linux/net/batman-adv/routing.c
Antonio Quartulli 371351731e batman-adv: change interface_rx to get orig node
In order to understand  where a broadcast packet is coming from and use
this information to detect not yet announced clients, this patch modifies the
interface_rx() function by passing a new argument: the orig node
corresponding to the node that originated the received packet (if known).
This new argument if not NULL for broadcast packets only (other packets does not
have source field).

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-08-23 14:20:22 +02:00

1202 lines
32 KiB
C

/* 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 batadv_route_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if);
void batadv_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct batadv_hashtable *hash = bat_priv->orig_hash;
struct hlist_node *node;
struct hlist_head *head;
struct batadv_orig_node *orig_node;
unsigned long *word;
uint32_t i;
size_t word_index;
uint8_t *w;
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 * BATADV_NUM_WORDS;
word = &(orig_node->bcast_own[word_index]);
batadv_bit_get_packet(bat_priv, word, 1, 0);
w = &orig_node->bcast_own_sum[hard_iface->if_num];
*w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
spin_unlock_bh(&orig_node->ogm_cnt_lock);
}
rcu_read_unlock();
}
}
static void _batadv_update_route(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node)
{
struct batadv_neigh_node *curr_router;
curr_router = batadv_orig_node_get_router(orig_node);
/* route deleted */
if ((curr_router) && (!neigh_node)) {
batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
"Deleting route towards: %pM\n", orig_node->orig);
batadv_tt_global_del_orig(bat_priv, orig_node,
"Deleted route towards originator");
/* route added */
} else if ((!curr_router) && (neigh_node)) {
batadv_dbg(BATADV_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) {
batadv_dbg(BATADV_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)
batadv_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)
batadv_neigh_node_free_ref(curr_router);
}
void batadv_update_route(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node)
{
struct batadv_neigh_node *router = NULL;
if (!orig_node)
goto out;
router = batadv_orig_node_get_router(orig_node);
if (router != neigh_node)
_batadv_update_route(bat_priv, orig_node, neigh_node);
out:
if (router)
batadv_neigh_node_free_ref(router);
}
/* caller must hold the neigh_list_lock */
void batadv_bonding_candidate_del(struct batadv_orig_node *orig_node,
struct batadv_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);
batadv_neigh_node_free_ref(neigh_node);
atomic_dec(&orig_node->bond_candidates);
out:
return;
}
void batadv_bonding_candidate_add(struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node)
{
struct hlist_node *node;
struct batadv_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 (!batadv_compare_eth(orig_node->orig,
neigh_node->orig_node->primary_addr))
goto candidate_del;
router = batadv_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 - BATADV_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) ||
(batadv_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:
batadv_bonding_candidate_del(orig_node, neigh_node);
out:
spin_unlock_bh(&orig_node->neigh_list_lock);
if (router)
batadv_neigh_node_free_ref(router);
}
/* copy primary address for bonding */
void
batadv_bonding_save_primary(const struct batadv_orig_node *orig_node,
struct batadv_orig_node *orig_neigh_node,
const struct batadv_ogm_packet *batman_ogm_packet)
{
if (!(batman_ogm_packet->flags & BATADV_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 batadv_window_protected(struct batadv_priv *bat_priv, int32_t seq_num_diff,
unsigned long *last_reset)
{
if (seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE ||
seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
if (!batadv_has_timed_out(*last_reset,
BATADV_RESET_PROTECTION_MS))
return 1;
*last_reset = jiffies;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"old packet received, start protection\n");
}
return 0;
}
bool batadv_check_management_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
int header_len)
{
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, header_len)))
return false;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* packet with broadcast indication but unicast recipient */
if (!is_broadcast_ether_addr(ethhdr->h_dest))
return false;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
return false;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, 0) < 0)
return false;
/* keep skb linear */
if (skb_linearize(skb) < 0)
return false;
return true;
}
static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv,
struct sk_buff *skb, size_t icmp_len)
{
struct batadv_hard_iface *primary_if = NULL;
struct batadv_orig_node *orig_node = NULL;
struct batadv_neigh_node *router = NULL;
struct batadv_icmp_packet_rr *icmp_packet;
int ret = NET_RX_DROP;
icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
/* add data to device queue */
if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
batadv_socket_receive_packet(icmp_packet, icmp_len);
goto out;
}
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* answer echo request (ping) */
/* get routing information */
orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
if (!orig_node)
goto out;
router = batadv_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, ETH_HLEN) < 0)
goto out;
icmp_packet = (struct batadv_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 = BATADV_ECHO_REPLY;
icmp_packet->header.ttl = BATADV_TTL;
batadv_send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
if (router)
batadv_neigh_node_free_ref(router);
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
struct batadv_hard_iface *primary_if = NULL;
struct batadv_orig_node *orig_node = NULL;
struct batadv_neigh_node *router = NULL;
struct batadv_icmp_packet *icmp_packet;
int ret = NET_RX_DROP;
icmp_packet = (struct batadv_icmp_packet *)skb->data;
/* send TTL exceeded if packet is an echo request (traceroute) */
if (icmp_packet->msg_type != BATADV_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 = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* get routing information */
orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig);
if (!orig_node)
goto out;
router = batadv_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, ETH_HLEN) < 0)
goto out;
icmp_packet = (struct batadv_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 = BATADV_TTL_EXCEEDED;
icmp_packet->header.ttl = BATADV_TTL;
batadv_send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
if (router)
batadv_neigh_node_free_ref(router);
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
int batadv_recv_icmp_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_icmp_packet_rr *icmp_packet;
struct ethhdr *ethhdr;
struct batadv_orig_node *orig_node = NULL;
struct batadv_neigh_node *router = NULL;
int hdr_size = sizeof(struct batadv_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 batadv_icmp_packet_rr))
hdr_size = sizeof(struct batadv_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 (!batadv_is_my_mac(ethhdr->h_dest))
goto out;
icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
/* add record route information if not full */
if ((hdr_size == sizeof(struct batadv_icmp_packet_rr)) &&
(icmp_packet->rr_cur < BATADV_RR_LEN)) {
memcpy(&(icmp_packet->rr[icmp_packet->rr_cur]),
ethhdr->h_dest, ETH_ALEN);
icmp_packet->rr_cur++;
}
/* packet for me */
if (batadv_is_my_mac(icmp_packet->dst))
return batadv_recv_my_icmp_packet(bat_priv, skb, hdr_size);
/* TTL exceeded */
if (icmp_packet->header.ttl < 2)
return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
/* get routing information */
orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
if (!orig_node)
goto out;
router = batadv_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, ETH_HLEN) < 0)
goto out;
icmp_packet = (struct batadv_icmp_packet_rr *)skb->data;
/* decrement ttl */
icmp_packet->header.ttl--;
/* route it */
batadv_send_skb_packet(skb, router->if_incoming, router->addr);
ret = NET_RX_SUCCESS;
out:
if (router)
batadv_neigh_node_free_ref(router);
if (orig_node)
batadv_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 batadv_neigh_node *
batadv_find_bond_router(struct batadv_orig_node *primary_orig,
const struct batadv_hard_iface *recv_if)
{
struct batadv_neigh_node *tmp_neigh_node;
struct batadv_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 batadv_neigh_node *
batadv_find_ifalter_router(struct batadv_orig_node *primary_orig,
const struct batadv_hard_iface *recv_if)
{
struct batadv_neigh_node *tmp_neigh_node;
struct batadv_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)
batadv_neigh_node_free_ref(router);
router = tmp_neigh_node;
atomic_inc_not_zero(&router->refcount);
}
batadv_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;
}
static int batadv_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 (!batadv_is_my_mac(ethhdr->h_dest))
return -1;
return 0;
}
int batadv_recv_tt_query(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_tt_query_packet *tt_query;
uint16_t tt_size;
int hdr_size = sizeof(*tt_query);
char tt_flag;
size_t packet_size;
if (batadv_check_unicast_packet(skb, hdr_size) < 0)
return NET_RX_DROP;
/* I could need to modify it */
if (skb_cow(skb, sizeof(struct batadv_tt_query_packet)) < 0)
goto out;
tt_query = (struct batadv_tt_query_packet *)skb->data;
switch (tt_query->flags & BATADV_TT_QUERY_TYPE_MASK) {
case BATADV_TT_REQUEST:
batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_RX);
/* If we cannot provide an answer the tt_request is
* forwarded
*/
if (!batadv_send_tt_response(bat_priv, tt_query)) {
if (tt_query->flags & BATADV_TT_FULL_TABLE)
tt_flag = 'F';
else
tt_flag = '.';
batadv_dbg(BATADV_DBG_TT, bat_priv,
"Routing TT_REQUEST to %pM [%c]\n",
tt_query->dst,
tt_flag);
return batadv_route_unicast_packet(skb, recv_if);
}
break;
case BATADV_TT_RESPONSE:
batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_RX);
if (batadv_is_my_mac(tt_query->dst)) {
/* packet needs to be linearized to access the TT
* changes
*/
if (skb_linearize(skb) < 0)
goto out;
/* skb_linearize() possibly changed skb->data */
tt_query = (struct batadv_tt_query_packet *)skb->data;
tt_size = batadv_tt_len(ntohs(tt_query->tt_data));
/* Ensure we have all the claimed data */
packet_size = sizeof(struct batadv_tt_query_packet);
packet_size += tt_size;
if (unlikely(skb_headlen(skb) < packet_size))
goto out;
batadv_handle_tt_response(bat_priv, tt_query);
} else {
if (tt_query->flags & BATADV_TT_FULL_TABLE)
tt_flag = 'F';
else
tt_flag = '.';
batadv_dbg(BATADV_DBG_TT, bat_priv,
"Routing TT_RESPONSE to %pM [%c]\n",
tt_query->dst,
tt_flag);
return batadv_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 batadv_recv_roam_adv(struct sk_buff *skb, struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_roam_adv_packet *roam_adv_packet;
struct batadv_orig_node *orig_node;
struct ethhdr *ethhdr;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb,
sizeof(struct batadv_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;
batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_RX);
roam_adv_packet = (struct batadv_roam_adv_packet *)skb->data;
if (!batadv_is_my_mac(roam_adv_packet->dst))
return batadv_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 (batadv_bla_is_backbone_gw_orig(bat_priv, roam_adv_packet->src))
goto out;
orig_node = batadv_orig_hash_find(bat_priv, roam_adv_packet->src);
if (!orig_node)
goto out;
batadv_dbg(BATADV_DBG_TT, bat_priv,
"Received ROAMING_ADV from %pM (client %pM)\n",
roam_adv_packet->src, roam_adv_packet->client);
batadv_tt_global_add(bat_priv, orig_node, roam_adv_packet->client,
BATADV_TT_CLIENT_ROAM,
atomic_read(&orig_node->last_ttvn) + 1);
/* 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;
batadv_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 batadv_neigh_node *
batadv_find_router(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
const struct batadv_hard_iface *recv_if)
{
struct batadv_orig_node *primary_orig_node;
struct batadv_orig_node *router_orig;
struct batadv_neigh_node *router;
static uint8_t zero_mac[ETH_ALEN] = {0, 0, 0, 0, 0, 0};
int bonding_enabled;
uint8_t *primary_addr;
if (!orig_node)
return NULL;
router = batadv_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;
primary_addr = router_orig->primary_addr;
/* if we have something in the primary_addr, we can search
* for a potential bonding candidate.
*/
if (batadv_compare_eth(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 (batadv_compare_eth(primary_addr, router_orig->orig)) {
primary_orig_node = router_orig;
} else {
primary_orig_node = batadv_orig_hash_find(bat_priv,
primary_addr);
if (!primary_orig_node)
goto return_router;
batadv_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.
*/
batadv_neigh_node_free_ref(router);
if (bonding_enabled)
router = batadv_find_bond_router(primary_orig_node, recv_if);
else
router = batadv_find_ifalter_router(primary_orig_node, recv_if);
return_router:
if (router && router->if_incoming->if_status != BATADV_IF_ACTIVE)
goto err_unlock;
rcu_read_unlock();
return router;
err_unlock:
rcu_read_unlock();
err:
if (router)
batadv_neigh_node_free_ref(router);
return NULL;
}
static int batadv_route_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_orig_node *orig_node = NULL;
struct batadv_neigh_node *neigh_node = NULL;
struct batadv_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 batadv_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 = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
if (!orig_node)
goto out;
/* find_router() increases neigh_nodes refcount if found. */
neigh_node = batadv_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, ETH_HLEN) < 0)
goto out;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
if (unicast_packet->header.packet_type == BATADV_UNICAST &&
atomic_read(&bat_priv->fragmentation) &&
skb->len > neigh_node->if_incoming->net_dev->mtu) {
ret = batadv_frag_send_skb(skb, bat_priv,
neigh_node->if_incoming,
neigh_node->addr);
goto out;
}
if (unicast_packet->header.packet_type == BATADV_UNICAST_FRAG &&
batadv_frag_can_reassemble(skb,
neigh_node->if_incoming->net_dev->mtu)) {
ret = batadv_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 batadv_unicast_packet *)skb->data;
}
/* decrement ttl */
unicast_packet->header.ttl--;
/* Update stats counter */
batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
skb->len + ETH_HLEN);
/* route it */
batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
ret = NET_RX_SUCCESS;
out:
if (neigh_node)
batadv_neigh_node_free_ref(neigh_node);
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
struct sk_buff *skb) {
uint8_t curr_ttvn;
struct batadv_orig_node *orig_node;
struct ethhdr *ethhdr;
struct batadv_hard_iface *primary_if;
struct batadv_unicast_packet *unicast_packet;
bool tt_poss_change;
int is_old_ttvn;
/* I could need to modify it */
if (skb_cow(skb, sizeof(struct batadv_unicast_packet)) < 0)
return 0;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
if (batadv_is_my_mac(unicast_packet->dest)) {
tt_poss_change = bat_priv->tt.poss_change;
curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
} else {
orig_node = batadv_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;
batadv_orig_node_free_ref(orig_node);
}
/* Check whether I have to reroute the packet */
is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
if (is_old_ttvn || tt_poss_change) {
/* check if there is enough data before accessing it */
if (pskb_may_pull(skb, sizeof(struct batadv_unicast_packet) +
ETH_HLEN) < 0)
return 0;
ethhdr = (struct ethhdr *)(skb->data + sizeof(*unicast_packet));
/* we don't have an updated route for this client, so we should
* not try to reroute the packet!!
*/
if (batadv_tt_global_client_is_roaming(bat_priv,
ethhdr->h_dest))
return 1;
orig_node = batadv_transtable_search(bat_priv, NULL,
ethhdr->h_dest);
if (!orig_node) {
if (!batadv_is_my_client(bat_priv, ethhdr->h_dest))
return 0;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
return 0;
memcpy(unicast_packet->dest,
primary_if->net_dev->dev_addr, ETH_ALEN);
batadv_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);
batadv_orig_node_free_ref(orig_node);
}
batadv_dbg(BATADV_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);
unicast_packet->ttvn = curr_ttvn;
}
return 1;
}
int batadv_recv_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_unicast_packet *unicast_packet;
int hdr_size = sizeof(*unicast_packet);
if (batadv_check_unicast_packet(skb, hdr_size) < 0)
return NET_RX_DROP;
if (!batadv_check_unicast_ttvn(bat_priv, skb))
return NET_RX_DROP;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* packet for me */
if (batadv_is_my_mac(unicast_packet->dest)) {
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
NULL);
return NET_RX_SUCCESS;
}
return batadv_route_unicast_packet(skb, recv_if);
}
int batadv_recv_ucast_frag_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_unicast_frag_packet *unicast_packet;
int hdr_size = sizeof(*unicast_packet);
struct sk_buff *new_skb = NULL;
int ret;
if (batadv_check_unicast_packet(skb, hdr_size) < 0)
return NET_RX_DROP;
if (!batadv_check_unicast_ttvn(bat_priv, skb))
return NET_RX_DROP;
unicast_packet = (struct batadv_unicast_frag_packet *)skb->data;
/* packet for me */
if (batadv_is_my_mac(unicast_packet->dest)) {
ret = batadv_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;
batadv_interface_rx(recv_if->soft_iface, new_skb, recv_if,
sizeof(struct batadv_unicast_packet), NULL);
return NET_RX_SUCCESS;
}
return batadv_route_unicast_packet(skb, recv_if);
}
int batadv_recv_bcast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_orig_node *orig_node = NULL;
struct batadv_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 (batadv_is_my_mac(ethhdr->h_source))
goto out;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
/* ignore broadcasts originated by myself */
if (batadv_is_my_mac(bcast_packet->orig))
goto out;
if (bcast_packet->header.ttl < 2)
goto out;
orig_node = batadv_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 (batadv_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 (batadv_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 (batadv_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);
/* check whether this has been sent by another originator before */
if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
goto out;
/* rebroadcast packet */
batadv_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 (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size))
goto out;
/* broadcast for me */
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
orig_node);
ret = NET_RX_SUCCESS;
goto out;
spin_unlock:
spin_unlock_bh(&orig_node->bcast_seqno_lock);
out:
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
int batadv_recv_vis_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_vis_packet *vis_packet;
struct ethhdr *ethhdr;
struct batadv_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 batadv_vis_packet *)skb->data;
ethhdr = (struct ethhdr *)skb_mac_header(skb);
/* not for me */
if (!batadv_is_my_mac(ethhdr->h_dest))
return NET_RX_DROP;
/* ignore own packets */
if (batadv_is_my_mac(vis_packet->vis_orig))
return NET_RX_DROP;
if (batadv_is_my_mac(vis_packet->sender_orig))
return NET_RX_DROP;
switch (vis_packet->vis_type) {
case BATADV_VIS_TYPE_SERVER_SYNC:
batadv_receive_server_sync_packet(bat_priv, vis_packet,
skb_headlen(skb));
break;
case BATADV_VIS_TYPE_CLIENT_UPDATE:
batadv_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;
}