From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Thu, 5 Apr 2018 19:22:20 +0000 (+0100)
Subject: [Rework] Restore leaky bucket model in ratelimit plugin
X-Git-Tag: 1.7.3~27
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1f0732d5bcd916c8d005800eeef98c2257d3e822;p=thirdparty%2Frspamd.git

[Rework] Restore leaky bucket model in ratelimit plugin
---

diff --git a/src/plugins/lua/ratelimit.lua b/src/plugins/lua/ratelimit.lua
index 8e5cab328d..54c40dc771 100644
--- a/src/plugins/lua/ratelimit.lua
+++ b/src/plugins/lua/ratelimit.lua
@@ -21,27 +21,124 @@ end
 
 -- A plugin that implements ratelimits using redis
 
-local E, settings = {}, {}
+local E = {}
 local N = 'ratelimit'
+local redis_params
 -- Senders that are considered as bounce
-local bounce_senders = {'postmaster', 'mailer-daemon', '', 'null', 'fetchmail-daemon', 'mdaemon'}
+local settings = {
+  bounce_senders = { 'postmaster', 'mailer-daemon', '', 'null', 'fetchmail-daemon', 'mdaemon' },
 -- Do not check ratelimits for these recipients
-local whitelisted_rcpts = {'postmaster', 'mailer-daemon'}
-local whitelisted_ip
-local whitelisted_user
-local max_rcpt = 5
-local redis_params
-local ratelimit_symbol
-local info_symbol
--- Do not delay mail after 1 day
-local use_ip_score = false
-local rl_prefix = 'RL'
-local ip_score_lower_bound = 10
-local ip_score_ham_multiplier = 1.1
-local ip_score_spam_divisor = 1.1
-local limits_hash
-
-local message_func = function(_, limit_type)
+  whitelisted_rcpts = { 'postmaster', 'mailer-daemon' },
+  whitelisted_ip = {},
+  whitelisted_user = {},
+  prefix = 'RL',
+  ham_factor_rate = 1.01,
+  spam_factor_rate = 0.99,
+  ham_factor_burst = 1.02,
+  spam_factor_burst = 0.98,
+  max_rate_mult = 5,
+  max_bucket_mult = 10,
+  expire = 60 * 60 * 24 * 2, -- 2 days by default
+  limits = {},
+  allow_local = false,
+}
+
+-- Checks bucket, updating it if needed
+-- KEYS[1] - prefix to update, e.g. RL_<triplet>_<seconds>
+-- KEYS[2] - current time in milliseconds
+-- KEYS[3] - bucket leak rate (messages per millisecond)
+-- KEYS[4] - bucket burst
+-- KEYS[5] - expire for a bucket
+-- return 1 if message should be ratelimited and 0 if not
+-- Redis keys used:
+--   l - last hit
+--   b - current burst
+--   dr - current dynamic rate multiplier (*10000)
+--   db - current dynamic burst multiplier (*10000)
+local bucket_check_script = [[
+  local last = redis.call('HGET', KEYS[1], 'l')
+  local now = tonumber(KEYS[2])
+  if not last then
+    -- New bucket
+    redis.call('HSET', KEYS[1], 'l', KEYS[2])
+    redis.call('HSET', KEYS[1], 'b', '0')
+    redis.call('HSET', KEYS[1], 'dr', '10000')
+    redis.call('HSET', KEYS[1], 'db', '10000')
+    redis.call('EXPIRE', KEYS[1], KEYS[5])
+    return 0
+  end
+
+  last = tonumber(last)
+  local burst = tonumber(redis.call('HGET', KEYS[1], 'b'))
+  -- Perform leak
+  if burst > 0 then
+   if last < tonumber(KEYS[2]) then
+    local rate = tonumber(KEYS[3])
+    local dyn = tonumber(redis.call('HGET', KEYS[1], 'dr')) / 10000.0
+    rate = rate * dyn
+    redis.call('HINCRBYFLOAT', KEYS[1], 'b', -((now - last) * rate))
+   end
+   local dyn = tonumber(redis.call('HGET', KEYS[1], 'db')) / 10000.0
+
+   if tonumber(burst) * tonumber(dyn) > tonumber(KEYS[4]) then
+    return 1
+   end
+  else
+    redis.call('HSET', KEYS[1], 'b', '0')
+  end
+
+  return 0
+]]
+local bucket_check_id
+
+
+-- Updates a bucket
+-- KEYS[1] - prefix to update, e.g. RL_<triplet>_<seconds>
+-- KEYS[2] - current time in milliseconds
+-- KEYS[3] - dynamic rate multiplier
+-- KEYS[4] - dynamic burst multiplier
+-- KEYS[5] - max dyn rate (min: 1/x)
+-- KEYS[6] - max burst rate (min: 1/x)
+-- KEYS[7] - expire for a bucket
+-- Redis keys used:
+--   l - last hit
+--   b - current burst
+--   dr - current dynamic rate multiplier
+--   db - current dynamic burst multiplier
+local bucket_update_script = [[
+  local last = redis.call('HGET', KEYS[1], 'l')
+  local now = tonumber(KEYS[2])
+  if not last then
+    -- New bucket
+    redis.call('HSET', KEYS[1], 'l', KEYS[2])
+    redis.call('HSET', KEYS[1], 'b', '1')
+    redis.call('HSET', KEYS[1], 'dr', '10000')
+    redis.call('HSET', KEYS[1], 'db', '10000')
+    redis.call('EXPIRE', KEYS[1], KEYS[7])
+    return
+  end
+
+  local burst = tonumber(redis.call('HGET', KEYS[1], 'b'))
+  local db = tonumber(redis.call('HGET', KEYS[1], 'db')) / 10000
+  local dr = tonumber(redis.call('HGET', KEYS[1], 'dr')) / 10000
+
+  if dr < tonumber(KEYS[5]) and dr > 1.0 / tonumber(KEYS[5]) then
+    dr = dr * tonumber(KEYS[3])
+    redis.call('HSET', KEYS[1], 'dr', tostring(math.floor(dr * 10000)))
+  end
+
+  if db < tonumber(KEYS[6]) and db > 1.0 / tonumber(KEYS[6]) then
+    db = db * tonumber(KEYS[4])
+    redis.call('HSET', KEYS[1], 'db', tostring(math.floor(db * 10000)))
+  end
+
+  redis.call('HINCRBYFLOAT', KEYS[1], 'b', 1)
+  redis.call('HSET', KEYS[1], 'l', KEYS[2])
+  redis.call('EXPIRE', KEYS[1], KEYS[7])
+]]
+local bucket_update_id
+
+local message_func = function(_, limit_type, _)
   return string.format('Ratelimit "%s" exceeded', limit_type)
 end
 
@@ -53,120 +150,11 @@ local fun = require "fun"
 local lua_maps = require "lua_maps"
 local lua_util = require "lua_util"
 
-local user_keywords = {'user'}
-
-local redis_script_id
-local redis_script = [[local bucket
-local limited = false
-local buckets = {}
-local queue_id = table.remove(ARGV)
-local now = table.remove(ARGV)
-
-local argi = 0
-for i = 1, #KEYS do
-  local key = KEYS[i]
-  local period = tonumber(ARGV[argi+1])
-  local limit = tonumber(ARGV[argi+2])
-  if not buckets[key] then
-    buckets[key] = {
-      max_period = period,
-      limits = { {period, limit} },
-    }
-  else
-    table.insert(buckets[key].limits, {period, limit})
-    if period > buckets[key].max_period then
-      buckets[key].max_period = period
-    end
-  end
-  argi = argi + 2
-end
 
-for k, v in pairs(buckets) do
-  local maxp = v.max_period
-  redis.call('ZREMRANGEBYSCORE', k, '-inf', now - maxp)
-  for _, lim in ipairs(v.limits) do
-    local period = lim[1]
-    local limit = lim[2]
-    local rate
-    if period == maxp then
-      rate = redis.call('ZCARD', k)
-    else
-      rate = redis.call('ZCOUNT', k, now - period, '+inf')
-    end
-    if rate and rate >= limit then
-      limited = true
-      bucket = k
-    end
-  end
-  redis.call('EXPIRE', k, maxp)
-  if limited then break end
-end
-
-if not limited then
-  for k in pairs(buckets) do
-    redis.call('ZADD', k, now, queue_id)
-  end
-end
-
-return {limited, bucket}]]
-
-local redis_script_symbol = [[local limited = false
-local buckets, results = {}, {}
-local queue_id = table.remove(ARGV)
-local now = table.remove(ARGV)
-
-local argi = 0
-for i = 1, #KEYS do
-  local key = KEYS[i]
-  local period = tonumber(ARGV[argi+1])
-  local limit = tonumber(ARGV[argi+2])
-  if not buckets[key] then
-    buckets[key] = {
-      max_period = period,
-      limits = { {period, limit} },
-    }
-  else
-    table.insert(buckets[key].limits, {period, limit})
-    if period > buckets[key].max_period then
-      buckets[key].max_period = period
-    end
-  end
-  argi = argi + 2
-end
-
-for k, v in pairs(buckets) do
-  local maxp = v.max_period
-  redis.call('ZREMRANGEBYSCORE', k, '-inf', now - maxp)
-  for _, lim in ipairs(v.limits) do
-    local period = lim[1]
-    local limit = lim[2]
-    local rate
-    if period == maxp then
-      rate = redis.call('ZCARD', k)
-    else
-      rate = redis.call('ZCOUNT', k, now - period, '+inf')
-    end
-    if rate then
-      local mult = 2 * math.tanh(rate / (limit * 2))
-      if mult >= 0.5 then
-        table.insert(results, {k, tostring(mult)})
-      end
-    end
-  end
-  redis.call('ZADD', k, now, queue_id)
-  redis.call('EXPIRE', k, maxp)
-end
-
-return results]]
 
 local function load_scripts(cfg, ev_base)
-  local script
-  if ratelimit_symbol then
-    script = redis_script_symbol
-  else
-    script = redis_script
-  end
-  redis_script_id = lua_redis.add_redis_script(script, redis_params)
+  bucket_check_id = lua_redis.add_redis_script(bucket_check_script, redis_params)
+  bucket_update_id = lua_redis.add_redis_script(bucket_update_script, redis_params)
 end
 
 local limit_parser
@@ -233,43 +221,23 @@ local function parse_string_limit(lim, no_error)
   return nil
 end
 
-local function resize_element(x_score, x_total, element)
-  local x_ip_score
-  if not x_total then x_total = 0 end
-  if x_total < ip_score_lower_bound or x_total <= 0 then
-    x_score = 1
-  else
-    x_score = x_score / x_total
-  end
-  if x_score > 0 then
-    x_ip_score = x_score / ip_score_spam_divisor
-    element = element * rspamd_util.tanh(2.718281 * x_ip_score)
-  elseif x_score < 0 then
-    x_ip_score = ((1 + (x_score * -1)) * ip_score_ham_multiplier)
-    element = element * x_ip_score
-  end
-  return element
-end
-
 --- Check whether this addr is bounce
 local function check_bounce(from)
-  return fun.any(function(b) return b == from end, bounce_senders)
+  return fun.any(function(b) return b == from end, settings.bounce_senders)
 end
 
-local custom_keywords = {}
-
 local keywords = {
   ['ip'] = {
-    ['get_value'] = function(task)
+    get_value = function(task)
       local ip = task:get_ip()
-      if ip and ip:is_valid() then return ip end
+      if ip and ip:is_valid() then return tostring(ip) end
       return nil
     end,
   },
   ['rip'] = {
     ['get_value'] = function(task)
       local ip = task:get_ip()
-      if ip and ip:is_valid() and not ip:is_local() then return ip end
+      if ip and ip:is_valid() and not ip:is_local() then return tostring(ip) end
       return nil
     end,
   },
@@ -312,140 +280,44 @@ local keywords = {
     end,
   },
   ['to'] = {
-    ['get_value'] = function()
-      return '%s' -- 'to' is special
+    ['get_value'] = function(task)
+      return task:get_principal_recipient()
     end,
   },
 }
 
-local function dynamic_rate_key(task, rtype)
-  local key_t = {rl_prefix, rtype}
-  local key_keywords = rspamd_str_split(rtype, '_')
-  local have_to, have_user = false, false
+local function gen_rate_key(task, rtype, bucket)
+  local key_t = {settings.prefix, tostring(lua_util.round(100000.0 / bucket[1]))}
+  local key_keywords = lua_util.str_split(rtype, '_')
+  local have_user = false
+
   for _, v in ipairs(key_keywords) do
-    if (custom_keywords[v] and type(custom_keywords[v]['condition']) == 'function') then
-      if not custom_keywords[v]['condition']() then return nil end
-    end
     local ret
-    if custom_keywords[v] and type(custom_keywords[v]['get_value']) == 'function' then
-      ret = custom_keywords[v]['get_value'](task)
-    elseif keywords[v] and type(keywords[v]['get_value']) == 'function' then
+
+    if keywords[v] and type(keywords[v]['get_value']) == 'function' then
       ret = keywords[v]['get_value'](task)
     end
     if not ret then return nil end
-    for _, uk in ipairs(user_keywords) do
-      if v == uk then have_user = true end
-      if have_user then break end
-    end
-    if v == 'to' then have_to = true end
+    if v == 'user' then have_user = true end
     if type(ret) ~= 'string' then ret = tostring(ret) end
     table.insert(key_t, ret)
   end
-  if (not have_user) and task:get_user() then
+
+  if have_user and not task:get_user() then
     return nil
   end
-  if not have_to then
-    return table.concat(key_t, ":")
-  else
-    local rate_keys = {}
-    local rcpts = task:get_recipients(0)
-    if not ((rcpts or E)[1] or E).addr then
-      return nil
-    end
-    local key_s = table.concat(key_t, ":")
-    local total_rcpt = 0
-    for _, r in ipairs(rcpts) do
-      if r['addr'] and total_rcpt < max_rcpt then
-        local key_f = string.format(key_s, string.lower(r['addr']))
-        table.insert(rate_keys, key_f)
-        total_rcpt = total_rcpt + 1
-      end
-    end
-    return rate_keys
-  end
-end
 
-local function process_buckets(task, buckets)
-  if not buckets then return end
-  local function rl_redis_cb(err, data)
-    if err then
-      rspamd_logger.infox(task, 'got error while setting limit: %1', err)
-    end
-    if not data then return end
-    if data[1] == 1 then
-      if info_symbol then
-        task:insert_result(info_symbol, 1.0, data[2])
-      end
-      rspamd_logger.infox(task,
-        'ratelimit "%s" exceeded',
-        data[2])
-      task:set_pre_result('soft reject',
-        message_func(task, data[2]))
-    end
-  end
-  local function rl_symbol_redis_cb(err, data)
-    if err then
-      rspamd_logger.infox(task, 'got error while setting limit: %1', err)
-    end
-    if not data then return end
-    for i, b in ipairs(data) do
-      task:insert_result(ratelimit_symbol, b[2], string.format('%s:%s:%s', i, b[1], b[2]))
-    end
-  end
-  local redis_cb = rl_redis_cb
-  if ratelimit_symbol then redis_cb = rl_symbol_redis_cb end
-  local kwargs, args = {}, {}
-  for _, bucket in ipairs(buckets) do
-    table.insert(kwargs, bucket[2])
-  end
-  for _, bucket in ipairs(buckets) do
-    if use_ip_score then
-      local asn_score,total_asn,
-        country_score,total_country,
-        ipnet_score,total_ipnet,
-        ip_score, total_ip = task:get_mempool():get_variable('ip_score',
-        'double,double,double,double,double,double,double,double')
-      local key_keywords = rspamd_str_split(bucket[2], '_')
-      local has_asn, has_ip = false, false
-      for _, v in ipairs(key_keywords) do
-        if v == "asn" then has_asn = true end
-        if v == "ip" then has_ip = true end
-        if has_ip and has_asn then break end
-      end
-      if has_asn and not has_ip then
-        bucket[1][2] = resize_element(asn_score, total_asn, bucket[1][2])
-      elseif has_ip then
-        if total_ip and total_ip > ip_score_lower_bound then
-          bucket[1][2] = resize_element(ip_score, total_ip, bucket[1][2])
-        elseif total_ipnet and total_ipnet > ip_score_lower_bound then
-          bucket[1][2] = resize_element(ipnet_score, total_ipnet, bucket[1][2])
-        elseif total_asn and total_asn > ip_score_lower_bound then
-          bucket[1][2] = resize_element(asn_score, total_asn, bucket[1][2])
-        elseif total_country and total_country > ip_score_lower_bound then
-          bucket[1][2] = resize_element(country_score, total_country, bucket[1][2])
-        else
-          bucket[1][2] = resize_element(ip_score, total_ip, bucket[1][2])
-        end
-      end
-    end
-    table.insert(args, bucket[1][1])
-    table.insert(args, bucket[1][2])
-  end
-  table.insert(args, rspamd_util.get_time())
-  table.insert(args, task:get_queue_id() or task:get_uid())
-  local ret = lua_redis.exec_redis_script(redis_script_id, {task = task, is_write = true}, redis_cb, kwargs, args)
-  if not ret then
-    rspamd_logger.errx(task, 'got error connecting to redis')
-  end
+  return table.concat(key_t, ":")
 end
 
 local function ratelimit_cb(task)
-  if rspamd_lua_utils.is_rspamc_or_controller(task) then return end
-  local args = {}
+  if not settings.allow_local and
+          rspamd_lua_utils.is_rspamc_or_controller(task) then return end
+
   -- Get initial task data
   local ip = task:get_from_ip()
-  if ip and ip:is_valid() and whitelisted_ip then
-    if whitelisted_ip:get_key(ip) then
+  if ip and ip:is_valid() and settings.whitelisted_ip then
+    if settings.whitelisted_ip:get_key(ip) then
       -- Do not check whitelisted ip
       rspamd_logger.infox(task, 'skip ratelimit for whitelisted IP')
       return
@@ -459,131 +331,121 @@ local function ratelimit_cb(task)
       fun.each(function(type) table.insert(rcpts_user, r[type]) end, {'user', 'addr'})
     end, rcpts)
 
-    if fun.any(function(r) return whitelisted_rcpts:get_key(r) end, rcpts_user) then
+    if fun.any(function(r) return settings.whitelisted_rcpts:get_key(r) end, rcpts_user) then
       rspamd_logger.infox(task, 'skip ratelimit for whitelisted recipient')
       return
     end
   end
   -- Get user (authuser)
-  if whitelisted_user then
+  if settings.whitelisted_user then
     local auser = task:get_user()
-    if whitelisted_user:get_key(auser) then
+    if settings.whitelisted_user:get_key(auser) then
       rspamd_logger.infox(task, 'skip ratelimit for whitelisted user')
       return
     end
   end
+  -- Now create all ratelimit prefixes
+  local prefixes = {}
+  local nprefixes = 0
+
+  for k,v in pairs(settings.limits) do
+    for _,bucket in ipairs(v) do
+      local prefix = gen_rate_key(task, k, bucket)
+
+      if prefix then
+        prefixes[prefix] = bucket
+        nprefixes = nprefixes + 1
+      end
+    end
+  end
 
-  local redis_keys = {}
-  local redis_keys_rev = {}
-  local function collect_redis_keys()
-    local function collect_cb(err, data)
+  local function gen_check_cb(prefix, bucket)
+    return function(err, data)
       if err then
-        rspamd_logger.errx(task, 'redis error: %1', err)
-      else
-        for i, d in ipairs(data) do
-          if type(d) == 'string' then
-            local plim, size = parse_string_limit(d)
-            if plim then
-              table.insert(args, {{plim, size}, redis_keys_rev[i]})
-            end
-          end
+        rspamd_logger.errx('cannot check limit %s: %s %s', prefix, err, data)
+      end
+      if data and data == 1 then
+        if settings.info_symbol then
+          task:insert_result(settings.info_symbol, 1.0, prefix)
         end
-        return process_buckets(task, args)
+        rspamd_logger.infox(task,
+                'ratelimit "%s" exceeded, (%s / %s)',
+                prefix, bucket[2], bucket[1])
+        task:set_pre_result('soft reject',
+                message_func(task, prefix, bucket))
       end
     end
-    local params, method
-    if limits_hash then
-      params = {limits_hash, rspamd_lua_utils.unpack(redis_keys)}
-      method = 'HMGET'
-    else
-      method = 'MGET'
-      params = redis_keys
-    end
-    local requested_keys = rspamd_redis_make_request(task,
-      redis_params, -- connect params
-      nil, -- hash key
-      true, -- is write
-      collect_cb, --callback
-      method, -- command
-      params -- arguments
-    )
-    if not requested_keys then
-      rspamd_logger.errx(task, 'got error connecting to redis')
-      return process_buckets(task, args)
+  end
+
+  if nprefixes > 0 then
+    -- Save prefixes to the cache to allow update
+    task:cache_set('ratelimit_prefixes', prefixes)
+    local now = rspamd_util.get_time()
+    now = lua_util.round(now * 1000.0) -- Get milliseconds
+    -- Now call check script for all defined prefixes
+
+    for pr,bucket in pairs(prefixes) do
+      local rate = (1.0 / bucket[1]) / 1000.0 -- Leak rate in messages/ms
+      rspamd_logger.debugm(N, task, "check limit %s (%s/%s)",
+          pr, bucket[2], bucket[1])
+      lua_redis.exec_redis_script(bucket_check_id,
+              {task = task, is_write = true},
+              gen_check_cb(pr, bucket),
+              {pr, tostring(now), tostring(rate), tostring(bucket[2]),
+                  tostring(settings.expire)})
     end
   end
+end
 
-  local rate_key
-  for k in pairs(settings) do
-    rate_key = dynamic_rate_key(task, k)
-    if rate_key then
-      if type(rate_key) == 'table' then
-        for _, rk in ipairs(rate_key) do
-          if type(settings[k]) == 'string' and
-              (custom_keywords[settings[k]] and type(custom_keywords[settings[k]]['get_limit']) == 'function') then
-            local res = custom_keywords[settings[k]]['get_limit'](task)
-            if type(res) == 'string' then res = {res} end
-            for _, r in ipairs(res) do
-              local plim, size = parse_string_limit(r, true)
-              if plim then
-                table.insert(args, {{plim, size}, rk})
-              else
-                local rkey = string.match(settings[k], 'redis:(.*)')
-                if rkey then
-                  table.insert(redis_keys, rkey)
-                  redis_keys_rev[#redis_keys] = rk
-                else
-                  rspamd_logger.infox(task, "Don't know what to do with limit: %1", settings[k])
-                end
-              end
-            end
-          end
-        end
-      else
-        if type(settings[k]) == 'string' and
-          (custom_keywords[settings[k]] and type(custom_keywords[settings[k]]['get_limit']) == 'function') then
-          local res = custom_keywords[settings[k]]['get_limit'](task)
-          if type(res) == 'string' then res = {res} end
-          for _, r in ipairs(res) do
-            local plim, size = parse_string_limit(r, true)
-            if plim then
-              table.insert(args, {{plim, size}, rate_key})
-            else
-              local rkey = string.match(r, 'redis:(.*)')
-              if rkey then
-                table.insert(redis_keys, rkey)
-                redis_keys_rev[#redis_keys] = rate_key
-              else
-                rspamd_logger.infox(task, "Don't know what to do with limit: %1", settings[k])
-              end
-            end
-          end
-        elseif type(settings[k]) == 'table' then
-          for _, rl in ipairs(settings[k]) do
-            table.insert(args, {{rl[1], rl[2]}, rate_key})
-          end
-        elseif type(settings[k]) == 'string' then
-          local rkey = string.match(settings[k], 'redis:(.*)')
-          if rkey then
-            table.insert(redis_keys, rkey)
-            redis_keys_rev[#redis_keys] = rate_key
-          else
-            rspamd_logger.infox(task, "Don't know what to do with limit: %1", settings[k])
-          end
+local function ratelimit_update_cb(task)
+  local prefixes = task:cache_get('ratelimit_prefixes')
+
+  if prefixes then
+    local action = task:get_metric_action()
+    local is_spam = true
+
+    if action == 'soft reject' then
+      -- Already rate limited/greylisted, do nothing
+      rspamd_logger.debugm(N, task, 'already soft rejected, do not update')
+    elseif action == 'no action' then
+      is_spam = false
+    end
+
+    local mult_burst = settings.ham_factor_burst
+    local mult_rate = settings.ham_factor_burst
+
+    if is_spam then
+      mult_burst = settings.spam_factor_burst
+      mult_rate = settings.spam_factor_rate
+    end
+
+    -- Update each bucket
+    for k, v in pairs(prefixes) do
+      local function update_bucket_cb(err, _)
+        if err then
+          rspamd_logger.errx(task, 'cannot update rate bucket %s: %s',
+              k, err)
         end
       end
+      local now = rspamd_util.get_time()
+      now = lua_util.round(now * 1000.0) -- Get milliseconds
+      rspamd_logger.debugm(N, task, "update limit %s (%s/%s)",
+              k, v[2], v[1])
+      lua_redis.exec_redis_script(bucket_update_id,
+              {task = task, is_write = true},
+              update_bucket_cb,
+              {k, tostring(now), tostring(mult_rate), tostring(mult_burst),
+               tostring(settings.max_rate_mult), tostring(settings.max_bucket_mult),
+               tostring(settings.expire)})
     end
   end
-
-  if redis_keys[1] then
-    return collect_redis_keys()
-  else
-    return process_buckets(task, args)
-  end
 end
 
 local opts = rspamd_config:get_all_opt(N)
 if opts then
+
+  settings = lua_util.override_defaults(settings, opts)
+
   if opts['limit'] then
     rspamd_logger.errx(rspamd_config, 'Legacy ratelimit config format no longer supported')
   end
@@ -592,12 +454,12 @@ if opts then
     -- new way of setting limits
     fun.each(function(t, lim)
       if type(lim) == 'table' then
-        settings[t] = {}
+        settings.limits[t] = {}
         if #lim == 2 and tonumber(lim[1]) and tonumber(lim[2]) then
           -- Old style ratelimit
           rspamd_logger.warnx(rspamd_config, 'old style ratelimit for %s', t)
           if tonumber(lim[1]) > 0 and tonumber(lim[2]) > 0 then
-            table.insert(settings[t], {1.0/lim[2], lim[1]})
+            table.insert(settings.limits[t], {1.0/lim[2], lim[1]})
           elseif lim[1] ~= 0 then
             rspamd_logger.warnx(rspamd_config, 'invalid numbers for %s', t)
           else
@@ -607,31 +469,24 @@ if opts then
           fun.each(function(l)
             local plim, size = parse_string_limit(l)
             if plim then
-              table.insert(settings[t], {plim, size})
+              table.insert(settings.limits[t], {plim, size})
             end
           end, lim)
         end
       elseif type(lim) == 'string' then
         local plim, size = parse_string_limit(lim)
         if plim then
-          settings[t] = { {plim, size} }
+          settings.limits[t] = { {plim, size} }
         end
       end
     end, opts['rates'])
   end
 
-  if opts['dynamic_rates'] and type(opts['dynamic_rates']) == 'table' then
-    fun.each(function(t, lim)
-      if type(lim) == 'string' then
-        settings[t] = lim
-      end
-    end, opts['dynamic_rates'])
-  end
-
   local enabled_limits = fun.totable(fun.map(function(t)
     return t
   end, settings))
-  rspamd_logger.infox(rspamd_config, 'enabled rate buckets: [%1]', table.concat(enabled_limits, ','))
+  rspamd_logger.infox(rspamd_config,
+          'enabled rate buckets: [%1]', table.concat(enabled_limits, ','))
 
   -- Ret, ret, ret: stupid legacy stuff:
   -- If we have a string with commas then load it as as static map
@@ -640,70 +495,41 @@ if opts then
   local wrcpts = opts['whitelisted_rcpts']
   if type(wrcpts) == 'string' then
     if string.find(wrcpts, ',') then
-      whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(
+      settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(
         lua_util.rspamd_str_split(wrcpts, ','), 'set', 'Ratelimit whitelisted rcpts')
     else
-      whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
+      settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
         'Ratelimit whitelisted rcpts')
     end
   elseif type(opts['whitelisted_rcpts']) == 'table' then
-    whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
+    settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
       'Ratelimit whitelisted rcpts')
   else
     -- Stupid default...
-    whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(whitelisted_rcpts, 'set',
-      'Ratelimit whitelisted rcpts')
+    settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(
+        opts.whitelisted_rcpts, 'set', 'Ratelimit whitelisted rcpts')
   end
 
   if opts['whitelisted_ip'] then
-    whitelisted_ip = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_ip', 'radix',
+    settings.whitelisted_ip = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_ip', 'radix',
       'Ratelimit whitelist ip map')
   end
 
   if opts['whitelisted_user'] then
-    whitelisted_user = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_user', 'set',
+    settings.whitelisted_user = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_user', 'set',
       'Ratelimit whitelist user map')
   end
 
-  if opts['symbol'] then
-    -- We want symbol instead of pre-result
-    ratelimit_symbol = opts['symbol']
-  end
-
-  if opts['info_symbol'] then
-    -- We want symbol in addition to pre-result
-    info_symbol = opts['info_symbol']
-  end
-
-  if opts['max_rcpt'] then
-    max_rcpt = tonumber(opts['max_rcpt'])
-  end
-
-  if opts['use_ip_score'] then
-    use_ip_score = true
-    local ip_score_opts = rspamd_config:get_all_opt('ip_score')
-    if ip_score_opts and ip_score_opts['lower_bound'] then
-      ip_score_lower_bound = ip_score_opts['lower_bound']
-    end
-  end
-
   if opts['custom_keywords'] then
-    custom_keywords = dofile(opts['custom_keywords'])
-  end
-
-  if opts['user_keywords'] then
-    user_keywords = opts['user_keywords']
+    settings.custom_keywords = dofile(opts['custom_keywords'])
   end
 
   if opts['message_func'] then
     message_func = assert(load(opts['message_func']))()
   end
 
-  if opts['limits_hash'] then
-    limits_hash = opts['limits_hash']
-  end
+  redis_params = lua_redis.parse_redis_server('ratelimit')
 
-  redis_params = rspamd_parse_redis_server('ratelimit')
   if not redis_params then
     rspamd_logger.infox(rspamd_config, 'no servers are specified, disabling module')
     lua_util.disable_module(N, "redis")
@@ -715,25 +541,30 @@ if opts then
       callback = ratelimit_cb,
       flags = 'empty',
     }
-    if use_ip_score then
-      s.type = 'normal'
-    end
-    if ratelimit_symbol then
-      s.name = ratelimit_symbol
-    elseif info_symbol then
-      s.name = info_symbol
+
+    if settings.symbol then
+      s.name = settings.symbol
+    elseif settings.info_symbol then
+      s.name = settings.info_symbol
     end
+
     rspamd_config:register_symbol(s)
-    if use_ip_score then
-      rspamd_config:register_dependency(s.name, 'IP_SCORE')
-    end
-    for _, v in pairs(custom_keywords) do
-      if type(v) == 'table' and type(v['init']) == 'function' then
-        v['init']()
+    rspamd_config:register_symbol {
+      type = 'idempotent',
+      name = 'RATELIMIT_UPDATE',
+      callback = ratelimit_update_cb,
+    }
+
+    if settings.custom_keywords then
+      for _, v in pairs(settings.custom_keywords) do
+        if type(v) == 'table' and type(v['init']) == 'function' then
+          v['init']()
+        end
       end
     end
   end
 end
+
 rspamd_config:add_on_load(function(cfg, ev_base, worker)
   load_scripts(cfg, ev_base)
 end)