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-rw-r--r--net/rxrpc/conn_object.c340
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 000000000..896d84493
--- /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("");
+}