From owner-freebsd-hackers Mon Nov 18 16:53:06 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id QAA29858 for hackers-outgoing; Mon, 18 Nov 1996 16:53:06 -0800 (PST) Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id QAA29450 for ; Mon, 18 Nov 1996 16:50:37 -0800 (PST) Received: from sax.sax.de (sax.sax.de [193.175.26.33]) by irz301.inf.tu-dresden.de (8.6.12/8.6.12-s1) with ESMTP id BAA02326; Tue, 19 Nov 1996 01:49:52 +0100 Received: (from uucp@localhost) by sax.sax.de (8.6.12/8.6.12-s1) with UUCP id BAA19041; Tue, 19 Nov 1996 01:49:52 +0100 Received: (from j@localhost) by uriah.heep.sax.de (8.8.2/8.6.9) id BAA03594; Tue, 19 Nov 1996 01:42:07 +0100 (MET) From: J Wunsch Message-Id: <199611190042.BAA03594@uriah.heep.sax.de> Subject: Re: sendmail without DNS (was: Re: BoS: Exploit for sendmail smtpd bug (ver. 8.7-8.8.2).) To: freebsd-hackers@freebsd.org (FreeBSD hackers) Date: Tue, 19 Nov 1996 01:42:07 +0100 (MET) Cc: marcs@znep.com (Marc Slemko) Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: from Marc Slemko at "Nov 18, 96 12:17:21 pm" X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E X-Mailer: ELM [version 2.4ME+ PL17 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk As Marc Slemko wrote: > I have tried nocanonify, nodns, a service.switch file and perhaps a few > other things that I can't remember right now, but sendmail still tries to > do DNS lookups. You must do something wrong. I'm using a local nameserver, but as you can see, it's only used for local lookups: uriah # kill -USR1 `cat /var/run/named.pid ` uriah # echo "hi you" | mail -s "test mail" marcs@znep.com uriah # kill -USR2 `cat /var/run/named.pid ` uriah # cat /var/tmp/named.run Debug turned ON, Level 1 datagram from [127.0.0.1].4970, fd 6, len 35; now Tue Nov 19 01:33:38 1996 req: nlookup(uriah.heep.sax.de) id 22463 type=1 class=1 req: found 'uriah.heep.sax.de' as 'uriah.heep.sax.de' (cname=0) ns_req: answer -> [127.0.0.1].4970 fd=6 id=22463 size=124 Local datagram from [127.0.0.1].4971, fd 6, len 42; now Tue Nov 19 01:33:38 1996 req: nlookup(1.0.168.192.in-addr.arpa) id 22464 type=12 class=1 req: found '1.0.168.192.in-addr.arpa' as '1.0.168.192.in-addr.arpa' (cname=0) ns_req: answer -> [127.0.0.1].4971 fd=6 id=22464 size=139 Local Debug turned OFF That's a simple turnaround for resolving the local host name. We can even stop the nameserver just for testing: uriah # kill -STOP `cat /var/run/named.pid ` uriah # (echo "/bind/s/^/#"; echo "w"; echo "q") | ed /etc/host.conf 105 #bind 106 uriah # echo "hi you" | mail -s "test mail" marcs@znep.com uriah # mailq Mail Queue (1 request) --Q-ID-- --Size-- -----Q-Time----- ------------Sender/Recipient------------ BAA03279* (no control file) (Well, that's the queue file from my /etc/daily that's just running right now. Your mail did already go out to the UUCP spool by that time, no additional delay for nameserver attempts etc.) uriah # kill -CONT `cat /var/run/named.pid ` This is with no compile-time sendmail trickery, a plain sendmail compilation from -current (as of a few weeks ago), with the following .mc file: include(`../m4/cf.m4') VERSIONID(`$Id: uriah.mc,v 1.11 1996/04/27 10:15:52 r Exp $') OSTYPE(bsd4.4)dnl FEATURE(nodns)dnl FEATURE(nocanonify)dnl FEATURE(mailertable)dnl define(`confMIME_FORMAT_ERRORS', `False') define(`confMESSAGE_TIMEOUT', `7d/3d') define(`UUCP_RELAY', sax.sax.de) define(`UUCP_MAX_SIZE', 200000) define(`LOCAL_MAILER_ARGS', `mail -b $u') MAILER(local)dnl MAILER(smtp)dnl MAILER(uucp)dnl Op noreceipts Cw uriah uriah.sax.de Cw heep.sax.de Cw jette jette.sax.de Cw uriah.UUCP Cw ppp-uriah.interface-business.de -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)