Merge branch 'io-limit' into 'next'

Add basic rate limitation for Lua file access

See merge request STJr/SRB2!1947

src/blua/liolib.c

@@ -24,12 +24,14 @@
 #include "../byteptr.h"
 #include "../lua_script.h"
 #include "../m_misc.h"
+#include "../i_time.h"
 
 
 #define IO_INPUT	1
 #define IO_OUTPUT	2
 
-#define FILELIMIT (1024 * 1024) // Size limit for reading/writing files
+#define MAXBYTESPERMINUTE (10 * 1024 * 1024) // Rate limit for writing files
+#define MAXOPENSPERMINUTE 50 // Rate limit for opening new files
 
 #define FMT_FILECALLBACKID "file_callback_%d"
 
@@ -46,6 +48,10 @@ static const char *whitelist[] = {
 };
 
 
+static INT64 numwrittenbytes = 0;
+static INT64 numopenedfiles = 0;
+
+
 static int pushresult (lua_State *L, int i, const char *filename) {
   int en = errno;  /* calls to Lua API may change this value */
   if (i) {
@@ -252,6 +258,17 @@ static int io_openlocal (lua_State *L) {
 			        "Files can't be opened while being downloaded\n",
 			        filename);
 
+  // Reading not restricted
+  if (client && (strchr(mode, 'w') || strchr(mode, 'a') || strchr(mode, '+')))
+  {
+    if (numopenedfiles >= (I_GetTime() / (60*TICRATE) + 1) * MAXOPENSPERMINUTE)
+      I_Error("Access denied to %s\n"
+              "File opening rate exceeded\n",
+              filename);
+
+    numopenedfiles++;
+  }
+
 	MakePathDirs(realfilename);
 
 	// Open and return the file
@@ -527,10 +544,13 @@ static int g_write (lua_State *L, FILE *f, int arg) {
     else {
       size_t l;
       const char *s = luaL_checklstring(L, arg, &l);
-      if (ftell(f) + l > FILELIMIT) {
-          luaL_error(L,"write limit bypassed in file. Changes have been discarded.");
+      if (client) {
+        if (numwrittenbytes + l > (I_GetTime() / (60*TICRATE) + 1) * MAXBYTESPERMINUTE) {
+            luaL_error(L,"file write rate limit exceeded; changes have been discarded");
             break;
         }
+        numwrittenbytes += l;
+      }
       status = status && (fwrite(s, sizeof(char), l, f) == l);
     }
   }

src/i_time.c

@@ -43,18 +43,20 @@ tic_t I_GetTime(void)
 
 void I_InitializeTime(void)
 {
-	g_time.time = 0;
-	g_time.timefrac = 0;
-
-	enterprecise = 0;
-	oldenterprecise = 0;
-	tictimer = 0.0;
-
 	CV_RegisterVar(&cv_timescale);
 
 	// I_StartupTimer is preserved for potential subsystems that need to setup
 	// timing information for I_GetPreciseTime and sleeping
 	I_StartupTimer();
+
+	g_time.time = 0;
+	g_time.timefrac = 0;
+
+	enterprecise = I_GetPreciseTime();
+	oldenterprecise = enterprecise;
+	entertic = 0;
+	oldentertics = 0;
+	tictimer = 0.0;
 }
 
 void I_UpdateTime(fixed_t timescale)