# Pastebin 4KvmSnFU
local function auth(client, data)
 -- Authentication here
end

local function run(client, data)
 -- Running code here
end

local dispatch = { ["auth"] = do_auth, ["run"] = do_run}

......
somewhere down in the code later:
......

local state = "auth"
while true do
    data = get_next_packet()

    state = dispatch[state](client, data)
end