asterisk/callerid.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief CallerID Generation support 
 *
 * \author Mark Spencer <markster@digium.com> 
 */

#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>
#include <ctype.h>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/ulaw.h"
#include "asterisk/alaw.h"
#include "asterisk/frame.h"
#include "asterisk/channel.h"
#include "asterisk/callerid.h"
#include "asterisk/logger.h"
#include "asterisk/fskmodem.h"
#include "asterisk/options.h"
#include "asterisk/utils.h"

struct callerid_state {
	fsk_data fskd;
	char rawdata[256];
	short oldstuff[160];
	int oldlen;
	int pos;
	int type;
	int cksum;
	char name[64];
	char number[64];
	int flags;
	int sawflag;
	int len;

	int skipflag; 
	unsigned short crc;
};


float cid_dr[4], cid_di[4];
float clidsb = 8000.0 / 1200.0;
float sasdr, sasdi;
float casdr1, casdi1, casdr2, casdi2;

#define CALLERID_SPACE	2200.0		/*!< 2200 hz for "0" */
#define CALLERID_MARK	1200.0		/*!< 1200 hz for "1" */
#define SAS_FREQ		 440.0
#define CAS_FREQ1		2130.0
#define CAS_FREQ2		2750.0

#define AST_CALLERID_UNKNOWN	"<unknown>"

static inline void gen_tones(unsigned char *buf, int len, int codec, float ddr1, float ddi1, float ddr2, float ddi2, float *cr1, float *ci1, float *cr2, float *ci2)
{
	int x;
	float t;
	for (x=0;x<len;x++) {
		t = *cr1 * ddr1 - *ci1 * ddi1;
		*ci1 = *cr1 * ddi1 + *ci1 * ddr1;
		*cr1 = t;
		t = 2.0 - (*cr1 * *cr1 + *ci1 * *ci1);
		*cr1 *= t;
		*ci1 *= t; 	

		t = *cr2 * ddr2 - *ci2 * ddi2;
		*ci2 = *cr2 * ddi2 + *ci2 * ddr2;
		*cr2 = t;
		t = 2.0 - (*cr2 * *cr2 + *ci2 * *ci2);
		*cr2 *= t;
		*ci2 *= t; 	
		buf[x] = AST_LIN2X((*cr1 + *cr2) * 2048.0);
	}
}

static inline void gen_tone(unsigned char *buf, int len, int codec, float ddr1, float ddi1, float *cr1, float *ci1)
{
	int x;
	float t;
	for (x=0;x<len;x++) {
		t = *cr1 * ddr1 - *ci1 * ddi1;
		*ci1 = *cr1 * ddi1 + *ci1 * ddr1;
		*cr1 = t;
		t = 2.0 - (*cr1 * *cr1 + *ci1 * *ci1);
		*cr1 *= t;
		*ci1 *= t; 	
		buf[x] = AST_LIN2X(*cr1 * 8192.0);
	}
}

/*! \brief Initialize stuff for inverse FFT */
void callerid_init(void)
{
	cid_dr[0] = cos(CALLERID_SPACE * 2.0 * M_PI / 8000.0);
	cid_di[0] = sin(CALLERID_SPACE * 2.0 * M_PI / 8000.0);
	cid_dr[1] = cos(CALLERID_MARK * 2.0 * M_PI / 8000.0);
	cid_di[1] = sin(CALLERID_MARK * 2.0 * M_PI / 8000.0);
	sasdr = cos(SAS_FREQ * 2.0 * M_PI / 8000.0);
	sasdi = sin(SAS_FREQ * 2.0 * M_PI / 8000.0);
	casdr1 = cos(CAS_FREQ1 * 2.0 * M_PI / 8000.0);
	casdi1 = sin(CAS_FREQ1 * 2.0 * M_PI / 8000.0);
	casdr2 = cos(CAS_FREQ2 * 2.0 * M_PI / 8000.0);
	casdi2 = sin(CAS_FREQ2 * 2.0 * M_PI / 8000.0);
}

struct callerid_state *callerid_new(int cid_signalling)
{
	struct callerid_state *cid;

	if ((cid = ast_calloc(1, sizeof(*cid)))) {
		cid->fskd.spb = 7.0;          	/* 1200 baud */
		/* cid->fskd.hdlc = 0; */     	/* Async */
		cid->fskd.nbit = 8;           	/* 8 bits */
		cid->fskd.nstop = 1.0;        	/* 1 stop bit */
		/* cid->fskd.paridad = 0; */  	/* No parity */
		cid->fskd.bw = 1;             	/* Filter 800 Hz */
		if (cid_signalling == 2) {    	/* v23 signalling */
			cid->fskd.f_mark_idx =  4;	/* 1300 Hz */
			cid->fskd.f_space_idx = 5;	/* 2100 Hz */
		} else {                      	/* Bell 202 signalling as default */
			cid->fskd.f_mark_idx =  2;	/* 1200 Hz */
			cid->fskd.f_space_idx = 3;	/* 2200 Hz */
		}
		/* cid->fskd.pcola = 0; */    	/* No clue */
		/* cid->fskd.cont = 0.0; */   	/* Digital PLL reset */
		/* cid->fskd.x0 = 0.0; */
		/* cid->fskd.state = 0; */
		cid->flags = CID_UNKNOWN_NAME | CID_UNKNOWN_NUMBER;
		/* cid->pos = 0; */
	}

	return cid;
}

void callerid_get(struct callerid_state *cid, char **name, char **number, int *flags)
{
	*flags = cid->flags;
	if (cid->flags & (CID_UNKNOWN_NAME | CID_PRIVATE_NUMBER))
		*name = NULL;
	else
		*name = cid->name;
	if (cid->flags & (CID_UNKNOWN_NUMBER | CID_PRIVATE_NUMBER))
		*number = NULL;
	else
		*number = cid->number;
}

void callerid_get_dtmf(char *cidstring, char *number, int *flags)
{
	int i;
	int code;

	/* "Clear" the number-buffer. */
	number[0] = 0;

	if (strlen(cidstring) < 2) {
		ast_log(LOG_DEBUG, "No cid detected\n");
		*flags = CID_UNKNOWN_NUMBER;
		return;
	}
	
	/* Detect protocol and special types */
	if (cidstring[0] == 'B') {
		/* Handle special codes */
		code = atoi(&cidstring[1]);
		if (code == 0)
			*flags = CID_UNKNOWN_NUMBER;
		else if (code == 10) 
			*flags = CID_PRIVATE_NUMBER;
		else
			ast_log(LOG_DEBUG, "Unknown DTMF code %d\n", code);
	} else if (cidstring[0] == 'D' && cidstring[2] == '#') {
		/* .DK special code */
		if (cidstring[1] == '1')
			*flags = CID_PRIVATE_NUMBER;
		if (cidstring[1] == '2' || cidstring[1] == '3')
			*flags = CID_UNKNOWN_NUMBER;
	} else if (cidstring[0] == 'D' || cidstring[0] == 'A') {
		/* "Standard" callerid */
		for (i = 1; i < strlen(cidstring); i++ ) {
			if (cidstring[i] == 'C' || cidstring[i] == '#')
				break;
			if (isdigit(cidstring[i]))
				number[i-1] = cidstring[i];
			else
				ast_log(LOG_DEBUG, "Unknown CID digit '%c'\n",
					cidstring[i]);
		}
		number[i-1] = 0;
	} else if (isdigit(cidstring[0])) {
		/* It begins with a digit, so we parse it as a number and hope
		 * for the best */
		ast_log(LOG_WARNING, "Couldn't detect start-character. CID "
			"parsing might be unreliable\n");
		for (i = 0; i < strlen(cidstring); i++) {
			if (isdigit(cidstring[i]))
				number[i] = cidstring[i];
			else
				break;
		}
		number[i] = 0;
	} else {
		ast_log(LOG_DEBUG, "Unknown CID protocol, start digit '%c'\n", 
			cidstring[0]);
		*flags = CID_UNKNOWN_NUMBER;
	}
}

int ast_gen_cas(unsigned char *outbuf, int sendsas, int len, int codec)
{
	int pos = 0;
	int saslen=2400;
	float cr1 = 1.0;
	float ci1 = 0.0;
	float cr2 = 1.0;
	float ci2 = 0.0;
	if (sendsas) {
		if (len < saslen)
			return -1;
		gen_tone(outbuf, saslen, codec, sasdr, sasdi, &cr1, &ci1);
		len -= saslen;
		pos += saslen;
		cr2 = cr1;
		ci2 = ci1;
	}
	gen_tones(outbuf + pos, len, codec, casdr1, casdi1, casdr2, casdi2, &cr1, &ci1, &cr2, &ci2);
	return 0;
}

static unsigned short calc_crc(unsigned short crc, unsigned char data)
{
	unsigned int i, j, org, dst;
	org = data;
	dst = 0;

	for (i=0; i < CHAR_BIT; i++) {
		org <<= 1;
		dst >>= 1;
		if (org & 0x100) {
			dst |= 0x80;
		}
	}
	data = (unsigned char)dst;
	crc ^= (unsigned int)data << (16 - CHAR_BIT);
	for ( j=0; j<CHAR_BIT; j++ ) {
		if ( crc & 0x8000U )
			crc = (crc << 1) ^ 0x1021U ;
		else
			crc <<= 1 ;
	}
   	return crc;
}

int callerid_feed_jp(struct callerid_state *cid, unsigned char *ubuf, int len, int codec)
{
	int mylen = len;
	int olen;
	int b = 'X';
	int b2 ;
	int res;
	int x;
	short *buf;
	short *obuf;

	if (!(buf = ast_calloc(1, 2 * len + cid->oldlen))) {
		return -1;
	}

	obuf = buf;
	memcpy(buf, cid->oldstuff, cid->oldlen);
	mylen += cid->oldlen/2;

	for (x=0;x<len;x++) 
		buf[x+cid->oldlen/2] = AST_XLAW(ubuf[x]);

	while (mylen >= 160) {
	b = b2 = 0 ;
		olen = mylen;
		res = fsk_serie(&cid->fskd, buf, &mylen, &b);

		if (mylen < 0) {
			ast_log(LOG_ERROR, "fsk_serie made mylen < 0 (%d)\n", mylen);
			return -1;
		}

		buf += (olen - mylen);

		if (res < 0) {
			ast_log(LOG_NOTICE, "fsk_serie failed\n");
			return -1;
		}

		if (res == 1) {

			b2 = b ;
			b  = b & 0x7f ;

			/* crc checksum calculation */
			if ( cid->sawflag > 1 ) {
				cid->crc = calc_crc(cid->crc, (unsigned char)b2);
			}

			/* Ignore invalid bytes */
			if (b > 0xff) {
				continue;
			}

			/* skip DLE if needed */
			if ( cid->sawflag > 0 ) {
				if ( cid->sawflag != 5 && cid->skipflag == 0 && b == 0x10 ) {
					cid->skipflag = 1 ;
					continue ;
				}
			}
			if ( cid->skipflag == 1 ) {
				cid->skipflag = 0 ;
			}

			/* caller id retrieval */
			switch(cid->sawflag) {
				case 0: /* DLE */
					if (b == 0x10) {
						cid->sawflag = 1;
						cid->skipflag = 0;
						cid->crc = 0;
					}
					break;
				case 1: /* SOH */
					if (b == 0x01) {
						cid->sawflag = 2;
					}
					break ;
				case 2: /* HEADER */
					if (b == 0x07) {
						cid->sawflag = 3;
					}
					break;
				case 3: /* STX */
					if (b == 0x02) {
						cid->sawflag = 4;
					}
					break;
				case 4: /* SERVICE TYPE */
					if (b == 0x40) {
						cid->sawflag = 5;
					}
					break;
				case 5: /* Frame Length */
					cid->sawflag = 6;
					break;	
				case 6: /* NUMBER TYPE */
					cid->sawflag = 7;
					cid->pos = 0;
					cid->rawdata[cid->pos++] = b;
					break;
				case 7:	/* NUMBER LENGTH */
					cid->sawflag = 8;
					cid->len = b;
					if ( (cid->len+2) >= sizeof( cid->rawdata ) ) {
						ast_log(LOG_WARNING, "too long caller id string\n" ) ;
						return -1;
					}
					cid->rawdata[cid->pos++] = b;
					break;
				case 8:	/* Retrieve message */
					cid->rawdata[cid->pos++] = b;
					cid->len--;
					if (cid->len<=0) {
						cid->rawdata[cid->pos] = '\0';
						cid->sawflag = 9;
					}
					break;
				case 9:	/* ETX */
					cid->sawflag = 10;
					break;
				case 10: /* CRC Checksum 1 */
					cid->sawflag = 11;
					break;
				case 11: /* CRC Checksum 2 */
					cid->sawflag = 12;
					if ( cid->crc != 0 ) {
						ast_log(LOG_WARNING, "crc checksum error\n" ) ;
						return -1;
					} 
					/* extract caller id data */
					for (x=0; x<cid->pos; ) {
						switch (cid->rawdata[x++]) {
						case 0x02: /* caller id  number */
							cid->number[0] = '\0';
							cid->name[0] = '\0';
							cid->flags = 0;
							res = cid->rawdata[x++];
							ast_copy_string(cid->number, &cid->rawdata[x], res+1 );
							x += res;
							break;
						case 0x21: /* additional information */
							/* length */
							x++; 
							/* number type */
                        		   		switch (cid->rawdata[x]) { 
							case 0x00: /* unknown */
							case 0x01: /* international number */
							case 0x02: /* domestic number */
							case 0x03: /* network */
							case 0x04: /* local call */
							case 0x06: /* short dial number */
							case 0x07: /* reserved */
							default:   /* reserved */
								if (option_debug > 1)
									ast_log(LOG_DEBUG, "cid info:#1=%X\n", cid->rawdata[x]);
								break ;
							}
							x++; 
							/* numbering plan octed 4 */
							x++; 
							/* numbering plan octed 5 */
							switch (cid->rawdata[x]) { 
							case 0x00: /* unknown */
							case 0x01: /* recommendation E.164 ISDN */
							case 0x03: /* recommendation X.121 */
							case 0x04: /* telex dial plan */
							case 0x08: /* domestic dial plan */
							case 0x09: /* private dial plan */
							case 0x05: /* reserved */
							default:   /* reserved */
								if (option_debug > 1)
									ast_log(LOG_DEBUG, "cid info:#2=%X\n", cid->rawdata[x]);
								break ;
							}
							x++; 
							break ;
						case 0x04: /* no callerid reason */
							/* length */
							x++; 
							/* no callerid reason code */
							switch (cid->rawdata[x]) {
							case 'P': /* caller id denied by user */
							case 'O': /* service not available */
							case 'C': /* pay phone */
							case 'S': /* service congested */
                    						cid->flags |= CID_UNKNOWN_NUMBER;
								if (option_debug > 1)
									ast_log(LOG_DEBUG, "no cid reason:%c\n",cid->rawdata[x]);
								break ;
							}
							x++; 
							break ;
						case 0x09: /* dialed number */
							/* length */
							res = cid->rawdata[x++];
							/* dialed number */
							x += res;
							break ;
						case 0x22: /* dialed number additional information */
							/* length */
							x++;
							/* number type */
							switch (cid->rawdata[x]) {
							case 0x00: /* unknown */
							case 0x01: /* international number */
							case 0x02: /* domestic number */
							case 0x03: /* network */
							case 0x04: /* local call */
							case 0x06: /* short dial number */
							case 0x07: /* reserved */
							default:   /* reserved */
								if (option_debug > 1)
									ast_log(LOG_NOTICE, "did info:#1=%X\n", cid->rawdata[x]);
								break ;
							}
							x++;
							/* numbering plan octed 4 */
							x++;
                                			/* numbering plan octed 5 */
							switch (cid->rawdata[x]) {
							case 0x00: /* unknown */
							case 0x01: /* recommendation E.164 ISDN */
							case 0x03: /* recommendation X.121 */
							case 0x04: /* telex dial plan */
							case 0x08: /* domestic dial plan */
							case 0x09: /* private dial plan */
							case 0x05: /* reserved */
							default:   /* reserved */
								if (option_debug > 1)
									ast_log(LOG_DEBUG, "did info:#2=%X\n", cid->rawdata[x]);
								break ;
							}
							x++;
							break ;
						}
					}
					return 1;
					break;
				default:
					ast_log(LOG_ERROR, "invalid value in sawflag %d\n", cid->sawflag);
			}
		}
	}
	if (mylen) {
		memcpy(cid->oldstuff, buf, mylen * 2);
		cid->oldlen = mylen * 2;
	} else
		cid->oldlen = 0;
	free(obuf);
	return 0;
}


int callerid_feed(struct callerid_state *cid, unsigned char *ubuf, int len, int codec)
{
	int mylen = len;
	int olen;
	int b = 'X';
	int res;
	int x;
	short *buf;
	short *obuf;

	if (!(buf = ast_calloc(1, 2 * len + cid->oldlen))) {
		return -1;
	}

	obuf = buf;
	memcpy(buf, cid->oldstuff, cid->oldlen);
	mylen += cid->oldlen/2;

	for (x=0;x<len;x++) 
		buf[x+cid->oldlen/2] = AST_XLAW(ubuf[x]);
	while(mylen >= 160) {
		olen = mylen;
		res = fsk_serie(&cid->fskd, buf, &mylen, &b);
		if (mylen < 0) {
			ast_log(LOG_ERROR, "fsk_serie made mylen < 0 (%d)\n", mylen);
			return -1;
		}
		buf += (olen - mylen);
		if (res < 0) {
			ast_log(LOG_NOTICE, "fsk_serie failed\n");
			return -1;
		}
		if (res == 1) {
			/* Ignore invalid bytes */
			if (b > 0xff)
				continue;
			switch(cid->sawflag) {
			case 0: /* Look for flag */
				if (b == 'U')
					cid->sawflag = 2;
				break;
			case 2: /* Get lead-in */
				if ((b == 0x04) || (b == 0x80)) {
					cid->type = b;
					cid->sawflag = 3;
					cid->cksum = b;
				}
				break;
			case 3:	/* Get length */
				/* Not a lead in.  We're ready  */
				cid->sawflag = 4;
				cid->len = b;
				cid->pos = 0;
				cid->cksum += b;
				break;
			case 4: /* Retrieve message */
				if (cid->pos >= 128) {
					ast_log(LOG_WARNING, "Caller ID too long???\n");
					return -1;
				}
				cid->rawdata[cid->pos++] = b;
				cid->len--;
				cid->cksum += b;
				if (!cid->len) {
					cid->rawdata[cid->pos] = '\0';
					cid->sawflag = 5;
				}
				break;
			case 5: /* Check checksum */
				if (b != (256 - (cid->cksum & 0xff))) {
					ast_log(LOG_NOTICE, "Caller*ID failed checksum\n");
					/* Try again */
					cid->sawflag = 0;
					break;
				}
		
				cid->number[0] = '\0';
				cid->name[0] = '\0';
				/* If we get this far we're fine.  */
				if (cid->type == 0x80) {
					/* MDMF */
					/* Go through each element and process */
					for (x=0;x< cid->pos;) {
						switch(cid->rawdata[x++]) {
						case 1:
							/* Date */
							break;
						case 2: /* Number */
						case 3: /* Number (for Zebble) */
						case 4: /* Number */
							res = cid->rawdata[x];
							if (res > 32) {
								ast_log(LOG_NOTICE, "Truncating long caller ID number from %d bytes to 32\n", cid->rawdata[x]);
								res = 32; 
							}
							if (ast_strlen_zero(cid->number)) {
								memcpy(cid->number, cid->rawdata + x + 1, res);
								/* Null terminate */
								cid->number[res] = '\0';
							}
							break;
						case 6: /* Stentor Call Qualifier (ie. Long Distance call) */
							break;
						case 7: /* Name */
						case 8: /* Name */
							res = cid->rawdata[x];
							if (res > 32) {
								ast_log(LOG_NOTICE, "Truncating long caller ID name from %d bytes to 32\n", cid->rawdata[x]);
								res = 32; 
							}
							memcpy(cid->name, cid->rawdata + x + 1, res);
							cid->name[res] = '\0';
							break;
						case 17: /* UK: Call type, 1=Voice Call, 2=Ringback when free, 129=Message waiting  */
						case 19: /* UK: Network message system status (Number of messages waiting) */
						case 22: /* Something French */
							break;
						default:
							ast_log(LOG_NOTICE, "Unknown IE %d\n", cid->rawdata[x-1]);
						}
						x += cid->rawdata[x];
						x++;
					}
				} else {
					/* SDMF */
					ast_copy_string(cid->number, cid->rawdata + 8, sizeof(cid->number));
				}
				/* Update flags */
				cid->flags = 0;
				if (!strcmp(cid->number, "P")) {
					strcpy(cid->number, "");
					cid->flags |= CID_PRIVATE_NUMBER;
				} else if (!strcmp(cid->number, "O") || ast_strlen_zero(cid->number)) {
					strcpy(cid->number, "");
					cid->flags |= CID_UNKNOWN_NUMBER;
				}
				if (!strcmp(cid->name, "P")) {
					strcpy(cid->name, "");
					cid->flags |= CID_PRIVATE_NAME;
				} else if (!strcmp(cid->name, "O") || ast_strlen_zero(cid->name)) {
					strcpy(cid->name, "");
					cid->flags |= CID_UNKNOWN_NAME;
				}
				return 1;
				break;
			default:
				ast_log(LOG_ERROR, "Dunno what to do with a digit in sawflag %d\n", cid->sawflag);
			}
		}
	}
	if (mylen) {
		memcpy(cid->oldstuff, buf, mylen * 2);
		cid->oldlen = mylen * 2;
	} else
		cid->oldlen = 0;
	free(obuf);
	return 0;
}

void callerid_free(struct callerid_state *cid)
{
	free(cid);
}

static int callerid_genmsg(char *msg, int size, char *number, char *name, int flags)
{
	time_t t;
	struct tm tm;
	char *ptr;
	int res;
	int i,x;
	/* Get the time */
	time(&t);
	localtime_r(&t,&tm);
	
	ptr = msg;
	
	/* Format time and message header */
	res = snprintf(ptr, size, "\001\010%02d%02d%02d%02d", tm.tm_mon + 1,
				tm.tm_mday, tm.tm_hour, tm.tm_min);
	size -= res;
	ptr += res;
	if (ast_strlen_zero(number) || (flags & CID_UNKNOWN_NUMBER)) {
		/* Indicate number not known */
		res = snprintf(ptr, size, "\004\001O");
		size -= res;
		ptr += res;
	} else if (flags & CID_PRIVATE_NUMBER) {
		/* Indicate number is private */
		res = snprintf(ptr, size, "\004\001P");
		size -= res;
		ptr += res;
	} else {
		/* Send up to 16 digits of number MAX */
		i = strlen(number);
		if (i > 16) i = 16;
		res = snprintf(ptr, size, "\002%c", i);
		size -= res;
		ptr += res;
		for (x = 0; x < i; x++)
			ptr[x] = number[x];
		ptr[i] = '\0';
		ptr += i;
		size -= i;
	}

	if (ast_strlen_zero(name) || (flags & CID_UNKNOWN_NAME)) {
		/* Indicate name not known */
		res = snprintf(ptr, size, "\010\001O");
		size -= res;
		ptr += res;
	} else if (flags & CID_PRIVATE_NAME) {
		/* Indicate name is private */
		res = snprintf(ptr, size, "\010\001P");
		size -= res;
		ptr += res;
	} else {
		/* Send up to 16 digits of name MAX */
		i = strlen(name);
		if (i > 16) i = 16;
		res = snprintf(ptr, size, "\007%c", i);
		size -= res;
		ptr += res;
		for (x=0;x<i;x++)
			ptr[x] = name[x];
		ptr[i] = '\0';
		ptr += i;
		size -= i;
	}
	return (ptr - msg);
	
}

int vmwi_generate(unsigned char *buf, int active, int mdmf, int codec)
{
	unsigned char msg[256];
	int len=0;
	int sum;
	int x;
	int bytes = 0;
	float cr = 1.0;
	float ci = 0.0;
	float scont = 0.0;
	if (mdmf) {
		/* MDMF Message waiting */
		msg[len++] = 0x82;
		/* Length is 3 */
		msg[len++] = 3;
		/* IE is "Message Waiting Parameter" */
		msg[len++] = 0xb;
		/* Length of IE is one */
		msg[len++] = 1;
		/* Active or not */
		if (active)
			msg[len++] = 0xff;
		else
			msg[len++] = 0x00;
	} else {
		/* SDMF Message waiting */
		msg[len++] = 0x6;
		/* Length is 3 */
		msg[len++] = 3;
		if (active) {
			msg[len++] = 0x42;
			msg[len++] = 0x42;
			msg[len++] = 0x42;
		} else {
			msg[len++] = 0x6f;
			msg[len++] = 0x6f;
			msg[len++] = 0x6f;
		}
	}
	sum = 0;
	for (x=0; x<len; x++)
		sum += msg[x];
	sum = (256 - (sum & 255));
	msg[len++] = sum;
	/* Wait a half a second */
	for (x=0; x<4000; x++)
		PUT_BYTE(0x7f);
	/* Transmit 30 0x55's (looks like a square wave) for channel seizure */
	for (x=0; x<30; x++)
		PUT_CLID(0x55);
	/* Send 170ms of callerid marks */
	for (x=0; x<170; x++)
		PUT_CLID_MARKMS;
	for (x=0; x<len; x++) {
		PUT_CLID(msg[x]);
	}
	/* Send 50 more ms of marks */
	for (x=0; x<50; x++)
		PUT_CLID_MARKMS;
	return bytes;
}

int callerid_generate(unsigned char *buf, char *number, char *name, int flags, int callwaiting, int codec)
{
	int bytes=0;
	int x, sum;
	int len;

	/* Initial carriers (real/imaginary) */
	float cr = 1.0;
	float ci = 0.0;
	float scont = 0.0;
	char msg[256];
	len = callerid_genmsg(msg, sizeof(msg), number, name, flags);
	if (!callwaiting) {
		/* Wait a half a second */
		for (x=0; x<4000; x++)
			PUT_BYTE(0x7f);
		/* Transmit 30 0x55's (looks like a square wave) for channel seizure */
		for (x=0; x<30; x++)
			PUT_CLID(0x55);
	}
	/* Send 150ms of callerid marks */
	for (x=0; x<150; x++)
		PUT_CLID_MARKMS;
	/* Send 0x80 indicating MDMF format */
	PUT_CLID(0x80);
	/* Put length of whole message */
	PUT_CLID(len);
	sum = 0x80 + strlen(msg);
	/* Put each character of message and update checksum */
	for (x=0; x<len; x++) {
		PUT_CLID(msg[x]);
		sum += msg[x];
	}
	/* Send 2's compliment of sum */
	PUT_CLID(256 - (sum & 255));

	/* Send 50 more ms of marks */
	for (x=0; x<50; x++)
		PUT_CLID_MARKMS;
	
	return bytes;
}

/*! \brief Clean up phone string
 * remove '(', ' ', ')', non-trailing '.', and '-' not in square brackets.
 * Basically, remove anything that could be invalid in a pattern.
 */
void ast_shrink_phone_number(char *n)
{
	int x, y=0;
	int bracketed = 0;

	for (x=0; n[x]; x++) {
		switch(n[x]) {
		case '[':
			bracketed++;
			n[y++] = n[x];
			break;
		case ']':
			bracketed--;
			n[y++] = n[x];
			break;
		case '-':
			if (bracketed)
				n[y++] = n[x];
			break;
		case '.':
			if (!n[x+1])
				n[y++] = n[x];
			break;
		default:
			if (!strchr("( )", n[x]))
				n[y++] = n[x];
		}
	}
	n[y] = '\0';
}

/*! \brief Checks if phone number consists of valid characters 
	\param exten	String that needs to be checked
	\param valid	Valid characters in string
	\return 1 if valid string, 0 if string contains invalid characters
*/
static int ast_is_valid_string(const char *exten, const char *valid)
{
	int x;

	if (ast_strlen_zero(exten))
		return 0;
	for (x=0; exten[x]; x++)
		if (!strchr(valid, exten[x]))
			return 0;
	return 1;
}

/*! \brief checks if string consists only of digits and * \# and + 
	\return 1 if string is valid AST phone number
	\return 0 if not
*/
int ast_isphonenumber(const char *n)
{
	return ast_is_valid_string(n, "0123456789*#+");
}

/*! \brief checks if string consists only of digits and ( ) - * \# and + 
	Pre-qualifies the string for ast_shrink_phone_number()
	\return 1 if string is valid AST shrinkable phone number
	\return 0 if not
*/
int ast_is_shrinkable_phonenumber(const char *exten)
{
	return ast_is_valid_string(exten, "0123456789*#+()-.");
}

/*! \brief parse string for caller id information 
	\return always returns 0, as the code always returns something.
  XXX note that 'name' is not parsed consistently e.g. we have

	input			location	name
	" foo bar " <123>	123		' foo bar ' (with spaces around)
	" foo bar "		NULL		'foo bar' (without spaces around)
	" foo bar  <123>"	123		'" foo bar'
  The parsing of leading and trailing space/quotes should be more consistent.
*/
int ast_callerid_parse(char *instr, char **name, char **location)
{
	char *ns, *ne, *ls, *le;

	/* Try "name" <location> format or name <location> format */
	if ((ls = strchr(instr, '<')) && (le = strchr(ls, '>'))) {
		*ls = *le = '\0';	/* location found, trim off the brackets */
		*location = ls + 1;	/* and this is the result */
		if ((ns = strchr(instr, '"')) && (ne = strchr(ns + 1, '"'))) {
			*ns = *ne = '\0';	/* trim off the quotes */
			*name = ns + 1;		/* and this is the name */
		} else { /* no quotes, trim off leading and trailing spaces */
			*name = ast_skip_blanks(instr);
			ast_trim_blanks(*name);
		}
	} else {	/* no valid brackets */
		char tmp[256];

		ast_copy_string(tmp, instr, sizeof(tmp));
		ast_shrink_phone_number(tmp);
		if (ast_isphonenumber(tmp)) {	/* Assume it's just a location */
			*name = NULL;
			strcpy(instr, tmp); /* safe, because tmp will always be the same size or smaller than instr */
			*location = instr;
		} else { /* Assume it's just a name. */
			*location = NULL;
			if ((ns = strchr(instr, '"')) && (ne = strchr(ns + 1, '"'))) {
				*ns = *ne = '\0';	/* trim off the quotes */
				*name = ns + 1;		/* and this is the name */
			} else { /* no quotes, trim off leading and trailing spaces */
				*name = ast_skip_blanks(instr);
				ast_trim_blanks(*name);
			}
		}
	}
	return 0;
}

static int __ast_callerid_generate(unsigned char *buf, char *name, char *number, int callwaiting, int codec)
{
	if (ast_strlen_zero(name))
		name = NULL;
	if (ast_strlen_zero(number))
		number = NULL;
	return callerid_generate(buf, number, name, 0, callwaiting, codec);
}

int ast_callerid_generate(unsigned char *buf, char *name, char *number, int codec)
{
	return __ast_callerid_generate(buf, name, number, 0, codec);
}

int ast_callerid_callwaiting_generate(unsigned char *buf, char *name, char *number, int codec)
{
	return __ast_callerid_generate(buf, name, number, 1, codec);
}

char *ast_callerid_merge(char *buf, int bufsiz, const char *name, const char *num, const char *unknown)
{
	if (!unknown)
		unknown = "<unknown>";
	if (name && num)
		snprintf(buf, bufsiz, "\"%s\" <%s>", name, num);
	else if (name) 
		ast_copy_string(buf, name, bufsiz);
	else if (num)
		ast_copy_string(buf, num, bufsiz);
	else
		ast_copy_string(buf, unknown, bufsiz);
	return buf;
}

int ast_callerid_split(const char *buf, char *name, int namelen, char *num, int numlen)
{
	char *tmp;
	char *l = NULL, *n = NULL;

	tmp = ast_strdupa(buf);
	if (!tmp) {
		name[0] = '\0';
		num[0] = '\0';
		return -1;
	}
	ast_callerid_parse(tmp, &n, &l);
	if (n)
		ast_copy_string(name, n, namelen);
	else
		name[0] = '\0';
	if (l) {
		ast_shrink_phone_number(l);
		ast_copy_string(num, l, numlen);
	} else
		num[0] = '\0';
	return 0;
}

/*! \brief Translation table for Caller ID Presentation settings */
static struct {
	int val;
	char *name;
	char *description;
} pres_types[] = {
	{  AST_PRES_ALLOWED_USER_NUMBER_NOT_SCREENED, "allowed_not_screened", "Presentation Allowed, Not Screened"},
	{  AST_PRES_ALLOWED_USER_NUMBER_PASSED_SCREEN, "allowed_passed_screen", "Presentation Allowed, Passed Screen"},
	{  AST_PRES_ALLOWED_USER_NUMBER_FAILED_SCREEN, "allowed_failed_screen", "Presentation Allowed, Failed Screen"},
	{  AST_PRES_ALLOWED_NETWORK_NUMBER, "allowed", "Presentation Allowed, Network Number"},
	{  AST_PRES_PROHIB_USER_NUMBER_NOT_SCREENED, "prohib_not_screened", "Presentation Prohibited, Not Screened"},
	{  AST_PRES_PROHIB_USER_NUMBER_PASSED_SCREEN, "prohib_passed_screen", "Presentation Prohibited, Passed Screen"},
	{  AST_PRES_PROHIB_USER_NUMBER_FAILED_SCREEN, "prohib_failed_screen", "Presentation Prohibited, Failed Screen"},
	{  AST_PRES_PROHIB_NETWORK_NUMBER, "prohib", "Presentation Prohibited, Network Number"},
	{  AST_PRES_NUMBER_NOT_AVAILABLE, "unavailable", "Number Unavailable"},
};

/*! \brief Convert caller ID text code to value 
	used in config file parsing
	\param data text string
	\return value AST_PRES_ from callerid.h 
*/
int ast_parse_caller_presentation(const char *data)
{
	int i;

	for (i = 0; i < ((sizeof(pres_types) / sizeof(pres_types[0]))); i++) {
		if (!strcasecmp(pres_types[i].name, data))
			return pres_types[i].val;
	}

	return -1;
}

/*! \brief Convert caller ID pres value to explanatory string 
	\param data value (see callerid.h AST_PRES_ ) 
	\return string for human presentation
*/
const char *ast_describe_caller_presentation(int data)
{
	int i;

	for (i = 0; i < ((sizeof(pres_types) / sizeof(pres_types[0]))); i++) {
		if (pres_types[i].val == data)
			return pres_types[i].description;
	}

	return "unknown";
}