##
## Generic data connection package
##
package Net::FTP::dataconn;
use 5.008001;
use strict;
use warnings;
use Carp;
use Errno;
use Net::Cmd;
our $VERSION = '3.13';
$Net::FTP::IOCLASS or die "please load Net::FTP before Net::FTP::dataconn";
our @ISA = $Net::FTP::IOCLASS;
sub reading {
my $data = shift;
${*$data}{'net_ftp_bytesread'} = 0;
}
sub abort {
my $data = shift;
my $ftp = ${*$data}{'net_ftp_cmd'};
# no need to abort if we have finished the xfer
return $data->close
if ${*$data}{'net_ftp_eof'};
# for some reason if we continuously open RETR connections and not
# read a single byte, then abort them after a while the server will
# close our connection, this prevents the unexpected EOF on the
# command channel -- GMB
if (exists ${*$data}{'net_ftp_bytesread'}
&& (${*$data}{'net_ftp_bytesread'} == 0))
{
my $buf = "";
my $timeout = $data->timeout;
$data->can_read($timeout) && sysread($data, $buf, 1);
}
${*$data}{'net_ftp_eof'} = 1; # fake
$ftp->abort; # this will close me
}
sub _close {
my $data = shift;
my $ftp = ${*$data}{'net_ftp_cmd'};
$data->SUPER::close();
delete ${*$ftp}{'net_ftp_dataconn'}
if defined $ftp
&& exists ${*$ftp}{'net_ftp_dataconn'}
&& $data == ${*$ftp}{'net_ftp_dataconn'};
}
sub close {
my $data = shift;
my $ftp = ${*$data}{'net_ftp_cmd'};
if (exists ${*$data}{'net_ftp_bytesread'} && !${*$data}{'net_ftp_eof'}) {
my $junk;
eval { local($SIG{__DIE__}); $data->read($junk, 1, 0) };
return $data->abort unless ${*$data}{'net_ftp_eof'};
}
$data->_close;
return unless defined $ftp;
$ftp->response() == CMD_OK
&& $ftp->message =~ /unique file name:\s*(\S*)\s*\)/
&& (${*$ftp}{'net_ftp_unique'} = $1);
$ftp->status == CMD_OK;
}
sub _select {
my ($data, $timeout, $do_read) = @_;
my ($rin, $rout, $win, $wout, $tout, $nfound);
vec($rin = '', fileno($data), 1) = 1;
($win, $rin) = ($rin, $win) unless $do_read;
while (1) {
$nfound = select($rout = $rin, $wout = $win, undef, $tout = $timeout);
last if $nfound >= 0;
croak "select: $!"
unless $!{EINTR};
}
$nfound;
}
sub can_read {
_select(@_[0, 1], 1);
}
sub can_write {
_select(@_[0, 1], 0);
}
sub cmd {
my $ftp = shift;
${*$ftp}{'net_ftp_cmd'};
}
sub bytes_read {
my $ftp = shift;
${*$ftp}{'net_ftp_bytesread'} || 0;
}
1;
__END__
=head1 NAME
Net::FTP::dataconn - FTP Client data connection class
=head1 SYNOPSIS
# Perform IO operations on an FTP client data connection object:
$num_bytes_read = $obj->read($buffer, $size);
$num_bytes_read = $obj->read($buffer, $size, $timeout);
$num_bytes_written = $obj->write($buffer, $size);
$num_bytes_written = $obj->write($buffer, $size, $timeout);
$num_bytes_read_so_far = $obj->bytes_read();
$obj->abort();
$closed_successfully = $obj->close();
=head1 DESCRIPTION
Some of the methods defined in C<Net::FTP> return an object which will
be derived from this class. The dataconn class itself is derived from
the C<IO::Socket::INET> class, so any normal IO operations can be performed.
However the following methods are defined in the dataconn class and IO should
be performed using these.
=over 4
=item C<read($buffer, $size[, $timeout])>
Read C<$size> bytes of data from the server and place it into C<$buffer>, also
performing any <CRLF> translation necessary. C<$timeout> is optional, if not
given, the timeout value from the command connection will be used.
Returns the number of bytes read before any <CRLF> translation.
=item C<write($buffer, $size[, $timeout])>
Write C<$size> bytes of data from C<$buffer> to the server, also
performing any <CRLF> translation necessary. C<$timeout> is optional, if not
given, the timeout value from the command connection will be used.
Returns the number of bytes written before any <CRLF> translation.
=item C<bytes_read()>
Returns the number of bytes read so far.
=item C<abort()>
Abort the current data transfer.
=item C<close()>
Close the data connection and get a response from the FTP server. Returns
I<true> if the connection was closed successfully and the first digit of
the response from the server was a '2'.
=back
=head1 EXPORTS
I<None>.
=head1 KNOWN BUGS
I<None>.
=head1 AUTHOR
Graham Barr E<lt>L<gbarr@pobox.com|mailto:gbarr@pobox.com>E<gt>.
Steve Hay E<lt>L<shay@cpan.org|mailto:shay@cpan.org>E<gt> is now maintaining
libnet as of version 1.22_02.
=head1 COPYRIGHT
Copyright (C) 1997-2010 Graham Barr. All rights reserved.
Copyright (C) 2013-2014, 2020 Steve Hay. All rights reserved.
=head1 LICENCE
This module is free software; you can redistribute it and/or modify it under the
same terms as Perl itself, i.e. under the terms of either the GNU General Public
License or the Artistic License, as specified in the F<LICENCE> file.
=head1 VERSION
Version 3.13
=head1 DATE
23 Dec 2020
=head1 HISTORY
See the F<Changes> file.
=cut
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