87fff6492b7aaebbb9d7d1411de73db02332dcb3
[unix-history] / usr / src / usr.bin / tn3270 / api / api_exch.h
/*
* Copyright (c) 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)api_exch.h 3.4 (Berkeley) %G%
*/
/*
* 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 */
};