1/*	$OpenBSD: look_up.c,v 1.13 2016/02/01 07:29:25 mestre Exp $	*/
2/*	$NetBSD: look_up.c,v 1.3 1994/12/09 02:14:21 jtc Exp $	*/
3
4/*
5 * Copyright (c) 1983, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/socket.h>
34
35#include <errno.h>
36#include <unistd.h>
37
38#include "talk.h"
39#include "talk_ctl.h"
40
41/*
42 * See if the local daemon has an invitation for us.
43 */
44int
45check_local(void)
46{
47	CTL_RESPONSE response;
48
49	/* the rest of msg was set up in get_names */
50#ifdef MSG_EOR
51	/* copy new style sockaddr to old, swap family (short in old) */
52	msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
53	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
54#else
55	msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
56#endif
57	/* must be initiating a talk */
58	if (!look_for_invite(&response))
59		return (0);
60	/*
61	 * There was an invitation waiting for us,
62	 * so connect with the other (hopefully waiting) party
63	 */
64	current_state = "Waiting to connect with caller";
65	do {
66		if (ntohs(response.addr.sa_family) != AF_INET)
67			quit("Response uses invalid network address", 1);
68		errno = 0;
69		if (connect(sockt, (struct sockaddr *)&response.addr,
70			    sizeof (response.addr)) != -1)
71			return (1);
72	} while (errno == EINTR);
73
74	if (errno == ECONNREFUSED) {
75		/*
76		 * The caller gave up, but his invitation somehow
77		 * was not cleared. Clear it and initiate an
78		 * invitation. (We know there are no newer invitations,
79		 * the talkd works LIFO.)
80		 */
81		ctl_transact(his_machine_addr, msg, DELETE, &response);
82		close(sockt);
83		open_sockt();
84		return (0);
85	}
86	quit("Unable to connect with initiator", 1);
87	return (0);
88}
89
90/*
91 * Look for an invitation on 'machine'
92 */
93int
94look_for_invite(CTL_RESPONSE *rp)
95{
96	current_state = "Checking for invitation on caller's machine";
97	ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
98	/* the switch is for later options, such as multiple invitations */
99	switch (rp->answer) {
100	case SUCCESS:
101		msg.id_num = htonl(rp->id_num);
102		return (1);
103	default:
104		/* there wasn't an invitation waiting for us */
105		return (0);
106	}
107}
108