zdev: Add support for handling auto-configuration data

Auto-configuration is the name of a new configuration target that is
supported by chzdev and lszdev besides the existing active and
persistent configuration targets. Directives created in this new
configuration are stored as udev rules in the /run/udev/rules.d
directory.

Auto-configuration directives are only in effect if there are no
directives for the same device in the user-provided persistent
configuration. This allows users to override auto-configuration
directives if necessary.

Due to the volatile nature of the /run directory, auto-configuration
directives are cleared on reboot. Therefore mechanisms that generate
auto-configuration directives must recreate them on every boot.

The lszdev tool displays auto-configuration data both in list view
as well as in detail view. Users can specify the new option --auto-conf
to only show data from this configuration target.

Mechanisms that generate automated configuration directives can use
chzdev together with the --auto-conf option to create the corresponding
udev rules.

Note: This change does not include a mechanism that generates
      auto-configuration directives.

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

zdev/src/lszdev.c

@@ -59,6 +59,7 @@ struct options {
 	config_t config;
 	unsigned int active:1;
 	unsigned int persistent:1;
+	unsigned int auto_conf:1;
 	struct util_list *columns;	/* List of struct strlist_node */
 	unsigned int no_headings:1;
 	struct util_list *base;		/* List of struct strlist_node */
@@ -98,6 +99,7 @@ enum {
 	OPT_VERBOSE		= 'V',
 	OPT_QUIET		= 'q',
 	OPT_PAIRS		= 'P',
+	OPT_AUTO_CONF		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 };
 
 static struct opts_conflict conflict_list[] = {
@@ -150,6 +152,7 @@ static const struct option opt_list[] = {
 	/* Options. */
 	{ "active",		no_argument,	NULL, OPT_ACTIVE },
 	{ "persistent",		no_argument,	NULL, OPT_PERSISTENT },
+	{ "auto-conf",		no_argument,	NULL, OPT_AUTO_CONF },
 	{ "columns",		required_argument, NULL, OPT_COLUMNS },
 	{ "no-headings",	no_argument,	NULL, OPT_NO_HEADINGS },
 	{ "base",		required_argument, NULL, OPT_BASE },
@@ -623,6 +626,11 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 			opts->persistent = 1;
 			break;
 
+		case OPT_AUTO_CONF:
+			/* --auto-conf */
+			opts->auto_conf = 1;
+			break;
+
 		case OPT_COLUMNS:
 			/* --columns COLUMN */
 			strlist_add_multi(opts->columns, optarg, ",", 0);
@@ -685,7 +693,15 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 		goto out;
 
 	/* Determine configuration set. */
-	opts->config = get_config(opts->active, opts->persistent);
+	if (!opts->active && !opts->persistent && !opts->auto_conf) {
+		/* Default display targets are active + persistent - note that
+		 * autoconf data is still shown when available to make users
+		 * aware of this type of data. */
+		opts->config = config_active | config_persistent;
+	} else {
+		opts->config = get_config(opts->active, opts->persistent,
+					  opts->auto_conf);
+	}
 
 	/* Handle positional parameters. */
 	rc = parse_positional(opts, argc, argv, optind);
@@ -725,6 +741,7 @@ enum dev_table_id {
 	dev_netdevs,
 	dev_exists,
 	dev_pers,
+	dev_auto,
 	dev_online,
 	dev_failed,
 	dev_modules,
@@ -744,6 +761,8 @@ static struct column *dev_table = COLUMN_ARRAY(
 	       "Device exists in the active configuration"),
 	COLUMN("PERS",		align_left, dev_pers, 1,
 	       "Device is configured persistently"),
+	COLUMN("AUTO",		align_left, dev_auto, 0,
+	       "Auto-configuration exists for device"),
 	COLUMN("FAILED",	align_left, dev_failed, 0,
 	       "Device is in error"),
 	COLUMN("NAMES",		align_left, dev_names, 1,
@@ -762,21 +781,34 @@ static struct column *dev_table = COLUMN_ARRAY(
 	       "Path to specific attribute in active configuration")
 );
 
-static char *merge_str(const char *act, const char *pers)
+static char *merge_str(const char *act, const char *pers, const char *ac,
+		       config_t config)
 {
 	char *str;
+	size_t len;
 
-	if (act && pers) {
-		if (strcmp(act, pers) == 0)
-			str = misc_strdup(act);
-		else
-			str = misc_asprintf("%s/%s", act, pers);
-	} else if (act)
-		str = misc_strdup(act);
-	else if (pers)
-		str = misc_strdup(pers);
-	else
-		str = misc_strdup("-");
+	act	= act  ? act  : "-";
+	pers	= pers ? pers : "-";
+	ac	= ac   ? ac   : "-";
+
+	if (strcmp(act, pers) == 0 && strcmp(act, ac) == 0)
+		return misc_strdup(act);
+
+	len = strlen(act) + strlen(pers) + strlen(ac) + /* 3 * / + NUL */ 4;
+	str = misc_malloc(len);
+
+	if (SCOPE_ACTIVE(config))
+		strcat(str, act);
+	if (SCOPE_PERSISTENT(config)) {
+		if (*str)
+			strcat(str, "/");
+		strcat(str, pers);
+	}
+	if (SCOPE_AUTOCONF(config)) {
+		if (*str)
+			strcat(str, "/");
+		strcat(str, ac);
+	}
 
 	return str;
 }
@@ -821,10 +853,9 @@ static char *get_attr(struct device *dev, const char *name, config_t config)
 	struct setting_list *list;
 	struct setting *s;
 
-	if (config == config_active)
-		list = dev->active.settings;
-	else
-		list = dev->persistent.settings;
+	list = device_get_setting_list(dev, config);
+	if (!list)
+		return NULL;
 	s = setting_list_find(list, name);
 	if (!s) {
 		if (config == config_active) {
@@ -841,7 +872,7 @@ static char *get_attr(struct device *dev, const char *name, config_t config)
 static char *dev_table_get_attr(struct device *dev, const char *attr,
 				config_t config)
 {
-	char *act = NULL, *pers = NULL, *str;
+	char *act = NULL, *pers = NULL, *ac = NULL, *str;
 	const char *name;
 
 	name = strchr(attr, ':');
@@ -853,10 +884,13 @@ static char *dev_table_get_attr(struct device *dev, const char *attr,
 		act = get_attr(dev, name, config_active);
 	if (SCOPE_PERSISTENT(config))
 		pers = get_attr(dev, name, config_persistent);
+	if (SCOPE_AUTOCONF(config))
+		ac = get_attr(dev, name, config_autoconf);
 
-	str = merge_str(act, pers);
+	str = merge_str(act, pers, ac, config);
 	free(act);
 	free(pers);
+	free(ac);
 
 	return str;
 }
@@ -904,7 +938,11 @@ static char *dev_table_get_value(void *item, int id, const char *heading,
 		return misc_strdup(YESNO(dev->active.exists ||
 					 dev->active.definable));
 	case dev_pers:
+		if (!dev->persistent.exists && dev->autoconf.exists)
+			return misc_strdup("auto");
 		return misc_strdup(YESNO(dev->persistent.exists));
+	case dev_auto:
+		return misc_strdup(YESNO(dev->autoconf.exists));
 	case dev_online:
 		return dev_table_get_online(dev, config_active);
 	case dev_failed:
@@ -942,6 +980,7 @@ static read_scope_t get_scope(struct options *opts)
 		case dev_netdevs:
 		case dev_exists:
 		case dev_pers:
+		case dev_auto:
 		case dev_online:
 		case dev_modules:
 			continue;
@@ -960,14 +999,21 @@ static struct util_list *dev_table_build(struct options *opts,
 	struct util_list *selected, *devices = NULL;
 	struct selected_dev_node *sel;
 	struct device *dev;
-	int active, persistent;
+	int active, persistent, autoconf;
 	read_scope_t scope;
 	exit_code_t rc;
+	config_t config = opts->config;
 
 	scope = get_scope(opts);
 	selected = selected_dev_list_new();
+
+	/* Read auto-config data when no configuration set was specified to
+	 * make user aware of auto-config data. */
+	if (!opts->active && !opts->persistent && !opts->auto_conf)
+		config |= config_autoconf;
+
 	rc = select_devices(opts->select, selected, 1, 0, opts->pairs,
-			    opts->config, scope, err_print);
+			    config, scope, err_print);
 	if (rc)
 		goto out;
 	devices = ptrlist_new();
@@ -987,7 +1033,8 @@ static struct util_list *dev_table_build(struct options *opts,
 		/* Only process existing devices. */
 		active = dev->active.exists || dev->active.definable;
 		persistent = dev->persistent.exists;
-		if (!active && !persistent)
+		autoconf = dev->autoconf.exists;
+		if (!active && !persistent && !autoconf)
 			continue;
 
 		ptrlist_add(devices, dev);
@@ -1025,9 +1072,11 @@ static exit_code_t do_list_devices(struct options *opts)
 	if (!items)
 		return EXIT_EMPTY_SELECTION;
 
-	/* Adjust columns visible depending on --active and --persistent. */
+	/* Adjust columns visible depending on selected config set. */
 	table_set_default(dev_table, dev_online, SCOPE_ACTIVE(opts->config));
 	table_set_default(dev_table, dev_pers, SCOPE_PERSISTENT(opts->config));
+	table_set_default(dev_table, dev_auto, SCOPE_AUTOCONF(opts->config) &&
+					       !SCOPE_PERSISTENT(opts->config));
 	table_set_default(dev_table, dev_names, SCOPE_ACTIVE(opts->config));
 
 	/* Display table. */
@@ -1057,17 +1106,20 @@ enum settings_table_id {
 	settings_readonly,
 	settings_active,
 	settings_persistent,
+	settings_autoconf,
 };
 
 static struct column *settings_table = COLUMN_ARRAY(
 	COLUMN("ATTRIBUTE", align_left, settings_attribute, 1, ""),
 	COLUMN("READONLY", align_left, settings_readonly, 1, ""),
 	COLUMN("ACTIVE", align_left, settings_active, 1, ""),
-	COLUMN("PERSISTENT", align_left, settings_persistent, 1, "")
+	COLUMN("PERSISTENT", align_left, settings_persistent, 1, ""),
+	COLUMN("AUTOCONF", align_left, settings_autoconf, 0, "")
 );
 
 static struct util_list *settings_table_build(struct setting_list *active,
 					      struct setting_list *persistent,
+					      struct setting_list *autoconf,
 					      bool readonly)
 {
 	struct util_list *names, *items;
@@ -1088,6 +1140,10 @@ static struct util_list *settings_table_build(struct setting_list *active,
 		util_list_iterate(&persistent->list, s)
 			strlist_add(names, s->name);
 	}
+	if (autoconf && !readonly) {
+		util_list_iterate(&autoconf->list, s)
+			strlist_add(names, s->name);
+	}
 	strlist_sort_unique(names, str_cmp);
 
 	/* Convert strlist to ptrlist. */
@@ -1102,6 +1158,7 @@ static struct util_list *settings_table_build(struct setting_list *active,
 struct settings_table_data {
 	struct setting_list *active;
 	struct setting_list *persistent;
+	struct setting_list *autoconf;
 	int pairs;
 	bool readonly;
 };
@@ -1124,12 +1181,17 @@ static char *settings_table_get_value(void *item, int id, const char *heading,
 	case settings_persistent:
 		list = stdata->persistent;
 		break;
+	case settings_autoconf:
+		list = stdata->autoconf;
+		break;
 	default:
 		break;
 	}
 	if (list) {
 		s = setting_list_find(list, name);
-		if (s && !(id == settings_persistent && s->derived)) {
+		if (s &&
+		    !((id == settings_persistent || id == settings_autoconf) &&
+		      s->derived)) {
 			if (stdata->pairs)
 				return misc_strdup(s->value);
 			else
@@ -1145,6 +1207,7 @@ static char *settings_table_get_value(void *item, int id, const char *heading,
 
 static void settings_table_print(struct setting_list *active,
 				 struct setting_list *persistent,
+				 struct setting_list *autoconf,
 				 struct options *opts, int ind, bool readonly,
 				 bool neednl)
 {
@@ -1154,7 +1217,7 @@ static void settings_table_print(struct setting_list *active,
 	items = settings_table_build(
 			SCOPE_ACTIVE(opts->config) ? active : NULL,
 			SCOPE_PERSISTENT(opts->config) ? persistent : NULL,
-			readonly);
+			autoconf, readonly);
 	if (util_list_is_empty(items)) {
 		if (!opts->pairs && !readonly)
 			indent(ind, "%sNo settings found\n",
@@ -1170,8 +1233,12 @@ static void settings_table_print(struct setting_list *active,
 			  SCOPE_ACTIVE(opts->config));
 	table_set_default(settings_table, settings_persistent,
 			  SCOPE_PERSISTENT(opts->config) && !readonly ? 1 : 0);
+	table_set_default(settings_table, settings_autoconf,
+			  (SCOPE_AUTOCONF(opts->config) || autoconf) &&
+				!readonly ? 1 : 0);
 	data.active = active;
 	data.persistent = persistent;
+	data.autoconf = autoconf;
 	data.pairs = opts->pairs;
 	table_print(settings_table, settings_table_get_value, &data, items,
 		    NULL, 1, opts->pairs, ind, 0);
@@ -1253,7 +1320,7 @@ static exit_code_t do_info_type(struct options *opts)
 		}
 	} else {
 		settings_table_print(dt->active_settings,
-				     dt->persistent_settings, opts,
+				     dt->persistent_settings, NULL, opts,
 				     INFO_INDENT, false, false);
 	}
 
@@ -1280,7 +1347,7 @@ static void do_info_one_device(struct device *dev, struct options *opts)
 {
 	struct subtype *st = dev->subtype;
 	char *names, *bdevs, *cdevs, *ndevs, *modules, *online, *path, *key;
-	const char *id, *type, *exists, *persist, *prefix;
+	const char *id, *type, *exists, *persist, *ac, *prefix;
 	struct util_list *resources, *errors;
 	struct strlist_node *s;
 	bool first;
@@ -1299,6 +1366,7 @@ static void do_info_one_device(struct device *dev, struct options *opts)
 	errors	= subtype_get_errors(dev->subtype, dev->id);
 	exists	= YESNO(dev->active.exists || dev->active.definable);
 	persist	= YESNO(dev->persistent.exists);
+	ac	= YESNO(dev->autoconf.exists);
 
 	/* Print information. */
 	if (opts->pairs) {
@@ -1316,6 +1384,8 @@ static void do_info_one_device(struct device *dev, struct options *opts)
 		print_pair("ONLINE", online);
 		print_pair("EXISTS", exists);
 		print_pair("PERSISTENT", persist);
+		if (SCOPE_AUTOCONF(opts->config) || dev->autoconf.exists)
+			print_pair("AUTOCONF", ac);
 		if (errors) {
 			util_list_iterate(errors, s)
 				print_pair("ERROR", s->str);
@@ -1341,6 +1411,8 @@ static void do_info_one_device(struct device *dev, struct options *opts)
 		print_info("Online", online);
 		print_info("Exists", exists);
 		print_info("Persistent", persist);
+		if (SCOPE_AUTOCONF(opts->config) || dev->autoconf.exists)
+			print_info("Auto-configured", ac);
 		if (errors) {
 			first = true;
 			util_list_iterate(errors, s) {
@@ -1382,11 +1454,17 @@ static void do_info_one_device(struct device *dev, struct options *opts)
 
 	settings_table_print(dev->active.exists ? dev->active.settings : NULL,
 			     dev->persistent.exists ? dev->persistent.settings :
-			     NULL, opts, INFO_INDENT, false, !opts->pairs);
+			     NULL,
+			     dev->autoconf.exists ? dev->autoconf.settings :
+			     NULL,
+			     opts, INFO_INDENT, false, !opts->pairs);
 
 	settings_table_print(dev->active.exists ? dev->active.settings : NULL,
 			     dev->persistent.exists ? dev->persistent.settings :
-			     NULL, opts, INFO_INDENT, true, !opts->pairs);
+			     NULL,
+			     dev->autoconf.exists ? dev->autoconf.settings :
+			     NULL,
+			     opts, INFO_INDENT, true, !opts->pairs);
 
 	strlist_free(errors);
 	free(online);
@@ -1404,9 +1482,10 @@ static exit_code_t do_info_devices(struct options *opts)
 	struct util_list *selected;
 	struct selected_dev_node *sel;
 	struct device *dev;
-	int found, active, persistent;
+	int found, active, persistent, autoconf;
 	exit_code_t rc, drc = EXIT_OK;
 	read_scope_t scope;
+	config_t config = opts->config;
 
 	if (opts->info > 1)
 		scope = scope_all;
@@ -1415,7 +1494,13 @@ static exit_code_t do_info_devices(struct options *opts)
 
 	/* Get list of selected devices. */
 	selected = selected_dev_list_new();
-	select_devices(opts->select, selected, 1, 0, opts->pairs, opts->config,
+
+	/* Read auto-config data when no configuration set was specified to
+	 * make user aware of auto-config data. */
+	if (!opts->active && !opts->persistent && !opts->auto_conf)
+		config |= config_autoconf;
+
+	select_devices(opts->select, selected, 1, 0, opts->pairs, config,
 		       scope, err_print);
 
 	/* Process selected devices. */
@@ -1434,9 +1519,8 @@ static exit_code_t do_info_devices(struct options *opts)
 		/* Only process existing devices. */
 		active = dev->active.exists || dev->active.definable;
 		persistent = dev->persistent.exists;
-		if ((opts->config == config_active && !active) ||
-		    (opts->config == config_persistent && !persistent) ||
-		    (opts->config == config_all && !active && !persistent))
+		autoconf = dev->autoconf.exists;
+		if (!active && !persistent && !autoconf)
 			continue;
 		if (found > 0)
 			printf("\n");