linux/net/batman-adv/bat_v_ogm.c
Sven Eckelmann cfa55c6d47 batman-adv: Drop publication years from copyright info
The batman-adv source code was using the year of publication (to net-next)
as "last" year for the copyright statement. The whole source code mentioned
in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity
regarding the publishing year.

This avoided having outdated (in sense of year information - not copyright
holder) publishing information inside several files. But since the simple
"update copyright year" commit (without other changes) in the file was not
well received in the upstream kernel, the option to not have a copyright
year (for initial and last publication) in the files are chosen instead.
More detailed information about the years can still be retrieved from the
SCM system.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2021-02-06 09:22:10 +01:00

1099 lines
33 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Antonio Quartulli
*/
#include "bat_v_ogm.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/minmax.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/prandom.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <uapi/linux/batadv_packet.h>
#include "bat_algo.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "originator.h"
#include "routing.h"
#include "send.h"
#include "translation-table.h"
#include "tvlv.h"
/**
* batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
* @bat_priv: the bat priv with all the soft interface information
* @addr: the address of the originator
*
* Return: the orig_node corresponding to the specified address. If such an
* object does not exist, it is allocated here. In case of allocation failure
* returns NULL.
*/
struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
const u8 *addr)
{
struct batadv_orig_node *orig_node;
int hash_added;
orig_node = batadv_orig_hash_find(bat_priv, addr);
if (orig_node)
return orig_node;
orig_node = batadv_orig_node_new(bat_priv, addr);
if (!orig_node)
return NULL;
kref_get(&orig_node->refcount);
hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
batadv_choose_orig, orig_node,
&orig_node->hash_entry);
if (hash_added != 0) {
/* remove refcnt for newly created orig_node and hash entry */
batadv_orig_node_put(orig_node);
batadv_orig_node_put(orig_node);
orig_node = NULL;
}
return orig_node;
}
/**
* batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
* @hard_iface: the interface to use to send the OGM
*/
static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
{
unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
/* msecs * [0.9, 1.1] */
msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
msecs_to_jiffies(msecs / 1000));
}
/**
* batadv_v_ogm_start_timer() - restart the OGM sending timer
* @bat_priv: the bat priv with all the soft interface information
*/
static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
{
unsigned long msecs;
/* this function may be invoked in different contexts (ogm rescheduling
* or hard_iface activation), but the work timer should not be reset
*/
if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
return;
msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
msecs += prandom_u32_max(2 * BATADV_JITTER);
queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
msecs_to_jiffies(msecs));
}
/**
* batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
* @skb: the OGM to send
* @hard_iface: the interface to use to send the OGM
*/
static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
if (hard_iface->if_status != BATADV_IF_ACTIVE)
return;
batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
skb->len + ETH_HLEN);
batadv_send_broadcast_skb(skb, hard_iface);
}
/**
* batadv_v_ogm_len() - OGMv2 packet length
* @skb: the OGM to check
*
* Return: Length of the given OGMv2 packet, including tvlv length, excluding
* ethernet header length.
*/
static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
{
struct batadv_ogm2_packet *ogm_packet;
ogm_packet = (struct batadv_ogm2_packet *)skb->data;
return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
}
/**
* batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
* @skb: the OGM to check
* @hard_iface: the interface to use to send the OGM
*
* Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
*
* Return: True, if the given OGMv2 packet still fits, false otherwise.
*/
static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface)
{
unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
BATADV_MAX_AGGREGATION_BYTES);
unsigned int ogm_len = batadv_v_ogm_len(skb);
lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
return hard_iface->bat_v.aggr_len + ogm_len <= max;
}
/**
* batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
* @hard_iface: the interface holding the aggregation queue
*
* Empties the OGMv2 aggregation queue and frees all the skbs it contains.
*
* Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
*/
static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
{
lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
__skb_queue_purge(&hard_iface->bat_v.aggr_list);
hard_iface->bat_v.aggr_len = 0;
}
/**
* batadv_v_ogm_aggr_send() - flush & send aggregation queue
* @hard_iface: the interface with the aggregation queue to flush
*
* Aggregates all OGMv2 packets currently in the aggregation queue into a
* single OGMv2 packet and transmits this aggregate.
*
* The aggregation queue is empty after this call.
*
* Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
*/
static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
{
unsigned int aggr_len = hard_iface->bat_v.aggr_len;
struct sk_buff *skb_aggr;
unsigned int ogm_len;
struct sk_buff *skb;
lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
if (!aggr_len)
return;
skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
if (!skb_aggr) {
batadv_v_ogm_aggr_list_free(hard_iface);
return;
}
skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
skb_reset_network_header(skb_aggr);
while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
ogm_len = batadv_v_ogm_len(skb);
skb_put_data(skb_aggr, skb->data, ogm_len);
consume_skb(skb);
}
batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
}
/**
* batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
* @skb: the OGM to queue
* @hard_iface: the interface to queue the OGM on
*/
static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
if (!atomic_read(&bat_priv->aggregated_ogms)) {
batadv_v_ogm_send_to_if(skb, hard_iface);
return;
}
spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
if (!batadv_v_ogm_queue_left(skb, hard_iface))
batadv_v_ogm_aggr_send(hard_iface);
hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
__skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
}
/**
* batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
* @bat_priv: the bat priv with all the soft interface information
*/
static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
{
struct batadv_hard_iface *hard_iface;
struct batadv_ogm2_packet *ogm_packet;
struct sk_buff *skb, *skb_tmp;
unsigned char *ogm_buff;
int ogm_buff_len;
u16 tvlv_len = 0;
int ret;
lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
goto out;
ogm_buff = bat_priv->bat_v.ogm_buff;
ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
/* tt changes have to be committed before the tvlv data is
* appended as it may alter the tt tvlv container
*/
batadv_tt_local_commit_changes(bat_priv);
tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
&ogm_buff_len,
BATADV_OGM2_HLEN);
bat_priv->bat_v.ogm_buff = ogm_buff;
bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
if (!skb)
goto reschedule;
skb_reserve(skb, ETH_HLEN);
skb_put_data(skb, ogm_buff, ogm_buff_len);
ogm_packet = (struct batadv_ogm2_packet *)skb->data;
ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
atomic_inc(&bat_priv->bat_v.ogm_seqno);
ogm_packet->tvlv_len = htons(tvlv_len);
/* broadcast on every interface */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (hard_iface->soft_iface != bat_priv->soft_iface)
continue;
if (!kref_get_unless_zero(&hard_iface->refcount))
continue;
ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
if (ret) {
char *type;
switch (ret) {
case BATADV_HARDIF_BCAST_NORECIPIENT:
type = "no neighbor";
break;
case BATADV_HARDIF_BCAST_DUPFWD:
type = "single neighbor is source";
break;
case BATADV_HARDIF_BCAST_DUPORIG:
type = "single neighbor is originator";
break;
default:
type = "unknown";
}
batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
hard_iface->net_dev->name, type);
batadv_hardif_put(hard_iface);
continue;
}
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
ogm_packet->orig, ntohl(ogm_packet->seqno),
ntohl(ogm_packet->throughput), ogm_packet->ttl,
hard_iface->net_dev->name,
hard_iface->net_dev->dev_addr);
/* this skb gets consumed by batadv_v_ogm_send_to_if() */
skb_tmp = skb_clone(skb, GFP_ATOMIC);
if (!skb_tmp) {
batadv_hardif_put(hard_iface);
break;
}
batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
batadv_hardif_put(hard_iface);
}
rcu_read_unlock();
consume_skb(skb);
reschedule:
batadv_v_ogm_start_timer(bat_priv);
out:
return;
}
/**
* batadv_v_ogm_send() - periodic worker broadcasting the own OGM
* @work: work queue item
*/
static void batadv_v_ogm_send(struct work_struct *work)
{
struct batadv_priv_bat_v *bat_v;
struct batadv_priv *bat_priv;
bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
batadv_v_ogm_send_softif(bat_priv);
mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}
/**
* batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
* @work: work queue item
*
* Emits aggregated OGM messages in regular intervals.
*/
void batadv_v_ogm_aggr_work(struct work_struct *work)
{
struct batadv_hard_iface_bat_v *batv;
struct batadv_hard_iface *hard_iface;
batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_aggr_send(hard_iface);
spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_start_queue_timer(hard_iface);
}
/**
* batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
* @hard_iface: the interface to prepare
*
* Takes care of scheduling its own OGM sending routine for this interface.
*
* Return: 0 on success or a negative error code otherwise
*/
int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
batadv_v_ogm_start_queue_timer(hard_iface);
batadv_v_ogm_start_timer(bat_priv);
return 0;
}
/**
* batadv_v_ogm_iface_disable() - release OGM interface private resources
* @hard_iface: interface for which the resources have to be released
*/
void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
{
cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_aggr_list_free(hard_iface);
spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
}
/**
* batadv_v_ogm_primary_iface_set() - set a new primary interface
* @primary_iface: the new primary interface
*/
void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
{
struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
struct batadv_ogm2_packet *ogm_packet;
mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
if (!bat_priv->bat_v.ogm_buff)
goto unlock;
ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
unlock:
mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}
/**
* batadv_v_forward_penalty() - apply a penalty to the throughput metric
* forwarded with B.A.T.M.A.N. V OGMs
* @bat_priv: the bat priv with all the soft interface information
* @if_incoming: the interface where the OGM has been received
* @if_outgoing: the interface where the OGM has to be forwarded to
* @throughput: the current throughput
*
* Apply a penalty on the current throughput metric value based on the
* characteristic of the interface where the OGM has been received.
*
* Initially the per hardif hop penalty is applied to the throughput. After
* that the return value is then computed as follows:
* - throughput * 50% if the incoming and outgoing interface are the
* same WiFi interface and the throughput is above
* 1MBit/s
* - throughput if the outgoing interface is the default
* interface (i.e. this OGM is processed for the
* internal table and not forwarded)
* - throughput * node hop penalty otherwise
*
* Return: the penalised throughput metric.
*/
static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing,
u32 throughput)
{
int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
int hop_penalty = atomic_read(&bat_priv->hop_penalty);
int hop_penalty_max = BATADV_TQ_MAX_VALUE;
/* Apply per hardif hop penalty */
throughput = throughput * (hop_penalty_max - if_hop_penalty) /
hop_penalty_max;
/* Don't apply hop penalty in default originator table. */
if (if_outgoing == BATADV_IF_DEFAULT)
return throughput;
/* Forwarding on the same WiFi interface cuts the throughput in half
* due to the store & forward characteristics of WIFI.
* Very low throughput values are the exception.
*/
if (throughput > 10 &&
if_incoming == if_outgoing &&
!(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
return throughput / 2;
/* hop penalty of 255 equals 100% */
return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
}
/**
* batadv_v_ogm_forward() - check conditions and forward an OGM to the given
* outgoing interface
* @bat_priv: the bat priv with all the soft interface information
* @ogm_received: previously received OGM to be forwarded
* @orig_node: the originator which has been updated
* @neigh_node: the neigh_node through with the OGM has been received
* @if_incoming: the interface on which this OGM was received on
* @if_outgoing: the interface to which the OGM has to be forwarded to
*
* Forward an OGM to an interface after having altered the throughput metric and
* the TTL value contained in it. The original OGM isn't modified.
*/
static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
const struct batadv_ogm2_packet *ogm_received,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node,
struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing)
{
struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
struct batadv_orig_ifinfo *orig_ifinfo = NULL;
struct batadv_neigh_node *router = NULL;
struct batadv_ogm2_packet *ogm_forward;
unsigned char *skb_buff;
struct sk_buff *skb;
size_t packet_len;
u16 tvlv_len;
/* only forward for specific interfaces, not for the default one. */
if (if_outgoing == BATADV_IF_DEFAULT)
goto out;
orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
if (!orig_ifinfo)
goto out;
/* acquire possibly updated router */
router = batadv_orig_router_get(orig_node, if_outgoing);
/* strict rule: forward packets coming from the best next hop only */
if (neigh_node != router)
goto out;
/* don't forward the same seqno twice on one interface */
if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
goto out;
orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
if (ogm_received->ttl <= 1) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
goto out;
}
neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
if (!neigh_ifinfo)
goto out;
tvlv_len = ntohs(ogm_received->tvlv_len);
packet_len = BATADV_OGM2_HLEN + tvlv_len;
skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
ETH_HLEN + packet_len);
if (!skb)
goto out;
skb_reserve(skb, ETH_HLEN);
skb_buff = skb_put_data(skb, ogm_received, packet_len);
/* apply forward penalty */
ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
ogm_forward->ttl--;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
ogm_forward->ttl, if_incoming->net_dev->name);
batadv_v_ogm_queue_on_if(skb, if_outgoing);
out:
if (orig_ifinfo)
batadv_orig_ifinfo_put(orig_ifinfo);
if (router)
batadv_neigh_node_put(router);
if (neigh_ifinfo)
batadv_neigh_ifinfo_put(neigh_ifinfo);
}
/**
* batadv_v_ogm_metric_update() - update route metric based on OGM
* @bat_priv: the bat priv with all the soft interface information
* @ogm2: OGM2 structure
* @orig_node: Originator structure for which the OGM has been received
* @neigh_node: the neigh_node through with the OGM has been received
* @if_incoming: the interface where this packet was received
* @if_outgoing: the interface for which the packet should be considered
*
* Return:
* 1 if the OGM is new,
* 0 if it is not new but valid,
* <0 on error (e.g. old OGM)
*/
static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
const struct batadv_ogm2_packet *ogm2,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node,
struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing)
{
struct batadv_orig_ifinfo *orig_ifinfo;
struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
bool protection_started = false;
int ret = -EINVAL;
u32 path_throughput;
s32 seq_diff;
orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
if (!orig_ifinfo)
goto out;
seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
if (!hlist_empty(&orig_node->neigh_list) &&
batadv_window_protected(bat_priv, seq_diff,
BATADV_OGM_MAX_AGE,
&orig_ifinfo->batman_seqno_reset,
&protection_started)) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: packet within window protection time from %pM\n",
ogm2->orig);
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Last reset: %ld, %ld\n",
orig_ifinfo->batman_seqno_reset, jiffies);
goto out;
}
/* drop packets with old seqnos, however accept the first packet after
* a host has been rebooted.
*/
if (seq_diff < 0 && !protection_started)
goto out;
neigh_node->last_seen = jiffies;
orig_node->last_seen = jiffies;
orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
orig_ifinfo->last_ttl = ogm2->ttl;
neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
if (!neigh_ifinfo)
goto out;
path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
if_outgoing,
ntohl(ogm2->throughput));
neigh_ifinfo->bat_v.throughput = path_throughput;
neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
neigh_ifinfo->last_ttl = ogm2->ttl;
if (seq_diff > 0 || protection_started)
ret = 1;
else
ret = 0;
out:
if (orig_ifinfo)
batadv_orig_ifinfo_put(orig_ifinfo);
if (neigh_ifinfo)
batadv_neigh_ifinfo_put(neigh_ifinfo);
return ret;
}
/**
* batadv_v_ogm_route_update() - update routes based on OGM
* @bat_priv: the bat priv with all the soft interface information
* @ethhdr: the Ethernet header of the OGM2
* @ogm2: OGM2 structure
* @orig_node: Originator structure for which the OGM has been received
* @neigh_node: the neigh_node through with the OGM has been received
* @if_incoming: the interface where this packet was received
* @if_outgoing: the interface for which the packet should be considered
*
* Return: true if the packet should be forwarded, false otherwise
*/
static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
const struct ethhdr *ethhdr,
const struct batadv_ogm2_packet *ogm2,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node,
struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing)
{
struct batadv_neigh_node *router = NULL;
struct batadv_orig_node *orig_neigh_node;
struct batadv_neigh_node *orig_neigh_router = NULL;
struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
u32 router_throughput, neigh_throughput;
u32 router_last_seqno;
u32 neigh_last_seqno;
s32 neigh_seq_diff;
bool forward = false;
orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
if (!orig_neigh_node)
goto out;
orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
if_outgoing);
/* drop packet if sender is not a direct neighbor and if we
* don't route towards it
*/
router = batadv_orig_router_get(orig_node, if_outgoing);
if (router && router->orig_node != orig_node && !orig_neigh_router) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: OGM via unknown neighbor!\n");
goto out;
}
/* Mark the OGM to be considered for forwarding, and update routes
* if needed.
*/
forward = true;
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Searching and updating originator entry of received packet\n");
/* if this neighbor already is our next hop there is nothing
* to change
*/
if (router == neigh_node)
goto out;
/* don't consider neighbours with worse throughput.
* also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
* the last received seqno from our best next hop.
*/
if (router) {
router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
/* if these are not allocated, something is wrong. */
if (!router_ifinfo || !neigh_ifinfo)
goto out;
neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
router_last_seqno = router_ifinfo->bat_v.last_seqno;
neigh_seq_diff = neigh_last_seqno - router_last_seqno;
router_throughput = router_ifinfo->bat_v.throughput;
neigh_throughput = neigh_ifinfo->bat_v.throughput;
if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
router_throughput >= neigh_throughput)
goto out;
}
batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
out:
if (router)
batadv_neigh_node_put(router);
if (orig_neigh_router)
batadv_neigh_node_put(orig_neigh_router);
if (orig_neigh_node)
batadv_orig_node_put(orig_neigh_node);
if (router_ifinfo)
batadv_neigh_ifinfo_put(router_ifinfo);
if (neigh_ifinfo)
batadv_neigh_ifinfo_put(neigh_ifinfo);
return forward;
}
/**
* batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
* @bat_priv: the bat priv with all the soft interface information
* @ethhdr: the Ethernet header of the OGM2
* @ogm2: OGM2 structure
* @orig_node: Originator structure for which the OGM has been received
* @neigh_node: the neigh_node through with the OGM has been received
* @if_incoming: the interface where this packet was received
* @if_outgoing: the interface for which the packet should be considered
*/
static void
batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
const struct ethhdr *ethhdr,
const struct batadv_ogm2_packet *ogm2,
struct batadv_orig_node *orig_node,
struct batadv_neigh_node *neigh_node,
struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing)
{
int seqno_age;
bool forward;
/* first, update the metric with according sanity checks */
seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
neigh_node, if_incoming,
if_outgoing);
/* outdated sequence numbers are to be discarded */
if (seqno_age < 0)
return;
/* only unknown & newer OGMs contain TVLVs we are interested in */
if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
batadv_tvlv_containers_process(bat_priv, true, orig_node,
NULL, NULL,
(unsigned char *)(ogm2 + 1),
ntohs(ogm2->tvlv_len));
/* if the metric update went through, update routes if needed */
forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
neigh_node, if_incoming,
if_outgoing);
/* if the routes have been processed correctly, check and forward */
if (forward)
batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
if_incoming, if_outgoing);
}
/**
* batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
* @buff_pos: current position in the skb
* @packet_len: total length of the skb
* @ogm2_packet: potential OGM2 in buffer
*
* Return: true if there is enough space for another OGM, false otherwise.
*/
static bool
batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
const struct batadv_ogm2_packet *ogm2_packet)
{
int next_buff_pos = 0;
/* check if there is enough space for the header */
next_buff_pos += buff_pos + sizeof(*ogm2_packet);
if (next_buff_pos > packet_len)
return false;
/* check if there is enough space for the optional TVLV */
next_buff_pos += ntohs(ogm2_packet->tvlv_len);
return (next_buff_pos <= packet_len) &&
(next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
}
/**
* batadv_v_ogm_process() - process an incoming batman v OGM
* @skb: the skb containing the OGM
* @ogm_offset: offset to the OGM which should be processed (for aggregates)
* @if_incoming: the interface where this packet was received
*/
static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
struct batadv_hard_iface *if_incoming)
{
struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct ethhdr *ethhdr;
struct batadv_orig_node *orig_node = NULL;
struct batadv_hardif_neigh_node *hardif_neigh = NULL;
struct batadv_neigh_node *neigh_node = NULL;
struct batadv_hard_iface *hard_iface;
struct batadv_ogm2_packet *ogm_packet;
u32 ogm_throughput, link_throughput, path_throughput;
int ret;
ethhdr = eth_hdr(skb);
ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
ogm_throughput = ntohl(ogm_packet->throughput);
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
ethhdr->h_source, if_incoming->net_dev->name,
if_incoming->net_dev->dev_addr, ogm_packet->orig,
ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
ogm_packet->version, ntohs(ogm_packet->tvlv_len));
if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: originator packet from ourself\n");
return;
}
/* If the throughput metric is 0, immediately drop the packet. No need
* to create orig_node / neigh_node for an unusable route.
*/
if (ogm_throughput == 0) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: originator packet with throughput metric of 0\n");
return;
}
/* require ELP packets be to received from this neighbor first */
hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
if (!hardif_neigh) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Drop packet: OGM via unknown neighbor!\n");
goto out;
}
orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
if (!orig_node)
goto out;
neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
ethhdr->h_source);
if (!neigh_node)
goto out;
/* Update the received throughput metric to match the link
* characteristic:
* - If this OGM traveled one hop so far (emitted by single hop
* neighbor) the path throughput metric equals the link throughput.
* - For OGMs traversing more than hop the path throughput metric is
* the smaller of the path throughput and the link throughput.
*/
link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
path_throughput = min_t(u32, link_throughput, ogm_throughput);
ogm_packet->throughput = htonl(path_throughput);
batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
neigh_node, if_incoming,
BATADV_IF_DEFAULT);
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (hard_iface->if_status != BATADV_IF_ACTIVE)
continue;
if (hard_iface->soft_iface != bat_priv->soft_iface)
continue;
if (!kref_get_unless_zero(&hard_iface->refcount))
continue;
ret = batadv_hardif_no_broadcast(hard_iface,
ogm_packet->orig,
hardif_neigh->orig);
if (ret) {
char *type;
switch (ret) {
case BATADV_HARDIF_BCAST_NORECIPIENT:
type = "no neighbor";
break;
case BATADV_HARDIF_BCAST_DUPFWD:
type = "single neighbor is source";
break;
case BATADV_HARDIF_BCAST_DUPORIG:
type = "single neighbor is originator";
break;
default:
type = "unknown";
}
batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
ogm_packet->orig, hard_iface->net_dev->name,
type);
batadv_hardif_put(hard_iface);
continue;
}
batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
orig_node, neigh_node,
if_incoming, hard_iface);
batadv_hardif_put(hard_iface);
}
rcu_read_unlock();
out:
if (orig_node)
batadv_orig_node_put(orig_node);
if (neigh_node)
batadv_neigh_node_put(neigh_node);
if (hardif_neigh)
batadv_hardif_neigh_put(hardif_neigh);
}
/**
* batadv_v_ogm_packet_recv() - OGM2 receiving handler
* @skb: the received OGM
* @if_incoming: the interface where this OGM has been received
*
* Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
* (without freeing the skb) on failure
*/
int batadv_v_ogm_packet_recv(struct sk_buff *skb,
struct batadv_hard_iface *if_incoming)
{
struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct batadv_ogm2_packet *ogm_packet;
struct ethhdr *ethhdr = eth_hdr(skb);
int ogm_offset;
u8 *packet_pos;
int ret = NET_RX_DROP;
/* did we receive a OGM2 packet on an interface that does not have
* B.A.T.M.A.N. V enabled ?
*/
if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
goto free_skb;
if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
goto free_skb;
if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
goto free_skb;
batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
skb->len + ETH_HLEN);
ogm_offset = 0;
ogm_packet = (struct batadv_ogm2_packet *)skb->data;
while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
ogm_packet)) {
batadv_v_ogm_process(skb, ogm_offset, if_incoming);
ogm_offset += BATADV_OGM2_HLEN;
ogm_offset += ntohs(ogm_packet->tvlv_len);
packet_pos = skb->data + ogm_offset;
ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
}
ret = NET_RX_SUCCESS;
free_skb:
if (ret == NET_RX_SUCCESS)
consume_skb(skb);
else
kfree_skb(skb);
return ret;
}
/**
* batadv_v_ogm_init() - initialise the OGM2 engine
* @bat_priv: the bat priv with all the soft interface information
*
* Return: 0 on success or a negative error code in case of failure
*/
int batadv_v_ogm_init(struct batadv_priv *bat_priv)
{
struct batadv_ogm2_packet *ogm_packet;
unsigned char *ogm_buff;
u32 random_seqno;
bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
if (!ogm_buff)
return -ENOMEM;
bat_priv->bat_v.ogm_buff = ogm_buff;
ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
ogm_packet->packet_type = BATADV_OGM2;
ogm_packet->version = BATADV_COMPAT_VERSION;
ogm_packet->ttl = BATADV_TTL;
ogm_packet->flags = BATADV_NO_FLAGS;
ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
/* randomize initial seqno to avoid collision */
get_random_bytes(&random_seqno, sizeof(random_seqno));
atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
return 0;
}
/**
* batadv_v_ogm_free() - free OGM private resources
* @bat_priv: the bat priv with all the soft interface information
*/
void batadv_v_ogm_free(struct batadv_priv *bat_priv)
{
cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
kfree(bat_priv->bat_v.ogm_buff);
bat_priv->bat_v.ogm_buff = NULL;
bat_priv->bat_v.ogm_buff_len = 0;
mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}