/*
 * Copyright (c) 1983 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     5.7 (Berkeley) 4/3/91
 */

/*
 * 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.
 */
#define NAME_SIZE       12
#define TTY_SIZE        16

OBJECT CTL_MSG
    vers:UBYTE,           /* protocol version */
    type:UBYTE,           /* request type, see below */
    answer:UBYTE,         /* not used */
    pad:UBYTE,
    id_num:ULONG,         /* message id */
    addr:osockaddr,         /* old (4.3) style */
    ctl_addr:osockaddr,     /* old (4.3) style */
    pid:LONG,            /* caller's process id */
    l_name[NAME_SIZE]:BYTE,  /* caller's name */
    r_name[NAME_SIZE]:BYTE,  /* callee's name */
    r_tty[TTY_SIZE]:BYTE  /* callee's tty name */


/*
 * Server->client response message format.
 */
OBJECT CTL_RESPONSE
    vers:UBYTE,           /* protocol version */
    type:UBYTE,           /* type of request message, see below */
    answer:UBYTE,         /* respose to request message, see below */
    pad:UBYTE,
    id_num:ULONG,         /* message id */
    addr:osockaddr /* address for establishing conversation */


#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 */


