1 /* $NetBSD: look_up.c,v 1.8 2012/03/20 20:34:59 matt Exp $ */
2
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 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)look_up.c 8.1 (Berkeley) 6/6/93";
36 #endif
37 __RCSID("$NetBSD: look_up.c,v 1.8 2012/03/20 20:34:59 matt Exp $");
38 #endif /* not lint */
39
40 #include "talk.h"
41 #include <errno.h>
42 #include <unistd.h>
43 #include "talk_ctl.h"
44
45 /*
46 * See if the local daemon has an invitation for us.
47 */
48 int
check_local(void)49 check_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 #ifdef MSG_EOR
57 /* copy new style sockaddr to old, swap family (short in old) */
58 msg.ctl_addr = *(struct talkd_sockaddr *)(void *)&ctl_addr;
59 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
60 #else
61 msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
62 #endif
63 /* must be initiating a talk */
64 if (!look_for_invite(rp))
65 return (0);
66 /*
67 * There was an invitation waiting for us,
68 * so connect with the other (hopefully waiting) party
69 */
70 current_state = "Waiting to connect with caller";
71 do {
72 if (rp->addr.sa_family != AF_INET)
73 p_error("Response uses invalid network address");
74
75 (void)memcpy(&addr, &rp->addr.sa_family, sizeof(addr));
76 addr.sa_family = rp->addr.sa_family;
77 addr.sa_len = sizeof(addr);
78
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 */
103 int
look_for_invite(CTL_RESPONSE * rp)104 look_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