[net.unix-wizards] On 4.2BSD be careful with /bin/login

bjf@utcs.UUCP (Bruce Freeman) (11/22/84)

About two weeks ago we made the change to /bin/login of having it check
that its parent process id was 1. It is important on 4.2 systems that you
put this check in the right place since /bin/login is invoked by servers
such as rlogind and telnetd whose process id's are certainly not 1!
We found out quite quickly that we put the test in the wrong place (the first
line in main()) thereby preventing rlogin from working to our system.
However I soon realized my mistake and I moved the check further down after
it has been determined that the person logging in is not doing so from a
server. Everything now seems to work fine, one can use rlogin but one can't
type (login foo). Programmer 1, 4.2 0.
-- 
Bruce Freeman	University of Toronto	{decvax|ihnp4|utzoo}!utcs!bjf

Ron Natalie <ron@BRL-TGR> (11/26/84)

If the parent of a process dies, the PPID becomes 1.  You check for the
PPID being "1" won't eliminate the problem, your users will just get
cleverer.

-Ron