glibc/sysdeps/mach/hurd/access.c
1995-02-18 01:27:10 +00:00

139 lines
4.2 KiB
C

/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/port.h>
#include <hurd/id.h>
#include <fcntl.h>
/* Test for access to FILE by our real user and group IDs. */
int
DEFUN(__access, (file, type), CONST char *file AND int type)
{
error_t err;
file_t crdir, cwdir, rcrdir, rcwdir, io;
struct hurd_userlink crdir_ulink, cwdir_ulink;
int flags, allowed;
mach_port_t ref;
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
/* Get _hurd_id up to date. */
if (err = _hurd_check_ids ())
goto lose;
if (_hurd_id.rid_auth == MACH_PORT_NULL)
{
/* Set up _hurd_id.rid_auth. This is a special auth server port
which uses the real uid and gid (the first aux uid and gid) as
the only effective uid and gid. */
if (_hurd_id.aux.nuids < 1 || _hurd_id.aux.ngids < 1)
{
/* We do not have a real UID and GID. Lose, lose, lose! */
err = EGRATUITOUS;
goto lose;
}
/* Create a new auth port using our real UID and GID (the first
auxiliary UID and GID) as the only effective IDs. */
if (err = __USEPORT (AUTH,
__auth_makeauth (port,
NULL, MACH_MSG_TYPE_COPY_SEND, 0,
_hurd_id.aux.uids, 1,
_hurd_id.aux.gids, 1,
_hurd_id.aux.uids,
_hurd_id.aux.nuids,
_hurd_id.aux.gids,
_hurd_id.aux.ngids,
&_hurd_id.rid_auth)))
goto lose;
}
/* Get a port to our root directory, authenticated with the real IDs. */
crdir = _hurd_port_get (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink);
ref = __mach_reply_port ();
err = __io_reauthenticate (crdir, ref, MACH_MSG_TYPE_MAKE_SEND);
if (!err)
err = __auth_user_authenticate (_hurd_id.rid_auth,
crdir,
ref, MACH_MSG_TYPE_MAKE_SEND,
&rcrdir);
_hurd_port_free (&_hurd_ports[INIT_PORT_CRDIR], &crdir_ulink, crdir);
__mach_port_destroy (__mach_task_self (), ref);
if (!err)
{
/* Get a port to our current working directory, authenticated with
the real IDs. */
cwdir = _hurd_port_get (&_hurd_ports[INIT_PORT_CWDIR], &cwdir_ulink);
ref = __mach_reply_port ();
err = __io_reauthenticate (cwdir, ref, MACH_MSG_TYPE_MAKE_SEND);
if (!err)
err = __auth_user_authenticate (_hurd_id.rid_auth,
cwdir,
ref, MACH_MSG_TYPE_MAKE_SEND,
&rcwdir);
_hurd_port_free (&_hurd_ports[INIT_PORT_CWDIR], &cwdir_ulink, cwdir);
__mach_port_destroy (__mach_task_self (), ref);
}
/* We are done with _hurd_id.rid_auth now. */
lose:
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (err)
return __hurd_fail (err);
/* Now do a path lookup on FILE, using the crdir and cwdir
reauthenticated with _hurd_id.rid_auth. */
err = __hurd_file_name_lookup (rcrdir, rcwdir, file, 0, 0, &io);
__mach_port_deallocate (__mach_task_self (), rcrdir);
__mach_port_deallocate (__mach_task_self (), rcwdir);
if (err)
return __hurd_fail (err);
/* Find out what types of access we are allowed to this file. */
err = __file_check_access (io, &allowed);
__mach_port_deallocate (__mach_task_self (), io);
if (err)
return __hurd_fail (err);
flags = 0;
if (type & R_OK)
flags |= O_READ;
if (type & W_OK)
flags |= O_WRITE;
if (type & X_OK)
flags |= O_EXEC;
if (flags & ~allowed)
/* We are not allowed all the requested types of access. */
return __hurd_fail (EACCES);
return 0;
}
weak_alias (__access, access)