rxrpc: Support network namespacing

Support network namespacing in AF_RXRPC with the following changes:

 (1) All the local endpoint, peer and call lists, locks, counters, etc. are
     moved into the per-namespace record.

 (2) All the connection tracking is moved into the per-namespace record
     with the exception of the client connection ID tree, which is kept
     global so that connection IDs are kept unique per-machine.

 (3) Each namespace gets its own epoch.  This allows each network namespace
     to pretend to be a separate client machine.

 (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and
     the contents reflect the namespace.

fs/afs/ should be okay with this patch as it explicitly requires the current
net namespace to be init_net to permit a mount to proceed at the moment.  It
will, however, need updating so that cells, IP addresses and DNS records are
per-namespace also.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 85 insertions, 0 deletions

diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
new file mode 100644
index 000000000000..26449a6bb076
--- /dev/null
+++ b/net/rxrpc/net_ns.c
@@ -0,0 +1,85 @@
+/* rxrpc network namespace handling.
+ *
+ * Copyright (C) 2017 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 Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/proc_fs.h>
+#include "ar-internal.h"
+
+unsigned int rxrpc_net_id;
+
+/*
+ * Initialise a per-network namespace record.
+ */
+static __net_init int rxrpc_init_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+	int ret;
+
+	get_random_bytes(&rxnet->epoch, sizeof(rxnet->epoch));
+	rxnet->epoch |= RXRPC_RANDOM_EPOCH;
+
+	INIT_LIST_HEAD(&rxnet->calls);
+	rwlock_init(&rxnet->call_lock);
+
+	INIT_LIST_HEAD(&rxnet->conn_proc_list);
+	INIT_LIST_HEAD(&rxnet->service_conns);
+	rwlock_init(&rxnet->conn_lock);
+	INIT_DELAYED_WORK(&rxnet->service_conn_reaper,
+			  rxrpc_service_connection_reaper);
+
+	rxnet->nr_client_conns = 0;
+	rxnet->nr_active_client_conns = 0;
+	rxnet->kill_all_client_conns = false;
+	spin_lock_init(&rxnet->client_conn_cache_lock);
+	spin_lock_init(&rxnet->client_conn_discard_lock);
+	INIT_LIST_HEAD(&rxnet->waiting_client_conns);
+	INIT_LIST_HEAD(&rxnet->active_client_conns);
+	INIT_LIST_HEAD(&rxnet->idle_client_conns);
+	INIT_DELAYED_WORK(&rxnet->client_conn_reaper,
+			  rxrpc_discard_expired_client_conns);
+
+	INIT_LIST_HEAD(&rxnet->local_endpoints);
+	mutex_init(&rxnet->local_mutex);
+	hash_init(rxnet->peer_hash);
+	spin_lock_init(&rxnet->peer_hash_lock);
+
+	ret = -ENOMEM;
+	rxnet->proc_net = proc_net_mkdir(net, "rxrpc", net->proc_net);
+	if (!rxnet->proc_net)
+		goto err_proc;
+
+	proc_create("calls", 0444, rxnet->proc_net, &rxrpc_call_seq_fops);
+	proc_create("conns", 0444, rxnet->proc_net, &rxrpc_connection_seq_fops);
+	return 0;
+
+	proc_remove(rxnet->proc_net);
+err_proc:
+	return ret;
+}
+
+/*
+ * Clean up a per-network namespace record.
+ */
+static __net_exit void rxrpc_exit_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+
+	rxrpc_destroy_all_calls(rxnet);
+	rxrpc_destroy_all_connections(rxnet);
+	rxrpc_destroy_all_locals(rxnet);
+	proc_remove(rxnet->proc_net);
+}
+
+struct pernet_operations rxrpc_net_ops = {
+	.init	= rxrpc_init_net,
+	.exit	= rxrpc_exit_net,
+	.id	= &rxrpc_net_id,
+	.size	= sizeof(struct rxrpc_net),
+};