Those are needlessly complicated. You're replicating functions inet_aton and inet_ntoa of the core module Socket:

use Socket qw( inet_aton inet_ntoa );

sub DottedQuadToLong {
   # Accepts triton.littlefish.ca
   # Accepts 24.72.30.83
   # Accepts 407379539
   # etc
   return unpack('N', inet_aton(shift));
}

sub LongToDottedQuad {
   return inet_ntoa(pack('N', shift));
}
[download]

Here are alternatives that only use pack and unpack (but only accept addresses of the form a.b.c.d):

sub DottedQuadToLong {
   return unpack('N', (pack 'C4', split(/\./, shift)));
}

sub LongToDottedQuad {
   return join('.', unpack('C4', pack('N', shift)));
}
[download]