mirror of
https://github.com/rspamd/rspamd.git
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314 lines
10 KiB
Lua
314 lines
10 KiB
Lua
--[[
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Copyright (c) 2018, Vsevolod Stakhov <vsevolod@highsecure.ru>
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Copyright (c) 2019, Carsten Rosenberg <c.rosenberg@heinlein-support.de>
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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]]--
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--[[[
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-- @module icap
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-- This module contains icap access functions.
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-- Currently tested with Symantec, Sophos Savdi, ClamAV/c-icap
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--]]
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local lua_util = require "lua_util"
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local tcp = require "rspamd_tcp"
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local upstream_list = require "rspamd_upstream_list"
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local rspamd_logger = require "rspamd_logger"
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local common = require "lua_scanners/common"
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local N = 'icap'
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local function icap_check(task, content, digest, rule)
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local function icap_check_uncached ()
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local upstream = rule.upstreams:get_upstream_round_robin()
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local addr = upstream:get_addr()
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local retransmits = rule.retransmits
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local respond_headers = {}
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-- Build the icap queries
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local options_request = {
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"OPTIONS icap://" .. addr:to_string() .. ":" .. addr:get_port() .. "/" .. rule.scheme .. " ICAP/1.0\r\n",
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"Host:" .. addr:to_string() .. "\r\n",
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"User-Agent: Rspamd\r\n",
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"Encapsulated: null-body=0\r\n\r\n",
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}
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local size = string.format("%x", tonumber(#content))
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lua_util.debugm(rule.name, task, '%s: size: %s',
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rule.log_prefix, size)
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local function get_respond_query()
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table.insert(respond_headers, 1,
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'RESPMOD icap://' .. addr:to_string() .. ':' .. addr:get_port() .. '/'
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.. rule.scheme .. ' ICAP/1.0\r\n')
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table.insert(respond_headers, 'Encapsulated: res-body=0\r\n')
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table.insert(respond_headers, '\r\n')
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table.insert(respond_headers, size .. '\r\n')
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table.insert(respond_headers, content)
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table.insert(respond_headers, '\r\n0\r\n\r\n')
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return respond_headers
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end
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local function add_respond_header(name, value)
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table.insert(respond_headers, name .. ': ' .. value .. '\r\n' )
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end
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local function icap_result_header_table(result)
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local icap_headers = {}
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for s in result:gmatch("[^\r\n]+") do
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if string.find(s, '^ICAP') then
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icap_headers['icap'] = s
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end
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if string.find(s, '[%a%d-+]-: ') then
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local _,_,key,value = tostring(s):find("([%a%d-+]-):%s(.+)")
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icap_headers[key] = value
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end
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end
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lua_util.debugm(rule.name, task, '%s: icap_headers: %s',
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rule.log_prefix, icap_headers)
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return icap_headers
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end
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local function icap_parse_result(icap_headers)
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local threat_string = {}
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--[[
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@ToDo: handle type in response
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Generic Strings:
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X-Infection-Found: Type=0; Resolution=2; Threat=Troj/DocDl-OYC;
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X-Infection-Found: Type=0; Resolution=2; Threat=W97M.Downloader;
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Symantec String:
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X-Infection-Found: Type=2; Resolution=2; Threat=Container size violation
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X-Infection-Found: Type=2; Resolution=2; Threat=Encrypted container violation;
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Sophos Strings:
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X-Virus-ID: Troj/DocDl-OYC
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]] --
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if icap_headers['X-Infection-Found'] ~= nil then
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local _,_,icap_type,_,icap_threat =
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icap_headers['X-Infection-Found']:find("Type=(.-); Resolution=(.-); Threat=(.-);$")
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if not icap_type or icap_type == 2 then
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-- error returned
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lua_util.debugm(rule.name, task,
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'%s: icap error X-Infection-Found: %s', rule.log_prefix, icap_threat)
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common.yield_result(task, rule, icap_threat, 0, 'fail')
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else
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lua_util.debugm(rule.name, task,
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'%s: icap X-Infection-Found: %s', rule.log_prefix, icap_threat)
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table.insert(threat_string, icap_threat)
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end
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elseif icap_headers['X-Virus-ID'] ~= nil then
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lua_util.debugm(rule.name, task,
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'%s: icap X-Virus-ID: %s', rule.log_prefix, icap_headers['X-Virus-ID'])
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table.insert(threat_string, icap_headers['X-Virus-ID'])
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end
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if #threat_string > 0 then
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common.yield_result(task, rule, threat_string, rule.default_score)
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common.save_av_cache(task, digest, rule, threat_string, rule.default_score)
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else
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common.save_av_cache(task, digest, rule, 'OK', 0)
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common.log_clean(task, rule)
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end
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end
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local function icap_r_respond_cb(err, data, conn)
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local result = tostring(data)
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conn:close()
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local icap_headers = icap_result_header_table(result)
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-- Find ICAP/1.x 2xx response
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if string.find(icap_headers.icap, 'ICAP%/1%.. 2%d%d') then
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icap_parse_result(icap_headers)
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elseif string.find(icap_headers.icap, 'ICAP%/1%.. [45]%d%d') then
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-- Find ICAP/1.x 5/4xx response
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--[[
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Symantec String:
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ICAP/1.0 539 Aborted - No AV scanning license
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SquidClamAV/C-ICAP:
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ICAP/1.0 500 Server error
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]]--
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rspamd_logger.errx(task, '%s: ICAP ERROR: %s', rule.log_prefix, icap_headers.icap)
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common.yield_result(task, rule, icap_headers.icap, 0.0, 'fail')
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return false
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else
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rspamd_logger.errx(task, '%s: unhandled response |%s|',
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rule.log_prefix, string.gsub(result, "\r\n", ", "))
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common.yield_result(task, rule, 'unhandled icap response: ' .. icap_headers.icap, 0.0, 'fail')
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end
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end
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local function icap_w_respond_cb(err, conn)
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conn:add_read(icap_r_respond_cb, '\r\n\r\n')
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end
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local function icap_r_options_cb(err, data, conn)
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local icap_headers = icap_result_header_table(tostring(data))
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if string.find(icap_headers.icap, 'ICAP%/1%.. 2%d%d') then
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if icap_headers['Methods'] ~= nil and string.find(icap_headers['Methods'], 'RESPMOD') then
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if icap_headers['Allow'] ~= nil and string.find(icap_headers['Allow'], '204') then
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add_respond_header('Allow', '204')
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end
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conn:add_write(icap_w_respond_cb, get_respond_query())
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else
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rspamd_logger.errx(task, '%s: RESPMOD method not advertised: Methods: %s',
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rule.log_prefix, icap_headers['Methods'])
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common.yield_result(task, rule, 'NO RESPMOD', 0.0, 'fail')
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end
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else
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rspamd_logger.errx(task, '%s: OPTIONS query failed: %s',
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rule.log_prefix, icap_headers.icap)
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common.yield_result(task, rule, 'OPTIONS query failed', 0.0, 'fail')
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end
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end
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local function icap_callback(err, conn)
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local function icap_requery(error)
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-- set current upstream to fail because an error occurred
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upstream:fail()
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-- retry with another upstream until retransmits exceeds
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if retransmits > 0 then
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retransmits = retransmits - 1
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lua_util.debugm(rule.name, task,
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'%s: Request Error: %s - retries left: %s',
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rule.log_prefix, error, retransmits)
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-- Select a different upstream!
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upstream = rule.upstreams:get_upstream_round_robin()
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addr = upstream:get_addr()
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lua_util.debugm(rule.name, task, '%s: retry IP: %s:%s',
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rule.log_prefix, addr, addr:get_port())
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tcp.request({
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task = task,
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host = addr:to_string(),
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port = addr:get_port(),
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timeout = rule.timeout,
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stop_pattern = '\r\n',
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data = options_request,
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read = false,
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callback = icap_callback,
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})
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else
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rspamd_logger.errx(task, '%s: failed to scan, maximum retransmits '..
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'exceed - err: %s', rule.log_prefix, error)
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common.yield_result(task, rule, 'failed - err: ' .. error, 0.0, 'fail')
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end
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end
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if err then
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icap_requery(err)
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else
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-- set upstream ok
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if upstream then upstream:ok() end
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conn:add_read(icap_r_options_cb, '\r\n\r\n')
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end
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end
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tcp.request({
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task = task,
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host = addr:to_string(),
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port = addr:get_port(),
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timeout = rule.timeout,
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stop_pattern = '\r\n',
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data = options_request,
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read = false,
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callback = icap_callback,
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})
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end
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if common.need_av_check(task, content, rule) then
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if common.check_av_cache(task, digest, rule, icap_check_uncached) then
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return
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else
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icap_check_uncached()
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end
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end
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end
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local function icap_config(opts)
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local icap_conf = {
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name = N,
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scan_mime_parts = true,
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scan_all_mime_parts = true,
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scan_text_mime = false,
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scan_image_mime = false,
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scheme = "scan",
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default_port = 4020,
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timeout = 10.0,
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log_clean = false,
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retransmits = 2,
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cache_expire = 7200, -- expire redis in one hour
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message = '${SCANNER}: threat found with icap scanner: "${VIRUS}"',
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detection_category = "virus",
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default_score = 1,
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action = false,
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}
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icap_conf = lua_util.override_defaults(icap_conf, opts)
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if not icap_conf.prefix then
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icap_conf.prefix = 'rs_' .. icap_conf.name .. '_'
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end
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if not icap_conf.log_prefix then
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icap_conf.log_prefix = icap_conf.name .. ' (' .. icap_conf.type .. ')'
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end
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if not icap_conf.log_prefix then
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if icap_conf.name:lower() == icap_conf.type:lower() then
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icap_conf.log_prefix = icap_conf.name
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else
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icap_conf.log_prefix = icap_conf.name .. ' (' .. icap_conf.type .. ')'
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end
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end
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if not icap_conf.servers then
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rspamd_logger.errx(rspamd_config, 'no servers defined')
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return nil
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end
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icap_conf.upstreams = upstream_list.create(rspamd_config,
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icap_conf.servers,
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icap_conf.default_port)
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if icap_conf.upstreams then
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lua_util.add_debug_alias('external_services', icap_conf.name)
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return icap_conf
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end
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rspamd_logger.errx(rspamd_config, 'cannot parse servers %s',
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icap_conf.servers)
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return nil
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end
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return {
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type = {N, 'virus', 'virus', 'scanner'},
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description = 'generic icap antivirus',
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configure = icap_config,
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check = icap_check,
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name = N
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}
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