Drawbridge 2.0.1

INTRODUCTION:

Drawbridge is a copyrighted but freely distributable bridging IP filter
with a powerful syntax and good performance. It uses a PC with either
two Ethernet cards or two FDDI cards to perform the filtering. It is
composed of three different tools:  Filter, Filter Compiler and Filter
Manager. This distribution is version 2.0.1 which is a major overhaul of
Filter.

To get a better idea of how Drawbridge works and how it is used, begin
with the paper tamu.ps in the doc directory. It describes the entire
suite of TAMU security tools. (Note that this paper is in the process
of being updated, though the portions concerning Drawbridge are up to 
date.)

AVAILABILITY:

Drawbridge is available via anonymous ftp from net.tamu.edu in
pub/security/TAMU as:

drawbridge-2.0.1.tar.gz

The package should untar into 4 directories:

  doc    - directory with documentation about Drawbridge
     (including three papers referenced in the documentation)
  fm     - directory with source code for the Filter Manager plus
     a binary for Solaris 2.3 on Sparc.
  fc     - directory with source code for the Filter Compiler plus
     a binary for Solaris 2.3 on Sparc.
  filter - directory with three PKZIP archives and PKUNZIP.EXE
    ndis.zip   - PKZIP archive containing version 2.1 of the 
           NDIS 2.01 utilities.
    filter.zip - PKZIP archive with source code and
           executable for the Filter.
    config.zip - PKZIP archive with example config.sys,
           protocol.ini, autoexec.bat and the latest 
           SMC driver for the Ethernet cards required 
           by earlier versions of Drawbridge.

And 2 files:

  README   - this file
  COPYING - copyright notice.


REQUIREMENTS:

The requirements are less stringent in Drawbridge version 2.0.1.
Filter is compiled for and requires an 80386 or higher processor (it is
documented in the makefile how to compile specifically for a higher
processor). Any Ethernet or FDDI boards for any bus may be used as long
as they have DOS NDIS 2.01 drivers.

NOTE! These drivers *must* support promiscuous mode, *must* allow you
to configure the driver to support two cards in one PC, and *must*
provide access to the native media frame format. Be careful to confirm
this before you settle on any adapters. Some drivers do not support
these features.

It is recommended that you use a PC with a hard disk, however, you can
build a setup that uses a floppy. The reason for recommending a hard
disk is that when Filter performs a write and writes all of its tables
to disk, *all packet forwarding stops* for the duration of the write.
This may take a substantial amount of time on a floppy depending on
the configuration loaded into Filter.


BUILDING:

The Filter Compiler and Filter Manager both require an ANSI C compiler;
the GNU C Compiler (gcc) is recommended. The Filter has been compiled
with Borland C++ 4.02 and Borland Turbo Assembler 4.0 but will compile
with Borland C++ 3.0. An executable version of Filter is provided in
case you do not have access to these tools.

To build Filter Compiler (fc) and Filter Manager (fm), just go into the
respective directories and type "make <platform>" where <platform> is
solaris, aix, etc. (see the makefile comments for currently supported
platforms). If you type just "make" the makefiles will attempt to build
for Solaris 2.X by default. To install fc and fm, edit the makefiles to
set the destination directory, become root and type "make install".

To build Filter, unarchive the PKZIP archive, go to the source directory
and type "make". (If you don't have Borland C++ you can just use the
supplied executable.)


CONTACTS:

There is now a mailing list for Drawbridge. To subscribe, send email to
majordomo@net.tamu.edu and put subscribe drawbridge in the body of the
message.

Any suggestions or comments on Drawbridge should be sent to the
maintainers at drawbridge-owner@net.tamu.edu.

Any and all feedback on this package is welcome. Also, ports of the
Filter Compiler and Filter Manager to other platforms would be
appreciated.

Drawbridge is designed and programmed by:

David K. Hess
Douglas Lee Schales
David R. Safford

Texas A&M University
March 24, 1997