From: Alistair Francis <redacted>

When reporting the msg-type to userspace let's also support reporting
KeyUpdate events. This supports reporting a client/server event and if
the other side requested a KeyUpdateRequest.

Link: https://datatracker.ietf.org/doc/html/rfc8446#section-4.6.3
Signed-off-by: Alistair Francis <redacted>
---
v3:
  - Fixup yamllint and kernel-doc failures

  Documentation/netlink/specs/handshake.yaml | 16 +++++++++-
  Documentation/networking/tls-handshake.rst |  4 +--
  drivers/nvme/host/tcp.c                    | 12 ++++++--
  drivers/nvme/target/tcp.c                  | 11 +++++--
  include/net/handshake.h                    | 10 +++++--
  include/uapi/linux/handshake.h             | 13 +++++++++
  net/handshake/tlshd.c                      | 34 ++++++++++++++++++----
  7 files changed, 84 insertions(+), 16 deletions(-)

diff --git a/Documentation/netlink/specs/handshake.yaml b/Documentation/netlink/specs/handshake.yaml
index a273bc74d26f..c72ec8fa7d7a 100644
--- a/Documentation/netlink/specs/handshake.yaml
+++ b/Documentation/netlink/specs/handshake.yaml

@@ -21,12 +21,18 @@ definitions:
      type: enum
      name: msg-type
      value-start: 0
-    entries: [unspec, clienthello, serverhello]
+    entries: [unspec, clienthello, serverhello, clientkeyupdate,
+              clientkeyupdaterequest, serverkeyupdate, serverkeyupdaterequest]
    -
      type: enum
      name: auth
      value-start: 0
      entries: [unspec, unauth, psk, x509]
+  -
+    type: enum
+    name: key-update-type
+    value-start: 0
+    entries: [unspec, send, received, received_request_update]
  
  attribute-sets:
    -

@@ -74,6 +80,13 @@ attribute-sets:
        -
          name: keyring
          type: u32
+      -
+        name: key-update-request
+        type: u32
+        enum: key-update-type
+      -
+        name: key-serial
+        type: u32
    -
      name: done
      attributes:

@@ -116,6 +129,7 @@ operations:
              - certificate
              - peername
              - keyring
+            - key-serial
      -
        name: done
        doc: Handler reports handshake completion

diff --git a/Documentation/networking/tls-handshake.rst b/Documentation/networking/tls-handshake.rst
index d7287890056a..f858011e5bfb 100644
--- a/Documentation/networking/tls-handshake.rst
+++ b/Documentation/networking/tls-handshake.rst

@@ -110,7 +110,7 @@ To initiate a client-side TLS handshake with a pre-shared key, use:
  
  .. code-block:: c
  
-  ret = tls_client_hello_psk(args, gfp_flags);
+  ret = tls_client_hello_psk(args, gfp_flags, handshake_key_update_type);
  
  However, in this case, the consumer fills in the @ta_my_peerids array
  with serial numbers of keys containing the peer identities it wishes

@@ -140,7 +140,7 @@ or
  
  .. code-block:: c
  
-  ret = tls_server_hello_psk(args, gfp_flags);
+  ret = tls_server_hello_psk(args, gfp_flags, handshake_key_update_type);
  
  The argument structure is filled in as above.