diff --git a/Documentation/netlink/specs/handshake.yaml b/Documentation/netlink/specs/handshake.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..0333d92b1438d0e00236c796b549930ac33d900c
--- /dev/null
+++ b/Documentation/netlink/specs/handshake.yaml
@@ -0,0 +1,122 @@
+# 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, 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
diff --git a/MAINTAINERS b/MAINTAINERS
index 4fc57dfd5fd0a673230f565d955d0e5801d17d1c..cdc7748d15b81ddfe23b0fa4e28100904d09e284 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8947,6 +8947,15 @@ 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: 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/trace/events/handshake.h b/include/trace/events/handshake.h
new file mode 100644
index 0000000000000000000000000000000000000000..8dadcab5f12af451a245ee8358f743a50cc29f41
--- /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 0000000000000000000000000000000000000000..7f66ff489b872dbfa83eaa0d49e0687de7a35d6c
--- /dev/null
+++ b/include/uapi/linux/handshake.h
@@ -0,0 +1,71 @@
+/* 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_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"
+
+#endif /* _UAPI_LINUX_HANDSHAKE_H */
diff --git a/net/Kconfig b/net/Kconfig
index f806722bccf450c62e07bfdb245e5195ac4a156d..4b800706cc76dfa271bfa293bd03d4a40507ce04 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -68,6 +68,11 @@ 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 INET
bool "TCP/IP networking"
help
diff --git a/net/Makefile b/net/Makefile
index 87592009366f987739a728e536c86f06159a3c15..4c4dc535453dff3a11d230ebde5dbdd03c687f2b 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/Makefile b/net/handshake/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..d38736de45dadfc132deb750f5c98fe95bde65fd
--- /dev/null
+++ b/net/handshake/Makefile
@@ -0,0 +1,11 @@
+# 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 trace.o
diff --git a/net/handshake/genl.c b/net/handshake/genl.c
new file mode 100644
index 0000000000000000000000000000000000000000..652f37d19bd61420823ebdcd4ea51450c865825e
--- /dev/null
+++ b/net/handshake/genl.c
@@ -0,0 +1,57 @@
+// 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, 1),
+};
+
+/* 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", },
+};
+
+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 0000000000000000000000000000000000000000..a1eb7ccccc7fdfb8bc9adc8bfaed723e1d2a65d6
--- /dev/null
+++ b/net/handshake/genl.h
@@ -0,0 +1,23 @@
+/* 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,
+};
+
+extern struct genl_family handshake_nl_family;
+
+#endif /* _LINUX_HANDSHAKE_GEN_H */
diff --git a/net/handshake/handshake.h b/net/handshake/handshake.h
new file mode 100644
index 0000000000000000000000000000000000000000..52568dbe24f1a084821e2d2e7716da8c01338b7a
--- /dev/null
+++ b/net/handshake/handshake.h
@@ -0,0 +1,82 @@
+/* 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 _INTERNAL_HANDSHAKE_H
+#define _INTERNAL_HANDSHAKE_H
+
+/* Per-net namespace context */
+struct handshake_net {
+ spinlock_t hn_lock; /* protects next 3 fields */
+ int hn_pending;
+ int hn_pending_max;
+ struct list_head hn_requests;
+
+ unsigned long hn_flags;
+};
+
+enum hn_flags_bits {
+ HANDSHAKE_F_NET_DRAINING,
+};
+
+struct handshake_proto;
+
+/* One handshake request */
+struct handshake_req {
+ struct list_head hr_list;
+ struct rhash_head hr_rhash;
+ unsigned long hr_flags;
+ const struct handshake_proto *hr_proto;
+ struct sock *hr_sk;
+ void (*hr_odestruct)(struct sock *sk);
+
+ /* Always the last field */
+ char hr_priv[];
+};
+
+enum hr_flags_bits {
+ HANDSHAKE_F_REQ_COMPLETED,
+};
+
+/* Invariants for all handshake requests for one transport layer
+ * security protocol
+ */
+struct handshake_proto {
+ int hp_handler_class;
+ size_t hp_privsize;
+
+ int (*hp_accept)(struct handshake_req *req,
+ struct genl_info *info, int fd);
+ void (*hp_done)(struct handshake_req *req,
+ unsigned int status,
+ struct genl_info *info);
+ void (*hp_destroy)(struct handshake_req *req);
+};
+
+/* netlink.c */
+int handshake_genl_notify(struct net *net, const struct handshake_proto *proto,
+ gfp_t flags);
+struct nlmsghdr *handshake_genl_put(struct sk_buff *msg,
+ struct genl_info *info);
+struct handshake_net *handshake_pernet(struct net *net);
+
+/* request.c */
+struct handshake_req *handshake_req_alloc(const struct handshake_proto *proto,
+ gfp_t flags);
+int handshake_req_hash_init(void);
+void handshake_req_hash_destroy(void);
+void *handshake_req_private(struct handshake_req *req);
+struct handshake_req *handshake_req_hash_lookup(struct sock *sk);
+struct handshake_req *handshake_req_next(struct handshake_net *hn, int class);
+int handshake_req_submit(struct socket *sock, struct handshake_req *req,
+ gfp_t flags);
+void handshake_complete(struct handshake_req *req, unsigned int status,
+ struct genl_info *info);
+bool handshake_req_cancel(struct sock *sk);
+
+#endif /* _INTERNAL_HANDSHAKE_H */
diff --git a/net/handshake/netlink.c b/net/handshake/netlink.c
new file mode 100644
index 0000000000000000000000000000000000000000..7264cac0404764f5772ce04e78833614035aeed7
--- /dev/null
+++ b/net/handshake/netlink.c
@@ -0,0 +1,312 @@
+// 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.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/mm.h>
+
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <net/netns/generic.h>
+
+#include <uapi/linux/handshake.h>
+#include "handshake.h"
+#include "genl.h"
+
+#include <trace/events/handshake.h>
+
+/**
+ * handshake_genl_notify - Notify handlers that a request is waiting
+ * @net: target network namespace
+ * @proto: handshake protocol
+ * @flags: memory allocation control flags
+ *
+ * Returns zero on success or a negative errno if notification failed.
+ */
+int handshake_genl_notify(struct net *net, const struct handshake_proto *proto,
+ gfp_t flags)
+{
+ struct sk_buff *msg;
+ void *hdr;
+
+ if (!genl_has_listeners(&handshake_nl_family, net,
+ proto->hp_handler_class))
+ return -ESRCH;
+
+ msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ hdr = genlmsg_put(msg, 0, 0, &handshake_nl_family, 0,
+ HANDSHAKE_CMD_READY);
+ if (!hdr)
+ goto out_free;
+
+ if (nla_put_u32(msg, HANDSHAKE_A_ACCEPT_HANDLER_CLASS,
+ proto->hp_handler_class) < 0) {
+ genlmsg_cancel(msg, hdr);
+ goto out_free;
+ }
+
+ genlmsg_end(msg, hdr);
+ return genlmsg_multicast_netns(&handshake_nl_family, net, msg,
+ 0, proto->hp_handler_class, flags);
+
+out_free:
+ nlmsg_free(msg);
+ return -EMSGSIZE;
+}
+
+/**
+ * handshake_genl_put - Create a generic netlink message header
+ * @msg: buffer in which to create the header
+ * @info: generic netlink message context
+ *
+ * Returns a ready-to-use header, or NULL.
+ */
+struct nlmsghdr *handshake_genl_put(struct sk_buff *msg,
+ struct genl_info *info)
+{
+ return genlmsg_put(msg, info->snd_portid, info->snd_seq,
+ &handshake_nl_family, 0, info->genlhdr->cmd);
+}
+EXPORT_SYMBOL(handshake_genl_put);
+
+/*
+ * dup() a kernel socket for use as a user space file descriptor
+ * in the current process. The kernel socket must have an
+ * instatiated struct file.
+ *
+ * Implicit argument: "current()"
+ */
+static int handshake_dup(struct socket *sock)
+{
+ struct file *file;
+ int newfd;
+
+ if (!sock->file)
+ return -EBADF;
+
+ file = get_file(sock->file);
+ newfd = get_unused_fd_flags(O_CLOEXEC);
+ if (newfd < 0) {
+ fput(file);
+ return newfd;
+ }
+
+ fd_install(newfd, file);
+ return newfd;
+}
+
+int handshake_nl_accept_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net *net = sock_net(skb->sk);
+ struct handshake_net *hn = handshake_pernet(net);
+ struct handshake_req *req = NULL;
+ struct socket *sock;
+ int class, fd, err;
+
+ err = -EOPNOTSUPP;
+ if (!hn)
+ goto out_status;
+
+ err = -EINVAL;
+ if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_ACCEPT_HANDLER_CLASS))
+ goto out_status;
+ class = nla_get_u32(info->attrs[HANDSHAKE_A_ACCEPT_HANDLER_CLASS]);
+
+ err = -EAGAIN;
+ req = handshake_req_next(hn, class);
+ if (!req)
+ goto out_status;
+
+ sock = req->hr_sk->sk_socket;
+ fd = handshake_dup(sock);
+ if (fd < 0) {
+ err = fd;
+ goto out_complete;
+ }
+ err = req->hr_proto->hp_accept(req, info, fd);
+ if (err)
+ goto out_complete;
+
+ trace_handshake_cmd_accept(net, req, req->hr_sk, fd);
+ return 0;
+
+out_complete:
+ handshake_complete(req, -EIO, NULL);
+ fput(sock->file);
+out_status:
+ trace_handshake_cmd_accept_err(net, req, NULL, err);
+ return err;
+}
+
+int handshake_nl_done_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net *net = sock_net(skb->sk);
+ struct socket *sock = NULL;
+ struct handshake_req *req;
+ int fd, status, err;
+
+ if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_DONE_SOCKFD))
+ return -EINVAL;
+ fd = nla_get_u32(info->attrs[HANDSHAKE_A_DONE_SOCKFD]);
+
+ err = 0;
+ sock = sockfd_lookup(fd, &err);
+ if (err) {
+ err = -EBADF;
+ goto out_status;
+ }
+
+ req = handshake_req_hash_lookup(sock->sk);
+ if (!req) {
+ err = -EBUSY;
+ fput(sock->file);
+ goto out_status;
+ }
+
+ trace_handshake_cmd_done(net, req, sock->sk, fd);
+
+ status = -EIO;
+ if (info->attrs[HANDSHAKE_A_DONE_STATUS])
+ status = nla_get_u32(info->attrs[HANDSHAKE_A_DONE_STATUS]);
+
+ handshake_complete(req, status, info);
+ fput(sock->file);
+ return 0;
+
+out_status:
+ trace_handshake_cmd_done_err(net, req, sock->sk, err);
+ return err;
+}
+
+static unsigned int handshake_net_id;
+
+static int __net_init handshake_net_init(struct net *net)
+{
+ struct handshake_net *hn = net_generic(net, handshake_net_id);
+ unsigned long tmp;
+ struct sysinfo si;
+
+ /*
+ * Arbitrary limit to prevent handshakes that do not make
+ * progress from clogging up the system. The cap scales up
+ * with the amount of physical memory on the system.
+ */
+ si_meminfo(&si);
+ tmp = si.totalram / (25 * si.mem_unit);
+ hn->hn_pending_max = clamp(tmp, 3UL, 50UL);
+
+ spin_lock_init(&hn->hn_lock);
+ hn->hn_pending = 0;
+ hn->hn_flags = 0;
+ INIT_LIST_HEAD(&hn->hn_requests);
+ return 0;
+}
+
+static void __net_exit handshake_net_exit(struct net *net)
+{
+ struct handshake_net *hn = net_generic(net, handshake_net_id);
+ struct handshake_req *req;
+ LIST_HEAD(requests);
+
+ /*
+ * Drain the net's pending list. Requests that have been
+ * accepted and are in progress will be destroyed when
+ * the socket is closed.
+ */
+ spin_lock(&hn->hn_lock);
+ set_bit(HANDSHAKE_F_NET_DRAINING, &hn->hn_flags);
+ list_splice_init(&requests, &hn->hn_requests);
+ spin_unlock(&hn->hn_lock);
+
+ while (!list_empty(&requests)) {
+ req = list_first_entry(&requests, struct handshake_req, hr_list);
+ list_del(&req->hr_list);
+
+ /*
+ * Requests on this list have not yet been
+ * accepted, so they do not have an fd to put.
+ */
+
+ handshake_complete(req, -ETIMEDOUT, NULL);
+ }
+}
+
+static struct pernet_operations __net_initdata handshake_genl_net_ops = {
+ .init = handshake_net_init,
+ .exit = handshake_net_exit,
+ .id = &handshake_net_id,
+ .size = sizeof(struct handshake_net),
+};
+
+/**
+ * handshake_pernet - Get the handshake private per-net structure
+ * @net: network namespace
+ *
+ * Returns a pointer to the net's private per-net structure for the
+ * handshake module, or NULL if handshake_init() failed.
+ */
+struct handshake_net *handshake_pernet(struct net *net)
+{
+ return handshake_net_id ?
+ net_generic(net, handshake_net_id) : NULL;
+}
+
+static int __init handshake_init(void)
+{
+ int ret;
+
+ ret = handshake_req_hash_init();
+ if (ret) {
+ pr_warn("handshake: hash initialization failed (%d)\n", ret);
+ return ret;
+ }
+
+ ret = genl_register_family(&handshake_nl_family);
+ if (ret) {
+ pr_warn("handshake: netlink registration failed (%d)\n", ret);
+ handshake_req_hash_destroy();
+ return ret;
+ }
+
+ /*
+ * ORDER: register_pernet_subsys must be done last.
+ *
+ * If initialization does not make it past pernet_subsys
+ * registration, then handshake_net_id will remain 0. That
+ * shunts the handshake consumer API to return ENOTSUPP
+ * to prevent it from dereferencing something that hasn't
+ * been allocated.
+ */
+ ret = register_pernet_subsys(&handshake_genl_net_ops);
+ if (ret) {
+ pr_warn("handshake: pernet registration failed (%d)\n", ret);
+ genl_unregister_family(&handshake_nl_family);
+ handshake_req_hash_destroy();
+ }
+
+ return ret;
+}
+
+static void __exit handshake_exit(void)
+{
+ unregister_pernet_subsys(&handshake_genl_net_ops);
+ handshake_net_id = 0;
+
+ handshake_req_hash_destroy();
+ genl_unregister_family(&handshake_nl_family);
+}
+
+module_init(handshake_init);
+module_exit(handshake_exit);
diff --git a/net/handshake/request.c b/net/handshake/request.c
new file mode 100644
index 0000000000000000000000000000000000000000..d5b2bc6de0572835bccceacd9d78b3efe97400eb
--- /dev/null
+++ b/net/handshake/request.c
@@ -0,0 +1,339 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Handshake request lifetime events
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2023, Oracle and/or its affiliates.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet.h>
+#include <linux/fdtable.h>
+#include <linux/rhashtable.h>
+
+#include <net/sock.h>
+#include <net/genetlink.h>
+#include <net/netns/generic.h>
+
+#include <uapi/linux/handshake.h>
+#include "handshake.h"
+
+#include <trace/events/handshake.h>
+
+/*
+ * We need both a handshake_req -> sock mapping, and a sock ->
+ * handshake_req mapping. Both are one-to-one.
+ *
+ * To avoid adding another pointer field to struct sock, net/handshake
+ * maintains a hash table, indexed by the memory address of @sock, to
+ * find the struct handshake_req outstanding for that socket. The
+ * reverse direction uses a simple pointer field in the handshake_req
+ * struct.
+ */
+
+static struct rhashtable handshake_rhashtbl ____cacheline_aligned_in_smp;
+
+static const struct rhashtable_params handshake_rhash_params = {
+ .key_len = sizeof_field(struct handshake_req, hr_sk),
+ .key_offset = offsetof(struct handshake_req, hr_sk),
+ .head_offset = offsetof(struct handshake_req, hr_rhash),
+ .automatic_shrinking = true,
+};
+
+int handshake_req_hash_init(void)
+{
+ return rhashtable_init(&handshake_rhashtbl, &handshake_rhash_params);
+}
+
+void handshake_req_hash_destroy(void)
+{
+ rhashtable_destroy(&handshake_rhashtbl);
+}
+
+struct handshake_req *handshake_req_hash_lookup(struct sock *sk)
+{
+ return rhashtable_lookup_fast(&handshake_rhashtbl, &sk,
+ handshake_rhash_params);
+}
+
+static bool handshake_req_hash_add(struct handshake_req *req)
+{
+ int ret;
+
+ ret = rhashtable_lookup_insert_fast(&handshake_rhashtbl,
+ &req->hr_rhash,
+ handshake_rhash_params);
+ return ret == 0;
+}
+
+static void handshake_req_destroy(struct handshake_req *req)
+{
+ if (req->hr_proto->hp_destroy)
+ req->hr_proto->hp_destroy(req);
+ rhashtable_remove_fast(&handshake_rhashtbl, &req->hr_rhash,
+ handshake_rhash_params);
+ kfree(req);
+}
+
+static void handshake_sk_destruct(struct sock *sk)
+{
+ void (*sk_destruct)(struct sock *sk);
+ struct handshake_req *req;
+
+ req = handshake_req_hash_lookup(sk);
+ if (!req)
+ return;
+
+ trace_handshake_destruct(sock_net(sk), req, sk);
+ sk_destruct = req->hr_odestruct;
+ handshake_req_destroy(req);
+ if (sk_destruct)
+ sk_destruct(sk);
+}
+
+/**
+ * handshake_req_alloc - Allocate a handshake request
+ * @proto: security protocol
+ * @flags: memory allocation flags
+ *
+ * Returns an initialized handshake_req or NULL.
+ */
+struct handshake_req *handshake_req_alloc(const struct handshake_proto *proto,
+ gfp_t flags)
+{
+ struct handshake_req *req;
+
+ if (!proto)
+ return NULL;
+ if (proto->hp_handler_class <= HANDSHAKE_HANDLER_CLASS_NONE)
+ return NULL;
+ if (proto->hp_handler_class >= HANDSHAKE_HANDLER_CLASS_MAX)
+ return NULL;
+ if (!proto->hp_accept || !proto->hp_done)
+ return NULL;
+
+ req = kzalloc(struct_size(req, hr_priv, proto->hp_privsize), flags);
+ if (!req)
+ return NULL;
+
+ INIT_LIST_HEAD(&req->hr_list);
+ req->hr_proto = proto;
+ return req;
+}
+EXPORT_SYMBOL(handshake_req_alloc);
+
+/**
+ * handshake_req_private - Get per-handshake private data
+ * @req: handshake arguments
+ *
+ */
+void *handshake_req_private(struct handshake_req *req)
+{
+ return (void *)&req->hr_priv;
+}
+EXPORT_SYMBOL(handshake_req_private);
+
+static bool __add_pending_locked(struct handshake_net *hn,
+ struct handshake_req *req)
+{
+ if (WARN_ON_ONCE(!list_empty(&req->hr_list)))
+ return false;
+ hn->hn_pending++;
+ list_add_tail(&req->hr_list, &hn->hn_requests);
+ return true;
+}
+
+static void __remove_pending_locked(struct handshake_net *hn,
+ struct handshake_req *req)
+{
+ hn->hn_pending--;
+ list_del_init(&req->hr_list);
+}
+
+/*
+ * Returns %true if the request was found on @net's pending list,
+ * otherwise %false.
+ *
+ * If @req was on a pending list, it has not yet been accepted.
+ */
+static bool remove_pending(struct handshake_net *hn, struct handshake_req *req)
+{
+ bool ret = false;
+
+ spin_lock(&hn->hn_lock);
+ if (!list_empty(&req->hr_list)) {
+ __remove_pending_locked(hn, req);
+ ret = true;
+ }
+ spin_unlock(&hn->hn_lock);
+
+ return ret;
+}
+
+struct handshake_req *handshake_req_next(struct handshake_net *hn, int class)
+{
+ struct handshake_req *req, *pos;
+
+ req = NULL;
+ spin_lock(&hn->hn_lock);
+ list_for_each_entry(pos, &hn->hn_requests, hr_list) {
+ if (pos->hr_proto->hp_handler_class != class)
+ continue;
+ __remove_pending_locked(hn, pos);
+ req = pos;
+ break;
+ }
+ spin_unlock(&hn->hn_lock);
+
+ return req;
+}
+
+/**
+ * handshake_req_submit - Submit a handshake request
+ * @sock: open socket on which to perform the handshake
+ * @req: handshake arguments
+ * @flags: memory allocation flags
+ *
+ * Return values:
+ * %0: Request queued
+ * %-EINVAL: Invalid argument
+ * %-EBUSY: A handshake is already under way for this socket
+ * %-ESRCH: No handshake agent is available
+ * %-EAGAIN: Too many pending handshake requests
+ * %-ENOMEM: Failed to allocate memory
+ * %-EMSGSIZE: Failed to construct notification message
+ * %-EOPNOTSUPP: Handshake module not initialized
+ *
+ * A zero return value from handshake_req_submit() means that
+ * exactly one subsequent completion callback is guaranteed.
+ *
+ * A negative return value from handshake_req_submit() means that
+ * no completion callback will be done and that @req has been
+ * destroyed.
+ */
+int handshake_req_submit(struct socket *sock, struct handshake_req *req,
+ gfp_t flags)
+{
+ struct handshake_net *hn;
+ struct net *net;
+ int ret;
+
+ if (!sock || !req || !sock->file) {
+ kfree(req);
+ return -EINVAL;
+ }
+
+ req->hr_sk = sock->sk;
+ if (!req->hr_sk) {
+ kfree(req);
+ return -EINVAL;
+ }
+ req->hr_odestruct = req->hr_sk->sk_destruct;
+ req->hr_sk->sk_destruct = handshake_sk_destruct;
+
+ ret = -EOPNOTSUPP;
+ net = sock_net(req->hr_sk);
+ hn = handshake_pernet(net);
+ if (!hn)
+ goto out_err;
+
+ ret = -EAGAIN;
+ if (READ_ONCE(hn->hn_pending) >= hn->hn_pending_max)
+ goto out_err;
+
+ spin_lock(&hn->hn_lock);
+ ret = -EOPNOTSUPP;
+ if (test_bit(HANDSHAKE_F_NET_DRAINING, &hn->hn_flags))
+ goto out_unlock;
+ ret = -EBUSY;
+ if (!handshake_req_hash_add(req))
+ goto out_unlock;
+ if (!__add_pending_locked(hn, req))
+ goto out_unlock;
+ spin_unlock(&hn->hn_lock);
+
+ ret = handshake_genl_notify(net, req->hr_proto, flags);
+ if (ret) {
+ trace_handshake_notify_err(net, req, req->hr_sk, ret);
+ if (remove_pending(hn, req))
+ goto out_err;
+ }
+
+ /* Prevent socket release while a handshake request is pending */
+ sock_hold(req->hr_sk);
+
+ trace_handshake_submit(net, req, req->hr_sk);
+ return 0;
+
+out_unlock:
+ spin_unlock(&hn->hn_lock);
+out_err:
+ trace_handshake_submit_err(net, req, req->hr_sk, ret);
+ handshake_req_destroy(req);
+ return ret;
+}
+EXPORT_SYMBOL(handshake_req_submit);
+
+void handshake_complete(struct handshake_req *req, unsigned int status,
+ struct genl_info *info)
+{
+ struct sock *sk = req->hr_sk;
+ struct net *net = sock_net(sk);
+
+ if (!test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED, &req->hr_flags)) {
+ trace_handshake_complete(net, req, sk, status);
+ req->hr_proto->hp_done(req, status, info);
+
+ /* Handshake request is no longer pending */
+ sock_put(sk);
+ }
+}
+
+/**
+ * handshake_req_cancel - Cancel an in-progress handshake
+ * @sk: socket on which there is an ongoing handshake
+ *
+ * Request cancellation races with request completion. To determine
+ * who won, callers examine the return value from this function.
+ *
+ * Return values:
+ * %true - Uncompleted handshake request was canceled
+ * %false - Handshake request already completed or not found
+ */
+bool handshake_req_cancel(struct sock *sk)
+{
+ struct handshake_req *req;
+ struct handshake_net *hn;
+ struct net *net;
+
+ net = sock_net(sk);
+ req = handshake_req_hash_lookup(sk);
+ if (!req) {
+ trace_handshake_cancel_none(net, req, sk);
+ return false;
+ }
+
+ hn = handshake_pernet(net);
+ if (hn && remove_pending(hn, req)) {
+ /* Request hadn't been accepted */
+ goto out_true;
+ }
+ if (test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED, &req->hr_flags)) {
+ /* Request already completed */
+ trace_handshake_cancel_busy(net, req, sk);
+ return false;
+ }
+
+out_true:
+ trace_handshake_cancel(net, req, sk);
+
+ /* Handshake request is no longer pending */
+ sock_put(sk);
+ return true;
+}
+EXPORT_SYMBOL(handshake_req_cancel);
diff --git a/net/handshake/trace.c b/net/handshake/trace.c
new file mode 100644
index 0000000000000000000000000000000000000000..1c4d8e27e17a75af23fb91f56c2ce5522948cc87
--- /dev/null
+++ b/net/handshake/trace.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Trace points for transport security layer handshakes.
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2023, Oracle and/or its affiliates.
+ */
+
+#include <linux/types.h>
+
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "handshake.h"
+
+#define CREATE_TRACE_POINTS
+
+#include <trace/events/handshake.h>