Third try at setuid help ...

Wayne Hathaway wayne at AMES-NAS.ARPA
Thu Nov 7 05:55:37 AEST 1985


Apologies if this has gotten through before, but I haven't
seen it reflected back ...

--------

We have installed Berkeley sockets et al in VAX System V.2,
and are running into a particular problem in porting ftpd
(the FTP daemon).  It seems that this daemon, which starts
out as root, first validates the username and password as
per the protocol, and then does a setuid to change to that
user.  Unfortunately, when a request is made that involves
opening a data connection, the daemon must access a socket
that is "reserved" (under 1024), which requires that it be
root!  In 4.2BSD this is no problem, due to the setreuid
mechanism.  But what about System V?  We really don't want
to have to shoehorn setreuid into System V (due to large
changes over Version 7 setuid, among other things), but ...

The question:  Does anybody know of a version of ftpd
that does NOT have this problem?  Or some solution we
have not thought of?

With any assistance being appreciated, I say adthanksvance
and go back to other less interesting things ...

Wayne Hathaway

	wayne at ames-nas.arpa
	{dual,ihnp4,hao,vortex}!ames!amelia!wayne


PS:  Does anybody know why the System V.2 setuid(2) man
page has so little to do with reality?  It is a LARGE
change over previous versions, and does not agree at
all with the code.  The reason I ask is that if setuid
really worked the way the man page says, we would have
no problem!



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