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>
This commit is contained in:
David Howells
2016-04-04 14:00:37 +01:00
parent 85f32278bd
commit cc8feb8edd
5 changed files with 64 additions and 77 deletions

View File

@@ -37,6 +37,8 @@ struct rxrpc_crypt {
#define rxrpc_queue_call(CALL) rxrpc_queue_work(&(CALL)->processor)
#define rxrpc_queue_conn(CONN) rxrpc_queue_work(&(CONN)->processor)
struct rxrpc_connection;
/*
* sk_state for RxRPC sockets
*/
@@ -57,7 +59,6 @@ struct rxrpc_sock {
struct sock sk;
rxrpc_interceptor_t interceptor; /* kernel service Rx interceptor function */
struct rxrpc_local *local; /* local endpoint */
struct rxrpc_connection *conn; /* exclusive virtual connection */
struct list_head listen_link; /* link in the local endpoint's listen list */
struct list_head secureq; /* calls awaiting connection security clearance */
struct list_head acceptq; /* calls awaiting acceptance */
@@ -66,13 +67,13 @@ struct rxrpc_sock {
struct rb_root calls; /* outstanding calls on this socket */
unsigned long flags;
#define RXRPC_SOCK_CONNECTED 0 /* connect_srx is set */
#define RXRPC_SOCK_EXCLUSIVE_CONN 1 /* exclusive connection for a client socket */
rwlock_t call_lock; /* lock for calls */
u32 min_sec_level; /* minimum security level */
#define RXRPC_SECURITY_MAX RXRPC_SECURITY_ENCRYPT
bool exclusive; /* Exclusive connection for a client socket */
sa_family_t family; /* Protocol family created with */
struct sockaddr_rxrpc srx; /* local address */
struct sockaddr_rxrpc connect_srx; /* Default client address from connect() */
sa_family_t family; /* protocol family created with */
};
#define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)