Internal, sets STP state. On BSD-like, it is required to specify the
    STP physical interface

def _bsd_stp(br, state, iface):
    '''
    Internal, sets STP state. On BSD-like, it is required to specify the
    STP physical interface
    '''
    kernel = __grains__['kernel']
    if kernel == 'NetBSD':
        cmd = _tool_path('brconfig')
    else:
        cmd = _tool_path('ifconfig')

    if not br or not iface:
        return False

    return __salt__['cmd.run']('{0} {1} {2} {3}'.format(cmd, br, state, iface),
                               python_shell=False)