From d2da61aa0cf73dadc31eb3fd4202c04faf0e7653 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Wed, 11 Sep 2013 10:59:06 +0200
Subject: Filesystem: Change rtems_filesystem_chown()

Implement POSIX requirements in the high-level file system layer.  Use
common implementation for all change owner variants.
---
 cpukit/libcsupport/src/fchown.c | 52 ++++++++++++++++++++++++++++++-----------
 1 file changed, 39 insertions(+), 13 deletions(-)

(limited to 'cpukit/libcsupport/src/fchown.c')

diff --git a/cpukit/libcsupport/src/fchown.c b/cpukit/libcsupport/src/fchown.c
index ec84fe4f47..2e741592da 100644
--- a/cpukit/libcsupport/src/fchown.c
+++ b/cpukit/libcsupport/src/fchown.c
@@ -22,30 +22,56 @@
 
 #include <rtems/libio_.h>
 
+int rtems_filesystem_chown(
+  const rtems_filesystem_location_info_t *loc,
+  uid_t owner,
+  gid_t group
+)
+{
+  const rtems_filesystem_mount_table_entry_t *mt_entry = loc->mt_entry;
+  int rv;
+
+  if ( mt_entry->writeable || rtems_filesystem_location_is_null( loc ) ) {
+    struct stat st;
+
+    memset( &st, 0, sizeof(st) );
+
+    rv = (*loc->handlers->fstat_h)( loc, &st );
+    if ( rv == 0 ) {
+      uid_t uid = geteuid();
+
+      if ( uid == 0 || st.st_uid == uid ) {
+        rv = (*mt_entry->ops->chown_h)( loc, owner, group );
+      } else {
+        errno = EPERM;
+        rv = -1;
+      }
+    }
+  } else {
+    errno = EROFS;
+    rv = -1;
+  }
+
+  return rv;
+}
+
 /**
  *  POSIX 1003.1b 5.6.5 - Change Owner and Group of a File
  */
 int fchown( int fd, uid_t owner, gid_t group )
 {
-  int rv = 0;
+  int rv;
   rtems_libio_t *iop;
 
   rtems_libio_check_fd( fd );
   iop = rtems_libio_iop( fd );
   rtems_libio_check_is_open(iop);
 
-  if (iop->pathinfo.mt_entry->writeable) {
-    rtems_filesystem_instance_lock( &iop->pathinfo );
-    rv = (*iop->pathinfo.mt_entry->ops->chown_h)(
-      &iop->pathinfo,
-      owner,
-      group
-    );
-    rtems_filesystem_instance_unlock( &iop->pathinfo );
-  } else {
-    errno = EROFS;
-    rv = -1;
-  }
+  rtems_filesystem_instance_lock( &iop->pathinfo );
+
+  rv = rtems_filesystem_chown( &iop->pathinfo, owner, group );
+
+  rtems_filesystem_instance_unlock( &iop->pathinfo );
 
   return rv;
 }
-- 
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