Date: Thu, 28 Jul 2016 23:21:01 -0300 From: "Dr. Rolf Jansen" <rj@obsigna.com> To: freebsd-ipfw@freebsd.org Cc: Julian Elischer <julian@freebsd.org> Subject: Re: ipfw divert filter for IPv4 geo-blocking Message-ID: <0D3C9016-7A4A-46BA-B35F-3844D07562A8@obsigna.com> In-Reply-To: <677900fb-c717-743f-fcfe-86b603466e33@freebsd.org> References: <61DFB3E2-6E34-4EEA-8AC6-70094CEACA72@cyclaero.com> <CAHu1Y739PvFqqEKE74BjzgLa7NNG6Kh55NPnU5MaA-8HsrjkFw@mail.gmail.com> <4D047727-F7D0-4BEE-BD42-2501F44C9550@obsigna.com> <c2cd797d-66db-8673-af4e-552dfa916a76@freebsd.org> <9641D08A-0501-4AA2-9DF6-D5AFE6CB2975@obsigna.com> <4d76a492-17ae-cbff-f92f-5bbbb1339aad@freebsd.org> <C0CC7001-16FE-40BF-A96A-1FA51A0AFBA7@obsigna.com> <677900fb-c717-743f-fcfe-86b603466e33@freebsd.org>
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> Am 27.07.2016 um 12:31 schrieb Julian Elischer <julian@freebsd.org>: > On 27/07/2016 9:36 PM, Dr. Rolf Jansen wrote: >>> Am 26.07.2016 um 23:03 schrieb Julian Elischer <julian@freebsd.org>: >>> On 27/07/2016 3:06 AM, Dr. Rolf Jansen wrote: >>>> There is another tool called geoip , that I uploaded to GitHub, and = that I use for looking up country codes by IP addresses on the command = line. >>>>=20 >>>> https://github.com/cyclaero/ipdb/blob/master/geoip.c >>>>=20 >>>> This one could easily be extended to produce sorted IP ranges per = CC that could be fed into tables of ipfw. I am thinking of adding a = command line option for specifying CC's for which the IP ranges should = be exported, something like: >>>>=20 >>>> geoip -e DE:BR:US:IT:FR:ES >>>>=20 >>>> And this could print sorted IP-Ranges belonging to the listed = countries. For this purpose, what would be the ideal format for directly = feeding the produced output into ipfw tables? >>> The format for using tables directly is the same as that used for = routing tables. >>> =E2=80=A6 >>> table 5 add 1.1.1.0/32 1000 >>> =E2=80=A6 >>> your application becomes an application for configuring the = firewall. >>> (which you do by feeding commands down a pipe to ipfw, which is = started as 'ipfw -q /dev/stdin') >> I finished adding a second usage form for the geoip tool, namely = generation of ipfw table construction directives filtered by country = codes. > wow, wonderful! >=20 > with that tool, and ipfw tables we have a fully functional geo = blocking/munging solution in about 4 lines of shell script. Unfortunately, I finally discovered that ipfw tables as they are, are = unsuitable for the given purpose, because for some reason ipfw mangles = about 20 % of the passed IP address/masklen pairs. For example: # ipfw table 1 add 201.222.20.0/20 # ipfw table 1 list --> 201.222.16.0/20 0 $ geoip 201.222.20.1 --> 201.222.20.1 in 201.222.20.0-201.222.31.255 in BR $ geoip 201.222.16.1 --> 201.222.16.1 in 201.222.16.0-201.222.19.255 in AR Effectively, I asked ipfw to add an IP-range of Brazil to table 1, but = it actually added another one which belongs to Argentina. This doesn't = make too much sense, does it? For the time being I switched my servers back to geo-blocking with the = divert filter daemon. Best regards Rolf
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