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freebsd/usr.bin/talk/get_names.c
Joerg Wunsch 285926046a Make talk automagically find out the interface IP address where the
remote peer will be connected through.  This avoids the ``Checking for
invitation on caller's machine'' problem for multi-homed hosts.

Thanks to: Garrett, for his `find_interface' example
1996-03-09 19:23:01 +00:00

117 lines
3.7 KiB
C

/*
* Copyright (c) 1983, 1993
* The 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 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include <unistd.h>
#include <string.h>
#include <sys/param.h>
#include <pwd.h>
#include "talk.h"
extern CTL_MSG msg;
/*
* Determine the local and remote user, tty, and machines
*/
void
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 */
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';
}