1 | /* Copyright (C) 1993-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <unistd.h> |
20 | #include <hurd.h> |
21 | #include <hurd/fd.h> |
22 | #include <string.h> |
23 | |
24 | error_t |
25 | _hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes, loff_t offset) |
26 | { |
27 | error_t err; |
28 | char *data; |
29 | mach_msg_type_number_t nread; |
30 | |
31 | error_t readfd (io_t port) |
32 | { |
33 | return __io_read (port, &data, &nread, offset, *nbytes); |
34 | } |
35 | |
36 | data = buf; |
37 | nread = *nbytes; |
38 | if (err = HURD_FD_PORT_USE_CANCEL (fd, _hurd_ctty_input (port, ctty, readfd))) |
39 | return err; |
40 | |
41 | if (data != buf) |
42 | { |
43 | if (nread > *nbytes) /* Sanity check for bogus server. */ |
44 | { |
45 | __vm_deallocate (__mach_task_self (), (vm_address_t) data, nread); |
46 | return EGRATUITOUS; |
47 | } |
48 | memcpy (buf, data, nread); |
49 | __vm_deallocate (__mach_task_self (), (vm_address_t) data, nread); |
50 | } |
51 | |
52 | *nbytes = nread; |
53 | return 0; |
54 | } |
55 | |