1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33
34__FBSDID("$FreeBSD$");
35
36#ifndef lint
37static const char sccsid[] = "@(#)look_up.c	8.1 (Berkeley) 6/6/93";
38#endif
39
40#include <sys/types.h>
41#include <sys/socket.h>
42#include <protocols/talkd.h>
43
44#include <errno.h>
45#include <string.h>
46#include <unistd.h>
47
48#include "talk_ctl.h"
49#include "talk.h"
50
51/*
52 * See if the local daemon has an invitation for us.
53 */
54int
55check_local(void)
56{
57	CTL_RESPONSE response;
58	CTL_RESPONSE *rp = &response;
59	struct sockaddr addr;
60
61	/* the rest of msg was set up in get_names */
62	/* copy new style sockaddr to old, swap family (short in old) */
63	msg.ctl_addr = *(struct tsockaddr *)&ctl_addr;
64	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
65	/* must be initiating a talk */
66	if (!look_for_invite(rp))
67		return (0);
68	/*
69	 * There was an invitation waiting for us,
70	 * so connect with the other (hopefully waiting) party
71	 */
72	current_state = "Waiting to connect with caller";
73	do {
74		if (rp->addr.sa_family != AF_INET)
75			p_error("Response uses invalid network address");
76		(void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr));
77		addr.sa_family = rp->addr.sa_family;
78		addr.sa_len = sizeof(addr);
79		errno = 0;
80		if (connect(sockt, &addr, sizeof(addr)) != -1)
81			return (1);
82	} while (errno == EINTR);
83	if (errno == ECONNREFUSED) {
84		/*
85		 * The caller gave up, but his invitation somehow
86		 * was not cleared. Clear it and initiate an
87		 * invitation. (We know there are no newer invitations,
88		 * the talkd works LIFO.)
89		 */
90		ctl_transact(his_machine_addr, msg, DELETE, rp);
91		close(sockt);
92		open_sockt();
93		return (0);
94	}
95	p_error("Unable to connect with initiator");
96	/*NOTREACHED*/
97	return (0);
98}
99
100/*
101 * Look for an invitation on 'machine'
102 */
103int
104look_for_invite(CTL_RESPONSE *rp)
105{
106	current_state = "Checking for invitation on caller's machine";
107	ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
108	/* the switch is for later options, such as multiple invitations */
109	switch (rp->answer) {
110
111	case SUCCESS:
112		msg.id_num = htonl(rp->id_num);
113		return (1);
114
115	default:
116		/* there wasn't an invitation waiting for us */
117		return (0);
118	}
119}
120