xref: /dragonfly/usr.bin/talk/look_up.c (revision 52f9f0d9)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#)look_up.c	8.1 (Berkeley) 6/6/93
34  * $FreeBSD: src/usr.bin/talk/look_up.c,v 1.5 1999/08/28 01:06:14 peter Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/socket.h>
39 #include <protocols/talkd.h>
40 #include <errno.h>
41 #include "talk_ctl.h"
42 #include "talk.h"
43 
44 /*
45  * See if the local daemon has an invitation for us.
46  */
47 int
48 check_local(void)
49 {
50 	CTL_RESPONSE response;
51 	CTL_RESPONSE *rp = &response;
52 
53 	/* the rest of msg was set up in get_names */
54 #ifdef MSG_EOR
55 	/* copy new style sockaddr to old, swap family (short in old) */
56 	msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
57 	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
58 #else
59 	msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
60 #endif
61 	/* must be initiating a talk */
62 	if (!look_for_invite(rp))
63 		return (0);
64 	/*
65 	 * There was an invitation waiting for us,
66 	 * so connect with the other (hopefully waiting) party
67 	 */
68 	current_state = "Waiting to connect with caller";
69 	do {
70 		if (rp->addr.sa_family != AF_INET)
71 			p_error("Response uses invalid network address");
72 		errno = 0;
73 		if (connect(sockt,
74 		    (struct sockaddr *)&rp->addr, sizeof (rp->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  */
97 int
98 look_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