utils: Resolve symlinks with an absolute target in bd_utils_resolve_device

src/utils/dev_utils.c

@@ -21,6 +21,7 @@
 #include <libudev.h>
 #include <sys/stat.h>
 #include <errno.h>
+#include <stdlib.h>
 
 #include "dev_utils.h"
 
@@ -94,7 +95,15 @@ gchar* bd_utils_resolve_device (const gchar *dev_spec, GError **error) {
     }
     g_free (path);
 
-    if (g_str_has_prefix (symlink, "../"))
+    if (g_path_is_absolute (symlink)) {
+        /* the target may be another symlink, resolve it completely */
+        path = realpath (symlink, NULL);
+        if (!path) {
+            g_set_error (error, BD_UTILS_DEV_UTILS_ERROR, BD_UTILS_DEV_UTILS_ERROR_FAILED,
+                         "Failed to resolve '%s': %s", dev_spec, strerror_l (errno, _C_LOCALE));
+            return NULL;
+        }
+    } else if (g_str_has_prefix (symlink, "../"))
         path = g_strdup_printf ("/dev/%s", symlink + 3);
     else
         path = g_strdup_printf ("/dev/%s", symlink);

tests/utils_test.py

@@ -468,6 +468,13 @@ def test_resolve_device(self):
         # should resolve the other symlink even without the "/dev" prefix
         self.assertEqual(BlockDev.utils_resolve_device(dev_link2[5:]), dev_node)
 
+        # should resolve a symlink with an absolute target
+        abs_link = "/dev/utilsTestAbsoluteLink"
+        os.symlink(dev_node, abs_link)
+        self.addCleanup(os.unlink, abs_link)
+        self.assertEqual(BlockDev.utils_resolve_device(abs_link), dev_node)
+        self.assertEqual(BlockDev.utils_resolve_device(abs_link[5:]), dev_node)
+
         # vg is not a block device, shouldn't be resolved
         with self.assertRaisesRegex(GLib.GError, "not a block device"):
             BlockDev.utils_resolve_device("/dev/utilsTestVG")