Message-ID: <20251017042312.1271322-5-alistair.francis@wdc.com>
Date: Fri, 17 Oct 2025 14:23:09 +1000
From: alistair23@...il.com
To: chuck.lever@...cle.com,
	hare@...nel.org,
	kernel-tls-handshake@...ts.linux.dev,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org,
	linux-nvme@...ts.infradead.org,
	linux-nfs@...r.kernel.org
Cc: kbusch@...nel.org,
	axboe@...nel.dk,
	hch@....de,
	sagi@...mberg.me,
	kch@...dia.com,
	hare@...e.de,
	alistair23@...il.com,
	Alistair Francis <alistair.francis@....com>
Subject: [PATCH v4 4/7] net/handshake: Support KeyUpdate message types

From: Alistair Francis <alistair.francis@....com>

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 <alistair.francis@....com>
---
v4:
 - Don't overload existing functions, instead create new ones
v3:
 - Fixup yamllint and kernel-doc failures

 Documentation/netlink/specs/handshake.yaml | 16 ++++-
 drivers/nvme/host/tcp.c                    | 15 +++-
 drivers/nvme/target/tcp.c                  | 10 ++-
 include/net/handshake.h                    |  8 +++
 include/uapi/linux/handshake.h             | 13 ++++
 net/handshake/tlshd.c                      | 83 +++++++++++++++++++++-
 6 files changed, 137 insertions(+), 8 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/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 611be56f8013..2696bf97dfac 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -20,6 +20,7 @@
 #include <linux/iov_iter.h>
 #include <net/busy_poll.h>
 #include <trace/events/sock.h>
+#include <uapi/linux/handshake.h>
 
 #include "nvme.h"
 #include "fabrics.h"
@@ -206,6 +207,10 @@ static struct workqueue_struct *nvme_tcp_wq;
 static const struct blk_mq_ops nvme_tcp_mq_ops;
 static const struct blk_mq_ops nvme_tcp_admin_mq_ops;
 static int nvme_tcp_try_send(struct nvme_tcp_queue *queue);
+static int nvme_tcp_start_tls(struct nvme_ctrl *nctrl,
+			      struct nvme_tcp_queue *queue,
+			      key_serial_t pskid,
+			      handshake_key_update_type keyupdate);
 
 static inline struct nvme_tcp_ctrl *to_tcp_ctrl(struct nvme_ctrl *ctrl)
 {
@@ -1726,7 +1731,8 @@ static void nvme_tcp_tls_done(void *data, int status, key_serial_t pskid,
 
 static int nvme_tcp_start_tls(struct nvme_ctrl *nctrl,
 			      struct nvme_tcp_queue *queue,
-			      key_serial_t pskid)
+			      key_serial_t pskid,
+			      handshake_key_update_type keyupdate)
 {
 	int qid = nvme_tcp_queue_id(queue);
 	int ret;
@@ -1748,7 +1754,10 @@ static int nvme_tcp_start_tls(struct nvme_ctrl *nctrl,
 	args.ta_timeout_ms = tls_handshake_timeout * 1000;
 	queue->tls_err = -EOPNOTSUPP;
 	init_completion(&queue->tls_complete);
-	ret = tls_client_hello_psk(&args, GFP_KERNEL);
+	if (keyupdate == HANDSHAKE_KEY_UPDATE_TYPE_UNSPEC)
+		ret = tls_client_hello_psk(&args, GFP_KERNEL);
+	else
+		ret = tls_client_keyupdate_psk(&args, GFP_KERNEL, keyupdate);
 	if (ret) {
 		dev_err(nctrl->device, "queue %d: failed to start TLS: %d\n",
 			qid, ret);
@@ -1898,7 +1907,7 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid,
 
 	/* If PSKs are configured try to start TLS */
 	if (nvme_tcp_tls_configured(nctrl) && pskid) {
-		ret = nvme_tcp_start_tls(nctrl, queue, pskid);
+		ret = nvme_tcp_start_tls(nctrl, queue, pskid, HANDSHAKE_KEY_UPDATE_TYPE_UNSPEC);
 		if (ret)
 			goto err_init_connect;
 	}
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 4ef4dd140ada..8aeec4a7f136 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1833,7 +1833,8 @@ static void nvmet_tcp_tls_handshake_timeout(struct work_struct *w)
 	kref_put(&queue->kref, nvmet_tcp_release_queue);
 }
 
-static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue)
+static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue,
+	handshake_key_update_type keyupdate)
 {
 	int ret = -EOPNOTSUPP;
 	struct tls_handshake_args args;
@@ -1852,7 +1853,10 @@ static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue)
 	args.ta_keyring = key_serial(queue->port->nport->keyring);
 	args.ta_timeout_ms = tls_handshake_timeout * 1000;
 
-	ret = tls_server_hello_psk(&args, GFP_KERNEL);
+	if (keyupdate == HANDSHAKE_KEY_UPDATE_TYPE_UNSPEC)
+		ret = tls_server_hello_psk(&args, GFP_KERNEL);
+	else
+		ret = tls_server_keyupdate_psk(&args, GFP_KERNEL, keyupdate);
 	if (ret) {
 		kref_put(&queue->kref, nvmet_tcp_release_queue);
 		pr_err("failed to start TLS, err=%d\n", ret);
@@ -1934,7 +1938,7 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
 		sk->sk_data_ready = port->data_ready;
 		write_unlock_bh(&sk->sk_callback_lock);
 		if (!nvmet_tcp_try_peek_pdu(queue)) {
-			if (!nvmet_tcp_tls_handshake(queue))
+			if (!nvmet_tcp_tls_handshake(queue, HANDSHAKE_KEY_UPDATE_TYPE_UNSPEC))
 				return;
 			/* TLS handshake failed, terminate the connection */
 			goto out_destroy_sq;
diff --git a/include/net/handshake.h b/include/net/handshake.h
index dc2222fd6d99..084c92a20b68 100644
--- a/include/net/handshake.h
+++ b/include/net/handshake.h
@@ -10,6 +10,10 @@
 #ifndef _NET_HANDSHAKE_H
 #define _NET_HANDSHAKE_H
 
+#include <uapi/linux/handshake.h>
+
+#define handshake_key_update_type u32
+
 enum {
 	TLS_NO_KEYRING = 0,
 	TLS_NO_PEERID = 0,
@@ -38,8 +42,12 @@ struct tls_handshake_args {
 int tls_client_hello_anon(const struct tls_handshake_args *args, gfp_t flags);
 int tls_client_hello_x509(const struct tls_handshake_args *args, gfp_t flags);
 int tls_client_hello_psk(const struct tls_handshake_args *args, gfp_t flags);
+int tls_client_keyupdate_psk(const struct tls_handshake_args *args, gfp_t flags,
+			     handshake_key_update_type keyupdate);
 int tls_server_hello_x509(const struct tls_handshake_args *args, gfp_t flags);
 int tls_server_hello_psk(const struct tls_handshake_args *args, gfp_t flags);
+int tls_server_keyupdate_psk(const struct tls_handshake_args *args, gfp_t flags,
+			     handshake_key_update_type keyupdate);
 
 bool tls_handshake_cancel(struct sock *sk);
 void tls_handshake_close(struct socket *sock);
diff --git a/include/uapi/linux/handshake.h b/include/uapi/linux/handshake.h
index b68ffbaa5f31..b691530073c6 100644
--- a/include/uapi/linux/handshake.h
+++ b/include/uapi/linux/handshake.h
@@ -19,6 +19,10 @@ enum handshake_msg_type {
 	HANDSHAKE_MSG_TYPE_UNSPEC,
 	HANDSHAKE_MSG_TYPE_CLIENTHELLO,
 	HANDSHAKE_MSG_TYPE_SERVERHELLO,
+	HANDSHAKE_MSG_TYPE_CLIENTKEYUPDATE,
+	HANDSHAKE_MSG_TYPE_CLIENTKEYUPDATEREQUEST,
+	HANDSHAKE_MSG_TYPE_SERVERKEYUPDATE,
+	HANDSHAKE_MSG_TYPE_SERVERKEYUPDATEREQUEST,
 };
 
 enum handshake_auth {
@@ -28,6 +32,13 @@ enum handshake_auth {
 	HANDSHAKE_AUTH_X509,
 };
 
+enum handshake_key_update_type {
+	HANDSHAKE_KEY_UPDATE_TYPE_UNSPEC,
+	HANDSHAKE_KEY_UPDATE_TYPE_SEND,
+	HANDSHAKE_KEY_UPDATE_TYPE_RECEIVED,
+	HANDSHAKE_KEY_UPDATE_TYPE_RECEIVED_REQUEST_UPDATE,
+};
+
 enum {
 	HANDSHAKE_A_X509_CERT = 1,
 	HANDSHAKE_A_X509_PRIVKEY,
@@ -46,6 +57,8 @@ enum {
 	HANDSHAKE_A_ACCEPT_CERTIFICATE,
 	HANDSHAKE_A_ACCEPT_PEERNAME,
 	HANDSHAKE_A_ACCEPT_KEYRING,
+	HANDSHAKE_A_ACCEPT_KEY_UPDATE_REQUEST,
+	HANDSHAKE_A_ACCEPT_KEY_SERIAL,
 
 	__HANDSHAKE_A_ACCEPT_MAX,
 	HANDSHAKE_A_ACCEPT_MAX = (__HANDSHAKE_A_ACCEPT_MAX - 1)
diff --git a/net/handshake/tlshd.c b/net/handshake/tlshd.c
index 2549c5dbccd8..c40839977ab9 100644
--- a/net/handshake/tlshd.c
+++ b/net/handshake/tlshd.c
@@ -41,6 +41,7 @@ struct tls_handshake_req {
 	unsigned int		th_num_peerids;
 	key_serial_t		th_peerid[5];
 
+	int			th_key_update_request;
 	key_serial_t		user_session_id;
 };
 
@@ -58,7 +59,8 @@ tls_handshake_req_init(struct handshake_req *req,
 	treq->th_num_peerids = 0;
 	treq->th_certificate = TLS_NO_CERT;
 	treq->th_privkey = TLS_NO_PRIVKEY;
-	treq->user_session_id = TLS_NO_PRIVKEY;
+	treq->user_session_id = args->user_session_id;
+
 	return treq;
 }
 
@@ -265,6 +267,16 @@ static int tls_handshake_accept(struct handshake_req *req,
 		break;
 	}
 
+	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_KEY_SERIAL,
+			  treq->user_session_id);
+	if (ret < 0)
+		goto out_cancel;
+
+	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_KEY_UPDATE_REQUEST,
+			  treq->th_key_update_request);
+	if (ret < 0)
+		goto out_cancel;
+
 	genlmsg_end(msg, hdr);
 	return genlmsg_reply(msg, info);
 
@@ -372,6 +384,44 @@ int tls_client_hello_psk(const struct tls_handshake_args *args, gfp_t flags)
 }
 EXPORT_SYMBOL(tls_client_hello_psk);
 
+/**
+ * tls_client_keyupdate_psk - request a PSK-based TLS handshake on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ * @keyupdate: specifies the type of KeyUpdate operation
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-EINVAL: Wrong number of local peer IDs
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_client_keyupdate_psk(const struct tls_handshake_args *args, gfp_t flags,
+			     handshake_key_update_type keyupdate)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+	unsigned int i;
+
+	if (!args->ta_num_peerids ||
+	    args->ta_num_peerids > ARRAY_SIZE(treq->th_peerid))
+		return -EINVAL;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTKEYUPDATE;
+	treq->th_key_update_request = keyupdate;
+	treq->th_auth_mode = HANDSHAKE_AUTH_PSK;
+	treq->th_num_peerids = args->ta_num_peerids;
+	for (i = 0; i < args->ta_num_peerids; i++)
+		treq->th_peerid[i] = args->ta_my_peerids[i];
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_client_keyupdate_psk);
+
 /**
  * tls_server_hello_x509 - request a server TLS handshake on a socket
  * @args: socket and handshake parameters for this request
@@ -428,6 +478,37 @@ int tls_server_hello_psk(const struct tls_handshake_args *args, gfp_t flags)
 }
 EXPORT_SYMBOL(tls_server_hello_psk);
 
+/**
+ * tls_server_keyupdate_psk - request a server TLS KeyUpdate on a socket
+ * @args: socket and handshake parameters for this request
+ * @flags: memory allocation control flags
+ * @keyupdate: specifies the type of KeyUpdate operation
+ *
+ * Return values:
+ *   %0: Handshake request enqueue; ->done will be called when complete
+ *   %-ESRCH: No user agent is available
+ *   %-ENOMEM: Memory allocation failed
+ */
+int tls_server_keyupdate_psk(const struct tls_handshake_args *args, gfp_t flags,
+			     handshake_key_update_type keyupdate)
+{
+	struct tls_handshake_req *treq;
+	struct handshake_req *req;
+
+	req = handshake_req_alloc(&tls_handshake_proto, flags);
+	if (!req)
+		return -ENOMEM;
+	treq = tls_handshake_req_init(req, args);
+	treq->th_type = HANDSHAKE_MSG_TYPE_SERVERKEYUPDATE;
+	treq->th_key_update_request = keyupdate;
+	treq->th_auth_mode = HANDSHAKE_AUTH_PSK;
+	treq->th_num_peerids = 1;
+	treq->th_peerid[0] = args->ta_my_peerids[0];
+
+	return handshake_req_submit(args->ta_sock, req, flags);
+}
+EXPORT_SYMBOL(tls_server_keyupdate_psk);
+
 /**
  * tls_handshake_cancel - cancel a pending handshake
  * @sk: socket on which there is an ongoing handshake
-- 
2.51.0

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