Implements add host to drop pool by alert callback (#5405)

scripts/lua/modules/pools/drop_host_pool_utils.lua

@@ -0,0 +1,79 @@
+--
+-- (C) 2017-21 - ntop.org
+--
+
+local dirs = ntop.getDirs()
+package.path = dirs.installdir .. "/scripts/lua/modules/pools/?.lua;" .. package.path
+
+local pools = require "pools"
+local host_pools = require "host_pools"
+
+-- Retrieve the info from the pool
+local pool_info = ntop.getDropPoolInfo()
+    
+local drop_host_pool_utils = {}
+local drop_host_pool_id
+
+-- ############################################
+
+function drop_host_pool_utils.check_periodic_hosts_list()
+    -- Check the list length
+    local list_len = ntop.llenCache(pool_info.list_key)
+
+    if list_len == 0 then
+        return
+    end     
+
+    -- Retrieve the pool
+    local blocked_hosts_pool_id = -2
+    -- Get the pool name
+    local blocked_hosts_pool_name = pools.DROP_HOST_POOL_NAME
+    local host_pool = host_pools:create()
+    local all_pools = host_pool:get_all_pools()
+    local blocked_hosts_pool_members = {}
+
+    -- Check the existance of the pool   
+    for _, value in pairs(all_pools) do
+        if value["name"] == blocked_hosts_pool_name then
+            blocked_hosts_pool_id = value["id"]
+            blocked_hosts_pool_members = value.members
+            goto continue
+        end
+    end
+
+    ::continue::
+
+    -- Check the hosts inside the list
+    while list_len > 0 do
+        local data = ntop.lpopCache(pool_info.list_key)
+        local curr_time = os.time(os.date("!*t"))
+        local host
+        local time
+
+        host, time = data:match("(%w+)_(%w+)")
+
+        -- The host needs to be unbanned
+        if curr_time >= tonumber(time) + pool_info.expiration_time then
+            for i, value in pairs(blocked_hosts_pool_members) do
+                -- Member found, remove it
+                if string.find(value, host) then
+                    host_pool:bind_member(value, 0)
+                    goto continue_check
+                end
+            end        
+            ::continue_check::
+        else
+        -- The host needs to be added again at the start of the list (ordered by time)
+            ntop.lpushCache(pool_info.list_key, data)
+            goto end_check
+        end
+
+        list_len = list_len - 1
+    end 
+
+    ::end_check::
+end 
+
+-- ############################################
+
+return drop_host_pool_utils