[deliverable/linux.git] / net / rds / tcp_listen.c

/*
 * Copyright (c) 2006 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/in.h>
#include <net/tcp.h>

#include "rds.h"
#include "tcp.h"

/*
 * cheesy, but simple..
 */
static void rds_tcp_accept_worker(struct work_struct *work);
static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
static struct socket *rds_tcp_listen_sock;

static int rds_tcp_keepalive(struct socket *sock)
{
	/* values below based on xs_udp_default_timeout */
	int keepidle = 5; /* send a probe 'keepidle' secs after last data */
	int keepcnt = 5; /* number of unack'ed probes before declaring dead */
	int keepalive = 1;
	int ret = 0;

	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
				(char *)&keepalive, sizeof(keepalive));
	if (ret < 0)
		goto bail;

	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
				(char *)&keepcnt, sizeof(keepcnt));
	if (ret < 0)
		goto bail;

	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
				(char *)&keepidle, sizeof(keepidle));
	if (ret < 0)
		goto bail;

	/* KEEPINTVL is the interval between successive probes. We follow
	 * the model in xs_tcp_finish_connecting() and re-use keepidle.
	 */
	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
				(char *)&keepidle, sizeof(keepidle));
bail:
	return ret;
}

static int rds_tcp_accept_one(struct socket *sock)
{
	struct socket *new_sock = NULL;
	struct rds_connection *conn;
	int ret;
	struct inet_sock *inet;
	struct rds_tcp_connection *rs_tcp;

	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
			       sock->sk->sk_protocol, &new_sock);
	if (ret)
		goto out;

	new_sock->type = sock->type;
	new_sock->ops = sock->ops;
	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
	if (ret < 0)
		goto out;

	ret = rds_tcp_keepalive(new_sock);
	if (ret < 0)
		goto out;

	rds_tcp_tune(new_sock);

	inet = inet_sk(new_sock->sk);

	rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
		 &inet->inet_saddr, ntohs(inet->inet_sport),
		 &inet->inet_daddr, ntohs(inet->inet_dport));

	conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
			       &rds_tcp_transport, GFP_KERNEL);
	if (IS_ERR(conn)) {
		ret = PTR_ERR(conn);
		goto out;
	}
	/* An incoming SYN request came in, and TCP just accepted it.
	 * We always create a new conn for listen side of TCP, and do not
	 * add it to the c_hash_list.
	 *
	 * If the client reboots, this conn will need to be cleaned up.
	 * rds_tcp_state_change() will do that cleanup
	 */
	rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
	WARN_ON(!rs_tcp || rs_tcp->t_sock);

	/*
	 * see the comment above rds_queue_delayed_reconnect()
	 */
	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
		if (rds_conn_state(conn) == RDS_CONN_UP)
			rds_tcp_stats_inc(s_tcp_listen_closed_stale);
		else
			rds_tcp_stats_inc(s_tcp_connect_raced);
		rds_conn_drop(conn);
		ret = 0;
		goto out;
	}

	rds_tcp_set_callbacks(new_sock, conn);
	rds_connect_complete(conn);
	new_sock = NULL;
	ret = 0;

out:
	if (new_sock)
		sock_release(new_sock);
	return ret;
}

static void rds_tcp_accept_worker(struct work_struct *work)
{
	while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
		cond_resched();
}

void rds_tcp_listen_data_ready(struct sock *sk)
{
	void (*ready)(struct sock *sk);

	rdsdebug("listen data ready sk %p\n", sk);

	read_lock(&sk->sk_callback_lock);
	ready = sk->sk_user_data;
	if (!ready) { /* check for teardown race */
		ready = sk->sk_data_ready;
		goto out;
	}

	/*
	 * ->sk_data_ready is also called for a newly established child socket
	 * before it has been accepted and the accepter has set up their
	 * data_ready.. we only want to queue listen work for our listening
	 * socket
	 */
	if (sk->sk_state == TCP_LISTEN)
		queue_work(rds_wq, &rds_tcp_listen_work);

out:
	read_unlock(&sk->sk_callback_lock);
	ready(sk);
}

int rds_tcp_listen_init(void)
{
	struct sockaddr_in sin;
	struct socket *sock = NULL;
	int ret;

	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
	if (ret < 0)
		goto out;

	sock->sk->sk_reuse = SK_CAN_REUSE;
	rds_tcp_nonagle(sock);

	write_lock_bh(&sock->sk->sk_callback_lock);
	sock->sk->sk_user_data = sock->sk->sk_data_ready;
	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
	write_unlock_bh(&sock->sk->sk_callback_lock);

	sin.sin_family = PF_INET;
	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);

	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
	if (ret < 0)
		goto out;

	ret = sock->ops->listen(sock, 64);
	if (ret < 0)
		goto out;

	rds_tcp_listen_sock = sock;
	sock = NULL;
out:
	if (sock)
		sock_release(sock);
	return ret;
}

void rds_tcp_listen_stop(void)
{
	struct socket *sock = rds_tcp_listen_sock;
	struct sock *sk;

	if (!sock)
		return;

	sk = sock->sk;

	/* serialize with and prevent further callbacks */
	lock_sock(sk);
	write_lock_bh(&sk->sk_callback_lock);
	if (sk->sk_user_data) {
		sk->sk_data_ready = sk->sk_user_data;
		sk->sk_user_data = NULL;
	}
	write_unlock_bh(&sk->sk_callback_lock);
	release_sock(sk);

	/* wait for accepts to stop and close the socket */
	flush_workqueue(rds_wq);
	sock_release(sock);
	rds_tcp_listen_sock = NULL;
}
Commit	Line	Data
70041088 AG	1	/*
	2	* Copyright (c) 2006 Oracle. All rights reserved.
	3	*
	4	* This software is available to you under a choice of one of two
	5	* licenses. You may choose to be licensed under the terms of the GNU
	6	* General Public License (GPL) Version 2, available from the file
	7	* COPYING in the main directory of this source tree, or the
	8	* OpenIB.org BSD license below:
	9	*
	10	* Redistribution and use in source and binary forms, with or
	11	* without modification, are permitted provided that the following
	12	* conditions are met:
	13	*
	14	* - Redistributions of source code must retain the above
	15	* copyright notice, this list of conditions and the following
	16	* disclaimer.
	17	*
	18	* - Redistributions in binary form must reproduce the above
	19	* copyright notice, this list of conditions and the following
	20	* disclaimer in the documentation and/or other materials
	21	* provided with the distribution.
	22	*
	23	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	24	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	25	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	26	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	27	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	28	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	29	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	30	* SOFTWARE.
	31	*
	32	*/
	33	#include <linux/kernel.h>
5a0e3ad6	34	#include <linux/gfp.h>
70041088 AG	35	#include <linux/in.h>
	36	#include <net/tcp.h>
	37
	38	#include "rds.h"
	39	#include "tcp.h"
	40
	41	/*
	42	* cheesy, but simple..
	43	*/
	44	static void rds_tcp_accept_worker(struct work_struct *work);
	45	static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
	46	static struct socket *rds_tcp_listen_sock;
	47
f711a6ae SV	48	static int rds_tcp_keepalive(struct socket *sock)
	49	{
	50	/* values below based on xs_udp_default_timeout */
	51	int keepidle = 5; /* send a probe 'keepidle' secs after last data */
	52	int keepcnt = 5; /* number of unack'ed probes before declaring dead */
	53	int keepalive = 1;
	54	int ret = 0;
	55
	56	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
	57	(char *)&keepalive, sizeof(keepalive));
	58	if (ret < 0)
	59	goto bail;
	60
	61	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
	62	(char *)&keepcnt, sizeof(keepcnt));
	63	if (ret < 0)
	64	goto bail;
	65
	66	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
	67	(char *)&keepidle, sizeof(keepidle));
	68	if (ret < 0)
	69	goto bail;
	70
	71	/* KEEPINTVL is the interval between successive probes. We follow
	72	* the model in xs_tcp_finish_connecting() and re-use keepidle.
	73	*/
	74	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
	75	(char *)&keepidle, sizeof(keepidle));
	76	bail:
	77	return ret;
	78	}
	79
70041088 AG	80	static int rds_tcp_accept_one(struct socket *sock)
	81	{
	82	struct socket *new_sock = NULL;
	83	struct rds_connection *conn;
	84	int ret;
	85	struct inet_sock *inet;
f711a6ae	86	struct rds_tcp_connection *rs_tcp;
70041088 AG	87
	88	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
	89	sock->sk->sk_protocol, &new_sock);
	90	if (ret)
	91	goto out;
	92
	93	new_sock->type = sock->type;
	94	new_sock->ops = sock->ops;
	95	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
	96	if (ret < 0)
	97	goto out;
	98
f711a6ae SV	99	ret = rds_tcp_keepalive(new_sock);
	100	if (ret < 0)
	101	goto out;
	102
70041088 AG	103	rds_tcp_tune(new_sock);
	104
	105	inet = inet_sk(new_sock->sk);
	106
6884b348 JP	107	rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
	108	&inet->inet_saddr, ntohs(inet->inet_sport),
	109	&inet->inet_daddr, ntohs(inet->inet_dport));
70041088	110
c720c7e8 ED	111	conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
c720c7e8 ED	112	&rds_tcp_transport, GFP_KERNEL);
70041088 AG	113	if (IS_ERR(conn)) {
	114	ret = PTR_ERR(conn);
	115	goto out;
	116	}
f711a6ae SV	117	/* An incoming SYN request came in, and TCP just accepted it.
	118	* We always create a new conn for listen side of TCP, and do not
	119	* add it to the c_hash_list.
	120	*
	121	* If the client reboots, this conn will need to be cleaned up.
	122	* rds_tcp_state_change() will do that cleanup
	123	*/
	124	rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
	125	WARN_ON(!rs_tcp \|\| rs_tcp->t_sock);
70041088 AG	126
	127	/*
	128	* see the comment above rds_queue_delayed_reconnect()
	129	*/
	130	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
	131	if (rds_conn_state(conn) == RDS_CONN_UP)
	132	rds_tcp_stats_inc(s_tcp_listen_closed_stale);
	133	else
	134	rds_tcp_stats_inc(s_tcp_connect_raced);
	135	rds_conn_drop(conn);
	136	ret = 0;
	137	goto out;
	138	}
	139
	140	rds_tcp_set_callbacks(new_sock, conn);
	141	rds_connect_complete(conn);
	142	new_sock = NULL;
	143	ret = 0;
	144
	145	out:
	146	if (new_sock)
	147	sock_release(new_sock);
	148	return ret;
	149	}
	150
	151	static void rds_tcp_accept_worker(struct work_struct *work)
	152	{
	153	while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
	154	cond_resched();
	155	}
	156
676d2369	157	void rds_tcp_listen_data_ready(struct sock *sk)
70041088	158	{
676d2369	159	void (ready)(struct sock sk);
70041088 AG	160
	161	rdsdebug("listen data ready sk %p\n", sk);
	162
bfdc587c	163	read_lock(&sk->sk_callback_lock);
70041088	164	ready = sk->sk_user_data;
8690bfa1	165	if (!ready) { /* check for teardown race */
70041088 AG	166	ready = sk->sk_data_ready;
	167	goto out;
	168	}
	169
	170	/*
	171	* ->sk_data_ready is also called for a newly established child socket
	172	* before it has been accepted and the accepter has set up their
	173	* data_ready.. we only want to queue listen work for our listening
	174	* socket
	175	*/
	176	if (sk->sk_state == TCP_LISTEN)
	177	queue_work(rds_wq, &rds_tcp_listen_work);
	178
	179	out:
bfdc587c	180	read_unlock(&sk->sk_callback_lock);
676d2369	181	ready(sk);
70041088 AG	182	}
70041088 AG	183
ef87b7ea	184	int rds_tcp_listen_init(void)
70041088 AG	185	{
	186	struct sockaddr_in sin;
	187	struct socket *sock = NULL;
	188	int ret;
	189
	190	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
	191	if (ret < 0)
	192	goto out;
	193
4a17fd52	194	sock->sk->sk_reuse = SK_CAN_REUSE;
70041088 AG	195	rds_tcp_nonagle(sock);
	196
	197	write_lock_bh(&sock->sk->sk_callback_lock);
	198	sock->sk->sk_user_data = sock->sk->sk_data_ready;
	199	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
	200	write_unlock_bh(&sock->sk->sk_callback_lock);
	201
01728371	202	sin.sin_family = PF_INET;
70041088 AG	203	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
	204	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
	205
	206	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
	207	if (ret < 0)
	208	goto out;
	209
	210	ret = sock->ops->listen(sock, 64);
	211	if (ret < 0)
	212	goto out;
	213
	214	rds_tcp_listen_sock = sock;
	215	sock = NULL;
	216	out:
	217	if (sock)
	218	sock_release(sock);
	219	return ret;
	220	}
	221
	222	void rds_tcp_listen_stop(void)
	223	{
	224	struct socket *sock = rds_tcp_listen_sock;
	225	struct sock *sk;
	226
8690bfa1	227	if (!sock)
70041088 AG	228	return;
	229
	230	sk = sock->sk;
	231
	232	/* serialize with and prevent further callbacks */
	233	lock_sock(sk);
	234	write_lock_bh(&sk->sk_callback_lock);
	235	if (sk->sk_user_data) {
	236	sk->sk_data_ready = sk->sk_user_data;
	237	sk->sk_user_data = NULL;
	238	}
	239	write_unlock_bh(&sk->sk_callback_lock);
	240	release_sock(sk);
	241
	242	/* wait for accepts to stop and close the socket */
	243	flush_workqueue(rds_wq);
	244	sock_release(sock);
	245	rds_tcp_listen_sock = NULL;
	246	}