Date: Sun, 14 Sep 2014 21:44:05 +1000 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: Willem Jan Withagen <wjw@digiware.nl> Cc: "Alexander V. Chernikov" <melifaro@freebsd.org>, Freddie Cash <fjwcash@gmail.com>, bycn82 <bycn82@gmail.com>, freebsd-ipfw@freebsd.org Subject: Re: IPFW rule sets and automatic rule numbering Message-ID: <20140914204055.K61666@sola.nimnet.asn.au> In-Reply-To: <54156FBB.1030907@digiware.nl> References: <CAOjFWZ4rx4FAc4AoPw3d=cSg4-z_QOWEF=phkT2PuzfUjn0y5A@mail.gmail.com> <CAOjFWZ6i1%2BgCZ9jMnBNEGqL7airdxN3d=B0__Z_Zj1gGG4APKg@mail.gmail.com> <541469D4.6070107@gmail.com> <CAOjFWZ749EazFz1prFRfidp9bqmqO%2B=%2BXFsu7mVtE%2Bnq2CxwKw@mail.gmail.com> <54156FBB.1030907@digiware.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, 14 Sep 2014 12:36:43 +0200, Willem Jan Withagen wrote: > On 13-9-2014 21:51, Freddie Cash wrote: > > You can replicate it using 3 rules, loaded into two sets: > > > > ipfw set disable 1 > > ipfw add allow ip from any to any > > ipfw add 65524 allow ip from any to any > > ipfw add allow ip from any to any > > ipfw set swap 1 0 > > > > Run that two or 3 times. Every rule will be numbered 65534 after the 2nd or > > 3rd run. > > > > > I expected it to be numbered 10, 65524, 65534 after every run. > > > > However, after reading the man page a few more times and thinking about it > > a little more, it makes sense that the numbering is global across all sets, > > as you can have multiple sets enabled simultaneously. > > > > It just doesn't mesh with my desire to use auto numbering. I'm in the midst > > of manually numbering all my rules now. :) > This is easily circumvented by making shure that the first rule is > > ipfw add 10 ..... > like: > ipfw add count ip4 from any to any via vlan126 > (vlan126 is my outside connection) > And then you are home free. > > I actually use this to also separate diffent types of block by injecting: > ipfw add <blocknumber> count ip from any to any > > like: > 03000 713812041 425643462848 count ip from any to any > 03010 0 0 deny ip6 from fc00::/7 to any via vlan126 > > And the 3000 block contains all antispoofing and likes. I'd almost replied along the same lines - also tending to number first rules in a block and then add unnumbered rules until other sections - before realising that once Freddie had added his rule 65524, maybe in another set, it's game over; every unnumbered rule added after that is going to be >= 65524 and <= 65534. And even as you have it above, if you rerun your script again without flushing the entire ruleset, apart from specifically numbered rule/s, everything will get readded after the highest rule previously used. Alexander said: > I think we can consider implementing sysctl which permits per-set > auto-numbering. Perhaps rather than a separate high water mark per set that would be reset on set N flush - which I think is what Alexander means? - if one could set something like maybe 'net.inet.ip.fw.autoinc_last' which would default, as now, to the highest rule added so far, but could be reset to something else before adding more auto_inc rules? Might get tricky, and of course it has to not break older rule scripts - some VERY old :) cheers, Ian
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20140914204055.K61666>