This series adds support for kernel TLS encryption over TCP sockets.
A standard TCP socket is converted to a TLS socket using a setsockopt.
Only symmetric crypto is done in the kernel, as well as TLS record
framing. The handshake remains in userspace, and the negotiated
cipher keys/iv are provided to the TCP socket.
We implemented support for this API in OpenSSL 1.1.0, the code is
available at https://github.com/Mellanox/tls-openssl/tree/master
It should work with any TLS library with similar modifications,
a test tool using gnutls is here: https://github.com/Mellanox/tls-af_ktls_tool
RFC patch to openssl:
https://mta.openssl.org/pipermail/openssl-dev/2017-June/009384.html
Changes from V2:
* EXPORT_SYMBOL_GPL in patch 1
* Ensure cleanup code always called before sk_stream_kill_queues to
avoid warnings
Changes from V1:
* EXPORT_SYMBOL GPL in patch 2
* Add link to OpenSSL patch & gnutls example in documentation patch.
* sk_write_pending check was rolled in to wait_for_memory path,
avoids special case and fixes lock inbalance issue.
* Unify flag handling for sendmsg/sendfile
Changes from RFC V2:
* Generic ULP (upper layer protocol) framework instead of TLS specific
setsockopts
* Dropped Mellanox hardware patches, will come as separate series.
Framework will work for both.
* Socket based on changing TCP proto_ops instead of crypto framework
* Merged code with Mellanox's hardware tls offload
* Zerocopy sendmsg support added - sendpage/sendfile is no longer
necessary for zerocopy optimization