1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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#ifndef _PROTOCOLS_TALKD_H_
33#define _PROTOCOLS_TALKD_H_
34
35/*
36 * This describes the protocol used by the talk server and clients.
37 *
38 * The talk server acts a repository of invitations, responding to
39 * requests by clients wishing to rendezvous for the purpose of
40 * holding a conversation. In normal operation, a client, the caller,
41 * initiates a rendezvous by sending a CTL_MSG to the server of
42 * type LOOK_UP. This causes the server to search its invitation
43 * tables to check if an invitation currently exists for the caller
44 * (to speak to the callee specified in the message). If the lookup
45 * fails, the caller then sends an ANNOUNCE message causing the server
46 * to broadcast an announcement on the callee's login ports requesting
47 * contact. When the callee responds, the local server uses the
48 * recorded invitation to respond with the appropriate rendezvous
49 * address and the caller and callee client programs establish a
50 * stream connection through which the conversation takes place.
51 */
52
53/*
54 * The talk protocol embeds a 4.3BSD sockaddr. Define our own version
55 * rather then relying on namespace pollution in kernel headers.
56 */
57struct tsockaddr {
58 unsigned short sa_family;
59 char sa_data[14];
60};
61
62/*
63 * Client->server request message format.
64 */
65typedef struct {
66 u_char vers; /* protocol version */
67 u_char type; /* request type, see below */
68 u_char answer; /* not used */
69 u_char pad;
70 u_int32_t id_num; /* message id */
71 struct tsockaddr addr; /* old (4.3) style */
72 struct tsockaddr ctl_addr; /* old (4.3) style */
73 int32_t pid; /* caller's process id */
74#define NAME_SIZE 12
75 char l_name[NAME_SIZE];/* caller's name */
76 char r_name[NAME_SIZE];/* callee's name */
77#define TTY_SIZE 16
78 char r_tty[TTY_SIZE];/* callee's tty name */
79} CTL_MSG;
80
81/*
82 * Server->client response message format.
83 */
84typedef struct {
85 u_char vers; /* protocol version */
86 u_char type; /* type of request message, see below */
87 u_char answer; /* respose to request message, see below */
88 u_char pad;
89 u_int32_t id_num; /* message id */
90 struct tsockaddr addr; /* address for establishing conversation */
91} CTL_RESPONSE;
92
93#define TALK_VERSION 1 /* protocol version */
94
95/* message type values */
96#define LEAVE_INVITE 0 /* leave invitation with server */
97#define LOOK_UP 1 /* check for invitation by callee */
98#define DELETE 2 /* delete invitation by caller */
99#define ANNOUNCE 3 /* announce invitation by caller */
100
101/* answer values */
102#define SUCCESS 0 /* operation completed properly */
103#define NOT_HERE 1 /* callee not logged in */
104#define FAILED 2 /* operation failed for unexplained reason */
105#define MACHINE_UNKNOWN 3 /* caller's machine name unknown */
106#define PERMISSION_DENIED 4 /* callee's tty doesn't permit announce */
107#define UNKNOWN_REQUEST 5 /* request has invalid type value */
108#define BADVERSION 6 /* request has invalid protocol version */
109#define BADADDR 7 /* request has invalid addr value */
110#define BADCTLADDR 8 /* request has invalid ctl_addr value */
111
112/*
113 * Operational parameters.
114 */
115#define MAX_LIFE 60 /* max time daemon saves invitations */
116/* RING_WAIT should be 10's of seconds less than MAX_LIFE */
117#define RING_WAIT 30 /* time to wait before resending invitation */
118
119#endif /* !_TALKD_H_ */