[linux.git] / net / rds / tcp.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/slab.h>
#include <linux/in.h>
#include <linux/module.h>
#include <net/tcp.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/tcp.h>

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

/* only for info exporting */
static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
static LIST_HEAD(rds_tcp_tc_list);
static unsigned int rds_tcp_tc_count;

/* Track rds_tcp_connection structs so they can be cleaned up */
static DEFINE_SPINLOCK(rds_tcp_conn_lock);
static LIST_HEAD(rds_tcp_conn_list);

static struct kmem_cache *rds_tcp_conn_slab;

#define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)

/* doing it this way avoids calling tcp_sk() */
void rds_tcp_nonagle(struct socket *sock)
{
	mm_segment_t oldfs = get_fs();
	int val = 1;

	set_fs(KERNEL_DS);
	sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
			      sizeof(val));
	set_fs(oldfs);
}

/* All module specific customizations to the RDS-TCP socket should be done in
 * rds_tcp_tune() and applied after socket creation. In general these
 * customizations should be tunable via module_param()
 */
void rds_tcp_tune(struct socket *sock)
{
	rds_tcp_nonagle(sock);
}

u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
{
	return tcp_sk(tc->t_sock->sk)->snd_nxt;
}

u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
{
	return tcp_sk(tc->t_sock->sk)->snd_una;
}

void rds_tcp_restore_callbacks(struct socket *sock,
			       struct rds_tcp_connection *tc)
{
	rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
	write_lock_bh(&sock->sk->sk_callback_lock);

	/* done under the callback_lock to serialize with write_space */
	spin_lock(&rds_tcp_tc_list_lock);
	list_del_init(&tc->t_list_item);
	rds_tcp_tc_count--;
	spin_unlock(&rds_tcp_tc_list_lock);

	tc->t_sock = NULL;

	sock->sk->sk_write_space = tc->t_orig_write_space;
	sock->sk->sk_data_ready = tc->t_orig_data_ready;
	sock->sk->sk_state_change = tc->t_orig_state_change;
	sock->sk->sk_user_data = NULL;

	write_unlock_bh(&sock->sk->sk_callback_lock);
}

/*
 * This is the only path that sets tc->t_sock.  Send and receive trust that
 * it is set.  The RDS_CONN_CONNECTED bit protects those paths from being
 * called while it isn't set.
 */
void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
{
	struct rds_tcp_connection *tc = conn->c_transport_data;

	rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
	write_lock_bh(&sock->sk->sk_callback_lock);

	/* done under the callback_lock to serialize with write_space */
	spin_lock(&rds_tcp_tc_list_lock);
	list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
	rds_tcp_tc_count++;
	spin_unlock(&rds_tcp_tc_list_lock);

	/* accepted sockets need our listen data ready undone */
	if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
		sock->sk->sk_data_ready = sock->sk->sk_user_data;

	tc->t_sock = sock;
	tc->conn = conn;
	tc->t_orig_data_ready = sock->sk->sk_data_ready;
	tc->t_orig_write_space = sock->sk->sk_write_space;
	tc->t_orig_state_change = sock->sk->sk_state_change;

	sock->sk->sk_user_data = conn;
	sock->sk->sk_data_ready = rds_tcp_data_ready;
	sock->sk->sk_write_space = rds_tcp_write_space;
	sock->sk->sk_state_change = rds_tcp_state_change;

	write_unlock_bh(&sock->sk->sk_callback_lock);
}

static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
			    struct rds_info_iterator *iter,
			    struct rds_info_lengths *lens)
{
	struct rds_info_tcp_socket tsinfo;
	struct rds_tcp_connection *tc;
	unsigned long flags;
	struct sockaddr_in sin;
	int sinlen;

	spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);

	if (len / sizeof(tsinfo) < rds_tcp_tc_count)
		goto out;

	list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {

		sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
		tsinfo.local_addr = sin.sin_addr.s_addr;
		tsinfo.local_port = sin.sin_port;
		sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
		tsinfo.peer_addr = sin.sin_addr.s_addr;
		tsinfo.peer_port = sin.sin_port;

		tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
		tsinfo.data_rem = tc->t_tinc_data_rem;
		tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
		tsinfo.last_expected_una = tc->t_last_expected_una;
		tsinfo.last_seen_una = tc->t_last_seen_una;

		rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
	}

out:
	lens->nr = rds_tcp_tc_count;
	lens->each = sizeof(tsinfo);

	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
}

static int rds_tcp_laddr_check(struct net *net, __be32 addr)
{
	if (inet_addr_type(net, addr) == RTN_LOCAL)
		return 0;
	return -EADDRNOTAVAIL;
}

static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
{
	struct rds_tcp_connection *tc;

	tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
	if (!tc)
		return -ENOMEM;

	tc->t_sock = NULL;
	tc->t_tinc = NULL;
	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
	tc->t_tinc_data_rem = 0;

	conn->c_transport_data = tc;

	spin_lock_irq(&rds_tcp_conn_lock);
	list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
	spin_unlock_irq(&rds_tcp_conn_lock);

	rdsdebug("alloced tc %p\n", conn->c_transport_data);
	return 0;
}

static void rds_tcp_conn_free(void *arg)
{
	struct rds_tcp_connection *tc = arg;
	unsigned long flags;
	rdsdebug("freeing tc %p\n", tc);

	spin_lock_irqsave(&rds_tcp_conn_lock, flags);
	list_del(&tc->t_tcp_node);
	spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);

	kmem_cache_free(rds_tcp_conn_slab, tc);
}

static void rds_tcp_destroy_conns(void)
{
	struct rds_tcp_connection *tc, *_tc;
	LIST_HEAD(tmp_list);

	/* avoid calling conn_destroy with irqs off */
	spin_lock_irq(&rds_tcp_conn_lock);
	list_splice(&rds_tcp_conn_list, &tmp_list);
	INIT_LIST_HEAD(&rds_tcp_conn_list);
	spin_unlock_irq(&rds_tcp_conn_lock);

	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
		if (tc->conn->c_passive)
			rds_conn_destroy(tc->conn->c_passive);
		rds_conn_destroy(tc->conn);
	}
}

static void rds_tcp_exit(void);

struct rds_transport rds_tcp_transport = {
	.laddr_check		= rds_tcp_laddr_check,
	.xmit_prepare		= rds_tcp_xmit_prepare,
	.xmit_complete		= rds_tcp_xmit_complete,
	.xmit			= rds_tcp_xmit,
	.recv			= rds_tcp_recv,
	.conn_alloc		= rds_tcp_conn_alloc,
	.conn_free		= rds_tcp_conn_free,
	.conn_connect		= rds_tcp_conn_connect,
	.conn_shutdown		= rds_tcp_conn_shutdown,
	.inc_copy_to_user	= rds_tcp_inc_copy_to_user,
	.inc_free		= rds_tcp_inc_free,
	.stats_info_copy	= rds_tcp_stats_info_copy,
	.exit			= rds_tcp_exit,
	.t_owner		= THIS_MODULE,
	.t_name			= "tcp",
	.t_type			= RDS_TRANS_TCP,
	.t_prefer_loopback	= 1,
};

static int rds_tcp_netid;

/* per-network namespace private data for this module */
struct rds_tcp_net {
	struct socket *rds_tcp_listen_sock;
	struct work_struct rds_tcp_accept_w;
};

static void rds_tcp_accept_worker(struct work_struct *work)
{
	struct rds_tcp_net *rtn = container_of(work,
					       struct rds_tcp_net,
					       rds_tcp_accept_w);

	while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
		cond_resched();
}

void rds_tcp_accept_work(struct sock *sk)
{
	struct net *net = sock_net(sk);
	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	queue_work(rds_wq, &rtn->rds_tcp_accept_w);
}

static __net_init int rds_tcp_init_net(struct net *net)
{
	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net);
	if (!rtn->rds_tcp_listen_sock) {
		pr_warn("could not set up listen sock\n");
		return -EAFNOSUPPORT;
	}
	INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
	return 0;
}

static void __net_exit rds_tcp_exit_net(struct net *net)
{
	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	/* If rds_tcp_exit_net() is called as a result of netns deletion,
	 * the rds_tcp_kill_sock() device notifier would already have cleaned
	 * up the listen socket, thus there is no work to do in this function.
	 *
	 * If rds_tcp_exit_net() is called as a result of module unload,
	 * i.e., due to rds_tcp_exit() -> unregister_pernet_subsys(), then
	 * we do need to clean up the listen socket here.
	 */
	if (rtn->rds_tcp_listen_sock) {
		rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
		rtn->rds_tcp_listen_sock = NULL;
		flush_work(&rtn->rds_tcp_accept_w);
	}
}

static struct pernet_operations rds_tcp_net_ops = {
	.init = rds_tcp_init_net,
	.exit = rds_tcp_exit_net,
	.id = &rds_tcp_netid,
	.size = sizeof(struct rds_tcp_net),
};

static void rds_tcp_kill_sock(struct net *net)
{
	struct rds_tcp_connection *tc, *_tc;
	struct sock *sk;
	LIST_HEAD(tmp_list);
	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
	rtn->rds_tcp_listen_sock = NULL;
	flush_work(&rtn->rds_tcp_accept_w);
	spin_lock_irq(&rds_tcp_conn_lock);
	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
		struct net *c_net = read_pnet(&tc->conn->c_net);

		if (net != c_net || !tc->t_sock)
			continue;
		list_move_tail(&tc->t_tcp_node, &tmp_list);
	}
	spin_unlock_irq(&rds_tcp_conn_lock);
	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
		sk = tc->t_sock->sk;
		sk->sk_prot->disconnect(sk, 0);
		tcp_done(sk);
		if (tc->conn->c_passive)
			rds_conn_destroy(tc->conn->c_passive);
		rds_conn_destroy(tc->conn);
	}
}

static int rds_tcp_dev_event(struct notifier_block *this,
			     unsigned long event, void *ptr)
{
	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	/* rds-tcp registers as a pernet subys, so the ->exit will only
	 * get invoked after network acitivity has quiesced. We need to
	 * clean up all sockets  to quiesce network activity, and use
	 * the unregistration of the per-net loopback device as a trigger
	 * to start that cleanup.
	 */
	if (event == NETDEV_UNREGISTER_FINAL &&
	    dev->ifindex == LOOPBACK_IFINDEX)
		rds_tcp_kill_sock(dev_net(dev));

	return NOTIFY_DONE;
}

static struct notifier_block rds_tcp_dev_notifier = {
	.notifier_call        = rds_tcp_dev_event,
	.priority = -10, /* must be called after other network notifiers */
};

static void rds_tcp_exit(void)
{
	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
	unregister_pernet_subsys(&rds_tcp_net_ops);
	if (unregister_netdevice_notifier(&rds_tcp_dev_notifier))
		pr_warn("could not unregister rds_tcp_dev_notifier\n");
	rds_tcp_destroy_conns();
	rds_trans_unregister(&rds_tcp_transport);
	rds_tcp_recv_exit();
	kmem_cache_destroy(rds_tcp_conn_slab);
}
module_exit(rds_tcp_exit);

static int rds_tcp_init(void)
{
	int ret;

	rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
					      sizeof(struct rds_tcp_connection),
					      0, 0, NULL);
	if (!rds_tcp_conn_slab) {
		ret = -ENOMEM;
		goto out;
	}

	ret = register_netdevice_notifier(&rds_tcp_dev_notifier);
	if (ret) {
		pr_warn("could not register rds_tcp_dev_notifier\n");
		goto out;
	}

	ret = register_pernet_subsys(&rds_tcp_net_ops);
	if (ret)
		goto out_slab;

	ret = rds_tcp_recv_init();
	if (ret)
		goto out_slab;

	ret = rds_trans_register(&rds_tcp_transport);
	if (ret)
		goto out_recv;

	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);

	goto out;

out_recv:
	rds_tcp_recv_exit();
out_slab:
	unregister_pernet_subsys(&rds_tcp_net_ops);
	kmem_cache_destroy(rds_tcp_conn_slab);
out:
	return ret;
}
module_init(rds_tcp_init);

MODULE_AUTHOR("Oracle Corporation <[email protected]>");
MODULE_DESCRIPTION("RDS: TCP transport");
MODULE_LICENSE("Dual BSD/GPL");
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/slab.h>
70041088	35	#include <linux/in.h>
3a9a231d	36	#include <linux/module.h>
70041088	37	#include <net/tcp.h>
467fa153 SV	38	#include <net/net_namespace.h>
	39	#include <net/netns/generic.h>
	40	#include <net/tcp.h>
70041088 AG	41
	42	#include "rds.h"
	43	#include "tcp.h"
	44
	45	/* only for info exporting */
	46	static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
	47	static LIST_HEAD(rds_tcp_tc_list);
ff51bf84	48	static unsigned int rds_tcp_tc_count;
70041088 AG	49
	50	/* Track rds_tcp_connection structs so they can be cleaned up */
	51	static DEFINE_SPINLOCK(rds_tcp_conn_lock);
	52	static LIST_HEAD(rds_tcp_conn_list);
	53
	54	static struct kmem_cache *rds_tcp_conn_slab;
	55
	56	#define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)
	57
	58	/* doing it this way avoids calling tcp_sk() */
	59	void rds_tcp_nonagle(struct socket *sock)
	60	{
	61	mm_segment_t oldfs = get_fs();
	62	int val = 1;
	63
	64	set_fs(KERNEL_DS);
	65	sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
	66	sizeof(val));
	67	set_fs(oldfs);
	68	}
	69
1edd6a14 SV	70	/* All module specific customizations to the RDS-TCP socket should be done in
	71	* rds_tcp_tune() and applied after socket creation. In general these
	72	* customizations should be tunable via module_param()
	73	*/
70041088 AG	74	void rds_tcp_tune(struct socket *sock)
70041088 AG	75	{
70041088	76	rds_tcp_nonagle(sock);
70041088 AG	77	}
	78
	79	u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
	80	{
	81	return tcp_sk(tc->t_sock->sk)->snd_nxt;
	82	}
	83
	84	u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
	85	{
	86	return tcp_sk(tc->t_sock->sk)->snd_una;
	87	}
	88
	89	void rds_tcp_restore_callbacks(struct socket *sock,
	90	struct rds_tcp_connection *tc)
	91	{
	92	rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
	93	write_lock_bh(&sock->sk->sk_callback_lock);
	94
	95	/* done under the callback_lock to serialize with write_space */
	96	spin_lock(&rds_tcp_tc_list_lock);
	97	list_del_init(&tc->t_list_item);
	98	rds_tcp_tc_count--;
	99	spin_unlock(&rds_tcp_tc_list_lock);
	100
	101	tc->t_sock = NULL;
	102
	103	sock->sk->sk_write_space = tc->t_orig_write_space;
	104	sock->sk->sk_data_ready = tc->t_orig_data_ready;
	105	sock->sk->sk_state_change = tc->t_orig_state_change;
	106	sock->sk->sk_user_data = NULL;
	107
	108	write_unlock_bh(&sock->sk->sk_callback_lock);
	109	}
	110
	111	/*
	112	* This is the only path that sets tc->t_sock. Send and receive trust that
	113	* it is set. The RDS_CONN_CONNECTED bit protects those paths from being
	114	* called while it isn't set.
	115	*/
	116	void rds_tcp_set_callbacks(struct socket sock, struct rds_connection conn)
	117	{
	118	struct rds_tcp_connection *tc = conn->c_transport_data;
	119
	120	rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
	121	write_lock_bh(&sock->sk->sk_callback_lock);
	122
	123	/* done under the callback_lock to serialize with write_space */
	124	spin_lock(&rds_tcp_tc_list_lock);
	125	list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
	126	rds_tcp_tc_count++;
	127	spin_unlock(&rds_tcp_tc_list_lock);
	128
	129	/* accepted sockets need our listen data ready undone */
	130	if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
	131	sock->sk->sk_data_ready = sock->sk->sk_user_data;
	132
	133	tc->t_sock = sock;
	134	tc->conn = conn;
	135	tc->t_orig_data_ready = sock->sk->sk_data_ready;
	136	tc->t_orig_write_space = sock->sk->sk_write_space;
	137	tc->t_orig_state_change = sock->sk->sk_state_change;
	138
	139	sock->sk->sk_user_data = conn;
	140	sock->sk->sk_data_ready = rds_tcp_data_ready;
141	sock->sk->sk_write_space = rds_tcp_write_space;
142	sock->sk->sk_state_change = rds_tcp_state_change;
143
144	write_unlock_bh(&sock->sk->sk_callback_lock);
145	}
146
147	static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
148	struct rds_info_iterator *iter,
149	struct rds_info_lengths *lens)
150	{
151	struct rds_info_tcp_socket tsinfo;
152	struct rds_tcp_connection *tc;
153	unsigned long flags;
154	struct sockaddr_in sin;
155	int sinlen;
156
157	spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
158
159	if (len / sizeof(tsinfo) < rds_tcp_tc_count)
160	goto out;
161
162	list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
163
164	sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
165	tsinfo.local_addr = sin.sin_addr.s_addr;
166	tsinfo.local_port = sin.sin_port;
167	sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
168	tsinfo.peer_addr = sin.sin_addr.s_addr;
169	tsinfo.peer_port = sin.sin_port;
170
171	tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
172	tsinfo.data_rem = tc->t_tinc_data_rem;
173	tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
174	tsinfo.last_expected_una = tc->t_last_expected_una;
175	tsinfo.last_seen_una = tc->t_last_seen_una;
176
177	rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
178	}
179
180	out:
181	lens->nr = rds_tcp_tc_count;
182	lens->each = sizeof(tsinfo);
183
184	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
185	}
186
d5a8ac28	187	static int rds_tcp_laddr_check(struct net *net, __be32 addr)
70041088	188	{
d5a8ac28	189	if (inet_addr_type(net, addr) == RTN_LOCAL)
70041088 AG	190	return 0;
	191	return -EADDRNOTAVAIL;
	192	}
	193
	194	static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
	195	{
	196	struct rds_tcp_connection *tc;
	197
	198	tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
8690bfa1	199	if (!tc)
70041088 AG	200	return -ENOMEM;
	201
	202	tc->t_sock = NULL;
	203	tc->t_tinc = NULL;
	204	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
	205	tc->t_tinc_data_rem = 0;
	206
	207	conn->c_transport_data = tc;
	208
	209	spin_lock_irq(&rds_tcp_conn_lock);
	210	list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
	211	spin_unlock_irq(&rds_tcp_conn_lock);
	212
	213	rdsdebug("alloced tc %p\n", conn->c_transport_data);
	214	return 0;
	215	}
	216
	217	static void rds_tcp_conn_free(void *arg)
	218	{
	219	struct rds_tcp_connection *tc = arg;
8200a59f	220	unsigned long flags;
70041088	221	rdsdebug("freeing tc %p\n", tc);
8200a59f PE	222
	223	spin_lock_irqsave(&rds_tcp_conn_lock, flags);
	224	list_del(&tc->t_tcp_node);
	225	spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
	226
70041088 AG	227	kmem_cache_free(rds_tcp_conn_slab, tc);
	228	}
	229
	230	static void rds_tcp_destroy_conns(void)
	231	{
	232	struct rds_tcp_connection tc, _tc;
	233	LIST_HEAD(tmp_list);
	234
	235	/* avoid calling conn_destroy with irqs off */
	236	spin_lock_irq(&rds_tcp_conn_lock);
	237	list_splice(&rds_tcp_conn_list, &tmp_list);
	238	INIT_LIST_HEAD(&rds_tcp_conn_list);
	239	spin_unlock_irq(&rds_tcp_conn_lock);
	240
	241	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
	242	if (tc->conn->c_passive)
	243	rds_conn_destroy(tc->conn->c_passive);
	244	rds_conn_destroy(tc->conn);
	245	}
	246	}
	247
467fa153	248	static void rds_tcp_exit(void);
70041088 AG	249
	250	struct rds_transport rds_tcp_transport = {
	251	.laddr_check = rds_tcp_laddr_check,
	252	.xmit_prepare = rds_tcp_xmit_prepare,
	253	.xmit_complete = rds_tcp_xmit_complete,
70041088 AG	254	.xmit = rds_tcp_xmit,
	255	.recv = rds_tcp_recv,
	256	.conn_alloc = rds_tcp_conn_alloc,
	257	.conn_free = rds_tcp_conn_free,
	258	.conn_connect = rds_tcp_conn_connect,
	259	.conn_shutdown = rds_tcp_conn_shutdown,
	260	.inc_copy_to_user = rds_tcp_inc_copy_to_user,
70041088 AG	261	.inc_free = rds_tcp_inc_free,
	262	.stats_info_copy = rds_tcp_stats_info_copy,
	263	.exit = rds_tcp_exit,
	264	.t_owner = THIS_MODULE,
	265	.t_name = "tcp",
335776bd	266	.t_type = RDS_TRANS_TCP,
70041088 AG	267	.t_prefer_loopback = 1,
	268	};
	269
467fa153 SV	270	static int rds_tcp_netid;
	271
	272	/* per-network namespace private data for this module */
	273	struct rds_tcp_net {
	274	struct socket *rds_tcp_listen_sock;
	275	struct work_struct rds_tcp_accept_w;
	276	};
	277
	278	static void rds_tcp_accept_worker(struct work_struct *work)
	279	{
	280	struct rds_tcp_net *rtn = container_of(work,
	281	struct rds_tcp_net,
	282	rds_tcp_accept_w);
	283
	284	while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
	285	cond_resched();
	286	}
	287
	288	void rds_tcp_accept_work(struct sock *sk)
	289	{
	290	struct net *net = sock_net(sk);
	291	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
	292
	293	queue_work(rds_wq, &rtn->rds_tcp_accept_w);
	294	}
	295
	296	static __net_init int rds_tcp_init_net(struct net *net)
	297	{
	298	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
	299
	300	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net);
	301	if (!rtn->rds_tcp_listen_sock) {
	302	pr_warn("could not set up listen sock\n");
	303	return -EAFNOSUPPORT;
	304	}
	305	INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
	306	return 0;
	307	}
	308
	309	static void __net_exit rds_tcp_exit_net(struct net *net)
	310	{
	311	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
	312
	313	/* If rds_tcp_exit_net() is called as a result of netns deletion,
	314	* the rds_tcp_kill_sock() device notifier would already have cleaned
	315	* up the listen socket, thus there is no work to do in this function.
	316	*
	317	* If rds_tcp_exit_net() is called as a result of module unload,
	318	* i.e., due to rds_tcp_exit() -> unregister_pernet_subsys(), then
	319	* we do need to clean up the listen socket here.
	320	*/
	321	if (rtn->rds_tcp_listen_sock) {
	322	rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
	323	rtn->rds_tcp_listen_sock = NULL;
	324	flush_work(&rtn->rds_tcp_accept_w);
	325	}
	326	}
	327
	328	static struct pernet_operations rds_tcp_net_ops = {
	329	.init = rds_tcp_init_net,
	330	.exit = rds_tcp_exit_net,
	331	.id = &rds_tcp_netid,
	332	.size = sizeof(struct rds_tcp_net),
	333	};
334
335	static void rds_tcp_kill_sock(struct net *net)
336	{
337	struct rds_tcp_connection tc, _tc;
338	struct sock *sk;
339	LIST_HEAD(tmp_list);
340	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
341
342	rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
343	rtn->rds_tcp_listen_sock = NULL;
344	flush_work(&rtn->rds_tcp_accept_w);
345	spin_lock_irq(&rds_tcp_conn_lock);
346	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
347	struct net *c_net = read_pnet(&tc->conn->c_net);
348
349	if (net != c_net \|\| !tc->t_sock)
350	continue;
351	list_move_tail(&tc->t_tcp_node, &tmp_list);
352	}
353	spin_unlock_irq(&rds_tcp_conn_lock);
354	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
355	sk = tc->t_sock->sk;
356	sk->sk_prot->disconnect(sk, 0);
357	tcp_done(sk);
358	if (tc->conn->c_passive)
359	rds_conn_destroy(tc->conn->c_passive);
360	rds_conn_destroy(tc->conn);
361	}
362	}
363
364	static int rds_tcp_dev_event(struct notifier_block *this,
365	unsigned long event, void *ptr)
366	{
367	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
368
369	/* rds-tcp registers as a pernet subys, so the ->exit will only
370	* get invoked after network acitivity has quiesced. We need to
371	* clean up all sockets to quiesce network activity, and use
372	* the unregistration of the per-net loopback device as a trigger
373	* to start that cleanup.
374	*/
375	if (event == NETDEV_UNREGISTER_FINAL &&
376	dev->ifindex == LOOPBACK_IFINDEX)
377	rds_tcp_kill_sock(dev_net(dev));
378
379	return NOTIFY_DONE;
380	}
381
382	static struct notifier_block rds_tcp_dev_notifier = {
383	.notifier_call = rds_tcp_dev_event,
384	.priority = -10, /* must be called after other network notifiers */
385	};
386
387	static void rds_tcp_exit(void)
388	{
389	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
390	unregister_pernet_subsys(&rds_tcp_net_ops);
391	if (unregister_netdevice_notifier(&rds_tcp_dev_notifier))
392	pr_warn("could not unregister rds_tcp_dev_notifier\n");
393	rds_tcp_destroy_conns();
394	rds_trans_unregister(&rds_tcp_transport);
395	rds_tcp_recv_exit();
396	kmem_cache_destroy(rds_tcp_conn_slab);
397	}
398	module_exit(rds_tcp_exit);
399
ff51bf84	400	static int rds_tcp_init(void)
70041088 AG	401	{
	402	int ret;
	403
	404	rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
	405	sizeof(struct rds_tcp_connection),
	406	0, 0, NULL);
8690bfa1	407	if (!rds_tcp_conn_slab) {
70041088 AG	408	ret = -ENOMEM;
	409	goto out;
	410	}
	411
467fa153 SV	412	ret = register_netdevice_notifier(&rds_tcp_dev_notifier);
	413	if (ret) {
	414	pr_warn("could not register rds_tcp_dev_notifier\n");
	415	goto out;
	416	}
	417
	418	ret = register_pernet_subsys(&rds_tcp_net_ops);
	419	if (ret)
	420	goto out_slab;
	421
70041088 AG	422	ret = rds_tcp_recv_init();
	423	if (ret)
	424	goto out_slab;
	425
	426	ret = rds_trans_register(&rds_tcp_transport);
	427	if (ret)
	428	goto out_recv;
	429
70041088 AG	430	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
	431
	432	goto out;
	433
70041088 AG	434	out_recv:
	435	rds_tcp_recv_exit();
	436	out_slab:
467fa153	437	unregister_pernet_subsys(&rds_tcp_net_ops);
70041088 AG	438	kmem_cache_destroy(rds_tcp_conn_slab);
	439	out:
	440	return ret;
	441	}
	442	module_init(rds_tcp_init);
	443
	444	MODULE_AUTHOR("Oracle Corporation <[email protected]>");
	445	MODULE_DESCRIPTION("RDS: TCP transport");
	446	MODULE_LICENSE("Dual BSD/GPL");
	447