Re: [PATCH] iptables: add -C to check for existing rules

[Patrick McHardy <kaber@trash.net>]

Am 08.03.2011 12:56, schrieb Stefan Tomanek:
> It is often useful to check whether a specific rule is already present
> in a chain without actually modifying the iptables config.
> 
> Services like fail2ban usually employ techniques like grepping through
> the output of "iptables -L" which is quite error prone.
> 
> This patch adds a new operation -C to the iptables command which mostly
> works like -D; it can detect and indicate the existence of the specified
> rule by modifying the exit code. The new operation TC_CHECK_ENTRY uses
> the same code as the -D operation, whose functions got a dry-run
> parameter appended.

Looks fine to me. I'll apply this if nobody else objects.