Date: Thu, 8 Mar 2007 19:43:22 -0500 From: Charles Sprickman <spork@bway.net> To: Christopher Hilton <chris@vindaloo.com> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: OpenBSD's spamd. Message-ID: <0D61B3BC-F865-4AF2-A2AB-9CDCCBF8C04D@bway.net> In-Reply-To: <45887C16.2010801@vindaloo.com> References: <200612191347.kBJDlg5c058711@lurza.secnetix.de> <45881546.30400@vindaloo.com> <Pine.OSX.4.61.0612191425220.354@white.nat.fasttrackmonkey.com> <45887C16.2010801@vindaloo.com>
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On Dec 19, 2006, at 6:56 PM, Christopher Hilton wrote: > Charles Sprickman wrote: >> On Tue, 19 Dec 2006, Christopher Hilton wrote: >>> Oliver Fromme wrote: >>>> Dimitry Andric wrote: >>>> > Oliver Fromme wrote: >>>> > > What does stuttering mean? Is it similar to sendmail's >>>> > > "greet_pause" feature? >>>> > > See here: >>>> > http://www.ualberta.ca/~beck/nycbug06/spamd/mgp00014.html >>>> >>>> OK, so the answer to my question seems to be "yes". :-) >>>> >>> >>> Actually I'd say it's similar. If you telnet to port 25 on a >>> server that's using sendmail's greet_pause option I'm assuming >>> that you get nothing for 5 seconds. OpenSD's Spamd sends the >>> initial greeting at a rate of one character per second and only >>> accepts data from you at the same rate. >> It also sets the window size to something like 1 byte. :) > > Yes, it does. This results in the remote smtp daemon getting bound > up by it's own kernel. > >> Someone had mentioned that this would consume many threads/ >> processes, but that is not the case. Bob explained that spamd >> runs in a select() loop. I don't totally understand that, but to >> me it sounds like the same methodology that thttpd used, and that >> sure scaled up nice. > > It keeps an array of file descriptors, one for each connection to > the remote smtp daemon. It periodically uses the select(2) system > call to see which of the descriptors is ready and services them > accordingly. > >> Here's what I think is the latest version of Bob's talk. It's >> quite good. >> http://www.ualberta.ca/~beck/nycbug06/spamd/ >> There's audio available here: >> http://www.nycbsdcon.org/slides > > I heard the talk in the beginning of November, right about the > middle of the big October/November spamming event of '06. To me the > most interesting part of the talk was when he spoke about the > results of tarpitting his greylisted connections and how he > eliminated 1,300,000 Mail messages from a total of 3,000,000 before > they ever hit his MTA. That's the feature that's missing from > FreeBSD since the port pulls spamd from OpenBSD 3.7 and the > tarpitting feature was added in the revision right after the > release 3.7 tag. > >> Was the original question "when will the FreeBSD port be >> updated"?? :) > > Yes. There's lots of ways to do it. One could pull diff from the > openbsd cvs servers and drop it into the patch directory. That > should go cleanly but it would be nice to get this revved up to the > latest release. I've got a copy of the latest code to compile. The > call symantics of openbsd's openlog_r(3) and syslog_r(3) differ > from FreeBSD openlog(3) and syslog(3). But It should work. I need > to throw some polish on it but after I do I'll post the patches > here and send them to the port maintainer. I know this is kind of old, but I'm needing to work with spamd on FreeBSD and I noticed the port is still stuck at the 3.7 version. Do you have anything that you'd like people to test? Thanks, Charles > -- Chris
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