NAME
tryfrom, sffinger — utility programs for TCP Wrappers
SYNOPSIS
/usr/bin/tryfrom
/usr/bin/sffinger
DESCRIPTION
tryfrom
This program identifies the end-point details related to a
connection. This program must be called via a remote shell command
as shown below.
It is used
to find out if the hostname and the address are properly recognized,
and also if the username lookup works properly.
# remsh host /usr/bin/tryfrom
tryfrom
prints the following output when it is invoked:
client address (%a):
client hostname (%n):
client username (%u):
client info (%c):
server address (%A):
server hostname (%N):
server process (%d):
server info (%s):
The information related to the client describes how the remote host
recognizes the client in terms of address, name and user name. The
information related to the server gives the remote host's
details.
See
hosts_access(5)
manual page for more information on
%letter
expressions.
sffinger
This is a wrapper program to the
finger(1)
client which offers better protection against the possible damage from
data sent by the remote
finger
server. This command accepts all the options
supported by
finger(1).
It is recommended to use this program in the implementation of
traps in the access control language of
/etc/hosts.allow
and
/etc/hosts.deny.
See
hosts_access(5)
man page for more information on setting traps.
This program restricts each line length to 128 bytes and total response to
a maximum of 100000 bytes.
sffinger
uses 60 seconds time-out value in getting the response from the remote host's
finger
server.
AUTHOR
Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands