1/* $NetBSD: talkd.h,v 1.12 2025/07/11 22:19:53 andvar 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 * @(#)talkd.h 8.1 (Berkeley) 6/2/93
32 */
33
34#ifndef _PROTOCOLS_TALKD_H_
35#define _PROTOCOLS_TALKD_H_
36
37#include <stdint.h>
38
39/*
40 * This describes the protocol used by the talk server and clients.
41 *
42 * The talk server acts a repository of invitations, responding to
43 * requests by clients wishing to rendezvous for the purpose of
44 * holding a conversation. In normal operation, a client, the caller,
45 * initiates a rendezvous by sending a CTL_MSG to the server of
46 * type LOOK_UP. This causes the server to search its invitation
47 * tables to check if an invitation currently exists for the caller
48 * (to speak to the callee specified in the message). If the lookup
49 * fails, the caller then sends an ANNOUNCE message causing the server
50 * to broadcast an announcement on the callee's login ports requesting
51 * contact. When the callee responds, the local server uses the
52 * recorded invitation to respond with the appropriate rendezvous
53 * address and the caller and callee client programs establish a
54 * stream connection through which the conversation takes place.
55 */
56
57/*
58 * 4.3 compat sockaddr
59 */
60struct talkd_sockaddr {
61 uint16_t sa_family; /* address family */
62 char sa_data[14]; /* up to 14 bytes of direct address */
63};
64
65/*
66 * Client->server request message format.
67 */
68typedef struct {
69 unsigned char vers; /* protocol version */
70 unsigned char type; /* request type, see below */
71 unsigned char answer; /* not used */
72 unsigned char pad;
73 uint32_t id_num; /* message id */
74 struct talkd_sockaddr addr; /* old (4.3) style */
75 struct talkd_sockaddr ctl_addr;/* old (4.3) style */
76 int32_t pid; /* caller's process id */
77#define NAME_SIZE 12
78 char l_name[NAME_SIZE]; /* caller's name */
79 char r_name[NAME_SIZE]; /* callee's name */
80#define TTY_SIZE 16
81 char r_tty[TTY_SIZE]; /* callee's tty name */
82} CTL_MSG;
83
84/*
85 * Server->client response message format.
86 */
87typedef struct {
88 unsigned char vers; /* protocol version */
89 unsigned char type; /* type of request message, see below */
90 unsigned char answer; /* response to request message, see below */
91 unsigned char pad;
92 uint32_t id_num; /* message id */
93 struct talkd_sockaddr addr; /* address for establishing conversation */
94} CTL_RESPONSE;
95
96#define TALK_VERSION 1 /* protocol version */
97
98/* message type values */
99#define LEAVE_INVITE 0 /* leave invitation with server */
100#define LOOK_UP 1 /* check for invitation by callee */
101#define DELETE 2 /* delete invitation by caller */
102#define ANNOUNCE 3 /* announce invitation by caller */
103
104/* answer values */
105#define SUCCESS 0 /* operation completed properly */
106#define NOT_HERE 1 /* callee not logged in */
107#define FAILED 2 /* operation failed for unexplained reason */
108#define MACHINE_UNKNOWN 3 /* caller's machine name unknown */
109#define PERMISSION_DENIED 4 /* callee's tty doesn't permit announce */
110#define UNKNOWN_REQUEST 5 /* request has invalid type value */
111#define BADVERSION 6 /* request has invalid protocol version */
112#define BADADDR 7 /* request has invalid addr value */
113#define BADCTLADDR 8 /* request has invalid ctl_addr value */
114
115/*
116 * Operational parameters.
117 */
118#define MAX_LIFE 60 /* max time daemon saves invitations */
119/* RING_WAIT should be 10's of seconds less than MAX_LIFE */
120#define RING_WAIT 30 /* time to wait before resending invitation */
121
122#endif /* !_PROTOCOLS_TALKD_H_ */