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-rw-r--r--.gitignore1
-rw-r--r--Documentation/netlink/specs/handshake.yaml124
-rw-r--r--Documentation/networking/index.rst1
-rw-r--r--Documentation/networking/tls-handshake.rst217
-rw-r--r--MAINTAINERS11
-rw-r--r--include/net/handshake.h43
-rw-r--r--include/trace/events/handshake.h159
-rw-r--r--include/uapi/linux/handshake.h73
-rw-r--r--net/Kconfig20
-rw-r--r--net/Makefile1
-rw-r--r--net/handshake/.kunitconfig11
-rw-r--r--net/handshake/Makefile13
-rw-r--r--net/handshake/genl.c58
-rw-r--r--net/handshake/genl.h24
-rw-r--r--net/handshake/handshake-test.c523
-rw-r--r--net/handshake/handshake.h87
-rw-r--r--net/handshake/netlink.c319
-rw-r--r--net/handshake/request.c344
-rw-r--r--net/handshake/tlshd.c418
-rw-r--r--net/handshake/trace.c20
20 files changed, 2467 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore
index 70ec6037fa7a..51117ba29c88 100644
--- a/.gitignore
+++ b/.gitignore
@@ -105,6 +105,7 @@ modules.order
!.gitignore
!.mailmap
!.rustfmt.toml
+!.kunitconfig
#
# Generated include files
diff --git a/Documentation/netlink/specs/handshake.yaml b/Documentation/netlink/specs/handshake.yaml
new file mode 100644
index 000000000000..614f1a585511
--- /dev/null
+++ b/Documentation/netlink/specs/handshake.yaml
@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+#
+# Author: Chuck Lever <chuck.lever@oracle.com>
+#
+# Copyright (c) 2023, Oracle and/or its affiliates.
+#
+
+name: handshake
+
+protocol: genetlink
+
+doc: Netlink protocol to request a transport layer security handshake.
+
+definitions:
+ -
+ type: enum
+ name: handler-class
+ value-start: 0
+ entries: [ none, tlshd, max ]
+ -
+ type: enum
+ name: msg-type
+ value-start: 0
+ entries: [ unspec, clienthello, serverhello ]
+ -
+ type: enum
+ name: auth
+ value-start: 0
+ entries: [ unspec, unauth, psk, x509 ]
+
+attribute-sets:
+ -
+ name: x509
+ attributes:
+ -
+ name: cert
+ type: u32
+ -
+ name: privkey
+ type: u32
+ -
+ name: accept
+ attributes:
+ -
+ name: sockfd
+ type: u32
+ -
+ name: handler-class
+ type: u32
+ enum: handler-class
+ -
+ name: message-type
+ type: u32
+ enum: msg-type
+ -
+ name: timeout
+ type: u32
+ -
+ name: auth-mode
+ type: u32
+ enum: auth
+ -
+ name: peer-identity
+ type: u32
+ multi-attr: true
+ -
+ name: certificate
+ type: nest
+ nested-attributes: x509
+ multi-attr: true
+ -
+ name: done
+ attributes:
+ -
+ name: status
+ type: u32
+ -
+ name: sockfd
+ type: u32
+ -
+ name: remote-auth
+ type: u32
+ multi-attr: true
+
+operations:
+ list:
+ -
+ name: ready
+ doc: Notify handlers that a new handshake request is waiting
+ notify: accept
+ -
+ name: accept
+ doc: Handler retrieves next queued handshake request
+ attribute-set: accept
+ flags: [ admin-perm ]
+ do:
+ request:
+ attributes:
+ - handler-class
+ reply:
+ attributes:
+ - sockfd
+ - message-type
+ - timeout
+ - auth-mode
+ - peer-identity
+ - certificate
+ -
+ name: done
+ doc: Handler reports handshake completion
+ attribute-set: done
+ do:
+ request:
+ attributes:
+ - status
+ - sockfd
+ - remote-auth
+
+mcast-groups:
+ list:
+ -
+ name: none
+ -
+ name: tlshd
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 24bb256d6d53..a164ff074356 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -36,6 +36,7 @@ Contents:
scaling
tls
tls-offload
+ tls-handshake
nfc
6lowpan
6pack
diff --git a/Documentation/networking/tls-handshake.rst b/Documentation/networking/tls-handshake.rst
new file mode 100644
index 000000000000..a2817a88e905
--- /dev/null
+++ b/Documentation/networking/tls-handshake.rst
@@ -0,0 +1,217 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================
+In-Kernel TLS Handshake
+=======================
+
+Overview
+========
+
+Transport Layer Security (TLS) is a Upper Layer Protocol (ULP) that runs
+over TCP. TLS provides end-to-end data integrity and confidentiality in
+addition to peer authentication.
+
+The kernel's kTLS implementation handles the TLS record subprotocol, but
+does not handle the TLS handshake subprotocol which is used to establish
+a TLS session. Kernel consumers can use the API described here to
+request TLS session establishment.
+
+There are several possible ways to provide a handshake service in the
+kernel. The API described here is designed to hide the details of those
+implementations so that in-kernel TLS consumers do not need to be
+aware of how the handshake gets done.
+
+
+User handshake agent
+====================
+
+As of this writing, there is no TLS handshake implementation in the
+Linux kernel. To provide a handshake service, a handshake agent
+(typically in user space) is started in each network namespace where a
+kernel consumer might require a TLS handshake. Handshake agents listen
+for events sent from the kernel that indicate a handshake request is
+waiting.
+
+An open socket is passed to a handshake agent via a netlink operation,
+which creates a socket descriptor in the agent's file descriptor table.
+If the handshake completes successfully, the handshake agent promotes
+the socket to use the TLS ULP and sets the session information using the
+SOL_TLS socket options. The handshake agent returns the socket to the
+kernel via a second netlink operation.
+
+
+Kernel Handshake API
+====================
+
+A kernel TLS consumer initiates a client-side TLS handshake on an open
+socket by invoking one of the tls_client_hello() functions. First, it
+fills in a structure that contains the parameters of the request:
+
+.. code-block:: c
+
+ struct tls_handshake_args {
+ struct socket *ta_sock;
+ tls_done_func_t ta_done;
+ void *ta_data;
+ unsigned int ta_timeout_ms;
+ key_serial_t ta_keyring;
+ key_serial_t ta_my_cert;
+ key_serial_t ta_my_privkey;
+ unsigned int ta_num_peerids;
+ key_serial_t ta_my_peerids[5];
+ };
+
+The @ta_sock field references an open and connected socket. The consumer
+must hold a reference on the socket to prevent it from being destroyed
+while the handshake is in progress. The consumer must also have
+instantiated a struct file in sock->file.
+
+
+@ta_done contains a callback function that is invoked when the handshake
+has completed. Further explanation of this function is in the "Handshake
+Completion" sesction below.
+
+The consumer can fill in the @ta_timeout_ms field to force the servicing
+handshake agent to exit after a number of milliseconds. This enables the
+socket to be fully closed once both the kernel and the handshake agent
+have closed their endpoints.
+
+Authentication material such as x.509 certificates, private certificate
+keys, and pre-shared keys are provided to the handshake agent in keys
+that are instantiated by the consumer before making the handshake
+request. The consumer can provide a private keyring that is linked into
+the handshake agent's process keyring in the @ta_keyring field to prevent
+access of those keys by other subsystems.
+
+To request an x.509-authenticated TLS session, the consumer fills in
+the @ta_my_cert and @ta_my_privkey fields with the serial numbers of
+keys containing an x.509 certificate and the private key for that
+certificate. Then, it invokes this function:
+
+.. code-block:: c
+
+ ret = tls_client_hello_x509(args, gfp_flags);
+
+The function returns zero when the handshake request is under way. A
+zero return guarantees the callback function @ta_done will be invoked
+for this socket. The function returns a negative errno if the handshake
+could not be started. A negative errno guarantees the callback function
+@ta_done will not be invoked on this socket.
+
+
+To initiate a client-side TLS handshake with a pre-shared key, use:
+
+.. code-block:: c
+
+ ret = tls_client_hello_psk(args, gfp_flags);
+
+However, in this case, the consumer fills in the @ta_my_peerids array
+with serial numbers of keys containing the peer identities it wishes
+to offer, and the @ta_num_peerids field with the number of array
+entries it has filled in. The other fields are filled in as above.
+
+
+To initiate an anonymous client-side TLS handshake use:
+
+.. code-block:: c
+
+ ret = tls_client_hello_anon(args, gfp_flags);
+
+The handshake agent presents no peer identity information to the remote
+during this type of handshake. Only server authentication (ie the client
+verifies the server's identity) is performed during the handshake. Thus
+the established session uses encryption only.
+
+
+Consumers that are in-kernel servers use:
+
+.. code-block:: c
+
+ ret = tls_server_hello_x509(args, gfp_flags);
+
+or
+
+.. code-block:: c
+
+ ret = tls_server_hello_psk(args, gfp_flags);
+
+The argument structure is filled in as above.
+
+
+If the consumer needs to cancel the handshake request, say, due to a ^C
+or other exigent event, the consumer can invoke:
+
+.. code-block:: c
+
+ bool tls_handshake_cancel(sock);
+
+This function returns true if the handshake request associated with
+@sock has been canceled. The consumer's handshake completion callback
+will not be invoked. If this function returns false, then the consumer's
+completion callback has already been invoked.
+
+
+Handshake Completion
+====================
+
+When the handshake agent has completed processing, it notifies the
+kernel that the socket may be used by the consumer again. At this point,
+the consumer's handshake completion callback, provided in the @ta_done
+field in the tls_handshake_args structure, is invoked.
+
+The synopsis of this function is:
+
+.. code-block:: c
+
+ typedef void (*tls_done_func_t)(void *data, int status,
+ key_serial_t peerid);
+
+The consumer provides a cookie in the @ta_data field of the
+tls_handshake_args structure that is returned in the @data parameter of
+this callback. The consumer uses the cookie to match the callback to the
+thread waiting for the handshake to complete.
+
+The success status of the handshake is returned via the @status
+parameter:
+
++------------+----------------------------------------------+
+| status | meaning |
++============+==============================================+
+| 0 | TLS session established successfully |
++------------+----------------------------------------------+
+| -EACCESS | Remote peer rejected the handshake or |
+| | authentication failed |
++------------+----------------------------------------------+
+| -ENOMEM | Temporary resource allocation failure |
++------------+----------------------------------------------+
+| -EINVAL | Consumer provided an invalid argument |
++------------+----------------------------------------------+
+| -ENOKEY | Missing authentication material |
++------------+----------------------------------------------+
+| -EIO | An unexpected fault occurred |
++------------+----------------------------------------------+
+
+The @peerid parameter contains the serial number of a key containing the
+remote peer's identity or the value TLS_NO_PEERID if the session is not
+authenticated.
+
+A best practice is to close and destroy the socket immediately if the
+handshake failed.
+
+
+Other considerations
+--------------------
+
+While a handshake is under way, the kernel consumer must alter the
+socket's sk_data_ready callback function to ignore all incoming data.
+Once the handshake completion callback function has been invoked, normal
+receive operation can be resumed.
+
+Once a TLS session is established, the consumer must provide a buffer
+for and then examine the control message (CMSG) that is part of every
+subsequent sock_recvmsg(). Each control message indicates whether the
+received message data is TLS record data or session metadata.
+
+See tls.rst for details on how a kTLS consumer recognizes incoming
+(decrypted) application data, alerts, and handshake packets once the
+socket has been promoted to use the TLS ULP.
diff --git a/MAINTAINERS b/MAINTAINERS
index 4fc57dfd5fd0..04ebde8ccb75 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8947,6 +8947,17 @@ Q: http://patchwork.linuxtv.org/project/linux-media/list/
T: git git://linuxtv.org/anttip/media_tree.git
F: drivers/media/usb/hackrf/
+HANDSHAKE UPCALL FOR TRANSPORT LAYER SECURITY
+M: Chuck Lever <chuck.lever@oracle.com>
+L: kernel-tls-handshake@lists.linux.dev
+L: netdev@vger.kernel.org
+S: Maintained
+F: Documentation/netlink/specs/handshake.yaml
+F: Documentation/networking/tls-handshake.rst
+F: include/net/handshake.h
+F: include/trace/events/handshake.h
+F: net/handshake/
+
HANTRO VPU CODEC DRIVER
M: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
M: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/include/net/handshake.h b/include/net/handshake.h
new file mode 100644
index 000000000000..3352b1ab43b3
--- /dev/null
+++ b/include/net/handshake.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Generic netlink HANDSHAKE service.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2023, Oracle and/or its affiliates.
+ */
+
+#ifndef _NET_HANDSHAKE_H
+#define _NET_HANDSHAKE_H
+
+enum {
+ TLS_NO_KEYRING = 0,
+ TLS_NO_PEERID = 0,
+ TLS_NO_CERT = 0,
+ TLS_NO_PRIVKEY = 0,
+};
+
+typedef void (*tls_done_func_t)(void *data, int status,
+ key_serial_t peerid);
+
+struct tls_handshake_args {
+ struct socket *ta_sock;
+ tls_done_func_t ta_done;
+ void *ta_data;
+ unsigned int ta_timeout_ms;
+ key_serial_t ta_keyring;
+ key_serial_t ta_my_cert;
+ key_serial_t ta_my_privkey;
+ unsigned int ta_num_peerids;
+ key_serial_t ta_my_peerids[5];
+};
+
+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_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);
+
+bool tls_handshake_cancel(struct sock *sk);
+
+#endif /* _NET_HANDSHAKE_H */
diff --git a/include/trace/events/handshake.h b/include/trace/events/handshake.h
new file mode 100644
index 000000000000..8dadcab5f12a
--- /dev/null
+++ b/include/trace/events/handshake.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM handshake
+
+#if !defined(_TRACE_HANDSHAKE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HANDSHAKE_H
+
+#include <linux/net.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(handshake_event_class,
+ TP_PROTO(
+ const struct net *net,
+ const struct handshake_req *req,
+ const struct sock *sk
+ ),
+ TP_ARGS(net, req, sk),
+ TP_STRUCT__entry(
+ __field(const void *, req)
+ __field(const void *, sk)
+ __field(unsigned int, netns_ino)
+ ),
+ TP_fast_assign(
+ __entry->req = req;
+ __entry->sk = sk;
+ __entry->netns_ino = net->ns.inum;
+ ),
+ TP_printk("req=%p sk=%p",
+ __entry->req, __entry->sk
+ )
+);
+#define DEFINE_HANDSHAKE_EVENT(name) \
+ DEFINE_EVENT(handshake_event_class, name, \
+ TP_PROTO( \
+ const struct net *net, \
+ const struct handshake_req *req, \
+ const struct sock *sk \
+ ), \
+ TP_ARGS(net, req, sk))
+
+DECLARE_EVENT_CLASS(handshake_fd_class,
+ TP_PROTO(
+ const struct net *net,
+ const struct handshake_req *req,
+ const struct sock *sk,
+ int fd
+ ),
+ TP_ARGS(net, req, sk, fd),
+ TP_STRUCT__entry(
+ __field(const void *, req)
+ __field(const void *, sk)
+ __field(int, fd)
+ __field(unsigned int, netns_ino)
+ ),
+ TP_fast_assign(
+ __entry->req = req;
+ __entry->sk = req->hr_sk;
+ __entry->fd = fd;
+ __entry->netns_ino = net->ns.inum;
+ ),
+ TP_printk("req=%p sk=%p fd=%d",
+ __entry->req, __entry->sk, __entry->fd
+ )
+);
+#define DEFINE_HANDSHAKE_FD_EVENT(name) \
+ DEFINE_EVENT(handshake_fd_class, name, \
+ TP_PROTO( \
+ const struct net *net, \
+ const struct handshake_req *req, \
+ const struct sock *sk, \
+ int fd \
+ ), \
+ TP_ARGS(net, req, sk, fd))
+
+DECLARE_EVENT_CLASS(handshake_error_class,
+ TP_PROTO(
+ const struct net *net,
+ const struct handshake_req *req,
+ const struct sock *sk,
+ int err
+ ),
+ TP_ARGS(net, req, sk, err),
+ TP_STRUCT__entry(
+ __field(const void *, req)
+ __field(const void *, sk)
+ __field(int, err)
+ __field(unsigned int, netns_ino)
+ ),
+ TP_fast_assign(
+ __entry->req = req;
+ __entry->sk = sk;
+ __entry->err = err;
+ __entry->netns_ino = net->ns.inum;
+ ),
+ TP_printk("req=%p sk=%p err=%d",
+ __entry->req, __entry->sk, __entry->err
+ )
+);
+#define DEFINE_HANDSHAKE_ERROR(name) \
+ DEFINE_EVENT(handshake_error_class, name, \
+ TP_PROTO( \
+ const struct net *net, \
+ const struct handshake_req *req, \
+ const struct sock *sk, \
+ int err \
+ ), \
+ TP_ARGS(net, req, sk, err))
+
+
+/*
+ * Request lifetime events
+ */
+
+DEFINE_HANDSHAKE_EVENT(handshake_submit);
+DEFINE_HANDSHAKE_ERROR(handshake_submit_err);
+DEFINE_HANDSHAKE_EVENT(handshake_cancel);
+DEFINE_HANDSHAKE_EVENT(handshake_cancel_none);
+DEFINE_HANDSHAKE_EVENT(handshake_cancel_busy);
+DEFINE_HANDSHAKE_EVENT(handshake_destruct);
+
+
+TRACE_EVENT(handshake_complete,
+ TP_PROTO(
+ const struct net *net,
+ const struct handshake_req *req,
+ const struct sock *sk,
+ int status
+ ),
+ TP_ARGS(net, req, sk, status),
+ TP_STRUCT__entry(
+ __field(const void *, req)
+ __field(const void *, sk)
+ __field(int, status)
+ __field(unsigned int, netns_ino)
+ ),
+ TP_fast_assign(
+ __entry->req = req;
+ __entry->sk = sk;
+ __entry->status = status;
+ __entry->netns_ino = net->ns.inum;
+ ),
+ TP_printk("req=%p sk=%p status=%d",
+ __entry->req, __entry->sk, __entry->status
+ )
+);
+
+/*
+ * Netlink events
+ */
+
+DEFINE_HANDSHAKE_ERROR(handshake_notify_err);
+DEFINE_HANDSHAKE_FD_EVENT(handshake_cmd_accept);
+DEFINE_HANDSHAKE_ERROR(handshake_cmd_accept_err);
+DEFINE_HANDSHAKE_FD_EVENT(handshake_cmd_done);
+DEFINE_HANDSHAKE_ERROR(handshake_cmd_done_err);
+
+#endif /* _TRACE_HANDSHAKE_H */
+
+#include <trace/define_trace.h>
diff --git a/include/uapi/linux/handshake.h b/include/uapi/linux/handshake.h
new file mode 100644
index 000000000000..1de4d0b95325
--- /dev/null
+++ b/include/uapi/linux/handshake.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/* Documentation/netlink/specs/handshake.yaml */
+/* YNL-GEN uapi header */
+
+#ifndef _UAPI_LINUX_HANDSHAKE_H
+#define _UAPI_LINUX_HANDSHAKE_H
+
+#define HANDSHAKE_FAMILY_NAME "handshake"
+#define HANDSHAKE_FAMILY_VERSION 1
+
+enum handshake_handler_class {
+ HANDSHAKE_HANDLER_CLASS_NONE,
+ HANDSHAKE_HANDLER_CLASS_TLSHD,
+ HANDSHAKE_HANDLER_CLASS_MAX,
+};
+
+enum handshake_msg_type {
+ HANDSHAKE_MSG_TYPE_UNSPEC,
+ HANDSHAKE_MSG_TYPE_CLIENTHELLO,
+ HANDSHAKE_MSG_TYPE_SERVERHELLO,
+};
+
+enum handshake_auth {
+ HANDSHAKE_AUTH_UNSPEC,
+ HANDSHAKE_AUTH_UNAUTH,
+ HANDSHAKE_AUTH_PSK,
+ HANDSHAKE_AUTH_X509,
+};
+
+enum {
+ HANDSHAKE_A_X509_CERT = 1,
+ HANDSHAKE_A_X509_PRIVKEY,
+
+ __HANDSHAKE_A_X509_MAX,
+ HANDSHAKE_A_X509_MAX = (__HANDSHAKE_A_X509_MAX - 1)
+};
+
+enum {
+ HANDSHAKE_A_ACCEPT_SOCKFD = 1,
+ HANDSHAKE_A_ACCEPT_HANDLER_CLASS,
+ HANDSHAKE_A_ACCEPT_MESSAGE_TYPE,
+ HANDSHAKE_A_ACCEPT_TIMEOUT,
+ HANDSHAKE_A_ACCEPT_AUTH_MODE,
+ HANDSHAKE_A_ACCEPT_PEER_IDENTITY,
+ HANDSHAKE_A_ACCEPT_CERTIFICATE,
+
+ __HANDSHAKE_A_ACCEPT_MAX,
+ HANDSHAKE_A_ACCEPT_MAX = (__HANDSHAKE_A_ACCEPT_MAX - 1)
+};
+
+enum {
+ HANDSHAKE_A_DONE_STATUS = 1,
+ HANDSHAKE_A_DONE_SOCKFD,
+ HANDSHAKE_A_DONE_REMOTE_AUTH,
+
+ __HANDSHAKE_A_DONE_MAX,
+ HANDSHAKE_A_DONE_MAX = (__HANDSHAKE_A_DONE_MAX - 1)
+};
+
+enum {
+ HANDSHAKE_CMD_READY = 1,
+ HANDSHAKE_CMD_ACCEPT,
+ HANDSHAKE_CMD_DONE,
+
+ __HANDSHAKE_CMD_MAX,
+ HANDSHAKE_CMD_MAX = (__HANDSHAKE_CMD_MAX - 1)
+};
+
+#define HANDSHAKE_MCGRP_NONE "none"
+#define HANDSHAKE_MCGRP_TLSHD "tlshd"
+
+#endif /* _UAPI_LINUX_HANDSHAKE_H */
diff --git a/net/Kconfig b/net/Kconfig
index f806722bccf4..7d39c1773eb4 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -68,6 +68,26 @@ source "net/iucv/Kconfig"
source "net/smc/Kconfig"
source "net/xdp/Kconfig"
+config NET_HANDSHAKE
+ bool
+ depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP
+ default y
+
+config NET_HANDSHAKE_KUNIT_TEST
+ tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS
+ default KUNIT_ALL_TESTS
+ depends on KUNIT
+ help
+ This builds the KUnit tests for the handshake upcall mechanism.
+
+ KUnit tests run during boot and output the results to the debug
+ log in TAP format (https://testanything.org/). Only useful for
+ kernel devs running KUnit test harness and are not for inclusion
+ into a production build.
+
+ For more information on KUnit and unit tests in general, refer
+ to the KUnit documentation in Documentation/dev-tools/kunit/.
+
config INET
bool "TCP/IP networking"
help
diff --git a/net/Makefile b/net/Makefile
index 87592009366f..4c4dc535453d 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -79,3 +79,4 @@ obj-$(CONFIG_NET_NCSI) += ncsi/
obj-$(CONFIG_XDP_SOCKETS) += xdp/
obj-$(CONFIG_MPTCP) += mptcp/
obj-$(CONFIG_MCTP) += mctp/
+obj-$(CONFIG_NET_HANDSHAKE) += handshake/
diff --git a/net/handshake/.kunitconfig b/net/handshake/.kunitconfig
new file mode 100644
index 000000000000..5c48cf4abca2
--- /dev/null
+++ b/net/handshake/.kunitconfig
@@ -0,0 +1,11 @@
+CONFIG_KUNIT=y
+CONFIG_UBSAN=y
+CONFIG_STACKTRACE=y
+CONFIG_NET=y
+CONFIG_NETWORK_FILESYSTEMS=y
+CONFIG_INET=y
+CONFIG_MULTIUSER=y
+CONFIG_NFS_FS=y
+CONFIG_SUNRPC=y
+CONFIG_NET_HANDSHAKE=y
+CONFIG_NET_HANDSHAKE_KUNIT_TEST=y
diff --git a/net/handshake/Makefile b/net/handshake/Makefile
new file mode 100644
index 000000000000..247d73c6ff6e
--- /dev/null
+++ b/net/handshake/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Generic HANDSHAKE service
+#
+# Author: Chuck Lever <chuck.lever@oracle.com>
+#
+# Copyright (c) 2023, Oracle and/or its affiliates.
+#
+
+obj-y += handshake.o
+handshake-y := genl.o netlink.o request.o tlshd.o trace.o
+
+obj-$(CONFIG_NET_HANDSHAKE_KUNIT_TEST) += handshake-test.o
diff --git a/net/handshake/genl.c b/net/handshake/genl.c
new file mode 100644
index 000000000000..9f29efb1493e
--- /dev/null
+++ b/net/handshake/genl.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Do not edit directly, auto-generated from: */
+/* Documentation/netlink/specs/handshake.yaml */
+/* YNL-GEN kernel source */
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "genl.h"
+
+#include <linux/handshake.h>
+
+/* HANDSHAKE_CMD_ACCEPT - do */
+static const struct nla_policy handshake_accept_nl_policy[HANDSHAKE_A_ACCEPT_HANDLER_CLASS + 1] = {
+ [HANDSHAKE_A_ACCEPT_HANDLER_CLASS] = NLA_POLICY_MAX(NLA_U32, 2),
+};
+
+/* HANDSHAKE_CMD_DONE - do */
+static const struct nla_policy handshake_done_nl_policy[HANDSHAKE_A_DONE_REMOTE_AUTH + 1] = {
+ [HANDSHAKE_A_DONE_STATUS] = { .type = NLA_U32, },
+ [HANDSHAKE_A_DONE_SOCKFD] = { .type = NLA_U32, },
+ [HANDSHAKE_A_DONE_REMOTE_AUTH] = { .type = NLA_U32, },
+};
+
+/* Ops table for handshake */
+static const struct genl_split_ops handshake_nl_ops[] = {
+ {
+ .cmd = HANDSHAKE_CMD_ACCEPT,
+ .doit = handshake_nl_accept_doit,
+ .policy = handshake_accept_nl_policy,
+ .maxattr = HANDSHAKE_A_ACCEPT_HANDLER_CLASS,
+ .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+ },
+ {
+ .cmd = HANDSHAKE_CMD_DONE,
+ .doit = handshake_nl_done_doit,
+ .policy = handshake_done_nl_policy,
+ .maxattr = HANDSHAKE_A_DONE_REMOTE_AUTH,
+ .flags = GENL_CMD_CAP_DO,
+ },
+};
+
+static const struct genl_multicast_group handshake_nl_mcgrps[] = {
+ [HANDSHAKE_NLGRP_NONE] = { "none", },
+ [HANDSHAKE_NLGRP_TLSHD] = { "tlshd", },
+};
+
+struct genl_family handshake_nl_family __ro_after_init = {
+ .name = HANDSHAKE_FAMILY_NAME,
+ .version = HANDSHAKE_FAMILY_VERSION,
+ .netnsok = true,
+ .parallel_ops = true,
+ .module = THIS_MODULE,
+ .split_ops = handshake_nl_ops,
+ .n_split_ops = ARRAY_SIZE(handshake_nl_ops),
+ .mcgrps = handshake_nl_mcgrps,
+ .n_mcgrps = ARRAY_SIZE(handshake_nl_mcgrps),
+};
diff --git a/net/handshake/genl.h b/net/handshake/genl.h
new file mode 100644
index 000000000000..2c1f1aa6a02a
--- /dev/null
+++ b/net/handshake/genl.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/* Documentation/netlink/specs/handshake.yaml */
+/* YNL-GEN kernel header */
+
+#ifndef _LINUX_HANDSHAKE_GEN_H
+#define _LINUX_HANDSHAKE_GEN_H
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include <linux/handshake.h>
+
+int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info);
+int handshake_nl_done_doit(struct sk_buff *skb, struct genl_info *info);
+
+enum {
+ HANDSHAKE_NLGRP_NONE,
+ HANDSHAKE_NLGRP_TLSHD,
+};
+
+extern struct genl_family handshake_nl_family;
+
+#endif /* _LINUX_HANDSHAKE_GEN_H */
diff --git a/net/handshake/handshake-test.c b/net/handshake/handshake-test.c
new file mode 100644
index 000000000000..e6adc5dec11a
--- /dev/null
+++ b/net/handshake/handshake-test.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * KUnit test of the handshake upcall mechanism.
+ */
+
+#include <kunit/test.h>
+#include <kunit/visibility.h>
+
+#include <linux/kernel.h>
+
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <net/netns/generic.h>
+
+#include <uapi/linux/handshake.h>
+#include "handshake.h"
+
+MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
+
+static int test_accept_func(struct handshake_req *req, struct genl_info *info,
+ int fd)
+{
+ return 0;
+}
+
+static void test_done_func(struct handshake_req *req, unsigned int status,
+ struct genl_info *info)
+{
+}
+
+struct handshake_req_alloc_test_param {
+ const char *desc;
+ struct handshake_proto *proto;
+ gfp_t gfp;
+ bool expect_success;
+};
+
+static struct handshake_proto handshake_req_alloc_proto_2 = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_NONE,
+};
+
+static struct handshake_proto handshake_req_alloc_proto_3 = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_MAX,
+};
+
+static struct handshake_proto handshake_req_alloc_proto_4 = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_TLSHD,
+};
+
+static struct handshake_proto handshake_req_alloc_proto_5 = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_TLSHD,
+ .hp_accept = test_accept_func,
+};
+
+static struct handshake_proto handshake_req_alloc_proto_6 = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_TLSHD,
+ .hp_privsize = UINT_MAX,
+ .hp_accept = test_accept_func,
+ .hp_done = test_done_func,
+};
+
+static struct handshake_proto handshake_req_alloc_proto_good = {
+ .hp_handler_class = HANDSHAKE_HANDLER_CLASS_TLSHD,
+ .hp_accept = test_accept_func,
+ .hp_done = test_done_func,
+};
+
+static const
+struct handshake_req_alloc_test_param handshake_req_alloc_params[] = {
+ {
+ .desc = "handshake_req_alloc NULL proto",
+ .proto = NULL,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc CLASS_NONE",
+ .proto = &handshake_req_alloc_proto_2,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc CLASS_MAX",
+ .proto = &handshake_req_alloc_proto_3,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc no callbacks",
+ .proto = &handshake_req_alloc_proto_4,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc no done callback",
+ .proto = &handshake_req_alloc_proto_5,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc excessive privsize",
+ .proto = &handshake_req_alloc_proto_6,
+ .gfp = GFP_KERNEL,
+ .expect_success = false,
+ },
+ {
+ .desc = "handshake_req_alloc all good",
+ .proto = &handshake_req_alloc_proto_good,
+ .gfp = GFP_KERNEL,
+ .expect_success = true,
+ },
+};
+
+static void
+handshake_req_alloc_get_desc(const struct handshake_req_alloc_test_param *param,
+ char *desc)
+{
+ strscpy(desc, param->desc, KUNIT_PARAM_DESC_SIZE);
+}
+
+/* Creates the function handshake_req_alloc_gen_params */
+KUNIT_ARRAY_PARAM(handshake_req_alloc, handshake_req_alloc_params,
+ handshake_req_alloc_get_desc);
+
+static void handshake_req_alloc_case(struct kunit *test)
+{
+ const struct handshake_req_alloc_test_param *param = test->param_value;
+ struct handshake_req *result;
+
+ /* Arrange */
+
+ /* Act */
+ result = handshake_req_alloc(param->proto, param->gfp);
+
+ /* Assert */
+ if (param->expect_success)
+ KUNIT_EXPECT_NOT_NULL(test, result);
+ else
+ KUNIT_EXPECT_NULL(test, result);
+