Commit 33912c26 authored by David Howells's avatar David Howells Committed by David S. Miller
Browse files

rxrpc: Allow list of in-use local UDP endpoints to be viewed in /proc 



Allow the list of in-use local UDP endpoints in the current network
namespace to be viewed in /proc.

To aid with this, the endpoint list is converted to an hlist and RCU-safe
manipulation is used so that the list can be read with only the RCU
read lock held.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0598cec9

net/rxrpc/ar-internal.h

+3 −2
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ struct rxrpc_net { 
	struct work_struct	client_conn_reaper;

	struct timer_list	client_conn_reap_timer;



	struct list_head	local_endpoints;

	struct hlist_head	local_endpoints;

	struct mutex		local_mutex;	/* Lock for ->local_endpoints */



	DECLARE_HASHTABLE	(peer_hash, 10);
@@ -281,7 +281,7 @@ struct rxrpc_local { 
	atomic_t		active_users;	/* Number of users of the local endpoint */

	atomic_t		usage;		/* Number of references to the structure */

	struct rxrpc_net	*rxnet;		/* The network ns in which this resides */

	struct list_head	link;

	struct hlist_node	link;

	struct socket		*socket;	/* my UDP socket */

	struct work_struct	processor;

	struct rxrpc_sock __rcu	*service;	/* Service(s) listening on this endpoint */
@@ -1014,6 +1014,7 @@ void rxrpc_put_peer_locked(struct rxrpc_peer *); 
extern const struct seq_operations rxrpc_call_seq_ops;

extern const struct seq_operations rxrpc_connection_seq_ops;

extern const struct seq_operations rxrpc_peer_seq_ops;

extern const struct seq_operations rxrpc_local_seq_ops;



/*

 * recvmsg.c

net/rxrpc/local_object.c

+18 −19
Original line number Diff line number Diff line
@@ -82,7 +82,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, 
		atomic_set(&local->usage, 1);

		atomic_set(&local->active_users, 1);

		local->rxnet = rxnet;

		INIT_LIST_HEAD(&local->link);

		INIT_HLIST_NODE(&local->link);

		INIT_WORK(&local->processor, rxrpc_local_processor);

		init_rwsem(&local->defrag_sem);

		skb_queue_head_init(&local->reject_queue);
@@ -180,7 +180,7 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, 
{

	struct rxrpc_local *local;

	struct rxrpc_net *rxnet = rxrpc_net(net);

	struct list_head *cursor;

	struct hlist_node *cursor;

	const char *age;

	long diff;

	int ret;
@@ -190,16 +190,12 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, 


	mutex_lock(&rxnet->local_mutex);



	for (cursor = rxnet->local_endpoints.next;

	     cursor != &rxnet->local_endpoints;

	     cursor = cursor->next) {

		local = list_entry(cursor, struct rxrpc_local, link);

	hlist_for_each(cursor, &rxnet->local_endpoints) {

		local = hlist_entry(cursor, struct rxrpc_local, link);



		diff = rxrpc_local_cmp_key(local, srx);

		if (diff < 0)

		if (diff != 0)

			continue;

		if (diff > 0)

			break;



		/* Services aren't allowed to share transport sockets, so

		 * reject that here.  It is possible that the object is dying -
@@ -211,9 +207,10 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, 
			goto addr_in_use;

		}



		/* Found a match.  We replace a dying object.  Attempting to

		 * bind the transport socket may still fail if we're attempting

		 * to use a local address that the dying object is still using.

		/* Found a match.  We want to replace a dying object.

		 * Attempting to bind the transport socket may still fail if

		 * we're attempting to use a local address that the dying

		 * object is still using.

		 */

		if (!rxrpc_use_local(local))

			break;
@@ -230,10 +227,12 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, 
	if (ret < 0)

		goto sock_error;



	if (cursor != &rxnet->local_endpoints)

		list_replace_init(cursor, &local->link);

	else

		list_add_tail(&local->link, cursor);

	if (cursor) {

		hlist_replace_rcu(cursor, &local->link);

		cursor->pprev = NULL;

	} else {

		hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);

	}

	age = "new";



found:
@@ -374,7 +373,7 @@ static void rxrpc_local_destroyer(struct rxrpc_local *local) 
	local->dead = true;



	mutex_lock(&rxnet->local_mutex);

	list_del_init(&local->link);

	hlist_del_init_rcu(&local->link);

	mutex_unlock(&rxnet->local_mutex);



	rxrpc_clean_up_local_conns(local);
@@ -458,9 +457,9 @@ void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet) 


	flush_workqueue(rxrpc_workqueue);



	if (!list_empty(&rxnet->local_endpoints)) {

	if (!hlist_empty(&rxnet->local_endpoints)) {

		mutex_lock(&rxnet->local_mutex);

		list_for_each_entry(local, &rxnet->local_endpoints, link) {

		hlist_for_each_entry(local, &rxnet->local_endpoints, link) {

			pr_err("AF_RXRPC: Leaked local %p {%d}\n",

			       local, atomic_read(&local->usage));

		}

net/rxrpc/net_ns.c

+4 −1
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ static __net_init int rxrpc_init_net(struct net *net) 
	timer_setup(&rxnet->client_conn_reap_timer,

		    rxrpc_client_conn_reap_timeout, 0);



	INIT_LIST_HEAD(&rxnet->local_endpoints);

	INIT_HLIST_HEAD(&rxnet->local_endpoints);

	mutex_init(&rxnet->local_mutex);



	hash_init(rxnet->peer_hash);
@@ -98,6 +98,9 @@ static __net_init int rxrpc_init_net(struct net *net) 
	proc_create_net("peers", 0444, rxnet->proc_net,

			&rxrpc_peer_seq_ops,

			sizeof(struct seq_net_private));

	proc_create_net("locals", 0444, rxnet->proc_net,

			&rxrpc_local_seq_ops,

			sizeof(struct seq_net_private));

	return 0;



err_proc:

net/rxrpc/proc.c

+69 −0
Original line number Diff line number Diff line
@@ -334,3 +334,72 @@ const struct seq_operations rxrpc_peer_seq_ops = { 
	.stop   = rxrpc_peer_seq_stop,

	.show   = rxrpc_peer_seq_show,

};



/*

 * Generate a list of extant virtual local endpoints in /proc/net/rxrpc/locals

 */

static int rxrpc_local_seq_show(struct seq_file *seq, void *v)

{

	struct rxrpc_local *local;

	char lbuff[50];



	if (v == SEQ_START_TOKEN) {

		seq_puts(seq,

			 "Proto Local                                          "

			 " Use Act\n");

		return 0;

	}



	local = hlist_entry(v, struct rxrpc_local, link);



	sprintf(lbuff, "%pISpc", &local->srx.transport);



	seq_printf(seq,

		   "UDP   %-47.47s %3u %3u\n",

		   lbuff,

		   atomic_read(&local->usage),

		   atomic_read(&local->active_users));



	return 0;

}



static void *rxrpc_local_seq_start(struct seq_file *seq, loff_t *_pos)

	__acquires(rcu)

{

	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));

	unsigned int n;



	rcu_read_lock();



	if (*_pos >= UINT_MAX)

		return NULL;



	n = *_pos;

	if (n == 0)

		return SEQ_START_TOKEN;



	return seq_hlist_start_rcu(&rxnet->local_endpoints, n - 1);

}



static void *rxrpc_local_seq_next(struct seq_file *seq, void *v, loff_t *_pos)

{

	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));



	if (*_pos >= UINT_MAX)

		return NULL;



	return seq_hlist_next_rcu(v, &rxnet->local_endpoints, _pos);

}



static void rxrpc_local_seq_stop(struct seq_file *seq, void *v)

	__releases(rcu)

{

	rcu_read_unlock();

}



const struct seq_operations rxrpc_local_seq_ops = {

	.start  = rxrpc_local_seq_start,

	.next   = rxrpc_local_seq_next,

	.stop   = rxrpc_local_seq_stop,

	.show   = rxrpc_local_seq_show,

};