#!/bin/bash -

# Round-Robin Login to a Machine by SSH
# By Andre Masella (andre at masella dot no dash ip dot org)

# To login, just run this script. Run with -auth to register all machines
# in known_hosts.

TEMP=`getopt -o am:d: -n 'sshany' -- "$@"`

if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi

eval set -- "$TEMP"

AUTH=no

while true ; do
        case "$1" in
                -m)
                        machines="$machines $2$domain"
                        shift 2
                        ;;
                -d)
                        domain=".$2"
                        shift 2
                        ;;
                -a)
                        AUTH="yes"
                        shift
                        ;;
                --)
                        shift
                        break
                        ;;
                *) echo "Internal error!" ; exit 1 ;;
        esac
done

if [ "x$machines" = x ]
then
	echo "$0 [-d domainsuffix] -m machine1 -m machine2 ... [ -d domainsuffix -m machineA -m machine B ...] -- paramaters to ssh"
	exit 1
fi

# Check if the user wants to build the fingerprint cache...
if [ $AUTH = yes ]
then
	echo "Building Authentication List..."
	
	for machine in $machines
	do
		# Check if the host is up.
		if nc -w 1 -z $machine 22 2>/dev/null
		then
			echo "Registering $machine"
			# Obliterate it from the known_hosts file.
			sed -i '/^'$machine'/d' ~/.ssh/known_hosts
			# Request the key.
			ssh-keyscan -t rsa,dsa $machine 2> /dev/null >>  ~/.ssh/known_hosts
		else
			echo "$machine is unavailable."
		fi
	done
	exit 0
fi

while [ ! -z "$machines" ]
do
	# Pick a host.
	count=`echo $machines | wc -w | tr -d " "`
	machine=`echo $machines | cut -f $(($count*$RANDOM/32768 + 1)) -d " "`
	machines="`echo $machines | sed -e "s/$machine//g;s/  / /g;s/^ //g;s/ $//g"`"

	# Try to login
	nc -w 1 -z $machine 22 && exec ssh -X $machine "$@"
done

exit 1