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get_names.c revision 1.3 
      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