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|
/* Test for access to file, relative to open directory. Hurd version.
Copyright (C) 2006-2024 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <unistd.h>
#include <sys/types.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/port.h>
#include <hurd/id.h>
#include <hurd/lookup.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
__faccessat_common (int fd, const char *file, int type, int at_flags,
int (*errfunc) (error_t))
{
error_t err;
file_t rcrdir, rcwdir, io;
int flags, allowed;
if ((at_flags & AT_EACCESS) == AT_EACCESS)
{
/* Use effective permissions. */
io = __file_name_lookup_at (fd, at_flags &~ AT_EACCESS, file, 0, 0);
if (io == MACH_PORT_NULL)
return -1;
}
else
{
/* We have to use real permissions instead of the
usual effective permissions. */
int hurd_flags = 0;
err = __hurd_at_flags (&at_flags, &hurd_flags);
if (err)
return errfunc (err);
error_t reauthenticate_cwdir_at (file_t *result)
{
/* Get a port to the FD directory, authenticated with the real IDs. */
error_t err;
mach_port_t ref;
ref = __mach_reply_port ();
err = HURD_DPORT_USE
(fd,
({
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 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:
if (fd == AT_FDCWD || file[0] == '/')
return (reauthenticate (INIT_PORT_CWDIR, &rcwdir) ?:
(*operate) (rcwdir));
else
return (reauthenticate_cwdir_at (&rcwdir) ?:
(*operate) (rcwdir));
default:
return _hurd_ports_use (which, operate);
}
}
rcrdir = rcwdir = MACH_PORT_NULL;
retry:
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, hurd_flags, 0, &io);
/* We are done with _hurd_id.rid_auth now. */
lose:
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (err == EINTR)
/* Got a signal while inside an RPC of the critical section, retry again */
goto retry;
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);
}
/* If all we wanted was to check for a file existing at the path,
then we already got our answer, and we don't need to call
file_check_access (). */
if (type == F_OK)
{
__mach_port_deallocate (__mach_task_self (), io);
return 0;
}
/* 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;
}
int
__faccessat_noerrno (int fd, const char *file, int type, int at_flags)
{
return __faccessat_common (fd, file, type, at_flags, hurd_fail_noerrno);
}
int
__faccessat (int fd, const char *file, int type, int at_flags)
{
return __faccessat_common (fd, file, type, at_flags, hurd_fail_seterrno);
}
weak_alias (__faccessat, faccessat)
|
