[mirror_ubuntu-bionic-kernel.git] / net / rxrpc / conn_object.c

/* RxRPC virtual connection handler, common bits.
 *
 * Copyright (C) 2007, 2016 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.
 */

#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);
		spin_lock_init(&conn->channel_lock);
		INIT_LIST_HEAD(&conn->waiting_calls);
		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.
 *
 * 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_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(local, &srx, skb) < 0)
		goto not_found;

	k.epoch	= sp->hdr.epoch;
	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;

	/* We may have to handle mixing IPv4 and IPv6 */
	if (srx.transport.family != local->srx.transport.family) {
		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;
		conn = rxrpc_find_service_conn_rcu(peer, skb);
		if (!conn || atomic_read(&conn->usage) == 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 || atomic_read(&conn->usage) == 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);
		if (call->abort_code) {
			chan->last_abort = call->abort_code;
			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
		} else {
			chan->last_seq = call->rx_hard_ack;
			chan->last_type = RXRPC_PACKET_TYPE_ACK;
		}
		/* 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;

	spin_lock_bh(&conn->params.peer->lock);
	hlist_del_init(&call->error_link);
	spin_unlock_bh(&conn->params.peer->lock);

	if (rxrpc_is_client_call(call))
		return rxrpc_disconnect_client_call(call);

	spin_lock(&conn->channel_lock);
	__rxrpc_disconnect_call(conn, call);
	spin_unlock(&conn->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 n = __atomic_add_unless(&conn->usage, 1, 0);
	if (n == 0)
		return false;
	if (rxrpc_queue_work(&conn->processor))
		trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 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 = atomic_read(&conn->usage);

		trace_rxrpc_conn(conn, rxrpc_conn_seen, n, here);
	}
}

/*
 * Get a ref on a connection.
 */
void rxrpc_get_connection(struct rxrpc_connection *conn)
{
	const void *here = __builtin_return_address(0);
	int n = atomic_inc_return(&conn->usage);

	trace_rxrpc_conn(conn, rxrpc_conn_got, n, here);
}

/*
 * 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);

	if (conn) {
		int n = __atomic_add_unless(&conn->usage, 1, 0);
		if (n > 0)
			trace_rxrpc_conn(conn, rxrpc_conn_got, n + 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);
	int n;

	n = atomic_dec_return(&conn->usage);
	trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here);
	ASSERTCMP(n, >=, 0);
	if (n == 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, atomic_read(&conn->usage));

	ASSERTCMP(atomic_read(&conn->usage), ==, 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_peer(conn->params.peer);
	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(atomic_read(&conn->usage), >, 0);
		if (likely(atomic_read(&conn->usage) > 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, atomic_read(&conn->usage),
			       (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 (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
			continue;
		trace_rxrpc_conn(conn, rxrpc_conn_reap_service, 0, 0);

		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(atomic_read(&conn->usage), ==, 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("");

	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, atomic_read(&conn->usage));
		leak = true;
	}
	write_unlock(&rxnet->conn_lock);
	BUG_ON(leak);

	ASSERT(list_empty(&rxnet->conn_proc_list));

	_leave("");
}
Commit	Line	Data
45025bce	1	/* RxRPC virtual connection handler, common bits.
17926a79	2	*
45025bce	3	* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
17926a79 DH	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
9b6d5398 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9b6d5398 JP	13
17926a79	14	#include <linux/module.h>
5a0e3ad6	15	#include <linux/slab.h>
17926a79 DH	16	#include <linux/net.h>
17926a79 DH	17	#include <linux/skbuff.h>
17926a79 DH	18	#include "ar-internal.h"
17926a79 DH	19
5873c083 DH	20	/*
	21	* Time till a connection expires after last use (in seconds).
	22	*/
f859ab61 DH	23	unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
f859ab61 DH	24	unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
5873c083	25
45025bce DH	26	static void rxrpc_destroy_connection(struct rcu_head *);
45025bce DH	27
3136ef49 DH	28	static void rxrpc_connection_timer(struct timer_list *timer)
	29	{
	30	struct rxrpc_connection *conn =
	31	container_of(timer, struct rxrpc_connection, timer);
	32
	33	rxrpc_queue_conn(conn);
	34	}
	35
17926a79 DH	36	/*
	37	* allocate a new connection
	38	*/
c6d2b8d7	39	struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
17926a79 DH	40	{
	41	struct rxrpc_connection *conn;
	42
	43	_enter("");
	44
	45	conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
	46	if (conn) {
45025bce	47	INIT_LIST_HEAD(&conn->cache_link);
999b69f8	48	spin_lock_init(&conn->channel_lock);
45025bce	49	INIT_LIST_HEAD(&conn->waiting_calls);
3136ef49	50	timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
17926a79	51	INIT_WORK(&conn->processor, &rxrpc_process_connection);
4d028b2c	52	INIT_LIST_HEAD(&conn->proc_link);
999b69f8	53	INIT_LIST_HEAD(&conn->link);
17926a79	54	skb_queue_head_init(&conn->rx_queue);
e0e4d82f	55	conn->security = &rxrpc_no_security;
17926a79	56	spin_lock_init(&conn->state_lock);
17926a79	57	conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
17926a79	58	conn->size_align = 4;
f51b4480	59	conn->idle_timestamp = jiffies;
17926a79 DH	60	}
17926a79 DH	61
16c61add	62	_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
17926a79 DH	63	return conn;
	64	}
	65
17926a79	66	/*
8496af50 DH	67	* Look up a connection in the cache by protocol parameters.
	68	*
	69	* If successful, a pointer to the connection is returned, but no ref is taken.
	70	* NULL is returned if there is no match.
	71	*
	72	* The caller must be holding the RCU read lock.
17926a79	73	*/
8496af50 DH	74	struct rxrpc_connection rxrpc_find_connection_rcu(struct rxrpc_local local,
8496af50 DH	75	struct sk_buff *skb)
17926a79 DH	76	{
17926a79 DH	77	struct rxrpc_connection *conn;
1291e9d1	78	struct rxrpc_conn_proto k;
42886ffe	79	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1291e9d1 DH	80	struct sockaddr_rxrpc srx;
1291e9d1 DH	81	struct rxrpc_peer *peer;
17926a79	82
8496af50	83	_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
17926a79	84
7b674e39	85	if (rxrpc_extract_addr_from_skb(local, &srx, skb) < 0)
1291e9d1	86	goto not_found;
17926a79	87
8496af50 DH	88	k.epoch = sp->hdr.epoch;
	89	k.cid = sp->hdr.cid & RXRPC_CIDMASK;
	90
1291e9d1 DH	91	/* We may have to handle mixing IPv4 and IPv6 */
	92	if (srx.transport.family != local->srx.transport.family) {
	93	pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
	94	srx.transport.family,
	95	local->srx.transport.family);
	96	goto not_found;
	97	}
	98
	99	k.epoch = sp->hdr.epoch;
	100	k.cid = sp->hdr.cid & RXRPC_CIDMASK;
17926a79	101
d693ee4e	102	if (rxrpc_to_server(sp)) {
1291e9d1 DH	103	/* We need to look up service connections by the full protocol
	104	* parameter set. We look up the peer first as an intermediate
	105	* step and then the connection from the peer's tree.
	106	*/
	107	peer = rxrpc_lookup_peer_rcu(local, &srx);
	108	if (!peer)
	109	goto not_found;
8496af50 DH	110	conn = rxrpc_find_service_conn_rcu(peer, skb);
	111	if (!conn \|\| atomic_read(&conn->usage) == 0)
	112	goto not_found;
	113	_leave(" = %p", conn);
	114	return conn;
4a3388c8	115	} else {
8496af50 DH	116	/* Look up client connections by connection ID alone as their
	117	* IDs are unique for this machine.
	118	*/
1291e9d1	119	conn = idr_find(&rxrpc_client_conn_ids,
8496af50 DH	120	sp->hdr.cid >> RXRPC_CIDSHIFT);
	121	if (!conn \|\| atomic_read(&conn->usage) == 0) {
	122	_debug("no conn");
	123	goto not_found;
	124	}
	125
	126	if (conn->proto.epoch != k.epoch \|\|
1291e9d1 DH	127	conn->params.local != local)
	128	goto not_found;
	129
	130	peer = conn->params.peer;
	131	switch (srx.transport.family) {
	132	case AF_INET:
	133	if (peer->srx.transport.sin.sin_port !=
	134	srx.transport.sin.sin_port \|\|
	135	peer->srx.transport.sin.sin_addr.s_addr !=
	136	srx.transport.sin.sin_addr.s_addr)
	137	goto not_found;
	138	break;
d1912747	139	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	140	case AF_INET6:
	141	if (peer->srx.transport.sin6.sin6_port !=
	142	srx.transport.sin6.sin6_port \|\|
	143	memcmp(&peer->srx.transport.sin6.sin6_addr,
	144	&srx.transport.sin6.sin6_addr,
	145	sizeof(struct in6_addr)) != 0)
	146	goto not_found;
	147	break;
d1912747	148	#endif
1291e9d1 DH	149	default:
	150	BUG();
	151	}
	152
1291e9d1 DH	153	_leave(" = %p", conn);
1291e9d1 DH	154	return conn;
17926a79 DH	155	}
17926a79 DH	156
1291e9d1	157	not_found:
17926a79 DH	158	_leave(" = NULL");
17926a79 DH	159	return NULL;
17926a79 DH	160	}
17926a79 DH	161
999b69f8 DH	162	/*
999b69f8 DH	163	* Disconnect a call and clear any channel it occupies when that call
a1399f8b DH	164	* terminates. The caller must hold the channel_lock and must release the
a1399f8b DH	165	* call's ref on the connection.
999b69f8	166	*/
45025bce DH	167	void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
45025bce DH	168	struct rxrpc_call *call)
999b69f8	169	{
01a90a45 DH	170	struct rxrpc_channel *chan =
01a90a45 DH	171	&conn->channels[call->cid & RXRPC_CHANNELMASK];
999b69f8	172
01a90a45	173	_enter("%d,%x", conn->debug_id, call->cid);
999b69f8	174
a1399f8b DH	175	if (rcu_access_pointer(chan->call) == call) {
	176	/* Save the result of the call so that we can repeat it if necessary
	177	* through the channel, whilst disposing of the actual call record.
	178	*/
b1d9f7fd	179	trace_rxrpc_disconnect_call(call);
f5c17aae DH	180	if (call->abort_code) {
f5c17aae DH	181	chan->last_abort = call->abort_code;
18bfeba5 DH	182	chan->last_type = RXRPC_PACKET_TYPE_ABORT;
18bfeba5 DH	183	} else {
248f219c	184	chan->last_seq = call->rx_hard_ack;
18bfeba5 DH	185	chan->last_type = RXRPC_PACKET_TYPE_ACK;
	186	}
	187	/* Sync with rxrpc_conn_retransmit(). */
a1399f8b DH	188	smp_wmb();
	189	chan->last_call = chan->call_id;
	190	chan->call_id = chan->call_counter;
e653cfe4	191
a1399f8b	192	rcu_assign_pointer(chan->call, NULL);
999b69f8	193	}
e653cfe4	194
a1399f8b DH	195	_leave("");
	196	}
	197
	198	/*
	199	* Disconnect a call and clear any channel it occupies when that call
	200	* terminates.
	201	*/
	202	void rxrpc_disconnect_call(struct rxrpc_call *call)
	203	{
	204	struct rxrpc_connection *conn = call->conn;
	205
f7aec129 DH	206	call->peer->cong_cwnd = call->cong_cwnd;
f7aec129 DH	207
248f219c DH	208	spin_lock_bh(&conn->params.peer->lock);
	209	hlist_del_init(&call->error_link);
	210	spin_unlock_bh(&conn->params.peer->lock);
	211
45025bce DH	212	if (rxrpc_is_client_call(call))
	213	return rxrpc_disconnect_client_call(call);
	214
a1399f8b	215	spin_lock(&conn->channel_lock);
45025bce	216	__rxrpc_disconnect_call(conn, call);
e653cfe4 DH	217	spin_unlock(&conn->channel_lock);
e653cfe4 DH	218
cf5bc5e2	219	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
f51b4480	220	conn->idle_timestamp = jiffies;
999b69f8 DH	221	}
999b69f8 DH	222
45025bce DH	223	/*
	224	* Kill off a connection.
	225	*/
	226	void rxrpc_kill_connection(struct rxrpc_connection *conn)
	227	{
2baec2c3 DH	228	struct rxrpc_net *rxnet = conn->params.local->rxnet;
2baec2c3 DH	229
45025bce DH	230	ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
	231	!rcu_access_pointer(conn->channels[1].call) &&
	232	!rcu_access_pointer(conn->channels[2].call) &&
	233	!rcu_access_pointer(conn->channels[3].call));
	234	ASSERT(list_empty(&conn->cache_link));
	235
2baec2c3	236	write_lock(&rxnet->conn_lock);
45025bce	237	list_del_init(&conn->proc_link);
2baec2c3	238	write_unlock(&rxnet->conn_lock);
45025bce DH	239
	240	/* Drain the Rx queue. Note that even though we've unpublished, an
	241	* incoming packet could still be being added to our Rx queue, so we
	242	* will need to drain it again in the RCU cleanup handler.
	243	*/
	244	rxrpc_purge_queue(&conn->rx_queue);
	245
	246	/* Leave final destruction to RCU. The connection processor work item
	247	* must carry a ref on the connection to prevent us getting here whilst
	248	* it is queued or running.
	249	*/
	250	call_rcu(&conn->rcu, rxrpc_destroy_connection);
	251	}
	252
17926a79	253	/*
363deeab DH	254	* Queue a connection's work processor, getting a ref to pass to the work
363deeab DH	255	* queue.
17926a79	256	*/
363deeab	257	bool rxrpc_queue_conn(struct rxrpc_connection *conn)
17926a79	258	{
363deeab DH	259	const void *here = __builtin_return_address(0);
	260	int n = __atomic_add_unless(&conn->usage, 1, 0);
	261	if (n == 0)
	262	return false;
	263	if (rxrpc_queue_work(&conn->processor))
	264	trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 1, here);
	265	else
	266	rxrpc_put_connection(conn);
	267	return true;
	268	}
	269
	270	/*
	271	* Note the re-emergence of a connection.
	272	*/
	273	void rxrpc_see_connection(struct rxrpc_connection *conn)
	274	{
	275	const void *here = __builtin_return_address(0);
	276	if (conn) {
	277	int n = atomic_read(&conn->usage);
	278
	279	trace_rxrpc_conn(conn, rxrpc_conn_seen, n, here);
	280	}
	281	}
	282
	283	/*
	284	* Get a ref on a connection.
	285	*/
	286	void rxrpc_get_connection(struct rxrpc_connection *conn)
	287	{
	288	const void *here = __builtin_return_address(0);
	289	int n = atomic_inc_return(&conn->usage);
	290
	291	trace_rxrpc_conn(conn, rxrpc_conn_got, n, here);
	292	}
	293
	294	/*
	295	* Try to get a ref on a connection.
	296	*/
	297	struct rxrpc_connection *
	298	rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
	299	{
	300	const void *here = __builtin_return_address(0);
	301
	302	if (conn) {
	303	int n = __atomic_add_unless(&conn->usage, 1, 0);
	304	if (n > 0)
	305	trace_rxrpc_conn(conn, rxrpc_conn_got, n + 1, here);
	306	else
	307	conn = NULL;
	308	}
	309	return conn;
	310	}
	311
3d18cbb7 DH	312	/*
	313	* Set the service connection reap timer.
	314	*/
	315	static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
	316	unsigned long reap_at)
	317	{
	318	if (rxnet->live)
	319	timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
	320	}
	321
363deeab DH	322	/*
	323	* Release a service connection
	324	*/
	325	void rxrpc_put_service_conn(struct rxrpc_connection *conn)
	326	{
	327	const void *here = __builtin_return_address(0);
	328	int n;
	329
	330	n = atomic_dec_return(&conn->usage);
	331	trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here);
	332	ASSERTCMP(n, >=, 0);
3d18cbb7 DH	333	if (n == 1)
	334	rxrpc_set_service_reap_timer(conn->params.local->rxnet,
	335	jiffies + rxrpc_connection_expiry);
17926a79 DH	336	}
	337
	338	/*
	339	* destroy a virtual connection
	340	*/
dee46364	341	static void rxrpc_destroy_connection(struct rcu_head *rcu)
17926a79	342	{
dee46364 DH	343	struct rxrpc_connection *conn =
	344	container_of(rcu, struct rxrpc_connection, rcu);
	345
	346	_enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
17926a79 DH	347
	348	ASSERTCMP(atomic_read(&conn->usage), ==, 0);
	349
	350	_net("DESTROY CONN %d", conn->debug_id);
	351
3136ef49	352	del_timer_sync(&conn->timer);
17926a79 DH	353	rxrpc_purge_queue(&conn->rx_queue);
17926a79 DH	354
e0e4d82f	355	conn->security->clear(conn);
19ffa01c	356	key_put(conn->params.key);
e0e4d82f	357	key_put(conn->server_key);
aa390bbe DH	358	rxrpc_put_peer(conn->params.peer);
aa390bbe DH	359	rxrpc_put_local(conn->params.local);
e0e4d82f	360
17926a79 DH	361	kfree(conn);
	362	_leave("");
	363	}
	364
	365	/*
45025bce	366	* reap dead service connections
17926a79	367	*/
2baec2c3	368	void rxrpc_service_connection_reaper(struct work_struct *work)
17926a79 DH	369	{
17926a79 DH	370	struct rxrpc_connection conn, _p;
2baec2c3	371	struct rxrpc_net *rxnet =
3d18cbb7	372	container_of(work, struct rxrpc_net, service_conn_reaper);
f859ab61	373	unsigned long expire_at, earliest, idle_timestamp, now;
17926a79 DH	374
	375	LIST_HEAD(graveyard);
	376
	377	_enter("");
	378
f51b4480	379	now = jiffies;
f859ab61	380	earliest = now + MAX_JIFFY_OFFSET;
17926a79	381
2baec2c3 DH	382	write_lock(&rxnet->conn_lock);
2baec2c3 DH	383	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
001c1122 DH	384	ASSERTCMP(atomic_read(&conn->usage), >, 0);
001c1122 DH	385	if (likely(atomic_read(&conn->usage) > 1))
17926a79	386	continue;
00e90712 DH	387	if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
00e90712 DH	388	continue;
17926a79	389
580b8978	390	if (rxnet->live && !conn->params.local->dead) {
f859ab61 DH	391	idle_timestamp = READ_ONCE(conn->idle_timestamp);
	392	expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
	393	if (conn->params.local->service_closed)
	394	expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
	395
	396	_debug("reap CONN %d { u=%d,t=%ld }",
	397	conn->debug_id, atomic_read(&conn->usage),
	398	(long)expire_at - (long)now);
	399
	400	if (time_before(now, expire_at)) {
	401	if (time_before(expire_at, earliest))
	402	earliest = expire_at;
	403	continue;
	404	}
17926a79	405	}
001c1122 DH	406
	407	/* The usage count sits at 1 whilst the object is unused on the
	408	* list; we reduce that to 0 to make the object unavailable.
	409	*/
	410	if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
	411	continue;
f859ab61	412	trace_rxrpc_conn(conn, rxrpc_conn_reap_service, 0, 0);
001c1122 DH	413
001c1122 DH	414	if (rxrpc_conn_is_client(conn))
45025bce	415	BUG();
001c1122 DH	416	else
	417	rxrpc_unpublish_service_conn(conn);
	418
	419	list_move_tail(&conn->link, &graveyard);
17926a79	420	}
2baec2c3	421	write_unlock(&rxnet->conn_lock);
17926a79	422
f859ab61 DH	423	if (earliest != now + MAX_JIFFY_OFFSET) {
f859ab61 DH	424	_debug("reschedule reaper %ld", (long)earliest - (long)now);
f51b4480	425	ASSERT(time_after(earliest, now));
3d7682af	426	rxrpc_set_service_reap_timer(rxnet, earliest);
17926a79 DH	427	}
17926a79 DH	428
17926a79 DH	429	while (!list_empty(&graveyard)) {
	430	conn = list_entry(graveyard.next, struct rxrpc_connection,
	431	link);
	432	list_del_init(&conn->link);
	433
	434	ASSERTCMP(atomic_read(&conn->usage), ==, 0);
45025bce	435	rxrpc_kill_connection(conn);
17926a79 DH	436	}
	437
	438	_leave("");
	439	}
	440
	441	/*
45025bce DH	442	* preemptively destroy all the service connection records rather than
45025bce DH	443	* waiting for them to time out
17926a79	444	*/
2baec2c3	445	void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
17926a79	446	{
dee46364 DH	447	struct rxrpc_connection conn, _p;
	448	bool leak = false;
	449
17926a79 DH	450	_enter("");
17926a79 DH	451
2baec2c3	452	rxrpc_destroy_all_client_connections(rxnet);
45025bce	453
3d18cbb7 DH	454	del_timer_sync(&rxnet->service_conn_reap_timer);
3d18cbb7 DH	455	rxrpc_queue_work(&rxnet->service_conn_reaper);
dee46364 DH	456	flush_workqueue(rxrpc_workqueue);
dee46364 DH	457
2baec2c3 DH	458	write_lock(&rxnet->conn_lock);
2baec2c3 DH	459	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
dee46364 DH	460	pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
	461	conn, atomic_read(&conn->usage));
	462	leak = true;
	463	}
2baec2c3	464	write_unlock(&rxnet->conn_lock);
dee46364 DH	465	BUG_ON(leak);
dee46364 DH	466
2baec2c3	467	ASSERT(list_empty(&rxnet->conn_proc_list));
17926a79 DH	468
	469	_leave("");
	470	}