diff options
authorAlin Năstac <>2015-10-22 16:41:03 +0200
committerFlorian Westphal <>2015-10-28 01:52:14 +0100
commit4c3e5cd3dbae3ea773e9dcca7cf019b2713af70d (patch)
parentf8079671326e9fd079391d24911a9a8a77f1d6fd (diff)
ebtables: Allow RETURN target rules in user defined chains
During loop checking ebtables marks entries with '1 << NF_BR_NUMHOOKS' if they're called from a base chain rather than a user defined chain. This can be used by ebtables targets that can encode a special return value to bail out if e.g. RETURN is used from a base chain. Unfortunately, this is broken, since the '1 << NF_BR_NUMHOOKS' is also copied to called user-defined-chains (i.e., a user defined chain can no longer be distinguished from a base chain): root@OpenWrt:~# ebtables -N foo root@OpenWrt:~# ebtables -A OUTPUT -j foo root@OpenWrt:~# ebtables -A foo -j mark --mark-or 3 --mark-target RETURN --mark-target RETURN not allowed on base chain. This works if -A OUTPUT -j foo is omitted, but will still appear if we try to call foo from OUTPUT afterwards. After this patch we still reject '-A OUTPUT -j mark .. --mark-target RETURN'. Signed-off-by: Florian Westphal <>
1 files changed, 1 insertions, 1 deletions
diff --git a/libebtc.c b/libebtc.c
index 17ba8f2..74830ec 100644
--- a/libebtc.c
+++ b/libebtc.c
@@ -1102,7 +1102,7 @@ void ebt_check_for_loops(struct ebt_u_replace *replace)
/* check if we've dealt with this chain already */
if (entries2->hook_mask & (1<<i))
goto letscontinue;
- entries2->hook_mask |= entries->hook_mask;
+ entries2->hook_mask |= entries->hook_mask & ~(1 << NF_BR_NUMHOOKS);
/* Jump to the chain, make sure we know how to get back */
stack[sp].chain_nr = chain_nr;
stack[sp].n = j;