Commit 28036f44 authored by David Howells's avatar David Howells
Browse files

rxrpc: Permit multiple service binding 



Permit bind() to be called on an AF_RXRPC socket more than once (currently
maximum twice) to bind multiple listening services to it.  There are some
restrictions:

 (1) All bind() calls involved must have a non-zero service ID.

 (2) The service IDs must all be different.

 (3) The rest of the address (notably the transport part) must be the same
     in all (a single UDP socket is shared).

 (4) This must be done before listen() or sendmsg() is called.

This allows someone to connect to the service socket with different service
IDs and lays the foundation for service upgrading.

The service ID used by an incoming call can be extracted from the msg_name
returned by recvmsg().

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent 68d6d1ae

Documentation/networking/rxrpc.txt

+4 −0
Original line number Diff line number Diff line
@@ -600,6 +600,10 @@ A server would be set up to accept operations in the following manner: 
	};

	bind(server, &srx, sizeof(srx));



     More than one service ID may be bound to a socket, provided the transport

     parameters are the same.  The limit is currently two.  To do this, bind()

     should be called twice.



 (3) The server is then set to listen out for incoming calls:



	listen(server, 100);

net/rxrpc/af_rxrpc.c

+40 −22
Original line number Diff line number Diff line
@@ -144,13 +144,9 @@ static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len) 


	lock_sock(&rx->sk);



	if (rx->sk.sk_state != RXRPC_UNBOUND) {

		ret = -EINVAL;

		goto error_unlock;

	}



	memcpy(&rx->srx, srx, sizeof(rx->srx));



	switch (rx->sk.sk_state) {

	case RXRPC_UNBOUND:

		rx->srx = *srx;

		local = rxrpc_lookup_local(sock_net(&rx->sk), &rx->srx);

		if (IS_ERR(local)) {

			ret = PTR_ERR(local);
@@ -170,6 +166,27 @@ static int rxrpc_bind(struct socket *sock, struct sockaddr *saddr, int len) 
			rx->local = local;

			rx->sk.sk_state = RXRPC_CLIENT_BOUND;

		}

		break;



	case RXRPC_SERVER_BOUND:

		ret = -EINVAL;

		if (service_id == 0)

			goto error_unlock;

		ret = -EADDRINUSE;

		if (service_id == rx->srx.srx_service)

			goto error_unlock;

		ret = -EINVAL;

		srx->srx_service = rx->srx.srx_service;

		if (memcmp(srx, &rx->srx, sizeof(*srx)) != 0)

			goto error_unlock;

		rx->second_service = service_id;

		rx->sk.sk_state = RXRPC_SERVER_BOUND2;

		break;



	default:

		ret = -EINVAL;

		goto error_unlock;

	}



	release_sock(&rx->sk);

	_leave(" = 0");
@@ -205,6 +222,7 @@ static int rxrpc_listen(struct socket *sock, int backlog) 
		ret = -EADDRNOTAVAIL;

		break;

	case RXRPC_SERVER_BOUND:

	case RXRPC_SERVER_BOUND2:

		ASSERT(rx->local != NULL);

		max = READ_ONCE(rxrpc_max_backlog);

		ret = -EINVAL;

net/rxrpc/ar-internal.h

+2 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ enum { 
	RXRPC_CLIENT_UNBOUND,		/* Unbound socket used as client */

	RXRPC_CLIENT_BOUND,		/* client local address bound */

	RXRPC_SERVER_BOUND,		/* server local address bound */

	RXRPC_SERVER_BOUND2,		/* second server local address bound */

	RXRPC_SERVER_LISTENING,		/* server listening for connections */

	RXRPC_SERVER_LISTEN_DISABLED,	/* server listening disabled */

	RXRPC_CLOSE,			/* socket is being closed */
@@ -142,6 +143,7 @@ struct rxrpc_sock { 
	u32			min_sec_level;	/* minimum security level */

#define RXRPC_SECURITY_MAX	RXRPC_SECURITY_ENCRYPT

	bool			exclusive;	/* Exclusive connection for a client socket */

	u16			second_service;	/* Additional service bound to the endpoint */

	sa_family_t		family;		/* Protocol family created with */

	struct sockaddr_rxrpc	srx;		/* local address */

	struct sockaddr_rxrpc	connect_srx;	/* Default client address from connect() */

net/rxrpc/call_accept.c

+2 −1
Original line number Diff line number Diff line
@@ -341,7 +341,8 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local, 


	/* Get the socket providing the service */

	rx = rcu_dereference(local->service);

	if (rx && service_id == rx->srx.srx_service)

	if (rx && (service_id == rx->srx.srx_service ||

		   service_id == rx->second_service))

		goto found_service;



	trace_rxrpc_abort("INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,

net/rxrpc/local_object.c

+1 −0
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, 
		rwlock_init(&local->services_lock);

		local->debug_id = atomic_inc_return(&rxrpc_debug_id);

		memcpy(&local->srx, srx, sizeof(*srx));

		local->srx.srx_service = 0;

	}



	_leave(" = %p", local);

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