123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596 |
- --[[
- Copyright (c) 2011-2017, Vsevolod Stakhov <vsevolod@highsecure.ru>
- Copyright (c) 2016-2017, Andrew Lewis <nerf@judo.za.org>
-
- 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
-
- -- A plugin that implements ratelimits using redis
-
- local E = {}
- local N = 'ratelimit'
- local redis_params
- -- Senders that are considered as bounce
- local settings = {
- bounce_senders = { 'postmaster', 'mailer-daemon', '', 'null', 'fetchmail-daemon', 'mdaemon' },
- -- Do not check ratelimits for these recipients
- whitelisted_rcpts = { 'postmaster', 'mailer-daemon' },
- prefix = 'RL',
- ham_factor_rate = 1.01,
- spam_factor_rate = 0.99,
- ham_factor_burst = 1.02,
- spam_factor_burst = 0.98,
- max_rate_mult = 5,
- max_bucket_mult = 10,
- expire = 60 * 60 * 24 * 2, -- 2 days by default
- limits = {},
- allow_local = false,
- }
-
- -- Checks bucket, updating it if needed
- -- KEYS[1] - prefix to update, e.g. RL_<triplet>_<seconds>
- -- KEYS[2] - current time in milliseconds
- -- KEYS[3] - bucket leak rate (messages per millisecond)
- -- KEYS[4] - bucket burst
- -- KEYS[5] - expire for a bucket
- -- return 1 if message should be ratelimited and 0 if not
- -- Redis keys used:
- -- l - last hit
- -- b - current burst
- -- dr - current dynamic rate multiplier (*10000)
- -- db - current dynamic burst multiplier (*10000)
- local bucket_check_script = [[
- local last = redis.call('HGET', KEYS[1], 'l')
- local now = tonumber(KEYS[2])
- local dynr, dynb = 0, 0
- if not last then
- -- New bucket
- redis.call('HSET', KEYS[1], 'l', KEYS[2])
- redis.call('HSET', KEYS[1], 'b', '0')
- redis.call('HSET', KEYS[1], 'dr', '10000')
- redis.call('HSET', KEYS[1], 'db', '10000')
- redis.call('EXPIRE', KEYS[1], KEYS[5])
- return {0, 0, 1, 1}
- end
-
- last = tonumber(last)
- local burst = tonumber(redis.call('HGET', KEYS[1], 'b'))
- -- Perform leak
- if burst > 0 then
- if last < tonumber(KEYS[2]) then
- local rate = tonumber(KEYS[3])
- dynr = tonumber(redis.call('HGET', KEYS[1], 'dr')) / 10000.0
- rate = rate * dynr
- local leaked = ((now - last) * rate)
- burst = burst - leaked
- redis.call('HINCRBYFLOAT', KEYS[1], 'b', -(leaked))
- end
- dynb = tonumber(redis.call('HGET', KEYS[1], 'db')) / 10000.0
-
- if burst * dynb > tonumber(KEYS[4]) then
- return {1, burst, dynr, dynb}
- end
- else
- burst = 0
- redis.call('HSET', KEYS[1], 'b', '0')
- end
-
- return {0, burst, tostring(dynr), tostring(dynb)}
- ]]
- local bucket_check_id
-
-
- -- Updates a bucket
- -- KEYS[1] - prefix to update, e.g. RL_<triplet>_<seconds>
- -- KEYS[2] - current time in milliseconds
- -- KEYS[3] - dynamic rate multiplier
- -- KEYS[4] - dynamic burst multiplier
- -- KEYS[5] - max dyn rate (min: 1/x)
- -- KEYS[6] - max burst rate (min: 1/x)
- -- KEYS[7] - expire for a bucket
- -- Redis keys used:
- -- l - last hit
- -- b - current burst
- -- dr - current dynamic rate multiplier
- -- db - current dynamic burst multiplier
- local bucket_update_script = [[
- local last = redis.call('HGET', KEYS[1], 'l')
- local now = tonumber(KEYS[2])
- if not last then
- -- New bucket
- redis.call('HSET', KEYS[1], 'l', KEYS[2])
- redis.call('HSET', KEYS[1], 'b', '1')
- redis.call('HSET', KEYS[1], 'dr', '10000')
- redis.call('HSET', KEYS[1], 'db', '10000')
- redis.call('EXPIRE', KEYS[1], KEYS[7])
- return {1, 1, 1}
- end
-
- local burst = tonumber(redis.call('HGET', KEYS[1], 'b'))
- local db = tonumber(redis.call('HGET', KEYS[1], 'db')) / 10000
- local dr = tonumber(redis.call('HGET', KEYS[1], 'dr')) / 10000
-
- if dr < tonumber(KEYS[5]) and dr > 1.0 / tonumber(KEYS[5]) then
- dr = dr * tonumber(KEYS[3])
- redis.call('HSET', KEYS[1], 'dr', tostring(math.floor(dr * 10000)))
- end
-
- if db < tonumber(KEYS[6]) and db > 1.0 / tonumber(KEYS[6]) then
- db = db * tonumber(KEYS[4])
- redis.call('HSET', KEYS[1], 'db', tostring(math.floor(db * 10000)))
- end
-
- redis.call('HINCRBYFLOAT', KEYS[1], 'b', 1)
- redis.call('HSET', KEYS[1], 'l', KEYS[2])
- redis.call('EXPIRE', KEYS[1], KEYS[7])
-
- return {burst, tostring(dr), tostring(db)}
- ]]
- local bucket_update_id
-
- -- message_func(task, limit_type, prefix, bucket)
- local message_func = function(_, limit_type, _, _)
- return string.format('Ratelimit "%s" exceeded', limit_type)
- end
-
- local rspamd_logger = require "rspamd_logger"
- local rspamd_util = require "rspamd_util"
- local rspamd_lua_utils = require "lua_util"
- local lua_redis = require "lua_redis"
- local fun = require "fun"
- local lua_maps = require "lua_maps"
- local lua_util = require "lua_util"
- local rspamd_hash = require "rspamd_cryptobox_hash"
-
-
- local function load_scripts(cfg, ev_base)
- bucket_check_id = lua_redis.add_redis_script(bucket_check_script, redis_params)
- bucket_update_id = lua_redis.add_redis_script(bucket_update_script, redis_params)
- end
-
- local limit_parser
- local function parse_string_limit(lim, no_error)
- local function parse_time_suffix(s)
- if s == 's' then
- return 1
- elseif s == 'm' then
- return 60
- elseif s == 'h' then
- return 3600
- elseif s == 'd' then
- return 86400
- end
- end
- local function parse_num_suffix(s)
- if s == '' then
- return 1
- elseif s == 'k' then
- return 1000
- elseif s == 'm' then
- return 1000000
- elseif s == 'g' then
- return 1000000000
- end
- end
- local lpeg = require "lpeg"
-
- if not limit_parser then
- local digit = lpeg.R("09")
- limit_parser = {}
- limit_parser.integer =
- (lpeg.S("+-") ^ -1) *
- (digit ^ 1)
- limit_parser.fractional =
- (lpeg.P(".") ) *
- (digit ^ 1)
- limit_parser.number =
- (limit_parser.integer *
- (limit_parser.fractional ^ -1)) +
- (lpeg.S("+-") * limit_parser.fractional)
- limit_parser.time = lpeg.Cf(lpeg.Cc(1) *
- (limit_parser.number / tonumber) *
- ((lpeg.S("smhd") / parse_time_suffix) ^ -1),
- function (acc, val) return acc * val end)
- limit_parser.suffixed_number = lpeg.Cf(lpeg.Cc(1) *
- (limit_parser.number / tonumber) *
- ((lpeg.S("kmg") / parse_num_suffix) ^ -1),
- function (acc, val) return acc * val end)
- limit_parser.limit = lpeg.Ct(limit_parser.suffixed_number *
- (lpeg.S(" ") ^ 0) * lpeg.S("/") * (lpeg.S(" ") ^ 0) *
- limit_parser.time)
- end
- local t = lpeg.match(limit_parser.limit, lim)
-
- if t and t[1] and t[2] and t[2] ~= 0 then
- return t[2], t[1]
- end
-
- if not no_error then
- rspamd_logger.errx(rspamd_config, 'bad limit: %s', lim)
- end
-
- return nil
- end
-
- --- Check whether this addr is bounce
- local function check_bounce(from)
- return fun.any(function(b) return b == from end, settings.bounce_senders)
- end
-
- local keywords = {
- ['ip'] = {
- ['get_value'] = function(task)
- local ip = task:get_ip()
- if ip and ip:is_valid() then return tostring(ip) end
- return nil
- end,
- },
- ['rip'] = {
- ['get_value'] = function(task)
- local ip = task:get_ip()
- if ip and ip:is_valid() and not ip:is_local() then return tostring(ip) end
- return nil
- end,
- },
- ['from'] = {
- ['get_value'] = function(task)
- local from = task:get_from(0)
- if ((from or E)[1] or E).addr then
- return string.lower(from[1]['addr'])
- end
- return nil
- end,
- },
- ['bounce'] = {
- ['get_value'] = function(task)
- local from = task:get_from(0)
- if not ((from or E)[1] or E).user then
- return '_'
- end
- if check_bounce(from[1]['user']) then return '_' else return nil end
- end,
- },
- ['asn'] = {
- ['get_value'] = function(task)
- local asn = task:get_mempool():get_variable('asn')
- if not asn then
- return nil
- else
- return asn
- end
- end,
- },
- ['user'] = {
- ['get_value'] = function(task)
- local auser = task:get_user()
- if not auser then
- return nil
- else
- return auser
- end
- end,
- },
- ['to'] = {
- ['get_value'] = function(task)
- return task:get_principal_recipient()
- end,
- },
- }
-
- local function gen_rate_key(task, rtype, bucket)
- local key_t = {tostring(lua_util.round(100000.0 / bucket[1]))}
- local key_keywords = lua_util.str_split(rtype, '_')
- local have_user = false
-
- for _, v in ipairs(key_keywords) do
- local ret
-
- if keywords[v] and type(keywords[v]['get_value']) == 'function' then
- ret = keywords[v]['get_value'](task)
- end
- if not ret then return nil end
- if v == 'user' then have_user = true end
- if type(ret) ~= 'string' then ret = tostring(ret) end
- table.insert(key_t, ret)
- end
-
- if have_user and not task:get_user() then
- return nil
- end
-
- return table.concat(key_t, ":")
- end
-
- local function ratelimit_cb(task)
- if not settings.allow_local and
- rspamd_lua_utils.is_rspamc_or_controller(task) then return end
-
- -- Get initial task data
- local ip = task:get_from_ip()
- if ip and ip:is_valid() and settings.whitelisted_ip then
- if settings.whitelisted_ip:get_key(ip) then
- -- Do not check whitelisted ip
- rspamd_logger.infox(task, 'skip ratelimit for whitelisted IP')
- return
- end
- end
- -- Parse all rcpts
- local rcpts = task:get_recipients()
- local rcpts_user = {}
- if rcpts then
- fun.each(function(r)
- fun.each(function(type) table.insert(rcpts_user, r[type]) end, {'user', 'addr'})
- end, rcpts)
-
- if fun.any(function(r) return settings.whitelisted_rcpts:get_key(r) end, rcpts_user) then
- rspamd_logger.infox(task, 'skip ratelimit for whitelisted recipient')
- return
- end
- end
- -- Get user (authuser)
- if settings.whitelisted_user then
- local auser = task:get_user()
- if settings.whitelisted_user:get_key(auser) then
- rspamd_logger.infox(task, 'skip ratelimit for whitelisted user')
- return
- end
- end
- -- Now create all ratelimit prefixes
- local prefixes = {}
- local nprefixes = 0
-
- for k,v in pairs(settings.limits) do
- for _,bucket in ipairs(v) do
- local prefix = gen_rate_key(task, k, bucket)
-
- if prefix then
- local hash_len = 24
- if hash_len > #prefix then hash_len = #prefix end
- local hash = settings.prefix ..
- string.sub(rspamd_hash.create(prefix):base32(), 1, hash_len)
- prefixes[prefix] = {
- bucket = bucket,
- name = k,
- hash = hash
- }
- nprefixes = nprefixes + 1
- end
- end
- end
-
- local function gen_check_cb(prefix, bucket, lim_name)
- return function(err, data)
- if err then
- rspamd_logger.errx('cannot check limit %s: %s %s', prefix, err, data)
- elseif type(data) == 'table' and data[1] and data[1] == 1 then
- -- set symbol only and do NOT soft reject
- if settings.symbol then
- task:insert_result(settings.symbol, 0.0, lim_name .. "(" .. prefix .. ")")
- rspamd_logger.infox(task,
- 'set_symbol_only: ratelimit "%s(%s)" exceeded, (%s / %s): %s (%s:%s dyn)',
- lim_name, prefix, bucket[2], bucket[1], data[2], data[3], data[4])
- return
- -- set INFO symbol and soft reject
- elseif settings.info_symbol then
- task:insert_result(settings.info_symbol, 1.0, lim_name .. "(" .. prefix .. ")")
- end
- rspamd_logger.infox(task,
- 'ratelimit "%s(%s)" exceeded, (%s / %s): %s (%s:%s dyn)',
- lim_name, prefix, bucket[2], bucket[1], data[2], data[3], data[4])
- task:set_pre_result('soft reject',
- message_func(task, lim_name, prefix, bucket))
- end
- end
- end
-
- if nprefixes > 0 then
- -- Save prefixes to the cache to allow update
- task:cache_set('ratelimit_prefixes', prefixes)
- local now = rspamd_util.get_time()
- now = lua_util.round(now * 1000.0) -- Get milliseconds
- -- Now call check script for all defined prefixes
-
- for pr,value in pairs(prefixes) do
- local bucket = value.bucket
- local rate = (1.0 / bucket[1]) / 1000.0 -- Leak rate in messages/ms
- rspamd_logger.debugm(N, task, "check limit %s:%s -> %s (%s/%s)",
- value.name, pr, value.hash, bucket[2], bucket[1])
- lua_redis.exec_redis_script(bucket_check_id,
- {key = value.hash, task = task, is_write = true},
- gen_check_cb(pr, bucket, value.name),
- {value.hash, tostring(now), tostring(rate), tostring(bucket[2]),
- tostring(settings.expire)})
- end
- end
- end
-
- local function ratelimit_update_cb(task)
- local prefixes = task:cache_get('ratelimit_prefixes')
-
- if prefixes then
- local action = task:get_metric_action()
- local is_spam = true
-
- if action == 'soft reject' then
- -- Already rate limited/greylisted, do nothing
- rspamd_logger.debugm(N, task, 'already soft rejected, do not update')
- return
- elseif action == 'no action' then
- is_spam = false
- end
-
- local mult_burst = settings.ham_factor_burst
- local mult_rate = settings.ham_factor_burst
-
- if is_spam then
- mult_burst = settings.spam_factor_burst
- mult_rate = settings.spam_factor_rate
- end
-
- -- Update each bucket
- for k, v in pairs(prefixes) do
- local bucket = v.bucket
- local function update_bucket_cb(err, data)
- if err then
- rspamd_logger.errx(task, 'cannot update rate bucket %s: %s',
- k, err)
- else
- rspamd_logger.debugm(N, task,
- "updated limit %s:%s -> %s (%s/%s), burst: %s, dyn_rate: %s, dyn_burst: %s",
- v.name, k, v.hash, bucket[2], bucket[1], data[1], data[2], data[3])
- end
- end
- local now = rspamd_util.get_time()
- now = lua_util.round(now * 1000.0) -- Get milliseconds
-
- lua_redis.exec_redis_script(bucket_update_id,
- {key = v.hash, task = task, is_write = true},
- update_bucket_cb,
- {v.hash, tostring(now), tostring(mult_rate), tostring(mult_burst),
- tostring(settings.max_rate_mult), tostring(settings.max_bucket_mult),
- tostring(settings.expire)})
- end
- end
- end
-
- local opts = rspamd_config:get_all_opt(N)
- if opts then
-
- settings = lua_util.override_defaults(settings, opts)
-
- if opts['limit'] then
- rspamd_logger.errx(rspamd_config, 'Legacy ratelimit config format no longer supported')
- end
-
- if opts['rates'] and type(opts['rates']) == 'table' then
- -- new way of setting limits
- fun.each(function(t, lim)
- if type(lim) == 'table' then
- settings.limits[t] = {}
- if #lim == 2 and tonumber(lim[1]) and tonumber(lim[2]) then
- -- Old style ratelimit
- rspamd_logger.warnx(rspamd_config, 'old style ratelimit for %s', t)
- if tonumber(lim[1]) > 0 and tonumber(lim[2]) > 0 then
- table.insert(settings.limits[t], {1.0/lim[2], lim[1]})
- elseif lim[1] ~= 0 then
- rspamd_logger.warnx(rspamd_config, 'invalid numbers for %s', t)
- else
- rspamd_logger.infox(rspamd_config, 'disable limit %s, burst is zero', t)
- end
- else
- fun.each(function(l)
- local plim, size = parse_string_limit(l)
- if plim then
- table.insert(settings.limits[t], {plim, size})
- end
- end, lim)
- end
- elseif type(lim) == 'string' then
- local plim, size = parse_string_limit(lim)
- if plim then
- settings.limits[t] = { {plim, size} }
- end
- end
- end, opts['rates'])
- end
-
- local enabled_limits = fun.totable(fun.map(function(t)
- return t
- end, settings.limits))
- rspamd_logger.infox(rspamd_config,
- 'enabled rate buckets: [%1]', table.concat(enabled_limits, ','))
-
- -- Ret, ret, ret: stupid legacy stuff:
- -- If we have a string with commas then load it as as static map
- -- otherwise, apply normal logic of Rspamd maps
-
- local wrcpts = opts['whitelisted_rcpts']
- if type(wrcpts) == 'string' then
- if string.find(wrcpts, ',') then
- settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(
- lua_util.rspamd_str_split(wrcpts, ','), 'set', 'Ratelimit whitelisted rcpts')
- else
- settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
- 'Ratelimit whitelisted rcpts')
- end
- elseif type(opts['whitelisted_rcpts']) == 'table' then
- settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(wrcpts, 'set',
- 'Ratelimit whitelisted rcpts')
- else
- -- Stupid default...
- settings.whitelisted_rcpts = lua_maps.rspamd_map_add_from_ucl(
- settings.whitelisted_rcpts, 'set', 'Ratelimit whitelisted rcpts')
- end
-
- if opts['whitelisted_ip'] then
- settings.whitelisted_ip = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_ip', 'radix',
- 'Ratelimit whitelist ip map')
- end
-
- if opts['whitelisted_user'] then
- settings.whitelisted_user = lua_maps.rspamd_map_add('ratelimit', 'whitelisted_user', 'set',
- 'Ratelimit whitelist user map')
- end
-
- if opts['custom_keywords'] then
- settings.custom_keywords = dofile(opts['custom_keywords'])
- end
-
- if opts['message_func'] then
- message_func = assert(load(opts['message_func']))()
- end
-
- redis_params = lua_redis.parse_redis_server('ratelimit')
-
- if not redis_params then
- rspamd_logger.infox(rspamd_config, 'no servers are specified, disabling module')
- lua_util.disable_module(N, "redis")
- else
- local s = {
- type = 'prefilter,nostat',
- name = 'RATELIMIT_CHECK',
- priority = 4,
- callback = ratelimit_cb,
- flags = 'empty',
- }
-
- if settings.symbol then
- s.name = settings.symbol
- elseif settings.info_symbol then
- s.name = settings.info_symbol
- end
-
- rspamd_config:register_symbol(s)
- rspamd_config:register_symbol {
- type = 'idempotent',
- name = 'RATELIMIT_UPDATE',
- callback = ratelimit_update_cb,
- }
-
- if settings.custom_keywords then
- for _, v in pairs(settings.custom_keywords) do
- if type(v) == 'table' and type(v['init']) == 'function' then
- v['init']()
- end
- end
- end
- end
- end
-
- rspamd_config:add_on_load(function(cfg, ev_base, worker)
- load_scripts(cfg, ev_base)
- end)
|