view mod_register_dnsbl/mod_register_dnsbl.lua @ 5818:d3b69859553a

mod_password_policy: Change error type from 'cancel' to 'modify' This makes more sense, as the problem relates to the data that has been entered, and therefore the request could be retried with different data.
author Matthew Wild <mwild1@gmail.com>
date Mon, 08 Jan 2024 17:28:39 +0000
parents 82482e7e92cb
children
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local adns = require "net.adns";
local async = require "util.async";
local inet_pton = require "util.net".pton;
local to_hex = require "util.hex".to;

local rbl = module:get_option_string("registration_rbl");

local function reverse(ip, suffix)
	local n, err = inet_pton(ip);
	if not n then return n, err end
	if #n == 4 then
		local a,b,c,d = n:byte(1,4);
		return ("%d.%d.%d.%d.%s"):format(d,c,b,a, suffix);
	elseif #n == 16 then
		return to_hex(n):reverse():gsub("%x", "%1.") .. suffix;
	end
end

module:hook("user-registering", function (event)
	local session, ip = event.session, event.ip;
	local log = (session and session.log) or module._log;
	if not ip then
		log("debug", "Unable to check DNSBL when IP is unknown");
		return;
	end
	local rbl_ip, err = reverse(ip, rbl);
	if not rbl_ip then
		log("debug", "Unable to check DNSBL for ip %s: %s", ip, err);
		return;
	end

	local wait, done = async.waiter();
	adns.lookup(function (reply)
		if reply and reply[1] and reply[1].a then
			log("debug", "DNSBL response: %s IN A %s", rbl_ip, reply[1].a);
			log("info", "Blocking %s from registering %s (dnsbl hit)", ip, event.username);
			event.allowed = false;
			event.reason = "Blocked by DNSBL";
		end
		done();
	end, rbl_ip);
	wait();
end);