gatekeeper(1)

NAME
gatekeeper - a simple firewall daemon.

SYNOPSIS
gatekeeper inside-if outside-if

DESCRIPTION
gatekeeper is a daemon that manages kernel packet filters as well as user-level connection filtering between two ethernet interfaces. Filtering rules are read from the file /etc/gatekeeper.cf [gatekeeper.cf(5)] at startup and when a HUP signal is sent to the gatekeeper process. The inside interface needs to be up and have an IP address, and the outside interface needs to be up, but not have an IP address.

For gatekeeper to work, you need a specially patched version of the Linux kernel; the Webshield (these kernel modifications were written as part of the original Webshield project at McAfee, and are thus GPLed) patches allow you to set up a bridge between two interfaces where one interface (the internal interface) is a regular interface, with IP address and everything, but the other interface (the external interface) having no IP address or any other way of being accessed.

When running, a gatekeeper daemon is controlled by signals.

HUP causes gatekeeper to flush and reload its filter rules from /etc/gatekeeper.cf

USR1
    turns on connection filter logging to syslog.

USR2
    turns off connection filter logging to syslog.

NOTES
The necessary patches to the 2.0.28 Linux kernel can be found at http://www.pell.portland.or.us/~orc/Webshield or on recent Mastodon distributions.

BUGS
There is no nice way of logging kernel packet filter activities. You need to set up that logging with other programs.

AUTHOR
David Parsons <orc@pell.chi.il.us>

SEE ALSO
gatekeeper(8), gatekeeper.cf(5), brcmd(1), ipfw(1), fwlint(1).