linux/net/batman-adv/routing.c

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/*
* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
*
* Marek Lindner, 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 "routing.h"
#include "send.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "icmp_socket.h"
#include "translation-table.h"
#include "originator.h"
#include "vis.h"
#include "unicast.h"
#include "bridge_loop_avoidance.h"
static int route_unicast_packet(struct sk_buff *skb,
struct hard_iface *recv_if);
void slide_own_bcast_window(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct hashtable_t *hash = bat_priv->orig_hash;
struct hlist_node *node;
struct hlist_head *head;
struct orig_node *orig_node;
unsigned long *word;
uint32_t i;
size_t word_index;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
spin_lock_bh(&orig_node->ogm_cnt_lock);
word_index = hard_iface->if_num * NUM_WORDS;
word = &(orig_node->bcast_own[word_index]);
bit_get_packet(bat_priv, word, 1, 0);
orig_node->bcast_own_sum[hard_iface->if_num] =
bitmap_weight(word, TQ_LOCAL_WINDOW_SIZE);
spin_unlock_bh(&orig_node->ogm_cnt_lock);
}
rcu_read_unlock();
}
}
static void _update_route(struct bat_priv *bat_priv,
struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
struct neigh_node *curr_router;
curr_router = orig_node_get_router(orig_node);
/* route deleted */
if ((curr_router) && (!neigh_node)) {
bat_dbg(DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n",
orig_node->orig);
tt_global_del_orig(bat_priv, orig_node,
"Deleted route towards originator");
/* route added */
} else if ((!curr_router) && (neigh_node)) {
bat_dbg(DBG_ROUTES, bat_priv,
"Adding route towards: %pM (via %pM)\n",
orig_node->orig, neigh_node->addr);
/* route changed */
} else if (neigh_node && curr_router) {
bat_dbg(DBG_ROUTES, bat_priv,
"Changing route towards: %pM (now via %pM - was via %pM)\n",
orig_node->orig, neigh_node->addr,
curr_router->addr);
}
if (curr_router)
neigh_node_free_ref(curr_router);
/* increase refcount of new best neighbor */
if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount))
neigh_node = NULL;
spin_lock_bh(&orig_node->neigh_list_lock);
rcu_assign_pointer(orig_node->router, neigh_node);
spin_unlock_bh(&orig_node->neigh_list_lock);
/* decrease refcount of previous best neighbor */
if (curr_router)
neigh_node_free_ref(curr_router);
}
void update_route(struct bat_priv *bat_priv, struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
struct neigh_node *router = NULL;
if (!orig_node)
goto out;
router = orig_node_get_router(orig_node);
if (router != neigh_node)
_update_route(bat_priv, orig_node, neigh_node);
out:
if (router)
neigh_node_free_ref(router);
}
/* caller must hold the neigh_list_lock */
void bonding_candidate_del(struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
/* this neighbor is not part of our candidate list */
if (list_empty(&neigh_node->bonding_list))
goto out;
list_del_rcu(&neigh_node->bonding_list);
INIT_LIST_HEAD(&neigh_node->bonding_list);
neigh_node_free_ref(neigh_node);
atomic_dec(&orig_node->bond_candidates);
out:
return;
}
void bonding_candidate_add(struct orig_node *orig_node,
struct neigh_node *neigh_node)
{
struct hlist_node *node;
struct neigh_node *tmp_neigh_node, *router = NULL;
uint8_t interference_candidate = 0;
spin_lock_bh(&orig_node->neigh_list_lock);
/* only consider if it has the same primary address ... */
if (!compare_eth(orig_node->orig,
neigh_node->orig_node->primary_addr))
goto candidate_del;
router = orig_node_get_router(orig_node);
if (!router)
goto candidate_del;
/* ... and is good enough to be considered */
if (neigh_node->tq_avg < router->tq_avg - BONDING_TQ_THRESHOLD)
goto candidate_del;
/**
* check if we have another candidate with the same mac address or
* interface. If we do, we won't select this candidate because of
* possible interference.
*/
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
if (tmp_neigh_node == neigh_node)
continue;
/* we only care if the other candidate is even
* considered as candidate. */
if (list_empty(&tmp_neigh_node->bonding_list))
continue;
if ((neigh_node->if_incoming == tmp_neigh_node->if_incoming) ||
(compare_eth(neigh_node->addr, tmp_neigh_node->addr))) {
interference_candidate = 1;
break;
}
}
/* don't care further if it is an interference candidate */
if (interference_candidate)
goto candidate_del;
/* this neighbor already is part of our candidate list */
if (!list_empty(&neigh_node->bonding_list))
goto out;
if (!atomic_inc_not_zero(&neigh_node->refcount))
goto out;
list_add_rcu(&neigh_node->bonding_list, &orig_node->bond_list);
atomic_inc(&orig_node->bond_candidates);
goto out;
candidate_del:
bonding_candidate_del(orig_node, neigh_node);
out:
spin_unlock_bh(&orig_node->neigh_list_lock);
if (router)
neigh_node_free_ref(router);
}
/* copy primary address for bonding */
void bonding_save_primary(const struct orig_node *orig_node,
struct orig_node *orig_neigh_node,
const struct batman_ogm_packet *batman_ogm_packet)
{
if (!(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
return;
memcpy(orig_neigh_node->primary_addr, orig_node->orig, ETH_ALEN);
}
/* checks whether the host restarted and is in the protection time.
* returns:
* 0 if the packet is to be accepted
* 1 if the packet is to be ignored.
*/
int window_protected(struct bat_priv *bat_priv, int32_t seq_num_diff,
unsigned long *last_reset)
{
if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) ||
(seq_num_diff >= EXPECTED_SEQNO_RANGE)) {
if (has_timed_out(*last_reset, RESET_PROTECTION_MS)) {
*last_reset = jiffies;
bat_dbg(DBG_BATMAN, bat_priv,
"old packet received, start protection\n");
return 0;
} else {
return 1;
}
}
return 0;
}
int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, BATMAN_OGM_LEN)))
return NET_RX_DROP;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with broadcast indication but unicast recipient */
if (!is_broadcast_ether_addr(ethhdr->h_dest))
return NET_RX_DROP;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
return NET_RX_DROP;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, 0) < 0)
return NET_RX_DROP;
/* keep skb linear */
if (skb_linearize(skb) < 0)
return NET_RX_DROP;
bat_priv->bat_algo_ops->bat_ogm_receive(hard_iface, skb);
kfree_skb(skb);
return NET_RX_SUCCESS;
}
static int recv_my_icmp_packet(struct bat_priv *bat_priv,
struct sk_buff *skb, size_t icmp_len)
{
struct hard_iface *primary_if = NULL;
struct orig_node *orig_node = NULL;
struct neigh_node *router = NULL;
struct icmp_packet_rr *icmp_packet;
int ret = NET_RX_DROP;
icmp_packet = (struct icmp_packet_rr *)skb->data;
/* add data to device queue */
if (icmp_packet->msg_type != ECHO_REQUEST) {
bat_socket_receive_packet(icmp_packet, icmp_len);
goto out;
}
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* answer echo request (ping) */
/* get routing information */
orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
if (!orig_node)
goto out;
router = orig_node_get_router(orig_node);
if (!router)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
goto out;
icmp_packet = (struct icmp_packet_rr *)skb->data;
memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
icmp_packet->msg_type = ECHO_REPLY;
icmp_packet->header.ttl = TTL;
send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (primary_if)
hardif_free_ref(primary_if);
if (router)
neigh_node_free_ref(router);
if (orig_node)
orig_node_free_ref(orig_node);
return ret;
}
static int recv_icmp_ttl_exceeded(struct bat_priv *bat_priv,
struct sk_buff *skb)
{
struct hard_iface *primary_if = NULL;
struct orig_node *orig_node = NULL;
struct neigh_node *router = NULL;
struct icmp_packet *icmp_packet;
int ret = NET_RX_DROP;
icmp_packet = (struct icmp_packet *)skb->data;
/* send TTL exceeded if packet is an echo request (traceroute) */
if (icmp_packet->msg_type != ECHO_REQUEST) {
pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n",
icmp_packet->orig, icmp_packet->dst);
goto out;
}
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* get routing information */
orig_node = orig_hash_find(bat_priv, icmp_packet->orig);
if (!orig_node)
goto out;
router = orig_node_get_router(orig_node);
if (!router)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
goto out;
icmp_packet = (struct icmp_packet *)skb->data;
memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN);
memcpy(icmp_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN);
icmp_packet->msg_type = TTL_EXCEEDED;
icmp_packet->header.ttl = TTL;
send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (primary_if)
hardif_free_ref(primary_if);
if (router)
neigh_node_free_ref(router);
if (orig_node)
orig_node_free_ref(orig_node);
return ret;
}
int recv_icmp_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct icmp_packet_rr *icmp_packet;
struct ethhdr *ethhdr;
struct orig_node *orig_node = NULL;
struct neigh_node *router = NULL;
int hdr_size = sizeof(struct icmp_packet);
int ret = NET_RX_DROP;
/**
* we truncate all incoming icmp packets if they don't match our size
*/
if (skb->len >= sizeof(struct icmp_packet_rr))
hdr_size = sizeof(struct icmp_packet_rr);
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto out;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
goto out;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
goto out;
/* not for me */
if (!is_my_mac(ethhdr->h_dest))
goto out;
icmp_packet = (struct icmp_packet_rr *)skb->data;
/* add record route information if not full */
if ((hdr_size == sizeof(struct icmp_packet_rr)) &&
(icmp_packet->rr_cur < BAT_RR_LEN)) {
memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
ethhdr->h_dest, ETH_ALEN);
icmp_packet->rr_cur++;
}
/* packet for me */
if (is_my_mac(icmp_packet->dst))
return recv_my_icmp_packet(bat_priv, skb, hdr_size);
/* TTL exceeded */
if (icmp_packet->header.ttl < 2)
return recv_icmp_ttl_exceeded(bat_priv, skb);
/* get routing information */
orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
if (!orig_node)
goto out;
router = orig_node_get_router(orig_node);
if (!router)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
goto out;
icmp_packet = (struct icmp_packet_rr *)skb->data;
/* decrement ttl */
icmp_packet->header.ttl--;
/* route it */
send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (router)
neigh_node_free_ref(router);
if (orig_node)
orig_node_free_ref(orig_node);
return ret;
}
/* In the bonding case, send the packets in a round
* robin fashion over the remaining interfaces.
*
* This method rotates the bonding list and increases the
* returned router's refcount. */
static struct neigh_node *find_bond_router(struct orig_node *primary_orig,
const struct hard_iface *recv_if)
{
struct neigh_node *tmp_neigh_node;
struct neigh_node *router = NULL, *first_candidate = NULL;
rcu_read_lock();
list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
bonding_list) {
if (!first_candidate)
first_candidate = tmp_neigh_node;
/* recv_if == NULL on the first node. */
if (tmp_neigh_node->if_incoming == recv_if)
continue;
if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
continue;
router = tmp_neigh_node;
break;
}
/* use the first candidate if nothing was found. */
if (!router && first_candidate &&
atomic_inc_not_zero(&first_candidate->refcount))
router = first_candidate;
if (!router)
goto out;
/* selected should point to the next element
* after the current router */
spin_lock_bh(&primary_orig->neigh_list_lock);
/* this is a list_move(), which unfortunately
* does not exist as rcu version */
list_del_rcu(&primary_orig->bond_list);
list_add_rcu(&primary_orig->bond_list,
&router->bonding_list);
spin_unlock_bh(&primary_orig->neigh_list_lock);
out:
rcu_read_unlock();
return router;
}
/* Interface Alternating: Use the best of the
* remaining candidates which are not using
* this interface.
*
* Increases the returned router's refcount */
static struct neigh_node *find_ifalter_router(struct orig_node *primary_orig,
const struct hard_iface *recv_if)
{
struct neigh_node *tmp_neigh_node;
struct neigh_node *router = NULL, *first_candidate = NULL;
rcu_read_lock();
list_for_each_entry_rcu(tmp_neigh_node, &primary_orig->bond_list,
bonding_list) {
if (!first_candidate)
first_candidate = tmp_neigh_node;
/* recv_if == NULL on the first node. */
if (tmp_neigh_node->if_incoming == recv_if)
continue;
if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
continue;
/* if we don't have a router yet
* or this one is better, choose it. */
if ((!router) ||
(tmp_neigh_node->tq_avg > router->tq_avg)) {
/* decrement refcount of
* previously selected router */
if (router)
neigh_node_free_ref(router);
router = tmp_neigh_node;
atomic_inc_not_zero(&router->refcount);
}
neigh_node_free_ref(tmp_neigh_node);
}
/* use the first candidate if nothing was found. */
if (!router && first_candidate &&
atomic_inc_not_zero(&first_candidate->refcount))
router = first_candidate;
rcu_read_unlock();
return router;
}
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
int recv_tt_query(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct tt_query_packet *tt_query;
uint16_t tt_len;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, sizeof(struct tt_query_packet))))
goto out;
/* I could need to modify it */
if (skb_cow(skb, sizeof(struct tt_query_packet)) < 0)
goto out;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
goto out;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
goto out;
tt_query = (struct tt_query_packet *)skb->data;
tt_query->tt_data = ntohs(tt_query->tt_data);
switch (tt_query->flags & TT_QUERY_TYPE_MASK) {
case TT_REQUEST:
/* If we cannot provide an answer the tt_request is
* forwarded */
if (!send_tt_response(bat_priv, tt_query)) {
bat_dbg(DBG_TT, bat_priv,
"Routing TT_REQUEST to %pM [%c]\n",
tt_query->dst,
(tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
tt_query->tt_data = htons(tt_query->tt_data);
return route_unicast_packet(skb, recv_if);
}
break;
case TT_RESPONSE:
if (is_my_mac(tt_query->dst)) {
/* packet needs to be linearized to access the TT
* changes */
if (skb_linearize(skb) < 0)
goto out;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
tt_len = tt_query->tt_data * sizeof(struct tt_change);
/* Ensure we have all the claimed data */
if (unlikely(skb_headlen(skb) <
sizeof(struct tt_query_packet) + tt_len))
goto out;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
handle_tt_response(bat_priv, tt_query);
} else {
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
bat_dbg(DBG_TT, bat_priv,
"Routing TT_RESPONSE to %pM [%c]\n",
tt_query->dst,
(tt_query->flags & TT_FULL_TABLE ? 'F' : '.'));
tt_query->tt_data = htons(tt_query->tt_data);
return route_unicast_packet(skb, recv_if);
}
break;
}
out:
/* returning NET_RX_DROP will make the caller function kfree the skb */
return NET_RX_DROP;
}
int recv_roam_adv(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct roam_adv_packet *roam_adv_packet;
struct orig_node *orig_node;
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, sizeof(struct roam_adv_packet))))
goto out;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
goto out;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
goto out;
roam_adv_packet = (struct roam_adv_packet *)skb->data;
if (!is_my_mac(roam_adv_packet->dst))
return route_unicast_packet(skb, recv_if);
/* check if it is a backbone gateway. we don't accept
* roaming advertisement from it, as it has the same
* entries as we have.
*/
if (bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
goto out;
orig_node = orig_hash_find(bat_priv, roam_adv_packet->src);
if (!orig_node)
goto out;
bat_dbg(DBG_TT, bat_priv,
"Received ROAMING_ADV from %pM (client %pM)\n",
roam_adv_packet->src, roam_adv_packet->client);
tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
atomic_read(&orig_node->last_ttvn) + 1, true, false);
/* Roaming phase starts: I have new information but the ttvn has not
* been incremented yet. This flag will make me check all the incoming
* packets for the correct destination. */
bat_priv->tt_poss_change = true;
orig_node_free_ref(orig_node);
out:
/* returning NET_RX_DROP will make the caller function kfree the skb */
return NET_RX_DROP;
}
/* find a suitable router for this originator, and use
* bonding if possible. increases the found neighbors
* refcount.*/
struct neigh_node *find_router(struct bat_priv *bat_priv,
struct orig_node *orig_node,
const struct hard_iface *recv_if)
{
struct orig_node *primary_orig_node;
struct orig_node *router_orig;
struct neigh_node *router;
static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
int bonding_enabled;
if (!orig_node)
return NULL;
router = orig_node_get_router(orig_node);
if (!router)
goto err;
/* without bonding, the first node should
* always choose the default router. */
bonding_enabled = atomic_read(&bat_priv->bonding);
rcu_read_lock();
/* select default router to output */
router_orig = router->orig_node;
if (!router_orig)
goto err_unlock;
if ((!recv_if) && (!bonding_enabled))
goto return_router;
/* if we have something in the primary_addr, we can search
* for a potential bonding candidate. */
if (compare_eth(router_orig->primary_addr, zero_mac))
goto return_router;
/* find the orig_node which has the primary interface. might
* even be the same as our router_orig in many cases */
if (compare_eth(router_orig->primary_addr, router_orig->orig)) {
primary_orig_node = router_orig;
} else {
primary_orig_node = orig_hash_find(bat_priv,
router_orig->primary_addr);
if (!primary_orig_node)
goto return_router;
orig_node_free_ref(primary_orig_node);
}
/* with less than 2 candidates, we can't do any
* bonding and prefer the original router. */
if (atomic_read(&primary_orig_node->bond_candidates) < 2)
goto return_router;
/* all nodes between should choose a candidate which
* is is not on the interface where the packet came
* in. */
neigh_node_free_ref(router);
if (bonding_enabled)
router = find_bond_router(primary_orig_node, recv_if);
else
router = find_ifalter_router(primary_orig_node, recv_if);
return_router:
if (router && router->if_incoming->if_status != IF_ACTIVE)
goto err_unlock;
rcu_read_unlock();
return router;
err_unlock:
rcu_read_unlock();
err:
if (router)
neigh_node_free_ref(router);
return NULL;
}
static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
{
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
return -1;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
return -1;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
return -1;
/* not for me */
if (!is_my_mac(ethhdr->h_dest))
return -1;
return 0;
}
static int route_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct orig_node *orig_node = NULL;
struct neigh_node *neigh_node = NULL;
struct unicast_packet *unicast_packet;
struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb);
int ret = NET_RX_DROP;
struct sk_buff *new_skb;
unicast_packet = (struct unicast_packet *)skb->data;
/* TTL exceeded */
if (unicast_packet->header.ttl < 2) {
pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n",
ethhdr->h_source, unicast_packet->dest);
goto out;
}
/* get routing information */
orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
if (!orig_node)
goto out;
/* find_router() increases neigh_nodes refcount if found. */
neigh_node = find_router(bat_priv, orig_node, recv_if);
if (!neigh_node)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
goto out;
unicast_packet = (struct unicast_packet *)skb->data;
if (unicast_packet->header.packet_type == BAT_UNICAST &&
atomic_read(&bat_priv->fragmentation) &&
skb->len > neigh_node->if_incoming->net_dev->mtu) {
ret = frag_send_skb(skb, bat_priv,
neigh_node->if_incoming, neigh_node->addr);
goto out;
}
if (unicast_packet->header.packet_type == BAT_UNICAST_FRAG &&
frag_can_reassemble(skb, neigh_node->if_incoming->net_dev->mtu)) {
ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
if (ret == NET_RX_DROP)
goto out;
/* packet was buffered for late merge */
if (!new_skb) {
ret = NET_RX_SUCCESS;
goto out;
}
skb = new_skb;
unicast_packet = (struct unicast_packet *)skb->data;
}
/* decrement ttl */
unicast_packet->header.ttl--;
/* route it */
send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
ret = NET_RX_SUCCESS;
out:
if (neigh_node)
neigh_node_free_ref(neigh_node);
if (orig_node)
orig_node_free_ref(orig_node);
return ret;
}
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
static int check_unicast_ttvn(struct bat_priv *bat_priv,
struct sk_buff *skb) {
uint8_t curr_ttvn;
struct orig_node *orig_node;
struct ethhdr *ethhdr;
struct hard_iface *primary_if;
struct unicast_packet *unicast_packet;
bool tt_poss_change;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
/* I could need to modify it */
if (skb_cow(skb, sizeof(struct unicast_packet)) < 0)
return 0;
unicast_packet = (struct unicast_packet *)skb->data;
if (is_my_mac(unicast_packet->dest)) {
tt_poss_change = bat_priv->tt_poss_change;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
curr_ttvn = (uint8_t)atomic_read(&bat_priv->ttvn);
} else {
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
orig_node = orig_hash_find(bat_priv, unicast_packet->dest);
if (!orig_node)
return 0;
curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
tt_poss_change = orig_node->tt_poss_change;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
orig_node_free_ref(orig_node);
}
/* Check whether I have to reroute the packet */
if (seq_before(unicast_packet->ttvn, curr_ttvn) || tt_poss_change) {
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
/* Linearize the skb before accessing it */
if (skb_linearize(skb) < 0)
return 0;
ethhdr = (struct ethhdr *)(skb->data +
sizeof(struct unicast_packet));
orig_node = transtable_search(bat_priv, NULL, ethhdr->h_dest);
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
if (!orig_node) {
if (!is_my_client(bat_priv, ethhdr->h_dest))
return 0;
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
return 0;
memcpy(unicast_packet->dest,
primary_if->net_dev->dev_addr, ETH_ALEN);
hardif_free_ref(primary_if);
} else {
memcpy(unicast_packet->dest, orig_node->orig,
ETH_ALEN);
curr_ttvn = (uint8_t)
atomic_read(&orig_node->last_ttvn);
orig_node_free_ref(orig_node);
}
bat_dbg(DBG_ROUTES, bat_priv,
"TTVN mismatch (old_ttvn %u new_ttvn %u)! Rerouting unicast packet (for %pM) to %pM\n",
unicast_packet->ttvn, curr_ttvn, ethhdr->h_dest,
unicast_packet->dest);
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
unicast_packet->ttvn = curr_ttvn;
}
return 1;
}
int recv_unicast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct unicast_packet *unicast_packet;
int hdr_size = sizeof(*unicast_packet);
if (check_unicast_packet(skb, hdr_size) < 0)
return NET_RX_DROP;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
if (!check_unicast_ttvn(bat_priv, skb))
return NET_RX_DROP;
unicast_packet = (struct unicast_packet *)skb->data;
/* packet for me */
if (is_my_mac(unicast_packet->dest)) {
interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
return NET_RX_SUCCESS;
}
return route_unicast_packet(skb, recv_if);
}
int recv_ucast_frag_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct unicast_frag_packet *unicast_packet;
int hdr_size = sizeof(*unicast_packet);
struct sk_buff *new_skb = NULL;
int ret;
if (check_unicast_packet(skb, hdr_size) < 0)
return NET_RX_DROP;
batman-adv: improved client announcement mechanism The client announcement mechanism informs every mesh node in the network of any connected non-mesh client, in order to find the path towards that client from any given point in the mesh. The old implementation was based on the simple idea of appending a data buffer to each OGM containing all the client MAC addresses the node is serving. All other nodes can populate their global translation tables (table which links client MAC addresses to node addresses) using this MAC address buffer and linking it to the node's address contained in the OGM. A node that wants to contact a client has to lookup the node the client is connected to and its address in the global translation table. It is easy to understand that this implementation suffers from several issues: - big overhead (each and every OGM contains the entire list of connected clients) - high latencies for client route updates due to long OGM trip time and OGM losses The new implementation addresses these issues by appending client changes (new client joined or a client left) to the OGM instead of filling it with all the client addresses each time. In this way nodes can modify their global tables by means of "updates", thus reducing the overhead within the OGMs. To keep the entire network in sync each node maintains a translation table version number (ttvn) and a translation table checksum. These values are spread with the OGM to allow all the network participants to determine whether or not they need to update their translation table information. When a translation table lookup is performed in order to send a packet to a client attached to another node, the destination's ttvn is added to the payload packet. Forwarding nodes can compare the packet's ttvn with their destination's ttvn (this node could have a fresher information than the source) and re-route the packet if necessary. This greatly reduces the packet loss of clients roaming from one AP to the next. Signed-off-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-04-27 12:27:44 +00:00
if (!check_unicast_ttvn(bat_priv, skb))
return NET_RX_DROP;
unicast_packet = (struct unicast_frag_packet *)skb->data;
/* packet for me */
if (is_my_mac(unicast_packet->dest)) {
ret = frag_reassemble_skb(skb, bat_priv, &new_skb);
if (ret == NET_RX_DROP)
return NET_RX_DROP;
/* packet was buffered for late merge */
if (!new_skb)
return NET_RX_SUCCESS;
interface_rx(recv_if->soft_iface, new_skb, recv_if,
sizeof(struct unicast_packet));
return NET_RX_SUCCESS;
}
return route_unicast_packet(skb, recv_if);
}
int recv_bcast_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct orig_node *orig_node = NULL;
struct bcast_packet *bcast_packet;
struct ethhdr *ethhdr;
int hdr_size = sizeof(*bcast_packet);
int ret = NET_RX_DROP;
int32_t seq_diff;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto out;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with broadcast indication but unicast recipient */
if (!is_broadcast_ether_addr(ethhdr->h_dest))
goto out;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
goto out;
/* ignore broadcasts sent by myself */
if (is_my_mac(ethhdr->h_source))
goto out;
bcast_packet = (struct bcast_packet *)skb->data;
/* ignore broadcasts originated by myself */
if (is_my_mac(bcast_packet->orig))
goto out;
if (bcast_packet->header.ttl < 2)
goto out;
orig_node = orig_hash_find(bat_priv, bcast_packet->orig);
if (!orig_node)
goto out;
spin_lock_bh(&orig_node->bcast_seqno_lock);
/* check whether the packet is a duplicate */
if (bat_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
ntohl(bcast_packet->seqno)))
goto spin_unlock;
seq_diff = ntohl(bcast_packet->seqno) - orig_node->last_bcast_seqno;
/* check whether the packet is old and the host just restarted. */
if (window_protected(bat_priv, seq_diff,
&orig_node->bcast_seqno_reset))
goto spin_unlock;
/* mark broadcast in flood history, update window position
* if required. */
if (bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1))
orig_node->last_bcast_seqno = ntohl(bcast_packet->seqno);
spin_unlock_bh(&orig_node->bcast_seqno_lock);
/* rebroadcast packet */
add_bcast_packet_to_list(bat_priv, skb, 1);
/* don't hand the broadcast up if it is from an originator
* from the same backbone.
*/
if (bla_is_backbone_gw(skb, orig_node, hdr_size))
goto out;
/* broadcast for me */
interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
ret = NET_RX_SUCCESS;
goto out;
spin_unlock:
spin_unlock_bh(&orig_node->bcast_seqno_lock);
out:
if (orig_node)
orig_node_free_ref(orig_node);
return ret;
}
int recv_vis_packet(struct sk_buff *skb, struct hard_iface *recv_if)
{
struct vis_packet *vis_packet;
struct ethhdr *ethhdr;
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
int hdr_size = sizeof(*vis_packet);
/* keep skb linear */
if (skb_linearize(skb) < 0)
return NET_RX_DROP;
if (unlikely(!pskb_may_pull(skb, hdr_size)))
return NET_RX_DROP;
vis_packet = (struct vis_packet *)skb->data;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* not for me */
if (!is_my_mac(ethhdr->h_dest))
return NET_RX_DROP;
/* ignore own packets */
if (is_my_mac(vis_packet->vis_orig))
return NET_RX_DROP;
if (is_my_mac(vis_packet->sender_orig))
return NET_RX_DROP;
switch (vis_packet->vis_type) {
case VIS_TYPE_SERVER_SYNC:
receive_server_sync_packet(bat_priv, vis_packet,
skb_headlen(skb));
break;
case VIS_TYPE_CLIENT_UPDATE:
receive_client_update_packet(bat_priv, vis_packet,
skb_headlen(skb));
break;
default: /* ignore unknown packet */
break;
}
/* We take a copy of the data in the packet, so we should
always free the skbuf. */
return NET_RX_DROP;
}