rxrpc: Fix exclusive connection handling

"Exclusive connections" are meant to be used for a single client call and
then scrapped.  The idea is to limit the use of the negotiated security
context.  The current code, however, isn't doing this: it is instead
restricting the socket to a single virtual connection and doing all the
calls over that.

This is changed such that the socket no longer maintains a special virtual
connection over which it will do all the calls, but rather gets a new one
each time a new exclusive call is made.

Further, using a socket option for this is a poor choice.  It should be
done on sendmsg with a control message marker instead so that calls can be
marked exclusive individually.  To that end, add RXRPC_EXCLUSIVE_CALL
which, if passed to sendmsg() as a control message element, will cause the
call to be done on an single-use connection.

The socket option (RXRPC_EXCLUSIVE_CONNECTION) still exists and, if set,
will override any lack of RXRPC_EXCLUSIVE_CALL being specified so that
programs using the setsockopt() will appear to work the same.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 1 insertions, 6 deletions

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 48b45a0280c0..73f5c553eef4 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -494,7 +494,7 @@ static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
 			ret = -EISCONN;
 			if (rx->sk.sk_state != RXRPC_UNBOUND)
 				goto error;
-			set_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags);
+			rx->exclusive = true;
 			goto success;
 
 		case RXRPC_SECURITY_KEY:
@@ -669,11 +669,6 @@ static int rxrpc_release_sock(struct sock *sk)
 	flush_workqueue(rxrpc_workqueue);
 	rxrpc_purge_queue(&sk->sk_receive_queue);
 
-	if (rx->conn) {
-		rxrpc_put_connection(rx->conn);
-		rx->conn = NULL;
-	}
-
 	if (rx->local) {
 		rxrpc_put_local(rx->local);
 		rx->local = NULL;