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 */
44 int
check_local(void)45 check_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 */
93 int
look_for_invite(CTL_RESPONSE * rp)94 look_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