File Coverage

blib/lib/POE/Component/IRC/Plugin/DCC.pm

Criterion	Covered	Total	%
statement	234	291	80.4
branch	80	118	67.8
condition	13	27	48.1
subroutine	31	32	96.8
pod	4	8	50.0
total	362	476	76.0

package POE::Component::IRC::Plugin::DCC;
our $AUTHORITY = 'cpan:HINRIK';
$POE::Component::IRC::Plugin::DCC::VERSION = '6.92';
use strict;
use warnings FATAL => 'all';
use Carp;
use File::Basename qw(fileparse);
use File::Glob ':glob';
use File::Spec::Functions 'rel2abs';
use POE qw(Driver::SysRW Filter::Line Filter::Stream
           Wheel::ReadWrite Wheel::SocketFactory);
use POE::Component::IRC::Plugin qw(:ALL);
use Socket qw(INADDR_ANY unpack_sockaddr_in inet_aton inet_ntoa);

use constant {
    OUT_BLOCKSIZE  => 1024,   # Send DCC data in 1k chunks
    IN_BLOCKSIZE   => 10_240, # 10k per DCC socket read
    LISTEN_TIMEOUT => 300,    # Five minutes for listening DCCs
};

sub new {
    my ($package) = shift;
    croak "$package requires an even number of arguments" if @_ & 1;
    my %self = @_;
    return bless \%self, $package;
}

sub PCI_register {
    my ($self, $irc) = @_;

    $self->{irc} = $irc;

    POE::Session->create(
        object_states => [
            $self => [qw(
                _start
                _dcc_read
                _dcc_failed
                _dcc_timeout
                _dcc_up
                _U_dcc
                _U_dcc_accept
                _U_dcc_chat
                _U_dcc_close
                _U_dcc_resume
                _cancel_timeout
            )],
        ],
    );

    $irc->plugin_register($self, 'SERVER', qw(disconnected dcc_request));
    $irc->plugin_register($self, 'USER', qw(dcc dcc_accept dcc_chat dcc_close dcc_resume));

    return 1;
}

sub PCI_unregister {
    my ($self) = @_;
    delete $self->{irc};
    delete $self->{$_} for qw(wheelmap dcc);
    $poe_kernel->refcount_decrement($self->{session_id}, __PACKAGE__);
    return 1;
}

sub _start {
    my ($kernel, $self) = @_[KERNEL, OBJECT];
    $self->{session_id} = $_[SESSION]->ID();
    $kernel->refcount_increment($self->{session_id}, __PACKAGE__);
    return;
}

# set the dcc ports
sub dccports {
    my ($self, $value) = @_;
    $self->{dccports} = $value;
    return;
}

# set the NAT address
sub nataddr {
    my ($self, $value) = @_;
    $self->{nataddr} = $value;
    return;
}

# returns information about a connection
sub dcc_info {
    my ($self, $id) = @_;

    if (!$self->{dcc}->{$id}) {
        warn "dcc_info: Unknown wheel ID: $id\n";
        return;
    }

    my %info;
    @info{qw(nick type port file size done peeraddr)}
        = @{ $self->{dcc}->{$id} }{qw(
            nick type port file size done peeraddr
        )};
    return \%info;
}

sub _quote_file {
    my ($file) = @_;

    if ($file =~ /[\s"]/) {
        $file =~ s|"|\\"|g;
        $file = qq{"$file"};
    }
    return $file;
}

sub S_disconnected {
    my ($self) = $_;
    # clean up old cookies for any ignored RESUME requests
    delete $self->{resuming};
    return PCI_EAT_NONE;
}

sub S_dcc_request {
    my ($self, $irc) = splice @_, 0, 2;
    my ($user, $type, $port, $cookie, $file, $size) = map { ref =~ /REF|SCALAR/ && ${ $_ } } @_;
    my $nick = (split /!/, $user)[0];

    if ($type eq 'ACCEPT' && $self->{resuming}->{"$port+$nick"}) {
        # the old cookie has the peer's address
        my $old_cookie = delete $self->{resuming}->{"$port+$nick"};
        $irc->yield(dcc_accept => $old_cookie);
    }
    elsif ($type eq 'RESUME') {
        for my $cookie (values %{ $self->{dcc} }) {
            next if $cookie->{nick} ne $nick;
            next if $cookie->{port} ne $port;
            $file = _quote_file($file);
            $cookie->{done} = $size;
            $irc->yield(ctcp => $nick => "DCC ACCEPT $file $port $size");
            last;
        }
    }

    return PCI_EAT_NONE;
}

# this is a stub handler for all U_dcc* events which redispatches them as
# events to our own POE session so that we can do stuff related to it,
# namely create wheels and set alarms/delays
sub _default {
    my ($self, $irc, $event) = splice @_, 0, 3;
    return PCI_EAT_NONE if $event !~ /^U_dcc(?:_accept|_chat|_close|_resume)?$/;
    $event =~ s/^U_/_U_/;
    pop @_;
    my @args = map { $$_ } @_;
    $poe_kernel->call($self->{session_id}, $event, @args);
    return PCI_EAT_NONE;
}

# Attempt to initiate a DCC SEND or CHAT connection with another person.
sub _U_dcc {
    my ($kernel, $self, $nick, $type, $file, $blocksize, $timeout)
        = @_[KERNEL, OBJECT, ARG0..$#_];

    if (!defined $type) {
        warn "The 'dcc' command requires at least two arguments\n";
        return;
    }

    my $irc = $self->{irc};
    my ($bindport, $bindaddr, $factory, $port, $addr, $size);

    $type = uc $type;
    if ($type eq 'CHAT') {
        $file = 'chat';   # As per the semi-specification
    }
    elsif ($type eq 'SEND') {
        if (!defined $file) {
            warn "The 'dcc' command requires three arguments for a SEND\n";
            return;
        }
        $file = rel2abs(bsd_glob($file));
        $size = (stat $file)[7];
        if (!defined $size) {
            $irc->send_event(
                'irc_dcc_error',
                undef,
                "Couldn't get ${file}'s size: $!",
                $nick,
                $type,
                undef,
                $file,
            );
            return;
        }
    }

    $bindaddr = $irc->localaddr();

    if ($self->{dccports}) {
        $bindport = shift @{ $self->{dccports} };
        if (!defined $bindport) {
          warn "dcc: Can't allocate listen port for DCC $type\n";
          return;
        }
    }

    $factory = POE::Wheel::SocketFactory->new(
        BindAddress  => $bindaddr || INADDR_ANY,
        BindPort     => $bindport,
        SuccessEvent => '_dcc_up',
        FailureEvent => '_dcc_failed',
        Reuse        => 'yes',
    );

    ($port, $addr) = unpack_sockaddr_in($factory->getsockname());
    $addr = inet_aton($self->{nataddr}) if $self->{nataddr};

    if (!defined $addr) {
        warn "dcc: Can't determine our IP address! ($!)\n";
        return;
    }
    $addr = unpack 'N', $addr;

    my $basename = fileparse($file);
    $basename = _quote_file($basename);

    # Tell the other end that we're waiting for them to connect.
    $irc->yield(ctcp => $nick => "DCC $type $basename $addr $port" . ($size ? " $size" : ''));

    my $alarm_id = $kernel->delay_set(
        '_dcc_timeout', ($timeout || LISTEN_TIMEOUT), $factory->ID,
    );

    # Store the state for this connection.
    $self->{dcc}->{ $factory->ID } = {
        open      => 0,
        nick      => $nick,
        type      => $type,
        file      => $file,
        size      => $size,
        port      => $port,
        addr      => $addr,
        done      => 0,
        blocksize => ($blocksize || OUT_BLOCKSIZE),
        listener  => 1,
        factory   => $factory,
        alarm_id  => $alarm_id,
    };

    return;
}

# Accepts a proposed DCC connection to another client. See '_dcc_up' for
# the rest of the logic for this.
sub _U_dcc_accept {
    my ($self, $cookie, $myfile) = @_[OBJECT, ARG0, ARG1];

    if (!defined $cookie) {
        warn "The 'dcc_accept' command requires at least one argument\n";
        return;
    }

    if ($cookie->{type} eq 'SEND') {
        $cookie->{type} = 'GET';
        $cookie->{file} = $myfile if defined $myfile;   # filename override
    }

    my $factory = POE::Wheel::SocketFactory->new(
        RemoteAddress => sprintf("%vd", pack("N", $cookie->{addr})),
        RemotePort    => $cookie->{port},
        SuccessEvent  => '_dcc_up',
        FailureEvent  => '_dcc_failed',
    );

    $self->{dcc}->{$factory->ID} = $cookie;
    $self->{dcc}->{$factory->ID}->{factory} = $factory;

    return;
}

# Send data over a DCC CHAT connection.
sub _U_dcc_chat {
    my ($self, $id, @data) = @_[OBJECT, ARG0..$#_];

    if (!defined $id || !@data) {
        warn "The 'dcc_chat' command requires at least two arguments\n";
        return;
    }

    if (!exists $self->{dcc}->{$id}) {
        warn "dcc_chat: Unknown wheel ID: $id\n";
        return;
    }

    if (!exists $self->{dcc}->{$id}->{wheel}) {
        warn "dcc_chat: No DCC wheel for id $id!\n";
        return;
    }

    if ($self->{dcc}->{$id}->{type} ne 'CHAT') {
        warn "dcc_chat: id $id isn't associated with a DCC CHAT connection!\n";
        return;
    }

    $self->{dcc}->{$id}->{wheel}->put(join "\n", @data);
    return;
}

# Terminate a DCC connection manually.
sub _U_dcc_close {
    my ($kernel, $self, $id) = @_[KERNEL, OBJECT, ARG0];
    my $irc = $self->{irc};

    if (!defined $id) {
        warn "The 'dcc_close' command requires an id argument\n";
        return;
    }

    if (!exists $self->{dcc}->{$id}) {
        warn "dcc_close: Unknown wheel ID: $id\n";
        return;
    }

    if (!exists $self->{dcc}->{$id}->{wheel}) {
        warn "dcc_close: No DCC wheel for id $id!\n";
        return;
    }

    # pending data, wait till it has been flushed
    if ($self->{dcc}->{$id}->{wheel}->get_driver_out_octets()) {
        $kernel->delay_set(_U_dcc_close => 2, $id);
        return;
    }

    $irc->send_event(
        'irc_dcc_done',
        $id,
        @{ $self->{dcc}->{$id} }{qw(
            nick type port file size done peeraddr
        )},
    );

    # Reclaim our port if necessary.
    if ($self->{dcc}->{$id}->{listener} && $self->{dccports}) {
        push ( @{ $self->{dccports} }, $self->{dcc}->{$id}->{port} );
    }

    $self->_remove_dcc($id);
    return;
}

## no critic (InputOutput::RequireBriefOpen)
sub _U_dcc_resume {
    my ($self, $cookie, $myfile) = @_[OBJECT, ARG0, ARG1];
    my $irc = $self->{irc};

    my $sender_file = _quote_file($cookie->{file});
    $cookie->{file} = $myfile if defined $myfile;
    $cookie->{done} = -s $cookie->{file};
    $cookie->{resuming} = 1;

    if (open(my $handle, '>>', $cookie->{file})) {
        $irc->yield(ctcp => $cookie->{nick} => "DCC RESUME $sender_file $cookie->{port} $cookie->{done}");
        $self->{resuming}->{"$cookie->{port}+$cookie->{nick}"} = $cookie;
    }
    else {
        warn "dcc_resume: Can't append to file '$cookie->{file}'\n";
        return;
    }

    return;
}

# Accept incoming data on a DCC socket.
sub _dcc_read {
    my ($kernel, $self, $data, $id) = @_[KERNEL, OBJECT, ARG0, ARG1];
    my $irc = $self->{irc};

    $id = $self->{wheelmap}->{$id};
    if ($self->{dcc}{$id}{alarm_id}) {
        $kernel->call($self->{session_id}, '_cancel_timeout', $id);
    }

    if ($self->{dcc}->{$id}->{type} eq 'GET') {
        # Acknowledge the received data.
        print {$self->{dcc}->{$id}->{fh}} $data;
        $self->{dcc}->{$id}->{done} += length $data;
        $self->{dcc}->{$id}->{wheel}->put(
            pack 'N', $self->{dcc}->{$id}->{done}
        );

        # Send an event to let people know about the newly arrived data.
        $irc->send_event(
            'irc_dcc_get',
            $id,
            @{ $self->{dcc}->{$id} }{qw(
                nick port file size done peeraddr
            )},
        );
    }
    elsif ($self->{dcc}->{$id}->{type} eq 'SEND') {
        # Record the client's download progress.
        $self->{dcc}->{$id}->{done} = unpack 'N', substr( $data, -4 );

        $irc->send_event(
            'irc_dcc_send',
            $id,
            @{ $self->{dcc}->{$id} }{qw(
                nick port file size done peeraddr
            )},
        );

        # Are we done yet?
        if ($self->{dcc}->{$id}->{done} >= $self->{dcc}->{$id}->{size}) {
            # Reclaim our port if necessary.
            if ( $self->{dcc}->{$id}->{listener} && $self->{dccports}) {
                push @{ $self->{dccports} }, $self->{dcc}->{$id}->{port};
            }

            $irc->send_event(
                'irc_dcc_done',
                $id,
                @{ $self->{dcc}->{$id} }{qw(
                    nick type port file size done peeraddr
                )},
            );

            $self->_remove_dcc($id);
            return;
        }

        # Send the next 'blocksize'-sized packet.
        read $self->{dcc}->{$id}->{fh}, $data,
            $self->{dcc}->{$id}->{blocksize};
        $self->{dcc}->{$id}->{wheel}->put( $data );
    }
    else {
        $irc->send_event(
            'irc_dcc_' . lc $self->{dcc}->{$id}->{type},
            $id,
            @{ $self->{dcc}->{$id} }{qw(nick port)},
            $data,
            $self->{dcc}->{$id}->{peeraddr},
        );
    }

    return;
}

# What happens when an attempted DCC connection fails.
sub _dcc_failed {
    my ($self, $operation, $errnum, $errstr, $id) = @_[OBJECT, ARG0 .. ARG3];
    my $irc = $self->{irc};

    if (!exists $self->{dcc}->{$id}) {
        if (exists $self->{wheelmap}->{$id}) {
            $id = $self->{wheelmap}->{$id};
        }
        else {
            warn "_dcc_failed: Unknown wheel ID: $id\n";
            return;
        }
    }

    # Reclaim our port if necessary.
    if ( $self->{dcc}->{$id}->{listener} && $self->{dccports}) {
        push ( @{ $self->{dccports} }, $self->{dcc}->{$id}->{port} );
    }

    DCC: {
        last DCC if $errnum != 0;

        # Did the peer of a DCC GET connection close the socket after the file
        # transfer finished? If so, it's not really an error.
        if ($self->{dcc}->{$id}->{type} eq 'GET') {
            if ($self->{dcc}->{$id}->{done} < $self->{dcc}->{$id}->{size}) {
                last DCC;
            }
        }

        if ($self->{dcc}->{$id}->{type} =~ /^(GET|CHAT)$/) {
            $irc->send_event(
                'irc_dcc_done',
                $id,
                @{ $self->{dcc}->{$id} }{qw(
                    nick type port file size done peeraddr
                )},
            );

            $self->_remove_dcc($id);
        }

        return;
    }

    # something went wrong
    if ($errnum == 0 && $self->{dcc}->{$id}->{type} eq 'GET') {
        $errstr = 'Aborted by sender';
    }
    else {
        $errstr = $errstr
            ? $errstr = "$operation error $errnum: $errstr"
            : $errstr = "$operation error $errnum"
        ;
    }

    $irc->send_event(
        'irc_dcc_error',
        $id,
        $errstr,
        @{ $self->{dcc}->{$id} }{qw(
            nick type port file size done peeraddr
        )},
    );

    $self->_remove_dcc($id);
    return;
}

# What happens when a DCC connection sits waiting for the other end to
# pick up the phone for too long.
sub _dcc_timeout {
    my ($kernel, $self, $id) = @_[KERNEL, OBJECT, ARG0];

    if (exists $self->{dcc}->{$id} && !$self->{dcc}->{$id}->{open}) {
        $kernel->yield(
            '_dcc_failed',
            'connection',
            0,
            'DCC connection timed out',
            $id,
        );
    }
    return;
}

# This event occurs when a DCC connection is established.
## no critic (InputOutput::RequireBriefOpen)
sub _dcc_up {
    my ($kernel, $self, $sock, $peeraddr, $id) =
        @_[KERNEL, OBJECT, ARG0, ARG1, ARG3];
    my $irc = $self->{irc};

    # Delete the listening socket and monitor the accepted socket
    # for incoming data
    delete $self->{dcc}->{$id}->{factory};
    $self->{dcc}->{$id}->{open} = 1;
    $self->{dcc}->{$id}->{peeraddr} = inet_ntoa($peeraddr);

    $self->{dcc}->{$id}->{wheel} = POE::Wheel::ReadWrite->new(
        Handle => $sock,
        Driver => ($self->{dcc}->{$id}->{type} eq 'GET'
            ? POE::Driver::SysRW->new( BlockSize => IN_BLOCKSIZE )
            : POE::Driver::SysRW->new()
        ),
        Filter => ($self->{dcc}->{$id}->{type} eq 'CHAT'
            ? POE::Filter::Line->new( Literal => "\012" )
            : POE::Filter::Stream->new()
        ),
        InputEvent => '_dcc_read',
        ErrorEvent => '_dcc_failed',
    );

    $self->{wheelmap}->{ $self->{dcc}->{$id}->{wheel}->ID } = $id;

    my $handle;
    if ($self->{dcc}->{$id}->{type} eq 'GET') {
        # check if we're resuming
        my $mode = $self->{dcc}->{$id}->{resuming} ? '>>' : '>';

        if ( !open $handle, $mode, $self->{dcc}->{$id}->{file} ) {
            $kernel->yield(_dcc_failed => 'open file', $! + 0, $!, $id);
            return;
        }

        binmode $handle;
        $self->{dcc}->{$id}->{fh} = $handle;
    }
    elsif ($self->{dcc}->{$id}->{type} eq 'SEND') {
        if (!open $handle, '<', $self->{dcc}->{$id}->{file}) {
            $kernel->yield(_dcc_failed => 'open file', $! + 0, $!, $id);
            return;
        }

        binmode $handle;
        seek $handle, $self->{dcc}{$id}{done}, 0;
        # Send the first packet to get the ball rolling.
        read $handle, my $buffer, $self->{dcc}->{$id}->{blocksize};
        $self->{dcc}->{$id}->{wheel}->put($buffer);
        $self->{dcc}->{$id}->{fh} = $handle;
    }

    # Tell any listening sessions that the connection is up.
    $irc->send_event(
        'irc_dcc_start',
        $id,
        @{ $self->{dcc}->{$id} }{qw(
            nick type port file size peeraddr
        )},
    );

    return;
}

sub _cancel_timeout {
    my ($kernel, $self, $id) = @_[KERNEL, OBJECT, ARG0];
    my $alarm_id = delete $self->{dcc}{$id}{alarm_id};
    $kernel->alarm_remove($alarm_id);
    return;
}

sub _remove_dcc {
    my ($self, $id) = @_;

    if (exists $self->{dcc}{$id}{alarm_id}) {
        $poe_kernel->call($self->{session_id}, '_cancel_timeout', $id);
    }

    if (exists $self->{dcc}{$id}{wheel}) {
        delete $self->{wheelmap}{ $self->{dcc}{$id}{wheel}->ID };
        if ($^O =~ /cygwin|MSWin/) {
          $self->{dcc}{$id}{wheel}->$_ for qw(shutdown_input shutdown_output);
        }
    }

    # flush the filehandle
    close $self->{dcc}{$id}{fh} if $self->{dcc}{$id}{type} eq 'GET';

    delete $self->{dcc}{$id};
    return;
}

1;

=encoding utf8

=head1 NAME

POE::Component::IRC::Plugin::DCC - A PoCo-IRC plugin providing support for
DCC transfers

=head1 SYNOPSIS

 # send a file
 my $file = '/home/user/secret.pdf';
 my $recipient = 'that_guy';
 $irc->yield(dcc => $recipient => SEND => $file);

 # receive a file
 sub irc_dcc_request {
     my ($user, $type, $port, $cookie, $file, $size, $addr) = @_[ARG0..$#_];
     return if $type ne 'SEND';

     my $irc = $_[SENDER]->get_heap();
     my $nick = (split /!/, $user)[0];

     print "$nick wants to send me '$file' ($size bytes) from $addr:$port\n");
     $irc->yield(dcc_accept => $cookie);
 }

=head1 DESCRIPTION

This plugin provides the IRC commands needed to make use of DCC. It is used
internally by L so there's no
need to add it manually.

=head1 METHODS

=head2 C

Takes no arguments.

Returns a plugin object suitable for feeding to
L's C method.

=head2 C

Sets the TCP ports that can be used for DCC sends. Takes one argument,
an arrayref containing the port numbers.

=head2 C

Sets the public NAT address to be used for DCC sends.

=head2 C

Takes one argument, a DCC connection id (see below). Returns a hash of
information about the connection. The keys are: B<'nick'>, B<'type'>,
B<'port'>, B<'file'>, B<'size'>, B<'done,'>, and B<'peeraddr'>.

=head1 COMMANDS

The plugin responds to the following
L commands.

=head2 C

Send a DCC SEND or CHAT request to another person. Takes at least two
arguments: the nickname of the person to send the request to and the type
of DCC request (SEND or CHAT). For SEND requests, be sure to add a third
argument for the filename you want to send. Optionally, you can add a fourth
argument for the DCC transfer blocksize, but the default of 1024 should
usually be fine. The fifth (and optional) argument is the request timeout
value in seconds (default: 300).

Incidentally, you can send other weird nonstandard kinds of DCCs too;
just put something besides 'SEND' or 'CHAT' (say, 'FOO') in the type
field, and you'll get back C events (with the same arguments as
L|/irc_dcc_chat>) when data arrives on its DCC connection.

If you are behind a firewall or Network Address Translation, you may want to
consult L's
L|POE::Component::IRC/spawn> for some parameters that are
useful with this command.

=head2 C

Accepts an incoming DCC connection from another host. First argument:
the magic cookie from an L|/irc_dcc_request> event.
In the case of a DCC GET, the second argument can optionally specify a
new name for the destination file of the DCC transfer, instead of using
the sender's name for it. (See the L|/irc_dcc_request>
section below for more details.)

=head2 C

Resumes a DCC SEND file transfer. First argument: the magic cookie from an
L|/irc_dcc_request> event. An optional second argument
provides the name of the file to which you want to write.

=head2 C

Sends lines of data to the person on the other side of a DCC CHAT connection.
The first argument should be the wheel id of the connection which you got
from an L|/irc_dcc_start> event, followed by all the data
you wish to send (it'll be separated with newlines for you).

=head2 C

Terminates a DCC SEND or GET connection prematurely, and causes DCC CHAT
connections to close gracefully. Takes one argument: the wheel id of the
connection which you got from an L|/irc_dcc_start>
(or similar) event.

=head1 OUTPUT EVENTS

=head2 C

B This event is actually emitted by
L, but documented here
to keep all the DCC documentation in one place. In case you were wondering.

You receive this event when another IRC client sends you a DCC
(e.g. SEND or CHAT) request out of the blue. You can examine the request
and decide whether or not to accept it (with L|/dcc_accept>)
here. In the case of DCC SENDs, you can also request to resume the file with
L|/dcc_resume>.

B DCC doesn't provide a way to explicitly reject requests, so if you
don't intend to accept one, just ignore it or send a
L or L
to the peer explaining why you're not going to accept.

=over 4

=item * C: the peer's nick!user@host

=item * C: the DCC type (e.g. 'CHAT' or 'SEND')

=item * C: the port which the peer is listening on

=item * C: this connection's "magic cookie"

=item * C: the file name (SEND only)

=item * C: the file size (SEND only)

=item * C: the IP address which the peer is listening on

=back

=head2 C

This event notifies you that a DCC connection has been successfully
established.

=over 4

=item * C: the connection's wheel id

=item * C: the peer's nickname

=item * C: the DCC type

=item * C: the port number

=item * C: the file name (SEND/GET only)

=item * C: the file size (SEND/GET only)

=item * C: the peer's IP address

=back

=head2 C

Notifies you that one line of text has been received from the
client on the other end of a DCC CHAT connection.

=over 4

=item * C: the connection's wheel id

=item * C: the peer's nickname

=item * C: the port number

=item * C: the text they sent

=item * C: the peer's IP address

=back

=head2 C

Notifies you that another block of data has been successfully
transferred from the client on the other end of your DCC GET connection.

=over 4

=item * C: the connection's wheel id

=item * C: the peer's nickname

=item * C: the port number

=item * C: the file name

=item * C: the file size

=item * C: transferred file size

=item * C: the peer's IP address

=back

=head2 C

Notifies you that another block of data has been successfully
transferred from you to the client on the other end of a DCC SEND
connection.

=over 4

=item * C: the connection's wheel id

=item * C: the peer's nickname

=item * C: the port number

=item * C: the file name

=item * C: the file size

=item * C: transferred file size

=item * C: the peer's IP address

=back

=head2 C

You receive this event when a DCC connection terminates normally.
Abnormal terminations are reported by L|/irc_dcc_error>.

=over 4

=item * C: the connection's wheel id

=item * C: the peer's nickname

=item * C: the DCC type

=item * C: the port number

=item * C: the filename (SEND/GET only)

=item * C: file size (SEND/GET only)

=item * C: transferred file size (SEND/GET only)

=item * C: the peer's IP address

=back

=head2 C

You get this event whenever a DCC connection or connection attempt
terminates unexpectedly or suffers some fatal error. Some of the
following values might be undefined depending the stage at which
the connection/attempt failed.

=over 4

=item * C: the connection's wheel id

=item * C: the error string

=item * C: the peer's nickname

=item * C: the DCC type

=item * C: the port number

=item * C: the file name

=item * C: file size in bytes

=item * C: transferred file size in bytes

=item * C: the peer's IP address

=back

=head1 AUTHOR

Dennis 'C' Taylor and Hinrik Ern SigurEsson, [e-mail]

=cut