Initial file dump from open source releaseHEADmaster

1 files changed, 935 insertions, 0 deletions

diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c
new file mode 100644
index 00000000..1625e579
--- /dev/null
+++ b/net/batman-adv/vis.c
@@ -0,0 +1,935 @@
+/* Copyright (C) 2008-2013 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 "soft-interface.h"
+#include "hard-interface.h"
+#include "hash.h"
+#include "originator.h"
+
+#define BATADV_MAX_VIS_PACKET_SIZE 1000
+
+/* hash class keys */
+static struct lock_class_key batadv_vis_hash_lock_class_key;
+
+/* free the info */
+static void batadv_free_info(struct kref *ref)
+{
+	struct batadv_vis_info *info;
+	struct batadv_priv *bat_priv;
+	struct batadv_vis_recvlist_node *entry, *tmp;
+
+	info = container_of(ref, struct batadv_vis_info, refcount);
+	bat_priv = info->bat_priv;
+
+	list_del_init(&info->send_list);
+	spin_lock_bh(&bat_priv->vis.list_lock);
+	list_for_each_entry_safe(entry, tmp, &info->recv_list, list) {
+		list_del(&entry->list);
+		kfree(entry);
+	}
+
+	spin_unlock_bh(&bat_priv->vis.list_lock);
+	kfree_skb(info->skb_packet);
+	kfree(info);
+}
+
+/* Compare two vis packets, used by the hashing algorithm */
+static int batadv_vis_info_cmp(const struct hlist_node *node, const void *data2)
+{
+	const struct batadv_vis_info *d1, *d2;
+	const struct batadv_vis_packet *p1, *p2;
+
+	d1 = container_of(node, struct batadv_vis_info, hash_entry);
+	d2 = data2;
+	p1 = (struct batadv_vis_packet *)d1->skb_packet->data;
+	p2 = (struct batadv_vis_packet *)d2->skb_packet->data;
+	return batadv_compare_eth(p1->vis_orig, p2->vis_orig);
+}
+
+/* hash function to choose an entry in a hash table of given size
+ * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
+ */
+static uint32_t batadv_vis_info_choose(const void *data, uint32_t size)
+{
+	const struct batadv_vis_info *vis_info = data;
+	const struct batadv_vis_packet *packet;
+	const unsigned char *key;
+	uint32_t hash = 0;
+	size_t i;
+
+	packet = (struct batadv_vis_packet *)vis_info->skb_packet->data;
+	key = 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;
+}
+
+static struct batadv_vis_info *
+batadv_vis_hash_find(struct batadv_priv *bat_priv, const void *data)
+{
+	struct batadv_hashtable *hash = bat_priv->vis.hash;
+	struct hlist_head *head;
+	struct batadv_vis_info *vis_info, *vis_info_tmp = NULL;
+	uint32_t index;
+
+	if (!hash)
+		return NULL;
+
+	index = batadv_vis_info_choose(data, hash->size);
+	head = &hash->table[index];
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(vis_info, head, hash_entry) {
+		if (!batadv_vis_info_cmp(&vis_info->hash_entry, data))
+			continue;
+
+		vis_info_tmp = vis_info;
+		break;
+	}
+	rcu_read_unlock();
+
+	return vis_info_tmp;
+}
+
+/* insert interface to the list of interfaces of one originator, if it
+ * does not already exist in the list
+ */
+static void batadv_vis_data_insert_interface(const uint8_t *interface,
+					     struct hlist_head *if_list,
+					     bool primary)
+{
+	struct batadv_vis_if_list_entry *entry;
+
+	hlist_for_each_entry(entry, if_list, list) {
+		if (batadv_compare_eth(entry->addr, interface))
+			return;
+	}
+
+	/* it's a new address, add it to the list */
+	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	if (!entry)
+		return;
+	memcpy(entry->addr, interface, ETH_ALEN);
+	entry->primary = primary;
+	hlist_add_head(&entry->list, if_list);
+}
+
+static void batadv_vis_data_read_prim_sec(struct seq_file *seq,
+					  const struct hlist_head *if_list)
+{
+	struct batadv_vis_if_list_entry *entry;
+
+	hlist_for_each_entry(entry, if_list, list) {
+		if (entry->primary)
+			seq_puts(seq, "PRIMARY, ");
+		else
+			seq_printf(seq,  "SEC %pM, ", entry->addr);
+	}
+}
+
+/* read an entry  */
+static ssize_t
+batadv_vis_data_read_entry(struct seq_file *seq,
+			   const struct batadv_vis_info_entry *entry,
+			   const uint8_t *src, bool primary)
+{
+	if (primary && entry->quality == 0)
+		return seq_printf(seq, "TT %pM, ", entry->dest);
+	else if (batadv_compare_eth(entry->src, src))
+		return seq_printf(seq, "TQ %pM %d, ", entry->dest,
+				  entry->quality);
+
+	return 0;
+}
+
+static void
+batadv_vis_data_insert_interfaces(struct hlist_head *list,
+				  struct batadv_vis_packet *packet,
+				  struct batadv_vis_info_entry *entries)
+{
+	int i;
+
+	for (i = 0; i < packet->entries; i++) {
+		if (entries[i].quality == 0)
+			continue;
+
+		if (batadv_compare_eth(entries[i].src, packet->vis_orig))
+			continue;
+
+		batadv_vis_data_insert_interface(entries[i].src, list, false);
+	}
+}
+
+static void batadv_vis_data_read_entries(struct seq_file *seq,
+					 struct hlist_head *list,
+					 struct batadv_vis_packet *packet,
+					 struct batadv_vis_info_entry *entries)
+{
+	int i;
+	struct batadv_vis_if_list_entry *entry;
+
+	hlist_for_each_entry(entry, list, list) {
+		seq_printf(seq, "%pM,", entry->addr);
+
+		for (i = 0; i < packet->entries; i++)
+			batadv_vis_data_read_entry(seq, &entries[i],
+						   entry->addr, entry->primary);
+
+		/* add primary/secondary records */
+		if (batadv_compare_eth(entry->addr, packet->vis_orig))
+			batadv_vis_data_read_prim_sec(seq, list);
+
+		seq_puts(seq, "\n");
+	}
+}
+
+static void batadv_vis_seq_print_text_bucket(struct seq_file *seq,
+					     const struct hlist_head *head)
+{
+	struct batadv_vis_info *info;
+	struct batadv_vis_packet *packet;
+	uint8_t *entries_pos;
+	struct batadv_vis_info_entry *entries;
+	struct batadv_vis_if_list_entry *entry;
+	struct hlist_node *n;
+
+	HLIST_HEAD(vis_if_list);
+
+	hlist_for_each_entry_rcu(info, head, hash_entry) {
+		packet = (struct batadv_vis_packet *)info->skb_packet->data;
+		entries_pos = (uint8_t *)packet + sizeof(*packet);
+		entries = (struct batadv_vis_info_entry *)entries_pos;
+
+		batadv_vis_data_insert_interface(packet->vis_orig, &vis_if_list,
+						 true);
+		batadv_vis_data_insert_interfaces(&vis_if_list, packet,
+						  entries);
+		batadv_vis_data_read_entries(seq, &vis_if_list, packet,
+					     entries);
+
+		hlist_for_each_entry_safe(entry, n, &vis_if_list, list) {
+			hlist_del(&entry->list);
+			kfree(entry);
+		}
+	}
+}
+
+int batadv_vis_seq_print_text(struct seq_file *seq, void *offset)
+{
+	struct batadv_hard_iface *primary_if;
+	struct hlist_head *head;
+	struct net_device *net_dev = (struct net_device *)seq->private;
+	struct batadv_priv *bat_priv = netdev_priv(net_dev);
+	struct batadv_hashtable *hash = bat_priv->vis.hash;
+	uint32_t i;
+	int ret = 0;
+	int vis_server = atomic_read(&bat_priv->vis_mode);
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+	if (!primary_if)
+		goto out;
+
+	if (vis_server == BATADV_VIS_TYPE_CLIENT_UPDATE)
+		goto out;
+
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+		batadv_vis_seq_print_text_bucket(seq, head);
+	}
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+
+out:
+	if (primary_if)
+		batadv_hardif_free_ref(primary_if);
+	return ret;
+}
+
+/* add the info packet to the send list, if it was not
+ * already linked in.
+ */
+static void batadv_send_list_add(struct batadv_priv *bat_priv,
+				 struct batadv_vis_info *info)
+{
+	if (list_empty(&info->send_list)) {
+		kref_get(&info->refcount);
+		list_add_tail(&info->send_list, &bat_priv->vis.send_list);
+	}
+}
+
+/* delete the info packet from the send list, if it was
+ * linked in.
+ */
+static void batadv_send_list_del(struct batadv_vis_info *info)
+{
+	if (!list_empty(&info->send_list)) {
+		list_del_init(&info->send_list);
+		kref_put(&info->refcount, batadv_free_info);
+	}
+}
+
+/* tries to add one entry to the receive list. */
+static void batadv_recv_list_add(struct batadv_priv *bat_priv,
+				 struct list_head *recv_list, const char *mac)
+{
+	struct batadv_vis_recvlist_node *entry;
+
+	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	if (!entry)
+		return;
+
+	memcpy(entry->mac, mac, ETH_ALEN);
+	spin_lock_bh(&bat_priv->vis.list_lock);
+	list_add_tail(&entry->list, recv_list);
+	spin_unlock_bh(&bat_priv->vis.list_lock);
+}
+
+/* returns 1 if this mac is in the recv_list */
+static int batadv_recv_list_is_in(struct batadv_priv *bat_priv,
+				  const struct list_head *recv_list,
+				  const char *mac)
+{
+	const struct batadv_vis_recvlist_node *entry;
+
+	spin_lock_bh(&bat_priv->vis.list_lock);
+	list_for_each_entry(entry, recv_list, list) {
+		if (batadv_compare_eth(entry->mac, mac)) {
+			spin_unlock_bh(&bat_priv->vis.list_lock);
+			return 1;
+		}
+	}
+	spin_unlock_bh(&bat_priv->vis.list_lock);
+	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.
+ */
+static struct batadv_vis_info *
+batadv_add_packet(struct batadv_priv *bat_priv,
+		  struct batadv_vis_packet *vis_packet, int vis_info_len,
+		  int *is_new, int make_broadcast)
+{
+	struct batadv_vis_info *info, *old_info;
+	struct batadv_vis_packet *search_packet, *old_packet;
+	struct batadv_vis_info search_elem;
+	struct batadv_vis_packet *packet;
+	struct sk_buff *tmp_skb;
+	int hash_added;
+	size_t len;
+	size_t max_entries;
+
+	*is_new = 0;
+	/* sanity check */
+	if (!bat_priv->vis.hash)
+		return NULL;
+
+	/* see if the packet is already in vis_hash */
+	search_elem.skb_packet = dev_alloc_skb(sizeof(*search_packet));
+	if (!search_elem.skb_packet)
+		return NULL;
+	len = sizeof(*search_packet);
+	tmp_skb = search_elem.skb_packet;
+	search_packet = (struct batadv_vis_packet *)skb_put(tmp_skb, len);
+
+	memcpy(search_packet->vis_orig, vis_packet->vis_orig, ETH_ALEN);
+	old_info = batadv_vis_hash_find(bat_priv, &search_elem);
+	kfree_skb(search_elem.skb_packet);
+
+	if (old_info) {
+		tmp_skb = old_info->skb_packet;
+		old_packet = (struct batadv_vis_packet *)tmp_skb->data;
+		if (!batadv_seq_after(ntohl(vis_packet->seqno),
+				      ntohl(old_packet->seqno))) {
+			if (old_packet->seqno == vis_packet->seqno) {
+				batadv_recv_list_add(bat_priv,
+						     &old_info->recv_list,
+						     vis_packet->sender_orig);
+				return old_info;
+			} else {
+				/* newer packet is already in hash. */
+				return NULL;
+			}
+		}
+		/* remove old entry */
+		batadv_hash_remove(bat_priv->vis.hash, batadv_vis_info_cmp,
+				   batadv_vis_info_choose, old_info);
+		batadv_send_list_del(old_info);
+		kref_put(&old_info->refcount, batadv_free_info);
+	}
+
+	info = kmalloc(sizeof(*info), GFP_ATOMIC);
+	if (!info)
+		return NULL;
+
+	len = sizeof(*packet) + vis_info_len;
+	info->skb_packet = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
+	if (!info->skb_packet) {
+		kfree(info);
+		return NULL;
+	}
+	skb_reserve(info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
+	packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
+
+	kref_init(&info->refcount);
+	INIT_LIST_HEAD(&info->send_list);
+	INIT_LIST_HEAD(&info->recv_list);
+	info->first_seen = jiffies;
+	info->bat_priv = bat_priv;
+	memcpy(packet, vis_packet, len);
+
+	/* initialize and add new packet. */
+	*is_new = 1;
+
+	/* Make it a broadcast packet, if required */
+	if (make_broadcast)
+		memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
+
+	/* repair if entries is longer than packet. */
+	max_entries = vis_info_len / sizeof(struct batadv_vis_info_entry);
+	if (packet->entries > max_entries)
+		packet->entries = max_entries;
+
+	batadv_recv_list_add(bat_priv, &info->recv_list, packet->sender_orig);
+
+	/* try to add it */
+	hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
+				     batadv_vis_info_choose, info,
+				     &info->hash_entry);
+	if (hash_added != 0) {
+		/* did not work (for some reason) */
+		kref_put(&info->refcount, batadv_free_info);
+		info = NULL;
+	}
+
+	return info;
+}
+
+/* handle the server sync packet, forward if needed. */
+void batadv_receive_server_sync_packet(struct batadv_priv *bat_priv,
+				       struct batadv_vis_packet *vis_packet,
+				       int vis_info_len)
+{
+	struct batadv_vis_info *info;
+	int is_new, make_broadcast;
+	int vis_server = atomic_read(&bat_priv->vis_mode);
+
+	make_broadcast = (vis_server == BATADV_VIS_TYPE_SERVER_SYNC);
+
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+	info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
+				 &is_new, make_broadcast);
+	if (!info)
+		goto end;
+
+	/* only if we are server ourselves and packet is newer than the one in
+	 * hash.
+	 */
+	if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC && is_new)
+		batadv_send_list_add(bat_priv, info);
+end:
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+}
+
+/* handle an incoming client update packet and schedule forward if needed. */
+void batadv_receive_client_update_packet(struct batadv_priv *bat_priv,
+					 struct batadv_vis_packet *vis_packet,
+					 int vis_info_len)
+{
+	struct batadv_vis_info *info;
+	struct batadv_vis_packet *packet;
+	int is_new;
+	int vis_server = atomic_read(&bat_priv->vis_mode);
+	int are_target = 0;
+
+	/* clients shall not broadcast. */
+	if (is_broadcast_ether_addr(vis_packet->target_orig))
+		return;
+
+	/* Are we the target for this VIS packet? */
+	if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC	&&
+	    batadv_is_my_mac(bat_priv, vis_packet->target_orig))
+		are_target = 1;
+
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+	info = batadv_add_packet(bat_priv, vis_packet, vis_info_len,
+				 &is_new, are_target);
+
+	if (!info)
+		goto end;
+	/* note that outdated packets will be dropped at this point. */
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+
+	/* send only if we're the target server or ... */
+	if (are_target && is_new) {
+		packet->vis_type = BATADV_VIS_TYPE_SERVER_SYNC;	/* upgrade! */
+		batadv_send_list_add(bat_priv, info);
+
+		/* ... we're not the recipient (and thus need to forward). */
+	} else if (!batadv_is_my_mac(bat_priv, packet->target_orig)) {
+		batadv_send_list_add(bat_priv, info);
+	}
+
+end:
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+}
+
+/* Walk the originators and find the VIS server with the best tq. Set the packet
+ * address to its address and return the best_tq.
+ *
+ * Must be called with the originator hash locked
+ */
+static int batadv_find_best_vis_server(struct batadv_priv *bat_priv,
+				       struct batadv_vis_info *info)
+{
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	struct batadv_neigh_node *router;
+	struct hlist_head *head;
+	struct batadv_orig_node *orig_node;
+	struct batadv_vis_packet *packet;
+	int best_tq = -1;
+	uint32_t i;
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+			router = batadv_orig_node_get_router(orig_node);
+			if (!router)
+				continue;
+
+			if ((orig_node->flags & BATADV_VIS_SERVER) &&
+			    (router->tq_avg > best_tq)) {
+				best_tq = router->tq_avg;
+				memcpy(packet->target_orig, orig_node->orig,
+				       ETH_ALEN);
+			}
+			batadv_neigh_node_free_ref(router);
+		}
+		rcu_read_unlock();
+	}
+
+	return best_tq;
+}
+
+/* Return true if the vis packet is full. */
+static bool batadv_vis_packet_full(const struct batadv_vis_info *info)
+{
+	const struct batadv_vis_packet *packet;
+	size_t num;
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+	num = BATADV_MAX_VIS_PACKET_SIZE / sizeof(struct batadv_vis_info_entry);
+
+	if (num < packet->entries + 1)
+		return true;
+	return false;
+}
+
+/* generates a packet of own vis data,
+ * returns 0 on success, -1 if no packet could be generated
+ */
+static int batadv_generate_vis_packet(struct batadv_priv *bat_priv)
+{
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	struct hlist_head *head;
+	struct batadv_orig_node *orig_node;
+	struct batadv_neigh_node *router;
+	struct batadv_vis_info *info = bat_priv->vis.my_info;
+	struct batadv_vis_packet *packet;
+	struct batadv_vis_info_entry *entry;
+	struct batadv_tt_common_entry *tt_common_entry;
+	uint8_t *packet_pos;
+	int best_tq = -1;
+	uint32_t i;
+
+	info->first_seen = jiffies;
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+	packet->vis_type = atomic_read(&bat_priv->vis_mode);
+
+	memcpy(packet->target_orig, batadv_broadcast_addr, ETH_ALEN);
+	packet->header.ttl = BATADV_TTL;
+	packet->seqno = htonl(ntohl(packet->seqno) + 1);
+	packet->entries = 0;
+	packet->reserved = 0;
+	skb_trim(info->skb_packet, sizeof(*packet));
+
+	if (packet->vis_type == BATADV_VIS_TYPE_CLIENT_UPDATE) {
+		best_tq = batadv_find_best_vis_server(bat_priv, info);
+
+		if (best_tq < 0)
+			return best_tq;
+	}
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+			router = batadv_orig_node_get_router(orig_node);
+			if (!router)
+				continue;
+
+			if (!batadv_compare_eth(router->addr, orig_node->orig))
+				goto next;
+
+			if (router->if_incoming->if_status != BATADV_IF_ACTIVE)
+				goto next;
+
+			if (router->tq_avg < 1)
+				goto next;
+
+			/* fill one entry into buffer. */
+			packet_pos = skb_put(info->skb_packet, sizeof(*entry));
+			entry = (struct batadv_vis_info_entry *)packet_pos;
+			memcpy(entry->src,
+			       router->if_incoming->net_dev->dev_addr,
+			       ETH_ALEN);
+			memcpy(entry->dest, orig_node->orig, ETH_ALEN);
+			entry->quality = router->tq_avg;
+			packet->entries++;
+
+next:
+			batadv_neigh_node_free_ref(router);
+
+			if (batadv_vis_packet_full(info))
+				goto unlock;
+		}
+		rcu_read_unlock();
+	}
+
+	hash = bat_priv->tt.local_hash;
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(tt_common_entry, head,
+					 hash_entry) {
+			packet_pos = skb_put(info->skb_packet, sizeof(*entry));
+			entry = (struct batadv_vis_info_entry *)packet_pos;
+			memset(entry->src, 0, ETH_ALEN);
+			memcpy(entry->dest, tt_common_entry->addr, ETH_ALEN);
+			entry->quality = 0; /* 0 means TT */
+			packet->entries++;
+
+			if (batadv_vis_packet_full(info))
+				goto unlock;
+		}
+		rcu_read_unlock();
+	}
+
+	return 0;
+
+unlock:
+	rcu_read_unlock();
+	return 0;
+}
+
+/* free old vis packets. Must be called with this vis_hash_lock
+ * held
+ */
+static void batadv_purge_vis_packets(struct batadv_priv *bat_priv)
+{
+	uint32_t i;
+	struct batadv_hashtable *hash = bat_priv->vis.hash;
+	struct hlist_node *node_tmp;
+	struct hlist_head *head;
+	struct batadv_vis_info *info;
+
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		hlist_for_each_entry_safe(info, node_tmp,
+					  head, hash_entry) {
+			/* never purge own data. */
+			if (info == bat_priv->vis.my_info)
+				continue;
+
+			if (batadv_has_timed_out(info->first_seen,
+						 BATADV_VIS_TIMEOUT)) {
+				hlist_del(&info->hash_entry);
+				batadv_send_list_del(info);
+				kref_put(&info->refcount, batadv_free_info);
+			}
+		}
+	}
+}
+
+static void batadv_broadcast_vis_packet(struct batadv_priv *bat_priv,
+					struct batadv_vis_info *info)
+{
+	struct batadv_hashtable *hash = bat_priv->orig_hash;
+	struct hlist_head *head;
+	struct batadv_orig_node *orig_node;
+	struct batadv_vis_packet *packet;
+	struct sk_buff *skb;
+	uint32_t i;
+
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+
+	/* send to all routers in range. */
+	for (i = 0; i < hash->size; i++) {
+		head = &hash->table[i];
+
+		rcu_read_lock();
+		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+			/* if it's a vis server and reachable, send it. */
+			if (!(orig_node->flags & BATADV_VIS_SERVER))
+				continue;
+
+			/* don't send it if we already received the packet from
+			 * this node.
+			 */
+			if (batadv_recv_list_is_in(bat_priv, &info->recv_list,
+						   orig_node->orig))
+				continue;
+
+			memcpy(packet->target_orig, orig_node->orig, ETH_ALEN);
+			skb = skb_clone(info->skb_packet, GFP_ATOMIC);
+			if (!skb)
+				continue;
+
+			if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
+				kfree_skb(skb);
+		}
+		rcu_read_unlock();
+	}
+}
+
+static void batadv_unicast_vis_packet(struct batadv_priv *bat_priv,
+				      struct batadv_vis_info *info)
+{
+	struct batadv_orig_node *orig_node;
+	struct sk_buff *skb;
+	struct batadv_vis_packet *packet;
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+
+	orig_node = batadv_orig_hash_find(bat_priv, packet->target_orig);
+	if (!orig_node)
+		goto out;
+
+	skb = skb_clone(info->skb_packet, GFP_ATOMIC);
+	if (!skb)
+		goto out;
+
+	if (!batadv_send_skb_to_orig(skb, orig_node, NULL))
+		kfree_skb(skb);
+
+out:
+	if (orig_node)
+		batadv_orig_node_free_ref(orig_node);
+}
+
+/* only send one vis packet. called from batadv_send_vis_packets() */
+static void batadv_send_vis_packet(struct batadv_priv *bat_priv,
+				   struct batadv_vis_info *info)
+{
+	struct batadv_hard_iface *primary_if;
+	struct batadv_vis_packet *packet;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+	if (!primary_if)
+		goto out;
+
+	packet = (struct batadv_vis_packet *)info->skb_packet->data;
+	if (packet->header.ttl < 2) {
+		pr_debug("Error - can't send vis packet: ttl exceeded\n");
+		goto out;
+	}
+
+	memcpy(packet->sender_orig, primary_if->net_dev->dev_addr, ETH_ALEN);
+	packet->header.ttl--;
+
+	if (is_broadcast_ether_addr(packet->target_orig))
+		batadv_broadcast_vis_packet(bat_priv, info);
+	else
+		batadv_unicast_vis_packet(bat_priv, info);
+	packet->header.ttl++; /* restore TTL */
+
+out:
+	if (primary_if)
+		batadv_hardif_free_ref(primary_if);
+}
+
+/* called from timer; send (and maybe generate) vis packet. */
+static void batadv_send_vis_packets(struct work_struct *work)
+{
+	struct delayed_work *delayed_work;
+	struct batadv_priv *bat_priv;
+	struct batadv_priv_vis *priv_vis;
+	struct batadv_vis_info *info;
+
+	delayed_work = container_of(work, struct delayed_work, work);
+	priv_vis = container_of(delayed_work, struct batadv_priv_vis, work);
+	bat_priv = container_of(priv_vis, struct batadv_priv, vis);
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+	batadv_purge_vis_packets(bat_priv);
+
+	if (batadv_generate_vis_packet(bat_priv) == 0) {
+		/* schedule if generation was successful */
+		batadv_send_list_add(bat_priv, bat_priv->vis.my_info);
+	}
+
+	while (!list_empty(&bat_priv->vis.send_list)) {
+		info = list_first_entry(&bat_priv->vis.send_list,
+					typeof(*info), send_list);
+
+		kref_get(&info->refcount);
+		spin_unlock_bh(&bat_priv->vis.hash_lock);
+
+		batadv_send_vis_packet(bat_priv, info);
+
+		spin_lock_bh(&bat_priv->vis.hash_lock);
+		batadv_send_list_del(info);
+		kref_put(&info->refcount, batadv_free_info);
+	}
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+
+	queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
+			   msecs_to_jiffies(BATADV_VIS_INTERVAL));
+}
+
+/* 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 batadv_vis_init(struct batadv_priv *bat_priv)
+{
+	struct batadv_vis_packet *packet;
+	int hash_added;
+	unsigned int len;
+	unsigned long first_seen;
+	struct sk_buff *tmp_skb;
+
+	if (bat_priv->vis.hash)
+		return 0;
+
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+
+	bat_priv->vis.hash = batadv_hash_new(256);
+	if (!bat_priv->vis.hash) {
+		pr_err("Can't initialize vis_hash\n");
+		goto err;
+	}
+
+	batadv_hash_set_lock_class(bat_priv->vis.hash,
+				   &batadv_vis_hash_lock_class_key);
+
+	bat_priv->vis.my_info = kmalloc(BATADV_MAX_VIS_PACKET_SIZE, GFP_ATOMIC);
+	if (!bat_priv->vis.my_info)
+		goto err;
+
+	len = sizeof(*packet) + BATADV_MAX_VIS_PACKET_SIZE;
+	len += ETH_HLEN + NET_IP_ALIGN;
+	bat_priv->vis.my_info->skb_packet = dev_alloc_skb(len);
+	if (!bat_priv->vis.my_info->skb_packet)
+		goto free_info;
+
+	skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN + NET_IP_ALIGN);
+	tmp_skb = bat_priv->vis.my_info->skb_packet;
+	packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));
+
+	/* prefill the vis info */
+	first_seen = jiffies - msecs_to_jiffies(BATADV_VIS_INTERVAL);
+	bat_priv->vis.my_info->first_seen = first_seen;
+	INIT_LIST_HEAD(&bat_priv->vis.my_info->recv_list);
+	INIT_LIST_HEAD(&bat_priv->vis.my_info->send_list);
+	kref_init(&bat_priv->vis.my_info->refcount);
+	bat_priv->vis.my_info->bat_priv = bat_priv;
+	packet->header.version = BATADV_COMPAT_VERSION;
+	packet->header.packet_type = BATADV_VIS;
+	packet->header.ttl = BATADV_TTL;
+	packet->seqno = 0;
+	packet->reserved = 0;
+	packet->entries = 0;
+
+	INIT_LIST_HEAD(&bat_priv->vis.send_list);
+
+	hash_added = batadv_hash_add(bat_priv->vis.hash, batadv_vis_info_cmp,
+				     batadv_vis_info_choose,
+				     bat_priv->vis.my_info,
+				     &bat_priv->vis.my_info->hash_entry);
+	if (hash_added != 0) {
+		pr_err("Can't add own vis packet into hash\n");
+		/* not in hash, need to remove it manually. */
+		kref_put(&bat_priv->vis.my_info->refcount, batadv_free_info);
+		goto err;
+	}
+
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+
+	INIT_DELAYED_WORK(&bat_priv->vis.work, batadv_send_vis_packets);
+	queue_delayed_work(batadv_event_workqueue, &bat_priv->vis.work,
+			   msecs_to_jiffies(BATADV_VIS_INTERVAL));
+
+	return 0;
+
+free_info:
+	kfree(bat_priv->vis.my_info);
+	bat_priv->vis.my_info = NULL;
+err:
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+	batadv_vis_quit(bat_priv);
+	return -ENOMEM;
+}
+
+/* Decrease the reference count on a hash item info */
+static void batadv_free_info_ref(struct hlist_node *node, void *arg)
+{
+	struct batadv_vis_info *info;
+
+	info = container_of(node, struct batadv_vis_info, hash_entry);
+	batadv_send_list_del(info);
+	kref_put(&info->refcount, batadv_free_info);
+}
+
+/* shutdown vis-server */
+void batadv_vis_quit(struct batadv_priv *bat_priv)
+{
+	if (!bat_priv->vis.hash)
+		return;
+
+	cancel_delayed_work_sync(&bat_priv->vis.work);
+
+	spin_lock_bh(&bat_priv->vis.hash_lock);
+	/* properly remove, kill timers ... */
+	batadv_hash_delete(bat_priv->vis.hash, batadv_free_info_ref, NULL);
+	bat_priv->vis.hash = NULL;
+	bat_priv->vis.my_info = NULL;
+	spin_unlock_bh(&bat_priv->vis.hash_lock);
+}