xprtsock.c

linux 内核源代码

	any.sa_family = AF_UNSPEC;
	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
	if (result)
		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
				result);
}

static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
{
	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);

	if (!transport->inet) {
		struct sock *sk = sock->sk;

		write_lock_bh(&sk->sk_callback_lock);

		sk->sk_user_data = xprt;
		transport->old_data_ready = sk->sk_data_ready;
		transport->old_state_change = sk->sk_state_change;
		transport->old_write_space = sk->sk_write_space;
		sk->sk_data_ready = xs_tcp_data_ready;
		sk->sk_state_change = xs_tcp_state_change;
		sk->sk_write_space = xs_tcp_write_space;
		sk->sk_allocation = GFP_ATOMIC;

		/* socket options */
		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
		sock_reset_flag(sk, SOCK_LINGER);
		tcp_sk(sk)->linger2 = 0;
		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;

		xprt_clear_connected(xprt);

		/* Reset to new socket */
		transport->sock = sock;
		transport->inet = sk;

		write_unlock_bh(&sk->sk_callback_lock);
	}

	/* Tell the socket layer to start connecting... */
	xprt->stat.connect_count++;
	xprt->stat.connect_start = jiffies;
	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
}

/**
 * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
 * @work: RPC transport to connect
 *
 * Invoked by a work queue tasklet.
 */
static void xs_tcp_connect_worker4(struct work_struct *work)
{
	struct sock_xprt *transport =
		container_of(work, struct sock_xprt, connect_worker.work);
	struct rpc_xprt *xprt = &transport->xprt;
	struct socket *sock = transport->sock;
	int err, status = -EIO;

	if (xprt->shutdown || !xprt_bound(xprt))
		goto out;

	if (!sock) {
		/* start from scratch */
		if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
			goto out;
		}
		xs_reclassify_socket4(sock);

		if (xs_bind4(transport, sock) < 0) {
			sock_release(sock);
			goto out;
		}
	} else
		/* "close" the socket, preserving the local port */
		xs_tcp_reuse_connection(xprt);

	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);

	status = xs_tcp_finish_connecting(xprt, sock);
	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
			xprt, -status, xprt_connected(xprt),
			sock->sk->sk_state);
	if (status < 0) {
		switch (status) {
			case -EINPROGRESS:
			case -EALREADY:
				goto out_clear;
			case -ECONNREFUSED:
			case -ECONNRESET:
				/* retry with existing socket, after a delay */
				break;
			default:
				/* get rid of existing socket, and retry */
				xs_close(xprt);
				break;
		}
	}
out:
	xprt_wake_pending_tasks(xprt, status);
out_clear:
	xprt_clear_connecting(xprt);
}

/**
 * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
 * @work: RPC transport to connect
 *
 * Invoked by a work queue tasklet.
 */
static void xs_tcp_connect_worker6(struct work_struct *work)
{
	struct sock_xprt *transport =
		container_of(work, struct sock_xprt, connect_worker.work);
	struct rpc_xprt *xprt = &transport->xprt;
	struct socket *sock = transport->sock;
	int err, status = -EIO;

	if (xprt->shutdown || !xprt_bound(xprt))
		goto out;

	if (!sock) {
		/* start from scratch */
		if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
			goto out;
		}
		xs_reclassify_socket6(sock);

		if (xs_bind6(transport, sock) < 0) {
			sock_release(sock);
			goto out;
		}
	} else
		/* "close" the socket, preserving the local port */
		xs_tcp_reuse_connection(xprt);

	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);

	status = xs_tcp_finish_connecting(xprt, sock);
	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
			xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
	if (status < 0) {
		switch (status) {
			case -EINPROGRESS:
			case -EALREADY:
				goto out_clear;
			case -ECONNREFUSED:
			case -ECONNRESET:
				/* retry with existing socket, after a delay */
				break;
			default:
				/* get rid of existing socket, and retry */
				xs_close(xprt);
				break;
		}
	}
out:
	xprt_wake_pending_tasks(xprt, status);
out_clear:
	xprt_clear_connecting(xprt);
}

/**
 * xs_connect - connect a socket to a remote endpoint
 * @task: address of RPC task that manages state of connect request
 *
 * TCP: If the remote end dropped the connection, delay reconnecting.
 *
 * UDP socket connects are synchronous, but we use a work queue anyway
 * to guarantee that even unprivileged user processes can set up a
 * socket on a privileged port.
 *
 * If a UDP socket connect fails, the delay behavior here prevents
 * retry floods (hard mounts).
 */
static void xs_connect(struct rpc_task *task)
{
	struct rpc_xprt *xprt = task->tk_xprt;
	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);

	if (xprt_test_and_set_connecting(xprt))
		return;

	if (transport->sock != NULL) {
		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
				"seconds\n",
				xprt, xprt->reestablish_timeout / HZ);
		queue_delayed_work(rpciod_workqueue,
				   &transport->connect_worker,
				   xprt->reestablish_timeout);
		xprt->reestablish_timeout <<= 1;
		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
	} else {
		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
		queue_delayed_work(rpciod_workqueue,
				   &transport->connect_worker, 0);
	}
}

/**
 * xs_udp_print_stats - display UDP socket-specifc stats
 * @xprt: rpc_xprt struct containing statistics
 * @seq: output file
 *
 */
static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
{
	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);

	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
			transport->port,
			xprt->stat.bind_count,
			xprt->stat.sends,
			xprt->stat.recvs,
			xprt->stat.bad_xids,
			xprt->stat.req_u,
			xprt->stat.bklog_u);
}

/**
 * xs_tcp_print_stats - display TCP socket-specifc stats
 * @xprt: rpc_xprt struct containing statistics
 * @seq: output file
 *
 */
static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
{
	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
	long idle_time = 0;

	if (xprt_connected(xprt))
		idle_time = (long)(jiffies - xprt->last_used) / HZ;

	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
			transport->port,
			xprt->stat.bind_count,
			xprt->stat.connect_count,
			xprt->stat.connect_time,
			idle_time,
			xprt->stat.sends,
			xprt->stat.recvs,
			xprt->stat.bad_xids,
			xprt->stat.req_u,
			xprt->stat.bklog_u);
}

static struct rpc_xprt_ops xs_udp_ops = {
	.set_buffer_size	= xs_udp_set_buffer_size,
	.reserve_xprt		= xprt_reserve_xprt_cong,
	.release_xprt		= xprt_release_xprt_cong,
	.rpcbind		= rpcb_getport_async,
	.set_port		= xs_set_port,
	.connect		= xs_connect,
	.buf_alloc		= rpc_malloc,
	.buf_free		= rpc_free,
	.send_request		= xs_udp_send_request,
	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
	.timer			= xs_udp_timer,
	.release_request	= xprt_release_rqst_cong,
	.close			= xs_close,
	.destroy		= xs_destroy,
	.print_stats		= xs_udp_print_stats,
};

static struct rpc_xprt_ops xs_tcp_ops = {
	.reserve_xprt		= xprt_reserve_xprt,
	.release_xprt		= xs_tcp_release_xprt,
	.rpcbind		= rpcb_getport_async,
	.set_port		= xs_set_port,
	.connect		= xs_connect,
	.buf_alloc		= rpc_malloc,
	.buf_free		= rpc_free,
	.send_request		= xs_tcp_send_request,
	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
	.close			= xs_close,
	.destroy		= xs_destroy,
	.print_stats		= xs_tcp_print_stats,
};

static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
				      unsigned int slot_table_size)
{
	struct rpc_xprt *xprt;
	struct sock_xprt *new;

	if (args->addrlen > sizeof(xprt->addr)) {
		dprintk("RPC:       xs_setup_xprt: address too large\n");
		return ERR_PTR(-EBADF);
	}

	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (new == NULL) {
		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
				"rpc_xprt\n");
		return ERR_PTR(-ENOMEM);
	}
	xprt = &new->xprt;

	xprt->max_reqs = slot_table_size;
	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
	if (xprt->slot == NULL) {
		kfree(xprt);
		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
				"table\n");
		return ERR_PTR(-ENOMEM);
	}

	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
	xprt->addrlen = args->addrlen;
	if (args->srcaddr)
		memcpy(&new->addr, args->srcaddr, args->addrlen);
	new->port = xs_get_random_port();

	return xprt;
}

/**
 * xs_setup_udp - Set up transport to use a UDP socket
 * @args: rpc transport creation arguments
 *
 */
static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
{
	struct sockaddr *addr = args->dstaddr;
	struct rpc_xprt *xprt;
	struct sock_xprt *transport;

	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
	if (IS_ERR(xprt))
		return xprt;
	transport = container_of(xprt, struct sock_xprt, xprt);

	xprt->prot = IPPROTO_UDP;
	xprt->tsh_size = 0;
	/* XXX: header size can vary due to auth type, IPv6, etc. */
	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);

	xprt->bind_timeout = XS_BIND_TO;
	xprt->connect_timeout = XS_UDP_CONN_TO;
	xprt->reestablish_timeout = XS_UDP_REEST_TO;
	xprt->idle_timeout = XS_IDLE_DISC_TO;

	xprt->ops = &xs_udp_ops;

	if (args->timeout)
		xprt->timeout = *args->timeout;
	else
		xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);

	switch (addr->sa_family) {
	case AF_INET:
		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
			xprt_set_bound(xprt);

		INIT_DELAYED_WORK(&transport->connect_worker,
					xs_udp_connect_worker4);
		xs_format_ipv4_peer_addresses(xprt);
		break;
	case AF_INET6:
		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
			xprt_set_bound(xprt);

		INIT_DELAYED_WORK(&transport->connect_worker,
					xs_udp_connect_worker6);
		xs_format_ipv6_peer_addresses(xprt);
		break;
	default:
		kfree(xprt);
		return ERR_PTR(-EAFNOSUPPORT);
	}

	dprintk("RPC:       set up transport to address %s\n",
			xprt->address_strings[RPC_DISPLAY_ALL]);

	if (try_module_get(THIS_MODULE))
		return xprt;

	kfree(xprt->slot);
	kfree(xprt);
	return ERR_PTR(-EINVAL);
}

/**
 * xs_setup_tcp - Set up transport to use a TCP socket
 * @args: rpc transport creation arguments
 *
 */
static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
{
	struct sockaddr *addr = args->dstaddr;
	struct rpc_xprt *xprt;
	struct sock_xprt *transport;

	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
	if (IS_ERR(xprt))
		return xprt;
	transport = container_of(xprt, struct sock_xprt, xprt);

	xprt->prot = IPPROTO_TCP;
	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;

	xprt->bind_timeout = XS_BIND_TO;
	xprt->connect_timeout = XS_TCP_CONN_TO;
	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
	xprt->idle_timeout = XS_IDLE_DISC_TO;

	xprt->ops = &xs_tcp_ops;

	if (args->timeout)
		xprt->timeout = *args->timeout;
	else
		xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);

	switch (addr->sa_family) {
	case AF_INET:
		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
			xprt_set_bound(xprt);

		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
		xs_format_ipv4_peer_addresses(xprt);
		break;
	case AF_INET6:
		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
			xprt_set_bound(xprt);

		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker6);
		xs_format_ipv6_peer_addresses(xprt);
		break;
	default:
		kfree(xprt);
		return ERR_PTR(-EAFNOSUPPORT);
	}

	dprintk("RPC:       set up transport to address %s\n",
			xprt->address_strings[RPC_DISPLAY_ALL]);

	if (try_module_get(THIS_MODULE))
		return xprt;

	kfree(xprt->slot);
	kfree(xprt);
	return ERR_PTR(-EINVAL);
}

static struct xprt_class	xs_udp_transport = {
	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
	.name		= "udp",
	.owner		= THIS_MODULE,
	.ident		= IPPROTO_UDP,
	.setup		= xs_setup_udp,
};

static struct xprt_class	xs_tcp_transport = {
	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
	.name		= "tcp",
	.owner		= THIS_MODULE,
	.ident		= IPPROTO_TCP,
	.setup		= xs_setup_tcp,
};

/**
 * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
 *
 */
int init_socket_xprt(void)
{
#ifdef RPC_DEBUG
	if (!sunrpc_table_header)
		sunrpc_table_header = register_sysctl_table(sunrpc_table);
#endif

	xprt_register_transport(&xs_udp_transport);
	xprt_register_transport(&xs_tcp_transport);

	return 0;
}

/**
 * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
 *
 */
void cleanup_socket_xprt(void)
{
#ifdef RPC_DEBUG
	if (sunrpc_table_header) {
		unregister_sysctl_table(sunrpc_table_header);
		sunrpc_table_header = NULL;
	}
#endif

	xprt_unregister_transport(&xs_udp_transport);
	xprt_unregister_transport(&xs_tcp_transport);
}