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
33
34#include <sys/types.h>
35#include <sys/socket.h>
36#include <protocols/talkd.h>
37
38#include <errno.h>
39#include <string.h>
40#include <unistd.h>
41
42#include "talk_ctl.h"
43#include "talk.h"
44
45/*
46 * See if the local daemon has an invitation for us.
47 */
48int
49check_local(void)
50{
51	CTL_RESPONSE response;
52	CTL_RESPONSE *rp = &response;
53	struct sockaddr addr;
54
55	/* the rest of msg was set up in get_names */
56	/* copy new style sockaddr to old, swap family (short in old) */
57	msg.ctl_addr = *(struct tsockaddr *)&ctl_addr;
58	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
59	/* must be initiating a talk */
60	if (!look_for_invite(rp))
61		return (0);
62	/*
63	 * There was an invitation waiting for us,
64	 * so connect with the other (hopefully waiting) party
65	 */
66	current_state = "Waiting to connect with caller";
67	do {
68		if (rp->addr.sa_family != AF_INET)
69			p_error("Response uses invalid network address");
70		(void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr));
71		addr.sa_family = rp->addr.sa_family;
72		addr.sa_len = sizeof(addr);
73		errno = 0;
74		if (connect(sockt, &addr, sizeof(addr)) != -1)
75			return (1);
76	} while (errno == EINTR);
77	if (errno == ECONNREFUSED) {
78		/*
79		 * The caller gave up, but his invitation somehow
80		 * was not cleared. Clear it and initiate an
81		 * invitation. (We know there are no newer invitations,
82		 * the talkd works LIFO.)
83		 */
84		ctl_transact(his_machine_addr, msg, DELETE, rp);
85		close(sockt);
86		open_sockt();
87		return (0);
88	}
89	p_error("Unable to connect with initiator");
90	/*NOTREACHED*/
91	return (0);
92}
93
94/*
95 * Look for an invitation on 'machine'
96 */
97int
98look_for_invite(CTL_RESPONSE *rp)
99{
100	current_state = "Checking for invitation on caller's machine";
101	ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
102	/* the switch is for later options, such as multiple invitations */
103	switch (rp->answer) {
104
105	case SUCCESS:
106		msg.id_num = htonl(rp->id_num);
107		return (1);
108
109	default:
110		/* there wasn't an invitation waiting for us */
111		return (0);
112	}
113}
114