1 files changed, 488 insertions, 0 deletions

diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
new file mode 100644
index 000000000..34d307368
--- /dev/null
+++ b/net/rxrpc/local_object.c
@@ -0,0 +1,488 @@
+// 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);
+
+		/* We want receive timestamps. */
+		sock_enable_timestamps(usk);
+		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);
+	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);
+}
+
+/*
+ * 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();
+	}
+}