From owner-freebsd-stable@FreeBSD.ORG Tue Dec 19 19:56:08 2006 Return-Path: X-Original-To: freebsd-stable@FreeBSD.ORG Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 30BBC16A4FE for ; Tue, 19 Dec 2006 19:56:08 +0000 (UTC) (envelope-from spork@bway.net) Received: from xena.bway.net (xena.bway.net [216.220.96.26]) by mx1.FreeBSD.org (Postfix) with ESMTP id CBB1043CA6 for ; Tue, 19 Dec 2006 19:55:37 +0000 (GMT) (envelope-from spork@bway.net) Received: (qmail 68623 invoked by uid 0); 19 Dec 2006 19:28:56 -0000 Received: from unknown (HELO white.nat.fasttrackmonkey.com) (spork@bway.net@216.220.116.154) by smtp.bway.net with (DHE-RSA-AES256-SHA encrypted) SMTP; 19 Dec 2006 19:28:56 -0000 Date: Tue, 19 Dec 2006 14:28:54 -0500 (EST) From: Charles Sprickman X-X-Sender: spork@white.nat.fasttrackmonkey.com To: Christopher Hilton In-Reply-To: <45881546.30400@vindaloo.com> Message-ID: References: <200612191347.kBJDlg5c058711@lurza.secnetix.de> <45881546.30400@vindaloo.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-stable@FreeBSD.ORG Subject: Re: OpenBSD's spamd. X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Dec 2006 19:56:08 -0000 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. :) 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. 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 Was the original question "when will the FreeBSD port be updated"?? :) Charles > Through experimentation Bob Beck determined that many spammers were dropping > the connection and forgetting about delivering the mail completely after > short and shorter intervals if the connection was rate limited to 1 character > / sec. When the spammers got down to 3 seconds he modified spamd to stutter > for 10 seconds on any connection. That feature came in on OpenBSD 3.8 > > -- Chris > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >