[Feature] lua_scanners - add Razor support

Thanks to @cgt for his initial work!

diff --git a/lualib/lua_scanners/razor.lua b/lualib/lua_scanners/razor.lua
new file mode 100644 (file)
index 0000000..6f03e2c
--- /dev/null
+++ b/lualib/lua_scanners/razor.lua
@@ -0,0 +1,187 @@
+--[[
+Copyright (c) 2018, Vsevolod Stakhov <vsevolod@highsecure.ru>
+Copyright (c) 2018, Carsten Rosenberg <c.rosenberg@heinlein-support.de>
+
+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.
+]]--
+
+--[[[
+-- @module razor
+-- This module contains razor access functions
+--]]
+
+local lua_util = require "lua_util"
+local tcp = require "rspamd_tcp"
+local upstream_list = require "rspamd_upstream_list"
+local rspamd_logger = require "rspamd_logger"
+local common = require "lua_scanners/common"
+local fun = require "fun"
+
+local N = 'razor'
+
+local function razor_config(opts)
+
+  local razor_conf = {
+    name = N,
+    default_port = 11342,
+    timeout = 5.0,
+    log_clean = false,
+    retransmits = 2,
+    cache_expire = 7200, -- expire redis in 2h
+    message = '${SCANNER}: spam message found: "${VIRUS}"',
+    detection_category = "hash",
+    default_score = 1,
+    action = false,
+    dynamic_scan = false,
+    symbol_fail = 'RAZOR_FAIL',
+    symbol = 'RAZOR',
+  }
+
+  razor_conf = lua_util.override_defaults(razor_conf, opts)
+
+  if not razor_conf.prefix then
+    razor_conf.prefix = 'rs_' .. razor_conf.name .. '_'
+  end
+
+  if not razor_conf.log_prefix then
+    razor_conf.log_prefix = razor_conf.name
+  end
+
+  if not razor_conf.servers and razor_conf.socket then
+    razor_conf.servers = razor_conf.socket
+  end
+
+  if not razor_conf.servers then
+    rspamd_logger.errx(rspamd_config, 'no servers defined')
+
+    return nil
+  end
+
+  razor_conf.upstreams = upstream_list.create(rspamd_config,
+      razor_conf.servers,
+      razor_conf.default_port)
+
+  if razor_conf.upstreams then
+    lua_util.add_debug_alias('external_services', razor_conf.name)
+    return razor_conf
+  end
+
+  rspamd_logger.errx(rspamd_config, 'cannot parse servers %s',
+      razor_conf['servers'])
+  return nil
+end
+
+
+local function razor_check(task, content, digest, rule)
+  local function razor_check_uncached ()
+    local upstream = rule.upstreams:get_upstream_round_robin()
+    local addr = upstream:get_addr()
+    local retransmits = rule.retransmits
+
+    local function razor_callback(err, data, conn)
+
+      local function razor_requery()
+        -- set current upstream to fail because an error occurred
+        upstream:fail()
+
+        -- retry with another upstream until retransmits exceeds
+        if retransmits > 0 then
+
+          retransmits = retransmits - 1
+
+          lua_util.debugm(rule.name, task, '%s: Request Error: %s - retries left: %s',
+            rule.log_prefix, err, retransmits)
+
+          -- Select a different upstream!
+          upstream = rule.upstreams:get_upstream_round_robin()
+          addr = upstream:get_addr()
+
+          lua_util.debugm(rule.name, task, '%s: retry IP: %s:%s',
+            rule.log_prefix, addr, addr:get_port())
+
+          tcp.request({
+            task = task,
+            host = addr:to_string(),
+            port = addr:get_port(),
+            timeout = rule.timeout or 2.0,
+            shutdown = true,
+            data = content,
+            callback = razor_callback,
+          })
+        else
+          rspamd_logger.errx(task, '%s: failed to scan, maximum retransmits '..
+            'exceed', rule.log_prefix)
+          common.yield_result(task, rule, 'failed to scan and retransmits exceed', 0.0, 'fail')
+        end
+      end
+
+      if err then
+
+        razor_requery()
+
+      else
+        -- Parse the response
+        if upstream then upstream:ok() end
+
+        --[[
+        @todo: Razorsocket currently only returns ham or spam. When the wrapper is fixed we should add dynamic scores here.
+        Maybe check spamassassin implementation.
+
+        This implementation is based on https://github.com/cgt/rspamd-plugins
+        Thanks @cgt!
+        ]] --
+
+        local threat_string = tostring(data)
+        if threat_string == "spam" then
+          lua_util.debugm(N, task, '%s: returned result is spam', rule['symbol'], rule['type'])
+          common.yield_result(task, rule, threat_string, rule.default_score)
+          common.save_cache(task, digest, rule, threat_string, rule.default_score)
+        elseif threat_string == "ham" then
+          if rule.log_clean then
+            rspamd_logger.infox(task, '%s: returned result is ham', rule['symbol'], rule['type'])
+          else
+            lua_util.debugm(N, task, '%s: returned result is ham', rule['symbol'], rule['type'])
+          end
+          common.save_cache(task, digest, rule, 'OK', rule.default_score)
+        else
+          rspamd_logger.errx(task,"%s - unknown response from razorfy: %s", addr:to_string(), threat_string)
+        end
+
+      end
+    end
+
+    tcp.request({
+      task = task,
+      host = addr:to_string(),
+      port = addr:get_port(),
+      timeout = rule.timeout or 2.0,
+      shutdown = true,
+      data = content,
+      callback = razor_callback,
+    })
+  end
+
+  if common.need_check(task, content, rule, digest, razor_check_uncached) then
+    return
+  else
+    razor_check_uncached()
+  end
+end
+
+return {
+  type = {'razor','spam', 'hash', 'scanner'},
+  description = 'razor bulk scanner',
+  configure = razor_config,
+  check = razor_check,
+  name = N
+}