chiark / gitweb /
libudev: udev_device_get_devname -> udev_device_get_devnode
[elogind.git] / udev / lib / libudev-device.c
index f400b621b7e10d611de2f08b5ccca96d2fc91241..731230efd0143858bd9da1072d60696fdbd6fd46 100644 (file)
@@ -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>
@@ -26,6 +24,7 @@
 #include <errno.h>
 #include <string.h>
 #include <dirent.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 
 #include "libudev.h"
@@ -52,16 +51,17 @@ 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 */
-       util_strlcpy(filename, udev_get_dev_path(udev), len);
+       util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len);
        start = util_strlcat(filename, "/.udev/db/", len);
-       util_strlcat(filename, devpath, len);
+       util_strlcat(filename, udev_device->devpath, len);
        return util_path_encode(&filename[start], len - start);
 }
 
@@ -73,7 +73,7 @@ static int device_read_db(struct udev_device *udev_device)
        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));
@@ -140,7 +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;
                }
        }
@@ -164,25 +164,26 @@ 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[UTIL_PATH_SIZE];
        struct stat statbuf;
@@ -190,14 +191,13 @@ struct udev_device *udev_device_new_from_devpath(struct udev *udev, const char *
 
        if (udev == NULL)
                return NULL;
-       if (devpath == NULL)
+       if (syspath == NULL)
                return NULL;
 
-       util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
-       util_strlcat(path, devpath, sizeof(path));
+       util_strlcpy(path, syspath, sizeof(path));
        util_strlcat(path, "/uevent", sizeof(path));
        if (stat(path, &statbuf) != 0) {
-               info(udev, "not a device :%s\n", devpath);
+               info(udev, "not a device :%s\n", syspath);
                return NULL;
        }
 
@@ -206,9 +206,9 @@ struct udev_device *udev_device_new_from_devpath(struct udev *udev, const char *
                return NULL;
 
        /* resolve possible symlink to real path */
-       util_strlcpy(path, devpath, sizeof(path));
+       util_strlcpy(path, syspath, sizeof(path));
        util_resolve_sys_link(udev, path, sizeof(path));
-       device_set_devpath(udev_device, 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)
@@ -225,23 +225,37 @@ static struct udev_device *device_new_from_parent(struct udev_device *udev_devic
        if (udev_device == NULL)
                return NULL;
 
-       util_strlcpy(path, udev_device_get_devpath(udev_device), sizeof(path));
+       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_devpath(udev_device->udev, path);
+               udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path);
                if (udev_device_parent != NULL)
-                       break;
+                       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 udev_device_parent;
+       return NULL;
 }
 
 struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
 {
-       if (udev_device->parent_device == NULL)
-               udev_device->parent_device = device_new_from_parent(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;
 }
 
@@ -302,6 +316,7 @@ void udev_device_unref(struct udev_device *udev_device)
        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);
 }
@@ -346,7 +361,7 @@ const char *udev_device_get_sysname(struct udev_device *udev_device)
 }
 
 /**
- * udev_device_get_devname:
+ * udev_device_get_devnode:
  * @udev_device: udev device
  *
  * Retrieve the device node file name belonging to the udev device.
@@ -354,7 +369,7 @@ const char *udev_device_get_sysname(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;
@@ -378,10 +393,29 @@ const char *udev_device_get_subsystem(struct udev_device *udev_device)
                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;
 }
 
 /**
@@ -438,17 +472,8 @@ int udev_device_get_properties(struct udev_device *udev_device,
        if (udev_device == NULL)
                return -1;
        list_for_each_entry(name_loop, &udev_device->env_list, node) {
-               char name[UTIL_NAME_SIZE];
-               char *val;
-
-               strncpy(name, name_loop->name, sizeof(name));
-               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;
@@ -462,7 +487,7 @@ const char *udev_device_get_driver(struct udev_device *udev_device)
                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;
@@ -489,14 +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))];
-       udev_device->sysname = strrchr(udev_device->syspath, '/');
-       if (udev_device->sysname != NULL)
-               udev_device->sysname = &udev_device->sysname[1];
+       pos = strrchr(udev_device->syspath, '/');
+       if (pos == NULL)
+               return -EINVAL;
+       udev_device->sysname = &pos[1];
        return 0;
 }
 
@@ -518,18 +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 (util_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 (util_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);