1 /* $NetBSD: get_names.c,v 1.16 2012/12/29 23:44:23 christos Exp $ */
2
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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)get_names.c 8.1 (Berkeley) 6/6/93";
36 #endif
37 __RCSID("$NetBSD: get_names.c,v 1.16 2012/12/29 23:44:23 christos Exp $");
38 #endif /* not lint */
39
40 #include "talk.h"
41 #include <err.h>
42 #include <sys/param.h>
43 #include <pwd.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include <util.h>
47
48 extern CTL_MSG msg;
49
50 /*
51 * Determine the local and remote user, tty, and machines
52 */
53 void
get_names(int argc,char * argv[])54 get_names(int argc, char *argv[])
55 {
56 char hostname[MAXHOSTNAMELEN + 1];
57 const char *his_name, *my_name;
58 const char *my_machine_name, *his_machine_name;
59 const char *his_tty;
60 char *cp;
61 char *names;
62
63 if (argc < 2 ) {
64 fprintf(stderr, "Usage: %s user [ttyname]\n", getprogname());
65 exit(1);
66 }
67 if (!isatty(0))
68 errx(EXIT_FAILURE, "Standard input must be a tty, "
69 "not a pipe or a file");
70 if ((my_name = getlogin()) == NULL) {
71 struct passwd *pw;
72
73 if ((pw = getpwuid(getuid())) == NULL)
74 errx(EXIT_FAILURE, "You don't exist. Go away.");
75 my_name = pw->pw_name;
76 }
77 if ((cp = getenv("TALKHOST")) != NULL)
78 (void)estrlcpy(hostname, cp, sizeof(hostname));
79 else {
80 if (gethostname(hostname, sizeof(hostname)) == -1)
81 err(EXIT_FAILURE, "gethostname");
82 hostname[sizeof(hostname) - 1] = '\0';
83 }
84 my_machine_name = hostname;
85 /* check for, and strip out, the machine name of the target */
86 names = strdup(argv[1]);
87 for (cp = names; *cp && !strchr("@:!.", *cp); cp++)
88 ;
89 if (*cp == '\0') {
90 /* this is a local to local talk */
91 his_name = names;
92 his_machine_name = my_machine_name;
93 } else {
94 if (*cp++ == '@') {
95 /* user@host */
96 his_name = names;
97 his_machine_name = cp;
98 } else {
99 /* host.user or host!user or host:user */
100 his_name = cp;
101 his_machine_name = names;
102 }
103 *--cp = '\0';
104 }
105 if (argc > 2)
106 his_tty = argv[2]; /* tty name is arg 2 */
107 else
108 his_tty = "";
109 get_addrs(my_machine_name, his_machine_name);
110 /*
111 * Initialize the message template.
112 */
113 msg.vers = TALK_VERSION;
114 msg.addr.sa_family = htons(AF_INET);
115 msg.ctl_addr.sa_family = htons(AF_INET);
116 msg.id_num = htonl(0);
117 strncpy(msg.l_name, my_name, NAME_SIZE);
118 msg.l_name[NAME_SIZE - 1] = '\0';
119 strncpy(msg.r_name, his_name, NAME_SIZE);
120 msg.r_name[NAME_SIZE - 1] = '\0';
121 strncpy(msg.r_tty, his_tty, TTY_SIZE);
122 msg.r_tty[TTY_SIZE - 1] = '\0';
123 free(names);
124 }
125