1 files changed, 91 insertions, 0 deletions
diff --git a/net/adns.lua b/net/adns.lua
new file mode 100644
index 00000000..cd69a627
--- /dev/null
+++ b/net/adns.lua
@@ -0,0 +1,91 @@
+-- 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
+
+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()));
+				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
+
+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
+
+function new_async_socket(sock, resolver)
+	local peername = "<unknown>";
+	local listener = {};
+	local handler = {};
+	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 = 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(dummy_send); return ret; end
+	handler.connect = function (_, ...) return sock:connect(...) end
+	--handler.send = function (_, data) _:write(data);  return _.sendbuffer and _.sendbuffer(); end
+	handler.send = function (_, data)
+		local getpeername = sock.getpeername;
+		log("debug", "Sending DNS query to %s", (getpeername and getpeername(sock)) or "<unconnected>");
+		return sock:send(data);
+	end
+	return handler;
+end
+
+dns.socket_wrapper_set(new_async_socket);
+
+return _M;