1 files changed, 117 insertions, 0 deletions
diff --git a/eval_safe.h b/eval_safe.h
new file mode 100644
index 0000000000..6748ca87fe
--- /dev/null
+++ b/eval_safe.h
@@ -0,0 +1,117 @@
+/*
+ * This file is included by eval.c
+ */
+
+/* safe-level:
+   0 - strings from streams/environment/ARGV are tainted (default)
+   1 - no dangerous operation by tainted value
+   2 - process/file operations prohibited
+   3 - all generated objects are tainted
+   4 - no global (non-tainted) variable modification/no direct output
+*/
+
+int
+rb_safe_level(void)
+{
+    return GET_THREAD()->safe_level;
+}
+
+void
+rb_set_safe_level_force(int safe)
+{
+    GET_THREAD()->safe_level = safe;
+}
+
+static VALUE safe_getter _((void));
+static void safe_setter _((VALUE val));
+
+#define PROC_TSHIFT (FL_USHIFT+1)
+#define PROC_TMASK  (FL_USER1|FL_USER2|FL_USER3)
+#define PROC_TMAX   (PROC_TMASK >> PROC_TSHIFT)
+#define PROC_NOSAFE FL_USER4
+
+#define SAFE_LEVEL_MAX PROC_TMASK
+
+/* $SAFE accessor */
+void
+rb_set_safe_level(int level)
+{
+    yarv_thread_t *th = GET_THREAD();
+
+    if (level > th->safe_level) {
+	if (level > SAFE_LEVEL_MAX) {
+	    level = SAFE_LEVEL_MAX;
+	}
+	th->safe_level = level;
+    }
+}
+
+static VALUE
+safe_getter(void)
+{
+    return INT2NUM(rb_safe_level());
+}
+
+static void
+safe_setter(VALUE val)
+{
+    int level = NUM2INT(val);
+    yarv_thread_t *th = GET_THREAD();
+
+    if (level < th->safe_level) {
+	rb_raise(rb_eSecurityError,
+		 "tried to downgrade safe level from %d to %d",
+		 th->safe_level, level);
+    }
+    if (level > SAFE_LEVEL_MAX) {
+	level = SAFE_LEVEL_MAX;
+    }
+    th->safe_level = level;
+}
+
+void
+rb_secure(int level)
+{
+    if (level <= rb_safe_level()) {
+	if (rb_frame_callee()) {
+	    rb_raise(rb_eSecurityError, "Insecure operation `%s' at level %d",
+		     rb_id2name(rb_frame_callee()), rb_safe_level());
+	}
+	else {
+	    rb_raise(rb_eSecurityError, "Insecure operation at level %d",
+		     rb_safe_level());
+	}
+    }
+}
+
+void
+rb_secure_update(VALUE obj)
+{
+    if (!OBJ_TAINTED(obj))
+	rb_secure(4);
+}
+
+void
+rb_check_safe_obj(VALUE x)
+{
+    if (rb_safe_level() > 0 && OBJ_TAINTED(x)) {
+	if (rb_frame_callee()) {
+	    rb_raise(rb_eSecurityError, "Insecure operation - %s",
+		     rb_id2name(rb_frame_callee()));
+	}
+	else {
+	    rb_raise(rb_eSecurityError, "Insecure operation: -r");
+	}
+    }
+    rb_secure(4);
+}
+
+void
+rb_check_safe_str(VALUE x)
+{
+    rb_check_safe_obj(x);
+    if (TYPE(x) != T_STRING) {
+	rb_raise(rb_eTypeError, "wrong argument type %s (expected String)",
+		 rb_obj_classname(x));
+    }
+}