réplica de
https://github.com/rspamd/rspamd.git
synced 2024-08-01 08:18:17 +02:00
119 líneas
3.9 KiB
Lua
119 líneas
3.9 KiB
Lua
--[[
|
|
Copyright (c) 2020, Anton Yuzhaninov <citrin@citrin.ru>
|
|
|
|
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.
|
|
]]--
|
|
|
|
-- Rule to detect bounces:
|
|
-- RFC 3464 Delivery status notifications and most common non-standard ones
|
|
|
|
local function make_subj_bounce_keywords_re()
|
|
-- Words and phrases commonly used in Subjects for bounces
|
|
-- We cannot practically test all localized Subjects, but luckily English is by far the most common here
|
|
local keywords = {
|
|
'could not send message',
|
|
"couldn't be delivered",
|
|
'delivery failed',
|
|
'delivery failure',
|
|
'delivery report',
|
|
'delivery status',
|
|
'delivery warning',
|
|
'failure delivery',
|
|
'failure notice',
|
|
"hasn't been delivered",
|
|
'mail failure',
|
|
'returned mail',
|
|
'undeliverable',
|
|
'undelivered',
|
|
}
|
|
return string.format([[Subject=/\b(%s)\b/i{header}]], table.concat(keywords, '|'))
|
|
end
|
|
|
|
config.regexp.SUBJ_BOUNCE_WORDS = {
|
|
re = make_subj_bounce_keywords_re(),
|
|
group = 'headers',
|
|
score = 0.0,
|
|
description = 'Words/phrases typical for DSN'
|
|
}
|
|
|
|
rspamd_config.BOUNCE = {
|
|
callback = function(task)
|
|
local from = task:get_from('smtp')
|
|
if from and from[1].addr ~= '' then
|
|
-- RFC 3464:
|
|
-- Whenever an SMTP transaction is used to send a DSN, the MAIL FROM
|
|
-- command MUST use a NULL return address, i.e., "MAIL FROM:<>"
|
|
-- In practise it is almost always the case for DSN
|
|
return false
|
|
end
|
|
|
|
|
|
local parts = task:get_parts()
|
|
local top_type, top_subtype, params = parts[1]:get_type_full()
|
|
-- RFC 3464, RFC 8098
|
|
if top_type == 'multipart' and top_subtype == 'report' and params and
|
|
(params['report-type'] == 'delivery-status' or params['report-type'] == 'disposition-notification') then
|
|
-- Assume that inner parts are OK, don't check them to save time
|
|
return true, 1.0, 'DSN'
|
|
end
|
|
|
|
-- Apply heuristics for non-standard bounces
|
|
local bounce_sender
|
|
local mime_from = task:get_from('mime')
|
|
if mime_from then
|
|
local from_user = mime_from[1].user:lower()
|
|
-- Check common bounce senders
|
|
if (from_user == 'postmaster' or from_user == 'mailer-daemon') then
|
|
bounce_sender = from_user
|
|
-- MDaemon >= 14.5 sends multipart/report (RFC 3464) DSN covered above,
|
|
-- but older versions send non-standard bounces with localized subjects and they
|
|
-- are still around
|
|
elseif from_user == 'mdaemon' and task:has_header('X-MDDSN-Message') then
|
|
return true, 1.0, 'MDaemon'
|
|
end
|
|
end
|
|
|
|
local subj_keywords = task:has_symbol('SUBJ_BOUNCE_WORDS')
|
|
|
|
if not (bounce_sender or subj_keywords) then
|
|
return false
|
|
end
|
|
|
|
if bounce_sender and subj_keywords then
|
|
return true, 0.5, bounce_sender .. '+subj'
|
|
end
|
|
|
|
-- Look for a message/rfc822(-headers) part inside
|
|
local rfc822_part
|
|
parts[10] = nil -- limit number of parts to check
|
|
for _, p in ipairs(parts) do
|
|
local mime_type, mime_subtype = p:get_type()
|
|
if (mime_subtype == 'rfc822' or mime_subtype == 'rfc822-headers') and
|
|
(mime_type == 'message' or mime_type == 'text') then
|
|
rfc822_part = mime_type .. '/' .. mime_subtype
|
|
break
|
|
end
|
|
end
|
|
|
|
if rfc822_part and bounce_sender then
|
|
return true, 0.5, bounce_sender .. '+' .. rfc822_part
|
|
elseif rfc822_part and subj_keywords then
|
|
return true, 0.2, rfc822_part .. '+subj'
|
|
end
|
|
end,
|
|
description = '(Non) Delivery Status Notification',
|
|
group = 'headers',
|
|
}
|
|
|
|
rspamd_config:register_dependency('BOUNCE', 'SUBJ_BOUNCE_WORDS')
|