rxrpc: Simplify connect() implementation and simplify sendmsg() op

Simplify the RxRPC connect() implementation.  It will just note the
destination address it is given, and if a sendmsg() comes along with no
address, this will be assigned as the address.  No transport struct will be
held internally, which will allow us to remove this later.

Simplify sendmsg() also.  Whilst a call is active, userspace refers to it
by a private unique user ID specified in a control message.  When sendmsg()
sees a user ID that doesn't map to an extant call, it creates a new call
for that user ID and attempts to add it.  If, when we try to add it, the
user ID is now registered, we now reject the message with -EEXIST.  We
should never see this situation unless two threads are racing, trying to
create a call with the same ID - which would be an error.

It also isn't required to provide sendmsg() with an address - provided the
control message data holds a user ID that maps to a currently active call.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 10 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 18ab5c50ba87..b89dcdcbc65a 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -39,9 +39,9 @@ struct rxrpc_crypt {
  * sk_state for RxRPC sockets
  */
 enum {
-	RXRPC_UNCONNECTED = 0,
+	RXRPC_UNBOUND = 0,
+	RXRPC_CLIENT_UNBOUND,		/* Unbound socket used as client */
 	RXRPC_CLIENT_BOUND,		/* client local address bound */
-	RXRPC_CLIENT_CONNECTED,		/* client is connected */
 	RXRPC_SERVER_BOUND,		/* server local address bound */
 	RXRPC_SERVER_LISTENING,		/* server listening for connections */
 	RXRPC_CLOSE,			/* socket is being closed */
@@ -55,8 +55,6 @@ struct rxrpc_sock {
 	struct sock		sk;
 	rxrpc_interceptor_t	interceptor;	/* kernel service Rx interceptor function */
 	struct rxrpc_local	*local;		/* local endpoint */
-	struct rxrpc_transport	*trans;		/* transport handler */
-	struct rxrpc_conn_bundle *bundle;	/* virtual connection bundle */
 	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 */
@@ -65,11 +63,13 @@ struct rxrpc_sock {
 	struct key		*securities;	/* list of server security descriptors */
 	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
 	struct sockaddr_rxrpc	srx;		/* local address */
+	struct sockaddr_rxrpc	connect_srx;	/* Default client address from connect() */
 	sa_family_t		proto;		/* protocol created with */
 };
 
@@ -477,6 +477,10 @@ extern u32 rxrpc_epoch;
 extern atomic_t rxrpc_debug_id;
 extern struct workqueue_struct *rxrpc_workqueue;
 
+extern struct rxrpc_transport *rxrpc_name_to_transport(struct rxrpc_sock *,
+						       struct sockaddr *,
+						       int, int, gfp_t);
+
 /*
  * ar-accept.c
  */
@@ -502,14 +506,14 @@ extern rwlock_t rxrpc_call_lock;
 
 struct rxrpc_call *rxrpc_find_call_hash(struct rxrpc_host_header *,
 					void *, sa_family_t, const void *);
-struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *,
+struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long);
+struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *,
 					 struct rxrpc_transport *,
 					 struct rxrpc_conn_bundle *,
-					 unsigned long, int, gfp_t);
+					 unsigned long, gfp_t);
 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *,
 				       struct rxrpc_connection *,
 				       struct rxrpc_host_header *);
-struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *, unsigned long);
 void rxrpc_release_call(struct rxrpc_call *);
 void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
 void __rxrpc_put_call(struct rxrpc_call *);
@@ -581,9 +585,7 @@ int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *, time_t,
 extern unsigned int rxrpc_resend_timeout;
 
 int rxrpc_send_packet(struct rxrpc_transport *, struct sk_buff *);
-int rxrpc_client_sendmsg(struct rxrpc_sock *, struct rxrpc_transport *,
-			 struct msghdr *, size_t);
-int rxrpc_server_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
+int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
 
 /*
  * ar-peer.c