handshake: Fix sign of key_serial_t fields

key_serial_t fields are signed integers. Use nla_get/put_s32 for
those to avoid implicit signed conversion in the netlink protocol.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/169530167716.8905.645746457741372879.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

handshake: Fix sign of socket file descriptor fields

Socket file descriptors are signed integers. Use nla_get/put_s32 for
those to avoid implicit signed conversion in the netlink protocol.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/169530165057.8905.8650469415145814828.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/handshake: Add API for sending TLS Closure alerts

This helper sends an alert only if a TLS session was established.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/169047936730.5241.618595693821012638.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/handshake: Enable the SNI extension to work properly

Enable the upper layer protocol to specify the SNI peername. This
avoids the need for tlshd to use a DNS lookup, which can return a
hostname that doesn't match the incoming certificate's SubjectName.

Fixes: 2fd5532044a8 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/handshake: Enable the SNI extension to work properly

Enable the upper layer protocol to specify the SNI peername. This
avoids the need for tlshd to use a DNS lookup, which can return a
hostname that doesn't match the incoming certificate's SubjectName.

Fixes: 2fd5532044a8 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/handshake: Add Kunit tests for the handshake consumer API

These verify the API contracts and help exercise lifetime rules for
consumer sockets and handshake_req structures.

One way to run these tests:

./tools/testing/kunit/kunit.py run --kunitconfig ./net/handshake/.kunitconfig

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/handshake: Add a kernel API for requesting a TLSv1.3 handshake

To enable kernel consumers of TLS to request a TLS handshake, add
support to net/handshake/ to request a handshake upcall.

This patch also acts as a template for adding handshake upcall
support for other kernel transport layer security providers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>