[PATCH] allow to specify node permissions in the rule

This allows to set the permissions along with the rule.

This is not a general replacement for the permissions config, but it
may be easier sometimes for the user to specify the permissions along
with the rule, cause the permissions config file wants the final node
name to match, which seems sometimes a bit difficult to guess, if
format % chars are used in the NAME field.

Any value not given in the rule is still be read from the permissions
file or set to the default. This one will also work:

  BUS="usb", KERNEL="video*", NAME="my-%k", OWNER="$local"

A few words to man page are also added and add_perm_dev() is moved into
namedev_parse.c where it belongs to.

namedev.c

@@ -46,6 +46,7 @@ static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *c
 LIST_HEAD(config_device_list);
 LIST_HEAD(perm_device_list);
 
+
 /* compare string with pattern (supports * ? [0-9] [!A-Z]) */
 static int strcmp_pattern(const char *p, const char *s)
 {
@@ -99,39 +100,6 @@ static int strcmp_pattern(const char *p, const char *s)
 	return 1;
 }
 
-#define copy_var(a, b, var)		\
-	if (b->var)			\
-		a->var = b->var;
-
-#define copy_string(a, b, var)		\
-	if (strlen(b->var))		\
-		strcpy(a->var, b->var);
-
-int add_perm_dev(struct perm_device *new_dev)
-{
-	struct perm_device *dev;
-	struct perm_device *tmp_dev;
-
-	/* update the values if we already have the device */
-	list_for_each_entry(dev, &perm_device_list, node) {
-		if (strcmp(new_dev->name, dev->name))
-			continue;
-		copy_var(dev, new_dev, mode);
-		copy_string(dev, new_dev, owner);
-		copy_string(dev, new_dev, group);
-		return 0;
-	}
-
-	/* not found, add new structure to the perm list */
-	tmp_dev = malloc(sizeof(*tmp_dev));
-	if (!tmp_dev)
-		return -ENOMEM;
-	memcpy(tmp_dev, new_dev, sizeof(*tmp_dev));
-	list_add_tail(&tmp_dev->node, &perm_device_list);
-	//dump_perm_dev(tmp_dev);
-	return 0;
-}
-
 static struct perm_device *find_perm(char *name)
 {
 	struct perm_device *perm;
@@ -865,22 +833,28 @@ int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *ud
 	goto done;
 
 found:
-	/* substitute placeholder */
 	apply_format(udev, udev->name, sizeof(udev->name),
 		     class_dev, sysfs_device);
 	udev->partitions = dev->partitions;
+
 done:
+	/* get permissions given in rule */
+	set_empty_perms(udev, dev->mode,
+			      dev->owner,
+			      dev->group);
+
+	/* get permissions given in config file or set defaults */
 	perm = find_perm(udev->name);
-	if (perm) {
-		udev->mode = perm->mode;
-		strfieldcpy(udev->owner, perm->owner);
-		strfieldcpy(udev->group, perm->group);
+	if (perm != NULL) {
+		set_empty_perms(udev, perm->mode,
+				      perm->owner,
+				      perm->group);
 	} else {
-		/* no matching perms found :( */
-		udev->mode = get_default_mode();
-		strfieldcpy(udev->owner, get_default_owner());
-		strfieldcpy(udev->group, get_default_group());
+		set_empty_perms(udev, get_default_mode(),
+				      get_default_owner(),
+				      get_default_group());
 	}
+
 	dbg("name, '%s' is going to have owner='%s', group='%s', mode = %#o",
 	    udev->name, udev->owner, udev->group, udev->mode);
 

namedev.h

@@ -44,6 +44,9 @@ struct sysfs_class_device;
 #define FIELD_KERNEL		"KERNEL"
 #define FIELD_NAME		"NAME"
 #define FIELD_SYMLINK		"SYMLINK"
+#define FIELD_OWNER		"OWNER"
+#define FIELD_GROUP		"GROUP"
+#define FIELD_MODE		"MODE"
 
 #define ATTR_PARTITIONS		"all_partitions"
 #define PARTITIONS_COUNT	15
@@ -54,6 +57,14 @@ struct sysfs_class_device;
 #define RULEFILE_EXT		".rules"
 #define PERMFILE_EXT		".permissions"
 
+#define set_empty_perms(dev, m, o, g)		\
+	if (dev->mode == 0)			\
+		dev->mode = m;			\
+	if (dev->owner[0] == '\0')		\
+		strfieldcpy(dev->owner, o);	\
+	if (dev->group[0] == '\0')		\
+		strfieldcpy(dev->group, g);
+
 struct sysfs_pair {
 	char file[FILE_SIZE];
 	char value[VALUE_SIZE];
@@ -71,6 +82,9 @@ struct config_device {
 	char name[NAME_SIZE];
 	char symlink[NAME_SIZE];
 	struct sysfs_pair sysfs_pair[MAX_SYSFS_PAIRS];
+	char owner[OWNER_SIZE];
+	char group[GROUP_SIZE];
+	unsigned int mode;
 	int partitions;
 	char config_file[NAME_SIZE];
 	int config_line;
@@ -93,7 +107,6 @@ extern int namedev_name_device(struct sysfs_class_device *class_dev, struct udev
 extern int namedev_init_permissions(void);
 extern int namedev_init_rules(void);
 
-extern int add_perm_dev(struct perm_device *new_dev);
 extern void dump_config_dev(struct config_device *dev);
 extern void dump_config_dev_list(void);
 extern void dump_perm_dev(struct perm_device *dev);

namedev_parse.c

@@ -43,6 +43,7 @@
 
 LIST_HEAD(file_list);
 
+
 static int add_config_dev(struct config_device *new_dev)
 {
 	struct config_device *tmp_dev;
@@ -61,9 +62,11 @@ void dump_config_dev(struct config_device *dev)
 	dbg_parse("name='%s', symlink='%s', bus='%s', place='%s', id='%s', "
 		  "sysfs_file[0]='%s', sysfs_value[0]='%s', "
 		  "kernel='%s', program='%s', result='%s'",
+		  "owner='%s', group='%s', mode=%#o",
 		  dev->name, dev->symlink, dev->bus, dev->place, dev->id,
 		  dev->sysfs_pair[0].file, dev->sysfs_pair[0].value,
-		  dev->kernel, dev->program, dev->result);
+		  dev->kernel, dev->program, dev->result,;
+		  dev->owner, dev->group, dev->mode);
 }
 
 void dump_config_dev_list(void)
@@ -74,6 +77,31 @@ void dump_config_dev_list(void)
 		dump_config_dev(dev);
 }
 
+static int add_perm_dev(struct perm_device *new_dev)
+{
+	struct perm_device *dev;
+	struct perm_device *tmp_dev;
+
+	/* update the values if we already have the device */
+	list_for_each_entry(dev, &perm_device_list, node) {
+		if (strcmp(new_dev->name, dev->name) != 0)
+			continue;
+
+		set_empty_perms(dev, new_dev->mode, new_dev->owner, new_dev->group);
+		return 0;
+	}
+
+	/* not found, add new structure to the perm list */
+	tmp_dev = malloc(sizeof(*tmp_dev));
+	if (!tmp_dev)
+		return -ENOMEM;
+
+	memcpy(tmp_dev, new_dev, sizeof(*tmp_dev));
+	list_add_tail(&tmp_dev->node, &perm_device_list);
+	//dump_perm_dev(tmp_dev);
+	return 0;
+}
+
 void dump_perm_dev(struct perm_device *dev)
 {
 	dbg_parse("name='%s', owner='%s', group='%s', mode=%#o",
@@ -240,12 +268,26 @@ static int namedev_parse_rules(char *filename)
 				continue;
 			}
 
+			if (strcasecmp(temp2, FIELD_OWNER) == 0) {
+				strfieldcpy(dev.owner, temp3);
+				continue;
+			}
+
+			if (strcasecmp(temp2, FIELD_GROUP) == 0) {
+				strfieldcpy(dev.group, temp3);
+				continue;
+			}
+
+			if (strcasecmp(temp2, FIELD_MODE) == 0) {
+				dev.mode = strtol(temp3, NULL, 8);
+				continue;
+			}
+
 			dbg("unknown type of field '%s'", temp2);
-			dbg("You might be using a rules file in the old format, please fix.");
 			goto error;
 		}
 
-		/* simple plausibility check for given keys */
+		/* simple plausibility checks for given keys */
 		if ((dev.sysfs_pair[0].file[0] == '\0') ^
 		    (dev.sysfs_pair[0].value[0] == '\0')) {
 			dbg("inconsistency in " FIELD_SYSFS " key");
@@ -336,14 +378,14 @@ static int namedev_parse_permissions(char *filename)
 		strfieldcpy(dev.group, temp2);
 
 		if (!temp) {
-			dbg("cannot parse line: %s", line);
+			dbg("cannot parse line '%s'", line);
 			continue;
 		}
 		dev.mode = strtol(temp, NULL, 8);
 
 		dbg_parse("name='%s', owner='%s', group='%s', mode=%#o",
-			  dev.name, dev.owner, dev.group,
-			  dev.mode);
+			  dev.name, dev.owner, dev.group, dev.mode);
+
 		retval = add_perm_dev(&dev);
 		if (retval) {
 			dbg("add_perm_dev returned with error %d", retval);

udev.8

@@ -220,6 +220,10 @@ to the symlink list of the rule which will create the node.
 This makes it possible to specify additional symlinks in a possibly
 separate rules file, while the device nodes are maintained by the
 distribution provided rules file.
+.TP
+.B OWNER, GROUP, MODE
+The permissions for this device. Every specified value overwrites the value
+given in the permissions file.
 .P
 .RB "The " NAME " ," SYMLINK " and " PROGRAM
 fields support simple printf-like string substitution: