Re: MARK and ! question

[Ruslan Spivak <alienoid@is.lg.ua>]

Chris Wilson wrote:

>Hi Ruslan, Hi Sven,
>
>  
>
>>>What about using a user-defined chain like this:
>>>
>>>iptables -t mangle -N setmark
>>>iptables -t mangle -A setmark -s ! 193.220.70.0/27 -d 193.220.70.32/27 \
>>>        -j RETURN
>>>iptables -t mangle -A setmark -s ! 193.108.240.0/22 -d 193.220.70.32/27 \
>>>        -j RETURN
>>>iptables -t mangle -A setmark -j MARK --set-mark 107
>>>iptables -t mangle -A POSTROUTING -j setmark
>>>      
>>>
>
>  
>
>>Thanks for your reply.
>>And can you describe how packet traverses such chain?
>>    
>>
>
>I think the ruleset above is wrong: the '!' should not be present here. 
>Allow me to explain the packet traversal when the same rules are used, but 
>with "!" removed:
>
>iptables -t mangle -N setmark
>iptables -t mangle -A setmark -s 193.220.70.0/27 -d 193.220.70.32/27 \
>        -j RETURN
>iptables -t mangle -A setmark -s 193.108.240.0/22 -d 193.220.70.32/27 \
>        -j RETURN
>iptables -t mangle -A setmark -j MARK --set-mark 107
>iptables -t mangle -A POSTROUTING -j setmark
>
>1. Packet enters POSTROUTING
>2. Packet jumps to "setmark" chain
>3. Packets having source address matching "193.220.70.0/27" are RETURNed 
>   to POSTROUTING
>4. Packets having source address matching "193.108.240.0/22" are RETURNed 
>   to POSTROUTING
>5. (now ONLY packets which do NOT have either of these source addresses 
>   are still in the "setmark" chain)
>6. All packets (still in the "setmark" chain) are marked with 107
>7. Packets fall off the end of the "setmark" chain and return to 
>   POSTROUTING (but they are now marked)
>8. Packets fall of the end of POSTROUTING and continue through the kernel 
>   (presumably to be delivered to a network device)
>
>Cheers, Chris.
>  
>
Sorry for disturbance, but one more question: it looks like all other 
packets not from

193.220.70.0/27 and not from 193.108.240.0/22 will be marked, but i need mark packets that have destination 193.220.70.32/27 and not from above mentioned networks. What else should i add or modify?

Thanks in advance.