Adds REST API and doc for broadcast domains (necessary for tests)

scripts/lua/rest/v1/get/interface/bcast_domains.lua

@@ -0,0 +1,38 @@
+--
+-- (C) 2013-21 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+require "lua_utils"
+local alert_utils = require "alert_utils"
+local json = require("dkjson")
+local rest_utils = require("rest_utils")
+
+--
+-- Read the broadcast domains discovered for an interface
+-- Example: curl -u admin:admin -H "Content-Type: application/json" -d '{"ifid": "1"}' http://localhost:3000/lua/rest/v1/get/interface/bcast_domains.lua
+--
+-- NOTE: in case of invalid login, no error is returned but redirected to login
+--
+
+local rc = rest_utils.consts.success.ok
+local res = {}
+
+local ifid = _GET["ifid"]
+
+if isEmptyString(ifid) then
+   rc = rest_utils.consts.err.invalid_interface
+   rest_utils.answer(rc)
+   return
+end
+
+interface.select(ifid)
+
+local ifstats = interface.getStats()
+
+res.bcast_domains = ifstats.bcast_domains;
+
+rest_utils.answer(rc, res)