xref: /OK3568_Linux_fs/kernel/arch/um/os-Linux/tty.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4*4882a593Smuzhiyun  */
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun #include <stdlib.h>
7*4882a593Smuzhiyun #include <unistd.h>
8*4882a593Smuzhiyun #include <errno.h>
9*4882a593Smuzhiyun #include <fcntl.h>
10*4882a593Smuzhiyun #include <kern_util.h>
11*4882a593Smuzhiyun #include <os.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun struct grantpt_info {
14*4882a593Smuzhiyun 	int fd;
15*4882a593Smuzhiyun 	int res;
16*4882a593Smuzhiyun 	int err;
17*4882a593Smuzhiyun };
18*4882a593Smuzhiyun 
grantpt_cb(void * arg)19*4882a593Smuzhiyun static void grantpt_cb(void *arg)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun 	struct grantpt_info *info = arg;
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun 	info->res = grantpt(info->fd);
24*4882a593Smuzhiyun 	info->err = errno;
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun 
get_pty(void)27*4882a593Smuzhiyun int get_pty(void)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun 	struct grantpt_info info;
30*4882a593Smuzhiyun 	int fd, err;
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun 	fd = open("/dev/ptmx", O_RDWR);
33*4882a593Smuzhiyun 	if (fd < 0) {
34*4882a593Smuzhiyun 		err = -errno;
35*4882a593Smuzhiyun 		printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
36*4882a593Smuzhiyun 		       "err = %d\n", errno);
37*4882a593Smuzhiyun 		return err;
38*4882a593Smuzhiyun 	}
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	info.fd = fd;
41*4882a593Smuzhiyun 	initial_thread_cb(grantpt_cb, &info);
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun 	if (info.res < 0) {
44*4882a593Smuzhiyun 		err = -info.err;
45*4882a593Smuzhiyun 		printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
46*4882a593Smuzhiyun 		       "errno = %d\n", -info.err);
47*4882a593Smuzhiyun 		goto out;
48*4882a593Smuzhiyun 	}
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	if (unlockpt(fd) < 0) {
51*4882a593Smuzhiyun 		err = -errno;
52*4882a593Smuzhiyun 		printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
53*4882a593Smuzhiyun 		       "errno = %d\n", errno);
54*4882a593Smuzhiyun 		goto out;
55*4882a593Smuzhiyun 	}
56*4882a593Smuzhiyun 	return fd;
57*4882a593Smuzhiyun out:
58*4882a593Smuzhiyun 	close(fd);
59*4882a593Smuzhiyun 	return err;
60*4882a593Smuzhiyun }
61