1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33
34__FBSDID("$FreeBSD$");
35
36#ifndef lint
37static const char sccsid[] = "@(#)get_names.c	8.1 (Berkeley) 6/6/93";
38#endif
39
40#include <sys/param.h>
41
42#include <err.h>
43#include <pwd.h>
44#include <stdlib.h>
45#include <string.h>
46#include <unistd.h>
47
48#include "talk.h"
49
50extern	CTL_MSG msg;
51
52static void
53usage(void)
54{
55	fprintf(stderr, "usage: talk person [ttyname]\n");
56	exit(1);
57}
58
59/*
60 * Determine the local and remote user, tty, and machines
61 */
62void
63get_names(int argc, char *argv[])
64{
65	char hostname[MAXHOSTNAMELEN];
66	char *his_name, *my_name;
67	const char *my_machine_name, *his_machine_name;
68	const char *his_tty;
69	char *cp;
70
71	if (argc < 2 )
72		usage();
73	if (!isatty(0))
74		errx(1, "standard input must be a tty, not a pipe or a file");
75	if ((my_name = getlogin()) == NULL) {
76		struct passwd *pw;
77
78		if ((pw = getpwuid(getuid())) == NULL)
79			errx(1, "you don't exist. Go away");
80		my_name = pw->pw_name;
81	}
82	gethostname(hostname, sizeof (hostname));
83	my_machine_name = hostname;
84	/* check for, and strip out, the machine name of the target */
85	cp = argv[1] + strcspn(argv[1], "@:!");
86	if (*cp == '\0') {
87		/* this is a local to local talk */
88		his_name = argv[1];
89		my_machine_name = his_machine_name = "localhost";
90	} else {
91		if (*cp++ == '@') {
92			/* user@host */
93			his_name = argv[1];
94			his_machine_name = cp;
95		} else {
96			/* host!user or host:user */
97			his_name = cp;
98			his_machine_name = argv[1];
99		}
100		*--cp = '\0';
101	}
102	if (argc > 2)
103		his_tty = argv[2];	/* tty name is arg 2 */
104	else
105		his_tty = "";
106	get_addrs(my_machine_name, his_machine_name);
107	/*
108	 * Initialize the message template.
109	 */
110	msg.vers = TALK_VERSION;
111	msg.addr.sa_family = htons(AF_INET);
112	msg.ctl_addr.sa_family = htons(AF_INET);
113	msg.id_num = htonl(0);
114	strlcpy(msg.l_name, my_name, NAME_SIZE);
115	strlcpy(msg.r_name, his_name, NAME_SIZE);
116	strlcpy(msg.r_tty, his_tty, TTY_SIZE);
117}
118