libudev: get rid of udev_sysfs.c

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

diff --git a/udev/lib/libudev-utils.c b/udev/lib/libudev-utils.c
index 8251b64da98b492dc63f2f7ec8cc5d52294bdad8..e5f1ed7c38d66af5a95b624a217e282553260f15 100644 (file)
--- a/udev/lib/libudev-utils.c
+++ b/udev/lib/libudev-utils.c
@@ -32,7 +32,7 @@
 #include "libudev-private.h"
 #include "../udev.h"
 
-ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *subsystem, size_t size)
+static ssize_t get_sys_link(struct udev *udev, const char *slink, const char *devpath, char *subsystem, size_t size)
 {
        char path[PATH_SIZE];
        ssize_t len;
@@ -40,7 +40,8 @@ ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *sub
 
        strlcpy(path, udev_get_sys_path(udev), sizeof(path));
        strlcat(path, devpath, sizeof(path));
-       strlcat(path, "/subsystem", sizeof(path));
+       strlcat(path, "/", sizeof(path));
+       strlcat(path, slink, sizeof(path));
        len = readlink(path, path, sizeof(path));
        if (len < 0 || len >= (ssize_t) sizeof(path))
                return -1;
@@ -51,3 +52,45 @@ ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *sub
        pos = &pos[1];
        return strlcpy(subsystem, pos, size);
 }
+
+ssize_t util_get_sys_subsystem(struct udev *udev, const char *devpath, char *subsystem, size_t size)
+{
+       return get_sys_link(udev, "subsystem", devpath, subsystem, size);
+}
+
+ssize_t util_get_sys_driver(struct udev *udev, const char *devpath, char *driver, size_t size)
+{
+       return get_sys_link(udev, "driver", devpath, driver, size);
+}
+
+int util_resolve_sys_link(struct udev *udev, char *devpath, size_t size)
+{
+       char link_path[PATH_SIZE];
+       char link_target[PATH_SIZE];
+       int len;
+       int i;
+       int back;
+
+       strlcpy(link_path, udev_get_sys_path(udev), sizeof(link_path));
+       strlcat(link_path, devpath, sizeof(link_path));
+       len = readlink(link_path, link_target, sizeof(link_target));
+       if (len <= 0)
+               return -1;
+       link_target[len] = '\0';
+       dbg(udev, "path link '%s' points to '%s'\n", devpath, link_target);
+
+       for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
+               ;
+       dbg(udev, "base '%s', tail '%s', back %i\n", devpath, &link_target[back * 3], back);
+       for (i = 0; i <= back; i++) {
+               char *pos = strrchr(devpath, '/');
+
+               if (pos == NULL)
+                       return -1;
+               pos[0] = '\0';
+       }
+       dbg(udev, "after moving back '%s'\n", devpath);
+       strlcat(devpath, "/", size);
+       strlcat(devpath, &link_target[back * 3], size);
+       return 0;
+}