// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 */

#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <kern_util.h>
#include <os.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;
}