batman-adv: Add inconsistent gateway netlink dump detection

The netlink dump functionality transfers a large number of entries from the
kernel to userspace. It is rather likely that the transfer has to
interrupted and later continued. During that time, it can happen that
either new entries are added or removed. The userspace could than either
receive some entries multiple times or miss entries.

Commit 670dc2833d ("netlink: advertise incomplete dumps") introduced a
mechanism to inform userspace about this problem. Userspace can then decide
whether it is necessary or not to retry dumping the information again.

The netlink dump functions have to be switched to exclusive locks to avoid
changes while the current message is prepared. And an external generation
sequence counter is introduced which tracks all modifications of the list.

Reported-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Sven Eckelmann
2018-10-30 22:01:23 +01:00
committed by Simon Wunderlich
parent 694127c1dd
commit 9264c85c8b
5 changed files with 41 additions and 19 deletions

View File

@@ -186,6 +186,8 @@ int batadv_mesh_init(struct net_device *soft_iface)
INIT_HLIST_HEAD(&bat_priv->softif_vlan_list);
INIT_HLIST_HEAD(&bat_priv->tp_list);
bat_priv->gw.generation = 0;
ret = batadv_v_mesh_init(bat_priv);
if (ret < 0)
goto err;