IMPORT: add {parent} to import the persistent data of the parent device

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

test/udev-test.pl

@@ -1471,6 +1471,27 @@ EOF
 KERNEL=="dontknow*|*nothing", NAME="nomatch"
 KERNEL=="dontknow*|ttyUSB*|nothing*", NAME="right"
 KERNEL=="ttyUSB*", NAME="wrong"
+EOF
+	},
+	{
+		desc		=> "IMPORT parent test sequence 1/2 (keep)",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "parent",
+		option		=> "keep",
+		rules		=> <<EOF
+KERNEL=="sda", IMPORT="/bin/echo -e \'PARENT_KEY=parent_right\\nWRONG_PARENT_KEY=parent_wrong'"
+KERNEL=="sda", NAME="parent"
+EOF
+	},
+	{
+		desc		=> "IMPORT parent test sequence 2/2 (keep)",
+		subsys		=> "block",
+		devpath		=> "/block/sda/sda1",
+		exp_name	=> "parentenv-parent_right",
+		option		=> "clean",
+		rules		=> <<EOF
+KERNEL=="sda1", IMPORT{parent}="PARENT*", NAME="parentenv-\$env{PARENT_KEY}\$env{WRONG_PARENT_KEY}"
 EOF
 	},
 );

udev_rules.c

@@ -281,6 +281,46 @@ static int import_program_into_env(struct udevice *udev, const char *program)
 	return import_keys_into_env(udev, result, reslen);
 }
 
+static int import_parent_into_env(struct udevice *udev, struct sysfs_class_device *class_dev, const char *filter)
+{
+	struct sysfs_class_device *parent = sysfs_get_classdev_parent(class_dev);
+	int rc = -1;
+
+	if (parent != NULL) {
+		struct udevice udev_parent;
+		struct name_entry *name_loop;
+
+		dbg("found parent '%s', get the node name", parent->path);
+		udev_init_device(&udev_parent, NULL, NULL, NULL);
+		/* import the udev_db of the parent */
+		if (udev_db_get_device(&udev_parent, &parent->path[strlen(sysfs_path)]) == 0) {
+			dbg("import stored parent env '%s'", udev_parent.name);
+			list_for_each_entry(name_loop, &udev_parent.env_list, node) {
+				char name[NAME_SIZE];
+				char *pos;
+
+				strlcpy(name, name_loop->name, sizeof(name));
+				pos = strchr(name, '=');
+				if (pos) {
+					pos[0] = '\0';
+					pos++;
+					if (strcmp_pattern(filter, name) == 0) {
+						dbg("import key '%s'", name_loop->name);
+						name_list_add(&udev->env_list, name_loop->name, 0);
+						setenv(name, pos, 1);
+					} else
+						dbg("skip key '%s'", name_loop->name);
+				}
+			}
+			rc = 0;
+		} else
+			dbg("parent not found in database");
+		udev_cleanup_device(&udev_parent);
+	}
+
+	return rc;
+}
+
 /* finds the lowest positive N such that <name>N isn't present in the udevdb
  * if <name> doesn't exist, 0 is returned, N otherwise
  */
@@ -604,8 +644,10 @@ found:
 				break;
 			}
 			pos = getenv(attr);
-			if (pos == NULL)
+			if (pos == NULL) {
+				dbg("env '%s' not avialable", attr);
 				break;
+			}
 			dbg("substitute env '%s=%s'", attr, pos);
 			strlcat(string, pos, maxsize);
 			break;
@@ -812,12 +854,15 @@ try_parent:
 		strlcpy(import, key_val(rule, &rule->import), sizeof(import));
 		apply_format(udev, import, sizeof(import), class_dev, sysfs_device);
 		dbg("check for IMPORT import='%s'", import);
-		if (rule->import_exec) {
+		if (rule->import_type == IMPORT_PROGRAM) {
 			dbg("run executable file import='%s'", import);
 			rc = import_program_into_env(udev, import);
-		} else {
+		} else if (rule->import_type == IMPORT_FILE) {
 			dbg("import file import='%s'", import);
 			rc = import_file_into_env(udev, import);
+		} else if (rule->import_type == IMPORT_PARENT && class_dev) {
+			dbg("import parent import='%s'", import);
+			rc = import_parent_into_env(udev, class_dev, import);
 		}
 		if (rc) {
 			dbg("IMPORT failed");

udev_rules.h

@@ -54,6 +54,13 @@ struct key_pairs {
 	struct key_pair keys[PAIRS_MAX];
 };
 
+enum import_type {
+	IMPORT_UNSET,
+	IMPORT_PROGRAM,
+	IMPORT_FILE,
+	IMPORT_PARENT,
+};
+
 struct udev_rule {
 	struct key kernel_name;
 	struct key subsystem;
@@ -66,6 +73,7 @@ struct udev_rule {
 	struct key result;
 	struct key modalias;
 	struct key import;
+	enum import_type import_type;
 	struct key wait_for_sysfs;
 	struct key_pairs sysfs;
 	struct key_pairs env;
@@ -81,8 +89,7 @@ struct udev_rule {
 	unsigned int partitions;
 	unsigned int last_rule:1,
 		     ignore_device:1,
-		     ignore_remove:1,
+		     ignore_remove:1;
-		     import_exec:1;
 
 	size_t bufsize;
 	char buf[];

udev_rules_parse.c

@@ -311,9 +311,13 @@ static int add_to_rules(struct udev_rules *rules, char *line)
 			attr = get_key_attribute(key + sizeof("IMPORT")-1);
 			if (attr && strstr(attr, "program")) {
 				dbg("IMPORT will be executed");
-				rule->import_exec = 1;
+				rule->import_type  = IMPORT_PROGRAM;
 			} else if (attr && strstr(attr, "file")) {
 				dbg("IMPORT will be included as file");
+				rule->import_type  = IMPORT_FILE;
+			} else if (attr && strstr(attr, "parent")) {
+				dbg("IMPORT will include the parent values");
+				rule->import_type = IMPORT_PARENT;
 			} else {
 				/* figure it out if it is executable */
 				char file[PATH_SIZE];
@@ -326,8 +330,11 @@ static int add_to_rules(struct udev_rules *rules, char *line)
 					pos[0] = '\0';
 				dbg("IMPORT auto mode for '%s'", file);
 				if (!lstat(file, &stats) && (stats.st_mode & S_IXUSR)) {
-						dbg("IMPORT is executable, will be executed");
+					dbg("IMPORT is executable, will be executed (autotype)");
-						rule->import_exec = 1;
+					rule->import_type  = IMPORT_PROGRAM;
+				} else {
+					dbg("IMPORT is not executable, will be included as file (autotype)");
+					rule->import_type  = IMPORT_FILE;
 				}
 			}
 			add_rule_key(rule, &rule->import, operation, value);