1 files changed, 70 insertions, 0 deletions
diff --git a/cpukit/libfs/src/defaults/default_lseek_file.c b/cpukit/libfs/src/defaults/default_lseek_file.c
new file mode 100644
index 0000000000..9d80b2a176
--- /dev/null
+++ b/cpukit/libfs/src/defaults/default_lseek_file.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2012 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Obere Lagerstr. 30
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/libio_.h>
+
+off_t rtems_filesystem_default_lseek_file(
+  rtems_libio_t *iop,
+  off_t offset,
+  int whence
+)
+{
+  off_t rv = 0;
+  off_t reference_offset;
+  off_t new_offset;
+  struct stat st;
+
+  switch ( whence ) {
+    case SEEK_SET:
+      reference_offset = 0;
+      break;
+    case SEEK_CUR:
+      reference_offset = iop->offset;
+      break;
+    case SEEK_END:
+      st.st_size = 0;
+      rv = (*iop->pathinfo.handlers->fstat_h)( &iop->pathinfo, &st );
+      reference_offset = st.st_size;
+      break;
+    default:
+      errno = EINVAL;
+      rv = -1;
+      break;
+  }
+  new_offset = reference_offset + offset;
+
+  if ( rv == 0 ) {
+    if (
+      (offset >= 0 && new_offset >= reference_offset)
+        || (offset < 0 && new_offset < reference_offset)
+    ) {
+      if ( new_offset >= 0 ) {
+        iop->offset = new_offset;
+        rv = new_offset;
+      } else {
+        errno = EINVAL;
+        rv = -1;
+      }
+    } else {
+      errno = EOVERFLOW;
+      rv = -1;
+    }
+  }
+
+  return rv;
+}