Use asio to resolve host name (or IP)

Fixes #735

SourceX/DiabloUI/selgame.cpp

@@ -53,7 +53,7 @@ constexpr UiArtText SELUDPGAME_DESCRIPTION_LABEL = UiArtText("Description:", { P
 
 UiListItem SELUDPGAME_DIALOG_ITEMS[] = {
 	{ "Create Game", 0 },
-	{ "Enter IP", 1 },
+	{ "Join Game", 1 },
 };
 UiItem SELUDPGAME_DIALOG[] = {
 	MAINMENU_BACKGROUND,
@@ -73,7 +73,8 @@ UiItem ENTERIP_DIALOG[] = {
 	SELUDPGAME_TITLE,
 	SELUDPGAME_DESCRIPTION_LABEL,
 	SELGAME_DESCRIPTION,
-	UiArtText("Enter IP", { PANEL_LEFT + 305, 211, 285, 33 }, UIS_CENTER | UIS_BIG),
+	UiArtText("Enter address", { PANEL_LEFT + 305, 211, 285, 33 }, UIS_CENTER | UIS_BIG),
+
 	UiEdit(selgame_Ip, 128, { PANEL_LEFT + 305, 314, 285, 33 }, UIS_MED | UIS_GOLD),
 	SELGAME_OK,
 	SELGAME_CANCEL,

SourceX/dvlnet/tcp_client.cpp

@@ -2,11 +2,14 @@
 
 #include <functional>
 #include <exception>
+#include <sstream>
 #include <system_error>
 #include <stdexcept>
 #include <sodium.h>
 #include <SDL.h>
 
+#include <asio/connect.hpp>
+
 namespace dvl {
 namespace net {
 
@@ -29,8 +32,9 @@ int tcp_client::join(std::string addrstr, std::string passwd)
 
 	setup_password(passwd);
 	try {
-		auto ipaddr = asio::ip::make_address(addrstr);
-		sock.connect(asio::ip::tcp::endpoint(ipaddr, default_port));
+		std::stringstream port;
+		port << default_port;
+		asio::connect(sock, resolver.resolve(addrstr, port.str()));
 		asio::ip::tcp::no_delay option(true);
 		sock.set_option(option);
 	} catch (std::exception &e) {

SourceX/dvlnet/tcp_client.h

@@ -34,6 +34,7 @@ private:
 	buffer_t recv_buffer = buffer_t(frame_queue::max_frame_size);
 
 	asio::io_context ioc;
+	asio::ip::tcp::resolver resolver = asio::ip::tcp::resolver(ioc);
 	asio::ip::tcp::socket sock = asio::ip::tcp::socket(ioc);
 	std::unique_ptr<tcp_server> local_server; // must be declared *after* ioc