batman-adv: detect not yet announced clients

With the current TT mechanism a new client joining the network is not
immediately able to communicate with other hosts because its MAC address has not
been announced yet. This situation holds until the first OGM containing its
joining event will be spread over the mesh network.

This behaviour can be acceptable in networks where the originator interval is a
small value (e.g. 1sec) but if that value is set to an higher time (e.g. 5secs)
the client could suffer from several malfunctions like DHCP client timeouts,
etc.

This patch adds an early detection mechanism that makes nodes in the network
able to recognise "not yet announced clients" by means of the broadcast packets
they emitted on connection (e.g. ARP or DHCP request). The added client will
then be confirmed upon receiving the OGM claiming it or purged if such OGM
is not received within a fixed amount of time.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h
index ffa87355096b..811fffd4760c 100644
--- a/net/batman-adv/translation-table.h
+++ b/net/batman-adv/translation-table.h
@@ -59,6 +59,8 @@ int batadv_tt_append_diff(struct batadv_priv *bat_priv,
 			  int packet_min_len);
 bool batadv_tt_global_client_is_roaming(struct batadv_priv *bat_priv,
 					uint8_t *addr);
-
+bool batadv_tt_add_temporary_global_entry(struct batadv_priv *bat_priv,
+					  struct batadv_orig_node *orig_node,
+					  const unsigned char *addr);
 
 #endif /* _NET_BATMAN_ADV_TRANSLATION_TABLE_H_ */