Add mime types checking plugin

src/plugins/lua/mime_types.lua

@@ -0,0 +1,86 @@
+--[[
+Copyright (c) 2016, Vsevolod Stakhov <vsevolod@highsecure.ru>
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+]]--
+
+-- This plugin implements mime types checks for mail messages
+local rspamd_logger = require "rspamd_logger"
+
+local settings = {
+  file = '',
+  symbol_unknown = 'MIME_UNKNOWN',
+  symbol_bad = 'MIME_BAD',
+  symbol_good = 'MIME_GOOD',
+}
+
+local map = nil
+
+local function check_mime_type(task)
+  local parts = task:get_parts()
+  
+  if parts then
+    for _,p in ipairs(parts) do
+      local type,subtype = p:get_type()
+      
+      if not type then
+        task:insert_result(settings['symbol_unknown'], 1.0, 'missing content type')
+      else
+        local ct = string.format('%s/%s', type, subtype)
+        local v = map:get_key(ct)
+        if v then
+          local n = tonumber(v)
+          
+          if n > 0 then
+            task:insert_result(settings['symbol_bad'], n, ct)
+          elseif n < 0 then
+            task:insert_result(settings['symbol_good'], -n, ct)
+          end
+        else
+          task:insert_result(settings['symbol_unknown'], 1.0, ct)
+        end
+      end
+    end
+  end
+end
+
+local opts =  rspamd_config:get_all_opt('mime_types')
+if opts then
+  for k,v in pairs(opts) do
+    settings[k] = v
+  end
+  
+  if settings['file'] and #settings['file'] > 0 then
+    map = rspamd_config:add_kv_map (settings['file'], 
+      'mime types map')
+    if map then
+      local id = rspamd_config:register_callback_symbol(1.0, check_mime_type)
+      rspamd_config:register_virtual_symbol(settings['symbol_unknown'], 1.0, id)
+      rspamd_config:register_virtual_symbol(settings['symbol_bad'], 1.0, id)
+      rspamd_config:register_virtual_symbol(settings['symbol_good'], 1.0, id)
+    else
+      rspamd_logger.warnx(rspamd_config, 'Cannot add mime_types: map doesn\'t exists: %1',
+        settings['file'])
+    end
+  end
+end