daemon: favor Socket.pm in Perl 5.14+ for IPv6

Users on Perl 5.14+ are common, so we can try the bundled Socket
(not "Socket6") module before attempting Socket6 for IPv6.

1 files changed, 14 insertions, 7 deletions

diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index 033dd98a..48051f48 100644
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -236,16 +236,23 @@ sub sockname ($) {
 
 sub unpack_ipv6 ($) {
         my ($addr) = @_;
+        my ($port, $host);
 
-        # TODO: support IO::Socket::IP which comes with Perl 5.24
-        # (perl-modules-5.24 in Debian)
+        # Socket.pm in Perl 5.14+ supports IPv6:
+        eval {
+                ($port, $host) = Socket::unpack_sockaddr_in6($addr);
+                $host = Socket::inet_ntop(Socket::AF_INET6(), $host);
+        };
 
-        # SpamAssassin and Net::Server use Socket6, so it may be installed
-        # on our system, already (otherwise die):
-        require Socket6;
+        if ($@) {
+                # Perl 5.12 or earlier?  SpamAssassin and Net::Server use
+                # Socket6, so it may be installed on our system, already
+                # (otherwise die here):
+                require Socket6;
 
-        my ($port, $host) = Socket6::unpack_sockaddr_in6($addr);
-        $host = Socket6::inet_ntop(Socket6::AF_INET6(), $host);
+                ($port, $host) = Socket6::unpack_sockaddr_in6($addr);
+                $host = Socket6::inet_ntop(Socket6::AF_INET6(), $host);
+        }
         ($host, $port);
 }