// 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_obj(struct rxrpc_local);	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->sk, &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();	}}