Re: [RFC] setting up throughput threshold indications to userspace

[Patrick McHardy <kaber@trash.net>]

Am 16.07.2010 10:20, schrieb Luciano Coelho:
> Hi all,
> 
> I've been trying to set up some rules that will send indications to the
> userspace about the current throughput of a certain interface.  The idea
> is to let the userspace enable or disable WLAN PS mode accordingly (the
> validity of this idea is another subject ;).
> 
> This is related to the discussion we had in the thread about the NFNOTIF
> thread.
> 
> I'm thinking about having this kind of ruleset:
> 
> -A INPUT -j throughput 
> -A above -m connmark --mark 0x1 -j RETURN 
> -A above -m rateest --rateest throughput --rateest-bps1 0bit --rateest-bps2 1000bit --rateest-gt -j LOG --log-prefix "ABOVE" 
> -A above -m rateest --rateest throughput --rateest-bps1 0bit --rateest-bps2 1000bit --rateest-gt -j CONNMARK --set-xmark 0x1/0xffffffff 
> -A below -m connmark --mark 0x2 -j RETURN 
> -A below -m rateest --rateest throughput --rateest-bps1 0bit --rateest-bps2 1000bit --rateest-lt -j LOG --log-prefix "BELOW" 
> -A below -m rateest --rateest throughput --rateest-bps1 0bit --rateest-bps2 1000bit --rateest-lt -j CONNMARK --set-xmark 0x2/0xffffffff 
> -A throughput -j RATEEST --rateest-name throughput --rateest-interval 250.0ms --rateest-ewmalog 500.0ms 
> -A throughput -j above 
> -A throughput -j below 
> 
> I'm using a normal LOG just for simplicity reasons, in real life I'd use
> NFLOG instead.
> 
> The idea here is that all packets would be collected by RATEEST for rate
> estimation and then I'd check whether the throughput is above the
> threshold.  If it is, I mark it as such and print the log.  Same thing
> for below the threshold.  The RETURN rules are there to prevent more LOG
> messages from being printed (what I need is to know only when the
> throughput "crosses" the threshold).
> 
> Do you think this works?

Looks reasonable, but you could probably simplify it a bit by adding
RETURN rules to the above/below chains when the threshold is below/
above the specified value. That way you only need a single rateest
match.

> There is one problem with this solution, which is that it works in a
> per-connection basis (due to CONNMARK).  This is not exactly what I
> want.  I need to have this on a per-ruleset basis.  For that, I need to
> have a MARK (variable?) which can be set independently of connections or
> packets.  This is similar to the proposed condition match, but what is
> missing there is a way to set the condition with iptables itself,
> without requiring the userspace to change the procfs file.  This could
> probably be achieved with a "CONDITION" target or something similar.
> Any ideas?

Sounds useful.