1 files changed, 139 insertions, 0 deletions
diff --git a/safe.c b/safe.c
new file mode 100644
index 0000000000..3575ecca15
--- /dev/null
+++ b/safe.c
@@ -0,0 +1,139 @@
+/**********************************************************************
+
+  safe.c -
+
+  $Author$
+  created at: Tue Sep 23 09:44:32 JST 2008
+
+  Copyright (C) 2008 Yukihiro Matsumoto
+
+**********************************************************************/
+
+/* safe-level:
+   0 - strings from streams/environment/ARGV are tainted (default)
+   1 - no dangerous operation by tainted value
+*/
+
+#define SAFE_LEVEL_MAX RUBY_SAFE_LEVEL_MAX
+
+#include "ruby/ruby.h"
+#include "vm_core.h"
+
+/* $SAFE accessor */
+
+#undef rb_secure
+#undef rb_set_safe_level
+#undef ruby_safe_level_2_warning
+
+int
+ruby_safe_level_2_warning(void)
+{
+    return 2;
+}
+
+int
+rb_safe_level(void)
+{
+    return GET_EC()->safe_level;
+}
+
+void
+rb_set_safe_level_force(int safe)
+{
+    GET_EC()->safe_level = safe;
+}
+
+void
+rb_set_safe_level(int level)
+{
+    rb_execution_context_t *ec = GET_EC();
+
+    if (level > ec->safe_level) {
+	if (level > SAFE_LEVEL_MAX) {
+	    rb_raise(rb_eArgError, "$SAFE=2 to 4 are obsolete");
+	}
+	/* block parameters */
+	rb_vm_stack_to_heap(ec);
+
+	ec->safe_level = level;
+    }
+}
+
+static VALUE
+safe_getter(void)
+{
+    return INT2NUM(rb_safe_level());
+}
+
+static void
+safe_setter(VALUE val)
+{
+    rb_execution_context_t *ec = GET_EC();
+    int current_level = ec->safe_level;
+    int level = NUM2INT(val);
+
+    if (level == current_level) {
+	return;
+    }
+    else if (level < current_level) {
+	rb_raise(rb_eSecurityError,
+		 "tried to downgrade safe level from %d to %d",
+		 current_level, level);
+    }
+    else if (level > SAFE_LEVEL_MAX) {
+	rb_raise(rb_eArgError, "$SAFE=2 to 4 are obsolete");
+    }
+
+    /* block parameters */
+    rb_vm_stack_to_heap(ec);
+
+    ec->safe_level = level;
+}
+
+void
+rb_secure(int level)
+{
+    if (level <= rb_safe_level()) {
+	ID caller_name = rb_frame_callee();
+	if (caller_name) {
+	    rb_raise(rb_eSecurityError, "Insecure operation `%"PRIsVALUE"' at level %d",
+		     rb_id2str(caller_name), rb_safe_level());
+	}
+	else {
+	    rb_raise(rb_eSecurityError, "Insecure operation at level %d",
+		     rb_safe_level());
+	}
+    }
+}
+
+void
+rb_secure_update(VALUE obj)
+{
+}
+
+void
+rb_insecure_operation(void)
+{
+    ID caller_name = rb_frame_callee();
+    if (caller_name) {
+	rb_raise(rb_eSecurityError, "Insecure operation - %"PRIsVALUE,
+		 rb_id2str(caller_name));
+    }
+    else {
+	rb_raise(rb_eSecurityError, "Insecure operation: -r");
+    }
+}
+
+void
+rb_check_safe_obj(VALUE x)
+{
+    if (rb_safe_level() > 0 && OBJ_TAINTED(x)) {
+	rb_insecure_operation();
+    }
+}
+
+void
+Init_safe(void)
+{
+    rb_define_virtual_variable("$SAFE", safe_getter, safe_setter);
+}