Apache uses custom BIO classes to manage socket I/O on connections
using SSL via OpenSSL. These custom BIO classes contain a ctrl
method which should return 0 for unknown requests. However, the
custom BIO classes in Apache were returning non-zero values for
unknown requests. This resulted in OpenSSL believing that BIOs
were using KTLS when they were not.
Note that Apache will not take advantage of KTLS currently since
it does not use OpenSSL's built-in BIO classes for sockets.