From 3a5f0d89b99ffb304b3b01a50466d461f94f54be Mon Sep 17 00:00:00 2001
From: Chris Tallon <chris@loggytronic.com>
Date: Sat, 12 Mar 2022 13:56:15 +0000
Subject: [PATCH] Server: Add --websocket_ipv4_only switch

Socket listening default changed to IPv4 and IPv6,
overridable to IPv4 only by using the command line switch.
---
 README.md                               | 2 +-
 src/Config.cpp                          | 8 ++++++++
 src/Config.h                            | 1 +
 src/websocketserver/WebSocketServer.cpp | 8 +++++++-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 568b9943..2d0159ff 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Binaries for Windows, MacOS, and Linux are available in the [Releases](https://g
 
 It is **highly recommended** to protect obs-websocket with a password against unauthorized control. To do this, open the "Websocket server settings" dialog under OBS' "Tools" menu. In the settings dialogs, you can enable or disable authentication and set a password for it.
 
-(Psst. You can use `--websocket_port`(value), `--websocket_password`(value), and `--websocket_debug`(flag) on the command line to override the configured values.)
+(Psst. You can use `--websocket_port`(value), `--websocket_password`(value), `--websocket_debug`(flag) and `--websocket_ipv4_only`(flag) on the command line to override the configured values.)
 
 ### Possible use cases
 
diff --git a/src/Config.cpp b/src/Config.cpp
index 5c45b2dd..2243183b 100644
--- a/src/Config.cpp
+++ b/src/Config.cpp
@@ -33,6 +33,7 @@ with this program. If not, see <https://www.gnu.org/licenses/>
 #define PARAM_PASSWORD "ServerPassword"
 
 #define CMDLINE_WEBSOCKET_PORT "websocket_port"
+#define CMDLINE_WEBSOCKET_IPV4_ONLY "websocket_ipv4_only"
 #define CMDLINE_WEBSOCKET_PASSWORD "websocket_password"
 #define CMDLINE_WEBSOCKET_DEBUG "websocket_debug"
 
@@ -42,6 +43,7 @@ Config::Config() :
 	FirstLoad(true),
 	ServerEnabled(true),
 	ServerPort(4455),
+	Ipv4Only(false),
 	DebugEnabled(false),
 	AlertsEnabled(false),
 	AuthRequired(true),
@@ -93,6 +95,12 @@ void Config::Load()
 		}
 	}
 
+	// Process `--websocket_ipv4_only` override
+	if (Utils::Platform::GetCommandLineFlagSet(CMDLINE_WEBSOCKET_IPV4_ONLY)) {
+		blog(LOG_INFO, "[Config::Load] --websocket_ipv4_only passed. Binding only to IPv4 interfaces.");
+		Ipv4Only = true;
+	}
+
 	// Process `--websocket_password` override
 	QString passwordArgument = Utils::Platform::GetCommandLineArgument(CMDLINE_WEBSOCKET_PASSWORD);
 	if (passwordArgument != "") {
diff --git a/src/Config.h b/src/Config.h
index beec3673..17533223 100644
--- a/src/Config.h
+++ b/src/Config.h
@@ -38,6 +38,7 @@ struct Config {
 	std::atomic<bool> FirstLoad;
 	std::atomic<bool> ServerEnabled;
 	std::atomic<uint16_t> ServerPort;
+	std::atomic<bool> Ipv4Only;
 	std::atomic<bool> DebugEnabled;
 	std::atomic<bool> AlertsEnabled;
 	std::atomic<bool> AuthRequired;
diff --git a/src/websocketserver/WebSocketServer.cpp b/src/websocketserver/WebSocketServer.cpp
index 0219922d..2fa1c40f 100644
--- a/src/websocketserver/WebSocketServer.cpp
+++ b/src/websocketserver/WebSocketServer.cpp
@@ -129,7 +129,13 @@ void WebSocketServer::Start()
 	_server.reset();
 
 	websocketpp::lib::error_code errorCode;
-	_server.listen(websocketpp::lib::asio::ip::tcp::v4(), conf->ServerPort, errorCode);
+	if (conf->Ipv4Only) {
+		blog(LOG_INFO, "[WebSocketServer::Start] Locked to IPv4 bindings");
+		_server.listen(websocketpp::lib::asio::ip::tcp::v4(), conf->ServerPort, errorCode);
+	} else {
+		blog(LOG_INFO, "[WebSocketServer::Start] Not locked to IPv4 bindings");
+		_server.listen(conf->ServerPort, errorCode);
+	}
 
 	if (errorCode) {
 		std::string errorCodeMessage = errorCode.message();