452 lines
10 KiB
C
452 lines
10 KiB
C
/* $NetBSD: api_exch.c,v 1.5 1998/07/26 22:38:15 mycroft Exp $ */
|
|
|
|
/*-
|
|
* 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
#if 0
|
|
static char sccsid[] = "@(#)api_exch.c 4.2 (Berkeley) 4/26/91";
|
|
#else
|
|
__RCSID("$NetBSD: api_exch.c,v 1.5 1998/07/26 22:38:15 mycroft Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
|
|
#include <stdio.h>
|
|
#ifdef __STDC__
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#endif
|
|
|
|
#include "../general/general.h"
|
|
|
|
#include "api_exch.h"
|
|
|
|
static int sock; /* Socket number */
|
|
|
|
static char whoarewe[40] = "";
|
|
#define WHO_ARE_WE() fprintf(stderr, "(API %s) ", whoarewe);
|
|
|
|
static enum {CONTENTION, SEND, RECEIVE } conversation;
|
|
|
|
static struct exch_exch exch_state;
|
|
|
|
static unsigned int
|
|
my_sequence,
|
|
your_sequence;
|
|
|
|
static char ibuffer[4000], *ibuf_next, *ibuf_last;
|
|
#define IBUFADDED(i) ibuf_last += (i)
|
|
#define IBUFAVAILABLE() (ibuf_last-ibuf_next)
|
|
#define IBUFFER() ibuffer
|
|
#define IBUFFREE() (ibuffer+sizeof ibuffer-ibuf_last-1)
|
|
#define IBUFGETBYTES(w,l) { memcpy(w, ibuf_next, l); ibuf_next += l; }
|
|
#define IBUFRESET() (ibuf_next = ibuf_last = ibuffer)
|
|
|
|
char obuffer[4000], *obuf_next;
|
|
#define OBUFADDBYTES(w,l) { memcpy(obuf_next, w, l); obuf_next += l; }
|
|
#define OBUFAVAILABLE() (obuf_next - obuffer)
|
|
#define OBUFFER() obuffer
|
|
#define OBUFRESET() obuf_next = obuffer
|
|
#define OBUFROOM() (obuffer+sizeof obuffer-obuf_next)
|
|
|
|
|
|
static int outflush __P((void));
|
|
static int iget __P((char *, int));
|
|
static char *exch_to_ascii __P((int));
|
|
static int send_state __P((void));
|
|
static int receive_state __P((void));
|
|
static int enter_receive __P((void));
|
|
static int enter_send __P((void));
|
|
|
|
static int
|
|
outflush()
|
|
{
|
|
int length = OBUFAVAILABLE();
|
|
|
|
if (length != 0) {
|
|
if (write(sock, OBUFFER(), length) != length) {
|
|
WHO_ARE_WE();
|
|
perror("write");
|
|
return -1;
|
|
}
|
|
OBUFRESET();
|
|
}
|
|
return 0; /* All OK */
|
|
}
|
|
|
|
|
|
static int
|
|
iget(location, length)
|
|
char *location;
|
|
int length;
|
|
{
|
|
int count;
|
|
|
|
if (OBUFAVAILABLE()) {
|
|
if (outflush() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
if ((count = IBUFAVAILABLE()) != 0) {
|
|
if (count > length) {
|
|
count = length;
|
|
}
|
|
IBUFGETBYTES(location, count);
|
|
length -= count;
|
|
location += count;
|
|
}
|
|
while (length) {
|
|
if (ibuf_next == ibuf_last) {
|
|
IBUFRESET();
|
|
}
|
|
if ((count = read(sock, IBUFFER(), IBUFFREE())) < 0) {
|
|
WHO_ARE_WE();
|
|
perror("read");
|
|
return -1;
|
|
}
|
|
if (count == 0) {
|
|
/* Reading past end-of-file */
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "End of file read\r\n");
|
|
return -1;
|
|
}
|
|
IBUFADDED(count);
|
|
if (count > length) {
|
|
count = length;
|
|
}
|
|
IBUFGETBYTES(location, count);
|
|
length -= count;
|
|
location += count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static char *
|
|
exch_to_ascii(exch)
|
|
int exch; /* opcode to decode */
|
|
{
|
|
switch (exch) {
|
|
case EXCH_EXCH_COMMAND:
|
|
return "Command";
|
|
case EXCH_EXCH_TYPE:
|
|
return "Type";
|
|
case EXCH_EXCH_TURNAROUND:
|
|
return "Turnaround";
|
|
case EXCH_EXCH_RTS:
|
|
return "Request to Send";
|
|
default:
|
|
{
|
|
static char unknown[40];
|
|
|
|
sprintf(unknown, "(Unknown exchange 0x%02x)", exch&0xff);
|
|
return unknown;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send the exch structure, updating the sequnce number field.
|
|
*/
|
|
|
|
static int
|
|
send_state()
|
|
{
|
|
if (OBUFROOM() < sizeof exch_state) {
|
|
if (outflush() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
my_sequence = (my_sequence+1)&0xff;
|
|
exch_state.my_sequence = my_sequence;
|
|
exch_state.your_sequence = your_sequence;
|
|
OBUFADDBYTES((char *)&exch_state, sizeof exch_state);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Receive the exch structure from the other side, checking
|
|
* sequence numbering.
|
|
*/
|
|
|
|
static int
|
|
receive_state()
|
|
{
|
|
if (iget((char *)&exch_state, sizeof exch_state) == -1) {
|
|
return -1;
|
|
}
|
|
if (conversation != CONTENTION) {
|
|
if (exch_state.your_sequence != my_sequence) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Send sequence number mismatch.\n");
|
|
return -1;
|
|
}
|
|
if (exch_state.my_sequence != ((++your_sequence)&0xff)) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Receive sequence number mismatch.\n");
|
|
return -1;
|
|
}
|
|
}
|
|
your_sequence = exch_state.my_sequence;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
enter_receive()
|
|
{
|
|
switch (conversation) {
|
|
case CONTENTION:
|
|
exch_state.opcode = EXCH_EXCH_TURNAROUND;
|
|
if (send_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (receive_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (exch_state.opcode != EXCH_EXCH_RTS) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "In CONTENTION state: ");
|
|
if (exch_state.opcode == EXCH_EXCH_TURNAROUND) {
|
|
fprintf(stderr,
|
|
"Both sides tried to enter RECEIVE state.\n");
|
|
} else {
|
|
fprintf(stderr,
|
|
"Protocol error trying to enter RECEIVE state.\n");
|
|
}
|
|
return -1;
|
|
}
|
|
break;
|
|
case SEND:
|
|
exch_state.opcode = EXCH_EXCH_TURNAROUND;
|
|
if (send_state() == -1) {
|
|
return -1;
|
|
}
|
|
break;
|
|
case RECEIVE:
|
|
abort(); /* Unhandled case; remove abort if we die here */
|
|
}
|
|
conversation = RECEIVE;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
enter_send()
|
|
{
|
|
switch (conversation) {
|
|
case CONTENTION:
|
|
exch_state.opcode = EXCH_EXCH_RTS;
|
|
if (send_state() == -1) {
|
|
return -1;
|
|
}
|
|
/* fall through */
|
|
case RECEIVE:
|
|
if (receive_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (exch_state.opcode != EXCH_EXCH_TURNAROUND) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Conversation error - both sides in SEND state.\n");
|
|
return -1;
|
|
}
|
|
case SEND:
|
|
abort(); /* Unhandled case; remove abort if we die here */
|
|
}
|
|
conversation = SEND;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
api_exch_nextcommand()
|
|
{
|
|
if (conversation != RECEIVE) {
|
|
if (enter_receive() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
if (receive_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (exch_state.opcode != EXCH_EXCH_COMMAND) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Expected a %s exchange, received a %s exchange.\n",
|
|
exch_to_ascii(EXCH_EXCH_COMMAND), exch_to_ascii(exch_state.opcode));
|
|
return -1;
|
|
}
|
|
return exch_state.command_or_type;
|
|
}
|
|
|
|
|
|
int
|
|
api_exch_incommand(command)
|
|
int command;
|
|
{
|
|
int i;
|
|
|
|
if ((i = api_exch_nextcommand()) == -1) {
|
|
return -1;
|
|
}
|
|
if (i != command) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Expected API command 0x%x, got API command 0x%x.\n",
|
|
command, i);
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
api_exch_outcommand(command)
|
|
int command;
|
|
{
|
|
if (conversation != SEND) {
|
|
if (enter_send() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
exch_state.command_or_type = command;
|
|
exch_state.opcode = EXCH_EXCH_COMMAND;
|
|
if (send_state() == -1) {
|
|
return -1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
|
|
int
|
|
api_exch_outtype(type, length, location)
|
|
int
|
|
type,
|
|
length;
|
|
const char
|
|
*location;
|
|
{
|
|
int netleng = length;
|
|
|
|
if (conversation != SEND) {
|
|
if (enter_send() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
exch_state.opcode = EXCH_EXCH_TYPE;
|
|
exch_state.command_or_type = type;
|
|
exch_state.length = netleng;
|
|
if (send_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (length) {
|
|
if (OBUFROOM() > length) {
|
|
OBUFADDBYTES(location, length);
|
|
} else {
|
|
if (outflush() == -1) {
|
|
return -1;
|
|
}
|
|
if (write(sock, location, length) != length) {
|
|
WHO_ARE_WE();
|
|
perror("write");
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
api_exch_intype(type, length, location)
|
|
int
|
|
type,
|
|
length;
|
|
char
|
|
*location;
|
|
{
|
|
int netleng = length;
|
|
|
|
if (conversation != RECEIVE) {
|
|
if (enter_receive() == -1) {
|
|
return -1;
|
|
}
|
|
}
|
|
if (receive_state() == -1) {
|
|
return -1;
|
|
}
|
|
if (exch_state.opcode != EXCH_EXCH_TYPE) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr,
|
|
"Expected to receive a %s exchange, received a %s exchange.\n",
|
|
exch_to_ascii(EXCH_EXCH_TYPE), exch_to_ascii(exch_state.opcode));
|
|
return -1;
|
|
}
|
|
if (exch_state.command_or_type != type) {
|
|
WHO_ARE_WE();
|
|
fprintf(stderr, "Expected type 0x%x, got type 0x%x.\n",
|
|
type, exch_state.command_or_type);
|
|
return -1;
|
|
}
|
|
if (exch_state.length != netleng) {
|
|
fprintf(stderr, "Type 0x%x - expected length %d, received length %u.\n",
|
|
type, length, exch_state.length);
|
|
return -1;
|
|
}
|
|
if (iget(location, length) == -1) {
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
api_exch_flush()
|
|
{
|
|
return outflush();
|
|
}
|
|
|
|
int
|
|
api_exch_init(sock_number, ourname)
|
|
int sock_number;
|
|
char *ourname;
|
|
{
|
|
sock = sock_number;
|
|
(void) strcpy(whoarewe, ourname); /* For error messages */
|
|
|
|
my_sequence = your_sequence = 0;
|
|
|
|
conversation = CONTENTION; /* We don't know which direction */
|
|
|
|
IBUFRESET();
|
|
OBUFRESET();
|
|
|
|
return 0;
|
|
}
|