app_sms.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2004 - 2005, Adrian Kennard, rights assigned to Digium
 *
 * 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 SMS application - ETSI ES 201 912 protocol 1 implementation
 * 
 * \par Development notes
 * \note The ETSI standards are available free of charge from ETSI at
 *	http://pda.etsi.org/pda/queryform.asp
 * 	Among the relevant documents here we have:
 *
 *	ES 201 912	SMS for PSTN/ISDN
 *	TS 123 040	Technical realization of SMS
 *
 * 
 * \ingroup applications
 *
 * \author Adrian Kennard (for the original protocol 1 code)
 * \author Filippo Grassilli (Hyppo) - protocol 2 support
 *		   Not fully tested, under development
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <dirent.h>
#include <ctype.h>
#include <sys/stat.h>

#include "asterisk/paths.h"	/* use ast_config_AST_SPOOL_DIR and LOG_DIR */
#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/alaw.h"
#include "asterisk/callerid.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"

/* #define OUTALAW */ /* enable this to output Alaw rather than linear */

/* ToDo */
/* Add full VP support */
/* Handle status report messages (generation and reception) */
/* Time zones on time stamps */
/* user ref field */

static volatile unsigned char message_ref;      /* arbitary message ref */
static volatile unsigned int seq;       /* arbitrary message sequence number for unqiue files */

static char log_file[255];

static char *app = "SMS";

static char *synopsis = "Communicates with SMS service centres and SMS capable analogue phones";

static char *descrip =
	"  SMS(name,[a][s][t][p(d)][r][o],addr,body):\n"
	"SMS handles exchange of SMS data with a call to/from SMS capable\n"
	"phone or SMS PSTN service center. Can send and/or receive SMS messages.\n"
	"Works to ETSI ES 201 912; compatible with BT SMS PSTN service in UK\n"
	"and Telecom Italia in Italy.\n"
	"Typical usage is to use to handle calls from the SMS service centre CLI,\n"
	"or to set up a call using 'outgoing' or manager interface to connect\n"
	"service centre to SMS()\n"
	"name is the name of the queue used in /var/spool/asterisk/sms\n"
	"Arguments:\n"
	" a  - answer, i.e. send initial FSK packet.\n"
	" s  - act as service centre talking to a phone.\n"
	" t  - use protocol 2 (default used is protocol 1).\n"
	" p(N)  - set the initial delay to N ms (default is 300).\n"
	"         addr and body are a deprecated format to send messages out.\n"
	" s  - set the Status Report Request (SRR) bit.\n"
	" o  - the body should be coded as octets not 7-bit symbols.\n"
	"Messages are processed as per text file message queues.\n" 
	"smsq (a separate software) is a command to generate message\n"
	"queues and send messages.\n"
	"NOTE: the protocol has tight delay bounds. Please use short frames\n"
	"and disable/keep short the jitter buffer on the ATA to make sure that\n"
	"respones (ACK etc.) are received in time.\n";

/*
 * 80 samples of a single period of the wave. At 8000 Hz, it means these
 * are the samples of a 100 Hz signal.
 * To pick the two carriers (1300Hz for '1' and 2100 Hz for '0') used by
 * the modulation, we should take one every 13 and 21 samples respectively.
 */
static signed short wave[] = {
	0, 392, 782, 1167, 1545, 1913, 2270, 2612, 2939, 3247, 3536, 3802, 4045, 4263, 4455, 4619, 4755, 4862, 4938, 4985,
	5000, 4985, 4938, 4862, 4755, 4619, 4455, 4263, 4045, 3802, 3536, 3247, 2939, 2612, 2270, 1913, 1545, 1167, 782, 392,
	0, -392, -782, -1167,
	 -1545, -1913, -2270, -2612, -2939, -3247, -3536, -3802, -4045, -4263, -4455, -4619, -4755, -4862, -4938, -4985, -5000,
	-4985, -4938, -4862,
	-4755, -4619, -4455, -4263, -4045, -3802, -3536, -3247, -2939, -2612, -2270, -1913, -1545, -1167, -782, -392
};

#ifdef OUTALAW
static unsigned char wavea[80];
typedef unsigned char output_t;
static const output_t *wave_out = wavea;	/* outgoing samples */
#define __OUT_FMT AST_FORMAT_ALAW;
#else
typedef signed short output_t;
static const output_t *wave_out = wave;		/* outgoing samples */
#define __OUT_FMT AST_FORMAT_SLINEAR
#endif

#define OSYNC_BITS	80	/* initial sync bits */

/*!
 * The SMS spec ETSI ES 201 912 defines two protocols with different message types.
 * Also note that the high bit is used to indicate whether the message
 * is complete or not, but in two opposite ways:
 * for Protocol 1, 0x80 means that the message is complete;
 * for Protocol 2, 0x00 means that the message is complete;
 */
enum message_types {
	DLL_SMS_MASK	= 0x7f,	/* mask for the valid bits */

	/* Protocol 1 values */
	DLL1_SMS_DATA		= 0x11,	/* data packet */
	DLL1_SMS_ERROR		= 0x12,
	DLL1_SMS_EST		= 0x13,	/* start the connection */
	DLL1_SMS_REL		= 0x14,	/* end the connection */
	DLL1_SMS_ACK		= 0x15,
	DLL1_SMS_NACK		= 0x16,

	DLL1_SMS_COMPLETE 	= 0x80,	/* packet is complete */
	DLL1_SMS_MORE 		= 0x00,	/* more data to follow */

	/* Protocol 2 values */
	DLL2_SMS_EST		= 0x7f,	/* magic number. No message body */
	DLL2_SMS_INFO_MO 	= 0x10,
	DLL2_SMS_INFO_MT 	= 0x11,
	DLL2_SMS_INFO_STA 	= 0x12,
	DLL2_SMS_NACK 		= 0x13,
	DLL2_SMS_ACK0 		= 0x14,	/* ack even-numbered frame */
	DLL2_SMS_ACK1 		= 0x15,	/* ack odd-numbered frame */
	DLL2_SMS_ENQ 		= 0x16,
	DLL2_SMS_REL 		= 0x17,	/* end the connection */

	DLL2_SMS_COMPLETE 	= 0x00,	/* packet is complete */
	DLL2_SMS_MORE 		= 0x80,	/* more data to follow */
};

/* SMS 7 bit character mapping to UCS-2 */
static const unsigned short defaultalphabet[] = {
	0x0040, 0x00A3, 0x0024, 0x00A5, 0x00E8, 0x00E9, 0x00F9, 0x00EC,
	0x00F2, 0x00E7, 0x000A, 0x00D8, 0x00F8, 0x000D, 0x00C5, 0x00E5,
	0x0394, 0x005F, 0x03A6, 0x0393, 0x039B, 0x03A9, 0x03A0, 0x03A8,
	0x03A3, 0x0398, 0x039E, 0x00A0, 0x00C6, 0x00E6, 0x00DF, 0x00C9,
	' ', '!', '"', '#', 164, '%', '&', 39, '(', ')', '*', '+', ',', '-', '.', '/',
	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=', '>', '?',
	161, 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
	'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 196, 214, 209, 220, 167,
	191, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
	'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 228, 246, 241, 252, 224,
};

static const unsigned short escapes[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x000C, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0x005E, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0x007B, 0x007D, 0, 0, 0, 0, 0, 0x005C,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x005B, 0x007E, 0x005D, 0,
	0x007C, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0x20AC, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};

#define SMSLEN		160	      /*!< max SMS length */
#define SMSLEN_8	140	      /*!< max SMS length for 8-bit char */

typedef struct sms_s {
	unsigned char hangup;        /*!< we are done... */
	unsigned char err;           /*!< set for any errors */
	unsigned char smsc:1;        /*!< we are SMSC */
	unsigned char rx:1;          /*!< this is a received message */
	char queue[30];              /*!< queue name */
	char oa[20];                 /*!< originating address */
	char da[20];                 /*!< destination address */
	struct timeval scts;         /*!< time stamp, UTC */
	unsigned char pid;           /*!< protocol ID */
	unsigned char dcs;           /*!< data coding scheme */
	short mr;                    /*!< message reference - actually a byte, but use -1 for not set */
	int udl;                     /*!< user data length */
	int udhl;                    /*!< user data header length */
	unsigned char srr:1;         /*!< Status Report request */
	unsigned char udhi:1;        /*!< User Data Header required, even if length 0 */
	unsigned char rp:1;          /*!< Reply Path */
	unsigned int vp;             /*!< validity period in minutes, 0 for not set */
	unsigned short ud[SMSLEN];   /*!< user data (message), UCS-2 coded */
	unsigned char udh[SMSLEN];   /*!< user data header */
	char cli[20];                /*!< caller ID */
	unsigned char ophase;        /*!< phase (0-79) for 0 and 1 frequencies (1300Hz and 2100Hz) */
	unsigned char ophasep;       /*!< phase (0-79) for 1200 bps */
	unsigned char obyte;         /*!< byte being sent */
	unsigned int opause;         /*!< silent pause before sending (in sample periods) */
	unsigned char obitp;         /*!< bit in byte */
	unsigned char osync;         /*!< sync bits to send */
	unsigned char obytep;        /*!< byte in data */
	unsigned char obyten;        /*!< bytes in data */
	unsigned char omsg[256];     /*!< data buffer (out) */
	unsigned char imsg[250];     /*!< data buffer (in) */
	signed long long ims0,
		imc0,
		ims1,
		imc1;                    /*!< magnitude averages sin/cos 0/1 */
	unsigned int idle;
	unsigned short imag;         /*!< signal level */
	unsigned char ips0;          /*!< phase sin for bit 0, start at  0 inc by 21 mod 80 */
	unsigned char ips1;          /*!< phase cos for bit 0, start at 20 inc by 21 mod 80 */
	unsigned char ipc0;          /*!< phase sin for bit 1, start at  0 inc by 13 mod 80 */
	unsigned char ipc1;          /*!< phase cos for bit 1, start at 20 inc by 13 mod 80 */
	unsigned char ibitl;         /*!< last bit */
	unsigned char ibitc;         /*!< bit run length count */
	unsigned char iphasep;       /*!< bit phase (0-79) for 1200 bps */
	unsigned char ibitn;         /*!< bit number in byte being received */
	unsigned char ibytev;        /*!< byte value being received */
	unsigned char ibytep;        /*!< byte pointer in message */
	unsigned char ibytec;        /*!< byte checksum for message */
	unsigned char ierr;          /*!< error flag */
	unsigned char ibith;         /*!< history of last bits */
	unsigned char ibitt;         /*!< total of 1's in last 3 bytes */
	/* more to go here */

	int opause_0;                /*!< initial delay in ms, p() option */
	int protocol;                /*!< ETSI SMS protocol to use (passed at app call) */
	int oseizure;                /*!< protocol 2: channel seizure bits to send */
	int framenumber;             /*!< protocol 2: frame number (for sending ACK0 or ACK1) */
	char udtxt[SMSLEN]; /*!< user data (message), PLAIN text */
} sms_t;

/* different types of encoding */
#define is7bit(dcs)	( ((dcs) & 0xC0) ? (!((dcs)&4) ) : (((dcs) & 0xc) == 0) )
#define is8bit(dcs)	( ((dcs) & 0xC0) ? ( ((dcs)&4) ) : (((dcs) & 0xc) == 4) )
#define is16bit(dcs)	( ((dcs) & 0xC0) ? 0	     : (((dcs) & 0xc) == 8) )

static void sms_messagetx(sms_t *h);

/*! \brief copy number, skipping non digits apart from leading + */
static void numcpy(char *d, char *s)
{
	if (*s == '+')
		*d++ = *s++;
	while (*s) {
  		if (isdigit(*s))
     			*d++ = *s;
		s++;
	}
	*d = 0;
}

/*! \brief static, return a date/time in ISO format */
static char *isodate(time_t t, char *buf, int len)
{
	struct ast_tm tm;
	struct timeval tv = { t, 0 };
	ast_localtime(&tv, &tm, NULL);
	ast_strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
	return buf;
}

/*! \brief Reads next UCS character from NUL terminated UTF-8 string and advance pointer */
/* for non valid UTF-8 sequences, returns character as is */
/* Does not advance pointer for null termination */
static long utf8decode(unsigned char **pp)
{
	unsigned char *p = *pp;
	if (!*p)
		return 0;		 /* null termination of string */
	(*pp)++;
	if (*p < 0xC0)
		return *p;		/* ascii or continuation character */
	if (*p < 0xE0) {
		if (*p < 0xC2 || (p[1] & 0xC0) != 0x80)
			return *p;	     /* not valid UTF-8 */
		(*pp)++;
		return ((*p & 0x1F) << 6) + (p[1] & 0x3F);
   	}
	if (*p < 0xF0) {
		if ((*p == 0xE0 && p[1] < 0xA0) || (p[1] & 0xC0) != 0x80 || (p[2] & 0xC0) != 0x80)
			 return *p;	     /* not valid UTF-8 */
		(*pp) += 2;
		return ((*p & 0x0F) << 12) + ((p[1] & 0x3F) << 6) + (p[2] & 0x3F);
	}
	if (*p < 0xF8) {
		if ((*p == 0xF0 && p[1] < 0x90) || (p[1] & 0xC0) != 0x80 || (p[2] & 0xC0) != 0x80 || (p[3] & 0xC0) != 0x80)
			return *p;	     /* not valid UTF-8 */
		(*pp) += 3;
		return ((*p & 0x07) << 18) + ((p[1] & 0x3F) << 12) + ((p[2] & 0x3F) << 6) + (p[3] & 0x3F);
	}
	if (*p < 0xFC) {
		if ((*p == 0xF8 && p[1] < 0x88) || (p[1] & 0xC0) != 0x80 || (p[2] & 0xC0) != 0x80 || (p[3] & 0xC0) != 0x80
			|| (p[4] & 0xC0) != 0x80)
			return *p;	     /* not valid UTF-8 */
		(*pp) += 4;
		return ((*p & 0x03) << 24) + ((p[1] & 0x3F) << 18) + ((p[2] & 0x3F) << 12) + ((p[3] & 0x3F) << 6) + (p[4] & 0x3F);
	}
	if (*p < 0xFE) {
		if ((*p == 0xFC && p[1] < 0x84) || (p[1] & 0xC0) != 0x80 || (p[2] & 0xC0) != 0x80 || (p[3] & 0xC0) != 0x80
			|| (p[4] & 0xC0) != 0x80 || (p[5] & 0xC0) != 0x80)
			return *p;	     /* not valid UTF-8 */
		(*pp) += 5;
		return ((*p & 0x01) << 30) + ((p[1] & 0x3F) << 24) + ((p[2] & 0x3F) << 18) + ((p[3] & 0x3F) << 12) + ((p[4] & 0x3F) << 6) + (p[5] & 0x3F);
	}
	return *p;		   /* not sensible */
}

/*! \brief takes a binary header (udhl bytes at udh) and UCS-2 message (udl characters at ud) and packs in to o using SMS 7 bit character codes */
/* The return value is the number of septets packed in to o, which is internally limited to SMSLEN */
/* o can be null, in which case this is used to validate or count only */
/* if the input contains invalid characters then the return value is -1 */
static int packsms7(unsigned char *o, int udhl, unsigned char *udh, int udl, unsigned short *ud)
{
	unsigned char p = 0;	/* output pointer (bytes) */
	unsigned char b = 0;	/* bit position */
	unsigned char n = 0;	/* output character count */
	unsigned char dummy[SMSLEN];

	if (o == NULL)		/* output to a dummy buffer if o not set */
		o = dummy;

	if (udhl) {			    /* header */
		o[p++] = udhl;
		b = 1;
		n = 1;
		while (udhl--) {
			o[p++] = *udh++;
			b += 8;
			while (b >= 7) {
				b -= 7;
				n++;
			}
			if (n >= SMSLEN)
				return n;
		}
		if (b) {
			b = 7 - b;
			if (++n >= SMSLEN)
				return n;
		};	/* filling to septet boundary */
	}
	o[p] = 0;
	/* message */
	while (udl--) {
		long u;
		unsigned char v;
		u = *ud++;
		/* XXX 0 is invalid ? */
		/* look up in defaultalphabet[]. If found, v is the 7-bit code */
		for (v = 0; v < 128 && defaultalphabet[v] != u; v++);
		if (v == 128 /* not found */ && u && n + 1 < SMSLEN) {
			/* if not found, look in the escapes table (we need 2 bytes) */
			for (v = 0; v < 128 && escapes[v] != u; v++);
			if (v < 128) {	/* escaped sequence, esc + v */
				/* store the low (8-b) bits in o[p], the remaining bits in o[p+1] */
				o[p] |= (27 << b);	/* the low bits go into o[p] */ 
				b += 7;
				if (b >= 8) {
					b -= 8;
					p++;
					o[p] = (27 >> (7 - b));
				}
				n++;
			}
		}
		if (v == 128)
			return -1;	     /* invalid character */
		/* store, same as above */
		o[p] |= (v << b);
		b += 7;
		if (b >= 8) {
			b -= 8;
			p++;
			o[p] = (v >> (7 - b));
		}
		if (++n >= SMSLEN)
			return n;
	}
	return n;
}

/*! \brief takes a binary header (udhl bytes at udh) and UCS-2 message (udl characters at ud)
 * and packs in to o using 8 bit character codes.
 * The return value is the number of bytes packed in to o, which is internally limited to 140.
 * o can be null, in which case this is used to validate or count only.
 * if the input contains invalid characters then the return value is -1
 */
static int packsms8(unsigned char *o, int udhl, unsigned char *udh, int udl, unsigned short *ud)
{
	unsigned char p = 0;
	unsigned char dummy[SMSLEN_8];

	if (o == NULL)
		o = dummy;
	/* header - no encoding */
	if (udhl) {
		o[p++] = udhl;
		while (udhl--) {
			o[p++] = *udh++;
			if (p >= SMSLEN_8)
				return p;
		}
	}
	while (udl--) {
		long u;
		u = *ud++;
		if (u < 0 || u > 0xFF)
			return -1;	     /* not valid */
		o[p++] = u;
		if (p >= SMSLEN_8)
			return p;
	}
	return p;
}

/*! \brief takes a binary header (udhl bytes at udh) and UCS-2 
	message (udl characters at ud) and packs in to o using 16 bit 
	UCS-2 character codes 
	The return value is the number of bytes packed in to o, which is 
	internally limited to 140 
	o can be null, in which case this is used to validate or count 
	only if the input contains invalid characters then 
	the return value is -1 */
static int packsms16(unsigned char *o, int udhl, unsigned char *udh, int udl, unsigned short *ud)
{
	unsigned char p = 0;
	unsigned char dummy[SMSLEN_8];

	if (o == NULL)
		o = dummy;
	/* header - no encoding */
	if (udhl) {
		o[p++] = udhl;
		while (udhl--) {
			o[p++] = *udh++;
			if (p >= SMSLEN_8)
				return p;
		}
	}
	while (udl--) {
		long u;
		u = *ud++;
		o[p++] = (u >> 8);
		if (p >= SMSLEN_8)
			return p - 1;	  /* could not fit last character */
		o[p++] = u;
		if (p >= SMSLEN_8)
			return p;
	}
	return p;
}

/*! \brief general pack, with length and data, 
	returns number of bytes of target used */
static int packsms(unsigned char dcs, unsigned char *base, unsigned int udhl, unsigned char *udh, int udl, unsigned short *ud)
{
	unsigned char *p = base;
	if (udl == 0)
		*p++ = 0;			/* no user data */
	else {
		
		int l = 0;
		if (is7bit(dcs)) {		/* 7 bit */
			l = packsms7(p + 1, udhl, udh, udl, ud);
			if (l < 0)
				l = 0;
			*p++ = l;
			p += (l * 7 + 7) / 8;
		} else if (is8bit(dcs)) {	/* 8 bit */
			l = packsms8(p + 1, udhl, udh, udl, ud);
			if (l < 0)
				l = 0;
			*p++ = l;
			p += l;
		} else {			/* UCS-2 */
			l = packsms16(p + 1, udhl, udh, udl, ud);
			if (l < 0)
				l = 0;
			*p++ = l;
			p += l;
		}
	}
	return p - base;
}


/*! \brief pack a date and return */
static void packdate(unsigned char *o, time_t w)
{
	struct ast_tm t;
	struct timeval tv = { w, 0 };
	int z;

	ast_localtime(&tv, &t, NULL);
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined( __NetBSD__ ) || defined(__APPLE__) || defined(__CYGWIN__)
	z = -t.tm_gmtoff / 60 / 15;
#else
	z = timezone / 60 / 15;
#endif
	*o++ = ((t.tm_year % 10) << 4) + (t.tm_year % 100) / 10;
	*o++ = (((t.tm_mon + 1) % 10) << 4) + (t.tm_mon + 1) / 10;
	*o++ = ((t.tm_mday % 10) << 4) + t.tm_mday / 10;
	*o++ = ((t.tm_hour % 10) << 4) + t.tm_hour / 10;
	*o++ = ((t.tm_min % 10) << 4) + t.tm_min / 10;
	*o++ = ((t.tm_sec % 10) << 4) + t.tm_sec / 10;
	if (z < 0)
		*o++ = (((-z) % 10) << 4) + (-z) / 10 + 0x08;
	else
		*o++ = ((z % 10) << 4) + z / 10;
}

/*! \brief unpack a date and return */
static time_t unpackdate(unsigned char *i)
{
	struct tm t;
	t.tm_year = 100 + (i[0] & 0xF) * 10 + (i[0] >> 4);
	t.tm_mon = (i[1] & 0xF) * 10 + (i[1] >> 4) - 1;
	t.tm_mday = (i[2] & 0xF) * 10 + (i[2] >> 4);
	t.tm_hour = (i[3] & 0xF) * 10 + (i[3] >> 4);
	t.tm_min = (i[4] & 0xF) * 10 + (i[4] >> 4);
	t.tm_sec = (i[5] & 0xF) * 10 + (i[5] >> 4);
	t.tm_isdst = 0;
	if (i[6] & 0x08)
		t.tm_min += 15 * ((i[6] & 0x7) * 10 + (i[6] >> 4));
	else
		t.tm_min -= 15 * ((i[6] & 0x7) * 10 + (i[6] >> 4));
	return mktime(&t);
}

/*! \brief unpacks bytes (7 bit encoding) at i, len l septets, 
	and places in udh and ud setting udhl and udl. udh not used 
	if udhi not set */
static void unpacksms7(unsigned char *i, unsigned char l, unsigned char *udh, int *udhl, unsigned short *ud, int *udl, char udhi)
{
	unsigned char b = 0, p = 0;
	unsigned short *o = ud;
	*udhl = 0;
	if (udhi && l) {		 /* header */
		int h = i[p];
		*udhl = h;
		if (h) {
			b = 1;
			p++;
			l--;
			while (h-- && l) {
				*udh++ = i[p++];
				b += 8;
				while (b >= 7) {
					b -= 7;
					l--;
					if (!l)
						break;
				}
			}
			/* adjust for fill, septets */
			if (b) {
				b = 7 - b;
				l--;
			}
		}
	}
	while (l--) {
		unsigned char v;
		if (b < 2)
			v = ((i[p] >> b) & 0x7F);	/* everything in one byte */
		else
			v = ((((i[p] >> b) + (i[p + 1] << (8 - b)))) & 0x7F);
		b += 7;
		if (b >= 8) {
			b -= 8;
			p++;
		}
		/* 0x00A0 is the encoding of ESC (27) in defaultalphabet */
		if (o > ud && o[-1] == 0x00A0 && escapes[v])
			o[-1] = escapes[v];
		else
			*o++ = defaultalphabet[v];
	}
	*udl = (o - ud);
}

/*! \brief unpacks bytes (8 bit encoding) at i, len l septets, 
      and places in udh and ud setting udhl and udl. udh not used 
      if udhi not set */
static void unpacksms8(unsigned char *i, unsigned char l, unsigned char *udh, int *udhl, unsigned short *ud, int *udl, char udhi)
{
	unsigned short *o = ud;
	*udhl = 0;
	if (udhi) {
		int n = *i;
		*udhl = n;
		if (n) {
			i++;
			l--;
			while (l && n) {
				l--;
				n--;
				*udh++ = *i++;
			}
		}
	}
	while (l--)
		*o++ = *i++;	  /* not to UTF-8 as explicitly 8 bit coding in DCS */
	*udl = (o - ud);
}

/*! \brief unpacks bytes (16 bit encoding) at i, len l septets,
	 and places in udh and ud setting udhl and udl. 
	udh not used if udhi not set */
static void unpacksms16(unsigned char *i, unsigned char l, unsigned char *udh, int *udhl, unsigned short *ud, int *udl, char udhi)
{
	unsigned short *o = ud;
	*udhl = 0;
	if (udhi) {
		int n = *i;
		*udhl = n;
		if (n) {
			i++;
			l--;
			while (l && n) {
				l--;
				n--;
				*udh++ = *i++;
			}
		}
	}
	while (l--) {
		int v = *i++;
		if (l--)
			v = (v << 8) + *i++;
		*o++ = v;
	}
	*udl = (o - ud);
}

/*! \brief general unpack - starts with length byte (octet or septet) and returns number of bytes used, inc length */
static int unpacksms(unsigned char dcs, unsigned char *i, unsigned char *udh, int *udhl, unsigned short *ud, int *udl, char udhi)
{
	int l = *i++;
	if (is7bit(dcs)) {
		unpacksms7(i, l, udh, udhl, ud, udl, udhi);
		l = (l * 7 + 7) / 8;		/* adjust length to return */
	} else if (is8bit(dcs))
		unpacksms8(i, l, udh, udhl, ud, udl, udhi);
	else
		unpacksms16(i, l, udh, udhl, ud, udl, udhi);
	return l + 1;
}

/*! \brief unpack an address from i, return byte length, unpack to o */
static unsigned char unpackaddress(char *o, unsigned char *i)
{
	unsigned char l = i[0],
		p;
	if (i[1] == 0x91)
		*o++ = '+';
	for (p = 0; p < l; p++) {
		if (p & 1)
			*o++ = (i[2 + p / 2] >> 4) + '0';
		else
			*o++ = (i[2 + p / 2] & 0xF) + '0';
	}
	*o = 0;
	return (l + 5) / 2;
}

/*! \brief store an address at o, and return number of bytes used */
static unsigned char packaddress(unsigned char *o, char *i)
{
	unsigned char p = 2;
	o[0] = 0;		/* number of bytes */
	if (*i == '+') {	/* record as bit 0 in byte 1 */
		i++;
		o[1] = 0x91;
	} else
		o[1] = 0x81;
	for ( ; *i ; i++) {
		if (!isdigit(*i))	/* ignore non-digits */
			continue;
		if (o[0] & 1)
			o[p++] |= ((*i & 0xF) << 4);
		else
			o[p] = (*i & 0xF);
		o[0]++;
	}
	if (o[0] & 1)
		o[p++] |= 0xF0;			  /* pad */
	return p;
}

/*! \brief Log the output, and remove file */
static void sms_log(sms_t * h, char status)
{
	int o;

	if (*h->oa == '\0' && *h->da == '\0')
		return;
	o = open(log_file, O_CREAT | O_APPEND | O_WRONLY, AST_FILE_MODE);
	if (o >= 0) {
		char line[1000], mrs[3] = "", *p;
		char buf[30];
		unsigned char n;

		if (h->mr >= 0)
			snprintf(mrs, sizeof(mrs), "%02X", h->mr);
		snprintf(line, sizeof(line), "%s %c%c%c%s %s %s %s ",
			isodate(time(NULL), buf, sizeof(buf)),
			status, h->rx ? 'I' : 'O', h->smsc ? 'S' : 'M', mrs, h->queue,
			S_OR(h->oa, "-"), S_OR(h->da, "-") );
		p = line + strlen(line);
		for (n = 0; n < h->udl; n++) {
			if (h->ud[n] == '\\') {
				*p++ = '\\';
				*p++ = '\\';
			} else if (h->ud[n] == '\n') {
				*p++ = '\\';
				*p++ = 'n';
			} else if (h->ud[n] == '\r') {
				*p++ = '\\';
				*p++ = 'r';
			} else if (h->ud[n] < 32 || h->ud[n] == 127)
				*p++ = 191;
			else
				*p++ = h->ud[n];
		}
		*p++ = '\n';
		*p = 0;
		write(o, line, strlen(line));
		close(o);
	}
	*h->oa = *h->da = h->udl = 0;
}

/*! \brief parse and delete a file */
static void sms_readfile(sms_t * h, char *fn)
{
	char line[1000];
	FILE *s;
	char dcsset = 0;		/* if DSC set */
	ast_log(LOG_EVENT, "Sending %s\n", fn);
	h->rx = h->udl = *h->oa = *h->da = h->pid = h->srr = h->udhi = h->rp = h->vp = h->udhl = 0;
	h->mr = -1;
	h->dcs = 0xF1;			/* normal messages class 1 */
	h->scts = ast_tvnow();
	s = fopen(fn, "r");
	if (s) {
		if (unlink(fn)) {	/* concurrent access, we lost */
			fclose(s);
			return;
		}
		while (fgets (line, sizeof(line), s)) {	/* process line in file */
			char *p;
			void *pp = &p;
			for (p = line; *p && *p != '\n' && *p != '\r'; p++);
			*p = 0;					 /* strip eoln */
			p = line;
			if (!*p || *p == ';')
				continue;			  /* blank line or comment, ignore */
			while (isalnum(*p)) {
				*p = tolower (*p);
				p++;
			}
			while (isspace (*p))
				*p++ = 0;
			if (*p == '=') {
				*p++ = 0;
				if (!strcmp(line, "ud")) {	 /* parse message (UTF-8) */
					unsigned char o = 0;
					memcpy(h->udtxt, p, SMSLEN);	/* for protocol 2 */
					while (*p && o < SMSLEN)
						h->ud[o++] = utf8decode(pp);
					h->udl = o;
					if (*p)
						ast_log(LOG_WARNING, "UD too long in %s\n", fn);
				} else {
					while (isspace (*p))
						p++;
					if (!strcmp(line, "oa") && strlen(p) < sizeof(h->oa))
						numcpy (h->oa, p);
					else if (!strcmp(line, "da") && strlen(p) < sizeof(h->oa))
						numcpy (h->da, p);
					else if (!strcmp(line, "pid"))
						h->pid = atoi(p);
					else if (!strcmp(line, "dcs")) {
						h->dcs = atoi(p);
						dcsset = 1;
					} else if (!strcmp(line, "mr"))
						h->mr = atoi(p);
					else if (!strcmp(line, "srr"))
						h->srr = (atoi(p) ? 1 : 0);
					else if (!strcmp(line, "vp"))
						h->vp = atoi(p);
					else if (!strcmp(line, "rp"))
						h->rp = (atoi(p) ? 1 : 0);
					else if (!strcmp(line, "scts")) {	/* get date/time */
						int Y,
						  m,
						  d,
						  H,
						  M,
						  S;
						if (sscanf (p, "%d-%d-%dT%d:%d:%d", &Y, &m, &d, &H, &M, &S) == 6) {
							struct ast_tm t = { 0, };
							t.tm_year = Y - 1900;
							t.tm_mon = m - 1;
							t.tm_mday = d;
							t.tm_hour = H;
							t.tm_min = M;
							t.tm_sec = S;
							t.tm_isdst = -1;
							h->scts = ast_mktime(&t, NULL);
							if (h->scts.tv_sec == 0)
								ast_log(LOG_WARNING, "Bad date/timein %s: %s", fn, p);
						}
					} else
						ast_log(LOG_WARNING, "Cannot parse in %s: %s=%si\n", fn, line, p);
				}
			} else if (*p == '#') {		/* raw hex format */
				*p++ = 0;
				if (*p == '#') {
					p++;
					if (!strcmp(line, "ud")) {	/* user data */
						int o = 0;
						while (*p && o < SMSLEN) {
							if (isxdigit(*p) && isxdigit(p[1]) && isxdigit(p[2]) && isxdigit(p[3])) {
								h->ud[o++] =
									(((isalpha(*p) ? 9 : 0) + (*p & 0xF)) << 12) +
									(((isalpha(p[1]) ? 9 : 0) + (p[1] & 0xF)) << 8) +
									(((isalpha(p[2]) ? 9 : 0) + (p[2] & 0xF)) << 4) + ((isalpha(p[3]) ? 9 : 0) + (p[3] & 0xF));
								p += 4;
							} else
								break;
						}
						h->udl = o;
						if (*p)
							ast_log(LOG_WARNING, "UD too long / invalid UCS-2 hex in %s\n", fn);
					} else
						ast_log(LOG_WARNING, "Only ud can use ## format, %s\n", fn);
				} else if (!strcmp(line, "ud")) {	/* user data */
					int o = 0;
					while (*p && o < SMSLEN) {
						if (isxdigit(*p) && isxdigit(p[1])) {
							h->ud[o++] = (((isalpha(*p) ? 9 : 0) + (*p & 0xF)) << 4) + ((isalpha(p[1]) ? 9 : 0) + (p[1] & 0xF));
							p += 2;
						} else
							break;
					}
					h->udl = o;
					if (*p)
						ast_log(LOG_WARNING, "UD too long / invalid UCS-1 hex in %s\n", fn);
				} else if (!strcmp(line, "udh")) {	/* user data header */
					unsigned char o = 0;
					h->udhi = 1;
					while (*p && o < SMSLEN) {
						if (isxdigit(*p) && isxdigit(p[1])) {
							h->udh[o] = (((isalpha(*p) ? 9 : 0) + (*p & 0xF)) << 4) + ((isalpha(p[1]) ? 9 : 0) + (p[1] & 0xF));
							o++;
							p += 2;
						} else
							break;
					}
					h->udhl = o;
					if (*p)
						ast_log(LOG_WARNING, "UDH too long / invalid hex in %s\n", fn);
				} else
					ast_log(LOG_WARNING, "Only ud and udh can use # format, %s\n", fn);
			} else
				ast_log(LOG_WARNING, "Cannot parse in %s: %s\n", fn, line);
		}
		fclose(s);
		if (!dcsset && packsms7(0, h->udhl, h->udh, h->udl, h->ud) < 0) {
			if (packsms8(0, h->udhl, h->udh, h->udl, h->ud) < 0) {
				if (packsms16(0, h->udhl, h->udh, h->udl, h->ud) < 0)
					ast_log(LOG_WARNING, "Invalid UTF-8 message even for UCS-2 (%s)\n", fn);
				else {
					h->dcs = 0x08;	/* default to 16 bit */
					ast_log(LOG_WARNING, "Sending in 16 bit format(%s)\n", fn);
				}
			} else {
				h->dcs = 0xF5;		/* default to 8 bit */
				ast_log(LOG_WARNING, "Sending in 8 bit format(%s)\n", fn);
			}
		}
		if (is7bit(h->dcs) && packsms7(0, h->udhl, h->udh, h->udl, h->ud) < 0)
			ast_log(LOG_WARNING, "Invalid 7 bit GSM data %s\n", fn);
		if (is8bit(h->dcs) && packsms8(0, h->udhl, h->udh, h->udl, h->ud) < 0)
			ast_log(LOG_WARNING, "Invalid 8 bit data %s\n", fn);
		if (is16bit(h->dcs) && packsms16(0, h->udhl, h->udh, h->udl, h->ud) < 0)
			ast_log(LOG_WARNING, "Invalid 16 bit data %s\n", fn);
	}
}

/*! \brief white a received text message to a file */
static void sms_writefile(sms_t * h)
{
	char fn[200] = "", fn2[200] = "";
	char buf[30];
	FILE *o;

	snprintf(fn, sizeof(fn), "%s/sms/%s", ast_config_AST_SPOOL_DIR, h->smsc ? h->rx ? "morx" : "mttx" : h->rx ? "mtrx" : "motx");
	ast_mkdir(fn, 0777);			/* ensure it exists */
	ast_copy_string(fn2, fn, sizeof(fn2));
	snprintf(fn2 + strlen(fn2), sizeof(fn2) - strlen(fn2), "/%s.%s-%d", h->queue, isodate(h->scts.tv_sec, buf, sizeof(buf)), seq++);
	snprintf(fn + strlen(fn), sizeof(fn) - strlen(fn), "/.%s", fn2 + strlen(fn) + 1);
	o = fopen(fn, "w");
	if (o == NULL)
		return;

	if (*h->oa)
		fprintf(o, "oa=%s\n", h->oa);
	if (*h->da)
		fprintf(o, "da=%s\n", h->da);
	if (h->udhi) {
		unsigned int p;
		fprintf(o, "udh#");
		for (p = 0; p < h->udhl; p++)
			fprintf(o, "%02X", h->udh[p]);
		fprintf(o, "\n");
	}
	if (h->udl) {
		unsigned int p;
		for (p = 0; p < h->udl && h->ud[p] >= ' '; p++);
		if (p < h->udl)
			fputc(';', o);	  /* cannot use ud=, but include as a comment for human readable */
		fprintf(o, "ud=");
		for (p = 0; p < h->udl; p++) {
			unsigned short v = h->ud[p];
			if (v < 32)
				fputc(191, o);
			else if (v < 0x80)
				fputc(v, o);
			else if (v < 0x800)
			{
				fputc(0xC0 + (v >> 6), o);
				fputc(0x80 + (v & 0x3F), o);
			} else
			{
				fputc(0xE0 + (v >> 12), o);
				fputc(0x80 + ((v >> 6) & 0x3F), o);
				fputc(0x80 + (v & 0x3F), o);
			}
		}
		fprintf(o, "\n");
		for (p = 0; p < h->udl && h->ud[p] >= ' '; p++);
		if (p < h->udl) {
			for (p = 0; p < h->udl && h->ud[p] < 0x100; p++);
			if (p == h->udl) {						 /* can write in ucs-1 hex */
				fprintf(o, "ud#");
				for (p = 0; p < h->udl; p++)
					fprintf(o, "%02X", h->ud[p]);
				fprintf(o, "\n");
			} else {						 /* write in UCS-2 */
				fprintf(o, "ud##");
				for (p = 0; p < h->udl; p++)
					fprintf(o, "%04X", h->ud[p]);
				fprintf(o, "\n");
			}
		}
	}
	if (h->scts.tv_sec) {
		char buf[30];
		fprintf(o, "scts=%s\n", isodate(h->scts.tv_sec, buf, sizeof(buf)));
	}
	if (h->pid)
		fprintf(o, "pid=%d\n", h->pid);
	if (h->dcs != 0xF1)
		fprintf(o, "dcs=%d\n", h->dcs);
	if (h->vp)
		fprintf(o, "vp=%d\n", h->vp);
	if (h->srr)
		fprintf(o, "srr=1\n");
	if (h->mr >= 0)
		fprintf(o, "mr=%d\n", h->mr);
	if (h->rp)
		fprintf(o, "rp=1\n");
	fclose(o);
	if (rename(fn, fn2))
		unlink(fn);
	else
		ast_log(LOG_EVENT, "Received to %s\n", fn2);
}