1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
|
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)talkd.h 8.1 (Berkeley) 6/2/93
*/
#ifndef _TALKD_H_
#define _TALKD_H_
/*
* This describes the protocol used by the talk server and clients.
*
* The talk server acts a repository of invitations, responding to
* requests by clients wishing to rendezvous for the purpose of
* holding a conversation. In normal operation, a client, the caller,
* initiates a rendezvous by sending a CTL_MSG to the server of
* type LOOK_UP. This causes the server to search its invitation
* tables to check if an invitation currently exists for the caller
* (to speak to the callee specified in the message). If the lookup
* fails, the caller then sends an ANNOUNCE message causing the server
* to broadcast an announcement on the callee's login ports requesting
* contact. When the callee responds, the local server uses the
* recorded invitation to respond with the appropriate rendezvous
* address and the caller and callee client programs establish a
* stream connection through which the conversation takes place.
*/
/*
* Client->server request message format.
*/
typedef struct {
u_char vers; /* protocol version */
u_char type; /* request type, see below */
u_char answer; /* not used */
u_char pad;
u_long id_num; /* message id */
struct osockaddr addr; /* old (4.3) style */
struct osockaddr ctl_addr; /* old (4.3) style */
long pid; /* caller's process id */
#define NAME_SIZE 12
char l_name[NAME_SIZE];/* caller's name */
char r_name[NAME_SIZE];/* callee's name */
#define TTY_SIZE 16
char r_tty[TTY_SIZE];/* callee's tty name */
} CTL_MSG;
/*
* Server->client response message format.
*/
typedef struct {
u_char vers; /* protocol version */
u_char type; /* type of request message, see below */
u_char answer; /* respose to request message, see below */
u_char pad;
u_long id_num; /* message id */
struct osockaddr addr; /* address for establishing conversation */
} CTL_RESPONSE;
#define TALK_VERSION 1 /* protocol version */
/* message type values */
#define LEAVE_INVITE 0 /* leave invitation with server */
#define LOOK_UP 1 /* check for invitation by callee */
#define DELETE 2 /* delete invitation by caller */
#define ANNOUNCE 3 /* announce invitation by caller */
/* answer values */
#define SUCCESS 0 /* operation completed properly */
#define NOT_HERE 1 /* callee not logged in */
#define FAILED 2 /* operation failed for unexplained reason */
#define MACHINE_UNKNOWN 3 /* caller's machine name unknown */
#define PERMISSION_DENIED 4 /* callee's tty doesn't permit announce */
#define UNKNOWN_REQUEST 5 /* request has invalid type value */
#define BADVERSION 6 /* request has invalid protocol version */
#define BADADDR 7 /* request has invalid addr value */
#define BADCTLADDR 8 /* request has invalid ctl_addr value */
/*
* Operational parameters.
*/
#define MAX_LIFE 60 /* max time daemon saves invitations */
/* RING_WAIT should be 10's of seconds less than MAX_LIFE */
#define RING_WAIT 30 /* time to wait before resending invitation */
#endif /* !_TALKD_H_ */
|
