lis-cain requires custom tftpy which you can clone from https://github.com/atonkyra/tftpy.git
on commit {
set clip = binary-to-ascii(10, 8, ".", leased-address);
set swmac = pick-first-value(binary-to-ascii(16, 8,":",suffix(option agent.remote-id, 6)), "");
set swport = pick-first-value(binary-to-ascii (10, 8, "/", suffix(option agent.circuit-id, 2)), "");
execute("/opt/lis-cain/dhcp-hook.py", clip, swmac, swport);
}