/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */



#include <sys/param.h>

#include <err.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "talk.h"

extern  CTL_MSG msg;

static void
usage(void)
{
        fprintf(stderr, "usage: talk person [ttyname]\n");
        exit(1);
}

/*
 * Determine the local and remote user, tty, and machines
 */
void
get_names(int argc, char *argv[])
{
        char hostname[MAXHOSTNAMELEN];
        char *his_name, *my_name;
        const char *my_machine_name, *his_machine_name;
        const char *his_tty;
        char *cp;

        if (argc < 2 )
                usage();
        if (!isatty(0))
                errx(1, "standard input must be a tty, not a pipe or a file");
        if ((my_name = getlogin()) == NULL) {
                struct passwd *pw;

                if ((pw = getpwuid(getuid())) == NULL)
                        errx(1, "you don't exist. Go away");
                my_name = pw->pw_name;
        }
        gethostname(hostname, sizeof (hostname));
        my_machine_name = hostname;
        /* check for, and strip out, the machine name of the target */
        cp = argv[1] + strcspn(argv[1], "@:!");
        if (*cp == '\0') {
                /* this is a local to local talk */
                his_name = argv[1];
                my_machine_name = his_machine_name = "localhost";
        } else {
                if (*cp++ == '@') {
                        /* user@host */
                        his_name = argv[1];
                        his_machine_name = cp;
                } else {
                        /* host!user or host:user */
                        his_name = cp;
                        his_machine_name = argv[1];
                }
                *--cp = '\0';
        }
        if (argc > 2)
                his_tty = argv[2];      /* tty name is arg 2 */
        else
                his_tty = "";
        get_addrs(my_machine_name, his_machine_name);
        /*
         * Initialize the message template.
         */
        msg.vers = TALK_VERSION;
        msg.addr.sa_family = htons(AF_INET);
        msg.ctl_addr.sa_family = htons(AF_INET);
        msg.id_num = htonl(0);
        strlcpy(msg.l_name, my_name, NAME_SIZE);
        strlcpy(msg.r_name, his_name, NAME_SIZE);
        strlcpy(msg.r_tty, his_tty, TTY_SIZE);
}