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From: "Linus Lüssing" <linus.luessing@c0d3.blue>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: [PATCH maint v4 0/3] batman-adv: mcast: BLA fixes
Date: Mon, 14 Sep 2020 21:48:34 +0200	[thread overview]
Message-ID: <20200914194837.10425-1-linus.luessing@c0d3.blue> (raw)

These are three fixes for issues which occur when using the batman-adv
multicast-to-unicast feature.

They fix issues when using the multicast-to-unicast conversion
while BLA is enabled and some nodes are sharing the same LAN side. Here
it either causes "just" duplicates in the "good" scenario (Patch 3/3).
But can also cause multiple BLA backbones to send a frame from the mesh
into the same, shared LAN segment (Patch 2/3). Or in the worst case, even
reflect packets back to the host in the shared LAN, which completely
confuses switches/bridges and ICMPv6 Neighbor Discovery (Patch 1/3).

Regards, Linus


Changelog v4:
* Patch 1/3:
  - fixed build with CONFIG_BATMAN_ADV_MCAST=n
    -> dummy for batadv_mcast_forw_send_orig()
* Patch 2/3:
  - fixed parameters for batadv_bla_rx() with CONFIG_BATMAN_ADV_BLA=n
    (bool is_bcast -> int packet_type)

Changelog v3:
* removed 1/4, as it was already applied
* renamed title (excluded TT, as already applied)

* Patch 1/3:
  - moved bla-backbone check into multicast code:
    -> to stay on the safe side for net, to touch less other code
       paths - the issue was observed specifically for multicast
       and the fix was tested for that
  - added a note regarding implications for mcast-fanout
* Patch 2/3:
  - previous approach was broken, it would break the DHCPv6 gateway
    code; instead distinguish by batadv 3 vs. 4 addr unicast header
  - added some more code comments
  - updated commit message with new approach
* Patch 3/3:
  - made code a bit more verbose and explicit
  - added some more code comments
  - added missing kernel doc for "orig" parameter to
    new batadv_bla_check_duplist()

Changelog v2:
* Adding "Fixes:" lines

             reply	other threads:[~2020-09-14 19:48 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-14 19:48 Linus Lüssing [this message]
2020-09-14 19:48 ` [PATCH maint v4 1/3] batman-adv: mcast: fix duplicate mcast packets in BLA backbone from LAN Linus Lüssing
2020-09-14 19:48 ` [PATCH maint v4 2/3] batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh Linus Lüssing
2020-09-14 19:48 ` [PATCH maint v4 3/3] batman-adv: mcast: fix duplicate mcast packets from BLA backbone to mesh Linus Lüssing

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