rxrpc: Reduce the rxrpc_local::services list to a pointer
Reduce the rxrpc_local::services list to just a pointer as we don't permit
multiple service endpoints to bind to a single transport endpoints (this is
excluded by rxrpc_lookup_local()).
The reason we don't allow this is that if you send a request to an AFS
filesystem service, it will try to talk back to your cache manager on the
port you sent from (this is how file change notifications are handled). To
prevent someone from stealing your CM callbacks, we don't let AF_RXRPC
sockets share a UDP socket if at least one of them has a service bound.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 6aadaa7..539db54 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -93,7 +93,6 @@
rxrpc_notify_new_call_t notify_new_call; /* Func to notify of new call */
rxrpc_discard_new_call_t discard_new_call; /* Func to discard a new call */
struct rxrpc_local *local; /* local endpoint */
- struct hlist_node listen_link; /* link in the local endpoint's listen list */
struct rxrpc_backlog *backlog; /* Preallocation for services */
spinlock_t incoming_lock; /* Incoming call vs service shutdown lock */
struct list_head sock_calls; /* List of calls owned by this socket */
@@ -216,7 +215,7 @@
struct list_head link;
struct socket *socket; /* my UDP socket */
struct work_struct processor;
- struct hlist_head services; /* services listening on this endpoint */
+ struct rxrpc_sock __rcu *service; /* Service(s) listening on this endpoint */
struct rw_semaphore defrag_sem; /* control re-enablement of IP DF bit */
struct sk_buff_head reject_queue; /* packets awaiting rejection */
struct sk_buff_head event_queue; /* endpoint event packets awaiting processing */