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Date:      Sun, 21 Nov 2004 13:16:42 +0200 (EET)
From:      Ciprian BADESCU <cbadescu@aspc.cs.utt.ro>
To:        freebsd-security@freebsd.org
Subject:   [Fwd: Re: Importing into rc.firewal rules]
Message-ID:  <2274.82.77.156.141.1101035802.squirrel@82.77.156.141>

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Hi,

> On Sat, Nov 20, 2004 at 01:32:15PM -0500, Francisco Reyes wrote:
>> I have a grown list of IPs that I am "deny ip from ###.### to any".
Infected machines, hackers, etc..
>>
>> Is there a way to have this list outside of rc.firewall and just read
it in?
>

from man ipfw

LOOKUP TABLES
   Lookup tables are useful to handle large sparse address sets, typically
from a hundred to several thousands of entries.  There could be 128
dif- ferent lookup tables, numbered 0 to 127.
   Each entry is represented by an addr[/masklen] and will match all
addresses with base addr (specified as a dotted quad or a hostname) and
mask width of masklen bits.  If masklen is not specified, it defaults
to 32.  When looking up an IP address in a table, the most specific
entry will match.  Associated with each entry is a 32-bit unsigned
value, which can optionally be checked by a rule matching code.  When
adding an entry, if value is not specified, it defaults to 0.
   An entry can be added to a table (add), removed from a table (delete),
a table can be examined (list) or flushed (flush).
   Internally, each table is stored in a Radix tree, the same way as the
routing table (see route(4)).
,

and here is an example:

${fwcmd} table 0 add 82.77.156.42
${fwcmd} add deny all from table\(0\) to any via ${oif}
${fwcmd} add deny all from any to table\(0\) via ${oif}
# I know, second rule, .... it's paranoic

To set the table you could use a file /etc/badboys
and a short shell script executed before the table denying rules:
for i in `cat /etc/badboys`; do ${fwcmd} table 0 add $i; done;


----
Ciprian Badescu





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