Reworks plugin loading and structure

Implements #4358

scripts/plugins/monitors/system/mud/user_scripts/flow/mud.lua

@@ -0,0 +1,65 @@
+--
+-- (C) 2019-20 - ntop.org
+--
+
+local mud_utils = require "mud_utils"
+local user_scripts = require("user_scripts")
+local discover = require("discover_utils")
+
+local enabled_device_types
+local max_recording
+
+-- #################################################################
+
+local script = {
+   -- Script category
+   category = user_scripts.script_categories.security,
+
+   -- NOTE: hooks defined below
+   hooks = {},
+   default_enabled = false,
+
+   default_value = {
+    device_types = {'printer', 'video', 'iot'},
+    max_recording = 3600,
+  },
+
+   gui = {
+      i18n_title = "flow_callbacks_config.mud",
+      i18n_description = "flow_callbacks_config.mud_description",
+      input_builder = "flow_mud",
+      item_list_type = "device_type",
+   }
+}
+
+-- #################################################################
+
+function script.setup()
+  enabled_device_types = nil
+
+  return(true)
+end
+
+-- #################################################################
+
+function script.hooks.protocolDetected(now, conf)
+  if(enabled_device_types == nil) then
+    local device_types = conf.device_types or script.default_value.device_types
+    max_recording = conf.max_recording or script.default_value.max_recording
+  
+    enabled_device_types = {}
+
+    -- Convert the device type into an ID
+    for _, devtype in pairs(device_types) do
+      local id = discover.devtype2id(devtype)
+
+      enabled_device_types[id] = true
+    end
+  end
+
+  mud_utils.handleFlow(now, enabled_device_types, max_recording)
+end
+
+-- #################################################################
+
+return script