af_rxrpc.c

linux 内核源代码

	int ret;

	_enter(",{%d},,%zu", rx->sk.sk_state, len);

	if (m->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	if (m->msg_name) {
		ret = rxrpc_validate_address(rx, m->msg_name, m->msg_namelen);
		if (ret < 0) {
			_leave(" = %d [bad addr]", ret);
			return ret;
		}
	}

	trans = NULL;
	lock_sock(&rx->sk);

	if (m->msg_name) {
		ret = -EISCONN;
		trans = rxrpc_name_to_transport(sock, m->msg_name,
						m->msg_namelen, 0, GFP_KERNEL);
		if (IS_ERR(trans)) {
			ret = PTR_ERR(trans);
			trans = NULL;
			goto out;
		}
	} else {
		trans = rx->trans;
		if (trans)
			atomic_inc(&trans->usage);
	}

	switch (rx->sk.sk_state) {
	case RXRPC_SERVER_LISTENING:
		if (!m->msg_name) {
			ret = rxrpc_server_sendmsg(iocb, rx, m, len);
			break;
		}
	case RXRPC_SERVER_BOUND:
	case RXRPC_CLIENT_BOUND:
		if (!m->msg_name) {
			ret = -ENOTCONN;
			break;
		}
	case RXRPC_CLIENT_CONNECTED:
		ret = rxrpc_client_sendmsg(iocb, rx, trans, m, len);
		break;
	default:
		ret = -ENOTCONN;
		break;
	}

out:
	release_sock(&rx->sk);
	if (trans)
		rxrpc_put_transport(trans);
	_leave(" = %d", ret);
	return ret;
}

/*
 * set RxRPC socket options
 */
static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
			    char __user *optval, int optlen)
{
	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
	unsigned min_sec_level;
	int ret;

	_enter(",%d,%d,,%d", level, optname, optlen);

	lock_sock(&rx->sk);
	ret = -EOPNOTSUPP;

	if (level == SOL_RXRPC) {
		switch (optname) {
		case RXRPC_EXCLUSIVE_CONNECTION:
			ret = -EINVAL;
			if (optlen != 0)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNCONNECTED)
				goto error;
			set_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags);
			goto success;

		case RXRPC_SECURITY_KEY:
			ret = -EINVAL;
			if (rx->key)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNCONNECTED)
				goto error;
			ret = rxrpc_request_key(rx, optval, optlen);
			goto error;

		case RXRPC_SECURITY_KEYRING:
			ret = -EINVAL;
			if (rx->key)
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNCONNECTED)
				goto error;
			ret = rxrpc_server_keyring(rx, optval, optlen);
			goto error;

		case RXRPC_MIN_SECURITY_LEVEL:
			ret = -EINVAL;
			if (optlen != sizeof(unsigned))
				goto error;
			ret = -EISCONN;
			if (rx->sk.sk_state != RXRPC_UNCONNECTED)
				goto error;
			ret = get_user(min_sec_level,
				       (unsigned __user *) optval);
			if (ret < 0)
				goto error;
			ret = -EINVAL;
			if (min_sec_level > RXRPC_SECURITY_MAX)
				goto error;
			rx->min_sec_level = min_sec_level;
			goto success;

		default:
			break;
		}
	}

success:
	ret = 0;
error:
	release_sock(&rx->sk);
	return ret;
}

/*
 * permit an RxRPC socket to be polled
 */
static unsigned int rxrpc_poll(struct file *file, struct socket *sock,
			       poll_table *wait)
{
	unsigned int mask;
	struct sock *sk = sock->sk;

	poll_wait(file, sk->sk_sleep, wait);
	mask = 0;

	/* the socket is readable if there are any messages waiting on the Rx
	 * queue */
	if (!skb_queue_empty(&sk->sk_receive_queue))
		mask |= POLLIN | POLLRDNORM;

	/* the socket is writable if there is space to add new data to the
	 * socket; there is no guarantee that any particular call in progress
	 * on the socket may have space in the Tx ACK window */
	if (rxrpc_writable(sk))
		mask |= POLLOUT | POLLWRNORM;

	return mask;
}

/*
 * create an RxRPC socket
 */
static int rxrpc_create(struct net *net, struct socket *sock, int protocol)
{
	struct rxrpc_sock *rx;
	struct sock *sk;

	_enter("%p,%d", sock, protocol);

	if (net != &init_net)
		return -EAFNOSUPPORT;

	/* we support transport protocol UDP only */
	if (protocol != PF_INET)
		return -EPROTONOSUPPORT;

	if (sock->type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	sock->ops = &rxrpc_rpc_ops;
	sock->state = SS_UNCONNECTED;

	sk = sk_alloc(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sk->sk_state		= RXRPC_UNCONNECTED;
	sk->sk_write_space	= rxrpc_write_space;
	sk->sk_max_ack_backlog	= sysctl_rxrpc_max_qlen;
	sk->sk_destruct		= rxrpc_sock_destructor;

	rx = rxrpc_sk(sk);
	rx->proto = protocol;
	rx->calls = RB_ROOT;

	INIT_LIST_HEAD(&rx->listen_link);
	INIT_LIST_HEAD(&rx->secureq);
	INIT_LIST_HEAD(&rx->acceptq);
	rwlock_init(&rx->call_lock);
	memset(&rx->srx, 0, sizeof(rx->srx));

	_leave(" = 0 [%p]", rx);
	return 0;
}

/*
 * RxRPC socket destructor
 */
static void rxrpc_sock_destructor(struct sock *sk)
{
	_enter("%p", sk);

	rxrpc_purge_queue(&sk->sk_receive_queue);

	BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
	BUG_TRAP(sk_unhashed(sk));
	BUG_TRAP(!sk->sk_socket);

	if (!sock_flag(sk, SOCK_DEAD)) {
		printk("Attempt to release alive rxrpc socket: %p\n", sk);
		return;
	}
}

/*
 * release an RxRPC socket
 */
static int rxrpc_release_sock(struct sock *sk)
{
	struct rxrpc_sock *rx = rxrpc_sk(sk);

	_enter("%p{%d,%d}", sk, sk->sk_state, atomic_read(&sk->sk_refcnt));

	/* declare the socket closed for business */
	sock_orphan(sk);
	sk->sk_shutdown = SHUTDOWN_MASK;

	spin_lock_bh(&sk->sk_receive_queue.lock);
	sk->sk_state = RXRPC_CLOSE;
	spin_unlock_bh(&sk->sk_receive_queue.lock);

	ASSERTCMP(rx->listen_link.next, !=, LIST_POISON1);

	if (!list_empty(&rx->listen_link)) {
		write_lock_bh(&rx->local->services_lock);
		list_del(&rx->listen_link);
		write_unlock_bh(&rx->local->services_lock);
	}

	/* try to flush out this socket */
	rxrpc_release_calls_on_socket(rx);
	flush_workqueue(rxrpc_workqueue);
	rxrpc_purge_queue(&sk->sk_receive_queue);

	if (rx->conn) {
		rxrpc_put_connection(rx->conn);
		rx->conn = NULL;
	}

	if (rx->bundle) {
		rxrpc_put_bundle(rx->trans, rx->bundle);
		rx->bundle = NULL;
	}
	if (rx->trans) {
		rxrpc_put_transport(rx->trans);
		rx->trans = NULL;
	}
	if (rx->local) {
		rxrpc_put_local(rx->local);
		rx->local = NULL;
	}

	key_put(rx->key);
	rx->key = NULL;
	key_put(rx->securities);
	rx->securities = NULL;
	sock_put(sk);

	_leave(" = 0");
	return 0;
}

/*
 * release an RxRPC BSD socket on close() or equivalent
 */
static int rxrpc_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	_enter("%p{%p}", sock, sk);

	if (!sk)
		return 0;

	sock->sk = NULL;

	return rxrpc_release_sock(sk);
}

/*
 * RxRPC network protocol
 */
static const struct proto_ops rxrpc_rpc_ops = {
	.family		= PF_UNIX,
	.owner		= THIS_MODULE,
	.release	= rxrpc_release,
	.bind		= rxrpc_bind,
	.connect	= rxrpc_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= sock_no_accept,
	.getname	= sock_no_getname,
	.poll		= rxrpc_poll,
	.ioctl		= sock_no_ioctl,
	.listen		= rxrpc_listen,
	.shutdown	= sock_no_shutdown,
	.setsockopt	= rxrpc_setsockopt,
	.getsockopt	= sock_no_getsockopt,
	.sendmsg	= rxrpc_sendmsg,
	.recvmsg	= rxrpc_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

static struct proto rxrpc_proto = {
	.name		= "RXRPC",
	.owner		= THIS_MODULE,
	.obj_size	= sizeof(struct rxrpc_sock),
	.max_header	= sizeof(struct rxrpc_header),
};

static struct net_proto_family rxrpc_family_ops = {
	.family	= PF_RXRPC,
	.create = rxrpc_create,
	.owner	= THIS_MODULE,
};

/*
 * initialise and register the RxRPC protocol
 */
static int __init af_rxrpc_init(void)
{
	struct sk_buff *dummy_skb;
	int ret = -1;

	BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof(dummy_skb->cb));

	rxrpc_epoch = htonl(get_seconds());

	ret = -ENOMEM;
	rxrpc_call_jar = kmem_cache_create(
		"rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
		SLAB_HWCACHE_ALIGN, NULL);
	if (!rxrpc_call_jar) {
		printk(KERN_NOTICE "RxRPC: Failed to allocate call jar\n");
		goto error_call_jar;
	}

	rxrpc_workqueue = create_workqueue("krxrpcd");
	if (!rxrpc_workqueue) {
		printk(KERN_NOTICE "RxRPC: Failed to allocate work queue\n");
		goto error_work_queue;
	}

	ret = proto_register(&rxrpc_proto, 1);
	if (ret < 0) {
		printk(KERN_CRIT "RxRPC: Cannot register protocol\n");
		goto error_proto;
	}

	ret = sock_register(&rxrpc_family_ops);
	if (ret < 0) {
		printk(KERN_CRIT "RxRPC: Cannot register socket family\n");
		goto error_sock;
	}

	ret = register_key_type(&key_type_rxrpc);
	if (ret < 0) {
		printk(KERN_CRIT "RxRPC: Cannot register client key type\n");
		goto error_key_type;
	}

	ret = register_key_type(&key_type_rxrpc_s);
	if (ret < 0) {
		printk(KERN_CRIT "RxRPC: Cannot register server key type\n");
		goto error_key_type_s;
	}

#ifdef CONFIG_PROC_FS
	proc_net_fops_create(&init_net, "rxrpc_calls", 0, &rxrpc_call_seq_fops);
	proc_net_fops_create(&init_net, "rxrpc_conns", 0, &rxrpc_connection_seq_fops);
#endif
	return 0;

error_key_type_s:
	unregister_key_type(&key_type_rxrpc);
error_key_type:
	sock_unregister(PF_RXRPC);
error_sock:
	proto_unregister(&rxrpc_proto);
error_proto:
	destroy_workqueue(rxrpc_workqueue);
error_work_queue:
	kmem_cache_destroy(rxrpc_call_jar);
error_call_jar:
	return ret;
}

/*
 * unregister the RxRPC protocol
 */
static void __exit af_rxrpc_exit(void)
{
	_enter("");
	unregister_key_type(&key_type_rxrpc_s);
	unregister_key_type(&key_type_rxrpc);
	sock_unregister(PF_RXRPC);
	proto_unregister(&rxrpc_proto);
	rxrpc_destroy_all_calls();
	rxrpc_destroy_all_connections();
	rxrpc_destroy_all_transports();
	rxrpc_destroy_all_peers();
	rxrpc_destroy_all_locals();

	ASSERTCMP(atomic_read(&rxrpc_n_skbs), ==, 0);

	_debug("flush scheduled work");
	flush_workqueue(rxrpc_workqueue);
	proc_net_remove(&init_net, "rxrpc_conns");
	proc_net_remove(&init_net, "rxrpc_calls");
	destroy_workqueue(rxrpc_workqueue);
	kmem_cache_destroy(rxrpc_call_jar);
	_leave("");
}

module_init(af_rxrpc_init);
module_exit(af_rxrpc_exit);