Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: bnr-fos!leibniz!hwt@watmath.waterloo.edu (Henry Troup)
Newsgroups: comp.sys.sun
Subject: writing daemons under SunOS 4.0?
Keywords: SunOS
Message-ID: <359@bnr-fos.UUCP>
Date: 4 Apr 89 02:01:45 GMT
Sender: usenet@rice.edu
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 15
Approved: Sun-Spots@rice.edu
Original-Date: 21 Mar 89 20:45:04 GMT
X-Sun-Spots-Digest: Volume 7, Issue 221, message 8 of 12

I'm writing a daemon process under SunOS 4.0.  I've made the program
setuid root, it immediately forks, and gets rid of its controlling
terminal.  But I can still kill the process from the general user I
started it from.  Is this the correct behaviour?

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[[ Making a program setuid only changes the "effective" uid, leaving the
"real" uid the same.  This used to be sufficient to prevent kill from
killing it, but apparently not anymore.  I wonder if that's a bug or more
SVID compliance?  Have the program use "setreuid(0,0)" to set both the
real and effective uid to root.  See the manual page setreuid(2) for more
details.  --wnl ]]