directionless

  # use as: ssh login1%host1:port1+login2%host2:port2+host3:port3 -l login3
  Host *+*
      ProxyCommand ssh $(echo %h | sed 's/+[^+]*$//;s/\([^+%%]*\)%%\([^+]*\)$/\2 -l \1/;s/:/ -p /') -W $(echo %h | sed 's/^.*+//;/:/!s/$/:%p/')