Shitty hack to work around broken CEC logic in XBMC. XBMC will just not execute any CEC command when it can't find a TV in the CEC network. I switch off my TV with sispmctl when i listen to music in the evening, so volup/down is broken.
This hack is basicaly throwing together the examples from libubus and libcec to create a frankendaemon that will respond to
ubus-invoke /var/ubus/cec volup
on keypress in keymap.xml.
since xbmcs Exec() crashes, i use ExecScript(bla.py) which does os.system()