minimodem-mirror/src/databits_callerid.c

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/*
* databits_callerid.c
*
* Copyright (C) 2012 Kamal Mostafa <kamal@whence.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "databits.h"
#include <stdio.h>
/*
* Caller-ID (USA SDMF/MDMF) databits decoder
*
* Reference: http://melabs.com/resources/callerid.htm
*/
#define CID_MSG_MDMF 0x80
#define CID_MSG_SDMF 0x04
#define CID_DATA_DATETIME 0x01
#define CID_DATA_PHONE 0x02
#define CID_DATA_PHONE_NA 0x04
#define CID_DATA_NAME 0x07
#define CID_DATA_NAME_NA 0x08
static const char *cid_datatype_names[] = {
"unknown0:", "Time:", "Phone:", "unknown3:",
"Phone:", "unknown5:", "unknown6:", "Name:",
"Name:"
};
static int cid_msgtype = 0;
static int cid_ndata = 0;
static unsigned char cid_buf[256];
static unsigned int
decode_mdmf_callerid( char *dataout_p, unsigned int dataout_size )
{
unsigned int dataout_n = 0;
unsigned int cid_i = 0;
unsigned int cid_msglen = cid_buf[1];
unsigned char *m = cid_buf + 2;
while ( cid_i < cid_msglen ) {
unsigned int cid_datatype = *m++;
if ( cid_datatype > CID_DATA_NAME_NA ) {
// FIXME: bad datastream -- print something here
return 0;
}
unsigned int cid_datalen = *m++;
if ( m + 2 + cid_datalen >= cid_buf + sizeof(cid_buf) ) {
// FIXME: bad datastream -- print something here
return 0;
}
// dataout_n += sprintf(dataout_p+dataout_n, "CID: %d (%d)\n", cid_datatype, cid_datalen);
dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
cid_datatype_names[cid_datatype]);
int prlen = 0;
char *prdata = NULL;
switch ( cid_datatype ) {
case CID_DATA_DATETIME:
dataout_n += sprintf(dataout_p+dataout_n,
"%.2s/%.2s %.2s:%.2s\n", m+0, m+2, m+4, m+6);
break;
case CID_DATA_PHONE:
if ( cid_datalen == 10 ) {
dataout_n += sprintf(dataout_p+dataout_n,
"%.3s-%.3s-%.4s\n", m+0, m+3, m+6);
break;
} else {
// fallthrough
}
case CID_DATA_NAME:
prdata = (char *)m;
prlen = cid_datalen;
break;
case CID_DATA_PHONE_NA:
case CID_DATA_NAME_NA:
if ( cid_datalen == 1 && *m == 'O' ) {
prdata = "[N/A]";
prlen = 5;
} else if ( cid_datalen == 1 && *m == 'P' ) {
prdata = "[blocked]";
prlen = 9;
}
break;
default:
// FIXME: warning here?
break;
}
if ( prdata )
dataout_n += sprintf(dataout_p+dataout_n, "%.*s\n", prlen, prdata);
m += cid_datalen;
cid_i += cid_datalen + 2;
}
return dataout_n;
}
static unsigned int
decode_sdmf_callerid( char *dataout_p, unsigned int dataout_size )
{
unsigned int dataout_n = 0;
unsigned int cid_msglen = cid_buf[1];
unsigned char *m = cid_buf + 2;
dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
cid_datatype_names[CID_DATA_DATETIME]);
dataout_n += sprintf(dataout_p+dataout_n, "%.2s/%.2s %.2s:%.2s\n",
m+0, m+2, m+4, m+6);
m += 8;
dataout_n += sprintf(dataout_p+dataout_n, "%-6s ",
cid_datatype_names[CID_DATA_PHONE]);
unsigned int cid_datalen = cid_msglen - 8;
if ( cid_datalen == 10 )
dataout_n += sprintf(dataout_p+dataout_n, "%.3s-%.3s-%.4s\n",
m+0, m+3, m+6);
else
dataout_n += sprintf(dataout_p+dataout_n, "%.*s\n",
cid_datalen, m);
return dataout_n;
}
static unsigned int
decode_cid_reset()
{
cid_msgtype = 0;
cid_ndata = 0;
return 0;
}
// FIXME: doesn't respect dataout_size at all!
/* returns nbytes decoded */
unsigned int
databits_decode_callerid( char *dataout_p, unsigned int dataout_size,
unsigned long long bits, unsigned int n_databits )
{
if ( ! dataout_p ) // databits processor reset
return decode_cid_reset();
if ( cid_msgtype == 0 ) {
if ( bits == CID_MSG_MDMF )
cid_msgtype = CID_MSG_MDMF;
else if ( bits == CID_MSG_SDMF )
cid_msgtype = CID_MSG_SDMF;
else
return 0;
cid_buf[cid_ndata++] = bits;
return 0;
}
if ( cid_ndata >= sizeof(cid_buf) ) {
// FIXME? buffer overflow; do what here?
return decode_cid_reset();
}
cid_buf[cid_ndata++] = bits;
// Collect input bytes until we've collected as many as the message
// length byte says there will be, plus two (the message type byte
// and the checksum byte)
unsigned long long cid_msglen = cid_buf[1];
if ( cid_ndata < cid_msglen + 2)
return 0;
// Now we have a whole CID message in cid_buf[] -- decode it
// FIXME: check the checksum
unsigned int dataout_n = 0;
dataout_n += sprintf(dataout_p+dataout_n, "CALLER-ID\n");
if ( cid_msgtype == CID_MSG_MDMF )
dataout_n += decode_mdmf_callerid(dataout_p+dataout_n,
dataout_size-dataout_n);
else
dataout_n += decode_sdmf_callerid(dataout_p+dataout_n,
dataout_size-dataout_n);
// All done; reset for the next one
decode_cid_reset();
return dataout_n;
}