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| author | Ruben Wisniewski <ruben@freifunk-nrw.de> | 2015-06-16 21:06:23 +0200 |
|---|---|---|
| committer | Antonio Quartulli <antonio@meshcoding.com> | 2015-08-11 18:10:04 +0200 |
| commit | 571a963768e7711e0bb5a30f71247b46ec9ca7b9 (patch) | |
| tree | 0dc9d00a5c8c27847ff5e92ad0a51ec5bbb2eb2f /net/batman-adv | |
| parent | batman-adv: Replace gw_reselect divisor with simple shift (diff) | |
| download | linux-571a963768e7711e0bb5a30f71247b46ec9ca7b9.tar.xz linux-571a963768e7711e0bb5a30f71247b46ec9ca7b9.zip | |
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]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/gateway_client.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index e1e1f317b915..4ac24d8d151b 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -153,7 +153,7 @@ 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; uint8_t max_tq = 0; uint8_t tq_avg; struct batadv_orig_node *orig_node; |