[Feature] Add some recursion protection to lua logger

2 files changed, 67 insertions, 17 deletions

diff --git a/src/lua/lua_common.h b/src/lua/lua_common.h
index 8ccb8bef0..af0b5f824 100644
--- a/src/lua/lua_common.h
+++ b/src/lua/lua_common.h
@@ -352,6 +352,14 @@ guint rspamd_lua_table_size (lua_State *L, gint tbl_pos);
 
 void lua_push_emails_address_list (lua_State *L, GPtrArray *addrs);
 
+
+#define TRACE_POINTS 6
+
+struct lua_logger_trace {
+	gint cur_level;
+	gconstpointer traces[TRACE_POINTS];
+};
+
 /**
  * Log lua object to string
  * @param L
@@ -361,7 +369,7 @@ void lua_push_emails_address_list (lua_State *L, GPtrArray *addrs);
  * @return
  */
 gsize lua_logger_out_type (lua_State *L, gint pos, gchar *outbuf,
-		gsize len);
+		gsize len, struct lua_logger_trace *trace);
 
 /**
  * Safely checks userdata to match specified class
diff --git a/src/lua/lua_logger.c b/src/lua/lua_logger.c
index 69fa8e420..abfc3e1fa 100644
--- a/src/lua/lua_logger.c
+++ b/src/lua/lua_logger.c
@@ -270,7 +270,8 @@ lua_logger_debug (lua_State *L)
 }
 
 static gsize
-lua_logger_out_str (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_str (lua_State *L, gint pos, gchar *outbuf, gsize len,
+					struct lua_logger_trace *trace)
 {
 	gsize slen;
 	const gchar *str = lua_tolstring (L, pos, &slen);
@@ -284,7 +285,8 @@ lua_logger_out_str (lua_State *L, gint pos, gchar *outbuf, gsize len)
 }
 
 static gsize
-lua_logger_out_num (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_num (lua_State *L, gint pos, gchar *outbuf, gsize len,
+					struct lua_logger_trace *trace)
 {
 	gdouble num = lua_tonumber (L, pos);
 	glong inum;
@@ -302,7 +304,8 @@ lua_logger_out_num (lua_State *L, gint pos, gchar *outbuf, gsize len)
 }
 
 static gsize
-lua_logger_out_boolean (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_boolean (lua_State *L, gint pos, gchar *outbuf, gsize len,
+						struct lua_logger_trace *trace)
 {
 	gboolean val = lua_toboolean (L, pos);
 	gsize r = 0;
@@ -313,7 +316,8 @@ lua_logger_out_boolean (lua_State *L, gint pos, gchar *outbuf, gsize len)
 }
 
 static gsize
-lua_logger_out_userdata (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_userdata (lua_State *L, gint pos, gchar *outbuf, gsize len,
+						 struct lua_logger_trace *trace)
 {
 	gint r, top;
 	const gchar *str = NULL;
@@ -383,17 +387,34 @@ lua_logger_out_userdata (lua_State *L, gint pos, gchar *outbuf, gsize len)
     if ((remain) == 0) { lua_pop (L, 1); break; }
 
 static gsize
-lua_logger_out_table (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_table (lua_State *L, gint pos, gchar *outbuf, gsize len,
+					  struct lua_logger_trace *trace)
 {
 	gchar *d = outbuf;
 	gsize remain = len, r;
 	gboolean first = TRUE;
-	gint i;
+	gconstpointer self = NULL;
+	gint i, tpos;
 
 	if (!lua_istable (L, pos) || remain == 0) {
 		return 0;
 	}
 
+	self = lua_topointer (L, pos);
+
+	/* Check if we have seen this pointer */
+	for (i = 0; i < TRACE_POINTS; i ++) {
+		if (trace->traces[i] == self) {
+			r = rspamd_snprintf (d, remain + 1, "ref(%p)", self);
+
+			d += r;
+
+			return (d - outbuf);
+		}
+	}
+
+	trace->traces[trace->cur_level % TRACE_POINTS] = self;
+
 	lua_pushvalue (L, pos);
 	r = rspamd_snprintf (d, remain + 1, "{");
 	remain -= r;
@@ -415,7 +436,14 @@ lua_logger_out_table (lua_State *L, gint pos, gchar *outbuf, gsize len)
 
 		r = rspamd_snprintf (d, remain + 1, "[%d] = ", i);
 		MOVE_BUF(d, remain, r);
-		r = lua_logger_out_type (L, lua_gettop (L), d, remain);
+		tpos = lua_gettop (L);
+
+		if (lua_topointer (L, tpos) == self) {
+			r = rspamd_snprintf (d, remain + 1, "__self");
+		}
+		else {
+			r = lua_logger_out_type (L, tpos, d, remain, trace);
+		}
 		MOVE_BUF(d, remain, r);
 
 		first = FALSE;
@@ -438,7 +466,14 @@ lua_logger_out_table (lua_State *L, gint pos, gchar *outbuf, gsize len)
 		r = rspamd_snprintf (d, remain + 1, "[%s] = ",
 				lua_tostring (L, -2));
 		MOVE_BUF(d, remain, r);
-		r = lua_logger_out_type (L, lua_gettop (L), d, remain);
+		tpos = lua_gettop (L);
+
+		if (lua_topointer (L, tpos) == self) {
+			r = rspamd_snprintf (d, remain + 1, "__self");
+		}
+		else {
+			r = lua_logger_out_type (L, tpos, d, remain, trace);
+		}
 		MOVE_BUF(d, remain, r);
 
 		first = FALSE;
@@ -455,7 +490,8 @@ lua_logger_out_table (lua_State *L, gint pos, gchar *outbuf, gsize len)
 #undef MOVE_BUF
 
 gsize
-lua_logger_out_type (lua_State *L, gint pos, gchar *outbuf, gsize len)
+lua_logger_out_type (lua_State *L, gint pos, gchar *outbuf, gsize len,
+					 struct lua_logger_trace *trace)
 {
 	gint type;
 	gsize r = 0;
@@ -465,19 +501,20 @@ lua_logger_out_type (lua_State *L, gint pos, gchar *outbuf, gsize len)
 	}
 
 	type = lua_type (L, pos);
+	trace->cur_level ++;
 
 	switch (type) {
 		case LUA_TNUMBER:
-			r = lua_logger_out_num (L, pos, outbuf, len);
+			r = lua_logger_out_num (L, pos, outbuf, len, trace);
 			break;
 		case LUA_TBOOLEAN:
-			r = lua_logger_out_boolean (L, pos, outbuf, len);
+			r = lua_logger_out_boolean (L, pos, outbuf, len, trace);
 			break;
 		case LUA_TTABLE:
-			r = lua_logger_out_table (L, pos, outbuf, len);
+			r = lua_logger_out_table (L, pos, outbuf, len, trace);
 			break;
 		case LUA_TUSERDATA:
-			r = lua_logger_out_userdata (L, pos, outbuf, len);
+			r = lua_logger_out_userdata (L, pos, outbuf, len, trace);
 			break;
 		case LUA_TFUNCTION:
 			r = rspamd_snprintf (outbuf, len + 1, "function");
@@ -490,10 +527,12 @@ lua_logger_out_type (lua_State *L, gint pos, gchar *outbuf, gsize len)
 			break;
 		default:
 			/* Try to push everything as string using tostring magic */
-			r = lua_logger_out_str (L, pos, outbuf, len);
+			r = lua_logger_out_str (L, pos, outbuf, len, trace);
 			break;
 	}
 
+	trace->cur_level --;
+
 	return r;
 }
 
@@ -595,6 +634,7 @@ lua_logger_log_format (lua_State *L, gint fmt_pos, gboolean is_string,
 	gsize r, cpylen = 0;
 	guint arg_num = 0, cur_arg;
 	bool num_arg = false;
+	struct lua_logger_trace tr;
 	enum {
 		copy_char = 0,
 		got_percent,
@@ -663,7 +703,8 @@ lua_logger_log_format (lua_State *L, gint fmt_pos, gboolean is_string,
 					return FALSE;
 				}
 
-				r = lua_logger_out_type (L, arg_num + 1, d, remain);
+				memset (&tr, 0, sizeof (tr));
+				r = lua_logger_out_type (L, arg_num + 1, d, remain, &tr);
 				g_assert (r <= remain);
 				remain -= r;
 				d += r;
@@ -690,7 +731,8 @@ lua_logger_log_format (lua_State *L, gint fmt_pos, gboolean is_string,
 			return FALSE;
 		}
 
-		r = lua_logger_out_type (L, arg_num + 1, d, remain);
+		memset (&tr, 0, sizeof (tr));
+		r = lua_logger_out_type (L, arg_num + 1, d, remain, &tr);
 		g_assert (r <= remain);
 		remain -= r;
 		d += r;