zdev: Implement internal device attributes

This change adds base infrastructure for implementing internal device
attributes. In the context of the zdev tools, an internal device
attribute is a new type of device attribute with the following
characteristics:

  - Can be set and removed like normal device attributes
  - Affects zdev-internal handling only
  - Does not correspond to an actual device attribute, that is
    it has no representation in SysFS
  - Can not be set in the active configuration
  - Name starts with "zdev:" to prevent conflicts with actual
    device attributes

Values for internal device attributes are stored in udev rules alongside
the normal persistent configuration of a device. They are encoded as
udev environment variables. Note that they have no further effect on
udev processing.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdev/include/attrib.h

@@ -189,6 +189,7 @@ struct value_map {
  *              in the persistent configuration
  * @nounload:   (Device type attributes only) This attribute can be set while
  *              the corresponding kernel module remains loaded.
+ * @internal:   This attribute only affects internal handling
  * @order:	A number indicating the order in which to apply attribute
  * @order_cmp:  A function determining if a setting for this attribute should
  *              be applied before (-1) or after (1) another setting, or
@@ -216,6 +217,7 @@ struct attrib {
 	unsigned int activerem	:1;
 	unsigned int defunset	:1;
 	unsigned int nounload	:1;
+	unsigned int internal	:1;
 
 	/* Optional */
 	int order;

zdev/include/internal.h

@@ -0,0 +1,20 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef INTERNAL_H
+#define INTERNAL_H
+
+#include <stdbool.h>
+
+#define INTERNAL_ATTR_PREFIX	"zdev:"
+
+const char *internal_get_name(const char *name);
+bool internal_by_name(const char *name);
+
+#endif /* INTERNAL_H */

zdev/include/misc.h

@@ -183,6 +183,7 @@ bool str_to_config(const char *, config_t *);
 char *quote_str(const char *, int);
 char *unquote_str(const char *);
 char *shrink_str(const char *);
+char *misc_strrstr(const char *haystack, const char *needle);
 
 struct util_list *strlist_new(void);
 void strlist_free(struct util_list *);

zdev/include/udev.h

@@ -13,6 +13,9 @@
 #include "lib/util_list.h"
 #include "exit_code.h"
 
+struct attrib;
+struct setting_list;
+
 extern int udev_need_settle;
 extern int udev_no_settle;
 
@@ -46,4 +49,8 @@ exit_code_t udev_remove_rule(const char *type, const char *id, bool autoconf);
 
 void udev_settle(void);
 
+void udev_add_internal_from_entry(struct setting_list *list,
+				  struct udev_entry_node *entry,
+				  struct attrib **attribs);
+
 #endif /* UDEV_H */