X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Flib%2Flibudev-device.c;h=731230efd0143858bd9da1072d60696fdbd6fd46;hp=e13146599cbe1354bd1b9c75e7bae90c210ae5d0;hb=fb762bb928772f1923fef1e342d8ebca9bf7691f;hpb=e88a82b5976b8066583936a2521ba3c70dd460dd

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index e13146599..731230efd 100644
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -17,8 +17,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "config.h"
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
@@ -26,17 +24,19 @@
 #include <errno.h>
 #include <string.h>
 #include <dirent.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 
 #include "libudev.h"
 #include "libudev-private.h"
-#include "../udev.h"
 
 struct udev_device {
 	int refcount;
 	struct udev *udev;
-	char *devpath;
+	struct udev_device *parent_device;
 	char *syspath;
+	const char *devpath;
+	const char *sysname;
 	char *devname;
 	char *subsystem;
 	struct list_head link_list;
@@ -51,35 +51,36 @@ struct udev_device {
 	int num_fake_partitions;
 	int devlink_priority;
 	int ignore_remove;
+	struct list_head attr_list;
 };
 
-static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
+static size_t syspath_to_db_path(struct udev_device *udev_device, char *filename, size_t len)
 {
 	size_t start;
 
 	/* translate to location of db file */
-	strlcpy(filename, udev_get_dev_path(udev), len);
-	start = strlcat(filename, "/.udev/db/", len);
-	strlcat(filename, devpath, len);
-	return path_encode(&filename[start], len - start);
+	util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len);
+	start = util_strlcat(filename, "/.udev/db/", len);
+	util_strlcat(filename, udev_device->devpath, len);
+	return util_path_encode(&filename[start], len - start);
 }
 
 static int device_read_db(struct udev_device *udev_device)
 {
 	struct stat stats;
-	char filename[PATH_SIZE];
-	char line[PATH_SIZE];
+	char filename[UTIL_PATH_SIZE];
+	char line[UTIL_LINE_SIZE];
 	FILE *f;
 	int rc = 0;
 
-	devpath_to_db_path(udev_device->udev, udev_device->devpath, filename, sizeof(filename));
+	syspath_to_db_path(udev_device, filename, sizeof(filename));
 
 	if (lstat(filename, &stats) != 0) {
 		info(udev_device->udev, "no db file to read %s: %s\n", filename, strerror(errno));
 		return -1;
 	}
 	if ((stats.st_mode & S_IFMT) == S_IFLNK) {
-		char target[NAME_SIZE];
+		char target[UTIL_PATH_SIZE];
 		int target_len;
 
 		info(udev_device->udev, "found a symlink as db file\n");
@@ -121,9 +122,9 @@ static int device_read_db(struct udev_device *udev_device)
 			device_set_devnum(udev_device, makedev(maj, min));
 			break;
 		case 'S':
-			strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
-			strlcat(filename, "/", sizeof(filename));
-			strlcat(filename, val, sizeof(filename));
+			util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename));
+			util_strlcat(filename, "/", sizeof(filename));
+			util_strlcat(filename, val, sizeof(filename));
 			device_add_devlink(udev_device, filename);
 			break;
 		case 'L':
@@ -139,7 +140,7 @@ static int device_read_db(struct udev_device *udev_device)
 			device_set_ignore_remove(udev_device, atoi(val));
 			break;
 		case 'E':
-			device_add_property(udev_device, val);
+			device_add_property_from_string(udev_device, val);
 			break;
 		}
 	}
@@ -163,58 +164,101 @@ struct udev_device *device_init(struct udev *udev)
 	udev_device->udev = udev;
 	INIT_LIST_HEAD(&udev_device->link_list);
 	INIT_LIST_HEAD(&udev_device->env_list);
+	INIT_LIST_HEAD(&udev_device->attr_list);
 	info(udev_device->udev, "udev_device: %p created\n", udev_device);
 	return udev_device;
 }
 
 /**
- * udev_device_new_from_devpath:
+ * udev_device_new_from_syspath:
  * @udev: udev library context
- * @devpath: sys device path
+ * @syspath: sys device path including sys directory
  *
- * Create new udev device, and fill in information from the sysfs
- * device and the udev database entry. The devpath must not contain
- * the sysfs mount path, and must contain a leading '/'.
+ * Create new udev device, and fill in information from the sys
+ * device and the udev database entry. The sypath is the absolute
+ * path to the device, including the sys mount point.
  *
  * The initial refcount is 1, and needs to be decremented to
  * release the ressources of the udev device.
  *
  * Returns: a new udev device, or #NULL, if it does not exist
  **/
-struct udev_device *udev_device_new_from_devpath(struct udev *udev, const char *devpath)
+struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 {
-	char path[PATH_SIZE];
+	char path[UTIL_PATH_SIZE];
 	struct stat statbuf;
 	struct udev_device *udev_device;
 
 	if (udev == NULL)
 		return NULL;
-	if (devpath == NULL)
+	if (syspath == NULL)
 		return NULL;
 
-	strlcpy(path, udev_get_sys_path(udev), sizeof(path));
-	strlcat(path, devpath, sizeof(path));
-	if (stat(path, &statbuf) != 0)
-		return NULL;
-	if (!S_ISDIR(statbuf.st_mode))
+	util_strlcpy(path, syspath, sizeof(path));
+	util_strlcat(path, "/uevent", sizeof(path));
+	if (stat(path, &statbuf) != 0) {
+		info(udev, "not a device :%s\n", syspath);
 		return NULL;
+	}
 
 	udev_device = device_init(udev);
 	if (udev_device == NULL)
 		return NULL;
 
 	/* resolve possible symlink to real path */
-	strlcpy(path, devpath, sizeof(path));
-	sysfs_resolve_link(udev, path, sizeof(path));
-	device_set_devpath(udev_device, path);
+	util_strlcpy(path, syspath, sizeof(path));
+	util_resolve_sys_link(udev, path, sizeof(path));
+	device_set_syspath(udev_device, path);
 	info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 
 	if (device_read_db(udev_device) >= 0)
 		info(udev, "device %p filled with udev database data\n", udev_device);
-
 	return udev_device;
 }
 
+static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
+{
+	struct udev_device *udev_device_parent = NULL;
+	char path[UTIL_PATH_SIZE];
+	char *pos;
+
+	if (udev_device == NULL)
+		return NULL;
+
+	util_strlcpy(path, udev_device->syspath, sizeof(path));
+	while (1) {
+		pos = strrchr(path, '/');
+		if (pos == path || pos == NULL)
+			break;
+		pos[0] = '\0';
+		udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
+		if (udev_device_parent != NULL)
+			return udev_device_parent;
+	}
+
+	/* follow "device" link in deprecated sys /sys/class/ layout */
+	if (strncmp(udev_device->devpath, "/class/", 7) == 0) {
+		util_strlcpy(path, udev_device->syspath, sizeof(path));
+		util_strlcat(path, "/device", sizeof(path));
+		if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0) {
+			udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
+			if (udev_device_parent != NULL)
+				return udev_device_parent;
+		}
+	}
+	return NULL;
+}
+
+struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
+{
+	if (udev_device->parent_device != NULL) {
+		info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
+		return udev_device->parent_device;
+	}
+	udev_device->parent_device = device_new_from_parent(udev_device);
+	return udev_device->parent_device;
+}
+
 /**
  * udev_device_get_udev:
  * @udev_device: udev device
@@ -261,15 +305,18 @@ void udev_device_unref(struct udev_device *udev_device)
 	udev_device->refcount--;
 	if (udev_device->refcount > 0)
 		return;
+	if (udev_device->parent_device != NULL)
+		udev_device_unref(udev_device->parent_device);
 	free(udev_device->syspath);
 	free(udev_device->devname);
 	free(udev_device->subsystem);
-	name_list_cleanup(udev_device->udev, &udev_device->link_list);
-	name_list_cleanup(udev_device->udev, &udev_device->env_list);
+	util_name_list_cleanup(udev_device->udev, &udev_device->link_list);
+	util_name_list_cleanup(udev_device->udev, &udev_device->env_list);
 	free(udev_device->action);
 	free(udev_device->driver);
 	free(udev_device->devpath_old);
 	free(udev_device->physdevpath);
+	util_name_list_cleanup(udev_device->udev, &udev_device->attr_list);
 	info(udev_device->udev, "udev_device: %p released\n", udev_device);
 	free(udev_device);
 }
@@ -306,8 +353,15 @@ const char *udev_device_get_syspath(struct udev_device *udev_device)
 	return udev_device->syspath;
 }
 
+const char *udev_device_get_sysname(struct udev_device *udev_device)
+{
+	if (udev_device == NULL)
+		return NULL;
+	return udev_device->sysname;
+}
+
 /**
- * udev_device_get_devname:
+ * udev_device_get_devnode:
  * @udev_device: udev device
  *
  * Retrieve the device node file name belonging to the udev device.
@@ -315,7 +369,7 @@ const char *udev_device_get_syspath(struct udev_device *udev_device)
  *
  * Returns: the device node file name of the udev device, or #NULL if no device node exists
  **/
-const char *udev_device_get_devname(struct udev_device *udev_device)
+const char *udev_device_get_devnode(struct udev_device *udev_device)
 {
 	if (udev_device == NULL)
 		return NULL;
@@ -333,16 +387,35 @@ const char *udev_device_get_devname(struct udev_device *udev_device)
  **/
 const char *udev_device_get_subsystem(struct udev_device *udev_device)
 {
-	char subsystem[NAME_SIZE];
+	char subsystem[UTIL_NAME_SIZE];
 
 	if (udev_device == NULL)
 		return NULL;
 	if (udev_device->subsystem != NULL)
 		return udev_device->subsystem;
-	if (util_get_sys_subsystem(udev_device->udev, udev_device->devpath, subsystem, sizeof(subsystem)) < 2)
-		return NULL;
-	udev_device->subsystem = strdup(subsystem);
-	return udev_device->subsystem;
+
+	/* read "subsytem" link */
+	if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) {
+		udev_device->subsystem = strdup(subsystem);
+		return udev_device->subsystem;
+	}
+
+	/* implicit names */
+	if (strncmp(udev_device->devpath, "/module/", 8) == 0) {
+		udev_device->subsystem = strdup("module");
+		return udev_device->subsystem;
+	}
+	if (strstr(udev_device->devpath, "/drivers/") != NULL) {
+		udev_device->subsystem = strdup("drivers");
+		return udev_device->subsystem;
+	}
+	if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 ||
+	    strncmp(udev_device->devpath, "/class/", 7) == 0 ||
+	    strncmp(udev_device->devpath, "/bus/", 5) == 0) {
+		udev_device->subsystem = strdup("subsystem");
+		return udev_device->subsystem;
+	}
+	return NULL;
 }
 
 /**
@@ -363,7 +436,7 @@ int udev_device_get_devlinks(struct udev_device *udev_device,
 			      int (*cb)(struct udev_device *udev_device, const char *value, void *data),
 			      void *data)
 {
-	struct name_entry *name_loop;
+	struct util_name_entry *name_loop;
 	int count = 0;
 
 	if (udev_device == NULL)
@@ -393,24 +466,14 @@ int udev_device_get_properties(struct udev_device *udev_device,
 				int (*cb)(struct udev_device *udev_device, const char *key, const char *value, void *data),
 				void *data)
 {
-	struct name_entry *name_loop;
+	struct util_name_entry *name_loop;
 	int count = 0;
 
 	if (udev_device == NULL)
 		return -1;
 	list_for_each_entry(name_loop, &udev_device->env_list, node) {
-		char name[PATH_SIZE];
-		char *val;
-
-		strncpy(name, name_loop->name, PATH_SIZE);
-		name[PATH_SIZE-1] = '\0';
-		val = strchr(name, '=');
-		if (val == NULL)
-			continue;
-		val[0] = '\0';
-		val = &val[1];
 		count++;
-		if (cb(udev_device, name, val, data) != 0)
+		if (cb(udev_device, name_loop->name, name_loop->value, data) != 0)
 			break;
 	}
 	return count;
@@ -418,13 +481,13 @@ int udev_device_get_properties(struct udev_device *udev_device,
 
 const char *udev_device_get_driver(struct udev_device *udev_device)
 {
-	char driver[NAME_SIZE];
+	char driver[UTIL_NAME_SIZE];
 
 	if (udev_device == NULL)
 		return NULL;
 	if (udev_device->driver != NULL)
 		return udev_device->driver;
-	if (util_get_sys_driver(udev_device->udev, udev_device->devpath, driver, sizeof(driver)) < 2)
+	if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2)
 		return NULL;
 	udev_device->driver = strdup(driver);
 	return udev_device->driver;
@@ -451,11 +514,93 @@ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 	return udev_device->seqnum;
 }
 
-int device_set_devpath(struct udev_device *udev_device, const char *devpath)
+const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr)
 {
-	if (asprintf(&udev_device->syspath, "%s%s", udev_get_sys_path(udev_device->udev), devpath) < 0)
+	struct util_name_entry *name_loop;
+	char path[UTIL_PATH_SIZE];
+	char value[UTIL_NAME_SIZE];
+	struct stat statbuf;
+	int fd;
+	ssize_t size;
+	const char *val = NULL;
+
+	/* look for possibly already cached result */
+	list_for_each_entry(name_loop, &udev_device->attr_list, node) {
+		if (strcmp(name_loop->name, attr) == 0) {
+			info(udev_device->udev, "'%s' in cache '%s'\n", attr, name_loop->value);
+			return name_loop->value;
+		}
+	}
+
+	util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path));
+	util_strlcat(path, "/", sizeof(path));
+	util_strlcat(path, attr, sizeof(path));
+
+	if (lstat(path, &statbuf) != 0) {
+		info(udev_device->udev, "stat '%s' failed: %s\n", path, strerror(errno));
+		goto out;
+	}
+
+	if (S_ISLNK(statbuf.st_mode)) {
+		/* links return the last element of the target path */
+		char target[UTIL_NAME_SIZE];
+		int len;
+		char *pos;
+
+		len = readlink(path, target, sizeof(target));
+		if (len > 0) {
+			target[len] = '\0';
+			pos = strrchr(target, '/');
+			if (pos != NULL) {
+				pos = &pos[1];
+				info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos);
+				val = util_name_list_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0)->value;
+			}
+		}
+		goto out;
+	}
+
+	/* skip directories */
+	if (S_ISDIR(statbuf.st_mode))
+		goto out;
+
+	/* skip non-readable files */
+	if ((statbuf.st_mode & S_IRUSR) == 0)
+		goto out;
+
+	/* read attribute value */
+	fd = open(path, O_RDONLY);
+	if (fd < 0) {
+		info(udev_device->udev, "attribute '%s' can not be opened\n", path);
+		goto out;
+	}
+	size = read(fd, value, sizeof(value));
+	close(fd);
+	if (size < 0)
+		goto out;
+	if (size == sizeof(value))
+		goto out;
+
+	/* got a valid value, store it in cache and return it */
+	value[size] = '\0';
+	util_remove_trailing_chars(value, '\n');
+	info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value);
+	val = util_name_list_add(udev_device->udev, &udev_device->attr_list, attr, value, 0)->value;
+out:
+	return val;
+}
+int device_set_syspath(struct udev_device *udev_device, const char *syspath)
+{
+	const char *pos;
+
+	udev_device->syspath = strdup(syspath);
+	if (udev_device->syspath ==  NULL)
 		return -ENOMEM;
 	udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))];
+	pos = strrchr(udev_device->syspath, '/');
+	if (pos == NULL)
+		return -EINVAL;
+	udev_device->sysname = &pos[1];
 	return 0;
 }
 
@@ -477,18 +622,35 @@ int device_set_devname(struct udev_device *udev_device, const char *devname)
 
 int device_add_devlink(struct udev_device *udev_device, const char *devlink)
 {
-	if (name_list_add(udev_device->udev, &udev_device->link_list, devlink, 0) == NULL)
+	if (util_name_list_add(udev_device->udev, &udev_device->link_list, devlink, NULL, 0) == NULL)
 		return -ENOMEM;
 	return 0;
 }
 
-int device_add_property(struct udev_device *udev_device, const char *property)
+int device_add_property(struct udev_device *udev_device, const char *key, const char *value)
 {
-	if (name_list_add(udev_device->udev, &udev_device->env_list, property, 0) == NULL)
+	if (util_name_list_add(udev_device->udev, &udev_device->env_list, key, value, 0) == NULL)
 		return -ENOMEM;
 	return 0;
 }
 
+int device_add_property_from_string(struct udev_device *udev_device, const char *property)
+{
+	char name[UTIL_PATH_SIZE];
+	char *val;
+
+	strncpy(name, property, sizeof(name));
+	val = strchr(name, '=');
+	if (val == NULL)
+		return -1;
+	val[0] = '\0';
+	val = &val[1];
+	if (val[0] == '\0')
+		val = NULL;
+	device_add_property(udev_device, name, val);
+	return 0;
+}
+
 int device_set_action(struct udev_device *udev_device, const char *action)
 {
 	udev_device->action = strdup(action);