-- Prosody IM -- Copyright (C) 2008-2009 Matthew Wild -- Copyright (C) 2008-2009 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local server = require "net.server"; local dns = require "net.dns"; local log = require "util.logger".init("adns"); local t_insert, t_remove = table.insert, table.remove; local coroutine, tostring, pcall = coroutine, tostring, pcall; module "adns" function lookup(handler, qname, qtype, qclass) return coroutine.wrap(function (peek) if peek then log("debug", "Records for %s already cached, using those...", qname); handler(peek); return; end log("debug", "Records for %s not in cache, sending query (%s)...", qname, tostring(coroutine.running())); dns.query(qname, qtype, qclass); coroutine.yield({ qclass or "IN", qtype or "A", qname, coroutine.running()}); -- Wait for reply log("debug", "Reply for %s (%s)", qname, tostring(coroutine.running())); local ok, err = pcall(handler, dns.peek(qname, qtype, qclass)); if not ok then log("error", "Error in DNS response handler: %s", tostring(err)); end end)(dns.peek(qname, qtype, qclass)); end function cancel(handle, call_handler) log("warn", "Cancelling DNS lookup for %s", tostring(handle[3])); dns.cancel(handle); if call_handler then coroutine.resume(handle[4]); end end function new_async_socket(sock, resolver) local peername = "<unknown>"; local listener = {}; local handler = {}; function listener.onincoming(conn, data) dns.feed(handler, data); end function listener.ondisconnect(conn, err) log("warn", "DNS socket for %s disconnected: %s", peername, err); local servers = resolver.server; if resolver.socketset[conn] == resolver.best_server and resolver.best_server == #servers then log("error", "Exhausted all %d configured DNS servers, next lookup will try %s again", #servers, servers[1]); end resolver:servfail(conn); -- Let the magic commence end handler = server.wrapclient(sock, "dns", 53, listener); if not handler then log("warn", "handler is nil"); end handler.settimeout = function () end handler.setsockname = function (_, ...) return sock:setsockname(...); end handler.setpeername = function (_, ...) peername = (...); local ret = sock:setpeername(...); _:set_send(sock.send); return ret; end handler.connect = function (_, ...) return sock:connect(...) end handler.send = function (_, data) _:write(data); return _.sendbuffer and _.sendbuffer(); end return handler; end dns:socket_wrapper_set(new_async_socket); return _M;