BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / tn3270 / api / api_exch.h

/*-
* Copyright (c) 1988 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.
*
*      @(#)api_exch.h  4.2 (Berkeley) 4/26/91
*/

/*
* This file describes the structures passed back and forth
* between the API client and API server on a Unix-based
* tn3270 implementation.
*/

/*
* The following are the low-level opcodes exchanged between the
* two sides.  These are designed to allow for type, sequence number,
* and direction checking.
*
* We enforce conversation flow.  There are three states: CONTENTION,
* SEND, and RECEIVE.  Both sides start in CONTENTION.
* We never leave RECEIVE state without first reading a TURNAROUND
* opcode.  We never leave SEND state without first writing a TURNAROUND
* opcode.  This scheme ensures that we always have conversation flowing
* in a synchronized direction (or detect an application error), and that
* we never hang with both sides trying to read from the "wire".
*
* State        event                   action
*
* CONTENTION   read request            send TURNAROUND
*                                      read RTS
*                                      enter RECEIVE
* CONTENTION   write request           send RTS
*                                      read TURNAROUND
*                                      enter SEND
*
* RECEIVE      read request            read whatever
* RECEIVE      write request           read TURNAROUND
*
* SEND         read request            send TURNAROUND
* SEND         write                   write whatever
*/

#define EXCH_EXCH_COMMAND       0       /* The following is a command */
#define EXCH_EXCH_TURNAROUND    1       /* Your turn to send */
#define EXCH_EXCH_RTS           2       /* Request to send */
#define EXCH_EXCH_TYPE          3       /* The following is a type */

struct exch_exch {
   char
       opcode;                 /* COMMAND, TURNAROUND, or TYPE */
   unsigned char
       my_sequence,            /* 0-ff, initially zero */
       your_sequence,          /* 0-ff, initially zero */
       command_or_type;        /* Application level command or type */
   unsigned short
       length;                 /* The length of any following data */
};

/*
* The following are the command codes which the higher level protocols
* send and receive.
*/

#define EXCH_CMD_ASSOCIATE      0       /* Connect [client->server] */
       /*
        * struct storage_desc
        * char key[]
        */
#define EXCH_CMD_DISASSOCIATE   1       /* Disconnect [client->server] */
#define EXCH_CMD_SEND_AUTH      2       /* Send password [server->client] */
       /*
        * struct storage_desc
        * char prompt[]
        * struct storage_desc
        * char seed[]
        */
#define EXCH_CMD_AUTH           3       /* Authorization [client->server] */
       /*
        * struct storage_desc
        * char authenticator[]
        */
#define EXCH_CMD_ASSOCIATED     4       /* Connected [server->client] */
#define EXCH_CMD_REJECTED       5       /* Too bad [server->client] */
       /*
        * struct storage_desc
        * char message[]
        */

#define EXCH_CMD_REQUEST        6       /* A request [client->server] */
       /* struct regs,
        * struct sregs,
        * struct storage_desc
        * char bytes[]
        */
#define EXCH_CMD_GIMME          7       /* Send storage [server->client] */
       /*
        * struct storage_desc
        */
#define EXCH_CMD_HEREIS         8       /* Here is storage [BOTH WAYS] */
       /*
        * struct storage_desc
        * char bytes[]
        */
#define EXCH_CMD_REPLY          9       /* End of discussion */
       /*
        * struct regs,
        * struct sregs,
        */

/*
* The following are typed parameters sent across the wire.
*
* This should be done much more generally, with some form of
* XDR or mapped conversation ability.
*/

#define EXCH_TYPE_REGS          0
#define EXCH_TYPE_SREGS         1
#define EXCH_TYPE_STORE_DESC    2
#define EXCH_TYPE_BYTES         3

/*
* each parameter that comes over looks like:
*
*      char                    type of following
*      short (2 bytes)         length of following (network byte order)
*      following
*/

struct storage_descriptor {
   long        location;       /* In network byte order */
   short       length;         /* In network byte order */
};