[Feature] Add rmilter_headers module (Fixes #1227)

diff --git a/src/plugins/lua/rmilter_headers.lua b/src/plugins/lua/rmilter_headers.lua
new file mode 100644 (file)
index 0000000..9e2f99a
--- /dev/null
+++ b/src/plugins/lua/rmilter_headers.lua
@@ -0,0 +1,178 @@
+--[[
+Copyright (c) 2016, Andrew Lewis <nerf@judo.za.org>
+Copyright (c) 2016, Vsevolod Stakhov <vsevolod@highsecure.ru>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+]]--
+
+-- A plugin that provides common header manipulations
+
+local logger = require "rspamd_logger"
+local N = 'rmilter_headers'
+
+local settings = {
+  routines = {
+    ['x-spamd-bar'] = {
+      header = 'X-Spamd-Bar',
+      positive = '+',
+      negative = '-',
+      neutral = '/',
+      remove = 1,
+    },
+    ['x-spam-level'] = {
+      header = 'X-Spam-Level',
+      char = '*',
+      remove = 1,
+    },
+    ['x-spam-status'] = {
+      header = 'X-Spam-Status',
+      remove = 1,
+    },
+  },
+}
+
+local active_routines = {}
+local routines = {}
+
+routines['x-spamd-bar'] = function(task, common_meta)
+  local common, add, remove = {}, {}, {}
+  if not common_meta['metric_score'] then
+    common['metric_score'] = task:get_metric_score('default')
+    common_meta['metric_score'] = common['metric_score']
+  end
+  local score = common_meta['metric_score'][1]
+  local spambar
+  if score <= -1 then
+    spambar = string.rep(settings.routines['x-spamd-bar'].negative, score*-1)
+  elseif score >= 1 then
+    spambar = string.rep(settings.routines['x-spamd-bar'].positive, score)
+  else
+    spambar = settings.routines['x-spamd-bar'].neutral
+  end
+  if settings.routines['x-spamd-bar'].remove then
+    remove[settings.routines['x-spamd-bar'].header] = settings.routines['x-spamd-bar'].remove
+  end
+  if spambar ~= '' then
+    add[settings.routines['x-spamd-bar'].header] = spambar
+  end
+  return nil, add, remove, common
+end
+
+routines['x-spam-level'] = function(task, common_meta)
+  local common, add, remove = {}, {}, {}
+  if not common_meta['metric_score'] then
+    common['metric_score'] = task:get_metric_score('default')
+    common_meta['metric_score'] = common['metric_score']
+  end
+  local score = common_meta['metric_score'][1]
+  if score < 1 then
+    return nil, {}, {}, common
+  end
+  if settings.routines['x-spam-level'].remove then
+    remove[settings.routines['x-spam-level'].header] = settings.routines['x-spam-level'].remove
+  end
+  add[settings.routines['x-spam-level'].header] = string.rep(settings.routines['x-spam-level'].char, score)
+  return nil, add, remove, common
+end
+
+routines['x-spam-status'] = function(task, common_meta)
+  local common, add, remove = {}, {}, {}
+  if not common_meta['metric_score'] then
+    common['metric_score'] = task:get_metric_score('default')
+    common_meta['metric_score'] = common['metric_score']
+  end
+  if not common_meta['metric_action'] then
+    common['metric_action'] = task:get_metric_action('default')
+    common_meta['metric_action'] = common['metric_action']
+  end
+  local score = common_meta['metric_score'][1]
+  local action = common_meta['metric_action']
+  local is_spam
+  local spamstatus
+  if action ~= 'no action' and action ~= 'greylist' then
+    is_spam = 'Yes'
+  else
+    is_spam = 'No'
+  end
+  spamstatus = is_spam .. ', score=' .. string.format('%.2f', score)
+  if settings.routines['x-spam-status'].remove then
+    remove[settings.routines['x-spam-status'].header] = settings.routines['x-spam-status'].remove
+  end
+  add[settings.routines['x-spam-status'].header] = spamstatus
+  return nil, add, remove, common
+end
+
+local function rmilter_headers(task)
+  local common_meta, to_add, to_remove = {}, {}, {}
+  for n, f in pairs(active_routines) do
+    local ok, err, add, remove, common = pcall(routines[f], task, common_meta)
+    if not ok then
+      logger.errx(task, 'call to %s failed: %s', n, err)
+    else
+      for k, v in pairs(add) do
+        to_add[k] = v
+      end
+      for k, v in pairs(remove) do
+        to_remove[k] = v
+      end
+      for k, v in pairs(common) do
+        common_meta[k] = v
+      end
+    end
+  end
+  if not next(to_add) then to_add = nil end
+  if not next(to_remove) then to_remove = nil end
+  if to_add or to_remove then
+    task:set_rmilter_reply({
+      add_headers = to_add,
+      remove_headers = to_remove
+    })
+  end
+end
+
+local opts = rspamd_config:get_all_opt(N)
+if not opts then return end
+if type(opts['use']) == 'string' then
+  opts['use'] = {opts['use']}
+end
+if type(opts['use']) ~= 'table' then
+  logger.errx(rspamd_config, 'unexpected type for "use" option: %s', type(opts['use']))
+  return
+end
+if type(opts['custom']) == 'table' then
+  for k, v in pairs(opts['custom']) do
+    local f, err = load(v)
+    if err then
+      logger.errx(rspamd_config, 'could not load "%s": %s', k, err)
+    else
+      routines[k] = f
+    end
+  end
+end
+for _, s in ipairs(opts['use']) do
+  if not routines[s] then
+    logger.errx(rspamd_config, 'routine "%s" does not exist', s)
+  else
+    table.insert(active_routines, s)
+  end
+end
+if (#active_routines < 1) then
+  logger.errx(rspamd_config, 'no active routines')
+  return
+end
+rspamd_config:register_symbol({
+  name = 'RMILTER_HEADERS',
+  type = 'postfilter',
+  callback = rmilter_headers,
+  priority = 10
+})