On 01/22/2013 08:13 AM, Tom Eastep wrote:
> On 01/22/2013 05:04 AM, Mr Dash Four wrote:
>> There is another (quite annoying) issue I've discovered with 4.5.12 
>> (maybe valid with 4.5.13 betas, don't know), which I think requires a 
>> little attention:
>>
>> shorewall.conf
>> ~~~~~~~~~~~~~~
>> RELATED_DISPOSITION=ACCEPT
>>
>> blrules
>> ~~~~~~~
>> WHITELIST fw net:+whitelist
>> <EOF>
>>
>> rules
>> ~~~~~
>> SECTION RELATED
>> IFLOG(accept,log,nflog1,2,mamas,DROP) $FW net
>> SECTION NEW
>> dropInvalid all all
>> [...]
>>
>> generates these rules:
>>
>> -A fw2net -m conntrack --ctstate NEW,INVALID -m set --match-set 
>> whitelist dst -j RETURN
>> -A fw2net -m conntrack --ctstate ESTABLISHED -j ACCEPT
>> -A fw2net -m conntrack --ctstate RELATED -j +fw2net
>> -A fw2net -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
>> -A fw2net -m conntrack --ctstate INVALID -j DROP
>>
>> 1st rule above: even though it is the only one which exists in "blrules" 
>> for this chain (fw2net), it should not have been optimised in this way 
>> (RETURN from fw2net will prevent further traversing!).
> 
> Yes -- that's a bug. Patch attached.
> 
>>
>> Also, why is --cstate INVALID included in that match (I do have 
>> BLACKLISTNEWONLY=Yes, but that doesn't explain the INVALID match being 
>> there)?
> 
> The rationale there is that sending packets in an invalid state should
> not allow someone to bypass the blacklist rules. So I would prefer to
> change the description of the BLACKLISTNEWONLY option rather than the code.
> 
>> The correct rule should have been a single "--cstate INVALID -j 
>> DROP", if anything (as shown in the last rule listed there).
>>
>> 2nd-to-last rule: where did that come from? I have similar rules 
>> generated for all of my other chains (net2fw, local2fw, fw2local ...).
> 
> Yes -- with RELATED_DISPOSITION=ACCEPT, simply accepting packets in
> ESTABLISHED state would be enough. That is a left-over from before I
> implemented RELATED_DISPOSITION.  I'll clean that up in this release.

I just took another look at this and I'm not clear where that is coming
from in your case. From my own ruleset:

-A net-fw -m conntrack --ctstate NEW,INVALID -j net-fw~
-A net-fw -i eth0 -j eth0_iop
-A net-fw -i eth1 -j eth1_iop
-A net-fw -m conntrack --ctstate ESTABLISHED -j ACCEPT
-A net-fw -m conntrack --ctstate RELATED -j +net-fw
-A net-fw -p tcp --syn -j @net-all
-A net-fw -p udp --dport 1194 -j ACCEPT
...

-Tom
-- 
Tom Eastep        \ When I die, I want to go like my Grandfather who
Shoreline,         \ died peacefully in his sleep. Not screaming like
Washington, USA     \ all of the passengers in his car
http://shorewall.net \________________________________________________

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