tty.c
/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include "kern_constants.h"
#include "kern_util.h"
#include "os.h"
#include "user.h"
struct grantpt_info {
int fd;
int res;
int err;
};
static void grantpt_cb(void *arg)
{
struct grantpt_info *info = arg;
info->res = grantpt(info->fd);
info->err = errno;
}
int get_pty(void)
{
struct grantpt_info info;
int fd, err;
fd = open("/dev/ptmx", O_RDWR);
if (fd < 0) {
err = -errno;
printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
"err = %d\n", errno);
return err;
}
info.fd = fd;
initial_thread_cb(grantpt_cb, &info);
if (info.res < 0) {
err = -info.err;
printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
"errno = %d\n", -info.err);
goto out;
}
if (unlockpt(fd) < 0) {
err = -errno;
printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
"errno = %d\n", errno);
goto out;
}
return fd;
out:
close(fd);
return err;
}