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
 34#ifndef _PROTOCOLS_TALKD_H_
 35#define	_PROTOCOLS_TALKD_H_
 36
 37/*
 38 * This describes the protocol used by the talk server and clients.
 39 *
 40 * The talk server acts a repository of invitations, responding to
 41 * requests by clients wishing to rendezvous for the purpose of
 42 * holding a conversation.  In normal operation, a client, the caller,
 43 * initiates a rendezvous by sending a CTL_MSG to the server of
 44 * type LOOK_UP.  This causes the server to search its invitation
 45 * tables to check if an invitation currently exists for the caller
 46 * (to speak to the callee specified in the message).  If the lookup
 47 * fails, the caller then sends an ANNOUNCE message causing the server
 48 * to broadcast an announcement on the callee's login ports requesting
 49 * contact.  When the callee responds, the local server uses the
 50 * recorded invitation to respond with the appropriate rendezvous
 51 * address and the caller and callee client programs establish a
 52 * stream connection through which the conversation takes place.
 53 */
 54
 55/*
 56 * The talk protocol embeds a 4.3BSD sockaddr.  Define our own version
 57 * rather then relying on namespace pollution in kernel headers.
 58 */
 59struct tsockaddr {
 60	unsigned short sa_family;
 61	char	sa_data[14];
 62};
 63
 64/*
 65 * Client->server request message format.
 66 */
 67typedef struct {
 68	u_char	vers;		/* protocol version */
 69	u_char	type;		/* request type, see below */
 70	u_char	answer;		/* not used */
 71	u_char	pad;
 72	u_int32_t	id_num;		/* message id */
 73	struct	tsockaddr addr;		/* old (4.3) style */
 74	struct	tsockaddr ctl_addr;	/* old (4.3) style */
 75	int32_t	pid;		/* caller's process id */
 76#define	NAME_SIZE	12
 77	char	l_name[NAME_SIZE];/* caller's name */
 78	char	r_name[NAME_SIZE];/* callee's name */
 79#define	TTY_SIZE	16
 80	char	r_tty[TTY_SIZE];/* callee's tty name */
 81} CTL_MSG;
 82
 83/*
 84 * Server->client response message format.
 85 */
 86typedef struct {
 87	u_char	vers;		/* protocol version */
 88	u_char	type;		/* type of request message, see below */
 89	u_char	answer;		/* respose to request message, see below */
 90	u_char	pad;
 91	u_int32_t	id_num;		/* message id */
 92	struct	tsockaddr addr;	/* address for establishing conversation */
 93} CTL_RESPONSE;
 94
 95#define	TALK_VERSION	1		/* protocol version */
 96
 97/* message type values */
 98#define LEAVE_INVITE	0	/* leave invitation with server */
 99#define LOOK_UP		1	/* check for invitation by callee */
100#define DELETE		2	/* delete invitation by caller */
101#define ANNOUNCE	3	/* announce invitation by caller */
102
103/* answer values */
104#define SUCCESS		0	/* operation completed properly */
105#define NOT_HERE	1	/* callee not logged in */
106#define FAILED		2	/* operation failed for unexplained reason */
107#define MACHINE_UNKNOWN	3	/* caller's machine name unknown */
108#define PERMISSION_DENIED 4	/* callee's tty doesn't permit announce */
109#define UNKNOWN_REQUEST	5	/* request has invalid type value */
110#define	BADVERSION	6	/* request has invalid protocol version */
111#define	BADADDR		7	/* request has invalid addr value */
112#define	BADCTLADDR	8	/* request has invalid ctl_addr value */
113
114/*
115 * Operational parameters.
116 */
117#define MAX_LIFE	60	/* max time daemon saves invitations */
118/* RING_WAIT should be 10's of seconds less than MAX_LIFE */
119#define RING_WAIT	30	/* time to wait before resending invitation */
120
121#endif /* !_TALKD_H_ */