Re: [PATCH net 07/10] batman-adv: tt: only transmit local ROAM flag together with DEL

[Sven Eckelmann <sven@narfation.org>]

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On Tuesday, 27 October 2026 09:55:22 CET netdev-bot+sashiko@kernel.org wrote:
> batman-adv: tt: only transmit local ROAM flag together with DEL
> 
> This patch stops local TT entries from sending BATADV_TT_CLIENT_ROAM
> unless it comes with BATADV_TT_CLIENT_DEL. The ROAM bit is now cleared
> for non-DEL events in __batadv_tt_local_event() and for full table
> responses in batadv_tt_local_valid(). The goal is to stop receivers from
> treating a plain ADD as a roaming advertisement.
[...]
> 
> [Severity: Medium]
> 
> Does this fix the requester-side symptom described in the commit
> message?
>
> The commit message says:
> 
>   When the requester is the node which sent the ROAMING_ADV, it then
>   marks its own (new) local client as roamed back to the old originator
>   and drops it when it is still NEW.


No, this is not the symptom. It is just the way the roaming works.

The relevant part is "But such a behavior doesn't make sense for non-ROAM_ADV 
because a new TTVN [...] should therefore be used to create a temporary (roam) 
global entry in a node." It is there to announce the "committed" local entries 
which everyone should use in their global table for this originator. And ADD 
is therefore required - but not the roaming flag because it would be 
interpreted as roaming announcement. See also 
https://www.open-mesh.org/projects/batman-adv/wiki/Client-roaming#Translation-table-consistency

There are also pending changes for TT which avoid this odd removal of the 
ROAMING and flash it out more in the receiver side [1,2,3].

Regards,
	Sven

[1] https://patchwork.open-mesh.org/project/b.a.t.m.a.n./patch/20261008-tt-avoid-unhashed-event-v2-2-7c4eed81606d@narfation.org/
[2] https://patchwork.open-mesh.org/project/b.a.t.m.a.n./patch/20261008-tt-avoid-unhashed-event-v2-3-7c4eed81606d@narfation.org/
[3] https://patchwork.open-mesh.org/project/b.a.t.m.a.n./patch/20261008-tt-avoid-unhashed-event-v2-4-7c4eed81606d@narfation.org/

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