Return to invite.c CVS log

Up to [local] / src / usr.bin / talk

handle ECONNABORTED errors from accept().  In many code blocks they can be
ignored silently and without aborting, much like EINTR and EWOULDBLOCK are.
ok's from various maintainers of these directories...

/*	$OpenBSD: invite.c,v 1.15 2013/03/11 17:40:11 deraadt Exp $	*/
/*	$NetBSD: invite.c,v 1.3 1994/12/09 02:14:18 jtc Exp $	*/

/*
 * 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. 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.
 */

#include "talk.h"
#include <arpa/inet.h>
#include <sys/time.h>
#include <netdb.h>
#include <errno.h>
#include <setjmp.h>
#include <unistd.h>
#include "talk_ctl.h"

#define STRING_LENGTH 158

/*
 * There wasn't an invitation waiting, so send a request containing
 * our sockt address to the remote talk daemon so it can invite
 * him
 */

/*
 * The msg.id's for the invitations
 * on the local and remote machines.
 * These are used to delete the
 * invitations.
 */
int	local_id, remote_id;
jmp_buf invitebuf;

void
invite_remote(void)
{
	int new_sockt;
	struct itimerval itimer;
	CTL_RESPONSE response;
	struct sockaddr rp;
	socklen_t rplen = sizeof(struct sockaddr);
	struct hostent *rphost;
	char rname[STRING_LENGTH];

	itimer.it_value.tv_sec = RING_WAIT;
	itimer.it_value.tv_usec = 0;
	itimer.it_interval = itimer.it_value;
	if (listen(sockt, 5) != 0)
		quit("Error on attempt to listen for caller", 1);
#ifdef MSG_EOR
	/* copy new style sockaddr to old, swap family (short in old) */
	msg.addr = *(struct osockaddr *)&my_addr;  /* XXX new to old  style*/
	msg.addr.sa_family = htons(my_addr.sin_family);
#else
	msg.addr = *(struct sockaddr *)&my_addr;
#endif
	msg.id_num = htonl(-1);		/* an impossible id_num */
	invitation_waiting = 1;
	announce_invite();
	/*
	 * Shut off the automatic messages for a while,
	 * so we can use the interrupt timer to resend the invitation.
	 * We no longer turn automatic messages back on to avoid a bonus
	 * message after we've connected; this is okay even though end_msgs()
	 * gets called again in main().
	 */
	end_msgs();
	setitimer(ITIMER_REAL, &itimer, (struct itimerval *)0);
	message("Waiting for your party to respond");
	signal(SIGALRM, re_invite);
	(void) setjmp(invitebuf);
	while ((new_sockt = accept(sockt, &rp, &rplen)) == -1) {
		if (errno == EINTR || errno == EWOULDBLOCK ||
		    errno == ECONNABORTED)
			continue;
		quit("Unable to connect with your party", 1);
	}
	close(sockt);
	sockt = new_sockt;

	/*
	 * Have the daemons delete the invitations now that we
	 * have connected.
	 */
	msg.id_num = htonl(local_id);
	ctl_transact(my_machine_addr, msg, DELETE, &response);
	msg.id_num = htonl(remote_id);
	ctl_transact(his_machine_addr, msg, DELETE, &response);
	invitation_waiting = 0;

	/*
	 * Check to see if the other guy is coming from the machine
	 * we expect.
	 */
	if (his_machine_addr.s_addr !=
	    ((struct sockaddr_in *)&rp)->sin_addr.s_addr) {
		rphost = gethostbyaddr((char *) &((struct sockaddr_in
		    *)&rp)->sin_addr, sizeof(struct in_addr), AF_INET);
		if (rphost)
			snprintf(rname, STRING_LENGTH,
			    "Answering talk request from %s@%s", msg.r_name,
			    rphost->h_name);
		else
			snprintf(rname, STRING_LENGTH,
			    "Answering talk request from %s@%s", msg.r_name,
			    inet_ntoa(((struct sockaddr_in *)&rp)->sin_addr));
		message(rname);
	}
}

/*
 * Routine called on interrupt to re-invite the callee
 */
void
re_invite(int dummy)
{
	message("Ringing your party again");
	/* force a re-announce */
	msg.id_num = htonl(remote_id + 1);
	announce_invite();
	longjmp(invitebuf, 1);
}

static	char *answers[] = {
	"answer #0",					/* SUCCESS */
	"Your party is not logged on",			/* NOT_HERE */
	"Target machine is too confused to talk to us",	/* FAILED */
	"Target machine does not recognize us",		/* MACHINE_UNKNOWN */
	"Your party is refusing messages",		/* PERMISSION_REFUSED */
	"Target machine can not handle remote talk",	/* UNKNOWN_REQUEST */
	"Target machine indicates protocol mismatch",	/* BADVERSION */
	"Target machine indicates protocol botch (addr)",/* BADADDR */
	"Target machine indicates protocol botch (ctl_addr)",/* BADCTLADDR */
};
#define NANSWERS (sizeof (answers) / sizeof (answers[0]))

/*
 * Transmit the invitation and process the response
 */
void
announce_invite(void)
{
	CTL_RESPONSE response;

	current_state = "Trying to connect to your party's talk daemon";
	ctl_transact(his_machine_addr, msg, ANNOUNCE, &response);
	remote_id = response.id_num;
	if (response.answer != SUCCESS)
		quit(response.answer < NANSWERS ? answers[response.answer] : NULL, 0);
	/* leave the actual invitation on my talk daemon */
	ctl_transact(my_machine_addr, msg, LEAVE_INVITE, &response);
	local_id = response.id_num;
}

/*
 * Tell the daemon to remove your invitation
 */
void
send_delete(void)
{

	msg.type = DELETE;
	/*
	 * This is just a extra clean up, so just send it
	 * and don't wait for an answer
	 */
	msg.id_num = htonl(remote_id);
	daemon_addr.sin_addr = his_machine_addr;
	if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
	    (struct sockaddr *)&daemon_addr,
	    sizeof (daemon_addr)) != sizeof(msg))
		warn("send_delete (remote)");
	msg.id_num = htonl(local_id);
	daemon_addr.sin_addr = my_machine_addr;
	if (sendto(ctl_sockt, &msg, sizeof (msg), 0,
	    (struct sockaddr *)&daemon_addr,
	    sizeof (daemon_addr)) != sizeof (msg))
		warn("send_delete (local)");
}