libudev: device - add device lookup by subsystem:sysname

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

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index 55fcad655e2ba092d53d0e1a6288d13ff2de65da..0cb992c9eacb34472957abc44cf8c2c92c0896f9 100644 (file)
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -381,6 +381,94 @@ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, de
        return device;
 }
 
+struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname)
+{
+       size_t sys_path_len;
+       char path_full[UTIL_PATH_SIZE];
+       char *path;
+       struct stat statbuf;
+
+       sys_path_len = util_strlcpy(path_full, udev_get_sys_path(udev), sizeof(path_full));
+       path = &path_full[sys_path_len];
+
+       if (strcmp(subsystem, "subsystem") == 0) {
+               util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
+               util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+
+               util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
+               util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+
+               util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
+               util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+               goto out;
+       }
+
+       if (strcmp(subsystem, "module") == 0) {
+               util_strlcpy(path, "/module/", sizeof(path_full) - sys_path_len);
+               util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+               goto out;
+       }
+
+       if (strcmp(subsystem, "drivers") == 0) {
+               char subsys[UTIL_NAME_SIZE];
+               char *driver;
+
+               util_strlcpy(subsys, sysname, sizeof(subsys));
+               driver = strchr(subsys, ':');
+               if (driver != NULL) {
+                       driver[0] = '\0';
+                       driver = &driver[1];
+                       util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
+                       if (stat(path_full, &statbuf) == 0)
+                               goto found;
+
+                       util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, subsys, sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, "/drivers/", sizeof(path_full) - sys_path_len);
+                       util_strlcat(path, driver, sizeof(path_full) - sys_path_len);
+                       if (stat(path_full, &statbuf) == 0)
+                               goto found;
+               }
+               goto out;
+       }
+
+       util_strlcpy(path, "/subsystem/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
+       util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+
+       util_strlcpy(path, "/bus/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
+       util_strlcat(path, "/devices/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+
+       util_strlcpy(path, "/class/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, subsystem, sizeof(path_full) - sys_path_len);
+       util_strlcat(path, "/", sizeof(path_full) - sys_path_len);
+       util_strlcat(path, sysname, sizeof(path_full) - sys_path_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+out:
+       return NULL;
+found:
+       return udev_device_new_from_syspath(udev, path_full);
+}
+
 static struct udev_device *device_new_from_parent(struct udev_device *udev_device)
 {
        struct udev_device *udev_device_parent = NULL;