rxrpc: procfs file to list local endpoints

Add a proc file to list local rxrpc endpoints using the object cache
facility to do much of the work.
Signed-off-by: David Howells <dhowells@redhat.com>

net/rxrpc/af_rxrpc.c

@@ -842,6 +842,8 @@ static int __init af_rxrpc_init(void)
 	proc_create("rxrpc_calls", 0, init_net.proc_net, &rxrpc_call_seq_fops);
 	proc_create("rxrpc_conns", 0, init_net.proc_net,
 		    &rxrpc_connection_seq_fops);
+	proc_create_data("rxrpc_locals", 0, init_net.proc_net,
+			 &objcache_seq_fops, &rxrpc_local_cache);
 #endif
 	return 0;
 
@@ -883,6 +885,7 @@ static void __exit af_rxrpc_exit(void)
 
 	_debug("flush scheduled work");
 	flush_workqueue(rxrpc_workqueue);
+	remove_proc_entry("rxrpc_locals", init_net.proc_net);
 	remove_proc_entry("rxrpc_conns", init_net.proc_net);
 	remove_proc_entry("rxrpc_calls", init_net.proc_net);
 	destroy_workqueue(rxrpc_workqueue);

net/rxrpc/local-object.c

@@ -19,6 +19,7 @@
 #include <net/af_rxrpc.h>
 #include "ar-internal.h"
 
+static int rxrpc_local_seq_show(struct seq_file *, void *);
 static void rxrpc_local_prepare_for_gc(struct obj_node *);
 static void rxrpc_local_gc_rcu(struct rcu_head *);
 static unsigned long rxrpc_local_hash_key(const void *);
@@ -29,6 +30,7 @@ static struct hlist_head rxrpc_local_cache_hash[16];
 
 struct objcache rxrpc_local_cache = {
 	.name		= "locals",
+	.seq_show	= rxrpc_local_seq_show,
 	.prepare_for_gc	= rxrpc_local_prepare_for_gc,
 	.gc_rcu		= rxrpc_local_gc_rcu,
 	.hash_key	= rxrpc_local_hash_key,
@@ -309,3 +311,30 @@ static void rxrpc_local_gc_rcu(struct rcu_head *rcu)
 	objcache_obj_rcu_done(&rxrpc_local_cache);
 	_leave("");
 }
+
+/*
+ * Display a local endpoint in /proc/net/rxrpc_locals.
+ */
+static int rxrpc_local_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_local *local;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq, "Use Proto LPort Local\n");
+		return 0;
+	}
+
+	local = hlist_entry(v, struct rxrpc_local, obj.link);
+
+	switch (local->srx.transport.family) {
+	case AF_INET:
+		seq_printf(seq,
+			   "%3d UDP   %5hu %pI4\n",
+			   atomic_read(&local->obj.usage),
+			   ntohs(local->srx.transport.sin.sin_port),
+			   &local->srx.transport.sin.sin_addr);
+		break;
+	}
+
+	return 0;
+}