Xref: utzoo comp.mail.sendmail:888 comp.bugs.4bsd:1331
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!ucsfcgl!cgl.ucsf.edu!gregc
From: gregc@cgl.ucsf.edu (Greg Couch)
Newsgroups: comp.mail.sendmail,comp.bugs.4bsd
Subject: How to prevent mail to non-existent accounts
Message-ID: <11680@cgl.ucsf.EDU>
Date: 11 Jul 89 22:09:36 GMT
Sender: daemon@cgl.ucsf.edu
Reply-To: gregc@cgl.ucsf.edu (Greg Couch)
Organization: UCSF Computer Graphics Lab
Lines: 42

A bit of background:  we share a password file amoung several 4.3 systems
and restrict access to a particular system by having login fail if the
user doesn't have a home directory on that system.  Thus we don't want
users to get mail on machines they can't access.

Enclosed is a small enhancement to reject mail to users that don't have
home directories.  Depending on how your site manages accounts, you might
want to disable mail to users with non-standard shells or to users whose
password entry is "*" or somesuch.

This patch works for sendmail versions 5.59 and 5.61.

	- Greg Couch
	gregc@cgl.ucsf.edu
	postmaster@cgl.ucsf.edu

------
sendmail/src/recipient.c:
------
RCS file: RCS/recipient.c,v
retrieving revision 1.1
diff -c -r1.1 recipient.c
*** /tmp/,RCSt1024920	Tue Jul 11 15:09:13 1989
--- recipient.c	Tue Jul 11 14:52:40 1989
***************
*** 303,309
  
  			/* warning -- finduser may trash buf */
  			pw = finduser(buf);
! 			if (pw == NULL)
  			{
  				a->q_flags |= QBADADDR;
  				giveresponse(EX_NOUSER, m, CurEnv);

--- 303,309 -----
  
  			/* warning -- finduser may trash buf */
  			pw = finduser(buf);
! 			if (pw == NULL || !safefile(pw->pw_dir, pw->pw_uid, S_IEXEC))
  			{
  				a->q_flags |= QBADADDR;
  				giveresponse(EX_NOUSER, m, CurEnv);