Add preliminary fann_score plugin

diff --git a/src/plugins/lua/fann_scores.lua b/src/plugins/lua/fann_scores.lua
new file mode 100644 (file)
index 0000000..0be8ad3
--- /dev/null
+++ b/src/plugins/lua/fann_scores.lua
@@ -0,0 +1,103 @@
+--[[
+Copyright (c) 2015, 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 is a concept of FANN scores adjustment
+-- NOT FOR PRODUCTION USE so far
+
+local rspamd_logger = require "rspamd_logger"
+local rspamd_fann = require "rspamd_fann"
+local rspamd_util = require "rspamd_util"
+local fann_symbol = 'FANN_SCORE'
+local ucl = require "ucl"
+
+-- Module vars
+local fann
+local symbols
+local nsymbols = 0
+local opts = rspamd_config:get_all_opt("fann_scores")
+
+local function fann_scores_filter(task)
+  local fann_input = {}
+
+  for sym,idx in pairs(symbols) do
+    if task:get_symbol(sym) then
+      fann_input[idx + 1] = 1
+    else
+      fann_input[idx + 1] = 0
+    end
+  end
+
+  local out = fann:test(nsymbols, fann_input)
+  local result = rspamd_util.tanh(2 * (out[1] - 0.5))
+
+  task:insert_result(fann_symbol, result, string.format('%.3f', out[1]))
+end
+
+if not rspamd_fann.is_enabled() then
+  rspamd_logger.errx(rspamd_config, 'fann is not compiled in rspamd, this ' ..
+    'module is eventually disabled')
+else
+  if not opts['fann_file'] or not opts['symbols_file'] then
+    rspamd_logger.errx(rspamd_config, 'fann_scores module requires ' ..
+      '`fann_file` and `symbols_file` to be specified')
+  else
+    fann = rspamd_fann.load(opts['fann_file'])
+
+    if not fann then
+      rspamd_logger.errx(rspamd_config, 'cannot load fann from %s',
+        opts['fann_file'])
+      return
+    end
+    -- Parse symbols
+    local parser = ucl.parser()
+    local res, err = parser:parse_file(opts['symbols_file'])
+    if not res then
+      rspamd_logger.errx(rspamd_config, 'cannot load symbols from %s: %s',
+        opts['symbols_file'], err)
+      return
+    end
+
+    symbols = parser:get_object()
+
+    -- Check sanity
+    for _,s in pairs(symbols) do nsymbols = nsymbols + 1 end
+    if fann:get_inputs() ~= nsymbols then
+      rspamd_logger.errx(rspamd_config, 'fann number of inputs: %s is not equal' ..
+          ' to symbols count: %s',
+        fann:get_inputs(), nsymbols)
+      return
+    end
+
+    if fann:get_outputs() ~= 1 then
+      rspamd_logger.errx(rspamd_config, 'fann nuber of outputs is invalid: %s',
+        fann:get_outputs())
+      return
+    end
+
+    rspamd_config:set_metric_symbol(fann_symbol, 3.0, 'Experimental FANN adjustment')
+    rspamd_config:register_post_filter(fann_scores_filter)
+  end
+end