           SPELL=knock
         VERSION=0.5
      PATCHLEVEL=1
          SOURCE=$SPELL-$VERSION.tar.gz
SOURCE_DIRECTORY="$BUILD_DIRECTORY/$SPELL-$VERSION"
   SOURCE_URL[0]=http://www.zeroflux.org/proj/$SPELL/files/$SOURCE
        WEB_SITE=http://www.zeroflux.org/projects/knock
         ENTERED=20060529
     SOURCE_HASH=sha512:c5f7f3320d4d9a41847dba0cda4d66852f983db419b23d3bf9c83d44a41ba437379bf6cee47a096c600841e321740849dac26d5c3afff9b3ae0178a2fcb6c35e
      LICENSE[0]=GPL
     GATHER_DOCS=off
           SHORT="port-knocking server and client"
cat << EOF
Port knocking is a stealthy system for network authentication across closed
ports.

knockd is a port-knock server. It listens to all traffic on an ethernet (or PPP)
interface, looking for special "knock" sequences of port-hits. A client makes
these port-hits by sending a TCP (or UDP) packet to a port on the server.

This port need not be open -- since knockd listens at the link-layer level,
it sees all traffic even if it's destined for a closed port. When the server
detects a specific sequence of port-hits, it runs a command defined in its
configuration file.

This can be used to open up holes in a firewall for quick access.
EOF
