TCPDMATCH(8) Maintenance Procedures TCPDMATCH(8)


tcpdmatch - tcp wrapper oracle


tcpdmatch [-d] [-i inet_conf] daemon client

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


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
maximal accuracy, it extracts additional information from your inetd
network 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 pretty-printed format; this makes it easier for you to spot
any discrepancies between what you want and what the program understands.


The following two 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 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

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'.


-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 network configuration file, or when you suspect that
the program uses the wrong one.


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

tcpdmatch in.telnetd localhost

The same request, pretending that hostname lookup failed:

tcpdmatch in.telnetd

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

tcpdmatch in.telnetd paranoid

On some systems, daemon names have no `in.' prefix, or tcpdmatch may need
some help to locate the inetd configuration file.


The default locations of the tcpd access control tables are:



tcpdchk(8), tcpd configuration checker
hosts_access(5), format of the tcpd access control tables.
hosts_options(5), format of the language extensions.
inetd.conf(5), format of the inetd control file.
inetd(8), how to invoke tcpd from inetd using the libwrap library.
inetadm(8), managing inetd services in the Service Management Framework.


Wietse Venema (
Department of Mathematics and Computing Science
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513
5600 MB Eindhoven, The Netherlands


See attributes(7) for descriptions of the following attributes:

|Interface Stability | Committed |

September 15, 2011 TCPDMATCH(8)