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OpenCloudOS-Kernel/net/batman-adv/bat_v_ogm.c

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// 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/container_of.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_ether.h>
#include <linux/jiffies.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/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 += get_random_u32_below(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 += get_random_u32_below(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:
batadv_orig_ifinfo_put(orig_ifinfo);
batadv_neigh_node_put(router);
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:
batadv_orig_ifinfo_put(orig_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:
batadv_neigh_node_put(router);
batadv_neigh_node_put(orig_neigh_router);
batadv_orig_node_put(orig_neigh_node);
batadv_neigh_ifinfo_put(router_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, BATADV_OGM2, orig_node,
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:
batadv_orig_node_put(orig_node);
batadv_neigh_node_put(neigh_node);
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);
}
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