linux/net/batman-adv
Andreas Pape a3a5129e12 batman-adv: handle race condition for claims between gateways
Consider the following situation which has been found in a test setup:
Gateway B has claimed client C and gateway A has the same backbone
network as B. C sends a broad- or multicast to B and directly after
this packet decides to send another packet to A due to a better TQ
value. B will forward the broad-/multicast into the backbone as it is
the responsible gw and after that A will claim C as it has been
chosen by C as the best gateway. If it now happens that A claims C
before it has received the broad-/multicast forwarded by B (due to
backbone topology or due to some delay in B when forwarding the
packet) we get a critical situation: in the current code A will
immediately unclaim C when receiving the multicast due to the
roaming client scenario although the position of C has not changed
in the mesh. If this happens the multi-/broadcast forwarded by B
will be sent back into the mesh by A and we have looping packets
until one of the gateways claims C again.
In order to prevent this, unclaiming of a client due to the roaming
client scenario is only done after a certain time is expired after
the last claim of the client. 100 ms are used here, which should be
slow enough for big backbones and slow gateways but fast enough not
to break the roaming client use case.

Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
[sven@narfation.org: fix conflicts with current version]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2017-03-22 10:30:53 +01:00
..
bat_algo.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_algo.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_iv_ogm.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_iv_ogm.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v_elp.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v_elp.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v_ogm.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v_ogm.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bat_v.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bitarray.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bitarray.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
bridge_loop_avoidance.c batman-adv: handle race condition for claims between gateways 2017-03-22 10:30:53 +01:00
bridge_loop_avoidance.h batman-adv: prevent multiple ARP replies sent by gateways if dat enabled 2017-03-22 10:30:53 +01:00
debugfs.c batman-adv: Fix includes for IS_ERR/ERR_PTR 2017-01-28 10:40:35 +01:00
debugfs.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
distributed-arp-table.c batman-adv: prevent duplication of ARP replies when DAT is used 2017-03-22 10:30:53 +01:00
distributed-arp-table.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
fragmentation.c Here are two batman-adv bugfixes: 2017-03-02 13:16:08 -08:00
fragmentation.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
gateway_client.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
gateway_client.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
gateway_common.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
gateway_common.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
hard-interface.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
hard-interface.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
hash.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
hash.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
icmp_socket.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
icmp_socket.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
Kconfig batman-adv: Allow selecting BATMAN V if CFG80211 is not built 2016-10-17 16:28:48 +02:00
log.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
log.h batman-adv: Fix possible side-effects in _batadv_dbg 2017-03-16 21:14:52 +01:00
main.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
main.h batman-adv: Convert BATADV_PRINT_VID macro to function 2017-03-16 21:14:53 +01:00
Makefile batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
multicast.c batman-adv: Reduce preprocessor checks in multicast.c 2017-03-16 21:14:50 +01:00
multicast.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
netlink.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
netlink.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
network-coding.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
network-coding.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
originator.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
originator.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
packet.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
routing.c batman-adv: changed debug messages for easier bla debugging 2017-03-22 10:30:53 +01:00
routing.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
send.c batman-adv: Fix double call of dev_queue_xmit 2017-01-28 10:40:35 +01:00
send.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
soft-interface.c batman-adv: Omit unnecessary memset of netdev private data 2017-03-17 12:53:35 +01:00
soft-interface.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
sysfs.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
sysfs.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
tp_meter.c batman-adv: Use __func__ to add function names to messages 2017-03-17 12:53:35 +01:00
tp_meter.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
translation-table.c batman-adv: Convert BATADV_PRINT_VID macro to function 2017-03-16 21:14:53 +01:00
translation-table.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
tvlv.c batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
tvlv.h batman-adv: update copyright years for 2017 2017-01-26 08:34:19 +01:00
types.h average: change to declare precision, not factor 2017-03-02 08:32:46 +01:00