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freeswitch/libs/spandsp/src/adsi.c

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/*
* SpanDSP - a series of DSP components for telephony
*
* adsi.c - Analogue display service interfaces of various types, including
* ADSI, TDD and most caller ID formats.
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2003 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*! \file */
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#include <math.h>
#endif
#if defined(HAVE_STDBOOL_H)
#include <stdbool.h>
#else
#include "spandsp/stdbool.h"
#endif
#include "floating_fudge.h"
#include <assert.h>
#include "spandsp/telephony.h"
#include "spandsp/alloc.h"
#include "spandsp/fast_convert.h"
#include "spandsp/logging.h"
#include "spandsp/queue.h"
#include "spandsp/complex.h"
#include "spandsp/dds.h"
#include "spandsp/power_meter.h"
#include "spandsp/async.h"
#include "spandsp/crc.h"
#include "spandsp/fsk.h"
#include "spandsp/tone_detect.h"
#include "spandsp/tone_generate.h"
#include "spandsp/super_tone_rx.h"
#include "spandsp/dtmf.h"
#include "spandsp/adsi.h"
#include "spandsp/private/logging.h"
#include "spandsp/private/queue.h"
#include "spandsp/private/tone_generate.h"
#include "spandsp/private/async.h"
#include "spandsp/private/power_meter.h"
#include "spandsp/private/fsk.h"
#include "spandsp/private/dtmf.h"
#include "spandsp/private/adsi.h"
/*! The baudot code to shift from alpha to digits and symbols */
#define BAUDOT_FIGURE_SHIFT 0x1B
/*! The baudot code to shift from digits and symbols to alpha */
#define BAUDOT_LETTER_SHIFT 0x1F
enum
{
SOH = 0x01,
STX = 0x02,
ETX = 0x03,
DLE = 0x10,
SUB = 0x1A
};
static uint16_t adsi_encode_baudot(adsi_tx_state_t *s, uint8_t ch);
static uint8_t adsi_decode_baudot(adsi_rx_state_t *s, uint8_t ch);
static int adsi_tx_get_bit(void *user_data)
{
int bit;
adsi_tx_state_t *s;
s = (adsi_tx_state_t *) user_data;
/* This is similar to the async. handling code in fsk.c, but a few special
things are needed in the preamble, and postamble of an ADSI message. */
if (s->bit_no < s->preamble_len)
{
/* Alternating bit preamble */
bit = s->bit_no & 1;
s->bit_no++;
}
else if (s->bit_no < s->preamble_len + s->preamble_ones_len)
{
/* All 1s for receiver conditioning */
/* NB: The receiver is an async one. It needs a rest after the
alternating 1/0 sequence so it can reliably pick up on
the next start bit, and sync to the byte stream. */
/* The length of this period varies with the circumstance */
bit = 1;
s->bit_no++;
}
else if (s->bit_no <= s->preamble_len + s->preamble_ones_len)
{
/* Push out the 8 bit async. chars, with an appropriate number of stop bits */
if (s->bit_pos == 0)
{
/* Start bit */
bit = 0;
s->bit_pos++;
}
else if (s->bit_pos < 1 + 8)
{
bit = (s->msg[s->byte_no] >> (s->bit_pos - 1)) & 1;
s->bit_pos++;
}
else if (s->bit_pos < 1 + 8 + s->stop_bits - 1)
{
/* Stop bit */
bit = 1;
s->bit_pos++;
}
else
{
/* Stop bit */
bit = 1;
s->bit_pos = 0;
if (++s->byte_no >= s->msg_len)
s->bit_no++;
}
}
else if (s->bit_no <= s->preamble_len + s->preamble_ones_len + s->postamble_ones_len)
{
/* Extra stop bits beyond the last character, to meet the specs., and ensure
all bits are out of the DSP before we shut off the FSK modem. */
bit = 1;
s->bit_no++;
}
else
{
bit = SIG_STATUS_END_OF_DATA;
if (s->tx_signal_on)
{
/* The FSK should now be switched off. */
s->tx_signal_on = false;
s->msg_len = 0;
}
}
//printf("Tx bit %d\n", bit);
return bit;
}
/*- End of function --------------------------------------------------------*/
static int adsi_tdd_get_async_byte(void *user_data)
{
adsi_tx_state_t *s;
s = (adsi_tx_state_t *) user_data;
if (s->byte_no < s->msg_len)
return s->msg[s->byte_no++];
if (s->tx_signal_on)
{
/* The FSK should now be switched off. */
s->tx_signal_on = false;
s->msg_len = 0;
}
return 0x1F;
}
/*- End of function --------------------------------------------------------*/
static void adsi_rx_put_bit(void *user_data, int bit)
{
adsi_rx_state_t *s;
int i;
int sum;
s = (adsi_rx_state_t *) user_data;
if (bit < 0)
{
/* Special conditions */
span_log(&s->logging, SPAN_LOG_FLOW, "ADSI signal status is %s (%d)\n", signal_status_to_str(bit), bit);
switch (bit)
{
case SIG_STATUS_CARRIER_UP:
s->consecutive_ones = 0;
s->bit_pos = 0;
s->in_progress = 0;
s->msg_len = 0;
break;
case SIG_STATUS_CARRIER_DOWN:
break;
default:
span_log(&s->logging, SPAN_LOG_WARNING, "Unexpected special put bit value - %d!\n", bit);
break;
}
return;
}
bit &= 1;
if (s->bit_pos == 0)
{
if (bit == 0)
{
/* Start bit */
s->bit_pos++;
if (s->consecutive_ones > 10)
{
/* This is a line idle condition, which means we should
restart message acquisition */
s->msg_len = 0;
}
s->consecutive_ones = 0;
}
else
{
s->consecutive_ones++;
}
}
else if (s->bit_pos <= 8)
{
s->in_progress >>= 1;
if (bit)
s->in_progress |= 0x80;
s->bit_pos++;
}
else
{
/* Stop bit */
if (bit)
{
if (s->msg_len < 256)
{
if (s->standard == ADSI_STANDARD_JCLIP)
{
if (s->msg_len == 0)
{
/* A message should start DLE SOH, but let's just check
we are starting with a DLE for now */
if (s->in_progress == (0x80 | DLE))
s->msg[s->msg_len++] = (uint8_t) s->in_progress;
}
else
{
s->msg[s->msg_len++] = (uint8_t) s->in_progress;
}
if (s->msg_len >= 11 && s->msg_len == ((s->msg[6] & 0x7F) + 11))
{
/* Test the CRC-16 */
if (crc_itu16_calc(s->msg + 2, s->msg_len - 2, 0) == 0)
{
/* Strip off the parity bits. It doesn't seem
worthwhile actually checking the parity if a
CRC check has succeeded. */
for (i = 0; i < s->msg_len - 2; i++)
s->msg[i] &= 0x7F;
/* Put everything, except the CRC octets */
s->put_msg(s->user_data, s->msg, s->msg_len - 2);
}
else
{
span_log(&s->logging, SPAN_LOG_WARNING, "CRC failed\n");
}
s->msg_len = 0;
}
}
else
{
s->msg[s->msg_len++] = (uint8_t) s->in_progress;
if (s->msg_len >= 3 && s->msg_len == (s->msg[1] + 3))
{
/* Test the checksum */
sum = 0;
for (i = 0; i < s->msg_len - 1; i++)
sum += s->msg[i];
if ((-sum & 0xFF) == s->msg[i])
s->put_msg(s->user_data, s->msg, s->msg_len - 1);
else
span_log(&s->logging, SPAN_LOG_WARNING, "Sumcheck failed\n");
s->msg_len = 0;
}
}
}
}
else
{
s->framing_errors++;
}
s->bit_pos = 0;
s->in_progress = 0;
}
}
/*- End of function --------------------------------------------------------*/
static void adsi_tdd_put_async_byte(void *user_data, int byte)
{
adsi_rx_state_t *s;
uint8_t octet;
s = (adsi_rx_state_t *) user_data;
//printf("Rx bit %x\n", bit);
if (byte < 0)
{
/* Special conditions */
span_log(&s->logging, SPAN_LOG_FLOW, "ADSI signal status is %s (%d)\n", signal_status_to_str(byte), byte);
switch (byte)
{
case SIG_STATUS_CARRIER_UP:
s->consecutive_ones = 0;
s->bit_pos = 0;
s->in_progress = 0;
s->msg_len = 0;
break;
case SIG_STATUS_CARRIER_DOWN:
if (s->msg_len > 0)
{
/* Whatever we have to date constitutes the message */
s->put_msg(s->user_data, s->msg, s->msg_len);
s->msg_len = 0;
}
break;
default:
span_log(&s->logging, SPAN_LOG_WARNING, "Unexpected special put byte value - %d!\n", byte);
break;
}
return;
}
if ((octet = adsi_decode_baudot(s, (uint8_t) (byte & 0x1F))))
s->msg[s->msg_len++] = octet;
if (s->msg_len >= 256)
{
s->put_msg(s->user_data, s->msg, s->msg_len);
s->msg_len = 0;
}
}
/*- End of function --------------------------------------------------------*/
static void adsi_rx_dtmf(void *user_data, const char *digits, int len)
{
adsi_rx_state_t *s;
s = (adsi_rx_state_t *) user_data;
if (s->msg_len == 0)
{
/* Message starting. Start a 10s timeout, to make things more noise
tolerant for a detector running continuously when on hook. */
s->in_progress = 80000;
}
/* It seems all the DTMF variants are a string of digits and letters,
terminated by a "#", or a "C". It appears these are unambiguous, and
non-conflicting. */
for ( ; len && s->msg_len < 256; len--)
{
s->msg[s->msg_len++] = *digits;
if (*digits == '#' || *digits == 'C')
{
s->put_msg(s->user_data, s->msg, s->msg_len);
s->msg_len = 0;
}
digits++;
}
}
/*- End of function --------------------------------------------------------*/
static void start_tx(adsi_tx_state_t *s)
{
switch (s->standard)
{
case ADSI_STANDARD_CLASS:
fsk_tx_init(&s->fsktx, &preset_fsk_specs[FSK_BELL202], adsi_tx_get_bit, s);
break;
case ADSI_STANDARD_CLIP:
case ADSI_STANDARD_ACLIP:
case ADSI_STANDARD_JCLIP:
fsk_tx_init(&s->fsktx, &preset_fsk_specs[FSK_V23CH1], adsi_tx_get_bit, s);
break;
case ADSI_STANDARD_CLIP_DTMF:
dtmf_tx_init(&s->dtmftx, NULL, NULL);
break;
case ADSI_STANDARD_TDD:
fsk_tx_init(&s->fsktx, &preset_fsk_specs[FSK_WEITBRECHT_4545], async_tx_get_bit, &s->asynctx);
async_tx_init(&s->asynctx, 5, ASYNC_PARITY_NONE, 2, false, adsi_tdd_get_async_byte, s);
/* Schedule an explicit shift at the start of baudot transmission */
s->baudot_shift = 2;
break;
}
s->tx_signal_on = true;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_rx(adsi_rx_state_t *s, const int16_t amp[], int len)
{
switch (s->standard)
{
case ADSI_STANDARD_CLIP_DTMF:
/* Apply a message timeout. */
s->in_progress -= len;
if (s->in_progress <= 0)
s->msg_len = 0;
dtmf_rx(&s->dtmfrx, amp, len);
break;
default:
fsk_rx(&s->fskrx, amp, len);
break;
}
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(logging_state_t *) adsi_rx_get_logging_state(adsi_rx_state_t *s)
{
return &s->logging;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(adsi_rx_state_t *) adsi_rx_init(adsi_rx_state_t *s,
int standard,
put_msg_func_t put_msg,
void *user_data)
{
if (s == NULL)
{
if ((s = (adsi_rx_state_t *) span_alloc(sizeof(*s))) == NULL)
return NULL;
}
memset(s, 0, sizeof(*s));
s->put_msg = put_msg;
s->user_data = user_data;
switch (standard)
{
case ADSI_STANDARD_CLASS:
fsk_rx_init(&s->fskrx, &preset_fsk_specs[FSK_BELL202], FSK_FRAME_MODE_ASYNC, adsi_rx_put_bit, s);
break;
case ADSI_STANDARD_CLIP:
case ADSI_STANDARD_ACLIP:
case ADSI_STANDARD_JCLIP:
fsk_rx_init(&s->fskrx, &preset_fsk_specs[FSK_V23CH1], FSK_FRAME_MODE_ASYNC, adsi_rx_put_bit, s);
break;
case ADSI_STANDARD_CLIP_DTMF:
dtmf_rx_init(&s->dtmfrx, adsi_rx_dtmf, s);
break;
case ADSI_STANDARD_TDD:
/* TDD uses 5 bit data, no parity and 1.5 stop bits. We scan for the first stop bit, and
ride over the fraction. */
fsk_rx_init(&s->fskrx, &preset_fsk_specs[FSK_WEITBRECHT_4545], FSK_FRAME_MODE_5N1_FRAMES, adsi_tdd_put_async_byte, s);
break;
}
s->standard = standard;
span_log_init(&s->logging, SPAN_LOG_NONE, NULL);
return s;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_rx_release(adsi_rx_state_t *s)
{
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_rx_free(adsi_rx_state_t *s)
{
span_free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_tx(adsi_tx_state_t *s, int16_t amp[], int max_len)
{
int len;
int lenx;
len = tone_gen(&s->alert_tone_gen, amp, max_len);
if (s->tx_signal_on)
{
switch (s->standard)
{
case ADSI_STANDARD_CLIP_DTMF:
if (len < max_len)
len += dtmf_tx(&s->dtmftx, amp, max_len - len);
break;
default:
if (len < max_len)
{
if ((lenx = fsk_tx(&s->fsktx, amp + len, max_len - len)) <= 0)
s->tx_signal_on = false;
len += lenx;
}
break;
}
}
return len;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(void) adsi_tx_send_alert_tone(adsi_tx_state_t *s)
{
tone_gen_init(&s->alert_tone_gen, &s->alert_tone_desc);
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(void) adsi_tx_set_preamble(adsi_tx_state_t *s,
int preamble_len,
int preamble_ones_len,
int postamble_ones_len,
int stop_bits)
{
if (preamble_len < 0)
{
if (s->standard == ADSI_STANDARD_JCLIP)
s->preamble_len = 0;
else
s->preamble_len = 300;
}
else
{
s->preamble_len = preamble_len;
}
if (preamble_ones_len < 0)
{
if (s->standard == ADSI_STANDARD_JCLIP)
s->preamble_ones_len = 75;
else
s->preamble_ones_len = 80;
}
else
{
s->preamble_ones_len = preamble_ones_len;
}
if (postamble_ones_len < 0)
{
#if 0
if (s->standard == ADSI_STANDARD_JCLIP)
s->postamble_ones_len = 5;
else
#endif
s->postamble_ones_len = 5;
}
else
{
s->postamble_ones_len = postamble_ones_len;
}
if (stop_bits < 0)
{
if (s->standard == ADSI_STANDARD_JCLIP)
s->stop_bits = 4;
else
s->stop_bits = 1;
}
else
{
s->stop_bits = stop_bits;
}
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_tx_put_message(adsi_tx_state_t *s, const uint8_t *msg, int len)
{
int i;
int j;
int k;
int byte;
int parity;
int sum;
size_t ii;
uint16_t crc_value;
/* Don't inject a new message when a previous one is still in progress */
if (s->msg_len > 0)
return 0;
if (!s->tx_signal_on)
{
/* We need to restart the modem */
start_tx(s);
}
switch (s->standard)
{
case ADSI_STANDARD_CLIP_DTMF:
if (len >= 128)
return -1;
len -= (int) dtmf_tx_put(&s->dtmftx, (char *) msg, len);
break;
case ADSI_STANDARD_JCLIP:
if (len > 128 - 9)
return -1;
i = 0;
s->msg[i++] = DLE;
s->msg[i++] = SOH;
s->msg[i++] = 0x07; //header
s->msg[i++] = DLE;
s->msg[i++] = STX;
s->msg[i++] = msg[0];
s->msg[i++] = (uint8_t) (len - 2);
/* We might need to byte stuff the overall length, but the rest of the
message should already be stuffed. */
if (len - 2 == DLE)
s->msg[i++] = DLE;
memcpy(&s->msg[i], &msg[2], len - 2);
i += len - 2;
s->msg[i++] = DLE;
s->msg[i++] = ETX;
/* Set the parity bits */
for (j = 0; j < i; j++)
{
byte = s->msg[j];
parity = 0;
for (k = 1; k <= 7; k++)
parity ^= (byte << k);
s->msg[j] = (s->msg[j] & 0x7F) | ((uint8_t) parity & 0x80);
}
crc_value = crc_itu16_calc(s->msg + 2, i - 2, 0);
s->msg[i++] = (uint8_t) (crc_value & 0xFF);
s->msg[i++] = (uint8_t) ((crc_value >> 8) & 0xFF);
s->msg_len = i;
break;
case ADSI_STANDARD_TDD:
if (len > 255)
return -1;
memcpy(s->msg, msg, len);
s->msg_len = len;
break;
default:
if (len > 255)
return -1;
memcpy(s->msg, msg, len);
/* Force the length in case it is wrong */
s->msg[1] = (uint8_t) (len - 2);
/* Add the sumcheck */
sum = 0;
for (ii = 0; ii < (size_t) len; ii++)
sum += s->msg[ii];
s->msg[len] = (uint8_t) ((-sum) & 0xFF);
s->msg_len = len + 1;
break;
}
/* Prepare the bit sequencing */
s->byte_no = 0;
s->bit_pos = 0;
s->bit_no = 0;
return len;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(logging_state_t *) adsi_tx_get_logging_state(adsi_tx_state_t *s)
{
return &s->logging;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(adsi_tx_state_t *) adsi_tx_init(adsi_tx_state_t *s, int standard)
{
if (s == NULL)
{
if ((s = (adsi_tx_state_t *) span_alloc(sizeof(*s))) == NULL)
return NULL;
}
memset(s, 0, sizeof(*s));
tone_gen_descriptor_init(&s->alert_tone_desc,
2130,
-13,
2750,
-13,
110,
60,
0,
0,
false);
s->standard = standard;
adsi_tx_set_preamble(s, -1, -1, -1, -1);
span_log_init(&s->logging, SPAN_LOG_NONE, NULL);
start_tx(s);
return s;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_tx_release(adsi_tx_state_t *s)
{
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_tx_free(adsi_tx_state_t *s)
{
span_free(s);
return 0;
}
/*- End of function --------------------------------------------------------*/
static uint16_t adsi_encode_baudot(adsi_tx_state_t *s, uint8_t ch)
{
static const uint8_t conv[128] =
{
0x00, /* NUL */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0x42, /* LF */
0xFF, /* */
0xFF, /* */
0x48, /* CR */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0xFF, /* */
0x44, /* */
0xFF, /* ! */
0xFF, /* " */
0x94, /* # */
0x89, /* $ */
0xFF, /* % */
0xFF, /* & */
0x85, /* ' */
0x8F, /* ( */
0x92, /* ) */
0x8B, /* * */
0x91, /* + */
0x8C, /* , */
0x83, /* - */
0x9C, /* . */
0x9D, /* / */
0x96, /* 0 */
0x97, /* 1 */
0x93, /* 2 */
0x81, /* 3 */
0x8A, /* 4 */
0x90, /* 5 */
0x95, /* 6 */
0x87, /* 7 */
0x86, /* 8 */
0x98, /* 9 */
0x8E, /* : */
0xFF, /* ; */
0xFF, /* < */
0x9E, /* = */
0xFF, /* > */
0x99, /* ? */
0xFF, /* @ */
0x03, /* A */
0x19, /* B */
0x0E, /* C */
0x09, /* D */
0x01, /* E */
0x0D, /* F */
0x1A, /* G */
0x14, /* H */
0x06, /* I */
0x0B, /* J */
0x0F, /* K */
0x12, /* L */
0x1C, /* M */
0x0C, /* N */
0x18, /* O */
0x16, /* P */
0x17, /* Q */
0x0A, /* R */
0x05, /* S */
0x10, /* T */
0x07, /* U */
0x1E, /* V */
0x13, /* W */
0x1D, /* X */
0x15, /* Y */
0x11, /* Z */
0xFF, /* [ */
0xFF, /* \ */
0xFF, /* ] */
0x9B, /* ^ */
0xFF, /* _ */
0xFF, /* ` */
0x03, /* a */
0x19, /* b */
0x0E, /* c */
0x09, /* d */
0x01, /* e */
0x0D, /* f */
0x1A, /* g */
0x14, /* h */
0x06, /* i */
0x0B, /* j */
0x0F, /* k */
0x12, /* l */
0x1C, /* m */
0x0C, /* n */
0x18, /* o */
0x16, /* p */
0x17, /* q */
0x0A, /* r */
0x05, /* s */
0x10, /* t */
0x07, /* u */
0x1E, /* v */
0x13, /* w */
0x1D, /* x */
0x15, /* y */
0x11, /* z */
0xFF, /* { */
0xFF, /* | */
0xFF, /* } */
0xFF, /* ~ */
0xFF, /* DEL */
};
uint16_t shift;
ch = conv[ch];
if (ch == 0xFF)
return 0;
if ((ch & 0x40))
return ch & 0x1F;
if ((ch & 0x80))
{
if (s->baudot_shift == 1)
return ch & 0x1F;
s->baudot_shift = 1;
shift = BAUDOT_FIGURE_SHIFT;
}
else
{
if (s->baudot_shift == 0)
return ch & 0x1F;
s->baudot_shift = 0;
shift = BAUDOT_LETTER_SHIFT;
}
return (shift << 5) | (ch & 0x1F);
}
/*- End of function --------------------------------------------------------*/
static uint8_t adsi_decode_baudot(adsi_rx_state_t *s, uint8_t ch)
{
static const uint8_t conv[2][32] =
{
{"\000E\nA SIU\rDRJNFCKTZLWHYPQOBG^MXV^"},
{"\0003\n- '87\r$4*,*:(5+)2#6019?*^./=^"}
};
switch (ch)
{
case BAUDOT_FIGURE_SHIFT:
s->baudot_shift = 1;
break;
case BAUDOT_LETTER_SHIFT:
s->baudot_shift = 0;
break;
default:
return conv[s->baudot_shift][ch];
}
/* return 0 if we did not produce a character */
return 0;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_next_field(adsi_rx_state_t *s, const uint8_t *msg, int msg_len, int pos, uint8_t *field_type, uint8_t const **field_body, int *field_len)
{
int i;
/* Return -1 for no more fields. Return -2 for message structure corrupt. */
switch (s->standard)
{
case ADSI_STANDARD_CLASS:
case ADSI_STANDARD_CLIP:
case ADSI_STANDARD_ACLIP:
if (pos >= msg_len)
return -1;
/* For MDMF type messages, these standards all use "IE" type fields - type,
length, contents - and similar headers */
if (pos <= 0)
{
/* Return the message type */
*field_type = msg[0];
*field_len = 0;
*field_body = NULL;
pos = 2;
}
else
{
if ((msg[0] & 0x80))
{
/* MDMF messages seem to always have a message type with the MSB set. Is that
guaranteed? */
*field_type = msg[pos++];
*field_len = msg[pos++];
*field_body = msg + pos;
}
else
{
/* SDMF */
*field_type = 0;
*field_len = msg_len - pos;
*field_body = msg + pos;
}
pos += *field_len;
}
if (pos > msg_len)
return -2;
break;
case ADSI_STANDARD_JCLIP:
if (pos >= msg_len - 2)
return -1;
if (pos <= 0)
{
/* Return the message type */
pos = 5;
*field_type = msg[pos++];
if (*field_type == DLE)
pos++;
if (msg[pos++] == DLE)
pos++;
*field_len = 0;
*field_body = NULL;
}
else
{
*field_type = msg[pos++];
if (*field_type == DLE)
pos++;
*field_len = msg[pos++];
if (*field_len == DLE)
pos++;
/* TODO: we assume here that the body contains no DLE's that would have been stuffed */
*field_body = msg + pos;
pos += *field_len;
}
if (pos > msg_len - 2)
return -2;
break;
case ADSI_STANDARD_CLIP_DTMF:
if (pos > msg_len)
return -1;
if (pos <= 0)
{
pos = 1;
*field_type = msg[msg_len - 1];
*field_len = 0;
*field_body = NULL;
}
else
{
/* Remove bias on the pos value */
pos--;
if (msg[pos] >= '0' && msg[pos] <= '9')
*field_type = CLIP_DTMF_HASH_UNSPECIFIED;
else
*field_type = msg[pos++];
*field_body = msg + pos;
i = pos;
while (i < msg_len && msg[i] >= '0' && msg[i] <= '9')
i++;
*field_len = i - pos;
pos = i;
/* Check if we have reached the end of message marker. */
if (msg[pos] == '#' || msg[pos] == 'C')
pos++;
if (pos > msg_len)
return -2;
/* Bias the pos value, so we don't return 0 inappropriately */
pos++;
}
break;
case ADSI_STANDARD_TDD:
if (pos >= msg_len)
return -1;
*field_type = 0;
*field_body = msg;
*field_len = msg_len;
pos = msg_len;
break;
}
return pos;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(int) adsi_add_field(adsi_tx_state_t *s, uint8_t *msg, int len, uint8_t field_type, uint8_t const *field_body, int field_len)
{
int i;
int x;
switch (s->standard)
{
case ADSI_STANDARD_CLASS:
case ADSI_STANDARD_CLIP:
case ADSI_STANDARD_ACLIP:
/* These standards all use "IE" type fields - type, length, value - and similar headers */
if (len <= 0)
{
/* Initialise a new message. The field type is actually the message type. */
msg[0] = field_type;
msg[1] = 0;
len = 2;
}
else
{
/* Add to a message in progress. */
if (field_type)
{
msg[len++] = field_type;
msg[len++] = (uint8_t) field_len;
if (field_len == DLE)
msg[len++] = (uint8_t) field_len;
memcpy(&msg[len], field_body, field_len);
len += field_len;
}
else
{
/* No field type or length, for restricted single message formats */
memcpy(&msg[len], field_body, field_len);
len += field_len;
}
}
break;
case ADSI_STANDARD_JCLIP:
/* This standard uses "IE" type fields - type, length, value - but escapes DLE characters,
to prevent immitation of a control octet. */
if (len <= 0)
{
/* Initialise a new message. The field type is actually the message type. */
msg[0] = field_type;
msg[1] = 0;
len = 2;
}
else
{
/* Add to a message in progress. */
msg[len++] = field_type;
if (field_type == DLE)
msg[len++] = field_type;
msg[len++] = (uint8_t) field_len;
if (field_len == DLE)
msg[len++] = (uint8_t) field_len;
for (i = 0; i < field_len; i++)
{
msg[len++] = field_body[i];
if (field_body[i] == DLE)
msg[len++] = field_body[i];
}
}
break;
case ADSI_STANDARD_CLIP_DTMF:
if (len <= 0)
{
/* Initialise a new message. The field type is actually the message type. */
msg[0] = field_type;
len = 1;
}
else
{
/* Save and reuse the terminator/message type */
x = msg[--len];
if (field_type != CLIP_DTMF_HASH_UNSPECIFIED)
msg[len++] = field_type;
memcpy(&msg[len], field_body, field_len);
msg[len + field_len] = (uint8_t) x;
len += (field_len + 1);
}
break;
case ADSI_STANDARD_TDD:
if (len < 0)
len = 0;
for (i = 0; i < field_len; i++)
{
if ((x = adsi_encode_baudot(s, field_body[i])))
{
if ((x & 0x3E0))
msg[len++] = (uint8_t) ((x >> 5) & 0x1F);
msg[len++] = (uint8_t) (x & 0x1F);
}
}
break;
}
return len;
}
/*- End of function --------------------------------------------------------*/
SPAN_DECLARE(const char *) adsi_standard_to_str(int standard)
{
switch (standard)
{
case ADSI_STANDARD_CLASS:
return "CLASS";
case ADSI_STANDARD_CLIP:
return "CLIP";
case ADSI_STANDARD_ACLIP:
return "A-CLIP";
case ADSI_STANDARD_JCLIP:
return "J-CLIP";
case ADSI_STANDARD_CLIP_DTMF:
return "CLIP-DTMF";
case ADSI_STANDARD_TDD:
return "TDD";
}
return "???";
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/
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