fingerd, in.fingerd - remote user information server
finger stream tcp nowait nobody /usr/sbin/in.fingerd in.fingerd
tcpd finger /usr/sbin/in.fingerd in.fingerd
Fingerd is a simple protocol based on RFC742 that provides an interface
to the Name and Finger programs at several network sites. The program is
supposed to return a friendly, human-oriented status report on either the
system at the moment or a particular person in depth. There is no
required format and the protocol consists mostly of specifying a single
Fingerd listens for TCP requests at port 79. Once connected it reads a
single command line terminated by a <CRLF> which is passed to finger(1).
Fingerd closes its connections as soon as the output is finished.
If the line is null (i.e. just a <CRLF> is sent) then finger returns a
``default'' report that lists all people logged into the system at that
If a user name is specified (e.g. eric<CRLF>) then the response lists
more extended information for only that particular user, whether logged
in or not. Allowable ``names'' in the command line include both ``login
names'' and ``user names''. If a name is ambiguous, all possible
derivations are returned.
Connecting directly to the server from a TIP or an equally narrow-minded
TELNET-protocol user program can result in meaningless attempts at option
negotiation being sent to the server, which will foul up the command line
interpretation. Fingerd should be taught to filter out IAC's and perhaps
even respond negatively (IAC WON'T) to all option commands received.