in reply to
Tunneling DBD::mysql connections over SSH without using external programs
Whereas Net::SSH::Perl seems the first natural choice, it looks like that module isn't ready for tunneling. Although there is a way to specify a number of options with the constructor,
"Net::SSH::Perl::Config understands a subset of the configuration directives that can live in these files; this subset matches up with the functionality that Net::SSH::Perl can support. Unknown keywords will simply be skipped."
LocalForward is _not_among the known options, so...
Other possible choices could be Net::SSH, Net::SSH2 or Net::SSH::Tunnel. However, these are just wrappers over the sytem-installed ssh and not pure Perl solutions, so if they 'hide the underlying system' enough or not for you remains your decision.
Maybe Net-OpenSSH-0.60 would work - but I haven't tried.