From: Simon Wunderlich <sw@simonwunderlich.de>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: Re: [B.A.T.M.A.N.] [PATCH maint v2] batman-adv: fix TT sync flag inconsistencies
Date: Mon, 31 Jul 2017 10:51:00 +0200 [thread overview]
Message-ID: <3509749.LU2Kc3mdbT@prime> (raw)
In-Reply-To: <20170706050225.24455-1-linus.luessing@c0d3.blue>
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On Thursday, July 6, 2017 7:02:25 AM CEST Linus Lüssing wrote:
> This patch fixes an issue in the translation table code potentially
> leading to a TT Request + Response storm. The issue may occur for nodes
> involving BLA and an inconsistent configuration of the batman-adv AP
> isolation feature. However, since the new multicast optimizations, a
> single, malformed packet may lead to a mesh-wide, persistent
> Denial-of-Service, too.
>
> The issue occurs because nodes are currently OR-ing the TT sync flags of
> all originators announcing a specific MAC address via the
> translation table. When an intermediate node now receives a TT Request
> and wants to answer this on behave of the destination node then this
> intermediate node now responds with an altered flag field and broken
> CRC. The next OGM of the real destination will lead to a CRC mismatch
> and triggering a TT Request and Response again.
>
> Furthermore, the OR-ing is currently never undone as long as at least
> one originator announcing the according MAC address remains, leading to
> the potential persistency of this issue.
>
> This patch fixes this issue by storing the flags used in the CRC
> calculation on a a per TT orig entry basis to be able to respond with
> the correct, original flags in an intermediate TT Response for one
> thing. And to be able to correctly unset sync flags once all nodes
> announcing a sync flag vanish for another.
>
> Fixes: fa614fd04692 ("batman-adv: fix tt_global_entries flags update")
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Applied in 2035bb89 with minor changes in the commit message
Thank you,
Simon
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prev parent reply other threads:[~2017-07-31 8:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-06 5:02 [B.A.T.M.A.N.] [PATCH maint v2] batman-adv: fix TT sync flag inconsistencies Linus Lüssing
2017-07-24 5:48 ` Antonio Quartulli
2017-07-29 8:25 ` Sven Eckelmann
2017-07-29 8:51 ` Linus Lüssing
2017-07-31 8:51 ` Simon Wunderlich [this message]
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