#!perl -w
use strict;
$|=1;
# todo: add support for decoding cell broadcast message pdu's  -> 23.041

# this script decodes raw smsses

# 27.005 - Use of Data Terminal Equipment - Data Circuit terminating Equipment (DTE-DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)
#    describes the at-commands involved in sending/receiving smsses

# 23.040 - Technical realization of Short Message Service (SMS)
#    describes the encoding of smsses

# 23.038 - Technical realization of Short Message Service (SMS)
#    describes the data coding schemes
#
#  ms = mobilestation
#  SC = servicecenter
my @pdutypes= (
    # ms->SC       |   SC->ms
 [ 'deliver-report', 'deliver' ],  # 0
 [ 'submit',   'submit-report' ],  # 1
 [ 'command',  'status-report' ],  # 2
 [ 'unknown-out', 'unknown-in' ],  # 3
);
#  RP = Reply-Path
#   H = UDHI - userdata header indicator
# SRI = status report indicator
# SRR = status report requested
# MMS = moremessages
#  RD = reject dups
# VPF = validity period format

#  MR = message reference
#  OA = origination address
#  DA = destination address
#  VP = validity period
# PID = protocol id
# DCS = data coding scheme
#SCTS = sc timestamp
#  DT = discharge time
# UDL = userdata lenght
#  UD = user data
# FCS = failure cause -- encoded as 'i'
#  PI = parameter indicator : bitmask
#  CT = command type
#  MN = message number
# CDL = commandata length
#  CD = command data
my %typeinfo= (                                           # 7  6 5    4 3 2   1 0 |
'deliver-report'=> ",FCS,PI,PID,DCS,UDL,UD,",             # -  H -    -   -   MTI | FCS, PI, PID, DCS, UDL, UD
'deliver'=>        ",OA,PID,DCS,SCTS,UDL,UD,",            # RP H SRI  -   MMS MTI | OA, PID, DCS, SCTS, UDL, UD
'submit'=>         ",MR,DA,PID,DCS,VP,UDL,UD,",           # RP H SRR  VPF RD  MTI | MR, DA, PID, DCS, VP, UDL, UD
'submit-report'=>  ",FCS,PI,SCTS,PID,DCS,UDL,UD,",        # -  H -    -   -   MTI | FCS, PI, SCTS, PID, DCS, UDL, UD
'status-report'=>  ",MR,RA,SCTS,DT,ST,PI,PID,DCS,UDL,UD,",# -  H SRQ  -   MMS MTI | MR, RA, SCTS, DT, ST, PI, PID, DCS, UDL, UD
'command'=>        ",MR,PID,CT,MN,DA,CDL,CD,",            # -  H SRR  -   -   MTI | MR, PID, CT, MN, DA, CDL, CD
);
sub hasfield {
    my ($pdutype, $field)= @_;
    return $typeinfo{$pdutype} =~ /,$field,/i;
}
my @numtypes= ( 'unknown', 'international', 'national', 'network', 'subscriber', 'alpha', 'abbrev', 'reserved' );
my @plantypes= ( 'Unknown', 'ISDN_e164', 'undef2', 'Data_x121', 'Telex', 'SCspec5', 'SCspec6', 'undef7', 'National', 'Private', 'ERMES', 'undefb', 'undefc', 'undefd', 'undefe', 'Reserved');

# TP-PID  protocol identifier
# bit7,6 == 00, bit5=0 : sme-to-sme protocol
# bit7,6 == 00, bit5=1 : telematic interworking
#   00000		implicit - device type is specific to this SC, or can be concluded on the basis of the address
#   00001		telex (or teletex reduced to telex format)
#   00010		group 3 telefax
#   00011		group 4 telefax
#   00100		voice telephone (i.e. conversion to speech)
#   00101		ERMES (European Radio Messaging System)
#   00110		National Paging system (known to the SC)
#   00111		Videotex (T.100 [20] /T.101 [21])
#   01000		teletex, carrier unspecified
#   01001		teletex, in PSPDN
#   01010		teletex, in CSPDN
#   01011		teletex, in analog PSTN
#   01100		teletex, in digital ISDN
#   01101		UCI (Universal Computer Interface, ETSI DE/PS 3 01-3)
#   01110..01111		(reserved, 2 combinations)
#   10000		a message handling facility (known to the SC)
#   10001		any public X.400-based message handling system
#   10010		Internet Electronic Mail
#   10011..10111		(reserved, 5 combinations)
#   11000..11110		values specific to each SC, usage based on mutual agreement between the SME and the SC 	(7 combinations available for each SC)
#   11111		A GSM/UMTS mobile station. The SC converts the SM from the received TP-DCS to any data coding scheme supported by the MS ( default )

# bit7,6=01 
# 000000		Short Message Type 0
# 000001		Replace Short Message Type 1
# 000010		Replace Short Message Type 2
# 000011		Replace Short Message Type 3
# 000100		Replace Short Message Type 4
# 000101		Replace Short Message Type 5
# 000110		Replace Short Message Type 6
# 000111		Replace Short Message Type 7
# 001000..011101		Reserved
# 011110		Enhanced Message Service (Obsolete)
# 011111		Return Call Message
# 100000..111011		Reserved
# 111100		ANSI-136 R-DATA
# 111101		ME Data download
# 111110		ME De-personalization Short Message
# 111111		(U)SIM Data download

# section 4.3: AT+CMGS=<length><CR>PDUDATA<CTRLZ>
#    length excluding smsc address
# section 4.2: AT+CMGR=<index><CR>
#   -> +CMGR: <stat>,[alpha],<length><CRLF>pdu
# +CMT: [<alpha>],<length><CRLF>pdu
#
# http://www.computer.org/portal/site/computer/menuitem.5d61c1d591162e4b0ef1bd108bcd45f3/index.jsp?&pName=computer_level1_article&TheCat=1055&path=computer/homepage/Dec07&file=howthings.xml&xsl=article.xsl&


#      type
#  91   1   - international
#  a1   2   - national
#  d0   5   - 7bit ascii
#  01   0
#  81   0
# struct address {
#     char nrofdigits;
#     struct {
#         int onebit:1
#         int numbertype:3;
#         int numberingplan:4;
#     } type;
#     char value[ceil(nrofdigits/2)]
# }

# numbertype
# 0 Unknown
# 1 International number
# 2 National number
# 3 Network specific number
# 4 Subscriber number
# 5 Alphanumeric, (coded according to 3GPP TS 23.038 [9] GSM 7-bit default alphabet)
# 6 Abbreviated number
# 7 Reserved for extension
#
# numberingplan
# 0	Unknown
# 1	ISDN/telephone numbering plan (E.164 [17]/E.163[18])
# 2
# 3	Data numbering plan (X.121)
# 4	Telex numbering plan
# 5	Service Centre Specific plan 1)
# 6	Service Centre Specific plan 1)
# 7
# 8	National numbering plan
# 9	Private numbering plan
# a	ERMES numbering plan (ETSI DE/PS 3 01-3)
# b
# c
# d
# e
# f	Reserved for extension

# sms-submit:
#       bb  
# 00   MTI,RD,VPF,SRR,UDHI,RP
# 01   MR
# 02   TP-DA
# ..
#      TP-PID
#      TP-DCS
#      TP-VP
# ..
#      TP-UDL
#      TP-UD

# SMS-DELIVER:
#       b   b   b    b bb  
#       
# 00   ,SRI,UDHI,RP,MMS,MTI
# 01   TP-DA

# 9.2.3.1 - TP-Message-Type-Indicator  (TP-MTI)
#  bits 1,0 of byte0 of all pdu's
#      xmit          |   recv
#   0 DELIVER-REPORT | DELIVER
#   1 SUBMIT         | SUBMIT-REPORT
#   2 COMMAND        | STATUS-REPORT
#   3 -              | -
 
# 9.2.3.2 - TP-More-Messages-to-Send  (TP-MMS)
#  bit 2 of byte0  of SMS-DELIVER and SMS-STATUS-REPORT
#   0  More messages are waiting for the MS in this SC
#   1  No more messages are waiting for the MS in this SC

# 9.2.3.25 TP-Reject-Duplicates (TP-RD)
#  bit 2 of byte0 of SMS-SUBMIT
#   0 Instruct the SC to accept an SMS-SUBMIT for an SM still held in the SC which has the same TP-MR and the same TP-DA as a previously  submitted SM from  the same OA.
#   1 Instruct the SC to reject an SMS-SUBMIT for an SM still held in the SC which has the same TP-MR and the same TP-DA as the  previously submitted SM  from the same OA. 

# 9.2.3.3 - TP-Validity-Period-Format (TP-VPF)
#  bit 4,3 of byte0 of SMS-SUBMIT
#   0  TP-VP field not present
#   1  TP-VP field present - relative format
#   2  TP-VP field present - enhanced format
#   3  TP-VP field present - absolute format 

# 9.2.3.4 - TP-Status-Report-Indication (TP-SRI)
#  bit 5 of byte0 of SMS-DELIVER
#   0  A status report shall not be returned to the SME
#   1  A status report shall be returned to the SME

# 9.2.3.26 - TP-Status-Report-Qualifier (TP-SRQ)
#  bit 5 of byte0 of SMS-STATUS-REPORT
#   0 The SMS-STATUS-REPORT is the result of a SMS-SUBMIT.
#   1 The SMS-STATUS-REPORT is the result of an SMS-COMMAND

# 9.2.3.5 - TP-Status-Report-Request (TP-SRR)
#  bit 5 of byte0 of SMS-SUBMIT, SMS-COMMAND
#   0  A status report is not requested
#   1  A status report is requested

# 9.2.3.23 - TP-User-Data-Header-Indicator (TP-UDHI)
#  bit 6 of byte0 of all pdu's
#   0 The TP-UD field contains only the short message
#   1 The beginning of the TP-UD field contains a Header in addition to the short message.

# 9.2.3.17 - TP-Reply-Path (TP-RP)
#  bit 7 of byte0 of SMS-DELIVER and SMS--SUBMIT
#   0  TP-Reply-Path parameter is not set in this SMS-SUBMIT/DELIVER
#   1  TP-Reply-Path parameter is set in this SMS-SUBMIT/DELIVER

if (@ARGV) {
    my $x= shift;
    if ($x =~ /([<>])?(\w+)/) {
        decodesms($1 ? ($1 eq "<" ? 1 : 0) : undef, $2);
    }
}
else {
    my $n=0;
    while (<>) {
        if (/([<>])?(\w+)/) {
            decodesms($1 ? ($1 eq "<" ? 1 : 0) : undef, $2);
            $n++;
        }
    }
    if ($n==0) {
        while (<>) {
            if (/^([<>])(\w{8,})/ || /"(<>)(\w+)"/) {
                print "decoding $_\n";
                decodesms($1 ? ($1 eq "<" ? 1 : 0) : undef, $2);
            }
            else {
                print $_;
            }
        }
    }
}
my %msgtypename=(
    0=> {0=>'DELIVER-REPORT', 1=>'DELIVER'},
    1=> {0=>'SUBMIT',         1=>'SUBMIT-REPORT'},
    2=> {0=>'COMMAND',        1=>'STATUS-REPORT'},
    3=> {0=>'-',              1=>'-'},
);
sub decodesms {
    my ($dir, $smshex)=@_;

    my $data= pack("H*", $smshex);
    my $ofs= 0;
    my $smsclen= unpack("C", substr($data, $ofs++, 1));
    my $smscdata= substr($data, $ofs, $smsclen);
    $ofs+=$smsclen;

    printf("smsc: %s\n", decode_address($smscdata));

    # if direction not known, assume it is outgoing when the smsc length == 0
    my $incoming= defined $dir ? $dir : $smsclen!=0;

    my $pduhdr= unpack("C", substr($data, $ofs++, 1));
    my $mti= ($pduhdr&3);
    my $pdutype= $pdutypes[$mti][$incoming];

    printf("%s %s\n", $pdutype, $mti?"done":"");

    if (hasfield($pdutype, "MR")) {
        # message reference
        my $mr= unpack("C", substr($data, $ofs++, 1));
        printf("MR: %02x\n", $mr);
    }
    if (hasfield($pdutype, "DA") || hasfield($pdutype, "OA")) {
        # destination/originating address
        my $srclen= unpack("C", substr($data, $ofs++, 1));
        my $srcnum= substr($data, $ofs, ($srclen-1)/2+2);
        $ofs += ($srclen-1)/2+2;
        printf("%s: %s\n", hasfield($pdutype, "DA")?"DA":hasfield($pdutype, "OA")?"OA":"??",
            decode_address($srcnum));
    }
    if (hasfield($pdutype, "PID")) {
        # protocol id
        # todo 
        my $protocol= unpack("C", substr($data, $ofs++, 1));
        printf("prot: %02x\n", $protocol);
        # 0x00
        # 0x0b
        # 0x0d
        # 0x10
    }
    my $dcs;
    if (hasfield($pdutype, "DCS")) {
        # data coding scheme
        # todo , see 23.038
        $dcs= unpack("C", substr($data, $ofs++, 1));
        printf("dcs: %02x\n", $dcs);
    }
    if (hasfield($pdutype, "VP") && ($pduhdr&0x18)) {
        # validity period
        my $vpf= ($pduhdr&0x18)>>3;
        my @fmt=qw(- rel enh abs);
        # rel: 1 byte
        # abs: 7 bytes
        # enh: 7 bytes
        if ($vpf==1) {
            my $vp= unpack("C", substr($data, $ofs++, 1));
            printf("VP: %s %d\n", $fmt[$vpf], $vp);
        }
        else {
            my $vp= substr($data, $ofs, 7);
            $ofs+=7;
            printf("VP: %s %s\n", $fmt[$vpf], unpack 'H*',$vp);
        }
    }
    if (hasfield($pdutype, "SCTS")) {
        # sc timestamp
        my $scts= unpack 'H*', unpack("a7", substr($data, $ofs, 7));
        $ofs+=7;
        $scts =~ s/(\w)(\w)/$2$1/g;
        printf("scts: %s\n", $scts);
    }
    my $udl;
    if (hasfield($pdutype, "UDL")) {
        # userdata length
        $udl= unpack("C", substr($data, $ofs++, 1));
    }
    if (hasfield($pdutype, "UD")) {
        # user data
        # $dcs=08 : unicode
        # $dcs=11 : 7bit
        if ($dcs&0x20) {
            printf("compressed[%02x]: %s\n", $udl, unpack("H*", substr($data, $ofs)));
        }
        elsif (($dcs&0x0c)==0) {
            # 7 bit data
            my $b7len= int(($udl*7)/8)+1;
            my $ud= substr($data, $ofs, $b7len);
            $ofs += $b7len;
            printf("msg: '%s'\n", substr(sms7to8bit($ud),0,$udl));
        }
        elsif (($dcs&0x0c)==0x04) {
            # 8 bit data
            my $ud= substr($data, $ofs, $udl);
            $ofs += ($udl*7)/8;
            printf("msg: '%s'\n", $ud);
        }
        elsif (($dcs&0x0c)==0x08) {
            # ucs2 data
            my $ud= substr($data, $ofs, $udl);
            $ofs += $udl;
            printf("msg: U'%s'\n", pack("U*", unpack("n*",$ud)));
        }
        # 0x91
        # 0xd0
        else {
            printf("msg: unknown encoding: %s\n", unpack("H*", substr($data, $ofs)));
        }
    }
    printf("leftover: %d\n", length($data)-$ofs);
}

sub decode_address {
    return "-" if ($_[0] eq "");
    my ($typebyte, $addr)= unpack("Ca*", $_[0]);
    my ($one, $type, $plan)=(($typebyte>>7)&1, ($typebyte>>4)&7, $typebyte&0xf);

    return sprintf("%d.%s.%s:%s", $one, $numtypes[$type], $plantypes[$plan], decodenumber($addr, $type))
}
sub sms7to8bit {
my @xlat= (
"@", "£", "\$", "¥", "è", "é", "ù", "ì", "ò", "Ç", "\n", "Ø", "ø", "\r", "Å", "å",
"∆", "_", "Φ", "Γ", "Λ", "Ω", "Π", "Ψ", "Σ", "Θ", "Ξ", "\x1b", "Æ", "æ", "ß", "É", 
"\x20", "!", "\x22", "#", "¤", "%", "&", "\x27", "(", ")", "*", "+", ",", "-", ".", "/",
"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", ":", ";", "<", "=", ">", "?",
"¡", "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", "Ä", "Ö", "Ñ", "Ü", "§",
"¿", "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", "ä", "ö", "ñ", "ü", "a",

);
my @xlat2= (
" ", " ", " ", " ", " ", " ", " ", " ", " ", " ", "\x03", " ", " ", " ", " ", " ",
" ", " ", " ", " ", "^", " ", " ", " ", " ", " ", " ", "\x1b", " ", " ", " ", " ",
" ", " ", " ", " ", " ", " ", " ", " ", "{", "}", " ", " ", " ", " ", " ", "\\",
" ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", "[", "~", "]", " ",
"|", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ",
" ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ",
" ", " ", " ", " ", " ", "€", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ",
" ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ",
);

#    printf("xx-%s\n", unpack("H*", $_[0]));
    my $bits= unpack("b*", $_[0]);
#    if (length($bits)%7) { $bits=substr($bits, 0, -(length($bits)%7)); }
    return join "", map { if ($esc) { $esc--; $xlat2[ord($_)] } elsif ($_ eq "\x1b") { $esc++ } else { $xlat[ord($_)] } } map { pack("b*", $_) } split /(\d{7})/, $bits;
}
sub decodenumber {
    my ($numdata, $type)= @_;
    if ($type==5) {
        my $str= sms7to8bit($numdata);
        $str =~ s/\x00$//;
        return $str;
    }
    else {
        (my $nr= unpack 'H*', $numdata) =~ s/(\w)(\w)/$2$1/g;
        return $nr;
    }
}