The Perl Toolchain Summit 2025 Needs You: You can help 🙏 Learn more

#!/usr/bin/perl
use strict;
use Socket qw(PF_INET6 PF_INET IPPROTO_IPV6 IPV6_V6ONLY);
eval { IO::Socket::IP->new( LocalHost => "::1" ) } or
plan skip_all => "Unable to bind to ::1";
eval { defined IPV6_V6ONLY } or
plan skip_all => "IPV6_V6ONLY not available";
# Don't be locale-sensitive
$! = Errno::ECONNREFUSED;
my $ECONNREFUSED_STR = "$!";
{
my $listensock = IO::Socket::IP->new(
Listen => 1,
Family => PF_INET6,
LocalPort => 0,
Type => SOCK_STREAM,
V6Only => 1,
) or die "Cannot listen on PF_INET6 - $@";
is( $listensock->getsockopt( IPPROTO_IPV6, IPV6_V6ONLY ), 1, 'IPV6_V6ONLY is 1 on $listensock' );
my $testsock = IO::Socket::IP->new(
Family => PF_INET,
PeerHost => "127.0.0.1",
PeerPort => $listensock->sockport,
Type => SOCK_STREAM,
);
my $err = "$@";
ok( !defined $testsock, 'Unable to connect PF_INET socket to PF_INET6 socket with V6Only true' );
like( $err, qr/\Q$ECONNREFUSED_STR/, 'Socket creation fails with connection refused' );
}
SKIP: {
skip "This platform does not allow turning IPV6_V6ONLY off", 3 unless IO::Socket::IP->CAN_DISABLE_V6ONLY;
local $ENV{LANG} = "C"; # avoid locale-dependent error messages
my $listensock = IO::Socket::IP->new(
Listen => 1,
Family => PF_INET6,
LocalPort => 0,
Type => SOCK_STREAM,
V6Only => 0,
) or die "Cannot listen on PF_INET6 - $@";
is( $listensock->getsockopt( IPPROTO_IPV6, IPV6_V6ONLY ), 0, 'IPV6_V6ONLY is 0 on $listensock' );
my $testsock = IO::Socket::IP->new(
Family => PF_INET,
PeerHost => "127.0.0.1",
PeerPort => $listensock->sockport,
Type => SOCK_STREAM,
);
my $err = "$@";
ok( defined $testsock, 'Connected PF_INET socket to PF_INET6 socket with V6Only false' ) or
diag( "IO::Socket::IP->new failed - $err" );
is( $testsock->peerport, $listensock->sockport, 'Test socket connected to correct peer port' );
}
done_testing;