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 *	@(#)talkd.h	8.1 (Berkeley) 6/2/93
32 *
33 * $FreeBSD$
34 */
35
36#ifndef _PROTOCOLS_TALKD_H_
37#define	_PROTOCOLS_TALKD_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 * The talk protocol embeds a 4.3BSD sockaddr.  Define our own version
59 * rather then relying on namespace polution in kernel headers.
60 */
61struct tsockaddr {
62	unsigned short sa_family;
63	char	sa_data[14];
64};
65
66/*
67 * Client->server request message format.
68 */
69typedef struct {
70	u_char	vers;		/* protocol version */
71	u_char	type;		/* request type, see below */
72	u_char	answer;		/* not used */
73	u_char	pad;
74	u_int32_t	id_num;		/* message id */
75	struct	tsockaddr addr;		/* old (4.3) style */
76	struct	tsockaddr ctl_addr;	/* old (4.3) style */
77	int32_t	pid;		/* caller's process id */
78#define	NAME_SIZE	12
79	char	l_name[NAME_SIZE];/* caller's name */
80	char	r_name[NAME_SIZE];/* callee's name */
81#define	TTY_SIZE	16
82	char	r_tty[TTY_SIZE];/* callee's tty name */
83} CTL_MSG;
84
85/*
86 * Server->client response message format.
87 */
88typedef struct {
89	u_char	vers;		/* protocol version */
90	u_char	type;		/* type of request message, see below */
91	u_char	answer;		/* respose to request message, see below */
92	u_char	pad;
93	u_int32_t	id_num;		/* message id */
94	struct	tsockaddr addr;	/* address for establishing conversation */
95} CTL_RESPONSE;
96
97#define	TALK_VERSION	1		/* protocol version */
98
99/* message type values */
100#define LEAVE_INVITE	0	/* leave invitation with server */
101#define LOOK_UP		1	/* check for invitation by callee */
102#define DELETE		2	/* delete invitation by caller */
103#define ANNOUNCE	3	/* announce invitation by caller */
104
105/* answer values */
106#define SUCCESS		0	/* operation completed properly */
107#define NOT_HERE	1	/* callee not logged in */
108#define FAILED		2	/* operation failed for unexplained reason */
109#define MACHINE_UNKNOWN	3	/* caller's machine name unknown */
110#define PERMISSION_DENIED 4	/* callee's tty doesn't permit announce */
111#define UNKNOWN_REQUEST	5	/* request has invalid type value */
112#define	BADVERSION	6	/* request has invalid protocol version */
113#define	BADADDR		7	/* request has invalid addr value */
114#define	BADCTLADDR	8	/* request has invalid ctl_addr value */
115
116/*
117 * Operational parameters.
118 */
119#define MAX_LIFE	60	/* max time daemon saves invitations */
120/* RING_WAIT should be 10's of seconds less than MAX_LIFE */
121#define RING_WAIT	30	/* time to wait before resending invitation */
122
123#endif /* !_TALKD_H_ */
124