zdev: implement option to identify files created by zdev

Enhance the 'chzdev' tool by introducing a new option to discern
files created by 'zdev-tools.' The command usage is as follows:

$ chzdev --is-owner <file-name>

When executed, the command will return an exit code of 0 for all
files generated by zdev-tools. In the case of an unknown file, the
tool will return the exit code 'EXIT_UNKNOWN_FILE i.e 33.'

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdev/include/exit_code.h

@@ -54,6 +54,9 @@ typedef enum {
 	EXIT_GROUP_FAILED	= 31, /* CCW group device grouping failed */
 	EXIT_UNGROUP_FAILED	= 32, /* CCW group device ungrouping failed */
 
+	/* is-owner related */
+	EXIT_UNKNOWN_FILE	= 33, /* The file is not generated by chzdev */
+
 	EXIT_INTERNAL_ERROR	= 99, /* An internal error occurred */
 } exit_code_t;
 

zdev/include/zdev.h

@@ -24,6 +24,7 @@
 #define NUM_SITES 11
 #define NUM_USER_SITES (NUM_SITES - 1)
 #define SITE_FALLBACK NUM_USER_SITES
+#define CHZDEV_HEADER "# Generated by chzdev"
 
 /* Helper to find the availability of site-configuration */
 #define dev_site_configured(dev, x) (dev->site_specific[(x)].exists && \

zdev/man/chzdev.8

@@ -601,6 +601,18 @@ Combining apparently inconsistent settings
 .PP
 .RE
 .
+.OD is-owner "" "FILENAME"
+Detect if the file mentioned is generated by zdev tools.
+
+Return 0 if the
+.IR FILENAME
+is generated by zdev tools and 33 otherwise.
+
+.B Example:
+.CL chzdev --is-owner /etc/udev/rules/41-dasd-0.0.1234.rules
+
+.PP
+.
 .OD no-root-update "" ""
 Skip root device update.
 
@@ -916,6 +928,14 @@ CCW group device: Grouping failed
 CCW group device: Ungrouping failed
 .PP
 .TP
+.B 33
+The file specified by
+.nh
+\-\-is-owner
+.hy
+is not generated by zdev
+.PP
+.TP
 .B 99
 An internal error occurred
 .PP

zdev/src/chzdev.c

@@ -50,6 +50,7 @@
  * diff of simple function parameter modifications to pass this value.
  */
 int global_site_id = SITE_FALLBACK;
+#define MAX_HEADER_LENGTH sizeof(CHZDEV_HEADER)
 
 /* Main program action. */
 typedef enum {
@@ -60,6 +61,7 @@ typedef enum {
 	ACT_HELP_ATTRIBS,
 	ACT_EXPORT,
 	ACT_IMPORT,
+	ACT_IS_OWNER,
 	ACT_APPLY,
 	ACT_HELP,
 	ACT_VERSION,
@@ -86,6 +88,7 @@ struct options {
 	unsigned int help_attribs:1;
 	char *export;
 	char *import;
+	char *is_owner;
 	unsigned int apply:1;
 	unsigned int help:1;
 	unsigned int version:1;
@@ -134,6 +137,7 @@ enum {
 	OPT_LIST_TYPES		= 'L',
 	OPT_EXPORT		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 	OPT_IMPORT		= (OPT_ANONYMOUS_BASE+__COUNTER__),
+	OPT_IS_OWNER		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 	OPT_APPLY		= (OPT_ANONYMOUS_BASE+__COUNTER__),
 	OPT_ACTIVE		= 'a',
 	OPT_PERSISTENT		= 'p',
@@ -187,6 +191,13 @@ static struct opts_conflict conflict_list[] = {
 		      OPT_REMOVE_ALL, OPT_CONFIGURED, OPT_EXISTING, OPT_BY_PATH,
 		      OPT_BY_ATTRIB, OPT_BY_NODE, OPT_BY_INTERFACE,
 		      OPT_DECONFIGURE_ALL, 0),
+	OPTS_CONFLICT(OPT_IS_OWNER,
+		      OPT_DECONFIGURE, OPT_HELP_ATTRIBS, OPT_LIST_TYPES,
+		      OPT_EXPORT, OPT_IMPORT, OPT_APPLY, OPT_REMOVE,
+		      OPT_REMOVE_ALL, OPT_CONFIGURED, OPT_EXISTING, OPT_ONLINE,
+		      OPT_OFFLINE, OPT_BY_PATH, OPT_BY_NODE, OPT_BY_INTERFACE,
+		      OPT_BY_ATTRIB, OPT_ACTIVE, OPT_PERSISTENT, OPT_FAILED,
+		      OPT_DECONFIGURE_ALL, 0),
 	OPTS_CONFLICT(OPT_APPLY,
 		      OPT_DECONFIGURE, OPT_LIST_ATTRIBS, OPT_HELP_ATTRIBS,
 		      OPT_LIST_TYPES, OPT_EXPORT, OPT_IMPORT, OPT_REMOVE,
@@ -227,6 +238,7 @@ static const struct option opt_list[] = {
 	{ "list-types",		no_argument,	NULL, OPT_LIST_TYPES },
 	{ "export",		required_argument, NULL, OPT_EXPORT },
 	{ "import",		required_argument, NULL, OPT_IMPORT },
+	{ "is-owner",		required_argument, NULL, OPT_IS_OWNER },
 	{ "apply",		no_argument,	NULL, OPT_APPLY },
 	{ "help",		no_argument,	NULL, OPT_HELP },
 	{ "version",		no_argument,	NULL, OPT_VERSION },
@@ -278,6 +290,7 @@ static void free_options(struct options *opts)
 		return;
 	free(opts->export);
 	free(opts->import);
+	free(opts->is_owner);
 	select_opts_free(opts->select);
 	strlist_free(opts->positional);
 	strlist_free(opts->settings);
@@ -318,6 +331,8 @@ static action_t get_action(struct options *opts)
 		return ACT_EXPORT;
 	if (opts->import)
 		return ACT_IMPORT;
+	if (opts->is_owner)
+		return ACT_IS_OWNER;
 	if (opts->apply)
 		return ACT_APPLY;
 	return ACT_CONFIGURE;
@@ -339,6 +354,8 @@ static const char *get_action_option(action_t action)
 		return "--export";
 	case ACT_IMPORT:
 		return "--import";
+	case ACT_IS_OWNER:
+		return "--is-owner";
 	case ACT_APPLY:
 		return "--apply";
 	case ACT_HELP:
@@ -902,6 +919,16 @@ static exit_code_t parse_options(struct options *opts, int argc, char *argv[])
 			opts->import = misc_strdup(optarg);
 			break;
 
+		case OPT_IS_OWNER:
+			/* --is-owner */
+			if (opts->is_owner) {
+				error("Cannot specify '--is-owner' multiple "
+				      "times\n");
+				return EXIT_USAGE_ERROR;
+			}
+			opts->is_owner = misc_strdup(optarg);
+			break;
+
 		case OPT_APPLY:
 			/* --apply */
 			opts->apply = 1;
@@ -2929,6 +2956,39 @@ static void apply_selection_to_import(struct util_list *objects,
 	}
 }
 
+static exit_code_t zdev_file_detect(FILE *fd)
+{
+	char buffer[MAX_HEADER_LENGTH];
+
+	if (fgets(buffer, MAX_HEADER_LENGTH, fd)) {
+		if (starts_with(buffer, CHZDEV_HEADER))
+			return EXIT_OK;
+	} else {
+		return EXIT_RUNTIME_ERROR;
+	}
+
+	return EXIT_UNKNOWN_FILE;
+}
+
+/* Check if the file mentioned is generated by zdev */
+static exit_code_t do_is_owner(struct options *opts)
+{
+	FILE *fd;
+	exit_code_t rc = EXIT_OK;
+
+	fd = fopen(opts->is_owner, "r");
+	if (!fd) {
+		error("Could not open file %s: %s\n", opts->is_owner,
+		      strerror(errno));
+		return EXIT_RUNTIME_ERROR;
+	}
+
+	rc = zdev_file_detect(fd);
+
+	fclose(fd);
+	return rc;
+}
+
 /* Import configuration data. */
 static exit_code_t do_import(struct options *opts)
 {
@@ -3137,6 +3197,9 @@ int main(int argc, char *argv[])
 	case ACT_IMPORT:
 		rc = do_import(&opts);
 		break;
+	case ACT_IS_OWNER:
+		rc = do_is_owner(&opts);
+		break;
 	case ACT_APPLY:
 		rc = do_apply(&opts);
 		break;

zdev/src/chzdev_usage.txt

@@ -58,5 +58,6 @@ OPTIONS
       --no-settle        Do not wait for udev to settle
       --auto-conf        Apply changes to auto-configuration only
   -s, --site ID          Apply changes to the specified site only
+      --is-owner FILE    Examine whether the file is generated by zdev
   -V, --verbose          Print additional run-time information
   -q, --quiet            Print only minimal run-time information