Adding upstream version 3.8.1.upstream/3.8.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 235 insertions, 0 deletions

diff --git a/src/plugins/lua/maillist.lua b/src/plugins/lua/maillist.lua
new file mode 100644
index 0000000..be1401c
--- /dev/null
+++ b/src/plugins/lua/maillist.lua
@@ -0,0 +1,235 @@
+--[[
+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.
+]]--
+
+if confighelp then
+  return
+end
+
+-- Module for checking mail list headers
+local N = 'maillist'
+local symbol = 'MAILLIST'
+local lua_util = require "lua_util"
+-- EZMLM
+-- Mailing-List: .*run by ezmlm
+-- Precedence: bulk
+-- List-Post: <mailto:
+-- List-Help: <mailto:
+-- List-Unsubscribe: <mailto:[a-zA-Z\.-]+-unsubscribe@
+-- List-Subscribe: <mailto:[a-zA-Z\.-]+-subscribe@
+-- RFC 2919 headers exist
+local function check_ml_ezmlm(task)
+  -- Mailing-List
+  local header = task:get_header('mailing-list')
+  if not header or not string.find(header, 'ezmlm$') then
+    return false
+  end
+  -- Precedence
+  header = task:get_header('precedence')
+  if not header or not string.match(header, '^bulk$') then
+    return false
+  end
+  -- Other headers
+  header = task:get_header('list-post')
+  if not header or not string.find(header, '^<mailto:') then
+    return false
+  end
+  header = task:get_header('list-help')
+  if not header or not string.find(header, '^<mailto:') then
+    return false
+  end
+  -- Subscribe and unsubscribe
+  header = task:get_header('list-subscribe')
+  if not header or not string.find(header, '<mailto:[a-zA-Z.-]+-subscribe@') then
+    return false
+  end
+  header = task:get_header('list-unsubscribe')
+  if not header or not string.find(header, '<mailto:[a-zA-Z.-]+-unsubscribe@') then
+    return false
+  end
+
+  return true
+end
+
+-- GNU Mailman
+-- Two major versions currently in use and they use slightly different headers
+-- Mailman2: https://code.launchpad.net/~mailman-coders/mailman/2.1
+-- Mailman3: https://gitlab.com/mailman/mailman
+local function check_ml_mailman(task)
+  local header = task:get_header('X-Mailman-Version')
+  if not header then
+    return false
+  end
+  local mm_version = header:match('^([23])%.')
+  if not mm_version then
+    lua_util.debugm(N, task, 'unknown Mailman version: %s', header)
+    return false
+  end
+  lua_util.debugm(N, task, 'checking Mailman %s headers', mm_version)
+
+  -- XXX Some messages may not contain Precedence, but they are rare:
+  -- http://bazaar.launchpad.net/~mailman-coders/mailman/2.1/revision/1339
+  header = task:get_header('Precedence')
+  if not header or (header ~= 'bulk' and header ~= 'list') then
+    return false
+  end
+
+  -- Mailman 3 allows to disable all List-* headers in settings, but by default it adds them.
+  -- In all other cases all Mailman message should have List-Id header
+  if not task:has_header('List-Id') then
+    return false
+  end
+
+  if mm_version == '2' then
+    -- X-BeenThere present in all Mailman2 messages
+    if not task:has_header('X-BeenThere') then
+      return false
+    end
+    -- X-List-Administrivia: is only added to messages Mailman creates and
+    -- sends out of its own accord
+    header = task:get_header('X-List-Administrivia')
+    if header and header == 'yes' then
+      -- not much elase we can check, Subjects can be changed in settings
+      return true
+    end
+  else
+    -- Mailman 3
+    -- XXX not Mailman3 admin messages have this headers, but one
+    -- which don't usually have List-* headers examined below
+    if task:has_header('List-Administrivia') then
+      return true
+    end
+  end
+
+  -- List-Archive and List-Post are optional, check other headers
+  for _, h in ipairs({ 'List-Help', 'List-Subscribe', 'List-Unsubscribe' }) do
+    header = task:get_header(h)
+    if not (header and header:find('<mailto:', 1, true)) then
+      return false
+    end
+  end
+
+  return true
+end
+
+-- Google groups detector
+-- header exists X-Google-Loop
+-- RFC 2919 headers exist
+--
+local function check_ml_googlegroup(task)
+  return task:has_header('X-Google-Loop') or task:has_header('X-Google-Group-Id')
+end
+
+-- CGP detector
+-- X-Listserver = CommuniGate Pro LIST
+-- RFC 2919 headers exist
+--
+local function check_ml_cgp(task)
+  local header = task:get_header('X-Listserver')
+
+  if not header or string.sub(header, 0, 20) ~= 'CommuniGate Pro LIST' then
+    return false
+  end
+
+  return true
+end
+
+-- RFC 2919 headers
+local function check_generic_list_headers(task)
+  local score = 0
+  local has_subscribe, has_unsubscribe
+
+  local common_list_headers = {
+    ['List-Id'] = 0.75,
+    ['List-Archive'] = 0.125,
+    ['List-Owner'] = 0.125,
+    ['List-Help'] = 0.125,
+    ['List-Post'] = 0.125,
+    ['X-Loop'] = 0.125,
+    ['List-Subscribe'] = function()
+      has_subscribe = true
+      return 0.125
+    end,
+    ['List-Unsubscribe'] = function()
+      has_unsubscribe = true
+      return 0.125
+    end,
+    ['Precedence'] = function()
+      local header = task:get_header('Precedence')
+      if header and (header == 'list' or header == 'bulk') then
+        return 0.25
+      end
+    end,
+  }
+
+  for hname, hscore in pairs(common_list_headers) do
+    if task:has_header(hname) then
+      if type(hscore) == 'number' then
+        score = score + hscore
+        lua_util.debugm(N, task, 'has %s header, score = %s', hname, score)
+      else
+        local score_change = hscore()
+        if score and score_change then
+          score = score + score_change
+          lua_util.debugm(N, task, 'has %s header, score = %s', hname, score)
+        end
+      end
+    end
+  end
+
+  if has_subscribe and has_unsubscribe then
+    score = score + 0.25
+  end
+
+  lua_util.debugm(N, task, 'final maillist score %s', score)
+  return score
+end
+
+
+-- RFC 2919 headers exist
+local function check_maillist(task)
+  local score = check_generic_list_headers(task)
+  if score >= 1 then
+    if check_ml_ezmlm(task) then
+      task:insert_result(symbol, 1, 'ezmlm')
+    elseif check_ml_mailman(task) then
+      task:insert_result(symbol, 1, 'mailman')
+    elseif check_ml_googlegroup(task) then
+      task:insert_result(symbol, 1, 'googlegroups')
+    elseif check_ml_cgp(task) then
+      task:insert_result(symbol, 1, 'cgp')
+    else
+      if score > 2 then
+        score = 2
+      end
+      task:insert_result(symbol, 0.5 * score, 'generic')
+    end
+  end
+end
+
+
+
+-- Configuration
+local opts = rspamd_config:get_all_opt('maillist')
+if opts then
+  if opts['symbol'] then
+    symbol = opts['symbol']
+    rspamd_config:register_symbol({
+      name = symbol,
+      callback = check_maillist,
+      flags = 'nice'
+    })
+  end
+end