1 files changed, 123 insertions, 0 deletions
diff --git a/libtrivfs/fsys-getroot.c b/libtrivfs/fsys-getroot.c
new file mode 100644
index 00000000..d91b9fa8
--- /dev/null
+++ b/libtrivfs/fsys-getroot.c
@@ -0,0 +1,123 @@
+/*
+   Copyright (C) 1993,94,95,97,99 Free Software Foundation, Inc.
+
+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 the GNU Hurd; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* Written by Michael I. Bushnell.  */
+
+#include "priv.h"
+#include "fsys_S.h"
+#include "fsys_reply_U.h"
+#include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+
+kern_return_t
+trivfs_S_fsys_getroot (struct trivfs_control *cntl,
+		       mach_port_t reply_port,
+		       mach_msg_type_name_t reply_port_type,
+		       mach_port_t dotdot,
+		       uid_t *uids, u_int nuids,
+		       uid_t *gids, u_int ngids,
+		       int flags,
+		       retry_type *do_retry,
+		       char *retry_name,
+		       mach_port_t *newpt,
+		       mach_msg_type_name_t *newpttype)
+{
+  int perms;
+  error_t err = 0;
+  mach_port_t new_realnode;
+  struct trivfs_protid *cred;
+  struct iouser *user;
+  struct idvec *uvec, *gvec;
+
+  if (!cntl)
+    return EOPNOTSUPP;
+
+  if (trivfs_getroot_hook)
+    {
+      err = (*trivfs_getroot_hook) (cntl, reply_port, reply_port_type, dotdot,
+				    uids, nuids, gids, ngids, flags,
+				    do_retry, retry_name, newpt, newpttype);
+      if (err != EAGAIN)
+	return err;
+    }
+
+  if ((flags & O_WRITE & trivfs_allow_open) != (flags & O_WRITE))
+    return EROFS;
+  if ((flags & (O_READ|O_WRITE|O_EXEC) & trivfs_allow_open)
+      != (flags & (O_READ|O_WRITE|O_EXEC)))
+    return EACCES;
+
+  /* O_CREAT and O_EXCL are not meaningful here; O_NOLINK and O_NOTRANS
+     will only be useful when trivfs supports translators (which it doesn't
+     now). */
+  flags &= O_HURD;
+  flags &= ~(O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS);
+
+  err = io_restrict_auth (cntl->underlying,
+			  &new_realnode, uids, nuids, gids, ngids);
+  if (err)
+    return err;
+
+  uvec = make_idvec ();
+  gvec = make_idvec ();
+  idvec_set_ids (uvec, uids, nuids);
+  idvec_set_ids (gvec, gids, ngids);
+  user = iohelp_create_iouser (uvec, gvec); /* XXX check return value?  */
+
+  /* Validate permissions.  */
+  if (! trivfs_check_access_hook)
+    file_check_access (new_realnode, &perms);
+  else
+    (*trivfs_check_access_hook) (cntl, user, new_realnode, &perms);
+  if ((flags & (O_READ|O_WRITE|O_EXEC) & perms)
+      != (flags & (O_READ|O_WRITE|O_EXEC)))
+    err = EACCES;
+
+  if (!err && trivfs_check_open_hook)
+    err = (*trivfs_check_open_hook) (cntl, user, flags);
+  if (!err)
+    {
+      if (! trivfs_open_hook)
+	{
+	  err = trivfs_open (cntl, user, flags, new_realnode, &cred);
+	  if (!err)
+	    mach_port_deallocate (mach_task_self (), dotdot);
+	}
+      else
+	err = (*trivfs_open_hook) (cntl, user, dotdot, flags, new_realnode,
+				   &cred);
+    }
+
+  if (err)
+    {
+      mach_port_deallocate (mach_task_self (), new_realnode);
+      iohelp_free_iouser (user);
+    }
+  else
+    {
+      *do_retry = FS_RETRY_NORMAL;
+      *retry_name = '\0';
+      *newpt = ports_get_right (cred);
+      *newpttype = MACH_MSG_TYPE_MAKE_SEND;
+      ports_port_deref (cred);
+    }
+
+  return err;
+}