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. 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 * @(#)look_up.c 8.1 (Berkeley) 6/6/93
30 * $FreeBSD: src/usr.bin/talk/look_up.c,v 1.5 1999/08/28 01:06:14 peter Exp $
31 */
32
33 #include <sys/param.h>
34 #include <sys/socket.h>
35 #include <protocols/talkd.h>
36 #include <netinet/in.h>
37 #include <errno.h>
38 #include <string.h>
39 #include "talk_ctl.h"
40 #include "talk.h"
41
42 /*
43 * See if the local daemon has an invitation for us.
44 */
45 int
check_local(void)46 check_local(void)
47 {
48 CTL_RESPONSE response;
49 CTL_RESPONSE *rp = &response;
50
51 /* the rest of msg was set up in get_names */
52 #ifdef MSG_EOR
53 /* copy new style sockaddr to old, swap family (short in old) */
54 msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
55 msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
56 #else
57 msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
58 #endif
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 struct sockaddr_in addr;
69 struct sockaddr_in *raddr;
70
71 if (rp->addr.sa_family != AF_INET)
72 p_error("Response uses invalid network address");
73 raddr = (struct sockaddr_in *)&rp->addr;
74 memset(&addr, 0, sizeof(addr));
75 addr.sin_family = AF_INET;
76 addr.sin_port = raddr->sin_port;
77 addr.sin_addr = raddr->sin_addr;
78 errno = 0;
79 if (connect(sockt,
80 (struct sockaddr *)&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