xref: /netbsd-src/usr.bin/talk/get_names.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 /*static char sccsid[] = "from: @(#)get_names.c	5.9 (Berkeley) 3/1/91";*/
36 static char rcsid[] = "$Id: get_names.c,v 1.3 1994/04/17 12:31:05 deraadt Exp $";
37 #endif /* not lint */
38 
39 #include <sys/param.h>
40 #include <sys/socket.h>
41 #include <protocols/talkd.h>
42 #include <pwd.h>
43 #include <string.h>
44 #include "talk.h"
45 
46 char	*getlogin();
47 char	*ttyname();
48 char	*rindex();
49 extern	CTL_MSG msg;
50 
51 /*
52  * Determine the local and remote user, tty, and machines
53  */
54 get_names(argc, argv)
55 	int argc;
56 	char *argv[];
57 {
58 	char hostname[MAXHOSTNAMELEN];
59 	char *his_name, *my_name;
60 	char *my_machine_name, *his_machine_name;
61 	char *my_tty, *his_tty;
62 	register char *cp;
63 	char *names;
64 
65 	if (argc < 2 ) {
66 		printf("Usage: talk user [ttyname]\n");
67 		exit(-1);
68 	}
69 	if (!isatty(0)) {
70 		printf("Standard input must be a tty, not a pipe or a file\n");
71 		exit(-1);
72 	}
73 	if ((my_name = getlogin()) == NULL) {
74 		struct passwd *pw;
75 
76 		if ((pw = getpwuid(getuid())) == NULL) {
77 			printf("You don't exist. Go away.\n");
78 			exit(-1);
79 		}
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 	names = strdup(argv[1]);
86 	for (cp = names; *cp && !index("@:!.", *cp); cp++)
87 		;
88 	if (*cp == '\0') {
89 		/* this is a local to local talk */
90 		his_name = names;
91 		his_machine_name = my_machine_name;
92 	} else {
93 		if (*cp++ == '@') {
94 			/* user@host */
95 			his_name = names;
96 			his_machine_name = cp;
97 		} else {
98 			/* host.user or host!user or host:user */
99 			his_name = cp;
100 			his_machine_name = names;
101 		}
102 		*--cp = '\0';
103 	}
104 	if (argc > 2)
105 		his_tty = argv[2];	/* tty name is arg 2 */
106 	else
107 		his_tty = "";
108 	get_addrs(my_machine_name, his_machine_name);
109 	/*
110 	 * Initialize the message template.
111 	 */
112 	msg.vers = TALK_VERSION;
113 	msg.addr.sa_family = htons(AF_INET);
114 	msg.ctl_addr.sa_family = htons(AF_INET);
115 	msg.id_num = htonl(0);
116 	strncpy(msg.l_name, my_name, NAME_SIZE);
117 	msg.l_name[NAME_SIZE - 1] = '\0';
118 	strncpy(msg.r_name, his_name, NAME_SIZE);
119 	msg.r_name[NAME_SIZE - 1] = '\0';
120 	strncpy(msg.r_tty, his_tty, TTY_SIZE);
121 	msg.r_tty[TTY_SIZE - 1] = '\0';
122 }
123