best_tq) {
                              best_tq = orig_node->router->tq_avg;
                              memcpy(info->packet.target_orig, orig_node->orig,6);
                        }
                  }
            }
            if (best_tq < 0) {
                  spin_unlock(&orig_hash_lock);
                  return -1;
            }
      }
      hashit = NULL;

      entry_array = (struct vis_info_entry *)((char *)info + sizeof(struct vis_info));

      while (NULL != (hashit = hash_iterate(orig_hash, hashit))) {
            orig_node = hashit->bucket->data;
            if (orig_node->router != NULL
                  && memcmp(orig_node->router->addr, orig_node->orig, ETH_ALEN) == 0
                  && orig_node->router->tq_avg > 0) {

                  /* fill one entry into buffer. */
                  entry = &entry_array[info->packet.entries];

                  memcpy(entry->dest, orig_node->orig, ETH_ALEN);
                  entry->quality = orig_node->router->tq_avg;
                  info->packet.entries++;
                  /* don't fill more than 1000 bytes */
                  if (info->packet.entries + 1 > (1000 - sizeof(struct vis_info)) / sizeof(struct vis_info_entry)) {
                        spin_unlock(&orig_hash_lock);
                        return 0;
                  }
            }
      }

      spin_unlock(&orig_hash_lock);

      hashit = NULL;
      spin_lock_irqsave(&hna_local_hash_lock, flags);
      while (NULL != (hashit = hash_iterate(hna_local_hash, hashit))) {
            hna_local_entry = hashit->bucket->data;

            entry = &entry_array[info->packet.entries];

            memcpy(entry->dest, hna_local_entry->addr, ETH_ALEN);
            entry->quality = 0; /* 0 means HNA */
            info->packet.entries++;

            /* don't fill more than 1000 bytes */
            if (info->packet.entries + 1 > (1000 - sizeof(struct vis_info)) / sizeof(struct vis_info_entry)) {
                  spin_unlock_irqrestore(&hna_local_hash_lock, flags);
                  return 0;
            }
      }
      spin_unlock_irqrestore(&hna_local_hash_lock, flags);
      return 0;

}
void purge_vis_packets(void)
{
      struct hash_it_t *hashit = NULL;
      struct vis_info *info;

      spin_lock(&vis_hash_lock);
      while (NULL != (hashit = hash_iterate(vis_hash, hashit))) {
            info = hashit->bucket->data;
            if (info == my_vis_info)      /* never purge own data. */
                  continue;
            if (time_after(jiffies, info->first_seen + (VIS_TIMEOUT/1000)*HZ)) {
                  hash_remove_bucket(vis_hash, hashit);
                  free_info(info);
            }
      }
      spin_unlock(&vis_hash_lock);
}

/* called from timer; send (and maybe generate) vis packet. */
void send_vis_packets(struct work_struct *work)
{
      struct vis_info *info, *temp;

      purge_vis_packets();
      spin_lock(&vis_hash_lock);
      if (generate_vis_packet() == 0)
            /* schedule if generation was successful */
            list_add_tail(&my_vis_info->send_list, &send_list);

      list_for_each_entry_safe(info, temp, &send_list, send_list) {
            list_del_init(&info->send_list);
            send_vis_packet(info);
      }
      spin_unlock(&vis_hash_lock);
      start_vis_timer();

}

/* only send one vis packet. called from send_vis_packets() */
void send_vis_packet(struct vis_info *info)
{
      struct hash_it_t *hashit = NULL;
      struct orig_node *orig_node;
      int packet_length;


      if (info->packet.ttl < 2) {
            debug_log(LOG_TYPE_NOTICE, "Error - can't send vis packet: ttl exceeded\n");
            return;
      }

      memcpy(info->packet.sender_orig, mainIfAddr, ETH_ALEN);

      info->packet.ttl--;

      packet_length = sizeof(struct vis_packet) + info->packet.entries * sizeof(struct vis_info_entry);

      if (is_bcast(info->packet.target_orig)) {
            /* broadcast packet */
            spin_lock(&orig_hash_lock);

            /* send to all routers in range. */
            while (NULL != (hashit = hash_iterate(orig_hash, hashit))) {

                  orig_node = hashit->bucket->data;

                  /* if it's a vis server and reachable, send it. */
                  if ((orig_node != NULL) && (orig_node->flags & VIS_SERVER) && (orig_node->batman_if != NULL) && (orig_node->router != NULL)) {

                        /* don't send it if we already received the packet from this node. */
                        if (recv_list_is_in(&info->recv_list, orig_node->orig))
                              continue;


                        memcpy(info->packet.target_orig, orig_node->orig, ETH_ALEN);
                        send_raw_packet((unsigned char *) &info->packet, packet_length,
                                    orig_node->batman_if->net_dev->dev_addr, orig_node->router->addr, orig_node->batman_if);
                  }
            }
            memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN);

            spin_unlock(&orig_hash_lock);
      } else {
            /* unicast packet */
            spin_lock(&orig_hash_lock);
            orig_node = ((struct orig_node *) hash_find(orig_hash, info->packet.target_orig));

            if ((orig_node != NULL) && (orig_node->batman_if != NULL) && (orig_node->router != NULL)) {
                  send_raw_packet((unsigned char *) &info->packet, packet_length,
                              orig_node->batman_if->net_dev->dev_addr, orig_node->router->addr, orig_node->batman_if);
            }
            spin_unlock(&orig_hash_lock);

      }
      info->packet.ttl++; /* restore TTL */
}

/* init the vis server. this may only be called when if_list is already initialized
 * (e.g. bat0 is initialized, interfaces have been added) */
int vis_init(void)
{
      vis_hash = hash_new(256, vis_info_cmp, vis_info_choose);
      if (vis_hash == NULL) {
            debug_log(LOG_TYPE_CRIT, "Can't initialize vis_hash\n");
            return(-1);
      }

      my_vis_info = kmalloc(1000, GFP_KERNEL);
      if (my_vis_info == NULL) {
            vis_quit();
            debug_log(LOG_TYPE_CRIT, "Can't initialize vis packet\n");
            return(-1);
      }
      /* prefill the vis info */
      my_vis_info->first_seen = jiffies - atomic_read(&vis_interval);
      INIT_LIST_HEAD(&my_vis_info->recv_list);
      INIT_LIST_HEAD(&my_vis_info->send_list);
      my_vis_info->packet.version = COMPAT_VERSION;
      my_vis_info->packet.packet_type = BAT_VIS;
      my_vis_info->packet.vis_type = VIS_TYPE_CLIENT_UPDATE;
      my_vis_info->packet.ttl = TTL;
      my_vis_info->packet.seqno = 0;
      my_vis_info->packet.entries = 0;

      INIT_LIST_HEAD(&send_list);

      memcpy(my_vis_info->packet.vis_orig, mainIfAddr, ETH_ALEN);
      memcpy(my_vis_info->packet.sender_orig, mainIfAddr, ETH_ALEN);

      if (hash_add(vis_hash, my_vis_info) < 0) {
            debug_log(LOG_TYPE_CRIT, "Can't add own vis packet into hash\n");
            free_info(my_vis_info); /* not in hash, need to remove it manually. */
            vis_quit();
            return(-1);
      }

      start_vis_timer();
      return(0);
}

/* free the info */
void free_info(void *data)
{
      struct vis_info *info = data;
      struct recvlist_node *entry, *tmp;

      list_del_init(&info->send_list);
      list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
            list_del(&entry->list);
            kfree(entry);
      }
      kfree(info);
}

/* shutdown vis-server */
int vis_quit(void)
{
      if (vis_hash != NULL) {
            cancel_rearming_delayed_work(&vis_timer_wq);
            spin_lock(&vis_hash_lock);
            hash_delete(vis_hash, free_info);   /* properly remove, kill timers ... */
            vis_hash = NULL;
            my_vis_info = NULL;
            spin_unlock(&vis_hash_lock);
      }
      return(0);
}

/* schedule packets for (re)transmission */
void start_vis_timer(void)
{
      queue_delayed_work(bat_event_workqueue, &vis_timer_wq,  (atomic_read(&vis_interval)/1000) * HZ);
}


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