1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <stdlib.h>
7#include <unistd.h>
8#include <errno.h>
9#include <fcntl.h>
10#include <kern_util.h>
11#include <os.h>
12
13struct grantpt_info {
14	int fd;
15	int res;
16	int err;
17};
18
19static void grantpt_cb(void *arg)
20{
21	struct grantpt_info *info = arg;
22
23	info->res = grantpt(info->fd);
24	info->err = errno;
25}
26
27int get_pty(void)
28{
29	struct grantpt_info info;
30	int fd, err;
31
32	fd = open("/dev/ptmx", O_RDWR);
33	if (fd < 0) {
34		err = -errno;
35		printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
36		       "err = %d\n", errno);
37		return err;
38	}
39
40	info.fd = fd;
41	initial_thread_cb(grantpt_cb, &info);
42
43	if (info.res < 0) {
44		err = -info.err;
45		printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
46		       "errno = %d\n", -info.err);
47		goto out;
48	}
49
50	if (unlockpt(fd) < 0) {
51		err = -errno;
52		printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
53		       "errno = %d\n", errno);
54		goto out;
55	}
56	return fd;
57out:
58	close(fd);
59	return err;
60}
61