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/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
*
* Linus Lüssing , Marek Lindner
*
* This program is free software ; you can redistribute it and / or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation .
*
* This program is distributed in the hope that it will be useful , but
* WITHOUT ANY WARRANTY ; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE . See the GNU
* General Public License for more details .
*
* You should have received a copy of the GNU General Public License
* along with this program ; if not , see < http : //www.gnu.org/licenses/>.
*/
# include "bat_v_elp.h"
# include "main.h"
# include <linux/atomic.h>
# include <linux/byteorder/generic.h>
# include <linux/errno.h>
# include <linux/etherdevice.h>
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# include <linux/ethtool.h>
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# include <linux/fs.h>
# include <linux/if_ether.h>
# include <linux/jiffies.h>
# include <linux/kernel.h>
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# include <linux/kref.h>
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# include <linux/netdevice.h>
# include <linux/random.h>
# include <linux/rculist.h>
# include <linux/rcupdate.h>
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# include <linux/rtnetlink.h>
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# include <linux/skbuff.h>
# include <linux/stddef.h>
# include <linux/string.h>
# include <linux/types.h>
# include <linux/workqueue.h>
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# include <net/cfg80211.h>
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# include "bat_algo.h"
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# include "bat_v_ogm.h"
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# include "hard-interface.h"
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# include "log.h"
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# include "originator.h"
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# include "packet.h"
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# include "routing.h"
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# include "send.h"
/**
* batadv_v_elp_start_timer - restart timer for ELP periodic work
* @ hard_iface : the interface for which the timer has to be reset
*/
static void batadv_v_elp_start_timer ( struct batadv_hard_iface * hard_iface )
{
unsigned int msecs ;
msecs = atomic_read ( & hard_iface - > bat_v . elp_interval ) - BATADV_JITTER ;
msecs + = prandom_u32 ( ) % ( 2 * BATADV_JITTER ) ;
queue_delayed_work ( batadv_event_workqueue , & hard_iface - > bat_v . elp_wq ,
msecs_to_jiffies ( msecs ) ) ;
}
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/**
* batadv_v_elp_get_throughput - get the throughput towards a neighbour
* @ neigh : the neighbour for which the throughput has to be obtained
*
* Return : The throughput towards the given neighbour in multiples of 100 kpbs
* ( a value of ' 1 ' equals to 0.1 Mbps , ' 10 ' equals 1 Mbps , etc ) .
*/
static u32 batadv_v_elp_get_throughput ( struct batadv_hardif_neigh_node * neigh )
{
struct batadv_hard_iface * hard_iface = neigh - > if_incoming ;
struct ethtool_link_ksettings link_settings ;
struct station_info sinfo ;
u32 throughput ;
int ret ;
/* if the user specified a customised value for this interface, then
* return it directly
*/
throughput = atomic_read ( & hard_iface - > bat_v . throughput_override ) ;
if ( throughput ! = 0 )
return throughput ;
/* if this is a wireless device, then ask its throughput through
* cfg80211 API
*/
if ( batadv_is_wifi_netdev ( hard_iface - > net_dev ) ) {
if ( hard_iface - > net_dev - > ieee80211_ptr ) {
ret = cfg80211_get_station ( hard_iface - > net_dev ,
neigh - > addr , & sinfo ) ;
if ( ret = = - ENOENT ) {
/* Node is not associated anymore! It would be
* possible to delete this neighbor . For now set
* the throughput metric to 0.
*/
return 0 ;
}
if ( ! ret )
return sinfo . expected_throughput / 100 ;
}
/* unsupported WiFi driver version */
goto default_throughput ;
}
/* if not a wifi interface, check if this device provides data via
* ethtool ( e . g . an Ethernet adapter )
*/
memset ( & link_settings , 0 , sizeof ( link_settings ) ) ;
rtnl_lock ( ) ;
ret = __ethtool_get_link_ksettings ( hard_iface - > net_dev , & link_settings ) ;
rtnl_unlock ( ) ;
if ( ret = = 0 ) {
/* link characteristics might change over time */
if ( link_settings . base . duplex = = DUPLEX_FULL )
hard_iface - > bat_v . flags | = BATADV_FULL_DUPLEX ;
else
hard_iface - > bat_v . flags & = ~ BATADV_FULL_DUPLEX ;
throughput = link_settings . base . speed ;
if ( throughput & & ( throughput ! = SPEED_UNKNOWN ) )
return throughput * 10 ;
}
default_throughput :
if ( ! ( hard_iface - > bat_v . flags & BATADV_WARNING_DEFAULT ) ) {
batadv_info ( hard_iface - > soft_iface ,
" WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver. \n " ,
hard_iface - > net_dev - > name ,
BATADV_THROUGHPUT_DEFAULT_VALUE / 10 ,
BATADV_THROUGHPUT_DEFAULT_VALUE % 10 ) ;
hard_iface - > bat_v . flags | = BATADV_WARNING_DEFAULT ;
}
/* if none of the above cases apply, return the base_throughput */
return BATADV_THROUGHPUT_DEFAULT_VALUE ;
}
/**
* batadv_v_elp_throughput_metric_update - worker updating the throughput metric
* of a single hop neighbour
* @ work : the work queue item
*/
void batadv_v_elp_throughput_metric_update ( struct work_struct * work )
{
struct batadv_hardif_neigh_node_bat_v * neigh_bat_v ;
struct batadv_hardif_neigh_node * neigh ;
neigh_bat_v = container_of ( work , struct batadv_hardif_neigh_node_bat_v ,
metric_work ) ;
neigh = container_of ( neigh_bat_v , struct batadv_hardif_neigh_node ,
bat_v ) ;
ewma_throughput_add ( & neigh - > bat_v . throughput ,
batadv_v_elp_get_throughput ( neigh ) ) ;
/* decrement refcounter to balance increment performed before scheduling
* this task
*/
batadv_hardif_neigh_put ( neigh ) ;
}
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/**
* batadv_v_elp_wifi_neigh_probe - send link probing packets to a neighbour
* @ neigh : the neighbour to probe
*
* Sends a predefined number of unicast wifi packets to a given neighbour in
* order to trigger the throughput estimation on this link by the RC algorithm .
* Packets are sent only if there there is not enough payload unicast traffic
* towards this neighbour . .
*
* Return : True on success and false in case of error during skb preparation .
*/
static bool
batadv_v_elp_wifi_neigh_probe ( struct batadv_hardif_neigh_node * neigh )
{
struct batadv_hard_iface * hard_iface = neigh - > if_incoming ;
struct batadv_priv * bat_priv = netdev_priv ( hard_iface - > soft_iface ) ;
unsigned long last_tx_diff ;
struct sk_buff * skb ;
int probe_len , i ;
int elp_skb_len ;
/* this probing routine is for Wifi neighbours only */
if ( ! batadv_is_wifi_netdev ( hard_iface - > net_dev ) )
return true ;
/* probe the neighbor only if no unicast packets have been sent
* to it in the last 100 milliseconds : this is the rate control
* algorithm sampling interval ( minstrel ) . In this way , if not
* enough traffic has been sent to the neighbor , batman - adv can
* generate 2 probe packets and push the RC algorithm to perform
* the sampling
*/
last_tx_diff = jiffies_to_msecs ( jiffies - neigh - > bat_v . last_unicast_tx ) ;
if ( last_tx_diff < = BATADV_ELP_PROBE_MAX_TX_DIFF )
return true ;
probe_len = max_t ( int , sizeof ( struct batadv_elp_packet ) ,
BATADV_ELP_MIN_PROBE_SIZE ) ;
for ( i = 0 ; i < BATADV_ELP_PROBES_PER_NODE ; i + + ) {
elp_skb_len = hard_iface - > bat_v . elp_skb - > len ;
skb = skb_copy_expand ( hard_iface - > bat_v . elp_skb , 0 ,
probe_len - elp_skb_len ,
GFP_ATOMIC ) ;
if ( ! skb )
return false ;
/* Tell the skb to get as big as the allocated space (we want
* the packet to be exactly of that size to make the link
* throughput estimation effective .
*/
skb_put ( skb , probe_len - hard_iface - > bat_v . elp_skb - > len ) ;
batadv_dbg ( BATADV_DBG_BATMAN , bat_priv ,
" Sending unicast (probe) ELP packet on interface %s to %pM \n " ,
hard_iface - > net_dev - > name , neigh - > addr ) ;
batadv_send_skb_packet ( skb , hard_iface , neigh - > addr ) ;
}
return true ;
}
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/**
* batadv_v_elp_periodic_work - ELP periodic task per interface
* @ work : work queue item
*
* Emits broadcast ELP message in regular intervals .
*/
static void batadv_v_elp_periodic_work ( struct work_struct * work )
{
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struct batadv_hardif_neigh_node * hardif_neigh ;
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struct batadv_hard_iface * hard_iface ;
struct batadv_hard_iface_bat_v * bat_v ;
struct batadv_elp_packet * elp_packet ;
struct batadv_priv * bat_priv ;
struct sk_buff * skb ;
u32 elp_interval ;
bat_v = container_of ( work , struct batadv_hard_iface_bat_v , elp_wq . work ) ;
hard_iface = container_of ( bat_v , struct batadv_hard_iface , bat_v ) ;
bat_priv = netdev_priv ( hard_iface - > soft_iface ) ;
if ( atomic_read ( & bat_priv - > mesh_state ) = = BATADV_MESH_DEACTIVATING )
goto out ;
/* we are in the process of shutting this interface down */
if ( ( hard_iface - > if_status = = BATADV_IF_NOT_IN_USE ) | |
( hard_iface - > if_status = = BATADV_IF_TO_BE_REMOVED ) )
goto out ;
/* the interface was enabled but may not be ready yet */
if ( hard_iface - > if_status ! = BATADV_IF_ACTIVE )
goto restart_timer ;
skb = skb_copy ( hard_iface - > bat_v . elp_skb , GFP_ATOMIC ) ;
if ( ! skb )
goto restart_timer ;
elp_packet = ( struct batadv_elp_packet * ) skb - > data ;
elp_packet - > seqno = htonl ( atomic_read ( & hard_iface - > bat_v . elp_seqno ) ) ;
elp_interval = atomic_read ( & hard_iface - > bat_v . elp_interval ) ;
elp_packet - > elp_interval = htonl ( elp_interval ) ;
batadv_dbg ( BATADV_DBG_BATMAN , bat_priv ,
" Sending broadcast ELP packet on interface %s, seqno %u \n " ,
hard_iface - > net_dev - > name ,
atomic_read ( & hard_iface - > bat_v . elp_seqno ) ) ;
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batadv_send_broadcast_skb ( skb , hard_iface ) ;
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atomic_inc ( & hard_iface - > bat_v . elp_seqno ) ;
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/* The throughput metric is updated on each sent packet. This way, if a
* node is dead and no longer sends packets , batman - adv is still able to
* react timely to its death .
*
* The throughput metric is updated by following these steps :
* 1 ) if the hard_iface is wifi = > send a number of unicast ELPs for
* probing / sampling to each neighbor
* 2 ) update the throughput metric value of each neighbor ( note that the
* value retrieved in this step might be 100 ms old because the
* probing packets at point 1 ) could still be in the HW queue )
*/
rcu_read_lock ( ) ;
hlist_for_each_entry_rcu ( hardif_neigh , & hard_iface - > neigh_list , list ) {
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if ( ! batadv_v_elp_wifi_neigh_probe ( hardif_neigh ) )
/* if something goes wrong while probing, better to stop
* sending packets immediately and reschedule the task
*/
break ;
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if ( ! kref_get_unless_zero ( & hardif_neigh - > refcount ) )
continue ;
/* Reading the estimated throughput from cfg80211 is a task that
* may sleep and that is not allowed in an rcu protected
* context . Therefore schedule a task for that .
*/
queue_work ( batadv_event_workqueue ,
& hardif_neigh - > bat_v . metric_work ) ;
}
rcu_read_unlock ( ) ;
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restart_timer :
batadv_v_elp_start_timer ( hard_iface ) ;
out :
return ;
}
/**
* batadv_v_elp_iface_enable - setup the ELP interface private resources
* @ hard_iface : interface for which the data has to be prepared
*
* Return : 0 on success or a - ENOMEM in case of failure .
*/
int batadv_v_elp_iface_enable ( struct batadv_hard_iface * hard_iface )
{
struct batadv_elp_packet * elp_packet ;
unsigned char * elp_buff ;
u32 random_seqno ;
size_t size ;
int res = - ENOMEM ;
size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN ;
hard_iface - > bat_v . elp_skb = dev_alloc_skb ( size ) ;
if ( ! hard_iface - > bat_v . elp_skb )
goto out ;
skb_reserve ( hard_iface - > bat_v . elp_skb , ETH_HLEN + NET_IP_ALIGN ) ;
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elp_buff = skb_put ( hard_iface - > bat_v . elp_skb , BATADV_ELP_HLEN ) ;
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elp_packet = ( struct batadv_elp_packet * ) elp_buff ;
memset ( elp_packet , 0 , BATADV_ELP_HLEN ) ;
elp_packet - > packet_type = BATADV_ELP ;
elp_packet - > version = BATADV_COMPAT_VERSION ;
/* randomize initial seqno to avoid collision */
get_random_bytes ( & random_seqno , sizeof ( random_seqno ) ) ;
atomic_set ( & hard_iface - > bat_v . elp_seqno , random_seqno ) ;
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/* assume full-duplex by default */
hard_iface - > bat_v . flags | = BATADV_FULL_DUPLEX ;
/* warn the user (again) if there is no throughput data is available */
hard_iface - > bat_v . flags & = ~ BATADV_WARNING_DEFAULT ;
if ( batadv_is_wifi_netdev ( hard_iface - > net_dev ) )
hard_iface - > bat_v . flags & = ~ BATADV_FULL_DUPLEX ;
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INIT_DELAYED_WORK ( & hard_iface - > bat_v . elp_wq ,
batadv_v_elp_periodic_work ) ;
batadv_v_elp_start_timer ( hard_iface ) ;
res = 0 ;
out :
return res ;
}
/**
* batadv_v_elp_iface_disable - release ELP interface private resources
* @ hard_iface : interface for which the resources have to be released
*/
void batadv_v_elp_iface_disable ( struct batadv_hard_iface * hard_iface )
{
cancel_delayed_work_sync ( & hard_iface - > bat_v . elp_wq ) ;
dev_kfree_skb ( hard_iface - > bat_v . elp_skb ) ;
hard_iface - > bat_v . elp_skb = NULL ;
}
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/**
* batadv_v_elp_iface_activate - update the ELP buffer belonging to the given
* hard - interface
* @ primary_iface : the new primary interface
* @ hard_iface : interface holding the to - be - updated buffer
*/
void batadv_v_elp_iface_activate ( struct batadv_hard_iface * primary_iface ,
struct batadv_hard_iface * hard_iface )
{
struct batadv_elp_packet * elp_packet ;
struct sk_buff * skb ;
if ( ! hard_iface - > bat_v . elp_skb )
return ;
skb = hard_iface - > bat_v . elp_skb ;
elp_packet = ( struct batadv_elp_packet * ) skb - > data ;
ether_addr_copy ( elp_packet - > orig ,
primary_iface - > net_dev - > dev_addr ) ;
}
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/**
* batadv_v_elp_primary_iface_set - change internal data to reflect the new
* primary interface
* @ primary_iface : the new primary interface
*/
void batadv_v_elp_primary_iface_set ( struct batadv_hard_iface * primary_iface )
{
struct batadv_hard_iface * hard_iface ;
/* update orig field of every elp iface belonging to this mesh */
rcu_read_lock ( ) ;
list_for_each_entry_rcu ( hard_iface , & batadv_hardif_list , list ) {
if ( primary_iface - > soft_iface ! = hard_iface - > soft_iface )
continue ;
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batadv_v_elp_iface_activate ( primary_iface , hard_iface ) ;
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}
rcu_read_unlock ( ) ;
}
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/**
* batadv_v_elp_neigh_update - update an ELP neighbour node
* @ bat_priv : the bat priv with all the soft interface information
* @ neigh_addr : the neighbour interface address
* @ if_incoming : the interface the packet was received through
* @ elp_packet : the received ELP packet
*
* Updates the ELP neighbour node state with the data received within the new
* ELP packet .
*/
static void batadv_v_elp_neigh_update ( struct batadv_priv * bat_priv ,
u8 * neigh_addr ,
struct batadv_hard_iface * if_incoming ,
struct batadv_elp_packet * elp_packet )
{
struct batadv_neigh_node * neigh ;
struct batadv_orig_node * orig_neigh ;
struct batadv_hardif_neigh_node * hardif_neigh ;
s32 seqno_diff ;
s32 elp_latest_seqno ;
orig_neigh = batadv_v_ogm_orig_get ( bat_priv , elp_packet - > orig ) ;
if ( ! orig_neigh )
return ;
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neigh = batadv_neigh_node_get_or_create ( orig_neigh ,
if_incoming , neigh_addr ) ;
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if ( ! neigh )
goto orig_free ;
hardif_neigh = batadv_hardif_neigh_get ( if_incoming , neigh_addr ) ;
if ( ! hardif_neigh )
goto neigh_free ;
elp_latest_seqno = hardif_neigh - > bat_v . elp_latest_seqno ;
seqno_diff = ntohl ( elp_packet - > seqno ) - elp_latest_seqno ;
/* known or older sequence numbers are ignored. However always adopt
* if the router seems to have been restarted .
*/
if ( seqno_diff < 1 & & seqno_diff > - BATADV_ELP_MAX_AGE )
goto hardif_free ;
neigh - > last_seen = jiffies ;
hardif_neigh - > last_seen = jiffies ;
hardif_neigh - > bat_v . elp_latest_seqno = ntohl ( elp_packet - > seqno ) ;
hardif_neigh - > bat_v . elp_interval = ntohl ( elp_packet - > elp_interval ) ;
hardif_free :
if ( hardif_neigh )
batadv_hardif_neigh_put ( hardif_neigh ) ;
neigh_free :
if ( neigh )
batadv_neigh_node_put ( neigh ) ;
orig_free :
if ( orig_neigh )
batadv_orig_node_put ( orig_neigh ) ;
}
/**
* batadv_v_elp_packet_recv - main ELP packet handler
* @ skb : the received packet
* @ if_incoming : the interface this packet was received through
*
* Return : NET_RX_SUCCESS and consumes the skb if the packet was peoperly
* processed or NET_RX_DROP in case of failure .
*/
int batadv_v_elp_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_elp_packet * elp_packet ;
struct batadv_hard_iface * primary_if ;
struct ethhdr * ethhdr = ( struct ethhdr * ) skb_mac_header ( skb ) ;
bool ret ;
ret = batadv_check_management_packet ( skb , if_incoming , BATADV_ELP_HLEN ) ;
if ( ! ret )
return NET_RX_DROP ;
if ( batadv_is_my_mac ( bat_priv , ethhdr - > h_source ) )
return NET_RX_DROP ;
/* did we receive a B.A.T.M.A.N. V ELP packet on an interface
* that does not have B . A . T . M . A . N . V ELP enabled ?
*/
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if ( strcmp ( bat_priv - > algo_ops - > name , " BATMAN_V " ) ! = 0 )
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return NET_RX_DROP ;
elp_packet = ( struct batadv_elp_packet * ) skb - > data ;
batadv_dbg ( BATADV_DBG_BATMAN , bat_priv ,
" Received ELP packet from %pM seqno %u ORIG: %pM \n " ,
ethhdr - > h_source , ntohl ( elp_packet - > seqno ) ,
elp_packet - > orig ) ;
primary_if = batadv_primary_if_get_selected ( bat_priv ) ;
if ( ! primary_if )
goto out ;
batadv_v_elp_neigh_update ( bat_priv , ethhdr - > h_source , if_incoming ,
elp_packet ) ;
out :
if ( primary_if )
batadv_hardif_put ( primary_if ) ;
consume_skb ( skb ) ;
return NET_RX_SUCCESS ;
}