diff options
Diffstat (limited to 'lualib')
| -rw-r--r-- | lualib/plugins/ratelimit.lua | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/lualib/plugins/ratelimit.lua b/lualib/plugins/ratelimit.lua new file mode 100644 index 000000000..24afed1f8 --- /dev/null +++ b/lualib/plugins/ratelimit.lua @@ -0,0 +1,155 @@ +--[[ +Copyright (c) 2024, 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. +]]-- + +local rspamd_logger = require "rspamd_logger" +local lua_util = require "lua_util" +local ts = require("tableshape").types + +local exports = {} + +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 + +local function str_to_rate(str) + local divider, divisor = parse_string_limit(str, false) + + if not divisor then + rspamd_logger.errx(rspamd_config, 'bad rate string: %s', str) + + return nil + end + + return divisor / divider +end + +local bucket_schema = ts.shape { + burst = ts.number + ts.string / lua_util.dehumanize_number, + rate = ts.number + ts.string / str_to_rate, + skip_recipients = ts.boolean:is_optional(), + symbol = ts.string:is_optional(), + message = ts.string:is_optional(), + skip_soft_reject = ts.boolean:is_optional(), +} + +exports.parse_limit = function(name, data) + if type(data) == 'table' then + -- 2 cases here: + -- * old limit in format [burst, rate] + -- * vector of strings in Andrew's string format (removed from 1.8.2) + -- * proper bucket table + if #data == 2 and tonumber(data[1]) and tonumber(data[2]) then + -- Old style ratelimit + rspamd_logger.warnx(rspamd_config, 'old style ratelimit for %s', name) + if tonumber(data[1]) > 0 and tonumber(data[2]) > 0 then + return { + burst = data[1], + rate = data[2] + } + elseif data[1] ~= 0 then + rspamd_logger.warnx(rspamd_config, 'invalid numbers for %s', name) + else + rspamd_logger.infox(rspamd_config, 'disable limit %s, burst is zero', name) + end + + return nil + else + local parsed_bucket, err = bucket_schema:transform(data) + + if not parsed_bucket or err then + rspamd_logger.errx(rspamd_config, 'cannot parse bucket for %s: %s; original value: %s', + name, err, data) + else + return parsed_bucket + end + end + elseif type(data) == 'string' then + local rep_rate, burst = parse_string_limit(data) + rspamd_logger.warnx(rspamd_config, 'old style rate bucket config detected for %s: %s', + name, data) + if rep_rate and burst then + return { + burst = burst, + rate = burst / rep_rate -- reciprocal + } + end + end + + return nil +end + +return exports
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