Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

31 files changed, 15919 insertions, 0 deletions

diff --git a/net/rxrpc/Kconfig b/net/rxrpc/Kconfig
new file mode 100644
index 000000000..d706bb408
--- /dev/null
+++ b/net/rxrpc/Kconfig
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RxRPC session sockets
+#
+
+config AF_RXRPC
+	tristate "RxRPC session sockets"
+	depends on INET
+	select CRYPTO
+	select KEYS
+	help
+	  Say Y or M here to include support for RxRPC session sockets (just
+	  the transport part, not the presentation part: (un)marshalling is
+	  left to the application).
+
+	  These are used for AFS kernel filesystem and userspace utilities.
+
+	  This module at the moment only supports client operations and is
+	  currently incomplete.
+
+	  See Documentation/networking/rxrpc.rst.
+
+config AF_RXRPC_IPV6
+	bool "IPv6 support for RxRPC"
+	depends on (IPV6 = m && AF_RXRPC = m) || (IPV6 = y && AF_RXRPC)
+	help
+	  Say Y here to allow AF_RXRPC to use IPV6 UDP as well as IPV4 UDP as
+	  its network transport.
+
+config AF_RXRPC_INJECT_LOSS
+	bool "Inject packet loss into RxRPC packet stream"
+	depends on AF_RXRPC
+	help
+	  Say Y here to inject packet loss by discarding some received and some
+	  transmitted packets.
+
+
+config AF_RXRPC_DEBUG
+	bool "RxRPC dynamic debugging"
+	depends on AF_RXRPC
+	help
+	  Say Y here to make runtime controllable debugging messages appear.
+
+	  See Documentation/networking/rxrpc.rst.
+
+
+config RXKAD
+	bool "RxRPC Kerberos security"
+	depends on AF_RXRPC
+	select CRYPTO
+	select CRYPTO_MANAGER
+	select CRYPTO_SKCIPHER
+	select CRYPTO_PCBC
+	select CRYPTO_FCRYPT
+	help
+	  Provide kerberos 4 and AFS kaserver security handling for AF_RXRPC
+	  through the use of the key retention service.
+
+	  See Documentation/networking/rxrpc.rst.
diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile
new file mode 100644
index 000000000..ddd0f9571
--- /dev/null
+++ b/net/rxrpc/Makefile
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Linux kernel RxRPC
+#
+
+obj-$(CONFIG_AF_RXRPC) += rxrpc.o
+
+rxrpc-y := \
+	af_rxrpc.o \
+	call_accept.o \
+	call_event.o \
+	call_object.o \
+	conn_client.o \
+	conn_event.o \
+	conn_object.o \
+	conn_service.o \
+	input.o \
+	insecure.o \
+	key.o \
+	local_event.o \
+	local_object.o \
+	misc.o \
+	net_ns.o \
+	output.o \
+	peer_event.o \
+	peer_object.o \
+	recvmsg.o \
+	rtt.o \
+	security.o \
+	sendmsg.o \
+	skbuff.o \
+	utils.o
+
+rxrpc-$(CONFIG_PROC_FS) += proc.o
+rxrpc-$(CONFIG_RXKAD) += rxkad.o
+rxrpc-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
new file mode 100644
index 000000000..0354f90dc
--- /dev/null
+++ b/net/rxrpc/af_rxrpc.c
@@ -0,0 +1,1077 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC implementation
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/random.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/key-type.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#define CREATE_TRACE_POINTS
+#include "ar-internal.h"
+
+MODULE_DESCRIPTION("RxRPC network protocol");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_RXRPC);
+
+unsigned int rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
+module_param_named(debug, rxrpc_debug, uint, 0644);
+MODULE_PARM_DESC(debug, "RxRPC debugging mask");
+
+static struct proto rxrpc_proto;
+static const struct proto_ops rxrpc_rpc_ops;
+
+/* current debugging ID */
+atomic_t rxrpc_debug_id;
+EXPORT_SYMBOL(rxrpc_debug_id);
+
+/* count of skbs currently in use */
+atomic_t rxrpc_n_tx_skbs, rxrpc_n_rx_skbs;
+
+struct workqueue_struct *rxrpc_workqueue;
+
+static void rxrpc_sock_destructor(struct sock *);
+
+/*
+ * see if an RxRPC socket is currently writable
+ */
+static inline int rxrpc_writable(struct sock *sk)
+{
+	return refcount_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
+}
+
+/*
+ * wait for write bufferage to become available
+ */
+static void rxrpc_write_space(struct sock *sk)
+{
+	_enter("%p", sk);
+	rcu_read_lock();
+	if (rxrpc_writable(sk)) {
+		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
+
+		if (skwq_has_sleeper(wq))
+			wake_up_interruptible(&wq->wait);
+		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
+	}
+	rcu_read_unlock();
+}
+
+/*
+ * validate an RxRPC address
+ */
+static int rxrpc_validate_address(struct rxrpc_sock *rx,
+				  struct sockaddr_rxrpc *srx,
+				  int len)
+{
+	unsigned int tail;
+
+	if (len < sizeof(struct sockaddr_rxrpc))
+		return -EINVAL;
+
+	if (srx->srx_family != AF_RXRPC)
+		return -EAFNOSUPPORT;
+
+	if (srx->transport_type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	len -= offsetof(struct sockaddr_rxrpc, transport);
+	if (srx->transport_len < sizeof(sa_family_t) ||
+	    srx->transport_len > len)
+		return -EINVAL;
+
+	if (srx->transport.family != rx->family &&
+	    srx->transport.family == AF_INET && rx->family != AF_INET6)
+		return -EAFNOSUPPORT;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		if (srx->transport_len < sizeof(struct sockaddr_in))
+			return -EINVAL;
+		tail = offsetof(struct sockaddr_rxrpc, transport.sin.__pad);
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		if (srx->transport_len < sizeof(struct sockaddr_in6))
+			return -EINVAL;
+		tail = offsetof(struct sockaddr_rxrpc, transport) +
+			sizeof(struct sockaddr_in6);
+		break;
+#endif
+
+	default:
+		return -EAFNOSUPPORT;
+	}
+
+	if (tail < len)
+		memset((void *)srx + tail, 0, len - tail);
+	_debug("INET: %pISp", &srx->transport);
+	return 0;
+}
+
+/*
+ * bind a local address to an RxRPC socket
+ */
+static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len)
+{
+	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)saddr;
+	struct rxrpc_local *local;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	u16 service_id;
+	int ret;
+
+	_enter("%p,%p,%d", rx, saddr, len);
+
+	ret = rxrpc_validate_address(rx, srx, len);
+	if (ret < 0)
+		goto error;
+	service_id = srx->srx_service;
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		rx->srx = *srx;
+		local = rxrpc_lookup_local(sock_net(&rx->sk), &rx->srx);
+		if (IS_ERR(local)) {
+			ret = PTR_ERR(local);
+			goto error_unlock;
+		}
+
+		if (service_id) {
+			write_lock(&local->services_lock);
+			if (rcu_access_pointer(local->service))
+				goto service_in_use;
+			rx->local = local;
+			rcu_assign_pointer(local->service, rx);
+			write_unlock(&local->services_lock);
+
+			rx->sk.sk_state = RXRPC_SERVER_BOUND;
+		} else {
+			rx->local = local;
+			rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+		}
+		break;
+
+	case RXRPC_SERVER_BOUND:
+		ret = -EINVAL;
+		if (service_id == 0)
+			goto error_unlock;
+		ret = -EADDRINUSE;
+		if (service_id == rx->srx.srx_service)
+			goto error_unlock;
+		ret = -EINVAL;
+		srx->srx_service = rx->srx.srx_service;
+		if (memcmp(srx, &rx->srx, sizeof(*srx)) != 0)
+			goto error_unlock;
+		rx->second_service = service_id;
+		rx->sk.sk_state = RXRPC_SERVER_BOUND2;
+		break;
+
+	default:
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	release_sock(&rx->sk);
+	_leave(" = 0");
+	return 0;
+
+service_in_use:
+	write_unlock(&local->services_lock);
+	rxrpc_unuse_local(local);
+	rxrpc_put_local(local);
+	ret = -EADDRINUSE;
+error_unlock:
+	release_sock(&rx->sk);
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * set the number of pending calls permitted on a listening socket
+ */
+static int rxrpc_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	unsigned int max, old;
+	int ret;
+
+	_enter("%p,%d", rx, backlog);
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		ret = -EADDRNOTAVAIL;
+		break;
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_BOUND2:
+		ASSERT(rx->local != NULL);
+		max = READ_ONCE(rxrpc_max_backlog);
+		ret = -EINVAL;
+		if (backlog == INT_MAX)
+			backlog = max;
+		else if (backlog < 0 || backlog > max)
+			break;
+		old = sk->sk_max_ack_backlog;
+		sk->sk_max_ack_backlog = backlog;
+		ret = rxrpc_service_prealloc(rx, GFP_KERNEL);
+		if (ret == 0)
+			rx->sk.sk_state = RXRPC_SERVER_LISTENING;
+		else
+			sk->sk_max_ack_backlog = old;
+		break;
+	case RXRPC_SERVER_LISTENING:
+		if (backlog == 0) {
+			rx->sk.sk_state = RXRPC_SERVER_LISTEN_DISABLED;
+			sk->sk_max_ack_backlog = 0;
+			rxrpc_discard_prealloc(rx);
+			ret = 0;
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EBUSY;
+		break;
+	}
+
+	release_sock(&rx->sk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_begin_call - Allow a kernel service to begin a call
+ * @sock: The socket on which to make the call
+ * @srx: The address of the peer to contact
+ * @key: The security context to use (defaults to socket setting)
+ * @user_call_ID: The ID to use
+ * @tx_total_len: Total length of data to transmit during the call (or -1)
+ * @gfp: The allocation constraints
+ * @notify_rx: Where to send notifications instead of socket queue
+ * @upgrade: Request service upgrade for call
+ * @interruptibility: The call is interruptible, or can be canceled.
+ * @debug_id: The debug ID for tracing to be assigned to the call
+ *
+ * Allow a kernel service to begin a call on the nominated socket.  This just
+ * sets up all the internal tracking structures and allocates connection and
+ * call IDs as appropriate.  The call to be used is returned.
+ *
+ * The default socket destination address and security may be overridden by
+ * supplying @srx and @key.
+ */
+struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
+					   struct sockaddr_rxrpc *srx,
+					   struct key *key,
+					   unsigned long user_call_ID,
+					   s64 tx_total_len,
+					   gfp_t gfp,
+					   rxrpc_notify_rx_t notify_rx,
+					   bool upgrade,
+					   enum rxrpc_interruptibility interruptibility,
+					   unsigned int debug_id)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_call_params p;
+	struct rxrpc_call *call;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter(",,%x,%lx", key_serial(key), user_call_ID);
+
+	ret = rxrpc_validate_address(rx, srx, sizeof(*srx));
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	lock_sock(&rx->sk);
+
+	if (!key)
+		key = rx->key;
+	if (key && !key->payload.data[0])
+		key = NULL; /* a no-security key */
+
+	memset(&p, 0, sizeof(p));
+	p.user_call_ID		= user_call_ID;
+	p.tx_total_len		= tx_total_len;
+	p.interruptibility	= interruptibility;
+	p.kernel		= true;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.key			= key;
+	cp.security_level	= rx->min_sec_level;
+	cp.exclusive		= false;
+	cp.upgrade		= upgrade;
+	cp.service_id		= srx->srx_service;
+	call = rxrpc_new_client_call(rx, &cp, srx, &p, gfp, debug_id);
+	/* The socket has been unlocked. */
+	if (!IS_ERR(call)) {
+		call->notify_rx = notify_rx;
+		mutex_unlock(&call->user_mutex);
+	}
+
+	rxrpc_put_peer(cp.peer);
+	_leave(" = %p", call);
+	return call;
+}
+EXPORT_SYMBOL(rxrpc_kernel_begin_call);
+
+/*
+ * Dummy function used to stop the notifier talking to recvmsg().
+ */
+static void rxrpc_dummy_notify_rx(struct sock *sk, struct rxrpc_call *rxcall,
+				  unsigned long call_user_ID)
+{
+}
+
+/**
+ * rxrpc_kernel_end_call - Allow a kernel service to end a call it was using
+ * @sock: The socket the call is on
+ * @call: The call to end
+ *
+ * Allow a kernel service to end a call it was using.  The call must be
+ * complete before this is called (the call should be aborted if necessary).
+ */
+void rxrpc_kernel_end_call(struct socket *sock, struct rxrpc_call *call)
+{
+	_enter("%d{%d}", call->debug_id, refcount_read(&call->ref));
+
+	mutex_lock(&call->user_mutex);
+	rxrpc_release_call(rxrpc_sk(sock->sk), call);
+
+	/* Make sure we're not going to call back into a kernel service */
+	if (call->notify_rx) {
+		spin_lock_bh(&call->notify_lock);
+		call->notify_rx = rxrpc_dummy_notify_rx;
+		spin_unlock_bh(&call->notify_lock);
+	}
+
+	mutex_unlock(&call->user_mutex);
+	rxrpc_put_call(call, rxrpc_call_put_kernel);
+}
+EXPORT_SYMBOL(rxrpc_kernel_end_call);
+
+/**
+ * rxrpc_kernel_check_life - Check to see whether a call is still alive
+ * @sock: The socket the call is on
+ * @call: The call to check
+ *
+ * Allow a kernel service to find out whether a call is still alive -
+ * ie. whether it has completed.
+ */
+bool rxrpc_kernel_check_life(const struct socket *sock,
+			     const struct rxrpc_call *call)
+{
+	return call->state != RXRPC_CALL_COMPLETE;
+}
+EXPORT_SYMBOL(rxrpc_kernel_check_life);
+
+/**
+ * rxrpc_kernel_get_epoch - Retrieve the epoch value from a call.
+ * @sock: The socket the call is on
+ * @call: The call to query
+ *
+ * Allow a kernel service to retrieve the epoch value from a service call to
+ * see if the client at the other end rebooted.
+ */
+u32 rxrpc_kernel_get_epoch(struct socket *sock, struct rxrpc_call *call)
+{
+	return call->conn->proto.epoch;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_epoch);
+
+/**
+ * rxrpc_kernel_new_call_notification - Get notifications of new calls
+ * @sock: The socket to intercept received messages on
+ * @notify_new_call: Function to be called when new calls appear
+ * @discard_new_call: Function to discard preallocated calls
+ *
+ * Allow a kernel service to be given notifications about new calls.
+ */
+void rxrpc_kernel_new_call_notification(
+	struct socket *sock,
+	rxrpc_notify_new_call_t notify_new_call,
+	rxrpc_discard_new_call_t discard_new_call)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+
+	rx->notify_new_call = notify_new_call;
+	rx->discard_new_call = discard_new_call;
+}
+EXPORT_SYMBOL(rxrpc_kernel_new_call_notification);
+
+/**
+ * rxrpc_kernel_set_max_life - Set maximum lifespan on a call
+ * @sock: The socket the call is on
+ * @call: The call to configure
+ * @hard_timeout: The maximum lifespan of the call in jiffies
+ *
+ * Set the maximum lifespan of a call.  The call will end with ETIME or
+ * ETIMEDOUT if it takes longer than this.
+ */
+void rxrpc_kernel_set_max_life(struct socket *sock, struct rxrpc_call *call,
+			       unsigned long hard_timeout)
+{
+	unsigned long now;
+
+	mutex_lock(&call->user_mutex);
+
+	now = jiffies;
+	hard_timeout += now;
+	WRITE_ONCE(call->expect_term_by, hard_timeout);
+	rxrpc_reduce_call_timer(call, hard_timeout, now, rxrpc_timer_set_for_hard);
+
+	mutex_unlock(&call->user_mutex);
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_max_life);
+
+/*
+ * connect an RxRPC socket
+ * - this just targets it at a specific destination; no actual connection
+ *   negotiation takes place
+ */
+static int rxrpc_connect(struct socket *sock, struct sockaddr *addr,
+			 int addr_len, int flags)
+{
+	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)addr;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter("%p,%p,%d,%d", rx, addr, addr_len, flags);
+
+	ret = rxrpc_validate_address(rx, srx, addr_len);
+	if (ret < 0) {
+		_leave(" = %d [bad addr]", ret);
+		return ret;
+	}
+
+	lock_sock(&rx->sk);
+
+	ret = -EISCONN;
+	if (test_bit(RXRPC_SOCK_CONNECTED, &rx->flags))
+		goto error;
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		rx->sk.sk_state = RXRPC_CLIENT_UNBOUND;
+	case RXRPC_CLIENT_UNBOUND:
+	case RXRPC_CLIENT_BOUND:
+		break;
+	default:
+		ret = -EBUSY;
+		goto error;
+	}
+
+	rx->connect_srx = *srx;
+	set_bit(RXRPC_SOCK_CONNECTED, &rx->flags);
+	ret = 0;
+
+error:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/*
+ * send a message through an RxRPC socket
+ * - in a client this does a number of things:
+ *   - finds/sets up a connection for the security specified (if any)
+ *   - initiates a call (ID in control data)
+ *   - ends the request phase of a call (if MSG_MORE is not set)
+ *   - sends a call data packet
+ *   - may send an abort (abort code in control data)
+ */
+static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter(",{%d},,%zu", rx->sk.sk_state, len);
+
+	if (m->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	if (m->msg_name) {
+		ret = rxrpc_validate_address(rx, m->msg_name, m->msg_namelen);
+		if (ret < 0) {
+			_leave(" = %d [bad addr]", ret);
+			return ret;
+		}
+	}
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+	case RXRPC_CLIENT_UNBOUND:
+		rx->srx.srx_family = AF_RXRPC;
+		rx->srx.srx_service = 0;
+		rx->srx.transport_type = SOCK_DGRAM;
+		rx->srx.transport.family = rx->family;
+		switch (rx->family) {
+		case AF_INET:
+			rx->srx.transport_len = sizeof(struct sockaddr_in);
+			break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+		case AF_INET6:
+			rx->srx.transport_len = sizeof(struct sockaddr_in6);
+			break;
+#endif
+		default:
+			ret = -EAFNOSUPPORT;
+			goto error_unlock;
+		}
+		local = rxrpc_lookup_local(sock_net(sock->sk), &rx->srx);
+		if (IS_ERR(local)) {
+			ret = PTR_ERR(local);
+			goto error_unlock;
+		}
+
+		rx->local = local;
+		rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+		fallthrough;
+
+	case RXRPC_CLIENT_BOUND:
+		if (!m->msg_name &&
+		    test_bit(RXRPC_SOCK_CONNECTED, &rx->flags)) {
+			m->msg_name = &rx->connect_srx;
+			m->msg_namelen = sizeof(rx->connect_srx);
+		}
+		fallthrough;
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_LISTENING:
+		ret = rxrpc_do_sendmsg(rx, m, len);
+		/* The socket has been unlocked */
+		goto out;
+	default:
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+error_unlock:
+	release_sock(&rx->sk);
+out:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+int rxrpc_sock_set_min_security_level(struct sock *sk, unsigned int val)
+{
+	if (sk->sk_state != RXRPC_UNBOUND)
+		return -EISCONN;
+	if (val > RXRPC_SECURITY_MAX)
+		return -EINVAL;
+	lock_sock(sk);
+	rxrpc_sk(sk)->min_sec_level = val;
+	release_sock(sk);
+	return 0;
+}
+EXPORT_SYMBOL(rxrpc_sock_set_min_security_level);
+
+/*
+ * set RxRPC socket options
+ */
+static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
+			    sockptr_t optval, unsigned int optlen)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	unsigned int min_sec_level;
+	u16 service_upgrade[2];
+	int ret;
+
+	_enter(",%d,%d,,%d", level, optname, optlen);
+
+	lock_sock(&rx->sk);
+	ret = -EOPNOTSUPP;
+
+	if (level == SOL_RXRPC) {
+		switch (optname) {
+		case RXRPC_EXCLUSIVE_CONNECTION:
+			ret = -EINVAL;
+			if (optlen != 0)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			rx->exclusive = true;
+			goto success;
+
+		case RXRPC_SECURITY_KEY:
+			ret = -EINVAL;
+			if (rx->key)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = rxrpc_request_key(rx, optval, optlen);
+			goto error;
+
+		case RXRPC_SECURITY_KEYRING:
+			ret = -EINVAL;
+			if (rx->key)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = rxrpc_server_keyring(rx, optval, optlen);
+			goto error;
+
+		case RXRPC_MIN_SECURITY_LEVEL:
+			ret = -EINVAL;
+			if (optlen != sizeof(unsigned int))
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = copy_from_sockptr(&min_sec_level, optval,
+				       sizeof(unsigned int));
+			if (ret < 0)
+				goto error;
+			ret = -EINVAL;
+			if (min_sec_level > RXRPC_SECURITY_MAX)
+				goto error;
+			rx->min_sec_level = min_sec_level;
+			goto success;
+
+		case RXRPC_UPGRADEABLE_SERVICE:
+			ret = -EINVAL;
+			if (optlen != sizeof(service_upgrade) ||
+			    rx->service_upgrade.from != 0)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_SERVER_BOUND2)
+				goto error;
+			ret = -EFAULT;
+			if (copy_from_sockptr(service_upgrade, optval,
+					   sizeof(service_upgrade)) != 0)
+				goto error;
+			ret = -EINVAL;
+			if ((service_upgrade[0] != rx->srx.srx_service ||
+			     service_upgrade[1] != rx->second_service) &&
+			    (service_upgrade[0] != rx->second_service ||
+			     service_upgrade[1] != rx->srx.srx_service))
+				goto error;
+			rx->service_upgrade.from = service_upgrade[0];
+			rx->service_upgrade.to = service_upgrade[1];
+			goto success;
+
+		default:
+			break;
+		}
+	}
+
+success:
+	ret = 0;
+error:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/*
+ * Get socket options.
+ */
+static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
+			    char __user *optval, int __user *_optlen)
+{
+	int optlen;
+
+	if (level != SOL_RXRPC)
+		return -EOPNOTSUPP;
+
+	if (get_user(optlen, _optlen))
+		return -EFAULT;
+
+	switch (optname) {
+	case RXRPC_SUPPORTED_CMSG:
+		if (optlen < sizeof(int))
+			return -ETOOSMALL;
+		if (put_user(RXRPC__SUPPORTED - 1, (int __user *)optval) ||
+		    put_user(sizeof(int), _optlen))
+			return -EFAULT;
+		return 0;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/*
+ * permit an RxRPC socket to be polled
+ */
+static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
+			       poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	__poll_t mask;
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	/* the socket is readable if there are any messages waiting on the Rx
+	 * queue */
+	if (!list_empty(&rx->recvmsg_q))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	/* the socket is writable if there is space to add new data to the
+	 * socket; there is no guarantee that any particular call in progress
+	 * on the socket may have space in the Tx ACK window */
+	if (rxrpc_writable(sk))
+		mask |= EPOLLOUT | EPOLLWRNORM;
+
+	return mask;
+}
+
+/*
+ * create an RxRPC socket
+ */
+static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
+			int kern)
+{
+	struct rxrpc_net *rxnet;
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+
+	_enter("%p,%d", sock, protocol);
+
+	/* we support transport protocol UDP/UDP6 only */
+	if (protocol != PF_INET &&
+	    IS_ENABLED(CONFIG_AF_RXRPC_IPV6) && protocol != PF_INET6)
+		return -EPROTONOSUPPORT;
+
+	if (sock->type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	sock->ops = &rxrpc_rpc_ops;
+	sock->state = SS_UNCONNECTED;
+
+	sk = sk_alloc(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto, kern);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock, sk);
+	sock_set_flag(sk, SOCK_RCU_FREE);
+	sk->sk_state		= RXRPC_UNBOUND;
+	sk->sk_write_space	= rxrpc_write_space;
+	sk->sk_max_ack_backlog	= 0;
+	sk->sk_destruct		= rxrpc_sock_destructor;
+
+	rx = rxrpc_sk(sk);
+	rx->family = protocol;
+	rx->calls = RB_ROOT;
+
+	spin_lock_init(&rx->incoming_lock);
+	INIT_LIST_HEAD(&rx->sock_calls);
+	INIT_LIST_HEAD(&rx->to_be_accepted);
+	INIT_LIST_HEAD(&rx->recvmsg_q);
+	rwlock_init(&rx->recvmsg_lock);
+	rwlock_init(&rx->call_lock);
+	memset(&rx->srx, 0, sizeof(rx->srx));
+
+	rxnet = rxrpc_net(sock_net(&rx->sk));
+	timer_reduce(&rxnet->peer_keepalive_timer, jiffies + 1);
+
+	_leave(" = 0 [%p]", rx);
+	return 0;
+}
+
+/*
+ * Kill all the calls on a socket and shut it down.
+ */
+static int rxrpc_shutdown(struct socket *sock, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	int ret = 0;
+
+	_enter("%p,%d", sk, flags);
+
+	if (flags != SHUT_RDWR)
+		return -EOPNOTSUPP;
+	if (sk->sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	lock_sock(sk);
+
+	spin_lock_bh(&sk->sk_receive_queue.lock);
+	if (sk->sk_state < RXRPC_CLOSE) {
+		sk->sk_state = RXRPC_CLOSE;
+		sk->sk_shutdown = SHUTDOWN_MASK;
+	} else {
+		ret = -ESHUTDOWN;
+	}
+	spin_unlock_bh(&sk->sk_receive_queue.lock);
+
+	rxrpc_discard_prealloc(rx);
+
+	release_sock(sk);
+	return ret;
+}
+
+/*
+ * RxRPC socket destructor
+ */
+static void rxrpc_sock_destructor(struct sock *sk)
+{
+	_enter("%p", sk);
+
+	rxrpc_purge_queue(&sk->sk_receive_queue);
+
+	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
+	WARN_ON(!sk_unhashed(sk));
+	WARN_ON(sk->sk_socket);
+
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		printk("Attempt to release alive rxrpc socket: %p\n", sk);
+		return;
+	}
+}
+
+/*
+ * release an RxRPC socket
+ */
+static int rxrpc_release_sock(struct sock *sk)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+
+	_enter("%p{%d,%d}", sk, sk->sk_state, refcount_read(&sk->sk_refcnt));
+
+	/* declare the socket closed for business */
+	sock_orphan(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	/* We want to kill off all connections from a service socket
+	 * as fast as possible because we can't share these; client
+	 * sockets, on the other hand, can share an endpoint.
+	 */
+	switch (sk->sk_state) {
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_BOUND2:
+	case RXRPC_SERVER_LISTENING:
+	case RXRPC_SERVER_LISTEN_DISABLED:
+		rx->local->service_closed = true;
+		break;
+	}
+
+	spin_lock_bh(&sk->sk_receive_queue.lock);
+	sk->sk_state = RXRPC_CLOSE;
+	spin_unlock_bh(&sk->sk_receive_queue.lock);
+
+	if (rx->local && rcu_access_pointer(rx->local->service) == rx) {
+		write_lock(&rx->local->services_lock);
+		rcu_assign_pointer(rx->local->service, NULL);
+		write_unlock(&rx->local->services_lock);
+	}
+
+	/* try to flush out this socket */
+	rxrpc_discard_prealloc(rx);
+	rxrpc_release_calls_on_socket(rx);
+	flush_workqueue(rxrpc_workqueue);
+	rxrpc_purge_queue(&sk->sk_receive_queue);
+
+	rxrpc_unuse_local(rx->local);
+	rxrpc_put_local(rx->local);
+	rx->local = NULL;
+	key_put(rx->key);
+	rx->key = NULL;
+	key_put(rx->securities);
+	rx->securities = NULL;
+	sock_put(sk);
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * release an RxRPC BSD socket on close() or equivalent
+ */
+static int rxrpc_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	_enter("%p{%p}", sock, sk);
+
+	if (!sk)
+		return 0;
+
+	sock->sk = NULL;
+
+	return rxrpc_release_sock(sk);
+}
+
+/*
+ * RxRPC network protocol
+ */
+static const struct proto_ops rxrpc_rpc_ops = {
+	.family		= PF_RXRPC,
+	.owner		= THIS_MODULE,
+	.release	= rxrpc_release,
+	.bind		= rxrpc_bind,
+	.connect	= rxrpc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= sock_no_accept,
+	.getname	= sock_no_getname,
+	.poll		= rxrpc_poll,
+	.ioctl		= sock_no_ioctl,
+	.listen		= rxrpc_listen,
+	.shutdown	= rxrpc_shutdown,
+	.setsockopt	= rxrpc_setsockopt,
+	.getsockopt	= rxrpc_getsockopt,
+	.sendmsg	= rxrpc_sendmsg,
+	.recvmsg	= rxrpc_recvmsg,
+	.mmap		= sock_no_mmap,
+	.sendpage	= sock_no_sendpage,
+};
+
+static struct proto rxrpc_proto = {
+	.name		= "RXRPC",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct rxrpc_sock),
+	.max_header	= sizeof(struct rxrpc_wire_header),
+};
+
+static const struct net_proto_family rxrpc_family_ops = {
+	.family	= PF_RXRPC,
+	.create = rxrpc_create,
+	.owner	= THIS_MODULE,
+};
+
+/*
+ * initialise and register the RxRPC protocol
+ */
+static int __init af_rxrpc_init(void)
+{
+	int ret = -1;
+	unsigned int tmp;
+
+	BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof_field(struct sk_buff, cb));
+
+	get_random_bytes(&tmp, sizeof(tmp));
+	tmp &= 0x3fffffff;
+	if (tmp == 0)
+		tmp = 1;
+	idr_set_cursor(&rxrpc_client_conn_ids, tmp);
+
+	ret = -ENOMEM;
+	rxrpc_call_jar = kmem_cache_create(
+		"rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
+		SLAB_HWCACHE_ALIGN, NULL);
+	if (!rxrpc_call_jar) {
+		pr_notice("Failed to allocate call jar\n");
+		goto error_call_jar;
+	}
+
+	rxrpc_workqueue = alloc_workqueue("krxrpcd", 0, 1);
+	if (!rxrpc_workqueue) {
+		pr_notice("Failed to allocate work queue\n");
+		goto error_work_queue;
+	}
+
+	ret = rxrpc_init_security();
+	if (ret < 0) {
+		pr_crit("Cannot initialise security\n");
+		goto error_security;
+	}
+
+	ret = register_pernet_device(&rxrpc_net_ops);
+	if (ret)
+		goto error_pernet;
+
+	ret = proto_register(&rxrpc_proto, 1);
+	if (ret < 0) {
+		pr_crit("Cannot register protocol\n");
+		goto error_proto;
+	}
+
+	ret = sock_register(&rxrpc_family_ops);
+	if (ret < 0) {
+		pr_crit("Cannot register socket family\n");
+		goto error_sock;
+	}
+
+	ret = register_key_type(&key_type_rxrpc);
+	if (ret < 0) {
+		pr_crit("Cannot register client key type\n");
+		goto error_key_type;
+	}
+
+	ret = register_key_type(&key_type_rxrpc_s);
+	if (ret < 0) {
+		pr_crit("Cannot register server key type\n");
+		goto error_key_type_s;
+	}
+
+	ret = rxrpc_sysctl_init();
+	if (ret < 0) {
+		pr_crit("Cannot register sysctls\n");
+		goto error_sysctls;
+	}
+
+	return 0;
+
+error_sysctls:
+	unregister_key_type(&key_type_rxrpc_s);
+error_key_type_s:
+	unregister_key_type(&key_type_rxrpc);
+error_key_type:
+	sock_unregister(PF_RXRPC);
+error_sock:
+	proto_unregister(&rxrpc_proto);
+error_proto:
+	unregister_pernet_device(&rxrpc_net_ops);
+error_pernet:
+	rxrpc_exit_security();
+error_security:
+	destroy_workqueue(rxrpc_workqueue);
+error_work_queue:
+	kmem_cache_destroy(rxrpc_call_jar);
+error_call_jar:
+	return ret;
+}
+
+/*
+ * unregister the RxRPC protocol
+ */
+static void __exit af_rxrpc_exit(void)
+{
+	_enter("");
+	rxrpc_sysctl_exit();
+	unregister_key_type(&key_type_rxrpc_s);
+	unregister_key_type(&key_type_rxrpc);
+	sock_unregister(PF_RXRPC);
+	proto_unregister(&rxrpc_proto);
+	unregister_pernet_device(&rxrpc_net_ops);
+	ASSERTCMP(atomic_read(&rxrpc_n_tx_skbs), ==, 0);
+	ASSERTCMP(atomic_read(&rxrpc_n_rx_skbs), ==, 0);
+
+	/* Make sure the local and peer records pinned by any dying connections
+	 * are released.
+	 */
+	rcu_barrier();
+	rxrpc_destroy_client_conn_ids();
+
+	destroy_workqueue(rxrpc_workqueue);
+	rxrpc_exit_security();
+	kmem_cache_destroy(rxrpc_call_jar);
+	_leave("");
+}
+
+module_init(af_rxrpc_init);
+module_exit(af_rxrpc_exit);
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
new file mode 100644
index 000000000..d86894a1c
--- /dev/null
+++ b/net/rxrpc/ar-internal.h
@@ -0,0 +1,1235 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* AF_RXRPC internal definitions
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/atomic.h>
+#include <linux/seqlock.h>
+#include <linux/win_minmax.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "protocol.h"
+
+#define FCRYPT_BSIZE 8
+struct rxrpc_crypt {
+	union {
+		u8	x[FCRYPT_BSIZE];
+		__be32	n[2];
+	};
+} __attribute__((aligned(8)));
+
+#define rxrpc_queue_work(WS)	queue_work(rxrpc_workqueue, (WS))
+#define rxrpc_queue_delayed_work(WS,D)	\
+	queue_delayed_work(rxrpc_workqueue, (WS), (D))
+
+struct rxrpc_connection;
+
+/*
+ * Mark applied to socket buffers in skb->mark.  skb->priority is used
+ * to pass supplementary information.
+ */
+enum rxrpc_skb_mark {
+	RXRPC_SKB_MARK_REJECT_BUSY,	/* Reject with BUSY */
+	RXRPC_SKB_MARK_REJECT_ABORT,	/* Reject with ABORT (code in skb->priority) */
+};
+
+/*
+ * sk_state for RxRPC sockets
+ */
+enum {
+	RXRPC_UNBOUND = 0,
+	RXRPC_CLIENT_UNBOUND,		/* Unbound socket used as client */
+	RXRPC_CLIENT_BOUND,		/* client local address bound */
+	RXRPC_SERVER_BOUND,		/* server local address bound */
+	RXRPC_SERVER_BOUND2,		/* second server local address bound */
+	RXRPC_SERVER_LISTENING,		/* server listening for connections */
+	RXRPC_SERVER_LISTEN_DISABLED,	/* server listening disabled */
+	RXRPC_CLOSE,			/* socket is being closed */
+};
+
+/*
+ * Per-network namespace data.
+ */
+struct rxrpc_net {
+	struct proc_dir_entry	*proc_net;	/* Subdir in /proc/net */
+	u32			epoch;		/* Local epoch for detecting local-end reset */
+	struct list_head	calls;		/* List of calls active in this namespace */
+	rwlock_t		call_lock;	/* Lock for ->calls */
+	atomic_t		nr_calls;	/* Count of allocated calls */
+
+	atomic_t		nr_conns;
+	struct list_head	conn_proc_list;	/* List of conns in this namespace for proc */
+	struct list_head	service_conns;	/* Service conns in this namespace */
+	rwlock_t		conn_lock;	/* Lock for ->conn_proc_list, ->service_conns */
+	struct work_struct	service_conn_reaper;
+	struct timer_list	service_conn_reap_timer;
+
+	bool			live;
+
+	bool			kill_all_client_conns;
+	atomic_t		nr_client_conns;
+	spinlock_t		client_conn_cache_lock; /* Lock for ->*_client_conns */
+	spinlock_t		client_conn_discard_lock; /* Prevent multiple discarders */
+	struct list_head	idle_client_conns;
+	struct work_struct	client_conn_reaper;
+	struct timer_list	client_conn_reap_timer;
+
+	struct hlist_head	local_endpoints;
+	struct mutex		local_mutex;	/* Lock for ->local_endpoints */
+
+	DECLARE_HASHTABLE	(peer_hash, 10);
+	spinlock_t		peer_hash_lock;	/* Lock for ->peer_hash */
+
+#define RXRPC_KEEPALIVE_TIME 20 /* NAT keepalive time in seconds */
+	u8			peer_keepalive_cursor;
+	time64_t		peer_keepalive_base;
+	struct list_head	peer_keepalive[32];
+	struct list_head	peer_keepalive_new;
+	struct timer_list	peer_keepalive_timer;
+	struct work_struct	peer_keepalive_work;
+};
+
+/*
+ * Service backlog preallocation.
+ *
+ * This contains circular buffers of preallocated peers, connections and calls
+ * for incoming service calls and their head and tail pointers.  This allows
+ * calls to be set up in the data_ready handler, thereby avoiding the need to
+ * shuffle packets around so much.
+ */
+struct rxrpc_backlog {
+	unsigned short		peer_backlog_head;
+	unsigned short		peer_backlog_tail;
+	unsigned short		conn_backlog_head;
+	unsigned short		conn_backlog_tail;
+	unsigned short		call_backlog_head;
+	unsigned short		call_backlog_tail;
+#define RXRPC_BACKLOG_MAX	32
+	struct rxrpc_peer	*peer_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_connection	*conn_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_call	*call_backlog[RXRPC_BACKLOG_MAX];
+};
+
+/*
+ * RxRPC socket definition
+ */
+struct rxrpc_sock {
+	/* WARNING: sk has to be the first member */
+	struct sock		sk;
+	rxrpc_notify_new_call_t	notify_new_call; /* Func to notify of new call */
+	rxrpc_discard_new_call_t discard_new_call; /* Func to discard a new call */
+	struct rxrpc_local	*local;		/* local endpoint */
+	struct rxrpc_backlog	*backlog;	/* Preallocation for services */
+	spinlock_t		incoming_lock;	/* Incoming call vs service shutdown lock */
+	struct list_head	sock_calls;	/* List of calls owned by this socket */
+	struct list_head	to_be_accepted;	/* calls awaiting acceptance */
+	struct list_head	recvmsg_q;	/* Calls awaiting recvmsg's attention  */
+	rwlock_t		recvmsg_lock;	/* Lock for recvmsg_q */
+	struct key		*key;		/* security for this socket */
+	struct key		*securities;	/* list of server security descriptors */
+	struct rb_root		calls;		/* User ID -> call mapping */
+	unsigned long		flags;
+#define RXRPC_SOCK_CONNECTED		0	/* connect_srx is set */
+	rwlock_t		call_lock;	/* lock for calls */
+	u32			min_sec_level;	/* minimum security level */
+#define RXRPC_SECURITY_MAX	RXRPC_SECURITY_ENCRYPT
+	bool			exclusive;	/* Exclusive connection for a client socket */
+	u16			second_service;	/* Additional service bound to the endpoint */
+	struct {
+		/* Service upgrade information */
+		u16		from;		/* Service ID to upgrade (if not 0) */
+		u16		to;		/* service ID to upgrade to */
+	} service_upgrade;
+	sa_family_t		family;		/* Protocol family created with */
+	struct sockaddr_rxrpc	srx;		/* Primary Service/local addresses */
+	struct sockaddr_rxrpc	connect_srx;	/* Default client address from connect() */
+};
+
+#define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)
+
+/*
+ * CPU-byteorder normalised Rx packet header.
+ */
+struct rxrpc_host_header {
+	u32		epoch;		/* client boot timestamp */
+	u32		cid;		/* connection and channel ID */
+	u32		callNumber;	/* call ID (0 for connection-level packets) */
+	u32		seq;		/* sequence number of pkt in call stream */
+	u32		serial;		/* serial number of pkt sent to network */
+	u8		type;		/* packet type */
+	u8		flags;		/* packet flags */
+	u8		userStatus;	/* app-layer defined status */
+	u8		securityIndex;	/* security protocol ID */
+	union {
+		u16	_rsvd;		/* reserved */
+		u16	cksum;		/* kerberos security checksum */
+	};
+	u16		serviceId;	/* service ID */
+} __packed;
+
+/*
+ * RxRPC socket buffer private variables
+ * - max 48 bytes (struct sk_buff::cb)
+ */
+struct rxrpc_skb_priv {
+	atomic_t	nr_ring_pins;		/* Number of rxtx ring pins */
+	u8		nr_subpackets;		/* Number of subpackets */
+	u8		rx_flags;		/* Received packet flags */
+#define RXRPC_SKB_INCL_LAST	0x01		/* - Includes last packet */
+#define RXRPC_SKB_TX_BUFFER	0x02		/* - Is transmit buffer */
+	union {
+		int		remain;		/* amount of space remaining for next write */
+
+		/* List of requested ACKs on subpackets */
+		unsigned long	rx_req_ack[(RXRPC_MAX_NR_JUMBO + BITS_PER_LONG - 1) /
+					   BITS_PER_LONG];
+	};
+
+	struct rxrpc_host_header hdr;		/* RxRPC packet header from this packet */
+};
+
+#define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)
+
+/*
+ * RxRPC security module interface
+ */
+struct rxrpc_security {
+	const char		*name;		/* name of this service */
+	u8			security_index;	/* security type provided */
+	u32			no_key_abort;	/* Abort code indicating no key */
+
+	/* Initialise a security service */
+	int (*init)(void);
+
+	/* Clean up a security service */
+	void (*exit)(void);
+
+	/* initialise a connection's security */
+	int (*init_connection_security)(struct rxrpc_connection *);
+
+	/* prime a connection's packet security */
+	int (*prime_packet_security)(struct rxrpc_connection *);
+
+	/* impose security on a packet */
+	int (*secure_packet)(struct rxrpc_call *,
+			     struct sk_buff *,
+			     size_t,
+			     void *);
+
+	/* verify the security on a received packet */
+	int (*verify_packet)(struct rxrpc_call *, struct sk_buff *,
+			     unsigned int, unsigned int, rxrpc_seq_t, u16);
+
+	/* Free crypto request on a call */
+	void (*free_call_crypto)(struct rxrpc_call *);
+
+	/* Locate the data in a received packet that has been verified. */
+	void (*locate_data)(struct rxrpc_call *, struct sk_buff *,
+			    unsigned int *, unsigned int *);
+
+	/* issue a challenge */
+	int (*issue_challenge)(struct rxrpc_connection *);
+
+	/* respond to a challenge */
+	int (*respond_to_challenge)(struct rxrpc_connection *,
+				    struct sk_buff *,
+				    u32 *);
+
+	/* verify a response */
+	int (*verify_response)(struct rxrpc_connection *,
+			       struct sk_buff *,
+			       u32 *);
+
+	/* clear connection security */
+	void (*clear)(struct rxrpc_connection *);
+};
+
+/*
+ * RxRPC local transport endpoint description
+ * - owned by a single AF_RXRPC socket
+ * - pointed to by transport socket struct sk_user_data
+ */
+struct rxrpc_local {
+	struct rcu_head		rcu;
+	atomic_t		active_users;	/* Number of users of the local endpoint */
+	refcount_t		ref;		/* Number of references to the structure */
+	struct rxrpc_net	*rxnet;		/* The network ns in which this resides */
+	struct hlist_node	link;
+	struct socket		*socket;	/* my UDP socket */
+	struct work_struct	processor;
+	struct rxrpc_sock __rcu	*service;	/* Service(s) listening on this endpoint */
+	struct rw_semaphore	defrag_sem;	/* control re-enablement of IP DF bit */
+	struct sk_buff_head	reject_queue;	/* packets awaiting rejection */
+	struct sk_buff_head	event_queue;	/* endpoint event packets awaiting processing */
+	struct rb_root		client_bundles;	/* Client connection bundles by socket params */
+	spinlock_t		client_bundles_lock; /* Lock for client_bundles */
+	spinlock_t		lock;		/* access lock */
+	rwlock_t		services_lock;	/* lock for services list */
+	int			debug_id;	/* debug ID for printks */
+	bool			dead;
+	bool			service_closed;	/* Service socket closed */
+	struct sockaddr_rxrpc	srx;		/* local address */
+};
+
+/*
+ * RxRPC remote transport endpoint definition
+ * - matched by local endpoint, remote port, address and protocol type
+ */
+struct rxrpc_peer {
+	struct rcu_head		rcu;		/* This must be first */
+	refcount_t		ref;
+	unsigned long		hash_key;
+	struct hlist_node	hash_link;
+	struct rxrpc_local	*local;
+	struct hlist_head	error_targets;	/* targets for net error distribution */
+	struct rb_root		service_conns;	/* Service connections */
+	struct list_head	keepalive_link;	/* Link in net->peer_keepalive[] */
+	time64_t		last_tx_at;	/* Last time packet sent here */
+	seqlock_t		service_conn_lock;
+	spinlock_t		lock;		/* access lock */
+	unsigned int		if_mtu;		/* interface MTU for this peer */
+	unsigned int		mtu;		/* network MTU for this peer */
+	unsigned int		maxdata;	/* data size (MTU - hdrsize) */
+	unsigned short		hdrsize;	/* header size (IP + UDP + RxRPC) */
+	int			debug_id;	/* debug ID for printks */
+	struct sockaddr_rxrpc	srx;		/* remote address */
+
+	/* calculated RTT cache */
+#define RXRPC_RTT_CACHE_SIZE 32
+	spinlock_t		rtt_input_lock;	/* RTT lock for input routine */
+	ktime_t			rtt_last_req;	/* Time of last RTT request */
+	unsigned int		rtt_count;	/* Number of samples we've got */
+
+	u32			srtt_us;	/* smoothed round trip time << 3 in usecs */
+	u32			mdev_us;	/* medium deviation			*/
+	u32			mdev_max_us;	/* maximal mdev for the last rtt period	*/
+	u32			rttvar_us;	/* smoothed mdev_max			*/
+	u32			rto_j;		/* Retransmission timeout in jiffies */
+	u8			backoff;	/* Backoff timeout */
+
+	u8			cong_cwnd;	/* Congestion window size */
+};
+
+/*
+ * Keys for matching a connection.
+ */
+struct rxrpc_conn_proto {
+	union {
+		struct {
+			u32	epoch;		/* epoch of this connection */
+			u32	cid;		/* connection ID */
+		};
+		u64		index_key;
+	};
+};
+
+struct rxrpc_conn_parameters {
+	struct rxrpc_local	*local;		/* Representation of local endpoint */
+	struct rxrpc_peer	*peer;		/* Remote endpoint */
+	struct key		*key;		/* Security details */
+	bool			exclusive;	/* T if conn is exclusive */
+	bool			upgrade;	/* T if service ID can be upgraded */
+	u16			service_id;	/* Service ID for this connection */
+	u32			security_level;	/* Security level selected */
+};
+
+/*
+ * Bits in the connection flags.
+ */
+enum rxrpc_conn_flag {
+	RXRPC_CONN_HAS_IDR,		/* Has a client conn ID assigned */
+	RXRPC_CONN_IN_SERVICE_CONNS,	/* Conn is in peer->service_conns */
+	RXRPC_CONN_DONT_REUSE,		/* Don't reuse this connection */
+	RXRPC_CONN_PROBING_FOR_UPGRADE,	/* Probing for service upgrade */
+	RXRPC_CONN_FINAL_ACK_0,		/* Need final ACK for channel 0 */
+	RXRPC_CONN_FINAL_ACK_1,		/* Need final ACK for channel 1 */
+	RXRPC_CONN_FINAL_ACK_2,		/* Need final ACK for channel 2 */
+	RXRPC_CONN_FINAL_ACK_3,		/* Need final ACK for channel 3 */
+};
+
+#define RXRPC_CONN_FINAL_ACK_MASK ((1UL << RXRPC_CONN_FINAL_ACK_0) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_1) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_2) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_3))
+
+/*
+ * Events that can be raised upon a connection.
+ */
+enum rxrpc_conn_event {
+	RXRPC_CONN_EV_CHALLENGE,	/* Send challenge packet */
+};
+
+/*
+ * The connection protocol state.
+ */
+enum rxrpc_conn_proto_state {
+	RXRPC_CONN_UNUSED,		/* Connection not yet attempted */
+	RXRPC_CONN_CLIENT,		/* Client connection */
+	RXRPC_CONN_SERVICE_PREALLOC,	/* Service connection preallocation */
+	RXRPC_CONN_SERVICE_UNSECURED,	/* Service unsecured connection */
+	RXRPC_CONN_SERVICE_CHALLENGING,	/* Service challenging for security */
+	RXRPC_CONN_SERVICE,		/* Service secured connection */
+	RXRPC_CONN_REMOTELY_ABORTED,	/* Conn aborted by peer */
+	RXRPC_CONN_LOCALLY_ABORTED,	/* Conn aborted locally */
+	RXRPC_CONN__NR_STATES
+};
+
+/*
+ * RxRPC client connection bundle.
+ */
+struct rxrpc_bundle {
+	struct rxrpc_conn_parameters params;
+	refcount_t		ref;
+	atomic_t		active;		/* Number of active users */
+	unsigned int		debug_id;
+	bool			try_upgrade;	/* True if the bundle is attempting upgrade */
+	bool			alloc_conn;	/* True if someone's getting a conn */
+	short			alloc_error;	/* Error from last conn allocation */
+	spinlock_t		channel_lock;
+	struct rb_node		local_node;	/* Node in local->client_conns */
+	struct list_head	waiting_calls;	/* Calls waiting for channels */
+	unsigned long		avail_chans;	/* Mask of available channels */
+	struct rxrpc_connection	*conns[4];	/* The connections in the bundle (max 4) */
+};
+
+/*
+ * RxRPC connection definition
+ * - matched by { local, peer, epoch, conn_id, direction }
+ * - each connection can only handle four simultaneous calls
+ */
+struct rxrpc_connection {
+	struct rxrpc_conn_proto	proto;
+	struct rxrpc_conn_parameters params;
+
+	refcount_t		ref;
+	struct rcu_head		rcu;
+	struct list_head	cache_link;
+
+	unsigned char		act_chans;	/* Mask of active channels */
+	struct rxrpc_channel {
+		unsigned long		final_ack_at;	/* Time at which to issue final ACK */
+		struct rxrpc_call __rcu	*call;		/* Active call */
+		unsigned int		call_debug_id;	/* call->debug_id */
+		u32			call_id;	/* ID of current call */
+		u32			call_counter;	/* Call ID counter */
+		u32			last_call;	/* ID of last call */
+		u8			last_type;	/* Type of last packet */
+		union {
+			u32		last_seq;
+			u32		last_abort;
+		};
+	} channels[RXRPC_MAXCALLS];
+
+	struct timer_list	timer;		/* Conn event timer */
+	struct work_struct	processor;	/* connection event processor */
+	struct rxrpc_bundle	*bundle;	/* Client connection bundle */
+	struct rb_node		service_node;	/* Node in peer->service_conns */
+	struct list_head	proc_link;	/* link in procfs list */
+	struct list_head	link;		/* link in master connection list */
+	struct sk_buff_head	rx_queue;	/* received conn-level packets */
+	const struct rxrpc_security *security;	/* applied security module */
+	struct key		*server_key;	/* security for this service */
+	struct crypto_sync_skcipher *cipher;	/* encryption handle */
+	struct rxrpc_crypt	csum_iv;	/* packet checksum base */
+	unsigned long		flags;
+	unsigned long		events;
+	unsigned long		idle_timestamp;	/* Time at which last became idle */
+	spinlock_t		state_lock;	/* state-change lock */
+	enum rxrpc_conn_proto_state state;	/* current state of connection */
+	u32			abort_code;	/* Abort code of connection abort */
+	int			debug_id;	/* debug ID for printks */
+	atomic_t		serial;		/* packet serial number counter */
+	unsigned int		hi_serial;	/* highest serial number received */
+	u32			security_nonce;	/* response re-use preventer */
+	u32			service_id;	/* Service ID, possibly upgraded */
+	u8			size_align;	/* data size alignment (for security) */
+	u8			security_size;	/* security header size */
+	u8			security_ix;	/* security type */
+	u8			out_clientflag;	/* RXRPC_CLIENT_INITIATED if we are client */
+	u8			bundle_shift;	/* Index into bundle->avail_chans */
+	short			error;		/* Local error code */
+};
+
+static inline bool rxrpc_to_server(const struct rxrpc_skb_priv *sp)
+{
+	return sp->hdr.flags & RXRPC_CLIENT_INITIATED;
+}
+
+static inline bool rxrpc_to_client(const struct rxrpc_skb_priv *sp)
+{
+	return !rxrpc_to_server(sp);
+}
+
+/*
+ * Flags in call->flags.
+ */
+enum rxrpc_call_flag {
+	RXRPC_CALL_RELEASED,		/* call has been released - no more message to userspace */
+	RXRPC_CALL_HAS_USERID,		/* has a user ID attached */
+	RXRPC_CALL_IS_SERVICE,		/* Call is service call */
+	RXRPC_CALL_EXPOSED,		/* The call was exposed to the world */
+	RXRPC_CALL_RX_LAST,		/* Received the last packet (at rxtx_top) */
+	RXRPC_CALL_TX_LAST,		/* Last packet in Tx buffer (at rxtx_top) */
+	RXRPC_CALL_SEND_PING,		/* A ping will need to be sent */
+	RXRPC_CALL_RETRANS_TIMEOUT,	/* Retransmission due to timeout occurred */
+	RXRPC_CALL_BEGAN_RX_TIMER,	/* We began the expect_rx_by timer */
+	RXRPC_CALL_RX_HEARD,		/* The peer responded at least once to this call */
+	RXRPC_CALL_RX_UNDERRUN,		/* Got data underrun */
+	RXRPC_CALL_DISCONNECTED,	/* The call has been disconnected */
+	RXRPC_CALL_KERNEL,		/* The call was made by the kernel */
+	RXRPC_CALL_UPGRADE,		/* Service upgrade was requested for the call */
+};
+
+/*
+ * Events that can be raised on a call.
+ */
+enum rxrpc_call_event {
+	RXRPC_CALL_EV_ACK,		/* need to generate ACK */
+	RXRPC_CALL_EV_ABORT,		/* need to generate abort */
+	RXRPC_CALL_EV_RESEND,		/* Tx resend required */
+	RXRPC_CALL_EV_PING,		/* Ping send required */
+	RXRPC_CALL_EV_EXPIRED,		/* Expiry occurred */
+	RXRPC_CALL_EV_ACK_LOST,		/* ACK may be lost, send ping */
+};
+
+/*
+ * The states that a call can be in.
+ */
+enum rxrpc_call_state {
+	RXRPC_CALL_UNINITIALISED,
+	RXRPC_CALL_CLIENT_AWAIT_CONN,	/* - client waiting for connection to become available */
+	RXRPC_CALL_CLIENT_SEND_REQUEST,	/* - client sending request phase */
+	RXRPC_CALL_CLIENT_AWAIT_REPLY,	/* - client awaiting reply */
+	RXRPC_CALL_CLIENT_RECV_REPLY,	/* - client receiving reply phase */
+	RXRPC_CALL_SERVER_PREALLOC,	/* - service preallocation */
+	RXRPC_CALL_SERVER_SECURING,	/* - server securing request connection */
+	RXRPC_CALL_SERVER_RECV_REQUEST,	/* - server receiving request */
+	RXRPC_CALL_SERVER_ACK_REQUEST,	/* - server pending ACK of request */
+	RXRPC_CALL_SERVER_SEND_REPLY,	/* - server sending reply */
+	RXRPC_CALL_SERVER_AWAIT_ACK,	/* - server awaiting final ACK */
+	RXRPC_CALL_COMPLETE,		/* - call complete */
+	NR__RXRPC_CALL_STATES
+};
+
+/*
+ * Call completion condition (state == RXRPC_CALL_COMPLETE).
+ */
+enum rxrpc_call_completion {
+	RXRPC_CALL_SUCCEEDED,		/* - Normal termination */
+	RXRPC_CALL_REMOTELY_ABORTED,	/* - call aborted by peer */
+	RXRPC_CALL_LOCALLY_ABORTED,	/* - call aborted locally on error or close */
+	RXRPC_CALL_LOCAL_ERROR,		/* - call failed due to local error */
+	RXRPC_CALL_NETWORK_ERROR,	/* - call terminated by network error */
+	NR__RXRPC_CALL_COMPLETIONS
+};
+
+/*
+ * Call Tx congestion management modes.
+ */
+enum rxrpc_congest_mode {
+	RXRPC_CALL_SLOW_START,
+	RXRPC_CALL_CONGEST_AVOIDANCE,
+	RXRPC_CALL_PACKET_LOSS,
+	RXRPC_CALL_FAST_RETRANSMIT,
+	NR__RXRPC_CONGEST_MODES
+};
+
+/*
+ * RxRPC call definition
+ * - matched by { connection, call_id }
+ */
+struct rxrpc_call {
+	struct rcu_head		rcu;
+	struct rxrpc_connection	*conn;		/* connection carrying call */
+	struct rxrpc_peer	*peer;		/* Peer record for remote address */
+	struct rxrpc_sock __rcu	*socket;	/* socket responsible */
+	struct rxrpc_net	*rxnet;		/* Network namespace to which call belongs */
+	const struct rxrpc_security *security;	/* applied security module */
+	struct mutex		user_mutex;	/* User access mutex */
+	unsigned long		ack_at;		/* When deferred ACK needs to happen */
+	unsigned long		ack_lost_at;	/* When ACK is figured as lost */
+	unsigned long		resend_at;	/* When next resend needs to happen */
+	unsigned long		ping_at;	/* When next to send a ping */
+	unsigned long		keepalive_at;	/* When next to send a keepalive ping */
+	unsigned long		expect_rx_by;	/* When we expect to get a packet by */
+	unsigned long		expect_req_by;	/* When we expect to get a request DATA packet by */
+	unsigned long		expect_term_by;	/* When we expect call termination by */
+	u32			next_rx_timo;	/* Timeout for next Rx packet (jif) */
+	u32			next_req_timo;	/* Timeout for next Rx request packet (jif) */
+	struct skcipher_request	*cipher_req;	/* Packet cipher request buffer */
+	struct timer_list	timer;		/* Combined event timer */
+	struct work_struct	processor;	/* Event processor */
+	rxrpc_notify_rx_t	notify_rx;	/* kernel service Rx notification function */
+	struct list_head	link;		/* link in master call list */
+	struct list_head	chan_wait_link;	/* Link in conn->bundle->waiting_calls */
+	struct hlist_node	error_link;	/* link in error distribution list */
+	struct list_head	accept_link;	/* Link in rx->acceptq */
+	struct list_head	recvmsg_link;	/* Link in rx->recvmsg_q */
+	struct list_head	sock_link;	/* Link in rx->sock_calls */
+	struct rb_node		sock_node;	/* Node in rx->calls */
+	struct sk_buff		*tx_pending;	/* Tx socket buffer being filled */
+	wait_queue_head_t	waitq;		/* Wait queue for channel or Tx */
+	s64			tx_total_len;	/* Total length left to be transmitted (or -1) */
+	__be32			crypto_buf[2];	/* Temporary packet crypto buffer */
+	unsigned long		user_call_ID;	/* user-defined call ID */
+	unsigned long		flags;
+	unsigned long		events;
+	spinlock_t		lock;
+	spinlock_t		notify_lock;	/* Kernel notification lock */
+	rwlock_t		state_lock;	/* lock for state transition */
+	u32			abort_code;	/* Local/remote abort code */
+	int			error;		/* Local error incurred */
+	enum rxrpc_call_state	state;		/* current state of call */
+	enum rxrpc_call_completion completion;	/* Call completion condition */
+	refcount_t		ref;
+	u16			service_id;	/* service ID */
+	u8			security_ix;	/* Security type */
+	enum rxrpc_interruptibility interruptibility; /* At what point call may be interrupted */
+	u32			call_id;	/* call ID on connection  */
+	u32			cid;		/* connection ID plus channel index */
+	int			debug_id;	/* debug ID for printks */
+	unsigned short		rx_pkt_offset;	/* Current recvmsg packet offset */
+	unsigned short		rx_pkt_len;	/* Current recvmsg packet len */
+	bool			rx_pkt_last;	/* Current recvmsg packet is last */
+
+	/* Rx/Tx circular buffer, depending on phase.
+	 *
+	 * In the Rx phase, packets are annotated with 0 or the number of the
+	 * segment of a jumbo packet each buffer refers to.  There can be up to
+	 * 47 segments in a maximum-size UDP packet.
+	 *
+	 * In the Tx phase, packets are annotated with which buffers have been
+	 * acked.
+	 */
+#define RXRPC_RXTX_BUFF_SIZE	64
+#define RXRPC_RXTX_BUFF_MASK	(RXRPC_RXTX_BUFF_SIZE - 1)
+#define RXRPC_INIT_RX_WINDOW_SIZE 63
+	struct sk_buff		**rxtx_buffer;
+	u8			*rxtx_annotations;
+#define RXRPC_TX_ANNO_ACK	0
+#define RXRPC_TX_ANNO_UNACK	1
+#define RXRPC_TX_ANNO_NAK	2
+#define RXRPC_TX_ANNO_RETRANS	3
+#define RXRPC_TX_ANNO_MASK	0x03
+#define RXRPC_TX_ANNO_LAST	0x04
+#define RXRPC_TX_ANNO_RESENT	0x08
+
+#define RXRPC_RX_ANNO_SUBPACKET	0x3f		/* Subpacket number in jumbogram */
+#define RXRPC_RX_ANNO_VERIFIED	0x80		/* Set if verified and decrypted */
+	rxrpc_seq_t		tx_hard_ack;	/* Dead slot in buffer; the first transmitted but
+						 * not hard-ACK'd packet follows this.
+						 */
+	rxrpc_seq_t		tx_top;		/* Highest Tx slot allocated. */
+	u16			tx_backoff;	/* Delay to insert due to Tx failure */
+
+	/* TCP-style slow-start congestion control [RFC5681].  Since the SMSS
+	 * is fixed, we keep these numbers in terms of segments (ie. DATA
+	 * packets) rather than bytes.
+	 */
+#define RXRPC_TX_SMSS		RXRPC_JUMBO_DATALEN
+	u8			cong_cwnd;	/* Congestion window size */
+	u8			cong_extra;	/* Extra to send for congestion management */
+	u8			cong_ssthresh;	/* Slow-start threshold */
+	enum rxrpc_congest_mode	cong_mode:8;	/* Congestion management mode */
+	u8			cong_dup_acks;	/* Count of ACKs showing missing packets */
+	u8			cong_cumul_acks; /* Cumulative ACK count */
+	ktime_t			cong_tstamp;	/* Last time cwnd was changed */
+
+	rxrpc_seq_t		rx_hard_ack;	/* Dead slot in buffer; the first received but not
+						 * consumed packet follows this.
+						 */
+	rxrpc_seq_t		rx_top;		/* Highest Rx slot allocated. */
+	rxrpc_seq_t		rx_expect_next;	/* Expected next packet sequence number */
+	rxrpc_serial_t		rx_serial;	/* Highest serial received for this call */
+	u8			rx_winsize;	/* Size of Rx window */
+	u8			tx_winsize;	/* Maximum size of Tx window */
+	bool			tx_phase;	/* T if transmission phase, F if receive phase */
+	u8			nr_jumbo_bad;	/* Number of jumbo dups/exceeds-windows */
+
+	spinlock_t		input_lock;	/* Lock for packet input to this call */
+
+	/* Receive-phase ACK management (ACKs we send). */
+	u8			ackr_reason;	/* reason to ACK */
+	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
+	rxrpc_seq_t		ackr_highest_seq; /* Higest sequence number received */
+	atomic_t		ackr_nr_unacked; /* Number of unacked packets */
+	atomic_t		ackr_nr_consumed; /* Number of packets needing hard ACK */
+
+	/* RTT management */
+	rxrpc_serial_t		rtt_serial[4];	/* Serial number of DATA or PING sent */
+	ktime_t			rtt_sent_at[4];	/* Time packet sent */
+	unsigned long		rtt_avail;	/* Mask of available slots in bits 0-3,
+						 * Mask of pending samples in 8-11 */
+#define RXRPC_CALL_RTT_AVAIL_MASK	0xf
+#define RXRPC_CALL_RTT_PEND_SHIFT	8
+
+	/* Transmission-phase ACK management (ACKs we've received). */
+	ktime_t			acks_latest_ts;	/* Timestamp of latest ACK received */
+	rxrpc_seq_t		acks_first_seq;	/* first sequence number received */
+	rxrpc_seq_t		acks_prev_seq;	/* Highest previousPacket received */
+	rxrpc_seq_t		acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */
+	rxrpc_seq_t		acks_lost_top;	/* tx_top at the time lost-ack ping sent */
+	rxrpc_serial_t		acks_lost_ping;	/* Serial number of probe ACK */
+};
+
+/*
+ * Summary of a new ACK and the changes it made to the Tx buffer packet states.
+ */
+struct rxrpc_ack_summary {
+	u8			ack_reason;
+	u8			nr_acks;		/* Number of ACKs in packet */
+	u8			nr_nacks;		/* Number of NACKs in packet */
+	u8			nr_new_acks;		/* Number of new ACKs in packet */
+	u8			nr_new_nacks;		/* Number of new NACKs in packet */
+	u8			nr_rot_new_acks;	/* Number of rotated new ACKs */
+	bool			new_low_nack;		/* T if new low NACK found */
+	bool			retrans_timeo;		/* T if reTx due to timeout happened */
+	u8			flight_size;		/* Number of unreceived transmissions */
+	/* Place to stash values for tracing */
+	enum rxrpc_congest_mode	mode:8;
+	u8			cwnd;
+	u8			ssthresh;
+	u8			dup_acks;
+	u8			cumulative_acks;
+};
+
+/*
+ * sendmsg() cmsg-specified parameters.
+ */
+enum rxrpc_command {
+	RXRPC_CMD_SEND_DATA,		/* send data message */
+	RXRPC_CMD_SEND_ABORT,		/* request abort generation */
+	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */
+	RXRPC_CMD_CHARGE_ACCEPT,	/* [server] charge accept preallocation */
+};
+
+struct rxrpc_call_params {
+	s64			tx_total_len;	/* Total Tx data length (if send data) */
+	unsigned long		user_call_ID;	/* User's call ID */
+	struct {
+		u32		hard;		/* Maximum lifetime (sec) */
+		u32		idle;		/* Max time since last data packet (msec) */
+		u32		normal;		/* Max time since last call packet (msec) */
+	} timeouts;
+	u8			nr_timeouts;	/* Number of timeouts specified */
+	bool			kernel;		/* T if kernel is making the call */
+	enum rxrpc_interruptibility interruptibility; /* How is interruptible is the call? */
+};
+
+struct rxrpc_send_params {
+	struct rxrpc_call_params call;
+	u32			abort_code;	/* Abort code to Tx (if abort) */
+	enum rxrpc_command	command : 8;	/* The command to implement */
+	bool			exclusive;	/* Shared or exclusive call */
+	bool			upgrade;	/* If the connection is upgradeable */
+};
+
+#include <trace/events/rxrpc.h>
+
+/*
+ * af_rxrpc.c
+ */
+extern atomic_t rxrpc_n_tx_skbs, rxrpc_n_rx_skbs;
+extern struct workqueue_struct *rxrpc_workqueue;
+
+/*
+ * call_accept.c
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *, gfp_t);
+void rxrpc_discard_prealloc(struct rxrpc_sock *);
+struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *,
+					   struct rxrpc_sock *,
+					   struct sk_buff *);
+void rxrpc_accept_incoming_calls(struct rxrpc_local *);
+int rxrpc_user_charge_accept(struct rxrpc_sock *, unsigned long);
+
+/*
+ * call_event.c
+ */
+void rxrpc_propose_ACK(struct rxrpc_call *, u8, u32, bool, bool,
+		       enum rxrpc_propose_ack_trace);
+void rxrpc_process_call(struct work_struct *);
+
+void rxrpc_reduce_call_timer(struct rxrpc_call *call,
+			     unsigned long expire_at,
+			     unsigned long now,
+			     enum rxrpc_timer_trace why);
+
+void rxrpc_delete_call_timer(struct rxrpc_call *call);
+
+/*
+ * call_object.c
+ */
+extern const char *const rxrpc_call_states[];
+extern const char *const rxrpc_call_completions[];
+extern unsigned int rxrpc_max_call_lifetime;
+extern struct kmem_cache *rxrpc_call_jar;
+
+struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long);
+struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *, gfp_t, unsigned int);
+struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *,
+					 struct rxrpc_conn_parameters *,
+					 struct sockaddr_rxrpc *,
+					 struct rxrpc_call_params *, gfp_t,
+					 unsigned int);
+void rxrpc_incoming_call(struct rxrpc_sock *, struct rxrpc_call *,
+			 struct sk_buff *);
+void rxrpc_release_call(struct rxrpc_sock *, struct rxrpc_call *);
+void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
+bool __rxrpc_queue_call(struct rxrpc_call *);
+bool rxrpc_queue_call(struct rxrpc_call *);
+void rxrpc_see_call(struct rxrpc_call *);
+bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op);
+void rxrpc_get_call(struct rxrpc_call *, enum rxrpc_call_trace);
+void rxrpc_put_call(struct rxrpc_call *, enum rxrpc_call_trace);
+void rxrpc_cleanup_call(struct rxrpc_call *);
+void rxrpc_destroy_all_calls(struct rxrpc_net *);
+
+static inline bool rxrpc_is_service_call(const struct rxrpc_call *call)
+{
+	return test_bit(RXRPC_CALL_IS_SERVICE, &call->flags);
+}
+
+static inline bool rxrpc_is_client_call(const struct rxrpc_call *call)
+{
+	return !rxrpc_is_service_call(call);
+}
+
+/*
+ * conn_client.c
+ */
+extern unsigned int rxrpc_reap_client_connections;
+extern unsigned long rxrpc_conn_idle_client_expiry;
+extern unsigned long rxrpc_conn_idle_client_fast_expiry;
+extern struct idr rxrpc_client_conn_ids;
+
+void rxrpc_destroy_client_conn_ids(void);
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *);
+void rxrpc_put_bundle(struct rxrpc_bundle *);
+int rxrpc_connect_call(struct rxrpc_sock *, struct rxrpc_call *,
+		       struct rxrpc_conn_parameters *, struct sockaddr_rxrpc *,
+		       gfp_t);
+void rxrpc_expose_client_call(struct rxrpc_call *);
+void rxrpc_disconnect_client_call(struct rxrpc_bundle *, struct rxrpc_call *);
+void rxrpc_put_client_conn(struct rxrpc_connection *);
+void rxrpc_discard_expired_client_conns(struct work_struct *);
+void rxrpc_destroy_all_client_connections(struct rxrpc_net *);
+void rxrpc_clean_up_local_conns(struct rxrpc_local *);
+
+/*
+ * conn_event.c
+ */
+void rxrpc_process_connection(struct work_struct *);
+void rxrpc_process_delayed_final_acks(struct rxrpc_connection *, bool);
+
+/*
+ * conn_object.c
+ */
+extern unsigned int rxrpc_connection_expiry;
+extern unsigned int rxrpc_closed_conn_expiry;
+
+struct rxrpc_connection *rxrpc_alloc_connection(gfp_t);
+struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *,
+						   struct sk_buff *,
+						   struct rxrpc_peer **);
+void __rxrpc_disconnect_call(struct rxrpc_connection *, struct rxrpc_call *);
+void rxrpc_disconnect_call(struct rxrpc_call *);
+void rxrpc_kill_connection(struct rxrpc_connection *);
+bool rxrpc_queue_conn(struct rxrpc_connection *);
+void rxrpc_see_connection(struct rxrpc_connection *);
+struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *);
+struct rxrpc_connection *rxrpc_get_connection_maybe(struct rxrpc_connection *);
+void rxrpc_put_service_conn(struct rxrpc_connection *);
+void rxrpc_service_connection_reaper(struct work_struct *);
+void rxrpc_destroy_all_connections(struct rxrpc_net *);
+
+static inline bool rxrpc_conn_is_client(const struct rxrpc_connection *conn)
+{
+	return conn->out_clientflag;
+}
+
+static inline bool rxrpc_conn_is_service(const struct rxrpc_connection *conn)
+{
+	return !rxrpc_conn_is_client(conn);
+}
+
+static inline void rxrpc_put_connection(struct rxrpc_connection *conn)
+{
+	if (!conn)
+		return;
+
+	if (rxrpc_conn_is_client(conn))
+		rxrpc_put_client_conn(conn);
+	else
+		rxrpc_put_service_conn(conn);
+}
+
+static inline void rxrpc_reduce_conn_timer(struct rxrpc_connection *conn,
+					   unsigned long expire_at)
+{
+	timer_reduce(&conn->timer, expire_at);
+}
+
+/*
+ * conn_service.c
+ */
+struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
+						     struct sk_buff *);
+struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *, gfp_t);
+void rxrpc_new_incoming_connection(struct rxrpc_sock *, struct rxrpc_connection *,
+				   const struct rxrpc_security *, struct key *,
+				   struct sk_buff *);
+void rxrpc_unpublish_service_conn(struct rxrpc_connection *);
+
+/*
+ * input.c
+ */
+int rxrpc_input_packet(struct sock *, struct sk_buff *);
+
+/*
+ * insecure.c
+ */
+extern const struct rxrpc_security rxrpc_no_security;
+
+/*
+ * key.c
+ */
+extern struct key_type key_type_rxrpc;
+extern struct key_type key_type_rxrpc_s;
+
+int rxrpc_request_key(struct rxrpc_sock *, sockptr_t , int);
+int rxrpc_server_keyring(struct rxrpc_sock *, sockptr_t, int);
+int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *, time64_t,
+			      u32);
+
+/*
+ * local_event.c
+ */
+extern void rxrpc_process_local_events(struct rxrpc_local *);
+
+/*
+ * local_object.c
+ */
+struct rxrpc_local *rxrpc_lookup_local(struct net *, const struct sockaddr_rxrpc *);
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *);
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *);
+void rxrpc_put_local(struct rxrpc_local *);
+struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *);
+void rxrpc_unuse_local(struct rxrpc_local *);
+void rxrpc_queue_local(struct rxrpc_local *);
+void rxrpc_destroy_all_locals(struct rxrpc_net *);
+
+static inline bool __rxrpc_unuse_local(struct rxrpc_local *local)
+{
+	return atomic_dec_return(&local->active_users) == 0;
+}
+
+static inline bool __rxrpc_use_local(struct rxrpc_local *local)
+{
+	return atomic_fetch_add_unless(&local->active_users, 1, 0) != 0;
+}
+
+/*
+ * misc.c
+ */
+extern unsigned int rxrpc_max_backlog __read_mostly;
+extern unsigned long rxrpc_requested_ack_delay;
+extern unsigned long rxrpc_soft_ack_delay;
+extern unsigned long rxrpc_idle_ack_delay;
+extern unsigned int rxrpc_rx_window_size;
+extern unsigned int rxrpc_rx_mtu;
+extern unsigned int rxrpc_rx_jumbo_max;
+
+extern const s8 rxrpc_ack_priority[];
+
+/*
+ * net_ns.c
+ */
+extern unsigned int rxrpc_net_id;
+extern struct pernet_operations rxrpc_net_ops;
+
+static inline struct rxrpc_net *rxrpc_net(struct net *net)
+{
+	return net_generic(net, rxrpc_net_id);
+}
+
+/*
+ * output.c
+ */
+int rxrpc_send_ack_packet(struct rxrpc_call *, bool, rxrpc_serial_t *);
+int rxrpc_send_abort_packet(struct rxrpc_call *);
+int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *, bool);
+void rxrpc_reject_packets(struct rxrpc_local *);
+void rxrpc_send_keepalive(struct rxrpc_peer *);
+
+/*
+ * peer_event.c
+ */
+void rxrpc_error_report(struct sock *);
+void rxrpc_peer_keepalive_worker(struct work_struct *);
+
+/*
+ * peer_object.c
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *,
+					 const struct sockaddr_rxrpc *);
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *, struct rxrpc_local *,
+				     struct sockaddr_rxrpc *, gfp_t);
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t);
+void rxrpc_new_incoming_peer(struct rxrpc_sock *, struct rxrpc_local *,
+			     struct rxrpc_peer *);
+void rxrpc_destroy_all_peers(struct rxrpc_net *);
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *);
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *);
+void rxrpc_put_peer(struct rxrpc_peer *);
+void rxrpc_put_peer_locked(struct rxrpc_peer *);
+
+/*
+ * proc.c
+ */
+extern const struct seq_operations rxrpc_call_seq_ops;
+extern const struct seq_operations rxrpc_connection_seq_ops;
+extern const struct seq_operations rxrpc_peer_seq_ops;
+extern const struct seq_operations rxrpc_local_seq_ops;
+
+/*
+ * recvmsg.c
+ */
+void rxrpc_notify_socket(struct rxrpc_call *);
+bool __rxrpc_set_call_completion(struct rxrpc_call *, enum rxrpc_call_completion, u32, int);
+bool rxrpc_set_call_completion(struct rxrpc_call *, enum rxrpc_call_completion, u32, int);
+bool __rxrpc_call_completed(struct rxrpc_call *);
+bool rxrpc_call_completed(struct rxrpc_call *);
+bool __rxrpc_abort_call(const char *, struct rxrpc_call *, rxrpc_seq_t, u32, int);
+bool rxrpc_abort_call(const char *, struct rxrpc_call *, rxrpc_seq_t, u32, int);
+int rxrpc_recvmsg(struct socket *, struct msghdr *, size_t, int);
+
+/*
+ * Abort a call due to a protocol error.
+ */
+static inline bool __rxrpc_abort_eproto(struct rxrpc_call *call,
+					struct sk_buff *skb,
+					const char *eproto_why,
+					const char *why,
+					u32 abort_code)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_rx_eproto(call, sp->hdr.serial, eproto_why);
+	return rxrpc_abort_call(why, call, sp->hdr.seq, abort_code, -EPROTO);
+}
+
+#define rxrpc_abort_eproto(call, skb, eproto_why, abort_why, abort_code) \
+	__rxrpc_abort_eproto((call), (skb), tracepoint_string(eproto_why), \
+			     (abort_why), (abort_code))
+
+/*
+ * rtt.c
+ */
+void rxrpc_peer_add_rtt(struct rxrpc_call *, enum rxrpc_rtt_rx_trace, int,
+			rxrpc_serial_t, rxrpc_serial_t, ktime_t, ktime_t);
+unsigned long rxrpc_get_rto_backoff(struct rxrpc_peer *, bool);
+void rxrpc_peer_init_rtt(struct rxrpc_peer *);
+
+/*
+ * rxkad.c
+ */
+#ifdef CONFIG_RXKAD
+extern const struct rxrpc_security rxkad;
+#endif
+
+/*
+ * security.c
+ */
+int __init rxrpc_init_security(void);
+void rxrpc_exit_security(void);
+int rxrpc_init_client_conn_security(struct rxrpc_connection *);
+bool rxrpc_look_up_server_security(struct rxrpc_local *, struct rxrpc_sock *,
+				   const struct rxrpc_security **, struct key **,
+				   struct sk_buff *);
+
+/*
+ * sendmsg.c
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
+
+/*
+ * skbuff.c
+ */
+void rxrpc_kernel_data_consumed(struct rxrpc_call *, struct sk_buff *);
+void rxrpc_packet_destructor(struct sk_buff *);
+void rxrpc_new_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_see_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_eaten_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_get_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_free_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_purge_queue(struct sk_buff_head *);
+
+/*
+ * sysctl.c
+ */
+#ifdef CONFIG_SYSCTL
+extern int __init rxrpc_sysctl_init(void);
+extern void rxrpc_sysctl_exit(void);
+#else
+static inline int __init rxrpc_sysctl_init(void) { return 0; }
+static inline void rxrpc_sysctl_exit(void) {}
+#endif
+
+/*
+ * utils.c
+ */
+int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *, struct sk_buff *);
+
+static inline bool before(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) < 0;
+}
+static inline bool before_eq(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) <= 0;
+}
+static inline bool after(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) > 0;
+}
+static inline bool after_eq(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) >= 0;
+}
+
+/*
+ * debug tracing
+ */
+extern unsigned int rxrpc_debug;
+
+#define dbgprintk(FMT,...) \
+	printk("[%-6.6s] "FMT"\n", current->comm ,##__VA_ARGS__)
+
+#define kenter(FMT,...)	dbgprintk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
+#define kleave(FMT,...)	dbgprintk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
+#define kdebug(FMT,...)	dbgprintk("    "FMT ,##__VA_ARGS__)
+#define kproto(FMT,...)	dbgprintk("### "FMT ,##__VA_ARGS__)
+#define knet(FMT,...)	dbgprintk("@@@ "FMT ,##__VA_ARGS__)
+
+
+#if defined(__KDEBUG)
+#define _enter(FMT,...)	kenter(FMT,##__VA_ARGS__)
+#define _leave(FMT,...)	kleave(FMT,##__VA_ARGS__)
+#define _debug(FMT,...)	kdebug(FMT,##__VA_ARGS__)
+#define _proto(FMT,...)	kproto(FMT,##__VA_ARGS__)
+#define _net(FMT,...)	knet(FMT,##__VA_ARGS__)
+
+#elif defined(CONFIG_AF_RXRPC_DEBUG)
+#define RXRPC_DEBUG_KENTER	0x01
+#define RXRPC_DEBUG_KLEAVE	0x02
+#define RXRPC_DEBUG_KDEBUG	0x04
+#define RXRPC_DEBUG_KPROTO	0x08
+#define RXRPC_DEBUG_KNET	0x10
+
+#define _enter(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KENTER))	\
+		kenter(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _leave(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KLEAVE))	\
+		kleave(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _debug(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KDEBUG))	\
+		kdebug(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _proto(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KPROTO))	\
+		kproto(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _net(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KNET))	\
+		knet(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#else
+#define _enter(FMT,...)	no_printk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
+#define _leave(FMT,...)	no_printk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
+#define _debug(FMT,...)	no_printk("    "FMT ,##__VA_ARGS__)
+#define _proto(FMT,...)	no_printk("### "FMT ,##__VA_ARGS__)
+#define _net(FMT,...)	no_printk("@@@ "FMT ,##__VA_ARGS__)
+#endif
+
+/*
+ * debug assertion checking
+ */
+#if 1 // defined(__KDEBUGALL)
+
+#define ASSERT(X)						\
+do {								\
+	if (unlikely(!(X))) {					\
+		pr_err("Assertion failed\n");			\
+		BUG();						\
+	}							\
+} while (0)
+
+#define ASSERTCMP(X, OP, Y)						\
+do {									\
+	__typeof__(X) _x = (X);						\
+	__typeof__(Y) _y = (__typeof__(X))(Y);				\
+	if (unlikely(!(_x OP _y))) {					\
+		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false\n", \
+		       (unsigned long)_x, (unsigned long)_x, #OP,	\
+		       (unsigned long)_y, (unsigned long)_y);		\
+		BUG();							\
+	}								\
+} while (0)
+
+#define ASSERTIF(C, X)						\
+do {								\
+	if (unlikely((C) && !(X))) {				\
+		pr_err("Assertion failed\n");			\
+		BUG();						\
+	}							\
+} while (0)
+
+#define ASSERTIFCMP(C, X, OP, Y)					\
+do {									\
+	__typeof__(X) _x = (X);						\
+	__typeof__(Y) _y = (__typeof__(X))(Y);				\
+	if (unlikely((C) && !(_x OP _y))) {				\
+		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false\n", \
+		       (unsigned long)_x, (unsigned long)_x, #OP,	\
+		       (unsigned long)_y, (unsigned long)_y);		\
+		BUG();							\
+	}								\
+} while (0)
+
+#else
+
+#define ASSERT(X)				\
+do {						\
+} while (0)
+
+#define ASSERTCMP(X, OP, Y)			\
+do {						\
+} while (0)
+
+#define ASSERTIF(C, X)				\
+do {						\
+} while (0)
+
+#define ASSERTIFCMP(C, X, OP, Y)		\
+do {						\
+} while (0)
+
+#endif /* __KDEBUGALL */
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
new file mode 100644
index 000000000..2a14d69b1
--- /dev/null
+++ b/net/rxrpc/call_accept.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* incoming call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+static void rxrpc_dummy_notify(struct sock *sk, struct rxrpc_call *call,
+			       unsigned long user_call_ID)
+{
+}
+
+/*
+ * Preallocate a single service call, connection and peer and, if possible,
+ * give them a user ID and attach the user's side of the ID to them.
+ */
+static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
+				      struct rxrpc_backlog *b,
+				      rxrpc_notify_rx_t notify_rx,
+				      rxrpc_user_attach_call_t user_attach_call,
+				      unsigned long user_call_ID, gfp_t gfp,
+				      unsigned int debug_id)
+{
+	const void *here = __builtin_return_address(0);
+	struct rxrpc_call *call, *xcall;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	struct rb_node *parent, **pp;
+	int max, tmp;
+	unsigned int size = RXRPC_BACKLOG_MAX;
+	unsigned int head, tail, call_head, call_tail;
+
+	max = rx->sk.sk_max_ack_backlog;
+	tmp = rx->sk.sk_ack_backlog;
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [full %u]", max);
+		return -ENOBUFS;
+	}
+	max -= tmp;
+
+	/* We don't need more conns and peers than we have calls, but on the
+	 * other hand, we shouldn't ever use more peers than conns or conns
+	 * than calls.
+	 */
+	call_head = b->call_backlog_head;
+	call_tail = READ_ONCE(b->call_backlog_tail);
+	tmp = CIRC_CNT(call_head, call_tail, size);
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [enough %u]", tmp);
+		return -ENOBUFS;
+	}
+	max = tmp + 1;
+
+	head = b->peer_backlog_head;
+	tail = READ_ONCE(b->peer_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
+		if (!peer)
+			return -ENOMEM;
+		b->peer_backlog[head] = peer;
+		smp_store_release(&b->peer_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	head = b->conn_backlog_head;
+	tail = READ_ONCE(b->conn_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_connection *conn;
+
+		conn = rxrpc_prealloc_service_connection(rxnet, gfp);
+		if (!conn)
+			return -ENOMEM;
+		b->conn_backlog[head] = conn;
+		smp_store_release(&b->conn_backlog_head,
+				  (head + 1) & (size - 1));
+
+		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service,
+				 refcount_read(&conn->ref), here);
+	}
+
+	/* Now it gets complicated, because calls get registered with the
+	 * socket here, with a user ID preassigned by the user.
+	 */
+	call = rxrpc_alloc_call(rx, gfp, debug_id);
+	if (!call)
+		return -ENOMEM;
+	call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
+	call->state = RXRPC_CALL_SERVER_PREALLOC;
+
+	trace_rxrpc_call(call->debug_id, rxrpc_call_new_service,
+			 refcount_read(&call->ref),
+			 here, (const void *)user_call_ID);
+
+	write_lock(&rx->call_lock);
+
+	/* Check the user ID isn't already in use */
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+		if (user_call_ID < xcall->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (user_call_ID > xcall->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto id_in_use;
+	}
+
+	call->user_call_ID = user_call_ID;
+	call->notify_rx = notify_rx;
+	if (user_attach_call) {
+		rxrpc_get_call(call, rxrpc_call_got_kernel);
+		user_attach_call(call, user_call_ID);
+	}
+
+	rxrpc_get_call(call, rxrpc_call_got_userid);
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+
+	list_add(&call->sock_link, &rx->sock_calls);
+
+	write_unlock(&rx->call_lock);
+
+	rxnet = call->rxnet;
+	write_lock(&rxnet->call_lock);
+	list_add_tail(&call->link, &rxnet->calls);
+	write_unlock(&rxnet->call_lock);
+
+	b->call_backlog[call_head] = call;
+	smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
+	_leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
+	return 0;
+
+id_in_use:
+	write_unlock(&rx->call_lock);
+	rxrpc_cleanup_call(call);
+	_leave(" = -EBADSLT");
+	return -EBADSLT;
+}
+
+/*
+ * Allocate the preallocation buffers for incoming service calls.  These must
+ * be charged manually.
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (!b) {
+		b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
+		if (!b)
+			return -ENOMEM;
+		rx->backlog = b;
+	}
+
+	return 0;
+}
+
+/*
+ * Discard the preallocation on a service.
+ */
+void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
+
+	if (!b)
+		return;
+	rx->backlog = NULL;
+
+	/* Make sure that there aren't any incoming calls in progress before we
+	 * clear the preallocation buffers.
+	 */
+	spin_lock_bh(&rx->incoming_lock);
+	spin_unlock_bh(&rx->incoming_lock);
+
+	head = b->peer_backlog_head;
+	tail = b->peer_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_peer *peer = b->peer_backlog[tail];
+		rxrpc_put_local(peer->local);
+		kfree(peer);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->conn_backlog_head;
+	tail = b->conn_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_connection *conn = b->conn_backlog[tail];
+		write_lock(&rxnet->conn_lock);
+		list_del(&conn->link);
+		list_del(&conn->proc_link);
+		write_unlock(&rxnet->conn_lock);
+		kfree(conn);
+		if (atomic_dec_and_test(&rxnet->nr_conns))
+			wake_up_var(&rxnet->nr_conns);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->call_backlog_head;
+	tail = b->call_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_call *call = b->call_backlog[tail];
+		rcu_assign_pointer(call->socket, rx);
+		if (rx->discard_new_call) {
+			_debug("discard %lx", call->user_call_ID);
+			rx->discard_new_call(call, call->user_call_ID);
+			if (call->notify_rx)
+				call->notify_rx = rxrpc_dummy_notify;
+			rxrpc_put_call(call, rxrpc_call_put_kernel);
+		}
+		rxrpc_call_completed(call);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	kfree(b);
+}
+
+/*
+ * Ping the other end to fill our RTT cache and to retrieve the rwind
+ * and MTU parameters.
+ */
+static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	ktime_t now = skb->tstamp;
+
+	if (call->peer->rtt_count < 3 ||
+	    ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
+				  true, true,
+				  rxrpc_propose_ack_ping_for_params);
+}
+
+/*
+ * Allocate a new incoming call from the prealloc pool, along with a connection
+ * and a peer as necessary.
+ */
+static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
+						    struct rxrpc_local *local,
+						    struct rxrpc_peer *peer,
+						    struct rxrpc_connection *conn,
+						    const struct rxrpc_security *sec,
+						    struct key *key,
+						    struct sk_buff *skb)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_call *call;
+	unsigned short call_head, conn_head, peer_head;
+	unsigned short call_tail, conn_tail, peer_tail;
+	unsigned short call_count, conn_count;
+
+	/* #calls >= #conns >= #peers must hold true. */
+	call_head = smp_load_acquire(&b->call_backlog_head);
+	call_tail = b->call_backlog_tail;
+	call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
+	conn_head = smp_load_acquire(&b->conn_backlog_head);
+	conn_tail = b->conn_backlog_tail;
+	conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
+	ASSERTCMP(conn_count, >=, call_count);
+	peer_head = smp_load_acquire(&b->peer_backlog_head);
+	peer_tail = b->peer_backlog_tail;
+	ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
+		  conn_count);
+
+	if (call_count == 0)
+		return NULL;
+
+	if (!conn) {
+		if (peer && !rxrpc_get_peer_maybe(peer))
+			peer = NULL;
+		if (!peer) {
+			peer = b->peer_backlog[peer_tail];
+			if (rxrpc_extract_addr_from_skb(&peer->srx, skb) < 0)
+				return NULL;
+			b->peer_backlog[peer_tail] = NULL;
+			smp_store_release(&b->peer_backlog_tail,
+					  (peer_tail + 1) &
+					  (RXRPC_BACKLOG_MAX - 1));
+
+			rxrpc_new_incoming_peer(rx, local, peer);
+		}
+
+		/* Now allocate and set up the connection */
+		conn = b->conn_backlog[conn_tail];
+		b->conn_backlog[conn_tail] = NULL;
+		smp_store_release(&b->conn_backlog_tail,
+				  (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+		conn->params.local = rxrpc_get_local(local);
+		conn->params.peer = peer;
+		rxrpc_see_connection(conn);
+		rxrpc_new_incoming_connection(rx, conn, sec, key, skb);
+	} else {
+		rxrpc_get_connection(conn);
+	}
+
+	/* And now we can allocate and set up a new call */
+	call = b->call_backlog[call_tail];
+	b->call_backlog[call_tail] = NULL;
+	smp_store_release(&b->call_backlog_tail,
+			  (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+
+	rxrpc_see_call(call);
+	call->conn = conn;
+	call->security = conn->security;
+	call->security_ix = conn->security_ix;
+	call->peer = rxrpc_get_peer(conn->params.peer);
+	call->cong_cwnd = call->peer->cong_cwnd;
+	return call;
+}
+
+/*
+ * Set up a new incoming call.  Called in BH context with the RCU read lock
+ * held.
+ *
+ * If this is for a kernel service, when we allocate the call, it will have
+ * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
+ * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
+ * services only have the ref from the backlog buffer.  We want to pass this
+ * ref to non-BH context to dispose of.
+ *
+ * If we want to report an error, we mark the skb with the packet type and
+ * abort code and return NULL.
+ *
+ * The call is returned with the user access mutex held.
+ */
+struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
+					   struct rxrpc_sock *rx,
+					   struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	const struct rxrpc_security *sec = NULL;
+	struct rxrpc_connection *conn;
+	struct rxrpc_peer *peer = NULL;
+	struct rxrpc_call *call = NULL;
+	struct key *key = NULL;
+
+	_enter("");
+
+	spin_lock(&rx->incoming_lock);
+	if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
+	    rx->sk.sk_state == RXRPC_CLOSE) {
+		trace_rxrpc_abort(0, "CLS", sp->hdr.cid, sp->hdr.callNumber,
+				  sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		goto no_call;
+	}
+
+	/* The peer, connection and call may all have sprung into existence due
+	 * to a duplicate packet being handled on another CPU in parallel, so
+	 * we have to recheck the routing.  However, we're now holding
+	 * rx->incoming_lock, so the values should remain stable.
+	 */
+	conn = rxrpc_find_connection_rcu(local, skb, &peer);
+
+	if (!conn && !rxrpc_look_up_server_security(local, rx, &sec, &key, skb))
+		goto no_call;
+
+	call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, key, skb);
+	key_put(key);
+	if (!call) {
+		skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
+		goto no_call;
+	}
+
+	trace_rxrpc_receive(call, rxrpc_receive_incoming,
+			    sp->hdr.serial, sp->hdr.seq);
+
+	/* Make the call live. */
+	rxrpc_incoming_call(rx, call, skb);
+	conn = call->conn;
+
+	if (rx->notify_new_call)
+		rx->notify_new_call(&rx->sk, call, call->user_call_ID);
+
+	spin_lock(&conn->state_lock);
+	switch (conn->state) {
+	case RXRPC_CONN_SERVICE_UNSECURED:
+		conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
+		set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
+		rxrpc_queue_conn(call->conn);
+		break;
+
+	case RXRPC_CONN_SERVICE:
+		write_lock(&call->state_lock);
+		if (call->state < RXRPC_CALL_COMPLETE)
+			call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
+		write_unlock(&call->state_lock);
+		break;
+
+	case RXRPC_CONN_REMOTELY_ABORTED:
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  conn->abort_code, conn->error);
+		break;
+	case RXRPC_CONN_LOCALLY_ABORTED:
+		rxrpc_abort_call("CON", call, sp->hdr.seq,
+				 conn->abort_code, conn->error);
+		break;
+	default:
+		BUG();
+	}
+	spin_unlock(&conn->state_lock);
+	spin_unlock(&rx->incoming_lock);
+
+	rxrpc_send_ping(call, skb);
+
+	/* We have to discard the prealloc queue's ref here and rely on a
+	 * combination of the RCU read lock and refs held either by the socket
+	 * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
+	 * service to prevent the call from being deallocated too early.
+	 */
+	rxrpc_put_call(call, rxrpc_call_put);
+
+	_leave(" = %p{%d}", call, call->debug_id);
+	return call;
+
+no_call:
+	spin_unlock(&rx->incoming_lock);
+	_leave(" = NULL [%u]", skb->mark);
+	return NULL;
+}
+
+/*
+ * Charge up socket with preallocated calls, attaching user call IDs.
+ */
+int rxrpc_user_charge_accept(struct rxrpc_sock *rx, unsigned long user_call_ID)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (rx->sk.sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, NULL, NULL, user_call_ID,
+					  GFP_KERNEL,
+					  atomic_inc_return(&rxrpc_debug_id));
+}
+
+/*
+ * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
+ * @sock: The socket on which to preallocate
+ * @notify_rx: Event notification function for the call
+ * @user_attach_call: Func to attach call to user_call_ID
+ * @user_call_ID: The tag to attach to the preallocated call
+ * @gfp: The allocation conditions.
+ * @debug_id: The tracing debug ID.
+ *
+ * Charge up the socket with preallocated calls, each with a user ID.  A
+ * function should be provided to effect the attachment from the user's side.
+ * The user is given a ref to hold on the call.
+ *
+ * Note that the call may be come connected before this function returns.
+ */
+int rxrpc_kernel_charge_accept(struct socket *sock,
+			       rxrpc_notify_rx_t notify_rx,
+			       rxrpc_user_attach_call_t user_attach_call,
+			       unsigned long user_call_ID, gfp_t gfp,
+			       unsigned int debug_id)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (sock->sk->sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, notify_rx,
+					  user_attach_call, user_call_ID,
+					  gfp, debug_id);
+}
+EXPORT_SYMBOL(rxrpc_kernel_charge_accept);
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
new file mode 100644
index 000000000..2a93e7b5f
--- /dev/null
+++ b/net/rxrpc/call_event.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Propose a PING ACK be sent.
+ */
+static void rxrpc_propose_ping(struct rxrpc_call *call,
+			       bool immediate, bool background)
+{
+	if (immediate) {
+		if (background &&
+		    !test_and_set_bit(RXRPC_CALL_EV_PING, &call->events))
+			rxrpc_queue_call(call);
+	} else {
+		unsigned long now = jiffies;
+		unsigned long ping_at = now + rxrpc_idle_ack_delay;
+
+		if (time_before(ping_at, call->ping_at)) {
+			WRITE_ONCE(call->ping_at, ping_at);
+			rxrpc_reduce_call_timer(call, ping_at, now,
+						rxrpc_timer_set_for_ping);
+		}
+	}
+}
+
+/*
+ * propose an ACK be sent
+ */
+static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
+				u32 serial, bool immediate, bool background,
+				enum rxrpc_propose_ack_trace why)
+{
+	enum rxrpc_propose_ack_outcome outcome = rxrpc_propose_ack_use;
+	unsigned long expiry = rxrpc_soft_ack_delay;
+	s8 prior = rxrpc_ack_priority[ack_reason];
+
+	/* Pings are handled specially because we don't want to accidentally
+	 * lose a ping response by subsuming it into a ping.
+	 */
+	if (ack_reason == RXRPC_ACK_PING) {
+		rxrpc_propose_ping(call, immediate, background);
+		goto trace;
+	}
+
+	/* Update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
+	 * numbers, but we don't alter the timeout.
+	 */
+	_debug("prior %u %u vs %u %u",
+	       ack_reason, prior,
+	       call->ackr_reason, rxrpc_ack_priority[call->ackr_reason]);
+	if (ack_reason == call->ackr_reason) {
+		if (RXRPC_ACK_UPDATEABLE & (1 << ack_reason)) {
+			outcome = rxrpc_propose_ack_update;
+			call->ackr_serial = serial;
+		}
+		if (!immediate)
+			goto trace;
+	} else if (prior > rxrpc_ack_priority[call->ackr_reason]) {
+		call->ackr_reason = ack_reason;
+		call->ackr_serial = serial;
+	} else {
+		outcome = rxrpc_propose_ack_subsume;
+	}
+
+	switch (ack_reason) {
+	case RXRPC_ACK_REQUESTED:
+		if (rxrpc_requested_ack_delay < expiry)
+			expiry = rxrpc_requested_ack_delay;
+		if (serial == 1)
+			immediate = false;
+		break;
+
+	case RXRPC_ACK_DELAY:
+		if (rxrpc_soft_ack_delay < expiry)
+			expiry = rxrpc_soft_ack_delay;
+		break;
+
+	case RXRPC_ACK_IDLE:
+		if (rxrpc_idle_ack_delay < expiry)
+			expiry = rxrpc_idle_ack_delay;
+		break;
+
+	default:
+		immediate = true;
+		break;
+	}
+
+	if (test_bit(RXRPC_CALL_EV_ACK, &call->events)) {
+		_debug("already scheduled");
+	} else if (immediate || expiry == 0) {
+		_debug("immediate ACK %lx", call->events);
+		if (!test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events) &&
+		    background)
+			rxrpc_queue_call(call);
+	} else {
+		unsigned long now = jiffies, ack_at;
+
+		if (call->peer->srtt_us != 0)
+			ack_at = usecs_to_jiffies(call->peer->srtt_us >> 3);
+		else
+			ack_at = expiry;
+
+		ack_at += READ_ONCE(call->tx_backoff);
+		ack_at += now;
+		if (time_before(ack_at, call->ack_at)) {
+			WRITE_ONCE(call->ack_at, ack_at);
+			rxrpc_reduce_call_timer(call, ack_at, now,
+						rxrpc_timer_set_for_ack);
+		}
+	}
+
+trace:
+	trace_rxrpc_propose_ack(call, why, ack_reason, serial, immediate,
+				background, outcome);
+}
+
+/*
+ * propose an ACK be sent, locking the call structure
+ */
+void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
+		       u32 serial, bool immediate, bool background,
+		       enum rxrpc_propose_ack_trace why)
+{
+	spin_lock_bh(&call->lock);
+	__rxrpc_propose_ACK(call, ack_reason, serial,
+			    immediate, background, why);
+	spin_unlock_bh(&call->lock);
+}
+
+/*
+ * Handle congestion being detected by the retransmit timeout.
+ */
+static void rxrpc_congestion_timeout(struct rxrpc_call *call)
+{
+	set_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags);
+}
+
+/*
+ * Perform retransmission of NAK'd and unack'd packets.
+ */
+static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
+{
+	struct sk_buff *skb;
+	unsigned long resend_at;
+	rxrpc_seq_t cursor, seq, top;
+	ktime_t now, max_age, oldest, ack_ts;
+	int ix;
+	u8 annotation, anno_type, retrans = 0, unacked = 0;
+
+	_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
+
+	now = ktime_get_real();
+	max_age = ktime_sub_us(now, jiffies_to_usecs(call->peer->rto_j));
+
+	spin_lock_bh(&call->lock);
+
+	cursor = call->tx_hard_ack;
+	top = call->tx_top;
+	ASSERT(before_eq(cursor, top));
+	if (cursor == top)
+		goto out_unlock;
+
+	/* Scan the packet list without dropping the lock and decide which of
+	 * the packets in the Tx buffer we're going to resend and what the new
+	 * resend timeout will be.
+	 */
+	trace_rxrpc_resend(call, (cursor + 1) & RXRPC_RXTX_BUFF_MASK);
+	oldest = now;
+	for (seq = cursor + 1; before_eq(seq, top); seq++) {
+		ix = seq & RXRPC_RXTX_BUFF_MASK;
+		annotation = call->rxtx_annotations[ix];
+		anno_type = annotation & RXRPC_TX_ANNO_MASK;
+		annotation &= ~RXRPC_TX_ANNO_MASK;
+		if (anno_type == RXRPC_TX_ANNO_ACK)
+			continue;
+
+		skb = call->rxtx_buffer[ix];
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+
+		if (anno_type == RXRPC_TX_ANNO_UNACK) {
+			if (ktime_after(skb->tstamp, max_age)) {
+				if (ktime_before(skb->tstamp, oldest))
+					oldest = skb->tstamp;
+				continue;
+			}
+			if (!(annotation & RXRPC_TX_ANNO_RESENT))
+				unacked++;
+		}
+
+		/* Okay, we need to retransmit a packet. */
+		call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
+		retrans++;
+		trace_rxrpc_retransmit(call, seq, annotation | anno_type,
+				       ktime_to_ns(ktime_sub(skb->tstamp, max_age)));
+	}
+
+	resend_at = nsecs_to_jiffies(ktime_to_ns(ktime_sub(now, oldest)));
+	resend_at += jiffies + rxrpc_get_rto_backoff(call->peer, retrans);
+	WRITE_ONCE(call->resend_at, resend_at);
+
+	if (unacked)
+		rxrpc_congestion_timeout(call);
+
+	/* If there was nothing that needed retransmission then it's likely
+	 * that an ACK got lost somewhere.  Send a ping to find out instead of
+	 * retransmitting data.
+	 */
+	if (!retrans) {
+		rxrpc_reduce_call_timer(call, resend_at, now_j,
+					rxrpc_timer_set_for_resend);
+		spin_unlock_bh(&call->lock);
+		ack_ts = ktime_sub(now, call->acks_latest_ts);
+		if (ktime_to_us(ack_ts) < (call->peer->srtt_us >> 3))
+			goto out;
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, true, false,
+				  rxrpc_propose_ack_ping_for_lost_ack);
+		rxrpc_send_ack_packet(call, true, NULL);
+		goto out;
+	}
+
+	/* Now go through the Tx window and perform the retransmissions.  We
+	 * have to drop the lock for each send.  If an ACK comes in whilst the
+	 * lock is dropped, it may clear some of the retransmission markers for
+	 * packets that it soft-ACKs.
+	 */
+	for (seq = cursor + 1; before_eq(seq, top); seq++) {
+		ix = seq & RXRPC_RXTX_BUFF_MASK;
+		annotation = call->rxtx_annotations[ix];
+		anno_type = annotation & RXRPC_TX_ANNO_MASK;
+		if (anno_type != RXRPC_TX_ANNO_RETRANS)
+			continue;
+
+		/* We need to reset the retransmission state, but we need to do
+		 * so before we drop the lock as a new ACK/NAK may come in and
+		 * confuse things
+		 */
+		annotation &= ~RXRPC_TX_ANNO_MASK;
+		annotation |= RXRPC_TX_ANNO_UNACK | RXRPC_TX_ANNO_RESENT;
+		call->rxtx_annotations[ix] = annotation;
+
+		skb = call->rxtx_buffer[ix];
+		if (!skb)
+			continue;
+
+		rxrpc_get_skb(skb, rxrpc_skb_got);
+		spin_unlock_bh(&call->lock);
+
+		if (rxrpc_send_data_packet(call, skb, true) < 0) {
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
+			return;
+		}
+
+		if (rxrpc_is_client_call(call))
+			rxrpc_expose_client_call(call);
+
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+		spin_lock_bh(&call->lock);
+		if (after(call->tx_hard_ack, seq))
+			seq = call->tx_hard_ack;
+	}
+
+out_unlock:
+	spin_unlock_bh(&call->lock);
+out:
+	_leave("");
+}
+
+/*
+ * Handle retransmission and deferred ACK/abort generation.
+ */
+void rxrpc_process_call(struct work_struct *work)
+{
+	struct rxrpc_call *call =
+		container_of(work, struct rxrpc_call, processor);
+	rxrpc_serial_t *send_ack;
+	unsigned long now, next, t;
+	unsigned int iterations = 0;
+
+	rxrpc_see_call(call);
+
+	//printk("\n--------------------\n");
+	_enter("{%d,%s,%lx}",
+	       call->debug_id, rxrpc_call_states[call->state], call->events);
+
+recheck_state:
+	/* Limit the number of times we do this before returning to the manager */
+	iterations++;
+	if (iterations > 5)
+		goto requeue;
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
+		rxrpc_send_abort_packet(call);
+		goto recheck_state;
+	}
+
+	if (call->state == RXRPC_CALL_COMPLETE) {
+		rxrpc_delete_call_timer(call);
+		goto out_put;
+	}
+
+	/* Work out if any timeouts tripped */
+	now = jiffies;
+	t = READ_ONCE(call->expect_rx_by);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_normal, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->expect_req_by);
+	if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST &&
+	    time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_idle, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->expect_term_by);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_hard, now);
+		set_bit(RXRPC_CALL_EV_EXPIRED, &call->events);
+	}
+
+	t = READ_ONCE(call->ack_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_ack, now);
+		cmpxchg(&call->ack_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_ACK, &call->events);
+	}
+
+	t = READ_ONCE(call->ack_lost_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_lost_ack, now);
+		cmpxchg(&call->ack_lost_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_ACK_LOST, &call->events);
+	}
+
+	t = READ_ONCE(call->keepalive_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_keepalive, now);
+		cmpxchg(&call->keepalive_at, t, now + MAX_JIFFY_OFFSET);
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, true, true,
+				  rxrpc_propose_ack_ping_for_keepalive);
+		set_bit(RXRPC_CALL_EV_PING, &call->events);
+	}
+
+	t = READ_ONCE(call->ping_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_ping, now);
+		cmpxchg(&call->ping_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_PING, &call->events);
+	}
+
+	t = READ_ONCE(call->resend_at);
+	if (time_after_eq(now, t)) {
+		trace_rxrpc_timer(call, rxrpc_timer_exp_resend, now);
+		cmpxchg(&call->resend_at, t, now + MAX_JIFFY_OFFSET);
+		set_bit(RXRPC_CALL_EV_RESEND, &call->events);
+	}
+
+	/* Process events */
+	if (test_and_clear_bit(RXRPC_CALL_EV_EXPIRED, &call->events)) {
+		if (test_bit(RXRPC_CALL_RX_HEARD, &call->flags) &&
+		    (int)call->conn->hi_serial - (int)call->rx_serial > 0) {
+			trace_rxrpc_call_reset(call);
+			rxrpc_abort_call("EXP", call, 0, RX_CALL_DEAD, -ECONNRESET);
+		} else {
+			rxrpc_abort_call("EXP", call, 0, RX_CALL_TIMEOUT, -ETIME);
+		}
+		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+		goto recheck_state;
+	}
+
+	send_ack = NULL;
+	if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events)) {
+		call->acks_lost_top = call->tx_top;
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, true, false,
+				  rxrpc_propose_ack_ping_for_lost_ack);
+		send_ack = &call->acks_lost_ping;
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events) ||
+	    send_ack) {
+		if (call->ackr_reason) {
+			rxrpc_send_ack_packet(call, false, send_ack);
+			goto recheck_state;
+		}
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_PING, &call->events)) {
+		rxrpc_send_ack_packet(call, true, NULL);
+		goto recheck_state;
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events) &&
+	    call->state != RXRPC_CALL_CLIENT_RECV_REPLY) {
+		rxrpc_resend(call, now);
+		goto recheck_state;
+	}
+
+	/* Make sure the timer is restarted */
+	next = call->expect_rx_by;
+
+#define set(T) { t = READ_ONCE(T); if (time_before(t, next)) next = t; }
+
+	set(call->expect_req_by);
+	set(call->expect_term_by);
+	set(call->ack_at);
+	set(call->ack_lost_at);
+	set(call->resend_at);
+	set(call->keepalive_at);
+	set(call->ping_at);
+
+	now = jiffies;
+	if (time_after_eq(now, next))
+		goto recheck_state;
+
+	rxrpc_reduce_call_timer(call, next, now, rxrpc_timer_restart);
+
+	/* other events may have been raised since we started checking */
+	if (call->events && call->state < RXRPC_CALL_COMPLETE)
+		goto requeue;
+
+out_put:
+	rxrpc_put_call(call, rxrpc_call_put);
+out:
+	_leave("");
+	return;
+
+requeue:
+	__rxrpc_queue_call(call);
+	goto out;
+}
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
new file mode 100644
index 000000000..10dad2834
--- /dev/null
+++ b/net/rxrpc/call_object.c
@@ -0,0 +1,737 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC individual remote procedure call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/spinlock_types.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
+	[RXRPC_CALL_UNINITIALISED]		= "Uninit  ",
+	[RXRPC_CALL_CLIENT_AWAIT_CONN]		= "ClWtConn",
+	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
+	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
+	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
+	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
+	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
+	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
+	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
+	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
+	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
+	[RXRPC_CALL_COMPLETE]			= "Complete",
+};
+
+const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
+	[RXRPC_CALL_SUCCEEDED]			= "Complete",
+	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
+	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
+	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
+	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
+};
+
+struct kmem_cache *rxrpc_call_jar;
+
+static struct semaphore rxrpc_call_limiter =
+	__SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000);
+static struct semaphore rxrpc_kernel_call_limiter =
+	__SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
+
+static void rxrpc_call_timer_expired(struct timer_list *t)
+{
+	struct rxrpc_call *call = from_timer(call, t, timer);
+
+	_enter("%d", call->debug_id);
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
+		__rxrpc_queue_call(call);
+	} else {
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+}
+
+void rxrpc_reduce_call_timer(struct rxrpc_call *call,
+			     unsigned long expire_at,
+			     unsigned long now,
+			     enum rxrpc_timer_trace why)
+{
+	if (rxrpc_try_get_call(call, rxrpc_call_got_timer)) {
+		trace_rxrpc_timer(call, why, now);
+		if (timer_reduce(&call->timer, expire_at))
+			rxrpc_put_call(call, rxrpc_call_put_notimer);
+	}
+}
+
+void rxrpc_delete_call_timer(struct rxrpc_call *call)
+{
+	if (del_timer_sync(&call->timer))
+		rxrpc_put_call(call, rxrpc_call_put_timer);
+}
+
+static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
+
+/*
+ * find an extant server call
+ * - called in process context with IRQs enabled
+ */
+struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
+					      unsigned long user_call_ID)
+{
+	struct rxrpc_call *call;
+	struct rb_node *p;
+
+	_enter("%p,%lx", rx, user_call_ID);
+
+	read_lock(&rx->call_lock);
+
+	p = rx->calls.rb_node;
+	while (p) {
+		call = rb_entry(p, struct rxrpc_call, sock_node);
+
+		if (user_call_ID < call->user_call_ID)
+			p = p->rb_left;
+		else if (user_call_ID > call->user_call_ID)
+			p = p->rb_right;
+		else
+			goto found_extant_call;
+	}
+
+	read_unlock(&rx->call_lock);
+	_leave(" = NULL");
+	return NULL;
+
+found_extant_call:
+	rxrpc_get_call(call, rxrpc_call_got);
+	read_unlock(&rx->call_lock);
+	_leave(" = %p [%d]", call, refcount_read(&call->ref));
+	return call;
+}
+
+/*
+ * allocate a new call
+ */
+struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
+				    unsigned int debug_id)
+{
+	struct rxrpc_call *call;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+
+	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
+	if (!call)
+		return NULL;
+
+	call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
+				    sizeof(struct sk_buff *),
+				    gfp);
+	if (!call->rxtx_buffer)
+		goto nomem;
+
+	call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
+	if (!call->rxtx_annotations)
+		goto nomem_2;
+
+	mutex_init(&call->user_mutex);
+
+	/* Prevent lockdep reporting a deadlock false positive between the afs
+	 * filesystem and sys_sendmsg() via the mmap sem.
+	 */
+	if (rx->sk.sk_kern_sock)
+		lockdep_set_class(&call->user_mutex,
+				  &rxrpc_call_user_mutex_lock_class_key);
+
+	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
+	INIT_WORK(&call->processor, &rxrpc_process_call);
+	INIT_LIST_HEAD(&call->link);
+	INIT_LIST_HEAD(&call->chan_wait_link);
+	INIT_LIST_HEAD(&call->accept_link);
+	INIT_LIST_HEAD(&call->recvmsg_link);
+	INIT_LIST_HEAD(&call->sock_link);
+	init_waitqueue_head(&call->waitq);
+	spin_lock_init(&call->lock);
+	spin_lock_init(&call->notify_lock);
+	spin_lock_init(&call->input_lock);
+	rwlock_init(&call->state_lock);
+	refcount_set(&call->ref, 1);
+	call->debug_id = debug_id;
+	call->tx_total_len = -1;
+	call->next_rx_timo = 20 * HZ;
+	call->next_req_timo = 1 * HZ;
+
+	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
+
+	/* Leave space in the ring to handle a maxed-out jumbo packet */
+	call->rx_winsize = rxrpc_rx_window_size;
+	call->tx_winsize = 16;
+	call->rx_expect_next = 1;
+
+	call->cong_cwnd = 2;
+	call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
+
+	call->rxnet = rxnet;
+	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
+	atomic_inc(&rxnet->nr_calls);
+	return call;
+
+nomem_2:
+	kfree(call->rxtx_buffer);
+nomem:
+	kmem_cache_free(rxrpc_call_jar, call);
+	return NULL;
+}
+
+/*
+ * Allocate a new client call.
+ */
+static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
+						  struct sockaddr_rxrpc *srx,
+						  gfp_t gfp,
+						  unsigned int debug_id)
+{
+	struct rxrpc_call *call;
+	ktime_t now;
+
+	_enter("");
+
+	call = rxrpc_alloc_call(rx, gfp, debug_id);
+	if (!call)
+		return ERR_PTR(-ENOMEM);
+	call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
+	call->service_id = srx->srx_service;
+	call->tx_phase = true;
+	now = ktime_get_real();
+	call->acks_latest_ts = now;
+	call->cong_tstamp = now;
+
+	_leave(" = %p", call);
+	return call;
+}
+
+/*
+ * Initiate the call ack/resend/expiry timer.
+ */
+static void rxrpc_start_call_timer(struct rxrpc_call *call)
+{
+	unsigned long now = jiffies;
+	unsigned long j = now + MAX_JIFFY_OFFSET;
+
+	call->ack_at = j;
+	call->ack_lost_at = j;
+	call->resend_at = j;
+	call->ping_at = j;
+	call->expect_rx_by = j;
+	call->expect_req_by = j;
+	call->expect_term_by = j;
+	call->timer.expires = now;
+}
+
+/*
+ * Wait for a call slot to become available.
+ */
+static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (p->kernel)
+		limiter = &rxrpc_kernel_call_limiter;
+	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
+		down(limiter);
+		return limiter;
+	}
+	return down_interruptible(limiter) < 0 ? NULL : limiter;
+}
+
+/*
+ * Release a call slot.
+ */
+static void rxrpc_put_call_slot(struct rxrpc_call *call)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
+		limiter = &rxrpc_kernel_call_limiter;
+	up(limiter);
+}
+
+/*
+ * Set up a call for the given parameters.
+ * - Called with the socket lock held, which it must release.
+ * - If it returns a call, the call's lock will need releasing by the caller.
+ */
+struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
+					 struct rxrpc_conn_parameters *cp,
+					 struct sockaddr_rxrpc *srx,
+					 struct rxrpc_call_params *p,
+					 gfp_t gfp,
+					 unsigned int debug_id)
+	__releases(&rx->sk.sk_lock.slock)
+	__acquires(&call->user_mutex)
+{
+	struct rxrpc_call *call, *xcall;
+	struct rxrpc_net *rxnet;
+	struct semaphore *limiter;
+	struct rb_node *parent, **pp;
+	const void *here = __builtin_return_address(0);
+	int ret;
+
+	_enter("%p,%lx", rx, p->user_call_ID);
+
+	limiter = rxrpc_get_call_slot(p, gfp);
+	if (!limiter) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-ERESTARTSYS);
+	}
+
+	call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
+	if (IS_ERR(call)) {
+		release_sock(&rx->sk);
+		up(limiter);
+		_leave(" = %ld", PTR_ERR(call));
+		return call;
+	}
+
+	call->interruptibility = p->interruptibility;
+	call->tx_total_len = p->tx_total_len;
+	trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
+			 refcount_read(&call->ref),
+			 here, (const void *)p->user_call_ID);
+	if (p->kernel)
+		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
+
+	/* We need to protect a partially set up call against the user as we
+	 * will be acting outside the socket lock.
+	 */
+	mutex_lock(&call->user_mutex);
+
+	/* Publish the call, even though it is incompletely set up as yet */
+	write_lock(&rx->call_lock);
+
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+
+		if (p->user_call_ID < xcall->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (p->user_call_ID > xcall->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto error_dup_user_ID;
+	}
+
+	rcu_assign_pointer(call->socket, rx);
+	call->user_call_ID = p->user_call_ID;
+	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+	rxrpc_get_call(call, rxrpc_call_got_userid);
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	list_add(&call->sock_link, &rx->sock_calls);
+
+	write_unlock(&rx->call_lock);
+
+	rxnet = call->rxnet;
+	write_lock(&rxnet->call_lock);
+	list_add_tail(&call->link, &rxnet->calls);
+	write_unlock(&rxnet->call_lock);
+
+	/* From this point on, the call is protected by its own lock. */
+	release_sock(&rx->sk);
+
+	/* Set up or get a connection record and set the protocol parameters,
+	 * including channel number and call ID.
+	 */
+	ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
+	if (ret < 0)
+		goto error_attached_to_socket;
+
+	trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
+			 refcount_read(&call->ref), here, NULL);
+
+	rxrpc_start_call_timer(call);
+
+	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
+
+	_leave(" = %p [new]", call);
+	return call;
+
+	/* We unexpectedly found the user ID in the list after taking
+	 * the call_lock.  This shouldn't happen unless the user races
+	 * with itself and tries to add the same user ID twice at the
+	 * same time in different threads.
+	 */
+error_dup_user_ID:
+	write_unlock(&rx->call_lock);
+	release_sock(&rx->sk);
+	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+				    RX_CALL_DEAD, -EEXIST);
+	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
+			 refcount_read(&call->ref), here, ERR_PTR(-EEXIST));
+	rxrpc_release_call(rx, call);
+	mutex_unlock(&call->user_mutex);
+	rxrpc_put_call(call, rxrpc_call_put);
+	_leave(" = -EEXIST");
+	return ERR_PTR(-EEXIST);
+
+	/* We got an error, but the call is attached to the socket and is in
+	 * need of release.  However, we might now race with recvmsg() when
+	 * completing the call queues it.  Return 0 from sys_sendmsg() and
+	 * leave the error to recvmsg() to deal with.
+	 */
+error_attached_to_socket:
+	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
+			 refcount_read(&call->ref), here, ERR_PTR(ret));
+	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+				    RX_CALL_DEAD, ret);
+	_leave(" = c=%08x [err]", call->debug_id);
+	return call;
+}
+
+/*
+ * Set up an incoming call.  call->conn points to the connection.
+ * This is called in BH context and isn't allowed to fail.
+ */
+void rxrpc_incoming_call(struct rxrpc_sock *rx,
+			 struct rxrpc_call *call,
+			 struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	u32 chan;
+
+	_enter(",%d", call->conn->debug_id);
+
+	rcu_assign_pointer(call->socket, rx);
+	call->call_id		= sp->hdr.callNumber;
+	call->service_id	= sp->hdr.serviceId;
+	call->cid		= sp->hdr.cid;
+	call->state		= RXRPC_CALL_SERVER_SECURING;
+	call->cong_tstamp	= skb->tstamp;
+
+	/* Set the channel for this call.  We don't get channel_lock as we're
+	 * only defending against the data_ready handler (which we're called
+	 * from) and the RESPONSE packet parser (which is only really
+	 * interested in call_counter and can cope with a disagreement with the
+	 * call pointer).
+	 */
+	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
+	conn->channels[chan].call_counter = call->call_id;
+	conn->channels[chan].call_id = call->call_id;
+	rcu_assign_pointer(conn->channels[chan].call, call);
+
+	spin_lock(&conn->params.peer->lock);
+	hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
+	spin_unlock(&conn->params.peer->lock);
+
+	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
+
+	rxrpc_start_call_timer(call);
+	_leave("");
+}
+
+/*
+ * Queue a call's work processor, getting a ref to pass to the work queue.
+ */
+bool rxrpc_queue_call(struct rxrpc_call *call)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	if (!__refcount_inc_not_zero(&call->ref, &n))
+		return false;
+	if (rxrpc_queue_work(&call->processor))
+		trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
+				 here, NULL);
+	else
+		rxrpc_put_call(call, rxrpc_call_put_noqueue);
+	return true;
+}
+
+/*
+ * Queue a call's work processor, passing the callers ref to the work queue.
+ */
+bool __rxrpc_queue_call(struct rxrpc_call *call)
+{
+	const void *here = __builtin_return_address(0);
+	int n = refcount_read(&call->ref);
+	ASSERTCMP(n, >=, 1);
+	if (rxrpc_queue_work(&call->processor))
+		trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
+				 here, NULL);
+	else
+		rxrpc_put_call(call, rxrpc_call_put_noqueue);
+	return true;
+}
+
+/*
+ * Note the re-emergence of a call.
+ */
+void rxrpc_see_call(struct rxrpc_call *call)
+{
+	const void *here = __builtin_return_address(0);
+	if (call) {
+		int n = refcount_read(&call->ref);
+
+		trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
+				 here, NULL);
+	}
+}
+
+bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	if (!__refcount_inc_not_zero(&call->ref, &n))
+		return false;
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
+	return true;
+}
+
+/*
+ * Note the addition of a ref on a call.
+ */
+void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	__refcount_inc(&call->ref, &n);
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
+}
+
+/*
+ * Clean up the RxTx skb ring.
+ */
+static void rxrpc_cleanup_ring(struct rxrpc_call *call)
+{
+	int i;
+
+	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
+		rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
+		call->rxtx_buffer[i] = NULL;
+	}
+}
+
+/*
+ * Detach a call from its owning socket.
+ */
+void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
+{
+	const void *here = __builtin_return_address(0);
+	struct rxrpc_connection *conn = call->conn;
+	bool put = false;
+
+	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
+
+	trace_rxrpc_call(call->debug_id, rxrpc_call_release,
+			 refcount_read(&call->ref),
+			 here, (const void *)call->flags);
+
+	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
+
+	spin_lock_bh(&call->lock);
+	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
+		BUG();
+	spin_unlock_bh(&call->lock);
+
+	rxrpc_put_call_slot(call);
+	rxrpc_delete_call_timer(call);
+
+	/* Make sure we don't get any more notifications */
+	write_lock_bh(&rx->recvmsg_lock);
+
+	if (!list_empty(&call->recvmsg_link)) {
+		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
+		       call, call->events, call->flags);
+		list_del(&call->recvmsg_link);
+		put = true;
+	}
+
+	/* list_empty() must return false in rxrpc_notify_socket() */
+	call->recvmsg_link.next = NULL;
+	call->recvmsg_link.prev = NULL;
+
+	write_unlock_bh(&rx->recvmsg_lock);
+	if (put)
+		rxrpc_put_call(call, rxrpc_call_put);
+
+	write_lock(&rx->call_lock);
+
+	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+		rb_erase(&call->sock_node, &rx->calls);
+		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
+		rxrpc_put_call(call, rxrpc_call_put_userid);
+	}
+
+	list_del(&call->sock_link);
+	write_unlock(&rx->call_lock);
+
+	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
+
+	if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		rxrpc_disconnect_call(call);
+	if (call->security)
+		call->security->free_call_crypto(call);
+	_leave("");
+}
+
+/*
+ * release all the calls associated with a socket
+ */
+void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
+{
+	struct rxrpc_call *call;
+
+	_enter("%p", rx);
+
+	while (!list_empty(&rx->to_be_accepted)) {
+		call = list_entry(rx->to_be_accepted.next,
+				  struct rxrpc_call, accept_link);
+		list_del(&call->accept_link);
+		rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+
+	while (!list_empty(&rx->sock_calls)) {
+		call = list_entry(rx->sock_calls.next,
+				  struct rxrpc_call, sock_link);
+		rxrpc_get_call(call, rxrpc_call_got);
+		rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
+		rxrpc_send_abort_packet(call);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+
+	_leave("");
+}
+
+/*
+ * release a call
+ */
+void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
+{
+	struct rxrpc_net *rxnet = call->rxnet;
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id = call->debug_id;
+	bool dead;
+	int n;
+
+	ASSERT(call != NULL);
+
+	dead = __refcount_dec_and_test(&call->ref, &n);
+	trace_rxrpc_call(debug_id, op, n, here, NULL);
+	if (dead) {
+		_debug("call %d dead", call->debug_id);
+		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
+
+		if (!list_empty(&call->link)) {
+			write_lock(&rxnet->call_lock);
+			list_del_init(&call->link);
+			write_unlock(&rxnet->call_lock);
+		}
+
+		rxrpc_cleanup_call(call);
+	}
+}
+
+/*
+ * Final call destruction - but must be done in process context.
+ */
+static void rxrpc_destroy_call(struct work_struct *work)
+{
+	struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
+	struct rxrpc_net *rxnet = call->rxnet;
+
+	rxrpc_delete_call_timer(call);
+
+	rxrpc_put_connection(call->conn);
+	rxrpc_put_peer(call->peer);
+	kfree(call->rxtx_buffer);
+	kfree(call->rxtx_annotations);
+	kmem_cache_free(rxrpc_call_jar, call);
+	if (atomic_dec_and_test(&rxnet->nr_calls))
+		wake_up_var(&rxnet->nr_calls);
+}
+
+/*
+ * Final call destruction under RCU.
+ */
+static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
+{
+	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
+
+	if (in_softirq()) {
+		INIT_WORK(&call->processor, rxrpc_destroy_call);
+		if (!rxrpc_queue_work(&call->processor))
+			BUG();
+	} else {
+		rxrpc_destroy_call(&call->processor);
+	}
+}
+
+/*
+ * clean up a call
+ */
+void rxrpc_cleanup_call(struct rxrpc_call *call)
+{
+	_net("DESTROY CALL %d", call->debug_id);
+
+	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
+
+	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
+	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
+
+	rxrpc_cleanup_ring(call);
+	rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
+
+	call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
+}
+
+/*
+ * Make sure that all calls are gone from a network namespace.  To reach this
+ * point, any open UDP sockets in that namespace must have been closed, so any
+ * outstanding calls cannot be doing I/O.
+ */
+void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_call *call;
+
+	_enter("");
+
+	if (!list_empty(&rxnet->calls)) {
+		write_lock(&rxnet->call_lock);
+
+		while (!list_empty(&rxnet->calls)) {
+			call = list_entry(rxnet->calls.next,
+					  struct rxrpc_call, link);
+			_debug("Zapping call %p", call);
+
+			rxrpc_see_call(call);
+			list_del_init(&call->link);
+
+			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
+			       call, refcount_read(&call->ref),
+			       rxrpc_call_states[call->state],
+			       call->flags, call->events);
+
+			write_unlock(&rxnet->call_lock);
+			cond_resched();
+			write_lock(&rxnet->call_lock);
+		}
+
+		write_unlock(&rxnet->call_lock);
+	}
+
+	atomic_dec(&rxnet->nr_calls);
+	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
+}
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
new file mode 100644
index 000000000..f5fa5f308
--- /dev/null
+++ b/net/rxrpc/conn_client.c
@@ -0,0 +1,1137 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Client connection-specific management code.
+ *
+ * Copyright (C) 2016, 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * Client connections need to be cached for a little while after they've made a
+ * call so as to handle retransmitted DATA packets in case the server didn't
+ * receive the final ACK or terminating ABORT we sent it.
+ *
+ * There are flags of relevance to the cache:
+ *
+ *  (2) DONT_REUSE - The connection should be discarded as soon as possible and
+ *      should not be reused.  This is set when an exclusive connection is used
+ *      or a call ID counter overflows.
+ *
+ * The caching state may only be changed if the cache lock is held.
+ *
+ * There are two idle client connection expiry durations.  If the total number
+ * of connections is below the reap threshold, we use the normal duration; if
+ * it's above, we use the fast duration.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/timer.h>
+#include <linux/sched/signal.h>
+
+#include "ar-internal.h"
+
+__read_mostly unsigned int rxrpc_reap_client_connections = 900;
+__read_mostly unsigned long rxrpc_conn_idle_client_expiry = 2 * 60 * HZ;
+__read_mostly unsigned long rxrpc_conn_idle_client_fast_expiry = 2 * HZ;
+
+/*
+ * We use machine-unique IDs for our client connections.
+ */
+DEFINE_IDR(rxrpc_client_conn_ids);
+static DEFINE_SPINLOCK(rxrpc_conn_id_lock);
+
+static void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle);
+
+/*
+ * Get a connection ID and epoch for a client connection from the global pool.
+ * The connection struct pointer is then recorded in the idr radix tree.  The
+ * epoch doesn't change until the client is rebooted (or, at least, unless the
+ * module is unloaded).
+ */
+static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
+					  gfp_t gfp)
+{
+	struct rxrpc_net *rxnet = conn->params.local->rxnet;
+	int id;
+
+	_enter("");
+
+	idr_preload(gfp);
+	spin_lock(&rxrpc_conn_id_lock);
+
+	id = idr_alloc_cyclic(&rxrpc_client_conn_ids, conn,
+			      1, 0x40000000, GFP_NOWAIT);
+	if (id < 0)
+		goto error;
+
+	spin_unlock(&rxrpc_conn_id_lock);
+	idr_preload_end();
+
+	conn->proto.epoch = rxnet->epoch;
+	conn->proto.cid = id << RXRPC_CIDSHIFT;
+	set_bit(RXRPC_CONN_HAS_IDR, &conn->flags);
+	_leave(" [CID %x]", conn->proto.cid);
+	return 0;
+
+error:
+	spin_unlock(&rxrpc_conn_id_lock);
+	idr_preload_end();
+	_leave(" = %d", id);
+	return id;
+}
+
+/*
+ * Release a connection ID for a client connection from the global pool.
+ */
+static void rxrpc_put_client_connection_id(struct rxrpc_connection *conn)
+{
+	if (test_bit(RXRPC_CONN_HAS_IDR, &conn->flags)) {
+		spin_lock(&rxrpc_conn_id_lock);
+		idr_remove(&rxrpc_client_conn_ids,
+			   conn->proto.cid >> RXRPC_CIDSHIFT);
+		spin_unlock(&rxrpc_conn_id_lock);
+	}
+}
+
+/*
+ * Destroy the client connection ID tree.
+ */
+void rxrpc_destroy_client_conn_ids(void)
+{
+	struct rxrpc_connection *conn;
+	int id;
+
+	if (!idr_is_empty(&rxrpc_client_conn_ids)) {
+		idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) {
+			pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
+			       conn, refcount_read(&conn->ref));
+		}
+		BUG();
+	}
+
+	idr_destroy(&rxrpc_client_conn_ids);
+}
+
+/*
+ * Allocate a connection bundle.
+ */
+static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_conn_parameters *cp,
+					       gfp_t gfp)
+{
+	struct rxrpc_bundle *bundle;
+
+	bundle = kzalloc(sizeof(*bundle), gfp);
+	if (bundle) {
+		bundle->params = *cp;
+		rxrpc_get_peer(bundle->params.peer);
+		refcount_set(&bundle->ref, 1);
+		atomic_set(&bundle->active, 1);
+		spin_lock_init(&bundle->channel_lock);
+		INIT_LIST_HEAD(&bundle->waiting_calls);
+	}
+	return bundle;
+}
+
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle)
+{
+	refcount_inc(&bundle->ref);
+	return bundle;
+}
+
+static void rxrpc_free_bundle(struct rxrpc_bundle *bundle)
+{
+	rxrpc_put_peer(bundle->params.peer);
+	kfree(bundle);
+}
+
+void rxrpc_put_bundle(struct rxrpc_bundle *bundle)
+{
+	unsigned int d = bundle->debug_id;
+	bool dead;
+	int r;
+
+	dead = __refcount_dec_and_test(&bundle->ref, &r);
+
+	_debug("PUT B=%x %d", d, r - 1);
+	if (dead)
+		rxrpc_free_bundle(bundle);
+}
+
+/*
+ * Allocate a client connection.
+ */
+static struct rxrpc_connection *
+rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle, gfp_t gfp)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet = bundle->params.local->rxnet;
+	int ret;
+
+	_enter("");
+
+	conn = rxrpc_alloc_connection(gfp);
+	if (!conn) {
+		_leave(" = -ENOMEM");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	refcount_set(&conn->ref, 1);
+	conn->bundle		= bundle;
+	conn->params		= bundle->params;
+	conn->out_clientflag	= RXRPC_CLIENT_INITIATED;
+	conn->state		= RXRPC_CONN_CLIENT;
+	conn->service_id	= conn->params.service_id;
+
+	ret = rxrpc_get_client_connection_id(conn, gfp);
+	if (ret < 0)
+		goto error_0;
+
+	ret = rxrpc_init_client_conn_security(conn);
+	if (ret < 0)
+		goto error_1;
+
+	ret = conn->security->prime_packet_security(conn);
+	if (ret < 0)
+		goto error_2;
+
+	atomic_inc(&rxnet->nr_conns);
+	write_lock(&rxnet->conn_lock);
+	list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+	write_unlock(&rxnet->conn_lock);
+
+	rxrpc_get_bundle(bundle);
+	rxrpc_get_peer(conn->params.peer);
+	rxrpc_get_local(conn->params.local);
+	key_get(conn->params.key);
+
+	trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_client,
+			 refcount_read(&conn->ref),
+			 __builtin_return_address(0));
+
+	atomic_inc(&rxnet->nr_client_conns);
+	trace_rxrpc_client(conn, -1, rxrpc_client_alloc);
+	_leave(" = %p", conn);
+	return conn;
+
+error_2:
+	conn->security->clear(conn);
+error_1:
+	rxrpc_put_client_connection_id(conn);
+error_0:
+	kfree(conn);
+	_leave(" = %d", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * Determine if a connection may be reused.
+ */
+static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_net *rxnet;
+	int id_cursor, id, distance, limit;
+
+	if (!conn)
+		goto dont_reuse;
+
+	rxnet = conn->params.local->rxnet;
+	if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
+		goto dont_reuse;
+
+	if (conn->state != RXRPC_CONN_CLIENT ||
+	    conn->proto.epoch != rxnet->epoch)
+		goto mark_dont_reuse;
+
+	/* The IDR tree gets very expensive on memory if the connection IDs are
+	 * widely scattered throughout the number space, so we shall want to
+	 * kill off connections that, say, have an ID more than about four
+	 * times the maximum number of client conns away from the current
+	 * allocation point to try and keep the IDs concentrated.
+	 */
+	id_cursor = idr_get_cursor(&rxrpc_client_conn_ids);
+	id = conn->proto.cid >> RXRPC_CIDSHIFT;
+	distance = id - id_cursor;
+	if (distance < 0)
+		distance = -distance;
+	limit = max_t(unsigned long, atomic_read(&rxnet->nr_conns) * 4, 1024);
+	if (distance > limit)
+		goto mark_dont_reuse;
+
+	return true;
+
+mark_dont_reuse:
+	set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+dont_reuse:
+	return false;
+}
+
+/*
+ * Look up the conn bundle that matches the connection parameters, adding it if
+ * it doesn't yet exist.
+ */
+static struct rxrpc_bundle *rxrpc_look_up_bundle(struct rxrpc_conn_parameters *cp,
+						 gfp_t gfp)
+{
+	static atomic_t rxrpc_bundle_id;
+	struct rxrpc_bundle *bundle, *candidate;
+	struct rxrpc_local *local = cp->local;
+	struct rb_node *p, **pp, *parent;
+	long diff;
+
+	_enter("{%px,%x,%u,%u}",
+	       cp->peer, key_serial(cp->key), cp->security_level, cp->upgrade);
+
+	if (cp->exclusive)
+		return rxrpc_alloc_bundle(cp, gfp);
+
+	/* First, see if the bundle is already there. */
+	_debug("search 1");
+	spin_lock(&local->client_bundles_lock);
+	p = local->client_bundles.rb_node;
+	while (p) {
+		bundle = rb_entry(p, struct rxrpc_bundle, local_node);
+
+#define cmp(X) ((long)bundle->params.X - (long)cp->X)
+		diff = (cmp(peer) ?:
+			cmp(key) ?:
+			cmp(security_level) ?:
+			cmp(upgrade));
+#undef cmp
+		if (diff < 0)
+			p = p->rb_left;
+		else if (diff > 0)
+			p = p->rb_right;
+		else
+			goto found_bundle;
+	}
+	spin_unlock(&local->client_bundles_lock);
+	_debug("not found");
+
+	/* It wasn't.  We need to add one. */
+	candidate = rxrpc_alloc_bundle(cp, gfp);
+	if (!candidate)
+		return NULL;
+
+	_debug("search 2");
+	spin_lock(&local->client_bundles_lock);
+	pp = &local->client_bundles.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		bundle = rb_entry(parent, struct rxrpc_bundle, local_node);
+
+#define cmp(X) ((long)bundle->params.X - (long)cp->X)
+		diff = (cmp(peer) ?:
+			cmp(key) ?:
+			cmp(security_level) ?:
+			cmp(upgrade));
+#undef cmp
+		if (diff < 0)
+			pp = &(*pp)->rb_left;
+		else if (diff > 0)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_bundle_free;
+	}
+
+	_debug("new bundle");
+	candidate->debug_id = atomic_inc_return(&rxrpc_bundle_id);
+	rb_link_node(&candidate->local_node, parent, pp);
+	rb_insert_color(&candidate->local_node, &local->client_bundles);
+	rxrpc_get_bundle(candidate);
+	spin_unlock(&local->client_bundles_lock);
+	_leave(" = %u [new]", candidate->debug_id);
+	return candidate;
+
+found_bundle_free:
+	rxrpc_free_bundle(candidate);
+found_bundle:
+	rxrpc_get_bundle(bundle);
+	atomic_inc(&bundle->active);
+	spin_unlock(&local->client_bundles_lock);
+	_leave(" = %u [found]", bundle->debug_id);
+	return bundle;
+}
+
+/*
+ * Create or find a client bundle to use for a call.
+ *
+ * If we return with a connection, the call will be on its waiting list.  It's
+ * left to the caller to assign a channel and wake up the call.
+ */
+static struct rxrpc_bundle *rxrpc_prep_call(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call,
+					    struct rxrpc_conn_parameters *cp,
+					    struct sockaddr_rxrpc *srx,
+					    gfp_t gfp)
+{
+	struct rxrpc_bundle *bundle;
+
+	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+	cp->peer = rxrpc_lookup_peer(rx, cp->local, srx, gfp);
+	if (!cp->peer)
+		goto error;
+
+	call->cong_cwnd = cp->peer->cong_cwnd;
+	if (call->cong_cwnd >= call->cong_ssthresh)
+		call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+	else
+		call->cong_mode = RXRPC_CALL_SLOW_START;
+	if (cp->upgrade)
+		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
+
+	/* Find the client connection bundle. */
+	bundle = rxrpc_look_up_bundle(cp, gfp);
+	if (!bundle)
+		goto error;
+
+	/* Get this call queued.  Someone else may activate it whilst we're
+	 * lining up a new connection, but that's fine.
+	 */
+	spin_lock(&bundle->channel_lock);
+	list_add_tail(&call->chan_wait_link, &bundle->waiting_calls);
+	spin_unlock(&bundle->channel_lock);
+
+	_leave(" = [B=%x]", bundle->debug_id);
+	return bundle;
+
+error:
+	_leave(" = -ENOMEM");
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Allocate a new connection and add it into a bundle.
+ */
+static void rxrpc_add_conn_to_bundle(struct rxrpc_bundle *bundle, gfp_t gfp)
+	__releases(bundle->channel_lock)
+{
+	struct rxrpc_connection *candidate = NULL, *old = NULL;
+	bool conflict;
+	int i;
+
+	_enter("");
+
+	conflict = bundle->alloc_conn;
+	if (!conflict)
+		bundle->alloc_conn = true;
+	spin_unlock(&bundle->channel_lock);
+	if (conflict) {
+		_leave(" [conf]");
+		return;
+	}
+
+	candidate = rxrpc_alloc_client_connection(bundle, gfp);
+
+	spin_lock(&bundle->channel_lock);
+	bundle->alloc_conn = false;
+
+	if (IS_ERR(candidate)) {
+		bundle->alloc_error = PTR_ERR(candidate);
+		spin_unlock(&bundle->channel_lock);
+		_leave(" [err %ld]", PTR_ERR(candidate));
+		return;
+	}
+
+	bundle->alloc_error = 0;
+
+	for (i = 0; i < ARRAY_SIZE(bundle->conns); i++) {
+		unsigned int shift = i * RXRPC_MAXCALLS;
+		int j;
+
+		old = bundle->conns[i];
+		if (!rxrpc_may_reuse_conn(old)) {
+			if (old)
+				trace_rxrpc_client(old, -1, rxrpc_client_replace);
+			candidate->bundle_shift = shift;
+			atomic_inc(&bundle->active);
+			bundle->conns[i] = candidate;
+			for (j = 0; j < RXRPC_MAXCALLS; j++)
+				set_bit(shift + j, &bundle->avail_chans);
+			candidate = NULL;
+			break;
+		}
+
+		old = NULL;
+	}
+
+	spin_unlock(&bundle->channel_lock);
+
+	if (candidate) {
+		_debug("discard C=%x", candidate->debug_id);
+		trace_rxrpc_client(candidate, -1, rxrpc_client_duplicate);
+		rxrpc_put_connection(candidate);
+	}
+
+	rxrpc_put_connection(old);
+	_leave("");
+}
+
+/*
+ * Add a connection to a bundle if there are no usable connections or we have
+ * connections waiting for extra capacity.
+ */
+static void rxrpc_maybe_add_conn(struct rxrpc_bundle *bundle, gfp_t gfp)
+{
+	struct rxrpc_call *call;
+	int i, usable;
+
+	_enter("");
+
+	spin_lock(&bundle->channel_lock);
+
+	/* See if there are any usable connections. */
+	usable = 0;
+	for (i = 0; i < ARRAY_SIZE(bundle->conns); i++)
+		if (rxrpc_may_reuse_conn(bundle->conns[i]))
+			usable++;
+
+	if (!usable && !list_empty(&bundle->waiting_calls)) {
+		call = list_first_entry(&bundle->waiting_calls,
+					struct rxrpc_call, chan_wait_link);
+		if (test_bit(RXRPC_CALL_UPGRADE, &call->flags))
+			bundle->try_upgrade = true;
+	}
+
+	if (!usable)
+		goto alloc_conn;
+
+	if (!bundle->avail_chans &&
+	    !bundle->try_upgrade &&
+	    !list_empty(&bundle->waiting_calls) &&
+	    usable < ARRAY_SIZE(bundle->conns))
+		goto alloc_conn;
+
+	spin_unlock(&bundle->channel_lock);
+	_leave("");
+	return;
+
+alloc_conn:
+	return rxrpc_add_conn_to_bundle(bundle, gfp);
+}
+
+/*
+ * Assign a channel to the call at the front of the queue and wake the call up.
+ * We don't increment the callNumber counter until this number has been exposed
+ * to the world.
+ */
+static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
+				       unsigned int channel)
+{
+	struct rxrpc_channel *chan = &conn->channels[channel];
+	struct rxrpc_bundle *bundle = conn->bundle;
+	struct rxrpc_call *call = list_entry(bundle->waiting_calls.next,
+					     struct rxrpc_call, chan_wait_link);
+	u32 call_id = chan->call_counter + 1;
+
+	_enter("C=%x,%u", conn->debug_id, channel);
+
+	trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate);
+
+	/* Cancel the final ACK on the previous call if it hasn't been sent yet
+	 * as the DATA packet will implicitly ACK it.
+	 */
+	clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+	clear_bit(conn->bundle_shift + channel, &bundle->avail_chans);
+
+	rxrpc_see_call(call);
+	list_del_init(&call->chan_wait_link);
+	call->peer	= rxrpc_get_peer(conn->params.peer);
+	call->conn	= rxrpc_get_connection(conn);
+	call->cid	= conn->proto.cid | channel;
+	call->call_id	= call_id;
+	call->security	= conn->security;
+	call->security_ix = conn->security_ix;
+	call->service_id = conn->service_id;
+
+	trace_rxrpc_connect_call(call);
+	_net("CONNECT call %08x:%08x as call %d on conn %d",
+	     call->cid, call->call_id, call->debug_id, conn->debug_id);
+
+	write_lock_bh(&call->state_lock);
+	call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
+	write_unlock_bh(&call->state_lock);
+
+	/* Paired with the read barrier in rxrpc_connect_call().  This orders
+	 * cid and epoch in the connection wrt to call_id without the need to
+	 * take the channel_lock.
+	 *
+	 * We provisionally assign a callNumber at this point, but we don't
+	 * confirm it until the call is about to be exposed.
+	 *
+	 * TODO: Pair with a barrier in the data_ready handler when that looks
+	 * at the call ID through a connection channel.
+	 */
+	smp_wmb();
+
+	chan->call_id		= call_id;
+	chan->call_debug_id	= call->debug_id;
+	rcu_assign_pointer(chan->call, call);
+	wake_up(&call->waitq);
+}
+
+/*
+ * Remove a connection from the idle list if it's on it.
+ */
+static void rxrpc_unidle_conn(struct rxrpc_bundle *bundle, struct rxrpc_connection *conn)
+{
+	struct rxrpc_net *rxnet = bundle->params.local->rxnet;
+	bool drop_ref;
+
+	if (!list_empty(&conn->cache_link)) {
+		drop_ref = false;
+		spin_lock(&rxnet->client_conn_cache_lock);
+		if (!list_empty(&conn->cache_link)) {
+			list_del_init(&conn->cache_link);
+			drop_ref = true;
+		}
+		spin_unlock(&rxnet->client_conn_cache_lock);
+		if (drop_ref)
+			rxrpc_put_connection(conn);
+	}
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls with channel_lock
+ * held by caller.
+ */
+static void rxrpc_activate_channels_locked(struct rxrpc_bundle *bundle)
+{
+	struct rxrpc_connection *conn;
+	unsigned long avail, mask;
+	unsigned int channel, slot;
+
+	if (bundle->try_upgrade)
+		mask = 1;
+	else
+		mask = ULONG_MAX;
+
+	while (!list_empty(&bundle->waiting_calls)) {
+		avail = bundle->avail_chans & mask;
+		if (!avail)
+			break;
+		channel = __ffs(avail);
+		clear_bit(channel, &bundle->avail_chans);
+
+		slot = channel / RXRPC_MAXCALLS;
+		conn = bundle->conns[slot];
+		if (!conn)
+			break;
+
+		if (bundle->try_upgrade)
+			set_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags);
+		rxrpc_unidle_conn(bundle, conn);
+
+		channel &= (RXRPC_MAXCALLS - 1);
+		conn->act_chans	|= 1 << channel;
+		rxrpc_activate_one_channel(conn, channel);
+	}
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls.
+ */
+static void rxrpc_activate_channels(struct rxrpc_bundle *bundle)
+{
+	_enter("B=%x", bundle->debug_id);
+
+	trace_rxrpc_client(NULL, -1, rxrpc_client_activate_chans);
+
+	if (!bundle->avail_chans)
+		return;
+
+	spin_lock(&bundle->channel_lock);
+	rxrpc_activate_channels_locked(bundle);
+	spin_unlock(&bundle->channel_lock);
+	_leave("");
+}
+
+/*
+ * Wait for a callNumber and a channel to be granted to a call.
+ */
+static int rxrpc_wait_for_channel(struct rxrpc_bundle *bundle,
+				  struct rxrpc_call *call, gfp_t gfp)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret = 0;
+
+	_enter("%d", call->debug_id);
+
+	if (!gfpflags_allow_blocking(gfp)) {
+		rxrpc_maybe_add_conn(bundle, gfp);
+		rxrpc_activate_channels(bundle);
+		ret = bundle->alloc_error ?: -EAGAIN;
+		goto out;
+	}
+
+	add_wait_queue_exclusive(&call->waitq, &myself);
+	for (;;) {
+		rxrpc_maybe_add_conn(bundle, gfp);
+		rxrpc_activate_channels(bundle);
+		ret = bundle->alloc_error;
+		if (ret < 0)
+			break;
+
+		switch (call->interruptibility) {
+		case RXRPC_INTERRUPTIBLE:
+		case RXRPC_PREINTERRUPTIBLE:
+			set_current_state(TASK_INTERRUPTIBLE);
+			break;
+		case RXRPC_UNINTERRUPTIBLE:
+		default:
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			break;
+		}
+		if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_AWAIT_CONN)
+			break;
+		if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
+		     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
+		    signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		schedule();
+	}
+	remove_wait_queue(&call->waitq, &myself);
+	__set_current_state(TASK_RUNNING);
+
+out:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * find a connection for a call
+ * - called in process context with IRQs enabled
+ */
+int rxrpc_connect_call(struct rxrpc_sock *rx,
+		       struct rxrpc_call *call,
+		       struct rxrpc_conn_parameters *cp,
+		       struct sockaddr_rxrpc *srx,
+		       gfp_t gfp)
+{
+	struct rxrpc_bundle *bundle;
+	struct rxrpc_net *rxnet = cp->local->rxnet;
+	int ret = 0;
+
+	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+	rxrpc_discard_expired_client_conns(&rxnet->client_conn_reaper);
+
+	bundle = rxrpc_prep_call(rx, call, cp, srx, gfp);
+	if (IS_ERR(bundle)) {
+		ret = PTR_ERR(bundle);
+		goto out;
+	}
+
+	if (call->state == RXRPC_CALL_CLIENT_AWAIT_CONN) {
+		ret = rxrpc_wait_for_channel(bundle, call, gfp);
+		if (ret < 0)
+			goto wait_failed;
+	}
+
+granted_channel:
+	/* Paired with the write barrier in rxrpc_activate_one_channel(). */
+	smp_rmb();
+
+out_put_bundle:
+	rxrpc_deactivate_bundle(bundle);
+	rxrpc_put_bundle(bundle);
+out:
+	_leave(" = %d", ret);
+	return ret;
+
+wait_failed:
+	spin_lock(&bundle->channel_lock);
+	list_del_init(&call->chan_wait_link);
+	spin_unlock(&bundle->channel_lock);
+
+	if (call->state != RXRPC_CALL_CLIENT_AWAIT_CONN) {
+		ret = 0;
+		goto granted_channel;
+	}
+
+	trace_rxrpc_client(call->conn, ret, rxrpc_client_chan_wait_failed);
+	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
+	rxrpc_disconnect_client_call(bundle, call);
+	goto out_put_bundle;
+}
+
+/*
+ * Note that a call, and thus a connection, is about to be exposed to the
+ * world.
+ */
+void rxrpc_expose_client_call(struct rxrpc_call *call)
+{
+	unsigned int channel = call->cid & RXRPC_CHANNELMASK;
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_channel *chan = &conn->channels[channel];
+
+	if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		/* Mark the call ID as being used.  If the callNumber counter
+		 * exceeds ~2 billion, we kill the connection after its
+		 * outstanding calls have finished so that the counter doesn't
+		 * wrap.
+		 */
+		chan->call_counter++;
+		if (chan->call_counter >= INT_MAX)
+			set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+		trace_rxrpc_client(conn, channel, rxrpc_client_exposed);
+	}
+}
+
+/*
+ * Set the reap timer.
+ */
+static void rxrpc_set_client_reap_timer(struct rxrpc_net *rxnet)
+{
+	if (!rxnet->kill_all_client_conns) {
+		unsigned long now = jiffies;
+		unsigned long reap_at = now + rxrpc_conn_idle_client_expiry;
+
+		if (rxnet->live)
+			timer_reduce(&rxnet->client_conn_reap_timer, reap_at);
+	}
+}
+
+/*
+ * Disconnect a client call.
+ */
+void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_channel *chan = NULL;
+	struct rxrpc_net *rxnet = bundle->params.local->rxnet;
+	unsigned int channel;
+	bool may_reuse;
+	u32 cid;
+
+	_enter("c=%x", call->debug_id);
+
+	spin_lock(&bundle->channel_lock);
+	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+
+	/* Calls that have never actually been assigned a channel can simply be
+	 * discarded.
+	 */
+	conn = call->conn;
+	if (!conn) {
+		_debug("call is waiting");
+		ASSERTCMP(call->call_id, ==, 0);
+		ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags));
+		list_del_init(&call->chan_wait_link);
+		goto out;
+	}
+
+	cid = call->cid;
+	channel = cid & RXRPC_CHANNELMASK;
+	chan = &conn->channels[channel];
+	trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
+
+	if (rcu_access_pointer(chan->call) != call) {
+		spin_unlock(&bundle->channel_lock);
+		BUG();
+	}
+
+	may_reuse = rxrpc_may_reuse_conn(conn);
+
+	/* If a client call was exposed to the world, we save the result for
+	 * retransmission.
+	 *
+	 * We use a barrier here so that the call number and abort code can be
+	 * read without needing to take a lock.
+	 *
+	 * TODO: Make the incoming packet handler check this and handle
+	 * terminal retransmission without requiring access to the call.
+	 */
+	if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		_debug("exposed %u,%u", call->call_id, call->abort_code);
+		__rxrpc_disconnect_call(conn, call);
+
+		if (test_and_clear_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) {
+			trace_rxrpc_client(conn, channel, rxrpc_client_to_active);
+			bundle->try_upgrade = false;
+			if (may_reuse)
+				rxrpc_activate_channels_locked(bundle);
+		}
+
+	}
+
+	/* See if we can pass the channel directly to another call. */
+	if (may_reuse && !list_empty(&bundle->waiting_calls)) {
+		trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass);
+		rxrpc_activate_one_channel(conn, channel);
+		goto out;
+	}
+
+	/* Schedule the final ACK to be transmitted in a short while so that it
+	 * can be skipped if we find a follow-on call.  The first DATA packet
+	 * of the follow on call will implicitly ACK this call.
+	 */
+	if (call->completion == RXRPC_CALL_SUCCEEDED &&
+	    test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		unsigned long final_ack_at = jiffies + 2;
+
+		WRITE_ONCE(chan->final_ack_at, final_ack_at);
+		smp_wmb(); /* vs rxrpc_process_delayed_final_acks() */
+		set_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+		rxrpc_reduce_conn_timer(conn, final_ack_at);
+	}
+
+	/* Deactivate the channel. */
+	rcu_assign_pointer(chan->call, NULL);
+	set_bit(conn->bundle_shift + channel, &conn->bundle->avail_chans);
+	conn->act_chans	&= ~(1 << channel);
+
+	/* If no channels remain active, then put the connection on the idle
+	 * list for a short while.  Give it a ref to stop it going away if it
+	 * becomes unbundled.
+	 */
+	if (!conn->act_chans) {
+		trace_rxrpc_client(conn, channel, rxrpc_client_to_idle);
+		conn->idle_timestamp = jiffies;
+
+		rxrpc_get_connection(conn);
+		spin_lock(&rxnet->client_conn_cache_lock);
+		list_move_tail(&conn->cache_link, &rxnet->idle_client_conns);
+		spin_unlock(&rxnet->client_conn_cache_lock);
+
+		rxrpc_set_client_reap_timer(rxnet);
+	}
+
+out:
+	spin_unlock(&bundle->channel_lock);
+	_leave("");
+	return;
+}
+
+/*
+ * Remove a connection from a bundle.
+ */
+static void rxrpc_unbundle_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_bundle *bundle = conn->bundle;
+	unsigned int bindex;
+	bool need_drop = false;
+	int i;
+
+	_enter("C=%x", conn->debug_id);
+
+	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+		rxrpc_process_delayed_final_acks(conn, true);
+
+	spin_lock(&bundle->channel_lock);
+	bindex = conn->bundle_shift / RXRPC_MAXCALLS;
+	if (bundle->conns[bindex] == conn) {
+		_debug("clear slot %u", bindex);
+		bundle->conns[bindex] = NULL;
+		for (i = 0; i < RXRPC_MAXCALLS; i++)
+			clear_bit(conn->bundle_shift + i, &bundle->avail_chans);
+		need_drop = true;
+	}
+	spin_unlock(&bundle->channel_lock);
+
+	if (need_drop) {
+		rxrpc_deactivate_bundle(bundle);
+		rxrpc_put_connection(conn);
+	}
+}
+
+/*
+ * Drop the active count on a bundle.
+ */
+static void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle)
+{
+	struct rxrpc_local *local = bundle->params.local;
+	bool need_put = false;
+
+	if (atomic_dec_and_lock(&bundle->active, &local->client_bundles_lock)) {
+		if (!bundle->params.exclusive) {
+			_debug("erase bundle");
+			rb_erase(&bundle->local_node, &local->client_bundles);
+			need_put = true;
+		}
+
+		spin_unlock(&local->client_bundles_lock);
+		if (need_put)
+			rxrpc_put_bundle(bundle);
+	}
+}
+
+/*
+ * Clean up a dead client connection.
+ */
+static void rxrpc_kill_client_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_local *local = conn->params.local;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	_enter("C=%x", conn->debug_id);
+
+	trace_rxrpc_client(conn, -1, rxrpc_client_cleanup);
+	atomic_dec(&rxnet->nr_client_conns);
+
+	rxrpc_put_client_connection_id(conn);
+	rxrpc_kill_connection(conn);
+}
+
+/*
+ * Clean up a dead client connections.
+ */
+void rxrpc_put_client_conn(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id = conn->debug_id;
+	bool dead;
+	int r;
+
+	dead = __refcount_dec_and_test(&conn->ref, &r);
+	trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, r - 1, here);
+	if (dead)
+		rxrpc_kill_client_conn(conn);
+}
+
+/*
+ * Discard expired client connections from the idle list.  Each conn in the
+ * idle list has been exposed and holds an extra ref because of that.
+ *
+ * This may be called from conn setup or from a work item so cannot be
+ * considered non-reentrant.
+ */
+void rxrpc_discard_expired_client_conns(struct work_struct *work)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet =
+		container_of(work, struct rxrpc_net, client_conn_reaper);
+	unsigned long expiry, conn_expires_at, now;
+	unsigned int nr_conns;
+
+	_enter("");
+
+	if (list_empty(&rxnet->idle_client_conns)) {
+		_leave(" [empty]");
+		return;
+	}
+
+	/* Don't double up on the discarding */
+	if (!spin_trylock(&rxnet->client_conn_discard_lock)) {
+		_leave(" [already]");
+		return;
+	}
+
+	/* We keep an estimate of what the number of conns ought to be after
+	 * we've discarded some so that we don't overdo the discarding.
+	 */
+	nr_conns = atomic_read(&rxnet->nr_client_conns);
+
+next:
+	spin_lock(&rxnet->client_conn_cache_lock);
+
+	if (list_empty(&rxnet->idle_client_conns))
+		goto out;
+
+	conn = list_entry(rxnet->idle_client_conns.next,
+			  struct rxrpc_connection, cache_link);
+
+	if (!rxnet->kill_all_client_conns) {
+		/* If the number of connections is over the reap limit, we
+		 * expedite discard by reducing the expiry timeout.  We must,
+		 * however, have at least a short grace period to be able to do
+		 * final-ACK or ABORT retransmission.
+		 */
+		expiry = rxrpc_conn_idle_client_expiry;
+		if (nr_conns > rxrpc_reap_client_connections)
+			expiry = rxrpc_conn_idle_client_fast_expiry;
+		if (conn->params.local->service_closed)
+			expiry = rxrpc_closed_conn_expiry * HZ;
+
+		conn_expires_at = conn->idle_timestamp + expiry;
+
+		now = READ_ONCE(jiffies);
+		if (time_after(conn_expires_at, now))
+			goto not_yet_expired;
+	}
+
+	trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+	list_del_init(&conn->cache_link);
+
+	spin_unlock(&rxnet->client_conn_cache_lock);
+
+	rxrpc_unbundle_conn(conn);
+	rxrpc_put_connection(conn); /* Drop the ->cache_link ref */
+
+	nr_conns--;
+	goto next;
+
+not_yet_expired:
+	/* The connection at the front of the queue hasn't yet expired, so
+	 * schedule the work item for that point if we discarded something.
+	 *
+	 * We don't worry if the work item is already scheduled - it can look
+	 * after rescheduling itself at a later time.  We could cancel it, but
+	 * then things get messier.
+	 */
+	_debug("not yet");
+	if (!rxnet->kill_all_client_conns)
+		timer_reduce(&rxnet->client_conn_reap_timer, conn_expires_at);
+
+out:
+	spin_unlock(&rxnet->client_conn_cache_lock);
+	spin_unlock(&rxnet->client_conn_discard_lock);
+	_leave("");
+}
+
+/*
+ * Preemptively destroy all the client connection records rather than waiting
+ * for them to time out
+ */
+void rxrpc_destroy_all_client_connections(struct rxrpc_net *rxnet)
+{
+	_enter("");
+
+	spin_lock(&rxnet->client_conn_cache_lock);
+	rxnet->kill_all_client_conns = true;
+	spin_unlock(&rxnet->client_conn_cache_lock);
+
+	del_timer_sync(&rxnet->client_conn_reap_timer);
+
+	if (!rxrpc_queue_work(&rxnet->client_conn_reaper))
+		_debug("destroy: queue failed");
+
+	_leave("");
+}
+
+/*
+ * Clean up the client connections on a local endpoint.
+ */
+void rxrpc_clean_up_local_conns(struct rxrpc_local *local)
+{
+	struct rxrpc_connection *conn, *tmp;
+	struct rxrpc_net *rxnet = local->rxnet;
+	LIST_HEAD(graveyard);
+
+	_enter("");
+
+	spin_lock(&rxnet->client_conn_cache_lock);
+
+	list_for_each_entry_safe(conn, tmp, &rxnet->idle_client_conns,
+				 cache_link) {
+		if (conn->params.local == local) {
+			trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+			list_move(&conn->cache_link, &graveyard);
+		}
+	}
+
+	spin_unlock(&rxnet->client_conn_cache_lock);
+
+	while (!list_empty(&graveyard)) {
+		conn = list_entry(graveyard.next,
+				  struct rxrpc_connection, cache_link);
+		list_del_init(&conn->cache_link);
+		rxrpc_unbundle_conn(conn);
+		rxrpc_put_connection(conn);
+	}
+
+	_leave(" [culled]");
+}
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
new file mode 100644
index 000000000..aff184145
--- /dev/null
+++ b/net/rxrpc/conn_event.c
@@ -0,0 +1,503 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* connection-level event handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+/*
+ * Retransmit terminal ACK or ABORT of the previous call.
+ */
+static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
+				       struct sk_buff *skb,
+				       unsigned int channel)
+{
+	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
+	struct rxrpc_channel *chan;
+	struct msghdr msg;
+	struct kvec iov[3];
+	struct {
+		struct rxrpc_wire_header whdr;
+		union {
+			__be32 abort_code;
+			struct rxrpc_ackpacket ack;
+		};
+	} __attribute__((packed)) pkt;
+	struct rxrpc_ackinfo ack_info;
+	size_t len;
+	int ret, ioc;
+	u32 serial, mtu, call_id, padding;
+
+	_enter("%d", conn->debug_id);
+
+	chan = &conn->channels[channel];
+
+	/* If the last call got moved on whilst we were waiting to run, just
+	 * ignore this packet.
+	 */
+	call_id = READ_ONCE(chan->last_call);
+	/* Sync with __rxrpc_disconnect_call() */
+	smp_rmb();
+	if (skb && call_id != sp->hdr.callNumber)
+		return;
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	iov[0].iov_base	= &pkt;
+	iov[0].iov_len	= sizeof(pkt.whdr);
+	iov[1].iov_base	= &padding;
+	iov[1].iov_len	= 3;
+	iov[2].iov_base	= &ack_info;
+	iov[2].iov_len	= sizeof(ack_info);
+
+	pkt.whdr.epoch		= htonl(conn->proto.epoch);
+	pkt.whdr.cid		= htonl(conn->proto.cid | channel);
+	pkt.whdr.callNumber	= htonl(call_id);
+	pkt.whdr.seq		= 0;
+	pkt.whdr.type		= chan->last_type;
+	pkt.whdr.flags		= conn->out_clientflag;
+	pkt.whdr.userStatus	= 0;
+	pkt.whdr.securityIndex	= conn->security_ix;
+	pkt.whdr._rsvd		= 0;
+	pkt.whdr.serviceId	= htons(conn->service_id);
+
+	len = sizeof(pkt.whdr);
+	switch (chan->last_type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		pkt.abort_code	= htonl(chan->last_abort);
+		iov[0].iov_len += sizeof(pkt.abort_code);
+		len += sizeof(pkt.abort_code);
+		ioc = 1;
+		break;
+
+	case RXRPC_PACKET_TYPE_ACK:
+		mtu = conn->params.peer->if_mtu;
+		mtu -= conn->params.peer->hdrsize;
+		pkt.ack.bufferSpace	= 0;
+		pkt.ack.maxSkew		= htons(skb ? skb->priority : 0);
+		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
+		pkt.ack.previousPacket	= htonl(chan->last_seq);
+		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
+		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
+		pkt.ack.nAcks		= 0;
+		ack_info.rxMTU		= htonl(rxrpc_rx_mtu);
+		ack_info.maxMTU		= htonl(mtu);
+		ack_info.rwind		= htonl(rxrpc_rx_window_size);
+		ack_info.jumbo_max	= htonl(rxrpc_rx_jumbo_max);
+		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
+		padding			= 0;
+		iov[0].iov_len += sizeof(pkt.ack);
+		len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
+		ioc = 3;
+		break;
+
+	default:
+		return;
+	}
+
+	/* Resync with __rxrpc_disconnect_call() and check that the last call
+	 * didn't get advanced whilst we were filling out the packets.
+	 */
+	smp_rmb();
+	if (READ_ONCE(chan->last_call) != call_id)
+		return;
+
+	serial = atomic_inc_return(&conn->serial);
+	pkt.whdr.serial = htonl(serial);
+
+	switch (chan->last_type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		_proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
+		break;
+	case RXRPC_PACKET_TYPE_ACK:
+		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
+				   ntohl(pkt.ack.firstPacket),
+				   ntohl(pkt.ack.serial),
+				   pkt.ack.reason, 0);
+		_proto("Tx ACK %%%u [re]", serial);
+		break;
+	}
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	if (ret < 0)
+		trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
+				    rxrpc_tx_point_call_final_resend);
+	else
+		trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
+				      rxrpc_tx_point_call_final_resend);
+
+	_leave("");
+}
+
+/*
+ * pass a connection-level abort onto all calls on that connection
+ */
+static void rxrpc_abort_calls(struct rxrpc_connection *conn,
+			      enum rxrpc_call_completion compl,
+			      rxrpc_serial_t serial)
+{
+	struct rxrpc_call *call;
+	int i;
+
+	_enter("{%d},%x", conn->debug_id, conn->abort_code);
+
+	spin_lock(&conn->bundle->channel_lock);
+
+	for (i = 0; i < RXRPC_MAXCALLS; i++) {
+		call = rcu_dereference_protected(
+			conn->channels[i].call,
+			lockdep_is_held(&conn->bundle->channel_lock));
+		if (call) {
+			if (compl == RXRPC_CALL_LOCALLY_ABORTED)
+				trace_rxrpc_abort(call->debug_id,
+						  "CON", call->cid,
+						  call->call_id, 0,
+						  conn->abort_code,
+						  conn->error);
+			else
+				trace_rxrpc_rx_abort(call, serial,
+						     conn->abort_code);
+			rxrpc_set_call_completion(call, compl,
+						  conn->abort_code,
+						  conn->error);
+		}
+	}
+
+	spin_unlock(&conn->bundle->channel_lock);
+	_leave("");
+}
+
+/*
+ * generate a connection-level abort
+ */
+static int rxrpc_abort_connection(struct rxrpc_connection *conn,
+				  int error, u32 abort_code)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	__be32 word;
+	size_t len;
+	u32 serial;
+	int ret;
+
+	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);
+
+	/* generate a connection-level abort */
+	spin_lock_bh(&conn->state_lock);
+	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
+		spin_unlock_bh(&conn->state_lock);
+		_leave(" = 0 [already dead]");
+		return 0;
+	}
+
+	conn->error = error;
+	conn->abort_code = abort_code;
+	conn->state = RXRPC_CONN_LOCALLY_ABORTED;
+	set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+	spin_unlock_bh(&conn->state_lock);
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(conn->proto.cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_ABORT;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	word		= htonl(conn->abort_code);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= &word;
+	iov[1].iov_len	= sizeof(word);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = atomic_inc_return(&conn->serial);
+	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_conn_abort);
+		_debug("sendmsg failed: %d", ret);
+		return -EAGAIN;
+	}
+
+	trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
+
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * mark a call as being on a now-secured channel
+ * - must be called with BH's disabled.
+ */
+static void rxrpc_call_is_secure(struct rxrpc_call *call)
+{
+	_enter("%p", call);
+	if (call) {
+		write_lock_bh(&call->state_lock);
+		if (call->state == RXRPC_CALL_SERVER_SECURING) {
+			call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
+			rxrpc_notify_socket(call);
+		}
+		write_unlock_bh(&call->state_lock);
+	}
+}
+
+/*
+ * connection-level Rx packet processor
+ */
+static int rxrpc_process_event(struct rxrpc_connection *conn,
+			       struct sk_buff *skb,
+			       u32 *_abort_code)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	__be32 wtmp;
+	u32 abort_code;
+	int loop, ret;
+
+	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
+		_leave(" = -ECONNABORTED [%u]", conn->state);
+		return -ECONNABORTED;
+	}
+
+	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_DATA:
+	case RXRPC_PACKET_TYPE_ACK:
+		rxrpc_conn_retransmit_call(conn, skb,
+					   sp->hdr.cid & RXRPC_CHANNELMASK);
+		return 0;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		/* Just ignore BUSY packets for now. */
+		return 0;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+				  &wtmp, sizeof(wtmp)) < 0) {
+			trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+					      tracepoint_string("bad_abort"));
+			return -EPROTO;
+		}
+		abort_code = ntohl(wtmp);
+		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
+
+		conn->error = -ECONNABORTED;
+		conn->abort_code = abort_code;
+		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
+		set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
+		return -ECONNABORTED;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		return conn->security->respond_to_challenge(conn, skb,
+							    _abort_code);
+
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		ret = conn->security->verify_response(conn, skb, _abort_code);
+		if (ret < 0)
+			return ret;
+
+		ret = conn->security->init_connection_security(conn);
+		if (ret < 0)
+			return ret;
+
+		ret = conn->security->prime_packet_security(conn);
+		if (ret < 0)
+			return ret;
+
+		spin_lock(&conn->bundle->channel_lock);
+		spin_lock_bh(&conn->state_lock);
+
+		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
+			conn->state = RXRPC_CONN_SERVICE;
+			spin_unlock_bh(&conn->state_lock);
+			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
+				rxrpc_call_is_secure(
+					rcu_dereference_protected(
+						conn->channels[loop].call,
+						lockdep_is_held(&conn->bundle->channel_lock)));
+		} else {
+			spin_unlock_bh(&conn->state_lock);
+		}
+
+		spin_unlock(&conn->bundle->channel_lock);
+		return 0;
+
+	default:
+		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+				      tracepoint_string("bad_conn_pkt"));
+		return -EPROTO;
+	}
+}
+
+/*
+ * set up security and issue a challenge
+ */
+static void rxrpc_secure_connection(struct rxrpc_connection *conn)
+{
+	u32 abort_code;
+	int ret;
+
+	_enter("{%d}", conn->debug_id);
+
+	ASSERT(conn->security_ix != 0);
+	ASSERT(conn->server_key);
+
+	if (conn->security->issue_challenge(conn) < 0) {
+		abort_code = RX_CALL_DEAD;
+		ret = -ENOMEM;
+		goto abort;
+	}
+
+	_leave("");
+	return;
+
+abort:
+	_debug("abort %d, %d", ret, abort_code);
+	rxrpc_abort_connection(conn, ret, abort_code);
+	_leave(" [aborted]");
+}
+
+/*
+ * Process delayed final ACKs that we haven't subsumed into a subsequent call.
+ */
+void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
+{
+	unsigned long j = jiffies, next_j;
+	unsigned int channel;
+	bool set;
+
+again:
+	next_j = j + LONG_MAX;
+	set = false;
+	for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
+		struct rxrpc_channel *chan = &conn->channels[channel];
+		unsigned long ack_at;
+
+		if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
+			continue;
+
+		smp_rmb(); /* vs rxrpc_disconnect_client_call */
+		ack_at = READ_ONCE(chan->final_ack_at);
+
+		if (time_before(j, ack_at) && !force) {
+			if (time_before(ack_at, next_j)) {
+				next_j = ack_at;
+				set = true;
+			}
+			continue;
+		}
+
+		if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
+				       &conn->flags))
+			rxrpc_conn_retransmit_call(conn, NULL, channel);
+	}
+
+	j = jiffies;
+	if (time_before_eq(next_j, j))
+		goto again;
+	if (set)
+		rxrpc_reduce_conn_timer(conn, next_j);
+}
+
+/*
+ * connection-level event processor
+ */
+static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
+{
+	struct sk_buff *skb;
+	u32 abort_code = RX_PROTOCOL_ERROR;
+	int ret;
+
+	if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
+		rxrpc_secure_connection(conn);
+
+	/* Process delayed ACKs whose time has come. */
+	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+		rxrpc_process_delayed_final_acks(conn, false);
+
+	/* go through the conn-level event packets, releasing the ref on this
+	 * connection that each one has when we've finished with it */
+	while ((skb = skb_dequeue(&conn->rx_queue))) {
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+		ret = rxrpc_process_event(conn, skb, &abort_code);
+		switch (ret) {
+		case -EPROTO:
+		case -EKEYEXPIRED:
+		case -EKEYREJECTED:
+			goto protocol_error;
+		case -ENOMEM:
+		case -EAGAIN:
+			goto requeue_and_leave;
+		case -ECONNABORTED:
+		default:
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
+			break;
+		}
+	}
+
+	return;
+
+requeue_and_leave:
+	skb_queue_head(&conn->rx_queue, skb);
+	return;
+
+protocol_error:
+	if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
+		goto requeue_and_leave;
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	return;
+}
+
+void rxrpc_process_connection(struct work_struct *work)
+{
+	struct rxrpc_connection *conn =
+		container_of(work, struct rxrpc_connection, processor);
+
+	rxrpc_see_connection(conn);
+
+	if (__rxrpc_use_local(conn->params.local)) {
+		rxrpc_do_process_connection(conn);
+		rxrpc_unuse_local(conn->params.local);
+	}
+
+	rxrpc_put_connection(conn);
+	_leave("");
+	return;
+}
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
new file mode 100644
index 000000000..d829b9755
--- /dev/null
+++ b/net/rxrpc/conn_object.c
@@ -0,0 +1,489 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC virtual connection handler, common bits.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include "ar-internal.h"
+
+/*
+ * Time till a connection expires after last use (in seconds).
+ */
+unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
+unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
+
+static void rxrpc_destroy_connection(struct rcu_head *);
+
+static void rxrpc_connection_timer(struct timer_list *timer)
+{
+	struct rxrpc_connection *conn =
+		container_of(timer, struct rxrpc_connection, timer);
+
+	rxrpc_queue_conn(conn);
+}
+
+/*
+ * allocate a new connection
+ */
+struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
+{
+	struct rxrpc_connection *conn;
+
+	_enter("");
+
+	conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
+	if (conn) {
+		INIT_LIST_HEAD(&conn->cache_link);
+		timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
+		INIT_WORK(&conn->processor, &rxrpc_process_connection);
+		INIT_LIST_HEAD(&conn->proc_link);
+		INIT_LIST_HEAD(&conn->link);
+		skb_queue_head_init(&conn->rx_queue);
+		conn->security = &rxrpc_no_security;
+		spin_lock_init(&conn->state_lock);
+		conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		conn->size_align = 4;
+		conn->idle_timestamp = jiffies;
+	}
+
+	_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
+	return conn;
+}
+
+/*
+ * Look up a connection in the cache by protocol parameters.
+ *
+ * If successful, a pointer to the connection is returned, but no ref is taken.
+ * NULL is returned if there is no match.
+ *
+ * When searching for a service call, if we find a peer but no connection, we
+ * return that through *_peer in case we need to create a new service call.
+ *
+ * The caller must be holding the RCU read lock.
+ */
+struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
+						   struct sk_buff *skb,
+						   struct rxrpc_peer **_peer)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_conn_proto k;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_peer *peer;
+
+	_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
+
+	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
+		goto not_found;
+
+	if (srx.transport.family != local->srx.transport.family &&
+	    (srx.transport.family == AF_INET &&
+	     local->srx.transport.family != AF_INET6)) {
+		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
+				    srx.transport.family,
+				    local->srx.transport.family);
+		goto not_found;
+	}
+
+	k.epoch	= sp->hdr.epoch;
+	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;
+
+	if (rxrpc_to_server(sp)) {
+		/* We need to look up service connections by the full protocol
+		 * parameter set.  We look up the peer first as an intermediate
+		 * step and then the connection from the peer's tree.
+		 */
+		peer = rxrpc_lookup_peer_rcu(local, &srx);
+		if (!peer)
+			goto not_found;
+		*_peer = peer;
+		conn = rxrpc_find_service_conn_rcu(peer, skb);
+		if (!conn || refcount_read(&conn->ref) == 0)
+			goto not_found;
+		_leave(" = %p", conn);
+		return conn;
+	} else {
+		/* Look up client connections by connection ID alone as their
+		 * IDs are unique for this machine.
+		 */
+		conn = idr_find(&rxrpc_client_conn_ids,
+				sp->hdr.cid >> RXRPC_CIDSHIFT);
+		if (!conn || refcount_read(&conn->ref) == 0) {
+			_debug("no conn");
+			goto not_found;
+		}
+
+		if (conn->proto.epoch != k.epoch ||
+		    conn->params.local != local)
+			goto not_found;
+
+		peer = conn->params.peer;
+		switch (srx.transport.family) {
+		case AF_INET:
+			if (peer->srx.transport.sin.sin_port !=
+			    srx.transport.sin.sin_port ||
+			    peer->srx.transport.sin.sin_addr.s_addr !=
+			    srx.transport.sin.sin_addr.s_addr)
+				goto not_found;
+			break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+		case AF_INET6:
+			if (peer->srx.transport.sin6.sin6_port !=
+			    srx.transport.sin6.sin6_port ||
+			    memcmp(&peer->srx.transport.sin6.sin6_addr,
+				   &srx.transport.sin6.sin6_addr,
+				   sizeof(struct in6_addr)) != 0)
+				goto not_found;
+			break;
+#endif
+		default:
+			BUG();
+		}
+
+		_leave(" = %p", conn);
+		return conn;
+	}
+
+not_found:
+	_leave(" = NULL");
+	return NULL;
+}
+
+/*
+ * Disconnect a call and clear any channel it occupies when that call
+ * terminates.  The caller must hold the channel_lock and must release the
+ * call's ref on the connection.
+ */
+void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
+			     struct rxrpc_call *call)
+{
+	struct rxrpc_channel *chan =
+		&conn->channels[call->cid & RXRPC_CHANNELMASK];
+
+	_enter("%d,%x", conn->debug_id, call->cid);
+
+	if (rcu_access_pointer(chan->call) == call) {
+		/* Save the result of the call so that we can repeat it if necessary
+		 * through the channel, whilst disposing of the actual call record.
+		 */
+		trace_rxrpc_disconnect_call(call);
+		switch (call->completion) {
+		case RXRPC_CALL_SUCCEEDED:
+			chan->last_seq = call->rx_hard_ack;
+			chan->last_type = RXRPC_PACKET_TYPE_ACK;
+			break;
+		case RXRPC_CALL_LOCALLY_ABORTED:
+			chan->last_abort = call->abort_code;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		default:
+			chan->last_abort = RX_CALL_DEAD;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		}
+
+		/* Sync with rxrpc_conn_retransmit(). */
+		smp_wmb();
+		chan->last_call = chan->call_id;
+		chan->call_id = chan->call_counter;
+
+		rcu_assign_pointer(chan->call, NULL);
+	}
+
+	_leave("");
+}
+
+/*
+ * Disconnect a call and clear any channel it occupies when that call
+ * terminates.
+ */
+void rxrpc_disconnect_call(struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn = call->conn;
+
+	call->peer->cong_cwnd = call->cong_cwnd;
+
+	if (!hlist_unhashed(&call->error_link)) {
+		spin_lock_bh(&call->peer->lock);
+		hlist_del_rcu(&call->error_link);
+		spin_unlock_bh(&call->peer->lock);
+	}
+
+	if (rxrpc_is_client_call(call))
+		return rxrpc_disconnect_client_call(conn->bundle, call);
+
+	spin_lock(&conn->bundle->channel_lock);
+	__rxrpc_disconnect_call(conn, call);
+	spin_unlock(&conn->bundle->channel_lock);
+
+	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+	conn->idle_timestamp = jiffies;
+}
+
+/*
+ * Kill off a connection.
+ */
+void rxrpc_kill_connection(struct rxrpc_connection *conn)
+{
+	struct rxrpc_net *rxnet = conn->params.local->rxnet;
+
+	ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
+	       !rcu_access_pointer(conn->channels[1].call) &&
+	       !rcu_access_pointer(conn->channels[2].call) &&
+	       !rcu_access_pointer(conn->channels[3].call));
+	ASSERT(list_empty(&conn->cache_link));
+
+	write_lock(&rxnet->conn_lock);
+	list_del_init(&conn->proc_link);
+	write_unlock(&rxnet->conn_lock);
+
+	/* Drain the Rx queue.  Note that even though we've unpublished, an
+	 * incoming packet could still be being added to our Rx queue, so we
+	 * will need to drain it again in the RCU cleanup handler.
+	 */
+	rxrpc_purge_queue(&conn->rx_queue);
+
+	/* Leave final destruction to RCU.  The connection processor work item
+	 * must carry a ref on the connection to prevent us getting here whilst
+	 * it is queued or running.
+	 */
+	call_rcu(&conn->rcu, rxrpc_destroy_connection);
+}
+
+/*
+ * Queue a connection's work processor, getting a ref to pass to the work
+ * queue.
+ */
+bool rxrpc_queue_conn(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	if (!__refcount_inc_not_zero(&conn->ref, &r))
+		return false;
+	if (rxrpc_queue_work(&conn->processor))
+		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, r + 1, here);
+	else
+		rxrpc_put_connection(conn);
+	return true;
+}
+
+/*
+ * Note the re-emergence of a connection.
+ */
+void rxrpc_see_connection(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	if (conn) {
+		int n = refcount_read(&conn->ref);
+
+		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
+	}
+}
+
+/*
+ * Get a ref on a connection.
+ */
+struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	__refcount_inc(&conn->ref, &r);
+	trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r, here);
+	return conn;
+}
+
+/*
+ * Try to get a ref on a connection.
+ */
+struct rxrpc_connection *
+rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	if (conn) {
+		if (__refcount_inc_not_zero(&conn->ref, &r))
+			trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r + 1, here);
+		else
+			conn = NULL;
+	}
+	return conn;
+}
+
+/*
+ * Set the service connection reap timer.
+ */
+static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
+					 unsigned long reap_at)
+{
+	if (rxnet->live)
+		timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
+}
+
+/*
+ * Release a service connection
+ */
+void rxrpc_put_service_conn(struct rxrpc_connection *conn)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id = conn->debug_id;
+	int r;
+
+	__refcount_dec(&conn->ref, &r);
+	trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, r - 1, here);
+	if (r - 1 == 1)
+		rxrpc_set_service_reap_timer(conn->params.local->rxnet,
+					     jiffies + rxrpc_connection_expiry);
+}
+
+/*
+ * destroy a virtual connection
+ */
+static void rxrpc_destroy_connection(struct rcu_head *rcu)
+{
+	struct rxrpc_connection *conn =
+		container_of(rcu, struct rxrpc_connection, rcu);
+
+	_enter("{%d,u=%d}", conn->debug_id, refcount_read(&conn->ref));
+
+	ASSERTCMP(refcount_read(&conn->ref), ==, 0);
+
+	_net("DESTROY CONN %d", conn->debug_id);
+
+	del_timer_sync(&conn->timer);
+	rxrpc_purge_queue(&conn->rx_queue);
+
+	conn->security->clear(conn);
+	key_put(conn->params.key);
+	key_put(conn->server_key);
+	rxrpc_put_bundle(conn->bundle);
+	rxrpc_put_peer(conn->params.peer);
+
+	if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
+		wake_up_var(&conn->params.local->rxnet->nr_conns);
+	rxrpc_put_local(conn->params.local);
+
+	kfree(conn);
+	_leave("");
+}
+
+/*
+ * reap dead service connections
+ */
+void rxrpc_service_connection_reaper(struct work_struct *work)
+{
+	struct rxrpc_connection *conn, *_p;
+	struct rxrpc_net *rxnet =
+		container_of(work, struct rxrpc_net, service_conn_reaper);
+	unsigned long expire_at, earliest, idle_timestamp, now;
+
+	LIST_HEAD(graveyard);
+
+	_enter("");
+
+	now = jiffies;
+	earliest = now + MAX_JIFFY_OFFSET;
+
+	write_lock(&rxnet->conn_lock);
+	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
+		ASSERTCMP(refcount_read(&conn->ref), >, 0);
+		if (likely(refcount_read(&conn->ref) > 1))
+			continue;
+		if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
+			continue;
+
+		if (rxnet->live && !conn->params.local->dead) {
+			idle_timestamp = READ_ONCE(conn->idle_timestamp);
+			expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
+			if (conn->params.local->service_closed)
+				expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
+
+			_debug("reap CONN %d { u=%d,t=%ld }",
+			       conn->debug_id, refcount_read(&conn->ref),
+			       (long)expire_at - (long)now);
+
+			if (time_before(now, expire_at)) {
+				if (time_before(expire_at, earliest))
+					earliest = expire_at;
+				continue;
+			}
+		}
+
+		/* The usage count sits at 1 whilst the object is unused on the
+		 * list; we reduce that to 0 to make the object unavailable.
+		 */
+		if (!refcount_dec_if_one(&conn->ref))
+			continue;
+		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
+
+		if (rxrpc_conn_is_client(conn))
+			BUG();
+		else
+			rxrpc_unpublish_service_conn(conn);
+
+		list_move_tail(&conn->link, &graveyard);
+	}
+	write_unlock(&rxnet->conn_lock);
+
+	if (earliest != now + MAX_JIFFY_OFFSET) {
+		_debug("reschedule reaper %ld", (long)earliest - (long)now);
+		ASSERT(time_after(earliest, now));
+		rxrpc_set_service_reap_timer(rxnet, earliest);
+	}
+
+	while (!list_empty(&graveyard)) {
+		conn = list_entry(graveyard.next, struct rxrpc_connection,
+				  link);
+		list_del_init(&conn->link);
+
+		ASSERTCMP(refcount_read(&conn->ref), ==, 0);
+		rxrpc_kill_connection(conn);
+	}
+
+	_leave("");
+}
+
+/*
+ * preemptively destroy all the service connection records rather than
+ * waiting for them to time out
+ */
+void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_connection *conn, *_p;
+	bool leak = false;
+
+	_enter("");
+
+	atomic_dec(&rxnet->nr_conns);
+	rxrpc_destroy_all_client_connections(rxnet);
+
+	del_timer_sync(&rxnet->service_conn_reap_timer);
+	rxrpc_queue_work(&rxnet->service_conn_reaper);
+	flush_workqueue(rxrpc_workqueue);
+
+	write_lock(&rxnet->conn_lock);
+	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
+		pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
+		       conn, refcount_read(&conn->ref));
+		leak = true;
+	}
+	write_unlock(&rxnet->conn_lock);
+	BUG_ON(leak);
+
+	ASSERT(list_empty(&rxnet->conn_proc_list));
+
+	/* We need to wait for the connections to be destroyed by RCU as they
+	 * pin things that we still need to get rid of.
+	 */
+	wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));
+	_leave("");
+}
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
new file mode 100644
index 000000000..68508166b
--- /dev/null
+++ b/net/rxrpc/conn_service.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Service connection management
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include "ar-internal.h"
+
+static struct rxrpc_bundle rxrpc_service_dummy_bundle = {
+	.ref		= REFCOUNT_INIT(1),
+	.debug_id	= UINT_MAX,
+	.channel_lock	= __SPIN_LOCK_UNLOCKED(&rxrpc_service_dummy_bundle.channel_lock),
+};
+
+/*
+ * Find a service connection under RCU conditions.
+ *
+ * We could use a hash table, but that is subject to bucket stuffing by an
+ * attacker as the client gets to pick the epoch and cid values and would know
+ * the hash function.  So, instead, we use a hash table for the peer and from
+ * that an rbtree to find the service connection.  Under ordinary circumstances
+ * it might be slower than a large hash table, but it is at least limited in
+ * depth.
+ */
+struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer,
+						     struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn = NULL;
+	struct rxrpc_conn_proto k;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rb_node *p;
+	unsigned int seq = 0;
+
+	k.epoch	= sp->hdr.epoch;
+	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;
+
+	do {
+		/* Unfortunately, rbtree walking doesn't give reliable results
+		 * under just the RCU read lock, so we have to check for
+		 * changes.
+		 */
+		read_seqbegin_or_lock(&peer->service_conn_lock, &seq);
+
+		p = rcu_dereference_raw(peer->service_conns.rb_node);
+		while (p) {
+			conn = rb_entry(p, struct rxrpc_connection, service_node);
+
+			if (conn->proto.index_key < k.index_key)
+				p = rcu_dereference_raw(p->rb_left);
+			else if (conn->proto.index_key > k.index_key)
+				p = rcu_dereference_raw(p->rb_right);
+			else
+				break;
+			conn = NULL;
+		}
+	} while (need_seqretry(&peer->service_conn_lock, seq));
+
+	done_seqretry(&peer->service_conn_lock, seq);
+	_leave(" = %d", conn ? conn->debug_id : -1);
+	return conn;
+}
+
+/*
+ * Insert a service connection into a peer's tree, thereby making it a target
+ * for incoming packets.
+ */
+static void rxrpc_publish_service_conn(struct rxrpc_peer *peer,
+				       struct rxrpc_connection *conn)
+{
+	struct rxrpc_connection *cursor = NULL;
+	struct rxrpc_conn_proto k = conn->proto;
+	struct rb_node **pp, *parent;
+
+	write_seqlock_bh(&peer->service_conn_lock);
+
+	pp = &peer->service_conns.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		cursor = rb_entry(parent,
+				  struct rxrpc_connection, service_node);
+
+		if (cursor->proto.index_key < k.index_key)
+			pp = &(*pp)->rb_left;
+		else if (cursor->proto.index_key > k.index_key)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_extant_conn;
+	}
+
+	rb_link_node_rcu(&conn->service_node, parent, pp);
+	rb_insert_color(&conn->service_node, &peer->service_conns);
+conn_published:
+	set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags);
+	write_sequnlock_bh(&peer->service_conn_lock);
+	_leave(" = %d [new]", conn->debug_id);
+	return;
+
+found_extant_conn:
+	if (refcount_read(&cursor->ref) == 0)
+		goto replace_old_connection;
+	write_sequnlock_bh(&peer->service_conn_lock);
+	/* We should not be able to get here.  rxrpc_incoming_connection() is
+	 * called in a non-reentrant context, so there can't be a race to
+	 * insert a new connection.
+	 */
+	BUG();
+
+replace_old_connection:
+	/* The old connection is from an outdated epoch. */
+	_debug("replace conn");
+	rb_replace_node_rcu(&cursor->service_node,
+			    &conn->service_node,
+			    &peer->service_conns);
+	clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &cursor->flags);
+	goto conn_published;
+}
+
+/*
+ * Preallocate a service connection.  The connection is placed on the proc and
+ * reap lists so that we don't have to get the lock from BH context.
+ */
+struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *rxnet,
+							   gfp_t gfp)
+{
+	struct rxrpc_connection *conn = rxrpc_alloc_connection(gfp);
+
+	if (conn) {
+		/* We maintain an extra ref on the connection whilst it is on
+		 * the rxrpc_connections list.
+		 */
+		conn->state = RXRPC_CONN_SERVICE_PREALLOC;
+		refcount_set(&conn->ref, 2);
+		conn->bundle = rxrpc_get_bundle(&rxrpc_service_dummy_bundle);
+
+		atomic_inc(&rxnet->nr_conns);
+		write_lock(&rxnet->conn_lock);
+		list_add_tail(&conn->link, &rxnet->service_conns);
+		list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+		write_unlock(&rxnet->conn_lock);
+
+		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service,
+				 refcount_read(&conn->ref),
+				 __builtin_return_address(0));
+	}
+
+	return conn;
+}
+
+/*
+ * Set up an incoming connection.  This is called in BH context with the RCU
+ * read lock held.
+ */
+void rxrpc_new_incoming_connection(struct rxrpc_sock *rx,
+				   struct rxrpc_connection *conn,
+				   const struct rxrpc_security *sec,
+				   struct key *key,
+				   struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	_enter("");
+
+	conn->proto.epoch	= sp->hdr.epoch;
+	conn->proto.cid		= sp->hdr.cid & RXRPC_CIDMASK;
+	conn->params.service_id	= sp->hdr.serviceId;
+	conn->service_id	= sp->hdr.serviceId;
+	conn->security_ix	= sp->hdr.securityIndex;
+	conn->out_clientflag	= 0;
+	conn->security		= sec;
+	conn->server_key	= key_get(key);
+	if (conn->security_ix)
+		conn->state	= RXRPC_CONN_SERVICE_UNSECURED;
+	else
+		conn->state	= RXRPC_CONN_SERVICE;
+
+	/* See if we should upgrade the service.  This can only happen on the
+	 * first packet on a new connection.  Once done, it applies to all
+	 * subsequent calls on that connection.
+	 */
+	if (sp->hdr.userStatus == RXRPC_USERSTATUS_SERVICE_UPGRADE &&
+	    conn->service_id == rx->service_upgrade.from)
+		conn->service_id = rx->service_upgrade.to;
+
+	/* Make the connection a target for incoming packets. */
+	rxrpc_publish_service_conn(conn->params.peer, conn);
+
+	_net("CONNECTION new %d {%x}", conn->debug_id, conn->proto.cid);
+}
+
+/*
+ * Remove the service connection from the peer's tree, thereby removing it as a
+ * target for incoming packets.
+ */
+void rxrpc_unpublish_service_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_peer *peer = conn->params.peer;
+
+	write_seqlock_bh(&peer->service_conn_lock);
+	if (test_and_clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags))
+		rb_erase(&conn->service_node, &peer->service_conns);
+	write_sequnlock_bh(&peer->service_conn_lock);
+}
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
new file mode 100644
index 000000000..e9178115a
--- /dev/null
+++ b/net/rxrpc/input.c
@@ -0,0 +1,1475 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC packet reception
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/udp.h>
+#include <net/net_namespace.h>
+#include "ar-internal.h"
+
+static void rxrpc_proto_abort(const char *why,
+			      struct rxrpc_call *call, rxrpc_seq_t seq)
+{
+	if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
+		set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+		rxrpc_queue_call(call);
+	}
+}
+
+/*
+ * Do TCP-style congestion management [RFC 5681].
+ */
+static void rxrpc_congestion_management(struct rxrpc_call *call,
+					struct sk_buff *skb,
+					struct rxrpc_ack_summary *summary,
+					rxrpc_serial_t acked_serial)
+{
+	enum rxrpc_congest_change change = rxrpc_cong_no_change;
+	unsigned int cumulative_acks = call->cong_cumul_acks;
+	unsigned int cwnd = call->cong_cwnd;
+	bool resend = false;
+
+	summary->flight_size =
+		(call->tx_top - call->tx_hard_ack) - summary->nr_acks;
+
+	if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
+		summary->retrans_timeo = true;
+		call->cong_ssthresh = max_t(unsigned int,
+					    summary->flight_size / 2, 2);
+		cwnd = 1;
+		if (cwnd >= call->cong_ssthresh &&
+		    call->cong_mode == RXRPC_CALL_SLOW_START) {
+			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+			call->cong_tstamp = skb->tstamp;
+			cumulative_acks = 0;
+		}
+	}
+
+	cumulative_acks += summary->nr_new_acks;
+	cumulative_acks += summary->nr_rot_new_acks;
+	if (cumulative_acks > 255)
+		cumulative_acks = 255;
+
+	summary->mode = call->cong_mode;
+	summary->cwnd = call->cong_cwnd;
+	summary->ssthresh = call->cong_ssthresh;
+	summary->cumulative_acks = cumulative_acks;
+	summary->dup_acks = call->cong_dup_acks;
+
+	switch (call->cong_mode) {
+	case RXRPC_CALL_SLOW_START:
+		if (summary->nr_nacks > 0)
+			goto packet_loss_detected;
+		if (summary->cumulative_acks > 0)
+			cwnd += 1;
+		if (cwnd >= call->cong_ssthresh) {
+			call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+			call->cong_tstamp = skb->tstamp;
+		}
+		goto out;
+
+	case RXRPC_CALL_CONGEST_AVOIDANCE:
+		if (summary->nr_nacks > 0)
+			goto packet_loss_detected;
+
+		/* We analyse the number of packets that get ACK'd per RTT
+		 * period and increase the window if we managed to fill it.
+		 */
+		if (call->peer->rtt_count == 0)
+			goto out;
+		if (ktime_before(skb->tstamp,
+				 ktime_add_us(call->cong_tstamp,
+					      call->peer->srtt_us >> 3)))
+			goto out_no_clear_ca;
+		change = rxrpc_cong_rtt_window_end;
+		call->cong_tstamp = skb->tstamp;
+		if (cumulative_acks >= cwnd)
+			cwnd++;
+		goto out;
+
+	case RXRPC_CALL_PACKET_LOSS:
+		if (summary->nr_nacks == 0)
+			goto resume_normality;
+
+		if (summary->new_low_nack) {
+			change = rxrpc_cong_new_low_nack;
+			call->cong_dup_acks = 1;
+			if (call->cong_extra > 1)
+				call->cong_extra = 1;
+			goto send_extra_data;
+		}
+
+		call->cong_dup_acks++;
+		if (call->cong_dup_acks < 3)
+			goto send_extra_data;
+
+		change = rxrpc_cong_begin_retransmission;
+		call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
+		call->cong_ssthresh = max_t(unsigned int,
+					    summary->flight_size / 2, 2);
+		cwnd = call->cong_ssthresh + 3;
+		call->cong_extra = 0;
+		call->cong_dup_acks = 0;
+		resend = true;
+		goto out;
+
+	case RXRPC_CALL_FAST_RETRANSMIT:
+		if (!summary->new_low_nack) {
+			if (summary->nr_new_acks == 0)
+				cwnd += 1;
+			call->cong_dup_acks++;
+			if (call->cong_dup_acks == 2) {
+				change = rxrpc_cong_retransmit_again;
+				call->cong_dup_acks = 0;
+				resend = true;
+			}
+		} else {
+			change = rxrpc_cong_progress;
+			cwnd = call->cong_ssthresh;
+			if (summary->nr_nacks == 0)
+				goto resume_normality;
+		}
+		goto out;
+
+	default:
+		BUG();
+		goto out;
+	}
+
+resume_normality:
+	change = rxrpc_cong_cleared_nacks;
+	call->cong_dup_acks = 0;
+	call->cong_extra = 0;
+	call->cong_tstamp = skb->tstamp;
+	if (cwnd < call->cong_ssthresh)
+		call->cong_mode = RXRPC_CALL_SLOW_START;
+	else
+		call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+out:
+	cumulative_acks = 0;
+out_no_clear_ca:
+	if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
+		cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
+	call->cong_cwnd = cwnd;
+	call->cong_cumul_acks = cumulative_acks;
+	trace_rxrpc_congest(call, summary, acked_serial, change);
+	if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+		rxrpc_queue_call(call);
+	return;
+
+packet_loss_detected:
+	change = rxrpc_cong_saw_nack;
+	call->cong_mode = RXRPC_CALL_PACKET_LOSS;
+	call->cong_dup_acks = 0;
+	goto send_extra_data;
+
+send_extra_data:
+	/* Send some previously unsent DATA if we have some to advance the ACK
+	 * state.
+	 */
+	if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
+	    RXRPC_TX_ANNO_LAST ||
+	    summary->nr_acks != call->tx_top - call->tx_hard_ack) {
+		call->cong_extra++;
+		wake_up(&call->waitq);
+	}
+	goto out_no_clear_ca;
+}
+
+/*
+ * Apply a hard ACK by advancing the Tx window.
+ */
+static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
+				   struct rxrpc_ack_summary *summary)
+{
+	struct sk_buff *skb, *list = NULL;
+	bool rot_last = false;
+	int ix;
+	u8 annotation;
+
+	if (call->acks_lowest_nak == call->tx_hard_ack) {
+		call->acks_lowest_nak = to;
+	} else if (before_eq(call->acks_lowest_nak, to)) {
+		summary->new_low_nack = true;
+		call->acks_lowest_nak = to;
+	}
+
+	spin_lock(&call->lock);
+
+	while (before(call->tx_hard_ack, to)) {
+		call->tx_hard_ack++;
+		ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
+		skb = call->rxtx_buffer[ix];
+		annotation = call->rxtx_annotations[ix];
+		rxrpc_see_skb(skb, rxrpc_skb_rotated);
+		call->rxtx_buffer[ix] = NULL;
+		call->rxtx_annotations[ix] = 0;
+		skb->next = list;
+		list = skb;
+
+		if (annotation & RXRPC_TX_ANNO_LAST) {
+			set_bit(RXRPC_CALL_TX_LAST, &call->flags);
+			rot_last = true;
+		}
+		if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
+			summary->nr_rot_new_acks++;
+	}
+
+	spin_unlock(&call->lock);
+
+	trace_rxrpc_transmit(call, (rot_last ?
+				    rxrpc_transmit_rotate_last :
+				    rxrpc_transmit_rotate));
+	wake_up(&call->waitq);
+
+	while (list) {
+		skb = list;
+		list = skb->next;
+		skb_mark_not_on_list(skb);
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	}
+
+	return rot_last;
+}
+
+/*
+ * End the transmission phase of a call.
+ *
+ * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
+ * or a final ACK packet.
+ */
+static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+			       const char *abort_why)
+{
+	unsigned int state;
+
+	ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
+
+	write_lock(&call->state_lock);
+
+	state = call->state;
+	switch (state) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		if (reply_begun)
+			call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
+		else
+			call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+		break;
+
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		__rxrpc_call_completed(call);
+		state = call->state;
+		break;
+
+	default:
+		goto bad_state;
+	}
+
+	write_unlock(&call->state_lock);
+	if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+		trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
+	else
+		trace_rxrpc_transmit(call, rxrpc_transmit_end);
+	_leave(" = ok");
+	return true;
+
+bad_state:
+	write_unlock(&call->state_lock);
+	kdebug("end_tx %s", rxrpc_call_states[call->state]);
+	rxrpc_proto_abort(abort_why, call, call->tx_top);
+	return false;
+}
+
+/*
+ * Begin the reply reception phase of a call.
+ */
+static bool rxrpc_receiving_reply(struct rxrpc_call *call)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	unsigned long now, timo;
+	rxrpc_seq_t top = READ_ONCE(call->tx_top);
+
+	if (call->ackr_reason) {
+		spin_lock_bh(&call->lock);
+		call->ackr_reason = 0;
+		spin_unlock_bh(&call->lock);
+		now = jiffies;
+		timo = now + MAX_JIFFY_OFFSET;
+		WRITE_ONCE(call->resend_at, timo);
+		WRITE_ONCE(call->ack_at, timo);
+		trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
+	}
+
+	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
+		if (!rxrpc_rotate_tx_window(call, top, &summary)) {
+			rxrpc_proto_abort("TXL", call, top);
+			return false;
+		}
+	}
+	if (!rxrpc_end_tx_phase(call, true, "ETD"))
+		return false;
+	call->tx_phase = false;
+	return true;
+}
+
+/*
+ * Scan a data packet to validate its structure and to work out how many
+ * subpackets it contains.
+ *
+ * A jumbo packet is a collection of consecutive packets glued together with
+ * little headers between that indicate how to change the initial header for
+ * each subpacket.
+ *
+ * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
+ * the last are RXRPC_JUMBO_DATALEN in size.  The last subpacket may be of any
+ * size.
+ */
+static bool rxrpc_validate_data(struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
+	unsigned int len = skb->len;
+	u8 flags = sp->hdr.flags;
+
+	for (;;) {
+		if (flags & RXRPC_REQUEST_ACK)
+			__set_bit(sp->nr_subpackets, sp->rx_req_ack);
+		sp->nr_subpackets++;
+
+		if (!(flags & RXRPC_JUMBO_PACKET))
+			break;
+
+		if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
+			goto protocol_error;
+		if (flags & RXRPC_LAST_PACKET)
+			goto protocol_error;
+		offset += RXRPC_JUMBO_DATALEN;
+		if (skb_copy_bits(skb, offset, &flags, 1) < 0)
+			goto protocol_error;
+		offset += sizeof(struct rxrpc_jumbo_header);
+	}
+
+	if (flags & RXRPC_LAST_PACKET)
+		sp->rx_flags |= RXRPC_SKB_INCL_LAST;
+	return true;
+
+protocol_error:
+	return false;
+}
+
+/*
+ * Handle reception of a duplicate packet.
+ *
+ * We have to take care to avoid an attack here whereby we're given a series of
+ * jumbograms, each with a sequence number one before the preceding one and
+ * filled up to maximum UDP size.  If they never send us the first packet in
+ * the sequence, they can cause us to have to hold on to around 2MiB of kernel
+ * space until the call times out.
+ *
+ * We limit the space usage by only accepting three duplicate jumbo packets per
+ * call.  After that, we tell the other side we're no longer accepting jumbos
+ * (that information is encoded in the ACK packet).
+ */
+static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
+				 bool is_jumbo, bool *_jumbo_bad)
+{
+	/* Discard normal packets that are duplicates. */
+	if (is_jumbo)
+		return;
+
+	/* Skip jumbo subpackets that are duplicates.  When we've had three or
+	 * more partially duplicate jumbo packets, we refuse to take any more
+	 * jumbos for this call.
+	 */
+	if (!*_jumbo_bad) {
+		call->nr_jumbo_bad++;
+		*_jumbo_bad = true;
+	}
+}
+
+/*
+ * Process a DATA packet, adding the packet to the Rx ring.  The caller's
+ * packet ref must be passed on or discarded.
+ */
+static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	enum rxrpc_call_state state;
+	unsigned int j, nr_subpackets, nr_unacked = 0;
+	rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial;
+	rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
+	bool immediate_ack = false, jumbo_bad = false;
+	u8 ack = 0;
+
+	_enter("{%u,%u},{%u,%u}",
+	       call->rx_hard_ack, call->rx_top, skb->len, seq0);
+
+	_proto("Rx DATA %%%u { #%u f=%02x n=%u }",
+	       sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
+
+	state = READ_ONCE(call->state);
+	if (state >= RXRPC_CALL_COMPLETE) {
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+		return;
+	}
+
+	if (state == RXRPC_CALL_SERVER_RECV_REQUEST) {
+		unsigned long timo = READ_ONCE(call->next_req_timo);
+		unsigned long now, expect_req_by;
+
+		if (timo) {
+			now = jiffies;
+			expect_req_by = now + timo;
+			WRITE_ONCE(call->expect_req_by, expect_req_by);
+			rxrpc_reduce_call_timer(call, expect_req_by, now,
+						rxrpc_timer_set_for_idle);
+		}
+	}
+
+	spin_lock(&call->input_lock);
+
+	/* Received data implicitly ACKs all of the request packets we sent
+	 * when we're acting as a client.
+	 */
+	if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
+	     state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
+	    !rxrpc_receiving_reply(call))
+		goto unlock;
+
+	hard_ack = READ_ONCE(call->rx_hard_ack);
+
+	nr_subpackets = sp->nr_subpackets;
+	if (nr_subpackets > 1) {
+		if (call->nr_jumbo_bad > 3) {
+			ack = RXRPC_ACK_NOSPACE;
+			ack_serial = serial;
+			goto ack;
+		}
+	}
+
+	for (j = 0; j < nr_subpackets; j++) {
+		rxrpc_serial_t serial = sp->hdr.serial + j;
+		rxrpc_seq_t seq = seq0 + j;
+		unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
+		bool terminal = (j == nr_subpackets - 1);
+		bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST);
+		u8 flags, annotation = j;
+
+		_proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
+		     j, serial, seq, terminal, last);
+
+		if (last) {
+			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+			    seq != call->rx_top) {
+				rxrpc_proto_abort("LSN", call, seq);
+				goto unlock;
+			}
+		} else {
+			if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+			    after_eq(seq, call->rx_top)) {
+				rxrpc_proto_abort("LSA", call, seq);
+				goto unlock;
+			}
+		}
+
+		flags = 0;
+		if (last)
+			flags |= RXRPC_LAST_PACKET;
+		if (!terminal)
+			flags |= RXRPC_JUMBO_PACKET;
+		if (test_bit(j, sp->rx_req_ack))
+			flags |= RXRPC_REQUEST_ACK;
+		trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
+
+		if (before_eq(seq, hard_ack)) {
+			ack = RXRPC_ACK_DUPLICATE;
+			ack_serial = serial;
+			continue;
+		}
+
+		if (call->rxtx_buffer[ix]) {
+			rxrpc_input_dup_data(call, seq, nr_subpackets > 1,
+					     &jumbo_bad);
+			if (ack != RXRPC_ACK_DUPLICATE) {
+				ack = RXRPC_ACK_DUPLICATE;
+				ack_serial = serial;
+			}
+			immediate_ack = true;
+			continue;
+		}
+
+		if (after(seq, hard_ack + call->rx_winsize)) {
+			ack = RXRPC_ACK_EXCEEDS_WINDOW;
+			ack_serial = serial;
+			if (flags & RXRPC_JUMBO_PACKET) {
+				if (!jumbo_bad) {
+					call->nr_jumbo_bad++;
+					jumbo_bad = true;
+				}
+			}
+
+			goto ack;
+		}
+
+		if (flags & RXRPC_REQUEST_ACK && !ack) {
+			ack = RXRPC_ACK_REQUESTED;
+			ack_serial = serial;
+		}
+
+		if (after(seq0, call->ackr_highest_seq))
+			call->ackr_highest_seq = seq0;
+
+		/* Queue the packet.  We use a couple of memory barriers here as need
+		 * to make sure that rx_top is perceived to be set after the buffer
+		 * pointer and that the buffer pointer is set after the annotation and
+		 * the skb data.
+		 *
+		 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
+		 * and also rxrpc_fill_out_ack().
+		 */
+		if (!terminal)
+			rxrpc_get_skb(skb, rxrpc_skb_got);
+		call->rxtx_annotations[ix] = annotation;
+		smp_wmb();
+		call->rxtx_buffer[ix] = skb;
+		if (after(seq, call->rx_top)) {
+			smp_store_release(&call->rx_top, seq);
+		} else if (before(seq, call->rx_top)) {
+			/* Send an immediate ACK if we fill in a hole */
+			if (!ack) {
+				ack = RXRPC_ACK_DELAY;
+				ack_serial = serial;
+			}
+			immediate_ack = true;
+		}
+
+		if (terminal) {
+			/* From this point on, we're not allowed to touch the
+			 * packet any longer as its ref now belongs to the Rx
+			 * ring.
+			 */
+			skb = NULL;
+			sp = NULL;
+		}
+
+		nr_unacked++;
+
+		if (last) {
+			set_bit(RXRPC_CALL_RX_LAST, &call->flags);
+			if (!ack) {
+				ack = RXRPC_ACK_DELAY;
+				ack_serial = serial;
+			}
+			trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
+		} else {
+			trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
+		}
+
+		if (after_eq(seq, call->rx_expect_next)) {
+			if (after(seq, call->rx_expect_next)) {
+				_net("OOS %u > %u", seq, call->rx_expect_next);
+				ack = RXRPC_ACK_OUT_OF_SEQUENCE;
+				ack_serial = serial;
+			}
+			call->rx_expect_next = seq + 1;
+		}
+		if (!ack)
+			ack_serial = serial;
+	}
+
+ack:
+	if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack)
+		ack = RXRPC_ACK_IDLE;
+
+	if (ack)
+		rxrpc_propose_ACK(call, ack, ack_serial,
+				  immediate_ack, true,
+				  rxrpc_propose_ack_input_data);
+	else
+		rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
+				  false, true,
+				  rxrpc_propose_ack_input_data);
+
+	trace_rxrpc_notify_socket(call->debug_id, serial);
+	rxrpc_notify_socket(call);
+
+unlock:
+	spin_unlock(&call->input_lock);
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" [queued]");
+}
+
+/*
+ * See if there's a cached RTT probe to complete.
+ */
+static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
+				     ktime_t resp_time,
+				     rxrpc_serial_t acked_serial,
+				     rxrpc_serial_t ack_serial,
+				     enum rxrpc_rtt_rx_trace type)
+{
+	rxrpc_serial_t orig_serial;
+	unsigned long avail;
+	ktime_t sent_at;
+	bool matched = false;
+	int i;
+
+	avail = READ_ONCE(call->rtt_avail);
+	smp_rmb(); /* Read avail bits before accessing data. */
+
+	for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
+		if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
+			continue;
+
+		sent_at = call->rtt_sent_at[i];
+		orig_serial = call->rtt_serial[i];
+
+		if (orig_serial == acked_serial) {
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_mb(); /* Read data before setting avail bit */
+			set_bit(i, &call->rtt_avail);
+			if (type != rxrpc_rtt_rx_cancel)
+				rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
+						   sent_at, resp_time);
+			else
+				trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i,
+						   orig_serial, acked_serial, 0, 0);
+			matched = true;
+		}
+
+		/* If a later serial is being acked, then mark this slot as
+		 * being available.
+		 */
+		if (after(acked_serial, orig_serial)) {
+			trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
+					   orig_serial, acked_serial, 0, 0);
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_wmb();
+			set_bit(i, &call->rtt_avail);
+		}
+	}
+
+	if (!matched)
+		trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
+}
+
+/*
+ * Process the response to a ping that we sent to find out if we lost an ACK.
+ *
+ * If we got back a ping response that indicates a lower tx_top than what we
+ * had at the time of the ping transmission, we adjudge all the DATA packets
+ * sent between the response tx_top and the ping-time tx_top to have been lost.
+ */
+static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
+{
+	rxrpc_seq_t top, bottom, seq;
+	bool resend = false;
+
+	spin_lock_bh(&call->lock);
+
+	bottom = call->tx_hard_ack + 1;
+	top = call->acks_lost_top;
+	if (before(bottom, top)) {
+		for (seq = bottom; before_eq(seq, top); seq++) {
+			int ix = seq & RXRPC_RXTX_BUFF_MASK;
+			u8 annotation = call->rxtx_annotations[ix];
+			u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
+
+			if (anno_type != RXRPC_TX_ANNO_UNACK)
+				continue;
+			annotation &= ~RXRPC_TX_ANNO_MASK;
+			annotation |= RXRPC_TX_ANNO_RETRANS;
+			call->rxtx_annotations[ix] = annotation;
+			resend = true;
+		}
+	}
+
+	spin_unlock_bh(&call->lock);
+
+	if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+		rxrpc_queue_call(call);
+}
+
+/*
+ * Process a ping response.
+ */
+static void rxrpc_input_ping_response(struct rxrpc_call *call,
+				      ktime_t resp_time,
+				      rxrpc_serial_t acked_serial,
+				      rxrpc_serial_t ack_serial)
+{
+	if (acked_serial == call->acks_lost_ping)
+		rxrpc_input_check_for_lost_ack(call);
+}
+
+/*
+ * Process the extra information that may be appended to an ACK packet
+ */
+static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
+				struct rxrpc_ackinfo *ackinfo)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_peer *peer;
+	unsigned int mtu;
+	bool wake = false;
+	u32 rwind = ntohl(ackinfo->rwind);
+
+	_proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
+	       sp->hdr.serial,
+	       ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
+	       rwind, ntohl(ackinfo->jumbo_max));
+
+	if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
+		rwind = RXRPC_RXTX_BUFF_SIZE - 1;
+	if (call->tx_winsize != rwind) {
+		if (rwind > call->tx_winsize)
+			wake = true;
+		trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
+		call->tx_winsize = rwind;
+	}
+
+	if (call->cong_ssthresh > rwind)
+		call->cong_ssthresh = rwind;
+
+	mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
+
+	peer = call->peer;
+	if (mtu < peer->maxdata) {
+		spin_lock_bh(&peer->lock);
+		peer->maxdata = mtu;
+		peer->mtu = mtu + peer->hdrsize;
+		spin_unlock_bh(&peer->lock);
+		_net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
+	}
+
+	if (wake)
+		wake_up(&call->waitq);
+}
+
+/*
+ * Process individual soft ACKs.
+ *
+ * Each ACK in the array corresponds to one packet and can be either an ACK or
+ * a NAK.  If we get find an explicitly NAK'd packet we resend immediately;
+ * packets that lie beyond the end of the ACK list are scheduled for resend by
+ * the timer on the basis that the peer might just not have processed them at
+ * the time the ACK was sent.
+ */
+static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
+				  rxrpc_seq_t seq, int nr_acks,
+				  struct rxrpc_ack_summary *summary)
+{
+	int ix;
+	u8 annotation, anno_type;
+
+	for (; nr_acks > 0; nr_acks--, seq++) {
+		ix = seq & RXRPC_RXTX_BUFF_MASK;
+		annotation = call->rxtx_annotations[ix];
+		anno_type = annotation & RXRPC_TX_ANNO_MASK;
+		annotation &= ~RXRPC_TX_ANNO_MASK;
+		switch (*acks++) {
+		case RXRPC_ACK_TYPE_ACK:
+			summary->nr_acks++;
+			if (anno_type == RXRPC_TX_ANNO_ACK)
+				continue;
+			summary->nr_new_acks++;
+			call->rxtx_annotations[ix] =
+				RXRPC_TX_ANNO_ACK | annotation;
+			break;
+		case RXRPC_ACK_TYPE_NACK:
+			if (!summary->nr_nacks &&
+			    call->acks_lowest_nak != seq) {
+				call->acks_lowest_nak = seq;
+				summary->new_low_nack = true;
+			}
+			summary->nr_nacks++;
+			if (anno_type == RXRPC_TX_ANNO_NAK)
+				continue;
+			summary->nr_new_nacks++;
+			if (anno_type == RXRPC_TX_ANNO_RETRANS)
+				continue;
+			call->rxtx_annotations[ix] =
+				RXRPC_TX_ANNO_NAK | annotation;
+			break;
+		default:
+			return rxrpc_proto_abort("SFT", call, 0);
+		}
+	}
+}
+
+/*
+ * Return true if the ACK is valid - ie. it doesn't appear to have regressed
+ * with respect to the ack state conveyed by preceding ACKs.
+ */
+static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
+			       rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
+{
+	rxrpc_seq_t base = READ_ONCE(call->acks_first_seq);
+
+	if (after(first_pkt, base))
+		return true; /* The window advanced */
+
+	if (before(first_pkt, base))
+		return false; /* firstPacket regressed */
+
+	if (after_eq(prev_pkt, call->acks_prev_seq))
+		return true; /* previousPacket hasn't regressed. */
+
+	/* Some rx implementations put a serial number in previousPacket. */
+	if (after_eq(prev_pkt, base + call->tx_winsize))
+		return false;
+	return true;
+}
+
+/*
+ * Process an ACK packet.
+ *
+ * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
+ * in the ACK array.  Anything before that is hard-ACK'd and may be discarded.
+ *
+ * A hard-ACK means that a packet has been processed and may be discarded; a
+ * soft-ACK means that the packet may be discarded and retransmission
+ * requested.  A phase is complete when all packets are hard-ACK'd.
+ */
+static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	union {
+		struct rxrpc_ackpacket ack;
+		struct rxrpc_ackinfo info;
+		u8 acks[RXRPC_MAXACKS];
+	} buf;
+	rxrpc_serial_t ack_serial, acked_serial;
+	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
+	int nr_acks, offset, ioffset;
+
+	_enter("");
+
+	offset = sizeof(struct rxrpc_wire_header);
+	if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
+		_debug("extraction failure");
+		return rxrpc_proto_abort("XAK", call, 0);
+	}
+	offset += sizeof(buf.ack);
+
+	ack_serial = sp->hdr.serial;
+	acked_serial = ntohl(buf.ack.serial);
+	first_soft_ack = ntohl(buf.ack.firstPacket);
+	prev_pkt = ntohl(buf.ack.previousPacket);
+	hard_ack = first_soft_ack - 1;
+	nr_acks = buf.ack.nAcks;
+	summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
+			      buf.ack.reason : RXRPC_ACK__INVALID);
+
+	trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
+			   first_soft_ack, prev_pkt,
+			   summary.ack_reason, nr_acks);
+
+	switch (buf.ack.reason) {
+	case RXRPC_ACK_PING_RESPONSE:
+		rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
+					  ack_serial);
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_ping_response);
+		break;
+	case RXRPC_ACK_REQUESTED:
+		rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+					 rxrpc_rtt_rx_requested_ack);
+		break;
+	default:
+		if (acked_serial != 0)
+			rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
+						 rxrpc_rtt_rx_cancel);
+		break;
+	}
+
+	if (buf.ack.reason == RXRPC_ACK_PING) {
+		_proto("Rx ACK %%%u PING Request", ack_serial);
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
+				  ack_serial, true, true,
+				  rxrpc_propose_ack_respond_to_ping);
+	} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
+				  ack_serial, true, true,
+				  rxrpc_propose_ack_respond_to_ack);
+	}
+
+	/* Discard any out-of-order or duplicate ACKs (outside lock). */
+	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
+		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
+					   first_soft_ack, call->acks_first_seq,
+					   prev_pkt, call->acks_prev_seq);
+		return;
+	}
+
+	buf.info.rxMTU = 0;
+	ioffset = offset + nr_acks + 3;
+	if (skb->len >= ioffset + sizeof(buf.info) &&
+	    skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
+		return rxrpc_proto_abort("XAI", call, 0);
+
+	spin_lock(&call->input_lock);
+
+	/* Discard any out-of-order or duplicate ACKs (inside lock). */
+	if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
+		trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
+					   first_soft_ack, call->acks_first_seq,
+					   prev_pkt, call->acks_prev_seq);
+		goto out;
+	}
+	call->acks_latest_ts = skb->tstamp;
+
+	call->acks_first_seq = first_soft_ack;
+	call->acks_prev_seq = prev_pkt;
+
+	/* Parse rwind and mtu sizes if provided. */
+	if (buf.info.rxMTU)
+		rxrpc_input_ackinfo(call, skb, &buf.info);
+
+	if (first_soft_ack == 0) {
+		rxrpc_proto_abort("AK0", call, 0);
+		goto out;
+	}
+
+	/* Ignore ACKs unless we are or have just been transmitting. */
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		break;
+	default:
+		goto out;
+	}
+
+	if (before(hard_ack, call->tx_hard_ack) ||
+	    after(hard_ack, call->tx_top)) {
+		rxrpc_proto_abort("AKW", call, 0);
+		goto out;
+	}
+	if (nr_acks > call->tx_top - hard_ack) {
+		rxrpc_proto_abort("AKN", call, 0);
+		goto out;
+	}
+
+	if (after(hard_ack, call->tx_hard_ack)) {
+		if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
+			rxrpc_end_tx_phase(call, false, "ETA");
+			goto out;
+		}
+	}
+
+	if (nr_acks > 0) {
+		if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
+			rxrpc_proto_abort("XSA", call, 0);
+			goto out;
+		}
+		rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
+				      &summary);
+	}
+
+	if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
+	    RXRPC_TX_ANNO_LAST &&
+	    summary.nr_acks == call->tx_top - hard_ack &&
+	    rxrpc_is_client_call(call))
+		rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial,
+				  false, true,
+				  rxrpc_propose_ack_ping_for_lost_reply);
+
+	rxrpc_congestion_management(call, skb, &summary, acked_serial);
+out:
+	spin_unlock(&call->input_lock);
+}
+
+/*
+ * Process an ACKALL packet.
+ */
+static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	_proto("Rx ACKALL %%%u", sp->hdr.serial);
+
+	spin_lock(&call->input_lock);
+
+	if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
+		rxrpc_end_tx_phase(call, false, "ETL");
+
+	spin_unlock(&call->input_lock);
+}
+
+/*
+ * Process an ABORT packet directed at a call.
+ */
+static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	__be32 wtmp;
+	u32 abort_code = RX_CALL_DEAD;
+
+	_enter("");
+
+	if (skb->len >= 4 &&
+	    skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &wtmp, sizeof(wtmp)) >= 0)
+		abort_code = ntohl(wtmp);
+
+	trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
+
+	_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
+
+	rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+				  abort_code, -ECONNABORTED);
+}
+
+/*
+ * Process an incoming call packet.
+ */
+static void rxrpc_input_call_packet(struct rxrpc_call *call,
+				    struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned long timo;
+
+	_enter("%p,%p", call, skb);
+
+	timo = READ_ONCE(call->next_rx_timo);
+	if (timo) {
+		unsigned long now = jiffies, expect_rx_by;
+
+		expect_rx_by = now + timo;
+		WRITE_ONCE(call->expect_rx_by, expect_rx_by);
+		rxrpc_reduce_call_timer(call, expect_rx_by, now,
+					rxrpc_timer_set_for_normal);
+	}
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_DATA:
+		rxrpc_input_data(call, skb);
+		goto no_free;
+
+	case RXRPC_PACKET_TYPE_ACK:
+		rxrpc_input_ack(call, skb);
+		break;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		_proto("Rx BUSY %%%u", sp->hdr.serial);
+
+		/* Just ignore BUSY packets from the server; the retry and
+		 * lifespan timers will take care of business.  BUSY packets
+		 * from the client don't make sense.
+		 */
+		break;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		rxrpc_input_abort(call, skb);
+		break;
+
+	case RXRPC_PACKET_TYPE_ACKALL:
+		rxrpc_input_ackall(call, skb);
+		break;
+
+	default:
+		break;
+	}
+
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+no_free:
+	_leave("");
+}
+
+/*
+ * Handle a new service call on a channel implicitly completing the preceding
+ * call on that channel.  This does not apply to client conns.
+ *
+ * TODO: If callNumber > call_id + 1, renegotiate security.
+ */
+static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
+					  struct rxrpc_connection *conn,
+					  struct rxrpc_call *call)
+{
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		rxrpc_call_completed(call);
+		fallthrough;
+	case RXRPC_CALL_COMPLETE:
+		break;
+	default:
+		if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
+			set_bit(RXRPC_CALL_EV_ABORT, &call->events);
+			rxrpc_queue_call(call);
+		}
+		trace_rxrpc_improper_term(call);
+		break;
+	}
+
+	spin_lock(&rx->incoming_lock);
+	__rxrpc_disconnect_call(conn, call);
+	spin_unlock(&rx->incoming_lock);
+}
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses, some aborts and call terminal packet
+ *   retransmission.
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+				      struct sk_buff *skb)
+{
+	_enter("%p,%p", conn, skb);
+
+	skb_queue_tail(&conn->rx_queue, skb);
+	rxrpc_queue_conn(conn);
+}
+
+/*
+ * post endpoint-level events to the local endpoint
+ * - this includes debug and version messages
+ */
+static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
+				       struct sk_buff *skb)
+{
+	_enter("%p,%p", local, skb);
+
+	if (rxrpc_get_local_maybe(local)) {
+		skb_queue_tail(&local->event_queue, skb);
+		rxrpc_queue_local(local);
+	} else {
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	}
+}
+
+/*
+ * put a packet up for transport-level abort
+ */
+static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	if (rxrpc_get_local_maybe(local)) {
+		skb_queue_tail(&local->reject_queue, skb);
+		rxrpc_queue_local(local);
+	} else {
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	}
+}
+
+/*
+ * Extract the wire header from a packet and translate the byte order.
+ */
+static noinline
+int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+
+	/* dig out the RxRPC connection details */
+	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
+		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+				      tracepoint_string("bad_hdr"));
+		return -EBADMSG;
+	}
+
+	memset(sp, 0, sizeof(*sp));
+	sp->hdr.epoch		= ntohl(whdr.epoch);
+	sp->hdr.cid		= ntohl(whdr.cid);
+	sp->hdr.callNumber	= ntohl(whdr.callNumber);
+	sp->hdr.seq		= ntohl(whdr.seq);
+	sp->hdr.serial		= ntohl(whdr.serial);
+	sp->hdr.flags		= whdr.flags;
+	sp->hdr.type		= whdr.type;
+	sp->hdr.userStatus	= whdr.userStatus;
+	sp->hdr.securityIndex	= whdr.securityIndex;
+	sp->hdr._rsvd		= ntohs(whdr._rsvd);
+	sp->hdr.serviceId	= ntohs(whdr.serviceId);
+	return 0;
+}
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ *
+ * [!] Note that as this is called from the encap_rcv hook, the socket is not
+ * held locked by the caller and nothing prevents sk_user_data on the UDP from
+ * being cleared in the middle of processing this function.
+ *
+ * Called with the RCU read lock held from the IP layer via UDP.
+ */
+int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
+{
+	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
+	struct rxrpc_connection *conn;
+	struct rxrpc_channel *chan;
+	struct rxrpc_call *call = NULL;
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_peer *peer = NULL;
+	struct rxrpc_sock *rx = NULL;
+	unsigned int channel;
+
+	_enter("%p", udp_sk);
+
+	if (unlikely(!local)) {
+		kfree_skb(skb);
+		return 0;
+	}
+	if (skb->tstamp == 0)
+		skb->tstamp = ktime_get_real();
+
+	rxrpc_new_skb(skb, rxrpc_skb_received);
+
+	skb_pull(skb, sizeof(struct udphdr));
+
+	/* The UDP protocol already released all skb resources;
+	 * we are free to add our own data there.
+	 */
+	sp = rxrpc_skb(skb);
+
+	/* dig out the RxRPC connection details */
+	if (rxrpc_extract_header(sp, skb) < 0)
+		goto bad_message;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+		static int lose;
+		if ((lose++ & 7) == 7) {
+			trace_rxrpc_rx_lose(sp);
+			rxrpc_free_skb(skb, rxrpc_skb_lost);
+			return 0;
+		}
+	}
+
+	if (skb->tstamp == 0)
+		skb->tstamp = ktime_get_real();
+	trace_rxrpc_rx_packet(sp);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_VERSION:
+		if (rxrpc_to_client(sp))
+			goto discard;
+		rxrpc_post_packet_to_local(local, skb);
+		goto out;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		if (rxrpc_to_server(sp))
+			goto discard;
+		fallthrough;
+	case RXRPC_PACKET_TYPE_ACK:
+	case RXRPC_PACKET_TYPE_ACKALL:
+		if (sp->hdr.callNumber == 0)
+			goto bad_message;
+		fallthrough;
+	case RXRPC_PACKET_TYPE_ABORT:
+		break;
+
+	case RXRPC_PACKET_TYPE_DATA:
+		if (sp->hdr.callNumber == 0 ||
+		    sp->hdr.seq == 0)
+			goto bad_message;
+		if (!rxrpc_validate_data(skb))
+			goto bad_message;
+
+		/* Unshare the packet so that it can be modified for in-place
+		 * decryption.
+		 */
+		if (sp->hdr.securityIndex != 0) {
+			struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
+			if (!nskb) {
+				rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
+				goto out;
+			}
+
+			if (nskb != skb) {
+				rxrpc_eaten_skb(skb, rxrpc_skb_received);
+				skb = nskb;
+				rxrpc_new_skb(skb, rxrpc_skb_unshared);
+				sp = rxrpc_skb(skb);
+			}
+		}
+		break;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		if (rxrpc_to_server(sp))
+			goto discard;
+		break;
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		if (rxrpc_to_client(sp))
+			goto discard;
+		break;
+
+		/* Packet types 9-11 should just be ignored. */
+	case RXRPC_PACKET_TYPE_PARAMS:
+	case RXRPC_PACKET_TYPE_10:
+	case RXRPC_PACKET_TYPE_11:
+		goto discard;
+
+	default:
+		_proto("Rx Bad Packet Type %u", sp->hdr.type);
+		goto bad_message;
+	}
+
+	if (sp->hdr.serviceId == 0)
+		goto bad_message;
+
+	if (rxrpc_to_server(sp)) {
+		/* Weed out packets to services we're not offering.  Packets
+		 * that would begin a call are explicitly rejected and the rest
+		 * are just discarded.
+		 */
+		rx = rcu_dereference(local->service);
+		if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
+			    sp->hdr.serviceId != rx->second_service)) {
+			if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+			    sp->hdr.seq == 1)
+				goto unsupported_service;
+			goto discard;
+		}
+	}
+
+	conn = rxrpc_find_connection_rcu(local, skb, &peer);
+	if (conn) {
+		if (sp->hdr.securityIndex != conn->security_ix)
+			goto wrong_security;
+
+		if (sp->hdr.serviceId != conn->service_id) {
+			int old_id;
+
+			if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
+				goto reupgrade;
+			old_id = cmpxchg(&conn->service_id, conn->params.service_id,
+					 sp->hdr.serviceId);
+
+			if (old_id != conn->params.service_id &&
+			    old_id != sp->hdr.serviceId)
+				goto reupgrade;
+		}
+
+		if (sp->hdr.callNumber == 0) {
+			/* Connection-level packet */
+			_debug("CONN %p {%d}", conn, conn->debug_id);
+			rxrpc_post_packet_to_conn(conn, skb);
+			goto out;
+		}
+
+		if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
+			conn->hi_serial = sp->hdr.serial;
+
+		/* Call-bound packets are routed by connection channel. */
+		channel = sp->hdr.cid & RXRPC_CHANNELMASK;
+		chan = &conn->channels[channel];
+
+		/* Ignore really old calls */
+		if (sp->hdr.callNumber < chan->last_call)
+			goto discard;
+
+		if (sp->hdr.callNumber == chan->last_call) {
+			if (chan->call ||
+			    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+				goto discard;
+
+			/* For the previous service call, if completed
+			 * successfully, we discard all further packets.
+			 */
+			if (rxrpc_conn_is_service(conn) &&
+			    chan->last_type == RXRPC_PACKET_TYPE_ACK)
+				goto discard;
+
+			/* But otherwise we need to retransmit the final packet
+			 * from data cached in the connection record.
+			 */
+			if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
+				trace_rxrpc_rx_data(chan->call_debug_id,
+						    sp->hdr.seq,
+						    sp->hdr.serial,
+						    sp->hdr.flags, 0);
+			rxrpc_post_packet_to_conn(conn, skb);
+			goto out;
+		}
+
+		call = rcu_dereference(chan->call);
+
+		if (sp->hdr.callNumber > chan->call_id) {
+			if (rxrpc_to_client(sp))
+				goto reject_packet;
+			if (call)
+				rxrpc_input_implicit_end_call(rx, conn, call);
+			call = NULL;
+		}
+
+		if (call) {
+			if (sp->hdr.serviceId != call->service_id)
+				call->service_id = sp->hdr.serviceId;
+			if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
+				call->rx_serial = sp->hdr.serial;
+			if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
+				set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
+		}
+	}
+
+	if (!call || refcount_read(&call->ref) == 0) {
+		if (rxrpc_to_client(sp) ||
+		    sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
+			goto bad_message;
+		if (sp->hdr.seq != 1)
+			goto discard;
+		call = rxrpc_new_incoming_call(local, rx, skb);
+		if (!call)
+			goto reject_packet;
+	}
+
+	/* Process a call packet; this either discards or passes on the ref
+	 * elsewhere.
+	 */
+	rxrpc_input_call_packet(call, skb);
+	goto out;
+
+discard:
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+out:
+	trace_rxrpc_rx_done(0, 0);
+	return 0;
+
+wrong_security:
+	trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  RXKADINCONSISTENCY, EBADMSG);
+	skb->priority = RXKADINCONSISTENCY;
+	goto post_abort;
+
+unsupported_service:
+	trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  RX_INVALID_OPERATION, EOPNOTSUPP);
+	skb->priority = RX_INVALID_OPERATION;
+	goto post_abort;
+
+reupgrade:
+	trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  RX_PROTOCOL_ERROR, EBADMSG);
+	goto protocol_error;
+
+bad_message:
+	trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  RX_PROTOCOL_ERROR, EBADMSG);
+protocol_error:
+	skb->priority = RX_PROTOCOL_ERROR;
+post_abort:
+	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+reject_packet:
+	trace_rxrpc_rx_done(skb->mark, skb->priority);
+	rxrpc_reject_packet(local, skb);
+	_leave(" [badmsg]");
+	return 0;
+}
diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
new file mode 100644
index 000000000..f6c59f5fa
--- /dev/null
+++ b/net/rxrpc/insecure.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Null security operations.
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static int none_init_connection_security(struct rxrpc_connection *conn)
+{
+	return 0;
+}
+
+static int none_prime_packet_security(struct rxrpc_connection *conn)
+{
+	return 0;
+}
+
+static int none_secure_packet(struct rxrpc_call *call,
+			      struct sk_buff *skb,
+			      size_t data_size,
+			      void *sechdr)
+{
+	return 0;
+}
+
+static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
+			      unsigned int offset, unsigned int len,
+			      rxrpc_seq_t seq, u16 expected_cksum)
+{
+	return 0;
+}
+
+static void none_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+static void none_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
+			     unsigned int *_offset, unsigned int *_len)
+{
+}
+
+static int none_respond_to_challenge(struct rxrpc_connection *conn,
+				     struct sk_buff *skb,
+				     u32 *_abort_code)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+			      tracepoint_string("chall_none"));
+	return -EPROTO;
+}
+
+static int none_verify_response(struct rxrpc_connection *conn,
+				struct sk_buff *skb,
+				u32 *_abort_code)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+			      tracepoint_string("resp_none"));
+	return -EPROTO;
+}
+
+static void none_clear(struct rxrpc_connection *conn)
+{
+}
+
+static int none_init(void)
+{
+	return 0;
+}
+
+static void none_exit(void)
+{
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxrpc_no_security = {
+	.name				= "none",
+	.security_index			= RXRPC_SECURITY_NONE,
+	.init				= none_init,
+	.exit				= none_exit,
+	.init_connection_security	= none_init_connection_security,
+	.prime_packet_security		= none_prime_packet_security,
+	.free_call_crypto		= none_free_call_crypto,
+	.secure_packet			= none_secure_packet,
+	.verify_packet			= none_verify_packet,
+	.locate_data			= none_locate_data,
+	.respond_to_challenge		= none_respond_to_challenge,
+	.verify_response		= none_verify_response,
+	.clear				= none_clear,
+};
diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
new file mode 100644
index 000000000..979338a64
--- /dev/null
+++ b/net/rxrpc/key.c
@@ -0,0 +1,1245 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *	"afs@CAMBRIDGE.REDHAT.COM>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_vet_description_s(const char *);
+static int rxrpc_preparse(struct key_preparsed_payload *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_destroy(struct key *);
+static void rxrpc_destroy_s(struct key *);
+static void rxrpc_describe(const struct key *, struct seq_file *);
+static long rxrpc_read(const struct key *, char *, size_t);
+
+/*
+ * rxrpc defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_rxrpc = {
+	.name		= "rxrpc",
+	.flags		= KEY_TYPE_NET_DOMAIN,
+	.preparse	= rxrpc_preparse,
+	.free_preparse	= rxrpc_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy,
+	.describe	= rxrpc_describe,
+	.read		= rxrpc_read,
+};
+EXPORT_SYMBOL(key_type_rxrpc);
+
+/*
+ * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
+ * description and an 8-byte decryption key as the payload
+ */
+struct key_type key_type_rxrpc_s = {
+	.name		= "rxrpc_s",
+	.flags		= KEY_TYPE_NET_DOMAIN,
+	.vet_description = rxrpc_vet_description_s,
+	.preparse	= rxrpc_preparse_s,
+	.free_preparse	= rxrpc_free_preparse_s,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy_s,
+	.describe	= rxrpc_describe,
+};
+
+/*
+ * Vet the description for an RxRPC server key
+ */
+static int rxrpc_vet_description_s(const char *desc)
+{
+	unsigned long num;
+	char *p;
+
+	num = simple_strtoul(desc, &p, 10);
+	if (*p != ':' || num > 65535)
+		return -EINVAL;
+	num = simple_strtoul(p + 1, &p, 10);
+	if (*p || num < 1 || num > 255)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * parse an RxKAD type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
+				    size_t datalen,
+				    const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	time64_t expiry;
+	size_t plen;
+	u32 tktlen;
+
+	_enter(",{%x,%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	if (toklen <= 8 * 4)
+		return -EKEYREJECTED;
+	tktlen = ntohl(xdr[7]);
+	_debug("tktlen: %x", tktlen);
+	if (tktlen > AFSTOKEN_RK_TIX_MAX)
+		return -EKEYREJECTED;
+	if (toklen < 8 * 4 + tktlen)
+		return -EKEYREJECTED;
+
+	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
+	prep->quotalen = datalen + plen;
+
+	plen -= sizeof(*token);
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		return -ENOMEM;
+
+	token->kad = kzalloc(plen, GFP_KERNEL);
+	if (!token->kad) {
+		kfree(token);
+		return -ENOMEM;
+	}
+
+	token->security_index	= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len	= tktlen;
+	token->kad->vice_id	= ntohl(xdr[0]);
+	token->kad->kvno	= ntohl(xdr[1]);
+	token->kad->start	= ntohl(xdr[4]);
+	token->kad->expiry	= ntohl(xdr[5]);
+	token->kad->primary_flag = ntohl(xdr[6]);
+	memcpy(&token->kad->session_key, &xdr[2], 8);
+	memcpy(&token->kad->ticket, &xdr[8], tktlen);
+
+	_debug("SCIX: %u", token->security_index);
+	_debug("TLEN: %u", token->kad->ticket_len);
+	_debug("EXPY: %x", token->kad->expiry);
+	_debug("KVNO: %u", token->kad->kvno);
+	_debug("PRIM: %u", token->kad->primary_flag);
+	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+	       token->kad->session_key[0], token->kad->session_key[1],
+	       token->kad->session_key[2], token->kad->session_key[3],
+	       token->kad->session_key[4], token->kad->session_key[5],
+	       token->kad->session_key[6], token->kad->session_key[7]);
+	if (token->kad->ticket_len >= 8)
+		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+		       token->kad->ticket[0], token->kad->ticket[1],
+		       token->kad->ticket[2], token->kad->ticket[3],
+		       token->kad->ticket[4], token->kad->ticket[5],
+		       token->kad->ticket[6], token->kad->ticket[7]);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+
+	_leave(" = 0");
+	return 0;
+}
+
+static void rxrpc_free_krb5_principal(struct krb5_principal *princ)
+{
+	int loop;
+
+	if (princ->name_parts) {
+		for (loop = princ->n_name_parts - 1; loop >= 0; loop--)
+			kfree(princ->name_parts[loop]);
+		kfree(princ->name_parts);
+	}
+	kfree(princ->realm);
+}
+
+static void rxrpc_free_krb5_tagged(struct krb5_tagged_data *td)
+{
+	kfree(td->data);
+}
+
+/*
+ * free up an RxK5 token
+ */
+static void rxrpc_rxk5_free(struct rxk5_key *rxk5)
+{
+	int loop;
+
+	rxrpc_free_krb5_principal(&rxk5->client);
+	rxrpc_free_krb5_principal(&rxk5->server);
+	rxrpc_free_krb5_tagged(&rxk5->session);
+
+	if (rxk5->addresses) {
+		for (loop = rxk5->n_addresses - 1; loop >= 0; loop--)
+			rxrpc_free_krb5_tagged(&rxk5->addresses[loop]);
+		kfree(rxk5->addresses);
+	}
+	if (rxk5->authdata) {
+		for (loop = rxk5->n_authdata - 1; loop >= 0; loop--)
+			rxrpc_free_krb5_tagged(&rxk5->authdata[loop]);
+		kfree(rxk5->authdata);
+	}
+
+	kfree(rxk5->ticket);
+	kfree(rxk5->ticket2);
+	kfree(rxk5);
+}
+
+/*
+ * extract a krb5 principal
+ */
+static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
+				       const __be32 **_xdr,
+				       unsigned int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, n_parts, loop, tmp, paddedlen;
+
+	/* there must be at least one name, and at least #names+1 length
+	 * words */
+	if (toklen <= 12)
+		return -EINVAL;
+
+	_enter(",{%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), toklen);
+
+	n_parts = ntohl(*xdr++);
+	toklen -= 4;
+	if (n_parts <= 0 || n_parts > AFSTOKEN_K5_COMPONENTS_MAX)
+		return -EINVAL;
+	princ->n_name_parts = n_parts;
+
+	if (toklen <= (n_parts + 1) * 4)
+		return -EINVAL;
+
+	princ->name_parts = kcalloc(n_parts, sizeof(char *), GFP_KERNEL);
+	if (!princ->name_parts)
+		return -ENOMEM;
+
+	for (loop = 0; loop < n_parts; loop++) {
+		if (toklen < 4)
+			return -EINVAL;
+		tmp = ntohl(*xdr++);
+		toklen -= 4;
+		if (tmp <= 0 || tmp > AFSTOKEN_STRING_MAX)
+			return -EINVAL;
+		paddedlen = (tmp + 3) & ~3;
+		if (paddedlen > toklen)
+			return -EINVAL;
+		princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
+		if (!princ->name_parts[loop])
+			return -ENOMEM;
+		memcpy(princ->name_parts[loop], xdr, tmp);
+		princ->name_parts[loop][tmp] = 0;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 2;
+	}
+
+	if (toklen < 4)
+		return -EINVAL;
+	tmp = ntohl(*xdr++);
+	toklen -= 4;
+	if (tmp <= 0 || tmp > AFSTOKEN_K5_REALM_MAX)
+		return -EINVAL;
+	paddedlen = (tmp + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+	if (!princ->realm)
+		return -ENOMEM;
+	memcpy(princ->realm, xdr, tmp);
+	princ->realm[tmp] = 0;
+	toklen -= paddedlen;
+	xdr += paddedlen >> 2;
+
+	_debug("%s/...@%s", princ->name_parts[0], princ->realm);
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract a piece of krb5 tagged data
+ */
+static int rxrpc_krb5_decode_tagged_data(struct krb5_tagged_data *td,
+					 size_t max_data_size,
+					 const __be32 **_xdr,
+					 unsigned int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, len, paddedlen;
+
+	/* there must be at least one tag and one length word */
+	if (toklen <= 8)
+		return -EINVAL;
+
+	_enter(",%zu,{%x,%x},%u",
+	       max_data_size, ntohl(xdr[0]), ntohl(xdr[1]), toklen);
+
+	td->tag = ntohl(*xdr++);
+	len = ntohl(*xdr++);
+	toklen -= 8;
+	if (len > max_data_size)
+		return -EINVAL;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	td->data_len = len;
+
+	if (len > 0) {
+		td->data = kmemdup(xdr, len, GFP_KERNEL);
+		if (!td->data)
+			return -ENOMEM;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 2;
+	}
+
+	_debug("tag %x len %x", td->tag, td->data_len);
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract an array of tagged data
+ */
+static int rxrpc_krb5_decode_tagged_array(struct krb5_tagged_data **_td,
+					  u8 *_n_elem,
+					  u8 max_n_elem,
+					  size_t max_elem_size,
+					  const __be32 **_xdr,
+					  unsigned int *_toklen)
+{
+	struct krb5_tagged_data *td;
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, n_elem, loop;
+	int ret;
+
+	/* there must be at least one count */
+	if (toklen < 4)
+		return -EINVAL;
+
+	_enter(",,%u,%zu,{%x},%u",
+	       max_n_elem, max_elem_size, ntohl(xdr[0]), toklen);
+
+	n_elem = ntohl(*xdr++);
+	toklen -= 4;
+	if (n_elem > max_n_elem)
+		return -EINVAL;
+	*_n_elem = n_elem;
+	if (n_elem > 0) {
+		if (toklen <= (n_elem + 1) * 4)
+			return -EINVAL;
+
+		_debug("n_elem %d", n_elem);
+
+		td = kcalloc(n_elem, sizeof(struct krb5_tagged_data),
+			     GFP_KERNEL);
+		if (!td)
+			return -ENOMEM;
+		*_td = td;
+
+		for (loop = 0; loop < n_elem; loop++) {
+			ret = rxrpc_krb5_decode_tagged_data(&td[loop],
+							    max_elem_size,
+							    &xdr, &toklen);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * extract a krb5 ticket
+ */
+static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
+				    const __be32 **_xdr, unsigned int *_toklen)
+{
+	const __be32 *xdr = *_xdr;
+	unsigned int toklen = *_toklen, len, paddedlen;
+
+	/* there must be at least one length word */
+	if (toklen <= 4)
+		return -EINVAL;
+
+	_enter(",{%x},%u", ntohl(xdr[0]), toklen);
+
+	len = ntohl(*xdr++);
+	toklen -= 4;
+	if (len > AFSTOKEN_K5_TIX_MAX)
+		return -EINVAL;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > toklen)
+		return -EINVAL;
+	*_tktlen = len;
+
+	_debug("ticket len %u", len);
+
+	if (len > 0) {
+		*_ticket = kmemdup(xdr, len, GFP_KERNEL);
+		if (!*_ticket)
+			return -ENOMEM;
+		toklen -= paddedlen;
+		xdr += paddedlen >> 2;
+	}
+
+	*_xdr = xdr;
+	*_toklen = toklen;
+	_leave(" = 0 [toklen=%u]", toklen);
+	return 0;
+}
+
+/*
+ * parse an RxK5 type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
+				   size_t datalen,
+				   const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	struct rxk5_key *rxk5;
+	const __be32 *end_xdr = xdr + (toklen >> 2);
+	time64_t expiry;
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	/* reserve some payload space for this subkey - the length of the token
+	 * is a reasonable approximation */
+	prep->quotalen = datalen + toklen;
+
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		return -ENOMEM;
+
+	rxk5 = kzalloc(sizeof(*rxk5), GFP_KERNEL);
+	if (!rxk5) {
+		kfree(token);
+		return -ENOMEM;
+	}
+
+	token->security_index = RXRPC_SECURITY_RXK5;
+	token->k5 = rxk5;
+
+	/* extract the principals */
+	ret = rxrpc_krb5_decode_principal(&rxk5->client, &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+	ret = rxrpc_krb5_decode_principal(&rxk5->server, &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	/* extract the session key and the encoding type (the tag field ->
+	 * ENCTYPE_xxx) */
+	ret = rxrpc_krb5_decode_tagged_data(&rxk5->session, AFSTOKEN_DATA_MAX,
+					    &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	if (toklen < 4 * 8 + 2 * 4)
+		goto inval;
+	rxk5->authtime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->starttime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->endtime	= be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->renew_till = be64_to_cpup((const __be64 *) xdr);
+	xdr += 2;
+	rxk5->is_skey = ntohl(*xdr++);
+	rxk5->flags = ntohl(*xdr++);
+	toklen -= 4 * 8 + 2 * 4;
+
+	_debug("times: a=%llx s=%llx e=%llx rt=%llx",
+	       rxk5->authtime, rxk5->starttime, rxk5->endtime,
+	       rxk5->renew_till);
+	_debug("is_skey=%x flags=%x", rxk5->is_skey, rxk5->flags);
+
+	/* extract the permitted client addresses */
+	ret = rxrpc_krb5_decode_tagged_array(&rxk5->addresses,
+					     &rxk5->n_addresses,
+					     AFSTOKEN_K5_ADDRESSES_MAX,
+					     AFSTOKEN_DATA_MAX,
+					     &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	/* extract the tickets */
+	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket, &rxk5->ticket_len,
+				       &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+	ret = rxrpc_krb5_decode_ticket(&rxk5->ticket2, &rxk5->ticket2_len,
+				       &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	/* extract the typed auth data */
+	ret = rxrpc_krb5_decode_tagged_array(&rxk5->authdata,
+					     &rxk5->n_authdata,
+					     AFSTOKEN_K5_AUTHDATA_MAX,
+					     AFSTOKEN_BDATALN_MAX,
+					     &xdr, &toklen);
+	if (ret < 0)
+		goto error;
+
+	ASSERTCMP((end_xdr - xdr) << 2, ==, toklen);
+
+	if (toklen != 0)
+		goto inval;
+
+	/* attach the payload */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	expiry = rxrpc_u32_to_time64(token->k5->endtime);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+
+	_leave(" = 0");
+	return 0;
+
+inval:
+	ret = -EINVAL;
+error:
+	rxrpc_rxk5_free(rxk5);
+	kfree(token);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * attempt to parse the data as the XDR format
+ * - the caller guarantees we have more than 7 words
+ */
+static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
+{
+	const __be32 *xdr = prep->data, *token;
+	const char *cp;
+	unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix;
+	size_t datalen = prep->datalen;
+	int ret;
+
+	_enter(",{%x,%x,%x,%x},%zu",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       prep->datalen);
+
+	if (datalen > AFSTOKEN_LENGTH_MAX)
+		goto not_xdr;
+
+	/* XDR is an array of __be32's */
+	if (datalen & 3)
+		goto not_xdr;
+
+	/* the flags should be 0 (the setpag bit must be handled by
+	 * userspace) */
+	if (ntohl(*xdr++) != 0)
+		goto not_xdr;
+	datalen -= 4;
+
+	/* check the cell name */
+	len = ntohl(*xdr++);
+	if (len < 1 || len > AFSTOKEN_CELL_MAX)
+		goto not_xdr;
+	datalen -= 4;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > datalen)
+		goto not_xdr;
+
+	cp = (const char *) xdr;
+	for (loop = 0; loop < len; loop++)
+		if (!isprint(cp[loop]))
+			goto not_xdr;
+	for (; loop < paddedlen; loop++)
+		if (cp[loop])
+			goto not_xdr;
+	_debug("cellname: [%u/%u] '%*.*s'",
+	       len, paddedlen, len, len, (const char *) xdr);
+	datalen -= paddedlen;
+	xdr += paddedlen >> 2;
+
+	/* get the token count */
+	if (datalen < 12)
+		goto not_xdr;
+	ntoken = ntohl(*xdr++);
+	datalen -= 4;
+	_debug("ntoken: %x", ntoken);
+	if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
+		goto not_xdr;
+
+	/* check each token wrapper */
+	token = xdr;
+	loop = ntoken;
+	do {
+		if (datalen < 8)
+			goto not_xdr;
+		toklen = ntohl(*xdr++);
+		sec_ix = ntohl(*xdr);
+		datalen -= 4;
+		_debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
+		paddedlen = (toklen + 3) & ~3;
+		if (toklen < 20 || toklen > datalen || paddedlen > datalen)
+			goto not_xdr;
+		datalen -= paddedlen;
+		xdr += paddedlen >> 2;
+
+	} while (--loop > 0);
+
+	_debug("remainder: %zu", datalen);
+	if (datalen != 0)
+		goto not_xdr;
+
+	/* okay: we're going to assume it's valid XDR format
+	 * - we ignore the cellname, relying on the key to be correctly named
+	 */
+	do {
+		xdr = token;
+		toklen = ntohl(*xdr++);
+		token = xdr + ((toklen + 3) >> 2);
+		sec_ix = ntohl(*xdr++);
+		toklen -= 4;
+
+		_debug("TOKEN type=%u [%p-%p]", sec_ix, xdr, token);
+
+		switch (sec_ix) {
+		case RXRPC_SECURITY_RXKAD:
+			ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
+			if (ret != 0)
+				goto error;
+			break;
+
+		case RXRPC_SECURITY_RXK5:
+			ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
+			if (ret != 0)
+				goto error;
+			break;
+
+		default:
+			ret = -EPROTONOSUPPORT;
+			goto error;
+		}
+
+	} while (--ntoken > 0);
+
+	_leave(" = 0");
+	return 0;
+
+not_xdr:
+	_leave(" = -EPROTO");
+	return -EPROTO;
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Preparse an rxrpc defined key.
+ *
+ * Data should be of the form:
+ *	OFFSET	LEN	CONTENT
+ *	0	4	key interface version number
+ *	4	2	security index (type)
+ *	6	2	ticket length
+ *	8	4	key expiry time (time_t)
+ *	12	4	kvno
+ *	16	8	session key
+ *	24	[len]	ticket
+ *
+ * if no data is provided, then a no-security key is made
+ */
+static int rxrpc_preparse(struct key_preparsed_payload *prep)
+{
+	const struct rxrpc_key_data_v1 *v1;
+	struct rxrpc_key_token *token, **pp;
+	time64_t expiry;
+	size_t plen;
+	u32 kver;
+	int ret;
+
+	_enter("%zu", prep->datalen);
+
+	/* handle a no-security key */
+	if (!prep->data && prep->datalen == 0)
+		return 0;
+
+	/* determine if the XDR payload format is being used */
+	if (prep->datalen > 7 * 4) {
+		ret = rxrpc_preparse_xdr(prep);
+		if (ret != -EPROTO)
+			return ret;
+	}
+
+	/* get the key interface version number */
+	ret = -EINVAL;
+	if (prep->datalen <= 4 || !prep->data)
+		goto error;
+	memcpy(&kver, prep->data, sizeof(kver));
+	prep->data += sizeof(kver);
+	prep->datalen -= sizeof(kver);
+
+	_debug("KEY I/F VERSION: %u", kver);
+
+	ret = -EKEYREJECTED;
+	if (kver != 1)
+		goto error;
+
+	/* deal with a version 1 key */
+	ret = -EINVAL;
+	if (prep->datalen < sizeof(*v1))
+		goto error;
+
+	v1 = prep->data;
+	if (prep->datalen != sizeof(*v1) + v1->ticket_length)
+		goto error;
+
+	_debug("SCIX: %u", v1->security_index);
+	_debug("TLEN: %u", v1->ticket_length);
+	_debug("EXPY: %x", v1->expiry);
+	_debug("KVNO: %u", v1->kvno);
+	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+	       v1->session_key[0], v1->session_key[1],
+	       v1->session_key[2], v1->session_key[3],
+	       v1->session_key[4], v1->session_key[5],
+	       v1->session_key[6], v1->session_key[7]);
+	if (v1->ticket_length >= 8)
+		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+		       v1->ticket[0], v1->ticket[1],
+		       v1->ticket[2], v1->ticket[3],
+		       v1->ticket[4], v1->ticket[5],
+		       v1->ticket[6], v1->ticket[7]);
+
+	ret = -EPROTONOSUPPORT;
+	if (v1->security_index != RXRPC_SECURITY_RXKAD)
+		goto error;
+
+	plen = sizeof(*token->kad) + v1->ticket_length;
+	prep->quotalen = plen + sizeof(*token);
+
+	ret = -ENOMEM;
+	token = kzalloc(sizeof(*token), GFP_KERNEL);
+	if (!token)
+		goto error;
+	token->kad = kzalloc(plen, GFP_KERNEL);
+	if (!token->kad)
+		goto error_free;
+
+	token->security_index		= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len		= v1->ticket_length;
+	token->kad->expiry		= v1->expiry;
+	token->kad->kvno		= v1->kvno;
+	memcpy(&token->kad->session_key, &v1->session_key, 8);
+	memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	pp = (struct rxrpc_key_token **)&prep->payload.data[0];
+	while (*pp)
+		pp = &(*pp)->next;
+	*pp = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+	token = NULL;
+	ret = 0;
+
+error_free:
+	kfree(token);
+error:
+	return ret;
+}
+
+/*
+ * Free token list.
+ */
+static void rxrpc_free_token_list(struct rxrpc_key_token *token)
+{
+	struct rxrpc_key_token *next;
+
+	for (; token; token = next) {
+		next = token->next;
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			kfree(token->kad);
+			break;
+		case RXRPC_SECURITY_RXK5:
+			if (token->k5)
+				rxrpc_rxk5_free(token->k5);
+			break;
+		default:
+			pr_err("Unknown token type %x on rxrpc key\n",
+			       token->security_index);
+			BUG();
+		}
+
+		kfree(token);
+	}
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
+{
+	rxrpc_free_token_list(prep->payload.data[0]);
+}
+
+/*
+ * Preparse a server secret key.
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
+{
+	struct crypto_skcipher *ci;
+
+	_enter("%zu", prep->datalen);
+
+	if (prep->datalen != 8)
+		return -EINVAL;
+
+	memcpy(&prep->payload.data[2], prep->data, 8);
+
+	ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(ci)) {
+		_leave(" = %ld", PTR_ERR(ci));
+		return PTR_ERR(ci);
+	}
+
+	if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
+		BUG();
+
+	prep->payload.data[0] = ci;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+	if (prep->payload.data[0])
+		crypto_free_skcipher(prep->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy(struct key *key)
+{
+	rxrpc_free_token_list(key->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy_s(struct key *key)
+{
+	if (key->payload.data[0]) {
+		crypto_free_skcipher(key->payload.data[0]);
+		key->payload.data[0] = NULL;
+	}
+}
+
+/*
+ * describe the rxrpc key
+ */
+static void rxrpc_describe(const struct key *key, struct seq_file *m)
+{
+	seq_puts(m, key->description);
+}
+
+/*
+ * grab the security key for a socket
+ */
+int rxrpc_request_key(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1 || rx->securities)
+		return -EINVAL;
+
+	description = memdup_sockptr_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key_net(&key_type_rxrpc, description, sock_net(&rx->sk), NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->key = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/*
+ * grab the security keyring for a server socket
+ */
+int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+		return -EINVAL;
+
+	description = memdup_sockptr_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key(&key_type_keyring, description, NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->securities = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/*
+ * generate a server data key
+ */
+int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
+			      const void *session_key,
+			      time64_t expiry,
+			      u32 kvno)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	struct {
+		u32 kver;
+		struct rxrpc_key_data_v1 v1;
+	} data;
+
+	_enter("");
+
+	key = key_alloc(&key_type_rxrpc, "x",
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
+			KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key)) {
+		_leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+		return -ENOMEM;
+	}
+
+	_debug("key %d", key_serial(key));
+
+	data.kver = 1;
+	data.v1.security_index = RXRPC_SECURITY_RXKAD;
+	data.v1.ticket_length = 0;
+	data.v1.expiry = rxrpc_time64_to_u32(expiry);
+	data.v1.kvno = 0;
+
+	memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
+
+	ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
+	if (ret < 0)
+		goto error;
+
+	conn->params.key = key;
+	_leave(" = 0 [%d]", key_serial(key));
+	return 0;
+
+error:
+	key_revoke(key);
+	key_put(key);
+	_leave(" = -ENOMEM [ins %d]", ret);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	key = key_alloc(&key_type_rxrpc, keyname,
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+			KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key))
+		return key;
+
+	ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+	if (ret < 0) {
+		key_revoke(key);
+		key_put(key);
+		return ERR_PTR(ret);
+	}
+
+	return key;
+}
+EXPORT_SYMBOL(rxrpc_get_null_key);
+
+/*
+ * read the contents of an rxrpc key
+ * - this returns the result in XDR form
+ */
+static long rxrpc_read(const struct key *key,
+		       char *buffer, size_t buflen)
+{
+	const struct rxrpc_key_token *token;
+	const struct krb5_principal *princ;
+	size_t size;
+	__be32 *xdr, *oldxdr;
+	u32 cnlen, toksize, ntoks, tok, zero;
+	u16 toksizes[AFSTOKEN_MAX];
+	int loop;
+
+	_enter("");
+
+	/* we don't know what form we should return non-AFS keys in */
+	if (memcmp(key->description, "afs@", 4) != 0)
+		return -EOPNOTSUPP;
+	cnlen = strlen(key->description + 4);
+
+#define RND(X) (((X) + 3) & ~3)
+
+	/* AFS keys we return in XDR form, so we need to work out the size of
+	 * the XDR */
+	size = 2 * 4;	/* flags, cellname len */
+	size += RND(cnlen);	/* cellname */
+	size += 1 * 4;	/* token count */
+
+	ntoks = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = 4;	/* sec index */
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,
+						 * end, primary, tktlen */
+			toksize += RND(token->kad->ticket_len);
+			break;
+
+		case RXRPC_SECURITY_RXK5:
+			princ = &token->k5->client;
+			toksize += 4 + princ->n_name_parts * 4;
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				toksize += RND(strlen(princ->name_parts[loop]));
+			toksize += 4 + RND(strlen(princ->realm));
+
+			princ = &token->k5->server;
+			toksize += 4 + princ->n_name_parts * 4;
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				toksize += RND(strlen(princ->name_parts[loop]));
+			toksize += 4 + RND(strlen(princ->realm));
+
+			toksize += 8 + RND(token->k5->session.data_len);
+
+			toksize += 4 * 8 + 2 * 4;
+
+			toksize += 4 + token->k5->n_addresses * 8;
+			for (loop = 0; loop < token->k5->n_addresses; loop++)
+				toksize += RND(token->k5->addresses[loop].data_len);
+
+			toksize += 4 + RND(token->k5->ticket_len);
+			toksize += 4 + RND(token->k5->ticket2_len);
+
+			toksize += 4 + token->k5->n_authdata * 8;
+			for (loop = 0; loop < token->k5->n_authdata; loop++)
+				toksize += RND(token->k5->authdata[loop].data_len);
+			break;
+
+		default: /* we have a ticket we can't encode */
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		_debug("token[%u]: toksize=%u", ntoks, toksize);
+		ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+
+		toksizes[ntoks++] = toksize;
+		size += toksize + 4; /* each token has a length word */
+	}
+
+#undef RND
+
+	if (!buffer || buflen < size)
+		return size;
+
+	xdr = (__be32 *)buffer;
+	zero = 0;
+#define ENCODE(x)				\
+	do {					\
+		*xdr++ = htonl(x);		\
+	} while(0)
+#define ENCODE_DATA(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		ENCODE(l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE_BYTES(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE64(x)					\
+	do {						\
+		__be64 y = cpu_to_be64(x);		\
+		memcpy(xdr, &y, 8);			\
+		xdr += 8 >> 2;				\
+	} while(0)
+#define ENCODE_STR(s)				\
+	do {					\
+		const char *_s = (s);		\
+		ENCODE_DATA(strlen(_s), _s);	\
+	} while(0)
+
+	ENCODE(0);					/* flags */
+	ENCODE_DATA(cnlen, key->description + 4);	/* cellname */
+	ENCODE(ntoks);
+
+	tok = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = toksizes[tok++];
+		ENCODE(toksize);
+		oldxdr = xdr;
+		ENCODE(token->security_index);
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			ENCODE(token->kad->vice_id);
+			ENCODE(token->kad->kvno);
+			ENCODE_BYTES(8, token->kad->session_key);
+			ENCODE(token->kad->start);
+			ENCODE(token->kad->expiry);
+			ENCODE(token->kad->primary_flag);
+			ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
+			break;
+
+		case RXRPC_SECURITY_RXK5:
+			princ = &token->k5->client;
+			ENCODE(princ->n_name_parts);
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				ENCODE_STR(princ->name_parts[loop]);
+			ENCODE_STR(princ->realm);
+
+			princ = &token->k5->server;
+			ENCODE(princ->n_name_parts);
+			for (loop = 0; loop < princ->n_name_parts; loop++)
+				ENCODE_STR(princ->name_parts[loop]);
+			ENCODE_STR(princ->realm);
+
+			ENCODE(token->k5->session.tag);
+			ENCODE_DATA(token->k5->session.data_len,
+				    token->k5->session.data);
+
+			ENCODE64(token->k5->authtime);
+			ENCODE64(token->k5->starttime);
+			ENCODE64(token->k5->endtime);
+			ENCODE64(token->k5->renew_till);
+			ENCODE(token->k5->is_skey);
+			ENCODE(token->k5->flags);
+
+			ENCODE(token->k5->n_addresses);
+			for (loop = 0; loop < token->k5->n_addresses; loop++) {
+				ENCODE(token->k5->addresses[loop].tag);
+				ENCODE_DATA(token->k5->addresses[loop].data_len,
+					    token->k5->addresses[loop].data);
+			}
+
+			ENCODE_DATA(token->k5->ticket_len, token->k5->ticket);
+			ENCODE_DATA(token->k5->ticket2_len, token->k5->ticket2);
+
+			ENCODE(token->k5->n_authdata);
+			for (loop = 0; loop < token->k5->n_authdata; loop++) {
+				ENCODE(token->k5->authdata[loop].tag);
+				ENCODE_DATA(token->k5->authdata[loop].data_len,
+					    token->k5->authdata[loop].data);
+			}
+			break;
+
+		default:
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
+			  toksize);
+	}
+
+#undef ENCODE_STR
+#undef ENCODE_DATA
+#undef ENCODE64
+#undef ENCODE
+
+	ASSERTCMP(tok, ==, ntoks);
+	ASSERTCMP((char __user *) xdr - buffer, ==, size);
+	_leave(" = %zu", size);
+	return size;
+}
diff --git a/net/rxrpc/local_event.c b/net/rxrpc/local_event.c
new file mode 100644
index 000000000..3ce6d628c
--- /dev/null
+++ b/net/rxrpc/local_event.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC local endpoint management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <generated/utsrelease.h>
+#include "ar-internal.h"
+
+static const char rxrpc_version_string[65] = "linux-" UTS_RELEASE " AF_RXRPC";
+
+/*
+ * Reply to a version request
+ */
+static void rxrpc_send_version_request(struct rxrpc_local *local,
+				       struct rxrpc_host_header *hdr,
+				       struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct sockaddr_rxrpc srx;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	int ret;
+
+	_enter("");
+
+	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
+		return;
+
+	msg.msg_name	= &srx.transport;
+	msg.msg_namelen	= srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(sp->hdr.epoch);
+	whdr.cid	= htonl(sp->hdr.cid);
+	whdr.callNumber	= htonl(sp->hdr.callNumber);
+	whdr.seq	= 0;
+	whdr.serial	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_VERSION;
+	whdr.flags	= RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED);
+	whdr.userStatus	= 0;
+	whdr.securityIndex = 0;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(sp->hdr.serviceId);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= (char *)rxrpc_version_string;
+	iov[1].iov_len	= sizeof(rxrpc_version_string);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	_proto("Tx VERSION (reply)");
+
+	ret = kernel_sendmsg(local->socket, &msg, iov, 2, len);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(local->debug_id, 0, ret,
+				    rxrpc_tx_point_version_reply);
+	else
+		trace_rxrpc_tx_packet(local->debug_id, &whdr,
+				      rxrpc_tx_point_version_reply);
+
+	_leave("");
+}
+
+/*
+ * Process event packets targetted at a local endpoint.
+ */
+void rxrpc_process_local_events(struct rxrpc_local *local)
+{
+	struct sk_buff *skb;
+	char v;
+
+	_enter("");
+
+	skb = skb_dequeue(&local->event_queue);
+	if (skb) {
+		struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+		_debug("{%d},{%u}", local->debug_id, sp->hdr.type);
+
+		switch (sp->hdr.type) {
+		case RXRPC_PACKET_TYPE_VERSION:
+			if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+					  &v, 1) < 0)
+				return;
+			_proto("Rx VERSION { %02x }", v);
+			if (v == 0)
+				rxrpc_send_version_request(local, &sp->hdr, skb);
+			break;
+
+		default:
+			/* Just ignore anything we don't understand */
+			break;
+		}
+
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	}
+
+	_leave("");
+}
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
new file mode 100644
index 000000000..2c66ee981
--- /dev/null
+++ b/net/rxrpc/local_object.c
@@ -0,0 +1,492 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Local endpoint object management
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/udp.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static void rxrpc_local_processor(struct work_struct *);
+static void rxrpc_local_rcu(struct rcu_head *);
+
+/*
+ * Compare a local to an address.  Return -ve, 0 or +ve to indicate less than,
+ * same or greater than.
+ *
+ * We explicitly don't compare the RxRPC service ID as we want to reject
+ * conflicting uses by differing services.  Further, we don't want to share
+ * addresses with different options (IPv6), so we don't compare those bits
+ * either.
+ */
+static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
+				const struct sockaddr_rxrpc *srx)
+{
+	long diff;
+
+	diff = ((local->srx.transport_type - srx->transport_type) ?:
+		(local->srx.transport_len - srx->transport_len) ?:
+		(local->srx.transport.family - srx->transport.family));
+	if (diff != 0)
+		return diff;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		/* If the choice of UDP port is left up to the transport, then
+		 * the endpoint record doesn't match.
+		 */
+		return ((u16 __force)local->srx.transport.sin.sin_port -
+			(u16 __force)srx->transport.sin.sin_port) ?:
+			memcmp(&local->srx.transport.sin.sin_addr,
+			       &srx->transport.sin.sin_addr,
+			       sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		/* If the choice of UDP6 port is left up to the transport, then
+		 * the endpoint record doesn't match.
+		 */
+		return ((u16 __force)local->srx.transport.sin6.sin6_port -
+			(u16 __force)srx->transport.sin6.sin6_port) ?:
+			memcmp(&local->srx.transport.sin6.sin6_addr,
+			       &srx->transport.sin6.sin6_addr,
+			       sizeof(struct in6_addr));
+#endif
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Allocate a new local endpoint.
+ */
+static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
+					     const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_local *local;
+
+	local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
+	if (local) {
+		refcount_set(&local->ref, 1);
+		atomic_set(&local->active_users, 1);
+		local->rxnet = rxnet;
+		INIT_HLIST_NODE(&local->link);
+		INIT_WORK(&local->processor, rxrpc_local_processor);
+		init_rwsem(&local->defrag_sem);
+		skb_queue_head_init(&local->reject_queue);
+		skb_queue_head_init(&local->event_queue);
+		local->client_bundles = RB_ROOT;
+		spin_lock_init(&local->client_bundles_lock);
+		spin_lock_init(&local->lock);
+		rwlock_init(&local->services_lock);
+		local->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		memcpy(&local->srx, srx, sizeof(*srx));
+		local->srx.srx_service = 0;
+		trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, NULL);
+	}
+
+	_leave(" = %p", local);
+	return local;
+}
+
+/*
+ * create the local socket
+ * - must be called with rxrpc_local_mutex locked
+ */
+static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
+{
+	struct sock *usk;
+	int ret;
+
+	_enter("%p{%d,%d}",
+	       local, local->srx.transport_type, local->srx.transport.family);
+
+	/* create a socket to represent the local endpoint */
+	ret = sock_create_kern(net, local->srx.transport.family,
+			       local->srx.transport_type, 0, &local->socket);
+	if (ret < 0) {
+		_leave(" = %d [socket]", ret);
+		return ret;
+	}
+
+	/* set the socket up */
+	usk = local->socket->sk;
+	inet_sk(usk)->mc_loop = 0;
+
+	/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
+	inet_inc_convert_csum(usk);
+
+	rcu_assign_sk_user_data(usk, local);
+
+	udp_sk(usk)->encap_type = UDP_ENCAP_RXRPC;
+	udp_sk(usk)->encap_rcv = rxrpc_input_packet;
+	udp_sk(usk)->encap_destroy = NULL;
+	udp_sk(usk)->gro_receive = NULL;
+	udp_sk(usk)->gro_complete = NULL;
+
+	udp_encap_enable();
+#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
+	if (local->srx.transport.family == AF_INET6)
+		udpv6_encap_enable();
+#endif
+	usk->sk_error_report = rxrpc_error_report;
+
+	/* if a local address was supplied then bind it */
+	if (local->srx.transport_len > sizeof(sa_family_t)) {
+		_debug("bind");
+		ret = kernel_bind(local->socket,
+				  (struct sockaddr *)&local->srx.transport,
+				  local->srx.transport_len);
+		if (ret < 0) {
+			_debug("bind failed %d", ret);
+			goto error;
+		}
+	}
+
+	switch (local->srx.transport.family) {
+	case AF_INET6:
+		/* we want to receive ICMPv6 errors */
+		ip6_sock_set_recverr(local->socket->sk);
+
+		/* Fall through and set IPv4 options too otherwise we don't get
+		 * errors from IPv4 packets sent through the IPv6 socket.
+		 */
+		fallthrough;
+	case AF_INET:
+		/* we want to receive ICMP errors */
+		ip_sock_set_recverr(local->socket->sk);
+
+		/* we want to set the don't fragment bit */
+		ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
+
+		/* We want receive timestamps. */
+		sock_enable_timestamps(local->socket->sk);
+		break;
+
+	default:
+		BUG();
+	}
+
+	_leave(" = 0");
+	return 0;
+
+error:
+	kernel_sock_shutdown(local->socket, SHUT_RDWR);
+	local->socket->sk->sk_user_data = NULL;
+	sock_release(local->socket);
+	local->socket = NULL;
+
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Look up or create a new local endpoint using the specified local address.
+ */
+struct rxrpc_local *rxrpc_lookup_local(struct net *net,
+				       const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+	struct hlist_node *cursor;
+	const char *age;
+	long diff;
+	int ret;
+
+	_enter("{%d,%d,%pISp}",
+	       srx->transport_type, srx->transport.family, &srx->transport);
+
+	mutex_lock(&rxnet->local_mutex);
+
+	hlist_for_each(cursor, &rxnet->local_endpoints) {
+		local = hlist_entry(cursor, struct rxrpc_local, link);
+
+		diff = rxrpc_local_cmp_key(local, srx);
+		if (diff != 0)
+			continue;
+
+		/* Services aren't allowed to share transport sockets, so
+		 * reject that here.  It is possible that the object is dying -
+		 * but it may also still have the local transport address that
+		 * we want bound.
+		 */
+		if (srx->srx_service) {
+			local = NULL;
+			goto addr_in_use;
+		}
+
+		/* Found a match.  We want to replace a dying object.
+		 * Attempting to bind the transport socket may still fail if
+		 * we're attempting to use a local address that the dying
+		 * object is still using.
+		 */
+		if (!rxrpc_use_local(local))
+			break;
+
+		age = "old";
+		goto found;
+	}
+
+	local = rxrpc_alloc_local(rxnet, srx);
+	if (!local)
+		goto nomem;
+
+	ret = rxrpc_open_socket(local, net);
+	if (ret < 0)
+		goto sock_error;
+
+	if (cursor) {
+		hlist_replace_rcu(cursor, &local->link);
+		cursor->pprev = NULL;
+	} else {
+		hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
+	}
+	age = "new";
+
+found:
+	mutex_unlock(&rxnet->local_mutex);
+
+	_net("LOCAL %s %d {%pISp}",
+	     age, local->debug_id, &local->srx.transport);
+
+	_leave(" = %p", local);
+	return local;
+
+nomem:
+	ret = -ENOMEM;
+sock_error:
+	mutex_unlock(&rxnet->local_mutex);
+	if (local)
+		call_rcu(&local->rcu, rxrpc_local_rcu);
+	_leave(" = %d", ret);
+	return ERR_PTR(ret);
+
+addr_in_use:
+	mutex_unlock(&rxnet->local_mutex);
+	_leave(" = -EADDRINUSE");
+	return ERR_PTR(-EADDRINUSE);
+}
+
+/*
+ * Get a ref on a local endpoint.
+ */
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	__refcount_inc(&local->ref, &r);
+	trace_rxrpc_local(local->debug_id, rxrpc_local_got, r + 1, here);
+	return local;
+}
+
+/*
+ * Get a ref on a local endpoint unless its usage has already reached 0.
+ */
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	if (local) {
+		if (__refcount_inc_not_zero(&local->ref, &r))
+			trace_rxrpc_local(local->debug_id, rxrpc_local_got,
+					  r + 1, here);
+		else
+			local = NULL;
+	}
+	return local;
+}
+
+/*
+ * Queue a local endpoint and pass the caller's reference to the work item.
+ */
+void rxrpc_queue_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id = local->debug_id;
+	int r = refcount_read(&local->ref);
+
+	if (rxrpc_queue_work(&local->processor))
+		trace_rxrpc_local(debug_id, rxrpc_local_queued, r + 1, here);
+	else
+		rxrpc_put_local(local);
+}
+
+/*
+ * Drop a ref on a local endpoint.
+ */
+void rxrpc_put_local(struct rxrpc_local *local)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (local) {
+		debug_id = local->debug_id;
+
+		dead = __refcount_dec_and_test(&local->ref, &r);
+		trace_rxrpc_local(debug_id, rxrpc_local_put, r, here);
+
+		if (dead)
+			call_rcu(&local->rcu, rxrpc_local_rcu);
+	}
+}
+
+/*
+ * Start using a local endpoint.
+ */
+struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local)
+{
+	local = rxrpc_get_local_maybe(local);
+	if (!local)
+		return NULL;
+
+	if (!__rxrpc_use_local(local)) {
+		rxrpc_put_local(local);
+		return NULL;
+	}
+
+	return local;
+}
+
+/*
+ * Cease using a local endpoint.  Once the number of active users reaches 0, we
+ * start the closure of the transport in the work processor.
+ */
+void rxrpc_unuse_local(struct rxrpc_local *local)
+{
+	if (local) {
+		if (__rxrpc_unuse_local(local)) {
+			rxrpc_get_local(local);
+			rxrpc_queue_local(local);
+		}
+	}
+}
+
+/*
+ * Destroy a local endpoint's socket and then hand the record to RCU to dispose
+ * of.
+ *
+ * Closing the socket cannot be done from bottom half context or RCU callback
+ * context because it might sleep.
+ */
+static void rxrpc_local_destroyer(struct rxrpc_local *local)
+{
+	struct socket *socket = local->socket;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	_enter("%d", local->debug_id);
+
+	local->dead = true;
+
+	mutex_lock(&rxnet->local_mutex);
+	hlist_del_init_rcu(&local->link);
+	mutex_unlock(&rxnet->local_mutex);
+
+	rxrpc_clean_up_local_conns(local);
+	rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
+	ASSERT(!local->service);
+
+	if (socket) {
+		local->socket = NULL;
+		kernel_sock_shutdown(socket, SHUT_RDWR);
+		socket->sk->sk_user_data = NULL;
+		sock_release(socket);
+	}
+
+	/* At this point, there should be no more packets coming in to the
+	 * local endpoint.
+	 */
+	rxrpc_purge_queue(&local->reject_queue);
+	rxrpc_purge_queue(&local->event_queue);
+}
+
+/*
+ * Process events on an endpoint.  The work item carries a ref which
+ * we must release.
+ */
+static void rxrpc_local_processor(struct work_struct *work)
+{
+	struct rxrpc_local *local =
+		container_of(work, struct rxrpc_local, processor);
+	bool again;
+
+	if (local->dead)
+		return;
+
+	trace_rxrpc_local(local->debug_id, rxrpc_local_processing,
+			  refcount_read(&local->ref), NULL);
+
+	do {
+		again = false;
+		if (!__rxrpc_use_local(local)) {
+			rxrpc_local_destroyer(local);
+			break;
+		}
+
+		if (!skb_queue_empty(&local->reject_queue)) {
+			rxrpc_reject_packets(local);
+			again = true;
+		}
+
+		if (!skb_queue_empty(&local->event_queue)) {
+			rxrpc_process_local_events(local);
+			again = true;
+		}
+
+		__rxrpc_unuse_local(local);
+	} while (again);
+
+	rxrpc_put_local(local);
+}
+
+/*
+ * Destroy a local endpoint after the RCU grace period expires.
+ */
+static void rxrpc_local_rcu(struct rcu_head *rcu)
+{
+	struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
+
+	_enter("%d", local->debug_id);
+
+	ASSERT(!work_pending(&local->processor));
+
+	_net("DESTROY LOCAL %d", local->debug_id);
+	kfree(local);
+	_leave("");
+}
+
+/*
+ * Verify the local endpoint list is empty by this point.
+ */
+void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_local *local;
+
+	_enter("");
+
+	flush_workqueue(rxrpc_workqueue);
+
+	if (!hlist_empty(&rxnet->local_endpoints)) {
+		mutex_lock(&rxnet->local_mutex);
+		hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
+			pr_err("AF_RXRPC: Leaked local %p {%d}\n",
+			       local, refcount_read(&local->ref));
+		}
+		mutex_unlock(&rxnet->local_mutex);
+		BUG();
+	}
+}
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
new file mode 100644
index 000000000..d4144fd86
--- /dev/null
+++ b/net/rxrpc/misc.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Miscellaneous bits
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * The maximum listening backlog queue size that may be set on a socket by
+ * listen().
+ */
+unsigned int rxrpc_max_backlog __read_mostly = 10;
+
+/*
+ * How long to wait before scheduling ACK generation after seeing a
+ * packet with RXRPC_REQUEST_ACK set (in jiffies).
+ */
+unsigned long rxrpc_requested_ack_delay = 1;
+
+/*
+ * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
+ *
+ * We use this when we've received new data packets.  If those packets aren't
+ * all consumed within this time we will send a DELAY ACK if an ACK was not
+ * requested to let the sender know it doesn't need to resend.
+ */
+unsigned long rxrpc_soft_ack_delay = HZ;
+
+/*
+ * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
+ *
+ * We use this when we've consumed some previously soft-ACK'd packets when
+ * further packets aren't immediately received to decide when to send an IDLE
+ * ACK let the other end know that it can free up its Tx buffer space.
+ */
+unsigned long rxrpc_idle_ack_delay = HZ / 2;
+
+/*
+ * Receive window size in packets.  This indicates the maximum number of
+ * unconsumed received packets we're willing to retain in memory.  Once this
+ * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
+ * packets.
+ */
+unsigned int rxrpc_rx_window_size = RXRPC_INIT_RX_WINDOW_SIZE;
+#if (RXRPC_RXTX_BUFF_SIZE - 1) < RXRPC_INIT_RX_WINDOW_SIZE
+#error Need to reduce RXRPC_INIT_RX_WINDOW_SIZE
+#endif
+
+/*
+ * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
+ * made by gluing normal packets together that we're willing to handle.
+ */
+unsigned int rxrpc_rx_mtu = 5692;
+
+/*
+ * The maximum number of fragments in a received jumbo packet that we tell the
+ * sender that we're willing to handle.
+ */
+unsigned int rxrpc_rx_jumbo_max = 4;
+
+const s8 rxrpc_ack_priority[] = {
+	[0]				= 0,
+	[RXRPC_ACK_DELAY]		= 1,
+	[RXRPC_ACK_REQUESTED]		= 2,
+	[RXRPC_ACK_IDLE]		= 3,
+	[RXRPC_ACK_DUPLICATE]		= 4,
+	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 5,
+	[RXRPC_ACK_EXCEEDS_WINDOW]	= 6,
+	[RXRPC_ACK_NOSPACE]		= 7,
+	[RXRPC_ACK_PING_RESPONSE]	= 8,
+};
diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
new file mode 100644
index 000000000..34f389975
--- /dev/null
+++ b/net/rxrpc/net_ns.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* rxrpc network namespace handling.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/proc_fs.h>
+#include "ar-internal.h"
+
+unsigned int rxrpc_net_id;
+
+static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
+{
+	struct rxrpc_net *rxnet =
+		container_of(timer, struct rxrpc_net, client_conn_reap_timer);
+
+	if (rxnet->live)
+		rxrpc_queue_work(&rxnet->client_conn_reaper);
+}
+
+static void rxrpc_service_conn_reap_timeout(struct timer_list *timer)
+{
+	struct rxrpc_net *rxnet =
+		container_of(timer, struct rxrpc_net, service_conn_reap_timer);
+
+	if (rxnet->live)
+		rxrpc_queue_work(&rxnet->service_conn_reaper);
+}
+
+static void rxrpc_peer_keepalive_timeout(struct timer_list *timer)
+{
+	struct rxrpc_net *rxnet =
+		container_of(timer, struct rxrpc_net, peer_keepalive_timer);
+
+	if (rxnet->live)
+		rxrpc_queue_work(&rxnet->peer_keepalive_work);
+}
+
+/*
+ * Initialise a per-network namespace record.
+ */
+static __net_init int rxrpc_init_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+	int ret, i;
+
+	rxnet->live = true;
+	get_random_bytes(&rxnet->epoch, sizeof(rxnet->epoch));
+	rxnet->epoch |= RXRPC_RANDOM_EPOCH;
+
+	INIT_LIST_HEAD(&rxnet->calls);
+	rwlock_init(&rxnet->call_lock);
+	atomic_set(&rxnet->nr_calls, 1);
+
+	atomic_set(&rxnet->nr_conns, 1);
+	INIT_LIST_HEAD(&rxnet->conn_proc_list);
+	INIT_LIST_HEAD(&rxnet->service_conns);
+	rwlock_init(&rxnet->conn_lock);
+	INIT_WORK(&rxnet->service_conn_reaper,
+		  rxrpc_service_connection_reaper);
+	timer_setup(&rxnet->service_conn_reap_timer,
+		    rxrpc_service_conn_reap_timeout, 0);
+
+	atomic_set(&rxnet->nr_client_conns, 0);
+	rxnet->kill_all_client_conns = false;
+	spin_lock_init(&rxnet->client_conn_cache_lock);
+	spin_lock_init(&rxnet->client_conn_discard_lock);
+	INIT_LIST_HEAD(&rxnet->idle_client_conns);
+	INIT_WORK(&rxnet->client_conn_reaper,
+		  rxrpc_discard_expired_client_conns);
+	timer_setup(&rxnet->client_conn_reap_timer,
+		    rxrpc_client_conn_reap_timeout, 0);
+
+	INIT_HLIST_HEAD(&rxnet->local_endpoints);
+	mutex_init(&rxnet->local_mutex);
+
+	hash_init(rxnet->peer_hash);
+	spin_lock_init(&rxnet->peer_hash_lock);
+	for (i = 0; i < ARRAY_SIZE(rxnet->peer_keepalive); i++)
+		INIT_LIST_HEAD(&rxnet->peer_keepalive[i]);
+	INIT_LIST_HEAD(&rxnet->peer_keepalive_new);
+	timer_setup(&rxnet->peer_keepalive_timer,
+		    rxrpc_peer_keepalive_timeout, 0);
+	INIT_WORK(&rxnet->peer_keepalive_work, rxrpc_peer_keepalive_worker);
+	rxnet->peer_keepalive_base = ktime_get_seconds();
+
+	ret = -ENOMEM;
+	rxnet->proc_net = proc_net_mkdir(net, "rxrpc", net->proc_net);
+	if (!rxnet->proc_net)
+		goto err_proc;
+
+	proc_create_net("calls", 0444, rxnet->proc_net, &rxrpc_call_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("conns", 0444, rxnet->proc_net,
+			&rxrpc_connection_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("peers", 0444, rxnet->proc_net,
+			&rxrpc_peer_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("locals", 0444, rxnet->proc_net,
+			&rxrpc_local_seq_ops,
+			sizeof(struct seq_net_private));
+	return 0;
+
+err_proc:
+	rxnet->live = false;
+	return ret;
+}
+
+/*
+ * Clean up a per-network namespace record.
+ */
+static __net_exit void rxrpc_exit_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+
+	rxnet->live = false;
+	del_timer_sync(&rxnet->peer_keepalive_timer);
+	cancel_work_sync(&rxnet->peer_keepalive_work);
+	/* Remove the timer again as the worker may have restarted it. */
+	del_timer_sync(&rxnet->peer_keepalive_timer);
+	rxrpc_destroy_all_calls(rxnet);
+	rxrpc_destroy_all_connections(rxnet);
+	rxrpc_destroy_all_peers(rxnet);
+	rxrpc_destroy_all_locals(rxnet);
+	proc_remove(rxnet->proc_net);
+}
+
+struct pernet_operations rxrpc_net_ops = {
+	.init	= rxrpc_init_net,
+	.exit	= rxrpc_exit_net,
+	.id	= &rxrpc_net_id,
+	.size	= sizeof(struct rxrpc_net),
+};
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
new file mode 100644
index 000000000..08c117bc0
--- /dev/null
+++ b/net/rxrpc/output.c
@@ -0,0 +1,679 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC packet transmission
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+struct rxrpc_ack_buffer {
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_ackpacket ack;
+	u8 acks[255];
+	u8 pad[3];
+	struct rxrpc_ackinfo ackinfo;
+};
+
+struct rxrpc_abort_buffer {
+	struct rxrpc_wire_header whdr;
+	__be32 abort_code;
+};
+
+static const char rxrpc_keepalive_string[] = "";
+
+/*
+ * Increase Tx backoff on transmission failure and clear it on success.
+ */
+static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
+{
+	if (ret < 0) {
+		u16 tx_backoff = READ_ONCE(call->tx_backoff);
+
+		if (tx_backoff < HZ)
+			WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
+	} else {
+		WRITE_ONCE(call->tx_backoff, 0);
+	}
+}
+
+/*
+ * Arrange for a keepalive ping a certain time after we last transmitted.  This
+ * lets the far side know we're still interested in this call and helps keep
+ * the route through any intervening firewall open.
+ *
+ * Receiving a response to the ping will prevent the ->expect_rx_by timer from
+ * expiring.
+ */
+static void rxrpc_set_keepalive(struct rxrpc_call *call)
+{
+	unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
+
+	keepalive_at += now;
+	WRITE_ONCE(call->keepalive_at, keepalive_at);
+	rxrpc_reduce_call_timer(call, keepalive_at, now,
+				rxrpc_timer_set_for_keepalive);
+}
+
+/*
+ * Fill out an ACK packet.
+ */
+static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
+				 struct rxrpc_call *call,
+				 struct rxrpc_ack_buffer *pkt,
+				 rxrpc_seq_t *_hard_ack,
+				 rxrpc_seq_t *_top,
+				 u8 reason)
+{
+	rxrpc_serial_t serial;
+	unsigned int tmp;
+	rxrpc_seq_t hard_ack, top, seq;
+	int ix;
+	u32 mtu, jmax;
+	u8 *ackp = pkt->acks;
+
+	tmp = atomic_xchg(&call->ackr_nr_unacked, 0);
+	tmp |= atomic_xchg(&call->ackr_nr_consumed, 0);
+	if (!tmp && (reason == RXRPC_ACK_DELAY ||
+		     reason == RXRPC_ACK_IDLE))
+		return 0;
+
+	/* Barrier against rxrpc_input_data(). */
+	serial = call->ackr_serial;
+	hard_ack = READ_ONCE(call->rx_hard_ack);
+	top = smp_load_acquire(&call->rx_top);
+	*_hard_ack = hard_ack;
+	*_top = top;
+
+	pkt->ack.bufferSpace	= htons(0);
+	pkt->ack.maxSkew	= htons(0);
+	pkt->ack.firstPacket	= htonl(hard_ack + 1);
+	pkt->ack.previousPacket	= htonl(call->ackr_highest_seq);
+	pkt->ack.serial		= htonl(serial);
+	pkt->ack.reason		= reason;
+	pkt->ack.nAcks		= top - hard_ack;
+
+	if (reason == RXRPC_ACK_PING)
+		pkt->whdr.flags |= RXRPC_REQUEST_ACK;
+
+	if (after(top, hard_ack)) {
+		seq = hard_ack + 1;
+		do {
+			ix = seq & RXRPC_RXTX_BUFF_MASK;
+			if (call->rxtx_buffer[ix])
+				*ackp++ = RXRPC_ACK_TYPE_ACK;
+			else
+				*ackp++ = RXRPC_ACK_TYPE_NACK;
+			seq++;
+		} while (before_eq(seq, top));
+	}
+
+	mtu = conn->params.peer->if_mtu;
+	mtu -= conn->params.peer->hdrsize;
+	jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
+	pkt->ackinfo.rxMTU	= htonl(rxrpc_rx_mtu);
+	pkt->ackinfo.maxMTU	= htonl(mtu);
+	pkt->ackinfo.rwind	= htonl(call->rx_winsize);
+	pkt->ackinfo.jumbo_max	= htonl(jmax);
+
+	*ackp++ = 0;
+	*ackp++ = 0;
+	*ackp++ = 0;
+	return top - hard_ack + 3;
+}
+
+/*
+ * Record the beginning of an RTT probe.
+ */
+static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
+				 enum rxrpc_rtt_tx_trace why)
+{
+	unsigned long avail = call->rtt_avail;
+	int rtt_slot = 9;
+
+	if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
+		goto no_slot;
+
+	rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
+	if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
+		goto no_slot;
+
+	call->rtt_serial[rtt_slot] = serial;
+	call->rtt_sent_at[rtt_slot] = ktime_get_real();
+	smp_wmb(); /* Write data before avail bit */
+	set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+
+	trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
+	return rtt_slot;
+
+no_slot:
+	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
+	return -1;
+}
+
+/*
+ * Cancel an RTT probe.
+ */
+static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
+				   rxrpc_serial_t serial, int rtt_slot)
+{
+	if (rtt_slot != -1) {
+		clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+		smp_wmb(); /* Clear pending bit before setting slot */
+		set_bit(rtt_slot, &call->rtt_avail);
+		trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial);
+	}
+}
+
+/*
+ * Send an ACK call packet.
+ */
+int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
+			  rxrpc_serial_t *_serial)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_ack_buffer *pkt;
+	struct msghdr msg;
+	struct kvec iov[2];
+	rxrpc_serial_t serial;
+	rxrpc_seq_t hard_ack, top;
+	size_t len, n;
+	int ret, rtt_slot = -1;
+	u8 reason;
+
+	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		return -ECONNRESET;
+
+	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt)
+		return -ENOMEM;
+
+	conn = call->conn;
+
+	msg.msg_name	= &call->peer->srx.transport;
+	msg.msg_namelen	= call->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	pkt->whdr.epoch		= htonl(conn->proto.epoch);
+	pkt->whdr.cid		= htonl(call->cid);
+	pkt->whdr.callNumber	= htonl(call->call_id);
+	pkt->whdr.seq		= 0;
+	pkt->whdr.type		= RXRPC_PACKET_TYPE_ACK;
+	pkt->whdr.flags		= RXRPC_SLOW_START_OK | conn->out_clientflag;
+	pkt->whdr.userStatus	= 0;
+	pkt->whdr.securityIndex	= call->security_ix;
+	pkt->whdr._rsvd		= 0;
+	pkt->whdr.serviceId	= htons(call->service_id);
+
+	spin_lock_bh(&call->lock);
+	if (ping) {
+		reason = RXRPC_ACK_PING;
+	} else {
+		reason = call->ackr_reason;
+		if (!call->ackr_reason) {
+			spin_unlock_bh(&call->lock);
+			ret = 0;
+			goto out;
+		}
+		call->ackr_reason = 0;
+	}
+	n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
+
+	spin_unlock_bh(&call->lock);
+	if (n == 0) {
+		kfree(pkt);
+		return 0;
+	}
+
+	iov[0].iov_base	= pkt;
+	iov[0].iov_len	= sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
+	iov[1].iov_base = &pkt->ackinfo;
+	iov[1].iov_len	= sizeof(pkt->ackinfo);
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = atomic_inc_return(&conn->serial);
+	pkt->whdr.serial = htonl(serial);
+	trace_rxrpc_tx_ack(call->debug_id, serial,
+			   ntohl(pkt->ack.firstPacket),
+			   ntohl(pkt->ack.serial),
+			   pkt->ack.reason, pkt->ack.nAcks);
+	if (_serial)
+		*_serial = serial;
+
+	if (ping)
+		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	if (ret < 0)
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_ack);
+	else
+		trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
+				      rxrpc_tx_point_call_ack);
+	rxrpc_tx_backoff(call, ret);
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		if (ret < 0) {
+			rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
+			rxrpc_propose_ACK(call, pkt->ack.reason,
+					  ntohl(pkt->ack.serial),
+					  false, true,
+					  rxrpc_propose_ack_retry_tx);
+		}
+
+		rxrpc_set_keepalive(call);
+	}
+
+out:
+	kfree(pkt);
+	return ret;
+}
+
+/*
+ * Send an ABORT call packet.
+ */
+int rxrpc_send_abort_packet(struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_abort_buffer pkt;
+	struct msghdr msg;
+	struct kvec iov[1];
+	rxrpc_serial_t serial;
+	int ret;
+
+	/* Don't bother sending aborts for a client call once the server has
+	 * hard-ACK'd all of its request data.  After that point, we're not
+	 * going to stop the operation proceeding, and whilst we might limit
+	 * the reply, it's not worth it if we can send a new call on the same
+	 * channel instead, thereby closing off this call.
+	 */
+	if (rxrpc_is_client_call(call) &&
+	    test_bit(RXRPC_CALL_TX_LAST, &call->flags))
+		return 0;
+
+	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		return -ECONNRESET;
+
+	conn = call->conn;
+
+	msg.msg_name	= &call->peer->srx.transport;
+	msg.msg_namelen	= call->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	pkt.whdr.epoch		= htonl(conn->proto.epoch);
+	pkt.whdr.cid		= htonl(call->cid);
+	pkt.whdr.callNumber	= htonl(call->call_id);
+	pkt.whdr.seq		= 0;
+	pkt.whdr.type		= RXRPC_PACKET_TYPE_ABORT;
+	pkt.whdr.flags		= conn->out_clientflag;
+	pkt.whdr.userStatus	= 0;
+	pkt.whdr.securityIndex	= call->security_ix;
+	pkt.whdr._rsvd		= 0;
+	pkt.whdr.serviceId	= htons(call->service_id);
+	pkt.abort_code		= htonl(call->abort_code);
+
+	iov[0].iov_base	= &pkt;
+	iov[0].iov_len	= sizeof(pkt);
+
+	serial = atomic_inc_return(&conn->serial);
+	pkt.whdr.serial = htonl(serial);
+
+	ret = kernel_sendmsg(conn->params.local->socket,
+			     &msg, iov, 1, sizeof(pkt));
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	if (ret < 0)
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_abort);
+	else
+		trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
+				      rxrpc_tx_point_call_abort);
+	rxrpc_tx_backoff(call, ret);
+	return ret;
+}
+
+/*
+ * send a packet through the transport endpoint
+ */
+int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
+			   bool retrans)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct msghdr msg;
+	struct kvec iov[2];
+	rxrpc_serial_t serial;
+	size_t len;
+	int ret, rtt_slot = -1;
+
+	_enter(",{%d}", skb->len);
+
+	if (hlist_unhashed(&call->error_link)) {
+		spin_lock_bh(&call->peer->lock);
+		hlist_add_head_rcu(&call->error_link, &call->peer->error_targets);
+		spin_unlock_bh(&call->peer->lock);
+	}
+
+	/* Each transmission of a Tx packet needs a new serial number */
+	serial = atomic_inc_return(&conn->serial);
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(call->cid);
+	whdr.callNumber	= htonl(call->call_id);
+	whdr.seq	= htonl(sp->hdr.seq);
+	whdr.serial	= htonl(serial);
+	whdr.type	= RXRPC_PACKET_TYPE_DATA;
+	whdr.flags	= sp->hdr.flags;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = call->security_ix;
+	whdr._rsvd	= htons(sp->hdr._rsvd);
+	whdr.serviceId	= htons(call->service_id);
+
+	if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
+	    sp->hdr.seq == 1)
+		whdr.userStatus	= RXRPC_USERSTATUS_SERVICE_UPGRADE;
+
+	iov[0].iov_base = &whdr;
+	iov[0].iov_len = sizeof(whdr);
+	iov[1].iov_base = skb->head;
+	iov[1].iov_len = skb->len;
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	msg.msg_name = &call->peer->srx.transport;
+	msg.msg_namelen = call->peer->srx.transport_len;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = 0;
+
+	/* If our RTT cache needs working on, request an ACK.  Also request
+	 * ACKs if a DATA packet appears to have been lost.
+	 *
+	 * However, we mustn't request an ACK on the last reply packet of a
+	 * service call, lest OpenAFS incorrectly send us an ACK with some
+	 * soft-ACKs in it and then never follow up with a proper hard ACK.
+	 */
+	if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
+	     rxrpc_to_server(sp)
+	     ) &&
+	    (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
+	     retrans ||
+	     call->cong_mode == RXRPC_CALL_SLOW_START ||
+	     (call->peer->rtt_count < 3 && sp->hdr.seq & 1) ||
+	     ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
+			  ktime_get_real())))
+		whdr.flags |= RXRPC_REQUEST_ACK;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+		static int lose;
+		if ((lose++ & 7) == 7) {
+			ret = 0;
+			trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
+					    whdr.flags, retrans, true);
+			goto done;
+		}
+	}
+
+	trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
+			    false);
+
+	/* send the packet with the don't fragment bit set if we currently
+	 * think it's small enough */
+	if (iov[1].iov_len >= call->peer->maxdata)
+		goto send_fragmentable;
+
+	down_read(&conn->params.local->defrag_sem);
+
+	sp->hdr.serial = serial;
+	smp_wmb(); /* Set serial before timestamp */
+	skb->tstamp = ktime_get_real();
+	if (whdr.flags & RXRPC_REQUEST_ACK)
+		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
+
+	/* send the packet by UDP
+	 * - returns -EMSGSIZE if UDP would have to fragment the packet
+	 *   to go out of the interface
+	 *   - in which case, we'll have processed the ICMP error
+	 *     message and update the peer record
+	 */
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+
+	up_read(&conn->params.local->defrag_sem);
+	if (ret < 0) {
+		rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_data_nofrag);
+	} else {
+		trace_rxrpc_tx_packet(call->debug_id, &whdr,
+				      rxrpc_tx_point_call_data_nofrag);
+	}
+
+	rxrpc_tx_backoff(call, ret);
+	if (ret == -EMSGSIZE)
+		goto send_fragmentable;
+
+done:
+	if (ret >= 0) {
+		if (whdr.flags & RXRPC_REQUEST_ACK) {
+			call->peer->rtt_last_req = skb->tstamp;
+			if (call->peer->rtt_count > 1) {
+				unsigned long nowj = jiffies, ack_lost_at;
+
+				ack_lost_at = rxrpc_get_rto_backoff(call->peer, false);
+				ack_lost_at += nowj;
+				WRITE_ONCE(call->ack_lost_at, ack_lost_at);
+				rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
+							rxrpc_timer_set_for_lost_ack);
+			}
+		}
+
+		if (sp->hdr.seq == 1 &&
+		    !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
+				      &call->flags)) {
+			unsigned long nowj = jiffies, expect_rx_by;
+
+			expect_rx_by = nowj + call->next_rx_timo;
+			WRITE_ONCE(call->expect_rx_by, expect_rx_by);
+			rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
+						rxrpc_timer_set_for_normal);
+		}
+
+		rxrpc_set_keepalive(call);
+	} else {
+		/* Cancel the call if the initial transmission fails,
+		 * particularly if that's due to network routing issues that
+		 * aren't going away anytime soon.  The layer above can arrange
+		 * the retransmission.
+		 */
+		if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
+			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+						  RX_USER_ABORT, ret);
+	}
+
+	_leave(" = %d [%u]", ret, call->peer->maxdata);
+	return ret;
+
+send_fragmentable:
+	/* attempt to send this message with fragmentation enabled */
+	_debug("send fragment");
+
+	down_write(&conn->params.local->defrag_sem);
+
+	sp->hdr.serial = serial;
+	smp_wmb(); /* Set serial before timestamp */
+	skb->tstamp = ktime_get_real();
+	if (whdr.flags & RXRPC_REQUEST_ACK)
+		rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
+
+	switch (conn->params.local->srx.transport.family) {
+	case AF_INET6:
+	case AF_INET:
+		ip_sock_set_mtu_discover(conn->params.local->socket->sk,
+				IP_PMTUDISC_DONT);
+		ret = kernel_sendmsg(conn->params.local->socket, &msg,
+				     iov, 2, len);
+		conn->params.peer->last_tx_at = ktime_get_seconds();
+
+		ip_sock_set_mtu_discover(conn->params.local->socket->sk,
+				IP_PMTUDISC_DO);
+		break;
+
+	default:
+		BUG();
+	}
+
+	if (ret < 0) {
+		rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_data_frag);
+	} else {
+		trace_rxrpc_tx_packet(call->debug_id, &whdr,
+				      rxrpc_tx_point_call_data_frag);
+	}
+	rxrpc_tx_backoff(call, ret);
+
+	up_write(&conn->params.local->defrag_sem);
+	goto done;
+}
+
+/*
+ * reject packets through the local endpoint
+ */
+void rxrpc_reject_packets(struct rxrpc_local *local)
+{
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_wire_header whdr;
+	struct sk_buff *skb;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t size;
+	__be32 code;
+	int ret, ioc;
+
+	_enter("%d", local->debug_id);
+
+	iov[0].iov_base = &whdr;
+	iov[0].iov_len = sizeof(whdr);
+	iov[1].iov_base = &code;
+	iov[1].iov_len = sizeof(code);
+
+	msg.msg_name = &srx.transport;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = 0;
+
+	memset(&whdr, 0, sizeof(whdr));
+
+	while ((skb = skb_dequeue(&local->reject_queue))) {
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+		sp = rxrpc_skb(skb);
+
+		switch (skb->mark) {
+		case RXRPC_SKB_MARK_REJECT_BUSY:
+			whdr.type = RXRPC_PACKET_TYPE_BUSY;
+			size = sizeof(whdr);
+			ioc = 1;
+			break;
+		case RXRPC_SKB_MARK_REJECT_ABORT:
+			whdr.type = RXRPC_PACKET_TYPE_ABORT;
+			code = htonl(skb->priority);
+			size = sizeof(whdr) + sizeof(code);
+			ioc = 2;
+			break;
+		default:
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
+			continue;
+		}
+
+		if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
+			msg.msg_namelen = srx.transport_len;
+
+			whdr.epoch	= htonl(sp->hdr.epoch);
+			whdr.cid	= htonl(sp->hdr.cid);
+			whdr.callNumber	= htonl(sp->hdr.callNumber);
+			whdr.serviceId	= htons(sp->hdr.serviceId);
+			whdr.flags	= sp->hdr.flags;
+			whdr.flags	^= RXRPC_CLIENT_INITIATED;
+			whdr.flags	&= RXRPC_CLIENT_INITIATED;
+
+			ret = kernel_sendmsg(local->socket, &msg,
+					     iov, ioc, size);
+			if (ret < 0)
+				trace_rxrpc_tx_fail(local->debug_id, 0, ret,
+						    rxrpc_tx_point_reject);
+			else
+				trace_rxrpc_tx_packet(local->debug_id, &whdr,
+						      rxrpc_tx_point_reject);
+		}
+
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+	}
+
+	_leave("");
+}
+
+/*
+ * Send a VERSION reply to a peer as a keepalive.
+ */
+void rxrpc_send_keepalive(struct rxrpc_peer *peer)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	int ret;
+
+	_enter("");
+
+	msg.msg_name	= &peer->srx.transport;
+	msg.msg_namelen	= peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(peer->local->rxnet->epoch);
+	whdr.cid	= 0;
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.serial	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
+	whdr.flags	= RXRPC_LAST_PACKET;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = 0;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= 0;
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= (char *)rxrpc_keepalive_string;
+	iov[1].iov_len	= sizeof(rxrpc_keepalive_string);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	_proto("Tx VERSION (keepalive)");
+
+	ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
+				    rxrpc_tx_point_version_keepalive);
+	else
+		trace_rxrpc_tx_packet(peer->debug_id, &whdr,
+				      rxrpc_tx_point_version_keepalive);
+
+	peer->last_tx_at = ktime_get_seconds();
+	_leave("");
+}
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
new file mode 100644
index 000000000..be032850a
--- /dev/null
+++ b/net/rxrpc/peer_event.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Peer event handling, typically ICMP messages.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *);
+static void rxrpc_distribute_error(struct rxrpc_peer *, int,
+				   enum rxrpc_call_completion);
+
+/*
+ * Find the peer associated with an ICMP packet.
+ */
+static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
+						     const struct sk_buff *skb,
+						     struct sockaddr_rxrpc *srx)
+{
+	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+
+	_enter("");
+
+	memset(srx, 0, sizeof(*srx));
+	srx->transport_type = local->srx.transport_type;
+	srx->transport_len = local->srx.transport_len;
+	srx->transport.family = local->srx.transport.family;
+
+	/* Can we see an ICMP4 packet on an ICMP6 listening socket?  and vice
+	 * versa?
+	 */
+	switch (srx->transport.family) {
+	case AF_INET:
+		srx->transport_len = sizeof(srx->transport.sin);
+		srx->transport.family = AF_INET;
+		srx->transport.sin.sin_port = serr->port;
+		switch (serr->ee.ee_origin) {
+		case SO_EE_ORIGIN_ICMP:
+			_net("Rx ICMP");
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in_addr));
+			break;
+		case SO_EE_ORIGIN_ICMP6:
+			_net("Rx ICMP6 on v4 sock");
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset + 12,
+			       sizeof(struct in_addr));
+			break;
+		default:
+			memcpy(&srx->transport.sin.sin_addr, &ip_hdr(skb)->saddr,
+			       sizeof(struct in_addr));
+			break;
+		}
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		switch (serr->ee.ee_origin) {
+		case SO_EE_ORIGIN_ICMP6:
+			_net("Rx ICMP6");
+			srx->transport.sin6.sin6_port = serr->port;
+			memcpy(&srx->transport.sin6.sin6_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in6_addr));
+			break;
+		case SO_EE_ORIGIN_ICMP:
+			_net("Rx ICMP on v6 sock");
+			srx->transport_len = sizeof(srx->transport.sin);
+			srx->transport.family = AF_INET;
+			srx->transport.sin.sin_port = serr->port;
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in_addr));
+			break;
+		default:
+			memcpy(&srx->transport.sin6.sin6_addr,
+			       &ipv6_hdr(skb)->saddr,
+			       sizeof(struct in6_addr));
+			break;
+		}
+		break;
+#endif
+
+	default:
+		BUG();
+	}
+
+	return rxrpc_lookup_peer_rcu(local, srx);
+}
+
+/*
+ * Handle an MTU/fragmentation problem.
+ */
+static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
+{
+	u32 mtu = serr->ee.ee_info;
+
+	_net("Rx ICMP Fragmentation Needed (%d)", mtu);
+
+	/* wind down the local interface MTU */
+	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
+		peer->if_mtu = mtu;
+		_net("I/F MTU %u", mtu);
+	}
+
+	if (mtu == 0) {
+		/* they didn't give us a size, estimate one */
+		mtu = peer->if_mtu;
+		if (mtu > 1500) {
+			mtu >>= 1;
+			if (mtu < 1500)
+				mtu = 1500;
+		} else {
+			mtu -= 100;
+			if (mtu < peer->hdrsize)
+				mtu = peer->hdrsize + 4;
+		}
+	}
+
+	if (mtu < peer->mtu) {
+		spin_lock_bh(&peer->lock);
+		peer->mtu = mtu;
+		peer->maxdata = peer->mtu - peer->hdrsize;
+		spin_unlock_bh(&peer->lock);
+		_net("Net MTU %u (maxdata %u)",
+		     peer->mtu, peer->maxdata);
+	}
+}
+
+/*
+ * Handle an error received on the local endpoint.
+ */
+void rxrpc_error_report(struct sock *sk)
+{
+	struct sock_exterr_skb *serr;
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_local *local;
+	struct rxrpc_peer *peer;
+	struct sk_buff *skb;
+
+	rcu_read_lock();
+	local = rcu_dereference_sk_user_data(sk);
+	if (unlikely(!local)) {
+		rcu_read_unlock();
+		return;
+	}
+	_enter("%p{%d}", sk, local->debug_id);
+
+	/* Clear the outstanding error value on the socket so that it doesn't
+	 * cause kernel_sendmsg() to return it later.
+	 */
+	sock_error(sk);
+
+	skb = sock_dequeue_err_skb(sk);
+	if (!skb) {
+		rcu_read_unlock();
+		_leave("UDP socket errqueue empty");
+		return;
+	}
+	rxrpc_new_skb(skb, rxrpc_skb_received);
+	serr = SKB_EXT_ERR(skb);
+	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
+		_leave("UDP empty message");
+		rcu_read_unlock();
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+		return;
+	}
+
+	peer = rxrpc_lookup_peer_icmp_rcu(local, skb, &srx);
+	if (peer && !rxrpc_get_peer_maybe(peer))
+		peer = NULL;
+	if (!peer) {
+		rcu_read_unlock();
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+		_leave(" [no peer]");
+		return;
+	}
+
+	trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
+
+	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
+	     serr->ee.ee_type == ICMP_DEST_UNREACH &&
+	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
+		rxrpc_adjust_mtu(peer, serr);
+		rcu_read_unlock();
+		rxrpc_free_skb(skb, rxrpc_skb_freed);
+		rxrpc_put_peer(peer);
+		_leave(" [MTU update]");
+		return;
+	}
+
+	rxrpc_store_error(peer, serr);
+	rcu_read_unlock();
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	rxrpc_put_peer(peer);
+
+	_leave("");
+}
+
+/*
+ * Map an error report to error codes on the peer record.
+ */
+static void rxrpc_store_error(struct rxrpc_peer *peer,
+			      struct sock_exterr_skb *serr)
+{
+	enum rxrpc_call_completion compl = RXRPC_CALL_NETWORK_ERROR;
+	struct sock_extended_err *ee;
+	int err;
+
+	_enter("");
+
+	ee = &serr->ee;
+
+	err = ee->ee_errno;
+
+	switch (ee->ee_origin) {
+	case SO_EE_ORIGIN_ICMP:
+		switch (ee->ee_type) {
+		case ICMP_DEST_UNREACH:
+			switch (ee->ee_code) {
+			case ICMP_NET_UNREACH:
+				_net("Rx Received ICMP Network Unreachable");
+				break;
+			case ICMP_HOST_UNREACH:
+				_net("Rx Received ICMP Host Unreachable");
+				break;
+			case ICMP_PORT_UNREACH:
+				_net("Rx Received ICMP Port Unreachable");
+				break;
+			case ICMP_NET_UNKNOWN:
+				_net("Rx Received ICMP Unknown Network");
+				break;
+			case ICMP_HOST_UNKNOWN:
+				_net("Rx Received ICMP Unknown Host");
+				break;
+			default:
+				_net("Rx Received ICMP DestUnreach code=%u",
+				     ee->ee_code);
+				break;
+			}
+			break;
+
+		case ICMP_TIME_EXCEEDED:
+			_net("Rx Received ICMP TTL Exceeded");
+			break;
+
+		default:
+			_proto("Rx Received ICMP error { type=%u code=%u }",
+			       ee->ee_type, ee->ee_code);
+			break;
+		}
+		break;
+
+	case SO_EE_ORIGIN_NONE:
+	case SO_EE_ORIGIN_LOCAL:
+		_proto("Rx Received local error { error=%d }", err);
+		compl = RXRPC_CALL_LOCAL_ERROR;
+		break;
+
+	case SO_EE_ORIGIN_ICMP6:
+		if (err == EACCES)
+			err = EHOSTUNREACH;
+		fallthrough;
+	default:
+		_proto("Rx Received error report { orig=%u }", ee->ee_origin);
+		break;
+	}
+
+	rxrpc_distribute_error(peer, err, compl);
+}
+
+/*
+ * Distribute an error that occurred on a peer.
+ */
+static void rxrpc_distribute_error(struct rxrpc_peer *peer, int error,
+				   enum rxrpc_call_completion compl)
+{
+	struct rxrpc_call *call;
+
+	hlist_for_each_entry_rcu(call, &peer->error_targets, error_link) {
+		rxrpc_see_call(call);
+		rxrpc_set_call_completion(call, compl, 0, -error);
+	}
+}
+
+/*
+ * Perform keep-alive pings.
+ */
+static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet,
+					  struct list_head *collector,
+					  time64_t base,
+					  u8 cursor)
+{
+	struct rxrpc_peer *peer;
+	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+	time64_t keepalive_at;
+	int slot;
+
+	spin_lock_bh(&rxnet->peer_hash_lock);
+
+	while (!list_empty(collector)) {
+		peer = list_entry(collector->next,
+				  struct rxrpc_peer, keepalive_link);
+
+		list_del_init(&peer->keepalive_link);
+		if (!rxrpc_get_peer_maybe(peer))
+			continue;
+
+		if (__rxrpc_use_local(peer->local)) {
+			spin_unlock_bh(&rxnet->peer_hash_lock);
+
+			keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
+			slot = keepalive_at - base;
+			_debug("%02x peer %u t=%d {%pISp}",
+			       cursor, peer->debug_id, slot, &peer->srx.transport);
+
+			if (keepalive_at <= base ||
+			    keepalive_at > base + RXRPC_KEEPALIVE_TIME) {
+				rxrpc_send_keepalive(peer);
+				slot = RXRPC_KEEPALIVE_TIME;
+			}
+
+			/* A transmission to this peer occurred since last we
+			 * examined it so put it into the appropriate future
+			 * bucket.
+			 */
+			slot += cursor;
+			slot &= mask;
+			spin_lock_bh(&rxnet->peer_hash_lock);
+			list_add_tail(&peer->keepalive_link,
+				      &rxnet->peer_keepalive[slot & mask]);
+			rxrpc_unuse_local(peer->local);
+		}
+		rxrpc_put_peer_locked(peer);
+	}
+
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+}
+
+/*
+ * Perform keep-alive pings with VERSION packets to keep any NAT alive.
+ */
+void rxrpc_peer_keepalive_worker(struct work_struct *work)
+{
+	struct rxrpc_net *rxnet =
+		container_of(work, struct rxrpc_net, peer_keepalive_work);
+	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+	time64_t base, now, delay;
+	u8 cursor, stop;
+	LIST_HEAD(collector);
+
+	now = ktime_get_seconds();
+	base = rxnet->peer_keepalive_base;
+	cursor = rxnet->peer_keepalive_cursor;
+	_enter("%lld,%u", base - now, cursor);
+
+	if (!rxnet->live)
+		return;
+
+	/* Remove to a temporary list all the peers that are currently lodged
+	 * in expired buckets plus all new peers.
+	 *
+	 * Everything in the bucket at the cursor is processed this
+	 * second; the bucket at cursor + 1 goes at now + 1s and so
+	 * on...
+	 */
+	spin_lock_bh(&rxnet->peer_hash_lock);
+	list_splice_init(&rxnet->peer_keepalive_new, &collector);
+
+	stop = cursor + ARRAY_SIZE(rxnet->peer_keepalive);
+	while (base <= now && (s8)(cursor - stop) < 0) {
+		list_splice_tail_init(&rxnet->peer_keepalive[cursor & mask],
+				      &collector);
+		base++;
+		cursor++;
+	}
+
+	base = now;
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+
+	rxnet->peer_keepalive_base = base;
+	rxnet->peer_keepalive_cursor = cursor;
+	rxrpc_peer_keepalive_dispatch(rxnet, &collector, base, cursor);
+	ASSERT(list_empty(&collector));
+
+	/* Schedule the timer for the next occupied timeslot. */
+	cursor = rxnet->peer_keepalive_cursor;
+	stop = cursor + RXRPC_KEEPALIVE_TIME - 1;
+	for (; (s8)(cursor - stop) < 0; cursor++) {
+		if (!list_empty(&rxnet->peer_keepalive[cursor & mask]))
+			break;
+		base++;
+	}
+
+	now = ktime_get_seconds();
+	delay = base - now;
+	if (delay < 1)
+		delay = 1;
+	delay *= HZ;
+	if (rxnet->live)
+		timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
+
+	_leave("");
+}
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
new file mode 100644
index 000000000..26d2ae9ba
--- /dev/null
+++ b/net/rxrpc/peer_object.c
@@ -0,0 +1,528 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC remote transport endpoint record management
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+#include "ar-internal.h"
+
+/*
+ * Hash a peer key.
+ */
+static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	const u16 *p;
+	unsigned int i, size;
+	unsigned long hash_key;
+
+	_enter("");
+
+	hash_key = (unsigned long)local / __alignof__(*local);
+	hash_key += srx->transport_type;
+	hash_key += srx->transport_len;
+	hash_key += srx->transport.family;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin.sin_addr);
+		p = (u16 *)&srx->transport.sin.sin_addr;
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin6.sin6_addr);
+		p = (u16 *)&srx->transport.sin6.sin6_addr;
+		break;
+#endif
+	default:
+		WARN(1, "AF_RXRPC: Unsupported transport address family\n");
+		return 0;
+	}
+
+	/* Step through the peer address in 16-bit portions for speed */
+	for (i = 0; i < size; i += sizeof(*p), p++)
+		hash_key += *p;
+
+	_leave(" 0x%lx", hash_key);
+	return hash_key;
+}
+
+/*
+ * Compare a peer to a key.  Return -ve, 0 or +ve to indicate less than, same
+ * or greater than.
+ *
+ * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
+ * buckets and mid-bucket insertion, so we don't make full use of this
+ * information at this point.
+ */
+static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
+			       struct rxrpc_local *local,
+			       const struct sockaddr_rxrpc *srx,
+			       unsigned long hash_key)
+{
+	long diff;
+
+	diff = ((peer->hash_key - hash_key) ?:
+		((unsigned long)peer->local - (unsigned long)local) ?:
+		(peer->srx.transport_type - srx->transport_type) ?:
+		(peer->srx.transport_len - srx->transport_len) ?:
+		(peer->srx.transport.family - srx->transport.family));
+	if (diff != 0)
+		return diff;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		return ((u16 __force)peer->srx.transport.sin.sin_port -
+			(u16 __force)srx->transport.sin.sin_port) ?:
+			memcmp(&peer->srx.transport.sin.sin_addr,
+			       &srx->transport.sin.sin_addr,
+			       sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		return ((u16 __force)peer->srx.transport.sin6.sin6_port -
+			(u16 __force)srx->transport.sin6.sin6_port) ?:
+			memcmp(&peer->srx.transport.sin6.sin6_addr,
+			       &srx->transport.sin6.sin6_addr,
+			       sizeof(struct in6_addr));
+#endif
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
+	struct rxrpc_local *local,
+	const struct sockaddr_rxrpc *srx,
+	unsigned long hash_key)
+{
+	struct rxrpc_peer *peer;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
+		if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
+		    refcount_read(&peer->ref) > 0)
+			return peer;
+	}
+
+	return NULL;
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_peer *peer;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer) {
+		_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
+		_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	}
+	return peer;
+}
+
+/*
+ * assess the MTU size for the network interface through which this peer is
+ * reached
+ */
+static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
+				  struct rxrpc_peer *peer)
+{
+	struct net *net = sock_net(&rx->sk);
+	struct dst_entry *dst;
+	struct rtable *rt;
+	struct flowi fl;
+	struct flowi4 *fl4 = &fl.u.ip4;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	struct flowi6 *fl6 = &fl.u.ip6;
+#endif
+
+	peer->if_mtu = 1500;
+
+	memset(&fl, 0, sizeof(fl));
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		rt = ip_route_output_ports(
+			net, fl4, NULL,
+			peer->srx.transport.sin.sin_addr.s_addr, 0,
+			htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
+		if (IS_ERR(rt)) {
+			_leave(" [route err %ld]", PTR_ERR(rt));
+			return;
+		}
+		dst = &rt->dst;
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		fl6->flowi6_iif = LOOPBACK_IFINDEX;
+		fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
+		fl6->flowi6_proto = IPPROTO_UDP;
+		memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
+		       sizeof(struct in6_addr));
+		fl6->fl6_dport = htons(7001);
+		fl6->fl6_sport = htons(7000);
+		dst = ip6_route_output(net, NULL, fl6);
+		if (dst->error) {
+			_leave(" [route err %d]", dst->error);
+			return;
+		}
+		break;
+#endif
+
+	default:
+		BUG();
+	}
+
+	peer->if_mtu = dst_mtu(dst);
+	dst_release(dst);
+
+	_leave(" [if_mtu %u]", peer->if_mtu);
+}
+
+/*
+ * Allocate a peer.
+ */
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp)
+{
+	const void *here = __builtin_return_address(0);
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
+	if (peer) {
+		refcount_set(&peer->ref, 1);
+		peer->local = rxrpc_get_local(local);
+		INIT_HLIST_HEAD(&peer->error_targets);
+		peer->service_conns = RB_ROOT;
+		seqlock_init(&peer->service_conn_lock);
+		spin_lock_init(&peer->lock);
+		spin_lock_init(&peer->rtt_input_lock);
+		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+
+		rxrpc_peer_init_rtt(peer);
+
+		if (RXRPC_TX_SMSS > 2190)
+			peer->cong_cwnd = 2;
+		else if (RXRPC_TX_SMSS > 1095)
+			peer->cong_cwnd = 3;
+		else
+			peer->cong_cwnd = 4;
+		trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+/*
+ * Initialise peer record.
+ */
+static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer,
+			    unsigned long hash_key)
+{
+	peer->hash_key = hash_key;
+	rxrpc_assess_MTU_size(rx, peer);
+	peer->mtu = peer->if_mtu;
+	peer->rtt_last_req = ktime_get_real();
+
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		peer->hdrsize = sizeof(struct iphdr);
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		peer->hdrsize = sizeof(struct ipv6hdr);
+		break;
+#endif
+	default:
+		BUG();
+	}
+
+	switch (peer->srx.transport_type) {
+	case SOCK_DGRAM:
+		peer->hdrsize += sizeof(struct udphdr);
+		break;
+	default:
+		BUG();
+	}
+
+	peer->hdrsize += sizeof(struct rxrpc_wire_header);
+	peer->maxdata = peer->mtu - peer->hdrsize;
+}
+
+/*
+ * Set up a new peer.
+ */
+static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx,
+					    struct rxrpc_local *local,
+					    struct sockaddr_rxrpc *srx,
+					    unsigned long hash_key,
+					    gfp_t gfp)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = rxrpc_alloc_peer(local, gfp);
+	if (peer) {
+		memcpy(&peer->srx, srx, sizeof(*srx));
+		rxrpc_init_peer(rx, peer, hash_key);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+static void rxrpc_free_peer(struct rxrpc_peer *peer)
+{
+	rxrpc_put_local(peer->local);
+	kfree_rcu(peer, rcu);
+}
+
+/*
+ * Set up a new incoming peer.  There shouldn't be any other matching peers
+ * since we've already done a search in the list from the non-reentrant context
+ * (the data_ready handler) that is the only place we can add new peers.
+ */
+void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local,
+			     struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key;
+
+	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
+	rxrpc_init_peer(rx, peer, hash_key);
+
+	spin_lock(&rxnet->peer_hash_lock);
+	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
+	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
+	spin_unlock(&rxnet->peer_hash_lock);
+}
+
+/*
+ * obtain a remote transport endpoint for the specified address
+ */
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx,
+				     struct rxrpc_local *local,
+				     struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+	struct rxrpc_peer *peer, *candidate;
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	_enter("{%pISp}", &srx->transport);
+
+	/* search the peer list first */
+	rcu_read_lock();
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer && !rxrpc_get_peer_maybe(peer))
+		peer = NULL;
+	rcu_read_unlock();
+
+	if (!peer) {
+		/* The peer is not yet present in hash - create a candidate
+		 * for a new record and then redo the search.
+		 */
+		candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp);
+		if (!candidate) {
+			_leave(" = NULL [nomem]");
+			return NULL;
+		}
+
+		spin_lock_bh(&rxnet->peer_hash_lock);
+
+		/* Need to check that we aren't racing with someone else */
+		peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+		if (peer && !rxrpc_get_peer_maybe(peer))
+			peer = NULL;
+		if (!peer) {
+			hash_add_rcu(rxnet->peer_hash,
+				     &candidate->hash_link, hash_key);
+			list_add_tail(&candidate->keepalive_link,
+				      &rxnet->peer_keepalive_new);
+		}
+
+		spin_unlock_bh(&rxnet->peer_hash_lock);
+
+		if (peer)
+			rxrpc_free_peer(candidate);
+		else
+			peer = candidate;
+	}
+
+	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
+
+	_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record.
+ */
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	__refcount_inc(&peer->ref, &r);
+	trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, r + 1, here);
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record unless its usage has already reached 0.
+ */
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer)
+{
+	const void *here = __builtin_return_address(0);
+	int r;
+
+	if (peer) {
+		if (__refcount_inc_not_zero(&peer->ref, &r))
+			trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, r + 1, here);
+		else
+			peer = NULL;
+	}
+	return peer;
+}
+
+/*
+ * Discard a peer record.
+ */
+static void __rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = peer->local->rxnet;
+
+	ASSERT(hlist_empty(&peer->error_targets));
+
+	spin_lock_bh(&rxnet->peer_hash_lock);
+	hash_del_rcu(&peer->hash_link);
+	list_del_init(&peer->keepalive_link);
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+
+	rxrpc_free_peer(peer);
+}
+
+/*
+ * Drop a ref on a peer record.
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (peer) {
+		debug_id = peer->debug_id;
+		dead = __refcount_dec_and_test(&peer->ref, &r);
+		trace_rxrpc_peer(debug_id, rxrpc_peer_put, r - 1, here);
+		if (dead)
+			__rxrpc_put_peer(peer);
+	}
+}
+
+/*
+ * Drop a ref on a peer record where the caller already holds the
+ * peer_hash_lock.
+ */
+void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
+{
+	const void *here = __builtin_return_address(0);
+	unsigned int debug_id = peer->debug_id;
+	bool dead;
+	int r;
+
+	dead = __refcount_dec_and_test(&peer->ref, &r);
+	trace_rxrpc_peer(debug_id, rxrpc_peer_put, r - 1, here);
+	if (dead) {
+		hash_del_rcu(&peer->hash_link);
+		list_del_init(&peer->keepalive_link);
+		rxrpc_free_peer(peer);
+	}
+}
+
+/*
+ * Make sure all peer records have been discarded.
+ */
+void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_peer *peer;
+	int i;
+
+	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
+		if (hlist_empty(&rxnet->peer_hash[i]))
+			continue;
+
+		hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
+			pr_err("Leaked peer %u {%u} %pISp\n",
+			       peer->debug_id,
+			       refcount_read(&peer->ref),
+			       &peer->srx.transport);
+		}
+	}
+}
+
+/**
+ * rxrpc_kernel_get_peer - Get the peer address of a call
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ * @_srx: Where to place the result
+ *
+ * Get the address of the remote peer in a call.
+ */
+void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
+			   struct sockaddr_rxrpc *_srx)
+{
+	*_srx = call->peer->srx;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer);
+
+/**
+ * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ * @_srtt: Where to store the SRTT value.
+ *
+ * Get the call's peer smoothed RTT in uS.
+ */
+bool rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call,
+			   u32 *_srtt)
+{
+	struct rxrpc_peer *peer = call->peer;
+
+	if (peer->rtt_count == 0) {
+		*_srtt = 1000000; /* 1S */
+		return false;
+	}
+
+	*_srtt = call->peer->srtt_us >> 3;
+	return true;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_srtt);
diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c
new file mode 100644
index 000000000..8967201fd
--- /dev/null
+++ b/net/rxrpc/proc.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* /proc/net/ support for AF_RXRPC
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static const char *const rxrpc_conn_states[RXRPC_CONN__NR_STATES] = {
+	[RXRPC_CONN_UNUSED]			= "Unused  ",
+	[RXRPC_CONN_CLIENT]			= "Client  ",
+	[RXRPC_CONN_SERVICE_PREALLOC]		= "SvPrealc",
+	[RXRPC_CONN_SERVICE_UNSECURED]		= "SvUnsec ",
+	[RXRPC_CONN_SERVICE_CHALLENGING]	= "SvChall ",
+	[RXRPC_CONN_SERVICE]			= "SvSecure",
+	[RXRPC_CONN_REMOTELY_ABORTED]		= "RmtAbort",
+	[RXRPC_CONN_LOCALLY_ABORTED]		= "LocAbort",
+};
+
+/*
+ * generate a list of extant and dead calls in /proc/net/rxrpc_calls
+ */
+static void *rxrpc_call_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+	__acquires(rxnet->call_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	rcu_read_lock();
+	read_lock(&rxnet->call_lock);
+	return seq_list_start_head(&rxnet->calls, *_pos);
+}
+
+static void *rxrpc_call_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	return seq_list_next(v, &rxnet->calls, pos);
+}
+
+static void rxrpc_call_seq_stop(struct seq_file *seq, void *v)
+	__releases(rxnet->call_lock)
+	__releases(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_unlock(&rxnet->call_lock);
+	rcu_read_unlock();
+}
+
+static int rxrpc_call_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_sock *rx;
+	struct rxrpc_peer *peer;
+	struct rxrpc_call *call;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned long timeout = 0;
+	rxrpc_seq_t tx_hard_ack, rx_hard_ack;
+	char lbuff[50], rbuff[50];
+
+	if (v == &rxnet->calls) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " SvID ConnID   CallID   End Use State    Abort   "
+			 " DebugId  TxSeq    TW RxSeq    RW RxSerial RxTimo\n");
+		return 0;
+	}
+
+	call = list_entry(v, struct rxrpc_call, link);
+
+	rx = rcu_dereference(call->socket);
+	if (rx) {
+		local = READ_ONCE(rx->local);
+		if (local)
+			sprintf(lbuff, "%pISpc", &local->srx.transport);
+		else
+			strcpy(lbuff, "no_local");
+	} else {
+		strcpy(lbuff, "no_socket");
+	}
+
+	peer = call->peer;
+	if (peer)
+		sprintf(rbuff, "%pISpc", &peer->srx.transport);
+	else
+		strcpy(rbuff, "no_connection");
+
+	if (call->state != RXRPC_CALL_SERVER_PREALLOC) {
+		timeout = READ_ONCE(call->expect_rx_by);
+		timeout -= jiffies;
+	}
+
+	tx_hard_ack = READ_ONCE(call->tx_hard_ack);
+	rx_hard_ack = READ_ONCE(call->rx_hard_ack);
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %4x %08x %08x %s %3u"
+		   " %-8.8s %08x %08x %08x %02x %08x %02x %08x %06lx\n",
+		   lbuff,
+		   rbuff,
+		   call->service_id,
+		   call->cid,
+		   call->call_id,
+		   rxrpc_is_service_call(call) ? "Svc" : "Clt",
+		   refcount_read(&call->ref),
+		   rxrpc_call_states[call->state],
+		   call->abort_code,
+		   call->debug_id,
+		   tx_hard_ack, READ_ONCE(call->tx_top) - tx_hard_ack,
+		   rx_hard_ack, READ_ONCE(call->rx_top) - rx_hard_ack,
+		   call->rx_serial,
+		   timeout);
+
+	return 0;
+}
+
+const struct seq_operations rxrpc_call_seq_ops = {
+	.start  = rxrpc_call_seq_start,
+	.next   = rxrpc_call_seq_next,
+	.stop   = rxrpc_call_seq_stop,
+	.show   = rxrpc_call_seq_show,
+};
+
+/*
+ * generate a list of extant virtual connections in /proc/net/rxrpc_conns
+ */
+static void *rxrpc_connection_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_lock(&rxnet->conn_lock);
+	return seq_list_start_head(&rxnet->conn_proc_list, *_pos);
+}
+
+static void *rxrpc_connection_seq_next(struct seq_file *seq, void *v,
+				       loff_t *pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	return seq_list_next(v, &rxnet->conn_proc_list, pos);
+}
+
+static void rxrpc_connection_seq_stop(struct seq_file *seq, void *v)
+	__releases(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_unlock(&rxnet->conn_lock);
+}
+
+static int rxrpc_connection_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	char lbuff[50], rbuff[50];
+
+	if (v == &rxnet->conn_proc_list) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " SvID ConnID   End Use State    Key     "
+			 " Serial   ISerial  CallId0  CallId1  CallId2  CallId3\n"
+			 );
+		return 0;
+	}
+
+	conn = list_entry(v, struct rxrpc_connection, proc_link);
+	if (conn->state == RXRPC_CONN_SERVICE_PREALLOC) {
+		strcpy(lbuff, "no_local");
+		strcpy(rbuff, "no_connection");
+		goto print;
+	}
+
+	sprintf(lbuff, "%pISpc", &conn->params.local->srx.transport);
+
+	sprintf(rbuff, "%pISpc", &conn->params.peer->srx.transport);
+print:
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %4x %08x %s %3u"
+		   " %s %08x %08x %08x %08x %08x %08x %08x\n",
+		   lbuff,
+		   rbuff,
+		   conn->service_id,
+		   conn->proto.cid,
+		   rxrpc_conn_is_service(conn) ? "Svc" : "Clt",
+		   refcount_read(&conn->ref),
+		   rxrpc_conn_states[conn->state],
+		   key_serial(conn->params.key),
+		   atomic_read(&conn->serial),
+		   conn->hi_serial,
+		   conn->channels[0].call_id,
+		   conn->channels[1].call_id,
+		   conn->channels[2].call_id,
+		   conn->channels[3].call_id);
+
+	return 0;
+}
+
+const struct seq_operations rxrpc_connection_seq_ops = {
+	.start  = rxrpc_connection_seq_start,
+	.next   = rxrpc_connection_seq_next,
+	.stop   = rxrpc_connection_seq_stop,
+	.show   = rxrpc_connection_seq_show,
+};
+
+/*
+ * generate a list of extant virtual peers in /proc/net/rxrpc/peers
+ */
+static int rxrpc_peer_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_peer *peer;
+	time64_t now;
+	char lbuff[50], rbuff[50];
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " Use  CW   MTU LastUse      RTT      RTO\n"
+			 );
+		return 0;
+	}
+
+	peer = list_entry(v, struct rxrpc_peer, hash_link);
+
+	sprintf(lbuff, "%pISpc", &peer->local->srx.transport);
+
+	sprintf(rbuff, "%pISpc", &peer->srx.transport);
+
+	now = ktime_get_seconds();
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %3u"
+		   " %3u %5u %6llus %8u %8u\n",
+		   lbuff,
+		   rbuff,
+		   refcount_read(&peer->ref),
+		   peer->cong_cwnd,
+		   peer->mtu,
+		   now - peer->last_tx_at,
+		   peer->srtt_us >> 3,
+		   jiffies_to_usecs(peer->rto_j));
+
+	return 0;
+}
+
+static void *rxrpc_peer_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int bucket, n;
+	unsigned int shift = 32 - HASH_BITS(rxnet->peer_hash);
+	void *p;
+
+	rcu_read_lock();
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	n = *_pos & ((1U << shift) - 1);
+	bucket = *_pos >> shift;
+	for (;;) {
+		if (bucket >= HASH_SIZE(rxnet->peer_hash)) {
+			*_pos = UINT_MAX;
+			return NULL;
+		}
+		if (n == 0) {
+			if (bucket == 0)
+				return SEQ_START_TOKEN;
+			*_pos += 1;
+			n++;
+		}
+
+		p = seq_hlist_start_rcu(&rxnet->peer_hash[bucket], n - 1);
+		if (p)
+			return p;
+		bucket++;
+		n = 1;
+		*_pos = (bucket << shift) | n;
+	}
+}
+
+static void *rxrpc_peer_seq_next(struct seq_file *seq, void *v, loff_t *_pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int bucket, n;
+	unsigned int shift = 32 - HASH_BITS(rxnet->peer_hash);
+	void *p;
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	bucket = *_pos >> shift;
+
+	p = seq_hlist_next_rcu(v, &rxnet->peer_hash[bucket], _pos);
+	if (p)
+		return p;
+
+	for (;;) {
+		bucket++;
+		n = 1;
+		*_pos = (bucket << shift) | n;
+
+		if (bucket >= HASH_SIZE(rxnet->peer_hash)) {
+			*_pos = UINT_MAX;
+			return NULL;
+		}
+		if (n == 0) {
+			*_pos += 1;
+			n++;
+		}
+
+		p = seq_hlist_start_rcu(&rxnet->peer_hash[bucket], n - 1);
+		if (p)
+			return p;
+	}
+}
+
+static void rxrpc_peer_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+
+const struct seq_operations rxrpc_peer_seq_ops = {
+	.start  = rxrpc_peer_seq_start,
+	.next   = rxrpc_peer_seq_next,
+	.stop   = rxrpc_peer_seq_stop,
+	.show   = rxrpc_peer_seq_show,
+};
+
+/*
+ * Generate a list of extant virtual local endpoints in /proc/net/rxrpc/locals
+ */
+static int rxrpc_local_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_local *local;
+	char lbuff[50];
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Use Act\n");
+		return 0;
+	}
+
+	local = hlist_entry(v, struct rxrpc_local, link);
+
+	sprintf(lbuff, "%pISpc", &local->srx.transport);
+
+	seq_printf(seq,
+		   "UDP   %-47.47s %3u %3u\n",
+		   lbuff,
+		   refcount_read(&local->ref),
+		   atomic_read(&local->active_users));
+
+	return 0;
+}
+
+static void *rxrpc_local_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int n;
+
+	rcu_read_lock();
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	n = *_pos;
+	if (n == 0)
+		return SEQ_START_TOKEN;
+
+	return seq_hlist_start_rcu(&rxnet->local_endpoints, n - 1);
+}
+
+static void *rxrpc_local_seq_next(struct seq_file *seq, void *v, loff_t *_pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	return seq_hlist_next_rcu(v, &rxnet->local_endpoints, _pos);
+}
+
+static void rxrpc_local_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+const struct seq_operations rxrpc_local_seq_ops = {
+	.start  = rxrpc_local_seq_start,
+	.next   = rxrpc_local_seq_next,
+	.stop   = rxrpc_local_seq_stop,
+	.show   = rxrpc_local_seq_show,
+};
diff --git a/net/rxrpc/protocol.h b/net/rxrpc/protocol.h
new file mode 100644
index 000000000..49bb97253
--- /dev/null
+++ b/net/rxrpc/protocol.h
@@ -0,0 +1,186 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* packet.h: Rx packet layout and definitions
+ *
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _LINUX_RXRPC_PACKET_H
+#define _LINUX_RXRPC_PACKET_H
+
+typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
+typedef u32	rxrpc_serial_t;	/* Rx message serial number */
+typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
+typedef __be32	rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx packet header
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_wire_header {
+	__be32		epoch;		/* client boot timestamp */
+#define RXRPC_RANDOM_EPOCH	0x80000000	/* Random if set, date-based if not */
+
+	__be32		cid;		/* connection and channel ID */
+#define RXRPC_MAXCALLS		4			/* max active calls per conn */
+#define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
+#define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
+#define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
+#define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */
+
+	__be32		callNumber;	/* call ID (0 for connection-level packets) */
+	__be32		seq;		/* sequence number of pkt in call stream */
+	__be32		serial;		/* serial number of pkt sent to network */
+
+	uint8_t		type;		/* packet type */
+#define RXRPC_PACKET_TYPE_DATA		1	/* data */
+#define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
+#define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
+#define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
+#define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
+#define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
+#define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
+#define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
+#define RXRPC_PACKET_TYPE_PARAMS	9	/* Parameter negotiation (unspec'd, ignore) */
+#define RXRPC_PACKET_TYPE_10		10	/* Ignored */
+#define RXRPC_PACKET_TYPE_11		11	/* Ignored */
+#define RXRPC_PACKET_TYPE_VERSION	13	/* version string request */
+
+	uint8_t		flags;		/* packet flags */
+#define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
+#define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
+#define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
+#define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
+#define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
+#define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
+
+	uint8_t		userStatus;	/* app-layer defined status */
+#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01	/* AuriStor service upgrade request */
+	
+	uint8_t		securityIndex;	/* security protocol ID */
+	union {
+		__be16	_rsvd;		/* reserved */
+		__be16	cksum;		/* kerberos security checksum */
+	};
+	__be16		serviceId;	/* service ID */
+
+} __packed;
+
+/*****************************************************************************/
+/*
+ * jumbo packet secondary header
+ * - can be mapped to read header by:
+ *   - new_serial = serial + 1
+ *   - new_seq = seq + 1
+ *   - new_flags = j_flags
+ *   - new__rsvd = j__rsvd
+ *   - duplicating all other fields
+ */
+struct rxrpc_jumbo_header {
+	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
+	uint8_t		pad;
+	union {
+		__be16	_rsvd;		/* reserved */
+		__be16	cksum;		/* kerberos security checksum */
+	};
+};
+
+#define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
+#define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
+
+/*
+ * The maximum number of subpackets that can possibly fit in a UDP packet is:
+ *
+ *	((max_IP - IP_hdr - UDP_hdr) / RXRPC_JUMBO_SUBPKTLEN) + 1
+ *	= ((65535 - 28 - 28) / 1416) + 1
+ *	= 46 non-terminal packets and 1 terminal packet.
+ */
+#define RXRPC_MAX_NR_JUMBO	47
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx ACK packet data payload
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_ackpacket {
+	__be16		bufferSpace;	/* number of packet buffers available */
+	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
+					 * received */
+	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
+	__be32		previousPacket;	/* sequence no of previous packet received */
+	__be32		serial;		/* serial no of packet that prompted this ACK */
+
+	uint8_t		reason;		/* reason for ACK */
+#define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
+#define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
+#define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
+#define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
+#define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
+#define RXRPC_ACK_PING			6	/* keep alive ACK */
+#define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
+#define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
+#define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
+#define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */
+
+	uint8_t		nAcks;		/* number of ACKs */
+#define RXRPC_MAXACKS	255
+
+	uint8_t		acks[0];	/* list of ACK/NAKs */
+#define RXRPC_ACK_TYPE_NACK		0
+#define RXRPC_ACK_TYPE_ACK		1
+
+} __packed;
+
+/* Some ACKs refer to specific packets and some are general and can be updated. */
+#define RXRPC_ACK_UPDATEABLE ((1 << RXRPC_ACK_REQUESTED)	|	\
+			      (1 << RXRPC_ACK_PING_RESPONSE)	|	\
+			      (1 << RXRPC_ACK_DELAY)		|	\
+			      (1 << RXRPC_ACK_IDLE))
+
+
+/*
+ * ACK packets can have a further piece of information tagged on the end
+ */
+struct rxrpc_ackinfo {
+	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
+	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
+	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
+	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
+};
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 challenge packet
+ */
+struct rxkad_challenge {
+	__be32		version;	/* version of this challenge type */
+	__be32		nonce;		/* encrypted random number */
+	__be32		min_level;	/* minimum security level */
+	__be32		__padding;	/* padding to 8-byte boundary */
+} __packed;
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 response packet
+ */
+struct rxkad_response {
+	__be32		version;	/* version of this response type */
+	__be32		__pad;
+
+	/* encrypted bit of the response */
+	struct {
+		__be32		epoch;		/* current epoch */
+		__be32		cid;		/* parent connection ID */
+		__be32		checksum;	/* checksum */
+		__be32		securityIndex;	/* security type */
+		__be32		call_id[4];	/* encrypted call IDs */
+		__be32		inc_nonce;	/* challenge nonce + 1 */
+		__be32		level;		/* desired level */
+	} encrypted;
+
+	__be32		kvno;		/* Kerberos key version number */
+	__be32		ticket_len;	/* Kerberos ticket length  */
+} __packed;
+
+#endif /* _LINUX_RXRPC_PACKET_H */
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
new file mode 100644
index 000000000..787826773
--- /dev/null
+++ b/net/rxrpc/recvmsg.c
@@ -0,0 +1,815 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC recvmsg() implementation
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Post a call for attention by the socket or kernel service.  Further
+ * notifications are suppressed by putting recvmsg_link on a dummy queue.
+ */
+void rxrpc_notify_socket(struct rxrpc_call *call)
+{
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+
+	_enter("%d", call->debug_id);
+
+	if (!list_empty(&call->recvmsg_link))
+		return;
+
+	rcu_read_lock();
+
+	rx = rcu_dereference(call->socket);
+	sk = &rx->sk;
+	if (rx && sk->sk_state < RXRPC_CLOSE) {
+		if (call->notify_rx) {
+			spin_lock_bh(&call->notify_lock);
+			call->notify_rx(sk, call, call->user_call_ID);
+			spin_unlock_bh(&call->notify_lock);
+		} else {
+			write_lock_bh(&rx->recvmsg_lock);
+			if (list_empty(&call->recvmsg_link)) {
+				rxrpc_get_call(call, rxrpc_call_got);
+				list_add_tail(&call->recvmsg_link, &rx->recvmsg_q);
+			}
+			write_unlock_bh(&rx->recvmsg_lock);
+
+			if (!sock_flag(sk, SOCK_DEAD)) {
+				_debug("call %ps", sk->sk_data_ready);
+				sk->sk_data_ready(sk);
+			}
+		}
+	}
+
+	rcu_read_unlock();
+	_leave("");
+}
+
+/*
+ * Transition a call to the complete state.
+ */
+bool __rxrpc_set_call_completion(struct rxrpc_call *call,
+				 enum rxrpc_call_completion compl,
+				 u32 abort_code,
+				 int error)
+{
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		call->abort_code = abort_code;
+		call->error = error;
+		call->completion = compl,
+		call->state = RXRPC_CALL_COMPLETE;
+		trace_rxrpc_call_complete(call);
+		wake_up(&call->waitq);
+		rxrpc_notify_socket(call);
+		return true;
+	}
+	return false;
+}
+
+bool rxrpc_set_call_completion(struct rxrpc_call *call,
+			       enum rxrpc_call_completion compl,
+			       u32 abort_code,
+			       int error)
+{
+	bool ret = false;
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		write_lock_bh(&call->state_lock);
+		ret = __rxrpc_set_call_completion(call, compl, abort_code, error);
+		write_unlock_bh(&call->state_lock);
+	}
+	return ret;
+}
+
+/*
+ * Record that a call successfully completed.
+ */
+bool __rxrpc_call_completed(struct rxrpc_call *call)
+{
+	return __rxrpc_set_call_completion(call, RXRPC_CALL_SUCCEEDED, 0, 0);
+}
+
+bool rxrpc_call_completed(struct rxrpc_call *call)
+{
+	bool ret = false;
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		write_lock_bh(&call->state_lock);
+		ret = __rxrpc_call_completed(call);
+		write_unlock_bh(&call->state_lock);
+	}
+	return ret;
+}
+
+/*
+ * Record that a call is locally aborted.
+ */
+bool __rxrpc_abort_call(const char *why, struct rxrpc_call *call,
+			rxrpc_seq_t seq, u32 abort_code, int error)
+{
+	trace_rxrpc_abort(call->debug_id, why, call->cid, call->call_id, seq,
+			  abort_code, error);
+	return __rxrpc_set_call_completion(call, RXRPC_CALL_LOCALLY_ABORTED,
+					   abort_code, error);
+}
+
+bool rxrpc_abort_call(const char *why, struct rxrpc_call *call,
+		      rxrpc_seq_t seq, u32 abort_code, int error)
+{
+	bool ret;
+
+	write_lock_bh(&call->state_lock);
+	ret = __rxrpc_abort_call(why, call, seq, abort_code, error);
+	write_unlock_bh(&call->state_lock);
+	return ret;
+}
+
+/*
+ * Pass a call terminating message to userspace.
+ */
+static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg)
+{
+	u32 tmp = 0;
+	int ret;
+
+	switch (call->completion) {
+	case RXRPC_CALL_SUCCEEDED:
+		ret = 0;
+		if (rxrpc_is_service_call(call))
+			ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp);
+		break;
+	case RXRPC_CALL_REMOTELY_ABORTED:
+		tmp = call->abort_code;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
+		break;
+	case RXRPC_CALL_LOCALLY_ABORTED:
+		tmp = call->abort_code;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
+		break;
+	case RXRPC_CALL_NETWORK_ERROR:
+		tmp = -call->error;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp);
+		break;
+	case RXRPC_CALL_LOCAL_ERROR:
+		tmp = -call->error;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp);
+		break;
+	default:
+		pr_err("Invalid terminal call state %u\n", call->state);
+		BUG();
+		break;
+	}
+
+	trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack,
+			    call->rx_pkt_offset, call->rx_pkt_len, ret);
+	return ret;
+}
+
+/*
+ * End the packet reception phase.
+ */
+static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
+{
+	_enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]);
+
+	trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top);
+	ASSERTCMP(call->rx_hard_ack, ==, call->rx_top);
+
+	if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) {
+		rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, serial, false, true,
+				  rxrpc_propose_ack_terminal_ack);
+		//rxrpc_send_ack_packet(call, false, NULL);
+	}
+
+	write_lock_bh(&call->state_lock);
+
+	switch (call->state) {
+	case RXRPC_CALL_CLIENT_RECV_REPLY:
+		__rxrpc_call_completed(call);
+		write_unlock_bh(&call->state_lock);
+		break;
+
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+		call->tx_phase = true;
+		call->state = RXRPC_CALL_SERVER_ACK_REQUEST;
+		call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
+		write_unlock_bh(&call->state_lock);
+		rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, false, true,
+				  rxrpc_propose_ack_processing_op);
+		break;
+	default:
+		write_unlock_bh(&call->state_lock);
+		break;
+	}
+}
+
+/*
+ * Discard a packet we've used up and advance the Rx window by one.
+ */
+static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	rxrpc_serial_t serial;
+	rxrpc_seq_t hard_ack, top;
+	bool last = false;
+	u8 subpacket;
+	int ix;
+
+	_enter("%d", call->debug_id);
+
+	hard_ack = call->rx_hard_ack;
+	top = smp_load_acquire(&call->rx_top);
+	ASSERT(before(hard_ack, top));
+
+	hard_ack++;
+	ix = hard_ack & RXRPC_RXTX_BUFF_MASK;
+	skb = call->rxtx_buffer[ix];
+	rxrpc_see_skb(skb, rxrpc_skb_rotated);
+	sp = rxrpc_skb(skb);
+
+	subpacket = call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
+	serial = sp->hdr.serial + subpacket;
+
+	if (subpacket == sp->nr_subpackets - 1 &&
+	    sp->rx_flags & RXRPC_SKB_INCL_LAST)
+		last = true;
+
+	call->rxtx_buffer[ix] = NULL;
+	call->rxtx_annotations[ix] = 0;
+	/* Barrier against rxrpc_input_data(). */
+	smp_store_release(&call->rx_hard_ack, hard_ack);
+
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+
+	trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack);
+	if (last) {
+		rxrpc_end_rx_phase(call, serial);
+	} else {
+		/* Check to see if there's an ACK that needs sending. */
+		if (atomic_inc_return(&call->ackr_nr_consumed) > 2)
+			rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, serial,
+					  true, false,
+					  rxrpc_propose_ack_rotate_rx);
+		if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY)
+			rxrpc_send_ack_packet(call, false, NULL);
+	}
+}
+
+/*
+ * Decrypt and verify a (sub)packet.  The packet's length may be changed due to
+ * padding, but if this is the case, the packet length will be resident in the
+ * socket buffer.  Note that we can't modify the master skb info as the skb may
+ * be the home to multiple subpackets.
+ */
+static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
+			       u8 annotation,
+			       unsigned int offset, unsigned int len)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	rxrpc_seq_t seq = sp->hdr.seq;
+	u16 cksum = sp->hdr.cksum;
+	u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
+
+	_enter("");
+
+	/* For all but the head jumbo subpacket, the security checksum is in a
+	 * jumbo header immediately prior to the data.
+	 */
+	if (subpacket > 0) {
+		__be16 tmp;
+		if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0)
+			BUG();
+		cksum = ntohs(tmp);
+		seq += subpacket;
+	}
+
+	return call->security->verify_packet(call, skb, offset, len,
+					     seq, cksum);
+}
+
+/*
+ * Locate the data within a packet.  This is complicated by:
+ *
+ * (1) An skb may contain a jumbo packet - so we have to find the appropriate
+ *     subpacket.
+ *
+ * (2) The (sub)packets may be encrypted and, if so, the encrypted portion
+ *     contains an extra header which includes the true length of the data,
+ *     excluding any encrypted padding.
+ */
+static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
+			     u8 *_annotation,
+			     unsigned int *_offset, unsigned int *_len,
+			     bool *_last)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
+	unsigned int len;
+	bool last = false;
+	int ret;
+	u8 annotation = *_annotation;
+	u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
+
+	/* Locate the subpacket */
+	offset += subpacket * RXRPC_JUMBO_SUBPKTLEN;
+	len = skb->len - offset;
+	if (subpacket < sp->nr_subpackets - 1)
+		len = RXRPC_JUMBO_DATALEN;
+	else if (sp->rx_flags & RXRPC_SKB_INCL_LAST)
+		last = true;
+
+	if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) {
+		ret = rxrpc_verify_packet(call, skb, annotation, offset, len);
+		if (ret < 0)
+			return ret;
+		*_annotation |= RXRPC_RX_ANNO_VERIFIED;
+	}
+
+	*_offset = offset;
+	*_len = len;
+	*_last = last;
+	call->security->locate_data(call, skb, _offset, _len);
+	return 0;
+}
+
+/*
+ * Deliver messages to a call.  This keeps processing packets until the buffer
+ * is filled and we find either more DATA (returns 0) or the end of the DATA
+ * (returns 1).  If more packets are required, it returns -EAGAIN.
+ */
+static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
+			      struct msghdr *msg, struct iov_iter *iter,
+			      size_t len, int flags, size_t *_offset)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	rxrpc_serial_t serial;
+	rxrpc_seq_t hard_ack, top, seq;
+	size_t remain;
+	bool rx_pkt_last;
+	unsigned int rx_pkt_offset, rx_pkt_len;
+	int ix, copy, ret = -EAGAIN, ret2;
+
+	if (test_and_clear_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags) &&
+	    call->ackr_reason)
+		rxrpc_send_ack_packet(call, false, NULL);
+
+	rx_pkt_offset = call->rx_pkt_offset;
+	rx_pkt_len = call->rx_pkt_len;
+	rx_pkt_last = call->rx_pkt_last;
+
+	if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) {
+		seq = call->rx_hard_ack;
+		ret = 1;
+		goto done;
+	}
+
+	/* Barriers against rxrpc_input_data(). */
+	hard_ack = call->rx_hard_ack;
+	seq = hard_ack + 1;
+
+	while (top = smp_load_acquire(&call->rx_top),
+	       before_eq(seq, top)
+	       ) {
+		ix = seq & RXRPC_RXTX_BUFF_MASK;
+		skb = call->rxtx_buffer[ix];
+		if (!skb) {
+			trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq,
+					    rx_pkt_offset, rx_pkt_len, 0);
+			break;
+		}
+		smp_rmb();
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+		sp = rxrpc_skb(skb);
+
+		if (!(flags & MSG_PEEK)) {
+			serial = sp->hdr.serial;
+			serial += call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
+			trace_rxrpc_receive(call, rxrpc_receive_front,
+					    serial, seq);
+		}
+
+		if (msg)
+			sock_recv_timestamp(msg, sock->sk, skb);
+
+		if (rx_pkt_offset == 0) {
+			ret2 = rxrpc_locate_data(call, skb,
+						 &call->rxtx_annotations[ix],
+						 &rx_pkt_offset, &rx_pkt_len,
+						 &rx_pkt_last);
+			trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq,
+					    rx_pkt_offset, rx_pkt_len, ret2);
+			if (ret2 < 0) {
+				ret = ret2;
+				goto out;
+			}
+		} else {
+			trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq,
+					    rx_pkt_offset, rx_pkt_len, 0);
+		}
+
+		/* We have to handle short, empty and used-up DATA packets. */
+		remain = len - *_offset;
+		copy = rx_pkt_len;
+		if (copy > remain)
+			copy = remain;
+		if (copy > 0) {
+			ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter,
+						      copy);
+			if (ret2 < 0) {
+				ret = ret2;
+				goto out;
+			}
+
+			/* handle piecemeal consumption of data packets */
+			rx_pkt_offset += copy;
+			rx_pkt_len -= copy;
+			*_offset += copy;
+		}
+
+		if (rx_pkt_len > 0) {
+			trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq,
+					    rx_pkt_offset, rx_pkt_len, 0);
+			ASSERTCMP(*_offset, ==, len);
+			ret = 0;
+			break;
+		}
+
+		/* The whole packet has been transferred. */
+		if (!(flags & MSG_PEEK))
+			rxrpc_rotate_rx_window(call);
+		rx_pkt_offset = 0;
+		rx_pkt_len = 0;
+
+		if (rx_pkt_last) {
+			ASSERTCMP(seq, ==, READ_ONCE(call->rx_top));
+			ret = 1;
+			goto out;
+		}
+
+		seq++;
+	}
+
+out:
+	if (!(flags & MSG_PEEK)) {
+		call->rx_pkt_offset = rx_pkt_offset;
+		call->rx_pkt_len = rx_pkt_len;
+		call->rx_pkt_last = rx_pkt_last;
+	}
+done:
+	trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq,
+			    rx_pkt_offset, rx_pkt_len, ret);
+	if (ret == -EAGAIN)
+		set_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags);
+	return ret;
+}
+
+/*
+ * Receive a message from an RxRPC socket
+ * - we need to be careful about two or more threads calling recvmsg
+ *   simultaneously
+ */
+int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		  int flags)
+{
+	struct rxrpc_call *call;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct list_head *l;
+	size_t copied = 0;
+	long timeo;
+	int ret;
+
+	DEFINE_WAIT(wait);
+
+	trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0);
+
+	if (flags & (MSG_OOB | MSG_TRUNC))
+		return -EOPNOTSUPP;
+
+	timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
+
+try_again:
+	lock_sock(&rx->sk);
+
+	/* Return immediately if a client socket has no outstanding calls */
+	if (RB_EMPTY_ROOT(&rx->calls) &&
+	    list_empty(&rx->recvmsg_q) &&
+	    rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
+		release_sock(&rx->sk);
+		return -EAGAIN;
+	}
+
+	if (list_empty(&rx->recvmsg_q)) {
+		ret = -EWOULDBLOCK;
+		if (timeo == 0) {
+			call = NULL;
+			goto error_no_call;
+		}
+
+		release_sock(&rx->sk);
+
+		/* Wait for something to happen */
+		prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
+					  TASK_INTERRUPTIBLE);
+		ret = sock_error(&rx->sk);
+		if (ret)
+			goto wait_error;
+
+		if (list_empty(&rx->recvmsg_q)) {
+			if (signal_pending(current))
+				goto wait_interrupted;
+			trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait,
+					    0, 0, 0, 0);
+			timeo = schedule_timeout(timeo);
+		}
+		finish_wait(sk_sleep(&rx->sk), &wait);
+		goto try_again;
+	}
+
+	/* Find the next call and dequeue it if we're not just peeking.  If we
+	 * do dequeue it, that comes with a ref that we will need to release.
+	 */
+	write_lock_bh(&rx->recvmsg_lock);
+	l = rx->recvmsg_q.next;
+	call = list_entry(l, struct rxrpc_call, recvmsg_link);
+	if (!(flags & MSG_PEEK))
+		list_del_init(&call->recvmsg_link);
+	else
+		rxrpc_get_call(call, rxrpc_call_got);
+	write_unlock_bh(&rx->recvmsg_lock);
+
+	trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0);
+
+	/* We're going to drop the socket lock, so we need to lock the call
+	 * against interference by sendmsg.
+	 */
+	if (!mutex_trylock(&call->user_mutex)) {
+		ret = -EWOULDBLOCK;
+		if (flags & MSG_DONTWAIT)
+			goto error_requeue_call;
+		ret = -ERESTARTSYS;
+		if (mutex_lock_interruptible(&call->user_mutex) < 0)
+			goto error_requeue_call;
+	}
+
+	release_sock(&rx->sk);
+
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
+		BUG();
+
+	if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+		if (flags & MSG_CMSG_COMPAT) {
+			unsigned int id32 = call->user_call_ID;
+
+			ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
+				       sizeof(unsigned int), &id32);
+		} else {
+			unsigned long idl = call->user_call_ID;
+
+			ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
+				       sizeof(unsigned long), &idl);
+		}
+		if (ret < 0)
+			goto error_unlock_call;
+	}
+
+	if (msg->msg_name && call->peer) {
+		struct sockaddr_rxrpc *srx = msg->msg_name;
+		size_t len = sizeof(call->peer->srx);
+
+		memcpy(msg->msg_name, &call->peer->srx, len);
+		srx->srx_service = call->service_id;
+		msg->msg_namelen = len;
+	}
+
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_CLIENT_RECV_REPLY:
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+	case RXRPC_CALL_SERVER_ACK_REQUEST:
+		ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len,
+					 flags, &copied);
+		if (ret == -EAGAIN)
+			ret = 0;
+
+		if (after(call->rx_top, call->rx_hard_ack) &&
+		    call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK])
+			rxrpc_notify_socket(call);
+		break;
+	default:
+		ret = 0;
+		break;
+	}
+
+	if (ret < 0)
+		goto error_unlock_call;
+
+	if (call->state == RXRPC_CALL_COMPLETE) {
+		ret = rxrpc_recvmsg_term(call, msg);
+		if (ret < 0)
+			goto error_unlock_call;
+		if (!(flags & MSG_PEEK))
+			rxrpc_release_call(rx, call);
+		msg->msg_flags |= MSG_EOR;
+		ret = 1;
+	}
+
+	if (ret == 0)
+		msg->msg_flags |= MSG_MORE;
+	else
+		msg->msg_flags &= ~MSG_MORE;
+	ret = copied;
+
+error_unlock_call:
+	mutex_unlock(&call->user_mutex);
+	rxrpc_put_call(call, rxrpc_call_put);
+	trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret);
+	return ret;
+
+error_requeue_call:
+	if (!(flags & MSG_PEEK)) {
+		write_lock_bh(&rx->recvmsg_lock);
+		list_add(&call->recvmsg_link, &rx->recvmsg_q);
+		write_unlock_bh(&rx->recvmsg_lock);
+		trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0);
+	} else {
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+error_no_call:
+	release_sock(&rx->sk);
+error_trace:
+	trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret);
+	return ret;
+
+wait_interrupted:
+	ret = sock_intr_errno(timeo);
+wait_error:
+	finish_wait(sk_sleep(&rx->sk), &wait);
+	call = NULL;
+	goto error_trace;
+}
+
+/**
+ * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
+ * @sock: The socket that the call exists on
+ * @call: The call to send data through
+ * @iter: The buffer to receive into
+ * @want_more: True if more data is expected to be read
+ * @_abort: Where the abort code is stored if -ECONNABORTED is returned
+ * @_service: Where to store the actual service ID (may be upgraded)
+ *
+ * Allow a kernel service to receive data and pick up information about the
+ * state of a call.  Returns 0 if got what was asked for and there's more
+ * available, 1 if we got what was asked for and we're at the end of the data
+ * and -EAGAIN if we need more data.
+ *
+ * Note that we may return -EAGAIN to drain empty packets at the end of the
+ * data, even if we've already copied over the requested data.
+ *
+ * *_abort should also be initialised to 0.
+ */
+int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
+			   struct iov_iter *iter,
+			   bool want_more, u32 *_abort, u16 *_service)
+{
+	size_t offset = 0;
+	int ret;
+
+	_enter("{%d,%s},%zu,%d",
+	       call->debug_id, rxrpc_call_states[call->state],
+	       iov_iter_count(iter), want_more);
+
+	ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_SECURING);
+
+	mutex_lock(&call->user_mutex);
+
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_CLIENT_RECV_REPLY:
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+	case RXRPC_CALL_SERVER_ACK_REQUEST:
+		ret = rxrpc_recvmsg_data(sock, call, NULL, iter,
+					 iov_iter_count(iter), 0,
+					 &offset);
+		if (ret < 0)
+			goto out;
+
+		/* We can only reach here with a partially full buffer if we
+		 * have reached the end of the data.  We must otherwise have a
+		 * full buffer or have been given -EAGAIN.
+		 */
+		if (ret == 1) {
+			if (iov_iter_count(iter) > 0)
+				goto short_data;
+			if (!want_more)
+				goto read_phase_complete;
+			ret = 0;
+			goto out;
+		}
+
+		if (!want_more)
+			goto excess_data;
+		goto out;
+
+	case RXRPC_CALL_COMPLETE:
+		goto call_complete;
+
+	default:
+		ret = -EINPROGRESS;
+		goto out;
+	}
+
+read_phase_complete:
+	ret = 1;
+out:
+	switch (call->ackr_reason) {
+	case RXRPC_ACK_IDLE:
+		break;
+	case RXRPC_ACK_DELAY:
+		if (ret != -EAGAIN)
+			break;
+		fallthrough;
+	default:
+		rxrpc_send_ack_packet(call, false, NULL);
+	}
+
+	if (_service)
+		*_service = call->service_id;
+	mutex_unlock(&call->user_mutex);
+	_leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
+	return ret;
+
+short_data:
+	trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data"));
+	ret = -EBADMSG;
+	goto out;
+excess_data:
+	trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data"));
+	ret = -EMSGSIZE;
+	goto out;
+call_complete:
+	*_abort = call->abort_code;
+	ret = call->error;
+	if (call->completion == RXRPC_CALL_SUCCEEDED) {
+		ret = 1;
+		if (iov_iter_count(iter) > 0)
+			ret = -ECONNRESET;
+	}
+	goto out;
+}
+EXPORT_SYMBOL(rxrpc_kernel_recv_data);
+
+/**
+ * rxrpc_kernel_get_reply_time - Get timestamp on first reply packet
+ * @sock: The socket that the call exists on
+ * @call: The call to query
+ * @_ts: Where to put the timestamp
+ *
+ * Retrieve the timestamp from the first DATA packet of the reply if it is
+ * in the ring.  Returns true if successful, false if not.
+ */
+bool rxrpc_kernel_get_reply_time(struct socket *sock, struct rxrpc_call *call,
+				 ktime_t *_ts)
+{
+	struct sk_buff *skb;
+	rxrpc_seq_t hard_ack, top, seq;
+	bool success = false;
+
+	mutex_lock(&call->user_mutex);
+
+	if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_RECV_REPLY)
+		goto out;
+
+	hard_ack = call->rx_hard_ack;
+	if (hard_ack != 0)
+		goto out;
+
+	seq = hard_ack + 1;
+	top = smp_load_acquire(&call->rx_top);
+	if (after(seq, top))
+		goto out;
+
+	skb = call->rxtx_buffer[seq & RXRPC_RXTX_BUFF_MASK];
+	if (!skb)
+		goto out;
+
+	*_ts = skb_get_ktime(skb);
+	success = true;
+
+out:
+	mutex_unlock(&call->user_mutex);
+	return success;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_reply_time);
diff --git a/net/rxrpc/rtt.c b/net/rxrpc/rtt.c
new file mode 100644
index 000000000..be61d6f5b
--- /dev/null
+++ b/net/rxrpc/rtt.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/* RTT/RTO calculation.
+ *
+ * Adapted from TCP for AF_RXRPC by David Howells (dhowells@redhat.com)
+ *
+ * https://tools.ietf.org/html/rfc6298
+ * https://tools.ietf.org/html/rfc1122#section-4.2.3.1
+ * http://ccr.sigcomm.org/archive/1995/jan95/ccr-9501-partridge87.pdf
+ */
+
+#include <linux/net.h>
+#include "ar-internal.h"
+
+#define RXRPC_RTO_MAX	((unsigned)(120 * HZ))
+#define RXRPC_TIMEOUT_INIT ((unsigned)(1*HZ))	/* RFC6298 2.1 initial RTO value	*/
+#define rxrpc_jiffies32 ((u32)jiffies)		/* As rxrpc_jiffies32 */
+
+static u32 rxrpc_rto_min_us(struct rxrpc_peer *peer)
+{
+	return 200;
+}
+
+static u32 __rxrpc_set_rto(const struct rxrpc_peer *peer)
+{
+	return usecs_to_jiffies((peer->srtt_us >> 3) + peer->rttvar_us);
+}
+
+static u32 rxrpc_bound_rto(u32 rto)
+{
+	return min(rto, RXRPC_RTO_MAX);
+}
+
+/*
+ * Called to compute a smoothed rtt estimate. The data fed to this
+ * routine either comes from timestamps, or from segments that were
+ * known _not_ to have been retransmitted [see Karn/Partridge
+ * Proceedings SIGCOMM 87]. The algorithm is from the SIGCOMM 88
+ * piece by Van Jacobson.
+ * NOTE: the next three routines used to be one big routine.
+ * To save cycles in the RFC 1323 implementation it was better to break
+ * it up into three procedures. -- erics
+ */
+static void rxrpc_rtt_estimator(struct rxrpc_peer *peer, long sample_rtt_us)
+{
+	long m = sample_rtt_us; /* RTT */
+	u32 srtt = peer->srtt_us;
+
+	/*	The following amusing code comes from Jacobson's
+	 *	article in SIGCOMM '88.  Note that rtt and mdev
+	 *	are scaled versions of rtt and mean deviation.
+	 *	This is designed to be as fast as possible
+	 *	m stands for "measurement".
+	 *
+	 *	On a 1990 paper the rto value is changed to:
+	 *	RTO = rtt + 4 * mdev
+	 *
+	 * Funny. This algorithm seems to be very broken.
+	 * These formulae increase RTO, when it should be decreased, increase
+	 * too slowly, when it should be increased quickly, decrease too quickly
+	 * etc. I guess in BSD RTO takes ONE value, so that it is absolutely
+	 * does not matter how to _calculate_ it. Seems, it was trap
+	 * that VJ failed to avoid. 8)
+	 */
+	if (srtt != 0) {
+		m -= (srtt >> 3);	/* m is now error in rtt est */
+		srtt += m;		/* rtt = 7/8 rtt + 1/8 new */
+		if (m < 0) {
+			m = -m;		/* m is now abs(error) */
+			m -= (peer->mdev_us >> 2);   /* similar update on mdev */
+			/* This is similar to one of Eifel findings.
+			 * Eifel blocks mdev updates when rtt decreases.
+			 * This solution is a bit different: we use finer gain
+			 * for mdev in this case (alpha*beta).
+			 * Like Eifel it also prevents growth of rto,
+			 * but also it limits too fast rto decreases,
+			 * happening in pure Eifel.
+			 */
+			if (m > 0)
+				m >>= 3;
+		} else {
+			m -= (peer->mdev_us >> 2);   /* similar update on mdev */
+		}
+
+		peer->mdev_us += m;		/* mdev = 3/4 mdev + 1/4 new */
+		if (peer->mdev_us > peer->mdev_max_us) {
+			peer->mdev_max_us = peer->mdev_us;
+			if (peer->mdev_max_us > peer->rttvar_us)
+				peer->rttvar_us = peer->mdev_max_us;
+		}
+	} else {
+		/* no previous measure. */
+		srtt = m << 3;		/* take the measured time to be rtt */
+		peer->mdev_us = m << 1;	/* make sure rto = 3*rtt */
+		peer->rttvar_us = max(peer->mdev_us, rxrpc_rto_min_us(peer));
+		peer->mdev_max_us = peer->rttvar_us;
+	}
+
+	peer->srtt_us = max(1U, srtt);
+}
+
+/*
+ * Calculate rto without backoff.  This is the second half of Van Jacobson's
+ * routine referred to above.
+ */
+static void rxrpc_set_rto(struct rxrpc_peer *peer)
+{
+	u32 rto;
+
+	/* 1. If rtt variance happened to be less 50msec, it is hallucination.
+	 *    It cannot be less due to utterly erratic ACK generation made
+	 *    at least by solaris and freebsd. "Erratic ACKs" has _nothing_
+	 *    to do with delayed acks, because at cwnd>2 true delack timeout
+	 *    is invisible. Actually, Linux-2.4 also generates erratic
+	 *    ACKs in some circumstances.
+	 */
+	rto = __rxrpc_set_rto(peer);
+
+	/* 2. Fixups made earlier cannot be right.
+	 *    If we do not estimate RTO correctly without them,
+	 *    all the algo is pure shit and should be replaced
+	 *    with correct one. It is exactly, which we pretend to do.
+	 */
+
+	/* NOTE: clamping at RXRPC_RTO_MIN is not required, current algo
+	 * guarantees that rto is higher.
+	 */
+	peer->rto_j = rxrpc_bound_rto(rto);
+}
+
+static void rxrpc_ack_update_rtt(struct rxrpc_peer *peer, long rtt_us)
+{
+	if (rtt_us < 0)
+		return;
+
+	//rxrpc_update_rtt_min(peer, rtt_us);
+	rxrpc_rtt_estimator(peer, rtt_us);
+	rxrpc_set_rto(peer);
+
+	/* RFC6298: only reset backoff on valid RTT measurement. */
+	peer->backoff = 0;
+}
+
+/*
+ * Add RTT information to cache.  This is called in softirq mode and has
+ * exclusive access to the peer RTT data.
+ */
+void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
+			int rtt_slot,
+			rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial,
+			ktime_t send_time, ktime_t resp_time)
+{
+	struct rxrpc_peer *peer = call->peer;
+	s64 rtt_us;
+
+	rtt_us = ktime_to_us(ktime_sub(resp_time, send_time));
+	if (rtt_us < 0)
+		return;
+
+	spin_lock(&peer->rtt_input_lock);
+	rxrpc_ack_update_rtt(peer, rtt_us);
+	if (peer->rtt_count < 3)
+		peer->rtt_count++;
+	spin_unlock(&peer->rtt_input_lock);
+
+	trace_rxrpc_rtt_rx(call, why, rtt_slot, send_serial, resp_serial,
+			   peer->srtt_us >> 3, peer->rto_j);
+}
+
+/*
+ * Get the retransmission timeout to set in jiffies, backing it off each time
+ * we retransmit.
+ */
+unsigned long rxrpc_get_rto_backoff(struct rxrpc_peer *peer, bool retrans)
+{
+	u64 timo_j;
+	u8 backoff = READ_ONCE(peer->backoff);
+
+	timo_j = peer->rto_j;
+	timo_j <<= backoff;
+	if (retrans && timo_j * 2 <= RXRPC_RTO_MAX)
+		WRITE_ONCE(peer->backoff, backoff + 1);
+
+	if (timo_j < 1)
+		timo_j = 1;
+
+	return timo_j;
+}
+
+void rxrpc_peer_init_rtt(struct rxrpc_peer *peer)
+{
+	peer->rto_j	= RXRPC_TIMEOUT_INIT;
+	peer->mdev_us	= jiffies_to_usecs(RXRPC_TIMEOUT_INIT);
+	peer->backoff	= 0;
+	//minmax_reset(&peer->rtt_min, rxrpc_jiffies32, ~0U);
+}
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
new file mode 100644
index 000000000..5345e8eef
--- /dev/null
+++ b/net/rxrpc/rxkad.c
@@ -0,0 +1,1309 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Kerberos-based RxRPC security
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/scatterlist.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+
+#define RXKAD_VERSION			2
+#define MAXKRB5TICKETLEN		1024
+#define RXKAD_TKT_TYPE_KERBEROS_V5	256
+#define ANAME_SZ			40	/* size of authentication name */
+#define INST_SZ				40	/* size of principal's instance */
+#define REALM_SZ			40	/* size of principal's auth domain */
+#define SNAME_SZ			40	/* size of service name */
+
+struct rxkad_level1_hdr {
+	__be32	data_size;	/* true data size (excluding padding) */
+};
+
+struct rxkad_level2_hdr {
+	__be32	data_size;	/* true data size (excluding padding) */
+	__be32	checksum;	/* decrypted data checksum */
+};
+
+/*
+ * this holds a pinned cipher so that keventd doesn't get called by the cipher
+ * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
+ * packets
+ */
+static struct crypto_sync_skcipher *rxkad_ci;
+static struct skcipher_request *rxkad_ci_req;
+static DEFINE_MUTEX(rxkad_ci_mutex);
+
+/*
+ * initialise connection security
+ */
+static int rxkad_init_connection_security(struct rxrpc_connection *conn)
+{
+	struct crypto_sync_skcipher *ci;
+	struct rxrpc_key_token *token;
+	int ret;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
+
+	token = conn->params.key->payload.data[0];
+	conn->security_ix = token->security_index;
+
+	ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
+	if (IS_ERR(ci)) {
+		_debug("no cipher");
+		ret = PTR_ERR(ci);
+		goto error;
+	}
+
+	if (crypto_sync_skcipher_setkey(ci, token->kad->session_key,
+				   sizeof(token->kad->session_key)) < 0)
+		BUG();
+
+	switch (conn->params.security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		break;
+	case RXRPC_SECURITY_AUTH:
+		conn->size_align = 8;
+		conn->security_size = sizeof(struct rxkad_level1_hdr);
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		conn->size_align = 8;
+		conn->security_size = sizeof(struct rxkad_level2_hdr);
+		break;
+	default:
+		ret = -EKEYREJECTED;
+		goto error;
+	}
+
+	conn->cipher = ci;
+	ret = 0;
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * prime the encryption state with the invariant parts of a connection's
+ * description
+ */
+static int rxkad_prime_packet_security(struct rxrpc_connection *conn)
+{
+	struct skcipher_request *req;
+	struct rxrpc_key_token *token;
+	struct scatterlist sg;
+	struct rxrpc_crypt iv;
+	__be32 *tmpbuf;
+	size_t tmpsize = 4 * sizeof(__be32);
+
+	_enter("");
+
+	if (!conn->params.key)
+		return 0;
+
+	tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
+	if (!tmpbuf)
+		return -ENOMEM;
+
+	req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS);
+	if (!req) {
+		kfree(tmpbuf);
+		return -ENOMEM;
+	}
+
+	token = conn->params.key->payload.data[0];
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
+
+	tmpbuf[0] = htonl(conn->proto.epoch);
+	tmpbuf[1] = htonl(conn->proto.cid);
+	tmpbuf[2] = 0;
+	tmpbuf[3] = htonl(conn->security_ix);
+
+	sg_init_one(&sg, tmpbuf, tmpsize);
+	skcipher_request_set_sync_tfm(req, conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
+	crypto_skcipher_encrypt(req);
+	skcipher_request_free(req);
+
+	memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv));
+	kfree(tmpbuf);
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Allocate and prepare the crypto request on a call.  For any particular call,
+ * this is called serially for the packets, so no lock should be necessary.
+ */
+static struct skcipher_request *rxkad_get_call_crypto(struct rxrpc_call *call)
+{
+	struct crypto_skcipher *tfm = &call->conn->cipher->base;
+	struct skcipher_request	*cipher_req = call->cipher_req;
+
+	if (!cipher_req) {
+		cipher_req = skcipher_request_alloc(tfm, GFP_NOFS);
+		if (!cipher_req)
+			return NULL;
+		call->cipher_req = cipher_req;
+	}
+
+	return cipher_req;
+}
+
+/*
+ * Clean up the crypto on a call.
+ */
+static void rxkad_free_call_crypto(struct rxrpc_call *call)
+{
+	if (call->cipher_req)
+		skcipher_request_free(call->cipher_req);
+	call->cipher_req = NULL;
+}
+
+/*
+ * partially encrypt a packet (level 1 security)
+ */
+static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
+				    struct sk_buff *skb,
+				    u32 data_size,
+				    void *sechdr,
+				    struct skcipher_request *req)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxkad_level1_hdr hdr;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg;
+	u16 check;
+
+	_enter("");
+
+	check = sp->hdr.seq ^ call->call_id;
+	data_size |= (u32)check << 16;
+
+	hdr.data_size = htonl(data_size);
+	memcpy(sechdr, &hdr, sizeof(hdr));
+
+	/* start the encryption afresh */
+	memset(&iv, 0, sizeof(iv));
+
+	sg_init_one(&sg, sechdr, 8);
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
+	crypto_skcipher_encrypt(req);
+	skcipher_request_zero(req);
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * wholly encrypt a packet (level 2 security)
+ */
+static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
+				       struct sk_buff *skb,
+				       u32 data_size,
+				       void *sechdr,
+				       struct skcipher_request *req)
+{
+	const struct rxrpc_key_token *token;
+	struct rxkad_level2_hdr rxkhdr;
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg[16];
+	unsigned int len;
+	u16 check;
+	int err;
+
+	sp = rxrpc_skb(skb);
+
+	_enter("");
+
+	check = sp->hdr.seq ^ call->call_id;
+
+	rxkhdr.data_size = htonl(data_size | (u32)check << 16);
+	rxkhdr.checksum = 0;
+	memcpy(sechdr, &rxkhdr, sizeof(rxkhdr));
+
+	/* encrypt from the session key */
+	token = call->conn->params.key->payload.data[0];
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
+
+	sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
+	crypto_skcipher_encrypt(req);
+
+	/* we want to encrypt the skbuff in-place */
+	err = -EMSGSIZE;
+	if (skb_shinfo(skb)->nr_frags > 16)
+		goto out;
+
+	len = data_size + call->conn->size_align - 1;
+	len &= ~(call->conn->size_align - 1);
+
+	sg_init_table(sg, ARRAY_SIZE(sg));
+	err = skb_to_sgvec(skb, sg, 0, len);
+	if (unlikely(err < 0))
+		goto out;
+	skcipher_request_set_crypt(req, sg, sg, len, iv.x);
+	crypto_skcipher_encrypt(req);
+
+	_leave(" = 0");
+	err = 0;
+
+out:
+	skcipher_request_zero(req);
+	return err;
+}
+
+/*
+ * checksum an RxRPC packet header
+ */
+static int rxkad_secure_packet(struct rxrpc_call *call,
+			       struct sk_buff *skb,
+			       size_t data_size,
+			       void *sechdr)
+{
+	struct rxrpc_skb_priv *sp;
+	struct skcipher_request	*req;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg;
+	u32 x, y;
+	int ret;
+
+	sp = rxrpc_skb(skb);
+
+	_enter("{%d{%x}},{#%u},%zu,",
+	       call->debug_id, key_serial(call->conn->params.key),
+	       sp->hdr.seq, data_size);
+
+	if (!call->conn->cipher)
+		return 0;
+
+	ret = key_validate(call->conn->params.key);
+	if (ret < 0)
+		return ret;
+
+	req = rxkad_get_call_crypto(call);
+	if (!req)
+		return -ENOMEM;
+
+	/* continue encrypting from where we left off */
+	memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
+
+	/* calculate the security checksum */
+	x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
+	x |= sp->hdr.seq & 0x3fffffff;
+	call->crypto_buf[0] = htonl(call->call_id);
+	call->crypto_buf[1] = htonl(x);
+
+	sg_init_one(&sg, call->crypto_buf, 8);
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
+	crypto_skcipher_encrypt(req);
+	skcipher_request_zero(req);
+
+	y = ntohl(call->crypto_buf[1]);
+	y = (y >> 16) & 0xffff;
+	if (y == 0)
+		y = 1; /* zero checksums are not permitted */
+	sp->hdr.cksum = y;
+
+	switch (call->conn->params.security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		ret = 0;
+		break;
+	case RXRPC_SECURITY_AUTH:
+		ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr,
+					       req);
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		ret = rxkad_secure_packet_encrypt(call, skb, data_size,
+						  sechdr, req);
+		break;
+	default:
+		ret = -EPERM;
+		break;
+	}
+
+	_leave(" = %d [set %hx]", ret, y);
+	return ret;
+}
+
+/*
+ * decrypt partial encryption on a packet (level 1 security)
+ */
+static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
+				 unsigned int offset, unsigned int len,
+				 rxrpc_seq_t seq,
+				 struct skcipher_request *req)
+{
+	struct rxkad_level1_hdr sechdr;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg[16];
+	bool aborted;
+	u32 data_size, buf;
+	u16 check;
+	int ret;
+
+	_enter("");
+
+	if (len < 8) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
+					   RXKADSEALEDINCON);
+		goto protocol_error;
+	}
+
+	/* Decrypt the skbuff in-place.  TODO: We really want to decrypt
+	 * directly into the target buffer.
+	 */
+	sg_init_table(sg, ARRAY_SIZE(sg));
+	ret = skb_to_sgvec(skb, sg, offset, 8);
+	if (unlikely(ret < 0))
+		return ret;
+
+	/* start the decryption afresh */
+	memset(&iv, 0, sizeof(iv));
+
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
+	crypto_skcipher_decrypt(req);
+	skcipher_request_zero(req);
+
+	/* Extract the decrypted packet length */
+	if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
+					     RXKADDATALEN);
+		goto protocol_error;
+	}
+	offset += sizeof(sechdr);
+	len -= sizeof(sechdr);
+
+	buf = ntohl(sechdr.data_size);
+	data_size = buf & 0xffff;
+
+	check = buf >> 16;
+	check ^= seq ^ call->call_id;
+	check &= 0xffff;
+	if (check != 0) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
+					     RXKADSEALEDINCON);
+		goto protocol_error;
+	}
+
+	if (data_size > len) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
+					     RXKADDATALEN);
+		goto protocol_error;
+	}
+
+	_leave(" = 0 [dlen=%x]", data_size);
+	return 0;
+
+protocol_error:
+	if (aborted)
+		rxrpc_send_abort_packet(call);
+	return -EPROTO;
+}
+
+/*
+ * wholly decrypt a packet (level 2 security)
+ */
+static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
+				 unsigned int offset, unsigned int len,
+				 rxrpc_seq_t seq,
+				 struct skcipher_request *req)
+{
+	const struct rxrpc_key_token *token;
+	struct rxkad_level2_hdr sechdr;
+	struct rxrpc_crypt iv;
+	struct scatterlist _sg[4], *sg;
+	bool aborted;
+	u32 data_size, buf;
+	u16 check;
+	int nsg, ret;
+
+	_enter(",{%d}", skb->len);
+
+	if (len < 8) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
+					     RXKADSEALEDINCON);
+		goto protocol_error;
+	}
+
+	/* Decrypt the skbuff in-place.  TODO: We really want to decrypt
+	 * directly into the target buffer.
+	 */
+	sg = _sg;
+	nsg = skb_shinfo(skb)->nr_frags + 1;
+	if (nsg <= 4) {
+		nsg = 4;
+	} else {
+		sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO);
+		if (!sg)
+			goto nomem;
+	}
+
+	sg_init_table(sg, nsg);
+	ret = skb_to_sgvec(skb, sg, offset, len);
+	if (unlikely(ret < 0)) {
+		if (sg != _sg)
+			kfree(sg);
+		return ret;
+	}
+
+	/* decrypt from the session key */
+	token = call->conn->params.key->payload.data[0];
+	memcpy(&iv, token->kad->session_key, sizeof(iv));
+
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sg, sg, len, iv.x);
+	crypto_skcipher_decrypt(req);
+	skcipher_request_zero(req);
+	if (sg != _sg)
+		kfree(sg);
+
+	/* Extract the decrypted packet length */
+	if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
+					     RXKADDATALEN);
+		goto protocol_error;
+	}
+	offset += sizeof(sechdr);
+	len -= sizeof(sechdr);
+
+	buf = ntohl(sechdr.data_size);
+	data_size = buf & 0xffff;
+
+	check = buf >> 16;
+	check ^= seq ^ call->call_id;
+	check &= 0xffff;
+	if (check != 0) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
+					     RXKADSEALEDINCON);
+		goto protocol_error;
+	}
+
+	if (data_size > len) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
+					     RXKADDATALEN);
+		goto protocol_error;
+	}
+
+	_leave(" = 0 [dlen=%x]", data_size);
+	return 0;
+
+protocol_error:
+	if (aborted)
+		rxrpc_send_abort_packet(call);
+	return -EPROTO;
+
+nomem:
+	_leave(" = -ENOMEM");
+	return -ENOMEM;
+}
+
+/*
+ * Verify the security on a received packet or subpacket (if part of a
+ * jumbo packet).
+ */
+static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
+			       unsigned int offset, unsigned int len,
+			       rxrpc_seq_t seq, u16 expected_cksum)
+{
+	struct skcipher_request	*req;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg;
+	bool aborted;
+	u16 cksum;
+	u32 x, y;
+
+	_enter("{%d{%x}},{#%u}",
+	       call->debug_id, key_serial(call->conn->params.key), seq);
+
+	if (!call->conn->cipher)
+		return 0;
+
+	req = rxkad_get_call_crypto(call);
+	if (!req)
+		return -ENOMEM;
+
+	/* continue encrypting from where we left off */
+	memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
+
+	/* validate the security checksum */
+	x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
+	x |= seq & 0x3fffffff;
+	call->crypto_buf[0] = htonl(call->call_id);
+	call->crypto_buf[1] = htonl(x);
+
+	sg_init_one(&sg, call->crypto_buf, 8);
+	skcipher_request_set_sync_tfm(req, call->conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
+	crypto_skcipher_encrypt(req);
+	skcipher_request_zero(req);
+
+	y = ntohl(call->crypto_buf[1]);
+	cksum = (y >> 16) & 0xffff;
+	if (cksum == 0)
+		cksum = 1; /* zero checksums are not permitted */
+
+	if (cksum != expected_cksum) {
+		aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
+					     RXKADSEALEDINCON);
+		goto protocol_error;
+	}
+
+	switch (call->conn->params.security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		return 0;
+	case RXRPC_SECURITY_AUTH:
+		return rxkad_verify_packet_1(call, skb, offset, len, seq, req);
+	case RXRPC_SECURITY_ENCRYPT:
+		return rxkad_verify_packet_2(call, skb, offset, len, seq, req);
+	default:
+		return -ENOANO;
+	}
+
+protocol_error:
+	if (aborted)
+		rxrpc_send_abort_packet(call);
+	return -EPROTO;
+}
+
+/*
+ * Locate the data contained in a packet that was partially encrypted.
+ */
+static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
+				unsigned int *_offset, unsigned int *_len)
+{
+	struct rxkad_level1_hdr sechdr;
+
+	if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
+		BUG();
+	*_offset += sizeof(sechdr);
+	*_len = ntohl(sechdr.data_size) & 0xffff;
+}
+
+/*
+ * Locate the data contained in a packet that was completely encrypted.
+ */
+static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
+				unsigned int *_offset, unsigned int *_len)
+{
+	struct rxkad_level2_hdr sechdr;
+
+	if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
+		BUG();
+	*_offset += sizeof(sechdr);
+	*_len = ntohl(sechdr.data_size) & 0xffff;
+}
+
+/*
+ * Locate the data contained in an already decrypted packet.
+ */
+static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
+			      unsigned int *_offset, unsigned int *_len)
+{
+	switch (call->conn->params.security_level) {
+	case RXRPC_SECURITY_AUTH:
+		rxkad_locate_data_1(call, skb, _offset, _len);
+		return;
+	case RXRPC_SECURITY_ENCRYPT:
+		rxkad_locate_data_2(call, skb, _offset, _len);
+		return;
+	default:
+		return;
+	}
+}
+
+/*
+ * issue a challenge
+ */
+static int rxkad_issue_challenge(struct rxrpc_connection *conn)
+{
+	struct rxkad_challenge challenge;
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	u32 serial;
+	int ret;
+
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
+
+	ret = key_validate(conn->server_key);
+	if (ret < 0)
+		return ret;
+
+	get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
+
+	challenge.version	= htonl(2);
+	challenge.nonce		= htonl(conn->security_nonce);
+	challenge.min_level	= htonl(0);
+	challenge.__padding	= 0;
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(conn->proto.cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_CHALLENGE;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= &challenge;
+	iov[1].iov_len	= sizeof(challenge);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = atomic_inc_return(&conn->serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx CHALLENGE %%%u", serial);
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_rxkad_challenge);
+		return -EAGAIN;
+	}
+
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	trace_rxrpc_tx_packet(conn->debug_id, &whdr,
+			      rxrpc_tx_point_rxkad_challenge);
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * send a Kerberos security response
+ */
+static int rxkad_send_response(struct rxrpc_connection *conn,
+			       struct rxrpc_host_header *hdr,
+			       struct rxkad_response *resp,
+			       const struct rxkad_key *s2)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t len;
+	u32 serial;
+	int ret;
+
+	_enter("");
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	memset(&whdr, 0, sizeof(whdr));
+	whdr.epoch	= htonl(hdr->epoch);
+	whdr.cid	= htonl(hdr->cid);
+	whdr.type	= RXRPC_PACKET_TYPE_RESPONSE;
+	whdr.flags	= conn->out_clientflag;
+	whdr.securityIndex = hdr->securityIndex;
+	whdr.serviceId	= htons(hdr->serviceId);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= resp;
+	iov[1].iov_len	= sizeof(*resp);
+	iov[2].iov_base	= (void *)s2->ticket;
+	iov[2].iov_len	= s2->ticket_len;
+
+	len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
+
+	serial = atomic_inc_return(&conn->serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx RESPONSE %%%u", serial);
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_rxkad_response);
+		return -EAGAIN;
+	}
+
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * calculate the response checksum
+ */
+static void rxkad_calc_response_checksum(struct rxkad_response *response)
+{
+	u32 csum = 1000003;
+	int loop;
+	u8 *p = (u8 *) response;
+
+	for (loop = sizeof(*response); loop > 0; loop--)
+		csum = csum * 0x10204081 + *p++;
+
+	response->encrypted.checksum = htonl(csum);
+}
+
+/*
+ * encrypt the response packet
+ */
+static int rxkad_encrypt_response(struct rxrpc_connection *conn,
+				  struct rxkad_response *resp,
+				  const struct rxkad_key *s2)
+{
+	struct skcipher_request *req;
+	struct rxrpc_crypt iv;
+	struct scatterlist sg[1];
+
+	req = skcipher_request_alloc(&conn->cipher->base, GFP_NOFS);
+	if (!req)
+		return -ENOMEM;
+
+	/* continue encrypting from where we left off */
+	memcpy(&iv, s2->session_key, sizeof(iv));
+
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
+	skcipher_request_set_sync_tfm(req, conn->cipher);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
+	crypto_skcipher_encrypt(req);
+	skcipher_request_free(req);
+	return 0;
+}
+
+/*
+ * respond to a challenge packet
+ */
+static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
+				      struct sk_buff *skb,
+				      u32 *_abort_code)
+{
+	const struct rxrpc_key_token *token;
+	struct rxkad_challenge challenge;
+	struct rxkad_response *resp;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	const char *eproto;
+	u32 version, nonce, min_level, abort_code;
+	int ret;
+
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
+
+	eproto = tracepoint_string("chall_no_key");
+	abort_code = RX_PROTOCOL_ERROR;
+	if (!conn->params.key)
+		goto protocol_error;
+
+	abort_code = RXKADEXPIRED;
+	ret = key_validate(conn->params.key);
+	if (ret < 0)
+		goto other_error;
+
+	eproto = tracepoint_string("chall_short");
+	abort_code = RXKADPACKETSHORT;
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &challenge, sizeof(challenge)) < 0)
+		goto protocol_error;
+
+	version = ntohl(challenge.version);
+	nonce = ntohl(challenge.nonce);
+	min_level = ntohl(challenge.min_level);
+
+	_proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
+	       sp->hdr.serial, version, nonce, min_level);
+
+	eproto = tracepoint_string("chall_ver");
+	abort_code = RXKADINCONSISTENCY;
+	if (version != RXKAD_VERSION)
+		goto protocol_error;
+
+	abort_code = RXKADLEVELFAIL;
+	ret = -EACCES;
+	if (conn->params.security_level < min_level)
+		goto other_error;
+
+	token = conn->params.key->payload.data[0];
+
+	/* build the response packet */
+	resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
+	if (!resp)
+		return -ENOMEM;
+
+	resp->version			= htonl(RXKAD_VERSION);
+	resp->encrypted.epoch		= htonl(conn->proto.epoch);
+	resp->encrypted.cid		= htonl(conn->proto.cid);
+	resp->encrypted.securityIndex	= htonl(conn->security_ix);
+	resp->encrypted.inc_nonce	= htonl(nonce + 1);
+	resp->encrypted.level		= htonl(conn->params.security_level);
+	resp->kvno			= htonl(token->kad->kvno);
+	resp->ticket_len		= htonl(token->kad->ticket_len);
+	resp->encrypted.call_id[0]	= htonl(conn->channels[0].call_counter);
+	resp->encrypted.call_id[1]	= htonl(conn->channels[1].call_counter);
+	resp->encrypted.call_id[2]	= htonl(conn->channels[2].call_counter);
+	resp->encrypted.call_id[3]	= htonl(conn->channels[3].call_counter);
+
+	/* calculate the response checksum and then do the encryption */
+	rxkad_calc_response_checksum(resp);
+	ret = rxkad_encrypt_response(conn, resp, token->kad);
+	if (ret == 0)
+		ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
+	kfree(resp);
+	return ret;
+
+protocol_error:
+	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+	ret = -EPROTO;
+other_error:
+	*_abort_code = abort_code;
+	return ret;
+}
+
+/*
+ * decrypt the kerberos IV ticket in the response
+ */
+static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
+				struct sk_buff *skb,
+				void *ticket, size_t ticket_len,
+				struct rxrpc_crypt *_session_key,
+				time64_t *_expiry,
+				u32 *_abort_code)
+{
+	struct skcipher_request *req;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_crypt iv, key;
+	struct scatterlist sg[1];
+	struct in_addr addr;
+	unsigned int life;
+	const char *eproto;
+	time64_t issue, now;
+	bool little_endian;
+	int ret;
+	u32 abort_code;
+	u8 *p, *q, *name, *end;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
+
+	*_expiry = 0;
+
+	ret = key_validate(conn->server_key);
+	if (ret < 0) {
+		switch (ret) {
+		case -EKEYEXPIRED:
+			abort_code = RXKADEXPIRED;
+			goto other_error;
+		default:
+			abort_code = RXKADNOAUTH;
+			goto other_error;
+		}
+	}
+
+	ASSERT(conn->server_key->payload.data[0] != NULL);
+	ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
+
+	memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
+
+	ret = -ENOMEM;
+	req = skcipher_request_alloc(conn->server_key->payload.data[0],
+				     GFP_NOFS);
+	if (!req)
+		goto temporary_error;
+
+	sg_init_one(&sg[0], ticket, ticket_len);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
+	crypto_skcipher_decrypt(req);
+	skcipher_request_free(req);
+
+	p = ticket;
+	end = p + ticket_len;
+
+#define Z(field)					\
+	({						\
+		u8 *__str = p;				\
+		eproto = tracepoint_string("rxkad_bad_"#field); \
+		q = memchr(p, 0, end - p);		\
+		if (!q || q - p > (field##_SZ))		\
+			goto bad_ticket;		\
+		for (; p < q; p++)			\
+			if (!isprint(*p))		\
+				goto bad_ticket;	\
+		p++;					\
+		__str;					\
+	})
+
+	/* extract the ticket flags */
+	_debug("KIV FLAGS: %x", *p);
+	little_endian = *p & 1;
+	p++;
+
+	/* extract the authentication name */
+	name = Z(ANAME);
+	_debug("KIV ANAME: %s", name);
+
+	/* extract the principal's instance */
+	name = Z(INST);
+	_debug("KIV INST : %s", name);
+
+	/* extract the principal's authentication domain */
+	name = Z(REALM);
+	_debug("KIV REALM: %s", name);
+
+	eproto = tracepoint_string("rxkad_bad_len");
+	if (end - p < 4 + 8 + 4 + 2)
+		goto bad_ticket;
+
+	/* get the IPv4 address of the entity that requested the ticket */
+	memcpy(&addr, p, sizeof(addr));
+	p += 4;
+	_debug("KIV ADDR : %pI4", &addr);
+
+	/* get the session key from the ticket */
+	memcpy(&key, p, sizeof(key));
+	p += 8;
+	_debug("KIV KEY  : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
+	memcpy(_session_key, &key, sizeof(key));
+
+	/* get the ticket's lifetime */
+	life = *p++ * 5 * 60;
+	_debug("KIV LIFE : %u", life);
+
+	/* get the issue time of the ticket */
+	if (little_endian) {
+		__le32 stamp;
+		memcpy(&stamp, p, 4);
+		issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
+	} else {
+		__be32 stamp;
+		memcpy(&stamp, p, 4);
+		issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
+	}
+	p += 4;
+	now = ktime_get_real_seconds();
+	_debug("KIV ISSUE: %llx [%llx]", issue, now);
+
+	/* check the ticket is in date */
+	if (issue > now) {
+		abort_code = RXKADNOAUTH;
+		ret = -EKEYREJECTED;
+		goto other_error;
+	}
+
+	if (issue < now - life) {
+		abort_code = RXKADEXPIRED;
+		ret = -EKEYEXPIRED;
+		goto other_error;
+	}
+
+	*_expiry = issue + life;
+
+	/* get the service name */
+	name = Z(SNAME);
+	_debug("KIV SNAME: %s", name);
+
+	/* get the service instance name */
+	name = Z(INST);
+	_debug("KIV SINST: %s", name);
+	return 0;
+
+bad_ticket:
+	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+	abort_code = RXKADBADTICKET;
+	ret = -EPROTO;
+other_error:
+	*_abort_code = abort_code;
+	return ret;
+temporary_error:
+	return ret;
+}
+
+/*
+ * decrypt the response packet
+ */
+static void rxkad_decrypt_response(struct rxrpc_connection *conn,
+				   struct rxkad_response *resp,
+				   const struct rxrpc_crypt *session_key)
+{
+	struct skcipher_request *req = rxkad_ci_req;
+	struct scatterlist sg[1];
+	struct rxrpc_crypt iv;
+
+	_enter(",,%08x%08x",
+	       ntohl(session_key->n[0]), ntohl(session_key->n[1]));
+
+	mutex_lock(&rxkad_ci_mutex);
+	if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
+					sizeof(*session_key)) < 0)
+		BUG();
+
+	memcpy(&iv, session_key, sizeof(iv));
+
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
+	skcipher_request_set_sync_tfm(req, rxkad_ci);
+	skcipher_request_set_callback(req, 0, NULL, NULL);
+	skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
+	crypto_skcipher_decrypt(req);
+	skcipher_request_zero(req);
+
+	mutex_unlock(&rxkad_ci_mutex);
+
+	_leave("");
+}
+
+/*
+ * verify a response
+ */
+static int rxkad_verify_response(struct rxrpc_connection *conn,
+				 struct sk_buff *skb,
+				 u32 *_abort_code)
+{
+	struct rxkad_response *response;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_crypt session_key;
+	const char *eproto;
+	time64_t expiry;
+	void *ticket;
+	u32 abort_code, version, kvno, ticket_len, level;
+	__be32 csum;
+	int ret, i;
+
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
+
+	ret = -ENOMEM;
+	response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
+	if (!response)
+		goto temporary_error;
+
+	eproto = tracepoint_string("rxkad_rsp_short");
+	abort_code = RXKADPACKETSHORT;
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  response, sizeof(*response)) < 0)
+		goto protocol_error;
+	if (!pskb_pull(skb, sizeof(*response)))
+		BUG();
+
+	version = ntohl(response->version);
+	ticket_len = ntohl(response->ticket_len);
+	kvno = ntohl(response->kvno);
+	_proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
+	       sp->hdr.serial, version, kvno, ticket_len);
+
+	eproto = tracepoint_string("rxkad_rsp_ver");
+	abort_code = RXKADINCONSISTENCY;
+	if (version != RXKAD_VERSION)
+		goto protocol_error;
+
+	eproto = tracepoint_string("rxkad_rsp_tktlen");
+	abort_code = RXKADTICKETLEN;
+	if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
+		goto protocol_error;
+
+	eproto = tracepoint_string("rxkad_rsp_unkkey");
+	abort_code = RXKADUNKNOWNKEY;
+	if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
+		goto protocol_error;
+
+	/* extract the kerberos ticket and decrypt and decode it */
+	ret = -ENOMEM;
+	ticket = kmalloc(ticket_len, GFP_NOFS);
+	if (!ticket)
+		goto temporary_error_free_resp;
+
+	eproto = tracepoint_string("rxkad_tkt_short");
+	abort_code = RXKADPACKETSHORT;
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  ticket, ticket_len) < 0)
+		goto protocol_error_free;
+
+	ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
+				   &expiry, _abort_code);
+	if (ret < 0)
+		goto temporary_error_free_ticket;
+
+	/* use the session key from inside the ticket to decrypt the
+	 * response */
+	rxkad_decrypt_response(conn, response, &session_key);
+
+	eproto = tracepoint_string("rxkad_rsp_param");
+	abort_code = RXKADSEALEDINCON;
+	if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
+		goto protocol_error_free;
+	if (ntohl(response->encrypted.cid) != conn->proto.cid)
+		goto protocol_error_free;
+	if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
+		goto protocol_error_free;
+	csum = response->encrypted.checksum;
+	response->encrypted.checksum = 0;
+	rxkad_calc_response_checksum(response);
+	eproto = tracepoint_string("rxkad_rsp_csum");
+	if (response->encrypted.checksum != csum)
+		goto protocol_error_free;
+
+	spin_lock(&conn->bundle->channel_lock);
+	for (i = 0; i < RXRPC_MAXCALLS; i++) {
+		struct rxrpc_call *call;
+		u32 call_id = ntohl(response->encrypted.call_id[i]);
+
+		eproto = tracepoint_string("rxkad_rsp_callid");
+		if (call_id > INT_MAX)
+			goto protocol_error_unlock;
+
+		eproto = tracepoint_string("rxkad_rsp_callctr");
+		if (call_id < conn->channels[i].call_counter)
+			goto protocol_error_unlock;
+
+		eproto = tracepoint_string("rxkad_rsp_callst");
+		if (call_id > conn->channels[i].call_counter) {
+			call = rcu_dereference_protected(
+				conn->channels[i].call,
+				lockdep_is_held(&conn->bundle->channel_lock));
+			if (call && call->state < RXRPC_CALL_COMPLETE)
+				goto protocol_error_unlock;
+			conn->channels[i].call_counter = call_id;
+		}
+	}
+	spin_unlock(&conn->bundle->channel_lock);
+
+	eproto = tracepoint_string("rxkad_rsp_seq");
+	abort_code = RXKADOUTOFSEQUENCE;
+	if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1)
+		goto protocol_error_free;
+
+	eproto = tracepoint_string("rxkad_rsp_level");
+	abort_code = RXKADLEVELFAIL;
+	level = ntohl(response->encrypted.level);
+	if (level > RXRPC_SECURITY_ENCRYPT)
+		goto protocol_error_free;
+	conn->params.security_level = level;
+
+	/* create a key to hold the security data and expiration time - after
+	 * this the connection security can be handled in exactly the same way
+	 * as for a client connection */
+	ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
+	if (ret < 0)
+		goto temporary_error_free_ticket;
+
+	kfree(ticket);
+	kfree(response);
+	_leave(" = 0");
+	return 0;
+
+protocol_error_unlock:
+	spin_unlock(&conn->bundle->channel_lock);
+protocol_error_free:
+	kfree(ticket);
+protocol_error:
+	kfree(response);
+	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+	*_abort_code = abort_code;
+	return -EPROTO;
+
+temporary_error_free_ticket:
+	kfree(ticket);
+temporary_error_free_resp:
+	kfree(response);
+temporary_error:
+	/* Ignore the response packet if we got a temporary error such as
+	 * ENOMEM.  We just want to send the challenge again.  Note that we
+	 * also come out this way if the ticket decryption fails.
+	 */
+	return ret;
+}
+
+/*
+ * clear the connection security
+ */
+static void rxkad_clear(struct rxrpc_connection *conn)
+{
+	_enter("");
+
+	if (conn->cipher)
+		crypto_free_sync_skcipher(conn->cipher);
+}
+
+/*
+ * Initialise the rxkad security service.
+ */
+static int rxkad_init(void)
+{
+	struct crypto_sync_skcipher *tfm;
+	struct skcipher_request *req;
+
+	/* pin the cipher we need so that the crypto layer doesn't invoke
+	 * keventd to go get it */
+	tfm = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	req = skcipher_request_alloc(&tfm->base, GFP_KERNEL);
+	if (!req)
+		goto nomem_tfm;
+
+	rxkad_ci_req = req;
+	rxkad_ci = tfm;
+	return 0;
+
+nomem_tfm:
+	crypto_free_sync_skcipher(tfm);
+	return -ENOMEM;
+}
+
+/*
+ * Clean up the rxkad security service.
+ */
+static void rxkad_exit(void)
+{
+	crypto_free_sync_skcipher(rxkad_ci);
+	skcipher_request_free(rxkad_ci_req);
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxkad = {
+	.name				= "rxkad",
+	.security_index			= RXRPC_SECURITY_RXKAD,
+	.no_key_abort			= RXKADUNKNOWNKEY,
+	.init				= rxkad_init,
+	.exit				= rxkad_exit,
+	.init_connection_security	= rxkad_init_connection_security,
+	.prime_packet_security		= rxkad_prime_packet_security,
+	.secure_packet			= rxkad_secure_packet,
+	.verify_packet			= rxkad_verify_packet,
+	.free_call_crypto		= rxkad_free_call_crypto,
+	.locate_data			= rxkad_locate_data,
+	.issue_challenge		= rxkad_issue_challenge,
+	.respond_to_challenge		= rxkad_respond_to_challenge,
+	.verify_response		= rxkad_verify_response,
+	.clear				= rxkad_clear,
+};
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
new file mode 100644
index 000000000..9b1fb9ed0
--- /dev/null
+++ b/net/rxrpc/security.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC security handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/crypto.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+
+static const struct rxrpc_security *rxrpc_security_types[] = {
+	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
+#ifdef CONFIG_RXKAD
+	[RXRPC_SECURITY_RXKAD]	= &rxkad,
+#endif
+};
+
+int __init rxrpc_init_security(void)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
+		if (rxrpc_security_types[i]) {
+			ret = rxrpc_security_types[i]->init();
+			if (ret < 0)
+				goto failed;
+		}
+	}
+
+	return 0;
+
+failed:
+	for (i--; i >= 0; i--)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+	return ret;
+}
+
+void rxrpc_exit_security(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+}
+
+/*
+ * look up an rxrpc security module
+ */
+static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
+{
+	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
+		return NULL;
+	return rxrpc_security_types[security_index];
+}
+
+/*
+ * initialise the security on a client connection
+ */
+int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
+{
+	const struct rxrpc_security *sec;
+	struct rxrpc_key_token *token;
+	struct key *key = conn->params.key;
+	int ret;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
+
+	if (!key)
+		return 0;
+
+	ret = key_validate(key);
+	if (ret < 0)
+		return ret;
+
+	token = key->payload.data[0];
+	if (!token)
+		return -EKEYREJECTED;
+
+	sec = rxrpc_security_lookup(token->security_index);
+	if (!sec)
+		return -EKEYREJECTED;
+	conn->security = sec;
+
+	ret = conn->security->init_connection_security(conn);
+	if (ret < 0) {
+		conn->security = &rxrpc_no_security;
+		return ret;
+	}
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Find the security key for a server connection.
+ */
+bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock *rx,
+				   const struct rxrpc_security **_sec,
+				   struct key **_key,
+				   struct sk_buff *skb)
+{
+	const struct rxrpc_security *sec;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	key_ref_t kref = NULL;
+	char kdesc[5 + 1 + 3 + 1];
+
+	_enter("");
+
+	sprintf(kdesc, "%u:%u", sp->hdr.serviceId, sp->hdr.securityIndex);
+
+	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
+	if (!sec) {
+		trace_rxrpc_abort(0, "SVS",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  RX_INVALID_OPERATION, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		return false;
+	}
+
+	if (sp->hdr.securityIndex == RXRPC_SECURITY_NONE)
+		goto out;
+
+	if (!rx->securities) {
+		trace_rxrpc_abort(0, "SVR",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  RX_INVALID_OPERATION, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		return false;
+	}
+
+	/* look through the service's keyring */
+	kref = keyring_search(make_key_ref(rx->securities, 1UL),
+			      &key_type_rxrpc_s, kdesc, true);
+	if (IS_ERR(kref)) {
+		trace_rxrpc_abort(0, "SVK",
+				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+				  sec->no_key_abort, EKEYREJECTED);
+		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+		skb->priority = sec->no_key_abort;
+		return false;
+	}
+
+out:
+	*_sec = sec;
+	*_key = key_ref_to_ptr(kref);
+	return true;
+}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644
index 000000000..1882fea71
--- /dev/null
+++ b/net/rxrpc/sendmsg.c
@@ -0,0 +1,899 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC sendmsg() implementation.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Return true if there's sufficient Tx queue space.
+ */
+static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
+{
+	unsigned int win_size =
+		min_t(unsigned int, call->tx_winsize,
+		      call->cong_cwnd + call->cong_extra);
+	rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
+
+	if (_tx_win)
+		*_tx_win = tx_win;
+	return call->tx_top - tx_win < win_size;
+}
+
+/*
+ * Wait for space to appear in the Tx queue or a signal to occur.
+ */
+static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
+					 struct rxrpc_call *call,
+					 long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo);
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly, but with
+ * a timeout of 2*RTT if no progress was made and a signal occurred.
+ */
+static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call)
+{
+	rxrpc_seq_t tx_start, tx_win;
+	signed long rtt, timeout;
+
+	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
+	rtt = usecs_to_jiffies(rtt) * 2;
+	if (rtt < 2)
+		rtt = 2;
+
+	timeout = rtt;
+	tx_start = READ_ONCE(call->tx_hard_ack);
+
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+
+		tx_win = READ_ONCE(call->tx_hard_ack);
+		if (rxrpc_check_tx_space(call, &tx_win))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		if (timeout == 0 &&
+		    tx_win == tx_start && signal_pending(current))
+			return -EINTR;
+
+		if (tx_win != tx_start) {
+			timeout = rtt;
+			tx_start = tx_win;
+		}
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		timeout = schedule_timeout(timeout);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly.
+ */
+static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call,
+					    long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (call->state >= RXRPC_CALL_COMPLETE)
+			return call->error;
+
+		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+				    struct rxrpc_call *call,
+				    long *timeo,
+				    bool waitall)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret;
+
+	_enter(",{%u,%u,%u}",
+	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
+
+	add_wait_queue(&call->waitq, &myself);
+
+	switch (call->interruptibility) {
+	case RXRPC_INTERRUPTIBLE:
+		if (waitall)
+			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
+		else
+			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
+		break;
+	case RXRPC_PREINTERRUPTIBLE:
+	case RXRPC_UNINTERRUPTIBLE:
+	default:
+		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
+		break;
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	set_current_state(TASK_RUNNING);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Schedule an instant Tx resend.
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
+{
+	spin_lock_bh(&call->lock);
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		call->rxtx_annotations[ix] =
+			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
+			RXRPC_TX_ANNO_RETRANS;
+		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
+			rxrpc_queue_call(call);
+	}
+
+	spin_unlock_bh(&call->lock);
+}
+
+/*
+ * Notify the owner of the call that the transmit phase is ended and the last
+ * packet has been queued.
+ */
+static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
+				rxrpc_notify_end_tx_t notify_end_tx)
+{
+	if (notify_end_tx)
+		notify_end_tx(&rx->sk, call, call->user_call_ID);
+}
+
+/*
+ * Queue a DATA packet for transmission, set the resend timeout and send
+ * the packet immediately.  Returns the error from rxrpc_send_data_packet()
+ * in case the caller wants to do something with it.
+ */
+static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
+			      struct sk_buff *skb, bool last,
+			      rxrpc_notify_end_tx_t notify_end_tx)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned long now;
+	rxrpc_seq_t seq = sp->hdr.seq;
+	int ret, ix;
+	u8 annotation = RXRPC_TX_ANNO_UNACK;
+
+	_net("queue skb %p [%d]", skb, seq);
+
+	ASSERTCMP(seq, ==, call->tx_top + 1);
+
+	if (last)
+		annotation |= RXRPC_TX_ANNO_LAST;
+
+	/* We have to set the timestamp before queueing as the retransmit
+	 * algorithm can see the packet as soon as we queue it.
+	 */
+	skb->tstamp = ktime_get_real();
+
+	ix = seq & RXRPC_RXTX_BUFF_MASK;
+	rxrpc_get_skb(skb, rxrpc_skb_got);
+	call->rxtx_annotations[ix] = annotation;
+	smp_wmb();
+	call->rxtx_buffer[ix] = skb;
+	call->tx_top = seq;
+	if (last)
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
+	else
+		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
+
+	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
+		_debug("________awaiting reply/ACK__________");
+		write_lock_bh(&call->state_lock);
+		switch (call->state) {
+		case RXRPC_CALL_CLIENT_SEND_REQUEST:
+			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+			rxrpc_notify_end_tx(rx, call, notify_end_tx);
+			break;
+		case RXRPC_CALL_SERVER_ACK_REQUEST:
+			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
+			now = jiffies;
+			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
+			if (call->ackr_reason == RXRPC_ACK_DELAY)
+				call->ackr_reason = 0;
+			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
+			if (!last)
+				break;
+			fallthrough;
+		case RXRPC_CALL_SERVER_SEND_REPLY:
+			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
+			rxrpc_notify_end_tx(rx, call, notify_end_tx);
+			break;
+		default:
+			break;
+		}
+		write_unlock_bh(&call->state_lock);
+	}
+
+	if (seq == 1 && rxrpc_is_client_call(call))
+		rxrpc_expose_client_call(call);
+
+	ret = rxrpc_send_data_packet(call, skb, false);
+	if (ret < 0) {
+		switch (ret) {
+		case -ENETUNREACH:
+		case -EHOSTUNREACH:
+		case -ECONNREFUSED:
+			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+						  0, ret);
+			goto out;
+		}
+		_debug("need instant resend %d", ret);
+		rxrpc_instant_resend(call, ix);
+	} else {
+		unsigned long now = jiffies;
+		unsigned long resend_at = now + call->peer->rto_j;
+
+		WRITE_ONCE(call->resend_at, resend_at);
+		rxrpc_reduce_call_timer(call, resend_at, now,
+					rxrpc_timer_set_for_send);
+	}
+
+out:
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - The caller holds the call user access mutex, but not the socket lock.
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len,
+			   rxrpc_notify_end_tx_t notify_end_tx,
+			   bool *_dropped_lock)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	struct sock *sk = &rx->sk;
+	enum rxrpc_call_state state;
+	long timeo;
+	bool more = msg->msg_flags & MSG_MORE;
+	int ret, copied = 0;
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	/* this should be in poll */
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+reload:
+	ret = -EPIPE;
+	if (sk->sk_shutdown & SEND_SHUTDOWN)
+		goto maybe_error;
+	state = READ_ONCE(call->state);
+	ret = -ESHUTDOWN;
+	if (state >= RXRPC_CALL_COMPLETE)
+		goto maybe_error;
+	ret = -EPROTO;
+	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+	    state != RXRPC_CALL_SERVER_SEND_REPLY)
+		goto maybe_error;
+
+	ret = -EMSGSIZE;
+	if (call->tx_total_len != -1) {
+		if (len - copied > call->tx_total_len)
+			goto maybe_error;
+		if (!more && len - copied != call->tx_total_len)
+			goto maybe_error;
+	}
+
+	skb = call->tx_pending;
+	call->tx_pending = NULL;
+	rxrpc_see_skb(skb, rxrpc_skb_seen);
+
+	do {
+		/* Check to see if there's a ping ACK to reply to. */
+		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
+			rxrpc_send_ack_packet(call, false, NULL);
+
+		if (!skb) {
+			size_t size, chunk, max, space;
+
+			_debug("alloc");
+
+			if (!rxrpc_check_tx_space(call, NULL))
+				goto wait_for_space;
+
+			max = RXRPC_JUMBO_DATALEN;
+			max -= call->conn->security_size;
+			max &= ~(call->conn->size_align - 1UL);
+
+			chunk = max;
+			if (chunk > msg_data_left(msg) && !more)
+				chunk = msg_data_left(msg);
+
+			space = chunk + call->conn->size_align;
+			space &= ~(call->conn->size_align - 1UL);
+
+			size = space + call->conn->security_size;
+
+			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+
+			/* create a buffer that we can retain until it's ACK'd */
+			skb = sock_alloc_send_skb(
+				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+			if (!skb)
+				goto maybe_error;
+
+			sp = rxrpc_skb(skb);
+			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
+			rxrpc_new_skb(skb, rxrpc_skb_new);
+
+			_debug("ALLOC SEND %p", skb);
+
+			ASSERTCMP(skb->mark, ==, 0);
+
+			_debug("HS: %u", call->conn->security_size);
+			skb_reserve(skb, call->conn->security_size);
+			skb->len += call->conn->security_size;
+
+			sp->remain = chunk;
+			if (sp->remain > skb_tailroom(skb))
+				sp->remain = skb_tailroom(skb);
+
+			_net("skb: hr %d, tr %d, hl %d, rm %d",
+			       skb_headroom(skb),
+			       skb_tailroom(skb),
+			       skb_headlen(skb),
+			       sp->remain);
+
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		}
+
+		_debug("append");
+		sp = rxrpc_skb(skb);
+
+		/* append next segment of data to the current buffer */
+		if (msg_data_left(msg) > 0) {
+			int copy = skb_tailroom(skb);
+			ASSERTCMP(copy, >, 0);
+			if (copy > msg_data_left(msg))
+				copy = msg_data_left(msg);
+			if (copy > sp->remain)
+				copy = sp->remain;
+
+			_debug("add");
+			ret = skb_add_data(skb, &msg->msg_iter, copy);
+			_debug("added");
+			if (ret < 0)
+				goto efault;
+			sp->remain -= copy;
+			skb->mark += copy;
+			copied += copy;
+			if (call->tx_total_len != -1)
+				call->tx_total_len -= copy;
+		}
+
+		/* check for the far side aborting the call or a network error
+		 * occurring */
+		if (call->state == RXRPC_CALL_COMPLETE)
+			goto call_terminated;
+
+		/* add the packet to the send queue if it's now full */
+		if (sp->remain <= 0 ||
+		    (msg_data_left(msg) == 0 && !more)) {
+			struct rxrpc_connection *conn = call->conn;
+			uint32_t seq;
+			size_t pad;
+
+			/* pad out if we're using security */
+			if (conn->security_ix) {
+				pad = conn->security_size + skb->mark;
+				pad = conn->size_align - pad;
+				pad &= conn->size_align - 1;
+				_debug("pad %zu", pad);
+				if (pad)
+					skb_put_zero(skb, pad);
+			}
+
+			seq = call->tx_top + 1;
+
+			sp->hdr.seq	= seq;
+			sp->hdr._rsvd	= 0;
+			sp->hdr.flags	= conn->out_clientflag;
+
+			if (msg_data_left(msg) == 0 && !more)
+				sp->hdr.flags |= RXRPC_LAST_PACKET;
+			else if (call->tx_top - call->tx_hard_ack <
+				 call->tx_winsize)
+				sp->hdr.flags |= RXRPC_MORE_PACKETS;
+
+			ret = call->security->secure_packet(
+				call, skb, skb->mark, skb->head);
+			if (ret < 0)
+				goto out;
+
+			ret = rxrpc_queue_packet(rx, call, skb,
+						 !msg_data_left(msg) && !more,
+						 notify_end_tx);
+			/* Should check for failure here */
+			skb = NULL;
+		}
+	} while (msg_data_left(msg) > 0);
+
+success:
+	ret = copied;
+	if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
+		read_lock_bh(&call->state_lock);
+		if (call->error < 0)
+			ret = call->error;
+		read_unlock_bh(&call->state_lock);
+	}
+out:
+	call->tx_pending = skb;
+	_leave(" = %d", ret);
+	return ret;
+
+call_terminated:
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	_leave(" = %d", call->error);
+	return call->error;
+
+maybe_error:
+	if (copied)
+		goto success;
+	goto out;
+
+efault:
+	ret = -EFAULT;
+	goto out;
+
+wait_for_space:
+	ret = -EAGAIN;
+	if (msg->msg_flags & MSG_DONTWAIT)
+		goto maybe_error;
+	mutex_unlock(&call->user_mutex);
+	*_dropped_lock = true;
+	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
+				       msg->msg_flags & MSG_WAITALL);
+	if (ret < 0)
+		goto maybe_error;
+	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
+		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
+			ret = sock_intr_errno(timeo);
+			goto maybe_error;
+		}
+	} else {
+		mutex_lock(&call->user_mutex);
+	}
+	*_dropped_lock = false;
+	goto reload;
+}
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
+{
+	struct cmsghdr *cmsg;
+	bool got_user_ID = false;
+	int len;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
+		_debug("CMSG %d, %d, %d",
+		       cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+		if (cmsg->cmsg_level != SOL_RXRPC)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case RXRPC_USER_CALL_ID:
+			if (msg->msg_flags & MSG_CMSG_COMPAT) {
+				if (len != sizeof(u32))
+					return -EINVAL;
+				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
+			} else {
+				if (len != sizeof(unsigned long))
+					return -EINVAL;
+				p->call.user_call_ID = *(unsigned long *)
+					CMSG_DATA(cmsg);
+			}
+			got_user_ID = true;
+			break;
+
+		case RXRPC_ABORT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_SEND_ABORT;
+			if (len != sizeof(p->abort_code))
+				return -EINVAL;
+			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
+			if (p->abort_code == 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_CHARGE_ACCEPT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_CHARGE_ACCEPT;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_EXCLUSIVE_CALL:
+			p->exclusive = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_UPGRADE_SERVICE:
+			p->upgrade = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_TX_LENGTH:
+			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
+				return -EINVAL;
+			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
+			if (p->call.tx_total_len < 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_SET_CALL_TIMEOUT:
+			if (len & 3 || len < 4 || len > 12)
+				return -EINVAL;
+			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
+			p->call.nr_timeouts = len / 4;
+			if (p->call.timeouts.hard > INT_MAX / HZ)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
+				return -ERANGE;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (!got_user_ID)
+		return -EINVAL;
+	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
+		return -EINVAL;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Create a new client call for sendmsg().
+ * - Called with the socket lock held, which it must release.
+ * - If it returns a call, the call's lock will need releasing by the caller.
+ */
+static struct rxrpc_call *
+rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+				  struct rxrpc_send_params *p)
+	__releases(&rx->sk.sk_lock.slock)
+	__acquires(&call->user_mutex)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_call *call;
+	struct key *key;
+
+	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
+
+	_enter("");
+
+	if (!msg->msg_name) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-EDESTADDRREQ);
+	}
+
+	key = rx->key;
+	if (key && !rx->key->payload.data[0])
+		key = NULL;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.key			= rx->key;
+	cp.security_level	= rx->min_sec_level;
+	cp.exclusive		= rx->exclusive | p->exclusive;
+	cp.upgrade		= p->upgrade;
+	cp.service_id		= srx->srx_service;
+	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
+				     atomic_inc_return(&rxrpc_debug_id));
+	/* The socket is now unlocked */
+
+	rxrpc_put_peer(cp.peer);
+	_leave(" = %p\n", call);
+	return call;
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+	__releases(&rx->sk.sk_lock.slock)
+	__releases(&call->user_mutex)
+{
+	enum rxrpc_call_state state;
+	struct rxrpc_call *call;
+	unsigned long now, j;
+	bool dropped_lock = false;
+	int ret;
+
+	struct rxrpc_send_params p = {
+		.call.tx_total_len	= -1,
+		.call.user_call_ID	= 0,
+		.call.nr_timeouts	= 0,
+		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
+		.abort_code		= 0,
+		.command		= RXRPC_CMD_SEND_DATA,
+		.exclusive		= false,
+		.upgrade		= false,
+	};
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_cmsg(msg, &p);
+	if (ret < 0)
+		goto error_release_sock;
+
+	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
+		ret = -EINVAL;
+		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
+			goto error_release_sock;
+		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
+		goto error_release_sock;
+	}
+
+	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
+	if (!call) {
+		ret = -EBADSLT;
+		if (p.command != RXRPC_CMD_SEND_DATA)
+			goto error_release_sock;
+		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
+		/* The socket is now unlocked... */
+		if (IS_ERR(call))
+			return PTR_ERR(call);
+		/* ... and we have the call lock. */
+		ret = 0;
+		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
+			goto out_put_unlock;
+	} else {
+		switch (READ_ONCE(call->state)) {
+		case RXRPC_CALL_UNINITIALISED:
+		case RXRPC_CALL_CLIENT_AWAIT_CONN:
+		case RXRPC_CALL_SERVER_PREALLOC:
+		case RXRPC_CALL_SERVER_SECURING:
+			rxrpc_put_call(call, rxrpc_call_put);
+			ret = -EBUSY;
+			goto error_release_sock;
+		default:
+			break;
+		}
+
+		ret = mutex_lock_interruptible(&call->user_mutex);
+		release_sock(&rx->sk);
+		if (ret < 0) {
+			ret = -ERESTARTSYS;
+			goto error_put;
+		}
+
+		if (p.call.tx_total_len != -1) {
+			ret = -EINVAL;
+			if (call->tx_total_len != -1 ||
+			    call->tx_pending ||
+			    call->tx_top != 0)
+				goto out_put_unlock;
+			call->tx_total_len = p.call.tx_total_len;
+		}
+	}
+
+	switch (p.call.nr_timeouts) {
+	case 3:
+		j = msecs_to_jiffies(p.call.timeouts.normal);
+		if (p.call.timeouts.normal > 0 && j == 0)
+			j = 1;
+		WRITE_ONCE(call->next_rx_timo, j);
+		fallthrough;
+	case 2:
+		j = msecs_to_jiffies(p.call.timeouts.idle);
+		if (p.call.timeouts.idle > 0 && j == 0)
+			j = 1;
+		WRITE_ONCE(call->next_req_timo, j);
+		fallthrough;
+	case 1:
+		if (p.call.timeouts.hard > 0) {
+			j = p.call.timeouts.hard * HZ;
+			now = jiffies;
+			j += now;
+			WRITE_ONCE(call->expect_term_by, j);
+			rxrpc_reduce_call_timer(call, j, now,
+						rxrpc_timer_set_for_hard);
+		}
+		break;
+	}
+
+	state = READ_ONCE(call->state);
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, state, call->conn);
+
+	if (state >= RXRPC_CALL_COMPLETE) {
+		/* it's too late for this call */
+		ret = -ESHUTDOWN;
+	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
+		ret = 0;
+		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
+			ret = rxrpc_send_abort_packet(call);
+	} else if (p.command != RXRPC_CMD_SEND_DATA) {
+		ret = -EINVAL;
+	} else {
+		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
+	}
+
+out_put_unlock:
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+error_put:
+	rxrpc_put_call(call, rxrpc_call_put);
+	_leave(" = %d", ret);
+	return ret;
+
+error_release_sock:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
+ * @sock: The socket the call is on
+ * @call: The call to send data through
+ * @msg: The data to send
+ * @len: The amount of data to send
+ * @notify_end_tx: Notification that the last packet is queued.
+ *
+ * Allow a kernel service to send data on a call.  The call must be in an state
+ * appropriate to sending data.  No control data should be supplied in @msg,
+ * nor should an address be supplied.  MSG_MORE should be flagged if there's
+ * more data to come, otherwise this data will end the transmission phase.
+ */
+int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len,
+			   rxrpc_notify_end_tx_t notify_end_tx)
+{
+	bool dropped_lock = false;
+	int ret;
+
+	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
+
+	ASSERTCMP(msg->msg_name, ==, NULL);
+	ASSERTCMP(msg->msg_control, ==, NULL);
+
+	mutex_lock(&call->user_mutex);
+
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	switch (READ_ONCE(call->state)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_SERVER_ACK_REQUEST:
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
+				      notify_end_tx, &dropped_lock);
+		break;
+	case RXRPC_CALL_COMPLETE:
+		read_lock_bh(&call->state_lock);
+		ret = call->error;
+		read_unlock_bh(&call->state_lock);
+		break;
+	default:
+		/* Request phase complete for this client call */
+		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
+		ret = -EPROTO;
+		break;
+	}
+
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+	_leave(" = %d", ret);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_send_data);
+
+/**
+ * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
+ * @sock: The socket the call is on
+ * @call: The call to be aborted
+ * @abort_code: The abort code to stick into the ABORT packet
+ * @error: Local error value
+ * @why: 3-char string indicating why.
+ *
+ * Allow a kernel service to abort a call, if it's still in an abortable state
+ * and return true if the call was aborted, false if it was already complete.
+ */
+bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
+			     u32 abort_code, int error, const char *why)
+{
+	bool aborted;
+
+	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
+
+	mutex_lock(&call->user_mutex);
+
+	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
+	if (aborted)
+		rxrpc_send_abort_packet(call);
+
+	mutex_unlock(&call->user_mutex);
+	return aborted;
+}
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);
+
+/**
+ * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
+ * @sock: The socket the call is on
+ * @call: The call to be informed
+ * @tx_total_len: The amount of data to be transmitted for this call
+ *
+ * Allow a kernel service to set the total transmit length on a call.  This
+ * allows buffer-to-packet encrypt-and-copy to be performed.
+ *
+ * This function is primarily for use for setting the reply length since the
+ * request length can be set when beginning the call.
+ */
+void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
+				s64 tx_total_len)
+{
+	WARN_ON(call->tx_total_len != -1);
+	call->tx_total_len = tx_total_len;
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c
new file mode 100644
index 000000000..580a5acff
--- /dev/null
+++ b/net/rxrpc/skbuff.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* ar-skbuff.c: socket buffer destruction handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+#define is_tx_skb(skb) (rxrpc_skb(skb)->rx_flags & RXRPC_SKB_TX_BUFFER)
+#define select_skb_count(skb) (is_tx_skb(skb) ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
+
+/*
+ * Note the allocation or reception of a socket buffer.
+ */
+void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
+			rxrpc_skb(skb)->rx_flags, here);
+}
+
+/*
+ * Note the re-emergence of a socket buffer from a queue or buffer.
+ */
+void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	if (skb) {
+		int n = atomic_read(select_skb_count(skb));
+		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
+				rxrpc_skb(skb)->rx_flags, here);
+	}
+}
+
+/*
+ * Note the addition of a ref on a socket buffer.
+ */
+void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
+			rxrpc_skb(skb)->rx_flags, here);
+	skb_get(skb);
+}
+
+/*
+ * Note the dropping of a ref on a socket buffer by the core.
+ */
+void rxrpc_eaten_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n = atomic_inc_return(&rxrpc_n_rx_skbs);
+	trace_rxrpc_skb(skb, op, 0, n, 0, here);
+}
+
+/*
+ * Note the destruction of a socket buffer.
+ */
+void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	if (skb) {
+		int n;
+		n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, op, refcount_read(&skb->users), n,
+				rxrpc_skb(skb)->rx_flags, here);
+		kfree_skb(skb);
+	}
+}
+
+/*
+ * Clear a queue of socket buffers.
+ */
+void rxrpc_purge_queue(struct sk_buff_head *list)
+{
+	const void *here = __builtin_return_address(0);
+	struct sk_buff *skb;
+	while ((skb = skb_dequeue((list))) != NULL) {
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, rxrpc_skb_purged,
+				refcount_read(&skb->users), n,
+				rxrpc_skb(skb)->rx_flags, here);
+		kfree_skb(skb);
+	}
+}
diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c
new file mode 100644
index 000000000..555e09107
--- /dev/null
+++ b/net/rxrpc/sysctl.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* sysctls for configuring RxRPC operating parameters
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/sysctl.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static struct ctl_table_header *rxrpc_sysctl_reg_table;
+static const unsigned int four = 4;
+static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1;
+static const unsigned int n_65535 = 65535;
+static const unsigned int n_max_acks = RXRPC_RXTX_BUFF_SIZE - 1;
+static const unsigned long one_jiffy = 1;
+static const unsigned long max_jiffies = MAX_JIFFY_OFFSET;
+
+/*
+ * RxRPC operating parameters.
+ *
+ * See Documentation/networking/rxrpc.rst and the variable definitions for more
+ * information on the individual parameters.
+ */
+static struct ctl_table rxrpc_sysctl_table[] = {
+	/* Values measured in milliseconds but used in jiffies */
+	{
+		.procname	= "req_ack_delay",
+		.data		= &rxrpc_requested_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "soft_ack_delay",
+		.data		= &rxrpc_soft_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "idle_ack_delay",
+		.data		= &rxrpc_idle_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "idle_conn_expiry",
+		.data		= &rxrpc_conn_idle_client_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "idle_conn_fast_expiry",
+		.data		= &rxrpc_conn_idle_client_fast_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+
+	/* Non-time values */
+	{
+		.procname	= "reap_client_conns",
+		.data		= &rxrpc_reap_client_connections,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "max_backlog",
+		.data		= &rxrpc_max_backlog,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&four,
+		.extra2		= (void *)&max_backlog,
+	},
+	{
+		.procname	= "rx_window_size",
+		.data		= &rxrpc_rx_window_size,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_max_acks,
+	},
+	{
+		.procname	= "rx_mtu",
+		.data		= &rxrpc_rx_mtu,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "rx_jumbo_max",
+		.data		= &rxrpc_rx_jumbo_max,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&four,
+	},
+
+	{ }
+};
+
+int __init rxrpc_sysctl_init(void)
+{
+	rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc",
+						     rxrpc_sysctl_table);
+	if (!rxrpc_sysctl_reg_table)
+		return -ENOMEM;
+	return 0;
+}
+
+void rxrpc_sysctl_exit(void)
+{
+	if (rxrpc_sysctl_reg_table)
+		unregister_net_sysctl_table(rxrpc_sysctl_reg_table);
+}
diff --git a/net/rxrpc/utils.c b/net/rxrpc/utils.c
new file mode 100644
index 000000000..2e4b9d86e
--- /dev/null
+++ b/net/rxrpc/utils.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Utility routines
+ *
+ * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include "ar-internal.h"
+
+/*
+ * Fill out a peer address from a socket buffer containing a packet.
+ */
+int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *srx, struct sk_buff *skb)
+{
+	memset(srx, 0, sizeof(*srx));
+
+	switch (ntohs(skb->protocol)) {
+	case ETH_P_IP:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin);
+		srx->transport.sin.sin_family = AF_INET;
+		srx->transport.sin.sin_port = udp_hdr(skb)->source;
+		srx->transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+		return 0;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case ETH_P_IPV6:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin6);
+		srx->transport.sin6.sin6_family = AF_INET6;
+		srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
+		srx->transport.sin6.sin6_addr = ipv6_hdr(skb)->saddr;
+		return 0;
+#endif
+
+	default:
+		pr_warn_ratelimited("AF_RXRPC: Unknown eth protocol %u\n",
+				    ntohs(skb->protocol));
+		return -EAFNOSUPPORT;
+	}
+}