[linux-2.6-block.git] / net / rxrpc / local_object.c

// 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/udp_tunnel.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

static void rxrpc_local_rcu(struct rcu_head *);

/*
 * Handle an ICMP/ICMP6 error turning up at the tunnel.  Push it through the
 * usual mechanism so that it gets parsed and presented through the UDP
 * socket's error_report().
 */
static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err,
				__be16 port, u32 info, u8 *payload)
{
	if (ip_hdr(skb)->version == IPVERSION)
		return ip_icmp_error(sk, skb, err, port, info, payload);
	if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6))
		return ipv6_icmp_error(sk, skb, err, port, info, payload);
}

/*
 * Set or clear the Don't Fragment flag on a socket.
 */
void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set)
{
	if (set)
		ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
	else
		ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DONT);
}

/*
 * 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();
	}
}

static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
{
	struct rxrpc_local *local =
		container_of(timer, struct rxrpc_local, client_conn_reap_timer);

	if (!local->kill_all_client_conns &&
	    test_and_set_bit(RXRPC_CLIENT_CONN_REAP_TIMER, &local->client_conn_flags))
		rxrpc_wake_up_io_thread(local);
}

/*
 * Allocate a new local endpoint.
 */
static struct rxrpc_local *rxrpc_alloc_local(struct net *net,
					     const struct sockaddr_rxrpc *srx)
{
	struct rxrpc_local *local;
	u32 tmp;

	local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
	if (local) {
		refcount_set(&local->ref, 1);
		atomic_set(&local->active_users, 1);
		local->net = net;
		local->rxnet = rxrpc_net(net);
		INIT_HLIST_NODE(&local->link);
		init_completion(&local->io_thread_ready);
#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
		skb_queue_head_init(&local->rx_delay_queue);
#endif
		skb_queue_head_init(&local->rx_queue);
		INIT_LIST_HEAD(&local->conn_attend_q);
		INIT_LIST_HEAD(&local->call_attend_q);

		local->client_bundles = RB_ROOT;
		spin_lock_init(&local->client_bundles_lock);
		local->kill_all_client_conns = false;
		INIT_LIST_HEAD(&local->idle_client_conns);
		timer_setup(&local->client_conn_reap_timer,
			    rxrpc_client_conn_reap_timeout, 0);

		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;
		idr_init(&local->conn_ids);
		get_random_bytes(&tmp, sizeof(tmp));
		tmp &= 0x3fffffff;
		if (tmp == 0)
			tmp = 1;
		idr_set_cursor(&local->conn_ids, tmp);
		INIT_LIST_HEAD(&local->new_client_calls);
		spin_lock_init(&local->client_call_lock);

		trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1);
	}

	_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 udp_tunnel_sock_cfg tuncfg = {NULL};
	struct sockaddr_rxrpc *srx = &local->srx;
	struct udp_port_cfg udp_conf = {0};
	struct task_struct *io_thread;
	struct sock *usk;
	int ret;

	_enter("%p{%d,%d}",
	       local, srx->transport_type, srx->transport.family);

	udp_conf.family = srx->transport.family;
	udp_conf.use_udp_checksums = true;
	if (udp_conf.family == AF_INET) {
		udp_conf.local_ip = srx->transport.sin.sin_addr;
		udp_conf.local_udp_port = srx->transport.sin.sin_port;
#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
	} else {
		udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
		udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
		udp_conf.use_udp6_tx_checksums = true;
		udp_conf.use_udp6_rx_checksums = true;
#endif
	}
	ret = udp_sock_create(net, &udp_conf, &local->socket);
	if (ret < 0) {
		_leave(" = %d [socket]", ret);
		return ret;
	}

	tuncfg.encap_type = UDP_ENCAP_RXRPC;
	tuncfg.encap_rcv = rxrpc_encap_rcv;
	tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
	tuncfg.sk_user_data = local;
	setup_udp_tunnel_sock(net, local->socket, &tuncfg);

	/* set the socket up */
	usk = local->socket->sk;
	usk->sk_error_report = rxrpc_error_report;

	switch (srx->transport.family) {
	case AF_INET6:
		/* we want to receive ICMPv6 errors */
		ip6_sock_set_recverr(usk);

		/* 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(usk);

		/* we want to set the don't fragment bit */
		rxrpc_local_dont_fragment(local, true);
		break;

	default:
		BUG();
	}

	io_thread = kthread_run(rxrpc_io_thread, local,
				"krxrpcio/%u", ntohs(udp_conf.local_udp_port));
	if (IS_ERR(io_thread)) {
		ret = PTR_ERR(io_thread);
		goto error_sock;
	}

	wait_for_completion(&local->io_thread_ready);
	WRITE_ONCE(local->io_thread, io_thread);
	_leave(" = 0");
	return 0;

error_sock:
	kernel_sock_shutdown(local->socket, SHUT_RDWR);
	local->socket->sk->sk_user_data = NULL;
	sock_release(local->socket);
	local->socket = NULL;
	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;
	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, rxrpc_local_use_lookup))
			break;

		goto found;
	}

	local = rxrpc_alloc_local(net, 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);
	}

found:
	mutex_unlock(&rxnet->local_mutex);
	_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,
				    enum rxrpc_local_trace why)
{
	int r, u;

	u = atomic_read(&local->active_users);
	__refcount_inc(&local->ref, &r);
	trace_rxrpc_local(local->debug_id, why, r + 1, u);
	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,
					  enum rxrpc_local_trace why)
{
	int r, u;

	if (local && __refcount_inc_not_zero(&local->ref, &r)) {
		u = atomic_read(&local->active_users);
		trace_rxrpc_local(local->debug_id, why, r + 1, u);
		return local;
	}

	return NULL;
}

/*
 * Drop a ref on a local endpoint.
 */
void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
{
	unsigned int debug_id;
	bool dead;
	int r, u;

	if (local) {
		debug_id = local->debug_id;

		u = atomic_read(&local->active_users);
		dead = __refcount_dec_and_test(&local->ref, &r);
		trace_rxrpc_local(debug_id, why, r, u);

		if (dead)
			call_rcu(&local->rcu, rxrpc_local_rcu);
	}
}

/*
 * Start using a local endpoint.
 */
struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local,
				    enum rxrpc_local_trace why)
{
	local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use);
	if (!local)
		return NULL;

	if (!__rxrpc_use_local(local, why)) {
		rxrpc_put_local(local, rxrpc_local_put_for_use);
		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 I/O thread..
 */
void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
{
	unsigned int debug_id;
	int r, u;

	if (local) {
		debug_id = local->debug_id;
		r = refcount_read(&local->ref);
		u = atomic_dec_return(&local->active_users);
		trace_rxrpc_local(debug_id, why, r, u);
		if (u == 0)
			kthread_stop(local->io_thread);
	}
}

/*
 * 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.
 */
void rxrpc_destroy_local(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.
	 */
#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
	rxrpc_purge_queue(&local->rx_delay_queue);
#endif
	rxrpc_purge_queue(&local->rx_queue);
	rxrpc_purge_client_connections(local);
	page_frag_cache_drain(&local->tx_alloc);
}

/*
 * 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);

	rxrpc_see_local(local, rxrpc_local_free);
	kfree(local);
}

/*
 * 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();
	}
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/* Local endpoint object management
	3	*
	4	* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
	6	*/
	7
	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	9
	10	#include <linux/module.h>
	11	#include <linux/net.h>
	12	#include <linux/skbuff.h>
	13	#include <linux/slab.h>
	14	#include <linux/udp.h>
	15	#include <linux/ip.h>
	16	#include <linux/hashtable.h>
	17	#include <net/sock.h>
	18	#include <net/udp.h>
	19	#include <net/udp_tunnel.h>
	20	#include <net/af_rxrpc.h>
	21	#include "ar-internal.h"
	22
	23	static void rxrpc_local_rcu(struct rcu_head *);
	24
	25	/*
	26	* Handle an ICMP/ICMP6 error turning up at the tunnel. Push it through the
	27	* usual mechanism so that it gets parsed and presented through the UDP
	28	* socket's error_report().
	29	*/
	30	static void rxrpc_encap_err_rcv(struct sock sk, struct sk_buff skb, int err,
	31	__be16 port, u32 info, u8 *payload)
	32	{
	33	if (ip_hdr(skb)->version == IPVERSION)
	34	return ip_icmp_error(sk, skb, err, port, info, payload);
	35	if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6))
	36	return ipv6_icmp_error(sk, skb, err, port, info, payload);
	37	}
	38
	39	/*
	40	* Set or clear the Don't Fragment flag on a socket.
	41	*/
	42	void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set)
	43	{
	44	if (set)
	45	ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
	46	else
	47	ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DONT);
	48	}
	49
	50	/*
	51	* Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
	52	* same or greater than.
	53	*
	54	* We explicitly don't compare the RxRPC service ID as we want to reject
	55	* conflicting uses by differing services. Further, we don't want to share
	56	* addresses with different options (IPv6), so we don't compare those bits
	57	* either.
	58	*/
	59	static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
	60	const struct sockaddr_rxrpc *srx)
	61	{
	62	long diff;
	63
	64	diff = ((local->srx.transport_type - srx->transport_type) ?:
	65	(local->srx.transport_len - srx->transport_len) ?:
	66	(local->srx.transport.family - srx->transport.family));
	67	if (diff != 0)
	68	return diff;
	69
	70	switch (srx->transport.family) {
	71	case AF_INET:
	72	/* If the choice of UDP port is left up to the transport, then
	73	* the endpoint record doesn't match.
	74	*/
	75	return ((u16 __force)local->srx.transport.sin.sin_port -
	76	(u16 __force)srx->transport.sin.sin_port) ?:
	77	memcmp(&local->srx.transport.sin.sin_addr,
	78	&srx->transport.sin.sin_addr,
	79	sizeof(struct in_addr));
	80	#ifdef CONFIG_AF_RXRPC_IPV6
	81	case AF_INET6:
	82	/* If the choice of UDP6 port is left up to the transport, then
	83	* the endpoint record doesn't match.
	84	*/
	85	return ((u16 __force)local->srx.transport.sin6.sin6_port -
	86	(u16 __force)srx->transport.sin6.sin6_port) ?:
	87	memcmp(&local->srx.transport.sin6.sin6_addr,
	88	&srx->transport.sin6.sin6_addr,
	89	sizeof(struct in6_addr));
	90	#endif
	91	default:
	92	BUG();
	93	}
	94	}
	95
	96	static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
	97	{
	98	struct rxrpc_local *local =
	99	container_of(timer, struct rxrpc_local, client_conn_reap_timer);
	100
	101	if (!local->kill_all_client_conns &&
	102	test_and_set_bit(RXRPC_CLIENT_CONN_REAP_TIMER, &local->client_conn_flags))
	103	rxrpc_wake_up_io_thread(local);
	104	}
	105
	106	/*
	107	* Allocate a new local endpoint.
	108	*/
	109	static struct rxrpc_local rxrpc_alloc_local(struct net net,
	110	const struct sockaddr_rxrpc *srx)
	111	{
	112	struct rxrpc_local *local;
	113	u32 tmp;
	114
	115	local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
	116	if (local) {
	117	refcount_set(&local->ref, 1);
	118	atomic_set(&local->active_users, 1);
	119	local->net = net;
	120	local->rxnet = rxrpc_net(net);
	121	INIT_HLIST_NODE(&local->link);
	122	init_completion(&local->io_thread_ready);
	123	#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
	124	skb_queue_head_init(&local->rx_delay_queue);
	125	#endif
	126	skb_queue_head_init(&local->rx_queue);
	127	INIT_LIST_HEAD(&local->conn_attend_q);
	128	INIT_LIST_HEAD(&local->call_attend_q);
	129
	130	local->client_bundles = RB_ROOT;
	131	spin_lock_init(&local->client_bundles_lock);
	132	local->kill_all_client_conns = false;
	133	INIT_LIST_HEAD(&local->idle_client_conns);
	134	timer_setup(&local->client_conn_reap_timer,
	135	rxrpc_client_conn_reap_timeout, 0);
	136
	137	spin_lock_init(&local->lock);
	138	rwlock_init(&local->services_lock);
	139	local->debug_id = atomic_inc_return(&rxrpc_debug_id);
	140	memcpy(&local->srx, srx, sizeof(*srx));
	141	local->srx.srx_service = 0;
	142	idr_init(&local->conn_ids);
	143	get_random_bytes(&tmp, sizeof(tmp));
	144	tmp &= 0x3fffffff;
	145	if (tmp == 0)
	146	tmp = 1;
	147	idr_set_cursor(&local->conn_ids, tmp);
	148	INIT_LIST_HEAD(&local->new_client_calls);
	149	spin_lock_init(&local->client_call_lock);
	150
	151	trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1);
	152	}
	153
	154	_leave(" = %p", local);
	155	return local;
	156	}
	157
	158	/*
	159	* create the local socket
	160	* - must be called with rxrpc_local_mutex locked
	161	*/
	162	static int rxrpc_open_socket(struct rxrpc_local local, struct net net)
	163	{
	164	struct udp_tunnel_sock_cfg tuncfg = {NULL};
	165	struct sockaddr_rxrpc *srx = &local->srx;
	166	struct udp_port_cfg udp_conf = {0};
	167	struct task_struct *io_thread;
	168	struct sock *usk;
	169	int ret;
	170
	171	_enter("%p{%d,%d}",
	172	local, srx->transport_type, srx->transport.family);
	173
	174	udp_conf.family = srx->transport.family;
	175	udp_conf.use_udp_checksums = true;
	176	if (udp_conf.family == AF_INET) {
	177	udp_conf.local_ip = srx->transport.sin.sin_addr;
	178	udp_conf.local_udp_port = srx->transport.sin.sin_port;
	179	#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
	180	} else {
	181	udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
	182	udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
	183	udp_conf.use_udp6_tx_checksums = true;
	184	udp_conf.use_udp6_rx_checksums = true;
	185	#endif
	186	}
	187	ret = udp_sock_create(net, &udp_conf, &local->socket);
	188	if (ret < 0) {
	189	_leave(" = %d [socket]", ret);
	190	return ret;
	191	}
	192
	193	tuncfg.encap_type = UDP_ENCAP_RXRPC;
	194	tuncfg.encap_rcv = rxrpc_encap_rcv;
	195	tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
	196	tuncfg.sk_user_data = local;
	197	setup_udp_tunnel_sock(net, local->socket, &tuncfg);
	198
	199	/* set the socket up */
	200	usk = local->socket->sk;
	201	usk->sk_error_report = rxrpc_error_report;
	202
	203	switch (srx->transport.family) {
	204	case AF_INET6:
	205	/* we want to receive ICMPv6 errors */
	206	ip6_sock_set_recverr(usk);
	207
	208	/* Fall through and set IPv4 options too otherwise we don't get
	209	* errors from IPv4 packets sent through the IPv6 socket.
	210	*/
	211	fallthrough;
	212	case AF_INET:
	213	/* we want to receive ICMP errors */
	214	ip_sock_set_recverr(usk);
	215
	216	/* we want to set the don't fragment bit */
	217	rxrpc_local_dont_fragment(local, true);
	218	break;
	219
	220	default:
	221	BUG();
	222	}
	223
	224	io_thread = kthread_run(rxrpc_io_thread, local,
	225	"krxrpcio/%u", ntohs(udp_conf.local_udp_port));
	226	if (IS_ERR(io_thread)) {
	227	ret = PTR_ERR(io_thread);
	228	goto error_sock;
	229	}
	230
	231	wait_for_completion(&local->io_thread_ready);
	232	WRITE_ONCE(local->io_thread, io_thread);
	233	_leave(" = 0");
	234	return 0;
	235
	236	error_sock:
	237	kernel_sock_shutdown(local->socket, SHUT_RDWR);
	238	local->socket->sk->sk_user_data = NULL;
	239	sock_release(local->socket);
	240	local->socket = NULL;
	241	return ret;
	242	}
	243
	244	/*
	245	* Look up or create a new local endpoint using the specified local address.
	246	*/
	247	struct rxrpc_local rxrpc_lookup_local(struct net net,
	248	const struct sockaddr_rxrpc *srx)
	249	{
	250	struct rxrpc_local *local;
	251	struct rxrpc_net *rxnet = rxrpc_net(net);
	252	struct hlist_node *cursor;
	253	long diff;
	254	int ret;
	255
	256	_enter("{%d,%d,%pISp}",
	257	srx->transport_type, srx->transport.family, &srx->transport);
	258
	259	mutex_lock(&rxnet->local_mutex);
	260
	261	hlist_for_each(cursor, &rxnet->local_endpoints) {
	262	local = hlist_entry(cursor, struct rxrpc_local, link);
	263
	264	diff = rxrpc_local_cmp_key(local, srx);
	265	if (diff != 0)
	266	continue;
	267
	268	/* Services aren't allowed to share transport sockets, so
	269	* reject that here. It is possible that the object is dying -
	270	* but it may also still have the local transport address that
	271	* we want bound.
	272	*/
	273	if (srx->srx_service) {
	274	local = NULL;
	275	goto addr_in_use;
	276	}
	277
	278	/* Found a match. We want to replace a dying object.
	279	* Attempting to bind the transport socket may still fail if
	280	* we're attempting to use a local address that the dying
	281	* object is still using.
	282	*/
	283	if (!rxrpc_use_local(local, rxrpc_local_use_lookup))
	284	break;
	285
	286	goto found;
	287	}
	288
	289	local = rxrpc_alloc_local(net, srx);
	290	if (!local)
	291	goto nomem;
	292
	293	ret = rxrpc_open_socket(local, net);
	294	if (ret < 0)
	295	goto sock_error;
	296
	297	if (cursor) {
	298	hlist_replace_rcu(cursor, &local->link);
	299	cursor->pprev = NULL;
	300	} else {
	301	hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
	302	}
	303
	304	found:
	305	mutex_unlock(&rxnet->local_mutex);
	306	_leave(" = %p", local);
	307	return local;
	308
	309	nomem:
	310	ret = -ENOMEM;
	311	sock_error:
	312	mutex_unlock(&rxnet->local_mutex);
	313	if (local)
	314	call_rcu(&local->rcu, rxrpc_local_rcu);
	315	_leave(" = %d", ret);
	316	return ERR_PTR(ret);
	317
	318	addr_in_use:
	319	mutex_unlock(&rxnet->local_mutex);
	320	_leave(" = -EADDRINUSE");
	321	return ERR_PTR(-EADDRINUSE);
	322	}
	323
	324	/*
	325	* Get a ref on a local endpoint.
	326	*/
	327	struct rxrpc_local rxrpc_get_local(struct rxrpc_local local,
	328	enum rxrpc_local_trace why)
	329	{
	330	int r, u;
	331
	332	u = atomic_read(&local->active_users);
	333	__refcount_inc(&local->ref, &r);
	334	trace_rxrpc_local(local->debug_id, why, r + 1, u);
	335	return local;
	336	}
	337
	338	/*
	339	* Get a ref on a local endpoint unless its usage has already reached 0.
	340	*/
	341	struct rxrpc_local rxrpc_get_local_maybe(struct rxrpc_local local,
	342	enum rxrpc_local_trace why)
	343	{
	344	int r, u;
	345
	346	if (local && __refcount_inc_not_zero(&local->ref, &r)) {
	347	u = atomic_read(&local->active_users);
	348	trace_rxrpc_local(local->debug_id, why, r + 1, u);
	349	return local;
	350	}
	351
	352	return NULL;
	353	}
	354
	355	/*
	356	* Drop a ref on a local endpoint.
	357	*/
	358	void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
	359	{
	360	unsigned int debug_id;
	361	bool dead;
	362	int r, u;
	363
	364	if (local) {
	365	debug_id = local->debug_id;
	366
	367	u = atomic_read(&local->active_users);
	368	dead = __refcount_dec_and_test(&local->ref, &r);
	369	trace_rxrpc_local(debug_id, why, r, u);
	370
	371	if (dead)
	372	call_rcu(&local->rcu, rxrpc_local_rcu);
	373	}
	374	}
	375
	376	/*
	377	* Start using a local endpoint.
	378	*/
	379	struct rxrpc_local rxrpc_use_local(struct rxrpc_local local,
	380	enum rxrpc_local_trace why)
	381	{
	382	local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use);
	383	if (!local)
	384	return NULL;
	385
	386	if (!__rxrpc_use_local(local, why)) {
	387	rxrpc_put_local(local, rxrpc_local_put_for_use);
	388	return NULL;
	389	}
	390
	391	return local;
	392	}
	393
	394	/*
	395	* Cease using a local endpoint. Once the number of active users reaches 0, we
	396	* start the closure of the transport in the I/O thread..
	397	*/
	398	void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
	399	{
	400	unsigned int debug_id;
	401	int r, u;
	402
	403	if (local) {
	404	debug_id = local->debug_id;
	405	r = refcount_read(&local->ref);
	406	u = atomic_dec_return(&local->active_users);
	407	trace_rxrpc_local(debug_id, why, r, u);
	408	if (u == 0)
	409	kthread_stop(local->io_thread);
	410	}
	411	}
	412
	413	/*
	414	* Destroy a local endpoint's socket and then hand the record to RCU to dispose
	415	* of.
	416	*
	417	* Closing the socket cannot be done from bottom half context or RCU callback
	418	* context because it might sleep.
	419	*/
	420	void rxrpc_destroy_local(struct rxrpc_local *local)
	421	{
	422	struct socket *socket = local->socket;
	423	struct rxrpc_net *rxnet = local->rxnet;
	424
	425	_enter("%d", local->debug_id);
	426
	427	local->dead = true;
	428
	429	mutex_lock(&rxnet->local_mutex);
	430	hlist_del_init_rcu(&local->link);
	431	mutex_unlock(&rxnet->local_mutex);
	432
	433	rxrpc_clean_up_local_conns(local);
	434	rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
	435	ASSERT(!local->service);
	436
	437	if (socket) {
	438	local->socket = NULL;
	439	kernel_sock_shutdown(socket, SHUT_RDWR);
	440	socket->sk->sk_user_data = NULL;
	441	sock_release(socket);
	442	}
	443
	444	/* At this point, there should be no more packets coming in to the
	445	* local endpoint.
	446	*/
	447	#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
	448	rxrpc_purge_queue(&local->rx_delay_queue);
	449	#endif
	450	rxrpc_purge_queue(&local->rx_queue);
	451	rxrpc_purge_client_connections(local);
	452	page_frag_cache_drain(&local->tx_alloc);
	453	}
	454
	455	/*
	456	* Destroy a local endpoint after the RCU grace period expires.
	457	*/
	458	static void rxrpc_local_rcu(struct rcu_head *rcu)
	459	{
	460	struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
	461
	462	rxrpc_see_local(local, rxrpc_local_free);
	463	kfree(local);
	464	}
	465
	466	/*
	467	* Verify the local endpoint list is empty by this point.
	468	*/
	469	void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
	470	{
	471	struct rxrpc_local *local;
	472
	473	_enter("");
	474
	475	flush_workqueue(rxrpc_workqueue);
	476
	477	if (!hlist_empty(&rxnet->local_endpoints)) {
	478	mutex_lock(&rxnet->local_mutex);
	479	hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
	480	pr_err("AF_RXRPC: Leaked local %p {%d}\n",
	481	local, refcount_read(&local->ref));
	482	}
	483	mutex_unlock(&rxnet->local_mutex);
	484	BUG();
	485	}
	486	}