xref: /freebsd/include/protocols/talkd.h (revision 3078531de10dcae44b253a35125c949ff4235284)
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  */
61 struct tsockaddr {
62 	unsigned short sa_family;
63 	char	sa_data[14];
64 };
65 
66 /*
67  * Client->server request message format.
68  */
69 typedef 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  */
88 typedef 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