engine: client: implement errormsg, secure client by checking server IP address we're connected to

engine/client/cl_demo.c

@@ -1154,6 +1154,7 @@ void CL_StopPlayback( void )
 		// let game known about demo state	
 		Cvar_FullSet( "cl_background", "0", FCVAR_READ_ONLY );
 		cls.state = ca_disconnected;
+		memset( &cls.serveradr, 0, sizeof( cls.serveradr ) );
 		cls.set_lastdemo = false;
 		S_StopBackgroundTrack();
 		cls.connect_time = 0;

engine/client/cl_gameui.c

@@ -503,6 +503,13 @@ void UI_AddTouchButtonToList( const char *name, const char *texture, const char
 	}
 }
 
+/*
+=================
+UI_ResetPing
+
+notify gameui dll about latency reset
+=================
+*/
 void UI_ResetPing( void )
 {
 	if( gameui.dllFuncs2.pfnResetPing )
@@ -511,11 +518,62 @@ void UI_ResetPing( void )
 	}
 }
 
+/*
+=================
+UI_ShowConnectionWarning
+
+show connection warning dialog implemented by gameui dll
+=================
+*/
 void UI_ShowConnectionWarning( void )
 {
-	if( gameui.dllFuncs2.pfnShowConnectionWarning )
+	if( cls.state != ca_connected )
+		return;
+
+	if( Host_IsLocalClient() )
+		return;
+
+	if( ++cl.lostpackets == 8 )
+	{
+		CL_Disconnect();
+		if( gameui.dllFuncs2.pfnShowConnectionWarning )
+		{
+			gameui.dllFuncs2.pfnShowConnectionWarning();
+		}
+		Con_DPrintf( S_WARN "Too many lost packets! Showing Network options menu\n" );
+	}
+}
+
+
+/*
+=================
+UI_ShowConnectionWarning
+
+show update dialog
+=================
+*/
+void UI_ShowUpdateDialog( qboolean preferStore )
+{
+	if( gameui.dllFuncs2.pfnShowUpdateDialog )
+	{
+		gameui.dllFuncs2.pfnShowUpdateDialog( preferStore );
+	}
+
+	Con_Printf( S_WARN "This version is not supported anymore. To continue, install latest engine version\n" );
+}
+
+/*
+=================
+UI_ShowConnectionWarning
+
+show message box
+=================
+*/
+void UI_ShowMessageBox( const char *text )
+{
+	if( gameui.dllFuncs2.pfnShowMessageBox )
 	{
-		gameui.dllFuncs2.pfnShowConnectionWarning();
+		gameui.dllFuncs2.pfnShowMessageBox( text );
 	}
 }
 

engine/client/cl_main.c

@@ -1098,6 +1098,8 @@ void CL_CheckForResend( void )
 		cls.signon = 0;
 		cls.state = ca_connecting;
 		Q_strncpy( cls.servername, "localhost", sizeof( cls.servername ));
+		cls.serveradr.type = NA_LOOPBACK;
+
 		// we don't need a challenge on the localhost
 		CL_SendConnectPacket();
 		return;
@@ -1150,6 +1152,7 @@ void CL_CheckForResend( void )
 		return;
 	}
 
+	cls.serveradr = adr;
 	cls.max_fragment_size = Q_max( FRAGMENT_MAX_SIZE, cls.max_fragment_size >> Q_min( 1, cls.connect_retry ));
 	cls.connect_time = host.realtime; // for retransmit requests
 	cls.connect_retry++;
@@ -1501,6 +1504,7 @@ void CL_Disconnect( void )
 	IN_LockInputDevices( false ); // unlock input devices
 
 	cls.state = ca_disconnected;
+	memset( &cls.serveradr, 0, sizeof( cls.serveradr ) );
 	cls.set_lastdemo = false;
 	cls.connect_retry = 0;
 	cls.signon = 0;
@@ -1858,6 +1862,19 @@ void CL_SetupOverviewParams( void )
 	}
 }
 
+/*
+=================
+CL_IsFromConnectingServer
+
+Used for connectionless packets, when netchan may not be ready.
+=================
+*/
+static qboolean CL_IsFromConnectingServer( netadr_t from )
+{
+	return NET_IsLocalAddress( from ) ||
+		NET_CompareAdr( cls.serveradr, from );
+}
+
 /*
 =================
 CL_ConnectionlessPacket
@@ -1887,6 +1904,9 @@ void CL_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 	// server connection
 	if( !Q_strcmp( c, "client_connect" ))
 	{
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
 		if( cls.state == ca_connected )
 		{
 			Con_DPrintf( S_ERROR "dup connect received. ignored\n");
@@ -1927,21 +1947,19 @@ void CL_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 		// print command from somewhere
 		Con_Printf( "%s", MSG_ReadString( msg ));
 	}
-	else if( !Q_strcmp( c, "errormsg" ))
-	{
-		args = MSG_ReadString( msg );
-		if( !Q_strcmp( args, "Server uses protocol version 48.\n" ))
-		{
-			cls.legacyserver = from;
-		}
-	}
 	else if( !Q_strcmp( c, "testpacket" ))
 	{
 		byte	recv_buf[NET_MAX_FRAGMENT];
-		dword	crcValue = MSG_ReadLong( msg );
+		dword	crcValue;
-		int	realsize = MSG_GetMaxBytes( msg ) - MSG_GetNumBytesRead( msg );
+		int	realsize;
 		dword	crcValue2 = 0;
 
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
+		crcValue = MSG_ReadLong( msg );
+		realsize = MSG_GetMaxBytes( msg ) - MSG_GetNumBytesRead( msg );
+
 		if( cls.max_fragment_size != MSG_GetMaxBytes( msg ))
 		{
 			if( cls.connect_retry >= CL_TEST_RETRIES )
@@ -1999,6 +2017,9 @@ void CL_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 	}
 	else if( !Q_strcmp( c, "challenge" ))
 	{
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
 		// challenge from the server we are connecting to
 		cls.challenge = Q_atoi( Cmd_Argv( 1 ));
 		CL_SendConnectPacket();
@@ -2006,11 +2027,17 @@ void CL_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 	}
 	else if( !Q_strcmp( c, "echo" ))
 	{
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
 		// echo request from server
 		Netchan_OutOfBandPrint( NS_CLIENT, from, "%s", Cmd_Argv( 1 ));
 	}
 	else if( !Q_strcmp( c, "disconnect" ))
 	{
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
 		// a disconnect message from the server, which will happen if the server
 		// dropped the connection but it is still getting packets from us
 		CL_Disconnect_f();
@@ -2021,6 +2048,48 @@ void CL_ConnectionlessPacket( netadr_t from, sizebuf_t *msg )
 			memset( &cls.legacyserver, 0, sizeof( cls.legacyserver ));
 		}
 	}
+	else if( !Q_strcmp( c, "errormsg" ))
+	{
+		if( !CL_IsFromConnectingServer( from ))
+			return;
+
+		args = MSG_ReadString( msg );
+
+		if( !Q_strcmp( args, "Server uses protocol version 48.\n" ))
+		{
+			cls.legacyserver = from;
+		}
+		else
+		{
+			if( UI_IsVisible() )
+				UI_ShowMessageBox( va("^3Server message^7\n%s", args ) );
+			Msg( "%s", args );
+		}
+	}
+	else if( !Q_strcmp( c, "updatemsg" ))
+	{
+		// got an update message from master server
+		// show update dialog from menu
+		netadr_t adr;
+		qboolean preferStore = true;
+
+		if( !Q_strcmp( Cmd_Argv( 1 ), "nostore" ) )
+			preferStore = false;
+
+		// trust only hardcoded master server
+		if( NET_StringToAdr( MASTERSERVER_ADR, &adr ) )
+		{
+			if( NET_CompareAdr( from, adr ))
+			{
+				UI_ShowUpdateDialog( preferStore );
+			}
+		}
+		else
+		{
+			// in case we don't have master anymore
+			UI_ShowUpdateDialog( preferStore );
+		}
+	}
 	else if( !Q_strcmp( c, "f" ))
 	{
 		// serverlist got from masterserver
@@ -2713,28 +2782,6 @@ void CL_Escape_f( void )
 	else UI_SetActiveMenu( true );
 }
 
-/*
-=================
-CL_WarnLostSplitPacket
-
-=================
-*/
-void CL_WarnLostSplitPacket( void )
-{
-	if( cls.state != ca_connected )
-		return;
-
-	if( Host_IsLocalClient() )
-		return;
-
-	if( ++cl.lostpackets == 8 )
-	{
-		CL_Disconnect();
-		UI_ShowConnectionWarning();
-		Con_DPrintf( S_WARN "Too many lost packets! Showing Network options menu\n" );
-	}
-}
-
 /*
 =================
 CL_InitLocal
@@ -2744,6 +2791,7 @@ void CL_InitLocal( void )
 {
 	cls.state = ca_disconnected;
 	cls.signon = 0;
+	memset( &cls.serveradr, 0, sizeof( cls.serveradr ) );
 
 	cl.resourcesneeded.pNext = cl.resourcesneeded.pPrev = &cl.resourcesneeded;
 	cl.resourcesonhand.pNext = cl.resourcesonhand.pPrev = &cl.resourcesonhand;

engine/client/client.h

@@ -618,11 +618,15 @@ typedef struct
 	file_t		*demoheader;		// contain demo startup info in case we record a demo on this level
 	qboolean internetservers_wait;	// internetservers is waiting for dns request
 	qboolean internetservers_pending;	// internetservers is waiting for dns request
+
+	// legacy mode support
 	qboolean legacymode;				// one-way 48 protocol compatibility
 	netadr_t legacyserver;
 	netadr_t legacyservers[MAX_LEGACY_SERVERS];
 	int	legacyservercount;
 	int extensions;
+
+	netadr_t serveradr;
 } client_static_t;
 
 #ifdef __cplusplus
@@ -1075,7 +1079,8 @@ void UI_CharEvent( int key );
 qboolean UI_MouseInRect( void );
 qboolean UI_IsVisible( void );
 void UI_ResetPing( void );
-void UI_ShowConnectionWarning( void );
+void UI_ShowUpdateDialog( qboolean preferStore );
+void UI_ShowMessageBox( const char *text );
 void UI_AddTouchButtonToList( const char *name, const char *texture, const char *command, unsigned char *color, int flags );
 void pfnPIC_Set( HIMAGE hPic, int r, int g, int b, int a );
 void pfnPIC_Draw( int x, int y, int width, int height, const wrect_t *prc );

engine/common/common.h

@@ -851,7 +851,6 @@ qboolean CL_IsInConsole( void );
 qboolean CL_IsThirdPerson( void );
 qboolean CL_IsIntermission( void );
 qboolean CL_Initialized( void );
-void CL_WarnLostSplitPacket( void );
 char *CL_Userinfo( void );
 void CL_LegacyUpdateInfo( void );
 void CL_CharEvent( int key );
@@ -952,6 +951,7 @@ void GL_FreeImage( const char *name );
 void VID_InitDefaultResolution( void );
 void VID_Init( void );
 void UI_SetActiveMenu( qboolean fActive );
+void UI_ShowConnectionWarning( void );
 void Cmd_Null_f( void );
 
 // soundlib shared exports

engine/common/dedicated.c

@@ -327,7 +327,7 @@ void CL_ClearStaticEntities( void )
 
 }
 
-void CL_WarnLostSplitPacket( void )
+void UI_ShowConnectionWarning( void )
 {
 
 }

engine/common/net_chan.c

@@ -140,7 +140,7 @@ qboolean NetSplit_GetLong( netsplit_t *ns, netadr_t *from, byte *data, size_t *l
 		// warn if previous packet not received
 		if( p->received < p->count )
 		{
-			CL_WarnLostSplitPacket();
+			UI_ShowConnectionWarning();
 			Con_Reportf( S_WARN "NetSplit_GetLong: lost packet %d\n", p->id );
 		}