1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31
32__FBSDID("$FreeBSD$");
33
34#ifndef lint
35static const char sccsid[] = "@(#)look_up.c	8.1 (Berkeley) 6/6/93";
36#endif
37
38#include <sys/types.h>
39#include <sys/socket.h>
40#include <protocols/talkd.h>
41
42#include <errno.h>
43#include <string.h>
44#include <unistd.h>
45
46#include "talk_ctl.h"
47#include "talk.h"
48
49/*
50 * See if the local daemon has an invitation for us.
51 */
52int
53check_local(void)
54{
55	CTL_RESPONSE response;
56	CTL_RESPONSE *rp = &response;
57	struct sockaddr addr;
58
59	/* the rest of msg was set up in get_names */
60#ifdef MSG_EOR
61	/* copy new style sockaddr to old, swap family (short in old) */
62	msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
63	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
64#else
65	msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
66#endif
67	/* must be initiating a talk */
68	if (!look_for_invite(rp))
69		return (0);
70	/*
71	 * There was an invitation waiting for us,
72	 * so connect with the other (hopefully waiting) party
73	 */
74	current_state = "Waiting to connect with caller";
75	do {
76		if (rp->addr.sa_family != AF_INET)
77			p_error("Response uses invalid network address");
78		(void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr));
79		addr.sa_family = rp->addr.sa_family;
80		addr.sa_len = sizeof(addr);
81		errno = 0;
82		if (connect(sockt, &addr, sizeof(addr)) != -1)
83			return (1);
84	} while (errno == EINTR);
85	if (errno == ECONNREFUSED) {
86		/*
87		 * The caller gave up, but his invitation somehow
88		 * was not cleared. Clear it and initiate an
89		 * invitation. (We know there are no newer invitations,
90		 * the talkd works LIFO.)
91		 */
92		ctl_transact(his_machine_addr, msg, DELETE, rp);
93		close(sockt);
94		open_sockt();
95		return (0);
96	}
97	p_error("Unable to connect with initiator");
98	/*NOTREACHED*/
99	return (0);
100}
101
102/*
103 * Look for an invitation on 'machine'
104 */
105int
106look_for_invite(CTL_RESPONSE *rp)
107{
108	current_state = "Checking for invitation on caller's machine";
109	ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
110	/* the switch is for later options, such as multiple invitations */
111	switch (rp->answer) {
112
113	case SUCCESS:
114		msg.id_num = htonl(rp->id_num);
115		return (1);
116
117	default:
118		/* there wasn't an invitation waiting for us */
119		return (0);
120	}
121}
122