hurd: Implement faccessat without AT_EACCESS flag

* hurd/hurd/fd.h: Include <fcntl.h>
(__hurd_at_flags): New function.
* hurd/lookup-at.c (__file_name_lookup_at): Replace flag computation
with call to __hurd_at_flags.
* include/unistd.h (__faccessat, __faccessat_noerrno): Add declaration.
* sysdeps/mach/hurd/access.c (access_common): Move implementation to
__faccessat
(hurd_fail_seterrno, hurd_fail_noerrno): Move to sysdeps/mach/hurd/faccessat.c.
(__access_noerrno): Use __faccessat_common instead of access_common.
(__access): Likewise.
* sysdeps/mach/hurd/euidaccess.c (__euidaccess): Replace implementation
with a call to __faccessat.
* sysdeps/mach/hurd/faccessat.c (faccessat): Rename into...
(__faccessat_common): ... this. Move implementation of __access into it when
AT_FLAGS does not contain AT_EACCESS. Make it call __hurd_at_flags, add
reauthenticate_cwdir_at helper to implement AT mechanism.
(__faccessat_noerrno): New function, just calls __faccessat_common.
(__faccessat): New function, just calls __faccessat_common.
(faccessat): Define weak alias.
This commit is contained in:
Samuel Thibault 2018-01-10 01:58:23 +01:00
parent 87faac5516
commit 09085ede12
7 changed files with 219 additions and 195 deletions

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@ -1,3 +1,25 @@
2018-01-10 Samuel Thibault <samuel.thibault@ens-lyon.org>
* hurd/hurd/fd.h: Include <fcntl.h>
(__hurd_at_flags): New function.
* hurd/lookup-at.c (__file_name_lookup_at): Replace flag computation
with call to __hurd_at_flags.
* include/unistd.h (__faccessat, __faccessat_noerrno): Add declaration.
* sysdeps/mach/hurd/access.c (access_common): Move implementation to
__faccessat
(hurd_fail_seterrno, hurd_fail_noerrno): Move to sysdeps/mach/hurd/faccessat.c.
(__access_noerrno): Use __faccessat_common instead of access_common.
(__access): Likewise.
* sysdeps/mach/hurd/euidaccess.c (__euidaccess): Replace implementation
with a call to __faccessat.
* sysdeps/mach/hurd/faccessat.c (faccessat): Rename into...
(__faccessat_common): ... this. Move implementation of __access into it when
AT_FLAGS does not contain AT_EACCESS. Make it call __hurd_at_flags, add
reauthenticate_cwdir_at helper to implement AT mechanism.
(__faccessat_noerrno): New function, just calls __faccessat_common.
(__faccessat): New function, just calls __faccessat_common.
(faccessat): Define weak alias.
2018-01-10 Joseph Myers <joseph@codesourcery.com>
[BZ #22691]

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@ -26,6 +26,7 @@
#include <hurd/hurd_types.h>
#include <hurd/port.h>
#include <sys/socket.h>
#include <fcntl.h>
/* Structure representing a file descriptor. */
@ -254,6 +255,26 @@ extern int _hurd_select (int nfds, struct pollfd *pollfds,
const struct timespec *timeout,
const sigset_t *sigmask);
/* Apply AT_FLAGS on FLAGS, in preparation for calling
__hurd_file_name_lookup. */
_HURD_FD_H_EXTERN_INLINE error_t
__hurd_at_flags (int *at_flags, int *flags)
{
if ((*at_flags & AT_SYMLINK_FOLLOW) && (*at_flags & AT_SYMLINK_NOFOLLOW))
return EINVAL;
*flags |= (*at_flags & AT_SYMLINK_NOFOLLOW) ? O_NOLINK : 0;
*at_flags &= ~AT_SYMLINK_NOFOLLOW;
if (*at_flags & AT_SYMLINK_FOLLOW)
*flags &= ~O_NOLINK;
*at_flags &= ~AT_SYMLINK_FOLLOW;
if (*at_flags != 0)
return EINVAL;
return 0;
}
/* Variant of file_name_lookup used in *at function implementations.
AT_FLAGS may only contain AT_SYMLINK_FOLLOW or AT_SYMLINK_NOFOLLOW,
which will remove and add O_NOLINK from FLAGS respectively.

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@ -29,16 +29,9 @@ __file_name_lookup_at (int fd, int at_flags,
error_t err;
file_t result;
if ((at_flags & AT_SYMLINK_FOLLOW) && (at_flags & AT_SYMLINK_NOFOLLOW))
return (__hurd_fail (EINVAL), MACH_PORT_NULL);
flags |= (at_flags & AT_SYMLINK_NOFOLLOW) ? O_NOLINK : 0;
at_flags &= ~AT_SYMLINK_NOFOLLOW;
if (at_flags & AT_SYMLINK_FOLLOW)
flags &= ~O_NOLINK;
at_flags &= ~AT_SYMLINK_FOLLOW;
if (at_flags != 0)
return (__hurd_fail (EINVAL), MACH_PORT_NULL);
err = __hurd_at_flags (&at_flags, &flags);
if (err)
return (__hurd_fail (err), MACH_PORT_NULL);
if (fd == AT_FDCWD || file_name[0] == '/')
return __file_name_lookup (file_name, flags, mode);

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@ -25,6 +25,9 @@ libc_hidden_proto (readlinkat)
/* Now define the internal interfaces. */
extern int __access (const char *__name, int __type) attribute_hidden;
extern int __euidaccess (const char *__name, int __type);
extern int __faccessat (int __fd, const char *__file, int __type, int __flag);
extern int __faccessat_noerrno (int __fd, const char *__file, int __type,
int __flag);
extern __off64_t __lseek64 (int __fd, __off64_t __offset, int __whence)
attribute_hidden;
extern __off_t __lseek (int __fd, __off_t __offset, int __whence);

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@ -15,145 +15,10 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#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
@ -161,13 +26,13 @@ access_common (const char *file, int type, int (*errfunc) (error_t))
int
__access_noerrno (const char *file, int type)
{
return access_common (file, type, hurd_fail_noerrno);
return __faccessat_noerrno (AT_FDCWD, file, type, 0);
}
/* 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);
return __faccessat (AT_FDCWD, file, type, 0);
}
weak_alias (__access, access)

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@ -16,42 +16,13 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <hurd.h>
int
__euidaccess (const char *file, int type)
{
error_t err;
file_t port;
int allowed, flags;
port = __file_name_lookup (file, 0, 0);
if (port == MACH_PORT_NULL)
return -1;
/* Find out what types of access we are allowed to this file. */
err = __file_check_access (port, &allowed);
__mach_port_deallocate (__mach_task_self (), port);
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;
return __faccessat (AT_FDCWD, file, type, AT_EACCESS);
}
weak_alias (__euidaccess, euidaccess)
weak_alias (__euidaccess, eaccess)

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@ -23,31 +23,167 @@
#include <sys/types.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <hurd/port.h>
#include <hurd/id.h>
#include <hurd/lookup.h>
int
faccessat (int fd, const char *file, int type, int flag)
static int
hurd_fail_seterrno (error_t err)
{
error_t err;
file_t port;
int allowed, flags;
return __hurd_fail (err);
}
if ((flag & AT_EACCESS) == 0)
static int
hurd_fail_noerrno (error_t err)
{
if (fd == AT_FDCWD || file[0] == '/')
return __access (file, type);
__set_errno (ENOTSUP); /* XXX later */
return -1;
}
port = __file_name_lookup_at (fd, flag &~ AT_EACCESS, file, 0, 0);
if (port == MACH_PORT_NULL)
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;
__hurd_at_flags (&at_flags, &hurd_flags);
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;
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 (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 (port, &allowed);
__mach_port_deallocate (__mach_task_self (), port);
err = __file_check_access (io, &allowed);
__mach_port_deallocate (__mach_task_self (), io);
if (err)
return __hurd_fail (err);
return errfunc (err);
flags = 0;
if (type & R_OK)
@ -59,7 +195,20 @@ faccessat (int fd, const char *file, int type, int flag)
if (flags & ~allowed)
/* We are not allowed all the requested types of access. */
return __hurd_fail (EACCES);
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)