Date: Mon, 17 Sep 2007 22:13:24 -0500 From: Erik Osterholm <freebsd-lists-erik@erikosterholm.org> To: Agus <agus.262@gmail.com> Cc: freebsd-questions@freebsd.org Subject: Re: How to add rule with pfctl... Message-ID: <20070918031323.GA46854@idoru.cepheid.org> In-Reply-To: <fda61bb50709171930l7508b458nca9320f3e3ee9cee@mail.gmail.com> References: <fda61bb50709151418r61b0e0b4rd889b517b954fae9@mail.gmail.com> <200709152336.27214.fbsd.questions@rachie.is-a-geek.net> <fda61bb50709170945u3a1fba81t8fa8244dbcfc5baf@mail.gmail.com> <46EEB13C.4020509@kinetix.gr> <fda61bb50709171930l7508b458nca9320f3e3ee9cee@mail.gmail.com>
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On Mon, Sep 17, 2007 at 11:30:03PM -0300, Agus wrote:
> Agus wrote:
> >
> > 2007/9/15, Mel <fbsd.questions@rachie.is-a-geek.net> <fbsd.questions@rachie.is-a-geek.net>:
> >
> > On Saturday 15 September 2007 23:18:17 Agus wrote:
> >
> > I am trying to figure out how to add a firewall rule with pfctl...
> > This is what i'm trying to do...
> >
> > I've got SEC that matches certain pattern and takes the IP from that and
> > want to trigger a firewall rule to block that IP....
> > Then after a couple of hours SEC will trigger the command to un-block
> >
> > the
> >
> > IP...
> > So what i need is the command to block an IP address from command line,
> >
> > not
> >
> > touching any pf.conf....
> >
> > If you don't need to add a rule but an IP, then tables are your friend.
> > Example for /etc/pf.conf:
> > # Placeholder for spammers table, non-routable network IP.
> > table <spammers> persist { 192.168.111.111 }
> > # Block this traffic
> > block return-rst in log on $ext_if proto tcp from <spammers> port smtp
> >
> > Then on the command line:
> > /sbin/pfctl -t spammers -Tadd ip.from.new.spammer
> > And to delete:
> > /sbin/pfctl -t spammers -Tdel ip.from.old.spammer
> >
> > --
> > Mel
> > _______________________________________________
> > freebsd-questions@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
> >
> > Hi,
> > I put this on /etc/pf.conf
> > external_addr="192.168.1.11" which is the address of the only interface.
> > This machine isn't a router.
> >
> > block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to
> > $external_addr port ssh
> >
> > but when i try to connect from 192.168.0.1 i connect with no problems...this
> > rule is to block access..
> > What am i doing wrong..is my first time with pf...
> >
> > Thankss...
> > _______________________________________________
> > freebsd-questions@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" <freebsd-questions-unsubscribe@freebsd.org>
> >
> > 2007/9/17, Goltsios Theodore <tgol@kinetix.gr>:
> Well I think that you mean to add this:
>
> ext_if="rl0" # Or whatever your interface is ifconfig helps to find out
> block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to $ext_if
> port ssh
>
> or even:
> ext_if="rl0"
> external_addr="192.168.1.11"
> block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to
> $external_addr port ssh
>
> Think of macros as variables. As long as you don't define them they don't
> exist (are empty).
>
>
>
> I knowTheodore, i've done it exactly like u put it....first declare macros
> and then the rule....
> but i couldn't block access to the machine....this rule is supposed to block
> all access to port 22 on the machine coming from 192.168.0.1....but I can
> access from there...
>
> i checked pfctl -e
> pfctl -sa
>
> and everything seems to be loaded...
>
> Thanks...
Are you sure that you're trying to block only from a specific host?
The source address shouldn't change, even if you're doing nat. I
would assume that you'd want an 'any' keyword there, rather than a
specific IP address.
Also, you can add hosts to the table automatically based on number of connections over a given period of time:
block quick from <blackhole>
pass on $ext_if inet proto tcp from any to $myip port 22 flags S/SA keep state (max-src-conn-rate 5/30, overload <blackhole> flush global)
The first rule blocks hosts from the blackhole table. The second adds
hosts to the blackhole table and kills their state if they connect
more than 5 times in 30 seconds. This is obviously tunable-- 3/30
would be 3 connections in 30 seconds, and 8/60 would be 8 connections
in 60 seconds.
Erik
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