- Fix potential out-of-bounds read in files.c, fix by using new FS_IsExt

- Add capability to load demos with com_protocol suffix, partially applied patches from Simon McVittie
- Fix demo loading if protocol number has more digits than 2
- Minor refactoring, replace all occurances of suffix "dm_" with global macro DEMOEXT

code/client/cl_main.c

@@ -627,14 +627,14 @@ void CL_Record_f( void ) {
 	if ( Cmd_Argc() == 2 ) {
 		s = Cmd_Argv(1);
 		Q_strncpyz( demoName, s, sizeof( demoName ) );
-		Com_sprintf (name, sizeof(name), "demos/%s.dm_%d", demoName, PROTOCOL_VERSION );
+		Com_sprintf (name, sizeof(name), "demos/%s.%s%d", demoName, DEMOEXT, com_protocol->integer );
 	} else {
 		int		number;
 
 		// scan for a free demo name
 		for ( number = 0 ; number <= 9999 ; number++ ) {
 			CL_DemoFilename( number, demoName );
-			Com_sprintf (name, sizeof(name), "demos/%s.dm_%d", demoName, PROTOCOL_VERSION );
+			Com_sprintf (name, sizeof(name), "demos/%s.%s%d", demoName, DEMOEXT, com_protocol->integer );
 
 			if (!FS_FileExists(name))
 				break;	// file doesn't exist
@@ -884,9 +884,22 @@ static void CL_WalkDemoExt(char *arg, char *name, int *demofile)
 {
 	int i = 0;
 	*demofile = 0;
+
+	Com_sprintf (name, MAX_OSPATH, "demos/%s.%s%d", arg, DEMOEXT, com_protocol->integer);
+
+	FS_FOpenFileRead( name, demofile, qtrue );
+
+	if (*demofile)
+	{
+		Com_Printf("Demo file: %s\n", name);
+		return;
+	}
+
+	Com_Printf("Not found: %s\n", name);
+
 	while(demo_protocols[i])
 	{
-		Com_sprintf (name, MAX_OSPATH, "demos/%s.dm_%d", arg, demo_protocols[i]);
+		Com_sprintf (name, MAX_OSPATH, "demos/%s.%s%d", arg, DEMOEXT, demo_protocols[i]);
 		FS_FOpenFileRead( name, demofile, qtrue );
 		if (*demofile)
 		{
@@ -910,7 +923,7 @@ static void CL_CompleteDemoName( char *args, int argNum )
 	{
 		char demoExt[ 16 ];
 
-		Com_sprintf( demoExt, sizeof( demoExt ), ".dm_%d", PROTOCOL_VERSION );
+		Com_sprintf(demoExt, sizeof(demoExt), ".%s%d", DEMOEXT, com_protocol->integer);
 		Field_CompleteFilename( "demos", demoExt, qtrue, qtrue );
 	}
 }
@@ -943,34 +956,41 @@ void CL_PlayDemo_f( void ) {
 	
 	CL_Disconnect( qtrue );
 
-	// check for an extension .dm_?? (?? is protocol)
-	ext_test = arg + strlen(arg) - 6;
-	if ((strlen(arg) > 6) && (ext_test[0] == '.') &&
-		((ext_test[1] == 'd') || (ext_test[1] == 'D')) &&
-		((ext_test[2] == 'm') || (ext_test[2] == 'M')) &&
-		(ext_test[3] == '_'))
+	// check for an extension .DEMOEXT_?? (?? is protocol)
+	ext_test = Q_strrchr(arg, '.');
+	
+	if(ext_test && !Q_stricmpn(ext_test + 1, DEMOEXT, ARRAY_LEN(DEMOEXT) - 1))
 	{
-		protocol = atoi(ext_test+4);
-		i=0;
-		while(demo_protocols[i])
+		protocol = atoi(ext_test + ARRAY_LEN(DEMOEXT));
+
+		for(i = 0; demo_protocols[i]; i++)
 		{
-			if (demo_protocols[i] == protocol)
+			if(demo_protocols[i] == protocol)
 				break;
-			i++;
 		}
-		if (demo_protocols[i])
+
+		if(demo_protocols[i] || protocol == com_protocol->integer)
 		{
-			Com_sprintf (name, sizeof(name), "demos/%s", arg);
-			FS_FOpenFileRead( name, &clc.demofile, qtrue );
-		} else {
-			Com_Printf("Protocol %d not supported for demos\n", protocol);
-			Q_strncpyz(retry, arg, sizeof(retry));
-			retry[strlen(retry)-6] = 0;
-			CL_WalkDemoExt( retry, name, &clc.demofile );
+			Com_sprintf(name, sizeof(name), "demos/%s", arg);
+			FS_FOpenFileRead(name, &clc.demofile, qtrue);
+		}
+		else
+		{
+			int len;
+
+			Com_Printf("Protocol %d not supported for demos\n", protocol);
+			len = ext_test - arg;
+
+			if(len >= ARRAY_LEN(retry))
+				len = ARRAY_LEN(retry) - 1;
+
+			Q_strncpyz(retry, arg, len + 1);
+			retry[len] = '\0';
+			CL_WalkDemoExt(retry, name, &clc.demofile);
 		}
-	} else {
-		CL_WalkDemoExt( arg, name, &clc.demofile );
 	}
+	else
+		CL_WalkDemoExt(arg, name, &clc.demofile);
 	
 	if (!clc.demofile) {
 		Com_Error( ERR_DROP, "couldn't open %s", name);

code/q3_ui/ui_demo2.c

@@ -223,7 +223,7 @@ static void Demos_MenuInit( void ) {
 	s_demos.list.generic.y			= 130;
 	s_demos.list.width				= 16;
 	s_demos.list.height				= 14;
-	Com_sprintf(extension, sizeof(extension), "dm_%d", (int)trap_Cvar_VariableValue( "protocol" ) );
+	Com_sprintf(extension, sizeof(extension), ".%s%d", DEMOEXT, (int) trap_Cvar_VariableValue("protocol"));
 	s_demos.list.numitems			= trap_FS_GetFileList( "demos", extension, s_demos.names, NAMEBUFSIZE );
 	s_demos.list.itemnames			= (const char **)s_demos.demolist;
 	s_demos.list.columns			= 3;

code/qcommon/files.c

@@ -941,6 +941,59 @@ qboolean FS_FilenameCompare( const char *s1, const char *s2 ) {
 	return qfalse;		// strings are equal
 }
 
+/*
+===========
+FS_IsExt
+
+Return qtrue if ext matches file extension filename
+===========
+*/
+
+qboolean FS_IsExt(const char *filename, const char *ext, int namelen)
+{
+	int extlen;
+
+	extlen = strlen(ext);
+
+	if(extlen > namelen)
+		return qfalse;
+
+	filename += namelen - extlen;
+
+	return !Q_stricmp(filename, ext);
+}
+
+/*
+===========
+FS_IsDemoExt
+
+Return qtrue if filename has a demo extension
+===========
+*/
+
+qboolean FS_IsDemoExt(const char *filename, int namelen)
+{
+	char *ext_test;
+	int index, protocol;
+
+	ext_test = Q_strrchr(filename, '.');
+	if(ext_test && !Q_stricmpn(ext_test + 1, DEMOEXT, ARRAY_LEN(DEMOEXT) - 1))
+	{
+		protocol = atoi(ext_test + ARRAY_LEN(DEMOEXT));
+
+		if(protocol == com_protocol->integer)
+			return qtrue;
+
+		for(index = 0; demo_protocols[index]; index++)
+		{
+			if(demo_protocols[index] == protocol)
+			return qtrue;
+		}
+	}
+
+	return qfalse;
+}
+
 /*
 ===========
 FS_FOpenFileRead
@@ -962,7 +1015,6 @@ int FS_FOpenFileRead( const char *filename, fileHandle_t *file, qboolean uniqueF
 	long			hash;
 	FILE			*temp;
 	int				l;
-	char demoExt[16];
 
 	hash = 0;
 
@@ -1009,7 +1061,6 @@ int FS_FOpenFileRead( const char *filename, fileHandle_t *file, qboolean uniqueF
 		Com_Error( ERR_FATAL, "FS_FOpenFileRead: NULL 'filename' parameter passed\n" );
 	}
 
-	Com_sprintf (demoExt, sizeof(demoExt), ".dm_%d",PROTOCOL_VERSION );
 	// qpaths are not supposed to have a leading slash
 	if ( filename[0] == '/' || filename[0] == '\\' ) {
 		filename++;
@@ -1061,16 +1112,19 @@ int FS_FOpenFileRead( const char *filename, fileHandle_t *file, qboolean uniqueF
 					// shaders, txt, arena files  by themselves do not count as a reference as 
 					// these are loaded from all pk3s 
 					// from every pk3 file.. 
-					l = strlen( filename );
-					if ( !(pak->referenced & FS_GENERAL_REF)) {
-						if ( Q_stricmp(filename + l - 7, ".shader") != 0 &&
-							Q_stricmp(filename + l - 4, ".txt") != 0 &&
-							Q_stricmp(filename + l - 4, ".cfg") != 0 &&
-							Q_stricmp(filename + l - 7, ".config") != 0 &&
-							strstr(filename, "levelshots") == NULL &&
-							Q_stricmp(filename + l - 4, ".bot") != 0 &&
-							Q_stricmp(filename + l - 6, ".arena") != 0 &&
-							Q_stricmp(filename + l - 5, ".menu") != 0) {
+					l = strlen(filename);
+					
+					if (!(pak->referenced & FS_GENERAL_REF))
+					{
+						if(!FS_IsExt(filename, ".shader", l) &&
+						   !FS_IsExt(filename, ".txt", l) &&
+						   !FS_IsExt(filename, ".cfg", l) &&
+						   !FS_IsExt(filename, ".config", l) &&
+						   !FS_IsExt(filename, ".bot", l) &&
+						   !FS_IsExt(filename, ".arena", l) &&
+						   !FS_IsExt(filename, ".menu", l) &&
+						   !strstr(filename, "levelshots"))
+						{
 							pak->referenced |= FS_GENERAL_REF;
 						}
 					}
@@ -1121,13 +1175,14 @@ int FS_FOpenFileRead( const char *filename, fileHandle_t *file, qboolean uniqueF
 			//   this test can make the search fail although the file is in the directory
 			// I had the problem on https://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=8
 			// turned out I used FS_FileExists instead
-			if ( fs_numServerPaks ) {
-
-				if ( Q_stricmp( filename + l - 4, ".cfg" )		// for config files
-					&& Q_stricmp( filename + l - 5, ".menu" )	// menu files
-					&& Q_stricmp( filename + l - 5, ".game" )	// menu files
-					&& Q_stricmp( filename + l - strlen(demoExt), demoExt )	// menu files
-					&& Q_stricmp( filename + l - 4, ".dat" ) ) {	// for journal files
+			if(fs_numServerPaks)
+			{
+				if(!FS_IsExt(filename, ".cfg", l) &&		// for config files
+				   !FS_IsExt(filename, ".menu", l) &&		// menu files
+				   !FS_IsExt(filename, ".game", l) &&		// menu files
+				   !FS_IsExt(filename, ".cfg", l) &&		// for journal files
+				   !FS_IsDemoExt(filename, l))			// demos
+				{
 					continue;
 				}
 			}

code/qcommon/q_shared.h

@@ -55,6 +55,8 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #define MAX_TEAMNAME		32
 #define MAX_MASTER_SERVERS      5	// number of supported master servers
 
+#define DEMOEXT	"dm_"			// standard demo extension
+
 #ifdef _MSC_VER
 
 #pragma warning(disable : 4018)     // signed/unsigned mismatch

code/ui/ui_atoms.c

@@ -162,7 +162,7 @@ void UI_LoadBestScores(const char *map, int game) {
 	}
 	UI_SetBestScores(&newInfo, qfalse);
 
-	Com_sprintf(fileName, MAX_QPATH, "demos/%s_%d.dm_%d", map, game, (int)trap_Cvar_VariableValue("protocol"));
+	Com_sprintf(fileName, MAX_QPATH, "demos/%s_%d.%s%d", map, game, DEMOEXT, (int)trap_Cvar_VariableValue("protocol"));
 	uiInfo.demoAvailable = qfalse;
 	if (trap_FS_FOpenFile(fileName, &f, FS_READ) >= 0) {
 		uiInfo.demoAvailable = qtrue;

code/ui/ui_main.c

@@ -2877,11 +2877,11 @@ static void UI_LoadDemos( void ) {
 	char	*demoname;
 	int		i, len;
 
-	Com_sprintf(demoExt, sizeof(demoExt), "dm_%d", (int)trap_Cvar_VariableValue("protocol"));
+	Com_sprintf(demoExt, sizeof(demoExt), "%s%d", DEMOEXT, (int)trap_Cvar_VariableValue("protocol"));
 
 	uiInfo.demoCount = trap_FS_GetFileList( "demos", demoExt, demolist, 4096 );
 
-	Com_sprintf(demoExt, sizeof(demoExt), ".dm_%d", (int)trap_Cvar_VariableValue("protocol"));
+	Com_sprintf(demoExt, sizeof(demoExt), ".%s%d", DEMOEXT, (int)trap_Cvar_VariableValue("protocol"));
 
 	if (uiInfo.demoCount) {
 		if (uiInfo.demoCount > MAX_DEMOS) {