[Minor] Lint Lua plugins & global functions

31 files changed, 377 insertions, 351 deletions

diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 000000000..5269a4dcc
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,36 @@
+codes = true
+std = 'min'
+
+exclude_files = {
+  '/**/src/plugins/lua/fann_classifier.lua',
+  '/**/src/plugins/lua/fann_scores.lua',
+  '/**/src/plugins/lua/fann_redis.lua',
+}
+
+globals = {
+  'classifiers',
+  'config',
+  'rspamd_config',
+  'rspamd_count_metatokens',
+  'rspamd_gen_metatokens',
+  'rspamd_parse_redis_server',
+  'rspamd_paths',
+  'rspamd_plugins',
+  'rspamd_redis_make_request',
+  'rspamd_str_split',
+  'rspamd_version',
+}
+
+ignore = {
+}
+
+files['/**/rules/regexp/headers.lua'].globals = {
+  'check_header_delimiter_empty',
+  'check_header_delimiter_tab',
+  'kmail_msgid',
+}
+
+files['/**/src/plugins/lua/spamassassin.lua'].globals = {
+  'ffi',
+  'jit',
+}
diff --git a/rules/html.lua b/rules/html.lua
index bedf0cc61..25578723e 100644
--- a/rules/html.lua
+++ b/rules/html.lua
@@ -182,7 +182,7 @@ rspamd_config.R_WHITE_ON_WHITE = {
         normal_len = p:get_length()
         local hc = p:get_html() -- we get HTML context
 
-        hc:foreach_tag({'font', 'span', 'div', 'p'}, function(tag, _)
+        hc:foreach_tag({'font', 'span', 'div', 'p'}, function(tag)
           local bl = tag:get_extra()
           if bl then
             if bl['bgcolor'] and bl['color'] and bl['visible'] then
diff --git a/rules/misc.lua b/rules/misc.lua
index 53e8a66f8..89ba97fb1 100644
--- a/rules/misc.lua
+++ b/rules/misc.lua
@@ -51,7 +51,7 @@ end
 
 rspamd_config.SUBJ_ALL_CAPS = {
   callback = function(task)
-    local caps_test = function(sbj, _)
+    local caps_test = function(sbj)
       return util.is_uppercase(sbj)
     end
     return test_subject(task, caps_test, 1.0/40.0)
diff --git a/rules/rspamd.classifiers.lua b/rules/rspamd.classifiers.lua
index ad8ca8d4b..1fb10a2f8 100644
--- a/rules/rspamd.classifiers.lua
+++ b/rules/rspamd.classifiers.lua
@@ -67,7 +67,7 @@ local function get_specific_statfiles(classifier, task)
 	end
 end
 
-classifiers['bayes'] = function(classifier, task, is_learn, _)
+classifiers['bayes'] = function(classifier, task, is_learn)
 	-- Subfunction for detection of message's language
 	local detect_language = function()
 		local parts = task:get_text_parts()
diff --git a/src/lua/global_functions.lua b/src/lua/global_functions.lua
index b8b840043..879309011 100644
--- a/src/lua/global_functions.lua
+++ b/src/lua/global_functions.lua
@@ -1,3 +1,4 @@
+local logger = require "rspamd_logger"
 
 -- This function parses redis server definition using either
 -- specific server string for this module or global
@@ -6,7 +7,6 @@ function rspamd_parse_redis_server(module_name)
 
   local default_port = 6379
   local default_timeout = 1.0
-  local logger = require "rspamd_logger"
   local upstream_list = require "rspamd_upstream_list"
 
   local function try_load_redis_servers(options)
@@ -313,9 +313,6 @@ local function meta_urls_function(task)
   return {0}
 end
 
-local function meta_attachments_function(task)
-end
-
 local metafunctions = {
   {
     cb = meta_size_function,
@@ -380,4 +377,4 @@ function rspamd_count_metatokens()
   end
 
   return total
-end
\ No newline at end of file
+end
diff --git a/src/plugins/lua/antivirus.lua b/src/plugins/lua/antivirus.lua
index d4a0f7bba..c55305f2a 100644
--- a/src/plugins/lua/antivirus.lua
+++ b/src/plugins/lua/antivirus.lua
@@ -16,7 +16,6 @@ limitations under the License.
 
 local rspamd_logger = require "rspamd_logger"
 local rspamd_util = require "rspamd_util"
-local rspamd_redis = require "rspamd_redis"
 local rspamd_regexp = require "rspamd_regexp"
 local tcp = require "rspamd_tcp"
 local upstream_list = require "rspamd_upstream_list"
@@ -191,6 +190,7 @@ local function check_av_cache(task, rule, fn)
         yield_result(task, rule, data)
       end
     else
+      rspamd_logger.errx(task, 'Got error checking cache: %1', err)
       fn()
     end
   end
@@ -219,7 +219,7 @@ end
 local function save_av_cache(task, rule, to_save)
   local key = task:get_digest()
 
-  local function redis_set_cb(err, data)
+  local function redis_set_cb(err)
     -- Do nothing
     if err then
       rspamd_logger.errx(task, 'failed to save virus cache for %s -> "%s": %s',
@@ -506,7 +506,7 @@ if opts and type(opts) == 'table' then
       if not cb then
         rspamd_logger.errx(rspamd_config, 'cannot add rule: "' .. k .. '"')
       else
-        local id = rspamd_config:register_symbol({
+        rspamd_config:register_symbol({
           type = 'normal',
           name = m['symbol'],
           callback = cb,
diff --git a/src/plugins/lua/asn.lua b/src/plugins/lua/asn.lua
index c31cc46c5..7fff000a4 100644
--- a/src/plugins/lua/asn.lua
+++ b/src/plugins/lua/asn.lua
@@ -17,7 +17,6 @@ limitations under the License.
 
 local rspamd_logger = require "rspamd_logger"
 local rspamd_regexp = require "rspamd_regexp"
-local rspamd_redis = require "rspamd_redis"
 
 local options = {
   provider_type = 'rspamd',
@@ -56,7 +55,10 @@ local function asn_check(task)
 
   local asn_check_func = {}
   function asn_check_func.rspamd(ip)
-    local function rspamd_dns_cb(resolver, to_resolve, results, err, key)
+    local function rspamd_dns_cb(_, _, results, dns_err)
+      if dns_err then
+        rspamd_logger.errx(task, 'error querying dns: %s', dns_err)
+      end
       if not (results and results[1]) then return end
       local parts = rspamd_re:split(results[1])
       -- "15169 | 8.8.8.0/24 | US | arin |" for 8.8.8.8
@@ -65,12 +67,13 @@ local function asn_check(task)
       if redis_params then
         local redis_key = options.key_prefix .. ip:to_string()
         local ret,conn,upstream
-        local function redis_asn_set_cb(err, data)
-          if not err then
+        local function redis_asn_set_cb(redis_err)
+          if not redis_err then
             upstream:ok()
           else
             rspamd_logger.infox(task, 'got error %s when setting asn record on server %s',
-              err, upstream:get_addr())
+              redis_err, upstream:get_addr())
+            upstream:fail()
           end
         end
         ret,conn,upstream = rspamd_redis_make_request(task,
@@ -81,7 +84,7 @@ local function asn_check(task)
           'HMSET', -- command
           {redis_key, "asn", parts[1], "net", parts[2], "country", parts[3]} -- arguments
         )
-        if conn then
+        if ret then
           conn:add_cmd('EXPIRE', {
             redis_key, tostring(options['expire'])
           })
@@ -107,10 +110,14 @@ local function asn_check(task)
       else
         asn_set(data[1], data[2], data[3])
         -- Refresh key
-        local function redis_asn_expire_cb(err, data)
+        local function redis_asn_expire_cb(redis_err)
+          if redis_err then
+            rspamd_logger.errx(task, 'Error setting expire: %s',
+                redis_err)
+          end
         end
 
-        local ret,_,_ = rspamd_redis_make_request(task,
+        local ret,_,upstream = rspamd_redis_make_request(task,
           redis_params, -- connect params
           key, -- hash key
           true, -- is write
@@ -118,6 +125,9 @@ local function asn_check(task)
           'EXPIRE', -- command
           {key, tostring(options.expire)} -- arguments
         )
+        if not ret then
+          upstream:fail()
+        end
       end
     end
 
diff --git a/src/plugins/lua/dcc.lua b/src/plugins/lua/dcc.lua
index cd8f76de2..446805811 100644
--- a/src/plugins/lua/dcc.lua
+++ b/src/plugins/lua/dcc.lua
@@ -70,21 +70,17 @@ local function check_dcc (task)
 
     if header then
       local _,_,info = header:find("; (.-)$")
-      if (result == 'A') then
-      -- Accept
-      elseif (result == 'G') then
-      -- Greylist
-      elseif (result == 'R') then
+      if (result == 'R') then
         -- Reject
         task:insert_result(symbol_bulk, 1.0, info)
-      elseif (result == 'S') then
-      -- Accept for some recipients only
       elseif (result == 'T') then
         -- Temporary failure
         logger.warnx(task, 'DCC returned a temporary failure result')
       else
-        -- Unknown result
-        logger.warnx(task, 'DCC result error: %1', result);
+        if result ~= 'A' and result ~= 'G' and result ~= 'S' then
+          -- Unknown result
+          logger.warnx(task, 'DCC result error: %1', result);
+        end
       end
     end
   end
diff --git a/src/plugins/lua/dmarc.lua b/src/plugins/lua/dmarc.lua
index 42f8d5ae3..cdbc8700e 100644
--- a/src/plugins/lua/dmarc.lua
+++ b/src/plugins/lua/dmarc.lua
@@ -17,10 +17,7 @@ limitations under the License.
 
 -- Dmarc policy filter
 
-local rspamd_regexp = require "rspamd_regexp"
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require "rspamd_redis"
-local upstream_list = require "rspamd_upstream_list"
 local rspamd_util = require "rspamd_util"
 local check_local = false
 local check_authed = false
@@ -52,7 +49,6 @@ local dmarc_symbols = {
 -- Default port for redis upstreams
 local redis_params = nil
 local dmarc_redis_key_prefix = "dmarc_"
-local dmarc_domain = nil
 local dmarc_reporting = false
 local dmarc_actions = {}
 
@@ -108,7 +104,7 @@ local function dmarc_callback(task)
     return maybe_force_action('na')
   end
 
-  local function dmarc_report_cb(err, data)
+  local function dmarc_report_cb(err)
     if not err then
       rspamd_logger.infox(task, '<%1> dmarc report saved for %2',
         task:get_message_id(), from[1]['domain'])
@@ -118,7 +114,7 @@ local function dmarc_callback(task)
     end
   end
 
-  local function dmarc_dns_cb(resolver, to_resolve, results, err, key)
+  local function dmarc_dns_cb(_, to_resolve, results, err)
 
     local lookup_domain = string.sub(to_resolve, 8)
     if err and (err ~= 'requested record is not found' and err ~= 'no records with this name') then
@@ -281,7 +277,7 @@ local function dmarc_callback(task)
     end
     local das = task:get_symbol(symbols['dkim_allow_symbol'])
     if das and das[1] and das[1]['options'] then
-      for i,dkim_domain in ipairs(das[1]['options']) do
+      for _,dkim_domain in ipairs(das[1]['options']) do
         if strict_dkim and rspamd_util.strequal_caseless(from[1]['domain'], dkim_domain) then
           dkim_ok = true
         elseif strict_dkim then
@@ -367,7 +363,7 @@ if opts and type(opts) ~= 'table' then
   end
 end
 
-local opts = rspamd_config:get_all_opt('dmarc')
+opts = rspamd_config:get_all_opt('dmarc')
 if not opts or type(opts) ~= 'table' then
   return
 end
@@ -397,9 +393,9 @@ if opts['key_prefix'] then
 end
 
 -- Check spf and dkim sections for changed symbols
-local function check_mopt(var, opts, name)
-  if opts[name] then
-    symbols['var'] = tostring(opts[name])
+local function check_mopt(var, m_opts, name)
+  if m_opts[name] then
+    symbols[var] = tostring(m_opts[name])
   end
 end
 
diff --git a/src/plugins/lua/dynamic_conf.lua b/src/plugins/lua/dynamic_conf.lua
index de3ec0828..b109c714f 100644
--- a/src/plugins/lua/dynamic_conf.lua
+++ b/src/plugins/lua/dynamic_conf.lua
@@ -15,7 +15,6 @@ limitations under the License.
 ]]--
 
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require 'rspamd_redis'
 local redis_params
 local ucl = require "ucl"
 local fun = require "fun"
@@ -92,7 +91,7 @@ local function redis_make_request(ev_base, cfg, key, is_write, callback, command
   return ret,conn,addr
 end
 
-local function apply_dynamic_actions(cfg, acts)
+local function apply_dynamic_actions(_, acts)
   fun.each(function(k, v)
      if type(v) == 'table' then
       v['name'] = k
@@ -117,7 +116,7 @@ local function apply_dynamic_actions(cfg, acts)
   end, acts))
 end
 
-local function apply_dynamic_scores(cfg, sc)
+local function apply_dynamic_scores(_, sc)
   fun.each(function(k, v)
     if type(v) == 'table' then
       v['name'] = k
@@ -154,13 +153,13 @@ local function apply_dynamic_conf(cfg, data)
   end
 
   if data['symbols_enabled'] then
-    fun.each(function(i, v)
+    fun.each(function(_, v)
       cfg:enable_symbol(v)
     end, data['symbols_enabled'])
   end
 
   if data['symbols_disabled'] then
-    fun.each(function(i, v)
+    fun.each(function(_, v)
       cfg:disable_symbol(v)
     end, data['symbols_disabled'])
   end
@@ -177,7 +176,7 @@ local function update_dynamic_conf(cfg, ev_base, recv)
       cur_settings.updates.actions = {}
     end
   end
-  local function redis_data_set_cb(err, data)
+  local function redis_data_set_cb(err)
     if err then
       rspamd_logger.errx(cfg, "cannot save dynamic conf to redis: %s", err)
     else
@@ -195,7 +194,7 @@ local function update_dynamic_conf(cfg, ev_base, recv)
       fun.each(function(k, v)
         cur_settings.data.scores[k] = v
       end,
-      fun.filter(function(k,v)
+      fun.filter(function(k)
         if cur_settings.updates.symbols[k] then
           return false
         end
@@ -209,7 +208,7 @@ local function update_dynamic_conf(cfg, ev_base, recv)
       fun.each(function(k, v)
         cur_settings.data.actions[k] = v
       end,
-      fun.filter(function(k,v)
+      fun.filter(function(k)
         if cur_settings.updates.actions[k] then
           return false
         end
@@ -223,10 +222,12 @@ local function update_dynamic_conf(cfg, ev_base, recv)
 end
 
 local function check_dynamic_conf(cfg, ev_base)
-  local function redis_load_cb(err, data)
-    if data and type(data) == 'string' then
+  local function redis_load_cb(redis_err, data)
+    if redis_err then
+      rspamd_logger.errx(cfg, "cannot read dynamic conf from redis: %s", redis_err)
+    elseif data and type(data) == 'string' then
       local parser = ucl.parser()
-      local res,err = parser:parse_string(data)
+      local _,err = parser:parse_string(data)
 
       if err then
         rspamd_logger.errx(cfg, "cannot load dynamic conf from redis: %s", err)
@@ -278,17 +279,17 @@ if section then
     settings[k] = v
   end
 
-  rspamd_config:add_on_load(function(cfg, ev_base)
+  rspamd_config:add_on_load(function(_, ev_base)
     rspamd_config:add_periodic(ev_base, 0.0,
-    function(cfg, ev_base)
-      check_dynamic_conf(cfg, ev_base)
+    function(cfg, _ev_base)
+      check_dynamic_conf(cfg, _ev_base)
       return settings.redis_watch_interval
     end, true)
   end)
 end
 
 -- Updates part
-local function add_dynamic_symbol(cfg, sym, score)
+local function add_dynamic_symbol(_, sym, score)
   local add = false
   if not cur_settings.data then
     cur_settings.data = {}
@@ -318,7 +319,7 @@ local function add_dynamic_symbol(cfg, sym, score)
   return add
 end
 
-local function add_dynamic_action(cfg, act, score)
+local function add_dynamic_action(_, act, score)
   local add = false
   if not cur_settings.data then
     cur_settings.data = {}
diff --git a/src/plugins/lua/emails.lua b/src/plugins/lua/emails.lua
index 9d9a54d03..83eb34ed0 100644
--- a/src/plugins/lua/emails.lua
+++ b/src/plugins/lua/emails.lua
@@ -24,15 +24,17 @@ local logger = require "rspamd_logger"
 
 -- Check rule for a single email
 local function check_email_rule(task, rule, addr)
-  local function emails_dns_cb(resolver, to_resolve, results, err)
-    if results then
+  local function emails_dns_cb(_, to_resolve, results, err)
+    if err then
+      logger.errx(task, 'Error querying DNS: %1', err)
+    elseif results then
       logger.infox(task, '<%1> email: [%2] resolved for symbol: %3',
         task:get_message_id(), to_resolve, rule['symbol'])
       task:insert_result(rule['symbol'], 1)
     end
   end
   if rule['dnsbl'] then
-    local to_resolve = ''
+    local to_resolve
     if rule['domain_only'] then
       to_resolve = string.format('%s.%s', addr:get_host(), rule['dnsbl'])
     else
diff --git a/src/plugins/lua/forged_recipients.lua b/src/plugins/lua/forged_recipients.lua
index 53d54be4e..7c3cd07f8 100644
--- a/src/plugins/lua/forged_recipients.lua
+++ b/src/plugins/lua/forged_recipients.lua
@@ -17,7 +17,6 @@ limitations under the License.
 -- Plugin for comparing smtp dialog recipients and sender with recipients and sender
 -- in mime headers
 
-local logger = require "rspamd_logger"
 local symbol_rcpt = 'FORGED_RECIPIENTS'
 local symbol_sender = 'FORGED_SENDER'
 
@@ -25,7 +24,7 @@ local function check_forged_headers(task)
   local auser = task:get_user()
   local smtp_rcpt = task:get_recipients(1)
   local smtp_from = task:get_from(1)
-  local res = false
+  local res
   local score = 1.0
 
   if not smtp_rcpt then return end
diff --git a/src/plugins/lua/greylist.lua b/src/plugins/lua/greylist.lua
index 3f51ba63a..5efd09389 100644
--- a/src/plugins/lua/greylist.lua
+++ b/src/plugins/lua/greylist.lua
@@ -53,11 +53,8 @@ local settings = {
 }
 
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require "rspamd_redis"
-local upstream_list = require "rspamd_upstream_list"
 local rspamd_util = require "rspamd_util"
 local fun = require "fun"
-local rspamd_cryptobox = require "rspamd_cryptobox"
 local hash = require "rspamd_cryptobox_hash"
 
 local function data_key(task)
@@ -144,8 +141,6 @@ local function check_time(task, tm, type)
 
     return true,false
   end
-
-  return false,false
 end
 
 local function greylist_check(task)
@@ -168,21 +163,11 @@ local function greylist_check(task)
   local hash_key = body_key .. meta_key
   local upstream
 
-  local function redis_set_cb(err, data)
-    if not err then
-      upstream:ok()
-    else
-      rspamd_logger.errx(task, 'got error %s when setting greylisting record on server %s',
-          err, upstream:get_addr())
-    end
-  end
-
   local function redis_get_cb(err, data)
     local ret_body = false
     local greylisted_body = false
     local ret_meta = false
     local greylisted_meta = false
-    local greylist_type
 
     if data then
       if data[1] and type(data[1]) ~= 'userdata' then
@@ -205,8 +190,6 @@ local function greylist_check(task)
         end
       end
 
-      upstream:ok()
-
       if not ret_body and not ret_meta then
         local end_time = rspamd_util.time_to_string(rspamd_util.get_time()
           + settings['timeout'])
@@ -216,11 +199,10 @@ local function greylist_check(task)
           settings['timeout'])
         rspamd_logger.infox(task, 'greylisted until "%s" using %s key',
           end_time, type)
-        task:insert_result(settings['symbol'], 0.0, 'greylisted', end_time,
-          greylist_type)
+        task:insert_result(settings['symbol'], 0.0, 'greylisted', end_time)
         if settings.message_func then
           task:set_pre_result('soft reject',
-            settings.message_func(task, end_time, greylist_type))
+            settings.message_func(task, end_time))
         else
           task:set_pre_result('soft reject', settings['message'])
         end
@@ -228,7 +210,9 @@ local function greylist_check(task)
     elseif err then
       rspamd_logger.errx(task, 'got error while getting greylisting keys: %1', err)
       upstream:fail()
+      return
     end
+    upstream:ok()
   end
 
   local ret, _
@@ -242,6 +226,7 @@ local function greylist_check(task)
   )
   if not ret then
     rspamd_logger.errx(task, 'cannot make redis request to check results')
+    upstream:fail()
   end
 end
 
@@ -284,12 +269,13 @@ local function greylist_set(task)
   local upstream, ret, conn
   local hash_key = body_key .. meta_key
 
-  local function redis_set_cb(err, data)
+  local function redis_set_cb(err)
     if not err then
       upstream:ok()
     else
       rspamd_logger.errx(task, 'got error %s when setting greylisting record on server %s',
           err, upstream:get_addr())
+      upstream:fail()
     end
   end
 
@@ -313,7 +299,7 @@ local function greylist_set(task)
       {body_key, tostring(settings['expire'])} -- arguments
     )
     -- Update greylisting record expire
-    if conn then
+    if ret then
       conn:add_cmd('EXPIRE', {
         meta_key, tostring(settings['expire'])
       })
@@ -329,7 +315,6 @@ local function greylist_set(task)
       'new record')
     task:set_pre_result(settings['action'], settings['message'])
     -- Create new record
-    local ret, conn
     ret,conn,upstream = rspamd_redis_make_request(task,
       redis_params, -- connect params
       hash_key, -- hash key
@@ -339,12 +324,10 @@ local function greylist_set(task)
       {body_key, tostring(settings['expire']), t} -- arguments
     )
 
-    if conn then
+    if ret then
       conn:add_cmd('SETEX', {
         meta_key, tostring(settings['expire']), t
       })
-      local end_time = rspamd_util.time_to_string(rspamd_util.get_time()
-        + settings['timeout'])
     else
       rspamd_logger.infox(task, 'got error while connecting to redis: %s',
       upstream:get_addr())
@@ -380,7 +363,7 @@ end
 local opts =  rspamd_config:get_all_opt('greylist')
 if opts then
   if opts['message_func'] then
-    settings.message_func = assert(loadstring(opts['message_func']))()
+    settings.message_func = assert(load(opts['message_func']))()
   end
   for k,v in pairs(opts) do
     if k ~= 'message_func' then
diff --git a/src/plugins/lua/hfilter.lua b/src/plugins/lua/hfilter.lua
index ea4830c67..6bf8358a9 100644
--- a/src/plugins/lua/hfilter.lua
+++ b/src/plugins/lua/hfilter.lua
@@ -22,7 +22,6 @@ limitations under the License.
 
 --local dumper = require 'pl.pretty'.dump
 local rspamd_regexp = require "rspamd_regexp"
-local rspamd_logger = require "rspamd_logger"
 local rspamc_local_helo = "rspamc.local"
 local checks_hellohost = {
   ['[.-]gprs[.-]'] = 5, ['gprs[.-][0-9]'] = 5, ['[0-9][.-]?gprs'] = 5,
@@ -69,30 +68,30 @@ local checks_hello = {
 }
 
 local checks_hello_badip = {
-  ['^0\\.'] = 5,
-  ['^::1$'] = 5, --loopback ipv4, ipv6
-  ['^127\\.'] = 5,
-  ['^10\\.'] = 5,
-  ['^192\\.168\\.'] = 5, --local ipv4
-  ['^172\\.1[6-9]\\.'] = 5,
-  ['^172\\.2[0-9]\\.'] = 5,
-  ['^172\\.3[01]\\.'] = 5,  --local ipv4
-  ['^169\\.254\\.'] = 5, --chanel ipv4
-  ['^192\\.0\\.0\\.'] = 5, --IETF Protocol
-  ['^192\\.88\\.99\\.'] = 5, --RFC3068
-  ['^100.6[4-9]\\.'] = 5,
-  ['^100.[7-9]\\d\\.'] = 5,
-  ['^100.1[01]\\d\\.'] = 5,
-  ['^100.12[0-7]\\d\\.'] = 5, --RFC6598
-  ['^\\d\\.\\d\\.\\d\\.255$'] = 5, --multicast ipv4
-  ['^192\\.0\\.2\\.'] = 5,
-  ['^198\\.51\\.100\\.'] = 5,
-  ['^203\\.0\\.113\\.'] = 5,  --sample
-  ['^fe[89ab][0-9a-f]::'] = 5,
-  ['^fe[cdf][0-9a-f]:'] = 5, --local ipv6 (fe80:: - febf::, fec0:: - feff::)
-  ['^2001:db8::'] = 5, --reserved RFC 3849 for ipv6
-  ['^fc00::'] = 5,
-  ['^ffxx::'] = 5 --unicast, multicast ipv6
+  ['^0\\.'] = 1,
+  ['^::1$'] = 1, --loopback ipv4, ipv6
+  ['^127\\.'] = 1,
+  ['^10\\.'] = 1,
+  ['^192\\.168\\.'] = 1, --local ipv4
+  ['^172\\.1[6-9]\\.'] = 1,
+  ['^172\\.2[0-9]\\.'] = 1,
+  ['^172\\.3[01]\\.'] = 1,  --local ipv4
+  ['^169\\.254\\.'] = 1, --chanel ipv4
+  ['^192\\.0\\.0\\.'] = 1, --IETF Protocol
+  ['^192\\.88\\.99\\.'] = 1, --RFC3068
+  ['^100.6[4-9]\\.'] = 1,
+  ['^100.[7-9]\\d\\.'] = 1,
+  ['^100.1[01]\\d\\.'] = 1,
+  ['^100.12[0-7]\\d\\.'] = 1, --RFC6598
+  ['^\\d\\.\\d\\.\\d\\.255$'] = 1, --multicast ipv4
+  ['^192\\.0\\.2\\.'] = 1,
+  ['^198\\.51\\.100\\.'] = 1,
+  ['^203\\.0\\.113\\.'] = 1,  --sample
+  ['^fe[89ab][0-9a-f]::'] = 1,
+  ['^fe[cdf][0-9a-f]:'] = 1, --local ipv6 (fe80:: - febf::, fec0:: - feff::)
+  ['^2001:db8::'] = 1, --reserved RFC 3849 for ipv6
+  ['^fc00::'] = 1,
+  ['^ffxx::'] = 1 --unicast, multicast ipv6
 }
 
 local checks_hello_bareip = {
@@ -143,7 +142,7 @@ local function check_host(task, host, symbol_suffix, eq_ip, eq_host)
   local failed_address = 0
   local resolved_address = {}
 
-  local function check_host_cb_mx(resolver, to_resolve, results, err)
+  local function check_host_cb_mx(_, _, results)
     task:inc_dns_req()
     if not results then
       task:insert_result('HFILTER_' .. symbol_suffix .. '_NORES_A_OR_MX', 1.0)
@@ -152,10 +151,10 @@ local function check_host(task, host, symbol_suffix, eq_ip, eq_host)
         if mx['name'] then
           local failed_mx_address = 0
           -- Capture failed_mx_address
-          local function check_host_cb_mx_a(resolver, to_resolve, results, err)
+          local function check_host_cb_mx_a(_, _, mx_results)
             task:inc_dns_req()
 
-            if not results then
+            if not mx_results then
               failed_mx_address = failed_mx_address + 1
             end
 
@@ -178,7 +177,7 @@ local function check_host(task, host, symbol_suffix, eq_ip, eq_host)
       end
     end
   end
-  local function check_host_cb_a(resolver, to_resolve, results, err)
+  local function check_host_cb_a(_, _, results)
     task:inc_dns_req()
 
     if not results then
@@ -259,7 +258,7 @@ local function hfilter(task)
         local hc = html_text_part:get_html()
         if hc then
           local url_len = 0
-          hc:foreach_tag('a', function(tag, len)
+          hc:foreach_tag('a', function(_, len)
             url_len = url_len + len
             return false
           end)
@@ -322,7 +321,7 @@ local function hfilter(task)
         local find_badip = false
         for regexp,weight in pairs(checks_hello_badip) do
           if check_regexp(helo, regexp) then
-            task:insert_result('HFILTER_HELO_BADIP', 1.0)
+            task:insert_result('HFILTER_HELO_BADIP', weight)
             find_badip = true
             break
           end
@@ -494,7 +493,7 @@ if opts and type(opts) ~= 'table' then
   end
 end
 
-local opts = rspamd_config:get_all_opt('hfilter')
+opts = rspamd_config:get_all_opt('hfilter')
 if opts then
   for k,v in pairs(opts) do
     config[k] = v
diff --git a/src/plugins/lua/ip_score.lua b/src/plugins/lua/ip_score.lua
index 28cffe452..d8f61f511 100644
--- a/src/plugins/lua/ip_score.lua
+++ b/src/plugins/lua/ip_score.lua
@@ -16,17 +16,15 @@ limitations under the License.
 
 -- IP score is a module that set ip score of specific ip, asn, country
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require "rspamd_redis"
-local upstream_list = require "rspamd_upstream_list"
 local rspamd_regexp = require "rspamd_regexp"
 local rspamd_util = require "rspamd_util"
-local _ = require "fun"
 
 -- Default settings
 local redis_params = nil
 local whitelist = nil
 local asn_cc_whitelist = nil
 local check_authed = false
+local check_local = false
 
 local options = {
   actions = { -- how each action is treated in scoring
@@ -105,20 +103,23 @@ local ip_score_set = function(task)
     return old_score + score, new_total
   end
 
-  local score_set_cb = function(err, data)
+  local score_set_cb = function(err)
     if err then
       rspamd_logger.infox(task, 'got error while IP score changing: %1', err)
     end
   end
 
   local ip = task:get_from_ip()
-  if task:get_user() or (ip and ip:is_local()) then
+  if not check_authed and task:get_user() then
     return
   end
   local action = task:get_metric_action(options['metric'])
   if not ip or not ip:is_valid() then
     return
   end
+  if not check_local and ip:is_local() then
+    return
+  end
 
   local pool = task:get_mempool()
   local asn, country, ipnet = ip_score_get_task_vars(task)
@@ -145,7 +146,6 @@ local ip_score_set = function(task)
   score = score_mult * rspamd_util.tanh (2.718281 * (score/options['score_divisor']))
 
   local hkey = ip_score_hash_key(asn, country, ipnet, ip)
-  local upstream,ret
 
   asn_score,total_asn = new_score_set(score, asn_score, total_asn)
   country_score,total_country = new_score_set(score, country_score, total_country)
@@ -157,7 +157,7 @@ local ip_score_set = function(task)
     options['ipnet_prefix'] .. ipnet, string.format('%f|%d', ipnet_score, total_ipnet),
     ip:to_string(), string.format('%f|%d', ip_score, total_ip)}
 
-  ret,_,upstream = rspamd_redis_make_request(task,
+  local ret,_,upstream = rspamd_redis_make_request(task,
     redis_params, -- connect params
     hkey, -- hash key
     true, -- is write
@@ -165,6 +165,11 @@ local ip_score_set = function(task)
     'HMSET', -- command
     redis_args -- arguments
   )
+  if not ret then
+    rspamd_logger.errx(task, 'Redis HMSET failed on %s', upstream:get_addr())
+    upstream:fail()
+    return
+  end
 
   -- Now insert final result
   asn_score = normalize_score(asn_score, total_asn, options['scores']['asn'])
@@ -209,8 +214,13 @@ end
 -- Check score for ip in keystorage
 local ip_score_check = function(task)
   local asn, country, ipnet = ip_score_get_task_vars(task)
+  local ip = task:get_from_ip()
 
   local ip_score_redis_cb = function(err, data)
+    if err then
+      rspamd_logger.errx(task, 'Redis error: %s', err)
+      -- XXX: upstreams
+    end
     local function calculate_score(score)
       local parts = asn_re:split(score)
       local rep = tonumber(parts[1])
@@ -248,7 +258,7 @@ local ip_score_check = function(task)
     end
   end
 
-  local function create_get_command(ip, asn, country, ipnet)
+  local function create_get_command()
     local cmd = 'HMGET'
 
     local args = {options['hash']}
@@ -277,7 +287,6 @@ local ip_score_check = function(task)
     return cmd, args
   end
 
-  local ip = task:get_from_ip()
   if task:get_user() or (ip and ip:is_local()) then
     rspamd_logger.infox(task, "skip IP Score for local networks and authorized users")
     return
@@ -300,7 +309,7 @@ local ip_score_check = function(task)
       end
     end
 
-    local cmd, args = create_get_command(ip, asn, country, ipnet)
+    local cmd, args = create_get_command()
 
     local ret,_,upstream = rspamd_redis_make_request(task,
       redis_params, -- connect params
@@ -310,6 +319,10 @@ local ip_score_check = function(task)
       cmd, -- command
       args -- arguments
     )
+    if not ret then
+      rspamd_logger.errx(task, 'Call to redis at %s failed', upstream:get_addr())
+      upstream:fail()
+    end
   end
 end
 
@@ -321,6 +334,9 @@ local configure_ip_score_module = function()
     if type(opts['check_authed']) == 'boolean' then
       check_authed = opts['check_authed']
     end
+    if type(opts['check_local']) == 'boolean' then
+      check_local = opts['check_local']
+    end
   end
   opts = rspamd_config:get_all_opt('ip_score')
   if not opts then return end
diff --git a/src/plugins/lua/maillist.lua b/src/plugins/lua/maillist.lua
index eb67a4f12..6a22fd1bf 100644
--- a/src/plugins/lua/maillist.lua
+++ b/src/plugins/lua/maillist.lua
@@ -17,7 +17,6 @@ limitations under the License.
 -- Module for checking mail list headers
 
 local symbol = 'MAILLIST'
-local rspamd_logger = require "rspamd_logger"
 -- EZMLM
 -- Mailing-List: .*run by ezmlm
 -- Precedence: bulk
@@ -219,7 +218,7 @@ local function check_ml_majordomo(task)
     return false
   end
 
-  local header = task:get_header('Precedence')
+  header = task:get_header('Precedence')
   if not header or (header ~= 'list' and header ~= 'bulk') then
     return false
   end
diff --git a/src/plugins/lua/metadata_exporter.lua b/src/plugins/lua/metadata_exporter.lua
index 62fdc0d64..70c10e6b7 100644
--- a/src/plugins/lua/metadata_exporter.lua
+++ b/src/plugins/lua/metadata_exporter.lua
@@ -46,18 +46,18 @@ if url then
   rspamd_http = require "rspamd_http"
 end
 if opts['select'] then
-  settings.select = assert(loadstring(opts['select']))()
+  settings.select = assert(load(opts['select']))()
 end
 if opts['format'] then
-  settings.format = assert(loadstring(opts['format']))()
+  settings.format = assert(load(opts['format']))()
 end
 if opts['mime_type'] then
   settings['mime_type'] = opts['mime_type']
 end
 
 local function metadata_exporter(task)
-  local ret,conn,upstream
-  local function http_callback(err, code, body, headers)
+  local _,ret,upstream
+  local function http_callback(err, code)
     if err then
       rspamd_logger.errx(task, 'got error %s in http callback', err)
     end
@@ -65,7 +65,7 @@ local function metadata_exporter(task)
       rspamd_logger.errx(task, 'got unexpected http status: %s', code)
     end
   end
-  local function redis_set_cb(err, data)
+  local function redis_set_cb(err)
     if err then
       rspamd_logger.errx(task, 'got error %s when publishing record on server %s',
           err, upstream:get_addr())
@@ -84,7 +84,7 @@ local function metadata_exporter(task)
     return
   end
   if channel then
-    ret,conn,upstream = rspamd_redis_make_request(task,
+    ret,_,upstream = rspamd_redis_make_request(task,
       redis_params, -- connect params
       nil, -- hash key
       true, -- is write
@@ -92,6 +92,10 @@ local function metadata_exporter(task)
       'PUBLISH', -- command
       {channel, data} -- arguments
     )
+    if not ret then
+      rspamd_logger.errx(task, 'Redis PUBLISH failed')
+      upstream:fail()
+    end
   end
   if url then
     rspamd_http.request({
diff --git a/src/plugins/lua/metric_exporter.lua b/src/plugins/lua/metric_exporter.lua
index eb56d8c23..85cace8ea 100644
--- a/src/plugins/lua/metric_exporter.lua
+++ b/src/plugins/lua/metric_exporter.lua
@@ -85,7 +85,7 @@ local function load_defaults(defaults)
   end
 end
 
-local function graphite_config(opts)
+local function graphite_config()
   load_defaults({
     host = 'localhost',
     port = 2003,
@@ -124,7 +124,7 @@ local function graphite_push(kwargs)
     data = {
       metrics_str,
     },
-    callback = (function (err, data)
+    callback = (function (err)
       if err then
         logger.errx('Push failed: %1', err)
         return
@@ -150,16 +150,16 @@ local function configure_metric_exporter()
   for k, v in pairs(opts) do
     settings[k] = v
   end
-  return backends[opts['backend']]['configure'](opts)
+  return backends[opts['backend']]['configure']()
 end
 
 if not configure_metric_exporter() then return end
 
-rspamd_config:add_on_load(function (cfg, ev_base, worker)
+rspamd_config:add_on_load(function (_, ev_base, worker)
   -- Exit unless we're the first 'normal' worker
   if not (worker:get_name() == 'normal' and worker:get_index() == 0) then return end
   -- Persist mempool variable to statefile on shutdown
-  rspamd_config:register_finish_script(function (task)
+  rspamd_config:register_finish_script(function ()
     local stamp = pool:get_variable(VAR_NAME, 'double')
     if not stamp then
       logger.warn('No last metric exporter push to persist to disk')
@@ -176,7 +176,7 @@ rspamd_config:add_on_load(function (cfg, ev_base, worker)
     end
   end)
   -- Push metrics to backend
-  local function push_metrics(worker, time)
+  local function push_metrics(time)
     logger.infox('Pushing metrics to %s backend', settings['backend'])
     local args = {
       ev_base = ev_base,
@@ -189,15 +189,15 @@ rspamd_config:add_on_load(function (cfg, ev_base, worker)
   end
   -- Push metrics at regular intervals
   local function schedule_regular_push()
-    rspamd_config:add_periodic(ev_base, settings['interval'], function (cfg, ev_base)
-      push_metrics(worker)
+    rspamd_config:add_periodic(ev_base, settings['interval'], function ()
+      push_metrics()
       return true
     end)
   end
   -- Push metrics to backend and reschedule check
   local function schedule_intermediate_push(when)
-    rspamd_config:add_periodic(ev_base, when, function (cfg, ev_base)
-      push_metrics(worker)
+    rspamd_config:add_periodic(ev_base, when, function ()
+      push_metrics()
       schedule_regular_push()
       return false
     end)
@@ -215,7 +215,7 @@ rspamd_config:add_on_load(function (cfg, ev_base, worker)
   end
   if not stamp then
     logger.debug('No state found - pushing stats immediately')
-    push_metrics(worker)
+    push_metrics()
     schedule_regular_push()
     return
   end
@@ -223,7 +223,7 @@ rspamd_config:add_on_load(function (cfg, ev_base, worker)
   local delta = stamp - time + settings['interval']
   if delta <= 0 then
     logger.debug('Last push is too old - pushing stats immediately')
-    push_metrics(worker, time)
+    push_metrics(time)
     schedule_regular_push()
     return
   end
diff --git a/src/plugins/lua/mime_types.lua b/src/plugins/lua/mime_types.lua
index e1b2123f4..a33bd28b9 100644
--- a/src/plugins/lua/mime_types.lua
+++ b/src/plugins/lua/mime_types.lua
@@ -15,8 +15,6 @@ limitations under the License.
 ]]--
 
 -- This plugin implements mime types checks for mail messages
-local rspamd_logger = require "rspamd_logger"
-local rspamd_regexp = require "rspamd_regexp"
 
 local settings = {
   file = '',
diff --git a/src/plugins/lua/multimap.lua b/src/plugins/lua/multimap.lua
index 54541f119..6d33cace8 100644
--- a/src/plugins/lua/multimap.lua
+++ b/src/plugins/lua/multimap.lua
@@ -22,7 +22,6 @@ local cdb = require "rspamd_cdb"
 local util = require "rspamd_util"
 local regexp = require "rspamd_regexp"
 local rspamd_expression = require "rspamd_expression"
-local rspamd_redis = require "rspamd_redis"
 local redis_params
 local fun = require "fun"
 
@@ -54,7 +53,7 @@ local value_types = {
     get_value = function(val) return val end,
   },
   content = {
-    get_value = function(val) return nil end,
+    get_value = function() return nil end,
   },
   hostname = {
     get_value = function(val) return val end,
@@ -267,7 +266,7 @@ local function apply_regexp_filter(task, filter, fn, r)
   return fn
 end
 
-local function apply_content_filter(task, filter, r)
+local function apply_content_filter(task, filter)
   if filter == 'body' then
     return {task:get_rawbody()}
   elseif filter == 'full' then
@@ -276,19 +275,19 @@ local function apply_content_filter(task, filter, r)
     return {task:get_raw_headers()}
   elseif filter == 'text' then
     local ret = {}
-    for i,p in ipairs(task:get_text_parts()) do
+    for _,p in ipairs(task:get_text_parts()) do
       table.insert(ret, p:get_content())
     end
     return ret
   elseif filter == 'rawtext' then
     local ret = {}
-    for i,p in ipairs(task:get_text_parts()) do
+    for _,p in ipairs(task:get_text_parts()) do
       table.insert(ret, p:get_raw_content())
     end
     return ret
   elseif filter == 'oneline' then
     local ret = {}
-    for i,p in ipairs(task:get_text_parts()) do
+    for _,p in ipairs(task:get_text_parts()) do
       table.insert(ret, p:get_content_oneline())
     end
     return ret
@@ -306,6 +305,7 @@ local multimap_filters = {
   url = apply_url_filter,
   filename = apply_filename_filter,
   mempool = apply_regexp_filter,
+  hostname = apply_hostname_filter,
   --content = apply_content_filter, -- Content filters are special :(
 }
 
@@ -359,8 +359,8 @@ local function multimap_callback(task, rule)
   end
 
   -- Parse result in form: <symbol>:<score>|<symbol>|<score>
-  local function parse_ret(rule, ret)
-    if ret and type(ret) == 'string' then
+  local function parse_ret(parse_rule, p_ret)
+    if p_ret and type(p_ret) == 'string' then
       local lpeg = require "lpeg"
       local number = {}
 
@@ -388,7 +388,7 @@ local function multimap_callback(task, rule)
       local symscore_cap = (symbol_cap * lpeg.P(":") * score_cap)
       local grammar = symscore_cap + symbol_cap + score_cap
       local parser = lpeg.Ct(grammar)
-      local tbl = parser:match(ret)
+      local tbl = parser:match(p_ret)
 
       if tbl then
         local sym = nil
@@ -403,15 +403,15 @@ local function multimap_callback(task, rule)
 
         return true,sym,score
       else
-        if ret ~= '' then
+        if p_ret ~= '' then
           rspamd_logger.infox(task, '%s: cannot parse string "%s"',
-            rule.symbol, ret)
+            parse_rule.symbol, p_ret)
         end
 
         return true,nil,1.0
       end
-    elseif type(ret) == 'boolean' then
-      return ret,nil,0.0
+    elseif type(p_ret) == 'boolean' then
+      return p_ret,nil,0.0
     end
 
     return false,nil,0.0
@@ -421,7 +421,7 @@ local function multimap_callback(task, rule)
   local function match_rule(r, value)
     local function rule_callback(result)
       if result then
-        local res,symbol,score = parse_ret(r, result)
+        local _,symbol,score = parse_ret(r, result)
         if symbol and r['symbols_set'] then
           if not r['symbols_set'][symbol] then
             rspamd_logger.infox(task, 'symbol %s is not registered for map %s, ' ..
@@ -495,7 +495,7 @@ local function multimap_callback(task, rule)
   end
 
   local function match_content(r)
-    local data = {}
+    local data
 
     if r['filter'] then
       data = apply_content_filter(task, r['filter'], r)
@@ -503,7 +503,7 @@ local function multimap_callback(task, rule)
       data = {task:get_content()}
     end
 
-    for i,v in ipairs(data) do
+    for _,v in ipairs(data) do
       match_rule(r, v)
     end
   end
@@ -527,7 +527,10 @@ local function multimap_callback(task, rule)
       if rt == 'ip' then
         match_rule(rule, ip)
       else
-        local cb = function (resolver, to_resolve, results, err, rbl)
+        local cb = function (_, _, results, err)
+          if err then
+            rspamd_logger.errx(task, 'DNS lookup failed: %s', err)
+          end
           if results then
             task:insert_result(rule['symbol'], 1, rule['map'])
 
@@ -558,18 +561,18 @@ local function multimap_callback(task, rule)
     end
   elseif rt == 'url' then
     if task:has_urls() then
-      local urls = task:get_urls()
-      for i,url in ipairs(urls) do
+      local msg_urls = task:get_urls()
+      for _,url in ipairs(msg_urls) do
         match_url(rule, url)
       end
     end
   elseif rt == 'filename' then
     local parts = task:get_parts()
-    for i,p in ipairs(parts) do
+    for _,p in ipairs(parts) do
       if p:is_archive() then
         local fnames = p:get_archive():get_files()
 
-        for ii,fn in ipairs(fnames) do
+        for _,fn in ipairs(fnames) do
           match_filename(rule, fn)
         end
       end
@@ -635,7 +638,6 @@ local function add_multimap_rule(key, newrule)
   end
   -- Check cdb flag
   if string.find(newrule['map'], '^cdb://.*$') then
-    local test = cdb.create(newrule['map'])
     newrule['cdb'] = cdb.create(newrule['map'])
     if newrule['cdb'] then
       ret = true
@@ -747,10 +749,10 @@ local function add_multimap_rule(key, newrule)
       end
 
       local function process_atom(atom, task)
-        local ret = task:has_symbol(atom)
-        rspamd_logger.debugx('check for symbol %s: %s', atom, ret)
+        local f_ret = task:has_symbol(atom)
+        rspamd_logger.debugx('check for symbol %s: %s', atom, f_ret)
 
-        if ret then
+        if f_ret then
           return 1
         end
 
diff --git a/src/plugins/lua/mx_check.lua b/src/plugins/lua/mx_check.lua
index 3e4f23a58..fbf68d6d7 100644
--- a/src/plugins/lua/mx_check.lua
+++ b/src/plugins/lua/mx_check.lua
@@ -17,7 +17,6 @@ limitations under the License.
 -- MX check plugin
 local rspamd_logger = require "rspamd_logger"
 local rspamd_tcp = require "rspamd_tcp"
-local rspamd_redis = require "rspamd_redis"
 local rspamd_util = require "rspamd_util"
 local fun = require "fun"
 
@@ -56,15 +55,19 @@ local function mx_check(task)
   end
 
   local valid = false
+  local ret,_,upstream
 
   local function check_results(mxes)
-    if fun.all(function(k, elt) return elt.checked end, mxes) then
+    if fun.all(function(_, elt) return elt.checked end, mxes) then
       -- Save cache
       local key = settings.key_prefix .. mx_domain
-      local function redis_cache_cb(err, data)
+      local function redis_cache_cb(err)
         if err ~= nil then
           rspamd_logger.errx(task, 'redis_cache_cb received error: %1', err)
+          upstream:fail()
           return
+        else
+          upstream:ok()
         end
       end
       if not valid then
@@ -78,7 +81,7 @@ local function mx_check(task)
         else
           task:insert_result(settings.symbol_bad_mx, 1.0)
         end
-        local ret,_,_ = rspamd_redis_make_request(task,
+        ret,_,upstream = rspamd_redis_make_request(task,
           redis_params, -- connect params
           key, -- hash key
           false, -- is write
@@ -86,13 +89,17 @@ local function mx_check(task)
           'SETEX', -- command
           {key, tostring(settings.expire_novalid), '0'} -- arguments
         )
+        if not ret then
+          rspamd_logger.errx(task, 'Redis SETEX failed')
+          upstream:fail()
+        end
       else
         local valid_mx = {}
-        fun.each(function(k, mx)
+        fun.each(function(k)
           table.insert(valid_mx, k)
-        end, fun.filter(function (k, elt) return elt.working end, mxes))
+        end, fun.filter(function (_, elt) return elt.working end, mxes))
         task:insert_result(settings.symbol_good_mx, 1.0, valid_mx)
-        local ret,_,_ = rspamd_redis_make_request(task,
+        ret,_,upstream = rspamd_redis_make_request(task,
           redis_params, -- connect params
           key, -- hash key
           false, -- is write
@@ -100,16 +107,20 @@ local function mx_check(task)
           'SETEX', -- command
           {key, tostring(settings.expire), table.concat(valid_mx, ';')} -- arguments
         )
+        if not ret then
+          rspamd_logger.errx(task, 'Redis SETEX failed')
+          upstream:fail()
+        end
       end
     end
   end
 
   local function gen_mx_a_callback(name, mxes)
-    return function(resolver, to_resolve, results, err, _, authenticated)
+    return function(_, _, results, err)
       mxes[name].ips = results
 
-      local function io_cb(err, data, conn)
-        if err then
+      local function io_cb(io_err)
+        if io_err then
           mxes[name].checked = true
         else
           mxes[name].checked = true
@@ -135,7 +146,7 @@ local function mx_check(task)
       else
         -- Try to open TCP connection to port 25
         for _,res in ipairs(results) do
-          local ret = rspamd_tcp.new({
+          local t_ret = rspamd_tcp.new({
             task = task,
             host = res:to_string(),
             callback = io_cb,
@@ -144,7 +155,7 @@ local function mx_check(task)
             port = 25
           })
 
-          if not ret then
+          if not t_ret then
             mxes[name].checked = true
           end
         end
@@ -153,7 +164,7 @@ local function mx_check(task)
     end
   end
 
-  local function mx_callback(resolver, to_resolve, results, err, _, authenticated)
+  local function mx_callback(_, _, results, err)
     local mxes = {}
     if err or not results then
       local r = task:get_resolver()
@@ -219,7 +230,7 @@ local function mx_check(task)
     end
 
     local key = settings.key_prefix .. mx_domain
-    local ret,_,_ = rspamd_redis_make_request(task,
+    ret,_,upstream = rspamd_redis_make_request(task,
       redis_params, -- connect params
       key, -- hash key
       false, -- is write
@@ -229,6 +240,7 @@ local function mx_check(task)
     )
 
     if not ret then
+      upstream:fail()
       local r = task:get_resolver()
       r:resolve('mx', {
         name = mx_domain,
diff --git a/src/plugins/lua/once_received.lua b/src/plugins/lua/once_received.lua
index 9b502defa..5cce56f62 100644
--- a/src/plugins/lua/once_received.lua
+++ b/src/plugins/lua/once_received.lua
@@ -30,7 +30,10 @@ local check_authed = false
 local function check_quantity_received (task)
   local recvh = task:get_received_headers()
 
-  local function recv_dns_cb(resolver, to_resolve, results, err)
+  local function recv_dns_cb(_, to_resolve, results, err)
+    if err then
+      rspamd_logger.errx(task, 'DNS lookup error: %s', err)
+    end
     task:inc_dns_req()
 
     if not results then
@@ -85,7 +88,6 @@ local function check_quantity_received (task)
     return
   end
 
-  local recvh = task:get_received_headers()
   if recvh and #recvh <= 1 then
     local ret = true
     local r = recvh[1]
@@ -94,13 +96,12 @@ local function check_quantity_received (task)
       return
     end
 
-    local hn = nil
     if r['real_hostname'] then
-      hn = string.lower(r['real_hostname'])
+      local rhn = string.lower(r['real_hostname'])
       -- Check for good hostname
-      if hn and good_hosts then
+      if rhn and good_hosts then
         for _,gh in ipairs(good_hosts) do
-          if string.find(hn, gh) then
+          if string.find(rhn, gh) then
             ret = false
             break
           end
@@ -148,10 +149,10 @@ if opts and type(opts) ~= 'table' then
   end
 end
 -- Configuration
-local opts =  rspamd_config:get_all_opt('once_received')
+opts = rspamd_config:get_all_opt('once_received')
 if opts then
   if opts['symbol'] then
-    local symbol = opts['symbol']
+    symbol = opts['symbol']
 
     local id = rspamd_config:register_symbol({
       name = symbol,
diff --git a/src/plugins/lua/phishing.lua b/src/plugins/lua/phishing.lua
index 371ed2963..015e079dd 100644
--- a/src/plugins/lua/phishing.lua
+++ b/src/plugins/lua/phishing.lua
@@ -26,7 +26,6 @@ local redirector_domains = {}
 local openphish_map = 'https://www.openphish.com/feed.txt'
 local phishtank_map = 'http://data.phishtank.com/data/online-valid.json'
 -- Not enabled by default as their feed is quite large
-local phishtank_enabled = false
 local openphish_premium = false
 local openphish_hash
 local phishtank_hash
@@ -41,7 +40,7 @@ if not (opts and type(opts) == 'table') then
 end
 
 local function phishing_cb(task)
-  local function check_phishing_map(map, url, symbol)
+  local function check_phishing_map(map, url, phish_symbol)
     local host = url:get_host()
 
     if host then
@@ -49,7 +48,6 @@ local function phishing_cb(task)
       local found_path = false
       local found_query = false
       local data = nil
-      local d
 
       if elt then
         local path = url:get_path()
@@ -69,14 +67,17 @@ local function phishing_cb(task)
             end
           end
         else
-          if not d['path'] then
-            found_path = true
-            found_query = true
+          for _,d in ipairs(elt) do
+            if not d['path'] then
+              found_path = true
+              found_query = true
+              break
+            end
           end
         end
 
         if found_path then
-          local args = nil
+          local args
 
           if type(data) == 'table' then
             args = {
@@ -92,15 +93,15 @@ local function phishing_cb(task)
 
           if found_query then
             -- Query + path match
-            task:insert_result(symbol, 1.0, args)
+            task:insert_result(phish_symbol, 1.0, args)
           else
             -- Host + path match
-            task:insert_result(symbol, 0.3, args)
+            task:insert_result(phish_symbol, 0.3, args)
           end
         else
           if url:is_phished() then
             -- Only host matches
-            task:insert_result(symbol, 0.1, host)
+            task:insert_result(phish_symbol, 0.1, host)
           end
         end
       end
@@ -138,7 +139,7 @@ local function phishing_cb(task)
         end
         rspamd_logger.debugx(task, "distance: %1 -> %2: %3", tld, ptld, dist)
 
-        local function found_in_map(map, url, weight)
+        local function found_in_map(map)
           if #map > 0 then
             for _,rule in ipairs(map) do
                 for _,dn in ipairs({url:get_tld(), url:get_host()}) do
@@ -151,7 +152,7 @@ local function phishing_cb(task)
           end
         end
 
-        if not found_in_map(redirector_domains, url, weight) then
+        if not found_in_map(redirector_domains) then
           if not found_in_map(strict_domains, purl, 1.0) then
             if domains then
               if domains:get_key(ptld) then
diff --git a/src/plugins/lua/ratelimit.lua b/src/plugins/lua/ratelimit.lua
index d6a2e7987..92d80fe32 100644
--- a/src/plugins/lua/ratelimit.lua
+++ b/src/plugins/lua/ratelimit.lua
@@ -36,13 +36,11 @@ local ip_score_lower_bound = 10
 local ip_score_ham_multiplier = 1.1
 local ip_score_spam_divisor = 1.1
 
-local message_func = function(task, limit_type, bucket, threshold)
+local message_func = function(_, limit_type)
   return string.format('Ratelimit "%s" exceeded', limit_type)
 end
 
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require "rspamd_redis"
-local upstream_list = require "rspamd_upstream_list"
 local rspamd_util = require "rspamd_util"
 local fun = require "fun"
 
@@ -152,7 +150,7 @@ local keywords = {
     end,
   },
   ['to'] = {
-    ['get_value'] = function(task)
+    ['get_value'] = function()
       return '%s' -- 'to' is special
     end,
   },
@@ -215,6 +213,8 @@ local function check_limits(task, args)
     if err then
       rspamd_logger.infox(task, 'got error while getting limit: %1', err)
       upstream:fail()
+    else
+      upstream:ok()
     end
     if not data then return end
     local ntime = rspamd_util.get_time()
@@ -307,6 +307,10 @@ local function check_limits(task, args)
     'mget', -- command
     fun.totable(fun.map(function(l) return l[2] end, args)) -- arguments
   )
+  if not ret then
+    rspamd_logger.errx(task, 'Redis MGET failed on %s', upstream:get_addr())
+    upstream:fail()
+  end
 end
 
 --- Set specific limit inside redis
@@ -314,7 +318,7 @@ local function set_limits(task, args)
   local key = fun.foldl(function(acc, k) return acc .. k[2] end, '', args)
   local ret, upstream
 
-  local function rate_set_cb(err, data)
+  local function rate_set_cb(err)
     if not err then
       upstream:ok()
     else
@@ -333,7 +337,6 @@ local function set_limits(task, args)
     fun.each(function(elt, limit)
       local bucket = elt[2]
       local rate = limit[1][2]
-      local threshold = limit[1][1]
       local atime = elt[1]
       local ctime = elt[3]
 
@@ -342,7 +345,6 @@ local function set_limits(task, args)
           atime - ctime)
         bucket = 1
         ctime = ntime
-        atime = ntime
       else
         if bucket > 0 then
           bucket = bucket - rate * (ntime - atime) + 1;
@@ -391,6 +393,10 @@ local function set_limits(task, args)
     'mget', -- command
     fun.totable(fun.map(function(l) return l[2] end, args)) -- arguments
   )
+  if not ret then
+    rspamd_logger.errx(task, 'Redis MGET failed on %s', upstream:get_addr())
+    upstream:fail()
+  end
 end
 
 --- Check or update ratelimit
@@ -428,7 +434,7 @@ local function rate_test_set(task, func)
   end
 
   local rate_key
-  for k, v in pairs(settings) do
+  for k in pairs(settings) do
     rate_key = dynamic_rate_key(task, k)
     if rate_key then
       if type(rate_key) == 'table' then
@@ -517,9 +523,9 @@ if opts then
     end, opts['dynamic_rates'])
   end
 
-  local enabled_limits = fun.totable(fun.map(function(t, lim)
+  local enabled_limits = fun.totable(fun.map(function(t)
     return t
-  end, fun.filter(function(t, lim)
+  end, fun.filter(function(_, lim)
     return type(lim) == 'string' or
         (type(lim) == 'table' and type(lim[1]) == 'number' and lim[1] > 0)
   end, settings)))
@@ -573,7 +579,7 @@ if opts then
   end
 
   if opts['message_func'] then
-    message_func = assert(loadstring(opts['message_func']))()
+    message_func = assert(load(opts['message_func']))()
   end
 
   redis_params = rspamd_parse_redis_server('ratelimit')
diff --git a/src/plugins/lua/rbl.lua b/src/plugins/lua/rbl.lua
index eb774e5b4..3308d0e5c 100644
--- a/src/plugins/lua/rbl.lua
+++ b/src/plugins/lua/rbl.lua
@@ -23,7 +23,6 @@ local rbls = {}
 local local_exclusions = nil
 
 local rspamd_logger = require 'rspamd_logger'
-local rspamd_ip = require 'rspamd_ip'
 local rspamd_util = require 'rspamd_util'
 local fun = require 'fun'
 
@@ -62,7 +61,10 @@ end
 
 local function rbl_cb (task)
   local function gen_rbl_callback(rule)
-    return function (resolver, to_resolve, results, err)
+    return function (_, to_resolve, results, err)
+      if err then
+        rspamd_logger.errx(task, 'DNS lookup error: %s', err)
+      end
       if not results then return end
 
       for _,rbl in ipairs(rule.rbls) do
@@ -72,7 +74,7 @@ local function rbl_cb (task)
         end
         for _,result in pairs(results) do
           local ipstr = result:to_string()
-          local foundrc, s
+          local foundrc
           for s,i in pairs(rbl['returncodes']) do
             if type(i) == 'string' then
               if string.find(ipstr, '^' .. i .. '$') then
@@ -126,7 +128,7 @@ local function rbl_cb (task)
   local havegot = {}
   local notgot = {}
 
-  local alive_rbls = fun.filter(function(k, rbl)
+  local alive_rbls = fun.filter(function(_, rbl)
     if not rbl.monitored:alive() then
       return false
     end
@@ -135,7 +137,7 @@ local function rbl_cb (task)
   end, rbls)
 
   -- Now exclude rbls, that are disabled by configuration
-  local enabled_rbls = fun.filter(function(k, rbl)
+  local enabled_rbls = fun.filter(function(_, rbl)
     if rbl['exclude_users'] then
       if not havegot['user'] and not notgot['user'] then
         havegot['user'] = task:get_user()
@@ -260,17 +262,17 @@ local function rbl_cb (task)
 
   -- Now we iterate over enabled rbls and fill params
   -- Helo RBLs
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     local to_resolve = havegot['helo'] .. '.' .. rbl['rbl']
     gen_rbl_rule(to_resolve, rbl)
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['helo'] then return true end
     return false
   end, enabled_rbls))
 
   -- DKIM RBLs
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     for _, d in ipairs(havegot['dkim']) do
       if rbl['dkim_domainonly'] then
         d = rspamd_util.get_tld(d)
@@ -279,13 +281,13 @@ local function rbl_cb (task)
       gen_rbl_rule(to_resolve, rbl)
     end
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['dkim'] then return true end
     return false
   end, enabled_rbls))
 
   -- Emails RBLs
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     if rbl['emails'] == 'domain_only' then
       for domain, _ in pairs(havegot['emails']) do
         local to_resolve = domain .. '.' .. rbl['rbl']
@@ -298,36 +300,36 @@ local function rbl_cb (task)
       end
     end
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['emails'] then return true end
     return false
   end, enabled_rbls))
 
   -- RDNS lists
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     local to_resolve = havegot['rdns'] .. '.' .. rbl['rbl']
     gen_rbl_rule(to_resolve, rbl)
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['rdns'] then return true end
     return false
   end, enabled_rbls))
 
   -- From lists
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     if (havegot['from']:get_version() == 6 and rbl['ipv6']) or
       (havegot['from']:get_version() == 4 and rbl['ipv4']) then
       local to_resolve = ip_to_rbl(havegot['from'], rbl['rbl'])
       gen_rbl_rule(to_resolve, rbl)
     end
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['from'] then return true end
     return false
   end, enabled_rbls))
 
   -- Received lists
-  fun.each(function(k, rbl)
+  fun.each(function(_, rbl)
     for _,rh in ipairs(havegot['received']) do
       if rh['real_ip'] and rh['real_ip']:is_valid() then
         if ((rh['real_ip']:get_version() == 6 and rbl['ipv6']) or
@@ -344,7 +346,7 @@ local function rbl_cb (task)
       end
     end
   end,
-  fun.filter(function(k, rbl)
+  fun.filter(function(_, rbl)
     if rbl['received'] then return true end
     return false
   end, enabled_rbls))
@@ -403,7 +405,6 @@ local default_defaults = {
   ['default_dkim'] = {[1] = false, [2] = 'dkim'},
   ['default_dkim_domainonly'] = {[1] = true, [2] = 'dkim_domainonly'},
   ['default_emails'] = {[1] = false, [2] = 'emails'},
-  ['default_exclude_users'] = {[1] = false, [2] = 'exclude_users'},
   ['default_exclude_private_ips'] = {[1] = true, [2] = 'exclude_private_ips'},
   ['default_exclude_users'] = {[1] = false, [2] = 'exclude_users'},
   ['default_exclude_local'] = {[1] = true, [2] = 'exclude_local'},
@@ -433,7 +434,6 @@ local id = rspamd_config:register_symbol({
 for key,rbl in pairs(opts['rbls']) do
   (function()
     if rbl['disabled'] then return end
-    local s
     for default, default_v in pairs(default_defaults) do
       if(rbl[default_v[2]] == nil) then
         rbl[default_v[2]] = opts[default]
@@ -501,7 +501,7 @@ for key,rbl in pairs(opts['rbls']) do
             elseif type(rbl['whitelist_exception']) == 'table' then
               local foundException = false
               for _, e in pairs(rbl['whitelist_exception']) do
-                if e == s then
+                if e == rbl['symbol'] then
                   foundException = true
                   break
                 end
diff --git a/src/plugins/lua/replies.lua b/src/plugins/lua/replies.lua
index 901595295..314f09083 100644
--- a/src/plugins/lua/replies.lua
+++ b/src/plugins/lua/replies.lua
@@ -19,7 +19,6 @@ limitations under the License.
 
 -- Default port for redis upstreams
 local redis_params
-local whitelisted_ip
 local settings = {
   action = nil,
   expire = 86400, -- 1 day by default
@@ -29,8 +28,6 @@ local settings = {
 }
 
 local rspamd_logger = require 'rspamd_logger'
-local rspamd_redis = require 'rspamd_redis'
-local upstream_list = require 'rspamd_upstream_list'
 local hash = require 'rspamd_cryptobox_hash'
 
 local function make_key(goop)
@@ -83,7 +80,7 @@ local function replies_check(task)
 end
 
 local function replies_set(task)
-  local function redis_set_cb(err, data)
+  local function redis_set_cb(err)
     if err ~=nil then
       rspamd_logger.errx('redis_set_cb received error: %1', err)
     end
diff --git a/src/plugins/lua/rspamd_update.lua b/src/plugins/lua/rspamd_update.lua
index 9ce38c8ab..f53967317 100644
--- a/src/plugins/lua/rspamd_update.lua
+++ b/src/plugins/lua/rspamd_update.lua
@@ -19,7 +19,6 @@ limitations under the License.
 local ucl = require "ucl"
 local fun = require "fun"
 local rspamd_logger = require "rspamd_logger"
-local updates_priority = 2
 local rspamd_config = rspamd_config
 local hash = require "rspamd_cryptobox_hash"
 local rspamd_version = rspamd_version
@@ -47,7 +46,7 @@ end
 
 local function process_rules(obj)
   fun.each(function(key, code)
-    local f = loadstring(code)
+    local f = load(code)
     if f then
       f()
     else
@@ -81,10 +80,9 @@ local function check_version(obj)
   return ret
 end
 
-local function gen_callback(map)
+local function gen_callback()
 
   return function(data)
-    local ucl = require "ucl"
     local parser = ucl.parser()
     local res,err = parser:parse_string(data)
 
@@ -97,12 +95,6 @@ local function gen_callback(map)
 
       if check_version(obj) then
 
-        local priority = updates_priority
-
-        if obj['priority'] then
-          priority = obj['priority']
-        end
-
         if obj['symbols'] then
           process_symbols(obj['symbols'])
         end
@@ -127,9 +119,7 @@ local section = rspamd_config:get_all_opt("rspamd_update")
 if section then
   local trusted_key
   fun.each(function(k, elt)
-    if k == 'priority' then
-      updates_priority = tonumber(elt)
-    elseif k == 'key' then
+    if k == 'key' then
       trusted_key = elt
     else
       local map = rspamd_config:add_map(elt, "rspamd updates map", nil)
diff --git a/src/plugins/lua/settings.lua b/src/plugins/lua/settings.lua
index 06573ffd7..e52a8ac66 100644
--- a/src/plugins/lua/settings.lua
+++ b/src/plugins/lua/settings.lua
@@ -19,7 +19,6 @@ limitations under the License.
 -- https://rspamd.com/doc/configuration/settings.html
 
 local rspamd_logger = require "rspamd_logger"
-local rspamd_redis = require 'rspamd_redis'
 local redis_params
 
 local settings = {}
@@ -43,6 +42,8 @@ local function check_query_settings(task)
       task:set_settings(parser:get_object())
 
       return true
+    else
+      rspamd_logger.errx(task, 'Parse error: %s', err)
     end
   end
 
@@ -136,7 +137,7 @@ local function check_settings(task)
     return false
   end
 
-  local function check_specific_setting(name, rule, ip, client_ip, from, rcpt,
+  local function check_specific_setting(_, rule, ip, client_ip, from, rcpt,
       user, auth_user)
     local res = false
 
@@ -254,13 +255,12 @@ local function check_settings(task)
   local user = {}
   if uname then
     user[1] = {}
-    for localpart, domainpart in string.gmatch(uname, "(.+)@(.+)") do
+    local localpart, domainpart = string.gmatch(uname, "(.+)@(.+)")()
+    if localpart then
       user[1]["user"] = localpart
       user[1]["domain"] = domainpart
       user[1]["addr"] = uname
-      break
-    end
-    if not user[1]["addr"] then
+    else
       user[1]["user"] = uname
       user[1]["addr"] = uname
     end
@@ -324,7 +324,7 @@ local function process_settings_table(tbl)
       local out = {}
 
       if type(ip) == "table" then
-        for i,v in ipairs(ip) do
+        for _,v in ipairs(ip) do
           table.insert(out, process_ip(v))
         end
       elseif type(ip) == "string" then
@@ -363,7 +363,7 @@ local function process_settings_table(tbl)
     local function process_addr(addr)
       local out = {}
       if type(addr) == "table" then
-        for i,v in ipairs(addr) do
+        for _,v in ipairs(addr) do
           table.insert(out, process_addr(v))
         end
       elseif type(addr) == "string" then
@@ -399,8 +399,8 @@ local function process_settings_table(tbl)
       return out
     end
 
-    local check_table = function(elt, out)
-      if type(elt) == 'string' then
+    local check_table = function(chk_elt, out)
+      if type(chk_elt) == 'string' then
         return {out}
       end
 
@@ -480,7 +480,7 @@ local function process_settings_table(tbl)
   max_pri = 0
   local nrules = 0
   settings_ids = {}
-  for k,v in pairs(settings) do settings[k]={} end
+  for k in pairs(settings) do settings[k]={} end
   -- fill new settings by priority
   fun.for_each(function(k, v)
     local pri = get_priority(v)
@@ -507,7 +507,6 @@ end
 
 -- Parse settings map from the ucl line
 local function process_settings_map(string)
-  local ucl = require "ucl"
   local parser = ucl.parser()
   local res,err = parser:parse_string(string)
   if not res then
@@ -530,12 +529,11 @@ local function gen_redis_callback(handler, id)
 
     local function redis_settings_cb(err, data)
       if not err and type(data) == 'string' then
-        local ucl = require "ucl"
         local parser = ucl.parser()
-        local res,err = parser:parse_string(data)
+        local res,ucl_err = parser:parse_string(data)
         if not res then
           rspamd_logger.warnx(rspamd_config, 'cannot parse settings from redis: %s',
-            err)
+            ucl_err)
         else
           local obj = parser:get_object()
           rspamd_logger.infox(task, "<%1> apply settings according to redis rule %2",
@@ -558,6 +556,9 @@ local function gen_redis_callback(handler, id)
       'GET', -- command
       {key} -- arguments
     )
+    if not ret then
+      rspamd_logger.errx(task, 'Redis GET failed: %s', ret)
+    end
   end
 end
 
@@ -570,7 +571,7 @@ if redis_section then
     local handlers = redis_section.handlers
 
     for _,h in ipairs(handlers) do
-      local chunk,err = loadstring(h)
+      local chunk,err = load(h)
 
       if not chunk then
         rspamd_logger.errx(rspamd_config, 'Cannot load handler from string: %s',
diff --git a/src/plugins/lua/spamassassin.lua b/src/plugins/lua/spamassassin.lua
index a29b6bbc7..07a80bb90 100644
--- a/src/plugins/lua/spamassassin.lua
+++ b/src/plugins/lua/spamassassin.lua
@@ -83,7 +83,6 @@ local symbols_replacements = {
 -- Internal variables
 local rules = {}
 local atoms = {}
-local metas = {}
 local scores = {}
 local scores_added = {}
 local external_deps = {}
@@ -171,7 +170,7 @@ local function process_regexp_opt(re, task, re_type, header, strong)
     if not strong then
       strong = 0
     else
-      string = 1
+      strong = 1
     end
     local iret = ffi.C.rspamd_re_cache_process_ffi (task, re, itype, header, strong)
 
@@ -196,14 +195,12 @@ local function handle_header_def(hline, cur_rule)
   -- Check if an re is an ordinary re
   local ordinary = true
 
-  for i,h in ipairs(hdrs) do
+  for _,h in ipairs(hdrs) do
     if h == 'ALL' or h == 'ALL:raw' then
       ordinary = false
       cur_rule['type'] = 'function'
       -- Pack closure
       local re = cur_rule['re']
-      local not_f = cur_rule['not']
-      local sym = cur_rule['symbol']
       -- Rule to match all headers
       rspamd_config:register_regexp({
         re = re,
@@ -235,7 +232,7 @@ local function handle_header_def(hline, cur_rule)
               local addr_parsed = util.parse_addr(str)
               local ret = {}
               if addr_parsed then
-                for i,elt in ipairs(addr_parsed) do
+                for _,elt in ipairs(addr_parsed) do
                   if elt['addr'] then
                     table.insert(ret, elt['addr'])
                   end
@@ -249,7 +246,7 @@ local function handle_header_def(hline, cur_rule)
               local addr_parsed = util.parse_addr(str)
               local ret = {}
               if addr_parsed then
-                for i,elt in ipairs(addr_parsed) do
+                for _,elt in ipairs(addr_parsed) do
                   if elt['name'] then
                     table.insert(ret, elt['name'])
                   end
@@ -269,7 +266,7 @@ local function handle_header_def(hline, cur_rule)
         end, fun.tail(args))
 
         local function split_hdr_param(param, headers)
-          for i,h in ipairs(headers) do
+          for _,hh in ipairs(headers) do
             local nparam = {}
             for k,v in pairs(param) do
               if k ~= 'header' then
@@ -277,7 +274,7 @@ local function handle_header_def(hline, cur_rule)
               end
             end
 
-            nparam['header'] = h
+            nparam['header'] = hh
             table.insert(hdr_params, nparam)
           end
         end
@@ -319,7 +316,7 @@ end
 
 local function gen_eval_rule(arg)
   local eval_funcs = {
-    {'check_freemail_from', function(task, remain)
+    {'check_freemail_from', function(task)
         local from = task:get_from('mime')
         if from and from[1] then
           return freemail_search(string.lower(from[1]['addr']))
@@ -327,26 +324,26 @@ local function gen_eval_rule(arg)
         return 0
       end},
     {'check_freemail_replyto',
-      function(task, remain)
+      function(task)
         return freemail_search(task:get_header('Reply-To'))
       end
     },
     {'check_freemail_header',
       function(task, remain)
         -- Remain here contains one or two args: header and regexp to match
-        local arg = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*%)$")
+        local larg = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*%)$")
         local re = nil
-        if not arg then
-          arg, re = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*,%s*['\"]([^%s]+)['\"]%s*%)$")
+        if not larg then
+          larg, re = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*,%s*['\"]([^%s]+)['\"]%s*%)$")
         end
 
-        if arg then
+        if larg then
           local h
-          if arg == 'EnvelopeFrom' then
+          if larg == 'EnvelopeFrom' then
             h = task:get_from('smtp')
             if h then h = h[1]['addr'] end
           else
-            h = task:get_header(arg)
+            h = task:get_header(larg)
           end
           if h then
             local hdr_freemail = freemail_search(string.lower(h))
@@ -372,7 +369,7 @@ local function gen_eval_rule(arg)
     },
     {
       'check_for_missing_to_header',
-      function (task, remain)
+      function (task)
         local th = task:get_recipients('mime')
         if not th or #th == 0 then
           return 1
@@ -383,7 +380,7 @@ local function gen_eval_rule(arg)
     },
     {
       'check_relays_unparseable',
-      function(task, remain)
+      function(task)
         local rh_mime = task:get_header_full('Received')
         local rh_parsed = task:get_received_headers()
 
@@ -433,13 +430,13 @@ local function gen_eval_rule(arg)
     {
       'check_for_mime',
       function(task, remain)
-        local arg = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*%)$")
+        local larg = string.match(remain, "^%(%s*['\"]([^%s]+)['\"]%s*%)$")
 
-        if arg then
-          if arg == 'mime_attachment' then
+        if larg then
+          if larg == 'mime_attachment' then
             local parts = task:get_parts()
             if parts then
-              for i,p in ipairs(parts) do
+              for _,p in ipairs(parts) do
                 if p:get_filename() then
                   return 1
                 end
@@ -455,7 +452,7 @@ local function gen_eval_rule(arg)
     },
     {
       'check_from_in_blacklist',
-      function(task, remain)
+      function(task)
         local from = task:get_from('mime')
         if from and from[1] and from[1]['addr'] then
           if sa_lists['from_blacklist'][string.lower(from[1]['addr'])] then
@@ -468,7 +465,7 @@ local function gen_eval_rule(arg)
     },
     {
       'check_from_in_whitelist',
-      function(task, remain)
+      function(task)
         local from = task:get_from('mime')
         if from and from[1] and from[1]['addr'] then
           if sa_lists['from_whitelist'][string.lower(from[1]['addr'])] then
@@ -481,7 +478,7 @@ local function gen_eval_rule(arg)
     },
     {
       'check_from_in_default_whitelist',
-      function(task, remain)
+      function(task)
         local from = task:get_from('mime')
         if from and from[1] and from[1]['addr'] then
           if sa_lists['from_def_whitelist'][string.lower(from[1]['addr'])] then
@@ -494,10 +491,10 @@ local function gen_eval_rule(arg)
     },
     {
       'check_to_in_blacklist',
-      function(task, remain)
+      function(task)
         local rcpt = task:get_recipients('mime')
         if rcpt then
-          for i,r in ipairs(rcpt) do
+          for _,r in ipairs(rcpt) do
             if sa_lists['to_blacklist'][string.lower(r['addr'])] then
               return 1
             end
@@ -509,10 +506,10 @@ local function gen_eval_rule(arg)
     },
     {
       'check_to_in_whitelist',
-      function(task, remain)
+      function(task)
         local rcpt = task:get_recipients('mime')
         if rcpt then
-          for i,r in ipairs(rcpt) do
+          for _,r in ipairs(rcpt) do
             if sa_lists['to_whitelist'][string.lower(r['addr'])] then
               return 1
             end
@@ -524,7 +521,7 @@ local function gen_eval_rule(arg)
     },
   }
 
-  for k,f in ipairs(eval_funcs) do
+  for _,f in ipairs(eval_funcs) do
     local pat = string.format('^%s', f[1])
     local first,last = string.find(arg, pat)
 
@@ -548,7 +545,7 @@ local function maybe_parse_sa_function(line)
   local substitutions = {
     {'^exists:',
       function(task) -- filter
-        local hdrs_check = {}
+        local hdrs_check
         if arg == 'MESSAGEID' then
           hdrs_check = {
             'Message-ID',
@@ -561,7 +558,7 @@ local function maybe_parse_sa_function(line)
           hdrs_check = {arg}
         end
 
-        for i,h in ipairs(hdrs_check) do
+        for _,h in ipairs(hdrs_check) do
           if task:get_header(h) then
             return 1
           end
@@ -589,7 +586,7 @@ local function maybe_parse_sa_function(line)
     },
   }
 
-  for k,s in ipairs(substitutions) do
+  for _,s in ipairs(substitutions) do
     if string.find(line, s[1]) then
       return s[2]
     end
@@ -723,8 +720,6 @@ local function process_sa_conf(f)
       end
     end
 
-    local slash = string.find(l, '/')
-
     -- Skip comments
     local words = fun.totable(fun.take_while(
       function(w) return string.sub(w, 1, 1) ~= '#' end,
@@ -777,7 +772,7 @@ local function process_sa_conf(f)
           valid_rule = true
           cur_rule['re']:set_max_hits(1)
           if cur_rule['header'] and cur_rule['ordinary'] then
-            for i,h in ipairs(cur_rule['header']) do
+            for _,h in ipairs(cur_rule['header']) do
               if type(h) == 'string' then
                 if cur_rule['mime'] then
                   rspamd_config:register_regexp({
@@ -1102,14 +1097,14 @@ local function apply_replacements(str)
   end
 
   local function replace_all_tags(s)
-    local str, matches
-    str = s
+    local sstr, _
+    sstr = s
     fun.each(function(n, t)
-        str,matches = string.gsub(str, string.format("<%s>", n),
+        sstr,_ = string.gsub(sstr, string.format("<%s>", n),
           string.format("%s%s%s", pre, t, post))
     end, replace['tags'])
 
-    return str
+    return sstr
   end
 
   local s = replace_all_tags(str)
@@ -1264,20 +1259,19 @@ local function post_process()
 
       -- Slow path
       fun.each(function(h)
-        local headers = {}
         local hname = h['header']
 
         local hdr
         if h['mime'] then
           local parts = task:get_parts()
-          for i, p in ipairs(parts) do
+          for _, p in ipairs(parts) do
             local m_hdr = p:get_header_full(hname, h['strong'])
 
             if m_hdr then
               if not hdr then
                 hdr = {}
               end
-              for k, mh in ipairs(m_hdr) do
+              for _, mh in ipairs(m_hdr) do
                 table.insert(hdr, mh)
               end
             end
@@ -1287,7 +1281,7 @@ local function post_process()
         end
 
         if hdr then
-          for n, rh in ipairs(hdr) do
+          for _, rh in ipairs(hdr) do
             -- Subject for optimization
             local str
             if h['raw'] then
@@ -1305,7 +1299,7 @@ local function post_process()
             if type(str) == 'string' then
               table.insert(check, str)
             else
-              for ii, c in ipairs(str) do
+              for _, c in ipairs(str) do
                 table.insert(check, c)
               end
             end
@@ -1321,7 +1315,7 @@ local function post_process()
       end
 
       local ret = 0
-      for i, c in ipairs(check) do
+      for _, c in ipairs(check) do
         local match = sa_regexp_match(c, r['re'], raw, r)
         if (match > 0 and not r['not']) or (match == 0 and r['not']) then
           ret = 1
@@ -1338,7 +1332,7 @@ local function post_process()
     end
     atoms[k] = f
   end,
-  fun.filter(function(k, r)
+  fun.filter(function(_, r)
       return r['type'] == 'header' and r['header']
   end,
   rules))
@@ -1360,7 +1354,7 @@ local function post_process()
     end
     atoms[k] = f
   end,
-    fun.filter(function(k, r)
+    fun.filter(function(_, r)
       return r['type'] == 'function' and r['function']
     end,
       rules))
@@ -1386,7 +1380,7 @@ local function post_process()
     end
     atoms[k] = f
   end,
-  fun.filter(function(k, r)
+  fun.filter(function(_, r)
       return r['type'] == 'part'
   end, rules))
 
@@ -1411,7 +1405,7 @@ local function post_process()
     end
     atoms[k] = f
   end,
-  fun.filter(function(k, r)
+  fun.filter(function(_, r)
       return r['type'] == 'sabody' or r['type'] == 'message' or r['type'] == 'sarawbody'
   end, rules))
 
@@ -1433,7 +1427,7 @@ local function post_process()
     end
     atoms[k] = f
   end,
-    fun.filter(function(k, r)
+    fun.filter(function(_, r)
       return r['type'] == 'uri'
     end,
       rules))
@@ -1484,7 +1478,7 @@ local function post_process()
         end
       end
     end,
-    fun.filter(function(k, r)
+    fun.filter(function(_, r)
         return r['type'] == 'meta'
       end,
       rules))
@@ -1495,9 +1489,9 @@ local function post_process()
       if r['expression'] then
         local expr_atoms = r['expression']:atoms()
 
-        for i,a in ipairs(expr_atoms) do
+        for _,a in ipairs(expr_atoms) do
           if not atoms[a] then
-            local rspamd_symbol, replaced_symbol = replace_symbol(a)
+            local rspamd_symbol = replace_symbol(a)
             rspamd_logger.debugx('atom %1 is a direct foreign dependency, ' ..
               'register dependency for %2 on %3',
               a, k, rspamd_symbol)
@@ -1511,7 +1505,7 @@ local function post_process()
         end
       end
     end,
-    fun.filter(function(k, r)
+    fun.filter(function(_, r)
       return r['type'] == 'meta'
     end,
     rules))
@@ -1520,7 +1514,7 @@ local function post_process()
   fun.each(function(k, r)
       if r['expression'] then
         local expr_atoms = r['expression']:atoms()
-        for i,a in ipairs(expr_atoms) do
+        for _,a in ipairs(expr_atoms) do
           if type(external_deps[a]) == 'table' then
             for _,dep in ipairs(external_deps[a]) do
               rspamd_logger.debugx('atom %1 holds a foreign dependency, ' ..
@@ -1539,7 +1533,7 @@ local function post_process()
         end
       end
     end,
-    fun.filter(function(k, r)
+    fun.filter(function(_, r)
       return r['type'] == 'meta'
     end,
     rules))
@@ -1572,15 +1566,15 @@ if type(section) == "table" then
     elseif k == 'match_limit' and type(fn) == 'number' then
       match_limit = fn
     elseif k == 'pcre_only' and type(fn) == 'table' then
-      for i,s in ipairs(fn) do
+      for _,s in ipairs(fn) do
         pcre_only_regexps[s] = 1
       end
     else
       if type(fn) == 'table' then
-        for k, elt in ipairs(fn) do
+        for _, elt in ipairs(fn) do
           local files = util.glob(elt)
 
-          for i,matched in ipairs(files) do
+          for _,matched in ipairs(files) do
             local f = io.open(matched, "r")
             if f then
               process_sa_conf(f)
@@ -1594,7 +1588,7 @@ if type(section) == "table" then
         -- assume string
         local files = util.glob(fn)
 
-        for i,matched in ipairs(files) do
+        for _,matched in ipairs(files) do
           local f = io.open(matched, "r")
           if f then
             process_sa_conf(f)
diff --git a/src/plugins/lua/trie.lua b/src/plugins/lua/trie.lua
index a0ac862a5..443f2e5de 100644
--- a/src/plugins/lua/trie.lua
+++ b/src/plugins/lua/trie.lua
@@ -160,7 +160,7 @@ if opts then
   end
 
   if id ~= -1 then
-    for sym, opt in pairs(opts) do
+    for sym in pairs(opts) do
       rspamd_config:register_symbol({
         name = sym,
         type = 'virtual',
diff --git a/src/plugins/lua/whitelist.lua b/src/plugins/lua/whitelist.lua
index 55d995ee5..0272a03d9 100644
--- a/src/plugins/lua/whitelist.lua
+++ b/src/plugins/lua/whitelist.lua
@@ -16,7 +16,6 @@ limitations under the License.
 
 local rspamd_logger = require "rspamd_logger"
 local rspamd_util = require "rspamd_util"
-local ucl = require "ucl"
 local fun = require "fun"
 
 local options = {
@@ -55,7 +54,6 @@ local function whitelist_cb(symbol, rule, task)
     return false,0.0
   end
 
-  local from = task:get_from(1)
   local found = false
   local mult = 1.0
   local spf_violated = false
@@ -170,18 +168,6 @@ local function gen_whitelist_cb(symbol, rule)
   end
 end
 
-local function process_whitelist_map(input)
-  local parser = ucl.parser()
-  local res,err = parser:parse_string(string)
-  if not res then
-    rspamd_logger.warnx(rspamd_config, 'cannot parse settings map: ' .. err)
-  else
-    local obj = parser:get_object()
-
-    options['rules'] = obj
-  end
-end
-
 local configure_whitelist_module = function()
   local opts =  rspamd_config:get_all_opt('whitelist')
   if opts then