Adds new REST API v2/

Addresses #5269

scripts/lua/rest/v2/get/flow/l4/counters.lua

@@ -0,0 +1,43 @@
+--
+-- (C) 2013-21 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
+
+require "lua_utils"
+local json = require ("dkjson")
+local tracker = require("tracker")
+local rest_utils = require("rest_utils")
+
+--
+-- Read number of active flows per protocol
+-- Example: curl -u admin:admin -H "Content-Type: application/json" -d '{"ifid": "1"}' http://localhost:3000/lua/rest/v2/get/flow/l4/counters.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
+   rest_utils.answer(rest_utils.consts.err.invalid_interface)
+   return
+end
+
+interface.select(ifid)
+
+local flowstats = interface.getActiveFlowsStats()
+local l4_proto = flowstats["l4_protocols"]
+
+for k,v in pairs(l4_proto, asc) do
+   res[#res + 1] = {
+      id = k,
+      count = v.count,
+   }
+end
+
+rest_utils.answer(rc, res)
+