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/* Copyright (C) 1991-2017 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, see
<http://www.gnu.org/licenses/>. */
#include <unistd.h>
#include <hurd.h>
#include <hurd/port.h>
#include <hurd/id.h>
#include <hurd/lookup.h>
#include <fcntl.h>
static int
hurd_fail_seterrno (error_t err)
{
return __hurd_fail (err);
}
static int
hurd_fail_noerrno (error_t err)
{
return -1;
}
static int
access_common (const char *file, int type, int (*errfunc) (error_t))
{
error_t err;
file_t rcrdir, rcwdir, io;
int flags, allowed;
error_t reauthenticate (int which, file_t *result)
{
/* Get a port to our root directory, authenticated with the real IDs. */
error_t err;
mach_port_t ref;
ref = __mach_reply_port ();
err = HURD_PORT_USE
(&_hurd_ports[which],
({
err = __io_reauthenticate (port, ref, MACH_MSG_TYPE_MAKE_SEND);
if (!err)
err = __auth_user_authenticate (_hurd_id.rid_auth,
ref, MACH_MSG_TYPE_MAKE_SEND,
result);
err;
}));
__mach_port_destroy (__mach_task_self (), ref);
return err;
}
error_t init_port (int which, error_t (*operate) (mach_port_t))
{
switch (which)
{
case INIT_PORT_AUTH:
return (*operate) (_hurd_id.rid_auth);
case INIT_PORT_CRDIR:
return (reauthenticate (INIT_PORT_CRDIR, &rcrdir) ?:
(*operate) (rcrdir));
case INIT_PORT_CWDIR:
return (reauthenticate (INIT_PORT_CWDIR, &rcwdir) ?:
(*operate) (rcwdir));
default:
return _hurd_ports_use (which, operate);
}
}
rcrdir = rcwdir = MACH_PORT_NULL;
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.uids,
_hurd_id.aux.nuids,
_hurd_id.aux.gids, 1,
_hurd_id.aux.gids,
_hurd_id.aux.ngids,
&_hurd_id.rid_auth)))
goto lose;
}
if (!err)
/* Look up the file name using the modified init ports. */
err = __hurd_file_name_lookup (&init_port, &__getdport, 0,
file, 0, 0, &io);
/* We are done with _hurd_id.rid_auth now. */
lose:
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (rcrdir != MACH_PORT_NULL)
__mach_port_deallocate (__mach_task_self (), rcrdir);
if (rcwdir != MACH_PORT_NULL)
__mach_port_deallocate (__mach_task_self (), rcwdir);
if (err)
return errfunc (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 errfunc (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 errfunc (EACCES);
return 0;
}
/* Test for access to FILE by our real user and group IDs without setting
errno. This may be unsafe to run during initialization of tunables
since access_common calls __hurd_file_name_lookup, which calls
__hurd_file_name_lookup_retry, which can set errno. */
int
__access_noerrno (const char *file, int type)
{
return access_common (file, type, hurd_fail_noerrno);
}
/* Test for access to FILE by our real user and group IDs. */
int
__access (const char *file, int type)
{
return access_common (file, type, hurd_fail_seterrno);
}
weak_alias (__access, access)
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