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local server = require "net.server";
local dns = require "net.dns";
local log = require "util.logger".init("adns");
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("debug", "Error in DNS response handler: %s", tostring(err));
end
end)(dns.peek(qname, qtype, qclass));
end
function cancel(handle, call_handler)
dns.cancel(handle);
if call_handler then
coroutine.resume(handle[4]);
end
end
function new_async_socket(sock)
local newconn = {};
local listener = {};
function listener.incoming(conn, data)
dns.feed(sock, data);
end
function listener.disconnect()
end
newconn.handler, newconn._socket = server.wrapclient(sock, "dns", 53, listener);
newconn.handler.settimeout = function () end
newconn.handler.setsockname = function (_, ...) return sock:setsockname(...); end
newconn.handler.setpeername = function (_, ...) local ret = sock:setpeername(...); _.setsend(sock.send); return ret; end
newconn.handler.connect = function (_, ...) return sock:connect(...) end
newconn.handler.send = function (_, data) _.write(data); return _.sendbuffer(); end
return newconn.handler;
end
dns:socket_wrapper_set(new_async_socket);
return _M;
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