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 32 #ifndef _PROTOCOLS_TALKD_H_ 33 #define _PROTOCOLS_TALKD_H_ 34 35 /* 36 * This describes the protocol used by the talk server and clients. 37 * 38 * The talk server acts a repository of invitations, responding to 39 * requests by clients wishing to rendezvous for the purpose of 40 * holding a conversation. In normal operation, a client, the caller, 41 * initiates a rendezvous by sending a CTL_MSG to the server of 42 * type LOOK_UP. This causes the server to search its invitation 43 * tables to check if an invitation currently exists for the caller 44 * (to speak to the callee specified in the message). If the lookup 45 * fails, the caller then sends an ANNOUNCE message causing the server 46 * to broadcast an announcement on the callee's login ports requesting 47 * contact. When the callee responds, the local server uses the 48 * recorded invitation to respond with the appropriate rendezvous 49 * address and the caller and callee client programs establish a 50 * stream connection through which the conversation takes place. 51 */ 52 53 /* 54 * The talk protocol embeds a 4.3BSD sockaddr. Define our own version 55 * rather then relying on namespace pollution in kernel headers. 56 */ 57 struct tsockaddr { 58 unsigned short sa_family; 59 char sa_data[14]; 60 }; 61 62 /* 63 * Client->server request message format. 64 */ 65 typedef struct { 66 u_char vers; /* protocol version */ 67 u_char type; /* request type, see below */ 68 u_char answer; /* not used */ 69 u_char pad; 70 u_int32_t id_num; /* message id */ 71 struct tsockaddr addr; /* old (4.3) style */ 72 struct tsockaddr ctl_addr; /* old (4.3) style */ 73 int32_t pid; /* caller's process id */ 74 #define NAME_SIZE 12 75 char l_name[NAME_SIZE];/* caller's name */ 76 char r_name[NAME_SIZE];/* callee's name */ 77 #define TTY_SIZE 16 78 char r_tty[TTY_SIZE];/* callee's tty name */ 79 } CTL_MSG; 80 81 /* 82 * Server->client response message format. 83 */ 84 typedef struct { 85 u_char vers; /* protocol version */ 86 u_char type; /* type of request message, see below */ 87 u_char answer; /* respose to request message, see below */ 88 u_char pad; 89 u_int32_t id_num; /* message id */ 90 struct tsockaddr addr; /* address for establishing conversation */ 91 } CTL_RESPONSE; 92 93 #define TALK_VERSION 1 /* protocol version */ 94 95 /* message type values */ 96 #define LEAVE_INVITE 0 /* leave invitation with server */ 97 #define LOOK_UP 1 /* check for invitation by callee */ 98 #define DELETE 2 /* delete invitation by caller */ 99 #define ANNOUNCE 3 /* announce invitation by caller */ 100 101 /* answer values */ 102 #define SUCCESS 0 /* operation completed properly */ 103 #define NOT_HERE 1 /* callee not logged in */ 104 #define FAILED 2 /* operation failed for unexplained reason */ 105 #define MACHINE_UNKNOWN 3 /* caller's machine name unknown */ 106 #define PERMISSION_DENIED 4 /* callee's tty doesn't permit announce */ 107 #define UNKNOWN_REQUEST 5 /* request has invalid type value */ 108 #define BADVERSION 6 /* request has invalid protocol version */ 109 #define BADADDR 7 /* request has invalid addr value */ 110 #define BADCTLADDR 8 /* request has invalid ctl_addr value */ 111 112 /* 113 * Operational parameters. 114 */ 115 #define MAX_LIFE 60 /* max time daemon saves invitations */ 116 /* RING_WAIT should be 10's of seconds less than MAX_LIFE */ 117 #define RING_WAIT 30 /* time to wait before resending invitation */ 118 119 #endif /* !_TALKD_H_ */ 120