linux-stable/net/batman-adv/routing.c
Linus Lüssing 0c4061c0d0 batman-adv: tvlv: prepare for tvlv enabled multicast packet type
Prepare TVLV infrastructure for more packet types, in particular the
upcoming batman-adv multicast packet type.

For that swap the OGM vs. unicast-tvlv packet boolean indicator to an
explicit unsigned integer packet type variable. And provide the skb
to a call to batadv_tvlv_containers_process(), as later the multicast
packet's TVLV handler will need to have access not only to the TVLV but
the full skb for forwarding. Forwarding will be invoked from the
multicast packet's TVLVs' contents later.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2023-01-21 19:01:59 +01:00

1272 lines
36 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*/
#include "routing.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kref.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <uapi/linux/batadv_packet.h>
#include "bitarray.h"
#include "bridge_loop_avoidance.h"
#include "distributed-arp-table.h"
#include "fragmentation.h"
#include "hard-interface.h"
#include "log.h"
#include "network-coding.h"
#include "originator.h"
#include "send.h"
#include "soft-interface.h"
#include "tp_meter.h"
#include "translation-table.h"
#include "tvlv.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;
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.
*/
/* increase refcount of new best neighbor */
if (neigh_node)
kref_get(&neigh_node->refcount);
curr_router = rcu_replace_pointer(orig_ifinfo->router, neigh_node,
true);
spin_unlock_bh(&orig_node->neigh_list_lock);
batadv_orig_ifinfo_put(orig_ifinfo);
/* 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);
}
/* decrease refcount of previous best neighbor */
batadv_neigh_node_put(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:
batadv_neigh_node_put(router);
}
/**
* batadv_window_protected() - checks whether the host restarted and is in the
* protection time.
* @bat_priv: the bat priv with all the soft interface information
* @seq_num_diff: difference between the current/received sequence number and
* the last sequence number
* @seq_old_max_diff: maximum age of sequence number not considered as restart
* @last_reset: jiffies timestamp of the last reset, will be updated when reset
* is detected
* @protection_started: is set to true if the protection window was started,
* doesn't change otherwise.
*
* Return:
* false if the packet is to be accepted.
* true if the packet is to be ignored.
*/
bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff,
s32 seq_old_max_diff, unsigned long *last_reset,
bool *protection_started)
{
if (seq_num_diff <= -seq_old_max_diff ||
seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) {
if (!batadv_has_timed_out(*last_reset,
BATADV_RESET_PROTECTION_MS))
return true;
*last_reset = jiffies;
if (protection_started)
*protection_started = true;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"old packet received, start protection\n");
}
return false;
}
/**
* batadv_check_management_packet() - Check preconditions for management packets
* @skb: incoming packet buffer
* @hard_iface: incoming hard interface
* @header_len: minimal header length of packet type
*
* Return: true when management preconditions are met, false otherwise
*/
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 invalid sender address */
if (!is_valid_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
*
* Return: 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_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_SUCCESS)
ret = NET_RX_SUCCESS;
/* skb was consumed */
skb = NULL;
break;
case BATADV_TP:
if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet)))
goto out;
batadv_tp_meter_recv(bat_priv, skb);
ret = NET_RX_SUCCESS;
/* skb was consumed */
skb = NULL;
goto out;
default:
/* drop unknown type */
goto out;
}
out:
batadv_hardif_put(primary_if);
batadv_orig_node_put(orig_node);
kfree_skb(skb);
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 res, 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;
res = batadv_send_skb_to_orig(skb, orig_node, NULL);
if (res == NET_RX_SUCCESS)
ret = NET_XMIT_SUCCESS;
/* skb was consumed */
skb = NULL;
out:
batadv_hardif_put(primary_if);
batadv_orig_node_put(orig_node);
kfree_skb(skb);
return ret;
}
/**
* batadv_recv_icmp_packet() - Process incoming icmp packet
* @skb: incoming packet buffer
* @recv_if: incoming hard interface
*
* Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
*/
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 res, ret = NET_RX_DROP;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto free_skb;
ethhdr = eth_hdr(skb);
/* packet with unicast indication but non-unicast recipient */
if (!is_valid_ether_addr(ethhdr->h_dest))
goto free_skb;
/* packet with broadcast/multicast sender address */
if (is_multicast_ether_addr(ethhdr->h_source))
goto free_skb;
/* not for me */
if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest))
goto free_skb;
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 free_skb;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto free_skb;
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 free_skb;
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 free_skb;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto put_orig_node;
icmph = (struct batadv_icmp_header *)skb->data;
/* decrement ttl */
icmph->ttl--;
/* route it */
res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
if (res == NET_XMIT_SUCCESS)
ret = NET_RX_SUCCESS;
/* skb was consumed */
skb = NULL;
put_orig_node:
batadv_orig_node_put(orig_node);
free_skb:
kfree_skb(skb);
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
*
* Checks for short header and bad addresses in the given packet.
*
* Return: 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 non-unicast recipient */
if (!is_valid_ether_addr(ethhdr->h_dest))
return -EBADR;
/* packet with broadcast/multicast sender address */
if (is_multicast_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)
kref_get(&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)
kref_get(&new_candidate->refcount);
orig_node->last_bonding_candidate = new_candidate;
spin_unlock_bh(&orig_node->neigh_list_lock);
batadv_orig_ifinfo_put(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
*
* Return: 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->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);
if (!router)
return router;
/* 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)))
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 chosen
* 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 (!kref_get_unless_zero(&cand->refcount))
continue;
cand_router = rcu_dereference(cand->router);
if (!cand_router)
goto next;
if (!kref_get_unless_zero(&cand_router->refcount)) {
cand_router = NULL;
goto next;
}
/* alternative candidate should be good enough to be
* considered
*/
if (!bao->neigh.is_similar_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) {
kref_get(&cand_router->refcount);
kref_get(&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_put(cand_router);
cand_router = NULL;
}
batadv_orig_ifinfo_put(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_put(router);
kref_get(&next_candidate_router->refcount);
router = next_candidate_router;
batadv_last_bonding_replace(orig_node, next_candidate);
} else if (first_candidate) {
batadv_neigh_node_put(router);
kref_get(&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_put(first_candidate_router);
batadv_orig_ifinfo_put(first_candidate);
}
if (next_candidate) {
batadv_neigh_node_put(next_candidate_router);
batadv_orig_ifinfo_put(next_candidate);
}
batadv_orig_ifinfo_put(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 free_skb;
}
/* get routing information */
orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest);
if (!orig_node)
goto free_skb;
/* create a copy of the skb, if needed, to modify it. */
if (skb_cow(skb, ETH_HLEN) < 0)
goto put_orig_node;
/* 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) {
ret = NET_RX_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);
}
/* skb was consumed */
skb = NULL;
put_orig_node:
batadv_orig_node_put(orig_node);
free_skb:
kfree_skb(skb);
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)
*
* Return: 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,
u8 *dst_addr, unsigned short vid)
{
struct batadv_orig_node *orig_node = NULL;
struct batadv_hard_iface *primary_if = NULL;
bool ret = false;
const u8 *orig_addr;
u8 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 = (u8)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 = (u8)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:
batadv_hardif_put(primary_if);
batadv_orig_node_put(orig_node);
return ret;
}
static bool 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;
u8 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 false;
/* create a copy of the skb (in case of for re-routing) to modify it. */
if (skb_cow(skb, sizeof(*unicast_packet)) < 0)
return false;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
vid = batadv_get_vid(skb, hdr_len);
ethhdr = (struct ethhdr *)(skb->data + hdr_len);
/* do not reroute multicast frames in a unicast header */
if (is_multicast_ether_addr(ethhdr->h_dest))
return true;
/* 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))
batadv_dbg_ratelimited(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 true;
}
/* 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 = (u8)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 false;
curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn);
batadv_orig_node_put(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 true;
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)) {
batadv_dbg_ratelimited(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 true;
}
/* 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 false;
/* 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 false;
/* 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_put(primary_if);
return true;
}
/**
* 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
*
* Return: 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)
goto free_skb;
/* 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))
goto free_skb;
return batadv_route_unicast_packet(skb, recv_if);
free_skb:
kfree_skb(skb);
return NET_RX_DROP;
}
/**
* batadv_recv_unicast_packet() - Process incoming unicast packet
* @skb: incoming packet buffer
* @recv_if: incoming hard interface
*
* Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
*/
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;
u8 *orig_addr, *orig_addr_gw;
struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL;
int check, hdr_size = sizeof(*unicast_packet);
enum batadv_subtype subtype;
int ret = NET_RX_DROP;
bool is4addr, is_gw;
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)
goto free_skb;
if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
goto free_skb;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* packet for me */
if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
/* If this is a unicast packet from another backgone gw,
* drop it.
*/
orig_addr_gw = eth_hdr(skb)->h_source;
orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw);
if (orig_node_gw) {
is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw,
hdr_size);
batadv_orig_node_put(orig_node_gw);
if (is_gw) {
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"%s(): Dropped unicast pkt received from another backbone gw %pM.\n",
__func__, orig_addr_gw);
goto free_skb;
}
}
if (is4addr) {
unicast_4addr_packet =
(struct batadv_unicast_4addr_packet *)skb->data;
subtype = unicast_4addr_packet->subtype;
batadv_dat_inc_counter(bat_priv, subtype);
/* Only payload data should be considered for speedy
* join. For example, DAT also uses unicast 4addr
* types, but those packets should not be considered
* for speedy join, since the clients do not actually
* reside at the sending originator.
*/
if (subtype == BATADV_P_DATA) {
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_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size);
batadv_interface_rx(recv_if->soft_iface, skb, hdr_size,
orig_node);
rx_success:
batadv_orig_node_put(orig_node);
return NET_RX_SUCCESS;
}
ret = batadv_route_unicast_packet(skb, recv_if);
/* skb was consumed */
skb = NULL;
free_skb:
kfree_skb(skb);
return ret;
}
/**
* 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
*
* Return: 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;
u16 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)
goto free_skb;
/* the header is likely to be modified while forwarding */
if (skb_cow(skb, hdr_size) < 0)
goto free_skb;
/* packet needs to be linearized to access the tvlv content */
if (skb_linearize(skb) < 0)
goto free_skb;
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)
goto free_skb;
ret = batadv_tvlv_containers_process(bat_priv, BATADV_UNICAST_TVLV,
NULL, skb, tvlv_buff,
tvlv_buff_len);
if (ret != NET_RX_SUCCESS) {
ret = batadv_route_unicast_packet(skb, recv_if);
/* skb was consumed */
skb = NULL;
}
free_skb:
kfree_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 still
* 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 free_skb;
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 free_skb;
skb->priority = frag_packet->priority + 256;
/* 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)) {
/* skb was consumed */
skb = NULL;
ret = NET_RX_SUCCESS;
goto put_orig_node;
}
batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
/* Add fragment to buffer and merge if possible. */
if (!batadv_frag_skb_buffer(&skb, orig_node_src))
goto put_orig_node;
/* 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);
/* skb was consumed */
skb = NULL;
}
ret = NET_RX_SUCCESS;
put_orig_node:
batadv_orig_node_put(orig_node_src);
free_skb:
kfree_skb(skb);
return ret;
}
/**
* batadv_recv_bcast_packet() - Process incoming broadcast packet
* @skb: incoming packet buffer
* @recv_if: incoming hard interface
*
* Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure
*/
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);
s32 seq_diff;
u32 seqno;
int ret;
/* drop packet if it has not necessary minimum size */
if (unlikely(!pskb_may_pull(skb, hdr_size)))
goto free_skb;
ethhdr = eth_hdr(skb);
/* packet with broadcast indication but unicast recipient */
if (!is_broadcast_ether_addr(ethhdr->h_dest))
goto free_skb;
/* packet with broadcast/multicast sender address */
if (is_multicast_ether_addr(ethhdr->h_source))
goto free_skb;
/* ignore broadcasts sent by myself */
if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
goto free_skb;
bcast_packet = (struct batadv_bcast_packet *)skb->data;
/* ignore broadcasts originated by myself */
if (batadv_is_my_mac(bat_priv, bcast_packet->orig))
goto free_skb;
if (bcast_packet->ttl-- < 2)
goto free_skb;
orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig);
if (!orig_node)
goto free_skb;
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,
BATADV_BCAST_MAX_AGE,
&orig_node->bcast_seqno_reset, NULL))
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 free_skb;
batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
/* rebroadcast packet */
ret = batadv_forw_bcast_packet(bat_priv, skb, 0, false);
if (ret == NETDEV_TX_BUSY)
goto free_skb;
/* 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 free_skb;
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_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size);
/* broadcast for me */
batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node);
rx_success:
ret = NET_RX_SUCCESS;
goto out;
spin_unlock:
spin_unlock_bh(&orig_node->bcast_seqno_lock);
free_skb:
kfree_skb(skb);
ret = NET_RX_DROP;
out:
batadv_orig_node_put(orig_node);
return ret;
}