-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 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; local function dummy_send(sock, data, i, j) return (j-i)+1; end local _ENV = nil; local 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())); local ok, err = dns.query(qname, qtype, qclass); if ok then coroutine.yield({ qclass or "IN", qtype or "A", qname, coroutine.running()}); -- Wait for reply log("debug", "Reply for %s (%s)", qname, tostring(coroutine.running())); end if ok then ok, err = pcall(handler, dns.peek(qname, qtype, qclass)); else log("error", "Error sending DNS query: %s", err); ok, err = pcall(handler, nil, err); end if not ok then log("error", "Error in DNS response handler: %s", tostring(err)); end end)(dns.peek(qname, qtype, qclass)); end local function cancel(handle, call_handler, reason) log("warn", "Cancelling DNS lookup for %s", tostring(handle[3])); dns.cancel(handle[1], handle[2], handle[3], handle[4], call_handler); end local function new_async_socket(sock, resolver) local peername = "<unknown>"; local listener = {}; local handler = {}; local err; function listener.onincoming(conn, data) if data then dns.feed(handler, data); end end function listener.ondisconnect(conn, err) if err then 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 end handler, err = server.wrapclient(sock, "dns", 53, listener); if not handler then return nil, err; end handler.settimeout = function () end handler.setsockname = function (_, ...) return sock:setsockname(...); end handler.setpeername = function (_, ...) peername = (...); local ret, err = sock:setpeername(...); _:set_send(dummy_send); return ret, err; end handler.connect = function (_, ...) return sock:connect(...) end --handler.send = function (_, data) _:write(data); return _.sendbuffer and _.sendbuffer(); end handler.send = function (_, data) log("debug", "Sending DNS query to %s", peername); return sock:send(data); end return handler; end dns.socket_wrapper_set(new_async_socket); return { lookup = lookup; cancel = cancel; new_async_socket = new_async_socket; };