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D-Modem/slmodemd/modem_pack.c
Dan Bastone 740ef1bfbf
initial commit (with submodule)
2022-12-01 21:40:04 +08:00

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/*
*
* Copyright (c) 2002, Smart Link Ltd.
* 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. Neither the name of the Smart Link Ltd. 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*
*/
/*
*
* modem_pack.c -- modem packer module.
*
* Author: Sasha K (sashak@smlink.com)
*
*
*/
#include <modem.h>
#include <modem_debug.h>
#define PACK_DBG(fmt,arg...) dprintf("%s: " fmt , m->name , ##arg)
#define PACK_ERR(fmt,arg...) eprintf("%s: " fmt , m->name , ##arg)
/* HDLC definitions */
#define HDLC_FLAG 0x7e
#define HDLC_ESCAPE (0x1f<<3)
/* bit ordering (reverse) table */
static const u8 _ordered[] = {
0x0,0x8,0x4,0xc,0x2,0xa,0x6,0xe,
0x1,0x9,0x5,0xd,0x3,0xb,0x7,0xf};
#define REVERSE_BITS(c) { (c) = _ordered[(c)&0xf]<<4 | _ordered[(c)>>4] ; }
/*
* Async packer
*
*/
#define START_BIT 0
#define STOP_BIT 1
#if 0
#define STOP_BITS(p) ((p)->stop_bits)
#define DATA_SIZE(p) ((p)->data_bits)
#define CHAR_SIZE(p) ((p)->char_size)
#define CHAR_DATA(p,ch) ( ( ~(0x1<<(CHAR_SIZE(p)-1)) & \
((ch)<<(p)->stop_bits) ) | \
((0x1<<(p)->stop_bits)-1) )
#else
#define STOP_BITS(p) 1
#define DATA_SIZE(p) 8
#define CHAR_SIZE(p) 10
#define CHAR_DATA(p,ch) (((ch)<<1)|0x1)
#endif
int modem_async_get_bits(struct modem *m, int nbits, u8 *bit_buf, int bit_cnt)
{
struct bits_state *s = &m->pack;
int ret = 0;
u8 ch;
do {
/* fill bits */
while ( bit_cnt > 0 && s->bit >= nbits) {
*bit_buf++ = (s->data>>(s->bit-nbits));
s->bit -= nbits;
ret ++;
bit_cnt--;
}
if (bit_cnt <= 0)
break;
/* get char */
if (!m->get_chars || m->get_chars(m, (char*)&ch, 1) != 1)
break;
REVERSE_BITS(ch);
s->data <<= CHAR_SIZE(m);
s->data |= CHAR_DATA(m,ch);
s->bit += CHAR_SIZE(m);
} while (1);
if (s->bit && bit_cnt > 0) {
/* left data + stops */
*bit_buf++ = (s->data<<(nbits-s->bit))|((0x1<<(nbits-s->bit))-1);
ret ++;
bit_cnt--;
s->bit = 0;
}
#if 0
memcpy(bit_buf,(1<<nbits)-1,bit_cnt);
ret += bit_cnt;
#else
while (bit_cnt > 0) {
/* fill stops */
*bit_buf++ = (1<<nbits)-1;
bit_cnt --;
ret ++;
}
#endif
return ret;
}
int modem_async_put_bits(struct modem *m, int nbits, u8 *bit_buf, int bit_cnt)
{
struct bits_state *s = &m->unpack;
int ret = 0;
u8 ch;
while(bit_cnt > 0) {
s->data<<= nbits;
s->data |= *bit_buf++ & ((0x1<<nbits)-1);
s->bit += nbits;
bit_cnt --;
ret++;
while(s->bit && s->data&(0x1<<(s->bit-1))) /* stop bit */
s->bit--;
while (s->bit >= CHAR_SIZE(m)) {
ch = s->data >>
(s->bit-(CHAR_SIZE(m)-STOP_BITS(m)));
s->bit-= CHAR_SIZE(m);
REVERSE_BITS(ch);
if (m->put_chars)
m->put_chars(m,(const char*)&ch,1);
}
}
return ret;
}
void modem_async_start(struct modem *m)
{
m->pack.bit = m->unpack.bit = 0;
m->pack.data = m->unpack.data = 0;
m->bit_timer_func = NULL;
m->bit_timer = 0;
}
/*
* Packer detector
*
*/
/*
* Detection phase description.
* originator - transmits ODPs until T400 timer is expired
* or until ADP is received.
*
* answer - transmits marks(1) until: detect phase termination,
* ODP receipt - send at least 10 ADPs,
* detection of start protocol phase (continuous flags).
*
*
*/
/* ODP: 0100010001 11111111 0100010011 11111111 */
#define ODP0 0x88
#define ODP1 0x89
/* ADP v42: 0101000101 11111111 0110000101 11111111 */
/* ADP v14: 0101000101 11111111 0000000001 11111111 */
#define ADP0 0xa2
#define ADP1_V14 0x00
#define ADP1_V42 0xc2
#define ADP1 ADP1_V42
#define MIN_RX_PATTERNS 2
#define MAX_TX_PATTERNS 16
#define PATTERN_SIZE 36
#define FILL_PATTERN_ODP(pat) { (pat)[0]=ODP0 ; (pat)[1]=ODP1; }
#define FILL_PATTERN_ADP(pat) { (pat)[0]=ADP0 ; (pat)[1]=ADP1; }
static void detector_start(struct modem *m)
{
PACK_DBG("detector start...\n");
m->packer.detector.tx_count = 1;
}
static void detector_finish(struct modem *m)
{
PACK_DBG("detector finished.\n");
// fixme: modem update config
m->cfg.ec = m->packer.detector.ec_enable;
modem_update_status(m,STATUS_PACK_LINK);
}
int modem_detector_get_bits(struct modem *m, int nbits, u8 *bit_buf, int bit_cnt)
{
struct bits_state *s = &m->pack;
struct detect_state *d = &m->packer.detector;
int ret = 0;
do {
/* fill bits */
while ( bit_cnt > 0 && s->bit >= nbits) {
*bit_buf++ = (s->data>>(s->bit-nbits));
s->bit -= nbits;
ret ++;
bit_cnt--;
}
if (bit_cnt <= 0)
break;
#if 0
s->data <<= 18;
s->data |= (0x1ff<<9)|(d->tx_pattern[d->tx_count++%2]);
s->bit += 18;
#else
/* get char */
s->data <<= 9;
s->data |= 0x1ff;
s->bit += 9;
if (d->tx_count > 0) {
s->data <<= 9;
s->data |= d->tx_pattern[d->tx_count++%2];
s->bit += 9;
}
#endif
} while (1);
return ret;
}
int modem_detector_put_bits(struct modem *m, int nbits, u8 *bit_buf, int bit_cnt)
{
struct bits_state *s = &m->unpack;
struct detect_state *d = &m->packer.detector;
int ret = 0;
u8 ch;
while(bit_cnt > 0) {
s->data<<= nbits;
s->data |= *bit_buf++ & ((0x1<<nbits)-1);
s->bit += nbits;
bit_cnt --;
ret++;
while(s->bit && s->data&(0x1<<(s->bit-1))) /* skip marks */
s->bit--;
while (s->bit >= 10 ) {
ch = s->data >> (s->bit-9);
s->bit-= 10;
PACK_DBG("rx pattern: 0x%02x.\n",ch);
if (ch == HDLC_FLAG) {
PACK_DBG("hdlc flag detected.\n");
d->ec_enable = 1;
m->bit_timer_func = detector_finish;
m->bit_timer = PATTERN_SIZE;
continue;
}
if (!d->rx_count) {
d->rx_count = (ch == d->rx_pattern[0]);
continue;
}
if (d->rx_count >= 2)
continue;
switch(ch) {
case ODP1:
//PACK_DBG("rx ODP.\n");
if (!m->caller) {
/* start replay ADP and leave detector */
d->tx_count = 1;
d->rx_count = 2;
d->ec_enable = 1;
m->bit_timer_func = detector_finish;
m->bit_timer = MAX_TX_PATTERNS*PATTERN_SIZE;
}
else
d->rx_count = 0;
break;
case ADP1_V14:
//PACK_DBG("rx ADP non v42.\n");
d->rx_count = 2;
d->ec_enable = 0;
m->bit_timer_func = detector_finish;
m->bit_timer = PATTERN_SIZE;
break;
case ADP1_V42:
//PACK_DBG("rx ADP v42.\n");
m->cfg.ec = 1;
d->rx_count = 2;
d->ec_enable = 1;
m->bit_timer_func = detector_finish;
m->bit_timer = PATTERN_SIZE;
break;
default:
d->rx_count = 0;
break;
}
}
}
return ret;
}
void modem_detector_start(struct modem *m) {
struct detect_state *d = &m->packer.detector;
int rate = 28800 ; // fixme: use real bit rate from modem
d->tx_count = 0; /* mute transmitter */
d->rx_count = 0;
d->ec_enable = 0;
if (m->caller) {
FILL_PATTERN_ODP(d->tx_pattern);
FILL_PATTERN_ADP(d->rx_pattern);
m->bit_timer_func = detector_start;
m->bit_timer = 64*8 ;
}
else {
FILL_PATTERN_ADP(d->tx_pattern);
FILL_PATTERN_ODP(d->rx_pattern);
m->bit_timer_func = detector_finish;
m->bit_timer = rate*3/4; /* T400 timeout */
}
m->pack.bit = m->unpack.bit = 0;
m->pack.data = m->unpack.data = 0;
}
/*
* HDLC packer
*
*/
/* static data */
/* fcs16 table */
static const
u16 fcs16_tab[256] = {
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
#define fcstab fcs16_tab
#define INIT_FCS16 0xffff /* Initial FCS16 value */
#define GOOD_FCS16 0xf0b8 /* Good final FCS16 value */
#define GET_FCS(fcs,c) (((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])
#define INIT_FCS INIT_FCS16 /* Initial FCS value */
#define GOOD_FCS GOOD_FCS16 /* Good final FCS value */
/* hdlc bit generators */
#define HDLC_PUT_BYTE { \
for( i = 0 ; i < 8 ; i++ ) { \
s->data<<=1; \
s->bit++; \
if(in&0x1) { \
h->tx_ones++; \
s->data |= 0x1; \
if (h->tx_ones==5) { \
s->data<<=1; \
s->bit++; \
h->tx_ones = 0; \
} \
} \
else { \
h->tx_ones = 0; \
} \
in>>=1; \
} }
int modem_hdlc_get_bits(struct modem *m, int nbits,
u8 *bit_buf, int bit_cnt)
{
struct hdlc_state *h = &m->packer.hdlc;
register struct bits_state *s = &m->pack;
register int i, ret = 0;
register u8 in, mask = ((1<<nbits) - 1);
do {
/* fill bits */
while ( bit_cnt > 0 && s->bit >= nbits) {
*bit_buf++ = (s->data>>(s->bit-nbits))&mask;
s->bit -= nbits;
ret ++;
bit_cnt--;
}
if (bit_cnt <= 0)
break;
if (!h->tx_frame) {
s->data <<= 8;
s->data |= HDLC_FLAG;
s->bit += 8;
if (h->get_tx_frame &&
(h->tx_frame = h->get_tx_frame(h->framer))) {
h->tx_frame->fcs = INIT_FCS;
h->tx_frame->count = 0;
}
}
else if(h->tx_frame->count == h->tx_frame->size) {
/* end frame */
/* put fcs */
h->tx_frame->fcs ^= 0xffff;
in = h->tx_frame->fcs&0xff;
HDLC_PUT_BYTE;
in = (h->tx_frame->fcs>>8)&0xff;
HDLC_PUT_BYTE;
h->tx_ones = 0;
/* frame complete callback */
if (h->tx_complete)
h->tx_complete(h->framer, h->tx_frame);
/* reset tx frame */
h->tx_frame = NULL;
/* put flags will done automatically */
}
else {
in = h->tx_frame->buf[h->tx_frame->count];
h->tx_frame->count++;
/* fixme: in order to speed up
fcs calc: copy it to local var */
h->tx_frame->fcs = GET_FCS(h->tx_frame->fcs,in);
HDLC_PUT_BYTE;
}
} while (1);
return ret;
}
int modem_hdlc_put_bits(struct modem *m, int nbits,
u8 *bit_buf, int bit_cnt)
{
struct hdlc_state *h = &m->packer.hdlc;
register struct bits_state *s = &m->unpack;
register int ret = 0;
register int i;
register u8 in, out, mask = ((0x1<<nbits)-1);
while(bit_cnt > 0) {
s->data <<= nbits;
s->data |= *bit_buf++ & mask;
s->bit += nbits;
bit_cnt--;
ret++;
/* 8 char, 2 possible escapes, +8 estimated flag */
if ( s->bit < 8 + 8 + 2)
continue;
out = 0;
// fixme: probably may be optimized by handling whole
// byte with masking
/* mask = 0x80; */
for ( i=0 ; i<8 ; i++ ) {
in = s->data >> (s->bit-8) ;
/* flag: finish frame */
if (in == HDLC_FLAG) {
/* end of frame */;
if ( !h->rx_frame->count ) {
//HDLC_DBG("empty.\n");
}
/* check frame for errors */
else if (h->rx_error) {
PACK_DBG("hdlc frame error.\n");
}
else if (i) {
PACK_DBG("hdlc frame integrity error.\n");
}
#if 1
else if ( h->rx_frame->count < 3 ) {
#else
else if ( h->rx_frame->count < 4 ) {
#endif
PACK_DBG("hdlc frame size error.\n");
}
else if ( h->rx_frame->fcs != GOOD_FCS ) {
PACK_DBG("hdlc frame fcs error.\n");
}
/* good frame */
else if ( h->rx_complete ) {
/* reduce fcs size */
h->rx_frame->count -= 2;
h->rx_complete(h->framer,h->rx_frame);
}
s->bit -= 8;
h->rx_ones = 0;
h->rx_error = 0;
h->rx_frame->fcs = INIT_FCS;
h->rx_frame->count = 0;
break;
}
else if(h->rx_error) {
s->bit--;
continue;
}
/* put reversed data bit */
out >>= 1;
if (in&0x80) {
out |= 0x80;
h->rx_ones++;
/* escape or idle reached */
if (h->rx_ones == 5) {
if (in&0x40) {
h->rx_error++;
h->rx_frame->count = 0;
}
s->bit--;
h->rx_ones = 0;
}
}
else
h->rx_ones = 0;
s->bit--;
}
/* finish char */
if(i==8 && !h->rx_error) {
if (h->rx_frame->count < h->rx_frame->size) {
h->rx_frame->buf[h->rx_frame->count] = out;
h->rx_frame->count++;
h->rx_frame->fcs = GET_FCS(h->rx_frame->fcs,out);
}
else { /* overflow */
PACK_DBG("hdlc rx frame overflow.\n");
h->rx_error++;
h->rx_frame->count = 0;
}
}
}
return ret;
}
void modem_hdlc_start(struct modem *m)
{
struct hdlc_state *h = &m->packer.hdlc;
PACK_DBG("hdlc_start...\n");
memset(h,0,sizeof(*h));
/* wait for flag to clear rx error state */
h->rx_error = 1;
/* rx frame */
h->rx_frame = &h->_rx_frame;
h->rx_frame->buf = h->_rx_buf;
h->rx_frame->count= 0;
h->rx_frame->size = sizeof(h->_rx_buf);
h->rx_frame->fcs = INIT_FCS;
/* tx frame */
h->tx_frame = 0;
m->pack.bit = m->unpack.bit = 0;
m->pack.data = m->unpack.data = 0;
m->bit_timer_func = NULL;
m->bit_timer = 0;
}
#if 0
// temp stupid things
static struct hdlc_frame *tmp_get_frame(void *framer)
{
frame_t *f;
struct modem *m = framer;
if(m->get_chars) {
f = &m->packer.hdlc._tx_frame;
f->buf = m->packer.hdlc._tx_buf;
f->size = m->get_chars(m,f->buf,sizeof(m->packer.hdlc._tx_buf));
if(f->size <= 0) {
return NULL;
}
PACK_DBG("get frame: %d...\n",f->size);
return f;
}
return NULL;
}
static void tmp_put_frame(void *framer, frame_t *fr)
{
struct modem *m = framer;
if(fr->count > 0 && m->put_chars) {
PACK_DBG("put frame: %d...\n",fr->count);
m->put_chars(m,fr->buf,fr->count);
}
return;
}
void tmp_init(struct modem *m)
{
m->packer.hdlc.get_tx_frame = tmp_get_frame;
m->packer.hdlc.rx_complete = tmp_put_frame;
m->packer.hdlc.framer = m;
}
#endif
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