1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
4 */
5
6 #include <stddef.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include "chan_user.h"
10 #include <os.h>
11
12 /* This address is used only as a unique identifier */
13 static int null_chan;
14
15 static void *null_init(char *str, int device, const struct chan_opts *opts)
16 {
17 return &null_chan;
18 }
19
20 static int null_open(int input, int output, int primary, void *d,
21 char **dev_out)
22 {
23 int fd;
24
25 *dev_out = NULL;
26
27 fd = open(DEV_NULL, O_RDWR);
28 return (fd < 0) ? -errno : fd;
29 }
30
31 static int null_read(int fd, __u8 *c_out, void *unused)
32 {
33 return -ENODEV;
34 }
35
36 static void null_free(void *data)
37 {
38 }
39
40 const struct chan_ops null_ops = {
41 .type = "null",
42 .init = null_init,
43 .open = null_open,
44 .close = generic_close,
45 .read = null_read,
46 .write = generic_write,
47 .console_write = generic_console_write,
48 .window_size = generic_window_size,
49 .free = null_free,
50 .winch = 0,
51 };
52
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