From: Alistair Francis <redacted>

The TLS 1.3 specification allows the TLS client or server to send a
KeyUpdate. This is generally used when the sequence is about to
overflow or after a certain amount of bytes have been encrypted.

The TLS spec doesn't mandate the conditions though, so a KeyUpdate
can be sent by the TLS client or server at any time. This includes
when running NVMe-OF over a TLS 1.3 connection.

As such Linux should be able to handle a KeyUpdate event, as the
other NVMe side could initiate a KeyUpdate.

Upcoming WD NVMe-TCP hardware controllers implement TLS support
and send KeyUpdate requests.

This series builds on top of the existing TLS EKEYEXPIRED work,
which already detects a KeyUpdate request. We can now pass that
information up to the NVMe layer (target and host) and then pass
it up to userspace.

Userspace (ktls-utils) will need to save the connection state
in the keyring during the initial handshake. The kernel then
provides the key serial back to userspace when handling a
KeyUpdate. Userspace can use this to restore the connection
information and then update the keys, this final process
is similar to the initial handshake.

Link: https://datatracker.ietf.org/doc/html/rfc8446#section-4.6.3

v2:
 - Change "key-serial" to "session-id"
 - Fix reported build failures
 - Drop tls_clear_err() function
 - Stop keep alive timer during KeyUpdate
 - Drop handshake message decoding in the NVMe layer

Alistair Francis (7):
  net/handshake: Store the key serial number on completion
  net/handshake: Make handshake_req_cancel public
  net/handshake: Expose handshake_sk_destruct_req publically
  nvmet: Expose nvmet_stop_keep_alive_timer publically
  net/handshake: Support KeyUpdate message types
  nvme-tcp: Support KeyUpdate
  nvmet-tcp: Support KeyUpdate

 Documentation/netlink/specs/handshake.yaml |  19 +++-
 Documentation/networking/tls-handshake.rst |   4 +-
 drivers/nvme/host/tcp.c                    |  88 +++++++++++++++--
 drivers/nvme/target/core.c                 |   1 +
 drivers/nvme/target/tcp.c                  | 104 +++++++++++++++++++--
 include/net/handshake.h                    |  17 +++-
 include/uapi/linux/handshake.h             |  14 +++
 net/handshake/genl.c                       |   5 +-
 net/handshake/handshake.h                  |   1 -
 net/handshake/request.c                    |  18 ++++
 net/handshake/tlshd.c                      |  46 +++++++--
 net/sunrpc/svcsock.c                       |   3 +-
 net/sunrpc/xprtsock.c                      |   3 +-
 13 files changed, 289 insertions(+), 34 deletions(-)

-- 
2.50.1