## ## Generic data connection package ## package Net::FTP::dataconn; use 5.008001; use strict; use warnings; use Carp; use Errno; use Net::Cmd; our $VERSION = '3.15'; $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 = $obj->close(); =head1 DESCRIPTION Some of the methods defined in C return an object which will be derived from this class. The dataconn class itself is derived from the C class, so any normal IO operations can be performed. However the following methods are defined in the dataconn class and IO should be performed using these. =over 4 =item C Read C<$size> bytes of data from the server and place it into C<$buffer>, also performing any translation necessary. C<$timeout> is optional, if not given, the timeout value from the command connection will be used. Returns the number of bytes read before any translation. =item C Write C<$size> bytes of data from C<$buffer> to the server, also performing any 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 translation. =item C Returns the number of bytes read so far. =item C Abort the current data transfer. =item C Close the data connection and get a response from the FTP server. Returns I if the connection was closed successfully and the first digit of the response from the server was a '2'. =back =head1 EXPORTS I. =head1 KNOWN BUGS I. =head1 AUTHOR Graham Barr ELE. Steve Hay ELE 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 file. =head1 VERSION Version 3.15 =head1 DATE 20 March 2023 =head1 HISTORY See the F file. =cut