318 lines
11 KiB
Perl
318 lines
11 KiB
Perl
#------------------------------------------------------------------------------
|
|
# File: Torrent.pm
|
|
#
|
|
# Description: Read information from BitTorrent file
|
|
#
|
|
# Revisions: 2013/08/27 - P. Harvey Created
|
|
#
|
|
# References: 1) https://wiki.theory.org/BitTorrentSpecification
|
|
#------------------------------------------------------------------------------
|
|
|
|
package Image::ExifTool::Torrent;
|
|
|
|
use strict;
|
|
use vars qw($VERSION);
|
|
use Image::ExifTool qw(:DataAccess :Utils);
|
|
|
|
$VERSION = '1.03';
|
|
|
|
sub ReadBencode($$);
|
|
sub ExtractTags($$$;$$@);
|
|
|
|
# tags extracted from BitTorrent files
|
|
%Image::ExifTool::Torrent::Main = (
|
|
GROUPS => { 2 => 'Document' },
|
|
NOTES => q{
|
|
Below are tags commonly found in BitTorrent files. As well as these tags,
|
|
any other existing tags will be extracted. For convenience, list items are
|
|
expanded into individual tags with an index in the tag name, but only the
|
|
tags with index "1" are listed in the tables below. See
|
|
L<https://wiki.theory.org/BitTorrentSpecification> for the BitTorrent
|
|
specification.
|
|
},
|
|
'announce' => { },
|
|
'announce-list' => { Name => 'AnnounceList1' },
|
|
'comment' => { },
|
|
'created by' => { Name => 'Creator' }, # software used to create the torrent
|
|
'creation date' => {
|
|
Name => 'CreateDate',
|
|
Groups => { 2 => 'Time' },
|
|
ValueConv => 'ConvertUnixTime($val,1)',
|
|
PrintConv => '$self->ConvertDateTime($val)',
|
|
},
|
|
'encoding' => { },
|
|
'info' => { SubDirectory => { TagTable => 'Image::ExifTool::Torrent::Info' } },
|
|
'url-list' => { Name => 'URLList1' },
|
|
);
|
|
|
|
%Image::ExifTool::Torrent::Info = (
|
|
GROUPS => { 2 => 'Document' },
|
|
'file-duration' => { Name => 'File1Duration' },
|
|
'file-media' => { Name => 'File1Media' },
|
|
'files' => { SubDirectory => { TagTable => 'Image::ExifTool::Torrent::Files' } },
|
|
'length' => { },
|
|
'md5sum' => { Name => 'MD5Sum' },
|
|
'name' => { },
|
|
'name.utf-8' => { Name => 'NameUTF-8' },
|
|
'piece length' => { Name => 'PieceLength' },
|
|
'pieces' => {
|
|
Name => 'Pieces',
|
|
Notes => 'concatenation of 20-byte SHA-1 digests for each piece',
|
|
},
|
|
'private' => { },
|
|
'profiles' => { SubDirectory => { TagTable => 'Image::ExifTool::Torrent::Profiles' } },
|
|
);
|
|
|
|
%Image::ExifTool::Torrent::Profiles = (
|
|
GROUPS => { 2 => 'Document' },
|
|
'width' => { Name => 'Profile1Width' },
|
|
'height' => { Name => 'Profile1Height' },
|
|
'acodec' => { Name => 'Profile1AudioCodec' },
|
|
'vcodec' => { Name => 'Profile1VideoCodec' },
|
|
);
|
|
|
|
%Image::ExifTool::Torrent::Files = (
|
|
GROUPS => { 2 => 'Document' },
|
|
'length' => { Name => 'File1Length', PrintConv => 'ConvertFileSize($val)' },
|
|
'md5sum' => { Name => 'File1MD5Sum' },
|
|
'path' => { Name => 'File1Path', JoinPath => 1 },
|
|
'path.utf-8' => { Name => 'File1PathUTF-8', JoinPath => 1 },
|
|
);
|
|
|
|
#------------------------------------------------------------------------------
|
|
# Read 64kB more data into buffer
|
|
# Inputs: 0) RAF ref, 1) buffer ref
|
|
# Returns: number of bytes read
|
|
# Notes: Sets BencodeEOF element of RAF on end of file
|
|
sub ReadMore($$)
|
|
{
|
|
my ($raf, $dataPt) = @_;
|
|
my $buf2;
|
|
my $n = $raf->Read($buf2, 65536);
|
|
$$raf{BencodeEOF} = 1 if $n != 65536;
|
|
$$dataPt = substr($$dataPt, pos($$dataPt)) . $buf2 if $n;
|
|
return $n;
|
|
}
|
|
|
|
#------------------------------------------------------------------------------
|
|
# Read bencoded value
|
|
# Inputs: 0) input file, 1) buffer (pos must be set to current position)
|
|
# Returns: HASH ref, ARRAY ref, SCALAR ref, SCALAR, or undef on error or end of data
|
|
# Notes: Sets BencodeError element of RAF on any error
|
|
sub ReadBencode($$)
|
|
{
|
|
my ($raf, $dataPt) = @_;
|
|
|
|
# read more if necessary (keep a minimum of 64 bytes in the buffer)
|
|
my $pos = pos($$dataPt);
|
|
return undef unless defined $pos;
|
|
my $remaining = length($$dataPt) - $pos;
|
|
ReadMore($raf, $dataPt) if $remaining < 64 and not $$raf{BencodeEOF};
|
|
|
|
# read next token
|
|
$$dataPt =~ /(.)/sg or return undef;
|
|
|
|
my $val;
|
|
my $tok = $1;
|
|
if ($tok eq 'i') { # integer
|
|
$$dataPt =~ /\G(-?\d+)e/g or return $val;
|
|
$val = $1;
|
|
} elsif ($tok eq 'd') { # dictionary
|
|
$val = { };
|
|
for (;;) {
|
|
my $k = ReadBencode($raf, $dataPt);
|
|
last unless defined $k;
|
|
# the key must be a byte string
|
|
if (ref $k) {
|
|
ref $k ne 'SCALAR' and $$raf{BencodeError} = 'Bad dictionary key', last;
|
|
$k = $$k;
|
|
}
|
|
my $v = ReadBencode($raf, $dataPt);
|
|
last unless defined $v;
|
|
$$val{$k} = $v;
|
|
}
|
|
} elsif ($tok eq 'l') { # list
|
|
$val = [ ];
|
|
for (;;) {
|
|
my $v = ReadBencode($raf, $dataPt);
|
|
last unless defined $v;
|
|
push @$val, $v;
|
|
}
|
|
} elsif ($tok eq 'e') { # end of dictionary or list
|
|
# return undef (no error)
|
|
} elsif ($tok =~ /^\d$/ and $$dataPt =~ /\G(\d*):/g) { # byte string
|
|
my $len = $tok . $1;
|
|
my $more = $len - (length($$dataPt) - pos($$dataPt));
|
|
my $value;
|
|
if ($more <= 0) {
|
|
$value = substr($$dataPt,pos($$dataPt),$len);
|
|
pos($$dataPt) = pos($$dataPt) + $len;
|
|
} elsif ($more > 10000000) {
|
|
# just skip over really long values
|
|
$val = \ "(Binary data $len bytes)" if $raf->Seek($more, 1);
|
|
} else {
|
|
# need to read more from file
|
|
my $buff;
|
|
my $n = $raf->Read($buff, $more);
|
|
if ($n == $more) {
|
|
$value = substr($$dataPt,pos($$dataPt)) . $buff;
|
|
$$dataPt = '';
|
|
pos($$dataPt) = 0;
|
|
}
|
|
}
|
|
if (defined $value) {
|
|
# return as binary data unless it is a reasonable-length ASCII string
|
|
if (length($value) > 256 or $value =~ /[^\t\x20-\x7e]/) {
|
|
$val = \$value;
|
|
} else {
|
|
$val = $value;
|
|
}
|
|
} elsif (not defined $val) {
|
|
$$raf{BencodeError} = 'Truncated byte string';
|
|
}
|
|
} else {
|
|
$$raf{BencodeError} = 'Bad format';
|
|
}
|
|
return $val;
|
|
}
|
|
|
|
#------------------------------------------------------------------------------
|
|
# Extract tags from dictionary hash
|
|
# Inputs: 0) ExifTool ref, 1) dictionary hash reference, 2) tag table ref,
|
|
# 3) parent hash ID, 4) parent hash name, 5-N) list indices
|
|
# Returns: number of tags extracted
|
|
sub ExtractTags($$$;$$@)
|
|
{
|
|
my ($et, $hashPtr, $tagTablePtr, $baseID, $baseName, @index) = @_;
|
|
my $count = 0;
|
|
my $tag;
|
|
foreach $tag (sort keys %$hashPtr) {
|
|
my $val = $$hashPtr{$tag};
|
|
my ($i, $j, @more);
|
|
for (; defined $val; $val = shift @more) {
|
|
my $id = defined $baseID ? "$baseID/$tag" : $tag;
|
|
unless ($$tagTablePtr{$id}) {
|
|
my $name = ucfirst $tag;
|
|
# capitalize all words in tag name and remove illegal characters
|
|
$name =~ s/[^-_a-zA-Z0-9]+(.?)/\U$1/g;
|
|
$name = "Tag$name" if length($name) < 2 or $name !~ /^[A-Z]/;
|
|
$name = $baseName . $name if defined $baseName; # add base name if necessary
|
|
AddTagToTable($tagTablePtr, $id, { Name => $name });
|
|
$et->VPrint(0, " [adding $id '${name}']\n");
|
|
}
|
|
my $tagInfo = $et->GetTagInfo($tagTablePtr, $id) or next;
|
|
if (ref $val eq 'ARRAY') {
|
|
if ($$tagInfo{JoinPath}) {
|
|
$val = join '/', @$val;
|
|
} else {
|
|
push @more, @$val;
|
|
next if ref $more[0] eq 'ARRAY'; # continue expanding nested lists
|
|
$val = shift @more;
|
|
$i or $i = 0, push(@index, $i);
|
|
}
|
|
}
|
|
$index[-1] = ++$i if defined $i;
|
|
if (@index) {
|
|
$id .= join '_', @index; # add instance number(s) to tag ID
|
|
unless ($$tagTablePtr{$id}) {
|
|
my $name = $$tagInfo{Name};
|
|
# embed indices at position of '1' in tag name
|
|
my $n = ($name =~ tr/1/#/);
|
|
for ($j=0; $j<$n; ++$j) {
|
|
my $idx = $index[$j] || '';
|
|
$name =~ s/#/$idx/;
|
|
}
|
|
# put remaining indices at end of tag name
|
|
for (; $j<@index; ++$j) {
|
|
$name .= '_' if $name =~ /\d$/;
|
|
$name .= $index[$j];
|
|
}
|
|
AddTagToTable($tagTablePtr, $id, { %$tagInfo, Name => $name });
|
|
}
|
|
$tagInfo = $et->GetTagInfo($tagTablePtr, $id) or next;
|
|
}
|
|
if (ref $val eq 'HASH') {
|
|
# extract tags from this dictionary
|
|
my ($table, $rootID, $rootName);
|
|
if ($$tagInfo{SubDirectory}) {
|
|
$table = GetTagTable($$tagInfo{SubDirectory}{TagTable});
|
|
} else {
|
|
$table = $tagTablePtr;
|
|
# use hash ID and Name as base for contained tags to avoid conflicts
|
|
$rootID = $id;
|
|
$rootName = $$tagInfo{Name};
|
|
}
|
|
$count += ExtractTags($et, $val, $table, $rootID, $rootName, @index);
|
|
} else {
|
|
# handle this simple tag value
|
|
$et->HandleTag($tagTablePtr, $id, $val);
|
|
++$count;
|
|
}
|
|
}
|
|
pop @index if defined $i;
|
|
}
|
|
return $count;
|
|
}
|
|
|
|
#------------------------------------------------------------------------------
|
|
# Process BitTorrent file
|
|
# Inputs: 0) ExifTool object reference, 1) dirInfo reference (with RAF set)
|
|
# Returns: 1 on success, 0 if this wasn't a valid BitTorrent file
|
|
sub ProcessTorrent($$)
|
|
{
|
|
my ($et, $dirInfo) = @_;
|
|
my $success = 0;
|
|
my $raf = $$dirInfo{RAF};
|
|
my $buff = '';
|
|
pos($buff) = 0;
|
|
my $dict = ReadBencode($raf, \$buff);
|
|
my $err = $$raf{BencodeError};
|
|
$et->Warn("Bencode error: $err") if $err;
|
|
if (ref $dict eq 'HASH' and $$dict{announce}) {
|
|
$et->SetFileType();
|
|
my $tagTablePtr = GetTagTable('Image::ExifTool::Torrent::Main');
|
|
ExtractTags($et, $dict, $tagTablePtr) and $success = 1;
|
|
}
|
|
return $success;
|
|
}
|
|
|
|
1; # end
|
|
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
Image::ExifTool::Torrent - Read information from BitTorrent file
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
This module is used by Image::ExifTool
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
This module contains definitions required by Image::ExifTool to read
|
|
bencoded information from BitTorrent files.
|
|
|
|
=head1 AUTHOR
|
|
|
|
Copyright 2003-2018, Phil Harvey (phil at owl.phy.queensu.ca)
|
|
|
|
This library is free software; you can redistribute it and/or modify it
|
|
under the same terms as Perl itself.
|
|
|
|
=head1 REFERENCES
|
|
|
|
=over 4
|
|
|
|
=item L<https://wiki.theory.org/BitTorrentSpecification>
|
|
|
|
=back
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<Image::ExifTool::TagNames/Torrent Tags>,
|
|
L<Image::ExifTool(3pm)|Image::ExifTool>
|
|
|
|
=cut
|
|
|