usr/src/usr.bin/talk/get_names.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)get_names.c 5.9 (Berkeley) 3/1/91";
#endif /* not lint */

#include <sys/param.h>
#include <sys/socket.h>
#include <protocols/talkd.h>
#include <pwd.h>
#include "talk.h"

char    *getlogin();
char    *ttyname();
char    *rindex();
extern  CTL_MSG msg;

/*
 * Determine the local and remote user, tty, and machines
 */
get_names(argc, argv)
        int argc;
        char *argv[];
{
        char hostname[MAXHOSTNAMELEN];
        char *his_name, *my_name;
        char *my_machine_name, *his_machine_name;
        char *my_tty, *his_tty;
        register char *cp;

        if (argc < 2 ) {
                printf("Usage: talk user [ttyname]\n");
                exit(-1);
        }
        if (!isatty(0)) {
                printf("Standard input must be a tty, not a pipe or a file\n");
                exit(-1);
        }
        if ((my_name = getlogin()) == NULL) {
                struct passwd *pw;

                if ((pw = getpwuid(getuid())) == NULL) {
                        printf("You don't exist. Go away.\n");
                        exit(-1);
                }
                my_name = pw->pw_name;
        }
        gethostname(hostname, sizeof (hostname));
        my_machine_name = hostname;
        /* check for, and strip out, the machine name of the target */
        for (cp = argv[1]; *cp && !index("@:!.", *cp); cp++)
                ;
        if (*cp == '\0') {
                /* this is a local to local talk */
                his_name = argv[1];
                his_machine_name = my_machine_name;
        } else {
                if (*cp++ == '@') {
                        /* user@host */
                        his_name = argv[1];
                        his_machine_name = cp;
                } else {
                        /* host.user or host!user or host:user */
                        his_name = cp;
                        his_machine_name = argv[1];
                }
                *--cp = '\0';
        }
        if (argc > 2)
                his_tty = argv[2];      /* tty name is arg 2 */
        else
                his_tty = "";
        get_addrs(my_machine_name, his_machine_name);
        /*
         * Initialize the message template.
         */
        msg.vers = TALK_VERSION;
        msg.addr.sa_family = htons(AF_INET);
        msg.ctl_addr.sa_family = htons(AF_INET);
        msg.id_num = htonl(0);
        strncpy(msg.l_name, my_name, NAME_SIZE);
        msg.l_name[NAME_SIZE - 1] = '\0';
        strncpy(msg.r_name, his_name, NAME_SIZE);
        msg.r_name[NAME_SIZE - 1] = '\0';
        strncpy(msg.r_tty, his_tty, TTY_SIZE);
        msg.r_tty[TTY_SIZE - 1] = '\0';
}