From d41a80bc2c54f37f769d71372adcb86949f25887 Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 17 Dec 2023 17:29:11 +0300
Subject: [PATCH] engine: add mask to sanitize possible engine features bits

---
 common/enginefeatures.h  | 12 ++++++++++++
 engine/client/cl_parse.c |  1 +
 engine/server/sv_phys.c  |  2 +-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/common/enginefeatures.h b/common/enginefeatures.h
index dc949dbf..8fe254d0 100644
--- a/common/enginefeatures.h
+++ b/common/enginefeatures.h
@@ -27,4 +27,16 @@ GNU General Public License for more details.
 #define ENGINE_COMPUTE_STUDIO_LERP	(1<<7)	// enable MOVETYPE_STEP lerping back in engine
 #define ENGINE_LINEAR_GAMMA_SPACE	(1<<8)	// disable influence of gamma/brightness cvars to textures/lightmaps, for mods with custom renderer
 
+// adjust the mask when features will be added or removed
+#define ENGINE_FEATURES_MASK      \
+	( ENGINE_WRITE_LARGE_COORD    \
+	| ENGINE_QUAKE_COMPATIBLE     \
+	| ENGINE_LOAD_DELUXEDATA      \
+	| ENGINE_PHYSICS_PUSHER_EXT   \
+	| ENGINE_LARGE_LIGHTMAPS      \
+	| ENGINE_COMPENSATE_QUAKE_BUG \
+	| ENGINE_IMPROVED_LINETRACE   \
+	| ENGINE_COMPUTE_STUDIO_LERP  \
+	| ENGINE_LINEAR_GAMMA_SPACE   )
+
 #endif//FEATURES_H
diff --git a/engine/client/cl_parse.c b/engine/client/cl_parse.c
index 81fd545f..f19de6e0 100644
--- a/engine/client/cl_parse.c
+++ b/engine/client/cl_parse.c
@@ -904,6 +904,7 @@ void CL_ParseServerData( sizebuf_t *msg, qboolean legacy )
 	background = MSG_ReadOneBit( msg );
 	Q_strncpy( gamefolder, MSG_ReadString( msg ), sizeof( gamefolder ));
 	host.features = (uint)MSG_ReadLong( msg );
+	host.features &= ENGINE_FEATURES_MASK;
 
 	if( !legacy )
 	{
diff --git a/engine/server/sv_phys.c b/engine/server/sv_phys.c
index 912932da..51e7cfff 100644
--- a/engine/server/sv_phys.c
+++ b/engine/server/sv_phys.c
@@ -2139,7 +2139,7 @@ qboolean SV_InitPhysicsAPI( void )
 			if( svgame.physFuncs.SV_CheckFeatures != NULL )
 			{
 				// grab common engine features (it will be shared across the network)
-				host.features = svgame.physFuncs.SV_CheckFeatures();
+				host.features = svgame.physFuncs.SV_CheckFeatures() & ENGINE_FEATURES_MASK;
 				Host_PrintEngineFeatures ();
 			}
 			return true;