IPv6 in Perl

A lot of people are talking about IPv6 lately. And perhaps with good reason - it's been years in coming, but finally we're really starting to run out of IPv4 addresses. Tools like the IPv4 Address Report may put a certain amount of panic on things with their realtime Flash-based countdown widget, but the problem is real and does need sorting.

The latest development release of Perl; perl-5.13.9, now has full support for IPv6, and the new address handling functions specified in RFC 2553. The new functions all live in Socket.

As well as the low-level AF_INET6 constant, and the pack_sockaddr_in6 and unpack_sockaddr_in6 structure functions (already in place in 5.13.8 in fact), there is now the full set of getaddrinfo, getnameinfo and associated constants. These allow fully protocol-agnostic handling of connections and addresses. There is now enough in core to support IO::Socket::IP. This is a fully protocol-agnostic replacement of IO::Socket::INET.

use IO::Socket::IP;

my $sock = IO::Socket::IP->new(
   PeerHost    => "www.google.com",
   PeerService => "www",
) or die "Cannot construct socket - $@";

printf "Now connected to %s:%s\n", $sock->peerhost_service;

...

What could be simpler?

Perhaps now is the time to make a case for putting IO::Socket::IP itself in the core distribution, such that when perl-5.14.0 comes out, it will be properly ready for the next 30 years of the Internet?

IO::Socket::IP's API is designed to be a drop-in replacement for the IPv4-only IO::Socket::INET. Any program currently using INET ought to work exactly the same, by simply substituting IP instead, and now will also work on IPv6.

If you maintain a distribution that uses IO::Socket::INET, please try out IO::Socket::IP instead. I'd be very keen to hear from anyone who finds it doesn't JustWork in their situation.

See also my earlier post on the subject; Perl - IO::Socket::IP