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v3.5.6
  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>
 34#include <linux/gfp.h>
 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 */
 44static void rds_tcp_accept_worker(struct work_struct *work);
 45static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
 46static struct socket *rds_tcp_listen_sock;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 47
 48static int rds_tcp_accept_one(struct socket *sock)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 49{
 50	struct socket *new_sock = NULL;
 51	struct rds_connection *conn;
 52	int ret;
 53	struct inet_sock *inet;
 54
 55	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
 56			       sock->sk->sk_protocol, &new_sock);
 
 
 
 
 
 
 
 57	if (ret)
 58		goto out;
 59
 60	new_sock->type = sock->type;
 
 
 
 
 
 
 
 
 
 
 61	new_sock->ops = sock->ops;
 62	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
 
 
 63	if (ret < 0)
 64		goto out;
 65
 66	rds_tcp_tune(new_sock);
 67
 68	inet = inet_sk(new_sock->sk);
 69
 70	rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
 71		 &inet->inet_saddr, ntohs(inet->inet_sport),
 72		 &inet->inet_daddr, ntohs(inet->inet_dport));
 73
 74	conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
 
 75			       &rds_tcp_transport, GFP_KERNEL);
 76	if (IS_ERR(conn)) {
 77		ret = PTR_ERR(conn);
 78		goto out;
 79	}
 80
 81	/*
 82	 * see the comment above rds_queue_delayed_reconnect()
 
 83	 */
 84	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 85		if (rds_conn_state(conn) == RDS_CONN_UP)
 86			rds_tcp_stats_inc(s_tcp_listen_closed_stale);
 87		else
 88			rds_tcp_stats_inc(s_tcp_connect_raced);
 89		rds_conn_drop(conn);
 90		ret = 0;
 91		goto out;
 
 
 
 
 
 
 
 
 
 92	}
 93
 94	rds_tcp_set_callbacks(new_sock, conn);
 95	rds_connect_complete(conn);
 96	new_sock = NULL;
 97	ret = 0;
 98
 
 
 
 
 
 
 
 
 
 
 
 
 99out:
 
 
100	if (new_sock)
101		sock_release(new_sock);
102	return ret;
103}
104
105static void rds_tcp_accept_worker(struct work_struct *work)
106{
107	while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
108		cond_resched();
109}
110
111void rds_tcp_listen_data_ready(struct sock *sk, int bytes)
112{
113	void (*ready)(struct sock *sk, int bytes);
114
115	rdsdebug("listen data ready sk %p\n", sk);
116
117	read_lock_bh(&sk->sk_callback_lock);
118	ready = sk->sk_user_data;
119	if (!ready) { /* check for teardown race */
120		ready = sk->sk_data_ready;
121		goto out;
122	}
123
124	/*
125	 * ->sk_data_ready is also called for a newly established child socket
126	 * before it has been accepted and the accepter has set up their
127	 * data_ready.. we only want to queue listen work for our listening
128	 * socket
 
 
 
129	 */
130	if (sk->sk_state == TCP_LISTEN)
131		queue_work(rds_wq, &rds_tcp_listen_work);
 
 
132
133out:
134	read_unlock_bh(&sk->sk_callback_lock);
135	ready(sk, bytes);
 
136}
137
138int rds_tcp_listen_init(void)
139{
140	struct sockaddr_in sin;
141	struct socket *sock = NULL;
142	int ret;
143
144	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
145	if (ret < 0)
146		goto out;
147
148	sock->sk->sk_reuse = SK_CAN_REUSE;
149	rds_tcp_nonagle(sock);
150
151	write_lock_bh(&sock->sk->sk_callback_lock);
152	sock->sk->sk_user_data = sock->sk->sk_data_ready;
153	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
154	write_unlock_bh(&sock->sk->sk_callback_lock);
155
156	sin.sin_family = PF_INET,
157	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
158	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
159
160	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
161	if (ret < 0)
162		goto out;
163
164	ret = sock->ops->listen(sock, 64);
165	if (ret < 0)
166		goto out;
167
168	rds_tcp_listen_sock = sock;
169	sock = NULL;
170out:
171	if (sock)
172		sock_release(sock);
173	return ret;
174}
175
176void rds_tcp_listen_stop(void)
177{
178	struct socket *sock = rds_tcp_listen_sock;
179	struct sock *sk;
180
181	if (!sock)
182		return;
183
184	sk = sock->sk;
185
186	/* serialize with and prevent further callbacks */
187	lock_sock(sk);
188	write_lock_bh(&sk->sk_callback_lock);
189	if (sk->sk_user_data) {
190		sk->sk_data_ready = sk->sk_user_data;
191		sk->sk_user_data = NULL;
192	}
193	write_unlock_bh(&sk->sk_callback_lock);
194	release_sock(sk);
195
196	/* wait for accepts to stop and close the socket */
197	flush_workqueue(rds_wq);
 
198	sock_release(sock);
199	rds_tcp_listen_sock = NULL;
200}
v4.17
  1/*
  2 * Copyright (c) 2006, 2018 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>
 34#include <linux/gfp.h>
 35#include <linux/in.h>
 36#include <net/tcp.h>
 37
 38#include "rds.h"
 39#include "tcp.h"
 40
 41int rds_tcp_keepalive(struct socket *sock)
 42{
 43	/* values below based on xs_udp_default_timeout */
 44	int keepidle = 5; /* send a probe 'keepidle' secs after last data */
 45	int keepcnt = 5; /* number of unack'ed probes before declaring dead */
 46	int keepalive = 1;
 47	int ret = 0;
 48
 49	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
 50				(char *)&keepalive, sizeof(keepalive));
 51	if (ret < 0)
 52		goto bail;
 53
 54	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
 55				(char *)&keepcnt, sizeof(keepcnt));
 56	if (ret < 0)
 57		goto bail;
 58
 59	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
 60				(char *)&keepidle, sizeof(keepidle));
 61	if (ret < 0)
 62		goto bail;
 63
 64	/* KEEPINTVL is the interval between successive probes. We follow
 65	 * the model in xs_tcp_finish_connecting() and re-use keepidle.
 66	 */
 67	ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
 68				(char *)&keepidle, sizeof(keepidle));
 69bail:
 70	return ret;
 71}
 72
 73/* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the
 74 * client's ipaddr < server's ipaddr. Otherwise, close the accepted
 75 * socket and force a reconneect from smaller -> larger ip addr. The reason
 76 * we special case cp_index 0 is to allow the rds probe ping itself to itself
 77 * get through efficiently.
 78 * Since reconnects are only initiated from the node with the numerically
 79 * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side
 80 * by moving them to CONNECTING in this function.
 81 */
 82static
 83struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
 84{
 85	int i;
 86	bool peer_is_smaller = IS_CANONICAL(conn->c_faddr, conn->c_laddr);
 87	int npaths = max_t(int, 1, conn->c_npaths);
 88
 89	/* for mprds, all paths MUST be initiated by the peer
 90	 * with the smaller address.
 91	 */
 92	if (!peer_is_smaller) {
 93		/* Make sure we initiate at least one path if this
 94		 * has not already been done; rds_start_mprds() will
 95		 * take care of additional paths, if necessary.
 96		 */
 97		if (npaths == 1)
 98			rds_conn_path_connect_if_down(&conn->c_path[0]);
 99		return NULL;
100	}
101
102	for (i = 0; i < npaths; i++) {
103		struct rds_conn_path *cp = &conn->c_path[i];
104
105		if (rds_conn_path_transition(cp, RDS_CONN_DOWN,
106					     RDS_CONN_CONNECTING) ||
107		    rds_conn_path_transition(cp, RDS_CONN_ERROR,
108					     RDS_CONN_CONNECTING)) {
109			return cp->cp_transport_data;
110		}
111	}
112	return NULL;
113}
114
115void rds_tcp_set_linger(struct socket *sock)
116{
117	struct linger no_linger = {
118		.l_onoff = 1,
119		.l_linger = 0,
120	};
121
122	kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
123			  (char *)&no_linger, sizeof(no_linger));
124}
125
126int rds_tcp_accept_one(struct socket *sock)
127{
128	struct socket *new_sock = NULL;
129	struct rds_connection *conn;
130	int ret;
131	struct inet_sock *inet;
132	struct rds_tcp_connection *rs_tcp = NULL;
133	int conn_state;
134	struct rds_conn_path *cp;
135
136	if (!sock) /* module unload or netns delete in progress */
137		return -ENETUNREACH;
138
139	ret = sock_create_lite(sock->sk->sk_family,
140			       sock->sk->sk_type, sock->sk->sk_protocol,
141			       &new_sock);
142	if (ret)
143		goto out;
144
145	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true);
146	if (ret < 0)
147		goto out;
148
149	/* sock_create_lite() does not get a hold on the owner module so we
150	 * need to do it here.  Note that sock_release() uses sock->ops to
151	 * determine if it needs to decrement the reference count.  So set
152	 * sock->ops after calling accept() in case that fails.  And there's
153	 * no need to do try_module_get() as the listener should have a hold
154	 * already.
155	 */
156	new_sock->ops = sock->ops;
157	__module_get(new_sock->ops->owner);
158
159	ret = rds_tcp_keepalive(new_sock);
160	if (ret < 0)
161		goto out;
162
163	rds_tcp_tune(new_sock);
164
165	inet = inet_sk(new_sock->sk);
166
167	rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
168		 &inet->inet_saddr, ntohs(inet->inet_sport),
169		 &inet->inet_daddr, ntohs(inet->inet_dport));
170
171	conn = rds_conn_create(sock_net(sock->sk),
172			       inet->inet_saddr, inet->inet_daddr,
173			       &rds_tcp_transport, GFP_KERNEL);
174	if (IS_ERR(conn)) {
175		ret = PTR_ERR(conn);
176		goto out;
177	}
178	/* An incoming SYN request came in, and TCP just accepted it.
179	 *
180	 * If the client reboots, this conn will need to be cleaned up.
181	 * rds_tcp_state_change() will do that cleanup
182	 */
183	rs_tcp = rds_tcp_accept_one_path(conn);
184	if (!rs_tcp)
185		goto rst_nsk;
186	mutex_lock(&rs_tcp->t_conn_path_lock);
187	cp = rs_tcp->t_cpath;
188	conn_state = rds_conn_path_state(cp);
189	WARN_ON(conn_state == RDS_CONN_UP);
190	if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR)
191		goto rst_nsk;
192	if (rs_tcp->t_sock) {
193		/* Duelling SYN has been handled in rds_tcp_accept_one() */
194		rds_tcp_reset_callbacks(new_sock, cp);
195		/* rds_connect_path_complete() marks RDS_CONN_UP */
196		rds_connect_path_complete(cp, RDS_CONN_RESETTING);
197	} else {
198		rds_tcp_set_callbacks(new_sock, cp);
199		rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
200	}
 
 
 
201	new_sock = NULL;
202	ret = 0;
203	if (conn->c_npaths == 0)
204		rds_send_ping(cp->cp_conn, cp->cp_index);
205	goto out;
206rst_nsk:
207	/* reset the newly returned accept sock and bail.
208	 * It is safe to set linger on new_sock because the RDS connection
209	 * has not been brought up on new_sock, so no RDS-level data could
210	 * be pending on it. By setting linger, we achieve the side-effect
211	 * of avoiding TIME_WAIT state on new_sock.
212	 */
213	rds_tcp_set_linger(new_sock);
214	kernel_sock_shutdown(new_sock, SHUT_RDWR);
215	ret = 0;
216out:
217	if (rs_tcp)
218		mutex_unlock(&rs_tcp->t_conn_path_lock);
219	if (new_sock)
220		sock_release(new_sock);
221	return ret;
222}
223
224void rds_tcp_listen_data_ready(struct sock *sk)
225{
226	void (*ready)(struct sock *sk);
 
 
 
 
 
 
227
228	rdsdebug("listen data ready sk %p\n", sk);
229
230	read_lock_bh(&sk->sk_callback_lock);
231	ready = sk->sk_user_data;
232	if (!ready) { /* check for teardown race */
233		ready = sk->sk_data_ready;
234		goto out;
235	}
236
237	/*
238	 * ->sk_data_ready is also called for a newly established child socket
239	 * before it has been accepted and the accepter has set up their
240	 * data_ready.. we only want to queue listen work for our listening
241	 * socket
242	 *
243	 * (*ready)() may be null if we are racing with netns delete, and
244	 * the listen socket is being torn down.
245	 */
246	if (sk->sk_state == TCP_LISTEN)
247		rds_tcp_accept_work(sk);
248	else
249		ready = rds_tcp_listen_sock_def_readable(sock_net(sk));
250
251out:
252	read_unlock_bh(&sk->sk_callback_lock);
253	if (ready)
254		ready(sk);
255}
256
257struct socket *rds_tcp_listen_init(struct net *net)
258{
259	struct sockaddr_in sin;
260	struct socket *sock = NULL;
261	int ret;
262
263	ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
264	if (ret < 0)
265		goto out;
266
267	sock->sk->sk_reuse = SK_CAN_REUSE;
268	rds_tcp_nonagle(sock);
269
270	write_lock_bh(&sock->sk->sk_callback_lock);
271	sock->sk->sk_user_data = sock->sk->sk_data_ready;
272	sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
273	write_unlock_bh(&sock->sk->sk_callback_lock);
274
275	sin.sin_family = PF_INET;
276	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
277	sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
278
279	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
280	if (ret < 0)
281		goto out;
282
283	ret = sock->ops->listen(sock, 64);
284	if (ret < 0)
285		goto out;
286
287	return sock;
 
288out:
289	if (sock)
290		sock_release(sock);
291	return NULL;
292}
293
294void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor)
295{
 
296	struct sock *sk;
297
298	if (!sock)
299		return;
300
301	sk = sock->sk;
302
303	/* serialize with and prevent further callbacks */
304	lock_sock(sk);
305	write_lock_bh(&sk->sk_callback_lock);
306	if (sk->sk_user_data) {
307		sk->sk_data_ready = sk->sk_user_data;
308		sk->sk_user_data = NULL;
309	}
310	write_unlock_bh(&sk->sk_callback_lock);
311	release_sock(sk);
312
313	/* wait for accepts to stop and close the socket */
314	flush_workqueue(rds_wq);
315	flush_work(acceptor);
316	sock_release(sock);
 
317}