| FINGERD(8) | System Manager's Manual | FINGERD(8) |
in.fingerd —
remote user information server
in.fingerd |
[-wulf] [-pL
path] [-t
timeout] |
Fingerd is a simple daemon based on
RFC1196 that provides an interface to the
“finger” program at most 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.
If the -w option is given, remote users
will get an additional “Welcome to ...” banner which also
shows some information (e.g. uptime, operating system name and release)
about the system the in.fingerd is running on. Some
sites may consider this a security risk as it gives out information that may
be useful to crackers.
If the -u option is given, requests of the
form “finger @host” are rejected.
If the -l option is given, information
about requests made is logged. This option probably violates users' privacy
and should not be used on multiuser boxes.
If the -f option is given, finger
forwarding (user@host1@host2) is allowed. Useful behind firewalls, but
probably not wise for security and resource reasons.
The -p option allows specification of an
alternate location for in.fingerd to find the “finger”
program. The -L option is equivalent.
The -t option specifies the time to wait
for a request before closing the connection. A value of 0 waits forever. The
default is 60 seconds.
Options to in.fingerd should be specified in /etc/inetd.conf.
The finger protocol consists mostly of specifying command
arguments. The inetd(8) “super-server” runs
in.fingerd for TCP requests received on port 79.
Once connected in.fingerd reads a single command
line terminated by a ⟨CRLF⟩ which is passed to
finger(1). It closes its connections as soon as all output
is finished.
If the line is empty (i.e. just a ⟨CRLF⟩ is sent)
then finger returns a “default” report that
lists all people logged into the system at that moment. This feature is
blocked by the -u option.
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.
The finger daemon appeared in 4.3BSD.
| August 29, 1996 | Linux NetKit (0.17) |