ntopng/scripts/callbacks/interface/alerts/host/request_reply_ratio.lua
2019-08-26 18:38:34 +02:00

68 lines
2.1 KiB
Lua

--
-- (C) 2019 - ntop.org
--
local alerts_api = require("alerts_api")
local alert_consts = require("alert_consts")
-- #################################################################
local function request_reply_ratio(params)
local info = params.entity_info
-- {requests, replies}
local to_check = {}
if(info["dns"] ~= nil) then
to_check["dns_sent"] = {info["dns"]["sent"]["num_queries"], (info["dns"]["sent"]["num_replies_ok"] + info["dns"]["sent"]["num_replies_error"])}
to_check["dns_rcvd"] = {info["dns"]["rcvd"]["num_queries"], (info["dns"]["rcvd"]["num_replies_ok"] + info["dns"]["rcvd"]["num_replies_error"])}
end
for key, values in pairs(to_check) do
local requests = values[1]
local replies = values[2]
local ratio = (replies * 100) / (requests+1)
local req_repl_type = alerts_api.requestReplyRatioType(key, requests, replies, params.granularity)
-- 10: some meaningful value
if((requests + replies > 10) and (ratio < tonumber(params.alert_config.edge))) then
alerts_api.trigger(params.alert_entity, req_repl_type)
else
alerts_api.release(params.alert_entity, req_repl_type)
end
end
end
-- #################################################################
local check_module = {
key = "request_reply_ratio",
check_function = request_reply_ratio,
default_value = "request_reply_ratio;lt;15", -- 15%
local_only = true,
granularity = {
-- executed only in the minute-by-minute check
"min"
},
gui = {
i18n_title = "entity_thresholds.request_reply_ratio_title",
i18n_description = "entity_thresholds.request_reply_ratio_description",
i18n_field_unit = alert_consts.field_units.percentage,
input_builder = alerts_api.threshold_cross_input_builder,
field_max = 65535,
field_min = 1,
field_operator = "lt";
}
}
-- #################################################################
function check_module.get_threshold_value(granularity, info)
return(info["hits.syn_flood_attacker"] or 0)
end
-- #################################################################
return check_module