/*
* Copyright (C) 2007-2011 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 "bat_ogm.h"
#include "translation-table.h"
#include "ring_buffer.h"
#include "originator.h"
#include "routing.h"
#include "gateway_common.h"
#include "gateway_client.h"
#include "hard-interface.h"
#include "send.h"
/* is there another aggregated packet here? */
static int bat_ogm_aggr_packet(int buff_pos, int packet_len,
int tt_num_changes)
{
int next_buff_pos = buff_pos + BATMAN_OGM_LEN + tt_len(tt_num_changes);
return (next_buff_pos <= packet_len) &&
(next_buff_pos <= MAX_AGGREGATION_BYTES);
}
static void bat_ogm_orig_update(struct bat_priv *bat_priv,
struct orig_node *orig_node,
const struct ethhdr *ethhdr,
const struct batman_ogm_packet
*batman_ogm_packet,
struct hard_iface *if_incoming,
const unsigned char *tt_buff, int is_duplicate)
{
struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
struct neigh_node *router = NULL;
struct orig_node *orig_node_tmp;
struct hlist_node *node;
uint8_t bcast_own_sum_orig, bcast_own_sum_neigh;
bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): "
"Searching and updating originator entry of received packet\n");
rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
(tmp_neigh_node->if_incoming == if_incoming) &&
atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
if (neigh_node)
neigh_node_free_ref(neigh_node);
neigh_node = tmp_neigh_node;
continue;
}
if (is_duplicate)
continue;
spin_lock_bh(&tmp_neigh_node->tq_lock);
ring_buffer_set(tmp_neigh_node->tq_recv,
&tmp_neigh_node->tq_index, 0);
tmp_neigh_node->tq_avg =
ring_buffer_avg(tmp_neigh_node->tq_recv);
spin_unlock_bh(&tmp_neigh_node->tq_lock);
}
if (!neigh_node) {
struct orig_node *orig_tmp;
orig_tmp = get_orig_node(bat_priv, ethhdr->h_source);
if (!orig_tmp)
goto unlock;
neigh_node = create_neighbor(orig_node, orig_tmp,
ethhdr->h_source, if_incoming);
orig_node_free_ref(orig_tmp);
if (!neigh_node)
goto unlock;
} else
bat_dbg(DBG_BATMAN, bat_priv,
"Updating existing last-hop neighbor of originator\n");
rcu_read_unlock();
orig_node->flags = batman_ogm_packet->flags;
neigh_node->last_valid = jiffies;
spin_lock_bh(&neigh_node->tq_lock);
ring_buffer_set(neigh_node->tq_recv,
&neigh_node->tq_index,
batman_ogm_packet->tq);
neigh_node->tq_avg = ring_buffer_avg(neigh_node->tq_recv);
spin_unlock_bh(&neigh_node->tq_lock);
if (!is_duplicate) {
orig_node->last_ttl = batman_ogm_packet->ttl;
neigh_node->last_ttl = batman_ogm_packet->ttl;
}
bonding_candidate_add(orig_node, neigh_node);
/* if this neighbor already is our next hop there is nothing
* to change */
router = orig_node_get_router(orig_node);
if (router == neigh_node)
goto update_tt;
/* if this neighbor does not offer a better TQ we won't consider it */
if (router && (router->tq_avg > neigh_node->tq_avg))
goto update_tt;
/* if the TQ is the same and the link not more symmetric we
* won't consider it either */
if (router && (neigh_node->tq_avg == router->tq_avg)) {
orig_node_tmp = router->orig_node;
spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
bcast_own_sum_orig =
orig_node_tmp->bcast_own_sum[if_incoming->if_num];
spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
orig_node_tmp = neigh_node->orig_node;
spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
bcast_own_sum_neigh =
orig_node_tmp->bcast_own_sum[if_incoming->if_num];
spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
if (bcast_own_sum_orig >= bcast_own_sum_neigh)
goto update_tt;
}
update_route(bat_priv, orig_node, neigh_node);
update_tt:
/* I have to check for transtable changes only if the OGM has been
* sent through a primary interface */
if (((batman_ogm_packet->orig != ethhdr->h_source) &&
(batman_ogm_packet->ttl > 2)) ||
(batman_ogm_packet->flags & PRIMARIES_FIRST_HOP))
tt_update_orig(bat_priv, orig_node, tt_buff,
batman_ogm_packet->tt_num_changes,
batman_ogm_packet->ttvn,
batman_ogm_packet->tt_crc);
if (orig_node->gw_flags != batman_ogm_packet->gw_flags)
gw_node_update(bat_priv, orig_node,
batman_ogm_packet->gw_flags);
orig_node->gw_flags = batman_ogm_packet->gw_flags;
/* restart gateway selection if fast or late switching was enabled */
if ((orig_node->gw_flags) &&
(atomic_read(&bat_priv->gw_mode) == GW_MODE_CLIENT) &&
(atomic_read(&bat_priv->gw_sel_class) > 2))
gw_check_election(bat_priv, orig_node);
goto out;
unlock:
rcu_read_unlock();
out:
if (neigh_node)
neigh_node_free_ref(neigh_node);
if (router)
neigh_node_free_ref(router);
}
static int bat_ogm_calc_tq(struct orig_node *orig_node,
struct orig_node *orig_neigh_node,
struct batman_ogm_packet *batman_ogm_packet,
struct hard_iface *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct neigh_node *neigh_node = NULL, *tmp_neigh_node;
struct hlist_node *node;
uint8_t total_count;
uint8_t orig_eq_count, neigh_rq_count, tq_own;
int tq_asym_penalty, ret = 0;
/* find corresponding one hop neighbor */
rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_neigh_node->neigh_list, list) {
if (!compare_eth(tmp_neigh_node->addr, orig_neigh_node->orig))
continue;
if (tmp_neigh_node->if_incoming != if_incoming)
continue;
if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
continue;
neigh_node = tmp_neigh_node;
break;
}
rcu_read_unlock();
if (!neigh_node)
neigh_node = create_neighbor(orig_neigh_node,
orig_neigh_node,
orig_neigh_node->orig,
if_incoming);
if (!neigh_node)
goto out;
/* if orig_node is direct neighbor update neigh_node last_valid */
if (orig_node == orig_neigh_node)
neigh_node->last_valid = jiffies;
orig_node->last_valid = jiffies;
/* find packet count of corresponding one hop neighbor */
spin_lock_bh(&orig_node->ogm_cnt_lock);
orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
neigh_rq_count = neigh_node->real_packet_count;
spin_unlock_bh(&orig_node->ogm_cnt_lock);
/* pay attention to not get a value bigger than 100 % */
total_count = (orig_eq_count > neigh_rq_count ?
neigh_rq_count : orig_eq_count);
/* if we have too few packets (too less data) we set tq_own to zero */
/* if we receive too few packets it is not considered bidirectional */
if ((total_count < TQ_LOCAL_BIDRECT_SEND_MINIMUM) ||
(neigh_rq_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM))
tq_own = 0;
else
/* neigh_node->real_packet_count is never zero as we
* only purge old information when getting new
* information */
tq_own = (TQ_MAX_VALUE * total_count) / neigh_rq_count;
/*
* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
* affect the nearly-symmetric links only a little, but
* punishes asymmetric links more. This will give a value
* between 0 and TQ_MAX_VALUE
*/
tq_asym_penalty = TQ_MAX_VALUE - (TQ_MAX_VALUE *
(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
(TQ_LOCAL_WINDOW_SIZE - neigh_rq_count)) /
(TQ_LOCAL_WINDOW_SIZE *
TQ_LOCAL_WINDOW_SIZE *
TQ_LOCAL_WINDOW_SIZE);
batman_ogm_packet->tq = ((batman_ogm_packet->tq * tq_own
* tq_asym_penalty) /
(TQ_MAX_VALUE * TQ_MAX_VALUE));
bat_dbg(DBG_BATMAN, bat_priv,
"bidirectional: "
"orig = %-15pM neigh = %-15pM => own_bcast = %2i, "
"real recv = %2i, local tq: %3i, asym_penalty: %3i, "
"total tq: %3i\n",
orig_node->orig, orig_neigh_node->orig, total_count,
neigh_rq_count, tq_own, tq_asym_penalty, batman_ogm_packet->tq);
/* if link has the minimum required transmission quality
* consider it bidirectional */
if (batman_ogm_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT)
ret = 1;
out:
if (neigh_node)
neigh_node_free_ref(neigh_node);
return ret;
}
/* processes a batman packet for all interfaces, adjusts the sequence number and
* finds out whether it is a duplicate.
* returns:
* 1 the packet is a duplicate
* 0 the packet has not yet been received
* -1 the packet is old and has been received while the seqno window
* was protected. Caller should drop it.
*/
static int bat_ogm_update_seqnos(const struct ethhdr *ethhdr,
const struct batman_ogm_packet
*batman_ogm_packet,
const struct hard_iface *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct orig_node *orig_node;
struct neigh_node *tmp_neigh_node;
struct hlist_node *node;
int is_duplicate = 0;
int32_t seq_diff;
int need_update = 0;
int set_mark, ret = -1;
orig_node = get_orig_node(bat_priv, batman_ogm_packet->orig);
if (!orig_node)
return 0;
spin_lock_bh(&orig_node->ogm_cnt_lock);
seq_diff = batman_ogm_packet->seqno - orig_node->last_real_seqno;
/* signalize caller that the packet is to be dropped. */
if (window_protected(bat_priv, seq_diff,
&orig_node->batman_seqno_reset))
goto out;
rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {
is_duplicate |= get_bit_status(tmp_neigh_node->real_bits,
orig_node->last_real_seqno,
batman_ogm_packet->seqno);
if (compare_eth(tmp_neigh_node->addr, ethhdr->h_source) &&
(tmp_neigh_node->if_incoming == if_incoming))
set_mark = 1;
else
set_mark = 0;
/* if the window moved, set the update flag. */
need_update |= bit_get_packet(bat_priv,
tmp_neigh_node->real_bits,
seq_diff, set_mark);
tmp_neigh_node->real_packet_count =
bit_packet_count(tmp_neigh_node->real_bits);
}
rcu_read_unlock();
if (need_update) {
bat_dbg(DBG_BATMAN, bat_priv,
"updating last_seqno: old %d, new %d\n",
orig_node->last_real_seqno, batman_ogm_packet->seqno);
orig_node->last_real_seqno = batman_ogm_packet->seqno;
}
ret = is_duplicate;
out:
spin_unlock_bh(&orig_node->ogm_cnt_lock);
orig_node_free_ref(orig_node);
return ret;
}
static void bat_ogm_process(const struct ethhdr *ethhdr,
struct batman_ogm_packet *batman_ogm_packet,
const unsigned char *tt_buff,
struct hard_iface *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct hard_iface *hard_iface;
struct orig_node *orig_neigh_node, *orig_node;
struct neigh_node *router = NULL, *router_router = NULL;
struct neigh_node *orig_neigh_router = NULL;
int has_directlink_flag;
int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
int is_broadcast = 0, is_bidirectional, is_single_hop_neigh;
int is_duplicate;
uint32_t if_incoming_seqno;
/* Silently drop when the batman packet is actually not a
* correct packet.
*
* This might happen if a packet is padded (e.g. Ethernet has a
* minimum frame length of 64 byte) and the aggregation interprets
* it as an additional length.
*
* TODO: A more sane solution would be to have a bit in the
* batman_ogm_packet to detect whether the packet is the last
* packet in an aggregation. Here we expect that the padding
* is always zero (or not 0x01)
*/
if (batman_ogm_packet->packet_type != BAT_OGM)
return;
/* could be changed by schedule_own_packet() */
if_incoming_seqno = atomic_read(&if_incoming->seqno);
has_directlink_flag = (batman_ogm_packet->flags & DIRECTLINK ? 1 : 0);
is_single_hop_neigh = (compare_eth(ethhdr->h_source,
batman_ogm_packet->orig) ? 1 : 0);
bat_dbg(DBG_BATMAN, bat_priv,
"Received BATMAN packet via NB: %pM, IF: %s [%pM] "
"(from OG: %pM, via prev OG: %pM, seqno %d, ttvn %u, "
"crc %u, changes %u, td %d, TTL %d, V %d, IDF %d)\n",
ethhdr->h_source, if_incoming->net_dev->name,
if_incoming->net_dev->dev_addr, batman_ogm_packet->orig,
batman_ogm_packet->prev_sender, batman_ogm_packet->seqno,
batman_ogm_packet->ttvn, batman_ogm_packet->tt_crc,
batman_ogm_packet->tt_num_changes, batman_ogm_packet->tq,
batman_ogm_packet->ttl, batman_ogm_packet->version,
has_directlink_flag);
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->if_status != IF_ACTIVE)
continue;
if (hard_iface->soft_iface != if_incoming->soft_iface)
continue;
if (compare_eth(ethhdr->h_source,
hard_iface->net_dev->dev_addr))
is_my_addr = 1;
if (compare_eth(batman_ogm_packet->orig,
hard_iface->net_dev->dev_addr))
is_my_orig = 1;
if (compare_eth(batman_ogm_packet->prev_sender,
hard_iface->net_dev->dev_addr))
is_my_oldorig = 1;
if (is_broadcast_ether_addr(ethhdr->h_source))
is_broadcast = 1;
}
rcu_read_unlock();
if (batman_ogm_packet->version != COMPAT_VERSION) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: incompatible batman version (%i)\n",
batman_ogm_packet->version);
return;
}
if (is_my_addr) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: received my own broadcast (sender: %pM"
")\n",
ethhdr->h_source);
return;
}
if (is_broadcast) {
bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
"ignoring all packets with broadcast source addr (sender: %pM"
")\n", ethhdr->h_source);
return;
}
if (is_my_orig) {
unsigned long *word;
int offset;
orig_neigh_node = get_orig_node(bat_priv, ethhdr->h_source);
if (!orig_neigh_node)
return;
/* neighbor has to indicate direct link and it has to
* come via the corresponding interface */
/* save packet seqno for bidirectional check */
if (has_directlink_flag &&
compare_eth(if_incoming->net_dev->dev_addr,
batman_ogm_packet->orig)) {
offset = if_incoming->if_num * NUM_WORDS;
spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
word = &(orig_neigh_node->bcast_own[offset]);
bit_mark(word,
if_incoming_seqno -
batman_ogm_packet->seqno - 2);
orig_neigh_node->bcast_own_sum[if_incoming->if_num] =
bit_packet_count(word);
spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
}
bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
"originator packet from myself (via neighbor)\n");
orig_node_free_ref(orig_neigh_node);
return;
}
if (is_my_oldorig) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: ignoring all rebroadcast echos (sender: "
"%pM)\n", ethhdr->h_source);
return;
}
orig_node = get_orig_node(bat_priv, batman_ogm_packet->orig);
if (!orig_node)
return;
is_duplicate = bat_ogm_update_seqnos(ethhdr, batman_ogm_packet,
if_incoming);
if (is_duplicate == -1) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: packet within seqno protection time "
"(sender: %pM)\n", ethhdr->h_source);
goto out;
}
if (batman_ogm_packet->tq == 0) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: originator packet with tq equal 0\n");
goto out;
}
router = orig_node_get_router(orig_node);
if (router)
router_router = orig_node_get_router(router->orig_node);
/* avoid temporary routing loops */
if (router && router_router &&
(compare_eth(router->addr, batman_ogm_packet->prev_sender)) &&
!(compare_eth(batman_ogm_packet->orig,
batman_ogm_packet->prev_sender)) &&
(compare_eth(router->addr, router_router->addr))) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: ignoring all rebroadcast packets that "
"may make me loop (sender: %pM)\n", ethhdr->h_source);
goto out;
}
/* if sender is a direct neighbor the sender mac equals
* originator mac */
orig_neigh_node = (is_single_hop_neigh ?
orig_node :
get_orig_node(bat_priv, ethhdr->h_source));
if (!orig_neigh_node)
goto out;
orig_neigh_router = orig_node_get_router(orig_neigh_node);
/* drop packet if sender is not a direct neighbor and if we
* don't route towards it */
if (!is_single_hop_neigh && (!orig_neigh_router)) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: OGM via unknown neighbor!\n");
goto out_neigh;
}
is_bidirectional = bat_ogm_calc_tq(orig_node, orig_neigh_node,
batman_ogm_packet, if_incoming);
bonding_save_primary(orig_node, orig_neigh_node, batman_ogm_packet);
/* update ranking if it is not a duplicate or has the same
* seqno and similar ttl as the non-duplicate */
if (is_bidirectional &&
(!is_duplicate ||
((orig_node->last_real_seqno == batman_ogm_packet->seqno) &&
(orig_node->last_ttl - 3 <= batman_ogm_packet->ttl))))
bat_ogm_orig_update(bat_priv, orig_node, ethhdr,
batman_ogm_packet, if_incoming,
tt_buff, is_duplicate);
/* is single hop (direct) neighbor */
if (is_single_hop_neigh) {
/* mark direct link on incoming interface */
schedule_forward_packet(orig_node, ethhdr, batman_ogm_packet,
1, if_incoming);
bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: "
"rebroadcast neighbor packet with direct link flag\n");
goto out_neigh;
}
/* multihop originator */
if (!is_bidirectional) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: not received via bidirectional link\n");
goto out_neigh;
}
if (is_duplicate) {
bat_dbg(DBG_BATMAN, bat_priv,
"Drop packet: duplicate packet received\n");
goto out_neigh;
}
bat_dbg(DBG_BATMAN, bat_priv,
"Forwarding packet: rebroadcast originator packet\n");
schedule_forward_packet(orig_node, ethhdr, batman_ogm_packet,
0, if_incoming);
out_neigh:
if ((orig_neigh_node) && (!is_single_hop_neigh))
orig_node_free_ref(orig_neigh_node);
out:
if (router)
neigh_node_free_ref(router);
if (router_router)
neigh_node_free_ref(router_router);
if (orig_neigh_router)
neigh_node_free_ref(orig_neigh_router);
orig_node_free_ref(orig_node);
}
void bat_ogm_receive(const struct ethhdr *ethhdr, unsigned char *packet_buff,
int packet_len, struct hard_iface *if_incoming)
{
struct batman_ogm_packet *batman_ogm_packet;
int buff_pos = 0;
unsigned char *tt_buff;
batman_ogm_packet = (struct batman_ogm_packet *)packet_buff;
/* unpack the aggregated packets and process them one by one */
do {
/* network to host order for our 32bit seqno and the
orig_interval */
batman_ogm_packet->seqno = ntohl(batman_ogm_packet->seqno);
batman_ogm_packet->tt_crc = ntohs(batman_ogm_packet->tt_crc);
tt_buff = packet_buff + buff_pos + BATMAN_OGM_LEN;
bat_ogm_process(ethhdr, batman_ogm_packet,
tt_buff, if_incoming);
buff_pos += BATMAN_OGM_LEN +
tt_len(batman_ogm_packet->tt_num_changes);
batman_ogm_packet = (struct batman_ogm_packet *)
(packet_buff + buff_pos);
} while (bat_ogm_aggr_packet(buff_pos, packet_len,
batman_ogm_packet->tt_num_changes));
}
