1 files changed, 340 insertions, 0 deletions
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
new file mode 100644
index 000000000000..896d84493a05
--- /dev/null
+++ b/net/rxrpc/conn_object.c
@@ -0,0 +1,340 @@
+/* RxRPC virtual connection handler
+ *
+ * Copyright (C) 2007 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 <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Time till a connection expires after last use (in seconds).
+ */
+unsigned int rxrpc_connection_expiry = 10 * 60;
+
+static void rxrpc_connection_reaper(struct work_struct *work);
+
+LIST_HEAD(rxrpc_connections);
+DEFINE_RWLOCK(rxrpc_connection_lock);
+static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
+
+/*
+ * 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) {
+		spin_lock_init(&conn->channel_lock);
+		init_waitqueue_head(&conn->channel_wq);
+		INIT_WORK(&conn->processor, &rxrpc_process_connection);
+		INIT_LIST_HEAD(&conn->link);
+		skb_queue_head_init(&conn->rx_queue);
+		conn->security = &rxrpc_no_security;
+		spin_lock_init(&conn->state_lock);
+		/* We maintain an extra ref on the connection whilst it is
+		 * on the rxrpc_connections list.
+		 */
+		atomic_set(&conn->usage, 2);
+		conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		atomic_set(&conn->avail_chans, RXRPC_MAXCALLS);
+		conn->size_align = 4;
+		conn->header_size = sizeof(struct rxrpc_wire_header);
+	}
+
+	_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(&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 (sp->hdr.flags & RXRPC_CLIENT_INITIATED) {
+		/* 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;
+		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_call *call)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_channel *chan = &conn->channels[call->channel];
+
+	_enter("%d,%d", conn->debug_id, call->channel);
+
+	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.
+		 */
+		chan->last_result = call->local_abort;
+		smp_wmb();
+		chan->last_call = chan->call_id;
+		chan->call_id = chan->call_counter;
+
+		rcu_assign_pointer(chan->call, NULL);
+		atomic_inc(&conn->avail_chans);
+		wake_up(&conn->channel_wq);
+	}
+
+	_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;
+
+	spin_lock(&conn->channel_lock);
+	__rxrpc_disconnect_call(call);
+	spin_unlock(&conn->channel_lock);
+
+	call->conn = NULL;
+	rxrpc_put_connection(conn);
+}
+
+/*
+ * release a virtual connection
+ */
+void rxrpc_put_connection(struct rxrpc_connection *conn)
+{
+	if (!conn)
+		return;
+
+	_enter("%p{u=%d,d=%d}",
+	       conn, atomic_read(&conn->usage), conn->debug_id);
+
+	ASSERTCMP(atomic_read(&conn->usage), >, 1);
+
+	conn->put_time = ktime_get_seconds();
+	if (atomic_dec_return(&conn->usage) == 1) {
+		_debug("zombie");
+		rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
+	}
+
+	_leave("");
+}
+
+/*
+ * 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);
+
+	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 connections
+ */
+static void rxrpc_connection_reaper(struct work_struct *work)
+{
+	struct rxrpc_connection *conn, *_p;
+	unsigned long reap_older_than, earliest, put_time, now;
+
+	LIST_HEAD(graveyard);
+
+	_enter("");
+
+	now = ktime_get_seconds();
+	reap_older_than =  now - rxrpc_connection_expiry;
+	earliest = ULONG_MAX;
+
+	write_lock(&rxrpc_connection_lock);
+	list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
+		ASSERTCMP(atomic_read(&conn->usage), >, 0);
+		if (likely(atomic_read(&conn->usage) > 1))
+			continue;
+
+		put_time = READ_ONCE(conn->put_time);
+		if (time_after(put_time, reap_older_than)) {
+			if (time_before(put_time, earliest))
+				earliest = put_time;
+			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;
+
+		if (rxrpc_conn_is_client(conn))
+			rxrpc_unpublish_client_conn(conn);
+		else
+			rxrpc_unpublish_service_conn(conn);
+
+		list_move_tail(&conn->link, &graveyard);
+	}
+	write_unlock(&rxrpc_connection_lock);
+
+	if (earliest != ULONG_MAX) {
+		_debug("reschedule reaper %ld", (long) earliest - now);
+		ASSERTCMP(earliest, >, now);
+		rxrpc_queue_delayed_work(&rxrpc_connection_reap,
+					 (earliest - now) * HZ);
+	}
+
+	while (!list_empty(&graveyard)) {
+		conn = list_entry(graveyard.next, struct rxrpc_connection,
+				  link);
+		list_del_init(&conn->link);
+
+		ASSERTCMP(atomic_read(&conn->usage), ==, 0);
+		skb_queue_purge(&conn->rx_queue);
+		call_rcu(&conn->rcu, rxrpc_destroy_connection);
+	}
+
+	_leave("");
+}
+
+/*
+ * preemptively destroy all the connection records rather than waiting for them
+ * to time out
+ */
+void __exit rxrpc_destroy_all_connections(void)
+{
+	struct rxrpc_connection *conn, *_p;
+	bool leak = false;
+
+	_enter("");
+
+	rxrpc_connection_expiry = 0;
+	cancel_delayed_work(&rxrpc_connection_reap);
+	rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
+	flush_workqueue(rxrpc_workqueue);
+
+	write_lock(&rxrpc_connection_lock);
+	list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
+		pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
+		       conn, atomic_read(&conn->usage));
+		leak = true;
+	}
+	write_unlock(&rxrpc_connection_lock);
+	BUG_ON(leak);
+
+	/* Make sure the local and peer records pinned by any dying connections
+	 * are released.
+	 */
+	rcu_barrier();
+	rxrpc_destroy_client_conn_ids();
+
+	_leave("");
+}