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Diffstat (limited to 'lualib/lua_scanners/savapi.lua')
| -rw-r--r-- | lualib/lua_scanners/savapi.lua | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/lualib/lua_scanners/savapi.lua b/lualib/lua_scanners/savapi.lua new file mode 100644 index 0000000..08f7b66 --- /dev/null +++ b/lualib/lua_scanners/savapi.lua @@ -0,0 +1,261 @@ +--[[ +Copyright (c) 2022, Vsevolod Stakhov <vsevolod@rspamd.com> + +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 savapi +-- This module contains avira savapi antivirus access functions +--]] + +local lua_util = require "lua_util" +local tcp = require "rspamd_tcp" +local upstream_list = require "rspamd_upstream_list" +local rspamd_util = require "rspamd_util" +local rspamd_logger = require "rspamd_logger" +local common = require "lua_scanners/common" + +local N = "savapi" + +local default_message = '${SCANNER}: virus found: "${VIRUS}"' + +local function savapi_config(opts) + local savapi_conf = { + name = N, + scan_mime_parts = true, + scan_text_mime = false, + scan_image_mime = false, + default_port = 4444, -- note: You must set ListenAddress in savapi.conf + product_id = 0, + log_clean = false, + timeout = 15.0, -- FIXME: this will break task_timeout! + retransmits = 1, -- FIXME: useless, for local files + cache_expire = 3600, -- expire redis in one hour + message = default_message, + detection_category = "virus", + tmpdir = '/tmp', + } + + savapi_conf = lua_util.override_defaults(savapi_conf, opts) + + if not savapi_conf.prefix then + savapi_conf.prefix = 'rs_' .. savapi_conf.name .. '_' + end + + if not savapi_conf.log_prefix then + if savapi_conf.name:lower() == savapi_conf.type:lower() then + savapi_conf.log_prefix = savapi_conf.name + else + savapi_conf.log_prefix = savapi_conf.name .. ' (' .. savapi_conf.type .. ')' + end + end + + if not savapi_conf['servers'] then + rspamd_logger.errx(rspamd_config, 'no servers defined') + + return nil + end + + savapi_conf['upstreams'] = upstream_list.create(rspamd_config, + savapi_conf['servers'], + savapi_conf.default_port) + + if savapi_conf['upstreams'] then + lua_util.add_debug_alias('antivirus', savapi_conf.name) + return savapi_conf + end + + rspamd_logger.errx(rspamd_config, 'cannot parse servers %s', + savapi_conf['servers']) + return nil +end + +local function savapi_check(task, content, digest, rule) + local function savapi_check_uncached () + local upstream = rule.upstreams:get_upstream_round_robin() + local addr = upstream:get_addr() + local retransmits = rule.retransmits + local fname = string.format('%s/%s.tmp', + rule.tmpdir, rspamd_util.random_hex(32)) + local message_fd = rspamd_util.create_file(fname) + + if not message_fd then + rspamd_logger.errx('cannot store file for savapi scan: %s', fname) + return + end + + if type(content) == 'string' then + -- Create rspamd_text + local rspamd_text = require "rspamd_text" + content = rspamd_text.fromstring(content) + end + content:save_in_file(message_fd) + + -- Ensure cleanup + task:get_mempool():add_destructor(function() + os.remove(fname) + rspamd_util.close_file(message_fd) + end) + + local vnames = {} + + -- Forward declaration for recursive calls + local savapi_scan1_cb + + local function savapi_fin_cb(err, conn) + local vnames_reordered = {} + -- Swap table + for virus, _ in pairs(vnames) do + table.insert(vnames_reordered, virus) + end + lua_util.debugm(rule.name, task, "%s: number of virus names found %s", rule['type'], #vnames_reordered) + if #vnames_reordered > 0 then + local vname = {} + for _, virus in ipairs(vnames_reordered) do + table.insert(vname, virus) + end + + common.yield_result(task, rule, vname) + common.save_cache(task, digest, rule, vname) + end + if conn then + conn:close() + end + end + + local function savapi_scan2_cb(err, data, conn) + local result = tostring(data) + lua_util.debugm(rule.name, task, "%s: got reply: %s", + rule.type, result) + + -- Terminal response - clean + if string.find(result, '200') or string.find(result, '210') then + if rule['log_clean'] then + rspamd_logger.infox(task, '%s: message or mime_part is clean', rule['type']) + end + common.save_cache(task, digest, rule, 'OK') + conn:add_write(savapi_fin_cb, 'QUIT\n') + + -- Terminal response - infected + elseif string.find(result, '319') then + conn:add_write(savapi_fin_cb, 'QUIT\n') + + -- Non-terminal response + elseif string.find(result, '310') then + local virus + virus = result:match "310.*<<<%s(.*)%s+;.*;.*" + if not virus then + virus = result:match "310%s(.*)%s+;.*;.*" + if not virus then + rspamd_logger.errx(task, "%s: virus result unparseable: %s", + rule['type'], result) + common.yield_result(task, rule, 'virus result unparseable: ' .. result, 0.0, 'fail') + return + end + end + -- Store unique virus names + vnames[virus] = 1 + -- More content is expected + conn:add_write(savapi_scan1_cb, '\n') + end + end + + savapi_scan1_cb = function(err, conn) + conn:add_read(savapi_scan2_cb, '\n') + end + + -- 100 PRODUCT:xyz + local function savapi_greet2_cb(err, data, conn) + local result = tostring(data) + if string.find(result, '100 PRODUCT') then + lua_util.debugm(rule.name, task, "%s: scanning file: %s", + rule['type'], fname) + conn:add_write(savapi_scan1_cb, { string.format('SCAN %s\n', + fname) }) + else + rspamd_logger.errx(task, '%s: invalid product id %s', rule['type'], + rule['product_id']) + common.yield_result(task, rule, 'invalid product id: ' .. result, 0.0, 'fail') + conn:add_write(savapi_fin_cb, 'QUIT\n') + end + end + + local function savapi_greet1_cb(err, conn) + conn:add_read(savapi_greet2_cb, '\n') + end + + local function savapi_callback_init(err, data, conn) + if err then + + -- retry with another upstream until retransmits exceeds + if retransmits > 0 then + + retransmits = retransmits - 1 + + -- Select a different upstream! + upstream = rule.upstreams:get_upstream_round_robin() + addr = upstream:get_addr() + + lua_util.debugm(rule.name, task, '%s: error: %s; retry IP: %s; retries left: %s', + rule.log_prefix, err, addr, retransmits) + + tcp.request({ + task = task, + host = addr:to_string(), + port = addr:get_port(), + upstream = upstream, + timeout = rule['timeout'], + callback = savapi_callback_init, + stop_pattern = { '\n' }, + }) + else + rspamd_logger.errx(task, '%s [%s]: failed to scan, maximum retransmits exceed', rule['symbol'], rule['type']) + common.yield_result(task, rule, 'failed to scan and retransmits exceed', 0.0, 'fail') + end + else + local result = tostring(data) + + -- 100 SAVAPI:4.0 greeting + if string.find(result, '100') then + conn:add_write(savapi_greet1_cb, { string.format('SET PRODUCT %s\n', rule['product_id']) }) + end + end + end + + tcp.request({ + task = task, + host = addr:to_string(), + port = addr:get_port(), + upstream = upstream, + timeout = rule['timeout'], + callback = savapi_callback_init, + stop_pattern = { '\n' }, + }) + end + + if common.condition_check_and_continue(task, content, rule, digest, savapi_check_uncached) then + return + else + savapi_check_uncached() + end + +end + +return { + type = 'antivirus', + description = 'savapi avira antivirus', + configure = savapi_config, + check = savapi_check, + name = N +} |