tcpdmatch(1)

NAME

tcpdmatch — evaluate tcp wrapper service requests

SYNOPSYS

/usr/bin/tcpdmatch [-d] [-i inet_conf] daemon client

/usr/bin/tcpdmatch [-d] [-i inet_conf] daemon[@server] [user @]client

DESCRIPTION

tcpdmatch predicts how the tcp wrapper would handle a specific request for service. Examples are given below.

The program examines the tcpd access control tables (default /etc/hosts.allow and /etc/hosts.deny) and prints its conclusion. For maximum accuracy, it extracts additional information from the inetd configuration file.

When tcpdmatch finds a match in the access control tables, it identifies the matched rule. In addition, it displays the optional shell commands or options in a printable format. The display helps you find any discrepancies between what you want and what tcpdmatch understands for the access control rules.

Arguments

The daemon and client arguments are always required.

daemon

A daemon process name. Typically, the last component of a daemon executable pathname.

client

A host name or network address, or one of the `unknown' or `paranoid' wildcard patterns.

When a client host name is specified, tcpdmatch gives a prediction for each address listed for that client.

When a client address is specified, tcpdmatch predicts what tcpd would do when the client name lookup fails.

Optional information specified with the daemon@server form:

server: A host name or network address, or one of the `unknown' or `paranoid' wildcard patterns. The default server name is `unknown'.

Optional information specified with the user@client form:

user: A client user identifier. Typically, a login name or a numeric userid. The default user name is `unknown'.

Options

-d: Examine hosts.allow and hosts.deny files in the current directory instead of the default ones.
-i inet_conf: Specify this option when tcpdmatch is unable to find your inetd.conf configuration file, or when you suspect that tcpdmatch is using the wrong file. inet_conf is the path name of the inetd.conf configuration file whose entries you want to examine.

EXAMPLES

To predict how tcpd would handle a telnet request from the local system:

tcpdmatch telnetd localhost

The same request, pretending that hostname lookup failed:

tcpdmatch telnetd 127.0.0.1

To predict what tcpd would do when the client name does not match the client address:

tcpdmatch telnetd paranoid

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

FILES

The default locations of the tcpd access control tables are:

/etc/hosts.allow: (daemon, client) pairs that are granted access.
/etc/hosts.deny: (daemon, client) pairs that are denied access.

tcpdmatch(1)

Technical documentation

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