1 files changed, 136 insertions, 0 deletions
diff --git a/io/tst-readlinkat.c b/io/tst-readlinkat.c
new file mode 100644
index 0000000000..891b6e6817
--- /dev/null
+++ b/io/tst-readlinkat.c
@@ -0,0 +1,136 @@
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+static void prepare (void);
+#define PREPARE(argc, argv) prepare ()
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+
+#include "../test-skeleton.c"
+
+static int dir_fd;
+
+static void
+prepare (void)
+{
+  size_t test_dir_len = strlen (test_dir);
+  static const char dir_name[] = "/tst-symlinkat.XXXXXX";
+
+  size_t dirbuflen = test_dir_len + sizeof (dir_name);
+  char *dirbuf = malloc (dirbuflen);
+  if (dirbuf == NULL)
+    {
+      puts ("out of memory");
+      exit (1);
+    }
+
+  snprintf (dirbuf, dirbuflen, "%s%s", test_dir, dir_name);
+  if (mkdtemp (dirbuf) == NULL)
+    {
+      puts ("cannot create temporary directory");
+      exit (1);
+    }
+
+  add_temp_file (dirbuf);
+
+  dir_fd = open (dirbuf, O_RDONLY | O_DIRECTORY);
+  if (dir_fd == -1)
+    {
+      puts ("cannot open directory");
+      exit (1);
+    }
+}
+
+
+static int
+do_test (void)
+{
+  /* fdopendir takes over the descriptor, make a copy.  */
+  int dupfd = dup (dir_fd);
+  if (dupfd == -1)
+    {
+      puts ("dup failed");
+      return 1;
+    }
+  if (lseek (dupfd, 0, SEEK_SET) != 0)
+    {
+      puts ("1st lseek failed");
+      return 1;
+    }
+
+  /* The directory should be empty safe the . and .. files.  */
+  DIR *dir = fdopendir (dupfd);
+  if (dir == NULL)
+    {
+      puts ("fdopendir failed");
+      return 1;
+    }
+  struct dirent64 *d;
+  while ((d = readdir64 (dir)) != NULL)
+    if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)
+      {
+	printf ("temp directory contains file \"%s\"\n", d->d_name);
+	return 1;
+      }
+  closedir (dir);
+
+  static const char symlinkcontent[] = "some-file";
+  if (symlinkat (symlinkcontent, dir_fd, "another-file") != 0)
+    {
+      puts ("symlinkat failed");
+      return 1;
+    }
+
+  struct stat64 st2;
+  if (fstatat64 (dir_fd, "another-file", &st2, AT_SYMLINK_NOFOLLOW) != 0)
+    {
+      puts ("fstatat64 failed");
+      return 1;
+    }
+  if (!S_ISLNK (st2.st_mode))
+    {
+      puts ("2nd fstatat64 does not show file is a symlink");
+      return 1;
+    }
+
+  if (fstatat64 (dir_fd, symlinkcontent, &st2, AT_SYMLINK_NOFOLLOW) == 0)
+    {
+      puts ("2nd fstatat64 succeeded");
+      return 1;
+    }
+
+  char buf[100];
+  int n = readlinkat (dir_fd, "another-file", buf, sizeof (buf));
+  if (n == -1)
+    {
+      puts ("readlinkat failed");
+      return 1;
+    }
+  if (n != sizeof (symlinkcontent) - 1)
+    {
+      printf ("readlinkat returned %d, expected %zu\n",
+	      n, sizeof (symlinkcontent) - 1);
+      return 1;
+    }
+  if (strncmp (buf, symlinkcontent, n) != 0)
+    {
+      puts ("readlinkat retrieved wrong link content");
+      return 1;
+    }
+
+  if (unlinkat (dir_fd, "another-file", 0) != 0)
+    {
+      puts ("unlinkat failed");
+      return 1;
+    }
+
+  close (dir_fd);
+
+  return 0;
+}