1 files changed, 44 insertions, 0 deletions
diff --git a/libfshelp/perms-checkdirmod.c b/libfshelp/perms-checkdirmod.c
new file mode 100644
index 00000000..db4b2e43
--- /dev/null
+++ b/libfshelp/perms-checkdirmod.c
@@ -0,0 +1,44 @@
+/* 
+   Copyright (C) 1999 Free Software Foundation, Inc.
+   Written by Thomas Bushnell, BSG.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+
+#include "fshelp.h"
+
+/* Check to see whether USER is allowed to modify DIR with respect to
+   existing file ST.  (If there is no existing file, pass 0 for ST.)
+   If the access is permissable return 0; otherwise return an
+   appropriate error code.  */
+error_t
+fshelp_checkdirmod (struct stat *dir, struct stat *st, struct iouser *user)
+{
+  error_t err;
+
+  /* The user must be able to write the directory. */
+  err = fshelp_access (dir, S_IWRITE, user);
+  if (err)
+    return err;
+
+  /* If the directory is sticky, the user must own either it or the file.  */
+  if ((dir->st_mode & S_ISVTX) && st
+      && fshelp_isowner (dir, user) && fshelp_isowner (st, user))
+    return EACCES;
+
+  return 0;
+}