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

/*
 *	Copyright (c) 1984-1987 by the Regents of the
 *	University of California and by Gregory Glenn Minshall.
 *
 *	Permission to use, copy, modify, and distribute these
 *	programs and their documentation for any purpose and
 *	without fee is hereby granted, provided that this
 *	copyright and permission appear on all copies and
 *	supporting documentation, the name of the Regents of
 *	the University of California not be used in advertising
 *	or publicity pertaining to distribution of the programs
 *	without specific prior permission, and notice be given in
 *	supporting documentation that copying and distribution is
 *	by permission of the Regents of the University of California
 *	and by Gregory Glenn Minshall.  Neither the Regents of the
 *	University of California nor Gregory Glenn Minshall make
 *	representations about the suitability of this software
 *	for any purpose.  It is provided "as is" without
 *	express or implied warranty.
 */

#ifndef lint
static char sccsid[] = "@(#)api_exch.c	1.8 (Berkeley) %G%";
#endif	/* not lint */

#include <stdio.h>

#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()
{
    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 i;
    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;
    }
    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;
	}
    }
    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;
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 i, 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 %d.\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;
    strcpy(whoarewe, ourname);		/* For error messages */

    my_sequence = your_sequence = 0;

    conversation = CONTENTION;		/* We don't know which direction */

    IBUFRESET();
    OBUFRESET();

    return 0;
}
Commit	Line	Data
992de934 GM	1	/*
	2	* Copyright (c) 1984-1987 by the Regents of the
	3	* University of California and by Gregory Glenn Minshall.
	4	*
	5	* Permission to use, copy, modify, and distribute these
	6	* programs and their documentation for any purpose and
	7	* without fee is hereby granted, provided that this
	8	* copyright and permission appear on all copies and
	9	* supporting documentation, the name of the Regents of
	10	* the University of California not be used in advertising
	11	* or publicity pertaining to distribution of the programs
	12	* without specific prior permission, and notice be given in
	13	* supporting documentation that copying and distribution is
	14	* by permission of the Regents of the University of California
	15	* and by Gregory Glenn Minshall. Neither the Regents of the
	16	* University of California nor Gregory Glenn Minshall make
	17	* representations about the suitability of this software
	18	* for any purpose. It is provided "as is" without
	19	* express or implied warranty.
	20	*/
	21
	22	#ifndef lint
	23	static char sccsid[] = "@(#)api_exch.c 1.8 (Berkeley) %G%";
	24	#endif /* not lint */
	25
ba212048 GM	26	#include <stdio.h>
ba212048 GM	27
1117b0bd GM	28	#include "../general/general.h"
1117b0bd GM	29
ba212048 GM	30	#include "api_exch.h"
ba212048 GM	31
62946391 GM	32	static int sock; /* Socket number */
62946391 GM	33
224a681b	34	static char whoarewe[40] = "";
d024bcc4 GM	35	#define WHO_ARE_WE() fprintf(stderr, "(API %s) ", whoarewe);
	36
	37	static enum {CONTENTION, SEND, RECEIVE } conversation;
	38
	39	static struct exch_exch exch_state;
	40
	41	static unsigned int
	42	my_sequence,
	43	your_sequence;
224a681b	44
8d951982	45	static char ibuffer[4000], ibuf_next, ibuf_last;
ba212048	46	#define IBUFADDED(i) ibuf_last += (i)
8d951982	47	#define IBUFAVAILABLE() (ibuf_last-ibuf_next)
ba212048	48	#define IBUFFER() ibuffer
8d951982	49	#define IBUFFREE() (ibuffer+sizeof ibuffer-ibuf_last-1)
d024bcc4	50	#define IBUFGETBYTES(w,l) { memcpy(w, ibuf_next, l); ibuf_next += l; }
ba212048 GM	51	#define IBUFRESET() (ibuf_next = ibuf_last = ibuffer)
ba212048 GM	52
8d951982	53	char obuffer[4000], *obuf_next;
ba212048	54	#define OBUFADDBYTES(w,l) { memcpy(obuf_next, w, l); obuf_next += l; }
ba212048 GM	55	#define OBUFAVAILABLE() (obuf_next - obuffer)
	56	#define OBUFFER() obuffer
	57	#define OBUFRESET() obuf_next = obuffer
	58	#define OBUFROOM() (obuffer+sizeof obuffer-obuf_next)
	59
	60
	61	static int
	62	outflush()
	63	{
	64	int length = OBUFAVAILABLE();
	65
	66	if (length != 0) {
	67	if (write(sock, OBUFFER(), length) != length) {
d024bcc4	68	WHO_ARE_WE();
224a681b	69	perror("write");
ba212048 GM	70	return -1;
	71	}
	72	OBUFRESET();
	73	}
	74	return 0; /* All OK */
	75	}
	76
	77
	78	static int
8d951982 GM	79	iget(location, length)
	80	char *location;
	81	int length;
ba212048 GM	82	{
ba212048 GM	83	int i;
8d951982	84	int count;
ba212048 GM	85
	86	if (OBUFAVAILABLE()) {
	87	if (outflush() == -1) {
	88	return -1;
	89	}
	90	}
8d951982 GM	91	if ((count = IBUFAVAILABLE()) != 0) {
	92	if (count > length) {
	93	count = length;
	94	}
	95	IBUFGETBYTES(location, count);
	96	length -= count;
	97	location += count;
d024bcc4	98	}
8d951982 GM	99	while (length) {
	100	if (ibuf_next == ibuf_last) {
	101	IBUFRESET();
	102	}
	103	if ((count = read(sock, IBUFFER(), IBUFFREE())) < 0) {
d024bcc4	104	WHO_ARE_WE();
224a681b GM	105	perror("read");
	106	return -1;
	107	}
8d951982	108	if (count == 0) {
224a681b	109	/* Reading past end-of-file */
d024bcc4 GM	110	WHO_ARE_WE();
d024bcc4 GM	111	fprintf(stderr, "End of file read\r\n");
ba212048 GM	112	return -1;
ba212048 GM	113	}
8d951982 GM	114	IBUFADDED(count);
	115	if (count > length) {
	116	count = length;
	117	}
	118	IBUFGETBYTES(location, count);
	119	length -= count;
	120	location += count;
ba212048 GM	121	}
	122	return 0;
	123	}
	124
d024bcc4 GM	125	static char *
	126	exch_to_ascii(exch)
	127	int exch; /* opcode to decode */
	128	{
	129	switch (exch) {
	130	case EXCH_EXCH_COMMAND:
	131	return "Command";
	132	case EXCH_EXCH_TYPE:
	133	return "Type";
	134	case EXCH_EXCH_TURNAROUND:
	135	return "Turnaround";
	136	case EXCH_EXCH_RTS:
	137	return "Request to Send";
	138	default:
	139	{
	140	static char unknown[40];
	141
	142	sprintf(unknown, "(Unknown exchange 0x%02x)", exch&0xff);
	143	return unknown;
	144	}
	145	}
	146	}
	147
	148	/*
	149	* Send the exch structure, updating the sequnce number field.
	150	*/
	151
	152	static int
	153	send_state()
	154	{
	155	if (OBUFROOM() < sizeof exch_state) {
	156	if (outflush() == -1) {
	157	return -1;
	158	}
	159	}
e1e082cf GM	160	my_sequence = (my_sequence+1)&0xff;
e1e082cf GM	161	exch_state.my_sequence = my_sequence;
d024bcc4 GM	162	exch_state.your_sequence = your_sequence;
	163	OBUFADDBYTES((char *)&exch_state, sizeof exch_state);
	164	return 0;
	165	}
	166
	167	/*
	168	* Receive the exch structure from the other side, checking
	169	* sequence numbering.
	170	*/
	171
	172	static int
	173	receive_state()
	174	{
8d951982 GM	175	if (iget((char *)&exch_state, sizeof exch_state) == -1) {
8d951982 GM	176	return -1;
d024bcc4	177	}
d024bcc4 GM	178	if (conversation != CONTENTION) {
	179	if (exch_state.your_sequence != my_sequence) {
	180	WHO_ARE_WE();
	181	fprintf(stderr, "Send sequence number mismatch.\n");
	182	return -1;
	183	}
e1e082cf	184	if (exch_state.my_sequence != ((++your_sequence)&0xff)) {
d024bcc4 GM	185	WHO_ARE_WE();
	186	fprintf(stderr, "Receive sequence number mismatch.\n");
	187	return -1;
	188	}
d024bcc4	189	}
e1e082cf	190	your_sequence = exch_state.my_sequence;
d024bcc4 GM	191	return 0;
	192	}
	193
	194	static int
	195	enter_receive()
	196	{
	197	switch (conversation) {
	198	case CONTENTION:
	199	exch_state.opcode = EXCH_EXCH_TURNAROUND;
	200	if (send_state() == -1) {
	201	return -1;
	202	}
	203	if (receive_state() == -1) {
	204	return -1;
	205	}
	206	if (exch_state.opcode != EXCH_EXCH_RTS) {
	207	WHO_ARE_WE();
	208	fprintf(stderr, "In CONTENTION state: ");
	209	if (exch_state.opcode == EXCH_EXCH_TURNAROUND) {
	210	fprintf(stderr,
	211	"Both sides tried to enter RECEIVE state.\n");
	212	} else {
	213	fprintf(stderr,
	214	"Protocol error trying to enter RECEIVE state.\n");
	215	}
	216	return -1;
	217	}
	218	break;
	219	case SEND:
	220	exch_state.opcode = EXCH_EXCH_TURNAROUND;
	221	if (send_state() == -1) {
	222	return -1;
	223	}
	224	break;
	225	}
	226	conversation = RECEIVE;
	227	return 0;
	228	}
	229
	230	static int
	231	enter_send()
	232	{
	233	switch (conversation) {
	234	case CONTENTION:
	235	exch_state.opcode = EXCH_EXCH_RTS;
	236	if (send_state() == -1) {
	237	return -1;
	238	}
	239	/* fall through */
	240	case RECEIVE:
	241	if (receive_state() == -1) {
	242	return -1;
	243	}
	244	if (exch_state.opcode != EXCH_EXCH_TURNAROUND) {
	245	WHO_ARE_WE();
	246	fprintf(stderr, "Conversation error - both sides in SEND state.\n");
	247	return -1;
	248	}
	249	}
	250	conversation = SEND;
	251	return 0;
	252	}
	253
62946391	254	int
d024bcc4	255	api_exch_nextcommand()
62946391	256	{
d024bcc4 GM	257	if (conversation != RECEIVE) {
d024bcc4 GM	258	if (enter_receive() == -1) {
62946391 GM	259	return -1;
	260	}
	261	}
d024bcc4 GM	262	if (receive_state() == -1) {
	263	return -1;
	264	}
	265	if (exch_state.opcode != EXCH_EXCH_COMMAND) {
	266	WHO_ARE_WE();
	267	fprintf(stderr, "Expected a %s exchange, received a %s exchange.\n",
	268	exch_to_ascii(EXCH_EXCH_COMMAND), exch_to_ascii(exch_state.opcode));
	269	return -1;
	270	}
	271	return exch_state.command_or_type;
62946391 GM	272	}
	273
	274
	275	int
ba212048 GM	276	api_exch_incommand(command)
	277	int command;
	278	{
	279	int i;
	280
d024bcc4 GM	281	if ((i = api_exch_nextcommand()) == -1) {
d024bcc4 GM	282	return -1;
ba212048	283	}
ba212048	284	if (i != command) {
d024bcc4	285	WHO_ARE_WE();
ba212048 GM	286	fprintf(stderr, "Expected API command 0x%x, got API command 0x%x.\n",
	287	command, i);
	288	return -1;
	289	}
	290	return 0;
	291	}
	292
	293
62946391	294	int
ba212048 GM	295	api_exch_outcommand(command)
	296	int command;
	297	{
d024bcc4 GM	298	if (conversation != SEND) {
d024bcc4 GM	299	if (enter_send() == -1) {
ba212048 GM	300	return -1;
	301	}
	302	}
d024bcc4 GM	303	exch_state.command_or_type = command;
	304	exch_state.opcode = EXCH_EXCH_COMMAND;
	305	if (send_state() == -1) {
	306	return -1;
	307	} else {
	308	return 0;
	309	}
ba212048 GM	310	}
	311
	312
62946391	313	int
ba212048 GM	314	api_exch_outtype(type, length, location)
	315	int
	316	type,
	317	length;
	318	char
	319	*location;
	320	{
1117b0bd	321	int netleng = length;
ba212048	322
d024bcc4 GM	323	if (conversation != SEND) {
d024bcc4 GM	324	if (enter_send() == -1) {
ba212048 GM	325	return -1;
	326	}
	327	}
d024bcc4 GM	328	exch_state.opcode = EXCH_EXCH_TYPE;
	329	exch_state.command_or_type = type;
	330	exch_state.length = netleng;
	331	if (send_state() == -1) {
	332	return -1;
	333	}
	334	if (length) {
	335	if (OBUFROOM() > length) {
	336	OBUFADDBYTES(location, length);
	337	} else {
	338	if (outflush() == -1) {
	339	return -1;
	340	}
	341	if (write(sock, location, length) != length) {
	342	WHO_ARE_WE();
	343	perror("write");
	344	return -1;
	345	}
ba212048 GM	346	}
ba212048 GM	347	}
d024bcc4	348	return 0;
ba212048 GM	349	}
	350
	351
62946391	352	int
ba212048 GM	353	api_exch_intype(type, length, location)
	354	int
	355	type,
	356	length;
	357	char
	358	*location;
	359	{
1117b0bd	360	int i, netleng = length;
ba212048	361
d024bcc4 GM	362	if (conversation != RECEIVE) {
d024bcc4 GM	363	if (enter_receive() == -1) {
ba212048 GM	364	return -1;
	365	}
	366	}
d024bcc4 GM	367	if (receive_state() == -1) {
	368	return -1;
	369	}
	370	if (exch_state.opcode != EXCH_EXCH_TYPE) {
	371	WHO_ARE_WE();
	372	fprintf(stderr,
	373	"Expected to receive a %s exchange, received a %s exchange.\n",
	374	exch_to_ascii(EXCH_EXCH_TYPE), exch_to_ascii(exch_state.opcode));
ba212048 GM	375	return -1;
ba212048 GM	376	}
d024bcc4 GM	377	if (exch_state.command_or_type != type) {
	378	WHO_ARE_WE();
	379	fprintf(stderr, "Expected type 0x%x, got type 0x%x.\n",
	380	type, exch_state.command_or_type);
	381	return -1;
	382	}
	383	if (exch_state.length != netleng) {
ba212048	384	fprintf(stderr, "Type 0x%x - expected length %d, received length %d.\n",
1117b0bd	385	type, length, exch_state.length);
ba212048 GM	386	return -1;
ba212048 GM	387	}
8d951982 GM	388	if (iget(location, length) == -1) {
8d951982 GM	389	return -1;
ba212048 GM	390	}
	391	return 0;
	392	}
62946391	393
d024bcc4 GM	394	int
	395	api_exch_flush()
	396	{
	397	return outflush();
	398	}
	399
62946391	400	int
224a681b	401	api_exch_init(sock_number, ourname)
62946391	402	int sock_number;
224a681b	403	char *ourname;
62946391 GM	404	{
62946391 GM	405	sock = sock_number;
224a681b	406	strcpy(whoarewe, ourname); /* For error messages */
62946391	407
d024bcc4 GM	408	my_sequence = your_sequence = 0;
	409
	410	conversation = CONTENTION; /* We don't know which direction */
	411
62946391 GM	412	IBUFRESET();
	413	OBUFRESET();
	414
	415	return 0;
	416	}