1 files changed, 491 insertions, 0 deletions

diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
new file mode 100644
index 000000000..2adb7c5c8
--- /dev/null
+++ b/net/rxrpc/conn_object.c
@@ -0,0 +1,491 @@
+/* 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.
+ *
+ * When searching for a service call, if we find a peer but no connection, we
+ * return that through *_peer in case we need to create a new service call.
+ *
+ * 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_peer **_peer)
+{
+	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;
+
+	/* 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;
+		*_peer = peer;
+		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);
+		switch (call->completion) {
+		case RXRPC_CALL_SUCCEEDED:
+			chan->last_seq = call->rx_hard_ack;
+			chan->last_type = RXRPC_PACKET_TYPE_ACK;
+			break;
+		case RXRPC_CALL_LOCALLY_ABORTED:
+			chan->last_abort = call->abort_code;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		default:
+			chan->last_abort = RX_USER_ABORT;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		}
+
+		/* 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;
+
+	if (!hlist_unhashed(&call->error_link)) {
+		spin_lock_bh(&call->peer->lock);
+		hlist_del_rcu(&call->error_link);
+		spin_unlock_bh(&call->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_fetch_add_unless(&conn->usage, 1, 0);
+	if (n == 0)
+		return false;
+	if (rxrpc_queue_work(&conn->processor))
+		trace_rxrpc_conn(conn->debug_id, 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->debug_id, 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->debug_id, 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_fetch_add_unless(&conn->usage, 1, 0);
+		if (n > 0)
+			trace_rxrpc_conn(conn->debug_id, 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);
+	unsigned int debug_id = conn->debug_id;
+	int n;
+
+	n = atomic_dec_return(&conn->usage);
+	trace_rxrpc_conn(debug_id, 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);
+
+	if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
+		wake_up_var(&conn->params.local->rxnet->nr_conns);
+	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->debug_id, rxrpc_conn_reap_service, 0, NULL);
+
+		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("");
+
+	atomic_dec(&rxnet->nr_conns);
+	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));
+
+	/* We need to wait for the connections to be destroyed by RCU as they
+	 * pin things that we still need to get rid of.
+	 */
+	wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));
+	_leave("");
+}