Path: utzoo!mnetor!uunet!husc6!think!bloom-beacon!jis@BITSY.MIT.EDU
From: jis@BITSY.MIT.EDU (Jeffrey I. Schiller)
Newsgroups: comp.bugs.4bsd
Subject: Re: sendmail aborts with longjmp botch
Message-ID: <3708@bloom-beacon.MIT.EDU>
Date: 13 Mar 88 02:44:13 GMT
References: <10581@mimsy.UUCP>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: jis@BITSY.MIT.EDU (Jeffrey I. Schiller)
Organization: Massachusetts Institute of Technology
Lines: 110
Summary: Chris' fix should work running at MIT for 1.5 years
In-reply-to: chris@mimsy.UUCP (Chris Torek)

Posting-Front-End: Gnews 1.0



	Chris's change should work. We ran into this problem awhile ago here
(with the "expert" mailing list). I thought we posted the fix (but I guess not).
In any event here are the diffs (against the version of sendmail we were using
then). This code has been in service at MIT since November of 1986.

			-Jeff

*** /tmp/,RCSt1005512	Sat Mar 12 21:22:30 1988
--- /tmp/,RCSt2005512	Sat Mar 12 21:22:37 1988
***************
*** 1,4 ****
--- 1,9 ----
  /*
+  *	$Source: /source/4.3/usr.lib/sendmail/src/RCS/usersmtp.c,v $
+  *	$Header: usersmtp.c,v 1.2 86/11/04 00:36:34 jis Exp $
+  */
+ 
+ /*
  **  Sendmail
  **  Copyright (c) 1983  Eric P. Allman
  **  Berkeley, California
***************
*** 67,74 ****
  **		creates connection and sends initial protocol.
  */
  
- jmp_buf	CtxGreeting;
- 
  smtpinit(m, pvp)
  	struct mailer *m;
  	char **pvp;
--- 72,77 ----
***************
*** 76,81 ****
--- 79,85 ----
  	register int r;
  	EVENT *gte;
  	char buf[MAXNAME];
+ 	time_t saveReadTimeout;
  	extern greettimeout();
  
  	/*
***************
*** 127,140 ****
  	**  Get the greeting message.
  	**	This should appear spontaneously.  Give it five minutes to
  	**	happen.
  	*/
  
- 	if (setjmp(CtxGreeting) != 0)
- 		goto tempfail;
- 	gte = setevent((time_t) 300, greettimeout, 0);
  	SmtpPhase = "greeting wait";
  	r = reply(m);
! 	clrevent(gte);
  	if (r < 0 || REPLYTYPE(r) != 2)
  		goto tempfail;
  
--- 131,160 ----
  	**  Get the greeting message.
  	**	This should appear spontaneously.  Give it five minutes to
  	**	happen.
+         **
+ 	**  JIS: We change the global variable ReadTimeout to be 5
+ 	**      minutes. This variable is used by the lowlevel routine
+ 	**      sfgets to determine how long to wait for input.
+ 	**      when we get our greeting we return ReadTimeout to its
+ 	**      previous state. IMPORTANT: The older code I replaced
+ 	**      used a separate timeout (via a setjmp and longjmp)
+ 	**      this LOSES REAL BIG if the 5 minute timeout goes off
+ 	**      for then sfgets gets its stack unwound and leaves
+ 	**      a lingering event that will eventually cause a longjmp
+ 	**      to some ancient stack history, sendmail then dies horribly.
+ 	**      This usually happens only when dealing with large mailing
+ 	**      lists ("xpert" in this case > 200 recipients), which is
+ 	**      the LAST place you want to dump core, for then the queue
+ 	**      files are out of date and LOTS of people get a duplicate
+ 	**      copy of the message that was in progress.
+ 	*
  	*/
  
  	SmtpPhase = "greeting wait";
+ 	saveReadTimeout = ReadTimeout;
+ 	ReadTimeout = 300;
  	r = reply(m);
! 	ReadTimeout = saveReadTimeout;
  	if (r < 0 || REPLYTYPE(r) != 2)
  		goto tempfail;
  
***************
*** 212,225 ****
    unavailable:
  	smtpquit(m);
  	return (EX_UNAVAILABLE);
- }
- 
- 
- static
- greettimeout()
- {
- 	/* timeout reading the greeting message */
- 	longjmp(CtxGreeting, 1);
  }
  /*
  **  SMTPRCPT -- designate recipient.
--- 232,237 ----

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