1 files changed, 58 insertions, 9 deletions

diff --git a/lib/faccessat.c b/lib/faccessat.c
index 6cf9c99df20..c1737d03a10 100644
--- a/lib/faccessat.c
+++ b/lib/faccessat.c
@@ -1,9 +1,9 @@
 /* Check the access rights of a file relative to an open directory.
-   Copyright (C) 2009-2017 Free Software Foundation, Inc.
+   Copyright (C) 2009-2022 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
+   the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
@@ -16,10 +16,34 @@
 
 /* written by Eric Blake */
 
+/* If the user's config.h happens to include <unistd.h>, let it include only
+   the system's <unistd.h> here, so that orig_faccessat doesn't recurse to
+   rpl_faccessat.  */
+#define _GL_INCLUDING_UNISTD_H
 #include <config.h>
 
+/* Specification.  */
 #include <unistd.h>
+
+#include <errno.h>
 #include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#undef _GL_INCLUDING_UNISTD_H
+
+#if HAVE_FACCESSAT
+static int
+orig_faccessat (int fd, char const *name, int mode, int flag)
+{
+  return faccessat (fd, name, mode, flag);
+}
+#endif
+
+/* Write "unistd.h" here, not <unistd.h>, otherwise OSF/1 5.1 DTK cc
+   eliminates this include because of the preliminary #include <unistd.h>
+   above.  */
+#include "unistd.h"
 
 #ifndef HAVE_ACCESS
 /* Mingw lacks access, but it also lacks real vs. effective ids, so
@@ -28,6 +52,29 @@
 # define access euidaccess
 #endif
 
+#if HAVE_FACCESSAT
+
+int
+rpl_faccessat (int fd, char const *file, int mode, int flag)
+{
+  int result = orig_faccessat (fd, file, mode, flag);
+
+  if (result == 0 && file[strlen (file) - 1] == '/')
+    {
+      struct stat st;
+      result = fstatat (fd, file, &st, 0);
+      if (result == 0 && !S_ISDIR (st.st_mode))
+        {
+          errno = ENOTDIR;
+          return -1;
+        }
+    }
+
+  return result;
+}
+
+#else /* !HAVE_FACCESSAT */
+
 /* Invoke access or euidaccess on file, FILE, using mode MODE, in the directory
    open on descriptor FD.  If possible, do it without changing the
    working directory.  Otherwise, resort to using save_cwd/fchdir, then
@@ -36,10 +83,12 @@
    Note that this implementation only supports AT_EACCESS, although some
    native versions also support AT_SYMLINK_NOFOLLOW.  */
 
-#define AT_FUNC_NAME faccessat
-#define AT_FUNC_F1 euidaccess
-#define AT_FUNC_F2 access
-#define AT_FUNC_USE_F1_COND AT_EACCESS
-#define AT_FUNC_POST_FILE_PARAM_DECLS , int mode, int flag
-#define AT_FUNC_POST_FILE_ARGS        , mode
-#include "at-func.c"
+# define AT_FUNC_NAME faccessat
+# define AT_FUNC_F1 euidaccess
+# define AT_FUNC_F2 access
+# define AT_FUNC_USE_F1_COND AT_EACCESS
+# define AT_FUNC_POST_FILE_PARAM_DECLS , int mode, int flag
+# define AT_FUNC_POST_FILE_ARGS        , mode
+# include "at-func.c"
+
+#endif