[B.A.T.M.A.N.] [PATCH] batman-adv: prevent adding of loop detection mac addresses to global tt

[B.A.T.M.A.N.] [PATCH] batman-adv: prevent adding of loop detection mac addresses to global tt

[Andreas Pape]

This patch prevents that entries in the global translation table are generated
for mac addresses used by loop detection frames.

Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
---
 net/batman-adv/translation-table.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index e75b493..ca1e0f7 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1618,8 +1618,10 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 	struct batadv_tt_common_entry *common;
 	u16 local_flags;

-	/* ignore global entries from backbone nodes */
-	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid))
+	/* ignore global entries from backbone nodes or
+	 * adding of entries related to loop detect frames */
+	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid) ||
+		batadv_bla_is_loopdetect_mac(tt_addr))
 		return true;

 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, tt_addr, vid);
--
1.7.0.4



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PHOENIX CONTACT ELECTRONICS GmbH

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Re: [B.A.T.M.A.N.] [PATCH] batman-adv: prevent adding of loop detection mac addresses to global tt

[Simon Wunderlich]

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On Thursday, June 1, 2017 10:58:04 AM CEST Andreas Pape wrote:
> This patch prevents that entries in the global translation table are
> generated for mac addresses used by loop detection frames.
> 
> Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
> ---
>  net/batman-adv/translation-table.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/net/batman-adv/translation-table.c
> b/net/batman-adv/translation-table.c index e75b493..ca1e0f7 100644
> --- a/net/batman-adv/translation-table.c
> +++ b/net/batman-adv/translation-table.c
> @@ -1618,8 +1618,10 @@ static bool batadv_tt_global_add(struct batadv_priv
> *bat_priv, struct batadv_tt_common_entry *common;
>  	u16 local_flags;
> 
> -	/* ignore global entries from backbone nodes */
> -	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid))
> +	/* ignore global entries from backbone nodes or
> +	 * adding of entries related to loop detect frames */
> +	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid) ||
> +		batadv_bla_is_loopdetect_mac(tt_addr))
>  		return true;
> 
>  	tt_global_entry = batadv_tt_global_hash_find(bat_priv, tt_addr, vid);

Thank you for your patch.

I was thinking, if we implement it like this we may still have problems if an 
older batman-adv version is adding the ba:be mac addresses locally. This could 
create a problem, because the transmitted tt table is not added completely, 
thus the CRC will not match and will lead to a "TT request/response loop".

What do you think? Maybe we should only add it for the speedy join case, but 
accept it if a node really added these mac addresses locally?

Thanks,
      Simon

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[B.A.T.M.A.N.] Antwort: Re: [PATCH] batman-adv: prevent adding of loop detection mac addresses to global tt

[Andreas Pape]

Hi Simon,

>
> I was thinking, if we implement it like this we may still have problems
if an
> older batman-adv version is adding the ba:be mac addresses locally.
> This could
> create a problem, because the transmitted tt table is not added
completely,
> thus the CRC will not match and will lead to a "TT request/response
loop".
>
> What do you think? Maybe we should only add it for the speedy join case,
but
> accept it if a node really added these mac addresses locally?

I'm afraid I haven't understood the speedy join mechanism / use case good
enough
to make a good proposal here, but I'm volunteering for testing if someone
else
has a better solution then my rough approach ;-)

Kind regards,
Andreas



..................................................................
PHOENIX CONTACT ELECTRONICS GmbH

Sitz der Gesellschaft / registered office of the company: 31812 Bad Pyrmont
USt-Id-Nr.: DE811742156
Amtsgericht Hannover HRB 100528 / district court Hannover HRB 100528
Geschäftsführer / Executive Board: Ulrich Leidecker, Christoph Leifer
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Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren, jegliche anderweitige Verwendung sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet.
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