Repository : ssh://git@open-mesh.org/batman-adv

On branch : maint

commit f63c54bba31d2c86269982fd8efdfb618f1daabe Author: Ruben Wisniewski ruben@freifunk-nrw.de Date: Tue May 26 18:34:27 2015 +0200

batman-adv: Avoid u32 overflow during gateway select

The gateway selection based on fast connections is using a single value calculated from the average tq (0-255) and the download bandwidth (in 100Kibit). The formula for the first step (tq ** 2 * 10000 * bandwidth) tends to overflow a u32 with low bandwidth settings like 50 [100KiBit] and a tq value of over 92.

Changing this to a 64 bit unsigned integer allows to support a bandwidth_down with up to ~2.8e10 [100KiBit] and a perfect tq of 255. This is ~6.6 times higher than the maximum possible value of the gateway announcement TVLV.

This problem only affects the non-default gw_sel_class 1.

Signed-off-by: Ruben Wisniewsi ruben@vfn-nrw.de [sven@narfation.org: rewritten commit message, changed to kernel type] Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Marek Lindner mareklindner@neomailbox.ch

f63c54bba31d2c86269982fd8efdfb618f1daabe gateway_client.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gateway_client.c b/gateway_client.c index a85eaca..3f32357 100644 --- a/gateway_client.c +++ b/gateway_client.c @@ -133,7 +133,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv) struct batadv_neigh_node *router; struct batadv_neigh_ifinfo *router_ifinfo; struct batadv_gw_node *gw_node, *curr_gw = NULL; - uint32_t max_gw_factor = 0, tmp_gw_factor = 0; + uint64_t max_gw_factor = 0, tmp_gw_factor = 0; uint32_t gw_divisor; uint8_t max_tq = 0; uint8_t tq_avg;