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
33
34 #include <sys/param.h>
35
36 #include <err.h>
37 #include <pwd.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41
42 #include "talk.h"
43
44 extern CTL_MSG msg;
45
46 static void
usage(void)47 usage(void)
48 {
49 fprintf(stderr, "usage: talk person [ttyname]\n");
50 exit(1);
51 }
52
53 /*
54 * Determine the local and remote user, tty, and machines
55 */
56 void
get_names(int argc,char * argv[])57 get_names(int argc, char *argv[])
58 {
59 char hostname[MAXHOSTNAMELEN];
60 char *his_name, *my_name;
61 const char *my_machine_name, *his_machine_name;
62 const char *his_tty;
63 char *cp;
64
65 if (argc < 2 )
66 usage();
67 if (!isatty(0))
68 errx(1, "standard input must be a tty, not a pipe or a file");
69 if ((my_name = getlogin()) == NULL) {
70 struct passwd *pw;
71
72 if ((pw = getpwuid(getuid())) == NULL)
73 errx(1, "you don't exist. Go away");
74 my_name = pw->pw_name;
75 }
76 gethostname(hostname, sizeof (hostname));
77 my_machine_name = hostname;
78 /* check for, and strip out, the machine name of the target */
79 cp = argv[1] + strcspn(argv[1], "@:!");
80 if (*cp == '\0') {
81 /* this is a local to local talk */
82 his_name = argv[1];
83 my_machine_name = his_machine_name = "localhost";
84 } else {
85 if (*cp++ == '@') {
86 /* user@host */
87 his_name = argv[1];
88 his_machine_name = cp;
89 } else {
90 /* host!user or host:user */
91 his_name = cp;
92 his_machine_name = argv[1];
93 }
94 *--cp = '\0';
95 }
96 if (argc > 2)
97 his_tty = argv[2]; /* tty name is arg 2 */
98 else
99 his_tty = "";
100 get_addrs(my_machine_name, his_machine_name);
101 /*
102 * Initialize the message template.
103 */
104 msg.vers = TALK_VERSION;
105 msg.addr.sa_family = htons(AF_INET);
106 msg.ctl_addr.sa_family = htons(AF_INET);
107 msg.id_num = htonl(0);
108 strlcpy(msg.l_name, my_name, NAME_SIZE);
109 strlcpy(msg.r_name, his_name, NAME_SIZE);
110 strlcpy(msg.r_tty, his_tty, TTY_SIZE);
111 }
112