Software /
code /
prosody
File
net/adns.lua @ 9042:734ba7080b35
moduleapi: Use :send API from :broadcast for compactness
author | Kim Alvefur <zash@zash.se> |
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date | Sat, 14 Jul 2018 21:25:34 +0200 |
parent | 8555:4f0f5b49bb03 |
child | 9731:47121e8dc5b1 |
child | 11266:2115496e8251 |
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-- 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 new_resolver = require "net.dns".resolver; local log = require "util.logger".init("adns"); local coroutine, tostring, pcall = coroutine, tostring, pcall; local setmetatable = setmetatable; local function dummy_send(sock, data, i, j) return (j-i)+1; end local _ENV = nil; -- luacheck: std none local async_resolver_methods = {}; local async_resolver_mt = { __index = async_resolver_methods }; local query_methods = {}; local query_mt = { __index = query_methods }; local function new_async_socket(sock, resolver) local peername = "<unknown>"; local listener = {}; local handler = {}; local err; function listener.onincoming(conn, data) if data then resolver: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 function async_resolver_methods:lookup(handler, qname, qtype, qclass) local resolver = self._resolver; 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 = resolver:query(qname, qtype, qclass); if ok then coroutine.yield(setmetatable({ resolver, qclass or "IN", qtype or "A", qname, coroutine.running()}, query_mt)); -- Wait for reply log("debug", "Reply for %s (%s)", qname, tostring(coroutine.running())); end if ok then ok, err = pcall(handler, resolver: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)(resolver:peek(qname, qtype, qclass)); end function query_methods:cancel(call_handler, reason) log("warn", "Cancelling DNS lookup for %s", tostring(self[4])); self[1].cancel(self[2], self[3], self[4], self[5], call_handler); end local function new_async_resolver() local resolver = new_resolver(); resolver:socket_wrapper_set(new_async_socket); return setmetatable({ _resolver = resolver}, async_resolver_mt); end return { lookup = function (...) return new_async_resolver():lookup(...); end; resolver = new_async_resolver; new_async_socket = new_async_socket; };