Repository : ssh://git@diktynna/batman-adv On branches: main,stable,main,stable

commit 4d49d6e9d60c41a6da727108518cb8fb33295537 Author: Remi Pommarel repk@triplefau.lt Date: Fri Nov 22 16:52:50 2024 +0100

batman-adv: Do not let TT changes list grows indefinitely

When TT changes list is too big to fit in packet due to MTU size, an empty OGM is sent expected other node to send TT request to get the changes. The issue is that tt.last_changeset was not built thus the originator was responding with previous changes to those TT requests (see batadv_send_my_tt_response). Also the changes list was never cleaned up effectively never ending growing from this point onwards, repeatedly sending the same TT response changes over and over, and creating a new empty OGM every OGM interval expecting for the local changes to be purged.

When there is more TT changes that can fit in packet, drop all changes, send empty OGM and wait for TT request so we can respond with a full table instead.

Fixes: 8405301b9794 ("batman-adv: tvlv - convert tt data sent within OGMs") Signed-off-by: Remi Pommarel repk@triplefau.lt Acked-by: Antonio Quartulli Antonio@mandelbit.com Signed-off-by: Sven Eckelmann sven@narfation.org

4d49d6e9d60c41a6da727108518cb8fb33295537 net/batman-adv/translation-table.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index bbab7491..53dea8ae 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -990,6 +990,7 @@ static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv) int tt_diff_len, tt_change_len = 0; int tt_diff_entries_num = 0; int tt_diff_entries_count = 0; + bool drop_changes = false; size_t tt_extra_len = 0; u16 tvlv_len;

@@ -997,10 +998,17 @@ static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv) tt_diff_len = batadv_tt_len(tt_diff_entries_num);

/* if we have too many changes for one packet don't send any - * and wait for the tt table request which will be fragmented + * and wait for the tt table request so we can reply with the full + * (fragmented) table. + * + * The local change history should still be cleaned up so the next + * TT round can start again with a clean state. */ - if (tt_diff_len > bat_priv->soft_iface->mtu) + if (tt_diff_len > bat_priv->soft_iface->mtu) { tt_diff_len = 0; + tt_diff_entries_num = 0; + drop_changes = true; + }

tvlv_len = batadv_tt_prepare_tvlv_local_data(bat_priv, &tt_data, &tt_change, &tt_diff_len); @@ -1009,7 +1017,7 @@ static void batadv_tt_tvlv_container_update(struct batadv_priv *bat_priv)

tt_data->flags = BATADV_TT_OGM_DIFF;

- if (tt_diff_len == 0) + if (!drop_changes && tt_diff_len == 0) goto container_register;

spin_lock_bh(&bat_priv->tt.changes_list_lock);