mdadm/SOURCES/0126-mdadm-do-not-allow-leading-dot-in-MD-device-name.patch

From 998544c198c156db027a6e4f1b201910b138041e Mon Sep 17 00:00:00 2001
From: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Date: Mon, 15 Jul 2024 12:29:24 +0200
Subject: [PATCH 126/157] mdadm: do not allow leading dot in MD device name

Do not allow to use '.' on first place for named MD device.
Having leading dot might be confusing, MD device cannot be hidden.
It also removes possibility to create md device with name '.'.

Additionally, code optimalizations are done.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
---
 config.c | 75 +++++++++++++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 34 deletions(-)

diff --git a/config.c b/config.c
index cd2379bd..6ea905f3 100644
--- a/config.c
+++ b/config.c
@@ -188,8 +188,36 @@ inline void ident_init(struct mddev_ident *ident)
 	ident->uuid_set = 0;
 }
 
+/** ident_check_name() - helper function to verify name.
+ * @name: name to check.
+ * @prop_name: the name of the property it is validated against, used for logging.
+ * @cmdline: context dependent actions.
+ *
+ * @name must follow name's criteria, be POSIX compatible and does not have leading dot.
+ */
+static mdadm_status_t ident_check_name(const char *name, const char *prop_name, const bool cmdline)
+{
+	if (!is_string_lq(name, MD_NAME_MAX + 1)) {
+		ident_log(prop_name, name, "Too long or empty", cmdline);
+		return MDADM_STATUS_ERROR;
+	}
+
+	if (*name == '.') {
+		/* MD device should not be considered as hidden. */
+		ident_log(prop_name, name, "Leading dot forbidden", cmdline);
+		return MDADM_STATUS_ERROR;
+	}
+
+	if (!is_name_posix_compatible(name)) {
+		ident_log(prop_name, name, "Not POSIX compatible", cmdline);
+		return MDADM_STATUS_ERROR;
+	}
+
+	return MDADM_STATUS_SUCCESS;
+}
+
 /**
- * _ident_set_devname()- verify devname and set it in &mddev_ident.
+ * _ident_set_devname() - verify devname and set it in &mddev_ident.
  * @ident: pointer to &mddev_ident.
  * @devname: devname to be set.
  * @cmdline: context dependent actions. If set, ignore keyword is not allowed.
@@ -202,8 +230,7 @@ inline void ident_init(struct mddev_ident *ident)
  *	/dev/md/{name}
  *	{name}
  *
- * {name} must follow name's criteria and be POSIX compatible.
- * If criteria passed, duplicate memory and set devname in @ident.
+ * If verification passed, duplicate memory and set devname in @ident.
  *
  * Return: %MDADM_STATUS_SUCCESS or %MDADM_STATUS_ERROR.
  */
@@ -216,6 +243,7 @@ mdadm_status_t _ident_set_devname(struct mddev_ident *ident, const char *devname
 	static const char named_dev_pref[] = DEV_NUM_PREF "_";
 	static const int named_dev_pref_size = sizeof(named_dev_pref) - 1;
 	const char *prop_name = "devname";
+	mdadm_status_t ret;
 	const char *name;
 
 	if (ident->devname) {
@@ -242,53 +270,40 @@ mdadm_status_t _ident_set_devname(struct mddev_ident *ident, const char *devname
 	else
 		name = devname;
 
-	if (is_name_posix_compatible(name) == false) {
-		ident_log(prop_name, name, "Not POSIX compatible", cmdline);
-		return MDADM_STATUS_ERROR;
-	}
-
-	if (is_string_lq(name, MD_NAME_MAX + 1) == false) {
-		ident_log(prop_name, devname, "Invalid length", cmdline);
-		return MDADM_STATUS_ERROR;
-	}
+	ret = ident_check_name(name, prop_name, cmdline);
+	if (ret)
+		return ret;
 pass:
 	ident->devname = xstrdup(devname);
 	return MDADM_STATUS_SUCCESS;
 }
 
 /**
- * _ident_set_name()- set name in &mddev_ident.
+ * _ident_set_name() - set name in &mddev_ident.
  * @ident: pointer to &mddev_ident.
  * @name: name to be set.
- * @cmdline: context dependent actions.
  *
  * If criteria passed, set name in @ident.
  * Note: name is not used by config file, it for cmdline only.
  *
  * Return: %MDADM_STATUS_SUCCESS or %MDADM_STATUS_ERROR.
  */
-static mdadm_status_t _ident_set_name(struct mddev_ident *ident, const char *name,
-				      const bool cmdline)
+mdadm_status_t ident_set_name(struct mddev_ident *ident, const char *name)
 {
 	assert(name);
 	assert(ident);
 
 	const char *prop_name = "name";
+	mdadm_status_t ret;
 
 	if (ident->name[0]) {
-		ident_log(prop_name, name, "Already defined", cmdline);
+		ident_log(prop_name, name, "Already defined", true);
 		return MDADM_STATUS_ERROR;
 	}
 
-	if (is_string_lq(name, MD_NAME_MAX + 1) == false) {
-		ident_log(prop_name, name, "Too long or empty", cmdline);
-		return MDADM_STATUS_ERROR;
-	}
-
-	if (is_name_posix_compatible(name) == false) {
-		ident_log(prop_name, name, "Not POSIX compatible", cmdline);
-		return MDADM_STATUS_ERROR;
-	}
+	ret = ident_check_name(name, prop_name, true);
+	if (ret)
+		return ret;
 
 	snprintf(ident->name, MD_NAME_MAX + 1, "%s", name);
 	return MDADM_STATUS_SUCCESS;
@@ -302,14 +317,6 @@ mdadm_status_t ident_set_devname(struct mddev_ident *ident, const char *name)
 	return _ident_set_devname(ident, name, true);
 }
 
-/**
- * ident_set_name()- exported, for cmdline.
- */
-mdadm_status_t ident_set_name(struct mddev_ident *ident, const char *name)
-{
-	return _ident_set_name(ident, name, true);
-}
-
 struct conf_dev {
 	struct conf_dev *next;
 	char *name;
-- 
2.41.0