1/* Change a port cell to a directory in an open file descriptor.
2 Copyright (C) 1999-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <unistd.h>
21#include <hurd.h>
22#include <hurd/port.h>
23#include <hurd/fd.h>
24#include <fcntl.h>
25
26int
27_hurd_change_directory_port_from_fd (struct hurd_port *portcell, int fd)
28{
29 int ret;
30 struct hurd_fd *d = _hurd_fd_get (fd);
31
32 if (!d)
33 return __hurd_fail (EBADF);
34
35retry:
36 HURD_CRITICAL_BEGIN;
37
38 ret = HURD_PORT_USE (&d->port,
39 ({
40 int ret;
41 /* We look up "." to force ENOTDIR if it's not a
42 directory and EACCES if we don't have search
43 permission. */
44 file_t dir = __file_name_lookup_under (port, ".",
45 O_NOTRANS, 0);
46 if (dir == MACH_PORT_NULL)
47 ret = -1;
48 else
49 {
50 _hurd_port_set (portcell, dir);
51 ret = 0;
52 }
53 ret;
54 }));
55
56 HURD_CRITICAL_END;
57 if (ret == -1 && errno == EINTR)
58 /* Got a signal while inside an RPC of the critical section, retry again */
59 goto retry;
60
61 return ret;
62}
63

source code of glibc/hurd/hurdfchdir.c