[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both

Provide AF_RXRPC sockets that can be used to talk to AFS servers, or serve
answers to AFS clients.  KerberosIV security is fully supported.  The patches
and some example test programs can be found in:

	http://people.redhat.com/~dhowells/rxrpc/

This will eventually replace the old implementation of kernel-only RxRPC
currently resident in net/rxrpc/.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 787 insertions, 0 deletions

diff --git a/net/rxrpc/ar-call.c b/net/rxrpc/ar-call.c
new file mode 100644
index 000000000000..ac31cceda2f1
--- /dev/null
+++ b/net/rxrpc/ar-call.c
@@ -0,0 +1,787 @@
+/* RxRPC individual remote procedure call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+struct kmem_cache *rxrpc_call_jar;
+LIST_HEAD(rxrpc_calls);
+DEFINE_RWLOCK(rxrpc_call_lock);
+static unsigned rxrpc_call_max_lifetime = 60;
+static unsigned rxrpc_dead_call_timeout = 10;
+
+static void rxrpc_destroy_call(struct work_struct *work);
+static void rxrpc_call_life_expired(unsigned long _call);
+static void rxrpc_dead_call_expired(unsigned long _call);
+static void rxrpc_ack_time_expired(unsigned long _call);
+static void rxrpc_resend_time_expired(unsigned long _call);
+
+/*
+ * allocate a new call
+ */
+static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
+{
+	struct rxrpc_call *call;
+
+	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
+	if (!call)
+		return NULL;
+
+	call->acks_winsz = 16;
+	call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
+				    gfp);
+	if (!call->acks_window) {
+		kmem_cache_free(rxrpc_call_jar, call);
+		return NULL;
+	}
+
+	setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
+		    (unsigned long) call);
+	setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
+		    (unsigned long) call);
+	setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
+		    (unsigned long) call);
+	setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
+		    (unsigned long) call);
+	INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
+	INIT_WORK(&call->processor, &rxrpc_process_call);
+	INIT_LIST_HEAD(&call->accept_link);
+	skb_queue_head_init(&call->rx_queue);
+	skb_queue_head_init(&call->rx_oos_queue);
+	init_waitqueue_head(&call->tx_waitq);
+	spin_lock_init(&call->lock);
+	rwlock_init(&call->state_lock);
+	atomic_set(&call->usage, 1);
+	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
+	call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
+
+	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
+
+	call->rx_data_expect = 1;
+	call->rx_data_eaten = 0;
+	call->rx_first_oos = 0;
+	call->ackr_win_top = call->rx_data_eaten + 1 + RXRPC_MAXACKS;
+	call->creation_jif = jiffies;
+	return call;
+}
+
+/*
+ * allocate a new client call and attempt to to get a connection slot for it
+ */
+static struct rxrpc_call *rxrpc_alloc_client_call(
+	struct rxrpc_sock *rx,
+	struct rxrpc_transport *trans,
+	struct rxrpc_conn_bundle *bundle,
+	gfp_t gfp)
+{
+	struct rxrpc_call *call;
+	int ret;
+
+	_enter("");
+
+	ASSERT(rx != NULL);
+	ASSERT(trans != NULL);
+	ASSERT(bundle != NULL);
+
+	call = rxrpc_alloc_call(gfp);
+	if (!call)
+		return ERR_PTR(-ENOMEM);
+
+	sock_hold(&rx->sk);
+	call->socket = rx;
+	call->rx_data_post = 1;
+
+	ret = rxrpc_connect_call(rx, trans, bundle, call, gfp);
+	if (ret < 0) {
+		kmem_cache_free(rxrpc_call_jar, call);
+		return ERR_PTR(ret);
+	}
+
+	spin_lock(&call->conn->trans->peer->lock);
+	list_add(&call->error_link, &call->conn->trans->peer->error_targets);
+	spin_unlock(&call->conn->trans->peer->lock);
+
+	call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
+	add_timer(&call->lifetimer);
+
+	_leave(" = %p", call);
+	return call;
+}
+
+/*
+ * set up a call for the given data
+ * - called in process context with IRQs enabled
+ */
+struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx,
+					 struct rxrpc_transport *trans,
+					 struct rxrpc_conn_bundle *bundle,
+					 unsigned long user_call_ID,
+					 int create,
+					 gfp_t gfp)
+{
+	struct rxrpc_call *call, *candidate;
+	struct rb_node *p, *parent, **pp;
+
+	_enter("%p,%d,%d,%lx,%d",
+	       rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1,
+	       user_call_ID, create);
+
+	/* search the extant calls first for one that matches the specified
+	 * user 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);
+
+	if (!create || !trans)
+		return ERR_PTR(-EBADSLT);
+
+	/* not yet present - create a candidate for a new record and then
+	 * redo the search */
+	candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp);
+	if (IS_ERR(candidate)) {
+		_leave(" = %ld", PTR_ERR(candidate));
+		return candidate;
+	}
+
+	candidate->user_call_ID = user_call_ID;
+	__set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags);
+
+	write_lock(&rx->call_lock);
+
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		call = rb_entry(parent, struct rxrpc_call, sock_node);
+
+		if (user_call_ID < call->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (user_call_ID > call->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_extant_second;
+	}
+
+	/* second search also failed; add the new call */
+	call = candidate;
+	candidate = NULL;
+	rxrpc_get_call(call);
+
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	write_unlock(&rx->call_lock);
+
+	write_lock_bh(&rxrpc_call_lock);
+	list_add_tail(&call->link, &rxrpc_calls);
+	write_unlock_bh(&rxrpc_call_lock);
+
+	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
+
+	_leave(" = %p [new]", call);
+	return call;
+
+	/* we found the call in the list immediately */
+found_extant_call:
+	rxrpc_get_call(call);
+	read_unlock(&rx->call_lock);
+	_leave(" = %p [extant %d]", call, atomic_read(&call->usage));
+	return call;
+
+	/* we found the call on the second time through the list */
+found_extant_second:
+	rxrpc_get_call(call);
+	write_unlock(&rx->call_lock);
+	rxrpc_put_call(candidate);
+	_leave(" = %p [second %d]", call, atomic_read(&call->usage));
+	return call;
+}
+
+/*
+ * set up an incoming call
+ * - called in process context with IRQs enabled
+ */
+struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
+				       struct rxrpc_connection *conn,
+				       struct rxrpc_header *hdr,
+				       gfp_t gfp)
+{
+	struct rxrpc_call *call, *candidate;
+	struct rb_node **p, *parent;
+	__be32 call_id;
+
+	_enter(",%d,,%x", conn->debug_id, gfp);
+
+	ASSERT(rx != NULL);
+
+	candidate = rxrpc_alloc_call(gfp);
+	if (!candidate)
+		return ERR_PTR(-EBUSY);
+
+	candidate->socket = rx;
+	candidate->conn = conn;
+	candidate->cid = hdr->cid;
+	candidate->call_id = hdr->callNumber;
+	candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK;
+	candidate->rx_data_post = 0;
+	candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
+	if (conn->security_ix > 0)
+		candidate->state = RXRPC_CALL_SERVER_SECURING;
+
+	write_lock_bh(&conn->lock);
+
+	/* set the channel for this call */
+	call = conn->channels[candidate->channel];
+	_debug("channel[%u] is %p", candidate->channel, call);
+	if (call && call->call_id == hdr->callNumber) {
+		/* already set; must've been a duplicate packet */
+		_debug("extant call [%d]", call->state);
+		ASSERTCMP(call->conn, ==, conn);
+
+		read_lock(&call->state_lock);
+		switch (call->state) {
+		case RXRPC_CALL_LOCALLY_ABORTED:
+			if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
+				schedule_work(&call->processor);
+		case RXRPC_CALL_REMOTELY_ABORTED:
+			read_unlock(&call->state_lock);
+			goto aborted_call;
+		default:
+			rxrpc_get_call(call);
+			read_unlock(&call->state_lock);
+			goto extant_call;
+		}
+	}
+
+	if (call) {
+		/* it seems the channel is still in use from the previous call
+		 * - ditch the old binding if its call is now complete */
+		_debug("CALL: %u { %s }",
+		       call->debug_id, rxrpc_call_states[call->state]);
+
+		if (call->state >= RXRPC_CALL_COMPLETE) {
+			conn->channels[call->channel] = NULL;
+		} else {
+			write_unlock_bh(&conn->lock);
+			kmem_cache_free(rxrpc_call_jar, candidate);
+			_leave(" = -EBUSY");
+			return ERR_PTR(-EBUSY);
+		}
+	}
+
+	/* check the call number isn't duplicate */
+	_debug("check dup");
+	call_id = hdr->callNumber;
+	p = &conn->calls.rb_node;
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		call = rb_entry(parent, struct rxrpc_call, conn_node);
+
+		if (call_id < call->call_id)
+			p = &(*p)->rb_left;
+		else if (call_id > call->call_id)
+			p = &(*p)->rb_right;
+		else
+			goto old_call;
+	}
+
+	/* make the call available */
+	_debug("new call");
+	call = candidate;
+	candidate = NULL;
+	rb_link_node(&call->conn_node, parent, p);
+	rb_insert_color(&call->conn_node, &conn->calls);
+	conn->channels[call->channel] = call;
+	sock_hold(&rx->sk);
+	atomic_inc(&conn->usage);
+	write_unlock_bh(&conn->lock);
+
+	spin_lock(&conn->trans->peer->lock);
+	list_add(&call->error_link, &conn->trans->peer->error_targets);
+	spin_unlock(&conn->trans->peer->lock);
+
+	write_lock_bh(&rxrpc_call_lock);
+	list_add_tail(&call->link, &rxrpc_calls);
+	write_unlock_bh(&rxrpc_call_lock);
+
+	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
+
+	call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
+	add_timer(&call->lifetimer);
+	_leave(" = %p {%d} [new]", call, call->debug_id);
+	return call;
+
+extant_call:
+	write_unlock_bh(&conn->lock);
+	kmem_cache_free(rxrpc_call_jar, candidate);
+	_leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
+	return call;
+
+aborted_call:
+	write_unlock_bh(&conn->lock);
+	kmem_cache_free(rxrpc_call_jar, candidate);
+	_leave(" = -ECONNABORTED");
+	return ERR_PTR(-ECONNABORTED);
+
+old_call:
+	write_unlock_bh(&conn->lock);
+	kmem_cache_free(rxrpc_call_jar, candidate);
+	_leave(" = -ECONNRESET [old]");
+	return ERR_PTR(-ECONNRESET);
+}
+
+/*
+ * find an extant server call
+ * - called in process context with IRQs enabled
+ */
+struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx,
+					  unsigned long user_call_ID)
+{
+	struct rxrpc_call *call;
+	struct rb_node *p;
+
+	_enter("%p,%lx", rx, user_call_ID);
+
+	/* search the extant calls for one that matches the specified user
+	 * 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;
+
+	/* we found the call in the list immediately */
+found_extant_call:
+	rxrpc_get_call(call);
+	read_unlock(&rx->call_lock);
+	_leave(" = %p [%d]", call, atomic_read(&call->usage));
+	return call;
+}
+
+/*
+ * detach a call from a socket and set up for release
+ */
+void rxrpc_release_call(struct rxrpc_call *call)
+{
+	struct rxrpc_sock *rx = call->socket;
+
+	_enter("{%d,%d,%d,%d}",
+	       call->debug_id, atomic_read(&call->usage),
+	       atomic_read(&call->ackr_not_idle),
+	       call->rx_first_oos);
+
+	spin_lock_bh(&call->lock);
+	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
+		BUG();
+	spin_unlock_bh(&call->lock);
+
+	/* dissociate from the socket
+	 * - the socket's ref on the call is passed to the death timer
+	 */
+	_debug("RELEASE CALL %p (%d CONN %p)",
+	       call, call->debug_id, call->conn);
+
+	write_lock_bh(&rx->call_lock);
+	if (!list_empty(&call->accept_link)) {
+		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
+		       call, call->events, call->flags);
+		ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
+		list_del_init(&call->accept_link);
+		sk_acceptq_removed(&rx->sk);
+	} else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+		rb_erase(&call->sock_node, &rx->calls);
+		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
+		clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+	}
+	write_unlock_bh(&rx->call_lock);
+
+	if (call->conn->out_clientflag)
+		spin_lock(&call->conn->trans->client_lock);
+	write_lock_bh(&call->conn->lock);
+
+	/* free up the channel for reuse */
+	if (call->conn->out_clientflag) {
+		call->conn->avail_calls++;
+		if (call->conn->avail_calls == RXRPC_MAXCALLS)
+			list_move_tail(&call->conn->bundle_link,
+				       &call->conn->bundle->unused_conns);
+		else if (call->conn->avail_calls == 1)
+			list_move_tail(&call->conn->bundle_link,
+				       &call->conn->bundle->avail_conns);
+	}
+
+	write_lock(&call->state_lock);
+	if (call->conn->channels[call->channel] == call)
+		call->conn->channels[call->channel] = NULL;
+
+	if (call->state < RXRPC_CALL_COMPLETE &&
+	    call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
+		_debug("+++ ABORTING STATE %d +++\n", call->state);
+		call->state = RXRPC_CALL_LOCALLY_ABORTED;
+		call->abort_code = RX_CALL_DEAD;
+		set_bit(RXRPC_CALL_ABORT, &call->events);
+		schedule_work(&call->processor);
+	}
+	write_unlock(&call->state_lock);
+	write_unlock_bh(&call->conn->lock);
+	if (call->conn->out_clientflag)
+		spin_unlock(&call->conn->trans->client_lock);
+
+	if (!skb_queue_empty(&call->rx_queue) ||
+	    !skb_queue_empty(&call->rx_oos_queue)) {
+		struct rxrpc_skb_priv *sp;
+		struct sk_buff *skb;
+
+		_debug("purge Rx queues");
+
+		spin_lock_bh(&call->lock);
+		while ((skb = skb_dequeue(&call->rx_queue)) ||
+		       (skb = skb_dequeue(&call->rx_oos_queue))) {
+			sp = rxrpc_skb(skb);
+			if (sp->call) {
+				ASSERTCMP(sp->call, ==, call);
+				rxrpc_put_call(call);
+				sp->call = NULL;
+			}
+			skb->destructor = NULL;
+			spin_unlock_bh(&call->lock);
+
+			_debug("- zap %s %%%u #%u",
+			       rxrpc_pkts[sp->hdr.type],
+			       ntohl(sp->hdr.serial),
+			       ntohl(sp->hdr.seq));
+			rxrpc_free_skb(skb);
+			spin_lock_bh(&call->lock);
+		}
+		spin_unlock_bh(&call->lock);
+
+		ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
+	}
+
+	del_timer_sync(&call->resend_timer);
+	del_timer_sync(&call->ack_timer);
+	del_timer_sync(&call->lifetimer);
+	call->deadspan.expires = jiffies + rxrpc_dead_call_timeout * HZ;
+	add_timer(&call->deadspan);
+
+	_leave("");
+}
+
+/*
+ * handle a dead call being ready for reaping
+ */
+static void rxrpc_dead_call_expired(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_enter("{%d}", call->debug_id);
+
+	write_lock_bh(&call->state_lock);
+	call->state = RXRPC_CALL_DEAD;
+	write_unlock_bh(&call->state_lock);
+	rxrpc_put_call(call);
+}
+
+/*
+ * mark a call as to be released, aborting it if it's still in progress
+ * - called with softirqs disabled
+ */
+static void rxrpc_mark_call_released(struct rxrpc_call *call)
+{
+	bool sched;
+
+	write_lock(&call->state_lock);
+	if (call->state < RXRPC_CALL_DEAD) {
+		sched = false;
+		if (call->state < RXRPC_CALL_COMPLETE) {
+			_debug("abort call %p", call);
+			call->state = RXRPC_CALL_LOCALLY_ABORTED;
+			call->abort_code = RX_CALL_DEAD;
+			if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
+				sched = true;
+		}
+		if (!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
+			sched = true;
+		if (sched)
+			schedule_work(&call->processor);
+	}
+	write_unlock(&call->state_lock);
+}
+
+/*
+ * release all the calls associated with a socket
+ */
+void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
+{
+	struct rxrpc_call *call;
+	struct rb_node *p;
+
+	_enter("%p", rx);
+
+	read_lock_bh(&rx->call_lock);
+
+	/* mark all the calls as no longer wanting incoming packets */
+	for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
+		call = rb_entry(p, struct rxrpc_call, sock_node);
+		rxrpc_mark_call_released(call);
+	}
+
+	/* kill the not-yet-accepted incoming calls */
+	list_for_each_entry(call, &rx->secureq, accept_link) {
+		rxrpc_mark_call_released(call);
+	}
+
+	list_for_each_entry(call, &rx->acceptq, accept_link) {
+		rxrpc_mark_call_released(call);
+	}
+
+	read_unlock_bh(&rx->call_lock);
+	_leave("");
+}
+
+/*
+ * release a call
+ */
+void __rxrpc_put_call(struct rxrpc_call *call)
+{
+	ASSERT(call != NULL);
+
+	_enter("%p{u=%d}", call, atomic_read(&call->usage));
+
+	ASSERTCMP(atomic_read(&call->usage), >, 0);
+
+	if (atomic_dec_and_test(&call->usage)) {
+		_debug("call %d dead", call->debug_id);
+		ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
+		schedule_work(&call->destroyer);
+	}
+	_leave("");
+}
+
+/*
+ * clean up a call
+ */
+static void rxrpc_cleanup_call(struct rxrpc_call *call)
+{
+	_net("DESTROY CALL %d", call->debug_id);
+
+	ASSERT(call->socket);
+
+	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
+
+	del_timer_sync(&call->lifetimer);
+	del_timer_sync(&call->deadspan);
+	del_timer_sync(&call->ack_timer);
+	del_timer_sync(&call->resend_timer);
+
+	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
+	ASSERTCMP(call->events, ==, 0);
+	if (work_pending(&call->processor)) {
+		_debug("defer destroy");
+		schedule_work(&call->destroyer);
+		return;
+	}
+
+	if (call->conn) {
+		spin_lock(&call->conn->trans->peer->lock);
+		list_del(&call->error_link);
+		spin_unlock(&call->conn->trans->peer->lock);
+
+		write_lock_bh(&call->conn->lock);
+		rb_erase(&call->conn_node, &call->conn->calls);
+		write_unlock_bh(&call->conn->lock);
+		rxrpc_put_connection(call->conn);
+	}
+
+	if (call->acks_window) {
+		_debug("kill Tx window %d",
+		       CIRC_CNT(call->acks_head, call->acks_tail,
+				call->acks_winsz));
+		smp_mb();
+		while (CIRC_CNT(call->acks_head, call->acks_tail,
+				call->acks_winsz) > 0) {
+			struct rxrpc_skb_priv *sp;
+			unsigned long _skb;
+
+			_skb = call->acks_window[call->acks_tail] & ~1;
+			sp = rxrpc_skb((struct sk_buff *) _skb);
+			_debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
+			rxrpc_free_skb((struct sk_buff *) _skb);
+			call->acks_tail =
+				(call->acks_tail + 1) & (call->acks_winsz - 1);
+		}
+
+		kfree(call->acks_window);
+	}
+
+	rxrpc_free_skb(call->tx_pending);
+
+	rxrpc_purge_queue(&call->rx_queue);
+	ASSERT(skb_queue_empty(&call->rx_oos_queue));
+	sock_put(&call->socket->sk);
+	kmem_cache_free(rxrpc_call_jar, call);
+}
+
+/*
+ * destroy a call
+ */
+static void rxrpc_destroy_call(struct work_struct *work)
+{
+	struct rxrpc_call *call =
+		container_of(work, struct rxrpc_call, destroyer);
+
+	_enter("%p{%d,%d,%p}",
+	       call, atomic_read(&call->usage), call->channel, call->conn);
+
+	ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
+
+	write_lock_bh(&rxrpc_call_lock);
+	list_del_init(&call->link);
+	write_unlock_bh(&rxrpc_call_lock);
+
+	rxrpc_cleanup_call(call);
+	_leave("");
+}
+
+/*
+ * preemptively destroy all the call records from a transport endpoint rather
+ * than waiting for them to time out
+ */
+void __exit rxrpc_destroy_all_calls(void)
+{
+	struct rxrpc_call *call;
+
+	_enter("");
+	write_lock_bh(&rxrpc_call_lock);
+
+	while (!list_empty(&rxrpc_calls)) {
+		call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
+		_debug("Zapping call %p", call);
+
+		list_del_init(&call->link);
+
+		switch (atomic_read(&call->usage)) {
+		case 0:
+			ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
+			break;
+		case 1:
+			if (del_timer_sync(&call->deadspan) != 0 &&
+			    call->state != RXRPC_CALL_DEAD)
+				rxrpc_dead_call_expired((unsigned long) call);
+			if (call->state != RXRPC_CALL_DEAD)
+				break;
+		default:
+			printk(KERN_ERR "RXRPC:"
+			       " Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
+			       call, atomic_read(&call->usage),
+			       atomic_read(&call->ackr_not_idle),
+			       rxrpc_call_states[call->state],
+			       call->flags, call->events);
+			if (!skb_queue_empty(&call->rx_queue))
+				printk(KERN_ERR"RXRPC: Rx queue occupied\n");
+			if (!skb_queue_empty(&call->rx_oos_queue))
+				printk(KERN_ERR"RXRPC: OOS queue occupied\n");
+			break;
+		}
+
+		write_unlock_bh(&rxrpc_call_lock);
+		cond_resched();
+		write_lock_bh(&rxrpc_call_lock);
+	}
+
+	write_unlock_bh(&rxrpc_call_lock);
+	_leave("");
+}
+
+/*
+ * handle call lifetime being exceeded
+ */
+static void rxrpc_call_life_expired(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		return;
+
+	_enter("{%d}", call->debug_id);
+	read_lock_bh(&call->state_lock);
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		set_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
+		schedule_work(&call->processor);
+	}
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * handle resend timer expiry
+ */
+static void rxrpc_resend_time_expired(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_enter("{%d}", call->debug_id);
+
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		return;
+
+	read_lock_bh(&call->state_lock);
+	clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+	if (call->state < RXRPC_CALL_COMPLETE &&
+	    !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
+		schedule_work(&call->processor);
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * handle ACK timer expiry
+ */
+static void rxrpc_ack_time_expired(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_enter("{%d}", call->debug_id);
+
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		return;
+
+	read_lock_bh(&call->state_lock);
+	if (call->state < RXRPC_CALL_COMPLETE &&
+	    !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
+		schedule_work(&call->processor);
+	read_unlock_bh(&call->state_lock);
+}