Date: Mon, 6 Nov 2017 16:41:41 +0100 From: Cos Chan <rosettas@gmail.com> To: Ian Smith <smithi@nimnet.asn.au> Cc: freebsd-questions <freebsd-questions@freebsd.org>, Carmel NY <carmel_ny@outlook.com> Subject: Re: How to setup IPFW working with blacklistd Message-ID: <CAKV%2BxLCizjt5M%2BmJmTZj-cr=D6rhXRwDjCkE=6Q-VQX73iY%2B4A@mail.gmail.com> In-Reply-To: <20171106235944.U9710@sola.nimnet.asn.au> References: <mailman.87.1509969603.28633.freebsd-questions@freebsd.org> <20171106235944.U9710@sola.nimnet.asn.au>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Nov 6, 2017 at 3:09 PM, Ian Smith <smithi@nimnet.asn.au> wrote:
> In freebsd-questions Digest, Vol 701, Issue 1, Message: 10
> On Mon, 6 Nov 2017 09:38:40 +0100 Cos Chan <rosettas@gmail.com> wrote:
>
> > Hi All
> >
> > I would run IPFW with blacklistd, my FreeBSD is 11.1-RELEASE-p1.
> >
> > my blacklistd is working fine to get sshd failed login attempts.
> > The out put:
> >
> > $ sudo blacklistctl dump -b
> > address/ma:port id nfail last access
> > 1.1.1.1/32:22 3/-1 2017/11/05 01:05:34
> > 2.2.2.2/32:22 3/-1 2017/11/05 13:22:53
> >
> > but I can't find information how to use the blacklistd database in IPFW
> > from IPFW manpage
> >
> > would anybody explain that to me?
>
> By all means work with Carmel's offer to look at parsing the database
> output. All I know about blacklistd(8), blacklistd.conf(5) and
> blacklistctl(8) is what I just now read skimming these manual pages.
>
> However I was surprised to see no mention of using tables rather than
> add)ing or rem)oving individual firewall rules - and you can't use
> 'flush' on individual rules in ipfw(8), only on whole sets of rules.
>
> Amother problem with adding/removing individual rules is you need to
> allocate a large enough block of rules, then specify distinct rule
> numbers to ipfw(8). Messy and error-prone, especially for deleting.
>
> So you might need to replace or modify /usr/libexec/blacklistd-helper,
> which I haven't seen but assume is a script, to use its parameters to
> generate commands more like:
>
> /sbin/ipfw table $TABLENAME add addr[/masklen] [value]
> and
> /sbin/ipfw table $OTHERNAME delete addr[/masklen]
>
> as appropriate. This is immensely more efficient than adding and
> deleting single rules on the fly, moreso if there are many entries.
>
> When adding entries, the optional [value] might be a latest timestamp,
> or an expiry timestamp, or anything else you might find useful.
>
> Of course you may need a number of different tables, for blocking ssh,
> webhosts, mailserver or other services, but then need just a few rules
> dedicated to denying (or even specifically enabling) hosts or ports to
> addr[/masklen/ entries in a particular table.
>
> ipfw add deny tcp from table \($SPAMMERS\) to any 25,587 setup
> ipfw add deny tcp from table \($SSHBADGUYS\) to me 22 setup
> ipfw add deny all from table \($REALLYNASTY\) to any in
>
> and such. Tables really are the way to go for this sort of thing.
>
thanks, I studied the /usr/libexec/blacklistd-helper, looks like it is good
as you said but it needs ipfw-blacklist.rc for ipfw?
if [ -f "/etc/ipfw-blacklist.rc" ]; then
pf="ipfw"
. /etc/ipfw-blacklist.rc
ipfw_offset=${ipfw_offset:-2000}
fi
I could not find this file in /etc/
the rc.conf file was modified to:
blacklistd_enable="YES"
blacklistd_flags="-C /usr/libexec/blacklistd-helper"
and the blacklistd restarted but no luck yet.
>
> cheers, Ian
>
--
with kind regards
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAKV%2BxLCizjt5M%2BmJmTZj-cr=D6rhXRwDjCkE=6Q-VQX73iY%2B4A>