1 files changed, 77 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/setresgid.c b/sysdeps/mach/hurd/setresgid.c
new file mode 100644
index 0000000000..d0ee412b46
--- /dev/null
+++ b/sysdeps/mach/hurd/setresgid.c
@@ -0,0 +1,77 @@
+/* setresgid -- set effective group ID, real group ID, and saved-set group ID
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <unistd.h>
+#include <hurd.h>
+#include <hurd/id.h>
+
+/* Set the effective group ID, real group ID, and saved-set group ID,
+   of the calling process to EGID, RGID, and SGID, respectively.  */
+int
+__setresgid (gid_t egid, gid_t rgid, gid_t sgid)
+{
+  auth_t newauth;
+  error_t err;
+  gid_t agids[2] = { rgid, sgid };
+
+  HURD_CRITICAL_BEGIN;
+  __mutex_lock (&_hurd_id.lock);
+  err = _hurd_check_ids ();
+
+  if (!err)
+    {
+      /* Make a new auth handle which has EGID as the first element in the
+         list of effective gids.  */
+
+      if (_hurd_id.gen.ngids > 0)
+	{
+	  _hurd_id.gen.gids[0] = egid;
+	  _hurd_id.valid = 0;
+	}
+      if (_hurd_id.aux.ngids > 1)
+	{
+	  _hurd_id.aux.gids[0] = rgid;
+	  _hurd_id.aux.gids[1] = sgid;
+	  _hurd_id.valid = 0;
+	}
+
+      err = __USEPORT (AUTH, __auth_makeauth
+		       (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
+			_hurd_id.gen.uids, _hurd_id.gen.nuids,
+			_hurd_id.aux.uids, _hurd_id.aux.nuids,
+			_hurd_id.gen.ngids ? _hurd_id.gen.gids : &egid,
+			_hurd_id.gen.ngids ?: 1,
+			_hurd_id.aux.ngids > 1 ? _hurd_id.aux.gids : agids,
+			_hurd_id.aux.ngids > 1 ? _hurd_id.aux.ngids : 2,
+			&newauth));
+    }
+
+  __mutex_unlock (&_hurd_id.lock);
+  HURD_CRITICAL_END;
+
+  if (err)
+    return __hurd_fail (err);
+
+  /* Install the new handle and reauthenticate everything.  */
+  err = __setauth (newauth);
+  __mach_port_deallocate (__mach_task_self (), newauth);
+  return err;
+}
+libc_hidden_def (__setresgid)