Mercurial > prosody-modules
view mod_limits/mod_limits.lua @ 1473:31c4d92a81e5
mod_auth_ha1: Skip commented lines
author | Matthew Wild <mwild1@gmail.com> |
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date | Sun, 27 Jul 2014 14:36:12 +0100 |
parents | 92db76641b3f |
children | 1c126c49f5c1 |
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-- mod_limits: Rate-limiting for Prosody -- Version: Alpha -- Author: Matthew Wild <mwild1@gmail.com> -- Because we deal we pre-authed sessions and streams we can't be host-specific module:set_global(); local filters = require "util.filters"; local throttle = require "util.throttle"; local timer = require "util.timer"; local limits_cfg = module:get_option("limits", {}); local limits_resolution = module:get_option_number("limits_resolution", 1); local default_bytes_per_second = 3000; local default_burst = 2; local rate_units = { b = 1, k = 3, m = 6, g = 9, t = 12 } -- Plan for the future. local function parse_rate(rate, sess_type) local quantity, unit, exp; if rate then quantity, unit = rate:match("^(%d+) ?([^/]+)/s$"); exp = quantity and rate_units[unit:sub(1,1):lower()]; end if not exp then module:log("error", "Error parsing rate for %s: %q, using default rate (%d bytes/s)", sess_type, rate, default_bytes_per_second); return default_bytes_per_second; end return quantity*(10^exp); end local function parse_burst(burst, sess_type) if type(burst) == "string" then burst = burst:match("^(%d+) ?s$"); end local n_burst = tonumber(burst); if not n_burst then module:log("error", "Unable to parse burst for %s: %q, using default burst interval (%ds)", sess_type, tostring(burst), default_burst); end return n_burst or default_burst; end -- Process config option into limits table: -- limits = { c2s = { bytes_per_second = X, burst_seconds = Y } } local limits = {}; for sess_type, sess_limits in pairs(limits_cfg) do limits[sess_type] = { bytes_per_second = parse_rate(sess_limits.rate, sess_type); burst_seconds = parse_burst(sess_limits.burst, sess_type); }; end local default_filter_set = {}; function default_filter_set.bytes_in(bytes, session) local throttle = session.throttle; if throttle then local ok, balance, outstanding = throttle:poll(#bytes, true); if not ok then session.log("debug", "Session over rate limit (%d) with %d (by %d), pausing", throttle.max, #bytes, outstanding); session.conn:pause(); -- Read no more data from the connection until there is no outstanding data local outstanding_data = bytes:sub(-outstanding); bytes = bytes:sub(1, #bytes-outstanding); timer.add_task(limits_resolution, function () if not session.conn then return; end if throttle:peek(#outstanding_data) then session.log("debug", "Resuming paused session"); session.conn:resume(); end -- Handle what we can of the outstanding data session.data(outstanding_data); end); end end return bytes; end local type_filters = { c2s = default_filter_set; s2sin = default_filter_set; s2sout = default_filter_set; }; local function filter_hook(session) local session_type = session.type:match("^[^_]+"); local filter_set, opts = type_filters[session_type], limits[session_type]; if opts then session.throttle = throttle.create(opts.bytes_per_second * opts.burst_seconds, opts.burst_seconds); filters.add_filter(session, "bytes/in", filter_set.bytes_in, 1000); end end function module.load() filters.add_filter_hook(filter_hook); end function module.unload() filters.remove_filter_hook(filter_hook); end