openwrt-routing/batman-adv/patches/0045-batman-adv-Fix-multica...

44 lines
1.9 KiB
Diff

From: Linus Lüssing <linus.luessing@c0d3.blue>
Date: Thu, 7 Jun 2018 00:46:24 +0200
Subject: batman-adv: Fix multicast TT issues with bogus ROAM flags
When a (broken) node wrongly sends multicast TT entries with a ROAM
flag then this causes any receiving node to drop all entries for the
same multicast MAC address announced by other nodes, leading to
packet loss.
Fix this DoS vector by only storing TT sync flags. For multicast TT
non-sync'ing flag bits like ROAM are unused so far anyway.
Fixes: 405cc1e5a81e ("batman-adv: Modified forwarding behaviour for multicast packets")
Reported-by: Leonardo Mörlein <me@irrelefant.net>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/c7054ffae0c3b08bb4bef3cffee1e0a543e14096
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index a8b4d9bcb318656022a30f742ede4f38a646d0d1..143a00f90d1d925aad7113f897d06f435f28dcd8 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1695,7 +1695,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
ether_addr_copy(common->addr, tt_addr);
common->vid = vid;
- common->flags = flags & (~BATADV_TT_SYNC_MASK);
+ if (!is_multicast_ether_addr(common->addr))
+ common->flags = flags & (~BATADV_TT_SYNC_MASK);
tt_global_entry->roam_at = 0;
/* node must store current time in case of roaming. This is
@@ -1759,7 +1760,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
* TT_CLIENT_TEMP, therefore they have to be copied in the
* client entry
*/
- common->flags |= flags & (~BATADV_TT_SYNC_MASK);
+ if (!is_multicast_ether_addr(common->addr))
+ common->flags |= flags & (~BATADV_TT_SYNC_MASK);
/* If there is the BATADV_TT_CLIENT_ROAM flag set, there is only
* one originator left in the list and we previously received a