@(#) README 1.30 97/03/21 19:27:21

This is the 7.6 version of the TCP/IP daemon wrapper package.

Thank you for using this program. If you like it, send me a postcard.
My postal address is at the bottom of this file.

Read the BLURB file for a brief summary of what is new. The CHANGES
file gives a complete account of differences with respect to previous
releases.

Announcements of new releases of this software are posted to Usenet
(comp.security.unix, comp.unix.admin), to the cert-tools mailing list,
and to a dedicated mailing list.  You can subscribe to the dedicated
mailing list by sending an email message to majordomo@wzv.win.tue.nl
with in the body (not subject):  subscribe tcp-wrappers-announce.

Table of contents
-----------------

    1 - Introduction
    2 - Disclaimer
    3 - Tutorials
                3.1 - How it works
                3.2 - Where the logging information goes
    4 - Features
                4.1 - Access control
                4.2 - Host name spoofing
                4.3 - Host address spoofing
                4.4 - Client username lookups
                4.5 - Language extensions
		4.6 - Multiple ftp/gopher/www archives on one host
		4.7 - Banner messages
		4.8 - Sequence number guessing
    5 - Other works
                5.1 - Related documents
                5.2 - Related software
    6 - Limitations
                6.1 - Known wrapper limitations
                6.2 - Known system software bugs
    7 - Configuration and installation
                7.1 - Easy configuration and installation
                7.2 - Advanced configuration and installation
                7.3 - Daemons with arbitrary path names
                7.4 - Building and testing the access control rules
                7.5 - Other applications
    8 - Acknowledgements

1 - Introduction
----------------

With this package you can monitor and filter incoming requests for the
SYSTAT, FINGER, FTP, TELNET, RLOGIN, RSH, EXEC, TFTP, TALK, and other
network services.

It supports both 4.3BSD-style sockets and System V.4-style TLI. Praise
yourself lucky if you don't know what that means.

The package provides tiny daemon wrapper programs that can be installed
without any changes to existing software or to existing configuration
files.  The wrappers report the name of the client host and of the
requested service; the wrappers do not exchange information with the
client or server applications, and impose no overhead on the actual
conversation between the client and server applications.

Optional features are: access control to restrict what systems can
connect to what network daemons; client user name lookups with the RFC
931 etc. protocol; additional protection against hosts that pretend to
have someone elses host name; additional protection against hosts that
pretend to have someone elses host address.

The programs are very portable. Build procedures are provided for many
common (and not so common) environments, and guidelines are provided in
case your environment is not among them.

Requirements are that network daemons are spawned by a super server
such as the inetd; a 4.3BSD-style socket programming interface and/or
System V.4-style TLI programming interface; and the availability of a
syslog(3) library and of a syslogd(8) daemon.  The wrappers should run
without modification on any system that satisfies these requirements.
Workarounds have been implemented for several common bugs in systems
software.

What to do if this is your first encounter with the wrapper programs:
1) read the tutorial sections for an introduction to the relevant
concepts and terminology; 2) glance over the security feature sections
in this document; 3) follow the installation instructions (easy or
advanced). I recommend that you first use the default security feature
settings.  Run the wrappers for a few days to become familiar with
their logs, before doing anything drastic such as cutting off access or
installing booby traps.

2 - Disclaimer
--------------

The wrapper programs rely on source address information obtained from
network packets. This information is provided by the client host. It is
not 100 percent reliable, although the wrappers do their best to expose
forgeries.

In the absence of cryptographic protection of message contents, and of
cryptographic authentication of message originators, all data from the
network should be treated with sound scepticism.

THIS RESTRICTION IS BY NO MEANS SPECIFIC TO THE TCP/IP PROTOCOLS.

3 - Tutorials
-------------

The tutorial sections give a gentle introduction to the operation of
the wrapper programs, and introduce some of the terminology that is
used in the remainder of the document: client, server, the inetd and
syslogd daemons, and their configuration files.

3.1 - How it works
------------------

Almost every a                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       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