modules: Add DNS module with Node.js compatible lookup().

modules/Makefile.am

@@ -36,6 +36,10 @@ conf_module_LTLIBRARIES =     \
 	conf/conf_serverinfo.la   \
 	conf/conf_listen.la
 
+dns_moduledir=@moduledir@
+dns_module_LTLIBRARIES = dns/dns.la
+dns_dns_la_SOURCES  = dns/dns.cc \
+                      dns/lookup.cc
 
 moduledir=@moduledir@
 future_la_SOURCES = future.cc

modules/dns/dns.cc

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "dns.h"
+
+namespace ircd {
+namespace js   {
+
+struct dns
+:trap
+{
+	using trap::trap;
+}
+dns{"dns"};
+
+} // namespace js
+} // namespace ircd
+
+ip::tcp::resolver tcp_resolver
+{
+	 *ircd::ios
+};
+
+ircd::mapi::fini dtors{[]
+{
+	tcp_resolver.cancel();
+}};
+
+ircd::mapi::header IRCD_MODULE
+{
+	"Client interface to the Domain Name Service",
+	ircd::mapi::NO_FLAGS,
+	&dtors
+};

modules/dns/dns.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <ircd/js/js.h>
+#include <boost/asio.hpp>
+
+namespace ip = boost::asio::ip;
+
+extern ip::tcp::resolver tcp_resolver;           // dns.cc

modules/dns/lookup.cc

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "dns.h"
+
+namespace ircd {
+namespace js   {
+
+extern trap dns;
+
+struct lookup
+:trap::function
+{
+	trap &future{trap::find("future")};
+
+	value handle_result(const boost::system::error_code &, ip::tcp::resolver::iterator &);
+	value on_call(object::handle obj, value::handle, const args &args) override;
+	using trap::function::function;
+}
+static lookup
+{
+	dns, "lookup"
+};
+
+
+} // namespace js
+} // namespace ircd
+
+// system-level hostname resolution
+//
+// args[0]: hostname     - string
+// args[1]: [options]    - object or integer; integer = 4 or 6
+// args[2]: [callback]   - function; undefined = yield
+//
+// https://nodejs.org/api/dns.html#dns_dns_lookup_hostname_options_callback
+//
+ircd::js::value
+ircd::js::lookup::on_call(object::handle obj,
+                          value::handle that,
+                          const args &args)
+{
+	const string hostname{args[0]};
+	const object options{args.has(1)? args[1] : value{}};         //TODO: Node.js options
+	const value callback{args.has(2)? args[2] : value{}};
+	const ip::tcp::resolver::query query
+	{
+		std::string(hostname),
+		std::string{}
+	};
+
+	auto &task(task::get());
+	contract result(ctor(future, vector<value>{{callback}}));
+	tcp_resolver.async_resolve(query, [this, result]
+	(const boost::system::error_code &ec, ip::tcp::resolver::iterator it)
+	mutable
+	{
+		result(std::bind(&lookup::handle_result, this, std::ref(ec), std::ref(it)));
+	});
+
+	return result;
+}
+
+ircd::js::value
+ircd::js::lookup::handle_result(const boost::system::error_code &ec,
+                                ip::tcp::resolver::iterator &it)
+{
+	static const ip::tcp::resolver::iterator end;
+
+	if(ec)
+		throw jserror("%s", ec.message().c_str());
+
+	vector<value> addrs;
+	for(; it != end; ++it)
+		addrs.append(string(it->endpoint().address().to_string()));
+
+	return object(addrs);
+}