[PATCH] add RUN key to be able to run rule based notification

SUBSYSTEM=="block", RUN="/sbin/program"
  will execute the program only for block device events.

ACTION="remove", SUBSYSTEM=="block", RUN"/sbin/program"
  will execute the program, if a block device is removed.

Makefile

@@ -51,7 +51,6 @@ VERSION =	056
 INSTALL_DIR =	/usr/local/bin
 RELEASE_NAME =	$(ROOT)-$(VERSION)
 LOCAL_CFG_DIR =	etc/udev
-HOTPLUG_EXEC =	$(ROOT)
 DESTDIR =
 KERNEL_DIR = /lib/modules/${shell uname -r}/build
 

test/udev-test.pl

@@ -1243,6 +1243,53 @@ KERNEL=="sda", SYSFS{nothing}!="", NAME="not-1-ok"
 KERNEL=="sda", SYSFS{nothing}=="", NAME="not-2-ok"
 KERNEL=="sda", SYSFS{vendor}!="", NAME="ok"
 KERNEL=="sda", SYSFS{vendor}=="", NAME="not-3-ok"
+EOF
+	},
+	{
+		desc		=> "check ACTION value",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "ok",
+		rules		=> <<EOF
+ACTION=="unknown", KERNEL=="sda", NAME="unknown-not-ok"
+ACTION=="add", KERNEL=="sda", NAME="ok"
+EOF
+	},
+	{
+		desc		=> "apply NAME only once",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "link",
+		exp_target	=> "ok",
+		rules		=> <<EOF
+KERNEL=="sda", NAME="ok"
+KERNEL=="sda", NAME="not-ok"
+KERNEL=="sda", SYMLINK+="link"
+EOF
+	},
+	{
+		desc		=> "test RUN key",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "testsymlink",
+		exp_target	=> "ok",
+		exp_rem_error	=> "yes",
+		option		=> "clean",
+		rules		=> <<EOF
+KERNEL=="sda", NAME="ok", RUN+="/bin/ln -s ok %r/testsymlink"
+KERNEL=="sda", NAME="not-ok"
+EOF
+	},
+	{
+		desc		=> "test RUN key remove",
+		subsys		=> "block",
+		devpath		=> "/block/sda",
+		exp_name	=> "testsymlink2",
+		exp_target	=> "ok2",
+		rules		=> <<EOF
+KERNEL=="sda", NAME="ok2", RUN+="/bin/ln -s ok2 %r/testsymlink2"
+KERNEL=="sda", ACTION=="remove", RUN+="/bin/rm -f %r/testsymlink2"
+KERNEL=="sda", NAME="not-ok2"
 EOF
 	},
 );

udev.8.in

@@ -111,6 +111,9 @@ Match the kernel device name.
 .B SUBSYSTEM
 Match the kernel subsystem name.
 .TP
+.B ACTION
+Match the kernel action name.
+.TP
 .B DRIVER
 Match the kernel driver name.
 .TP
@@ -170,6 +173,9 @@ distribution provided rules file.
 The permissions for the device node. Every specified value overwrites the
 compiled-in default value.
 .TP
+.B RUN
+Add a program to the list of programs to be executed for a specific device.
+.TP
 .B OPTIONS
 .B last_rule
 will be the last rule applied. No later rules will have any effect.
@@ -234,6 +240,9 @@ The node name of the parent device.
 .BI %s{ filename }
 The content of a sysfs attribute.
 .TP
+.B %r
+The udev_root value.
+.TP
 .B %e
 If a device node already exists with the name, the smallest positive
 decimal integer N is substituted such that the resulting name doesn't
@@ -344,6 +353,9 @@ config file.
 .B UDEV_LOG
 Overrides the log priority specified in the config file.
 .TP
+.B UDEV_RUN
+If set to "0", it disables the execution of programs added by rules.
+.TP
 .B UDEV_NO_DEVD
 The default behavior of
 .B udev
@@ -356,7 +368,6 @@ will skip this step.
 .nf
 /sbin/udev                           udev program
 /etc/udev/*                          udev config files
-/etc/hotplug.d/default/udev.hotplug  hotplug symlink to udev program
 /etc/dev.d/*                         programs invoked by udev
 .fi
 .SH "SEE ALSO"

udev.c

@@ -157,6 +157,8 @@ int main(int argc, char *argv[], char *envp[])
 	}
 
 	if (udev.type == DEV_BLOCK || udev.type == DEV_CLASS || udev.type == DEV_NET) {
+		udev_rules_init();
+
 		if (strcmp(action, "add") == 0) {
 			/* wait for sysfs and possibly add node */
 			dbg("udev add");
@@ -178,9 +180,6 @@ int main(int argc, char *argv[], char *envp[])
 
 			wait_for_class_device(class_dev, &error);
 
-			/* init rules */
-			udev_rules_init();
-
 			/* name, create node, store in db */
 			retval = udev_add_device(&udev, class_dev);
 
@@ -195,10 +194,24 @@ int main(int argc, char *argv[], char *envp[])
 				goto hotplug;
 			}
 
+			udev_rules_get_run(&udev);
+			if (udev.ignore_device) {
+				dbg("device event will be ignored");
+				goto hotplug;
+			}
+
 			/* get node from db, remove db-entry, delete created node */
 			retval = udev_remove_device(&udev);
 		}
 
+		if (udev_run && !list_empty(&udev.run_list)) {
+			struct name_entry *name_loop;
+
+			dbg("executing run list");
+			list_for_each_entry(name_loop, &udev.run_list, node)
+				execute_command(name_loop->name, udev.subsystem);
+		}
+
 		/* run dev.d/ scripts if we created/deleted a node or changed a netif name */
 		if (udev.devname[0] != '\0') {
 			setenv("DEVNAME", udev.devname, 1);

udev.h

@@ -58,6 +58,7 @@ enum device_type {
 struct udevice {
 	char devpath[PATH_SIZE];
 	char subsystem[NAME_SIZE];
+	char action[NAME_SIZE];
 
 	enum device_type type;
 	char name[PATH_SIZE];
@@ -67,9 +68,11 @@ struct udevice {
 	char group[USER_SIZE];
 	mode_t mode;
 	dev_t devt;
+	struct list_head run_list;
 
 	char tmp_node[PATH_SIZE];
 	int partitions;
+	int ignore_device;
 	int ignore_remove;
 	int config_line;
 	char config_file[PATH_SIZE];
@@ -93,6 +96,7 @@ extern char udev_db_path[PATH_SIZE];
 extern char udev_config_filename[PATH_SIZE];
 extern char udev_rules_filename[PATH_SIZE];
 extern int udev_log_priority;
+extern int udev_run;
 extern int udev_dev_d;
 extern int udev_hotplug_d;
 

udev_add.c

@@ -276,8 +276,11 @@ int udev_add_device(struct udevice *udev, struct sysfs_class_device *class_dev)
 		}
 	}
 
-	if (udev_rules_get_name(udev, class_dev) != 0)
+	udev_rules_get_name(udev, class_dev);
+	if (udev->ignore_device) {
+		dbg("device event will be ignored");
 		return 0;
+	}
 
 	dbg("adding name='%s'", udev->name);
 

udev_config.c

@@ -44,6 +44,7 @@ char udev_db_path[PATH_SIZE];
 char udev_config_filename[PATH_SIZE];
 char udev_rules_filename[PATH_SIZE];
 int udev_log_priority;
+int udev_run;
 int udev_dev_d;
 int udev_hotplug_d;
 
@@ -217,10 +218,16 @@ void udev_init_config(void)
 	strcpy(udev_config_filename, UDEV_CONFIG_FILE);
 	strcpy(udev_rules_filename, UDEV_RULES_FILE);
 	udev_log_priority = LOG_ERR;
+	udev_run = 1;
 	udev_dev_d = 1;
 	udev_hotplug_d = 1;
 	sysfs_get_mnt_path(sysfs_path, sizeof(sysfs_path));
 
+	/* disable RUN key execution */
+	env = getenv("UDEV_RUN");
+	if (env && !string_is_true(env))
+		udev_run = 0;
+
 	env = getenv("UDEV_NO_DEVD");
 	if (env && string_is_true(env))
 		udev_dev_d = 0;

udev_rules.c

@@ -474,6 +474,21 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule,
 {
 	struct sysfs_device *parent_device = sysfs_device;
 
+	if (rule->action_operation != KEY_OP_UNSET) {
+		dbg("check for " KEY_ACTION " rule->action='%s' udev->action='%s'",
+		    rule->action, udev->action);
+		if (strcmp_pattern(rule->action, udev->action) != 0) {
+			dbg(KEY_ACTION " is not matching");
+			if (rule->action_operation != KEY_OP_NOMATCH)
+				goto exit;
+		} else {
+			dbg(KEY_ACTION " matches");
+			if (rule->action_operation == KEY_OP_NOMATCH)
+				goto exit;
+		}
+		dbg(KEY_ACTION " key is true");
+	}
+
 	if (rule->kernel_operation != KEY_OP_UNSET) {
 		dbg("check for " KEY_KERNEL " rule->kernel='%s' udev_kernel_name='%s'",
 		    rule->kernel, udev->kernel_name);
@@ -716,12 +731,17 @@ int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_d
 	list_for_each_entry(rule, &udev_rule_list, node) {
 		dbg("process rule");
 		if (match_rule(udev, rule, class_dev, sysfs_device) == 0) {
+			if (udev->name[0] != '\0' && rule->name[0] != '\0') {
+				dbg("node name already set, rule ignored");
+				continue;
+			}
 
 			/* apply options */
 			if (rule->ignore_device) {
 				info("configured rule in '%s[%i]' applied, '%s' is ignored",
 				     rule->config_file, rule->config_line, udev->kernel_name);
-				return -1;
+				udev->ignore_device = 1;
+				return 0;
 			}
 			if (rule->ignore_remove) {
 				udev->ignore_remove = 1;
@@ -773,7 +793,7 @@ int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_d
 				name_list_add(&udev->symlink_list, pos, 0);
 			}
 
-			/* rule matches */
+			/* set name, later rules with name set will be ignored */
 			if (rule->name[0] != '\0') {
 				info("configured rule in '%s[%i]' applied, '%s' becomes '%s'",
 				     rule->config_file, rule->config_line, udev->kernel_name, rule->name);
@@ -786,20 +806,25 @@ int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_d
 				if (udev->type != DEV_NET)
 					dbg("name, '%s' is going to have owner='%s', group='%s', mode=%#o partitions=%i",
 					    udev->name, udev->owner, udev->group, udev->mode, udev->partitions);
+			}
 
-				break;
+			if (rule->run[0] != '\0') {
+				char program[PATH_SIZE];
+
+				strlcpy(program, rule->run, sizeof(program));
+				apply_format(udev, program, sizeof(program), class_dev, sysfs_device);
+				dbg("add run '%s'", program);
+				name_list_add(&udev->run_list, program, 0);
 			}
 
 			if (rule->last_rule) {
 				dbg("last rule to be applied");
 				break;
 			}
-
 		}
 	}
 
 	if (udev->name[0] == '\0') {
-		/* no rule matched, so we use the kernel name */
 		strlcpy(udev->name, udev->kernel_name, sizeof(udev->name));
 		info("no rule found, use kernel name '%s'", udev->name);
 	}
@@ -812,3 +837,116 @@ int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_d
 
 	return 0;
 }
+
+int udev_rules_get_run(struct udevice *udev)
+{
+	struct udev_rule *rule;
+	char program[PATH_SIZE];
+
+	/* look for a matching rule to apply */
+	list_for_each_entry(rule, &udev_rule_list, node) {
+		dbg("process rule");
+
+		if (rule->run[0] == '\0')
+			continue;
+
+		if (rule->name[0] != '\0' || rule->symlink[0] != '\0' ||
+		    rule->mode != 0000 || rule->owner[0] != '\0' || rule->group[0] != '\0') {
+			dbg("skip rule that names a device");
+			continue;
+		}
+
+		if (rule->action_operation != KEY_OP_UNSET) {
+			dbg("check for " KEY_ACTION " rule->action='%s' udev->action='%s'",
+			    rule->action, udev->action);
+			if (strcmp_pattern(rule->action, udev->action) != 0) {
+				dbg(KEY_ACTION " is not matching");
+				if (rule->action_operation != KEY_OP_NOMATCH)
+					continue;
+			} else {
+				dbg(KEY_ACTION " matches");
+				if (rule->action_operation == KEY_OP_NOMATCH)
+					continue;
+			}
+			dbg(KEY_ACTION " key is true");
+		}
+
+		if (rule->kernel_operation != KEY_OP_UNSET) {
+			dbg("check for " KEY_KERNEL " rule->kernel='%s' udev->kernel_name='%s'",
+			    rule->kernel, udev->kernel_name);
+			if (strcmp_pattern(rule->kernel, udev->kernel_name) != 0) {
+				dbg(KEY_KERNEL " is not matching");
+				if (rule->kernel_operation != KEY_OP_NOMATCH)
+					continue;
+		} else {
+				dbg(KEY_KERNEL " matches");
+				if (rule->kernel_operation == KEY_OP_NOMATCH)
+					continue;
+			}
+			dbg(KEY_KERNEL " key is true");
+		}
+
+		if (rule->subsystem_operation != KEY_OP_UNSET) {
+			dbg("check for " KEY_SUBSYSTEM " rule->subsystem='%s' udev->subsystem='%s'",
+			    rule->subsystem, udev->subsystem);
+			if (strcmp_pattern(rule->subsystem, udev->subsystem) != 0) {
+				dbg(KEY_SUBSYSTEM " is not matching");
+				if (rule->subsystem_operation != KEY_OP_NOMATCH)
+					continue;
+			} else {
+				dbg(KEY_SUBSYSTEM " matches");
+				if (rule->subsystem_operation == KEY_OP_NOMATCH)
+					continue;
+			}
+			dbg(KEY_SUBSYSTEM " key is true");
+		}
+
+		if (rule->env_pair_count) {
+			int i;
+
+			dbg("check for " KEY_ENV " pairs");
+			for (i = 0; i < rule->env_pair_count; i++) {
+				struct key_pair *pair;
+				const char *value;
+
+				pair = &rule->env_pair[i];
+				value = getenv(pair->name);
+				if (!value) {
+					dbg(KEY_ENV "{'%s'} is not found", pair->name);
+					continue;
+				}
+				if (strcmp_pattern(pair->value, value) != 0) {
+					dbg(KEY_ENV "{'%s'} is not matching", pair->name);
+					if (pair->operation != KEY_OP_NOMATCH)
+						continue;
+				} else {
+					dbg(KEY_ENV "{'%s'} matches", pair->name);
+					if (pair->operation == KEY_OP_NOMATCH)
+						continue;
+				}
+			}
+			dbg(KEY_ENV " key is true");
+		}
+
+		/* rule matches */
+
+		if (rule->ignore_device) {
+			info("configured rule in '%s[%i]' applied, '%s' is ignored",
+			     rule->config_file, rule->config_line, udev->kernel_name);
+			udev->ignore_device = 1;
+			return 0;
+		}
+
+		strlcpy(program, rule->run, sizeof(program));
+		apply_format(udev, program, sizeof(program), NULL, NULL);
+		dbg("add run '%s'", program);
+		name_list_add(&udev->run_list, program, 0);
+
+		if (rule->last_rule) {
+			dbg("last rule to be applied");
+			break;
+		}
+	}
+
+	return 0;
+}

udev_rules.h

@@ -30,6 +30,7 @@
 
 #define KEY_KERNEL		"KERNEL"
 #define KEY_SUBSYSTEM		"SUBSYSTEM"
+#define KEY_ACTION		"ACTION"
 #define KEY_BUS			"BUS"
 #define KEY_ID			"ID"
 #define KEY_PROGRAM		"PROGRAM"
@@ -42,6 +43,7 @@
 #define KEY_OWNER		"OWNER"
 #define KEY_GROUP		"GROUP"
 #define KEY_MODE		"MODE"
+#define KEY_RUN			"RUN"
 #define KEY_OPTIONS		"OPTIONS"
 
 #define OPTION_LAST_RULE	"last_rule"
@@ -75,6 +77,8 @@ struct udev_rule {
 	enum key_operation kernel_operation;
 	char subsystem[NAME_SIZE];
 	enum key_operation subsystem_operation;
+	char action[NAME_SIZE];
+	enum key_operation action_operation;
 	char bus[NAME_SIZE];
 	enum key_operation bus_operation;
 	char id[NAME_SIZE];
@@ -95,6 +99,7 @@ struct udev_rule {
 	char owner[USER_SIZE];
 	char group[USER_SIZE];
 	mode_t mode;
+	char run[PATH_SIZE];
 
 	int last_rule;
 	int ignore_device;
@@ -109,6 +114,7 @@ extern struct list_head udev_rule_list;
 
 extern int udev_rules_init(void);
 extern int udev_rules_get_name(struct udevice *udev, struct sysfs_class_device *class_dev);
+extern int udev_rules_get_run(struct udevice *udev);
 extern void udev_rules_close(void);
 
 #endif

udev_rules_parse.c

@@ -256,6 +256,13 @@ static int rules_parse(const char *filename)
 				continue;
 			}
 
+			if (strcasecmp(key, KEY_ACTION) == 0) {
+				strlcpy(rule.action, value, sizeof(rule.action));
+				rule.action_operation = operation;
+				valid = 1;
+				continue;
+			}
+
 			if (strcasecmp(key, KEY_BUS) == 0) {
 				strlcpy(rule.bus, value, sizeof(rule.bus));
 				rule.bus_operation = operation;
@@ -379,6 +386,12 @@ static int rules_parse(const char *filename)
 				continue;
 			}
 
+			if (strcasecmp(key, KEY_RUN) == 0) {
+				strlcpy(rule.run, value, sizeof(rule.run));
+				valid = 1;
+				continue;
+			}
+
 			if (strcasecmp(key, KEY_OPTIONS) == 0) {
 				if (strstr(value, OPTION_LAST_RULE) != NULL) {
 					dbg("last rule to be applied");

udev_utils.c

@@ -45,10 +45,14 @@ int udev_init_device(struct udevice *udev, const char* devpath, const char *subs
 
 	memset(udev, 0x00, sizeof(struct udevice));
 	INIT_LIST_HEAD(&udev->symlink_list);
+	INIT_LIST_HEAD(&udev->run_list);
 
 	if (subsystem)
 		strlcpy(udev->subsystem, subsystem, sizeof(udev->subsystem));
 
+	if (action)
+		strlcpy(udev->action, action, sizeof(udev->action));
+
 	if (devpath) {
 		strlcpy(udev->devpath, devpath, sizeof(udev->devpath));
 		remove_trailing_char(udev->devpath, '/');

udevd.c

@@ -145,7 +145,7 @@ static void msg_queue_insert(struct hotplug_msg *msg)
 }
 
 /* forks event and removes event from run queue when finished */
-static void udev_run(struct hotplug_msg *msg)
+static void execute_udev(struct hotplug_msg *msg)
 {
 	char *const argv[] = { "udev", msg->subsystem, NULL };
 	pid_t pid;
@@ -349,7 +349,7 @@ static void exec_queue_manager(void)
 		if (!msg) {
 			/* move event to run list */
 			list_move_tail(&loop_msg->node, &running_list);
-			udev_run(loop_msg);
+			execute_udev(loop_msg);
 			running++;
 			dbg("moved seq %llu to running list", loop_msg->seqnum);
 		} else {

udevstart.c

@@ -126,6 +126,14 @@ static int add_device(const char *path, const char *subsystem)
 	udev_init_device(&udev, devpath, subsystem, "add");
 	udev_add_device(&udev, class_dev);
 
+	if (udev_run && !list_empty(&udev.run_list)) {
+		struct name_entry *name_loop;
+
+		dbg("executing run list");
+		list_for_each_entry(name_loop, &udev.run_list, node)
+			execute_command(name_loop->name, udev.subsystem);
+	}
+
 	/* run dev.d/ scripts if we created a node or changed a netif name */
 	if (udev_dev_d && udev.devname[0] != '\0') {
 		setenv("DEVNAME", udev.devname, 1);