* Copyright (c) 1988 Regents of the University of California.
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at 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'' without express or implied warranty.
* @(#)api_exch.h 3.2 (Berkeley) %G%
* This file describes the structures passed back and forth
* between the API client and API server on a Unix-based
* 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".
* CONTENTION read request send TURNAROUND
* CONTENTION write request send RTS
* 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 */
opcode
, /* COMMAND, TURNAROUND, or TYPE */
my_sequence
, /* 0-ff, initially zero */
your_sequence
, /* 0-ff, initially zero */
command_or_type
; /* Application level command or type */
length
; /* The length of any following data */
* The following are the command codes which the higher level protocols
#define EXCH_CMD_ASSOCIATE 0 /* Connect [client->server] */
#define EXCH_CMD_DISASSOCIATE 1 /* Disconnect [client->server] */
#define EXCH_CMD_SEND_AUTH 2 /* Send password [server->client] */
#define EXCH_CMD_AUTH 3 /* Authorization [client->server] */
#define EXCH_CMD_ASSOCIATED 4 /* Connected [server->client] */
#define EXCH_CMD_REJECTED 5 /* Too bad [server->client] */
#define EXCH_CMD_REQUEST 6 /* A request [client->server] */
#define EXCH_CMD_GIMME 7 /* Send storage [server->client] */
#define EXCH_CMD_HEREIS 8 /* Here is storage [BOTH WAYS] */
#define EXCH_CMD_REPLY 9 /* End of discussion */
* 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_SREGS 1
#define EXCH_TYPE_STORE_DESC 2
#define EXCH_TYPE_BYTES 3
* each parameter that comes over looks like:
* short (2 bytes) length of following (network byte order)
struct storage_descriptor
{
long location
; /* In network byte order */
short length
; /* In network byte order */