lubudev: accept more sys directories as devices, and parent devices

[elogind.git] / udev / lib / libudev-device.c

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index b3731412b4de2b94d5dd4db1e63e8ab176193a05..a201fb25df95c17250ec184ce44822eeff8a200a 100644 (file)
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -229,6 +229,9 @@ struct udev_device *device_init(struct udev *udev)
  **/
 struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath)
 {
+       size_t len;
+       const char *subdir;
+       const char *pos;
        char path[UTIL_PATH_SIZE];
        struct stat statbuf;
        struct udev_device *udev_device;
@@ -238,20 +241,50 @@ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *
        if (syspath == NULL)
                return NULL;
 
-       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);
+       /* path starts in sys */
+       len = strlen(udev_get_sys_path(udev));
+       if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) {
+               info(udev, "not in sys :%s\n", syspath);
                return NULL;
        }
 
-       udev_device = device_init(udev);
-       if (udev_device == NULL)
+       /* path is not a root directory */
+       subdir = &syspath[len+1];
+       pos = strrchr(subdir, '/');
+       if (pos == NULL || pos < &subdir[2]) {
+               info(udev, "not in subdir :%s\n", syspath);
                return NULL;
+       }
 
        /* resolve possible symlink to real path */
        util_strlcpy(path, syspath, sizeof(path));
        util_resolve_sys_link(udev, path, sizeof(path));
+
+       /* path exists in sys */
+       if (strncmp(&syspath[len], "/devices/", 9) == 0 ||
+           strncmp(&syspath[len], "/class/", 7) == 0 ||
+           strncmp(&syspath[len], "/block/", 7) == 0) {
+               char file[UTIL_PATH_SIZE];
+
+               /* all "devices" require a "uevent" file */
+               util_strlcpy(file, path, sizeof(file));
+               util_strlcat(file, "/uevent", sizeof(file));
+               if (stat(file, &statbuf) != 0) {
+                       info(udev, "not a device: %s\n", syspath);
+                       return NULL;
+               }
+       } else {
+               /* everything else just needs to be a directory */
+               if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) {
+                       info(udev, "directory not found: %s\n", syspath);
+                       return NULL;
+               }
+       }
+
+       udev_device = device_init(udev);
+       if (udev_device == NULL)
+               return NULL;
+
        device_set_syspath(udev_device, path);
        info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device));
 
@@ -273,7 +306,7 @@ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, de
        else
                return NULL;
 
-       /* /sys/dev/{block,char}/<maj>:<min> links */
+       /* /sys/dev/{block,char}/<maj>:<min> link */
        snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev),
                 type_str, major(devnum), minor(devnum));
        if (util_resolve_sys_link(udev, path, sizeof(path)) == 0)
@@ -303,37 +336,39 @@ static struct udev_device *device_new_from_parent(struct udev_device *udev_devic
 {
        struct udev_device *udev_device_parent = NULL;
        char path[UTIL_PATH_SIZE];
-       char *pos;
+       const char *subdir;
 
-       if (udev_device == NULL)
-               return NULL;
+       /* follow "device" link in deprecated sys layout */
+       if (strncmp(udev_device->devpath, "/class/", 7) == 0 ||
+           strncmp(udev_device->devpath, "/block/", 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);
+               return udev_device_parent;
+       }
 
        util_strlcpy(path, udev_device->syspath, sizeof(path));
+       subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1];
        while (1) {
-               pos = strrchr(path, '/');
-               if (pos == path || pos == NULL)
+               char *pos;
+
+               pos = strrchr(subdir, '/');
+               if (pos == NULL || pos < &subdir[2])
                        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 == NULL)
+               return NULL;
+
        if (udev_device->parent_device != NULL) {
                info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device);
                return udev_device->parent_device;