vix@ubvax.UUCP (Paul Vixie) (07/20/87)
I have a mail wiz here who is implementing an SMTP mailer on his PC (I'll pause
here until the snickers and catcalls die down). He got the sending side to
work fairly well, but for reception of mail, he didn't want to tie up his PC
continuously while he waits for incoming SMTP connections. Remember, the PC
is NOT a multi-tasker.
Therefore he decided to just call up the Vax sendmail and say 'TURN' to get
his mail. He was surprised to see sendmail reply, 'command not recognized.'
I was surprised, when subsequently examining srvrsmtp.c, to see that there is
no mention of TURN in the list of known SMTP commands.
So, two questions:
(1) does sendmail really not support TURN?
(2) has anyone hacked this in?
Hacking it in doesn't seem to difficult -- if it hasn't been done, and I do it,
is anyone else interested in having the patches?
--
Paul Vixie
Consultant (408) 562-7970 (UB) (415) 674-7023 (me)
Ungermann-Bass {pyramid,cae780,amd,decvax,weitek,sco}!ubvax!vix
Santa Clara, CA vix@ubvax.ub.com (uucp) vix@Engr.UB.Com (CSNET)kevins@dartvax.UUCP (Kevin M. Schofield) (07/24/87)
In article <1726@ubvax.UUCP> vix@ubvax.UUCP (Paul Vixie) writes: > >Therefore he decided to just call up the Vax sendmail and say 'TURN' to get >his mail. He was surprised to see sendmail reply, 'command not recognized.' >I was surprised, when subsequently examining srvrsmtp.c, to see that there is >no mention of TURN in the list of known SMTP commands. > >So, two questions: > (1) does sendmail really not support TURN? > (2) has anyone hacked this in? > >Hacking it in doesn't seem to difficult -- if it hasn't been done, and I do it, >is anyone else interested in having the patches? >-- 1. Sendmail really does NOT support TURN (one in a LONG list of gripes I have with sendmail, after just finishing an implementation of SMTP for a computer that talks to our VAX). The minimum implementation of SMTP includes the following commands only: HELO MAIL RCPT DATA RSET NOOP QUIT 2. I doubt that you'll find anyone who has actually hacked it in... it's really a bigger deal than it seems. You have to teach sendmail how to read mail out of a mailbox, dig the appropriate information out of the headers, and send it along. You might be better off implementing uucp instead. (actually, I believe that's been done for the PC...) -Kevin
kyle@xanth.UUCP (Kyle Jones) (07/26/87)
> 2. I doubt that you'll find anyone who has actually hacked it in... it's > really a bigger deal than it seems. You have to teach sendmail how to read mail > out of a mailbox, dig the appropriate information out of the headers, and > send it along. You might be better off implementing uucp instead. (actually, > I believe that's been done for the PC...) > > -Kevin Sendmail wouldn't have to do all that! It would simply have to go through its queuefiles, looking at the envelope of each letter and determine which ones go to the host on the other end of the SMTP connection. The routines to do this are, of course, already part of sendmail. You just have to be familiar enough with sendmail internals to tie SMTP-receiver and the SMTP-sender code together.
galvin@udel.EDU (James M Galvin) (07/28/87)
In article <1701@xanth.UUCP> kyle@xanth.UUCP (Kyle Jones) writes: >> 2. I doubt that you'll find anyone who has actually hacked it in... it's >> really a bigger deal than it seems. >Sendmail wouldn't have to do all that! It would simply have to go through its >queuefiles, looking at the envelope of each letter and determine which ones go >to the host on the other end of the SMTP connection. The reason there is no TURN command is much more fundamental. How do you verify the identity of the "calling" entity reliably enough to believe you are giving the mail to the right entity? True, the security is marginally better when you are doing the "calling" to deliver, but it is better. -- James M Galvin