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simh.simh/PDP11/pdp11_ddcmp.h
Timothe Litt 7d4481659e DDCMP Trace enhancements 
o Decode Link as Q & S flags
o Decode NAK reasons as text
o Make decode strings/pointers const
2013-07-09 06:49:29 -04:00

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/* pdp11_ddcmp.h: Digital Data Communications Message Protocol support
Copyright (c) 2013, Mark Pizzolato
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of Robert M Supnik shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from Robert M Supnik.
Digital Data Communications Message Protocol - DDCMP support routines
29-May-13 MP Initial implementation
*/
#ifndef PDP11_DDCMP_H_
#define PDP11_DDCMP_H_ 0
#include "sim_tmxr.h"
/* DDCMP packet types */
#define DDCMP_SYN 0226u /* Sync character on synchronous links */
#define DDCMP_DEL 0377u /* Sync character on asynchronous links */
#define DDCMP_SOH 0201u /* Numbered Data Message Identifier */
#define DDCMP_ENQ 0005u /* Control Message Identifier */
#define DDCMP_DLE 0220u /* Maintenance Message Identifier */
/* Support routines */
/* crc16 polynomial x^16 + x^15 + x^2 + 1 (0xA001) CCITT LSB */
static uint16 crc16_nibble[16] = {
0x0000, 0xCC01, 0xD801, 0x1400, 0xF001, 0x3C00, 0x2800, 0xE401,
0xA001, 0x6C00, 0x7800, 0xB401, 0x5000, 0x9C01, 0x8801, 0x4400,
};
static uint16 ddcmp_crc16(uint16 crc, const void* vbuf, size_t len)
{
const unsigned char* buf = (const unsigned char*)vbuf;
while(0 != len--) {
crc = (crc>>4) ^ crc16_nibble[(*buf ^ crc) & 0xF];
crc = (crc>>4) ^ crc16_nibble[((*buf++)>>4 ^ crc) & 0xF];
};
return(crc);
}
/* Debug routines */
#include <ctype.h>
static void ddcmp_packet_trace (uint32 reason, DEVICE *dptr, const char *txt, const uint8 *msg, int32 len, t_bool detail)
{
if (sim_deb && dptr && (reason & dptr->dctrl)) {
sim_debug(reason, dptr, "%s len: %d\n", txt, len);
if (detail) {
int i, same, group, sidx, oidx;
char outbuf[80], strbuf[18];
static const char hex[] = "0123456789ABCDEF";
static const char *const flags [4] = { " ", " Q", "S ", "SQ" };
static const char *const nak[18] = { "", " (HCRC)", " (DCRC)", " (REPREPLY)", /* 0-3 */
"", "", "", "", /* 4-7 */
" (NOBUF)", " (RXOVR)", "", "", /* 8-11 */
"", "", "", "", /* 12-15 */
" (TOOLONG)", " (HDRFMT)" }; /* 16-17 */
const char *flag = flags[msg[2]>>6];
int msg2 = msg[2] & 0x3F;
switch (msg[0]) {
case DDCMP_SOH: /* Data Message */
sim_debug (reason, dptr, "Data Message, Flags: %s, Count: %d, Resp: %d, Num: %d, HDRCRC: %s, DATACRC: %s\n", flag, (msg2 << 8)|msg[1], msg[3], msg[4],
(0 == ddcmp_crc16 (0, msg, 8)) ? "OK" : "BAD", (0 == ddcmp_crc16 (0, msg+8, 2+((msg2 << 8)|msg[1]))) ? "OK" : "BAD");
break;
case DDCMP_ENQ: /* Control Message */
sim_debug (reason, dptr, "Control: Type: %d ", msg[1]);
switch (msg[1]) {
case 1: /* ACK */
sim_debug (reason, dptr, "(ACK) ACKSUB: %d, Flags: %s, Resp: %d\n", msg2, flag, msg[3]);
break;
case 2: /* NAK */
sim_debug (reason, dptr, "(NAK) Reason: %d%s, Flags: %s, Resp: %d\n", msg2, ((msg2 > 17)? "": nak[msg2]), flag, msg[3]);
break;
case 3: /* REP */
sim_debug (reason, dptr, "(REP) REPSUB: %d, Flags: %s, Num: %d\n", msg2, flag, msg[4]);
break;
case 6: /* STRT */
sim_debug (reason, dptr, "(STRT) STRTSUB: %d, Flags: %s\n", msg2, flag);
break;
case 7: /* STACK */
sim_debug (reason, dptr, "(STACK) STCKSUB: %d, Flags: %s\n", msg2, flag);
break;
default: /* Unknown */
sim_debug (reason, dptr, "(Unknown=0%o)\n", msg[1]);
break;
}
if (len != 8) {
sim_debug (reason, dptr, "Unexpected Control Message Length: %d expected 8\n", len);
}
if (0 != ddcmp_crc16 (0, msg, len)) {
sim_debug (reason, dptr, "Unexpected Message CRC\n");
}
break;
case DDCMP_DLE: /* Maintenance Message */
sim_debug (reason, dptr, "Maintenance Message, Flags: %s, Count: %d, HDRCRC: %s, DATACRC: %s\n", flag, (msg2 << 8)| msg[1],
(0 == ddcmp_crc16 (0, msg, 8)) ? "OK" : "BAD", (0 == ddcmp_crc16 (0, msg+8, 2+((msg2 << 8)| msg[1]))) ? "OK" : "BAD");
break;
}
for (i=same=0; i<len; i += 16) {
if ((i > 0) && (0 == memcmp(&msg[i], &msg[i-16], 16))) {
++same;
continue;
}
if (same > 0) {
sim_debug(reason, dptr, "%04X thru %04X same as above\n", i-(16*same), i-1);
same = 0;
}
group = (((len - i) > 16) ? 16 : (len - i));
for (sidx=oidx=0; sidx<group; ++sidx) {
outbuf[oidx++] = ' ';
outbuf[oidx++] = hex[(msg[i+sidx]>>4)&0xf];
outbuf[oidx++] = hex[msg[i+sidx]&0xf];
if (isprint(msg[i+sidx]))
strbuf[sidx] = msg[i+sidx];
else
strbuf[sidx] = '.';
}
outbuf[oidx] = '\0';
strbuf[sidx] = '\0';
sim_debug(reason, dptr, "%04X%-48s %s\n", i, outbuf, strbuf);
}
if (same > 0) {
sim_debug(reason, dptr, "%04X thru %04X same as above\n", i-(16*same), len-1);
}
}
}
}
uint16 ddcmp_crc16(uint16 crc, const void* vbuf, size_t len);
/* Get packet from specific line
Inputs:
*lp = pointer to terminal line descriptor
**pbuf = pointer to pointer of packet contents
*psize = pointer to packet size
Output:
SCPE_LOST link state lost
SCPE_OK Packet returned OR no packet available
Implementation notes:
1. If a packet is not yet available, then the pbuf address returned is
NULL, but success (SCPE_OK) is returned
receive break status associated with the character is cleared, and
SCPE_BREAK is ORed into the return value.
*/
static t_stat ddcmp_tmxr_get_packet_ln (TMLN *lp, const uint8 **pbuf, uint16 *psize)
{
int32 c;
size_t payloadsize;
while (TMXR_VALID & (c = tmxr_getc_ln (lp))) {
c &= ~TMXR_VALID;
if (lp->rxpboffset + 1 > lp->rxpbsize) {
lp->rxpbsize += 512;
lp->rxpb = (uint8 *)realloc (lp->rxpb, lp->rxpbsize);
}
lp->rxpb[lp->rxpboffset] = c;
if ((lp->rxpboffset == 0) && ((c == DDCMP_SYN) || (c == DDCMP_DEL))) {
tmxr_debug (TMXR_DBG_PRCV, lp, "Ignoring Interframe Sync Character", (char *)&lp->rxpb[0], 1);
continue;
}
lp->rxpboffset += 1;
if (lp->rxpboffset == 1) {
switch (c) {
default:
tmxr_debug (TMXR_DBG_PRCV, lp, "Ignoring unexpected byte in DDCMP mode", (char *)&lp->rxpb[0], 1);
lp->rxpboffset = 0;
case DDCMP_SOH:
case DDCMP_ENQ:
case DDCMP_DLE:
continue;
}
}
if (lp->rxpboffset >= 8) {
if (lp->rxpb[0] == DDCMP_ENQ) { /* Control Message? */
++lp->rxpcnt;
*pbuf = lp->rxpb;
*psize = 8;
lp->rxpboffset = 0;
ddcmp_packet_trace (TMXR_DBG_PRCV, lp->mp->dptr, "<<< RCV Packet", lp->rxpb, *psize, TRUE);
return SCPE_OK;
}
payloadsize = ((lp->rxpb[2] & 0x3F) << 8)| lp->rxpb[1];
if (lp->rxpboffset >= 10 + payloadsize) {
++lp->rxpcnt;
*pbuf = lp->rxpb;
*psize = 10 + payloadsize;
ddcmp_packet_trace (TMXR_DBG_PRCV, lp->mp->dptr, "<<< RCV Packet", lp->rxpb, *psize, TRUE);
lp->rxpboffset = 0;
return SCPE_OK;
}
}
}
*pbuf = NULL;
*psize = 0;
if (lp->conn)
return SCPE_OK;
return SCPE_LOST;
}
/* Store packet in line buffer
Inputs:
*lp = pointer to line descriptor
*buf = pointer to packet data
size = size of packet
Outputs:
status = ok, connection lost, or stall
Implementation notea:
1. If the line is not connected, SCPE_LOST is returned.
2. If prior packet transmission still in progress, SCPE_STALL is
returned and no packet data is stored. The caller must retry later.
*/
static t_stat ddcmp_tmxr_put_packet_ln (TMLN *lp, const uint8 *buf, size_t size)
{
t_stat r;
if (!lp->conn)
return SCPE_LOST;
if (lp->txppoffset < lp->txppsize) {
tmxr_debug (TMXR_DBG_PXMT, lp, "Skipped Sending Packet - Transmit Busy", (char *)&lp->txpb[3], size);
return SCPE_STALL;
}
if (lp->txpbsize < size) {
lp->txpbsize = size;
lp->txpb = (uint8 *)realloc (lp->txpb, lp->txpbsize);
}
memcpy (lp->txpb, buf, size);
lp->txppsize = size;
lp->txppoffset = 0;
ddcmp_packet_trace (TMXR_DBG_PXMT, lp->mp->dptr, ">>> XMT Packet", lp->txpb, lp->txppsize, TRUE);
++lp->txpcnt;
while ((lp->txppoffset < lp->txppsize) &&
(SCPE_OK == (r = tmxr_putc_ln (lp, lp->txpb[lp->txppoffset]))))
++lp->txppoffset;
tmxr_send_buffered_data (lp);
return lp->conn ? SCPE_OK : SCPE_LOST;
}
#endif /* PDP11_DDCMP_H_ */
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