blob: 9990d4040f6c3dc557d7d9b7a98ef43b888a6910 [file] [log] [blame]
/* Copyright (C) 2007-2014 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, see <http://www.gnu.org/licenses/>.
*/
#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 "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "network-coding.h"
#include "fragmentation.h"
#include <linux/if_vlan.h>
static int batadv_route_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if);
/**
* _batadv_update_route - set the router for this originator
* @bat_priv: the bat priv with all the soft interface information
* @orig_node: orig node which is to be configured
* @recv_if: the receive interface for which this route is set
* @neigh_node: neighbor which should be the next router
*
* This function does not perform any error checks
*/
static void _batadv_update_route(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if,
struct batadv_neigh_node *neigh_node)
{
struct batadv_orig_ifinfo *orig_ifinfo;
struct batadv_neigh_node *curr_router;
orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if);
if (!orig_ifinfo)
return;
rcu_read_lock();
curr_router = rcu_dereference(orig_ifinfo->router);
if (curr_router && !atomic_inc_not_zero(&curr_router->refcount))
curr_router = NULL;
rcu_read_unlock();
/* 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, -1,
"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);
/* curr_router used earlier may not be the current orig_ifinfo->router
* anymore because it was dereferenced outside of the neigh_list_lock
* protected region. After the new best neighbor has replace the current
* best neighbor the reference counter needs to decrease. Consequently,
* the code needs to ensure the curr_router variable contains a pointer
* to the replaced best neighbor.
*/
curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
rcu_assign_pointer(orig_ifinfo->router, neigh_node);
spin_unlock_bh(&orig_node->neigh_list_lock);
batadv_orig_ifinfo_free_ref(orig_ifinfo);
/* decrease refcount of previous best neighbor */
if (curr_router)
batadv_neigh_node_free_ref(curr_router);
}
/**
* batadv_update_route - set the router for this originator
* @bat_priv: the bat priv with all the soft interface information
* @orig_node: orig node which is to be configured
* @recv_if: the receive interface for which this route is set
* @neigh_node: neighbor which should be the next router
*/
void batadv_update_route(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if,
struct batadv_neigh_node *neigh_node)
{
struct batadv_neigh_node *router = NULL;
if (!orig_node)
goto out;
router = batadv_orig_router_get(orig_node, recv_if);
if (router != neigh_node)
_batadv_update_route(bat_priv, orig_node, recv_if, neigh_node);
out:
if (router)
batadv_neigh_node_free_ref(router);
}
/* 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 = eth_hdr(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;
}
/**
* batadv_recv_my_icmp_packet - receive an icmp packet locally
* @bat_priv: the bat priv with all the soft interface information
* @skb: icmp packet to process
*
* Returns NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
* otherwise.
*/
static int batadv_recv_my_icmp_packet(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_icmp_header *icmph;
int res, ret = NET_RX_DROP;
icmph = (struct batadv_icmp_header *)skb->data;
switch (icmph->msg_type) {
case BATADV_ECHO_REPLY:
case BATADV_DESTINATION_UNREACHABLE:
case BATADV_TTL_EXCEEDED:
/* receive the packet */
if (skb_linearize(skb) < 0)
break;
batadv_socket_receive_packet(icmph, skb->len);
break;
case BATADV_ECHO_REQUEST:
/* answer echo request (ping) */
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, icmph->orig);
if (!orig_node)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto out;
icmph = (struct batadv_icmp_header *)skb->data;
ether_addr_copy(icmph->dst, icmph->orig);
ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr);
icmph->msg_type = BATADV_ECHO_REPLY;
icmph->ttl = BATADV_TTL;
res = batadv_send_skb_to_orig(skb, orig_node, NULL);
if (res != NET_XMIT_DROP)
ret = NET_RX_SUCCESS;
break;
default:
/* drop unknown type */
goto out;
}
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
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_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;
/* 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;
ether_addr_copy(icmp_packet->dst, icmp_packet->orig);
ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr);
icmp_packet->msg_type = BATADV_TTL_EXCEEDED;
icmp_packet->ttl = BATADV_TTL;
if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
ret = NET_RX_SUCCESS;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
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_header *icmph;
struct batadv_icmp_packet_rr *icmp_packet_rr;
struct ethhdr *ethhdr;
struct batadv_orig_node *orig_node = NULL;
int hdr_size = sizeof(struct batadv_icmp_header);
int ret = NET_RX_DROP;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto out;
ethhdr = eth_hdr(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(bat_priv, ethhdr->h_dest))
goto out;
icmph = (struct batadv_icmp_header *)skb->data;
/* add record route information if not full */
if ((icmph->msg_type == BATADV_ECHO_REPLY ||
icmph->msg_type == BATADV_ECHO_REQUEST) &&
(skb->len >= sizeof(struct batadv_icmp_packet_rr))) {
if (skb_linearize(skb) < 0)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto out;
ethhdr = eth_hdr(skb);
icmph = (struct batadv_icmp_header *)skb->data;
icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
goto out;
ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur],
ethhdr->h_dest);
icmp_packet_rr->rr_cur++;
}
/* packet for me */
if (batadv_is_my_mac(bat_priv, icmph->dst))
return batadv_recv_my_icmp_packet(bat_priv, skb);
/* TTL exceeded */
if (icmph->ttl < 2)
return batadv_recv_icmp_ttl_exceeded(bat_priv, skb);
/* get routing information */
orig_node = batadv_orig_hash_find(bat_priv, icmph->dst);
if (!orig_node)
goto out;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto out;
icmph = (struct batadv_icmp_header *)skb->data;
/* decrement ttl */
icmph->ttl--;
/* route it */
if (batadv_send_skb_to_orig(skb, orig_node, recv_if) != NET_XMIT_DROP)
ret = NET_RX_SUCCESS;
out:
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
/**
* batadv_check_unicast_packet - Check for malformed unicast packets
* @bat_priv: the bat priv with all the soft interface information
* @skb: packet to check
* @hdr_size: size of header to pull
*
* Check for short header and bad addresses in given packet. Returns negative
* value when check fails and 0 otherwise. The negative value depends on the
* reason: -ENODATA for bad header, -EBADR for broadcast destination or source,
* and -EREMOTE for non-local (other host) destination.
*/
static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
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 -ENODATA;
ethhdr = eth_hdr(skb);
/* packet with unicast indication but broadcast recipient */
if (is_broadcast_ether_addr(ethhdr->h_dest))
return -EBADR;
/* packet with broadcast sender address */
if (is_broadcast_ether_addr(ethhdr->h_source))
return -EBADR;
/* not for me */
if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
return -EREMOTE;
return 0;
}
/**
* batadv_last_bonding_get - Get last_bonding_candidate of orig_node
* @orig_node: originator node whose last bonding candidate should be retrieved
*
* Return: last bonding candidate of router or NULL if not found
*
* The object is returned with refcounter increased by 1.
*/
static struct batadv_orig_ifinfo *
batadv_last_bonding_get(struct batadv_orig_node *orig_node)
{
struct batadv_orig_ifinfo *last_bonding_candidate;
spin_lock_bh(&orig_node->neigh_list_lock);
last_bonding_candidate = orig_node->last_bonding_candidate;
if (last_bonding_candidate)
atomic_inc(&last_bonding_candidate->refcount);
spin_unlock_bh(&orig_node->neigh_list_lock);
return last_bonding_candidate;
}
/**
* batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
* @orig_node: originator node whose bonding candidates should be replaced
* @new_candidate: new bonding candidate or NULL
*/
static void
batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
struct batadv_orig_ifinfo *new_candidate)
{
struct batadv_orig_ifinfo *old_candidate;
spin_lock_bh(&orig_node->neigh_list_lock);
old_candidate = orig_node->last_bonding_candidate;
if (new_candidate)
atomic_inc(&new_candidate->refcount);
orig_node->last_bonding_candidate = new_candidate;
spin_unlock_bh(&orig_node->neigh_list_lock);
if (old_candidate)
batadv_orig_ifinfo_free_ref(old_candidate);
}
/**
* batadv_find_router - find a suitable router for this originator
* @bat_priv: the bat priv with all the soft interface information
* @orig_node: the destination node
* @recv_if: pointer to interface this packet was received on
*
* Returns the router which should be used for this orig_node on
* this interface, or NULL if not available.
*/
struct batadv_neigh_node *
batadv_find_router(struct batadv_priv *bat_priv,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if)
{
struct batadv_algo_ops *bao = bat_priv->bat_algo_ops;
struct batadv_neigh_node *first_candidate_router = NULL;
struct batadv_neigh_node *next_candidate_router = NULL;
struct batadv_neigh_node *router, *cand_router = NULL;
struct batadv_neigh_node *last_cand_router = NULL;
struct batadv_orig_ifinfo *cand, *first_candidate = NULL;
struct batadv_orig_ifinfo *next_candidate = NULL;
struct batadv_orig_ifinfo *last_candidate;
bool last_candidate_found = false;
if (!orig_node)
return NULL;
router = batadv_orig_router_get(orig_node, recv_if);
/* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop)
* and if activated.
*/
if (recv_if == BATADV_IF_DEFAULT || !atomic_read(&bat_priv->bonding) ||
!router)
return router;
/* bonding: loop through the list of possible routers found
* for the various outgoing interfaces and find a candidate after
* the last chosen bonding candidate (next_candidate). If no such
* router is found, use the first candidate found (the previously
* chosen bonding candidate might have been the last one in the list).
* If this can't be found either, return the previously choosen
* router - obviously there are no other candidates.
*/
rcu_read_lock();
last_candidate = batadv_last_bonding_get(orig_node);
if (last_candidate)
last_cand_router = rcu_dereference(last_candidate->router);
hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) {
/* acquire some structures and references ... */
if (!atomic_inc_not_zero(&cand->refcount))
continue;
cand_router = rcu_dereference(cand->router);
if (!cand_router)
goto next;
if (!atomic_inc_not_zero(&cand_router->refcount)) {
cand_router = NULL;
goto next;
}
/* alternative candidate should be good enough to be
* considered
*/
if (!bao->bat_neigh_is_equiv_or_better(cand_router,
cand->if_outgoing,
router, recv_if))
goto next;
/* don't use the same router twice */
if (last_cand_router == cand_router)
goto next;
/* mark the first possible candidate */
if (!first_candidate) {
atomic_inc(&cand_router->refcount);
atomic_inc(&cand->refcount);
first_candidate = cand;
first_candidate_router = cand_router;
}
/* check if the loop has already passed the previously selected
* candidate ... this function should select the next candidate
* AFTER the previously used bonding candidate.
*/
if (!last_candidate || last_candidate_found) {
next_candidate = cand;
next_candidate_router = cand_router;
break;
}
if (last_candidate == cand)
last_candidate_found = true;
next:
/* free references */
if (cand_router) {
batadv_neigh_node_free_ref(cand_router);
cand_router = NULL;
}
batadv_orig_ifinfo_free_ref(cand);
}
rcu_read_unlock();
/* After finding candidates, handle the three cases:
* 1) there is a next candidate, use that
* 2) there is no next candidate, use the first of the list
* 3) there is no candidate at all, return the default router
*/
if (next_candidate) {
batadv_neigh_node_free_ref(router);
atomic_inc(&next_candidate_router->refcount);
router = next_candidate_router;
batadv_last_bonding_replace(orig_node, next_candidate);
} else if (first_candidate) {
batadv_neigh_node_free_ref(router);
atomic_inc(&first_candidate_router->refcount);
router = first_candidate_router;
batadv_last_bonding_replace(orig_node, first_candidate);
} else {
batadv_last_bonding_replace(orig_node, NULL);
}
/* cleanup of candidates */
if (first_candidate) {
batadv_neigh_node_free_ref(first_candidate_router);
batadv_orig_ifinfo_free_ref(first_candidate);
}
if (next_candidate) {
batadv_neigh_node_free_ref(next_candidate_router);
batadv_orig_ifinfo_free_ref(next_candidate);
}
if (last_candidate)
batadv_orig_ifinfo_free_ref(last_candidate);
return router;
}
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_unicast_packet *unicast_packet;
struct ethhdr *ethhdr = eth_hdr(skb);
int res, hdr_len, ret = NET_RX_DROP;
unsigned int len;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* TTL exceeded */
if (unicast_packet->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;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto out;
/* decrement ttl */
unicast_packet = (struct batadv_unicast_packet *)skb->data;
unicast_packet->ttl--;
switch (unicast_packet->packet_type) {
case BATADV_UNICAST_4ADDR:
hdr_len = sizeof(struct batadv_unicast_4addr_packet);
break;
case BATADV_UNICAST:
hdr_len = sizeof(struct batadv_unicast_packet);
break;
default:
/* other packet types not supported - yet */
hdr_len = -1;
break;
}
if (hdr_len > 0)
batadv_skb_set_priority(skb, hdr_len);
len = skb->len;
res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
/* translate transmit result into receive result */
if (res == NET_XMIT_SUCCESS) {
/* skb was transmitted and consumed */
batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
len + ETH_HLEN);
ret = NET_RX_SUCCESS;
} else if (res == NET_XMIT_POLICED) {
/* skb was buffered and consumed */
ret = NET_RX_SUCCESS;
}
out:
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return ret;
}
/**
* batadv_reroute_unicast_packet - update the unicast header for re-routing
* @bat_priv: the bat priv with all the soft interface information
* @skb: unicast packet to process
* @unicast_packet: the unicast header to be updated
* @dst_addr: the payload destination
* @vid: VLAN identifier
*
* Search the translation table for dst_addr and update the unicast header with
* the new corresponding information (originator address where the destination
* client currently is and its known TTVN)
*
* Returns true if the packet header has been updated, false otherwise
*/
static bool
batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
struct batadv_unicast_packet *unicast_packet,
uint8_t *dst_addr, unsigned short vid)
{
struct batadv_orig_node *orig_node = NULL;
struct batadv_hard_iface *primary_if = NULL;
bool ret = false;
uint8_t *orig_addr, orig_ttvn;
if (batadv_is_my_client(bat_priv, dst_addr, vid)) {
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
orig_addr = primary_if->net_dev->dev_addr;
orig_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
} else {
orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr,
vid);
if (!orig_node)
goto out;
if (batadv_compare_eth(orig_node->orig, unicast_packet->dest))
goto out;
orig_addr = orig_node->orig;
orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
}
/* update the packet header */
skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
ether_addr_copy(unicast_packet->dest, orig_addr);
unicast_packet->ttvn = orig_ttvn;
skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
ret = true;
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
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, int hdr_len) {
struct batadv_unicast_packet *unicast_packet;
struct batadv_hard_iface *primary_if;
struct batadv_orig_node *orig_node;
uint8_t curr_ttvn, old_ttvn;
struct ethhdr *ethhdr;
unsigned short vid;
int is_old_ttvn;
/* check if there is enough data before accessing it */
if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
return 0;
/* create a copy of the skb (in case of for re-routing) to modify it. */
if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
return 0;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
vid = batadv_get_vid(skb, hdr_len);
ethhdr = (struct ethhdr *)(skb->data + hdr_len);
/* check if the destination client was served by this node and it is now
* roaming. In this case, it means that the node has got a ROAM_ADV
* message and that it knows the new destination in the mesh to re-route
* the packet to
*/
if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
ethhdr->h_dest, vid))
net_ratelimited_function(batadv_dbg, BATADV_DBG_TT,
bat_priv,
"Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n",
unicast_packet->dest,
ethhdr->h_dest);
/* at this point the mesh destination should have been
* substituted with the originator address found in the global
* table. If not, let the packet go untouched anyway because
* there is nothing the node can do
*/
return 1;
}
/* retrieve the TTVN known by this node for the packet destination. This
* value is used later to check if the node which sent (or re-routed
* last time) the packet had an updated information or not
*/
curr_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
orig_node = batadv_orig_hash_find(bat_priv,
unicast_packet->dest);
/* if it is not possible to find the orig_node representing the
* destination, the packet can immediately be dropped as it will
* not be possible to deliver it
*/
if (!orig_node)
return 0;
curr_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
batadv_orig_node_free_ref(orig_node);
}
/* check if the TTVN contained in the packet is fresher than what the
* node knows
*/
is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn);
if (!is_old_ttvn)
return 1;
old_ttvn = unicast_packet->ttvn;
/* the packet was forged based on outdated network information. Its
* destination can possibly be updated and forwarded towards the new
* target host
*/
if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
ethhdr->h_dest, vid)) {
net_ratelimited_function(batadv_dbg, BATADV_DBG_TT, bat_priv,
"Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
unicast_packet->dest, ethhdr->h_dest,
old_ttvn, curr_ttvn);
return 1;
}
/* the packet has not been re-routed: either the destination is
* currently served by this node or there is no destination at all and
* it is possible to drop the packet
*/
if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid))
return 0;
/* update the header in order to let the packet be delivered to this
* node's soft interface
*/
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
return 0;
/* update the packet header */
skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
unicast_packet->ttvn = curr_ttvn;
skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
batadv_hardif_free_ref(primary_if);
return 1;
}
/**
* batadv_recv_unhandled_unicast_packet - receive and process packets which
* are in the unicast number space but not yet known to the implementation
* @skb: unicast tvlv packet to process
* @recv_if: pointer to interface this packet was received on
*
* Returns NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
* otherwise.
*/
int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_unicast_packet *unicast_packet;
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
int check, hdr_size = sizeof(*unicast_packet);
check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
if (check < 0)
return NET_RX_DROP;
/* we don't know about this type, drop it. */
unicast_packet = (struct batadv_unicast_packet *)skb->data;
if (batadv_is_my_mac(bat_priv, unicast_packet->dest))
return NET_RX_DROP;
return batadv_route_unicast_packet(skb, recv_if);
}
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;
struct batadv_unicast_4addr_packet *unicast_4addr_packet;
uint8_t *orig_addr;
struct batadv_orig_node *orig_node = NULL;
int check, hdr_size = sizeof(*unicast_packet);
bool is4addr;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
/* the caller function should have already pulled 2 bytes */
if (is4addr)
hdr_size = sizeof(*unicast_4addr_packet);
/* function returns -EREMOTE for promiscuous packets */
check = batadv_check_unicast_packet(bat_priv, skb, hdr_size);
/* Even though the packet is not for us, we might save it to use for
* decoding a later received coded packet
*/
if (check == -EREMOTE)
batadv_nc_skb_store_sniffed_unicast(bat_priv, skb);
if (check < 0)
return NET_RX_DROP;
if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
return NET_RX_DROP;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* packet for me */
if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
if (is4addr) {
unicast_4addr_packet =
(struct batadv_unicast_4addr_packet *)skb->data;
batadv_dat_inc_counter(bat_priv,
unicast_4addr_packet->subtype);
orig_addr = unicast_4addr_packet->src;
orig_node = batadv_orig_hash_find(bat_priv, orig_addr);
}
if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb,
hdr_size))
goto rx_success;
if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb,
hdr_size))
goto rx_success;
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
orig_node);
rx_success:
if (orig_node)
batadv_orig_node_free_ref(orig_node);
return NET_RX_SUCCESS;
}
return batadv_route_unicast_packet(skb, recv_if);
}
/**
* batadv_recv_unicast_tvlv - receive and process unicast tvlv packets
* @skb: unicast tvlv packet to process
* @recv_if: pointer to interface this packet was received on
* @dst_addr: the payload destination
*
* Returns NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP
* otherwise.
*/
int batadv_recv_unicast_tvlv(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
unsigned char *tvlv_buff;
uint16_t tvlv_buff_len;
int hdr_size = sizeof(*unicast_tvlv_packet);
int ret = NET_RX_DROP;
if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
return NET_RX_DROP;
/* the header is likely to be modified while forwarding */
if (skb_cow(skb, hdr_size) < 0)
return NET_RX_DROP;
/* packet needs to be linearized to access the tvlv content */
if (skb_linearize(skb) < 0)
return NET_RX_DROP;
unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data;
tvlv_buff = (unsigned char *)(skb->data + hdr_size);
tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len);
if (tvlv_buff_len > skb->len - hdr_size)
return NET_RX_DROP;
ret = batadv_tvlv_containers_process(bat_priv, false, NULL,
unicast_tvlv_packet->src,
unicast_tvlv_packet->dst,
tvlv_buff, tvlv_buff_len);
if (ret != NET_RX_SUCCESS)
ret = batadv_route_unicast_packet(skb, recv_if);
else
consume_skb(skb);
return ret;
}
/**
* batadv_recv_frag_packet - process received fragment
* @skb: the received fragment
* @recv_if: interface that the skb is received on
*
* This function does one of the three following things: 1) Forward fragment, if
* the assembled packet will exceed our MTU; 2) Buffer fragment, if we till
* lack further fragments; 3) Merge fragments, if we have all needed parts.
*
* Return NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise.
*/
int batadv_recv_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_orig_node *orig_node_src = NULL;
struct batadv_frag_packet *frag_packet;
int ret = NET_RX_DROP;
if (batadv_check_unicast_packet(bat_priv, skb,
sizeof(*frag_packet)) < 0)
goto out;
frag_packet = (struct batadv_frag_packet *)skb->data;
orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig);
if (!orig_node_src)
goto out;
/* Route the fragment if it is not for us and too big to be merged. */
if (!batadv_is_my_mac(bat_priv, frag_packet->dest) &&
batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) {
ret = NET_RX_SUCCESS;
goto out;
}
batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
/* batadv_frag_skb_buffer will always consume the skb and
* the caller should therefore never try to free the
* skb after this point
*/
ret = NET_RX_SUCCESS;
/* Add fragment to buffer and merge if possible. */
if (!batadv_frag_skb_buffer(&skb, orig_node_src))
goto out;
/* Deliver merged packet to the appropriate handler, if it was
* merged
*/
if (skb)
batadv_batman_skb_recv(skb, recv_if->net_dev,
&recv_if->batman_adv_ptype, NULL);
out:
if (orig_node_src)
batadv_orig_node_free_ref(orig_node_src);
return ret;
}
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;
uint32_t seqno;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto out;
ethhdr = eth_hdr(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(bat_priv, ethhdr->h_source))
goto out;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
/* ignore broadcasts originated by myself */
if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
goto out;
if (bcast_packet->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);
seqno = ntohl(bcast_packet->seqno);
/* check whether the packet is a duplicate */
if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno,
seqno))
goto spin_unlock;
seq_diff = 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 = 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, skb))
goto out;
batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
/* 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;
if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
goto rx_success;
if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
goto rx_success;
/* broadcast for me */
batadv_interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size,
orig_node);
rx_success:
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;
}