/*      $OpenBSD: ptmget.c,v 1.4 2021/10/24 21:24:20 deraadt Exp $ */
/*
 *      Written by Bob Beck <beck@openbsd.org> 2004 Public Domain.
 *      Basic test to ensure /dev/ptm works, and what it returns
 *      can be used via tty(4);
 */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/tty.h>
#include <sys/stat.h>

#include <err.h>
#include <fcntl.h>
#include <grp.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

int
main(int argc, char *argv[])
{
        int fd;
        struct ptmget ptm;
        struct termios ti;
        struct stat sb;
        struct group *gr;
        gid_t ttygid;

        if ((gr = getgrnam("tty")) != NULL)
                ttygid = gr->gr_gid;
        else
                ttygid = 4;
        fd = open("/dev/ptm", O_RDWR);
        if (fd == -1)
                err(1, "Can't open /dev/ptm");
        if ((ioctl(fd, PTMGET, &ptm) == -1))
                err(1, "ioctl PTMGET failed");
        if ((tcgetattr(ptm.sfd, &ti) == -1))
                err(1, "tcgetattr failed on slave");
        if ((tcgetattr(ptm.cfd, &ti) == -1))
                err(1, "tcgetattr failed on master");
        if ((ioctl(ptm.sfd, TIOCSTOP) == -1))
                err(1, "ioctl TIOCSTOP failed on slave");
        if ((ioctl(ptm.cfd, TIOCSTOP) == -1))
                err(1, "ioctl TIOCSTOP failed on master");
        bzero(&sb, sizeof(sb));
        if ((stat(ptm.sn, &sb) == -1))
                err(1, "can't stat slave %s", ptm.sn);
        if (sb.st_mode != (S_IFCHR | S_IWUSR | S_IRUSR | S_IWGRP))
                errx(1, "Bad mode %o on %s, should be %o", sb.st_mode,
                     ptm.sn, (S_IFCHR | S_IWUSR | S_IRUSR | S_IWGRP));
        if (sb.st_gid != ttygid)
                errx(1, "%s gid is %d not the tty group(%d)", ptm.sn,
                     sb.st_gid, ttygid);
        if (sb.st_uid != geteuid())
                errx(1, "%s owned by %d, not the current user (%d)", ptm.sn,
                     sb.st_uid, geteuid());
        return(0);
}